Caenorhabditis elegans histone deacetylase hda-1 is required for morphogenesis of the vulva and LIN-12/Notch-mediated specification of uterine cell fates.

PubMed

Ranawade, Ayush Vasant; Cumbo, Philip; Gupta, Bhagwati P

2013-08-07

Chromatin modification genes play crucial roles in development and disease. In Caenorhabditis elegans, the class I histone deacetylase family member hda-1, a component of the nucleosome remodeling and deacetylation complex, has been shown to control cell proliferation. We recovered hda-1 in an RNA interference screen for genes involved in the morphogenesis of the egg-laying system. We found that hda-1 mutants have abnormal vulva morphology and vulval-uterine connections (i.e., no uterine-seam cell). We characterized the vulval defects by using cell fate-specific markers and found that hda-1 is necessary for the specification of all seven vulval cell types. The analysis of the vulval-uterine connection defect revealed that hda-1 is required for the differentiation of the gonadal anchor cell (AC), which in turn induces ventral uterine granddaughters to adopt π fates, leading to the formation of the uterine-seam cell. Consistent with these results, hda-1 is expressed in the vulva and AC. A search for hda-1 target genes revealed that fos-1 (fos proto-oncogene family) acts downstream of hda-1 in vulval cells, whereas egl-43 (evi1 proto-oncogene family) and nhr-67 (tailless homolog, NHR family) mediate hda-1 function in the AC. Furthermore, we showed that AC expression of hda-1 plays a crucial role in the regulation of the lin-12/Notch ligand lag-2 to specify π cell fates. These results demonstrate the pivotal role of hda-1 in the formation of the vulva and the vulval-uterine connection. Given that hda-1 homologs are conserved across the phyla, our findings are likely to provide a better understanding of HDAC1 function in development and disease.

Caenorhabditis elegans Histone Deacetylase hda-1 Is Required for Morphogenesis of the Vulva and LIN-12/Notch-Mediated Specification of Uterine Cell Fates

PubMed Central

Ranawade, Ayush Vasant; Cumbo, Philip; Gupta, Bhagwati P.

2013-01-01

Chromatin modification genes play crucial roles in development and disease. In Caenorhabditis elegans, the class I histone deacetylase family member hda-1, a component of the nucleosome remodeling and deacetylation complex, has been shown to control cell proliferation. We recovered hda-1 in an RNA interference screen for genes involved in the morphogenesis of the egg-laying system. We found that hda-1 mutants have abnormal vulva morphology and vulval-uterine connections (i.e., no uterine-seam cell). We characterized the vulval defects by using cell fate-specific markers and found that hda-1 is necessary for the specification of all seven vulval cell types. The analysis of the vulval-uterine connection defect revealed that hda-1 is required for the differentiation of the gonadal anchor cell (AC), which in turn induces ventral uterine granddaughters to adopt π fates, leading to the formation of the uterine-seam cell. Consistent with these results, hda-1 is expressed in the vulva and AC. A search for hda-1 target genes revealed that fos-1 (fos proto-oncogene family) acts downstream of hda-1 in vulval cells, whereas egl-43 (evi1 proto-oncogene family) and nhr-67 (tailless homolog, NHR family) mediate hda-1 function in the AC. Furthermore, we showed that AC expression of hda-1 plays a crucial role in the regulation of the lin-12/Notch ligand lag-2 to specify π cell fates. These results demonstrate the pivotal role of hda-1 in the formation of the vulva and the vulval-uterine connection. Given that hda-1 homologs are conserved across the phyla, our findings are likely to provide a better understanding of HDAC1 function in development and disease. PMID:23797102

Notch-modifying xylosyltransferase-substrate complexes support an SNi-like retaining mechanism

PubMed Central

Yu, Hongjun; Takeuchi, Megumi; LeBarron, Jamie; Kantharia, Joshua; London, Erwin; Bakker, Hans; Haltiwanger, Robert S.; Li, Huilin; Takeuchi, Hideyuki

2015-01-01

A major remaining question in glycobiology is how a glycosyltransferase (GT) that retains the anomeric linkage of a sugar catalyzes the reaction. Xylosideα1–3 Xylosyltransferase (XXYLT1) is a retaining GT that regulates Notch receptor activation by adding xylose to the Notch extracellular domain. Here, using natural acceptor and donor substrates and active Mus musculus XXYLT1, we report a series of crystallographic snapshots along the reaction, including an unprecedented natural and competent Michaelis reaction complex for retaining enzymes. These structures strongly support the SNi-like reaction as the retaining mechanism for XXYLT1. Unexpectedly the Epidermal Growth Factor-like repeat acceptor substrate undergoes a large conformational change upon binding to the active site, providing a structural basis for substrate specificity. Our improved understanding of this retaining enzyme will accelerate the design of retaining GT inhibitors that can modulate Notch activity in pathological situations where dysregulation of Notch is known to cause cancer or developmental disorders. PMID:26414444

Notch-modifying xylosyltransferase structures support an S Ni-like retaining mechanism

DOE PAGES

Yu, Hongjun; Li, Huilin; Takeuchi, Megumi; ...

2015-09-28

A major question remaining in glycobiology is how a glycosyltransferase (GT) that retains the anomeric linkage of a sugar catalyzes the reaction. Xyloside α-1,3-xylosyltransferase (XXYLT1) is a retaining GT that regulates Notch receptor activation by adding xylose to the Notch extracellular domain. Here, using natural acceptor and donor substrates and active Mus musculus XXYLT1, we report a series of crystallographic snapshots along the reaction, including an unprecedented natural and competent Michaelis reaction complex for retaining enzymes. These structures strongly support the SNi-like reaction as the retaining mechanism for XXYLT1. Unexpectedly, the epidermal growth factor–like repeat acceptor substrate undergoes a largemore » conformational change upon binding to the active site, providing a structural basis for substrate specificity. As a result, our improved understanding of this retaining enzyme will accelerate the design of retaining GT inhibitors that can modulate Notch activity in pathological situations in which Notch dysregulation is known to cause cancer or developmental disorders.« less

Notch-modifying xylosyltransferase structures support an S Ni-like retaining mechanism

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yu, Hongjun; Li, Huilin; Takeuchi, Megumi

A major question remaining in glycobiology is how a glycosyltransferase (GT) that retains the anomeric linkage of a sugar catalyzes the reaction. Xyloside α-1,3-xylosyltransferase (XXYLT1) is a retaining GT that regulates Notch receptor activation by adding xylose to the Notch extracellular domain. Here, using natural acceptor and donor substrates and active Mus musculus XXYLT1, we report a series of crystallographic snapshots along the reaction, including an unprecedented natural and competent Michaelis reaction complex for retaining enzymes. These structures strongly support the SNi-like reaction as the retaining mechanism for XXYLT1. Unexpectedly, the epidermal growth factor–like repeat acceptor substrate undergoes a largemore » conformational change upon binding to the active site, providing a structural basis for substrate specificity. As a result, our improved understanding of this retaining enzyme will accelerate the design of retaining GT inhibitors that can modulate Notch activity in pathological situations in which Notch dysregulation is known to cause cancer or developmental disorders.« less

Structure and stability of the ankyrin domain of the Drosophila Notch receptor.

PubMed

Zweifel, Mark E; Leahy, Daniel J; Hughson, Frederick M; Barrick, Doug

2003-11-01

The Notch receptor contains a conserved ankyrin repeat domain that is required for Notch-mediated signal transduction. The ankyrin domain of Drosophila Notch contains six ankyrin sequence repeats previously identified as closely matching the ankyrin repeat consensus sequence, and a putative seventh C-terminal sequence repeat that exhibits lower similarity to the consensus sequence. To better understand the role of the Notch ankyrin domain in Notch-mediated signaling and to examine how structure is distributed among the seven ankyrin sequence repeats, we have determined the crystal structure of this domain to 2.0 angstroms resolution. The seventh, C-terminal, ankyrin sequence repeat adopts a regular ankyrin fold, but the first, N-terminal ankyrin repeat, which contains a 15-residue insertion, appears to be largely disordered. The structure reveals a substantial interface between ankyrin polypeptides, showing a high degree of shape and charge complementarity, which may be related to homotypic interactions suggested from indirect studies. However, the Notch ankyrin domain remains largely monomeric in solution, demonstrating that this interface alone is not sufficient to promote tight association. Using the structure, we have classified reported mutations within the Notch ankyrin domain that are known to disrupt signaling into those that affect buried residues and those restricted to surface residues. We show that the buried substitutions greatly decrease protein stability, whereas the surface substitutions have only a marginal affect on stability. The surface substitutions are thus likely to interfere with Notch signaling by disrupting specific Notch-effector interactions and map the sites of these interactions.

RITA, a novel modulator of Notch signalling, acts via nuclear export of RBP-J.

PubMed

Wacker, Stephan Armin; Alvarado, Cristobal; von Wichert, Götz; Knippschild, Uwe; Wiedenmann, Jörg; Clauss, Karen; Nienhaus, Gerd Ulrich; Hameister, Horst; Baumann, Bernd; Borggrefe, Tilman; Knöchel, Walter; Oswald, Franz

2011-01-05

The evolutionarily conserved Notch signal transduction pathway regulates fundamental cellular processes during embryonic development and in the adult. Ligand binding induces presenilin-dependent cleavage of the receptor and a subsequent nuclear translocation of the Notch intracellular domain (NICD). In the nucleus, NICD binds to the recombination signal sequence-binding protein J (RBP-J)/CBF-1 transcription factor to induce expression of Notch target genes. Here, we report the identification and functional characterization of RBP-J interacting and tubulin associated (RITA) (C12ORF52) as a novel RBP-J/CBF-1-interacting protein. RITA is a highly conserved 36 kDa protein that, most interestingly, binds to tubulin in the cytoplasm and shuttles rapidly between cytoplasm and nucleus. This shuttling RITA exports RBP-J/CBF-1 from the nucleus. Functionally, we show that RITA can reverse a Notch-induced loss of primary neurogenesis in Xenopus laevis. Furthermore, RITA is able to downregulate Notch-mediated transcription. Thus, we propose that RITA acts as a negative modulator of the Notch signalling pathway, controlling the level of nuclear RBP-J/CBF-1, where its amounts are limiting.

The crystal structure of a partial mouse Notch-1 ankyrin domain: Repeats 4 through 7 preserve an ankyrin fold

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lubman, Olga Y.; Kopan, Raphael; Waksman, Gabriel

Folding and stability of proteins containing ankyrin repeats (ARs) is of great interest because they mediate numerous protein-protein interactions involved in a wide range of regulatory cellular processes. Notch, an ankyrin domain containing protein, signals by converting a transcriptional repression complex into an activation complex. The Notch ANK domain is essential for Notch function and contains seven ARs. Here, we present the 2.2 {angstrom} crystal structure of ARs 4-7 from mouse Notch 1 (m1ANK). These C-terminal repeats were resistant to degradation during crystallization, and their secondary and tertiary structures are maintained in the absence of repeats 1-3. The crystallized fragmentmore » adopts a typical ankyrin fold including the poorly conserved seventh AR, as seen in the Drosophila Notch ANK domain (dANK). The structural preservation and stability of the C-terminal repeats shed a new light onto the mechanism of hetero-oligomeric assembly during Notch-mediated transcriptional activation.« less

O-GlcNAc on NOTCH1 EGF repeats regulates ligand-induced Notch signaling and vascular development in mammals.

PubMed

Sawaguchi, Shogo; Varshney, Shweta; Ogawa, Mitsutaka; Sakaidani, Yuta; Yagi, Hirokazu; Takeshita, Kyosuke; Murohara, Toyoaki; Kato, Koichi; Sundaram, Subha; Stanley, Pamela; Okajima, Tetsuya

2017-04-11

The glycosyltransferase EOGT transfers O-GlcNAc to a consensus site in epidermal growth factor-like (EGF) repeats of a limited number of secreted and membrane proteins, including Notch receptors. In EOGT-deficient cells, the binding of DLL1 and DLL4, but not JAG1, canonical Notch ligands was reduced, and ligand-induced Notch signaling was impaired. Mutagenesis of O-GlcNAc sites on NOTCH1 also resulted in decreased binding of DLL4. EOGT functions were investigated in retinal angiogenesis that depends on Notch signaling. Global or endothelial cell-specific deletion of Eogt resulted in defective retinal angiogenesis, with a mild phenotype similar to that caused by reduced Notch signaling in retina. Combined deficiency of different Notch1 mutant alleles exacerbated the abnormalities in Eogt -/- retina, and Notch target gene expression was decreased in Eogt -/- endothelial cells. Thus, O-GlcNAc on EGF repeats of Notch receptors mediates ligand-induced Notch signaling required in endothelial cells for optimal vascular development.

Context-Dependent Sensitivity to Mutations Disrupting the Structural Integrity of Individual EGF Repeats in the Mouse Notch Ligand DLL1

PubMed Central

Schuster-Gossler, Karin; Cordes, Ralf; Müller, Julia; Geffers, Insa; Delany-Heiken, Patricia; Taft, Manuel; Preller, Matthias; Gossler, Achim

2016-01-01

The highly conserved Notch-signaling pathway mediates cell-to-cell communication and is pivotal for multiple developmental processes and tissue homeostasis in adult organisms. Notch receptors and their ligands are transmembrane proteins with multiple epidermal-growth-factor-like (EGF) repeats in their extracellular domains. In vitro the EGF repeats of mammalian ligands that are essential for Notch activation have been defined. However, in vivo the significance of the structural integrity of each EGF repeat in the ligand ectodomain for ligand function is still unclear. Here, we analyzed the mouse Notch ligand DLL1. We expressed DLL1 proteins with mutations disrupting disulfide bridges in each individual EGF repeat from single-copy transgenes in the HPRT locus of embryonic stem cells. In Notch transactivation assays all mutations impinged on DLL1 function and affected both NOTCH1 and NOTCH2 receptors similarly. An allelic series in mice that carried the same point mutations in endogenous Dll1, generated using a mini-gene strategy, showed that early developmental processes depending on DLL1-mediated NOTCH activation were differently sensitive to mutation of individual EGF repeats in DLL1. Notably, some mutations affected only somite patterning and resulted in vertebral column defects resembling spondylocostal dysostosis. In conclusion, the structural integrity of each individual EGF repeat in the extracellular domain of DLL1 is necessary for full DLL1 activity, and certain mutations in Dll1 might contribute to spondylocostal dysostosis in humans. PMID:26801181

Inhibition of Delta-induced Notch signaling using fucose analogs

PubMed Central

Schneider, Michael; Kumar, Vivek; Nordstrøm, Lars Ulrik; Feng, Lei; Takeuchi, Hideyuki; Hao, Huilin; Luca, Vincent C.; Garcia, K. Christopher; Stanley, Pamela; Wu, Peng; Haltiwanger, Robert S.

2017-01-01

Notch is a cell-surface receptor that controls cell fate decisions and is regulated by O-glycans attached to epidermal growth factor-like (EGF) repeats in its extracellular domain. Protein O-fucosyltransferase 1 (Pofut1) modifies EGF repeats with O-fucose and is essential for Notch signaling. Constitutive activation of Notch signaling has been associated with a variety of human malignancies. Therefore, tools for inhibiting Notch activity are being developed as cancer therapeutics. Towards this end, we screened L-fucose analogs for their effects on Notch signaling. Two analogs, 6-alkynyl and 6-alkenyl fucose, were substrates of Pofut1 and were incorporated directly into Notch EGF repeats in cells. Both analogs were potent inhibitors of binding to and activation of Notch1 by Notch ligands Dll1 and Dll4, but not by Jag1. Mutagenesis and modeling studies suggest that incorporation of the analogs into EGF8 of Notch1 markedly reduces the ability of Delta ligands to bind and activate Notch1. PMID:29176671

H3K9me2/3 Binding of the MBT Domain Protein LIN-61 Is Essential for Caenorhabditis elegans Vulva Development

PubMed Central

Koester-Eiserfunke, Nora; Fischle, Wolfgang

2011-01-01

MBT domain proteins are involved in developmental processes and tumorigenesis. In vitro binding and mutagenesis studies have shown that individual MBT domains within clustered MBT repeat regions bind mono- and dimethylated histone lysine residues with little to no sequence specificity but discriminate against the tri- and unmethylated states. However, the exact function of promiscuous histone methyl-lysine binding in the biology of MBT domain proteins has not been elucidated. Here, we show that the Caenorhabditis elegans four MBT domain protein LIN-61, in contrast to other MBT repeat factors, specifically interacts with histone H3 when methylated on lysine 9, displaying a strong preference for di- and trimethylated states (H3K9me2/3). Although the fourth MBT repeat is implicated in this interaction, H3K9me2/3 binding minimally requires MBT repeats two to four. Further, mutagenesis of residues conserved with other methyl-lysine binding MBT regions in the fourth MBT repeat does not abolish interaction, implicating a distinct binding mode. In vivo, H3K9me2/3 interaction of LIN-61 is required for C. elegans vulva development within the synMuvB pathway. Mutant LIN-61 proteins deficient in H3K9me2/3 binding fail to rescue lin-61 synMuvB function. Also, previously identified point mutant synMuvB alleles are deficient in H3K9me2/3 interaction although these target residues that are outside of the fourth MBT repeat. Interestingly, lin-61 genetically interacts with two other synMuvB genes, hpl-2, an HP1 homologous H3K9me2/3 binding factor, and met-2, a SETDB1 homologous H3K9 methyl transferase (H3K9MT), in determining C. elegans vulva development and fertility. Besides identifying the first sequence specific and di-/trimethylation binding MBT domain protein, our studies imply complex multi-domain regulation of ligand interaction of MBT domains. Our results also introduce a mechanistic link between LIN-61 function and biology, and they establish interplay of the H3K9me2/3 binding proteins, LIN-61 and HPL-2, as well as the H3K9MT MET-2 in distinct developmental pathways. PMID:21437264

Morphogenesis of the C. elegans Intestine Involves Axon Guidance Genes

PubMed Central

Asan, Alparsan; Raiders, Stephan A.; Priess, James R.

2016-01-01

Genetic and molecular studies have provided considerable insight into how various tissue progenitors are specified in early embryogenesis, but much less is known about how those progenitors create three-dimensional tissues and organs. The C. elegans intestine provides a simple system for studying how a single progenitor, the E blastomere, builds an epithelial tube of 20 cells. As the E descendants divide, they form a primordium that transitions between different shapes over time. We used cell contours, traced from confocal optical z-stacks, to build a 3D graphic reconstruction of intestine development. The reconstruction revealed several new aspects of morphogenesis that extend and clarify previous observations. The first 8 E descendants form a plane of four right cells and four left cells; the plane arises through oriented cell divisions and VANG-1/Van Gogh-dependent repositioning of any non-planar cells. LIN-12/Notch signaling affects the left cells in the E8 primordium, and initiates later asymmetry in cell packing. The next few stages involve cell repositioning and intercalation events that shuttle cells to their final positions, like shifting blocks in a Rubik’s cube. Repositioning involves breaking and replacing specific adhesive contacts, and some of these events involve EFN-4/Ephrin, MAB-20/semaphorin-2a, and SAX-3/Robo. Once cells in the primordium align along a common axis and in the correct order, cells at the anterior end rotate clockwise around the axis of the intestine. The anterior rotation appears to align segments of the developing lumen into a continuous structure, and requires the secreted ligand UNC-6/netrin, the receptor UNC-40/DCC, and an interacting protein called MADD-2. Previous studies showed that rotation requires a second round of LIN-12/Notch signaling in cells on the right side of the primordium, and we show that MADD-2-GFP appears to be downregulated in those cells. PMID:27035721

Mapping Sites of O-Glycosylation and Fringe Elongation on Drosophila Notch*

PubMed Central

Harvey, Beth M.; Rana, Nadia A.; Moss, Hillary; Leonardi, Jessica; Jafar-Nejad, Hamed; Haltiwanger, Robert S.

2016-01-01

Glycosylation of the Notch receptor is essential for its activity and serves as an important modulator of signaling. Three major forms of O-glycosylation are predicted to occur at consensus sites within the epidermal growth factor-like repeats in the extracellular domain of the receptor: O-fucosylation, O-glucosylation, and O-GlcNAcylation. We have performed comprehensive mass spectral analyses of these three types of O-glycosylation on Drosophila Notch produced in S2 cells and identified peptides containing all 22 predicted O-fucose sites, all 18 predicted O-glucose sites, and all 18 putative O-GlcNAc sites. Using semiquantitative mass spectral methods, we have evaluated the occupancy and relative amounts of glycans at each site. The majority of the O-fucose sites were modified to high stoichiometries. Upon expression of the β3-N-acetylglucosaminyltransferase Fringe with Notch, we observed varying degrees of elongation beyond O-fucose monosaccharide, indicating that Fringe preferentially modifies certain sites more than others. Rumi modified O-glucose sites to high stoichiometries, although elongation of the O-glucose was site-specific. Although the current putative consensus sequence for O-GlcNAcylation predicts 18 O-GlcNAc sites on Notch, we only observed apparent O-GlcNAc modification at five sites. In addition, we performed mass spectral analysis on endogenous Notch purified from Drosophila embryos and found that the glycosylation states were similar to those found on Notch from S2 cells. These data provide foundational information for future studies investigating the mechanisms of how O-glycosylation regulates Notch activity. PMID:27268051

High Band Technology Program (HiTeP)

DTIC Science & Technology

2005-03-01

clock distribution circuit. One Receiver Memory module receives 60MHz reference sine wave and distributes 60MHz clock signals to all Receiver Memory...Diagram UNCLASSIFIED 23 in N00014-99-C-0314 Integrated Defense Systems Final Report 1 March 2005 .. 4.ran FibreXpress Fibre-Channel PMC "Motrl Medea FCR...the Electrically Short Crossed-Notch (ESCN). It is shorter than traditional traveling wave notch antennas. The 2X ECSN fin length is approximately 1.2

Notch-Induced Expression of FZD7 Requires Noncanonical NOTCH3 Signaling in Human Breast Epithelial Cells.

PubMed

Bhat, Vasudeva; Sun, Yu Jia; Weger, Steve; Raouf, Afshin

2016-04-01

The evolutionarily conserved Notch and Wnt signaling pathways have demonstrated roles in normal mammary gland development and in breast carcinogenesis. We previously reported that in human mammary gland, signaling through NOTCH3 alone regulates the commitment of the undifferentiated bipotential progenitors to the luminal cell fate, indicating that NOTCH3 may regulate the expression of unique genes apart from the other Notch receptors. In this study, we used gain of function and loss of function experiments and found that a Wnt signaling receptor, Frizzled7 (FZD7), is a unique and nonredundant target of NOTCH3 in human breast epithelial cells. Interestingly, neither the constitutively active forms of NOTCH1-2, 4 nor loss of expression of these receptors were able to alter expression of FZD7 in human breast epithelial cells. We further show that FZD7-expressing cells are found more frequently in the luminal progenitor-enriched subpopulation of cells obtained from breast reduction samples compared with the undifferentiated bipotent progenitors. Also, we show that NOTCH3-induced expression of FZD7 occurs in the absence of CSL (CBF1-Suppressor of Hairless-Lag-1). Our data suggest that noncanonical Notch signaling through NOTCH3 could modulate Wnt signaling via FZD7 and in this way, might be involved in luminal cell differentiation.

Thermodynamic and structural insights into CSL-DNA complexes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Friedmann, David R.; Kovall, Rhett A.

The Notch pathway is an intercellular signaling mechanism that plays important roles in cell fates decisions throughout the developing and adult organism. Extracellular complexation of Notch receptors with ligands ultimately results in changes in gene expression, which is regulated by the nuclear effector of the pathway, CSL (C-promoter binding factor 1 (CBF-1), suppressor of hairless (Su(H)), lin-12 and glp-1 (Lag-1)). CSL is a DNA binding protein that is involved in both repression and activation of transcription from genes that are responsive to Notch signaling. One well-characterized Notch target gene is hairy and enhancer of split-1 (HES-1), which is regulated bymore » a promoter element consisting of two CSL binding sites oriented in a head-to-head arrangement. Although previous studies have identified in vivo and consensus binding sites for CSL, and crystal structures of these complexes have been determined, to date, a quantitative description of the energetics that underlie CSL-DNA binding is unknown. Here, we provide a thermodynamic and structural analysis of the interaction between CSL and the two individual sites that comprise the HES-1 promoter element. Our comprehensive studies that analyze binding as a function of temperature, salt, and pH reveal moderate, but distinct, differences in the affinities of CSL for the two HES-1 binding sites. Similarly, our structural results indicate that overall CSL binds both DNA sites in a similar manner; however, minor changes are observed in both the conformation of CSL and DNA. Taken together, our results provide a quantitative and biophysical basis for understanding how CSL interacts with DNA sites in vivo.« less

Second generation γ-secretase modulators exhibit different modulation of Notch β and Aβ production.

PubMed

Wanngren, Johanna; Ottervald, Jan; Parpal, Santiago; Portelius, Erik; Strömberg, Kia; Borgegård, Tomas; Klintenberg, Rebecka; Juréus, Anders; Blomqvist, Jenny; Blennow, Kaj; Zetterberg, Henrik; Lundkvist, Johan; Rosqvist, Susanne; Karlström, Helena

2012-09-21

The γ-secretase complex is an appealing drug target when the therapeutic strategy is to alter amyloid-β peptide (Aβ) aggregation in Alzheimer disease. γ-Secretase is directly involved in Aβ formation and determines the pathogenic potential of Aβ by generating the aggregation-prone Aβ42 peptide. Because γ-secretase mediates cleavage of many substrates involved in cell signaling, such as the Notch receptor, it is crucial to sustain these pathways while altering the Aβ secretion. A way of avoiding interference with the physiological function of γ-secretase is to use γ-secretase modulators (GSMs) instead of inhibitors of the enzyme. GSMs modify the Aβ formation from producing the amyloid-prone Aβ42 variant to shorter and less amyloidogenic Aβ species. The modes of action of GSMs are not fully understood, and even though the pharmacology of GSMs has been thoroughly studied regarding Aβ generation, knowledge is lacking about their effects on other substrates, such as Notch. Here, using immunoprecipitation followed by MALDI-TOF MS analysis, we found that two novel, second generation GSMs modulate both Notch β and Aβ production. Moreover, by correlating S3-specific Val-1744 cleavage of Notch intracellular domain (Notch intracellular domain) to total Notch intracellular domain levels using immunocytochemistry, we also demonstrated that Notch intracellular domain is not modulated by the compounds. Interestingly, two well characterized, nonsteroidal anti-inflammatory drugs (nonsteroidal anti-inflammatory drug), R-flurbiprofen and sulindac sulfide, affect only Aβ and not Notch β formation, indicating that second generation GSMs and nonsteroidal anti-inflammatory drug-based GSMs have different modes of action regarding Notch processing.

High-speed tunable microwave photonic notch filter based on phase modulator incorporated Lyot filter.

PubMed

Ge, Jia; Feng, Hanlin; Scott, Guy; Fok, Mable P

2015-01-01

A high-speed tunable microwave photonic notch filter with ultrahigh rejection ratio is presented, which is achieved by semiconductor optical amplifier (SOA)-based single-sideband modulation and optical spectral filtering with a phase modulator-incorporated Lyot (PM-Lyot) filter. By varying the birefringence of the phase modulator through electro-optic effect, electrically tuning of the microwave photonic notch filter is experimentally achieved at tens of gigahertz speed. The use of SOA-polarizer based single-sideband modulation scheme provides good sideband suppression over a wide frequency range, resulting in an ultrahigh rejection ratio of the microwave photonic notch filter. Stable filter spectrum with bandstop rejection ratio over 60 dB is observed over a frequency tuning range from 1.8 to 10 GHz. Compare with standard interferometric notch filter, narrower bandwidth and sharper notch profile are achieved with the unique PM-Lyot filter, resulting in better filter selectivity. Moreover, bandwidth tuning is also achieved through polarization adjustment inside the PM-Lyot filter, that the 10-dB filter bandwidth is tuned from 0.81 to 1.85 GHz.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

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

No evidence for induction of key components of the Notch signaling pathway (Notch-1, Jagged-1) by treatment with UV-B, 1,25(OH)(2)D(3), and/or epigenetic drugs (TSA, 5-Aza) in human keratinocytes in vitro.

PubMed

Reichrath, Sandra; Reichrath, Jörg

2012-01-01

Notch signaling is of high importance for growth and survival of various cell types. We now analyzed the protein expression of two key components of the Notch signaling pathway (Notch-1, Jagged-1) in spontaneously immortalized (HaCaT) and in malignant (SCL-1) human keratinocytes, using western analysis. We found that Notch-1 and its corresponding ligand Jagged-1 are expressed in both cell lines, with no marked change following UV-B treatment. Moreover, treatment of both cell lines before or after UV-B irradiation with 1,25-dihydroxyvitamin D(3), the biologically active form of vitamin D, and/or epigenetic modulating drugs (TSA; 5-Aza) did not result in a marked modulation of the protein expression of Notch-1 or Jagged-1. Under the experimental conditions of this study, treatment with 1,25(OH)(2)D(3) protected human keratinocytes in part against the antiproliferative effects of UV-B-radiation. In conclusion, our findings do not point at a differential expression of these two key components of Notch signaling in non-malignant as compared to malignant human keratinocytes, indicating that alterations in their expression are not of importance for the photocarcinogenesis of human squamous cell carcinomas. Moreover, our findings do not support the hypothesis that modulation of Notch signaling may be involved in the photoprotective effect of 1,25-dihydroxyvitamin D(3), that we and others reported previously. Additionally, we demonstrate that epigenetic modulating drugs (TSA, 5-Aza) do not markedly modulate the expression Notch-1 or Jagged-1 in UV-B-treated human keratinocytes in vitro.

Notch/Her12 signalling modulates, motile/immotile cilia ratio downstream of Foxj1a in zebrafish left-right organizer

PubMed Central

Sampaio, Pedro; Pestana, Sara; Pinto, Andreia; Vaz, Andreia; Roxo-Rosa, Mónica; Gardner, Rui; Lopes, Telma; Schilling, Britta; Henry, Ian; Saúde, Leonor

2017-01-01

Foxj1a is necessary and sufficient to specify motile cilia. Using transcriptional studies and slow-scan two-photon live imaging capable of identifying the number of motile and immotile cilia, we now established that the final number of motile cilia depends on Notch signalling (NS). We found that despite all left-right organizer (LRO) cells express foxj1a and the ciliary axonemes of these cells have dynein arms, some cilia remain immotile. We identified that this decision is taken early in development in the Kupffer’s Vesicle (KV) precursors the readout being her12 transcription. We demonstrate that overexpression of either her12 or Notch intracellular domain (NICD) increases the number of immotile cilia at the expense of motile cilia, and leads to an accumulation of immotile cilia at the anterior half of the KV. This disrupts the normal fluid flow intensity and pattern, with consequent impact on dand5 expression pattern and left-right (L-R) axis establishment. PMID:28875937

A network model for the specification of vulval precursor cells and cell fusion control in Caenorhabditis elegans

PubMed Central

Weinstein, Nathan; Mendoza, Luis

2013-01-01

The vulva of Caenorhabditis elegans has been long used as an experimental model of cell differentiation and organogenesis. While it is known that the signaling cascades of Wnt, Ras/MAPK, and NOTCH interact to form a molecular network, there is no consensus regarding its precise topology and dynamical properties. We inferred the molecular network, and developed a multivalued synchronous discrete dynamic model to study its behavior. The model reproduces the patterns of activation reported for the following types of cell: vulval precursor, first fate, second fate, second fate with reversed polarity, third fate, and fusion fate. We simulated the fusion of cells, the determination of the first, second, and third fates, as well as the transition from the second to the first fate. We also used the model to simulate all possible single loss- and gain-of-function mutants, as well as some relevant double and triple mutants. Importantly, we associated most of these simulated mutants to multivulva, vulvaless, egg-laying defective, or defective polarity phenotypes. The model shows that it is necessary for RAL-1 to activate NOTCH signaling, since the repression of LIN-45 by RAL-1 would not suffice for a proper second fate determination in an environment lacking DSL ligands. We also found that the model requires the complex formed by LAG-1, LIN-12, and SEL-8 to inhibit the transcription of eff-1 in second fate cells. Our model is the largest reconstruction to date of the molecular network controlling the specification of vulval precursor cells and cell fusion control in C. elegans. According to our model, the process of fate determination in the vulval precursor cells is reversible, at least until either the cells fuse with the ventral hypoderm or divide, and therefore the cell fates must be maintained by the presence of extracellular signals. PMID:23785384

The adhesion force of Notch with Delta and the rate of Notch signaling.

PubMed

Ahimou, Francois; Mok, Lee-Peng; Bardot, Boris; Wesley, Cedric

2004-12-20

Notch signaling is repeatedly used during animal development to specify cell fates. Using atomic force microscopy on live cells, chemical inhibitors, and conventional analyses, we show that the rate of Notch signaling is linked to the adhesion force between cells expressing Notch receptors and Delta ligand. Both the Notch extracellular and intracellular domains are required for the high adhesion force with Delta. This high adhesion force is lost within minutes, primarily due to the action of Presenilin on Notch. Reduced turnover or Delta pulling accelerate this loss. These data suggest that strong adhesion between Notch and Delta might serve as a booster for initiating Notch signaling at a high rate.

The Mediator Kinase Module Restrains Epidermal Growth Factor Receptor Signaling and Represses Vulval Cell Fate Specification in Caenorhabditis elegans.

PubMed

Grants, Jennifer M; Ying, Lisa T L; Yoda, Akinori; You, Charlotte C; Okano, Hideyuki; Sawa, Hitoshi; Taubert, Stefan

2016-02-01

Cell signaling pathways that control proliferation and determine cell fates are tightly regulated to prevent developmental anomalies and cancer. Transcription factors and coregulators are important effectors of signaling pathway output, as they regulate downstream gene programs. In Caenorhabditis elegans, several subunits of the Mediator transcriptional coregulator complex promote or inhibit vulva development, but pertinent mechanisms are poorly defined. Here, we show that Mediator's dissociable cyclin dependent kinase 8 (CDK8) module (CKM), consisting of cdk-8, cic-1/Cyclin C, mdt-12/dpy-22, and mdt-13/let-19, is required to inhibit ectopic vulval cell fates downstream of the epidermal growth factor receptor (EGFR)-Ras-extracellular signal-regulated kinase (ERK) pathway. cdk-8 inhibits ectopic vulva formation by acting downstream of mpk-1/ERK, cell autonomously in vulval cells, and in a kinase-dependent manner. We also provide evidence that the CKM acts as a corepressor for the Ets-family transcription factor LIN-1, as cdk-8 promotes transcriptional repression by LIN-1. In addition, we find that CKM mutation alters Mediator subunit requirements in vulva development: the mdt-23/sur-2 subunit, which is required for vulva development in wild-type worms, is dispensable for ectopic vulva formation in CKM mutants, which instead display hallmarks of unrestrained Mediator tail module activity. We propose a model whereby the CKM controls EGFR-Ras-ERK transcriptional output by corepressing LIN-1 and by fine tuning Mediator specificity, thus balancing transcriptional repression vs. activation in a critical developmental signaling pathway. Collectively, these data offer an explanation for CKM repression of EGFR signaling output and ectopic vulva formation and provide the first evidence of Mediator CKM-tail module subunit crosstalk in animals. Copyright © 2016 by the Genetics Society of America.

Identification and Characterization of Genes That Interact with Lin-12 in Caenorhabditis Elegans

PubMed Central

Tax, F. E.; Thomas, J. H.; Ferguson, E. L.; Horvitz, H. R.

1997-01-01

We identified and characterized 14 extragenic mutations that suppressed the dominant egg-laying defect of certain lin-12 gain-of-function mutations. These suppressors defined seven genes: sup-17, lag-2, sel-4, sel-5, sel-6, sel-7 and sel-8. Mutations in six of the genes are recessive suppressors, whereas the two mutations that define the seventh gene, lag-2, are semi-dominant suppressors. These suppressor mutations were able to suppress other lin-12 gain-of-function mutations. The suppressor mutations arose at a very low frequency per gene, 10-50 times below the typical loss-of-function mutation frequency. The suppressor mutations in sup-17 and lag-2 were shown to be rare non-null alleles, and we present evidence that null mutations in these two genes cause lethality. Temperature-shift studies for two suppressor genes, sup-17 and lag-2, suggest that both genes act at approximately the same time as lin-12 in specifying a cell fate. Suppressor alleles of six of these genes enhanced a temperature-sensitive loss-of-function allele of glp-1, a gene related to lin-12 in structure and function. Our analysis of these suppressors suggests that the majority of these genes are part of a shared lin-12/glp-1 signal transduction pathway, or act to regulate the expression or stability of lin-12 and glp-1. PMID:9409830

Histone Code Modulation by Oncogenic PWWP-Domain Protein in Breast Cancers

DTIC Science & Technology

2014-08-01

discs, the Drosophila melanogaster homo- logue of human retinoblastoma binding protein 2. Genetics 2000; 156: 645-663. [10] Zeng J, Ge Z, Wang L...in breast cancer patients (7-11). Earlier, we used genomic analysis of copy number and gene expression to perform a detailed analysis of the 8p11-12...from the 8p11-12 region (14). Very recently, we searched the Cancer Genome Atlas database that contains 744 breast invasive carcinomas. We found DNA or

The RING finger/B-box factor TAM-1 and a retinoblastoma-like protein LIN-35 modulate context-dependent gene silencing in Caenorhabditis elegans.

PubMed

Hsieh, J; Liu, J; Kostas, S A; Chang, C; Sternberg, P W; Fire, A

1999-11-15

Context-dependent gene silencing is used by many organisms to stably modulate gene activity for large chromosomal regions. We have used tandem array transgenes as a model substrate in a screen for Caenorhabditis elegans mutants that affect context-dependent gene silencing in somatic tissues. This screen yielded multiple alleles of a previously uncharacterized gene, designated tam-1 (for tandem-array-modifier). Loss-of-function mutations in tam-1 led to a dramatic reduction in the activity of numerous highly repeated transgenes. These effects were apparently context dependent, as nonrepetitive transgenes retained activity in a tam-1 mutant background. In addition to the dramatic alterations in transgene activity, tam-1 mutants showed modest alterations in expression of a subset of endogenous cellular genes. These effects include genetic interactions that place tam-1 into a group called the class B synMuv genes (for a Synthetic Multivulva phenotype); this family plays a negative role in the regulation of RAS pathway activity in C. elegans. Loss-of-function mutants in other members of the class-B synMuv family, including lin-35, which encodes a protein similar to the tumor suppressor Rb, exhibit a hypersilencing in somatic transgenes similar to that of tam-1 mutants. Molecular analysis reveals that tam-1 encodes a broadly expressed nuclear protein with RING finger and B-box motifs.

Therapeutic NOTCH3 cysteine correction in CADASIL using exon skipping: in vitro proof of concept.

PubMed

Rutten, Julie W; Dauwerse, Hans G; Peters, Dorien J M; Goldfarb, Andrew; Venselaar, Hanka; Haffner, Christof; van Ommen, Gert-Jan B; Aartsma-Rus, Annemieke M; Lesnik Oberstein, Saskia A J

2016-04-01

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy, or CADASIL, is a hereditary cerebral small vessel disease caused by characteristic cysteine altering missense mutations in the NOTCH3 gene. NOTCH3 mutations in CADASIL result in an uneven number of cysteine residues in one of the 34 epidermal growth factor like-repeat (EGFr) domains of the NOTCH3 protein. The consequence of an unpaired cysteine residue in an EGFr domain is an increased multimerization tendency of mutant NOTCH3, leading to toxic accumulation of the protein in the (cerebro)vasculature, and ultimately reduced cerebral blood flow, recurrent stroke and vascular dementia. There is no therapy to delay or alleviate symptoms in CADASIL. We hypothesized that exclusion of the mutant EGFr domain from NOTCH3 would abolish the detrimental effect of the unpaired cysteine and thus prevent toxic NOTCH3 accumulation and the negative cascade of events leading to CADASIL. To accomplish this NOTCH3 cysteine correction by EGFr domain exclusion, we used pre-mRNA antisense-mediated skipping of specific NOTCH3 exons. Selection of these exons was achieved using in silico studies and based on the criterion that skipping of a particular exon or exon pair would modulate the protein in such a way that the mutant EGFr domain is eliminated, without otherwise corrupting NOTCH3 structure and function. Remarkably, we found that this strategy closely mimics evolutionary events, where the elimination and fusion of NOTCH EGFr domains led to the generation of four functional NOTCH homologues. We modelled a selection of exon skip strategies using cDNA constructs and show that the skip proteins retain normal protein processing, can bind ligand and be activated by ligand. We then determined the technical feasibility of targeted NOTCH3 exon skipping, by designing antisense oligonucleotides targeting exons 2-3, 4-5 and 6, which together harbour the majority of distinct CADASIL-causing mutations. Transfection of these antisense oligonucleotides into CADASIL patient-derived cerebral vascular smooth muscle cells resulted in successful exon skipping, without abrogating NOTCH3 signalling. Combined, these data provide proof of concept for this novel application of exon skipping, and are a first step towards the development of a rational therapeutic approach applicable to up to 94% of CADASIL-causing mutations. © The Author (2016). Published by Oxford University Press on behalf of the Guarantors of Brain. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Considerations on repeated repairing of weldments in Inconel 718 alloy

NASA Technical Reports Server (NTRS)

Bayless, E. O.; Lovoy, C. V.; Mcilwain, M. C.; Munafo, P.

1981-01-01

The effects of repeated weld repairs on the metallurgical characteristics, high cycle fatigue (HCF), and tensile properties of Inconel 718 butt weld joints were determined. A 1/4 in thick plate and a 1/2 in thick plate were used as well as tungsten inert gas welding, and Inconel 718 filler wire. Weld panels were subjected to 2, 6, and 12 repeated repairs and were made in a highly restrained condition. Post weld heat treatments were also conducted with the welded panel in the highly restrained condition. Results indicate that no significant metallurgical anomaly is evident as a result of up to twelve repeated weld repairs. No degradation in fatigue life is noted for up to twelve repeated repairs. Tensile results from specimens which contained up to twelve repeated weld repairs revealed no significant degradation in UTS and YS. However, a significant decrease in elongation is evident with specimens (solution treated and age hardened after welding) which contained twelve repeated repairs. The elongation loss is attributed to the presence of a severe notch on each side (fusion line) of the repair weld bead reinforcement.

The EGF Repeat-Specific O-GlcNAc-Transferase Eogt Interacts with Notch Signaling and Pyrimidine Metabolism Pathways in Drosophila

PubMed Central

Müller, Reto; Jenny, Andreas; Stanley, Pamela

2013-01-01

The O-GlcNAc transferase Eogt modifies EGF repeats in proteins that transit the secretory pathway, including Dumpy and Notch. In this paper, we show that the Notch ligands Delta and Serrate are also substrates of Eogt, that mutation of a putative UDP-GlcNAc binding DXD motif greatly reduces enzyme activity, and that Eogt and the cytoplasmic O-GlcNAc transferase Ogt have distinct substrates in Drosophila larvae. Loss of Eogt is larval lethal and disrupts Dumpy functions, but does not obviously perturb Notch signaling. To identify novel genetic interactions with eogt, we investigated dominant modification of wing blister formation caused by knock-down of eogt. Unexpectedly, heterozygosity for several members of the canonical Notch signaling pathway suppressed wing blister formation. And importantly, extensive genetic interactions with mutants in pyrimidine metabolism were identified. Removal of pyrimidine synthesis alleles suppressed wing blister formation, while removal of uracil catabolism alleles was synthetic lethal with eogt knock-down. Therefore, Eogt may regulate protein functions by O-GlcNAc modification of their EGF repeats, and cellular metabolism by affecting pyrimidine synthesis and catabolism. We propose that eogt knock-down in the wing leads to metabolic and signaling perturbations that increase cytosolic uracil levels, thereby causing wing blister formation. PMID:23671640

Mesoporous silica nanoparticle-based substrates for cell directed delivery of Notch signalling modulators to control myoblast differentiation

NASA Astrophysics Data System (ADS)

Böcking, Dominique; Wiltschka, Oliver; Niinimäki, Jenni; Shokry, Hussein; Brenner, Rolf; Lindén, Mika; Sahlgren, Cecilia

2014-01-01

Biochemical cues are critical to control stem cell function and can be utilized to develop smart biomaterials for stem cell engineering. The challenge is to deliver these cues in a restricted manner with spatial and temporal control. Here we have developed bilayer films of mesoporous silica nanoparticles for delayed cellular delivery of Notch modulators to promote muscle stem cell differentiation. We demonstrate that drug-loaded particles are internalized from the particle-covered surface, which allows for direct delivery of the drug into the cell and a delayed and confined drug release. Substrates of particles loaded with γ-secretase-inhibitors, which block the Notch signalling pathway, promoted efficient differentiation of myoblasts. The particle substrates were fully biocompatible and did not interfere with the inherent differentiation process. We further demonstrate that impregnating commercially available, biocompatible polymer scaffolds with MSNs allows for a free standing substrate for cell directed drug delivery.Biochemical cues are critical to control stem cell function and can be utilized to develop smart biomaterials for stem cell engineering. The challenge is to deliver these cues in a restricted manner with spatial and temporal control. Here we have developed bilayer films of mesoporous silica nanoparticles for delayed cellular delivery of Notch modulators to promote muscle stem cell differentiation. We demonstrate that drug-loaded particles are internalized from the particle-covered surface, which allows for direct delivery of the drug into the cell and a delayed and confined drug release. Substrates of particles loaded with γ-secretase-inhibitors, which block the Notch signalling pathway, promoted efficient differentiation of myoblasts. The particle substrates were fully biocompatible and did not interfere with the inherent differentiation process. We further demonstrate that impregnating commercially available, biocompatible polymer scaffolds with MSNs allows for a free standing substrate for cell directed drug delivery. Electronic supplementary information (ESI) available: (1) Particle characterization. (2) Immunohistochemistry and SEM analyses of C2C12 cells grown on films for 3, 6, 24 and 72 h. Light microscopy and WST1 analyses of cells grown on cover slips and films for 6, 24 and 72 h (3) Quantification of protein levels of C2C12 cells differentiating on cover slips versus MSN films. (4) Stability of MSN films in biological solution and the influence on cell viability. (5) Cell internalization of particles from MSN films and intracellular drug release at 12 and 24 h (6) Cell internalization and intracellular DiI release of MSNs from (3Dtro®) fiber scaffolds impregnated with MSNs. See DOI: 10.1039/c3nr04022d

[Prokaryotic Expression and Purification of the Notch Ligand and Its Effect on Hematopoiesis after Carbon Tetrachloride Damage].

PubMed

Chen, Juan-Juan; Huang, Si-Yong; Ma, Peng-Fei; Wu, Bi-Jia; Zhou, Si-Lang; Zhao, Yong-Xing; Gong, Jun-Mei; Liang, Ying-Min

2018-04-01

To express and purify the mouse endothelial cell-targeted recombinant Notch ligand protein mD1R, and to investigate its effect on hematopoiesis after carbon tetrachloride damage. PCR was performed to clone and construct the expression vector pET22b(+)-mD1R. The mD1R successfully transformed into E. coli was induced by IPTG, and purified with Ni 2+ -beads affinity chromatography. The target protein was detected by SDS-PAGE. The fluorescence-activated cell sorting analysis (FACS), cell adhesion test, immunofluorescence staining and quantitative real-time PCR were employed to detect the endothelial cell-targeted and Notch signaling-activated biological characteristics of mD1R. The carbon tetrachloride mouse model was established to observe the effects of mD1R on the hematopoietic stem cell (HSC), myeloid cells and lymphoid cells by flow cytometry. The Lin - Scal-1 + c-Kit + cells were sorted by magnetic bead, FACS was performed to analyze the cell cycle, and RT-PCR was employed to observe the expression of interleukin (IL)-10. The prokaryotic expression vector was successfully cloned and constructed. The purity and the activity were confirmed in mD1R recombinant protein. The purified mD1R activated the Notch signaling pathway of hematopoietic stem cells in carbon tetrachloride damaged mouse, and internally elevated the number of HSC and long-term HSC to 2.96-fold and 6.18-fold. In addition, mD1R improved the amplification of the myeloid progenitor cells and the myeloid-derived suppressor cells, particularly the granulocyte/monocyte into blood. Mechanistically, the further analyses suggested that Notch pathway could increase the proliferation of HSC and enhance expression of IL-10 after stress injury. A new and activated recombinant Notch ligand protein has been obtained successfully to communicate hematopoietic stem cells and hematopoietic microenvironment. The Notch- mediated intrinsic hematopoiesis has been regulated by the anti-inflammatory factor after stress injury.

Identification of small molecule Hes1 modulators as potential anticancer chemotherapeutics.

PubMed

Sail, Vibhavari; Hadden, M Kyle

2013-03-01

Hes1 is a key transcriptional regulator primarily controlled by the Notch signaling pathway, and recent studies have demonstrated both an oncogenic and tumor suppressor role for Hes1, depending on the cell type. Small molecules that activate and inhibit Hes1 activity hold promise as future anticancer chemotherapeutics. We have utilized a cell-based dual luciferase assay to identify modulators of Hes1 expression in a medium-throughput format. A modest screen was performed in HCT-116 colon cancer cell lines, and two small molecules were identified and characterized as Hes1 regulators. Compound 3 induced Hes1 expression and exhibited anticancer effects in pulmonary carcinoid tumor cells, a cell type in which the upregulated Notch/Hes1 signaling plays a tumor suppressive role. Treatment of HCT-116 cells with compound 12 resulted in Hes1 downregulation and antitumor effects. © 2012 John Wiley & Sons A/S.

Rho/ROCK-dependent inhibition of 3T3-L1 adipogenesis by G-protein-deamidating dermonecrotic toxins: differential regulation of Notch1, Pref1/Dlk1, and β-catenin signaling

PubMed Central

Bannai, Yuka; Aminova, Leila R.; Faulkner, Melinda J.; Ho, Mengfei; Wilson, Brenda A.

2012-01-01

The dermonecrotic toxins from Pasteurella multocida (PMT), Bordetella (DNT), Escherichia coli (CNF1-3), and Yersinia (CNFY) modulate their G-protein targets through deamidation and/or transglutamination of an active site Gln residue, which results in activation of the G protein and its cognate downstream signaling pathways. Whereas DNT and the CNFs act on small Rho GTPases, PMT acts on the α subunit of heterotrimeric Gq, Gi, and G12/13 proteins. We previously demonstrated that PMT potently blocks adipogenesis and adipocyte differentiation in a calcineurin-independent manner through downregulation of Notch1 and stabilization of β-catenin and Pref1/Dlk1, key proteins in signaling pathways strongly linked to cell fate decisions, including fat and bone development. Here, we report that similar to PMT, DNT, and CNF1 completely block adipogenesis and adipocyte differentiation by preventing upregulation of adipocyte markers, PPARγ and C/EBPα, while stabilizing the expression of Pref1/Dlk1 and β-catenin. We show that the Rho/ROCK inhibitor Y-27632 prevented or reversed these toxin-mediated effects, strongly supporting a role for Rho/ROCK signaling in dermonecrotic toxin-mediated inhibition of adipogenesis and adipocyte differentiation. Toxin treatment was also accompanied by downregulation of Notch1 expression, although this inhibition was independent of Rho/ROCK signaling. We further show that PMT-mediated downregulation of Notch1 expression occurs primarily through G12/13 signaling. Our results reveal new details of the pathways involved in dermonecrotic toxin action on adipocyte differentiation, and the role of Rho/ROCK signaling in mediating toxin effects on Wnt/β-catenin and Notch1 signaling, and in particular the role of Gq and G12/13 in mediating PMT effects on Rho/ROCK and Notch1 signaling. PMID:22919671

Ground-state geometries and stability of impurity doped clusters: LinBe and LinMg (n=1-12)

NASA Astrophysics Data System (ADS)

Deshpande, M.; Dhavale, A.; Zope, R. R.; Chacko, S.; Kanhere, D. G.

2000-12-01

We have investigated the ground-state geometries of LinBe and LinMg (n=1-12) clusters using ab initio molecular dynamics. These divalent impurities Be and Mg induce different geometries and follow a different growth path for n>5. LinMg clusters are significantly different from the host geometries while LinBe clusters can be approximately viewed as Be occupying an interstitial site in the host. Our results indicate that Be gets trapped inside the Li cage, while Mg remains on the surface of the cluster. Mg-induced geometries become three-dimensional earlier at n=4 as compared to the Be system. In spite of a distinct arrangement of atoms in both cases the character of the wave functions in the d manifold is remarkably similar. In both cases an eight valence electron system has been found to be the most stable, in conformity with the spherical jellium model.

PKCθ links proximal T cell and Notch signaling through localized regulation of the actin cytoskeleton

PubMed Central

Britton, Graham J; Ambler, Rachel; Clark, Danielle J; Hill, Elaine V; Tunbridge, Helen M; McNally, Kerrie E; Burton, Bronwen R; Butterweck, Philomena; Sabatos-Peyton, Catherine; Hampton-O’Neil, Lea A; Verkade, Paul; Wülfing, Christoph; Wraith, David Cameron

2017-01-01

Notch is a critical regulator of T cell differentiation and is activated through proteolytic cleavage in response to ligand engagement. Using murine myelin-reactive CD4 T cells, we demonstrate that proximal T cell signaling modulates Notch activation by a spatiotemporally constrained mechanism. The protein kinase PKCθ is a critical mediator of signaling by the T cell antigen receptor and the principal costimulatory receptor CD28. PKCθ selectively inactivates the negative regulator of F-actin generation, Coronin 1A, at the center of the T cell interface with the antigen presenting cell (APC). This allows for effective generation of the large actin-based lamellum required for recruitment of the Notch-processing membrane metalloproteinase ADAM10. Such enhancement of Notch activation is critical for efficient T cell proliferation and Th17 differentiation. We reveal a novel mechanism that, through modulation of the cytoskeleton, controls Notch activation at the T cell:APC interface thereby linking T cell receptor and Notch signaling pathways. DOI: http://dx.doi.org/10.7554/eLife.20003.001 PMID:28112644

Notch Signaling Modulates MUC16 Biosynthesis in an In Vitro Model of Human Corneal and Conjunctival Epithelial Cell Differentiation

PubMed Central

Xiong, Linjie; Woodward, Ashley M.

2011-01-01

Purpose. Notch proteins are a family of transmembrane receptors that coordinate binary cell fate decisions and differentiation in wet-surfaced epithelia. We sought to determine whether Notch signaling contributes to maintaining mucosal homeostasis by modulating the biosynthesis of cell surface-associated mucins in an in vitro model of human corneal (HCLE) and conjunctival (HCjE) epithelial cell differentiation. Methods. HCLE and HCjE cells were grown at different stages of differentiation, representing nondifferentiated (preconfluent and confluent) and differentiated (stratified) epithelial cultures. Notch signaling was blocked with the γ-secretase inhibitor dibenzazepine (DBZ). The presence of Notch intracellular domains (Notch1 to Notch3) and mucin protein (MUC1, -4, -16) was evaluated by electrophoresis and Western blot analysis. Mucin gene expression was determined by TaqMan real-time polymerase chain reaction. Results. Here we demonstrate that Notch3 is highly expressed in undifferentiated and differentiated HCLE and HCjE cells, and that Notch1 and Notch2 biosynthesis is enhanced by induction of differentiation with serum-containing media. Inhibition of Notch signaling with DBZ impaired MUC16 biosynthesis in a concentration-dependent manner in undifferentiated cells at both preconfluent and confluent stages, but not in postmitotic stratified cells. In contrast to protein levels, the amount of MUC16 transcripts were not significantly reduced after DBZ treatment, suggesting that Notch regulates MUC16 posttranscriptionally. Immunoblots of DBZ-treated epithelial cells grown at different stages of differentiation revealed no differences in the levels of MUC1 and MUC4. Conclusions. These results indicate that MUC16 biosynthesis is posttranscriptionally regulated by Notch signaling at early stages of epithelial cell differentiation, and suggest that Notch activation contributes to maintaining a mucosal phenotype at the ocular surface. PMID:21508102

Multi-domain utilization by TUT4 and TUT7 in control of let-7 biogenesis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Faehnle, Christopher R.; Walleshauser, Jack; Joshua-Tor, Leemor

2017-07-03

The uridyl transferases TUT4 and TUT7 (collectively called TUT4(7)) switch between two modes of activity, either promoting expression of let-7 microRNA (monoU) or marking it for degradation (oligoU). Lin28 modulates the switch via recruitment of TUT4(7) to the precursor pre-let-7 in stem cells and human cancers. We found that TUT4(7) utilize two multidomain functional modules during the switch from monoU to oligoU. The catalytic module (CM) is essential for both activities, while the Lin28-interacting module (LIM) is indispensable for oligoU. A TUT7 CM structure trapped in the monoU activity staterevealed a duplex-RNA-binding pocket that orients group II pre-let-7 hairpins tomore » favor monoU addition. Conversely, the switch to oligoU requires the ZK domain of Lin28 to drive the formation of a stable ternary complex between pre-let-7 and the inactive LIM. Finally, ZK2 of TUT4(7) aids oligoU addition by engaging the growing oligoU tail through uracil-specific interactions.« less

Notch3 Interactome Analysis Identified WWP2 as a Negative Regulator of Notch3 Signaling in Ovarian Cancer

PubMed Central

Guan, Bin; Wu, Ren-Chin; Zhu, Heng; Blackshaw, Seth; Shih, Ie-Ming; Wang, Tian-Li

2014-01-01

The Notch3 signaling pathway is thought to play a critical role in cancer development, as evidenced by the Notch3 amplification and rearrangement observed in human cancers. However, the molecular mechanism by which Notch3 signaling contributes to tumorigenesis is largely unknown. In an effort to identify the molecular modulators of the Notch3 signaling pathway, we screened for Notch3-intracellular domain (N3-ICD) interacting proteins using a human proteome microarray. Pathway analysis of the Notch3 interactome demonstrated that ubiquitin C was the molecular hub of the top functional network, suggesting the involvement of ubiquitination in modulating Notch3 signaling. Thereby, we focused on functional characterization of an E3 ubiquitin-protein ligase, WWP2, a top candidate in the Notch3 interactome list. Co-immunoprecipitation experiments showed that WWP2 interacted with N3-ICD but not with intracellular domains from other Notch receptors. Wild-type WWP2 but not ligase-deficient mutant WWP2 increases mono-ubiquitination of the membrane-tethered Notch3 fragment, therefore attenuating Notch3 pathway activity in cancer cells and leading to cell cycle arrest. The mono-ubiquitination by WWP2 may target an endosomal/lysosomal degradation fate for Notch3 as suggested by the fact that the process could be suppressed by the endosomal/lysosomal inhibitor. Analysis of The Cancer Genome Atlas dataset showed that the majority of ovarian carcinomas harbored homozygous or heterozygous deletions in WWP2 locus, and there was an inverse correlation in the expression levels between WWP2 and Notch3 in ovarian carcinomas. Furthermore, ectopic expression of WWP2 decreased tumor development in a mouse xenograft model and suppressed the Notch3-induced phenotypes including increase in cancer stem cell-like cell population and platinum resistance. Taken together, our results provide evidence that WWP2 serves as a tumor suppressor by negatively regulating Notch3 signaling in ovarian cancer. PMID:25356737

Carboxy-terminal truncation activates glp-1 protein to specify vulval fates in Caenorhabditis elegans.

PubMed

Mango, S E; Maine, E M; Kimble, J

1991-08-29

The glp-1 and lin-12 genes encode homologous transmembrane proteins that may act as receptors for cell interactions during development. The glp-1 product is required for induction of germ-line proliferation and for embryogenesis. By contrast, lin-12 mediates somatic cell interactions, including those between the precursor cells that form the vulval hypodermis (VPCs). Here we analyse an unusual allele of glp-1, glp-1(q35), which displays a semidominant multivulva phenotype (Muv), as well as the typical recessive, loss-of-function Glp phenotypes (sterility and embryonic lethality). We find that the effects of glp-1(q35) on VPC development mimic those of dominant lin-12 mutations, even in the absence of lin-12 activity. The glp-1(q35) gene bears a nonsense mutation predicted to eliminate the 122 C-terminal amino acids, including a ProGluSerThr (PEST) sequence thought to destabilize proteins. We suggest that the carboxy terminus bears a negative regulatory domain which normally inactivates glp-1 in the VPCs. We propose that inappropriate glp-1(q35) activity can substitute for lin-12 to determine vulval fate, perhaps by driving the VPCs to proliferate.

Epidermal Notch signalling: differentiation, cancer and adhesion.

PubMed

Watt, Fiona M; Estrach, Soline; Ambler, Carrie A

2008-04-01

The Notch pathway plays an important role in regulating epidermal differentiation. Notch ligands, receptors and effectors are expressed in a complex and dynamic pattern in embryonic and adult skin. Genetic ablation or activation of the pathway reveals that Notch signalling promotes differentiation of the hair follicle, sebaceous gland and interfollicular epidermal lineages and that Notch acts as an epidermal tumour suppressor. Notch signalling interacts with a range of other pathways to fulfil these functions and acts via RBP-Jkappa dependent and independent mechanisms. The effects on differentiation can be cell autonomous and non-autonomous, and Notch contributes to stem cell clustering via modulation of cell adhesion.

Notch Decoys that Selectively Block Dll/Notch or Jagged/Notch Disrupt Angiogenesis by Unique Mechanisms to Inhibit Tumor Growth

PubMed Central

Kangsamaksin, Thaned; Murtomaki, Aino; Kofler, Natalie M.; Cuervo, Henar; Chaudhri, Reyhaan A.; Tattersall, Ian W.; Rosenstiel, Paul E.; Shawber, Carrie J.; Kitajewski, Jan

2015-01-01

A pro-angiogenic role for Jagged-dependent activation of Notch signaling in the endothelium has yet to be described. Using proteins that encoded different NOTCH1 EGF-like repeats, we identified unique regions of DLL-class and JAG-class ligand/receptor interactions, and developed Notch decoys that function as ligand-specific Notch inhibitors. N110-24 decoy blocked JAG1/JAG2-mediated NOTCH1 signaling, angiogenic sprouting in vitro and retinal angiogenesis, demonstrating JAG-dependent Notch signal activation promotes angiogenesis. In tumors, N110-24 decoy reduced angiogenic sprouting, vessel perfusion, pericyte coverage, and tumor growth. JAG/NOTCH signaling uniquely inhibited expression of anti-angiogenic sVEFGFR-1/sFlt-1. N11-13 decoy interfered with DLL1/DLL4-mediated NOTCH1 signaling and caused endothelial hypersprouting in vitro, in retinal angiogenesis and in tumors. Thus, blockade of JAG- or DLL-mediated Notch signaling inhibits angiogenesis by distinct mechanisms. JAG/Notch signaling positively regulates angiogenesis by suppressing sVEGFR-1/sFlt-1 and promoting mural/endothelial cell interactions. Blockade of JAG-class ligands represents a novel, viable therapeutic approach to block tumor angiogenesis and growth. PMID:25387766

A Dynamic Attitude Measurement System Based on LINS

PubMed Central

Li, Hanzhou; Pan, Quan; Wang, Xiaoxu; Zhang, Juanni; Li, Jiang; Jiang, Xiangjun

2014-01-01

A dynamic attitude measurement system (DAMS) is developed based on a laser inertial navigation system (LINS). Three factors of the dynamic attitude measurement error using LINS are analyzed: dynamic error, time synchronization and phase lag. An optimal coning errors compensation algorithm is used to reduce coning errors, and two-axis wobbling verification experiments are presented in the paper. The tests indicate that the attitude accuracy is improved 2-fold by the algorithm. In order to decrease coning errors further, the attitude updating frequency is improved from 200 Hz to 2000 Hz. At the same time, a novel finite impulse response (FIR) filter with three notches is designed to filter the dither frequency of the ring laser gyro (RLG). The comparison tests suggest that the new filter is five times more effective than the old one. The paper indicates that phase-frequency characteristics of FIR filter and first-order holder of navigation computer constitute the main sources of phase lag in LINS. A formula to calculate the LINS attitude phase lag is introduced in the paper. The expressions of dynamic attitude errors induced by phase lag are derived. The paper proposes a novel synchronization mechanism that is able to simultaneously solve the problems of dynamic test synchronization and phase compensation. A single-axis turntable and a laser interferometer are applied to verify the synchronization mechanism. The experiments results show that the theoretically calculated values of phase lag and attitude error induced by phase lag can both match perfectly with testing data. The block diagram of DAMS and physical photos are presented in the paper. The final experiments demonstrate that the real-time attitude measurement accuracy of DAMS can reach up to 20″ (1σ) and the synchronization error is less than 0.2 ms on the condition of three axes wobbling for 10 min. PMID:25177802

Microbiota promote secretory cell determination in the intestinal epithelium by modulating host Notch signaling.

PubMed

Troll, Joshua V; Hamilton, M Kristina; Abel, Melissa L; Ganz, Julia; Bates, Jennifer M; Stephens, W Zac; Melancon, Ellie; van der Vaart, Michiel; Meijer, Annemarie H; Distel, Martin; Eisen, Judith S; Guillemin, Karen

2018-02-23

Resident microbes promote many aspects of host development, although the mechanisms by which microbiota influence host tissues remain unclear. We showed previously that the microbiota is required for allocation of appropriate numbers of secretory cells in the zebrafish intestinal epithelium. Because Notch signaling is crucial for secretory fate determination, we conducted epistasis experiments to establish whether the microbiota modulates host Notch signaling. We also investigated whether innate immune signaling transduces microbiota cues via the Myd88 adaptor protein. We provide the first evidence that microbiota-induced, Myd88-dependent signaling inhibits host Notch signaling in the intestinal epithelium, thereby promoting secretory cell fate determination. These results connect microbiota activity via innate immune signaling to the Notch pathway, which also plays crucial roles in intestinal homeostasis throughout life and when impaired can result in chronic inflammation and cancer. © 2018. Published by The Company of Biologists Ltd.

Spectrotemporal Modulation Sensitivity as a Predictor of Speech Intelligibility for Hearing-Impaired Listeners

PubMed Central

Bernstein, Joshua G.W.; Mehraei, Golbarg; Shamma, Shihab; Gallun, Frederick J.; Theodoroff, Sarah M.; Leek, Marjorie R.

2014-01-01

Background A model that can accurately predict speech intelligibility for a given hearing-impaired (HI) listener would be an important tool for hearing-aid fitting or hearing-aid algorithm development. Existing speech-intelligibility models do not incorporate variability in suprathreshold deficits that are not well predicted by classical audiometric measures. One possible approach to the incorporation of such deficits is to base intelligibility predictions on sensitivity to simultaneously spectrally and temporally modulated signals. Purpose The likelihood of success of this approach was evaluated by comparing estimates of spectrotemporal modulation (STM) sensitivity to speech intelligibility and to psychoacoustic estimates of frequency selectivity and temporal fine-structure (TFS) sensitivity across a group of HI listeners. Research Design The minimum modulation depth required to detect STM applied to an 86 dB SPL four-octave noise carrier was measured for combinations of temporal modulation rate (4, 12, or 32 Hz) and spectral modulation density (0.5, 1, 2, or 4 cycles/octave). STM sensitivity estimates for individual HI listeners were compared to estimates of frequency selectivity (measured using the notched-noise method at 500, 1000measured using the notched-noise method at 500, 2000, and 4000 Hz), TFS processing ability (2 Hz frequency-modulation detection thresholds for 500, 10002 Hz frequency-modulation detection thresholds for 500, 2000, and 4000 Hz carriers) and sentence intelligibility in noise (at a 0 dB signal-to-noise ratio) that were measured for the same listeners in a separate study. Study Sample Eight normal-hearing (NH) listeners and 12 listeners with a diagnosis of bilateral sensorineural hearing loss participated. Data Collection and Analysis STM sensitivity was compared between NH and HI listener groups using a repeated-measures analysis of variance. A stepwise regression analysis compared STM sensitivity for individual HI listeners to audiometric thresholds, age, and measures of frequency selectivity and TFS processing ability. A second stepwise regression analysis compared speech intelligibility to STM sensitivity and the audiogram-based Speech Intelligibility Index. Results STM detection thresholds were elevated for the HI listeners, but only for low rates and high densities. STM sensitivity for individual HI listeners was well predicted by a combination of estimates of frequency selectivity at 4000 Hz and TFS sensitivity at 500 Hz but was unrelated to audiometric thresholds. STM sensitivity accounted for an additional 40% of the variance in speech intelligibility beyond the 40% accounted for by the audibility-based Speech Intelligibility Index. Conclusions Impaired STM sensitivity likely results from a combination of a reduced ability to resolve spectral peaks and a reduced ability to use TFS information to follow spectral-peak movements. Combining STM sensitivity estimates with audiometric threshold measures for individual HI listeners provided a more accurate prediction of speech intelligibility than audiometric measures alone. These results suggest a significant likelihood of success for an STM-based model of speech intelligibility for HI listeners. PMID:23636210

Evaluation of Relative Position of Mandibular Foramen in Children as a Reference for Inferior Alveolar Nerve Block using Orthopantamograph.

PubMed

Krishnamurthy, Navin Hadadi; Unnikrishnan, Surej; Ramachandra, Jaya Agali; Arali, Veena

2017-03-01

The Mandibular Foramen (MF) is a landmark for administering local anaesthetic solution for Inferior Alveolar Nerve Block (IANB). The position of MF shows considerable variation among different ethnicity, ages and on either sides even within the same individual. Failure to achieve IANB leading to repeated injection of the local anaesthetic solution will not only pose a behaviour problem in children but can also lead to systemic toxic level of anaesthetic solution being administered. To determine the relative position of the mandibular foramen in 7 to 12-year-old children in relation to the mandibular occlusal plane and the deepest point on coronoid notch. Ninety orthopantamograph of 7 to 12-year-old children were selected from the database and were divided into three groups: Group 1 (G1): seven to eight-year-old, Group 2 (G2): 9 to 10-year-old and Group 3 (G3): 11 to 12-year-old. The radiographs were traced on acetate paper, anatomical landmarks were marked and linear measurements were noted from the Mandibular Lingula (ML) to the occlusal plane, and to the deepest point on coronoid notch. The data obtained was tabulated and subjected to statistical analysis. One way ANOVA test followed by Bonferroni post hoc analysis and Student's paired t-test were used. Mandibular foramen is approximately, 2-3 mm above the occlusal plane and 11.6-13.0 mm from deepest point of coronoid notch for seven to eight-year-old children, 3-4 mm above the occlusal plane and 13.0-13.9 mm from deepest point of coronoid notch for 9-10 year age group and 5.5-6.5 mm above the occlusal plane and 11.9-12.2 mm from deepest point of coronoid notch for children of the ages 11-12 years. The linear distance from the deepest point of coronoid notch to the mandibular lingula showed statistical significance in G2 vs G3 on right side G1 vs G2 and G2 vs G3 on the left side. The variance of this distance for either side showed statistical significance for G1 and G2. The distance from the mandibular lingula to the occlusal plane showed gradual increase in all the three groups, which was statistically significant. The position of the mandibular foramen is not bilaterally symmetrically for any of the considered age groups.

Coastal dune dynamics in response to excavated foredune notches

NASA Astrophysics Data System (ADS)

Ruessink, B. G.; Arens, S. M.; Kuipers, M.; Donker, J. J. A.

2018-04-01

Dune management along developed coasts has traditionally focussed on the suppression of the geomorphic dynamics of the foredune to improve its role in sea defence. Because a stabilized foredune acts as an almost total barrier to aeolian transport from the beach, the habitat diversity in the more landward dunes has degraded. With the overarching objective to mitigate this undesirable loss in biodiversity, dune management projects nowadays increasingly intend to restore aeolian dynamics by reconnecting the beach-dune system with notches excavated through the foredune. Here, we use repeat topographic survey data to examine the geomorphic response of a coastal dune system in the Dutch National Park Zuid-Kennemerland to five notches excavated in 2012-2013 within an 850-m stretch of the 20-m high established foredune. The notches were dug in a V-shape (viewed onshore), with a width between approximately 50 and 100 m at the top, a (cross-dune) length between 100 and 200 m, and excavation depths between 9 and 12.5 m. The 1 × 1 m digital terrain models, acquired with airborne Lidar and UAV photogrammetry, illustrate that during the 3-year survey period the notches developed into a U-shape because of wall deflation, and that up to 8-m thick and 150-m long depositional lobes formed landward of the notches. Sand budget computations showed that the sand volume of the entire study area increased by about 22,750 m3/year, which, given the 850-m width of the study area, corresponds to an aeolian input from the beach of approximately 26.5 m3/m/year. Between 2006 and 2012 all wind-blown beach sand deposited on the seaward side of the foredune; since 2013, the notches have caused 75% of the sand to be deposited landward of the foredune. This highlights that the notches are highly effective conduits for aeolian transport into the back dunes. Future monitoring is required to determine for how long the notches will stimulate aeolian dynamics and if (and when) vegetation eventually starts to regrow and enforces the degeneration of the notches.

Tension fracture of laminates for transport fuselage. Part 2: Large notches

NASA Technical Reports Server (NTRS)

Walker, Tom H.; Ilcewicz, Larry B.; Polland, D. R.; Poe, C. C., Jr.

1993-01-01

Tests were conducted on over 200 center-crack specimens to evaluate: (a) the tension-fracture performance of candidate materials and laminates for commercial fuselage applications; and (b) the accuracy of several failure criteria in predicting response. Crack lengths of up to 12 inches were considered. Other variables included fiber/matrix combination, layup, lamination manufacturing process, and intraply hybridization. Laminates fabricated using the automated tow-placement process provided significantly higher tension-fracture strengths than nominally identical tape laminates. This confirmed earlier findings for other layups, and possibly relates to a reduced stress concentration resulting from a larger scale of repeatable material inhomogeneity in the tow-placed laminates. Changes in material and layup result in a trade-off between small-notch and large-notch strengths. Toughened resins and 0 deg-dominate layups result in higher small-notch strengths but lower large-notch strengths than brittle resins, 90 deg and 45 deg dominated layups, and intraply S2-glass hybrid material forms. Test results indicate that strength-prediction methods that allow for a reduced order singularity of the crack-tip stress field are more successful at predicting failure over a range of notch sizes than those relying on the classical square-root singularity. The order of singularity required to accurately predict large-notch strength from small-notch data was affected by both material and layup. Measured crack-tip strain distributions were generally higher than those predicted using classical methods. Traditional methods of correcting for finite specimen width were found to be lacking, confirming earlier findings with other specimen geometries. Fracture tests of two stiffened panels, identical except for differing materials, with severed central stiffeners resulted in nearly identical damage progression and failure sequences. Strain-softening laws implemented within finite element models appear attractive to account for load redistribution in configured structure due to damage-induced crack tip softening

Effects of Range of Stress and of Special Notches on Fatigue Properties of Aluminum Alloys Suitable for Airplane Propellers

NASA Technical Reports Server (NTRS)

Dolan, Thomas J

1942-01-01

Laboratory tests were made to obtain information on the load-resisting properties of X76S-T aluminum alloy when subjected to static, impact, and repeated loads. Results are presented from static-load test of unnotched specimens in tension and in torsion and of notched specimens in tension. Charpy impact values obtained from bend tests on notched specimens and tension impact values for both notched and unnotched specimens tested at several different temperatures are included. The endurance limits obtained from repeated bending fatigue tests made on three different types of testing machine are given for unnotched polished specimens, and the endurance limits of notched specimens subjected to six different ranges of bending stress are also reported. The results indicated that: (a) polished rectangular specimens had an endurance limit about 30 percent less than that obtained for round specimens; (b) a comparison of endurance limits obtained from tests on three different types of machine indicated that there was no apparent effect of speed of testing on the endurance limit for the range of speeds used (1,750 to 13,000 rpm). (c) the fatigue strength (endurance limit) of the X76S-T alloy was greatly decreased by the presence of a notch in the specimens; (d) no complete fractures of the entire specimens occurred in notched fatigue specimens when subjected to stress cycles for which the mean stress at the notch during the cycle was a compressive stress; for this test condition a microscopic cracking occurred near the root of the notch and was used as a criterion of failure of the specimen. (e) as the mean stress at the notch was decreased from a tensile (+) stress to a compressive (-) stress, it was found that the alternating stress that could be superimposed on the mean stress in the cycle without causing failure of the specimens was increased.

The multiple roles of epidermal growth factor repeat O-glycans in animal development

PubMed Central

Haltom, Amanda R; Jafar-Nejad, Hamed

2015-01-01

The epidermal growth factor (EGF)-like repeat is a common, evolutionarily conserved motif found in secreted proteins and the extracellular domain of transmembrane proteins. EGF repeats harbor six cysteine residues which form three disulfide bonds and help generate the three-dimensional structure of the EGF repeat. A subset of EGF repeats harbor consensus sequences for the addition of one or more specific O-glycans, which are initiated by O-glucose, O-fucose or O-N-acetylglucosamine. These glycans are relatively rare compared to mucin-type O-glycans. However, genetic experiments in model organisms and cell-based assays indicate that at least some of the glycosyltransferases involved in the addition of O-glycans to EGF repeats play important roles in animal development. These studies, combined with state-of-the-art biochemical and structural biology experiments have started to provide an in-depth picture of how these glycans regulate the function of the proteins to which they are linked. In this review, we will discuss the biological roles assigned to EGF repeat O-glycans and the corresponding glycosyltransferases. Since Notch receptors are the best studied proteins with biologically-relevant O-glycans on EGF repeats, a significant part of this review is devoted to the role of these glycans in the regulation of the Notch signaling pathway. We also discuss recently identified proteins other than Notch which depend on EGF repeat glycans to function properly. Several glycosyltransferases involved in the addition or elongation of O-glycans on EGF repeats are mutated in human diseases. Therefore, mechanistic understanding of the functional roles of these carbohydrate modifications is of interest from both basic science and translational perspectives. PMID:26175457

Notch-1-PTEN-ERK1/2 signaling axis promotes HER2+ breast cancer cell proliferation and stem cell survival.

PubMed

Baker, Andrew; Wyatt, Debra; Bocchetta, Maurizio; Li, Jun; Filipovic, Aleksandra; Green, Andrew; Peiffer, Daniel S; Fuqua, Suzanne; Miele, Lucio; Albain, Kathy S; Osipo, Clodia

2018-05-10

Trastuzumab targets the HER2 receptor on breast cancer cells to attenuate HER2-driven tumor growth. However, resistance to trastuzumab-based therapy remains a major clinical problem for women with HER2+ breast cancer. Breast cancer stem cells (BCSCs) are suggested to be responsible for drug resistance and tumor recurrence. Notch signaling has been shown to promote BCSC survival and self-renewal. Trastuzumab-resistant cells have increased Notch-1 expression. Notch signaling drives cell proliferation in vitro and is required for tumor recurrence in vivo. We demonstrate herein a mechanism by which Notch-1 is required for trastuzumab resistance by repressing PTEN expression to contribute to activation of ERK1/2 signaling. Furthermore, Notch-1-mediated inhibition of PTEN is necessary for BCSC survival in vitro and in vivo. Inhibition of MEK1/2-ERK1/2 signaling in trastuzumab-resistant breast cancer cells mimics effects of Notch-1 knockdown on bulk cell proliferation and BCSC survival. These findings suggest that Notch-1 contributes to trastuzumab resistance by repressing PTEN and this may lead to hyperactivation of ERK1/2 signaling. Furthermore, high Notch-1 and low PTEN mRNA expression may predict poorer overall survival in women with breast cancer. Notch-1 protein expression predicts poorer survival in women with HER2+ breast cancer. These results support a potential future clinical trial combining anti-Notch-1 and anti-MEK/ERK therapy for trastuzumab-resistant breast cancer.

Tyrosine phosphorylation and proteolytic cleavage of Notch are required for non-canonical Notch/Abl signaling in Drosophila axon guidance.

PubMed

Kannan, Ramakrishnan; Cox, Eric; Wang, Lei; Kuzina, Irina; Gu, Qun; Giniger, Edward

2018-01-17

Notch signaling is required for the development and physiology of nearly every tissue in metazoans. Much of Notch signaling is mediated by transcriptional regulation of downstream target genes, but Notch controls axon patterning in Drosophila by local modulation of Abl tyrosine kinase signaling, via direct interactions with the Abl co-factors Disabled and Trio. Here, we show that Notch-Abl axonal signaling requires both of the proteolytic cleavage events that initiate canonical Notch signaling. We further show that some Notch protein is tyrosine phosphorylated in Drosophila , that this form of the protein is selectively associated with Disabled and Trio, and that relevant tyrosines are essential for Notch-dependent axon patterning but not for canonical Notch-dependent regulation of cell fate. Based on these data, we propose a model for the molecular mechanism by which Notch controls Abl signaling in Drosophila axons. © 2018. Published by The Company of Biologists Ltd.

Mechanisms of Lin28-Mediated miRNA and mRNA Regulation—A Structural and Functional Perspective

PubMed Central

Mayr, Florian; Heinemann, Udo

2013-01-01

Lin28 is an essential RNA-binding protein that is ubiquitously expressed in embryonic stem cells. Its physiological function has been linked to the regulation of differentiation, development, and oncogenesis as well as glucose metabolism. Lin28 mediates these pleiotropic functions by inhibiting let-7 miRNA biogenesis and by modulating the translation of target mRNAs. Both activities strongly depend on Lin28’s RNA-binding domains (RBDs), an N-terminal cold-shock domain (CSD) and a C-terminal Zn-knuckle domain (ZKD). Recent biochemical and structural studies revealed the mechanisms of how Lin28 controls let-7 biogenesis. Lin28 binds to the terminal loop of pri- and pre-let-7 miRNA and represses their processing by Drosha and Dicer. Several biochemical and structural studies showed that the specificity of this interaction is mainly mediated by the ZKD with a conserved GGAGA or GGAGA-like motif. Further RNA crosslinking and immunoprecipitation coupled to high-throughput sequencing (CLIP-seq) studies confirmed this binding motif and uncovered a large number of new mRNA binding sites. Here we review exciting recent progress in our understanding of how Lin28 binds structurally diverse RNAs and fulfills its pleiotropic functions. PMID:23939427

Active form Notch4 promotes the proliferation and differentiation of 3T3-L1 preadipocytes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lai, Peng-Yeh; Tsai, Chong-Bin; Department of Ophthalmology, Chiayi Christian Hospital, Chiayi 600, Taiwan, ROC

2013-01-18

Highlights: ► Notch4IC modulates the ERK pathway and cell cycle to promote 3T3-L1 proliferation. ► Notch4IC facilitates 3T3-L1 differentiation by up-regulating proadipogenic genes. ► Notch4IC promotes proliferation during the early stage of 3T3-L1 adipogenesis. ► Notch4IC enhances differentiation during subsequent stages of 3T3-L1 adipogenesis. -- Abstract: Adipose tissue is composed of adipocytes, which differentiate from precursor cells in a process called adipogenesis. Many signal molecules are involved in the transcriptional control of adipogenesis, including the Notch pathway. Previous adipogenic studies of Notch have focused on Notch1 and HES1; however, the role of other Notch receptors in adipogenesis remains unclear. Q-RT-PCRmore » analyses showed that the augmentation of Notch4 expression during the differentiation of 3T3-L1 preadipocytes was comparable to that of Notch1. To elucidate the role of Notch4 in adipogenesis, the human active form Notch4 (N4IC) was transiently transfected into 3T3-L1 cells. The expression of HES1, Hey1, C/EBPδ and PPARγ was up-regulated, and the expression of Pref-1, an adipogenic inhibitor, was down-regulated. To further characterize the effect of N4IC in adipogenesis, stable cells expressing human N4IC were established. The expression of N4IC promoted proliferation and enhanced differentiation of 3T3-L1 cells compared with those of control cells. These data suggest that N4IC promoted proliferation through modulating the ERK pathway and the cell cycle during the early stage of 3T3-L1 adipogenesis and facilitated differentiation through up-regulating adipogenic genes such as C/EBPα, PPARγ, aP2, LPL and HSL during the middle and late stages of 3T3-L1 adipogenesis.« less

Controllable Magnetization Processes Induced by Nucleation Sites in Permalloy Rings

NASA Astrophysics Data System (ADS)

Chen, Ying-Jiun; Hsu, Chia-Jung; Liao, Chun-Neng; Huang, Hao-Ting; Lee, Chiun-Peng; Chiu, Yi-Hsun; Tung, Tzu-Yun; Lai, Mei-Feng

2010-02-01

Different arrangements of notches as nucleation sites are demonstrated experimentally and numerically to effectively control the magnetization processes of permalloy rings. In the ring with notches at the same side with respect to field direction, two same-helicity vortex domain walls in the onion state lead to two-step switching going through flux-closure state; in the ring with diagonal notches two opposite-helicity vortex domain walls lead to one-step switching skipping flux-closure state. The switching processes are repeatable in contrast to rings without notches where helicites of two vortex domain walls are random so the switching processes can not be controlled.

Definition of a core module for the nuclear retrograde response to altered organellar gene expression identifies GLK overexpressors as gun mutants.

PubMed

Leister, Dario; Kleine, Tatjana

2016-07-01

Retrograde signaling can be triggered by changes in organellar gene expression (OGE) induced by inhibitors such as lincomycin (LIN) or mutations that perturb OGE. Thus, an insufficiency of the organelle-targeted prolyl-tRNA synthetase PRORS1 in Arabidopsis thaliana activates retrograde signaling and reduces the expression of nuclear genes for photosynthetic proteins. Recently, we showed that mTERF6, a member of the so-called mitochondrial transcription termination factor (mTERF) family, is involved in the formation of chloroplast (cp) isoleucine-tRNA. To obtain further insights into its functions, co-expression analysis of MTERF6, PRORS1 and two other genes for organellar aminoacyl-tRNA synthetases was conducted. The results suggest a prominent role of mTERF6 in aminoacylation activity, light signaling and seed storage. Analysis of changes in whole-genome transcriptomes in the mterf6-1 mutant showed that levels of nuclear transcripts for cp OGE proteins were particularly affected. Comparison of the mterf6-1 transcriptome with that of prors1-2 showed that reduced aminoacylation of proline (prors1-2) and isoleucine (mterf6-1) tRNAs alters retrograde signaling in similar ways. Database analyses indicate that comparable gene expression changes are provoked by treatment with LIN, norflurazon or high light. A core OGE response module was defined by identifying genes that were differentially expressed under at least four of six conditions relevant to OGE signaling. Based on this module, overexpressors of the Golden2-like transcription factors GLK1 and GLK2 were identified as genomes uncoupled mutants. © 2016 Scandinavian Plant Physiology Society.

Comodulation masking release in an off-frequency masking paradigm.

PubMed

Grzeschik, Ramona; Lübken, Björn; Verhey, Jesko L

2015-08-01

Detection threshold of a sinusoidal signal masked by a broadband masker is lower when on- and off-frequency masker components have a correlated envelope, compared to a condition in which these masker components have different envelopes. This effect is commonly referred to as comodulation masking release (CMR). The present study investigated if there is a CMR in the absence of a masker component at the signal frequency, i.e., in an off-frequency masking paradigm. Thresholds were measured for a 500-Hz signal in the presence of a broadband masker with a spectral notch at the signal frequency. Thresholds were significantly lower for a (co-)modulated than for an unmodulated masker for all notch widths up to 400 Hz. An additional experiment showed that the particularly large CMR for the no-notch condition was due to the way the modulated masker was generated. No CMR was measured when the notched-noise masker was replaced by a pair of narrowband noises. The addition of more remote masker bands resulted in a CMR of about 3-4 dB. The notched-noise data were predicted on the basis of a modulation-filterbank model. The predictions of the narrowband noise conditions indicated that all mechanisms underlying CMR might still not be fully understood.

Notch Signaling in Myeloid Cells as a Regulator of Tumor Immune Responses

PubMed Central

Hossain, Fokhrul; Majumder, Samarpan; Ucar, Deniz A.; Rodriguez, Paulo C.; Golde, Todd E.; Minter, Lisa M.; Osborne, Barbara A.; Miele, Lucio

2018-01-01

Cancer immunotherapy, which stimulates or augments host immune responses to treat malignancies, is the latest development in the rapidly advancing field of cancer immunology. The basic principles of immunotherapies are either to enhance the functions of specific components of the immune system or to neutralize immune-suppressive signals produced by cancer cells or tumor microenvironment cells. When successful, these approaches translate into long-term survival for patients. However, durable responses are only seen in a subset of patients and so far, only in some cancer types. As for other cancer treatments, resistance to immunotherapy can also develop. Numerous research groups are trying to understand why immunotherapy is effective in some patients but not others and to develop strategies to enhance the effectiveness of immunotherapy. The Notch signaling pathway is involved in many aspects of tumor biology, from angiogenesis to cancer stem cell maintenance to tumor immunity. The role of Notch in the development and modulation of the immune response is complex, involving an intricate crosstalk between antigen-presenting cells, T-cell subpopulations, cancer cells, and other components of the tumor microenvironment. Elegant studies have shown that Notch is a central mediator of tumor-induced T-cell anergy and that activation of Notch1 in CD8 T-cells enhances cancer immunotherapy. Tumor-infiltrating myeloid cells, including myeloid-derived suppressor cells, altered dendritic cells, and tumor-associated macrophages along with regulatory T cells, are major obstacles to the development of successful cancer immunotherapies. In this article, we focus on the roles of Notch signaling in modulating tumor-infiltrating myeloid cells and discuss implications for therapeutic strategies that modulate Notch signaling to enhance cancer immunotherapy.

Predicting repeat protein folding kinetics from an experimentally determined folding energy landscape

PubMed Central

Street, Timothy O; Barrick, Doug

2009-01-01

The Notch ankyrin domain is a repeat protein whose folding has been characterized through equilibrium and kinetic measurements. In previous work, equilibrium folding free energies of truncated constructs were used to generate an experimentally determined folding energy landscape (Mello and Barrick, Proc Natl Acad Sci USA 2004;101:14102–14107). Here, this folding energy landscape is used to parameterize a kinetic model in which local transition probabilities between partly folded states are based on energy values from the landscape. The landscape-based model correctly predicts highly diverse experimentally determined folding kinetics of the Notch ankyrin domain and sequence variants. These predictions include monophasic folding and biphasic unfolding, curvature in the unfolding limb of the chevron plot, population of a transient unfolding intermediate, relative folding rates of 19 variants spanning three orders of magnitude, and a change in the folding pathway that results from C-terminal stabilization. These findings indicate that the folding pathway(s) of the Notch ankyrin domain are thermodynamically selected: the primary determinants of kinetic behavior can be simply deduced from the local stability of individual repeats. PMID:19177351

Stage-specific effects of Notch activation during skeletal myogenesis

PubMed Central

Bi, Pengpeng; Yue, Feng; Sato, Yusuke; Wirbisky, Sara; Liu, Weiyi; Shan, Tizhong; Wen, Yefei; Zhou, Daoguo; Freeman, Jennifer; Kuang, Shihuan

2016-01-01

Skeletal myogenesis involves sequential activation, proliferation, self-renewal/differentiation and fusion of myogenic stem cells (satellite cells). Notch signaling is known to be essential for the maintenance of satellite cells, but its function in late-stage myogenesis, i.e. post-differentiation myocytes and post-fusion myotubes, is unknown. Using stage-specific Cre alleles, we uncovered distinct roles of Notch1 in mononucleated myocytes and multinucleated myotubes. Specifically, constitutive Notch1 activation dedifferentiates myocytes into Pax7 quiescent satellite cells, leading to severe defects in muscle growth and regeneration, and postnatal lethality. By contrast, myotube-specific Notch1 activation improves the regeneration and exercise performance of aged and dystrophic muscles. Mechanistically, Notch1 activation in myotubes upregulates the expression of Notch ligands, which modulate Notch signaling in the adjacent satellite cells to enhance their regenerative capacity. These results highlight context-dependent effects of Notch activation during myogenesis, and demonstrate that Notch1 activity improves myotube’s function as a stem cell niche. DOI: http://dx.doi.org/10.7554/eLife.17355.001 PMID:27644105

Lin28-let7 Modulates Radiosensitivity of Human Cancer Cells With Activation of K-Ras

DOE Office of Scientific and Technical Information (OSTI.GOV)

Oh, Jee-Sun.; Kim, Jae-Jin; Byun, Ju-Yeon

2010-01-15

Purpose: To evaluate the potential of targeting Lin28-let7 microRNA regulatory network for overcoming the radioresistance of cancer cells having activated K-Ras signaling. Methods and Materials: A549 lung carcinoma cells and ASPC1 pancreatic cancer cells possessing K-RAS mutation were transfected with pre-let7a microRNA or Lin28 siRNA, respectively. Clonogenic assay, quantitative reverse transcription polymerase chain reaction, and Western analysis were performed. The effects of Lin28 on SQ20B cells having wild-type K-RAS, and a normal fibroblast were also assessed. Results: The overexpression of let-7a decreased expression of K-Ras and radiosensitized A549 cells. Inhibition of Lin28, a repressor of let-7, attenuated K-Ras expression andmore » radiosensitized A549 and ASPC1 cells. Neither SQ20B cells expressing wild-type K-RAS nor HDF, the normal human fibroblasts, were radiosensitized by this approach. Conclusions: The Lin28-let7 regulatory network may be a potentially useful therapeutic target for overcoming the radioresistance of human cancers having activated K-Ras signaling.« less

The Murine Ortholog of Notchless, a Direct Regulator of the Notch Pathway in Drosophila melanogaster, Is Essential for Survival of Inner Cell Mass Cells

PubMed Central

Cormier, Sarah; Le Bras, Stéphanie; Souilhol, Céline; Vandormael-Pournin, Sandrine; Durand, Béatrice; Babinet, Charles; Baldacci, Patricia; Cohen-Tannoudji, Michel

2006-01-01

Notch signaling is an evolutionarily conserved pathway involved in intercellular communication and is essential for proper cell fate choices. Numerous genes participate in the modulation of the Notch signaling pathway activity. Among them, Notchless (Nle) is a direct regulator of the Notch activity identified in Drosophila melanogaster. Here, we characterized the murine ortholog of Nle and demonstrated that it has conserved the ability to modulate Notch signaling. We also generated mice deficient for mouse Nle (mNle) and showed that its disruption resulted in embryonic lethality shortly after implantation. In late mNle−/− blastocysts, inner cell mass (ICM) cells died through a caspase 3-dependent apoptotic process. Most deficient embryos exhibited a delay in the temporal down-regulation of Oct4 expression in the trophectoderm (TE). However, mNle-deficient TE was able to induce decidual swelling in vivo and properly differentiated in vitro. Hence, our results indicate that mNle is mainly required in ICM cells, being instrumental for their survival, and raise the possibility that the death of mNle-deficient embryos might result from abnormal Notch signaling during the first steps of development. PMID:16611995

The murine ortholog of notchless, a direct regulator of the notch pathway in Drosophila melanogaster, is essential for survival of inner cell mass cells.

PubMed

Cormier, Sarah; Le Bras, Stéphanie; Souilhol, Céline; Vandormael-Pournin, Sandrine; Durand, Béatrice; Babinet, Charles; Baldacci, Patricia; Cohen-Tannoudji, Michel

2006-05-01

Notch signaling is an evolutionarily conserved pathway involved in intercellular communication and is essential for proper cell fate choices. Numerous genes participate in the modulation of the Notch signaling pathway activity. Among them, Notchless (Nle) is a direct regulator of the Notch activity identified in Drosophila melanogaster. Here, we characterized the murine ortholog of Nle and demonstrated that it has conserved the ability to modulate Notch signaling. We also generated mice deficient for mouse Nle (mNle) and showed that its disruption resulted in embryonic lethality shortly after implantation. In late mNle(-/-) blastocysts, inner cell mass (ICM) cells died through a caspase 3-dependent apoptotic process. Most deficient embryos exhibited a delay in the temporal down-regulation of Oct4 expression in the trophectoderm (TE). However, mNle-deficient TE was able to induce decidual swelling in vivo and properly differentiated in vitro. Hence, our results indicate that mNle is mainly required in ICM cells, being instrumental for their survival, and raise the possibility that the death of mNle-deficient embryos might result from abnormal Notch signaling during the first steps of development.

SNX27 Deletion Causes Hydrocephalus by Impairing Ependymal Cell Differentiation and Ciliogenesis.

PubMed

Wang, Xin; Zhou, Ying; Wang, Jian; Tseng, I-Chu; Huang, Timothy; Zhao, Yingjun; Zheng, Qiuyang; Gao, Yue; Luo, Hong; Zhang, Xian; Bu, Guojun; Hong, Wanjin; Xu, Huaxi

2016-12-14

Hydrocephalus is a brain disorder derived from CSF accumulation due to defects in CSF clearance. Although dysfunctional apical cilia in the ependymal cell layer are causal to the onset of hydrocephalus, mechanisms underlying proper ependymal cell differentiation are largely unclear. SNX27 is a trafficking component required for normal brain function and was shown previously to suppress γ-secretase-dependent amyloid precursor protein and Notch cleavage. However, it was unclear how SNX27-dependent γ-secretase inhibition could contribute to brain development and pathophysiology. Here, we describe and characterize an Snx27-deleted mouse model for the ependymal layer defects of deciliation and hydrocephalus. SNX27 deficiency results in reductions in ependymal cells and cilia density, as well as severe postnatal hydrocephalus. Inhibition of Notch intracellular domain signaling with γ-secretase inhibitors reversed ependymal cells/cilia loss and dilation of lateral ventricles in Snx27-deficient mice, giving strong indication that Snx27 deletion triggers defects in ependymal layer formation and ciliogenesis through Notch hyperactivation. Together, these results suggest that SNX27 is essential for ependymal cell differentiation and ciliogenesis, and its deletion can promote hydrocephalus pathogenesis. Down's syndrome (DS) in humans and mouse models has been shown previously to confer a high risk for the development of pathological hydrocephalus. Because we have previously described SNX27 as a component that is consistently downregulated in DS, we present here a robust Snx27-deleted mouse model that produces hydrocephalus and associated ciliary defects with complete penetrance. In addition, we find that γ-secretase/Notch modulation may be a candidate drug target in SNX27-associated hydrocephalus such as that observed in DS. Based on these findings, we anticipate that future study will determine whether modulation of a SNX27/Notch/γ-secretase pathway can also be of therapeutic interest to congenital hydrocephalus. Copyright © 2016 the authors 0270-6474/16/3612586-12$15.00/0.

Therapeutic antibody targeting of Notch3 signaling prevents mural cell loss in CADASIL

PubMed Central

Machuca-Parra, Arturo I.; Bigger-Allen, Alexander A.; Sanchez, Angie V.; Saint-Geniez, Magali

2017-01-01

Cerebral autosomal-dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is a neurological syndrome characterized by small vessel disease (SVD), stroke, and vascular cognitive impairment and dementia caused by mutations in NOTCH3. No therapies are available for this condition. Loss of mural cells, which encompass pericytes and vascular smooth muscle cells, is a hallmark of CADASIL and other SVDs, including diabetic retinopathy, resulting in vascular instability. Here, we showed that Notch3 signaling is both necessary and sufficient to support mural cell coverage in arteries using genetic rescue in Notch3 knockout mice. Furthermore, we show that systemic administration of an agonist Notch3 antibody prevents mural cell loss and modifies plasma proteins associated with Notch3 activity, including endostatin/collagen 18α1 and Notch3 extracellular domain in mice with the C455R mutation, a CADASIL variant associated with Notch3 loss of function. These findings open opportunities for the treatment of CADASIL and other SVDs by modulating Notch3 signaling. PMID:28698285

Significance of lobular intraepithelial neoplasia at margins of breast conservation specimens: a report of 38 cases and literature review

PubMed Central

2010-01-01

Background Presence of lobular intraepithelial neoplasia (LIN) is not routinely reported as part of margin assessment in breast conservation therapy (BCT) as in ductal carcinoma in situ (DCIS). With new emerging evidence of LIN as possible precursor lesion, the hypothesis is that LIN at the margin may increase the risk of local recurrence with BCT. The aim is to determine whether there is an increase incidence of recurrence when LIN is found at surgical margins on BCT. Methods We retrospectively reviewed a total of 1,334 BCT at a single institution in a 10 year period. Inclusion criteria are positive margin with LIN from primary BCT containing invasive and/or in situ carcinoma with comparison to the negative control group who had similar diseases with negative margin for LIN. Results We identified 38 cases (2.8%) with LIN either lobular carcinoma in situ/atypical lobular hyperplasia (LCIS/ALH) at a margin on initial BCT with 36% recurrence rate. Of the 38 cases: 5 (13%) were lost to follow-up, 12 (32%) had no further procedures performed and 21 (55%) had re-excision. Out of 21 patients who had re-excisions, 12 (57%) had residual invasive carcinoma or DCIS, three (14%) had pleomorphic LCIS and 4 (19%) showed residual classic type LCIS. 71% had significant residual disease (local recurrence) and 29% had no residual disease. A negative control group consisted of 38 cases. We found two patients with bone or brain metastasis and one local recurrence. Clinical follow up periods range from 1 to 109 months. Conclusions LIN found at a margin on BCT showed a significant recurrent ipsilateral disease. Our study supports the view that LIN seen at the margin may play a role in recurrence. PMID:20727142

Redox-sensitive MAPK and Notch3 regulate fibroblast differentiation and activation: a dual role of ERK1/2.

PubMed

Lai, Jun-Mei; Zhang, Xiong; Liu, Fang-Fang; Yang, Rui; Li, Shen-Yu; Zhu, Lan-Bing; Zou, Ming; Cheng, Wen-Hsing; Zhu, Jian-Hong

2016-07-12

Myofibroblastic transformation, characterized by upregulation of α-smooth muscle actin in response to profibrotic agents such as TGF-β1, is considered as a major event leading to fibrosis. The mechanistic basis linking myofibroblast differentiation to idiopathic pulmonary fibrosis and the disease treatment remain elusive. In this study, we studied roles of MAPK, Notch, and reactive oxygen species (ROS) during the differentiation of IMR-90 lung fibroblasts at basal level and induced by TGF-β1. Our results demonstrated that ROS-dependent activation of p38, JNK1/2 and Notch3 promoted basal and TGF-β1-induced differentiation and expression of extracellular matrix proteins. In stark contrast, ERK1/2 was suppressed by ROS and exhibited an inhibitory effect on the differentiation but showed a weak promotion on the expression of extracellular matrix proteins. TGF-β1-induced Notch3 expression depended on p38 and JNK1/2. Interestingly, Notch3 was also downstream of ERK1/2, suggesting a complex role of ERK1/2 in lung function. Our results suggest a novel ROS-mediated shift of dominance from the inhibitory ERK1/2 to the stimulatory p38, JNK1/2 and Notch3 during the pathological progression of IPF. Thus, targeting ERK1/2 signaling for activation and p38, JNK1/2 and Notch3 for inhibition may be of clinical potential against lung fibrosis.

Angiopoietin-like proteins stimulate HSPC development through interaction with notch receptor signaling

PubMed Central

Lin, Michelle I; Price, Emily N; Boatman, Sonja; Hagedorn, Elliott J; Trompouki, Eirini; Satishchandran, Sruthi; Carspecken, Charles W; Uong, Audrey; DiBiase, Anthony; Yang, Song; Canver, Matthew C; Dahlberg, Ann; Lu, Zhigang; Zhang, Cheng Cheng; Orkin, Stuart H; Bernstein, Irwin D; Aster, Jon C; White, Richard M; Zon, Leonard I

2015-01-01

Angiopoietin-like proteins (angptls) are capable of ex vivo expansion of mouse and human hematopoietic stem and progenitor cells (HSPCs). Despite this intriguing ability, their mechanism is unknown. In this study, we show that angptl2 overexpression is sufficient to expand definitive HSPCs in zebrafish embryos. Angptl1/2 are required for definitive hematopoiesis and vascular specification of the hemogenic endothelium. The loss-of-function phenotype is reminiscent of the notch mutant mindbomb (mib), and a strong genetic interaction occurs between angptls and notch. Overexpressing angptl2 rescues mib while overexpressing notch rescues angptl1/2 morphants. Gene expression studies in ANGPTL2-stimulated CD34+ cells showed a strong MYC activation signature and myc overexpression in angptl1/2 morphants or mib restored HSPCs formation. ANGPTL2 can increase NOTCH activation in cultured cells and ANGPTL receptor interacted with NOTCH to regulate NOTCH cleavage. Together our data provide insight to the angptl-mediated notch activation through receptor interaction and subsequent activation of myc targets. DOI: http://dx.doi.org/10.7554/eLife.05544.001 PMID:25714926

The complex role of NOTCH receptors and their ligands in the development of hepatoblastoma, cholangiocarcinoma and hepatocellular carcinoma.

PubMed

Gil-García, Borja; Baladrón, Victoriano

2016-02-01

The NOTCH signalling pathway is one of the key molecular pathways of embryonic development and adult tissues homeostasis in mammals. Mammals have four NOTCH receptors and various ligands that modulate their activity. Many cell disorders, whose genesis involves the NOTCH signalling pathway, have been discovered, including cancer. The mechanisms by which these receptors and their ligands affect liver cell transformation are not yet well understood, and they seem to behave as both oncogenes and tumour-suppressor proteins. In this review, we discuss the published data regarding the role of these proteins in the development of hepatoblastoma, cholangiocarcinoma and hepatocellular carcinoma malignancies. The alteration of the NOTCH signalling pathway may be one of the main drivers of hepatic neoplastic growth. However, this signalling pathway might also modulate the development of specific liver tumour features. The complexity of the function of NOTCH receptors and their ligands may be due to their interactions with many other cell signalling pathways. Furthermore, the different levels of expression and activation of these receptors could be a reason for their distinct and sometimes contradictory effects. © 2015 Société Française des Microscopies and Société de Biologie Cellulaire de France. Published by John Wiley & Sons Ltd.

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) associated with a novel C82R mutation in the NOTCH3 gene.

PubMed

Zea-Sevilla, M Ascensión; Bermejo-Velasco, Pedro; Serrano-Heranz, Regino; Calero, Miguel

2015-01-01

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is a rare inherited cerebrovascular disease associated with mutations in the NOTCH3 gene on chromosome 19, and represents the most common hereditary stroke disorder. We describe a pedigree, which suffered the classical clinical CADASIL pattern of migraine headaches, recurrent subcortical infarcts, and subcortical dementia, associated with a previously undescribed missense mutation (c.[244T>C], p.[C82R]) in NOTCH3. This new mutation extends the list of known pathogenic mutations responsible for CADASIL, which are associated with an odd number of cysteine residues within any of the epidermal growth factor-like repeats of Notch3 receptor protein.

An automated walk-over weighing system as a tool for measuring liveweight change in lactating dairy cows.

PubMed

Dickinson, R A; Morton, J M; Beggs, D S; Anderson, G A; Pyman, M F; Mansell, P D; Blackwood, C B

2013-07-01

Automated walk-over weighing systems can be used to monitor liveweights of cattle. Minimal literature exists to describe agreement between automated and static scales, and no known studies describe repeatability when used for daily measurements of dairy cows. This study establishes the repeatability of an automated walk-over cattle-weighing system, and agreement with static electronic scales, when used in a commercial dairy herd to weigh lactating cows. Forty-six lactating dairy cows from a seasonal calving, pasture-based dairy herd in southwest Victoria, Australia, were weighed once using a set of static scales and repeatedly using an automated walk-over weighing system at the exit of a rotary dairy. Substantial agreement was observed between the automated and static scales when assessed using Lin's concordance correlation coefficient. Weights measured by the automated walkover scales were within 5% of those measured by the static scales in 96% of weighings. Bland and Altman's 95% limits of agreement were -23.3 to 43.6 kg, a range of 66.9 kg. The 95% repeatability coefficient for automated weighings was 46.3 kg. Removal of a single outlier from the data set increased Lin's concordance coefficient, narrowed Bland and Altman's 95% limits of agreement to a range of 32.5 kg, and reduced the 95% repeatability coefficient to 18.7 kg. Cow misbehavior during walk-over weighing accounted for many of the larger weight discrepancies. The automated walk-over weighing system showed substantial agreement with the static scales when assessed using Lin's concordance correlation coefficient. This contrasted with limited agreement when assessed using Bland and Altman's method, largely due to poor repeatability. This suggests the automated weighing system is inadequate for detecting small liveweight differences in individual cows based on comparisons of single weights. Misbehaviors and other factors can result in the recording of spurious values on walk-over scales. Excluding outlier weights and comparing means of 7 consecutive daily weights may improve agreement sufficiently to allow meaningful assessment of small short-term changes in automated weights in individuals and groups of cows. Copyright © 2013 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

NOTCH-mediated non-cell autonomous regulation of chromatin structure during senescence.

PubMed

Parry, Aled J; Hoare, Matthew; Bihary, Dóra; Hänsel-Hertsch, Robert; Smith, Stephen; Tomimatsu, Kosuke; Mannion, Elizabeth; Smith, Amy; D'Santos, Paula; Russell, I Alasdair; Balasubramanian, Shankar; Kimura, Hiroshi; Samarajiwa, Shamith A; Narita, Masashi

2018-05-09

Senescent cells interact with the surrounding microenvironment achieving diverse functional outcomes. We have recently identified that NOTCH1 can drive 'lateral induction' of a unique senescence phenotype in adjacent cells by specifically upregulating the NOTCH ligand JAG1. Here we show that NOTCH signalling can modulate chromatin structure autonomously and non-autonomously. In addition to senescence-associated heterochromatic foci (SAHF), oncogenic RAS-induced senescent (RIS) cells exhibit a massive increase in chromatin accessibility. NOTCH signalling suppresses SAHF and increased chromatin accessibility in this context. Strikingly, NOTCH-induced senescent cells, or cancer cells with high JAG1 expression, drive similar chromatin architectural changes in adjacent cells through cell-cell contact. Mechanistically, we show that NOTCH signalling represses the chromatin architectural protein HMGA1, an association found in multiple human cancers. Thus, HMGA1 is involved not only in SAHFs but also in RIS-driven chromatin accessibility. In conclusion, this study identifies that the JAG1-NOTCH-HMGA1 axis mediates the juxtacrine regulation of chromatin architecture.

Could Notch signaling pathway be a potential therapeutic option in renal diseases?

PubMed

Marquez-Exposito, Laura; Cantero-Navarro, Elena; Lavoz, Carolina; Fierro-Fernández, Marta; Poveda, Jonay; Rayego-Mateos, Sandra; Rodrigues-Diez, Raúl R; Morgado-Pascual, José Luis; Orejudo, Macarena; Mezzano, Sergio; Ruiz-Ortega, Marta

2018-02-10

Notch pathway regulates key processes in the kidney, involved in embryonic development and tissue damage. In many human chronic renal diseases a local activation of Notch pathway has been described, suggesting that several components of Notch pathway could be considered as biomarkers of renal damage. Experimental studies by genetic modulation of Notch components or pharmacological approaches by γ-secretase inhibitors have demonstrated the role of this pathway in renal regeneration renal, podocyte apoptosis, proliferation and fibroblasts activation, and induction of epithelial to mesenchymal transition of tubular epithelial cells. Recent studies suggest an interaction between Notch and NF-κB pathway involved in the regulation of renal inflammatory process. On the other hand, there are some miRNAs that could regulate Notch components and down-stream responses. All these data suggest that Notch blockade could be a novel therapeutic option for renal diseases. Copyright © 2018 Sociedad Española de Nefrología. Published by Elsevier España, S.L.U. All rights reserved.

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

PubMed Central

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

2010-01-01

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

Fracture modes in notched angleplied composite laminates

NASA Technical Reports Server (NTRS)

Irvine, T. B.; Ginty, C. A.

1984-01-01

The Composite Durability Structural Analysis (CODSTRAN) computer code is used to determine composite fracture. Fracture modes in solid and notched, unidirectional and angleplied graphite/epoxy composites were determined by using CODSTRAN. Experimental verification included both nondestructive (ultrasonic C-Scanning) and destructive (scanning electron microscopy) techniques. The fracture modes were found to be a function of ply orientations and whether the composite is notched or unnotched. Delaminations caused by stress concentrations around notch tips were also determined. Results indicate that the composite mechanics, structural analysis, laminate analysis, and fracture criteria modules embedded in CODSTRAN are valid for determining composite fracture modes.

Therapeutic antibody targeting of Notch3 signaling prevents mural cell loss in CADASIL.

PubMed

Machuca-Parra, Arturo I; Bigger-Allen, Alexander A; Sanchez, Angie V; Boutabla, Anissa; Cardona-Vélez, Jonathan; Amarnani, Dhanesh; Saint-Geniez, Magali; Siebel, Christian W; Kim, Leo A; D'Amore, Patricia A; Arboleda-Velasquez, Joseph F

2017-08-07

Cerebral autosomal-dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is a neurological syndrome characterized by small vessel disease (SVD), stroke, and vascular cognitive impairment and dementia caused by mutations in NOTCH3 No therapies are available for this condition. Loss of mural cells, which encompass pericytes and vascular smooth muscle cells, is a hallmark of CADASIL and other SVDs, including diabetic retinopathy, resulting in vascular instability. Here, we showed that Notch3 signaling is both necessary and sufficient to support mural cell coverage in arteries using genetic rescue in Notch3 knockout mice. Furthermore, we show that systemic administration of an agonist Notch3 antibody prevents mural cell loss and modifies plasma proteins associated with Notch3 activity, including endostatin/collagen 18α1 and Notch3 extracellular domain in mice with the C455R mutation, a CADASIL variant associated with Notch3 loss of function. These findings open opportunities for the treatment of CADASIL and other SVDs by modulating Notch3 signaling. © 2017 Machuca-Parra et al.

Stepwise assembly of multiple Lin28 proteins on the terminal loop of let-7 miRNA precursors

PubMed Central

Desjardins, Alexandre; Bouvette, Jonathan; Legault, Pascale

2014-01-01

Lin28 inhibits the biogenesis of let-7 miRNAs through direct interactions with let-7 precursors. Previous studies have described seemingly inconsistent Lin28 binding sites on pre-let-7 RNAs. Here, we reconcile these data by examining the binding mechanism of Lin28 to the terminal loop of pre-let-7g (TL-let-7g) using biochemical and biophysical methods. First, we investigate Lin28 binding to TL-let-7g variants and short RNA fragments and identify three independent binding sites for Lin28 on TL-let-7g. We then determine that Lin28 assembles in a stepwise manner on TL-let-7g to form a stable 1:3 complex. We show that the cold-shock domain (CSD) of Lin28 is responsible for remodelling the terminal loop of TL-let-7g, whereas the NCp7-like domain facilitates the initial binding of Lin28 to TL-let-7g. This stable binding of multiple Lin28 molecules to the terminal loop of pre-let-7g extends to other precursors of the let-7 family, but not to other pre-miRNAs tested. We propose a model for stepwise assembly of the 1:1, 1:2 and 1:3 pre-let-7g/Lin28 complexes. Stepwise multimerization of Lin28 on pre-let-7 is required for maximum inhibition of Dicer cleavage for a least one member of the let-7 family and may be important for orchestrating the activity of the several factors that regulate let-7 biogenesis. PMID:24452802

Tangeretin has anti-asthmatic effects via regulating PI3K and Notch signaling and modulating Th1/Th2/Th17 cytokine balance in neonatal asthmatic mice.

PubMed

Liu, L-L; Li, F-H; Zhang, Y; Zhang, X-F; Yang, J

2017-07-20

Asthma is a chronic allergic disease characterized by airway inflammation, airway hyper-responsiveness (AHR), and mucus hypersecretion. T-lymphocytes are involved in the pathogenesis of asthma, mediating airway inflammatory reactions by secreting cytokines. The phosphoinositide 3-kinase (PI3K) and Notch signaling pathways are associated with T cell signaling, proliferation, and differentiation, and are important in the progression of asthma. Thus, compounds that can modulate T cell proliferation and function may be of clinical value. Here, we assessed the effects of tangeretin, a plant-derived flavonoid, in experimental asthma. BALB/c mice at postnatal day (P) 12 were challenged with ovalbumin (OVA). Separate groups of mice (n=18/group) were administered tangeretin at 25 or 50 mg/kg body weight by oral gavage. Dexamethasone was used as a positive control. Tangeretin treatment reduced inflammatory cell infiltration in bronchoalveolar lavage fluid (BALF) and also restored the normal histology of lung tissues. OVA-specific IgE levels in serum and BALF were reduced. AHR, as determined by airway resistance and lung compliance, was normalized. Flow cytometry analyses revealed a reduced Th17 cell population. Tangeretin reduced the levels of Th2 and Th17 cytokines and raised IFN-γ levels. PI3K signaling was inhibited. The expressions of the Notch 1 receptor and its ligands Jagged 1 and 2 were downregulated by tangeretin. Our findings support the possible use of tangeretin for treating allergic asthma.

Tension fracture of laminates for transport fuselage. Part 1: Material screening

NASA Technical Reports Server (NTRS)

Walker, T. H.; Avery, W. B.; Ilcewicz, L. B.; Poe, C. C., Jr.; Harris, C. E.

1992-01-01

Transport fuselage structures are designed to contain pressure following a large penetrating damage event. Application of composites to fuselage structures requires a data base and supporting analysis on tension damage tolerance. Tests with 430 fracture specimens were used to accomplish the following: (1) identify critical material and laminate variables affecting notch sensitivity, (2) evaluate composite failure criteria, and (3) recommend a screening test method. Variables studied included fiber type, matrix toughness, lamination manufacturing process, and intraply hybridization. The laminates found to have the lowest notch sensitivity were manufactured using automated tow placement. This suggests a possible relationship between the stress distribution and repeatable levels of material inhomogeneity that are larger than found in traditional tape laminates. Laminates with the highest notch sensitivity consisted of toughened matrix materials that were resistant to a splitting phenomena that reduces stress concentrations in load bearing plies. Parameters for conventional fracture criteria were found to increase with the crack length of the smallest notch sizes studied. Most materials and laminate combinations followed less than a square root singularity for the largest crack sizes studied. Specimen geometry, notch type, and notch size were evaluated in developing a screening test procedure. Results indicate that a range of notch sizes must be tested to determine notch sensitivity.

The caenorhabditis elegans CDT-2 ubiquitin ligase is required for attenuation of EGFR signalling in vulva precursor cells

PubMed Central

2010-01-01

Background Attenuation of the EGFR (Epidermal Growth Factor Receptor) signalling cascade is crucial to control cell fate during development. A candidate-based RNAi approach in C. elegans identified CDT-2 as an attenuator of LET-23 (EGFR) signalling. Human CDT2 is a component of the conserved CDT2/CUL4/DDB1 ubiquitin ligase complex that plays a critical role in DNA replication and G2/M checkpoint. Within this complex, CDT2 is responsible for substrate recognition. This ubiquitin ligase complex has been shown in various organisms, including C. elegans, to target the replication-licensing factor CDT1, and the CDK inhibitor p21. However, no previous link to EGFR signalling has been identified. Results We have characterised CDT-2's role during vulva development and found that it is a novel attenuator of LET-23 signalling. CDT-2 acts redundantly with negative modulators of LET-23 signalling and CDT-2 or CUL-4 downregulation causes persistent expression of the egl-17::cfp transgene, a marker of LET-23 signalling during vulva development. In addition, we show that CDT-2 physically interacts with SEM-5 (GRB2), a known negative modulator of LET-23 signalling that directly binds LET-23, and provide genetic evidence consistent with CDT-2 functioning at or downstream of LET-23. Interestingly, both SEM-5 and CDT-2 were identified independently in a screen for genes involved in receptor-mediated endocytosis in oocytes, suggesting that attenuation of LET-23 by CDT-2 might be through regulation of endocytosis. Conclusions In this study, we have shown that CDT-2 and CUL-4, members of the CUL-4/DDB-1/CDT-2 E3 ubiquitin ligase complex attenuate LET-23 signalling in vulval precursor cells. In future, it will be interesting to investigate the potential link to endocytosis and to determine whether other signalling pathways dependent on endocytosis, e.g. LIN-12 (Notch) could be regulated by this ubiquitin ligase complex. This work has uncovered a novel function for the CUL-4/DDB-1/CDT-2 E3 ligase that may be relevant for its mammalian oncogenic activity. PMID:20977703

Tension fracture of laminates for transport fuselage. Part 1: Material screening

NASA Technical Reports Server (NTRS)

Walker, T. H.; Avery, W. B.; Ilcewicz, L. B.; Poe, C. C., Jr.; Harris, C. E.

1992-01-01

Transport fuselage structures are designed to contain pressure following a large penetrating damage event. Applications of composites to fuselage structures require a database and supporting analysis on tension damage tolerance. Tests with 430 fracture specimens were used to accomplish the following: (1) identify critical material and laminate variables affecting notch sensitivity; (2) evaluate composite failure criteria; and (3) recommend a screening test method. Variables studied included fiber type, matrix toughness, lamination manufacturing process, and intraply hybridization. The laminates found to have the lowest notch sensitivity were manufactured using automated tow placement. This suggests a possible relationship between the stress distribution and repeatable levels of material inhomogeneity that are larger than found in traditional tape laminates. Laminates with the highest notch sensitivity consisted of toughened matrix materials that were resistant to a splitting phenomena that reduces stress concentrations in major load bearing plies. Parameters for conventional fracture criteria were found to increase with crack length for the smallest notch sizes studied. Most material and laminate combinations followed less than a square root singularity for the largest crack sizes studied. Specimen geometry, notch type, and notch size were evaluated in developing a screening test procedure. Traitional methods of correcting for specimen finite width were found to be lacking. Results indicate that a range of notch sizes must be tested to determine notch sensitivity. Data for a single small notch size (0.25 in. diameter) was found to give no indication of the sensitivity of a particular material and laminate layup to larger notch sizes.

Overexpression of protein O-fucosyltransferase 1 accelerates hepatocellular carcinoma progression via the Notch signaling pathway

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ma, Lijie; Dong, Pingping; Liu, Longzi

Aberrant activation of Notch signaling frequently occurs in liver cancer, and is associated with liver malignancies. However, the mechanisms regulating pathologic Notch activation in hepatocellular carcinoma (HCC) remain unclear. Protein O-fucosyltransferase 1 (Pofut1) catalyzes the addition of O-linked fucose to the epidermal growth factor-like repeats of Notch. In the present study, we detected the expression of Pofut1 in 8 HCC cell lines and 253 human HCC tissues. We reported that Pofut1 was overexpressed in HCC cell lines and clinical HCC tissues, and Pofut1 overexpression clinically correlated with the unfavorable survival and high disease recurrence in HCC. The in vitro assay demonstratedmore » that Pofut1 overexpression accelerated the cell proliferation and migration in HCC cells. Furthermore, Pofut1 overexpression promoted the binding of Notch ligand Dll1 to Notch receptor, and hence activated Notch signaling pathway in HCC cells, indicating that Pofut1 overexpression could be a reason for the aberrant activation of Notch signaling in HCC. Taken together, our findings indicated that an aberrant activated Pofut1-Notch pathway was involved in HCC progression, and blockage of this pathway could be a promising strategy for the therapy of HCC. - Highlights: • Pofut1 overexpression in HCC was correlated with aggressive tumor behaviors. • Pofut1 overexpression in HCC was associated with poor prognosis. • Pofut1 promoted cell proliferation, migration and invasion in hepatoma cells. • Pofut1 activated Notch signaling pathway in hepatoma cells.« less

Chemotactic Cues for NOTCH1-Dependent Leukemia

PubMed Central

Piovan, Erich; Tosello, Valeria; Amadori, Alberto; Zanovello, Paola

2018-01-01

The NOTCH signaling pathway is a conserved signaling cascade that regulates many aspects of development and homeostasis in multiple organ systems. Aberrant activity of this signaling pathway is linked to the initiation and progression of several hematological malignancies, exemplified by T-cell acute lymphoblastic leukemia (T-ALL). Interestingly, frequent non-mutational activation of NOTCH1 signaling has recently been demonstrated in B-cell chronic lymphocytic leukemia (B-CLL), significantly extending the pathogenic significance of this pathway in B-CLL. Leukemia patients often present with high-blood cell counts, diffuse disease with infiltration of the bone marrow, secondary lymphoid organs, and diffusion to the central nervous system (CNS). Chemokines are chemotactic cytokines that regulate migration of cells between tissues and the positioning and interactions of cells within tissue. Homeostatic chemokines and their receptors have been implicated in regulating organ-specific infiltration, but may also directly and indirectly modulate tumor growth. Recently, oncogenic NOTCH1 has been shown to regulate infiltration of leukemic cells into the CNS hijacking the CC-chemokine ligand 19/CC-chemokine receptor 7 chemokine axis. In addition, a crucial role for the homing receptor axis CXC-chemokine ligand 12/CXC-chemokine receptor 4 has been demonstrated in leukemia maintenance and progression. Moreover, the CCL25/CCR9 axis has been implicated in the homing of leukemic cells into the gut, particularly in the presence of phosphatase and tensin homolog tumor suppressor loss. In this review, we summarize the latest developments regarding the role of NOTCH signaling in regulating the chemotactic microenvironmental cues involved in the generation and progression of T-ALL and compare these findings to B-CLL. PMID:29666622

Jagged1 is the pathological link between Wnt and Notch pathways in colorectal cancer

PubMed Central

Rodilla, Verónica; Villanueva, Alberto; Obrador-Hevia, Antonia; Robert-Moreno, Àlex; Fernández-Majada, Vanessa; Grilli, Andrea; López-Bigas, Nuria; Bellora, Nicolás; Albà, M. Mar; Torres, Ferran; Duñach, Mireia; Sanjuan, Xavier; Gonzalez, Sara; Gridley, Thomas; Capella, Gabriel; Bigas, Anna; Espinosa, Lluís

2009-01-01

Notch has been linked to β-catenin-dependent tumorigenesis; however, the mechanisms leading to Notch activation and the contribution of the Notch pathway to colorectal cancer is not yet understood. By microarray analysis, we have identified a group of genes downstream of Wnt/β-catenin (down-regulated when blocking Wnt/β-catenin) that are directly regulated by Notch (repressed by γ-secretase inhibitors and up-regulated by active Notch1 in the absence of β-catenin signaling). We demonstrate that Notch is downstream of Wnt in colorectal cancer cells through β-catenin-mediated transcriptional activation of the Notch-ligand Jagged1. Consistently, expression of activated Notch1 partially reverts the effects of blocking Wnt/β-catenin pathway in tumors implanted s.c. in nude mice. Crossing APCMin/+ with Jagged1+/Δ mice is sufficient to significantly reduce the size of the polyps arising in the APC mutant background indicating that Notch is an essential modulator of tumorigenesis induced by nuclear β-catenin. We show that this mechanism is operating in human tumors from Familial Adenomatous Polyposis patients. We conclude that Notch activation, accomplished by β-catenin-mediated up-regulation of Jagged1, is required for tumorigenesis in the intestine. The Notch-specific genetic signature is sufficient to block differentiation and promote vasculogenesis in tumors whereas proliferation depends on both pathways. PMID:19325125

Jagged1 is the pathological link between Wnt and Notch pathways in colorectal cancer.

PubMed

Rodilla, Verónica; Villanueva, Alberto; Obrador-Hevia, Antonia; Robert-Moreno, Alex; Fernández-Majada, Vanessa; Grilli, Andrea; López-Bigas, Nuria; Bellora, Nicolás; Albà, M Mar; Torres, Ferran; Duñach, Mireia; Sanjuan, Xavier; Gonzalez, Sara; Gridley, Thomas; Capella, Gabriel; Bigas, Anna; Espinosa, Lluís

2009-04-14

Notch has been linked to beta-catenin-dependent tumorigenesis; however, the mechanisms leading to Notch activation and the contribution of the Notch pathway to colorectal cancer is not yet understood. By microarray analysis, we have identified a group of genes downstream of Wnt/beta-catenin (down-regulated when blocking Wnt/beta-catenin) that are directly regulated by Notch (repressed by gamma-secretase inhibitors and up-regulated by active Notch1 in the absence of beta-catenin signaling). We demonstrate that Notch is downstream of Wnt in colorectal cancer cells through beta-catenin-mediated transcriptional activation of the Notch-ligand Jagged1. Consistently, expression of activated Notch1 partially reverts the effects of blocking Wnt/beta-catenin pathway in tumors implanted s.c. in nude mice. Crossing APC(Min/+) with Jagged1(+/Delta) mice is sufficient to significantly reduce the size of the polyps arising in the APC mutant background indicating that Notch is an essential modulator of tumorigenesis induced by nuclear beta-catenin. We show that this mechanism is operating in human tumors from Familial Adenomatous Polyposis patients. We conclude that Notch activation, accomplished by beta-catenin-mediated up-regulation of Jagged1, is required for tumorigenesis in the intestine. The Notch-specific genetic signature is sufficient to block differentiation and promote vasculogenesis in tumors whereas proliferation depends on both pathways.

Mechanism of insulin-stimulated clearance of plasma nonesterified fatty acids in humans.

PubMed

Carpentier, André C; Frisch, Frédérique; Brassard, Pascal; Lavoie, François; Bourbonnais, Annie; Cyr, Denis; Giguère, Robert; Baillargeon, Jean-Patrice

2007-03-01

Insulin increases plasma nonesterified fatty acid (NEFA) clearance in humans, but whether this is independent of change in plasma NEFA appearance is currently unknown. Nine nondiabetic men (age: 28+/-3 yr, body mass index: 27.2+/-1.7 kg/m2) underwent euglycemic clamps to maintain low (LINS) vs. high (HINS) physiological insulin levels for 6 h. An intravenous infusion of heparin+Intralipid (HI) was performed during 4 of the 6 h of the clamps (in the last 4 h at LINS and in the first 4 h at HINS), whereas saline infusion (SAL) was administered in the remaining 2 h to modulate plasma NEFA levels independently of plasma insulin levels. Four experimental conditions were obtained in each individual: LINS with saline (LINS/SAL) and with HI infusion (LINS/HI) and HINS with saline (HINS/SAL) and with HI infusion (HINS/HI). Plasma palmitate appearance during HINS/SAL was lower than during the three other experimental conditions (P<0.05). In contrast, plasma linoleate appearance, as expected, was increased by HI independently of insulin level (P<0.02). Plasma palmitate clearance during HINS/SAL was higher than LINS/SAL and LINS/HI (P<0.008), and this increase was blunted during HINS/HI. We observed a linear decrease in plasma palmitate clearance with increasing plasma NEFA appearance independent of insulin levels. Plasma NEFA levels increased exponentially with increase in plasma NEFA appearance. We conclude that insulin stimulates plasma NEFA clearance by reducing the endogenous appearance rate of NEFA. The relationship between plasma NEFA level and appearance rate is nonlinear.

The Significance of Notch1 Compared with Notch3 in High Metastasis and Poor Overall Survival in Hepatocellular Carcinoma

PubMed Central

Li, Qingjun; Sun, Wei; Zhang, Yong; Wang, Desheng; Dou, Kefeng

2013-01-01

Background The prognosis for patients with hepatocellular carcinoma (HCC) is poor, and the mechanisms underlying the development of HCC remain unclear. Notch1 and Notch3 may be involved in malignant transformation, although their roles remain unknown. Materials and Methods HCC tissues were stained with anti-Notch1 or -Notch3 antibody. The migration and invasion capacities of the cells were measured with transwell cell culture chambers. RT-PCR was used to measure the expression of Notch1 and Notch3 mRNA. Additionally, western blot analysis was used to assess the protein expression of Notch1, Notch3, CD44v6, E-cadherin, matrix metalloproteinase-2 (MMP-2), MMP-9, and urokinase-type plasminogen activator (uPA). RNA interference was used to down-regulate the expression of Notch1 and Notch3. Cell viability was assessed using MTT. Results Based on immunohistochemistry, high Notch1 expression was correlated with tumor size, tumor grade, metastasis, venous invasion and AJCC TNM stage. High Notch3 expression was only strongly correlated with metastasis, venous invasion and satellite lesions. Kaplan-Meier curves demonstrated that patients with high Notch1 or Notch3 expression were at a significantly increased risk for shortened survival time. In vitro, the down-regulation of Notch1 decreased the migration and invasion capacities of HCC cells by regulating CD44v6, E-cadherin, MMP-2, MMP-9, and uPA via the COX-2 and ERK1/2 pathways. Down-regulation of Notch3 only decreased the invasion capacity of HCC cells by regulating MMP-2 and MMP-9 via the ERK1/2 pathway. Conclusions Based on the migration and invasion of HCC, we hypothesize that targeting Notch1 may be more useful than Notch3 for designing novel preventive and therapeutic strategies for HCC in the near future. PMID:23468978

The Prevalence of Notched Audiograms in a Cross-Sectional Study of 12,055 Railway Workers

PubMed Central

Skogstad, Marit; Johnsen, Torstein Seip; Engdahl, Bo; Tambs, Kristian

2015-01-01

Objective: Noise-induced hearing loss (NIHL) is one of the most reported occupational diseases internationally. The occurrence of audiometric notches is emphasized in both American and European guidelines for the diagnosis of NIHL. The aim of this study was to describe the prevalence of notched audiograms among railway personnel with and without noise exposure to better assess the usefulness of such notches in the diagnosis of NIHL. Design: The most recent audiogram from 1994 to 2011 of a total of 12,055 railway workers, age 20 to 65 years, was obtained from the medical records of the occupational health service of the Norwegian State Railways (NSB). The prevalences of three types of notched audiograms, Coles notch, notch index, and 4 kHz notch, were computed, in relation to age, sex, and occupational noise exposure. Results: Coles notch in either ear was found in 63% of the male railway maintenance workers, exposed to noise levels of 75 to 90 dB(A), compared with 53% of the non-noise exposed (<70 dB(A)) traffic controllers (p < 0.001). The corresponding figures for the 4 kHz notch were 31% versus 21% (p < 0.001). For the notch index, 61% of the exposed and 51% of the controls had a notched audiogram (p < 0.001). For female workers, the prevalence of audiometric notches was lower, and the differences between noise exposed and nonexposed was smaller than those in men. Increasing age led to an increased prevalence of notches. Conclusions: Audiometric notches commonly occur among both noise-exposed and those not exposed to noise in railway personnel. The usefulness of audiometric notches in the diagnosis of NIHL is therefore limited. PMID:25470371

Comparison of Notch Strength between Gr/PEEK (APC-1 and APC-2) and Gr/Epoxy Composite Materials at Elevated Temperature.

DTIC Science & Technology

1985-12-01

J ub. we Jr. Captain, USARt Z712 AFIT/GAE/AA/85D- 12 Iv COMPARISON OF NOTCH STRENGTH BETWEEN GR/PEEK (APC-1 AND APC-2) AND GR/EPOXY COMPOSITE ...85D-12 COMPARISON OF NOTCH STRENGTH BETWEEN GR/PEEK _ (APC-1 AND APC-2) AND GR/EPOXY COMPOSITE MATERIAL AT ELEVATED TEMPERATURE THESIS Presented to the...unlimited Preface In this experimental investigation, the reduction of strength for notched composite laminates of Aromatic Polymer Composite , APC-2

Cyclic AMP Response Element Binding Protein Mediates Pathological Retinal Neovascularization via Modulating DLL4-NOTCH1 Signaling

PubMed Central

Singh, Nikhlesh K.; Kotla, Sivareddy; Kumar, Raj; Rao, Gadiparthi N.

2015-01-01

Retinal neovascularization is the most common cause of moderate to severe vision loss in all age groups. Despite the use of anti-VEGFA therapies, this complication continues to cause blindness, suggesting a role for additional molecules in retinal neovascularization. Besides VEGFA and VEGFB, hypoxia induced VEGFC expression robustly. Based on this finding, we tested the role of VEGFC in pathological retinal angiogenesis. VEGFC induced proliferation, migration, sprouting and tube formation of human retinal microvascular endothelial cells (HRMVECs) and these responses require CREB-mediated DLL4 expression and NOTCH1 activation. Furthermore, down regulation of VEGFC levels substantially reduced tip cell formation and retinal neovascularization in vivo. In addition, we observed that CREB via modulating the DLL4-NOTCH1 signaling mediates VEGFC-induced tip cell formation and retinal neovascularization. In regard to upstream mechanism, we found that down regulation of p38β levels inhibited hypoxia-induced CREB-DLL4-NOTCH1 activation, tip cell formation, sprouting and retinal neovascularization. Based on these findings, it may be suggested that VEGFC besides its role in the regulation of lymphangiogenesis also plays a role in pathological retinal angiogenesis and this effect depends on p38β and CREB-mediated activation of DLL4-NOTCH1 signaling. PMID:26870802

Fiber-distributed Ultra-wideband noise radar with steerable power spectrum and colorless base station.

PubMed

Zheng, Jianyu; Wang, Hui; Fu, Jianbin; Wei, Li; Pan, Shilong; Wang, Lixian; Liu, Jianguo; Zhu, Ninghua

2014-03-10

A fiber-distributed Ultra-wideband (UWB) noise radar was achieved, which consists of a chaotic UWB noise source based on optoelectronic oscillator (OEO), a fiber-distributed transmission link, a colorless base station (BS), and a cross-correlation processing module. Due to a polarization modulation based microwave photonic filter and an electrical UWB pass-band filter embedded in the feedback loop of the OEO, the power spectrum of chaotic UWB signal could be shaped and notch-filtered to avoid the spectrum-overlay-induced interference to the narrow band signals. Meanwhile, the wavelength-reusing could be implemented in the BS by means of the distributed polarization modulation-to-intensity modulation conversion. The experimental comparison for range finding was carried out as the chaotic UWB signal was notch-filtered at 5.2 GHz and 7.8 GHz or not. Measured results indicate that space resolution with cm-level could be realized after 3-km fiber transmission thanks to the excellent self-correlation property of the UWB noise signal provided by the OEO. The performance deterioration of the radar raised by the energy loss of the notch-filtered noise signal was negligible.

Counter Piracy: A Repeated Game with Asymmetric Information

DTIC Science & Technology

2009-09-01

Christopher D. Marsh Approved by: Kyle Y. Lin Thesis Advisor Timothy H. Chung Second Reader Robert F. Dell Chairman, Department of...encourage Malaysia and Indonesia to work with the Singapore Navy in coordinated patrols of the region. Increased cooperation in the region includes the

Suppression of p53 by Notch3 is mediated by Cyclin G1 and sustained by MDM2 and miR-221 axis in hepatocellular carcinoma

PubMed Central

Baglioni, Michele; Fornari, Francesca; Giannone, Ferdinando; Ravaioli, Matteo; Cescon, Matteo; Chieco, Pasquale; Bolondi, Luigi; Gramantieri, Laura

2014-01-01

To successfully target Notch receptors as part of a multidrug anticancer strategy, it will be essential to fully characterize the factors that are modulated by Notch signaling. We recently reported that Notch3 silencing in HCC results in p53 up-regulation in vitro and, therefore, we focused on the mechanisms that associate Notch3 to p53 protein expression. We explored the regulation of p53 by Notch3 signalling in three HCC cell lines HepG2, SNU398 and Hep3B.We found that Notch3 regulates p53 at post-transcriptional level controlling both Cyclin G1 expression and the feed-forward circuit involving p53, miR-221 and MDM2. Moreover, our results were validated in human HCCs and in a rat model of HCC treated with Notch3 siRNAs. Our findings are becoming an exciting area for further in-depth research toward targeted inactivation of Notch3 receptor as a novel therapeutic approach for increasing the drug-sensitivity, and thereby improving the treatment outcome of patients affected by HCC. Indeed, we proved that Notch3 silencing strongly increases the effects of Nutilin-3. With regard to therapeutic implications, Notch3-specific drugs could represent a valuable strategy to limit Notch signaling in the context of hepatocellular carcinoma over-expressing this receptor. PMID:25431954

Comparison of Two Methods for Calculating the Frictional Properties of Articular Cartilage Using a Simple Pendulum and Intact Mouse Knee Joints

PubMed Central

Drewniak, Elizabeth I.; Jay, Gregory D.; Fleming, Braden C.; Crisco, Joseph J.

2009-01-01

In attempts to better understand the etiology of osteoarthritis, a debilitating joint disease that results in the degeneration of articular cartilage in synovial joints, researchers have focused on joint tribology, the study of joint friction, lubrication, and wear. Several different approaches have been used to investigate the frictional properties of articular cartilage. In this study, we examined two analysis methods for calculating the coefficient of friction (μ) using a simple pendulum system and BL6 murine knee joints (n=10) as the fulcrum. A Stanton linear decay model (Lin μ) and an exponential model that accounts for viscous damping (Exp μ) were fit to the decaying pendulum oscillations. Root mean square error (RMSE), asymptotic standard error (ASE), and coefficient of variation (CV) were calculated to evaluate the fit and measurement precision of each model. This investigation demonstrated that while Lin μ was more repeatable, based on CV (5.0% for Lin μ; 18% for Exp μ), Exp μ provided a better fitting model, based on RMSE (0.165° for Exp μ; 0.391° for Lin μ) and ASE (0.033 for Exp μ; 0.185 for Lin μ), and had a significantly lower coefficient of friction value (0.022±0.007 for Exp μ; 0.042±0.016 for Lin μ) (p=0.001). This study details the use of a simple pendulum for examining cartilage properties in situ that will have applications investigating cartilage mechanics in a variety of species. The Exp μ model provided a more accurate fit to the experimental data for predicting the frictional properties of intact joints in pendulum systems. PMID:19632680

Protruding vulva mutants identify novel loci and Wnt signaling factors that function during Caenorhabditis elegans vulva development.

PubMed

Eisenmann, D M; Kim, S K

2000-11-01

The Caenorhabditis elegans vulva develops from the progeny of three vulval precursor cells (VPCs) induced to divide and differentiate by a signal from the somatic gonad. Evolutionarily conserved Ras and Notch extracellular signaling pathways are known to function during this process. To identify novel loci acting in vulval development, we carried out a genetic screen for mutants having a protruding-vulva (Pvl) mutant phenotype. Here we report the initial genetic characterization of several novel loci: bar-1, pvl-4, pvl-5, and pvl-6. In addition, on the basis of their Pvl phenotypes, we show that the previously identified genes lin-26, mom-3/mig-14, egl-18, and sem-4 also function during vulval development. Our characterization indicates that (1) pvl-4 and pvl-5 are required for generation/survival of the VPCs; (2) bar-1, mom-3/mig-14, egl-18, and sem-4 play a role in VPC fate specification; (3) lin-26 is required for proper VPC fate execution; and (4) pvl-6 acts during vulval morphogenesis. In addition, two of these genes, bar-1 and mom-3/mig-14, are known to function in processes regulated by Wnt signaling, suggesting that a Wnt signaling pathway is acting during vulval development.

Notch signaling modulates sleep homeostasis and learning after sleep deprivation in Drosophila.

PubMed

Seugnet, Laurent; Suzuki, Yasuko; Merlin, Gabriel; Gottschalk, Laura; Duntley, Stephen P; Shaw, Paul J

2011-05-24

The role of the transmembrane receptor Notch in the adult brain is poorly understood. Here, we provide evidence that bunched, a negative regulator of Notch, is involved in sleep homeostasis. Genetic evidence indicates that interfering with bunched activity in the mushroom bodies (MBs) abolishes sleep homeostasis. Combining bunched and Delta loss-of-function mutations rescues normal homeostasis, suggesting that Notch signaling may be involved in regulating sensitivity to sleep loss. Preventing the downregulation of Delta by overexpressing a wild-type transgene in MBs reduces sleep homeostasis and, importantly, prevents learning impairments induced by sleep deprivation. Similar resistance to sleep loss is observed with Notch(spl-1) gain-of-function mutants. Immunohistochemistry reveals that the Notch receptor is expressed in glia, whereas Delta is localized in neurons. Importantly, the expression in glia of the intracellular domain of Notch, a dominant activated form of the receptor, is sufficient to prevent learning deficits after sleep deprivation. Together, these results identify a novel neuron-glia signaling pathway dependent on Notch and regulated by bunched. These data highlight the emerging role of neuron-glia interactions in regulating both sleep and learning impairments associated with sleep loss. Copyright © 2011 Elsevier Ltd. All rights reserved.

Strain induced parametric pumping of a domain wall and its depinning from a notch

NASA Astrophysics Data System (ADS)

Nepal, Rabindra; Gungordu, Utkan; Kovalev, Alexey

Using Thiele's method and detailed micromagnetic simulations, we study resonant oscillation of a domain wall in a notch of a ferromagnetic nanowire due to the modulation of magnetic anisotropy by external AC strain. Such resonant oscillation results from the parametric pumping of domain wall by AC strain at frequency about double the free domain wall oscillation frequency, which is mainly determined by the perpendicular anisotropy and notch geometry. This effect leads to a substantial reduction in depinning field or current required to depin a domain wall from the notch, and offers a mechanism for efficient domain wall motion in a notched nanowire. Our theoretical model accounts for the pinning potential due to a notch by explicitly calculating ferromagnetic energy as a function of notch geometry parameters. We also find similar resonant domain wall oscillations and reduction in the domain wall depinning field or current due to surface acoustic wave in soft ferromagnetic nanowire without uniaxial anisotropy that energetically favors an in-plane domain wall. DOE Early Career Award DE-SC0014189 and DMR- 1420645.

Frequency agile microwave photonic notch filter with anomalously high stopband rejection.

PubMed

Marpaung, David; Morrison, Blair; Pant, Ravi; Eggleton, Benjamin J

2013-11-01

We report a novel class microwave photonic (MWP) notch filter with a very narrow isolation bandwidth (10 MHz), an ultrahigh stopband rejection (>60 dB), a wide frequency tuning (1-30 GHz), and flexible bandwidth reconfigurability (10-65 MHz). This performance is enabled by a new concept of sideband amplitude and phase controls using an electro-optic modulator and an optical filter. This concept enables energy efficient operation in active MWP notch filters, and opens up a pathway toward enabling low-power nanophotonic devices as high-performance RF filters.

Induced pluripotent stem cells with NOTCH1 gene mutation show impaired differentiation into smooth muscle and endothelial cells: Implications for bicuspid aortic valve-related aortopathy.

PubMed

Jiao, Jiao; Tian, Weihua; Qiu, Ping; Norton, Elizabeth L; Wang, Michael M; Chen, Y Eugene; Yang, Bo

2018-03-12

The NOTCH1 gene mutation has been identified in bicuspid aortic valve patients. We developed an in vitro model with human induced pluripotent stem cells (iPSCs) to evaluate the role of NOTCH1 in smooth muscle and endothelial cell (EC) differentiation. The iPSCs were derived from a patient with a normal tricuspid aortic valve and aorta. The NOTCH1 gene was targeted in iPSCs with the Clustered Regularly Interspaced Short Palindromic Repeats/CRISPR-associated protein 9 nuclease (Cas9) system. The NOTCH1 -/- (NOTCH1 homozygous knockout) and isogenic control iPSCs (wild type) were differentiated into neural crest stem cells (NCSCs) and into cardiovascular progenitor cells (CVPCs). The NCSCs were differentiated into smooth muscle cells (SMCs). The CVPCs were differentiated into ECs. The differentiations of SMCs and ECs were compared between NOTCH1 -/- and wild type cells. The expression of NCSC markers (SRY-related HMG-box 10 and transcription factor AP-2 alpha) was significantly lower in NOTCH1 -/- NCSCs than in wild type NCSCs. The SMCs derived from NOTCH1 -/- NCSCs showed immature morphology with smaller size and decreased expression of all SMC-specific contractile proteins. In NOTCH1 -/- CVPCs, the expression of ISL1, NKX2.5, and MYOCD was significantly lower than that in isogenic control CVPCs, indicating impaired differentiation from iPSCs to CVPCs. The NOTCH1 -/- ECs derived from CVPCs showed significantly lower expression of cluster of differentiation 105 and cluster of differentiation 31 mRNA and protein, indicating a defective differentiation process. NOTCH1 is critical in SMC and EC differentiation of iPSCs through NCSCs and CVPCs, respectively. NOTCH1 gene mutations might potentially contribute to the development of thoracic aortic aneurysms by affecting SMC differentiation in some patients with bicuspid aortic valve. Copyright © 2018 The American Association for Thoracic Surgery. Published by Elsevier Inc. All rights reserved.

Endodermal Hedgehog signals modulate Notch pathway activity in the developing digestive tract mesenchyme

PubMed Central

Kim, Tae-Hee; Kim, Byeong-Moo; Mao, Junhao; Rowan, Sheldon; Shivdasani, Ramesh A.

2011-01-01

The digestive tract epithelium and its adjoining mesenchyme undergo coordinated patterning and growth during development. The signals they exchange in the process are not fully characterized but include ligands of the Hedgehog (Hh) family, which originate in the epithelium and are necessary for mesenchymal cells to expand in number and drive elongation of the developing gut tube. The Notch signaling pathway has known requirements in fetal and adult intestinal epithelial progenitors. We detected Notch pathway activity in the embryonic gut mesenchyme and used conditional knockout mice to study its function. Selective disruption of the Notch effector gene RBP-Jκ (Rbpj) in the mesenchyme caused progressive loss of subepithelial fibroblasts and abbreviated gut length, revealing an unexpected requirement in this compartment. Surprisingly, constitutive Notch activity also induced rapid mesenchymal cell loss and impaired organogenesis, probably resulting from increased cell death and suggesting the need for a delicate balance in Notch signaling. Because digestive tract anomalies in mouse embryos with excess Notch activity phenocopy the absence of Hh signaling, we postulated that endodermal Hh restrains mesenchymal Notch pathway activity. Indeed, Hh-deficient embryos showed Notch overactivity in their defective gut mesenchyme and exposure to recombinant sonic hedgehog could override Notch-induced death of cultured fetal gut mesenchymal cells. These results reveal unexpected interactions between prominent signals in gastrointestinal development and provide a coherent explanation for Hh requirements in mesenchymal cell survival and organ growth. PMID:21750033

A Tail of Two Sites: A Bipartite Mechanism for Recognition of Notch Ligands by Mind Bomb E3 Ligases

DOE Office of Scientific and Technical Information (OSTI.GOV)

McMillan, Brian J.; Schnute, Björn; Ohlenhard, Nadja

Mind bomb (Mib) proteins are large, multi-domain E3 ligases that promote ubiquitination of the cytoplasmic tails of Notch ligands. This ubiquitination step marks the ligand proteins for epsin-dependent endocytosis, which is critical for in vivo Notch receptor activation. Here we present crystal structures of the substrate recognition domains of Mib1, both in isolation and in complex with peptides derived from Notch ligands. The structures, in combination with biochemical, cellular, and in vivo assays, show that Mib1 contains two independent substrate recognition domains that engage two distinct epitopes from the cytoplasmic tail of the ligand Jagged1, one in the intracellular membranemore » proximal region and the other near the C terminus. Together, these studies provide insights into the mechanism of ubiquitin transfer by Mind bomb E3 ligases, illuminate a key event in ligand-induced activation of Notch receptors, and identify a potential target for therapeutic modulation of Notch signal transduction in disease.« less

A Tail of Two Sites: A Bipartite Mechanism for Recognition of Notch Ligands by Mind Bomb E3 Ligases

PubMed Central

McMillan, Brian J.; Schnute, Björn; Ohlenhard, Nadja; Zimmerman, Brandon; Miles, Laura; Beglova, Natalia; Klein, Thomas; Blacklow, Stephen C.

2015-01-01

Summary Mind bomb (Mib) proteins are large, multi-domain E3 ligases that promote ubiquitination of the cytoplasmic tails of Notch ligands. This ubiquitination step marks the ligand proteins for epsin-dependent endocytosis, which is critical for in vivo Notch receptor activation. We present here crystal structures of the substrate recognition domains of Mib1, both in isolation and in complex with peptides derived from Notch ligands. The structures, in combination with biochemical, cellular and in vivo assays, show that Mib1 contains two independent substrate recognition domains that engage two distinct epitopes from the cytoplasmic tail of the ligand Jagged1, one in the intracellular membrane proximal region and the other near the C-terminus. Together, these studies provide new insights into the mechanism of ubiquitin transfer by Mind bomb E3 ligases, illuminate a key event in ligand-induced activation of Notch receptors, and identify a potential new target for therapeutic modulation of Notch signal transduction in disease. PMID:25747658

A Tail of Two Sites: A Bipartite Mechanism for Recognition of Notch Ligands by Mind Bomb E3 Ligases

DOE PAGES

McMillan, Brian J.; Schnute, Björn; Ohlenhard, Nadja; ...

2015-03-05

Mind bomb (Mib) proteins are large, multi-domain E3 ligases that promote ubiquitination of the cytoplasmic tails of Notch ligands. This ubiquitination step marks the ligand proteins for epsin-dependent endocytosis, which is critical for in vivo Notch receptor activation. Here we present crystal structures of the substrate recognition domains of Mib1, both in isolation and in complex with peptides derived from Notch ligands. The structures, in combination with biochemical, cellular, and in vivo assays, show that Mib1 contains two independent substrate recognition domains that engage two distinct epitopes from the cytoplasmic tail of the ligand Jagged1, one in the intracellular membranemore » proximal region and the other near the C terminus. Together, these studies provide insights into the mechanism of ubiquitin transfer by Mind bomb E3 ligases, illuminate a key event in ligand-induced activation of Notch receptors, and identify a potential target for therapeutic modulation of Notch signal transduction in disease.« less

A model of the regulatory network involved in the control of the cell cycle and cell differentiation in the Caenorhabditis elegans vulva.

PubMed

Weinstein, Nathan; Ortiz-Gutiérrez, Elizabeth; Muñoz, Stalin; Rosenblueth, David A; Álvarez-Buylla, Elena R; Mendoza, Luis

2015-03-13

There are recent experimental reports on the cross-regulation between molecules involved in the control of the cell cycle and the differentiation of the vulval precursor cells (VPCs) of Caenorhabditis elegans. Such discoveries provide novel clues on how the molecular mechanisms involved in the cell cycle and cell differentiation processes are coordinated during vulval development. Dynamic computational models are helpful to understand the integrated regulatory mechanisms affecting these cellular processes. Here we propose a simplified model of the regulatory network that includes sufficient molecules involved in the control of both the cell cycle and cell differentiation in the C. elegans vulva to recover their dynamic behavior. We first infer both the topology and the update rules of the cell cycle module from an expected time series. Next, we use a symbolic algorithmic approach to find which interactions must be included in the regulatory network. Finally, we use a continuous-time version of the update rules for the cell cycle module to validate the cyclic behavior of the network, as well as to rule out the presence of potential artifacts due to the synchronous updating of the discrete model. We analyze the dynamical behavior of the model for the wild type and several mutants, finding that most of the results are consistent with published experimental results. Our model shows that the regulation of Notch signaling by the cell cycle preserves the potential of the VPCs and the three vulval fates to differentiate and de-differentiate, allowing them to remain completely responsive to the concentration of LIN-3 and lateral signal in the extracellular microenvironment.

The fracture behavior of filament wound cylinders with surface flaws

NASA Technical Reports Server (NTRS)

Harris, C. E.; Morris, D. H.; Poe, C. C., Jr.

1985-01-01

The behavior of tensile coupons with surface notches of various semielliptical shapes has been evaluated for specimens obtained from a thick filament wound graphite/epoxy cylinder. Specimens with very shallow notches were observed to be notch insensitive and the unnotched strength from these specimens was determined to be 54.97 Ksi with an associated failure strain of 1.328 percent. Specimens with deeper notches were sensitive to notch depth and notch aspect ratio. Isotropic linear elastic fracture mechanics with an estimated fracture toughness of 27.2 Ksi-in.-to the 1/2 correctly predicted the influence of notch depth, aspect ratio and specimen finite width.

First-principles calculated decomposition pathways for LiBH4 nanoclusters

PubMed Central

Huang, Zhi-Quan; Chen, Wei-Chih; Chuang, Feng-Chuan; Majzoub, Eric H.; Ozoliņš, Vidvuds

2016-01-01

We analyze thermodynamic stability and decomposition pathways of LiBH4 nanoclusters using grand-canonical free-energy minimization based on total energies and vibrational frequencies obtained from density-functional theory (DFT) calculations. We consider (LiBH4)n nanoclusters with n = 2 to 12 as reactants, while the possible products include (Li)n, (B)n, (LiB)n, (LiH)n, and Li2BnHn; off-stoichiometric LinBnHm (m ≤ 4n) clusters were considered for n = 2, 3, and 6. Cluster ground-state configurations have been predicted using prototype electrostatic ground-state (PEGS) and genetic algorithm (GA) based structural optimizations. Free-energy calculations show hydrogen release pathways markedly differ from those in bulk LiBH4. While experiments have found that the bulk material decomposes into LiH and B, with Li2B12H12 as a kinetically inhibited intermediate phase, (LiBH4)n nanoclusters with n ≤ 12 are predicted to decompose into mixed LinBn clusters via a series of intermediate clusters of LinBnHm (m ≤ 4n). The calculated pressure-composition isotherms and temperature-pressure isobars exhibit sloping plateaus due to finite size effects on reaction thermodynamics. Generally, decomposition temperatures of free-standing clusters are found to increase with decreasing cluster size due to thermodynamic destabilization of reaction products. PMID:27189731

Activation of the Notch-1 signaling pathway may be involved in intracerebral hemorrhage-induced reactive astrogliosis in rats.

PubMed

Zhong, Jian-Hua; Zhou, Hua-Jun; Tang, Tao; Cui, Han-Jin; Yang, A-Li; Zhang, Qi-Mei; Zhou, Jing-Hua; Zhang, Qiang; Gong, Xun; Zhang, Zhao-Hui; Mei, Zhi-Gang

2017-10-27

OBJECTIVE Reactive astrogliosis, a key feature that is characterized by glial proliferation, has been observed in rat brains after intracerebral hemorrhage (ICH). However, the mechanisms that control reactive astrogliosis formation remain unknown. Notch-1 signaling plays a critical role in modulating reactive astrogliosis. The purpose of this paper was to establish whether Notch-1 signaling is involved in reactive astrogliosis after ICH. METHODS ICH was induced in adult male Sprague-Dawley rats via stereotactic injection of autologous blood into the right globus pallidus. N-[ N-(3,5-difluorophenacetyl)-l-alanyl]- S-phenylglycine t-butyl ester (DAPT) was injected into the lateral ventricle to block Notch-1 signaling. The rats' brains were perfused to identify proliferating cell nuclear antigen (PCNA)-positive/GFAP-positive nuclei. The expression of GFAP, Notch-1, and the activated form of Notch-1 (Notch intracellular domain [NICD]) and its ligand Jagged-1 was assessed using immunohistochemical and Western blot analyses, respectively. RESULTS Notch-1 signaling was upregulated and activated after ICH as confirmed by an increase in the expression of Notch-1 and NICD and its ligand Jagged-1. Remarkably, blockade of Notch-1 signaling with the specific inhibitor DAPT suppressed astrocytic proliferation and GFAP levels caused by ICH. In addition, DAPT improved neurological outcome after ICH. CONCLUSIONS Notch-1 signaling is a critical regulator of ICH-induced reactive astrogliosis, and its blockage may be a potential therapeutic strategy for hemorrhagic injury.

Notch pathway activity identifies cells with cancer stem cell-like properties and correlates with worse survival in lung adenocarcinoma

PubMed Central

Hassan, Khaled A.; Wang, Luo; Korkaya, Hasan; Chen, Guoan; Maillard, Ivan; Beer, David G.; Kalemkerian, Gregory P.; Wicha, Max S.

2013-01-01

Purpose The cancer stem cell theory postulates that tumors contain a subset of cells with stem cell properties of self-renewal, differentiation and tumor-initiation. The purpose of this study is to determine the role of Notch activity in identifying lung cancer stem cells. Experimental Design We investigated the role of Notch activity in lung adenocarcinoma utilizing a Notch GFP-reporter construct and a gamma-secretase inhibitor (GSI), which inhibits Notch pathway activity. Results Transduction of lung cancer cells with Notch GFP-reporter construct identified a subset of cells with high Notch activity (GFP-bright). GFP-bright cells had the ability to form more tumor spheres in serum-free media, and were able to generate both GFP-bright and GFP-dim (lower Notch activity) cell populations. GFP-bright cells were resistant to chemotherapy and were tumorigenic in serial xenotransplantation assays. Tumor xenografts of mice treated with GSI had decreased expression of downstream effectors of Notch pathway and failed to regenerate tumors upon reimplantation in NOD/SCID mice. Using multivariate analysis, we detected a statistically significant correlation between poor clinical outcome and Notch activity (reflected in increased Notch ligand expression or decreased expression of the negative modulators), in a group of 441 lung adenocarcinoma patients. This correlation was further confirmed in an independent group of 89 adenocarcinoma patients where Hes-1 overexpression correlated with poor overall survival. Conclusions Notch activity can identify lung cancer stem cell-like population and its inhibition may be an appropriate target for treating lung adenocarcinoma. PMID:23444212

Cutting efficiency of conventional and martensitic nickel-titanium instruments for coronal flaring.

PubMed

Morgental, Renata Dornelles; Vier-Pelisser, Fabiana Vieira; Kopper, Patrícia Maria Poli; de Figueiredo, José Antonio Poli; Peters, Ove A

2013-12-01

This study aimed at evaluating the influence of rotational speed and number of uses on the cutting efficiency of 4 nickel-titanium coronal flaring instruments against 2 substrates, bovine dentin and acrylic blocks. BioRaCe BR0, HyFlex CM1, ProFile OS#2, and ProTaper Sx were used in simulated lateral action against both substrates at 250 and 500 rpm up to 5 times, producing 5 notches in each block. Notch areas and lengths were measured under a stereomicroscope, and data were compared by using parametric tests (α = 0.05). Against both substrates, HyFlex CM1 and ProFile OS#2 were the most and the least cutting efficient instruments, respectively (P < .05). Against acrylic, area and length values at 500 rpm were significantly higher than those at 250 rpm for all brands. Against dentin, significant differences were detected between 250 and 500 rpm for HyFlex CM1 and ProTaper Sx (area) and for BioRace BR0, HyFlex CM1, and ProTaper Sx (length). Regarding cutting efficiency loss, area and length for notches 1 and 2 (first notches) and 4 and 5 (last notches) were similar against acrylic. Against dentin, length values for notches 1 and 2 were significantly higher than those for notches 4 and 5 in ProFile OS#2 and ProTaper Sx. A strong correlation was detected between the overall results obtained on acrylic and dentin for area and length (P < .0001), although further analysis showed that data against acrylic were a poor predictor of data against dentin after repeated use. HyFlex CM1 was the most cutting efficient instrument in lateral action. An increase in rotational speed improved the cutting efficiency. Results against acrylic showed a high correlation to data against dentin, but acrylic may not be a proper substrate when the intention is to assess cutting efficiency loss with repeated use. Copyright © 2013 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

A lncRNA fine tunes the dynamics of a cell state transition involving Lin28, let-7 and de novo DNA methylation

PubMed Central

Li, Meng Amy; Amaral, Paulo P; Cheung, Priscilla; Bergmann, Jan H; Kinoshita, Masaki; Kalkan, Tüzer; Ralser, Meryem; Robson, Sam; von Meyenn, Ferdinand; Paramor, Maike; Yang, Fengtang; Chen, Caifu; Nichols, Jennifer; Spector, David L; Kouzarides, Tony; He, Lin; Smith, Austin

2017-01-01

Execution of pluripotency requires progression from the naïve status represented by mouse embryonic stem cells (ESCs) to a state capacitated for lineage specification. This transition is coordinated at multiple levels. Non-coding RNAs may contribute to this regulatory orchestra. We identified a rodent-specific long non-coding RNA (lncRNA) linc1281, hereafter Ephemeron (Eprn), that modulates the dynamics of exit from naïve pluripotency. Eprn deletion delays the extinction of ESC identity, an effect associated with perduring Nanog expression. In the absence of Eprn, Lin28a expression is reduced which results in persistence of let-7 microRNAs, and the up-regulation of de novo methyltransferases Dnmt3a/b is delayed. Dnmt3a/b deletion retards ES cell transition, correlating with delayed Nanog promoter methylation and phenocopying loss of Eprn or Lin28a. The connection from lncRNA to miRNA and DNA methylation facilitates the acute extinction of naïve pluripotency, a pre-requisite for rapid progression from preimplantation epiblast to gastrulation in rodents. Eprn illustrates how lncRNAs may introduce species-specific network modulations. DOI: http://dx.doi.org/10.7554/eLife.23468.001 PMID:28820723

Activation of Notch1 inhibits medial edge epithelium apoptosis in all-trans retinoic acid-induced cleft palate in mice

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Yadong; Dong, Shiyi; Wang, Weicai

Administration of all-trans retinoic acid (atRA) on E12.0 (embryonic day 12.0) leads to failure of medial edge epithelium (MEE) disappearance and cleft palate. However, the molecular mechanism underlying the relationship between atRA and MEE remains to be identified. In this study, atRA (200 mg/kg) administered by gavage induced a 75% incidence of cleft palate in C57BL/6 mice. Notch1 was up-regulated in MEE cells in the atRA-treated group compared with the controls at E15.0, together with reduced apoptosis and elevated proliferation. Next, we investigated the mechanisms underlying atRA, Notch1 and MEE degradation in palate organ culture. Our results revealed that down-regulation ofmore » Notch1 partially rescued the inhibition of atRA-induced palate fusion. Molecular analysis indicated that atRA increased the expression of Notch1 and Rbpj and decreased the expression of P21. In addition, depletion of Notch1 expression decreased the expression of Rbpj and increased the expression of P21. Moreover, inhibition of Rbpj expression partially reversed atRA-induced MEE persistence and increased P21 expression. These findings demonstrate that atRA inhibits MEE degradation, which in turn induces a cleft palate, possibly through the Notch1/RBPjk/P21 signaling pathway. - Highlights: • atRA exposure on E12.0 induced MEE persistence and cleft palate. • Notch1 was up-regulated in MEE cells in the atRA-treated embryos. • atRA inhibits MEE degradation, which in turn induces cleft palate, possibly through the Notch1/RBPjk/P21 signaling pathway.« less

Hippo signaling is required for Notch-dependent smooth muscle differentiation of neural crest.

PubMed

Manderfield, Lauren J; Aghajanian, Haig; Engleka, Kurt A; Lim, Lillian Y; Liu, Feiyan; Jain, Rajan; Li, Li; Olson, Eric N; Epstein, Jonathan A

2015-09-01

Notch signaling has well-defined roles in the assembly of arterial walls and in the development of the endothelium and smooth muscle of the vasculature. Hippo signaling regulates cellular growth in many tissues, and contributes to regulation of organ size, in addition to other functions. Here, we show that the Notch and Hippo pathways converge to regulate smooth muscle differentiation of the neural crest, which is crucial for normal development of the aortic arch arteries and cranial vasculature during embryonic development. Neural crest-specific deletion of the Hippo effectors Yap and Taz produces neural crest precursors that migrate normally, but fail to produce vascular smooth muscle, and Notch target genes such as Jagged1 fail to activate normally. We show that Yap is normally recruited to a tissue-specific Jagged1 enhancer by directly interacting with the Notch intracellular domain (NICD). The Yap-NICD complex is recruited to chromatin by the DNA-binding protein Rbp-J in a Tead-independent fashion. Thus, Hippo signaling can modulate Notch signaling outputs, and components of the Hippo and Notch pathways physically interact. Convergence of Hippo and Notch pathways by the mechanisms described here might be relevant for the function of these signaling cascades in many tissues and in diseases such as cancer. © 2015. Published by The Company of Biologists Ltd.

Notch3 as a novel therapeutic target in metastatic medullary thyroid cancer.

PubMed

Lou, Irene; Odorico, Scott; Yu, Xiao-Min; Harrison, April; Jaskula-Sztul, Renata; Chen, Herbert

2018-01-01

Medullary thyroid cancer portends poor survival once liver metastasis occurs. We hypothesize that Notch3 overexpression in medullary thyroid cancer liver metastasis will decrease proliferation and growth of the tumor. TT cells were modified genetically to overexpress Notch3 in the presence of doxycycline, creating the TT-Notch3 cell line. Mice were injected intrasplenically with either TT-Notch3 or control vector TT-TRE cells. Each cell line had 3 treatment groups: control with 12 weeks of standard chow, early DOX with doxycycline chow at day 0 and for 70 days thereafter, and late DOX with doxycycline chow at 8 weeks. Each animal underwent micro-computed tomography to evaluate for tumor formation and tumor quantification was performed. Animals were killed at 12 weeks, and the harvested liver was stained with Ki-67, hematoxylin and eosin, and Notch3. Induction of Notch3 did not prevent formation of medullary thyroid cancer liver metastases as all mice in the early DOX group developed tumors. However, induction of Notch after medullary thyroid cancer liver tumor formation decreased tumor size, as seen on micro-computed tomography scans (late DOX group). This translated to a 37-fold decrease in tumor volume (P = .001). Notch3 overexpression also resulted in decreased Ki-67 index (P = .038). Moreover, Notch3 induction led to increased areas of neutrophil infiltration and necrosis on hematoxylin and eosin staining of the tumors CONCLUSION: Notch3 overexpression demonstrates an antiproliferative effect on established metastatic medullary thyroid cancer liver tumors and is a potential therapeutic target in treatment. Copyright © 2017 Elsevier Inc. All rights reserved.

ETOILE Regulates Developmental Patterning in the Filamentous Brown Alga Ectocarpus siliculosus[W

PubMed Central

Le Bail, Aude; Billoud, Bernard; Le Panse, Sophie; Chenivesse, Sabine; Charrier, Bénédicte

2011-01-01

Brown algae are multicellular marine organisms evolutionarily distant from both metazoans and land plants. The molecular or cellular mechanisms that govern the developmental patterning in brown algae are poorly characterized. Here, we report the first morphogenetic mutant, étoile (etl), produced in the brown algal model Ectocarpus siliculosus. Genetic, cellular, and morphometric analyses showed that a single recessive locus, ETL, regulates cell differentiation: etl cells display thickening of the extracellular matrix (ECM), and the elongated, apical, and actively dividing E cells are underrepresented. As a result of this defect, the overrepresentation of round, branch-initiating R cells in the etl mutant leads to the rapid induction of the branching process at the expense of the uniaxial growth in the primary filament. Computational modeling allowed the simulation of the etl mutant phenotype by including a modified response to the neighborhood information in the division rules used to specify wild-type development. Microarray experiments supported the hypothesis of a defect in cell–cell communication, as primarily Lin-Notch-domain transmembrane proteins, which share similarities with metazoan Notch proteins involved in binary cell differentiation were repressed in etl. Thus, our study highlights the role of the ECM and of novel transmembrane proteins in cell–cell communication during the establishment of the developmental pattern in this brown alga. PMID:21478443

A Wingless and Notch double-repression mechanism regulates G1–S transition in the Drosophila wing

PubMed Central

Herranz, Héctor; Pérez, Lidia; Martín, Francisco A; Milán, Marco

2008-01-01

The control of tissue growth and patterning is orchestrated in various multicellular tissues by the coordinated activity of the signalling molecules Wnt/Wingless (Wg) and Notch, and mutations in these pathways can cause cancer. The role of these molecules in the control of cell proliferation and the crosstalk between their corresponding pathways remain poorly understood. Crosstalk between Notch and Wg has been proposed to organize pattern and growth in the Drosophila wing primordium. Here we report that Wg and Notch act in a surprisingly linear pathway to control G1–S progression. We present evidence that these molecules exert their function by regulating the expression of the dmyc proto-oncogene and the bantam micro-RNA, which positively modulated the activity of the E2F transcription factor. Our results demonstrate that Notch acts in this cellular context as a repressor of cell-cycle progression and Wg has a permissive role in alleviating Notch-mediated repression of G1–S progression in wing cells. PMID:18451803

All-trans-retinoic Acid Modulates the Plasticity and Inhibits the Motility of Breast Cancer Cells: ROLE OF NOTCH1 AND TRANSFORMING GROWTH FACTOR (TGFβ).

PubMed

Zanetti, Adriana; Affatato, Roberta; Centritto, Floriana; Fratelli, Maddalena; Kurosaki, Mami; Barzago, Maria Monica; Bolis, Marco; Terao, Mineko; Garattini, Enrico; Paroni, Gabriela

2015-07-17

All-trans-retinoic acid (ATRA) is a natural compound proposed for the treatment/chemoprevention of breast cancer. Increasing evidence indicates that aberrant regulation of epithelial-to-mesenchymal transition (EMT) is a determinant of the cancer cell invasive and metastatic behavior. The effects of ATRA on EMT are largely unknown. In HER2-positive SKBR3 and UACC812 cells, showing co-amplification of the ERBB2 and RARA genes, ATRA activates a RARα-dependent epithelial differentiation program. In SKBR3 cells, this causes the formation/reorganization of adherens and tight junctions. Epithelial differentiation and augmented cell-cell contacts underlie the anti-migratory action exerted by the retinoid in cells exposed to the EMT-inducing factors EGF and heregulin-β1. Down-regulation of NOTCH1, an emerging EMT modulator, is involved in the inhibition of motility by ATRA. Indeed, the retinoid blocks NOTCH1 up-regulation by EGF and/or heregulin-β1. Pharmacological inhibition of γ-secretase and NOTCH1 processing also abrogates SKBR3 cell migration. Stimulation of TGFβ contributes to the anti-migratory effect of ATRA. The retinoid switches TGFβ from an EMT-inducing and pro-migratory determinant to an anti-migratory mediator. Inhibition of the NOTCH1 pathway not only plays a role in the anti-migratory action of ATRA; it is relevant also for the anti-proliferative activity of the retinoid in HCC1599 breast cancer cells, which are addicted to NOTCH1 for growth/viability. This effect is enhanced by the combination of ATRA and the γ-secretase inhibitor N-(N-(3,5-difluorophenacetyl)-l-alanyl)-S-phenylglycine t-butyl ester, supporting the concept that the two compounds act at the transcriptional and post-translational levels along the NOTCH1 pathway. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

Notch signaling regulates the responses of lipopolysaccharide-stimulated macrophages in the presence of immune complexes.

PubMed

Wongchana, Wipawee; Kongkavitoon, Pornrat; Tangtanatakul, Pattarin; Sittplangkoon, Chutamath; Butta, Patcharavadee; Chawalitpong, Supatta; Pattarakankul, Thitiporn; Osborne, Barbara A; Palaga, Tanapat

2018-01-01

Macrophages exhibit diverse effector phenotypes depending on the stimuli and their microenvironment. Classically activated macrophages are primed with interferon (IFN)γ and stimulated with pathogen-associated molecular patterns. They produce inflammatory mediators and inflammatory cytokines, such as IL-12. In the presence of immune complexes (ICs), activated macrophages have decreased IL-12 production and increased IL-10 production and presumably act as regulatory macrophages. Notch signaling has been shown to regulate the effector functions of classically activated macrophages. In this study, we investigated whether Notch signaling is active in lipopolysaccharide (LPS)-stimulated macrophages in the presence of ICs. LPS/IC stimulation increased the level of cleaved Notch1 in murine macrophages, while IC stimulation alone did not. Delta-like 4, but not Jagged1, was responsible for generating cleaved Notch1. The activation of Notch signaling by LPS/ICs depended upon NF-κB and MEK/Erk pathway activation. Macrophages with the targeted deletion of Rbpj, which encodes a DNA-binding protein central to canonical Notch signaling, produced significantly less IL-10 upon LPS/IC stimulation. A similar impact on IL-10 production was observed when Notch signaling was inhibited with a gamma-secretase inhibitor (GSI). Defects in NF-κB p50 nuclear localization were observed in GSI-treated macrophages and in Rbpj-/- macrophages, suggesting cross-regulation between the Notch and NF-κB pathways. Transcriptomic analysis revealed that Notch signaling regulates the transcription of genes involved in the cell cycle, macrophage activation, leukocyte migration and cytokine production in LPS/IC-stimulated macrophages. Taken together, these results suggest that the Notch signaling pathway plays an important role in regulating the functions of macrophages activated by LPS and ICs.

Physical Science Rocks! Outreach for Elementary Students

ERIC Educational Resources Information Center

McKone, Kevin

2010-01-01

Students at Copiah-Lincoln Community College (Co-Lin) have been hesitant to take courses in the physical sciences, mostly because of a lack of exposure to them in K-12 or a bad experience in this area. The college is addressing this need by exposing students to the physical sciences early on in their education. The science division at Co-Lin has…

The Endocannabinoid, Anandamide, Augments Notch-1 Signaling in Cultured Cortical Neurons Exposed to Amyloid-β and in the Cortex of Aged Rats*

PubMed Central

Tanveer, Riffat; Gowran, Aoife; Noonan, Janis; Keating, Sinead E.; Bowie, Andrew G.; Campbell, Veronica A.

2012-01-01

Aberrant Notch signaling has recently emerged as a possible mechanism for the altered neurogenesis, cognitive impairment, and learning and memory deficits associated with Alzheimer disease (AD). Recently, targeting the endocannabinoid system in models of AD has emerged as a potential approach to slow the progression of the disease process. Although studies have identified neuroprotective roles for endocannabinoids, there is a paucity of information on modulation of the pro-survival Notch pathway by endocannabinoids. In this study the influence of the endocannabinoids, anandamide (AEA) and 2-arachidonoylglycerol, on the Notch-1 pathway and on its endogenous regulators were investigated in an in vitro model of AD. We report that AEA up-regulates Notch-1 signaling in cultured neurons. We also provide evidence that although Aβ1–42 increases expression of the endogenous inhibitor of Notch-1, numb (Nb), this can be prevented by AEA and 2-arachidonoylglycerol. Interestingly, AEA up-regulated Nct expression, a component of γ-secretase, and this was found to play a crucial role in the enhanced Notch-1 signaling mediated by AEA. The stimulatory effects of AEA on Notch-1 signaling persisted in the presence of Aβ1–42. AEA was found to induce a preferential processing of Notch-1 over amyloid precursor protein to generate Aβ1–40. Aging, a natural process of neurodegeneration, was associated with a reduction in Notch-1 signaling in rat cortex and hippocampus, and this was restored with chronic treatment with URB 597. In summary, AEA has the proclivity to enhance Notch-1 signaling in an in vitro model of AD, which may have relevance for restoring neurogenesis and cognition in AD. PMID:22891244

Notch Signaling Contributes to Liver Inflammation by Regulation of Interleukin-22-Producing Cells in Hepatitis B Virus Infection

PubMed Central

Wei, Xin; Wang, Jiu-Ping; Hao, Chun-Qiu; Yang, Xiao-Fei; Wang, Lin-Xu; Huang, Chang-Xing; Bai, Xue-Fan; Lian, Jian-Qi; Zhang, Ye

2016-01-01

The mechanism of hepatitis B virus (HBV) induced liver inflammation is not fully elucidated. Notch signaling augmented interleukin (IL)-22 secretion in CD4+ T cells, and Notch-IL-22 axis fine-tuned inflammatory response. We previously demonstrated a proinflammatory role of IL-22 in HBV infection. Thus, in this study, we analyzed the role of Notch in development of IL-22-producing cells in HBV infection by inhibition of Notch signaling using γ-secretase inhibitor DAPT in both hydrodynamic induced HBV-infected mouse model and in peripheral blood cells isolated from patients with HBV infection. mRNA expressions of Notch1 and Notch2 were significantly increased in livers and CD4+ T cells upon HBV infection. Inhibition of Notch signaling in vivo leaded to the reduction in NKp46+ innate lymphoid cells 22 (ILC22) and lymphoid tissue inducer 4 (LTi4) cells in the liver. This process was accompanied by downregulating the expressions of IL-22 and related proinflammatory cytokines and chemokines in the liver, as well as blocking the recruitment of antigen-non-specific inflammatory cells into the liver and subsequent liver injury, but did not affect HBV antigens production and IL-22 secretion in the serum. Furthermore, IL-22 production in HBV non-specific cultured CD4+ T cells, but not HBV-specific CD4+ T cells, was reduced in response to in vitro inhibition of Notch signaling. In conclusion, Notch siganling appears to be an important mediator of the liver inflammation by modulating hepatic ILC22. The potential proinflammatory effect of Notch-mediated ILC22 may be significant for the development of new therapeutic approaches for treatment of hepatitis B. PMID:27800305

Notch-Boosted Domain Wall Propagation in Magnetic Nanowires

NASA Astrophysics Data System (ADS)

Wang, Xiang Rong; Yuan, Hauiyang

Magnetic domain wall (DW) motion along a nanowire underpins many proposals of spintronic devices. High DW propagation velocity is obviously important because it determines the device speed. Thus it is interesting to search for effective control knobs of DW dynamics. We report a counter-intuitive finding that notches in an otherwise homogeneous magnetic nanowire can boost current-induced domain wall (DW) propagation. DW motion in notch-modulated wires can be classified into three phases: 1) A DW is pinned around a notch when the current density is below the depinning current density. 2) DW propagation velocity above the depinning current density is boosted by notches when non-adiabatic spin-transfer torque strength is smaller than the Gilbert damping constant. The boost can be many-fold. 3) DW propagation velocity is hindered when non-adiabatic spin-transfer torque strength is larger than the Gilbert damping constant. This work was supported by Hong Kong GRF Grants (Nos. 163011151 and 605413) and the Grant from NNSF of China (No. 11374249).

Expression of Notch pathway genes in mammalian epidermis and modulation by beta-catenin.

PubMed

Ambler, Carrie A; Watt, Fiona M

2007-06-01

The Notch pathway is required for hair follicle maintenance and is activated through beta-catenin induced transcription of the Notch ligand Jagged1. We show that hair follicles in the resting phase express low levels of Jagged1 and Hes1, and other Notch target genes are undetectable. In growing (anagen) follicles, Jagged1 and Hes1 expression increases, Hes5 and HeyL are expressed in distinct cell layers, and Hey2 is expressed in the dermal papilla. When beta-catenin is activated by means of an inducible transgene, Jagged1, Hes1, Hes5, HeyL, and Hey2 are up-regulated, the sites of expression being the same in beta-catenin induced ectopic follicles as in anagen follicles. beta-Catenin also induces Hey1 in dermal papilla cells. beta-Catenin-induced up-regulation of Jagged1 precedes induction of other Notch target genes. The different sites of expression of Hes and Hey genes suggest input from additional signaling pathways. Copyright 2007 Wiley-Liss, Inc.

Inflammation increases NOTCH1 activity via MMP9 and is counteracted by Eicosapentaenoic Acid-free fatty acid in colon cancer cells

PubMed Central

Fazio, Chiara; Piazzi, Giulia; Vitaglione, Paola; Fogliano, Vincenzo; Munarini, Alessandra; Prossomariti, Anna; Milazzo, Maddalena; D’Angelo, Leonarda; Napolitano, Manuela; Chieco, Pasquale; Belluzzi, Andrea; Bazzoli, Franco; Ricciardiello, Luigi

2016-01-01

Aberrant NOTCH1 signalling is critically involved in multiple models of colorectal cancer (CRC) and a prominent role of NOTCH1 activity during inflammation has emerged. Epithelial to Mesenchymal Transition (EMT), a crucial event promoting malignant transformation, is regulated by inflammation and Metalloproteinase-9 (MMP9) plays an important role in this process. Eicosapentaenoic Acid (EPA), an omega-3 polyunsaturated fatty acid, was shown to prevent colonic tumors in different settings. We recently found that an extra-pure formulation of EPA as Free Fatty Acid (EPA-FFA) protects from colon cancer development in a mouse model of Colitis-Associated Cancer (CAC) through modulation of NOTCH1 signalling. In this study, we exposed colon cancer cells to an inflammatory stimulus represented by a cytokine-enriched Conditioned Medium (CM), obtained from THP1-differentiated macrophages. We found, for the first time, that CM strongly up-regulated NOTCH1 signalling and EMT markers, leading to increased invasiveness. Importantly, NOTCH1 signalling was dependent on MMP9 activity, upon CM exposure. We show that a non-cytotoxic pre-treatment with EPA-FFA antagonizes the effect of inflammation on NOTCH1 signalling, with reduction of MMP9 activity and invasiveness. In conclusion, our data suggest that, in CRC cells, inflammation induces NOTCH1 activity through MMP9 up-regulation and that this mechanism can be counteracted by EPA-FFA. PMID:26864323

Inflammation increases NOTCH1 activity via MMP9 and is counteracted by Eicosapentaenoic Acid-free fatty acid in colon cancer cells.

PubMed

Fazio, Chiara; Piazzi, Giulia; Vitaglione, Paola; Fogliano, Vincenzo; Munarini, Alessandra; Prossomariti, Anna; Milazzo, Maddalena; D'Angelo, Leonarda; Napolitano, Manuela; Chieco, Pasquale; Belluzzi, Andrea; Bazzoli, Franco; Ricciardiello, Luigi

2016-02-11

Aberrant NOTCH1 signalling is critically involved in multiple models of colorectal cancer (CRC) and a prominent role of NOTCH1 activity during inflammation has emerged. Epithelial to Mesenchymal Transition (EMT), a crucial event promoting malignant transformation, is regulated by inflammation and Metalloproteinase-9 (MMP9) plays an important role in this process. Eicosapentaenoic Acid (EPA), an omega-3 polyunsaturated fatty acid, was shown to prevent colonic tumors in different settings. We recently found that an extra-pure formulation of EPA as Free Fatty Acid (EPA-FFA) protects from colon cancer development in a mouse model of Colitis-Associated Cancer (CAC) through modulation of NOTCH1 signalling. In this study, we exposed colon cancer cells to an inflammatory stimulus represented by a cytokine-enriched Conditioned Medium (CM), obtained from THP1-differentiated macrophages. We found, for the first time, that CM strongly up-regulated NOTCH1 signalling and EMT markers, leading to increased invasiveness. Importantly, NOTCH1 signalling was dependent on MMP9 activity, upon CM exposure. We show that a non-cytotoxic pre-treatment with EPA-FFA antagonizes the effect of inflammation on NOTCH1 signalling, with reduction of MMP9 activity and invasiveness. In conclusion, our data suggest that, in CRC cells, inflammation induces NOTCH1 activity through MMP9 up-regulation and that this mechanism can be counteracted by EPA-FFA.

A Novel Assay for the Identification of NOTCH1 PEST Domain Mutations in Chronic Lymphocytic Leukemia

PubMed Central

Petroni, Roberta Cardoso; Muto, Nair Hideko; Sitnik, Roberta; de Carvalho, Flavia Pereira; Bacal, Nydia Strachman; Velloso, Elvira Deolinda Rodrigues Pereira; Oliveira, Gislaine Borba; Pinho, João Renato Rebello; Torres, Davi Coe; Mansur, Marcela Braga; Hassan, Rocio; Lorand-Metze, Irene Gyongyvér Heidemarie; Chiattone, Carlos Sérgio; Hamerschlak, Nelson; Mangueira, Cristovão Luis Pitangueira

2016-01-01

Aims. To develop a fast and robust DNA-based assay to detect insertions and deletions mutations in exon 34 that encodes the PEST domain of NOTCH1 in order to evaluate patients with chronic lymphocytic leukemia (CLL). Methods. We designed a multiplexed allele-specific polymerase chain reaction (PCR) combined with a fragment analysis assay to detect specifically the mutation c.7544_7545delCT and possibly other insertions and deletions in exon 34 of NOTCH1. Results. We evaluated our assay in peripheral blood samples from two cohorts of patients with CLL. The frequency of NOTCH1 mutations was 8.4% in the first cohort of 71 unselected CLL patients. We then evaluated a second cohort of 26 CLL patients with known cytogenetic abnormalities that were enriched for patients with trisomy 12. NOTCH1 mutations were detected in 43.7% of the patients with trisomy 12. Conclusions. We have developed a fast and robust assay combining allele-specific PCR and fragment analysis able to detect NOTCH1 PEST domain insertions and deletions. PMID:28074183

Three genes in the human MHC class III region near the junction with the class II: Gene for receptor of advanced glycosylation end products, PBX2 homeobox gene and a notch homolog, human counterpart of mouse mammary tumor gene int-3

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sugaya, K.; Fukagawa, T.; Matsumoto, K.

Cosmid walking of about 250 kb from MHC class III gene CYP21 to class II was conducted. The gene for receptor of advanced glycosylation end products of proteins (RAGE, a member of immunoglobulin super-family molecules), the PBX2 homeobox gene designated HOX12, and the human counterpart of the mouse mammary tumor gene int-3 were found. The contiguous RAGE and HOX12 genes were completely sequenced, and the human int-3 counterpart was partially sequenced and assigned to a Notch homolog. This human Notch homolog, designated NOTCH3, showed both the intracellular portion present in the mouse int-3 sequence and the extracellular portion absent inmore » the int-3. It thus corresponds to the intact form of a Notch-type transmembrane protein. About 20 kb of dense Alu clustering was found just centromeric to the NOTCH3. 48 refs., 9 figs., 2 tabs.« less

An AGEF-1/Arf GTPase/AP-1 Ensemble Antagonizes LET-23 EGFR Basolateral Localization and Signaling during C. elegans Vulva Induction

PubMed Central

Skorobogata, Olga; Escobar-Restrepo, Juan M.; Rocheleau, Christian E.

2014-01-01

LET-23 Epidermal Growth Factor Receptor (EGFR) signaling specifies the vulval cell fates during C. elegans larval development. LET-23 EGFR localization on the basolateral membrane of the vulval precursor cells (VPCs) is required to engage the LIN-3 EGF-like inductive signal. The LIN-2 Cask/LIN-7 Veli/LIN-10 Mint (LIN-2/7/10) complex binds LET-23 EGFR, is required for its basolateral membrane localization, and therefore, vulva induction. Besides the LIN-2/7/10 complex, the trafficking pathways that regulate LET-23 EGFR localization have not been defined. Here we identify vh4, a hypomorphic allele of agef-1, as a strong suppressor of the lin-2 mutant Vulvaless (Vul) phenotype. AGEF-1 is homologous to the mammalian BIG1 and BIG2 Arf GTPase guanine nucleotide exchange factors (GEFs), which regulate secretory traffic between the Trans-Golgi network, endosomes and the plasma membrane via activation of Arf GTPases and recruitment of the AP-1 clathrin adaptor complex. Consistent with a role in trafficking we show that AGEF-1 is required for protein secretion and that AGEF-1 and the AP-1 complex regulate endosome size in coelomocytes. The AP-1 complex has previously been implicated in negative regulation of LET-23 EGFR, however the mechanism was not known. Our genetic data indicate that AGEF-1 is a strong negative regulator of LET-23 EGFR signaling that functions in the VPCs at the level of the receptor. In line with AGEF-1 being an Arf GEF, we identify the ARF-1.2 and ARF-3 GTPases as also negatively regulating signaling. We find that the agef-1(vh4) mutation results in increased LET-23 EGFR on the basolateral membrane in both wild-type and lin-2 mutant animals. Furthermore, unc-101(RNAi), a component of the AP-1 complex, increased LET-23 EGFR on the basolateral membrane in lin-2 and agef-1(vh4); lin-2 mutant animals. Thus, an AGEF-1/Arf GTPase/AP-1 ensemble functions opposite the LIN-2/7/10 complex to antagonize LET-23 EGFR basolateral membrane localization and signaling. PMID:25329472

An AGEF-1/Arf GTPase/AP-1 ensemble antagonizes LET-23 EGFR basolateral localization and signaling during C. elegans vulva induction.

PubMed

Skorobogata, Olga; Escobar-Restrepo, Juan M; Rocheleau, Christian E

2014-10-01

LET-23 Epidermal Growth Factor Receptor (EGFR) signaling specifies the vulval cell fates during C. elegans larval development. LET-23 EGFR localization on the basolateral membrane of the vulval precursor cells (VPCs) is required to engage the LIN-3 EGF-like inductive signal. The LIN-2 Cask/LIN-7 Veli/LIN-10 Mint (LIN-2/7/10) complex binds LET-23 EGFR, is required for its basolateral membrane localization, and therefore, vulva induction. Besides the LIN-2/7/10 complex, the trafficking pathways that regulate LET-23 EGFR localization have not been defined. Here we identify vh4, a hypomorphic allele of agef-1, as a strong suppressor of the lin-2 mutant Vulvaless (Vul) phenotype. AGEF-1 is homologous to the mammalian BIG1 and BIG2 Arf GTPase guanine nucleotide exchange factors (GEFs), which regulate secretory traffic between the Trans-Golgi network, endosomes and the plasma membrane via activation of Arf GTPases and recruitment of the AP-1 clathrin adaptor complex. Consistent with a role in trafficking we show that AGEF-1 is required for protein secretion and that AGEF-1 and the AP-1 complex regulate endosome size in coelomocytes. The AP-1 complex has previously been implicated in negative regulation of LET-23 EGFR, however the mechanism was not known. Our genetic data indicate that AGEF-1 is a strong negative regulator of LET-23 EGFR signaling that functions in the VPCs at the level of the receptor. In line with AGEF-1 being an Arf GEF, we identify the ARF-1.2 and ARF-3 GTPases as also negatively regulating signaling. We find that the agef-1(vh4) mutation results in increased LET-23 EGFR on the basolateral membrane in both wild-type and lin-2 mutant animals. Furthermore, unc-101(RNAi), a component of the AP-1 complex, increased LET-23 EGFR on the basolateral membrane in lin-2 and agef-1(vh4); lin-2 mutant animals. Thus, an AGEF-1/Arf GTPase/AP-1 ensemble functions opposite the LIN-2/7/10 complex to antagonize LET-23 EGFR basolateral membrane localization and signaling.

Methylation of Notch3 modulates chemoresistance via P-glycoprotein.

PubMed

Gu, Xiaoting; Lu, Yangfan; He, Dongxu; Lu, Chunxiao; Jin, Jian; Lu, Xiaojie; Ma, Xin

2016-12-05

The global gene expression and DNA methylation of genes in adriamycin-resistant human breast cancer cells (MCF-7/ADM cells) are similar to those in paclitaxel-resistant MCF-7 cells (MCF-7/PTX) and are significantly different from those in wild-type MCF-7 cells. DNA methylation is associated with chemoresistance in breast cancer and changes the characteristics of chemoresistant and chemosensitive cells. Here, we showed that the tumor-suppressor gene Notch3 was inactivated due to epigenetic silencing DNA hypermethylation in MCF-7/ADM cells. In addition, the drug efflux pump P-glycoprotein was negatively regulated by Notch3 and highly expressed in MCF-7/ADM cells. Taken together, our findings demonstrated that hypermethylation of Notch3 causes activation of P-glycoprotein in adriamycin-resistant cells. Copyright © 2016 Elsevier B.V. All rights reserved.

Strength and Microstructure of Ceramics.

DTIC Science & Technology

1987-11-01

triangular slab. 12-mm edge length and 2-mm thickness. to produce crack 7 mm long. Starter notch length portantly. the strength plateau at small flaw sizes...however. a tapered the starter notch tip. "Pop-in" behavior of this kind is not uncom- geometry was used. width increasing in the direction of ultimate...mon in notched specimens, of course: in such cases the initial crack propagation. The main crack was started at a sawcut notch fracture response can be

Systemic Nicotine Increases Gain and Narrows Receptive Fields in A1 via Integrated Cortical and Subcortical Actions.

PubMed

Askew, Caitlin; Intskirveli, Irakli; Metherate, Raju

2017-01-01

Nicotine enhances sensory and cognitive processing via actions at nicotinic acetylcholine receptors (nAChRs), yet the precise circuit- and systems-level mechanisms remain unclear. In sensory cortex, nicotinic modulation of receptive fields (RFs) provides a model to probe mechanisms by which nAChRs regulate cortical circuits. Here, we examine RF modulation in mouse primary auditory cortex (A1) using a novel electrophysiological approach: current-source density (CSD) analysis of responses to tone-in-notched-noise (TINN) acoustic stimuli. TINN stimuli consist of a tone at the characteristic frequency (CF) of the recording site embedded within a white noise stimulus filtered to create a spectral "notch" of variable width centered on CF. Systemic nicotine (2.1 mg/kg) enhanced responses to the CF tone and to narrow-notch stimuli, yet reduced the response to wider-notch stimuli, indicating increased response gain within a narrowed RF. Subsequent manipulations showed that modulation of cortical RFs by systemic nicotine reflected effects at several levels in the auditory pathway: nicotine suppressed responses in the auditory midbrain and thalamus, with suppression increasing with spectral distance from CF so that RFs became narrower, and facilitated responses in the thalamocortical pathway, while nicotinic actions within A1 further contributed to both suppression and facilitation. Thus, multiple effects of systemic nicotine integrate along the ascending auditory pathway. These actions at nAChRs in cortical and subcortical circuits, which mimic effects of auditory attention, likely contribute to nicotinic enhancement of sensory and cognitive processing.

Primary cilia maintain corneal epithelial homeostasis by regulation of the Notch signaling pathway

PubMed Central

Grisanti, Laura; Revenkova, Ekaterina; Gordon, Ronald E.

2016-01-01

Primary cilia have been linked to signaling pathways involved in cell proliferation, cell motility and cell polarity. Defects in ciliary function result in developmental abnormalities and multiple ciliopathies. Patients affected by severe ciliopathies, such as Meckel syndrome, present several ocular surface disease conditions of unclear pathogenesis. Here, we show that primary cilia are predominantly present on basal cells of the mouse corneal epithelium (CE) throughout development and in the adult. Conditional ablation of cilia in the CE leads to an increase in proliferation and vertical migration of basal corneal epithelial cells (CECs). A consequent increase in cell density of suprabasal layers results in a thicker than normal CE. Surprisingly, in cilia-deficient CE, cilia-mediated signaling pathways, including Hh and Wnt pathways, were not affected but the intensity of Notch signaling was severely diminished. Although Notch1 and Notch2 receptors were expressed normally, nuclear Notch1 intracellular domain (N1ICD) expression was severely reduced. Postnatal development analysis revealed that in cilia-deficient CECs downregulation of the Notch pathway precedes cell proliferation defects. Thus, we have uncovered a function of the primary cilium in maintaining homeostasis of the CE by balancing proliferation and vertical migration of basal CECs through modulation of Notch signaling. PMID:27122169

Notch-Jagged complex structure implicates a catch bond in tuning ligand sensitivity

DOE PAGES

Luca, Vincent C.; Kim, Byoung Choul; Ge, Chenghao; ...

2017-03-02

Notch receptor activation initiates cell fate decisions and is distinctive in its reliance on mechanical force and protein glycosylation. The 2.5-angstrom-resolution crystal structure of the extracellular interacting region of Notch1 complexed with an engineered, high-affinity variant of Jagged1 (Jag1) reveals a binding interface that extends ~120 angstroms along five consecutive domains of each protein. O-Linked fucose modifications on Notch1 epidermal growth factor–like (EGF) domains 8 and 12 engage the EGF3 and C2 domains of Jag1, respectively, and different Notch1 domains are favored in binding to Jag1 than those that bind to the Delta-like 4 ligand. Jag1 undergoes conformational changes uponmore » Notch binding, exhibiting catch bond behavior that prolongs interactions in the range of forces required for Notch activation. In conclusion, this mechanism enables cellular forces to regulate binding, discriminate among Notch ligands, and potentiate Notch signaling.« less

Notch-Jagged complex structure implicates a catch bond in tuning ligand sensitivity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Luca, Vincent C.; Kim, Byoung Choul; Ge, Chenghao

Notch receptor activation initiates cell fate decisions and is distinctive in its reliance on mechanical force and protein glycosylation. The 2.5-angstrom-resolution crystal structure of the extracellular interacting region of Notch1 complexed with an engineered, high-affinity variant of Jagged1 (Jag1) reveals a binding interface that extends ~120 angstroms along five consecutive domains of each protein. O-Linked fucose modifications on Notch1 epidermal growth factor–like (EGF) domains 8 and 12 engage the EGF3 and C2 domains of Jag1, respectively, and different Notch1 domains are favored in binding to Jag1 than those that bind to the Delta-like 4 ligand. Jag1 undergoes conformational changes uponmore » Notch binding, exhibiting catch bond behavior that prolongs interactions in the range of forces required for Notch activation. In conclusion, this mechanism enables cellular forces to regulate binding, discriminate among Notch ligands, and potentiate Notch signaling.« less

Characterization of activating mutations of NOTCH3 in T-cell acute lymphoblastic leukemia and anti-leukemic activity of NOTCH3 inhibitory antibodies.

PubMed

Bernasconi-Elias, P; Hu, T; Jenkins, D; Firestone, B; Gans, S; Kurth, E; Capodieci, P; Deplazes-Lauber, J; Petropoulos, K; Thiel, P; Ponsel, D; Hee Choi, S; LeMotte, P; London, A; Goetcshkes, M; Nolin, E; Jones, M D; Slocum, K; Kluk, M J; Weinstock, D M; Christodoulou, A; Weinberg, O; Jaehrling, J; Ettenberg, S A; Buckler, A; Blacklow, S C; Aster, J C; Fryer, C J

2016-11-24

Notch receptors have been implicated as oncogenic drivers in several cancers, the most notable example being NOTCH1 in T-cell acute lymphoblastic leukemia (T-ALL). To characterize the role of activated NOTCH3 in cancer, we generated an antibody that detects the neo-epitope created upon gamma-secretase cleavage of NOTCH3 to release its intracellular domain (ICD3), and sequenced the negative regulatory region (NRR) and PEST (proline, glutamate, serine, threonine) domain coding regions of NOTCH3 in a panel of cell lines. We also characterize NOTCH3 tumor-associated mutations that result in activation of signaling and report new inhibitory antibodies. We determined the structural basis for receptor inhibition by obtaining the first co-crystal structure of a NOTCH3 antibody with the NRR protein and defined two distinct epitopes for NRR antibodies. The antibodies exhibit potent anti-leukemic activity in cell lines and tumor xenografts harboring NOTCH3 activating mutations. Screening of primary T-ALL samples reveals that 2 of 40 tumors examined show active NOTCH3 signaling. We also identified evidence of NOTCH3 activation in 12 of 24 patient-derived orthotopic xenograft models, 2 of which exhibit activation of NOTCH3 without activation of NOTCH1. Our studies provide additional insights into NOTCH3 activation and offer a path forward for identification of cancers that are likely to respond to therapy with NOTCH3 selective inhibitory antibodies.

Characterization of activating mutations of NOTCH3 in T cell acute lymphoblastic leukemia and anti-leukemic activity of NOTCH3 inhibitory antibodies

PubMed Central

Bernasconi-Elias, Paula; Hu, Tiancen; Jenkins, David; Firestone, Brant; Gans, Sara; Kurth, Esther; Capodieci, Paola; Deplazes-Lauber, Joelle; Petropoulos, Konstantin; Thiel, Phillip; Ponsel, Dirk; Choi, Sung Hee; LeMotte, Peter; London, Anne; Goetcshkes, Margaret; Nolin, Erin; Jones, Michael D.; Slocum, Kelly; Kluk, Michael J.; Weinstock, David M.; Christodoulou, Alexandra; Weinberg, Olga; Jaehrling, Jan; Ettenberg, Seth A.; Buckler, Alan; Blacklow, Stephen C.; Aster, Jon C.; Fryer, Christy J.

2016-01-01

Notch receptors have been implicated as oncogenic drivers in several cancers, the most notable example being NOTCH1 in T-cell acute lymphoblastic leukemia (T-ALL). To characterize the role of activated NOTCH3 in cancer, we generated an antibody that detects the neo-epitope created upon gamma-secretase cleavage of NOTCH3 to release its intracellular domain (ICD3), and sequenced the negative regulatory region (NRR) and PEST domain coding regions of NOTCH3 in a panel of cell lines. We also characterize NOTCH3 tumor-associated mutations that result in activation of signaling and report new inhibitory antibodies. We determined the structural basis for receptor inhibition by obtaining the first co-crystal structure of a NOTCH3 antibody with the NRR protein and defined two distinct epitopes for NRR antibodies. The antibodies exhibit potent anti-leukemic activity in cell lines and tumor xenografts harboring NOTCH3 activating mutations. Screening of primary T-ALL samples reveals that two of 40 tumors examined show active NOTCH3 signaling. We also identified evidence of NOTCH3 activation in 12 of 24 patient-derived orthotopic xenograft models, two of which exhibit activation of NOTCH3 without activation of NOTCH1. Our studies provide additional insights into NOTCH3 activation and offer a path forward for identification of cancers that are likely to respond to therapy with NOTCH3 selective inhibitory antibodies. PMID:27157619

Identification and characterization of a transient outward K+ current in human induced pluripotent stem cell-derived cardiomyocytes

PubMed Central

Cordeiro, Jonathan M.; Nesterenko, Vladislav V.; Sicouri, Serge; Goodrow, Robert J.; Treat, Jacqueline A.; Desai, Mayurika; Wu, Yuesheng; Doss, Michael Xavier; Antzelevitch, Charles; Di Diego, José M.

2013-01-01

Background The ability to recapitulate mature adult phenotypes is critical to the development of human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CM) as models of disease. The present study examines the characteristics of the transient outward current (Ito) and its contribution to the hiPSC-CM action potential (AP). Method Embryoid bodies were made from a hiPS cell line reprogrammed with Oct4, Nanog, Lin28 and Sox2. Sharp microelectrodes were used to record APs from beating-clusters (BC) and patch-clamp techniques were used to record Ito in single hiPSC-CM. mRNA levels of Kv1.4, KChIP2 and Kv4.3 were quantified from BCs. Results BCs exhibited spontaneous beating (60.5 ± 2.6 bpm) and maximum-diastolic-potential (MDP) of 67.8 ± 0.8 mV (n = 155). A small 4-aminopyridine-sensitive phase-1-repolarization was observed in only 6/155 BCs. A robust Ito was recorded in the majority of cells (13.7 ± 1.9 pA/pF at +40 mV; n = 14). Recovery of Ito from inactivation (at −80 mV) showed slow kinetics (τ1 = 200 ± 110 ms (12%) and τ2 = 2380 ± 240 ms (80%)) accounting for its minimal contribution to the AP. Transcript data revealed relatively high expression of Kv1.4 and low expression of KChIP2 compared to human native ventricular tissues. Mathematical modeling predicted that restoration of IK1 to normal levels would result in a more negative MDP and a prominent phase-1-repolarization. Conclusion The slow recovery kinetics of Ito coupled with a depolarized MDP account for the lack of an AP notch in the majority of hiPSC-CM. These characteristics reveal a deficiency for the development of in vitro models of inherited cardiac arrhythmia syndromes in which Ito-induced AP notch is central to the disease phenotype. PMID:23542310

Are false-positive rates leading to an overestimation of noise-induced hearing loss?

PubMed

Schlauch, Robert S; Carney, Edward

2011-04-01

To estimate false-positive rates for rules proposed to identify early noise-induced hearing loss (NIHL) using the presence of notches in audiograms. Audiograms collected from school-age children in a national survey of health and nutrition (the Third National Health and Nutrition Examination Survey [NHANES III]; National Center for Health Statistics, 1994) were examined using published rules for identifying noise notches at various pass-fail criteria. These results were compared with computer-simulated "flat" audiograms. The proportion of these identified as having a noise notch is an estimate of the false-positive rate for a particular rule. Audiograms from the NHANES III for children 6-11 years of age yielded notched audiograms at rates consistent with simulations, suggesting that this group does not have significant NIHL. Further, pass-fail criteria for rules suggested by expert clinicians, applied to NHANES III audiometric data, yielded unacceptably high false-positive rates. Computer simulations provide an effective method for estimating false-positive rates for protocols used to identify notched audiograms. Audiometric precision could possibly be improved by (a) eliminating systematic calibration errors, including a possible problem with reference levels for TDH-style earphones; (b) repeating and averaging threshold measurements; and (c) using earphones that yield lower variability for 6.0 and 8.0 kHz--2 frequencies critical for identifying noise notches.

Common NOTCH3 Variants and Cerebral Small-Vessel Disease.

PubMed

Rutten-Jacobs, Loes C A; Traylor, Matthew; Adib-Samii, Poneh; Thijs, Vincent; Sudlow, Cathie; Rothwell, Peter M; Boncoraglio, Giorgio; Dichgans, Martin; Bevan, Steve; Meschia, James; Levi, Christopher; Rost, Natalia S; Rosand, Jonathan; Hassan, Ahamad; Markus, Hugh S

2015-06-01

The most common monogenic cause of cerebral small-vessel disease is cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy, caused by NOTCH3 gene mutations. It has been hypothesized that more common variants in NOTCH3 may also contribute to the risk of sporadic small-vessel disease. Previously, 4 common variants (rs10404382, rs1043994, rs10423702, and rs1043997) were found to be associated with the presence of white matter hyperintensity in hypertensive community-dwelling elderly. We investigated the association of common single nucleotide polymorphisms (SNPs) in NOTCH3 in 1350 patients with MRI-confirmed lacunar stroke and 7397 controls, by meta-analysis of genome-wide association study data sets. In addition, we investigated the association of common SNPs in NOTCH3 with MRI white matter hyperintensity volumes in 3670 white patients with ischemic stroke. In each analysis, we considered all SNPs within the NOTCH3 gene, and within 50-kb upstream and downstream of the coding region. A total of 381 SNPs from the 1000 genome population with a mean allele frequency>0.01 were included in the analysis. A significance level of P<0.0015 was used, adjusted for the effective number of independent SNPs in the region using the Galwey method. We found no association of any common variants in NOTCH3 (including rs10404382, rs1043994, rs10423702, and rs1043997) with lacunar stroke or white matter hyperintensity volume. We repeated our analysis stratified for hypertension but again found no association. Our study does not support a role for common NOTCH3 variation in the risk of sporadic small-vessel disease. © 2015 The Authors.

mTOR-Notch3 signaling mediates pulmonary hypertension in hypoxia-exposed neonatal rats independent of changes in autophagy.

PubMed

Ivanovska, Julijana; Shah, Sparsh; Wong, Mathew J; Kantores, Crystal; Jain, Amish; Post, Martin; Yeganeh, Behzad; Jankov, Robert P

2017-11-01

Mammalian target of rapamycin (mTOR) is a pivotal regulator of cell proliferation, survival, and autophagy. Autophagy is increased in adult experimental chronic pulmonary hypertension (PHT), but its contributory role to pulmonary vascular disease remains uncertain and has yet to be explored in the neonatal animal. Notch is a major pro-proliferative pathway activated by mTOR. A direct relationship between autophagy and Notch signaling has not been previously explored. Our aim was to examine changes in mTOR-, Notch-, and autophagy-related pathways and the therapeutic effects of autophagy modulators in experimental chronic neonatal PHT secondary to chronic hypoxia. Rat pups were exposed to normoxia or hypoxia (13% O 2 ) from postnatal days 1-21, while receiving treatment with temsirolimus (mTOR inhibitor), DAPT (Notch inhibitor), or chloroquine (inhibitor of autophagic flux). Exposure to hypoxia up-regulated autophagy and Notch3 signaling markers in lung, pulmonary artery (PA), and PA-derived smooth muscle cells (SMCs). Temsirolimus prevented chronic PHT and attenuated PA and SMC signaling secondary to hypoxia. These effects were replicated by DAPT. mTOR or Notch inhibition also down-regulated smooth muscle content of platelet-derived growth factor β-receptor, a known contributor to vascular remodeling. In contrast, chloroquine had no modifying effects on markers of chronic PHT. Knockdown of Beclin-1 in SMCs had no effect on hypoxia-stimulated Notch3 signaling. mTOR-Notch3 signaling plays a critical role in experimental chronic neonatal PHT. Inhibition of autophagy did not suppress Notch signaling and had no effect on markers of chronic PHT. © 2017 Wiley Periodicals, Inc.

Mitotic Vulnerability in Triple-Negative Breast Cancer Associated with LIN9 Is Targetable with BET Inhibitors.

PubMed

Sahni, Jennifer M; Gayle, Sylvia S; Webb, Bryan M; Weber-Bonk, Kristen L; Seachrist, Darcie D; Singh, Salendra; Sizemore, Steven T; Restrepo, Nicole A; Bebek, Gurkan; Scacheri, Peter C; Varadan, Vinay; Summers, Matthew K; Keri, Ruth A

2017-10-01

Triple-negative breast cancers (TNBC) are highly aggressive, lack FDA-approved targeted therapies, and frequently recur, making the discovery of novel therapeutic targets for this disease imperative. Our previous analysis of the molecular mechanisms of action of bromodomain and extraterminal protein inhibitors (BETi) in TNBC revealed these drugs cause multinucleation, indicating BET proteins are essential for efficient mitosis and cytokinesis. Here, using live cell imaging, we show that BET inhibition prolonged mitotic progression and induced mitotic cell death, both of which are indicative of mitotic catastrophe. Mechanistically, the mitosis regulator LIN9 was a direct target of BET proteins that mediated the effects of BET proteins on mitosis in TNBC. Although BETi have been proposed to function by dismantling super-enhancers (SE), the LIN9 gene lacks an SE but was amplified or overexpressed in the majority of TNBCs. In addition, its mRNA expression predicted poor outcome across breast cancer subtypes. Together, these results provide a mechanism for cancer selectivity of BETi that extends beyond modulation of SE-associated genes and suggest that cancers dependent upon LIN9 overexpression may be particularly vulnerable to BETi. Cancer Res; 77(19); 5395-408. ©2017 AACR . ©2017 American Association for Cancer Research.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Frampton, Gabriel; Coufal, Monique; Li, Huang

The endocannabinoids anandamide (AEA) and 2-arachidonylglycerol (2-AG) have opposing effects on cholangiocarcinoma growth. Implicated in cancer, Notch signaling requires the {gamma}-secretase complex for activation. The aims of this study were to determine if the opposing effects of endocannabinoids depend on the differential activation of the Notch receptors and to demonstrate that the differential activation of these receptors are due to presenilin 1 containing- and presenilin 2 containing-{gamma}-secretase complexes. Mz-ChA-1 cells were treated with AEA or 2-AG. Notch receptor expression, activation, and nuclear translocation were determined. Specific roles for Notch 1 and 2 on cannabinoid-induced effects were determined by transient transfectionmore » of Notch 1 or 2 shRNA vectors before stimulation with AEA or 2-AG. Expression of presenilin 1 and 2 was determined after AEA or 2-AG treatment, and the involvement of presenilin 1 and 2 in the cannabinoid-induced effects was demonstrated in cell lines with low presenilin 1 or 2 expression. Antiproliferative effects of AEA required increased Notch 1 mRNA, activation, and nuclear translocation, whereas the growth-promoting effects induced by 2-AG required increased Notch 2 mRNA expression, activation, and nuclear translocation. AEA increased presenilin 1 expression and recruitment into the {gamma}-secretase complex, whereas 2-AG increased expression and recruitment of presenilin 2. The development of novel therapeutic strategies aimed at modulating the endocannabinoid system or mimicking the mode of action of AEA on Notch signaling pathways would prove beneficial for cholangiocarcinoma management.« less

Pathogenic Mutations Associated with Cerebral Autosomal Dominant Arteriopathy with Subcortical Infarcts and Leukoencephalopathy Differently Affect Jagged1 Binding and Notch3 Activity via the RBP/JK Signaling Pathway

PubMed Central

Joutel, Anne; Monet, Marie; Domenga, Valérie; Riant, Florence; Tournier-Lasserve, Elisabeth

2004-01-01

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is an inherited vascular dementia characterized by the degeneration of smooth-muscle cells in small cerebral arteries. CADASIL is caused by mutations in NOTCH3, one of the four mammalian homologs to the Drosophila melanogaster NOTCH gene. Disease-associated mutations are distributed throughout the 34 epidermal growth factor–like repeats (EGFRs) that compose the extracellular domain of the Notch3 receptor and result in a loss or a gain of a cysteine residue in one of these EGFRs. In human adults, Notch3 expression is highly restricted to vascular smooth-muscle cells. In patients with CADASIL, there is an abnormal accumulation of Notch3 in the vessel. Molecular pathways linking NOTCH3 mutations to degeneration of vascular smooth-muscle cells are as yet poorly understood. In this study, we investigated the effect of CADASIL mutations on Notch3 activity. We studied five naturally occurring mutations: R90C and C212S, located in the previously identified mutational hotspot EGFR2–5; C428S, shown in this study to be located in the ligand-binding domain EGFR10–11; and C542Y and R1006C, located in EGFR13 and EGFR26, respectively. All five mutant proteins were correctly processed. The C428S and C542Y mutant receptors exhibited a significant reduction in Jagged1-induced transcriptional activity of a RBP/JK responsive luciferase reporter, relative to wild-type Notch3. Impaired signaling activity of these two mutants arose through different mechanisms; the C428S mutant lost its Jagged1-binding ability, whereas C542Y retained it but exhibited an impaired presentation to the cell surface. In contrast, the R90C, C212S, and R1006C mutants retained the ability to bind Jagged1 and were associated with apparently normal levels of signaling activity. We conclude that mutations in Notch3 differently affect Jagged1 binding and Notch3 signaling via the RBP/JK pathway. PMID:14714274

Application of LC and LCoS in Multispectral Polarized Scene Projector (MPSP)

NASA Astrophysics Data System (ADS)

Yu, Haiping; Guo, Lei; Wang, Shenggang; Lippert, Jack; Li, Le

2017-02-01

A Multispectral Polarized Scene Projector (MPSP) had been developed in the short-wave infrared (SWIR) regime for the test & evaluation (T&E) of spectro-polarimetric imaging sensors. This MPSP generates multispectral and hyperspectral video images (up to 200 Hz) with 512×512 spatial resolution with active spatial, spectral, and polarization modulation with controlled bandwidth. It projects input SWIR radiant intensity scenes from stored memory with user selectable wavelength and bandwidth, as well as polarization states (six different states) controllable on a pixel level. The spectral contents are implemented by a tunable filter with variable bandpass built based on liquid crystal (LC) material, together with one passive visible and one passive SWIR cholesteric liquid crystal (CLC) notch filters, and one switchable CLC notch filter. The core of the MPSP hardware is the liquid-crystal-on-silicon (LCoS) spatial light modulators (SLMs) for intensity control and polarization modulation.

(−)-Epigallocatechin Gallate Targets Notch to Attenuate the Inflammatory Response in the Immediate Early Stage in Human Macrophages

PubMed Central

Wang, Tengfei; Xiang, Zemin; Wang, Ya; Li, Xi; Fang, Chongye; Song, Shuang; Li, Chunlei; Yu, Haishuang; Wang, Han; Yan, Liang; Hao, Shumei; Wang, Xuanjun; Sheng, Jun

2017-01-01

Inflammation plays important roles at different stages of diabetes mellitus, tumorigenesis, and cardiovascular diseases. (−)-Epigallocatechin gallate (EGCG) can attenuate inflammatory responses effectively. However, the immediate early mechanism of EGCG in inflammation remains unclear. Here, we showed that EGCG attenuated the inflammatory response in the immediate early stage of EGCG treatment by shutting off Notch signaling and that the effect did not involve the 67-kDa laminin receptor, the common receptor for EGCG. EGCG eliminated mature Notch from the cell membrane and the nuclear Notch intercellular domain, the active form of Notch, within 2 min by rapid degradation via the proteasome pathway. Transcription of the Notch target gene was downregulated simultaneously. Knockdown of Notch 1/2 expression by RNA interference impaired the downregulation of the inflammatory response elicited by EGCG. Further study showed that EGCG inhibited lipopolysaccharide-induced inflammation and turned off Notch signaling in human primary macrophages. Taken together, our results show that EGCG targets Notch to regulate the inflammatory response in the immediate early stage. PMID:28443100

Identification and characterization of tandem repeats in exon III of dopamine receptor D4 (DRD4) genes from different mammalian species.

PubMed

Larsen, Svend Arild; Mogensen, Line; Dietz, Rune; Baagøe, Hans Jørgen; Andersen, Mogens; Werge, Thomas; Rasmussen, Henrik Berg

2005-12-01

In this study we have identified and characterized dopamine receptor D4 (DRD4) exon III tandem repeats in 33 public available nucleotide sequences from different mammalian species. We found that the tandem repeat in canids could be described in a novel and simple way, namely, as a structure composed of 15- and 12- bp modules. Tandem repeats composed of 18-bp modules were found in sequences from the horse, zebra, onager, and donkey, Asiatic bear, polar bear, common raccoon, dolphin, harbor porpoise, and domestic cat. Several of these sequences have been analyzed previously without a tandem repeat being found. In the domestic cow and gray seal we identified tandem repeats composed of 36-bp modules, each consisting of two closely related 18-bp basic units. A tandem repeat consisting of 9-bp modules was identified in sequences from mink and ferret. In the European otter we detected an 18-bp tandem repeat, while a tandem repeat consisting of 27-bp modules was identified in a sequence from European badger. Both these tandem repeats were composed of 9-bp basic units, which were closely related with the 9-bp repeat modules identified in the mink and ferret. Tandem repeats could not be identified in sequences from rodents. All tandem repeats possessed a high GC content with a strong bias for C. On phylogenetic analysis of the tandem repeats evolutionary related species were clustered into the same groups. The degree of conservation of the tandem repeats varied significantly between species. The deduced amino acid sequences of most of the tandem repeats exhibited a high propensity for disorder. This was also the case with an amino acid sequence of the human DRD4 exon III tandem repeat, which was included in the study for comparative purposes. We identified proline-containing motifs for SH3 and WW domain binding proteins, potential phosphorylation sites, PDZ domain binding motifs, and FHA domain binding motifs in the amino acid sequences of the tandem repeats. The numbers of potential functional sites varied pronouncedly between species. Our observations provide a platform for future studies of the architecture and evolution of the DRD4 exon III tandem repeat, and they suggest that differences in the structure of this tandem repeat contribute to specialization and generation of diversity in receptor function.

Proinflammatory Cytokine Tumor Necrosis Factor (TNF)-like Weak Inducer of Apoptosis (TWEAK) Suppresses Satellite Cell Self-renewal through Inversely Modulating Notch and NF-κB Signaling Pathways*

PubMed Central

Ogura, Yuji; Mishra, Vivek; Hindi, Sajedah M.; Kuang, Shihuan; Kumar, Ashok

2013-01-01

Satellite cell self-renewal is an essential process to maintaining the robustness of skeletal muscle regenerative capacity. However, extrinsic factors that regulate self-renewal of satellite cells are not well understood. Here, we demonstrate that TWEAK cytokine reduces the proportion of Pax7+/MyoD− cells (an index of self-renewal) on myofiber explants and represses multiple components of Notch signaling in satellite cell cultures. The number of Pax7+ cells is significantly increased in skeletal muscle of TWEAK knock-out (KO) mice compared with wild-type in response to injury. Furthermore, Notch signaling is significantly elevated in cultured satellite cells and in regenerating myofibers of TWEAK-KO mice. Forced activation of Notch signaling through overexpression of the Notch1 intracellular domain (N1ICD) rescued the TWEAK-mediated inhibition of satellite cell self-renewal. TWEAK also activates the NF-κB transcription factor in satellite cells and inhibition of NF-κB significantly improved the number of Pax7+ cells in TWEAK-treated cultures. Furthermore, our results demonstrate that a reciprocal interaction between NF-κB and Notch signaling governs the inhibitory effect of TWEAK on satellite cell self-renewal. Collectively, our study demonstrates that TWEAK suppresses satellite cell self-renewal through activating NF-κB and repressing Notch signaling. PMID:24151074

Proinflammatory cytokine tumor necrosis factor (TNF)-like weak inducer of apoptosis (TWEAK) suppresses satellite cell self-renewal through inversely modulating Notch and NF-κB signaling pathways.

PubMed

Ogura, Yuji; Mishra, Vivek; Hindi, Sajedah M; Kuang, Shihuan; Kumar, Ashok

2013-12-06

Satellite cell self-renewal is an essential process to maintaining the robustness of skeletal muscle regenerative capacity. However, extrinsic factors that regulate self-renewal of satellite cells are not well understood. Here, we demonstrate that TWEAK cytokine reduces the proportion of Pax7(+)/MyoD(-) cells (an index of self-renewal) on myofiber explants and represses multiple components of Notch signaling in satellite cell cultures. The number of Pax7(+) cells is significantly increased in skeletal muscle of TWEAK knock-out (KO) mice compared with wild-type in response to injury. Furthermore, Notch signaling is significantly elevated in cultured satellite cells and in regenerating myofibers of TWEAK-KO mice. Forced activation of Notch signaling through overexpression of the Notch1 intracellular domain (N1ICD) rescued the TWEAK-mediated inhibition of satellite cell self-renewal. TWEAK also activates the NF-κB transcription factor in satellite cells and inhibition of NF-κB significantly improved the number of Pax7(+) cells in TWEAK-treated cultures. Furthermore, our results demonstrate that a reciprocal interaction between NF-κB and Notch signaling governs the inhibitory effect of TWEAK on satellite cell self-renewal. Collectively, our study demonstrates that TWEAK suppresses satellite cell self-renewal through activating NF-κB and repressing Notch signaling.

Mind bomb-1 is an essential modulator of long-term memory and synaptic plasticity via the Notch signaling pathway

PubMed Central

2012-01-01

Background Notch signaling is well recognized as a key regulator of the neuronal fate during embryonic development, but its function in the adult brain is still largely unknown. Mind bomb-1 (Mib1) is an essential positive regulator in the Notch pathway, acting non-autonomously in the signal-sending cells. Therefore, genetic ablation of Mib1 in mature neuron would give valuable insight to understand the cell-to-cell interaction between neurons via Notch signaling for their proper function. Results Here we show that the inactivation of Mib1 in mature neurons in forebrain results in impaired hippocampal dependent spatial memory and contextual fear memory. Consistently, hippocampal slices from Mib1-deficient mice show impaired late-phase, but not early-phase, long-term potentiation and long-term depression without change in basal synaptic transmission at SC-CA1 synapses. Conclusions These data suggest that Mib1-mediated Notch signaling is essential for long-lasting synaptic plasticity and memory formation in the rodent hippocampus. PMID:23111145

Role of Architecture in the Function and Specificity of Two Notch-Regulated Transcriptional Enhancer Modules

PubMed Central

Liu, Feng; Posakony, James W.

2012-01-01

In Drosophila melanogaster, cis-regulatory modules that are activated by the Notch cell–cell signaling pathway all contain two types of transcription factor binding sites: those for the pathway's transducing factor Suppressor of Hairless [Su(H)] and those for one or more tissue- or cell type–specific factors called “local activators.” The use of different “Su(H) plus local activator” motif combinations, or codes, is critical to ensure that only the correct subset of the broadly utilized Notch pathway's target genes are activated in each developmental context. However, much less is known about the role of enhancer “architecture”—the number, order, spacing, and orientation of its component transcription factor binding motifs—in determining the module's specificity. Here we investigate the relationship between architecture and function for two Notch-regulated enhancers with spatially distinct activities, each of which includes five high-affinity Su(H) sites. We find that the first, which is active specifically in the socket cells of external sensory organs, is largely resistant to perturbations of its architecture. By contrast, the second enhancer, active in the “non-SOP” cells of the proneural clusters from which neural precursors arise, is sensitive to even simple rearrangements of its transcription factor binding sites, responding with both loss of normal specificity and striking ectopic activity. Thus, diverse cryptic specificities can be inherent in an enhancer's particular combination of transcription factor binding motifs. We propose that for certain types of enhancer, architecture plays an essential role in determining specificity, not only by permitting factor–factor synergies necessary to generate the desired activity, but also by preventing other activator synergies that would otherwise lead to unwanted specificities. PMID:22792075

TRPC6 specifically interacts with APP to inhibit its cleavage by γ-secretase and reduce Aβ production

PubMed Central

Wang, Junfeng; Lu, Rui; Yang, Jian; Li, Hongyu; He, Zhuohao; Jing, Naihe; Wang, Xiaomin; Wang, Yizheng

2015-01-01

Generation of β-amyloid (Aβ) peptide in Alzheimer's disease involves cleavage of amyloid precursor protein (APP) by γ-secretase, a protease known to cleave several substrates, including Notch. Finding specific modulators for γ-secretase could be a potential avenue to treat the disease. Here, we report that transient receptor potential canonical (TRPC) 6 specifically interacts with APP leading to inhibition of its cleavage by γ-secretase and reduction in Aβ production. TRPC6 interacts with APP (C99), but not with Notch, and prevents C99 interaction with presenilin 1 (PS1). A fusion peptide derived from TRPC6 also reduces Aβ levels without effect on Notch cleavage. Crossing APP/PS1 mice with TRPC6 transgenic mice leads to a marked reduction in both plaque load and Aβ levels, and improvement in structural and behavioural impairment. Thus, TRPC6 specifically modulates γ-secretase cleavage of APP and preventing APP (C99) interaction with PS1 via TRPC6 could be a novel strategy to reduce Aβ formation. PMID:26581893

Yap1 as a New Therapeutic Target in Neurofibromatosis Type 2

DTIC Science & Technology

2014-05-01

binding sites (bold and underlined) present in the NOTCH2 promoter. Red box indicates area of genomic sequence (WT Notch2 prom) that was cloned into... Drosophila homolog of YAP. Cell 122, 421–434 22 Tao, W. et al. (1999) Human homologue of the Drosophila melanogaster lats tumour suppressor modulates... the hippo pathway basics The Hippo signaling cascade was first identified in Drosophila Melanogaster as an important regulator of organ size. The high

Method and apparatus for distributed sensing of volatiles using a long period fiber grating sensor with modulated plastic coating for environmental monitoring

NASA Technical Reports Server (NTRS)

Ponce, Adrian (Inventor); Kossakovski, Dmitri A. (Inventor); Bearman, Gregory H. (Inventor)

2010-01-01

Optical time domain reflectometry caused by absorption of a volatile or analyte into the fiber optic cladding is used as an optical nose. The fiber optics (14) are covered with a gas permeable film (44) which is patterned to leave millimeter wide gas permeable notches (48a-48d). The notches contain a sensing polymer that responds to different gases by expanding or contracting.

K-RasG12D–induced T-cell lymphoblastic lymphoma/leukemias harbor Notch1 mutations and are sensitive to γ-secretase inhibitors

PubMed Central

Cornejo, Melanie G.; Scholl, Claudia; Liu, Jianing; Leeman, Dena S.; Haydu, J. Erika; Fröhling, Stefan; Lee, Benjamin H.; Gilliland, D. Gary

2008-01-01

To study the impact of oncogenic K-Ras on T-cell leukemia/lymphoma development and progression, we made use of a conditional K-RasG12D murine knockin model, in which oncogenic K-Ras is expressed from its endogenous promoter. Transplantation of whole bone marrow cells that express oncogenic K-Ras into wild-type recipient mice resulted in a highly penetrant, aggressive T-cell leukemia/lymphoma. The lymphoblasts were composed of a CD4/CD8 double-positive population that aberrantly expressed CD44. Thymi of primary donor mice showed reduced cellularity, and immunophenotypic analysis demonstrated a block in differentiation at the double-negative 1 stage. With progression of disease, approximately 50% of mice acquired Notch1 mutations within the PEST domain. Of note, primary lymphoblasts were hypersensitive to γ-secretase inhibitor treatment, which is known to impair Notch signaling. This inhibition was Notch-specific as assessed by down-regulation of Notch1 target genes and intracellular cleaved Notch. We also observed that the oncogenic K-Ras-induced T-cell disease was responsive to rapamycin and inhibitors of the RAS/MAPK pathway. These data indicate that patients with T-cell leukemia with K-Ras mutations may benefit from therapies that target the NOTCH pathway alone or in combination with inhibition of the PI3K/AKT/MTOR and RAS/MAPK pathways. PMID:18663146

ERK inhibition enhances TSA-induced gastric cancer cell apoptosis via NF-κB-dependent and Notch-independent mechanism.

PubMed

Yao, Jun; Qian, Cui-Juan; Ye, Bei; Zhang, Xin; Liang, Yong

2012-09-04

To analyze the combined impact of the histone deacetylase inhibitor (HDACI) Trichostatin A (TSA) and the extracellular-signal-regulated kinase 1/2 (ERK1/2) inhibitor PD98059 on gastric cancer (GC) cell line SGC7901 growth. SGC7901 cells were treated with TSA, PD98059 or with a TSA-PD98059 combination. Effects of drug treatment on tumor cell proliferation, apoptosis, cell cycle progression, and cell signaling pathways were investigated by MTS assay, flow cytometry, Western blotting, chromatin immunoprecipitation (ChIP) assay, electrophoretic mobility shift assay (EMSA), and luciferase reporter assay, respectively. PD98059 enhanced TSA-induced cell growth arrest, apoptosis and activation of p21(WAF1/CIP1), but reversed TSA-induced activation of ERK1/2 and nuclear factor-κB (NF-κB). TSA alone up-regulated Notch1 and Hes1, and down-regulated Notch2, but PD98059 did not affect the trends of Notch1 and Notch2 induced by TSA. Particularly, PD98059 did potentiate the ability of TSA to down-regulate phospho-histone H3 protein, but increased levels of the acetylated forms of histone H3 bound to the p21(WAF1/CIP1) promoter, leading to enhanced expression of p21(WAF1/CIP1) in SGC7901 cells. PD98059 synergistically potentiates TSA-induced GC growth arrest and apoptosis by manipulating NF-κB and p21(WAF1/CIP1) independent of Notch. Therefore, concomitant administration of HDACIs and ERK1/2 inhibitors may be a promising treatment strategy for individuals with GC. Copyright © 2012 Elsevier Inc. All rights reserved.

Safety and Feasibility of Lin- Cells Administration to ALS Patients: A Novel View on Humoral Factors and miRNA Profiles.

PubMed

Sobuś, Anna; Baumert, Bartłomiej; Litwińska, Zofia; Gołąb-Janowska, Monika; Stępniewski, Jacek; Kotowski, Maciej; Pius-Sadowska, Ewa; Kawa, Miłosz P; Gródecka-Szwajkiewicz, Dorota; Peregud-Pogorzelski, Jarosław; Dulak, Józef; Nowacki, Przemysław; Machaliński, Bogusław

2018-04-27

Therapeutic options for amyotrophic lateral sclerosis (ALS) are still limited. Great hopes, however, are placed in growth factors that show neuroprotective abilities (e.g., nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), and vascular endothelial growth factor (VEGF)) and in the immune modulating features, in particular, the anti-inflammatory effects. In our study we aimed to investigate whether a bone marrow-derived lineage-negative (Lin-) cells population, after autologous application into cerebrospinal fluid (CSF), is able to produce noticeable concentrations of trophic factors and inflammatory-related proteins and thus influence the clinical course of ALS. To our knowledge, the evaluation of Lin- cells transplantation for ALS treatment has not been previously reported. Early hematopoietic Lin- cells were isolated from twelve ALS patients’ bone marrow, and later, the suspension of cells was administered into the subarachnoid space by lumbar puncture. Concentrations of selected proteins in the CSF and plasma were quantified by multiplex fluorescent bead-based immunoassays at different timepoints post-transplantation. We also chose microRNAs (miRNAs) related to muscle biology (miRNA-1, miRNA-133a, and miRNA-206) and angiogenesis and inflammation (miRNA-155 and miRNA-378) and tested, for the first time, their expression profiles in the CSF and plasma of ALS patients after Lin- cells transplantation. The injection of bone marrow cells resulted in decreased concentration of selected inflammatory proteins (C3) after Lin- cells injection, particularly in patients who had a better clinical outcome. Moreover, several analyzed miRNAs have changed expression levels in the CSF and plasma of ALS patients subsequent to Lin- cells administration. Interestingly, the expression of miR-206 increased in ALS patients, while miR-378 decreased both in the CSF and plasma one month after the cells’ injection. We propose that autologous lineage-negative early hematopoietic cells injected intrathecally may be a safe and feasible source of material for transplantations to the central nervous system (CNS) environment aimed at anti-inflammatory support provision for ALS adjuvant treatment strategies. Further research is needed to evaluate whether the observed effects could significantly influence the ALS progression.

The let-7/Lin28 axis regulates activation of hepatic stellate cells in alcoholic liver injury.

PubMed

McDaniel, Kelly; Huang, Li; Sato, Keisaku; Wu, Nan; Annable, Tami; Zhou, Tianhao; Ramos-Lorenzo, Sugeily; Wan, Ying; Huang, Qiaobing; Francis, Heather; Glaser, Shannon; Tsukamoto, Hidekazu; Alpini, Gianfranco; Meng, Fanyin

2017-07-07

The let-7/Lin28 axis is associated with the regulation of key cellular regulatory genes known as microRNAs in various human disorders and cancer development. This study evaluated the role of the let-7/Lin28 axis in regulating a mesenchymal phenotype of hepatic stellate cells in alcoholic liver injury. We identified that ethanol feeding significantly down-regulated several members of the let-7 family in mouse liver, including let-7a and let-7b. Similarly, the treatment of human hepatic stellate cells (HSCs) with lipopolysaccharide (LPS) and transforming growth factor-β (TGF-β) significantly decreased the expressions of let-7a and let-7b. Conversely, overexpression of let-7a and let-7b suppressed the myofibroblastic activation of cultured human HSCs induced by LPS and TGF-β, as evidenced by repressed ACTA2 (α-actin 2), COL1A1 (collagen 1A1), TIMP1 (TIMP metallopeptidase inhibitor 1), and FN1 (fibronectin 1); this supports the notion that HSC activation is controlled by let-7. A combination of bioinformatics, dual-luciferase reporter assay, and Western blot analysis revealed that Lin28B and high-mobility group AT-hook (HMGA2) were the direct targets of let-7a and let-7b. Furthermore, Lin28B deficiency increased the expression of let-7a/let-7b as well as reduced HSC activation and liver fibrosis in mice with alcoholic liver injury. This feedback regulation of let-7 by Lin28B is verified in hepatic stellate cells isolated by laser capture microdissection from the model. The identification of the let-7/Lin28 axis as an important regulator of HSC activation as well as its upstream modulators and down-stream targets will provide insights into the involvement of altered microRNA expression in contributing to the pathogenesis of alcoholic liver fibrosis and novel therapeutic approaches for human alcoholic liver diseases. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

FOXP3 expression is modulated by TGF-β1/NOTCH1 pathway in human melanoma

PubMed Central

Skarmoutsou, Eva; Bevelacqua, Valentina; D'Amico, Fabio; Russo, Angela; Spandidos, Demetrios A.; Scalisi, Aurora

2018-01-01

Forkhead box protein 3 (FOXP3) transcription factor is expressed by immune cells and several human cancers and is associated with tumor aggressiveness and unfavorable clinical outcomes. NOTCH and transforming growth factor-β (TGF-β) protumorigenic effects are mediated by FOXP3 expression in several cancer models; however, their interaction and role in melanoma is unknown. We investigated TGF-β-induced FOXP3 gene expression during NOTCH1 signaling inactivation. Primary (WM35) and metastatic melanoma (A375 and A2058) cell lines and normal melanocytes (NHEM) were used. FOXP3 subcellular distribution was evaluated by immuno cytochemical analysis. Gene expression levels were assessed by reverse transcription-quantitative polymerase chain reaction. Protein levels were assessed by western blot analysis. The γ-secretase inhibitor (GSI) was used for NOTCH1 inhibition and recombinant human (rh)TGF-β was used for melanoma cell stimulation. Cell proliferation and viability were respectively assessed by MTT and Trypan blue dye assays. FOXP3 mRNA and protein levels were progressively higher in WM35, A375 and A2058 cell lines compared to NHEM and their levels were further increased after stimulation with rh-TGF-β. TGF-β-mediated FOXP3 expression was mediated by NOTCH1 signaling. Inhibition of NOTCH1 with concomitant rh-TGF-β stimulation determined the reduction in gene expression and protein level of FOXP3. Finally, melanoma cell line proliferation and viability were reduced by NOTCH1 inhibition. The results show that nn increase in FOXP3 expression in metastatic melanoma cell lines is a potential marker of tumor aggressiveness and metastasis. NOTCH1 is a central mediator of TGF-β-mediated FOXP3 expression and NOTCH1 inhibition produces a significant reduction of melanoma cell proliferation and viability. PMID:29620159

Wnt and Notch Pathways Have Interrelated Opposing Roles on Prostate Progenitor Cell Proliferation and Differentiation

PubMed Central

Shahi, Payam; Seethammagari, Mamatha R.; Valdez, Joseph M.; Xin, Li; Spencer, David M.

2011-01-01

Tissue stem cells are capable of both self-renewal and differentiation to maintain a constant stem cell population and give rise to the plurality of cells within a tissue. Wnt signaling has been previously identified as a key mediator for the maintenance of tissue stem cells; however, possible cross-regulation with other developmentally critical signaling pathways involved in adult tissue homeostasis, such as Notch, is not well understood. By using an in vitro prostate stem cell colony (“prostasphere”) formation assay and in vivo prostate reconstitution experiments, we demonstrate that Wnt pathway induction on Sca-1+ CD49f+ basal/stem cells (B/SCs) promotes expansion of the basal epithelial compartment with noticeable increases in “triple positive” (cytokeratin [CK] 5+, CK8+, p63+) prostate progenitor cells, concomitant with upregulation of known Wnt target genes involved in cell-cycle induction. Moreover, Wnt induction affects expression of epithelial-to-mesenchymal transition signature genes, suggesting a possible mechanism for priming B/SC to act as potential tumor-initiating cells. Interestingly, induction of Wnt signaling in B/SCs results in downregulation of Notch1 transcripts, consistent with its postulated antiproliferative role in prostate cells. In contrast, induction of Notch signaling in prostate progenitors inhibits their proliferation and disrupts prostasphere formation. In vivo prostate reconstitution assays further demonstrate that induction of Notch in B/SCs disrupts proper acini formation in cells expressing the activated Notch1 allele, Notch-1 intracellular domain. These data emphasize the importance of Wnt/Notch cross-regulation in adult stem cell biology and suggest that Wnt signaling controls the proliferation and/or maintenance of epithelial progenitors via modulation of Notch signaling. PMID:21308863

Fatigue Crack Initiation.

DTIC Science & Technology

1991-01-01

here adopted. McCommon and Rosenberg [3] and MacCone et al . [4] showed that metals are subject to failure at temperatures as low as 1.7’K. This indicates...by Meke and Blochwitz [ 11 ] and Mughrabi [ 12] in their studies of persistent slip bands. Following the clue, which the observations on extrusions...compression as developed by Cooley and Lin, 1986 [33]. Lin et al ., 1987 [34]. Displacement component normal to the free surface is taken as a measure

Serum From Advanced Heart Failure Patients Promotes Angiogenic Sprouting and Affects the Notch Pathway in Human Endothelial Cells

PubMed Central

Pannella, Micaela; Caliceti, Cristiana; Fortini, Francesca; Aquila, Giorgio; Sega, Francesco Vieceli Dalla; Pannuti, Antonio; Fortini, Cinzia; Morelli, Marco Bruno; Fucili, Alessandro; Francolini, Gloria; Voltan, Rebecca; Secchiero, Paola; Dinelli, GiovannI; Leoncini, Emanuela; Ferracin, Manuela; Hrelia, Silvana; Miele, Lucio; Rizzo, Paola

2017-01-01

It is unknown whether components present in heart failure (HF) patients' serum provide an angiogenic stimulus. We sought to determine whether serum from HF patients affects angiogenesis and its major modulator, the Notch pathway, in human umbilical vein endothelial cells (HUVECs). In cells treated with serum from healthy subjects or from patients at different HF stage we determined: (1) Sprouting angiogenesis, by measuring cells network (closed tubes) in collagen gel. (2) Protein levels of Notch receptors 1, 2, 4, and ligands Jagged1, Delta-like4. We found a higher number of closed tubes in HUVECs treated with advanced HF patients serum in comparison with cells treated with serum from mild HF patients or controls. Furthermore, as indicated by the reduction of the active form of Notch4 (N4IC) and of Jagged1, advanced HF patients serum inhibited Notch signalling in HUVECs in comparison with mild HF patients' serum and controls. The circulating levels of NT-proBNP (N-terminal of the pro-hormone brain natriuretic peptide), a marker for the detection and evalutation of HF, were positively correlated with the number of closed tubes (r = 0.485) and negatively with Notch4IC and Jagged1 levels in sera-treated cells (r = −0.526 and r = −0.604, respectively). In conclusion, we found that sera from advanced HF patients promote sprouting angiogenesis and dysregulate Notch signaling in HUVECs. Our study provides in vitro evidence of an angiogenic stimulus arising during HF progression and suggests a role for the Notch pathway in it. PMID:26987674

Membrane receptor-dependent Notch1/Hes1 activation by melatonin protects against myocardial ischemia-reperfusion injury: in vivo and in vitro studies.

PubMed

Yu, Liming; Liang, Hongliang; Lu, Zhihong; Zhao, Guolong; Zhai, Mengen; Yang, Yang; Yang, Jian; Yi, Dinghua; Chen, Wensheng; Wang, Xiaowu; Duan, Weixun; Jin, Zhenxiao; Yu, Shiqiang

2015-11-01

Melatonin confers profound protective effect against myocardial ischemia-reperfusion injury (MI/RI). Activation of Notch1/Hairy and enhancer of split 1 (Hes1) signaling also ameliorates MI/RI. We hypothesize that melatonin attenuates MI/RI-induced oxidative damage by activating Notch1/Hes1 signaling pathway with phosphatase and tensin homolog deleted on chromosome 10 (Pten)/Akt acting as the downstream signaling pathway in a melatonin membrane receptor-dependent manner. Male Sprague Dawley rats were treated with melatonin (10 mg/kg/day) for 4 wk and then subjected to MI/R surgery. Melatonin significantly improved cardiac function and decreased myocardial apoptosis and oxidative damage. Furthermore, in cultured H9C2 cardiomyocytes, melatonin (100 μmol/L) attenuated simulated ischemia-reperfusion (SIR)-induced myocardial apoptosis and oxidative damage. Both in vivo and in vitro study demonstrated that melatonin treatment increased Notch1, Notch1 intracellular domain (NICD), Hes1, Bcl-2 expressions, and p-Akt/Akt ratio and decreased Pten, Bax, and caspase-3 expressions. However, these protective effects conferred by melatonin were blocked by DAPT (the specific inhibitor of Notch1 signaling), luzindole (the antagonist of melatonin membrane receptors), Notch1 siRNA, or Hes1 siRNA administration. In summary, our study demonstrates that melatonin treatment protects against MI/RI by modulating Notch1/Hes1 signaling in a receptor-dependent manner and Pten/Akt signaling pathways are key downstream mediators. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Constitutive activation of NOTCH1 signaling in Sertoli cells causes gonocyte exit from quiescence

PubMed Central

Garcia, Thomas Xavier; DeFalco, Tony; Capel, Blanche; Hofmann, Marie-Claude

2013-01-01

Notch signaling components have long been detected in Sertoli and germ cells in the developing and mature testis. However, the role of this pathway in testis development and spermatogenesis remains unknown. Using reporter mice expressing green fluorescent protein following Notch receptor activation, we found that Notch signaling was active in Sertoli cells at various fetal, neonatal, and adult stages. Since Notch signaling specifies stem cell fate in many developing and mature organ systems, we hypothesized that maintenance and differentiation of gonocytes and/or spermatogonial stem cells would be modulated through this pathway in Sertoli cells. To this end, we generated mutant mice constitutively expressing the active, intracellular domain of NOTCH1 (NICD1) in Sertoli cells. We found that mutant Sertoli cells were morphologically normal before and after birth, but presented a number of functional changes that drastically affected gonocyte numbers and physiology. We observed aberrant exit of gonocytes from mitotic arrest, migration toward cord periphery, and premature differentiation before birth. These events, presumably unsupported by the cellular microenvironment, were followed by gonocyte apoptosis and near complete disappearance of the gonocytes by day 2 after birth. Molecular analysis demonstrated that these effects are correlated with a dysregulation of Sertoli-expressed genes that are required for germ cell maintenance, such as Cyp26b1 and Gdnf. Taken together, our results demonstrate that Notch signaling is active in Sertoli cells throughout development and that proper regulation of Notch signaling in Sertoli cells is required for the maintenance of gonocytes in an undifferentiated state during fetal development. PMID:23391689

Pharmacological and Toxicological Properties of the Potent Oral γ-Secretase Modulator BPN-15606.

PubMed

Wagner, Steven L; Rynearson, Kevin D; Duddy, Steven K; Zhang, Can; Nguyen, Phuong D; Becker, Ann; Vo, Uyen; Masliah, Deborah; Monte, Louise; Klee, Justin B; Echmalian, Corinne M; Xia, Weiming; Quinti, Luisa; Johnson, Graham; Lin, Jiunn H; Kim, Doo Y; Mobley, William C; Rissman, Robert A; Tanzi, Rudolph E

2017-07-01

Alzheimer's disease (AD) is characterized neuropathologically by an abundance of 1) neuritic plaques, which are primarily composed of a fibrillar 42-amino-acid amyloid- β peptide (A β ), as well as 2) neurofibrillary tangles composed of aggregates of hyperphosporylated tau. Elevations in the concentrations of the A β 42 peptide in the brain, as a result of either increased production or decreased clearance, are postulated to initiate and drive the AD pathologic process. We initially introduced a novel class of bridged aromatics referred t γ -secretase modulatoro as γ -secretase modulators that inhibited the production of the A β 42 peptide and to a lesser degree the A β 40 peptide while concomitantly increasing the production of the carboxyl-truncated A β 38 and A β 37 peptides. These modulators potently lower A β 42 levels without inhibiting the γ -secretase-mediated proteolysis of Notch or causing accumulation of carboxyl-terminal fragments of APP. In this study, we report a large number of pharmacological studies and early assessment of toxicology characterizing a highly potent γ -secretase modulator (GSM), ( S )- N -(1-(4-fluorophenyl)ethyl)-6-(6-methoxy-5-(4-methyl-1 H -imidazol-1-yl)pyridin-2-yl)-4-methylpyridazin-3-amine (BPN-15606). BPN-15606 displayed the ability to significantly lower A β 42 levels in the central nervous system of rats and mice at doses as low as 5-10 mg/kg, significantly reduce A β neuritic plaque load in an AD transgenic mouse model, and significantly reduce levels of insoluble A β 42 and pThr181 tau in a three-dimensional human neural cell culture model. Results from repeat-dose toxicity studies in rats and dose escalation/repeat-dose toxicity studies in nonhuman primates have designated this GSM for 28-day Investigational New Drug-enabling good laboratory practice studies and positioned it as a candidate for human clinical trials. Copyright © 2017 by The Author(s).

Novel candidate genes may be possible predisposing factors revealed by whole exome sequencing in familial esophageal squamous cell carcinoma.

PubMed

Forouzanfar, Narjes; Baranova, Ancha; Milanizadeh, Saman; Heravi-Moussavi, Alireza; Jebelli, Amir; Abbaszadegan, Mohammad Reza

2017-05-01

Esophageal squamous cell carcinoma is one of the deadliest of all the cancers. Its metastatic properties portend poor prognosis and high rate of recurrence. A more advanced method to identify new molecular biomarkers predicting disease prognosis can be whole exome sequencing. Here, we report the most effective genetic variants of the Notch signaling pathway in esophageal squamous cell carcinoma susceptibility by whole exome sequencing. We analyzed nine probands in unrelated familial esophageal squamous cell carcinoma pedigrees to identify candidate genes. Genomic DNA was extracted and whole exome sequencing performed to generate information about genetic variants in the coding regions. Bioinformatics software applications were utilized to exploit statistical algorithms to demonstrate protein structure and variants conservation. Polymorphic regions were excluded by false-positive investigations. Gene-gene interactions were analyzed for Notch signaling pathway candidates. We identified novel and damaging variants of the Notch signaling pathway through extensive pathway-oriented filtering and functional predictions, which led to the study of 27 candidate novel mutations in all nine patients. Detection of the trinucleotide repeat containing 6B gene mutation (a slice site alteration) in five of the nine probands, but not in any of the healthy samples, suggested that it may be a susceptibility factor for familial esophageal squamous cell carcinoma. Noticeably, 8 of 27 novel candidate gene mutations (e.g. epidermal growth factor, signal transducer and activator of transcription 3, MET) act in a cascade leading to cell survival and proliferation. Our results suggest that the trinucleotide repeat containing 6B mutation may be a candidate predisposing gene in esophageal squamous cell carcinoma. In addition, some of the Notch signaling pathway genetic mutations may act as key contributors to esophageal squamous cell carcinoma.

Zeb2 recruits HDAC-NuRD to inhibit Notch and controls Schwann cell differentiation and remyelination.

PubMed

Wu, Lai Man Natalie; Wang, Jincheng; Conidi, Andrea; Zhao, Chuntao; Wang, Haibo; Ford, Zachary; Zhang, Liguo; Zweier, Christiane; Ayee, Brian G; Maurel, Patrice; Zwijsen, An; Chan, Jonah R; Jankowski, Michael P; Huylebroeck, Danny; Lu, Q Richard

2016-08-01

The mechanisms that coordinate and balance a complex network of opposing regulators to control Schwann cell (SC) differentiation remain elusive. Here we demonstrate that zinc-finger E-box-binding homeobox 2 (Zeb2, also called Sip1) transcription factor is a critical intrinsic timer that controls the onset of SC differentiation by recruiting histone deacetylases HDAC 1 and 2 (HDAC1/2) and nucleosome remodeling and deacetylase complex (NuRD) co-repressor complexes in mice. Zeb2 deletion arrests SCs at an undifferentiated state during peripheral nerve development and inhibits remyelination after injury. Zeb2 antagonizes inhibitory effectors including Notch and Sox2. Importantly, genome-wide transcriptome analysis reveals a Zeb2 target gene encoding the Notch effector Hey2 as a potent inhibitor for Schwann cell differentiation. Strikingly, a genetic Zeb2 variant associated with Mowat-Wilson syndrome disrupts the interaction with HDAC1/2-NuRD and abolishes Zeb2 activity for SC differentiation. Therefore, Zeb2 controls SC maturation by recruiting HDAC1/2-NuRD complexes and inhibiting a Notch-Hey2 signaling axis, pointing to the critical role of HDAC1/2-NuRD activity in peripheral neuropathies caused by ZEB2 mutations.

Structure of human POFUT1, its requirement in ligand-independent oncogenic Notch signaling, and functional effects of Dowling-Degos mutations

DOE Office of Scientific and Technical Information (OSTI.GOV)

McMillan, Brian J.; Zimmerman, Brandon; Egan, Emily D.

Protein O-fucosyltransferase-1 (POFUT1), which transfers fucose residues to acceptor sites on serine and threonine residues of epidermal growth factor-like repeats of recipient proteins, is essential for Notch signal transduction in mammals. Here, we examine the consequences of POFUT1 loss on the oncogenic signaling associated with certain leukemia-associated mutations of human Notch1, report the structures of human POFUT1 in free and GDP-fucose bound states, and assess the effects of Dowling-Degos mutations on human POFUT1 function. CRISPR-mediated knockout of POFUT1 in U2OS cells suppresses both normal Notch1 signaling, and the ligand-independent signaling associated with leukemogenic mutations of Notch1. Normal and oncogenic signalingmore » are rescued by wild-type POFUT1 but rescue is impaired by an active-site R240A mutation. The overall structure of the human enzyme closely resembles that of the Caenorhabditis elegans protein, with an overall backbone RMSD of 0.93 Å, despite primary sequence identity of only 39% in the mature protein. GDP-fucose binding to the human enzyme induces limited backbone conformational movement, though the side chains of R43 and D244 reorient to make direct contact with the fucose moiety in the complex. The reported Dowling-Degos mutations of POFUT1, except for M262T, fail to rescue Notch1 signaling efficiently in the CRISPR-engineered POFUT1 -/- background. Together, these studies identify POFUT1 as a potential target for cancers driven by Notch1 mutations and provide a structural roadmap for its inhibition.« less

MicroRNA-7a regulates Müller glia differentiation by attenuating Notch3 expression.

PubMed

Baba, Yukihiro; Aihara, Yuko; Watanabe, Sumiko

2015-09-01

miRNA-7a plays critical roles in various biological aspects in health and disease. We aimed to reveal roles of miR-7a in mouse retinal development by loss- and gain-of-function analyses of miR-7a. Plasmids encoding miR-7a or miR-7a-decoy (anti-sense miR-7a) were introduced into mouse retina at P0, and the retina was cultured as explant. Then, proliferation of retinal progenitors and differentiation of retinal subtypes were examined by immunostaining. miR-7a had no apparent effect on the proliferation of retinal progenitor cells. However, the expression of Müller glia marker, cyclin D3, was reduced by miR-7a overexpression and up-regulated by miR-7a decoy, suggesting that miR-7a negatively regulates differentiation of Müller glia. Targets of miR-7a, which were predicted by using a public program miRNA.org, and Notch3 was suggested to be one of candidate genes of miR-7a target. Notch3 3' UTR appeared to contain complementary sequence to the seed sequence of miR-7a. A reporter assay in NIH3T3 cells using a plasmid containing multiple repeats of potential target sequence of 3' Notch UTR showed that miR-7a suppress expression of reporter EGFP through 3'UTR region. Expression of sh-Notch3 and over-expression of NICD3 in retina suggested that miR-7a regulates Müller glia differentiation through attenuation of Notch3 expression. Taken together, we revealed that the miR-7a regulates the differentiation of Müller glia through the suppression of Notch3 expression. Copyright © 2015 Elsevier Ltd. All rights reserved.

Effects of anti-androgens cyproterone acetate, linuron, vinclozolin, and p,p'-DDE on the reproductive organs of the copepod Acartia tonsa.

PubMed

Watermann, Burkard T; Albanis, Triantafyllos A; Galassi, Silvana; Gnass, Katarina; Kusk, Kresten O; Sakkas, Vasilios A; Wollenberger, Leah

2016-11-09

The study was performed to detect the effects of anti-androgenic compounds on the reproduction. In this paper alterations observed in the marine calanoid copepod Acartia tonsa exposed to environmental concentrations of cyproterone acetate (CPA), linuron (LIN), vinclozolin (VIN), and 1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene (p,p'-DDE) for 21 days covering a full life cycle are described. Histological alterations were studied with a focus on reproductive organs, gonad and accessory sexual glands. Exposure to ≥1.2 µg L(-1) CPA caused degeneration of spermatocytes and deformation of the spermatophore in males. In a single male exposed to 33 µg L(-1) CPA, an ovotestis was observed. In CPA exposed females, enhancement of oogenesis, increase in apoptosis and a decrease in proliferation occurred. Exposure of males to ≥12 µg L(-1) LIN caused degenerative effects in spermatogonia, spermatocytes and spermatids, and at 4.7 µg L(-1) LIN, the spermatophore wall displayed an irregular formation. In LIN exposed females, no such structural alterations were found; however, the proliferation index was reduced at 29 µg L(-1) LIN. At an exposure concentration of ≥100 µg L(-1) VIN, distinct areas in male gonad were stimulated, whereas others displayed a disturbed spermatogenesis and a deformed spermatophore wall. In VIN exposed female A. tonsa, no effects were observed. Male A. tonsa exposed to p,p'-DDE displayed an impairment of spermatogenesis in all stages with increased degrees of apoptosis. In p,p'-DDE-exposed females, a statistical significant increase of the proliferation index and an intensification of oogenesis were observed at 0.0088 µg L(-1).

Classifying chemical mode of action using gene networks and machine learning: a case study with the herbicide linuron.

PubMed

Ornostay, Anna; Cowie, Andrew M; Hindle, Matthew; Baker, Christopher J O; Martyniuk, Christopher J

2013-12-01

The herbicide linuron (LIN) is an endocrine disruptor with an anti-androgenic mode of action. The objectives of this study were to (1) improve knowledge of androgen and anti-androgen signaling in the teleostean ovary and to (2) assess the ability of gene networks and machine learning to classify LIN as an anti-androgen using transcriptomic data. Ovarian explants from vitellogenic fathead minnows (FHMs) were exposed to three concentrations of either 5α-dihydrotestosterone (DHT), flutamide (FLUT), or LIN for 12h. Ovaries exposed to DHT showed a significant increase in 17β-estradiol (E2) production while FLUT and LIN had no effect on E2. To improve understanding of androgen receptor signaling in the ovary, a reciprocal gene expression network was constructed for DHT and FLUT using pathway analysis and these data suggested that steroid metabolism, translation, and DNA replication are processes regulated through AR signaling in the ovary. Sub-network enrichment analysis revealed that FLUT and LIN shared more regulated gene networks in common compared to DHT. Using transcriptomic datasets from different fish species, machine learning algorithms classified LIN successfully with other anti-androgens. This study advances knowledge regarding molecular signaling cascades in the ovary that are responsive to androgens and anti-androgens and provides proof of concept that gene network analysis and machine learning can classify priority chemicals using experimental transcriptomic data collected from different fish species. © 2013.

MAXI observation of a long X-ray burst from SAX J1712.6-3739

NASA Astrophysics Data System (ADS)

Iwakiri, W.; Negoro, H.; Serino, M.; in't Zand, J.; Kawai, N.; Nakajima, M.; Sakamaki, A.; Maruyama, W.; Mihara, T.; Nakahira, S.; Yatabe, F.; Takao, Y.; Matsuoka, M.; Sakamoto, T.; Sugita, S.; Kawakubo, Y.; Hashimoto, T.; Yoshida, A.; Sugizaki, M.; Tachibana, Y.; Morita, K.; Ueno, S.; Tomida, H.; Ishikawa, M.; Sugawara, Y.; Isobe, N.; Shimomukai, R.; Ueda, Y.; Tanimoto, A.; Morita, T.; Yamada, S.; Tsuboi, Y.; Sasaki, R.; Kawai, H.; Sato, T.; Tsunemi, H.; Yoneyama, T.; Yamauchi, M.; Hidaka, K.; Iwahori, S.; Kawamuro, T.; Yamaoka, K.; Shidatsu, M.

2018-05-01

We analyzed the MAXI observation of the long type-I X-ray burst from SAX J1712.6-3739 reported by Lin & Yu (ATel #11623, 2018). MAXI observed the region of SAX J1712.6-3739 during 09:25:38 to 09:26:58 UT May 8th 2018 which is about 8 minutes after the peak observed with Swift/BAT (at 09:18:12 UT according to Lin & Yu 2018).

Myeloid Notch1 deficiency activates the RhoA/ROCK pathway and aggravates hepatocellular damage in mouse ischemic livers.

PubMed

Lu, Ling; Yue, Shi; Jiang, Longfeng; Li, Changyong; Zhu, Qiang; Ke, Michael; Lu, Hao; Wang, Xuehao; Busuttil, Ronald W; Ying, Qi-Long; Kupiec-Weglinski, Jerzy W; Ke, Bibo

2018-03-01

Notch signaling plays an emerging role in the regulation of immune cell development and function during inflammatory response. Activation of the ras homolog gene family member A/Rho-associated protein kinase (ROCK) pathway promotes leukocyte accumulation in tissue injury. However, it remains unknown whether Notch signaling regulates ras homolog gene family member A/ROCK-mediated immune responses in liver ischemia and reperfusion (IR) injury. This study investigated intracellular signaling pathways regulated by Notch receptors in the IR-stressed liver and in vitro. In a mouse model of IR-induced liver inflammatory injury, we found that mice with myeloid-specific Notch1 knockout showed aggravated hepatocellular damage, with increased serum alanine aminotransferase levels, hepatocellular apoptosis, macrophage/neutrophil trafficking, and proinflammatory mediators compared to Notch1-proficient controls. Unlike in the controls, myeloid Notch1 ablation diminished hairy and enhancer of split-1 (Hes1) and augmented c-Jun N-terminal kinase (JNK)/stress-activated protein kinase-associated protein 1 (JSAP1), JNK, ROCK1, and phosphatase and tensin homolog (PTEN) activation in ischemic livers. Disruption of JSAP1 in myeloid-specific Notch1 knockout livers improved hepatocellular function and reduced JNK, ROCK1, PTEN, and toll-like receptor 4 activation. Moreover, ROCK1 knockdown inhibited PTEN and promoted Akt, leading to depressed toll-like receptor 4. In parallel in vitro studies, transfection of lentivirus-expressing Notch1 intracellular domain promoted Hes1 and inhibited JSAP1 in lipopolysaccharide-stimulated bone marrow-derived macrophages. Hes1 deletion enhanced JSAP1/JNK activation, whereas clustered regularly interspaced short palindromic repeats/CRISPR-associated protein 9-mediated JSAP1 knockout diminished ROCK1/PTEN and toll-like receptor 4 signaling. Myeloid Notch1 deficiency activates the ras homolog gene family member A/ROCK pathway and exacerbates hepatocellular injury by inhibiting transcriptional repressor Hes1 and inducing scaffold protein JSAP1 in IR-triggered liver inflammation; our findings underscore the crucial role of the Notch-Hes1 axis as a novel regulator of innate immunity-mediated inflammation and imply the therapeutic potential for the management of organ IR injury in transplant recipients. (Hepatology 2018;67:1041-1055). © 2017 by the American Association for the Study of Liver Diseases.

Notch signaling dynamics in the adult healthy prostate and in prostatic tumor development.

PubMed

Pedrosa, Ana-Rita; Graça, José L; Carvalho, Sandra; Peleteiro, Maria C; Duarte, António; Trindade, Alexandre

2016-01-01

The Notch signaling pathway has been implicated in prostate development, maintenance and tumorigenesis by its key role in cell-fate determination, differentiation and proliferation. Therefore, we proposed to analyze Notch family members transcription and expression, including ligands (Dll1, 3, 4 and Jagged1 and 2), receptors (Notch1-4) and effectors (Hes1, 2, 5 and Hey1, 2, L), in both normal and tumor bearing mouse prostates to better understand the dynamics of Notch signaling in prostate tumorigenesis. Wild type mice and transgenic adenocarcinoma of the mouse prostate model (TRAMP) mice were sacrificed at 18, 24 or 30 weeks of age and the prostates collected and processed for either whole prostate or prostate cell specific populations mRNA analysis and for protein expression analysis by immunohistochemistry and immunofluorescence. We observed that Dll1 and Dll4 are expressed in the luminal compartment of the mouse healthy prostate, whereas Jagged2 expression is restricted to the basal and stromal compartment. Additionally, Notch2 and Notch4 are normally expressed in the prostate luminal compartment while Notch2 and Notch3 are also expressed in the stromal layer of the healthy prostate. As prostate tumor development takes place, there is up-regulation of Notch components. Particularly, the prostate tumor lesions have increased expression of Jagged1 and 2, of Notch3 and of Hey1. We have also detected the presence of activated Notch3 in prostatic tumors that co-express Jagged1 and ultimately the Hey1 effector. Taken together our results point out the Notch axis Jagged1-2/Notch3/Hey1 to be important for prostate tumor development and worthy of additional functional studies and validation in human clinical disease. © 2015 Wiley Periodicals, Inc.

Notch signalling coordinates tissue growth and wing fate specification in Drosophila.

PubMed

Rafel, Neus; Milán, Marco

2008-12-01

During the development of a given organ, tissue growth and fate specification are simultaneously controlled by the activity of a discrete number of signalling molecules. Here, we report that these two processes are extraordinarily coordinated in the Drosophila wing primordium, which extensively proliferates during larval development to give rise to the dorsal thoracic body wall and the adult wing. The developmental decision between wing and body wall is defined by the opposing activities of two secreted signalling molecules, Wingless and the EGF receptor ligand Vein. Notch signalling is involved in the determination of a variety of cell fates, including growth and cell survival. We present evidence that growth of the wing primordium mediated by the activity of Notch is required for wing fate specification. Our data indicate that tissue size modulates the activity range of the signalling molecules Wingless and Vein. These results highlight a crucial role of Notch in linking proliferation and fate specification in the developing wing primordium.

The lack of autophagy triggers precocious activation of Notch signaling during Drosophila oogenesis.

PubMed

Barth, Julia M I; Hafen, Ernst; Köhler, Katja

2012-12-05

The proper balance of autophagy, a lysosome-mediated degradation process, is indispensable for oogenesis in Drosophila. We recently demonstrated that egg development depends on autophagy in the somatic follicle cells (FC), but not in the germline cells (GCs). However, the lack of autophagy only affects oogenesis when FCs are autophagy-deficient but GCs are wild type, indicating that a dysfunctional signaling between soma and germline may be responsible for the oogenesis defects. Thus, autophagy could play an essential role in modulating signal transduction pathways during egg development. Here, we provide further evidence for the necessity of autophagy during oogenesis and demonstrate that autophagy is especially required in subsets of FCs. Generation of autophagy-deficient FCs leads to a wide range of phenotypes that are similar to mutants with defects in the classical cell-cell signaling pathways in the ovary. Interestingly, we observe that loss of autophagy leads to a precocious activation of the Notch pathway in the FCs as monitored by the expression of Cut and Hindsight, two downstream effectors of Notch signaling. Our findings point to an unexpected function for autophagy in the modulation of the Notch signaling pathway during Drosophila oogenesis and suggest a function for autophagy in proper receptor activation. Egg development is affected by an imbalance of autophagy between signal sending (germline) and signal receiving cell (FC), thus the lack of autophagy in the germline is likely to decrease the amount of active ligand and accordingly compensates for increased signaling in autophagy-defective follicle cells.

In patients with chronic aplastic anemia, bone marrow-derived MSCs regulate the Treg/Th17 balance by influencing the Notch/RBP-J/FOXP3/RORγt pathway.

PubMed

Li, Hongbo; Wang, Lin; Pang, Yan; Jiang, Zujun; Liu, Zenghui; Xiao, Haowen; Chen, Haijia; Ge, Xiaohu; Lan, Hai; Xiao, Yang

2017-02-14

The standard treatment for aplastic anemia (AA) in young patients is a matched sibling hematopoietic stem cell transplant. Transfusion of a chronic AA patient with allogeneic bone marrow-derived mesenchymal stromal cells (BMMSCs) is currently being developed as a cell-based therapy, and the safety and efficacy of such transfusions are being continuously improved. Nevertheless, the mechanisms by which BMMSCs exert their therapeutic effects remain to be elucidated. In this study, mesenchymal stromal cells (MSCs) obtained from bone marrow donors were concentrated and intravenously injected into 15 chronic AA patients who had been refractory to prior immunosuppressive therapy. We showed that BMMSCs modulate the levels of Th1, Th2, Th17 and Treg cells, as well as their related cytokines in chronic AA patients. Furthermore, the percentages of Th1 and Th17 cells among the H-MSCs decreased significantly, while the percentage Treg cells increased. The Notch/RBP-J/FOXP3/RORγt pathway was involved in modulating the Treg/Th17 balance after MSCs were transfused in vitro. Additionally, the role played by transfused MSCs in regulating the Treg/Th17 balance via the Notch/RBP-J/FOXP3/RORγt pathway was further confirmed in an AA mouse model. In summary, in humans with chronic AA, BMMSCs regulate the Treg/Th17 balance by affecting the Notch/RBP-J/FOXP3/RORγt pathway.

Curcumin Induces Cell Death in Esophageal Cancer Cells through Modulating Notch Signaling

PubMed Central

Subramaniam, Dharmalingam; Ponnurangam, Sivapriya; Ramamoorthy, Prabhu; Standing, David; Battafarano, Richard J.; Anant, Shrikant; Sharma, Prateek

2012-01-01

Background Curcumin inhibits the growth of esophageal cancer cell lines; however, the mechanism of action is not well understood. It is becoming increasingly clear that aberrant activation of Notch signaling has been associated with the development of esophageal cancer. Here, we have determined that curcumin inhibits esophageal cancer growth via a mechanism mediated through the Notch signaling pathway. Methodology/Principal Findings In this study, we show that curcumin treatment resulted in a dose and time dependent inhibition of proliferation and colony formation in esophageal cancer cell lines. Furthermore, curcumin treatment induced apoptosis through caspase 3 activation, confirmed by an increase in the ratio of Bax to Bcl2. Cell cycle analysis demonstrated that curcumin treatment induced cell death and down regulated cyclin D1 levels. Curcumin treatment also resulted in reduced number and size of esophagospheres. Furthermore, curcumin treatment led to reduced Notch-1 activation, expression of Jagged-1 and its downstream target Hes-1. This reduction in Notch-1 activation was determined to be due to the down-regulation of critical components of the γ-secretase complex proteins such as Presenilin 1 and Nicastrin. The combination of a known γ-secretase inhibitor DAPT and curcumin further decreased proliferation and induced apoptosis in esophageal cancer cells. Finally, curcumin treatment down-regulate the expressions of Notch-1 specific microRNAs miR-21 and miR-34a, and upregulated tumor suppressor let-7a miRNA. Conclusion/Significance Curcumin is a potent inhibitor of esophageal cancer growth that targets the Notch-1 activating γ-secretase complex proteins. These data suggest that Notch signaling inhibition is a novel mechanism of action for curcumin during therapeutic intervention in esophageal cancers. PMID:22363450

From Broadband to Electrochromic Notch Filters with Printed Monochiral Carbon Nanotubes

PubMed Central

2018-01-01

Dense layers of semiconducting single-walled carbon nanotubes (SWNTs) serve as electrochromic (EC) materials in the near-infrared with high optical density and high conductivity. EC cells with tunable notch filter properties instead of broadband absorption are created via highly selective dispersion of specific semiconducting SWNTs through polymer-wrapping followed by deposition of thick films by aerosol-jet printing. A simple planar geometry with spray-coated mixed SWNTs as the counter electrode renders transparent metal oxides redundant and facilitates complete bleaching within a few seconds through iongel electrolytes with high ionic conductivities. Monochiral (6,5) SWNT films as working electrodes exhibit a narrow absorption band at 997 nm (full width at half-maximum of 55–73 nm) with voltage-dependent optical densities between 0.2 and 4.5 and a modulation depth of up to 43 dB. These (6,5) SWNT notch filters can retain more than 95% of maximum bleaching for several hours under open-circuit conditions. In addition, different levels of transmission can be set by applying constant low voltage (1.5 V) pulses with modulated width or by a given number of fixed short pulses. PMID:29521086

Endothelial jagged-2 sustains hematopoietic stem and progenitor reconstitution after myelosuppression.

PubMed

Guo, Peipei; Poulos, Michael G; Palikuqi, Brisa; Badwe, Chaitanya R; Lis, Raphael; Kunar, Balvir; Ding, Bi-Sen; Rabbany, Sina Y; Shido, Koji; Butler, Jason M; Rafii, Shahin

2017-12-01

Angiocrine factors, such as Notch ligands, supplied by the specialized endothelial cells (ECs) within the bone marrow and splenic vascular niche play an essential role in modulating the physiology of adult hematopoietic stem and progenitor cells (HSPCs). However, the relative contribution of various Notch ligands, specifically jagged-2, to the homeostasis of HSPCs is unknown. Here, we show that under steady state, jagged-2 is differentially expressed in tissue-specific vascular beds, but its expression is induced in hematopoietic vascular niches after myelosuppressive injury. We used mice with EC-specific deletion of the gene encoding jagged-2 (Jag2) to demonstrate that while EC-derived jagged-2 was dispensable for maintaining the capacity of HSPCs to repopulate under steady-state conditions, by activating Notch2 it did contribute to the recovery of HSPCs in response to myelosuppressive conditions. Engraftment and/or expansion of HSPCs was dependent on the expression of endothelial-derived jagged-2 following myeloablation. Additionally, jagged-2 expressed in bone marrow ECs regulated HSPC cell cycle and quiescence during regeneration. Endothelial-deployed jagged-2 triggered Notch2/Hey1, while tempering Notch2/Hes1 signaling in HSPCs. Collectively, these data demonstrate that EC-derived jagged-2 activates Notch2 signaling in HSPCs to promote hematopoietic recovery and has potential as a therapeutic target to accelerate balanced hematopoietic reconstitution after myelosuppression.

Endothelial jagged-2 sustains hematopoietic stem and progenitor reconstitution after myelosuppression

PubMed Central

Guo, Peipei; Poulos, Michael G.; Palikuqi, Brisa; Badwe, Chaitanya R.; Lis, Raphael; Kunar, Balvir; Ding, Bi-Sen; Rabbany, Sina Y.; Butler, Jason M.

2017-01-01

Angiocrine factors, such as Notch ligands, supplied by the specialized endothelial cells (ECs) within the bone marrow and splenic vascular niche play an essential role in modulating the physiology of adult hematopoietic stem and progenitor cells (HSPCs). However, the relative contribution of various Notch ligands, specifically jagged-2, to the homeostasis of HSPCs is unknown. Here, we show that under steady state, jagged-2 is differentially expressed in tissue-specific vascular beds, but its expression is induced in hematopoietic vascular niches after myelosuppressive injury. We used mice with EC-specific deletion of the gene encoding jagged-2 (Jag2) to demonstrate that while EC-derived jagged-2 was dispensable for maintaining the capacity of HSPCs to repopulate under steady-state conditions, by activating Notch2 it did contribute to the recovery of HSPCs in response to myelosuppressive conditions. Engraftment and/or expansion of HSPCs was dependent on the expression of endothelial-derived jagged-2 following myeloablation. Additionally, jagged-2 expressed in bone marrow ECs regulated HSPC cell cycle and quiescence during regeneration. Endothelial-deployed jagged-2 triggered Notch2/Hey1, while tempering Notch2/Hes1 signaling in HSPCs. Collectively, these data demonstrate that EC-derived jagged-2 activates Notch2 signaling in HSPCs to promote hematopoietic recovery and has potential as a therapeutic target to accelerate balanced hematopoietic reconstitution after myelosuppression. PMID:29058691

The Hajdu Cheney Mutation Is a Determinant of B-Cell Allocation of the Splenic Marginal Zone.

PubMed

Yu, Jungeun; Zanotti, Stefano; Walia, Bhavita; Jellison, Evan; Sanjay, Archana; Canalis, Ernesto

2018-01-01

The neurogenic locus notch homolog protein (Notch)-2 receptor is a determinant of B-cell allocation, and gain-of-NOTCH2-function mutations are associated with Hajdu-Cheney syndrome (HCS), a disease presenting with osteoporosis and acro-osteolysis. We generated a mouse model reproducing the HCS mutation (Notch2HCS), and heterozygous global mutant mice displayed gain-of-Notch2 function. In the mutant spleen, the characteristic perifollicular rim marking the marginal zone (MZ), which is the interface between the nonlymphoid red pulp and the lymphoid white pulp, merged with components of the white pulp. As a consequence, the MZ of Notch2HCS mice occupied most of the splenic structure. To explore the mechanisms involved, lymphocyte populations from the bone marrow and spleen were harvested from heterozygous Notch2HCS mice and sex-matched control littermates and analyzed by flow cytometry. Notch2HCS mice had an increase in CD21/35 high CD23 - splenic MZ B cells of approximately fivefold and a proportional decrease in splenic follicular B cells (CD21/35 int CD23 + ) at 1, 2, and 12 months of age. Western blot analysis revealed that Notch2HCS mutant splenocytes had increased phospho-Akt and phospho-Jun N-terminal kinase, and gene expression analysis of splenic CD19 + B cells demonstrated induction of Hes1 and Hes5 in Notch2HCS mutants. Anti-Notch2 antibodies decreased MZ B cells in control and Notch2HCS mice. In conclusion, Notch2HCS mutant mice have increased mature B cells in the MZ of the spleen. Copyright © 2018 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

Loss of Oncogenic Notch1 with Resistance to a PI3K Inhibitor in T Cell Leukaemia

PubMed Central

Dail, Monique; Wong, Jason; Lawrence, Jessica; O’Connor, Daniel; Nakitandwe, Joy; Chen, Shann-Ching; Xu, Jin; Lee, Leslie B; Akagi, Keiko; Li, Qing; Aster, Jon C.; Pear, Warren S.; Downing, James R; Sampath, Deepak; Shannon, Kevin

2014-01-01

Mutations that deregulate Notch1 and Ras/PI3 kinase/Akt signalling are prevalent in T lineage acute lymphoblastic leukaemia (T-ALL), and often coexist. The PI3 kinase inhibitor GDC-0941 was active against primary T-ALLs from wild-type and KrasG12D mice and addition of the MEK inhibitor PD0325901 increased efficacy. Mice invariably relapsed after treatment with drug resistant clones, most of which unexpectedly had reduced levels of activated Notch1 protein, down-regulated many Notch1 target genes, and exhibited cross-resistance to γ secretase inhibitors. Multiple resistant primary T-ALLs that emerged in vivo did not contain somatic Notch1 mutations present in the parental leukaemia. Importantly, resistant clones up-regulated PI3K signalling. Consistent with these data, inhibiting Notch1 activated the PI3K pathway, providing a likely mechanism for selection against oncogenic Notch1 signalling. These studies validate PI3K as a therapeutic target in T-ALL and raise the unexpected possibility that dual inhibition of PI3K and Notch1 signalling could facilitate drug resistance in T-ALL. PMID:25043004

Loss of oncogenic Notch1 with resistance to a PI3K inhibitor in T-cell leukaemia.

PubMed

Dail, Monique; Wong, Jason; Lawrence, Jessica; O'Connor, Daniel; Nakitandwe, Joy; Chen, Shann-Ching; Xu, Jin; Lee, Leslie B; Akagi, Keiko; Li, Qing; Aster, Jon C; Pear, Warren S; Downing, James R; Sampath, Deepak; Shannon, Kevin

2014-09-25

Mutations that deregulate Notch1 and Ras/phosphoinositide 3 kinase (PI3K)/Akt signalling are prevalent in T-cell acute lymphoblastic leukaemia (T-ALL), and often coexist. Here we show that the PI3K inhibitor GDC-0941 is active against primary T-ALLs from wild-type and Kras(G12D) mice, and addition of the MEK inhibitor PD0325901 increases its efficacy. Mice invariably relapsed after treatment with drug-resistant clones, most of which unexpectedly had reduced levels of activated Notch1 protein, downregulated many Notch1 target genes, and exhibited cross-resistance to γ-secretase inhibitors. Multiple resistant primary T-ALLs that emerged in vivo did not contain somatic Notch1 mutations present in the parental leukaemia. Importantly, resistant clones upregulated PI3K signalling. Consistent with these data, inhibiting Notch1 activated the PI3K pathway, providing a likely mechanism for selection against oncogenic Notch1 signalling. These studies validate PI3K as a therapeutic target in T-ALL and raise the unexpected possibility that dual inhibition of PI3K and Notch1 signalling could promote drug resistance in T-ALL.

Dynamics of Multiple lin Gene Expression in Sphingomonas paucimobilis B90A in Response to Different Hexachlorocyclohexane Isomers

PubMed Central

Suar, Mrutyunjay; van der Meer, Jan Roelof; Lawlor, Kirsten; Holliger, Christof; Lal, Rup

2004-01-01

Sphingomonas paucimobilis B90A is able to degrade the α-, β-, γ-, and δ-isomers of hexachlorocyclohexane (HCH). It contains the genes linA, linB, linC, linD, linE, and linR, which have been implicated in HCH degradation. In this study, dynamic expression of the lin genes was measured in chemostat-grown S. paucimobilis B90A by RNA dot blot hybridization and real-time reverse transcriptase PCR upon exposure to a pulse of different HCH isomers. Irrespective of the addition of HCH, linA, linB, and linC were all expressed constitutively. In contrast, linD and linE were induced with α-HCH (2 mg/liter) and γ-HCH (7 mg/liter). A sharp increase in mRNA levels for linD and linE was observed from 10 to 45 min after the addition of α- or γ-HCH. Induction of linD and linE was not detectable upon the addition of 0.7 mg of γ-HCH per liter, although the compound was degraded by the cells. The addition of β-HCH (5 mg/liter) or δ-HCH (20 mg/liter) did not lead to linE and linD induction, despite the fact that 50% of the compounds were degraded. This suggests that degradation of β- and δ-HCH proceeds by a different pathway than that of α- and γ-HCH. PMID:15528530

Streptomyces sp. is a powerful biotechnological tool for the biodegradation of HCH isomers: biochemical and molecular basis.

PubMed

Cuozzo, S A; Sineli, P E; Davila Costa, J; Tortella, G

2018-08-01

Actinobacteria are well-known degraders of toxic materials that have the ability to tolerate and remove organochloride pesticides; thus, they are used for bioremediation. The biodegradation of organochlorines by actinobacteria has been demonstrated in pure and mixed cultures with the concomitant production of metabolic intermediates including γ-pentachlorocyclohexene (γ-PCCH); 1,3,4,6-tetrachloro-1,4-cyclohexadiene (1,4-TCDN); 1,2-dichlorobenzene (1,2-DCB), 1,3-dichlorobenzene (1,3-DCB), or 1,4-dichlorobenzene (1,4-DCB); 1,2,3-trichlorobenzene (1,2,3-TCB), 1,2,4-trichlorobenzene (1,2,4-TCB), or 1,3,5-trichlorobenzene (1,3,5-TCB); 1,3-DCB; and 1,2-DCB. Chromatography coupled to mass spectrometric detection, especially GC-MS, is typically used to determine HCH-isomer metabolites. The important enzymes involved in HCH isomer degradation metabolic pathways include hexachlorocyclohexane dehydrochlorinase (LinA), haloalkane dehalogenase (LinB), and alcohol dehydrogenase (LinC). The metabolic versatility of these enzymes is known. Advances have been made in the identification of actinobacterial haloalkane dehydrogenase, which is encoded by linB. This knowledge will permit future improvements in biodegradation processes using Actinobacteria. The enzymatic and genetic characterizations of the molecular mechanisms involved in these processes have not been fully elucidated, necessitating further studies. New advances in this area suggest promising results. The scope of this paper encompasses the following: (i) the aerobic degradation pathways of hexachlorocyclohexane (HCH) isomers; (ii) the important genes and enzymes involved in the metabolic pathways of HCH isomer degradation; and (iii) the identification and quantification of intermediate metabolites through gas chromatography coupled to mass spectrometry (GC-MS).

The cyanogenic syndrome in rubber tree Hevea brasiliensis: tissue-damage-dependent activation of linamarase and hydroxynitrile lyase accelerates hydrogen cyanide release

PubMed Central

Kadow, Daniel; Voß, Karsten; Selmar, Dirk; Lieberei, Reinhard

2012-01-01

Background and Aims The release of hydrogen cyanide (HCN) from injured plant tissue affects multiple ecological interactions. Plant-derived HCN can act as a defence against herbivores and also plays an important role in plant–pathogen interactions. Crucial for activity as a feeding deterrent is the amount of HCN generated per unit time, referred to as cyanogenic capacity (HCNc). Strong intraspecific variation in HCNc has been observed among cyanogenic plants. This variation, in addition to genotypic variability (e.g. in Trifolium repens), can result from modifications in the expression level of the enzymes involved in either cyanogenic precursor formation or HCN release (as seen in Sorghum bicolor and Phaseolus lunatus). Thus, a modification or modulation of HCNc in reaction to the environment can only be achieved from one to the next generation when under genetic control and within days or hours when transcriptional regulations are involved. In the present study, it is shown that in rubber tree (Hevea brasiliensis) HCNc is modulated by post-translational activity regulation of the key enzymes for cyanide release. Methods Linamarase (LIN) and hydroxynitrile lyase (HNL) activity was determined by colorimetric assays utilizing dissociation of the substrates p-nitrophenyl-β-d-glucopyranoside and acetone cyanohydrin, respectively. Key Results In rubber tree leaves, LIN and HNL show up to ten-fold increased activity in response to tissue damage. This enzyme activation occurs within seconds and results in accelerated HCN formation. It is restricted to the damaged leaf area and depends on the severity of tissue damage. Conclusions LIN and HNL activation (in contrast to genetic and transcriptional regulations) allows an immediate, local and damage type-dependent modulation of the cyanogenic response. Accordingly, this post-translational activation plays a decisive role in the defence of H. brasiliensis against herbivores as well as pathogens and may allow more flexible reactions in response to these different antagonists. PMID:22451599

Crystal structures of MW1337R and lin2004: Representatives of a novel protein family that adopt a four-helical bundle fold

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kozbial, Piotr; Xu, Qingping; Chiu, Hsiu-Ju

2009-08-28

To extend the structural coverage of proteins with unknown functions, we targeted a novel protein family (Pfam accession number PF08807, DUF1798) for which we proposed and determined the structures of two representative members. The MW1337R gene of Staphylococcus aureus subsp. aureus Rosenbach (Wood 46) encodes a protein with a molecular weight of 13.8 kDa (residues 1-116) and a calculated isoelectric point of 5.15. The lin2004 gene of the nonspore-forming bacterium Listeria innocua Clip11262 encodes a protein with a molecular weight of 14.6 kDa (residues 1-121) and a calculated isoelectric point of 5.45. MW1337R and lin2004, as well as their homologs,more » which, so far, have been found only in Bacillus, Staphylococcus, Listeria, and related genera (Geobacillus, Exiguobacterium, and Oceanobacillus), have unknown functions and are annotated as hypothetical proteins. The genomic contexts of MW1337R and lin2004 are similar and conserved in related species. In prokaryotic genomes, most often, functionally interacting proteins are coded by genes, which are colocated in conserved operons. Proteins from the same operon as MW1337R and lin2004 either have unknown functions (i.e., belong to DUF1273, Pfam accession number PF06908) or are similar to ypsB from Bacillus subtilis. The function of ypsB is unclear, although it has a strong similarity to the N-terminal region of DivIVA, which was characterized as a bifunctional protein with distinct roles during vegetative growth and sporulation. In addition, members of the DUF1273 family display distant sequence similarity with the DprA/Smf protein, which acts downstream of the DNA uptake machinery, possibly in conjunction with RecA. The RecA activities in Bacillus subtilis are modulated by RecU Holliday-junction resolvase. In all analyzed cases, the gene coding for RecU is in the vicinity of MW1337R, lin2004, or their orthologs, but on a different operon located in the complementary DNA strand. Here, we report the crystal structures of MW1337R and lin2004, which were determined using the semiautomated, high-throughput pipeline of the Joint Center for Structural Genomics (JCSG), part of the National Institute of General Medical Sciences Protein Structure Initiative.« less

Disrupting Jagged1-Notch signaling impairs spatial memory formation in adult mice.

PubMed

Sargin, Derya; Botly, Leigh C P; Higgs, Gemma; Marsolais, Alexander; Frankland, Paul W; Egan, Sean E; Josselyn, Sheena A

2013-07-01

It is well-known that Notch signaling plays a critical role in brain development and growing evidence implicates this signaling pathway in adult synaptic plasticity and memory formation. The Notch1 receptor is activated by two subclasses of ligands, Delta-like (including Dll1 and Dll4) and Jagged (including Jag1 and Jag2). Ligand-induced Notch1 receptor signaling is modulated by a family of Fringe proteins, including Lunatic fringe (Lfng). Although Dll1, Jag1 and Lfng are critical regulators of Notch signaling, their relative contribution to memory formation in the adult brain is unknown. To investigate the roles of these important components of Notch signaling in memory formation, we examined spatial and fear memory formation in adult mice with reduced expression of Dll1, Jag1, Lfng and Dll1 plus Lfng. We also examined motor activity, anxiety-like behavior and sensorimotor gating using the acoustic startle response in these mice. Of the lines of mutant mice tested, we found that only mice with reduced Jag1 expression (mice heterozygous for a null mutation in Jag1, Jag1(+/-)) showed a selective impairment in spatial memory formation. Importantly, all other behavior including open field activity, conditioned fear memory (both context and discrete cue), acoustic startle response and prepulse inhibition, was normal in this line of mice. These results provide the first in vivo evidence that Jag1-Notch signaling is critical for memory formation in the adult brain. Crown Copyright © 2013. Published by Elsevier Inc. All rights reserved.

The expression of the Alzheimer’s Amyloid Precursor Protein-like gene is regulated by developmental timing microRNAs and their targets in Caenorhabditis elegans

PubMed Central

Niwa, Ryusuke; Zhou, Feng; Li, Chris; Slack, Frank J.

2008-01-01

Alzheimer’s Disease (AD) is a neurodegenerative disorder characterized by the accumulation of dense plaques in the brain, resulting in progressive dementia. A major plaque component is the β-amyloid peptide, which is a cleavage product of the amyloid precursor protein (APP). Studies of dominant inheritable familial AD support the hypothesis that APP is critical for AD development. On the other hand, the pathogenesis of amyloid plaque deposition in AD is thought to be the result of age-related changes with unknown mechanisms. Here we show that the Caenorhabditis elegans homolog of APP, APP-like-1 (apl-1), functions with and is under the control of molecules regulating developmental progression. In C. elegans, the timing of cell fate determination is controlled by the heterochronic genes, including let-7 microRNAs. C. elegans apl-1 shows significant genetic interactions with let-7 family microRNAs and let-7-targeted heterochronic genes, hbl-1, lin-41 and lin-42. apl-1 expression is upregulated during the last larval stage in hypodermal seam cells which is transcriptionally regulated by hbl-1, lin-41 and lin-42. Moreover, the levels of the apl-1 transcription are modulated by the activity of let-7 family microRNAs. Our works places apl-1 in a developmental timing pathway and may provide new insights into the time-dependent progression of AD. PMID:18262516

Effect of Thermal Treatment on the Mechanical and Toughness Properties of Extruded Sic sub w/Aluminum 6061 Metal Matrix Composite.

DTIC Science & Technology

1987-01-31

Charpy V-Notch_,,... i9,, STRACT (Continue on reverse if necessary and identify by block number) Mechanical, instrumented\\ Charpy V-potch (CVN) energy and...authors express their appreciation to Messrs. W. Willard and R. Gray for the fracture testing, Ensign M. Rennie for the instrumented Charpy V-notch...TO ALUMINUM GRAIN BOUNDARIES . . . . . . . . . 12 5 INSTRUMENTED CHARPY V-NOTCH LOAD AND ENERGY AGAINST TIME OUTPUTS FOR L-C ORIENTATION SiCwJAI 6061

A role for Lin28 in primordial germ cell development and germ cell malignancy

PubMed Central

West, Jason A.; Viswanathan, Srinivas R.; Yabuuchi, Akiko; Cunniff, Kerianne; Takeuchi, Ayumu; Park, In-Hyun; Sero, Julia E.; Zhu, Hao; Perez-Atayde, Antonio; Frazier, A. Lindsay; Surani, M. Azim; Daley, George Q.

2009-01-01

The rarity and inaccessibility of the earliest primordial germ cells (PGCs) in the mouse embryo thwarts efforts to investigate molecular mechanisms of germ cell specification. Stella marks the minute founder population of the germ lineage1,2. Here we differentiate mouse embryonic stem cells (ESCs) carrying a Stella transgenic reporter into putative PGCs in vitro. The Stella+ cells possess a transcriptional profile similar to embryo-derived PGCs, and like their counterparts in vivo, lose imprints in a time-dependent manner. Using inhibitory RNAs to screen candidate genes for effects on the development of Stella+ cells in vitro, we discovered that Lin28, a negative regulator of let-7 microRNA processing3-6, is essential for proper PGC development. We further show that Blimp1, a let-7 target and a master regulator of PGC specification7-9, can rescue the effect of Lin28-deficiency during PGC development, thereby establishing a mechanism of action for Lin28 during PGC specification. Over-expression of Lin28 promotes formation of Stella+ cells in vitro and PGCs in chimeric embryos, and is associated with human germ cell tumours. The differentiation of putative PGCs from ESCs in vitro recapitulates the early stages of gamete development in vivo, and provides an accessible system for discovering novel genes involved in germ cell development and malignancy. PMID:19578360

Explosive Joining for Nuclear-Reactor Repair

NASA Technical Reports Server (NTRS)

Bement, L. J.; Bailey, J. W.

1983-01-01

In explosive joining technique, adapter flange from fuel channel machined to incorporate a V-notch interface. Ribbon explosive, 1/2 inch (1.3 cm) in width, drives V-notched wall of adapter into bellows assembly, producing atomic-level metallurgical bond. Ribbon charge yields joint with double parent metal strength.

Predicting Prostate Cancer Progression at Time of Diagnosis

DTIC Science & Technology

2015-06-01

shall be subject to any penalty for failing to comply with a collection of information if it does not display a currently valid OMB control number...the UCSF specimens given an unexpected finding of different mean scores between the two cohorts and the Canary (Aim 2) specimens. The repeat analysis...PCA3 in an Active Surveillance Cohort: Results from a Baseline Analysis in the Canary Prostate Active Surveillance Study” (Lin DW et al, Clin Cancer

lin-4 and the NRDE pathway are required to activate a transgenic lin-4 reporter but not the endogenous lin-4 locus in C. elegans.

PubMed

Jiao, Alan L; Foster, Daniel J; Dixon, Julia; Slack, Frank J

2018-01-01

As the founding member of the microRNA (miRNA) gene family, insights into lin-4 regulation and function have laid a conceptual foundation for countless miRNA-related studies that followed. We previously showed that a transcriptional lin-4 reporter in C. elegans was positively regulated by a lin-4-complementary element (LCE), and by lin-4 itself. In this study, we sought to (1) identify additional factors required for lin-4 reporter expression, and (2) validate the endogenous relevance of a potential positive autoregulatory mechanism of lin-4 expression. We report that all four core nuclear RNAi factors (nrde-1, nrde-2, nrde-3 and nrde-4), positively regulate lin-4 reporter expression. In contrast, endogenous lin-4 levels were largely unaffected in nrde-2;nrde-3 mutants. Further, an endogenous LCE deletion generated by CRISPR-Cas9 revealed that the LCE was also not necessary for the activity of the endogenous lin-4 promoter. Finally, mutations in mature lin-4 did not reduce primary lin-4 transcript levels. Taken together, these data indicate that under growth conditions that reveal effects at the transgenic locus, a direct, positive autoregulatory mechanism of lin-4 expression does not occur in the context of the endogenous lin-4 locus.

Operating principles of Notch-Delta-Jagged module of cell-cell communication

NASA Astrophysics Data System (ADS)

Jolly, Mohit Kumar; Boareto, Marcelo; Lu, Mingyang; Onuchic, Jose' N.; Clementi, Cecilia; Ben-Jacob, Eshel

2015-05-01

Notch pathway is an evolutionarily conserved cell-cell communication mechanism governing cell-fate during development and tumor progression. It is activated when Notch receptor of one cell binds to either of its ligand—Delta or Jagged—of another cell. Notch-Delta (ND) signaling forms a two-way switch, and two cells interacting via ND signaling adopt different fates—Sender (high ligand, low receptor) and Receiver (low ligand, high receptor). Notch-Delta-Jagged signaling (NDJ) behaves as a three-way switch and enables an additional fate—hybrid Sender/Receiver (S/R) (medium ligand, medium receptor). Here, by extending our framework of NDJ signaling for a two-cell system, we show that higher production rate of Jagged, but not that of Delta, expands the range of parameters for which both cells attain the hybrid S/R state. Conversely, glycosyltransferase Fringe and cis-inhibition reduces this range of conditions, and reduces the relative stability of the hybrid S/R state, thereby promoting cell-fate divergence and consequently lateral inhibition-based patterns. Lastly, soluble Jagged drives the cells to attain the hybrid S/R state, and soluble Delta drives them to be Receivers. We also discuss the critical role of hybrid S/R state in promoting cancer metastasis by enabling collective cell migration and expanding cancer stem cell (CSC) population.

Dll4-Notch signaling determines the formation of native arterial collateral networks and arterial function in mouse ischemia models.

PubMed

Cristofaro, Brunella; Shi, Yu; Faria, Marcella; Suchting, Steven; Leroyer, Aurelie S; Trindade, Alexandre; Duarte, Antonio; Zovein, Ann C; Iruela-Arispe, M Luisa; Nih, Lina R; Kubis, Nathalie; Henrion, Daniel; Loufrani, Laurent; Todiras, Mihail; Schleifenbaum, Johanna; Gollasch, Maik; Zhuang, Zhen W; Simons, Michael; Eichmann, Anne; le Noble, Ferdinand

2013-04-01

Arteriogenesis requires growth of pre-existing arteriolar collateral networks and determines clinical outcome in arterial occlusive diseases. Factors responsible for the development of arteriolar collateral networks are poorly understood. The Notch ligand Delta-like 4 (Dll4) promotes arterial differentiation and restricts vessel branching. We hypothesized that Dll4 may act as a genetic determinant of collateral arterial networks and functional recovery in stroke and hind limb ischemia models in mice. Genetic loss- and gain-of-function approaches in mice showed that Dll4-Notch signaling restricts pial collateral artery formation by modulating arterial branching morphogenesis during embryogenesis. Adult Dll4(+/-) mice showed increased pial collateral numbers, but stroke volume upon middle cerebral artery occlusion was not reduced compared with wild-type littermates. Likewise, Dll4(+/-) mice showed reduced blood flow conductance after femoral artery occlusion, and, despite markedly increased angiogenesis, tissue ischemia was more severe. In peripheral arteries, loss of Dll4 adversely affected excitation-contraction coupling in arterial smooth muscle in response to vasopressor agents and arterial vessel wall adaption in response to increases in blood flow, collectively contributing to reduced flow reserve. We conclude that Dll4-Notch signaling modulates native collateral formation by acting on vascular branching morphogenesis during embryogenesis. Dll4 furthermore affects tissue perfusion by acting on arterial function and structure. Loss of Dll4 stimulates collateral formation and angiogenesis, but in the context of ischemic diseases such beneficial effects are overruled by adverse functional changes, demonstrating that ischemic recovery is not solely determined by collateral number but rather by vessel functionality.

Dll4-Notch signaling determines the formation of native arterial collateral networks and arterial function in mouse ischemia models

PubMed Central

Cristofaro, Brunella; Shi, Yu; Faria, Marcella; Suchting, Steven; Leroyer, Aurelie S.; Trindade, Alexandre; Duarte, Antonio; Zovein, Ann C.; Iruela-Arispe, M. Luisa; Nih, Lina R.; Kubis, Nathalie; Henrion, Daniel; Loufrani, Laurent; Todiras, Mihail; Schleifenbaum, Johanna; Gollasch, Maik; Zhuang, Zhen W.; Simons, Michael; Eichmann, Anne; le Noble, Ferdinand

2013-01-01

Arteriogenesis requires growth of pre-existing arteriolar collateral networks and determines clinical outcome in arterial occlusive diseases. Factors responsible for the development of arteriolar collateral networks are poorly understood. The Notch ligand Delta-like 4 (Dll4) promotes arterial differentiation and restricts vessel branching. We hypothesized that Dll4 may act as a genetic determinant of collateral arterial networks and functional recovery in stroke and hind limb ischemia models in mice. Genetic loss- and gain-of-function approaches in mice showed that Dll4-Notch signaling restricts pial collateral artery formation by modulating arterial branching morphogenesis during embryogenesis. Adult Dll4+/- mice showed increased pial collateral numbers, but stroke volume upon middle cerebral artery occlusion was not reduced compared with wild-type littermates. Likewise, Dll4+/- mice showed reduced blood flow conductance after femoral artery occlusion, and, despite markedly increased angiogenesis, tissue ischemia was more severe. In peripheral arteries, loss of Dll4 adversely affected excitation-contraction coupling in arterial smooth muscle in response to vasopressor agents and arterial vessel wall adaption in response to increases in blood flow, collectively contributing to reduced flow reserve. We conclude that Dll4-Notch signaling modulates native collateral formation by acting on vascular branching morphogenesis during embryogenesis. Dll4 furthermore affects tissue perfusion by acting on arterial function and structure. Loss of Dll4 stimulates collateral formation and angiogenesis, but in the context of ischemic diseases such beneficial effects are overruled by adverse functional changes, demonstrating that ischemic recovery is not solely determined by collateral number but rather by vessel functionality. PMID:23533173

Ring resonator-based on-chip modulation transformer for high-performance phase-modulated microwave photonic links.

PubMed

Zhuang, Leimeng; Taddei, Caterina; Hoekman, Marcel; Leinse, Arne; Heideman, René; van Dijk, Paulus; Roeloffzen, Chris

2013-11-04

In this paper, we propose and experimentally demonstrate a novel wideband on-chip photonic modulation transformer for phase-modulated microwave photonic links. The proposed device is able to transform phase-modulated optical signals into intensity-modulated versions (or vice versa) with nearly zero conversion of laser phase noise to intensity noise. It is constructed using waveguide-based ring resonators, which features simple architecture, stable operation, and easy reconfigurability. Beyond the stand-alone functionality, the proposed device can also be integrated with other functional building blocks of photonic integrated circuits (PICs) to create on-chip complex microwave photonic signal processors. As an application example, a PIC consisting of two such modulation transformers and a notch filter has been designed and realized in TriPleX(TM) waveguide technology. The realized device uses a 2 × 2 splitting circuit and 3 ring resonators with a free spectral range of 25 GHz, which are all equipped with continuous tuning elements. The device can perform phase-to-intensity modulation transform and carrier suppression simultaneously, which enables high-performance phase-modulated microwave photonics links (PM-MPLs). Associated with the bias-free and low-complexity advantages of the phase modulators, a single-fiber-span PM-MPL with a RF bandwidth of 12 GHz (3 dB-suppression band 6 to 18 GHz) has been demonstrated comprising the proposed PIC, where the achieved spurious-free dynamic range performance is comparable to that of Class-AB MPLs using low-biased Mach-Zehnder modulators.

LIN28 expression in malignant germ cell tumors down-regulates let-7 and increases oncogene levels

PubMed Central

Murray, Matthew J.; Saini, Harpreet K.; Siegler, Charlotte A.; Hanning, Jennifer E.; Barker, Emily M.; van Dongen, Stijn; Ward, Dawn M.; Raby, Katie L.; Groves, Ian J.; Scarpini, Cinzia G.; Pett, Mark R.; Thornton, Claire M.; Enright, Anton J.; Nicholson, James C.; Coleman, Nicholas

2013-01-01

Despite their clinico-pathologic heterogeneity, malignant germ-cell-tumors (GCTs) share molecular abnormalities that are likely to be functionally important. In this study, we investigated the potential significance of down-regulation of the let-7 family of tumor-suppressor microRNAs in malignant-GCTs. Microarray results from pediatric and adult samples (n=45) showed that LIN28, the negative-regulator of let-7 biogenesis, was abundant in malignant-GCTs, regardless of patient age, tumor site or histologic subtype. Indeed, a strong negative-correlation existed between LIN28 and let-7 levels in specimens with matched datasets. Low let-7 levels were biologically significant, since the sequence complementary to the 2-7nt common let-7 seed ‘GAGGUA’ was enriched in the 3′untranslated regions of mRNAs up-regulated in pediatric and adult malignant-GCTs, compared with normal gonads (a mixture of germ cells and somatic cells). We identified 27 mRNA targets of let-7 that were up-regulated in malignant-GCT cells, confirming significant negative-correlations with let-7 levels. Among 16 mRNAs examined in a largely independent set of specimens by qRT-PCR, we defined negative-associations with let-7e levels for six oncogenes, including MYCN, AURKB, CCNF, RRM2, MKI67 and C12orf5 (when including normal control tissues). Importantly, LIN28 depletion in malignant-GCT cells restored let-7 levels and repressed all of these oncogenic let-7 mRNA targets, with LIN28 levels correlating with cell proliferation and MYCN levels. Conversely, ectopic expression of let-7e was sufficient to reduce proliferation and down-regulate MYCN, AURKB and LIN28, the latter via a double-negative feedback loop. We concluded that the LIN28/let-7 pathway has a critical pathobiological role in malignant-GCTs and therefore offers a promising target for therapeutic intervention. PMID:23774216

Contributions of mRNA abundance, ribosome loading, and post- or peri-translational effects to temporal repression of C. elegans heterochronic miRNA targets

PubMed Central

Stadler, Michael; Artiles, Karen; Pak, Julia; Fire, Andrew

2012-01-01

miRNAs are post-transcriptional regulators of gene activity that reduce protein accumulation from target mRNAs. Elucidating precise molecular effects that animal miRNAs have on target transcripts has proven complex, with varied evidence indicating that miRNA regulation may produce different molecular outcomes in different species, systems, and/or physiological conditions. Here we use high-throughput ribosome profiling to analyze detailed translational parameters for five well-studied targets of miRNAs that regulate C. elegans developmental timing. For two targets of the miRNA lin-4 (lin-14 and lin-28), functional down-regulation was associated with decreases in both overall mRNA abundance and ribosome loading; however, these changes were of substantially smaller magnitude than corresponding changes observed in protein abundance. For three functional targets of the let-7 miRNA family for which down-regulation is critical in temporal progression of the animal (daf-12, hbl-1, and lin-41), we observed only modest changes in mRNA abundance and ribosome loading. lin-41 provides a striking example in that populations of ribosome-protected fragments from this gene remained essentially unchanged during the L3–L4 time interval when lin-41 activity is substantially down-regulated by let-7. Spectra of ribosomal positions were also examined for the five lin-4 and let-7 target mRNAs as a function of developmental time, with no indication of miRNA-induced ribosomal drop-off or significant pauses in translation. These data are consistent with models in which physiological regulation by this set of C. elegans miRNAs derives from combinatorial effects including suppressed recruitment/activation of translational machinery, compromised stability of target messages, and post- or peri-translational effects on lifetimes of polypeptide products. PMID:22855835

Analysis of transient hypermorphic activity of E(spl)D during R8 specification

PubMed Central

Majot, Adam T.

2017-01-01

Drosophila atonal (ato) is required for the specification of founding R8 photoreceptors during retinal development. ato is regulated via dual eye-specific enhancers; ato-3’ is subject to initial induction whereas 5’-ato facilitates Notch-mediated autoregulation. Notch is further utilized to induce bHLH repressors of the E(spl) locus to restrict Ato from its initial broad expression to individual cells. Although Notch operates in two, distinct phases, it has remained unclear how the two phases maintain independence from one another. The difference in these two phases has attributed to the hypothesized delayed expression of E(spl). However, immunofluorescence data indicate that E(spl) are expressed during early Ato patterning, suggesting a more sophisticated underlying mechanism. To probe this mechanism, we provide evidence that although E(spl) exert no influence on ato-3’, E(spl) repress 5’-ato and deletion of the E(spl) locus elicits precocious 5’-ato activity. Thus, E(spl) imposes a delay to the timing in which Ato initiates autoregulation. We next sought to understand this finding in the context of E(spl)D, which encodes a dysregulated variant of E(spl)M8 that perturbs R8 patterning, though, as previously reported, only in conjunction with the mutant receptor Nspl. We established a genetic interaction between E(spl)D and roughened eye (roe), a known modulator of Notch signaling in retinogenesis. This link further suggests a dosage-dependence between E(spl) and the proneural activators Ato and Sens, as indicated via interaction assays in which E(spl)D renders aberrant R8 patterning in conjunction with reduced proneural dosage. In total, the biphasicity of Notch signaling relies, to some degree, on the post-translational regulation of individual E(spl) members and, importantly, that post-translational regulation is likely necessary to modulate the level of E(spl) activity throughout the progression of Ato expression. PMID:29036187

SNX27 Deletion Causes Hydrocephalus by Impairing Ependymal Cell Differentiation and Ciliogenesis

PubMed Central

Zhou, Ying; Wang, Jian; Tseng, I-Chu; Huang, Timothy; Zhao, Yingjun; Zheng, Qiuyang; Gao, Yue; Luo, Hong; Zhang, Xian; Bu, Guojun; Hong, Wanjin

2016-01-01

Hydrocephalus is a brain disorder derived from CSF accumulation due to defects in CSF clearance. Although dysfunctional apical cilia in the ependymal cell layer are causal to the onset of hydrocephalus, mechanisms underlying proper ependymal cell differentiation are largely unclear. SNX27 is a trafficking component required for normal brain function and was shown previously to suppress γ-secretase-dependent amyloid precursor protein and Notch cleavage. However, it was unclear how SNX27-dependent γ-secretase inhibition could contribute to brain development and pathophysiology. Here, we describe and characterize an Snx27-deleted mouse model for the ependymal layer defects of deciliation and hydrocephalus. SNX27 deficiency results in reductions in ependymal cells and cilia density, as well as severe postnatal hydrocephalus. Inhibition of Notch intracellular domain signaling with γ-secretase inhibitors reversed ependymal cells/cilia loss and dilation of lateral ventricles in Snx27-deficient mice, giving strong indication that Snx27 deletion triggers defects in ependymal layer formation and ciliogenesis through Notch hyperactivation. Together, these results suggest that SNX27 is essential for ependymal cell differentiation and ciliogenesis, and its deletion can promote hydrocephalus pathogenesis. SIGNIFICANCE STATEMENT Down's syndrome (DS) in humans and mouse models has been shown previously to confer a high risk for the development of pathological hydrocephalus. Because we have previously described SNX27 as a component that is consistently downregulated in DS, we present here a robust Snx27-deleted mouse model that produces hydrocephalus and associated ciliary defects with complete penetrance. In addition, we find that γ-secretase/Notch modulation may be a candidate drug target in SNX27-associated hydrocephalus such as that observed in DS. Based on these findings, we anticipate that future study will determine whether modulation of a SNX27/Notch/γ-secretase pathway can also be of therapeutic interest to congenital hydrocephalus. PMID:27974614

Inter- and intraobserver reliability of the clock face representation as used to describe the femoral intercondylar notch.

PubMed

Azzam, Michael G; Lenarz, Christopher J; Farrow, Lutul D; Israel, Heidi A; Kieffer, David A; Kaar, Scott G

2011-08-01

To validate the use of the clock face reference as a reliable means of communicating femoral intercondylar notch position. A single red mark was made on ten identical left Sawbones femurs in the intercondylar notch at variable locations. Ten surgeons, who routinely perform ACL reconstructions, were presented the femurs in random order and asked to state the position of the mark to the nearest 30-min interval. Responses were recorded and then repeated 3 weeks later. The same 10 surgeons were presented with 30 actual arthroscopic photographs of the intercondylar notch, performed at 90° of knee flexion, with a probe pointing at various locations (10 knees; 3 photographs/knee) along the lateral aspect of the notch. The results were then analyzed with an ICC, Cronbach's alpha test, and descriptive statistics. For the Sawbones, the ICC was 0.996 while individual physician's Cronbach's alpha test ranged from 0.954 to 0.999, indicating a very high interobserver and intraobserver reliability. The mean range of responses among the 10 surgeons was 1.6 h, SD 0.6. For the photographs, the ICC was also high at 0.997. There was a mean range of 1.1 h, SD 0.4, among surgeons. The clock face method is commonly utilized for both placement of the femoral tunnel during ACL reconstruction as well as describing the location of the ACL femoral tunnel between communicating surgeons. Despite a high statistical interobserver correlation, there is significant range among different surgeons' responses. The present study questions the reliability of the clock face method for use between surgeons as a stand alone tool. Other methods also utilizing anatomic landmarks may be more accurate for describing intercondylar notch anatomy. III.

Notch/Delta signaling constrains reengineering of pro-T cells by PU.1

PubMed Central

Franco, Christopher B.; Scripture-Adams, Deirdre D.; Proekt, Irina; Taghon, Tom; Weiss, Angela H.; Yui, Mary A.; Adams, Stephanie L.; Diamond, Rochelle A.; Rothenberg, Ellen V.

2006-01-01

PU.1 is essential for early stages of mouse T cell development but antagonizes it if expressed constitutively. Two separable mechanisms are involved: attenuation and diversion. Dysregulated PU.1 expression inhibits pro-T cell survival, proliferation, and passage through β-selection by blocking essential T cell transcription factors, signaling molecules, and Rag gene expression, which expression of a rearranged T cell antigen receptor transgene cannot rescue. However, Bcl2 transgenic cells are protected from this attenuation and may even undergo β-selection, as shown by PU.1 transduction of defined subsets of Bcl2 transgenic fetal thymocytes with differentiation in OP9-DL1 and OP9 control cultures. The outcome of PU.1 expression in these cells depends on Notch/Delta signaling. PU.1 can efficiently divert thymocytes toward a myeloid-like state with multigene regulatory changes, but Notch/Delta signaling vetoes diversion. Gene expression analysis distinguishes sets of critical T lineage regulatory genes with different combinatorial responses to PU.1 and Notch/Delta signals, suggesting particular importance for inhibition of E proteins, Myb, and/or Gfi1 (growth factor independence 1) in diversion. However, Notch signaling only protects against diversion of cells that have undergone T lineage specification after Thy-1 and CD25 up-regulation. The results imply that in T cell precursors, Notch/Delta signaling normally acts to modulate and channel PU.1 transcriptional activities during the stages from T lineage specification until commitment. PMID:16880393

Antioxidant proteins TSA and PAG interact synergistically with Presenilin to modulate Notch signaling in Drosophila.

PubMed

Wangler, Michael F; Reiter, Lawrence T; Zimm, Georgianna; Trimble-Morgan, Jennifer; Wu, Jane; Bier, Ethan

2011-07-01

Alzheimer's disease (AD) pathogenesis is characterized by senile plaques in the brain and evidence of oxidative damage. Oxidative stress may precede plaque formation in AD; however, the link between oxidative damage and plaque formation remains unknown. Presenilins are transmembrane proteins in which mutations lead to accelerated plaque formation and early-onset familial Alzheimer's disease. Presenilins physically interact with two antioxidant enzymes thiol-specific antioxidant (TSA) and proliferation-associated gene (PAG) of the peroxiredoxin family. The functional consequences of these interactions are unclear. In the current study we expressed a presenilin transgene in Drosophila wing and sensory organ precursors of the fly. This caused phenotypes typical of Notch signaling loss-of-function mutations. We found that while expression of TSA or PAG alone produced no phenotype, co-expression of TSA and PAG with presenilin led to an enhanced Notch loss-of-function phenotype. This phenotype was more severe and more penetrant than that caused by the expression of Psn alone. In order to determine whether these phenotypes were indeed affecting Notch signaling, this experiment was performed in a genetic background carrying an activated Notch (Abruptex) allele. The phenotypes were almost completely rescued by this activated Notch allele. These results link peroxiredoxins with the in vivo function of Presenilin, which ultimately connects two key pathogenetic mechanisms in AD, namely, antioxidant activity and plaque formation, and raises the possibility of a role for peroxiredoxin family members in Alzheimer's pathogenesis.

ADAM10 regulates Notch function in intestinal stem cells of mice.

PubMed

Tsai, Yu-Hwai; VanDussen, Kelli L; Sawey, Eric T; Wade, Alex W; Kasper, Chelsea; Rakshit, Sabita; Bhatt, Riha G; Stoeck, Alex; Maillard, Ivan; Crawford, Howard C; Samuelson, Linda C; Dempsey, Peter J

2014-10-01

A disintegrin and metalloproteinase domain-containing protein 10 (ADAM10) is a cell surface sheddase that regulates physiologic processes, including Notch signaling. ADAM10 is expressed in all intestinal epithelial cell types, but the requirement for ADAM10 signaling in crypt homeostasis is not well defined. We analyzed intestinal tissues from mice with constitutive (Vil-Cre;Adam10(f/f) mice) and conditional (Vil-CreER;Adam10(f/f) and Leucine-rich repeat-containing GPCR5 [Lgr5]-CreER;Adam10(f/f) mice) deletion of ADAM10. We performed cell lineage-tracing experiments in mice that expressed a gain-of-function allele of Notch in the intestine (Rosa26(NICD)), or mice with intestine-specific disruption of Notch (Rosa26(DN-MAML)), to examine the effects of ADAM10 deletion on cell fate specification and intestinal stem cell maintenance. Loss of ADAM10 from developing and adult intestine caused lethality associated with altered intestinal morphology, reduced progenitor cell proliferation, and increased secretory cell differentiation. ADAM10 deletion led to the replacement of intestinal cell progenitors with 2 distinct, post-mitotic, secretory cell lineages: intermediate-like (Paneth/goblet) and enteroendocrine cells. Based on analysis of Rosa26(NICD) and Rosa26(DN-MAML) mice, we determined that ADAM10 controls these cell fate decisions by regulating Notch signaling. Cell lineage-tracing experiments showed that ADAM10 is required for survival of Lgr5(+) crypt-based columnar cells. Our findings indicate that Notch-activated stem cells have a competitive advantage for occupation of the stem cell niche. ADAM10 acts in a cell autonomous manner within the intestinal crypt compartment to regulate Notch signaling. This process is required for progenitor cell lineage specification and crypt-based columnar cell maintenance. Copyright © 2014 AGA Institute. Published by Elsevier Inc. All rights reserved.

LIN28 cooperates with WNT signaling to drive invasive intestinal and colorectal adenocarcinoma in mice and humans

PubMed Central

Tu, Ho-Chou; Schwitalla, Sarah; Qian, Zhirong; LaPier, Grace S.; Yermalovich, Alena; Ku, Yuan-Chieh; Chen, Shann-Ching; Viswanathan, Srinivas R.; Zhu, Hao; Nishihara, Reiko; Inamura, Kentaro; Kim, Sun A.; Morikawa, Teppei; Mima, Kosuke; Sukawa, Yasutaka; Yang, Juhong; Meredith, Gavin; Fuchs, Charles S.; Ogino, Shuji

2015-01-01

Colorectal cancer (CRC) remains a major contributor to cancer-related mortality. LIN28A and LIN28B are highly related RNA-binding protein paralogs that regulate biogenesis of let-7 microRNAs and influence development, metabolism, tissue regeneration, and oncogenesis. Here we demonstrate that overexpression of either LIN28 paralog cooperates with the Wnt pathway to promote invasive intestinal adenocarcinoma in murine models. When LIN28 alone is induced genetically, half of the resulting tumors harbor Ctnnb1 (β-catenin) mutation. When overexpressed in ApcMin/+ mice, LIN28 accelerates tumor formation and enhances proliferation and invasiveness. In conditional genetic models, enforced expression of a LIN28-resistant form of the let-7 microRNA reduces LIN28-induced tumor burden, while silencing of LIN28 expression reduces tumor volume and increases tumor differentiation, indicating that LIN28 contributes to tumor maintenance. We detected aberrant expression of LIN28A and/or LIN28B in 38% of a large series of human CRC samples (n = 595), where LIN28 expression levels were associated with invasive tumor growth. Our late-stage CRC murine models and analysis of primary human tumors demonstrate prominent roles for both LIN28 paralogs in promoting CRC growth and progression and implicate the LIN28/let-7 pathway as a therapeutic target. PMID:25956904

Factors influencing notching and necrosis of Dracaena deremensis Warneckii foliage

DOE Office of Scientific and Technical Information (OSTI.GOV)

Conover, C.A.; Poole, R.T.

1973-01-01

Quality of Dracaena deremensis Warneckii Engler. cuttings imported from Puerto Rico deteriorated during propagation and growing in commercial nurseries in Apopka, Florida. Foliage became necrotic with reddish brown spots occurring along edges, particularly in the white areas. As plants increased in size, notches occurred in the leaves. Tissue analyses indicated that Ca and Cu content decreased, F increased and Mg, Fe, Zn and Mn increased then decreased with time from importation. To determine possible method of alleviating the notching and necrosis, three 3x2x2 factorial experiments were established in 3 shade levels. Varying rates of boron, Osmocote (18-6-12) and Perk, amore » micronutrient blend, were applied to rooted Warneckii. Osmocote and Perk levels had no effect on necrosis or notching. Increasing light increased necrosis and increasing B decreased no. of notched leaves of plants grown under 80% shade. 11 references, 4 tables.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lin, J.S.; Miyamoto, Y.

The fracture behavior of graded Al{sub 2}O{sub 3}/TiC/Ni materials with a symmetric structure was investigated using single-edge notch-bend (SENB) specimens with surface compression. The fracture toughness of the graded materials was determined according to ASTM Standard E399. The results show that the effective fracture toughness increases with an increase in notch depth in the compressive stress zone, and reaches the maximum of 39.2 MPa m{sup 1/2} at the interface of compressive/tensile stress zones. Finite elements analysis reveals that the surface compression will be intensified at the notch root once the specimen is edge-notched because of the stress concentration, and themore » digress of the compressive stress intensification increases with an increase in notch depth. The dependence of the effective fracture toughness of the graded materials on the notch depth shows a behavior similar to the R-curve that is usually associated with microstructural toughening mechanisms. This toughening behavior is caused by the intensification of the compressive stress concentration with the increase of the notch depth. A theoretical analysis based on fracture mechanics verifies that the mechanical reliability of brittle ceramics can be improved effectively by tailoring and controlling the internal stresses.« less

Repression of Ccr9 transcription in mouse T lymphocyte progenitors by the Notch signaling pathway.

PubMed

Krishnamoorthy, Veena; Carr, Tiffany; de Pooter, Renee F; Emanuelle, Akinola Olumide; Akinola, Emanuelle Olumide; Gounari, Fotini; Kee, Barbara L

2015-04-01

The chemokine receptor CCR9 controls the immigration of multipotent hematopoietic progenitor cells into the thymus to sustain T cell development. Postimmigration, thymocytes downregulate CCR9 and migrate toward the subcapsular zone where they recombine their TCR β-chain and γ-chain gene loci. CCR9 is subsequently upregulated and participates in the localization of thymocytes during their selection for self-tolerant receptor specificities. Although the dynamic regulation of CCR9 is essential for early T cell development, the mechanisms controlling CCR9 expression have not been determined. In this article, we show that key regulators of T cell development, Notch1 and the E protein transcription factors E2A and HEB, coordinately control the expression of Ccr9. E2A and HEB bind at two putative enhancers upstream of Ccr9 and positively regulate CCR9 expression at multiple stages of T cell development. In contrast, the canonical Notch signaling pathway prevents the recruitment of p300 to the putative Ccr9 enhancers, resulting in decreased acetylation of histone H3 and a failure to recruit RNA polymerase II to the Ccr9 promoter. Although Notch signaling modestly modulates the binding of E proteins to one of the two Ccr9 enhancers, we found that Notch signaling represses Ccr9 in T cell lymphoma lines in which Ccr9 transcription is independent of E protein function. Our data support the hypothesis that activation of Notch1 has a dominant-negative effect on Ccr9 transcription and that Notch1 and E proteins control the dynamic expression of Ccr9 during T cell development. Copyright © 2015 by The American Association of Immunologists, Inc.

Oncogenic Kras initiates leukemia in hematopoietic stem cells.

PubMed

Sabnis, Amit J; Cheung, Laurene S; Dail, Monique; Kang, Hio Chung; Santaguida, Marianne; Hermiston, Michelle L; Passegué, Emmanuelle; Shannon, Kevin; Braun, Benjamin S

2009-03-17

How oncogenes modulate the self-renewal properties of cancer-initiating cells is incompletely understood. Activating KRAS and NRAS mutations are among the most common oncogenic lesions detected in human cancer, and occur in myeloproliferative disorders (MPDs) and leukemias. We investigated the effects of expressing oncogenic Kras(G12D) from its endogenous locus on the proliferation and tumor-initiating properties of murine hematopoietic stem and progenitor cells. MPD could be initiated by Kras(G12D) expression in a highly restricted population enriched for hematopoietic stem cells (HSCs), but not in common myeloid progenitors. Kras(G12D) HSCs demonstrated a marked in vivo competitive advantage over wild-type cells. Kras(G12D) expression also increased the fraction of proliferating HSCs and reduced the overall size of this compartment. Transplanted Kras(G12D) HSCs efficiently initiated acute T-lineage leukemia/lymphoma, which was associated with secondary Notch1 mutations in thymocytes. We conclude that MPD-initiating activity is restricted to the HSC compartment in Kras(G12D) mice, and that distinct self-renewing populations with cooperating mutations emerge during cancer progression.

Can flavonoid-rich chocolate modulate arterial elasticity and pathological uterine artery Doppler blood flow in pregnant women? A pilot study.

PubMed

von Wowern, Emma; Olofsson, Per

2018-09-01

Dark chocolate has shown beneficial effects on cardiovascular health and might also modulate hypertensive complications in pregnancy and uteroplacental blood flow. Increased uteroplacental resistance is associated with systemic arterial stiffness. We aimed to investigate the short-term effect of flavonoid-rich chocolate on arterial stiffness and Doppler blood flow velocimetry indexes in pregnant women with compromised uteroplacental blood flow. Doppler blood flow velocimetry and digital pulse wave analysis (DPA) were performed in 25 women pregnant in the second and third trimesters with uterine artery (UtA) score (UAS) 3-4, before and after 3 days of ingestion of chocolate with high flavonoid and antioxidant contents. UtA pulsatility index (PI), UtA diastolic notching, UAS (semiquantitative measure of PI and notching combined), and umbilical artery PI were calculated, and DPA variables representing central and peripheral maternal arteries were recorded. Mean UtA PI (p = .049) and UAS (p = .025) significantly decreased after chocolate consumption. There were no significant changes in UtA diastolic notching or any DPA indexes of arterial stiffness/vascular tone. Chocolate may have beneficial effects on the uteroplacental circulation, but in this pilot study, we could not demonstrate effects on arterial vascular tone as assessed by DPA.

Photonic crystal nanocavity assisted rejection ratio tunable notch microwave photonic filter

PubMed Central

Long, Yun; Xia, Jinsong; Zhang, Yong; Dong, Jianji; Wang, Jian

2017-01-01

Driven by the increasing demand on handing microwave signals with compact device, low power consumption, high efficiency and high reliability, it is highly desired to generate, distribute, and process microwave signals using photonic integrated circuits. Silicon photonics offers a promising platform facilitating ultracompact microwave photonic signal processing assisted by silicon nanophotonic devices. In this paper, we propose, theoretically analyze and experimentally demonstrate a simple scheme to realize ultracompact rejection ratio tunable notch microwave photonic filter (MPF) based on a silicon photonic crystal (PhC) nanocavity with fixed extinction ratio. Using a conventional modulation scheme with only a single phase modulator (PM), the rejection ratio of the presented MPF can be tuned from about 10 dB to beyond 60 dB. Moreover, the central frequency tunable operation in the high rejection ratio region is also demonstrated in the experiment. PMID:28067332

Photonic crystal nanocavity assisted rejection ratio tunable notch microwave photonic filter

NASA Astrophysics Data System (ADS)

Long, Yun; Xia, Jinsong; Zhang, Yong; Dong, Jianji; Wang, Jian

2017-01-01

Driven by the increasing demand on handing microwave signals with compact device, low power consumption, high efficiency and high reliability, it is highly desired to generate, distribute, and process microwave signals using photonic integrated circuits. Silicon photonics offers a promising platform facilitating ultracompact microwave photonic signal processing assisted by silicon nanophotonic devices. In this paper, we propose, theoretically analyze and experimentally demonstrate a simple scheme to realize ultracompact rejection ratio tunable notch microwave photonic filter (MPF) based on a silicon photonic crystal (PhC) nanocavity with fixed extinction ratio. Using a conventional modulation scheme with only a single phase modulator (PM), the rejection ratio of the presented MPF can be tuned from about 10 dB to beyond 60 dB. Moreover, the central frequency tunable operation in the high rejection ratio region is also demonstrated in the experiment.

Photonic crystal nanocavity assisted rejection ratio tunable notch microwave photonic filter.

PubMed

Long, Yun; Xia, Jinsong; Zhang, Yong; Dong, Jianji; Wang, Jian

2017-01-09

Driven by the increasing demand on handing microwave signals with compact device, low power consumption, high efficiency and high reliability, it is highly desired to generate, distribute, and process microwave signals using photonic integrated circuits. Silicon photonics offers a promising platform facilitating ultracompact microwave photonic signal processing assisted by silicon nanophotonic devices. In this paper, we propose, theoretically analyze and experimentally demonstrate a simple scheme to realize ultracompact rejection ratio tunable notch microwave photonic filter (MPF) based on a silicon photonic crystal (PhC) nanocavity with fixed extinction ratio. Using a conventional modulation scheme with only a single phase modulator (PM), the rejection ratio of the presented MPF can be tuned from about 10 dB to beyond 60 dB. Moreover, the central frequency tunable operation in the high rejection ratio region is also demonstrated in the experiment.

Shengui Sansheng San extraction is an angiogenic switch via regulations of AKT/mTOR, ERK1/2 and Notch1 signal pathways after ischemic stroke.

PubMed

Liu, Bowen; Luo, Cheng; Zheng, Zhaoguang; Xia, Zhenyan; Zhang, Qian; Ke, Chienchih; Liu, Renshyan; Zhao, Yonghua

2018-05-15

As a traditional Chinese herbal formula, Shengui Sansheng San (SSS) has been employed for stroke treatment more than 300 years. We hypothesize that SSS extraction is an angiogenic switch in penumbra post-stroke, and corresponding mechanisms are investigated. In present study, rats were subjected to permanent middle cerebral artery occlusion model (MCAo) and were treated with low, middle and high doses of SSS extraction. We assessed neurological function and survival rate, and measured infarct volume by 2,3,5-triphenyltetrazolium chloride staining on day 7 after ischemia. von Willebrand factor (vWF), stromal cell-derived factor-1 alpha (SDF-1α) /chemokine (C-X-C motif) receptor 4 (CXCR4) axis, vascular endothelial growth factor (VEGF)/VEGF receptor 2 (VEGFR2) as well as protein kinase B (AKT)/mammalian target of rapamycin (mTOR) /hypoxia-inducible factor-1 alpha (HIF-1α), extracellular signal-regulated kinase 1/2 (ERK1/2) and Notch1 signaling pathways were respectively investigated by immunofluorescence assay or western blotting in vivo and oxygen-glucose-deprived (OGD) brain microvascular endothelial cells (BMECs); simultaneously, wound healing of BMECs and tube formation assay were administrated. Compared to MCAo group, SSS extraction could significantly improve neurological functional scores, survival rate and cerebral infarct volume, enhance vWF + vascular density and perimeter, SDF-1α/CXCR4 axis, VEGF expression, as well as activate AKT/mTOR/HIF-1α and ERK1/2 and inhibit Notch1 pathways in penumbra. In vitro, containing SSS extraction serum increased BMEC migration, capillary formation and VEGF expression via up-regulations of AKT/mTOR and ERK1/2 pathways in OGD BMECs, but ERK inhibitor (U0126) reversed the result of VEGF expression in high dose of SSS group. Additionally, VEGFR2 and Notch1 expressions were suppressed by containing SSS extraction serum. All results were in dose dependent manner. Our study firstly demonstrates that SSS extraction is an angiogenic switch. Due to suppressed VEGFR2/Notch1 cascades and activated AKT/mTOR and ERK1/2 signals in BMECs, a feedback loop of angiogenic homeostasis is established. Furthermore, the comprehensive mediations of SDF-1α/CXCR4 axis, AKT/mTOR/HIF-α, ERK1/2 and Notch1 pathways in penumbra contribute to the improvements of neurological function, survival rate and infarct volume post-stroke. Copyright © 2018 Elsevier GmbH. All rights reserved.

Notch signaling proteins HES-1 and Hey-1 bind to insulin degrading enzyme (IDE) proximal promoter and repress its transcription and activity: Implications for cellular Aβ metabolism

PubMed Central

Leal, María C.; Surace, Ezequiel I.; Holgado, María P.; Ferrari, Carina C.; Tarelli, Rodolfo; Pitossi, Fernando; Wisniewski, Thomas; Castaño, Eduardo M.; Morelli, Laura

2012-01-01

Cerebral amyloid β (Aβ) accumulation is pathogenically associated with sporadic Alzheimer’s disease (SAD). BACE-1 is involved in Aβ generation while insulin-degrading enzyme (IDE) partakes in Aβ proteolytic clearance. Vulnerable regions in AD brains show increased BACE-1 protein levels and enzymatic activity while the opposite occurs with IDE. Another common feature in SAD brains is Notch1 overexpression. Here we demonstrate an increase in mRNA levels of Hey-1, a Notch target gene, and a decrease of IDE transcripts in the hippocampus of SAD brains as compared to controls. Transient transfection of Notch intracellular domain (NICD) in N2aSW cells, mouse neuroblastoma cells (N2a) stably expressing human amyloid precursor protein (APP) Swedish mutation, reduce IDE mRNA levels, promoting extracellular Aβ accumulation. Also, NICD, HES-1 and Hey-1 overexpression result in decreased IDE proximal promoter activity. This effect was mediated by 2 functional sites located at −379/−372 and −310 −303 from the first translation start site in the −575/−19 (556 bp) fragment of IDE proximal promoter. By site-directed mutagenesis of the IDE promoter region we reverted the inhibitory effect mediated by NICD transfection suggesting that these sites are indeed responsible for the Notch-mediated inhibition of the IDE gene expression. Intracranial injection of the Notch ligand JAG-1 in Tg2576 mice, expressing the Swedish mutation in human APP, induced overexpression of HES-1 and Hey-1 and reduction of IDE mRNA levels, respectively. Our results support our theory that a Notch-dependent IDE transcriptional modulation may impact on Aβ metabolism providing a functional link between Notch signaling and the amyloidogenic pathway in SAD. PMID:22036964

Wt1a, Foxc1a, and the Notch mediator Rbpj Physically Interact and Regulate the Formation of Podocytes in Zebrafish

PubMed Central

O’Brien, Lori L.; Grimaldi, Michael; Kostun, Zachary; Wingert, Rebecca A.; Selleck, Rori; Davidson, Alan J.

2011-01-01

Podocytes help form the glomerular blood filtration barrier in the kidney and their injury or loss leads to renal disease. The Wilms’ tumor suppressor-1 (Wt1) and the FoxC1/2 transcription factors, as well as Notch signaling, have been implicated as important regulators of podocyte fate. It is not known whether these factors work in parallel or sequentially on different gene targets, or as higher-order transcriptional complexes on common genes. Here, we use the zebrafish to demonstrate that embryos treated with morpholinos against wt1a, foxc1a, or the Notch transcriptional mediator rbpj develop fewer podocytes, as determined by wt1b, hey1 and nephrin expression, while embryos deficient in any two of these factors completely lack podocytes. From GST-pull-downs and co-immunoprecipitation experiments we show that Wt1a, Foxc1a, and Rbpj can physically interact with each other, whereas only Rbpj binds to the Notch intracellular domain (NICD). In transactivation assays, combinations of Wt1, FoxC1/2, and NICD synergistically induce the Hey1 promoter, and have additive or repressive effects on the Podocalyxin promoter, depending on dosage. Taken together, these data suggest that Wt1, FoxC1/2, and Notch signaling converge on common target genes where they physically interact to regulate a podocyte-specific gene program. These findings further our understanding of the transcriptional circuitry responsible for podocyte formation and differentiation during kidney development. PMID:21871448

Systemic Nicotine Increases Gain and Narrows Receptive Fields in A1 via Integrated Cortical and Subcortical Actions

PubMed Central

Intskirveli, Irakli

2017-01-01

Abstract Nicotine enhances sensory and cognitive processing via actions at nicotinic acetylcholine receptors (nAChRs), yet the precise circuit- and systems-level mechanisms remain unclear. In sensory cortex, nicotinic modulation of receptive fields (RFs) provides a model to probe mechanisms by which nAChRs regulate cortical circuits. Here, we examine RF modulation in mouse primary auditory cortex (A1) using a novel electrophysiological approach: current-source density (CSD) analysis of responses to tone-in-notched-noise (TINN) acoustic stimuli. TINN stimuli consist of a tone at the characteristic frequency (CF) of the recording site embedded within a white noise stimulus filtered to create a spectral “notch” of variable width centered on CF. Systemic nicotine (2.1 mg/kg) enhanced responses to the CF tone and to narrow-notch stimuli, yet reduced the response to wider-notch stimuli, indicating increased response gain within a narrowed RF. Subsequent manipulations showed that modulation of cortical RFs by systemic nicotine reflected effects at several levels in the auditory pathway: nicotine suppressed responses in the auditory midbrain and thalamus, with suppression increasing with spectral distance from CF so that RFs became narrower, and facilitated responses in the thalamocortical pathway, while nicotinic actions within A1 further contributed to both suppression and facilitation. Thus, multiple effects of systemic nicotine integrate along the ascending auditory pathway. These actions at nAChRs in cortical and subcortical circuits, which mimic effects of auditory attention, likely contribute to nicotinic enhancement of sensory and cognitive processing. PMID:28660244

Association between high levels of Notch3 expression and high invasion and poor overall survival rates in pancreatic ductal adenocarcinoma.

PubMed

Zhou, Jin-Xue; Zhou, Liang; Li, Qing-Jun; Feng, Wen; Wang, Pei-Min; Li, Er-Feng; Gong, Wen-Jing; Kou, Ming-Wen; Gou, Wei-Ting; Yang, Yan-Ling

2016-11-01

Pancreatic ductal adenocarcinoma (PDAC) is a commonly fatal tumour. It is characterized by early metastasis and high mortality. Many patients die as a result of PDAC tumour progression. However, the underlying mechanism of invasion and metastasis in PDAC is still not fully understood. Previous studies showed that the Notch signalling pathway may play an important role in the progression of tumour invasion and metastasis. However, it is not yet known whether the Notch signalling pathway participates in the progression of invasion in PDAC. In the present study, immunohistochemistry showed that a high expression of Notch3 was correlated with tumour grade, metastasis, venous invasion and American Joint Committee on Cancer (AJCC) tumor-node-metastasis (TNM) stage. Kaplan-Meier curves suggested that a high expression of Notch3 was a significant risk factor for shortened survival time. We also showed that inhibition of Notch3 had an anti‑invasion role in PDAC cells. In vitro, the inhibition of Notch3 reduced the migration and invasion capabilities of PDAC cells by regulating the expressions of E-cadherin, CD44v6, MMP-2, MMP-9, VEGF and uPA via regulating the COX-2 and ERK1/2 pathways. These results indicated that downregulation of the Notch signalling pathway may be a novel and useful approach for preventing and treating PDAC invasion.

[Treatment of proximal humeral fractures by reverse shoulder arthroplasty: mid-term evaluation of functional results and Notching].

PubMed

Hernández-Elena, J; de la Red-Gallego, M Á; Garcés-Zarzalejo, C; Pascual-Carra, M A; Pérez-Aguilar, M D; Rodríguez-López, T; Alfonso-Fernández, A; Pérez-Núñez, M I

2015-01-01

An analysis was made on relationship between Notching and functional and radiographic parameters after treatment of acute proximal humeral fractures with reverse total shoulder arthroplasty. A retrospective evaluation was performed on 37 patients with acute proximal humeral fracture treated by reversed shoulder arthroplasty. The mean follow-up was 24 months. Range of motion, intraoperative and postoperative complications were recorded. Nerot's classification was used to evaluate Notching. Patient satisfaction was evaluated with the Constant Score (CS). Statistical analysis was performed to evaluate the relationship between Notching and glenosphere position, or functional outcomes. Mean range of elevation, abduction, external and internal rotation were 106.22°, 104.46°, 46.08° and 40.27°, respectively. Mean CS was 63. Notching was present at 12 months in 29% of patients. Statistical analysis showed significance differences between age and CS, age and notching development, and tilt with notching. No statistical significance differences were found between elevation, abduction, internal and external rotation and CS either with scapular or glenosphere-neck angle. Reverse shoulder arthroplasty is a valuable option for acute humeral fractures in patients with osteoporosis and cuff-tear arthropathy. It leads to early pain relief and shoulder motion. Nevertheless, it is not exempt from complications, and long-term studies are needed to determine the importance of notching. Copyright © 2014 SECOT. Published by Elsevier Espana. All rights reserved.

Atomic clocks based on extened-cavity diode laser in multimode operation

NASA Astrophysics Data System (ADS)

Yim, Sin; Cho, D.

2011-05-01

We demonstrated the possibilities to develope an atomic clock based on coherent population trapping (CPT) without using a local oscillator and a modulator. Instead of using a modulator, we use two modes from a single extended-cavity diode laser in multimode operation. Two different types of feedback system are applied to stabilize a difference frequency between the two modes and eliminate the need for an extra frequency modulation. In the first type, we employ an electronic feedback using dispersion of the CPT resonance as an error signal. The two modes are phase locked with reference to a dispersion signal from a CPT resonance of 85Rb at 3.036 GHz ground hyperfine splitting. We use D1 transition at 794.8 nm with lin ⊥lin polarizations to obtain large-contrast CPT signal. Allan deviation of the beat frequency between the two modes is 1 ×10-10 at 200-s integration time. In the second type, we employ optoelectronic feedback to construct an opto-electronic oscillator (OEO). In an OEO, the beating signal between two modes is recovered by a fast photodiode, and its output is amplified and fed back to the laser diode by using a direct modulation of an injection current. When the OEO loop is closed, oscillation frequency depends on variations of the loop length. In order to stabilize an OEO loop length and thereby its oscillation frequency, CPT cell is inserted to play a role of microwave band pass filter. Allan deviation of the CPT-stabilized OEO is 2 ×10-10 at 100-s integration time.

Conversion of the LXR-agonist TO-901317--from inverse to normal modulation of gamma-secretase by addition of a carboxylic acid and a lipophilic anchor.

PubMed

Narlawar, Rajeshwar; Baumann, Karlheinz; Czech, Christian; Schmidt, Boris

2007-10-01

TO-901317, a LXR agonist, is an inverse modulator of Alzheimer's disease associated gamma-secretase. We synthesized TO-901317 analogous compound but replaced the hexafluorocarbinol moiety by an oxyacetic acid functionality and hypothesized that the replacement would change the mode of action from an inverse modulation to normal modulation of gamma-secretase. As anticipated, acid 9 was found to be an effective modulator of gamma-secretase and displayed activity at low micromolar concentration. This significant modification can be applied to several inverse gamma-secretase modulators. Such modulators may preserve the cleavage of other gamma-secretase substrates such as Notch.

MYCN-driven regulatory mechanisms controlling LIN28B in neuroblastoma

PubMed Central

Beckers, Anneleen; Van Peer, Gert; Carter, Daniel R.; Gartlgruber, Moritz; Herrmann, Carl; Agarwal, Saurabh; Helsmoortel, Hetty H.; Althoff, Kristina; Molenaar, Jan J.; Cheung, Belamy B.; Schulte, Johannes H.; Benoit, Yves; Shohet, Jason M.; Westermann, Frank; Marshall, Glenn M.; Vandesompele, Jo; De Preter, Katleen; Speleman, Frank

2016-01-01

LIN28B has been identified as an oncogene in various tumor entities, including neuroblastoma, a childhood cancer that originates from neural crest-derived cells, and is characterized by amplification of the MYCN oncogene. Recently, elevated LIN28B expression levels were shown to contribute to neuroblastoma tumorigenesis via let-7 dependent de-repression of MYCN. However, additional insight in the regulation of LIN28B in neuroblastoma is lacking. Therefore, we have performed a comprehensive analysis of the regulation of LIN28B in neuroblastoma, with a specific focus on the contribution of miRNAs. We show that MYCN regulates LIN28B expression in neuroblastoma tumors via two distinct parallel mechanisms. First, through an unbiased LIN28B-3′UTR reporter screen, we found that miR-26a-5p and miR-26b-5p regulate LIN28B expression. Next, we demonstrated that MYCN indirectly affects the expression of miR-26a-5p, and hence regulates LIN28B, therefor establishing a MYCN-miR-26a-5p-LIN28B regulatory axis. Second, we provide evidence that MYCN regulates LIN28B expression via interaction with the LIN28B promotor, establishing a direct MYCN-LIN28B regulatory axis. We believe that these findings mark LIN28B as an important effector of the MYCN oncogenic phenotype and underlines the importance of MYCN-regulated miRNAs in establishing the MYCN-driven oncogenic process. PMID:26123663

14q deletions are associated with trisomy 12, NOTCH1 mutations and unmutated IGHV genes in chronic lymphocytic leukemia and small lymphocytic lymphoma.

PubMed

Cosson, Adrien; Chapiro, Elise; Belhouachi, Nabila; Cung, Hong-Anh; Keren, Boris; Damm, Frederik; Algrin, Caroline; Lefebvre, Christine; Fert-Ferrer, Sandra; Luquet, Isabelle; Gachard, Nathalie; Mugneret, Francine; Terre, Christine; Collonge-Rame, Marie-Agnes; Michaux, Lucienne; Rafdord-Weiss, Isabelle; Talmant, Pascaline; Veronese, Lauren; Nadal, Nathalie; Struski, Stephanie; Barin, Carole; Helias, Catherine; Lafage, Marina; Lippert, Eric; Auger, Nathalie; Eclache, Virginie; Roos-Weil, Damien; Leblond, Veronique; Settegrana, Catherine; Maloum, Karim; Davi, Frederic; Merle-Beral, Helene; Lesty, Claude; Nguyen-Khac, Florence

2014-08-01

Deletions of the long arm of chromosome 14 [del(14q)] are rare but recurrently observed in mature B-cell neoplasms, particularly in chronic lymphocytic leukemia (CLL). To further characterize this aberration, we studied 81 cases with del(14q): 54 of CLL and 27 of small lymphocytic lymphoma (SLL), the largest reported series to date. Using karyotype and fluorescence in situ hybridization (FISH), the most frequent additional abnormality was trisomy 12 (tri12), observed in 28/79 (35%) cases, followed by del13q14 (12/79, 15%), delTP53 (11/80, 14%) delATM (5/79, 6%), and del6q21 (3/76, 4%). IGHV genes were unmutated in 41/53 (77%) patients, with a high frequency of IGHV1-69 (21/52, 40%). NOTCH1 gene was mutated in 14/45 (31%) patients. There was no significant difference in cytogenetic and molecular abnormalities between CLL and SLL. Investigations using FISH and SNP-array demonstrated the heterogeneous size of the 14q deletions. However, a group with the same del(14)(q24.1q32.33) was identified in 48% of cases. In this group, tri12 (P = 0.004) and NOTCH1 mutations (P = 0.02) were significantly more frequent than in the other patients. In CLL patients with del(14q), median treatment-free survival (TFS) was 27 months. In conclusion, del(14q) is associated with tri12 and with pejorative prognostic factors: unmutated IGHV genes (with over-representation of the IGHV1-69 repertoire), NOTCH1 mutations, and a short TFS. © 2014 Wiley Periodicals, Inc.

Evidence for the Induction of Key Components of the NOTCH Signaling Pathway via Deltamethrin and Azamethiphos Treatment in the Sea Louse Caligus rogercresseyi

PubMed Central

Boltaña, Sebastian; Chávez-Mardones, Jaqueline; Valenzuela-Muñoz, Valentina; Gallardo-Escárate, Cristian

2016-01-01

The extensive use of organophosphates and pyrethroids in the aquaculture industry has negatively impacted parasite sensitivity to the delousing effects of these antiparasitics, especially among sea lice species. The NOTCH signaling pathway is a positive regulator of ABC transporter subfamily C expression and plays a key role in the generation and modulation of pesticide resistance. However, little is known about the molecular mechanisms behind pesticide resistance, partly due to the lack of genomic and molecular information on the processes involved in the resistance mechanism of sea lice. Next-generation sequencing technologies provide an opportunity for rapid and cost-effective generation of genome-scale data. The present study, through RNA-seq analysis, determined that the sea louse Caligus rogercresseyi (C. rogercresseyi) specifically responds to the delousing drugs azamethiphos and deltamethrin at the transcriptomic level by differentially activating mRNA of the NOTCH signaling pathway and of ABC genes. These results suggest that frequent antiparasitic application may increase the activity of inhibitory mRNA components, thereby promoting inhibitory NOTCH output and conditions for increased resistance to delousing drugs. Moreover, data analysis underscored that key functions of NOTCH/ABC components were regulated during distinct phases of the drug response, thus indicating resistance modifications in C. rogercresseyi resulting from the frequent use of organophosphates and pyrethroids. PMID:27187362

Evidence for the Induction of Key Components of the NOTCH Signaling Pathway via Deltamethrin and Azamethiphos Treatment in the Sea Louse Caligus rogercresseyi.

PubMed

Boltaña, Sebastian; Chávez-Mardones, Jaqueline; Valenzuela-Muñoz, Valentina; Gallardo-Escárate, Cristian

2016-05-12

The extensive use of organophosphates and pyrethroids in the aquaculture industry has negatively impacted parasite sensitivity to the delousing effects of these antiparasitics, especially among sea lice species. The NOTCH signaling pathway is a positive regulator of ABC transporter subfamily C expression and plays a key role in the generation and modulation of pesticide resistance. However, little is known about the molecular mechanisms behind pesticide resistance, partly due to the lack of genomic and molecular information on the processes involved in the resistance mechanism of sea lice. Next-generation sequencing technologies provide an opportunity for rapid and cost-effective generation of genome-scale data. The present study, through RNA-seq analysis, determined that the sea louse Caligus rogercresseyi (C. rogercresseyi) specifically responds to the delousing drugs azamethiphos and deltamethrin at the transcriptomic level by differentially activating mRNA of the NOTCH signaling pathway and of ABC genes. These results suggest that frequent antiparasitic application may increase the activity of inhibitory mRNA components, thereby promoting inhibitory NOTCH output and conditions for increased resistance to delousing drugs. Moreover, data analysis underscored that key functions of NOTCH/ABC components were regulated during distinct phases of the drug response, thus indicating resistance modifications in C. rogercresseyi resulting from the frequent use of organophosphates and pyrethroids.

A Novel Notch-YAP Circuit Drives Stemness and Tumorigenesis in Embryonal Rhabdomyosarcoma.

PubMed

Slemmons, Katherine K; Crose, Lisa E S; Riedel, Stefan; Sushnitha, Manuela; Belyea, Brian; Linardic, Corinne M

2017-12-01

Rhabdomyosarcoma (RMS), a cancer characterized by skeletal muscle features, is the most common soft-tissue sarcoma of childhood. While low- and intermediate-risk groups have seen improved outcomes, high-risk patients still face a 5-year survival rate of <30%, a statistic that has not changed in over 40 years. Understanding the biologic underpinnings of RMS is critical. The developmental pathways of Notch and YAP have been identified as potent but independent oncogenic signals that support the embryonal variant of RMS (eRMS). Here, the cross-talk between these pathways and the impact on eRMS tumorigenesis is reported. Using human eRMS cells grown as three-dimensional (3D) rhabdospheres, which enriches in stem cells, it was found that Notch signaling transcriptionally upregulates YAP1 gene expression and YAP activity. Reciprocally, YAP transcriptionally upregulates the Notch ligand genes JAG1 and DLL1 and the core Notch transcription factor RBPJ This bidirectional circuit boosts expression of key stem cell genes, including SOX2 , which is functionally required for eRMS spheres. Silencing this circuit for therapeutic purposes may be challenging, because the inhibition of one node (e.g., pharmacologic Notch blockade) can be rescued by upregulation of another (constitutive YAP expression). Instead, dual inhibition of Notch and YAP is necessary. Finally, supporting the existence of this circuit beyond a model system, nuclear Notch and YAP protein expression are correlated in human eRMS tumors, and YAP suppression in vivo decreases Notch signaling and SOX2 expression. Implications: This study identifies a novel oncogenic signaling circuit driving eRMS stemness and tumorigenesis, and provides evidence and rationale for combination therapies co-targeting Notch and YAP. Mol Cancer Res; 15(12); 1777-91. ©2017 AACR . ©2017 American Association for Cancer Research.

Cbf11 and Cbf12, the fission yeast CSL proteins, play opposing roles in cell adhesion and coordination of cell and nuclear division

DOE Office of Scientific and Technical Information (OSTI.GOV)

Prevorovsky, Martin; Grousl, Tomas; Stanurova, Jana

The CSL (CBF1/RBP-J{kappa}/Suppressor of Hairless/LAG-1) family is comprised of transcription factors essential for metazoan development, mostly due to their involvement in the Notch receptor signaling pathway. Recently, we identified two novel classes of CSL genes in the genomes of several fungal species, organisms lacking the Notch pathway. In this study, we characterized experimentally cbf11{sup +} and cbf12{sup +}, the two CSL genes of Schizosaccharomyces pombe, in order to elucidate the CSL function in fungi. We provide evidence supporting their identity as genuine CSL genes. Both cbf11{sup +} and cbf12{sup +} are non-essential; they have distinct expression profiles and code formore » nuclear proteins with transcription activation potential. Significantly, we demonstrated that Cbf11 recognizes specifically the canonical CSL response element GTG{sup A}/{sub G}GAA in vitro. The deletion of cbf11{sup +} is associated with growth phenotypes and altered colony morphology. Furthermore, we found that Cbf11 and Cbf12 play opposite roles in cell adhesion, nuclear and cell division and their coordination. Disturbed balance of the two CSL proteins leads to cell separation defects (sep phenotype), cut phenotype, and high-frequency diploidization in heterothallic strains. Our data show that CSL proteins operate in an organism predating the Notch pathway, which should be of relevance to the understanding of (Notch-independent) CSL functions in metazoans.« less

The windowed sound therapy: a new empirical approach for an effectiv personalized treatment of tinnitus.

PubMed

Lugli, Marco; Romani, Romano; Ponzi, Stefano; Bacciu, Salvatore; Parmigiani, Stefano

2009-01-01

We auditorily stimulated patients affected by subjective tinnitus with broadband noise containing a notch around their tinnitus frequency. We assessed the long-term effects on tinnitus perception in patients listening to notched noise stimuli (referred to as windowed sound therapy [WST]) by measuring the variation of subjects' tinnitus loudness over a period of 2-12 months. We tested the effectiveness of WST using non-notched broadband noise and noise of water as control sound therapies. We found a significant long-term reduction of tinnitus loudness in subjects treated with notched noise but not in those treated with control stimulations. These results point to the importance of the personalized sound treatment of tinnitus sufferers for the development of an effective tinnitus sound therapy.

Lin28b is sufficient to drive liver cancer and necessary for its maintenance in murine models

PubMed Central

Nguyen, Liem H.; Robinton, Daisy A.; Seligson, Marc; Wu, Linwei; Li, Lin; Rakheja, Dinesh; Comerford, Sarah; Ramezani, Saleh; Sun, Xiankai; Parikh, Monisha; Yang, Erin; Powers, John T.; Shinoda, Gen; Shah, Samar; Hammer, Robert; Daley, George Q.; Zhu, Hao

2014-01-01

SUMMARY Lin28a/b are RNA-binding proteins that influence stem cell maintenance, metabolism, and oncogenesis. Poorly differentiated, aggressive cancers often overexpress Lin28, but its role in tumor initiation or maintenance has not been definitively addressed. We report that LIN28B overexpression is sufficient to initiate hepatoblastoma and hepatocellular carcinoma in murine models. We also detected Lin28b overexpression in MYC-driven hepatoblastomas, and liver-specific deletion of Lin28a/b reduced tumor burden, extended latency, and prolonged survival. Both intravenous siRNA against Lin28b and conditional Lin28b deletion reduced tumor burden and prolonged survival. Igf2bp proteins are upregulated and Igf2bp3 is required in the context of LIN28B overexpression to promote growth. Thus, multiple murine models demonstrate that Lin28b is both sufficient to initiate liver cancer and necessary for its maintenance. PMID:25117712

A reconfigurable microwave photonic filter with flexible tunability using a multi-wavelength laser and a multi-channel phase-shifted fiber Bragg grating

NASA Astrophysics Data System (ADS)

Shi, Nuannuan; Hao, Tengfei; Li, Wei; Zhu, Ninghua; Li, Ming

2018-01-01

We propose a photonic scheme to realize a reconfigurable microwave photonic filter (MPF) with flexible tunability using a multi-wavelength laser (MWL) and a multi-channel phase-shifted fiber Bragg grating (PS-FBG). The proposed MPF is capable of performing reconfigurability including single bandpass filter, two independently bandpass filter and a flat-top bandpass filter. The performance such as the central frequency and the bandwidth of passband is tuned by controlling the wavelengths of the MWL. In the MPF, The light waves from a MWL are sent to a phase modulator (PM) to generate the phase-modulated optical signals. By applying a multi-channel PS-FBG, which has a series of narrow notches in the reflection spectrum with the free spectral range (FSR) of 0.8 nm, the +1st sidebands are removed in the notches and the phased-modulated signals are converted to the intensity-modulated signals without beating signals generation between each two optical carriers. The proposed MPF is also experimentally verified. The 3-dB bandwidth of the MPF is broadened from 35 MHz to 135 MHz and the magnitude deviation of the top from the MPF is less than 0.2 dB within the frequency tunable range from 1 GHz to 5 GHz.

Egfl6 is involved in zebrafish notochord development.

PubMed

Wang, Xueqian; Wang, Xin; Yuan, Wei; Chai, Renjie; Liu, Dong

2015-08-01

The epidermal growth factor (EGF) repeat motif defines a superfamily of diverse protein involved in regulating a variety of cellular and physiological processes, such as cell cycle, cell adhesion, proliferation, migration, and neural development. Egfl6, an EGF protein, also named MAGE was first cloned in human tissue. Up to date, the study of zebrafish Egfl6 expression pattern and functional analysis of Egfl6 involved in embryonic development of vertebrate in vivo is thus far lacking. Here we reported that Egfl6 was involved in zebrafish notochord development. It was shown that Egfl6 mRNA was expressed in zebrafish, developing somites, fin epidermis, pharyngeal arches, and hindbrain region. Particularly the secreted Egfl6 protein was significantly accumulated in notochord. Loss of Egfl6 function in zebrafish embryos resulted in curved body with distorted notochord in the posterior trunk. It was observed that expression of all Notch ligand and receptors in notochord of 28 hpf Egfl6 morphants was not affected, except notch2, which was up-regulated. We found that inhibition of Notch signaling by DAPT efficiently rescued notochord developmental defect of Egfl6 deficiency embryos.

Partitioning-Defective 1a/b Depletion Impairs Glomerular and Proximal Tubule Development.

PubMed

Akchurin, Oleh; Du, Zhongfang; Ramkellawan, Nadira; Dalal, Vidhi; Han, Seung Hyeok; Pullman, James; Müsch, Anne; Susztak, Katalin; Reidy, Kimberly J

2016-12-01

The kidney is a highly polarized epithelial organ that develops from undifferentiated mesenchyme, although the mechanisms that regulate the development of renal epithelial polarity are incompletely understood. Partitioning-defective 1 (Par1) proteins have been implicated in cell polarity and epithelial morphogenesis; however, the role of these proteins in the developing kidney has not been established. Therefore, we studied the contribution of Par1a/b to renal epithelial development. We examined the renal phenotype of newborn compound mutant mice carrying only one allele of Par1a or Par1b. Loss of three out of four Par1a/b alleles resulted in severe renal hypoplasia, associated with impaired ureteric bud branching. Compared with kidneys of newborn control littermates, kidneys of newborn mutant mice exhibited dilated proximal tubules and immature glomeruli, and the renal proximal tubular epithelia lacked proper localization of adhesion complexes. Furthermore, Par1a/b mutants expressed low levels of renal Notch ligand Jag1, activated Notch2, and Notch effecter Hes1. Together, these data demonstrate that Par1a/b has a key role in glomerular and proximal tubule development, likely via modulation of Notch signaling. Copyright © 2016 by the American Society of Nephrology.

DNER, an epigenetically modulated gene, regulates glioblastoma-derived neurosphere cell differentiation and tumor propagation.

PubMed

Sun, Peng; Xia, Shuli; Lal, Bachchu; Eberhart, Charles G; Quinones-Hinojosa, Alfredo; Maciaczyk, Jarek; Matsui, William; Dimeco, Francesco; Piccirillo, Sara M; Vescovi, Angelo L; Laterra, John

2009-07-01

Neurospheres derived from glioblastoma (GBM) and other solid malignancies contain neoplastic stem-like cells that efficiently propagate tumor growth and resist cytotoxic therapeutics. The primary objective of this study was to use histone-modifying agents to elucidate mechanisms by which the phenotype and tumor-promoting capacity of GBM-derived neoplastic stem-like cells are regulated. Using established GBM-derived neurosphere lines and low passage primary GBM-derived neurospheres, we show that histone deacetylase (HDAC) inhibitors inhibit growth, induce differentiation, and induce apoptosis of neoplastic neurosphere cells. A specific gene product induced by HDAC inhibition, Delta/Notch-like epidermal growth factor-related receptor (DNER), inhibited the growth of GBM-derived neurospheres, induced their differentiation in vivo and in vitro, and inhibited their engraftment and growth as tumor xenografts. The differentiating and tumor suppressive effects of DNER, a noncanonical Notch ligand, contrast with the previously established tumor-promoting effects of canonical Notch signaling in brain cancer stem-like cells. Our findings are the first to implicate noncanonical Notch signaling in the regulation of neoplastic stem-like cells and suggest novel neoplastic stem cell targeting treatment strategies for GBM and potentially other solid malignancies.

First Report of Arg587Cys Mutation of Notch3 Gene in Two Chinese Families with CADASIL.

PubMed

You, Jinsong; Liao, Shaojun; Zhang, Foming; Ma, Zhaohui; Li, Guifu

2017-01-01

To explore Notch3 mutation sites of Chinese patients with cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL). Direct sequencing of all exons in Notch3 gene was performed on 12 unrelated suspected CADASIL cases from mainland China. A missense p.Arg587Cys (1759C>T) mutation in exon 11 was identified in 2 patients through genetic analysis. Chinese patients with CADASIL of R587C mutation in exon 11 was firstly reported. Copyright © 2017 National Stroke Association. Published by Elsevier Inc. All rights reserved.

Stochastic loss and gain of symmetric divisions in the C. elegans epidermis perturbs robustness of stem cell number

PubMed Central

Katsanos, Dimitris; Koneru, Sneha L.; Mestek Boukhibar, Lamia; Gritti, Nicola; Ghose, Ritobrata; Appleford, Peter J.; Doitsidou, Maria; Woollard, Alison; van Zon, Jeroen S.; Poole, Richard J.

2017-01-01

Biological systems are subject to inherent stochasticity. Nevertheless, development is remarkably robust, ensuring the consistency of key phenotypic traits such as correct cell numbers in a certain tissue. It is currently unclear which genes modulate phenotypic variability, what their relationship is to core components of developmental gene networks, and what is the developmental basis of variable phenotypes. Here, we start addressing these questions using the robust number of Caenorhabditis elegans epidermal stem cells, known as seam cells, as a readout. We employ genetics, cell lineage tracing, and single molecule imaging to show that mutations in lin-22, a Hes-related basic helix-loop-helix (bHLH) transcription factor, increase seam cell number variability. We show that the increase in phenotypic variability is due to stochastic conversion of normally symmetric cell divisions to asymmetric and vice versa during development, which affect the terminal seam cell number in opposing directions. We demonstrate that LIN-22 acts within the epidermal gene network to antagonise the Wnt signalling pathway. However, lin-22 mutants exhibit cell-to-cell variability in Wnt pathway activation, which correlates with and may drive phenotypic variability. Our study demonstrates the feasibility to study phenotypic trait variance in tractable model organisms using unbiased mutagenesis screens. PMID:29108019

PRODUCTION AND BIOLOGICAL SIGNIFICANCE OF METHYLATED TRIVALENT ARSENICALS

EPA Science Inventory

PRODUCTION AND BIOLOGICAL SIGNIFICANCE OF METHYLATED TRIVALENT ARSENICALS

Miroslav Styblo1,2,*, Zuzana Drobna1, Felecia S. Walton1, Ilona Jaspers1,2, Shan Lin3,
Stephen B. Waters3, David J. Thomas4

1Department of Pediatrics, 2Center for Environmental Medicine an...

[Valsartan inhibits angiotensin II-Notch signaling of mesangial cells induced by high glucose].

PubMed

Yuan, Qin; Lyu, Chuan; Wu, Can; Lei, Sha; Shao, Ying; Wang, Qiuyue

2016-01-01

To explore the role of angiotensin II (Ang II)-Notch signaling in high glucose-induced secretion of extracellular matrix of rat mesangial cells (RMCs) and to further investigate the protective effect of valsartan (one of Ang II receptor blockers) on kidney. Subcultured RMCs were divided into groups as follows: normal glucose group (5.5 mmol/L glucose); high glucose group (30 mmol/L glucose); high concentration of mannitol as osmotic control group (5.5 mmol/L glucose and 24.5 mmol/L mannitol); normal glucose plus 1 μmol/L N-[N-(3, 5-difluorophenacetyl)-L-alanyl ]-S-phenylglycine t-butyl ester (DAPT) group; normal glucose plus (1, 5, 10) μmol/L valsartan group; high glucose plus 1 μmol/L DAPT group; high glucose plus (1, 5, 10) μmol/L valsartan group. Cells and supernatants were harvested after 12, 24 and 48 hours. Notch1 expression was examined by Western blotting. Secretion of transforming growth factor (TGF-β) and fibronectin (FN) were detected by ELISA. Compared to the normal glucose group, Notch1 expression was elevated in the high glucose group after 12 hours, and peaked at 24 hours. Besides, secretion of TGF-β and FN were much higher in the high glucose group than in the normal glucose group in a time-dependent manner. Compared to the untreated group, Notch1 expression decreased in a dose-dependent manner in the valsartan or DAPT treated group under high glucose after 24 hours. After pre-treatment by either valsartan or DAPT in the high glucose group, secretion of TGF-β and FN obviously decreased as compared to the untreated group. Hyperglycemia could stimulate activation of Notch signaling in cultured RMCs, which may increase secretion of downstream fibrotic factors such as TGF-β and FN. Valsartan may decrease the secretion of downstream FN in a dose-dependent manner via inhibiting AngII-Notch signaling.

Initial results on computational performance of Intel Many Integrated Core (MIC) architecture: implementation of the Weather and Research Forecasting (WRF) Purdue-Lin microphysics scheme

NASA Astrophysics Data System (ADS)

Mielikainen, Jarno; Huang, Bormin; Huang, Allen H.

2014-10-01

Purdue-Lin scheme is a relatively sophisticated microphysics scheme in the Weather Research and Forecasting (WRF) model. The scheme includes six classes of hydro meteors: water vapor, cloud water, raid, cloud ice, snow and graupel. The scheme is very suitable for massively parallel computation as there are no interactions among horizontal grid points. In this paper, we accelerate the Purdue Lin scheme using Intel Many Integrated Core Architecture (MIC) hardware. The Intel Xeon Phi is a high performance coprocessor consists of up to 61 cores. The Xeon Phi is connected to a CPU via the PCI Express (PICe) bus. In this paper, we will discuss in detail the code optimization issues encountered while tuning the Purdue-Lin microphysics Fortran code for Xeon Phi. In particularly, getting a good performance required utilizing multiple cores, the wide vector operations and make efficient use of memory. The results show that the optimizations improved performance of the original code on Xeon Phi 5110P by a factor of 4.2x. Furthermore, the same optimizations improved performance on Intel Xeon E5-2603 CPU by a factor of 1.2x compared to the original code.

Modulation of gene expression via overlapping binding sites exerted by ZNF143, Notch1 and THAP11

PubMed Central

Ngondo-Mbongo, Richard Patryk; Myslinski, Evelyne; Aster, Jon C.; Carbon, Philippe

2013-01-01

ZNF143 is a zinc-finger protein involved in the transcriptional regulation of both coding and non-coding genes from polymerase II and III promoters. Our study deciphers the genome-wide regulatory role of ZNF143 in relation with the two previously unrelated transcription factors Notch1/ICN1 and thanatos-associated protein 11 (THAP11) in several human and murine cells. We show that two distinct motifs, SBS1 and SBS2, are associated to ZNF143-binding events in promoters of >3000 genes. Without co-occupation, these sites are also bound by Notch1/ICN1 in T-lymphoblastic leukaemia cells as well as by THAP11, a factor involved in self-renewal of embryonic stem cells. We present evidence that ICN1 binding overlaps with ZNF143 binding events at the SBS1 and SBS2 motifs, whereas the overlap occurs only at SBS2 for THAP11. We demonstrate that the three factors modulate expression of common target genes through the mutually exclusive occupation of overlapping binding sites. The model we propose predicts that the binding competition between the three factors controls biological processes such as rapid cell growth of both neoplastic and stem cells. Overall, our study establishes a novel relationship between ZNF143, THAP11 and ICN1 and reveals important insights into ZNF143-mediated gene regulation. PMID:23408857

Convective and microphysics parameterization impact on simulating heavy rainfall in Semarang (case study on February 12th, 2015)

NASA Astrophysics Data System (ADS)

Faridatussafura, Nurzaka; Wandala, Agie

2018-05-01

The meteorological model WRF-ARW version 3.8.1 is used for simulating the heavy rainfall in Semarang that occurred on February 12th, 2015. Two different convective schemes and two different microphysics scheme in a nested configuration were chosen. The sensitivity of those schemes in capturing the extreme weather event has been tested. GFS data were used for the initial and boundary condition. Verification on the twenty-four hours accumulated rainfall using GSMaPsatellite data shows that Kain-Fritsch convective scheme and Lin microphysics scheme is the best combination scheme among the others. The combination also gives the highest success ratio value in placing high intensity rainfall area. Based on the ROC diagram, KF-Lin shows the best performance in detecting high intensity rainfall. However, the combination still has high bias value.

Notch3 inhibits epithelial–mesenchymal transition by activating Kibra-mediated Hippo/YAP signaling in breast cancer epithelial cells

PubMed Central

Zhang, X; Liu, X; Luo, J; Xiao, W; Ye, X; Chen, M; Li, Y; Zhang, G-J

2016-01-01

Invasion, metastasis and chemoresistance are leading causes of death in breast cancer patients. A vital change of epithelial cells, epithelial–mesenchymal transition (EMT), is involved in these processes. Unfortunately, the molecular mechanisms controlling EMT remain to be elucidated. Our previous studies have shown that ectopic N3ICD expression inhibits EMT in MDA-MB-231, a triple-negative breast cancer (TNBC) epithelial cell line. To decipher the mechanism, we performed in-depth studies. Specifically, we found that overexpressing N3ICD transcriptionally upregulated the expression of Kibra, an upstream member of the Hippo pathway. Correspondingly, we also observed that phosphorylated Hippo pathway core kinases, including Lats1/2 and MST1/2, were increased and decreased by overexpressing and knocking down Notch3, respectively. Furthermore, we found that the oncogenic transcriptional coactivator yes-associated protein (YAP), which is negatively regulated by the Hippo pathway, was inhibited by overexpressing N3ICD in breast cancer epithelial cells. The ability of Kibra to inhibit EMT has been previously reported. We thus speculated that Notch3 inhibition of EMT is mediated by upregulated Kibra. To verify this hypothesis, a rescue experiment was performed. Evidently, the ability of Notch3 to inhibit EMT can be countered by knocking down Kibra expression. These data suggest that Notch3 inhibits EMT by activating the Hippo/YAP pathway by upregulating Kibra in breast cancer epithelial cells, and Kibra may be a downstream effector of Notch3. These findings deepen our understanding of EMT in both development and disease, and will undoubtedly help to provide new therapeutic strategies for interfering with cancer invasion and metastasis, especially for TNBC. PMID:27841855

NOR1 promotes hepatocellular carcinoma cell proliferation and migration through modulating the Notch signaling pathway

DOE Office of Scientific and Technical Information (OSTI.GOV)

You, Kun; Sun, Peisheng; Yue, Zhongyi

Hepatocellular carcinoma (HCC) is one of the most common malignant tumors worldwide. Previous studies have reported that the oxidored-nitro domain containing protein 1 (NOR1) is a novel tumor suppressor in several tumors. Recent evidence suggests that NOR1 is strongly expressed in HCC cells. However, its role and mechanism in HCC are unclear. In the current study, Western blot and qPCR detected strong NOR1 mRNA and protein expression in HepG2 and Hep3B cells. After transfection with NOR1 siRNA or pcDNA3.1-myc-his-NOR1, the proliferation and migration of HepG2 and Hep3B cells were analyzed in vitro. HepG2 or Hep3B cells overexpressing NOR1 showed anmore » increased proliferation and migration, whereas siRNA-mediated silencing of NOR1 showed the opposite effect. Furthermore, NOR1 activated the Notch signaling pathway, indicated by increased levels of Notch1, NICD, Hes1, and Hey1 in protein. Importantly, the Notch inhibitor DAPT downregulated Notch activation and further enhanced siNOR1-induced reduction of cell proliferation and migration in HepG2 and Hep3B cells, whereas DAPT reversed the effect of NOR1 overexpression on cell proliferation and migration. In conclusion, these results indicate that NOR1 may be involved in the progression of HCC and thus may be a potential target for the treatment of liver cancer. - Highlights: • NOR1 expression is up-regulated in HCC cells. • NOR1 promotes the proliferation and migration of HCC cells. • NOR1 promotes the progression of HCC cells by activating Notch pathway.« less

Differential regulation of Hes/Hey genes during inner ear development.

PubMed

Petrovic, Jelena; Gálvez, Hector; Neves, Joana; Abelló, Gina; Giraldez, Fernando

2015-07-01

Notch signaling plays a crucial role during inner ear development and regeneration. Hes/Hey genes encode for bHLH transcription factors identified as Notch targets. We have studied the expression and regulation of Hes/Hey genes during inner ear development in the chicken embryo. Among several Hes/Hey genes examined, only Hey1 and Hes5 map to the sensory regions, although with salient differences. Hey1 expression follows Jag1 expression except at early prosensory stages while Hes5 expression corresponds well to Dl1 expression throughout otic development. Although Hey1 and Hes5 are direct Notch downstream targets, they differ in the level of Notch required for activation. Moreover, they also differ in mRNA stability, showing different temporal decays after Notch blockade. In addition, Bmp, Wnt and Fgf pathways also modify Hey1 and Hes5 expression in the inner ear. Particularly, the Wnt pathway modulates Hey1 and Jag1 expression. Finally, gain of function experiments show that Hey1 and Hes5 cross-regulate each other in a complex manner. Both Hey1 and Hes5 repress Dl1 and Hes5 expression, suggesting that they prevent the transition to differentiation stages, probably by preventing Atoh1 expression. In spite of its association with Jag1, Hey1 does not seem to be instrumental for lateral induction as it does not promote Jag1 expression. We suggest that, besides being both targets of Notch, Hey1 and Hes5 are subject to a rather complex regulation that includes the stability of their transcripts, cross regulation and other signaling pathways. © 2014 Wiley Periodicals, Inc.

Developmental expression of the Notch signaling pathway genes during mouse preimplantation development.

PubMed

Cormier, Sarah; Vandormael-Pournin, Sandrine; Babinet, Charles; Cohen-Tannoudji, Michel

2004-10-01

Notch signaling is an evolutionary conserved pathway involved in intercellular signaling and essential for proper cell fate choices during development. Thus, it could be involved in mouse preimplantation development where intercellular signaling plays a crucial role, particularly between the inner cell mass and the trophectoderm of the blastocyst. At their face value, the phenotypes observed when disrupting each of the four Notch genes known in the mouse do not support this view as none of them involves perturbation of preimplantation development. However this could be due to functional redundancy and/or maternal expression. As a first step to address this issue, we decided to examine the expression in early development of various genes known to participate in Notch signaling. Here, we report on the expression pattern of Notch1-4, Jagged1 (Jag1), Jag2, Delta-like1 (Dll-1), Dll-3, Dll-4, Rbpsuh, Deltex1(Dtx1)and Dtx2 genes during preimplantation development from unfertilized eggs until late blastocyst stage using a RT-PCR strategy. We show that Notch1, 2, Jag1-2, Dll-3, Rbpsuh and Dtx2 transcripts are expressed at all stages. Notch4 and Dll-4 mRNAs are synthesized from the 2-cell through to the hatched blastocyst stage. Notch3, Dll-1 and Dtx1exhibit a stage dependent expression as their mRNAs are detected in 2-cell embryos and in hatched blastocysts, but are absent or weakly detected at the morula stage. Finally, we show that all the above genes are expressed both in Embryonic and Trophoblast Stem cells (ES and TS cells, respectively). Our results suggest that the Notch pathway may be active during mouse preimplantation development.

Lin28a regulates germ cell pool size and fertility

PubMed Central

Shinoda, Gen; de Soysa, T. Yvanka; Seligson, Marc T.; Yabuuchi, Akiko; Fujiwara, Yuko; Huang, Pei Yi; Hagan, John P.; Gregory, Richard I.; Moss, Eric G.; Daley, George Q.

2013-01-01

Overexpression of LIN28A is associated with human germ cell tumors and promotes primordial germ cell (PGC) development from embryonic stem cells in vitro and in chimeric mice. Knockdown of Lin28a inhibits PGC development in vitro, but how constitutional Lin28a deficiency affects the mammalian reproductive system in vivo remains unknown. Here, we generated Lin28a knockout (KO) mice and found that Lin28a deficiency compromises the size of the germ cell pool in both males and females by affecting PGC proliferation during embryogenesis. Interestingly however, in Lin28a KO males the germ cell pool partially recovers during postnatal expansion, while fertility remains impaired in both males and females mated to wild type mice. Embryonic overexpression of let-7, a microRNA negatively regulated by Lin28a, reduces the germ cell pool, corroborating the role of the Lin28a/let-7 axis in regulating the germ lineage. PMID:23378032

Reciprocal Expression of lin-41 and the microRNAs let-7 and mir-125 During Mouse Embryogenesis

PubMed Central

Schulman, Betsy R. Maller; Esquela-Kerscher, Aurora; Slack, Frank J.

2008-01-01

In C. elegans, heterochronic genes control the timing of cell fate determination during development. Two heterochronic genes, let-7 and lin-4, encode microRNAs (miRNAs) that down-regulate a third heterochronic gene lin-41 by binding to complementary sites in its 3’UTR. let-7 and lin-4 are conserved in mammals. Here we report the cloning and sequencing of mammalian lin-41 orthologs. We find that mouse and human lin-41 genes contain predicted conserved complementary sites for let-7 and the lin-4 ortholog, mir-125, in their 3’UTRs. Mouse lin-41 (Mlin-41) is temporally expressed in developing mouse embryos, most dramatically in the limb buds. Mlin-41 is down-regulated during mid-embryogenesis at the time when mouse let-7c and mir-125 RNA levels are up-regulated. Our results suggest that mammalian lin-41 is temporally regulated by miRNAs in order to direct key developmental events such as limb formation. PMID:16247770

A Network of Genes Antagonistic to the LIN-35 Retinoblastoma Protein of Caenorhabditis elegans

PubMed Central

Polley, Stanley R. G.; Fay, David S.

2012-01-01

The Caenorhabditis elegans pRb ortholog, LIN-35, functions in a wide range of cellular and developmental processes. This includes a role of LIN-35 in nutrient utilization by the intestine, which it carries out redundantly with SLR-2, a zinc-finger protein. This and other redundant functions of LIN-35 were identified in genetic screens for mutations that display synthetic phenotypes in conjunction with loss of lin-35. To explore the intestinal role of LIN-35, we conducted a genome-wide RNA-interference-feeding screen for suppressors of lin-35; slr-2 early larval arrest. Of the 26 suppressors identified, 17 fall into three functional classes: (1) ribosome biogenesis genes, (2) mitochondrial prohibitins, and (3) chromatin regulators. Further characterization indicates that different categories of suppressors act through distinct molecular mechanisms. We also tested lin-35; slr-2 suppressors, as well as suppressors of the synthetic multivulval phenotype, to determine the spectrum of lin-35-synthetic phenotypes that could be suppressed following inhibition of these genes. We identified 19 genes, most of which are evolutionarily conserved, that can suppress multiple unrelated lin-35-synthetic phenotypes. Our study reveals a network of genes broadly antagonistic to LIN-35 as well as genes specific to the role of LIN-35 in intestinal and vulval development. Suppressors of multiple lin-35 phenotypes may be candidate targets for anticancer therapies. Moreover, screening for suppressors of phenotypically distinct synthetic interactions, which share a common altered gene, may prove to be a novel and effective approach for identifying genes whose activities are most directly relevant to the core functions of the shared gene. PMID:22542970

CPW fed UWB antenna with enhanced bandwidth & dual band notch characteristics

NASA Astrophysics Data System (ADS)

Jangid, K. G.; Jain, P. K.; Sharma, B. R.; Saxena, V. K.; Kulhar, V. S.; Bhatnagar, D.

2018-05-01

This paper reports the design and performance of CPW fed UWB antenna having two U-shaped slots etched in the radiating structure. UWB performance of proposed structure is obtained through the truncated shape of the patch and L-slits etched in ground plane. By applying two U- shaped slots in a radiating patch, we achieved dual notch band characteristics. The proposed antenna is simulated by applying CST Microwave Studio simulator. This antenna provides wide impedance bandwidth of 12.585 GHz (2.74GHz - 15.325 GHz) with dual notched band characteristics. This antenna may be proved as a useful structure for modern wireless communication systems including UWB band.

Endothelial cells dynamically compete for the tip cell position during angiogenic sprouting.

PubMed

Jakobsson, Lars; Franco, Claudio A; Bentley, Katie; Collins, Russell T; Ponsioen, Bas; Aspalter, Irene M; Rosewell, Ian; Busse, Marta; Thurston, Gavin; Medvinsky, Alexander; Schulte-Merker, Stefan; Gerhardt, Holger

2010-10-01

Sprouting angiogenesis requires the coordinated behaviour of endothelial cells, regulated by Notch and vascular endothelial growth factor receptor (VEGFR) signalling. Here, we use computational modelling and genetic mosaic sprouting assays in vitro and in vivo to investigate the regulation and dynamics of endothelial cells during tip cell selection. We find that endothelial cells compete for the tip cell position through relative levels of Vegfr1 and Vegfr2, demonstrating a biological role for differential Vegfr regulation in individual endothelial cells. Differential Vegfr levels affect tip selection only in the presence of a functional Notch system by modulating the expression of the ligand Dll4. Time-lapse microscopy imaging of mosaic sprouts identifies dynamic position shuffling of tip and stalk cells in vitro and in vivo, indicating that the VEGFR-Dll4-Notch signalling circuit is constantly re-evaluated as cells meet new neighbours. The regular exchange of the leading tip cell raises novel implications for the concept of guided angiogenic sprouting.

Integrated β-catenin, BMP, PTEN, and Notch signalling patterns the nephron.

PubMed

Lindström, Nils O; Lawrence, Melanie L; Burn, Sally F; Johansson, Jeanette A; Bakker, Elvira R M; Ridgway, Rachel A; Chang, C-Hong; Karolak, Michele J; Oxburgh, Leif; Headon, Denis J; Sansom, Owen J; Smits, Ron; Davies, Jamie A; Hohenstein, Peter

2015-02-03

The different segments of the nephron and glomerulus in the kidney balance the processes of water homeostasis, solute recovery, blood filtration, and metabolite excretion. When segment function is disrupted, a range of pathological features are presented. Little is known about nephron patterning during embryogenesis. In this study, we demonstrate that the early nephron is patterned by a gradient in β-catenin activity along the axis of the nephron tubule. By modifying β-catenin activity, we force cells within nephrons to differentiate according to the imposed β-catenin activity level, thereby causing spatial shifts in nephron segments. The β-catenin signalling gradient interacts with the BMP pathway which, through PTEN/PI3K/AKT signalling, antagonises β-catenin activity and promotes segment identities associated with low β-catenin activity. β-catenin activity and PI3K signalling also integrate with Notch signalling to control segmentation: modulating β-catenin activity or PI3K rescues segment identities normally lost by inhibition of Notch. Our data therefore identifies a molecular network for nephron patterning.

Uncontrolled angiogenic precursor expansion causes coronary artery anomalies in mice lacking Pofut1.

PubMed

Wang, Yidong; Wu, Bingruo; Lu, Pengfei; Zhang, Donghong; Wu, Brian; Varshney, Shweta; Del Monte-Nieto, Gonzalo; Zhuang, Zhenwu; Charafeddine, Rabab; Kramer, Adam H; Sibinga, Nicolas E; Frangogiannis, Nikolaos G; Kitsis, Richard N; Adams, Ralf H; Alitalo, Kari; Sharp, David J; Harvey, Richard P; Stanley, Pamela; Zhou, Bin

2017-09-18

Coronary artery anomalies may cause life-threatening cardiac complications; however, developmental mechanisms underpinning coronary artery formation remain ill-defined. Here we identify an angiogenic cell population for coronary artery formation in mice. Regulated by a DLL4/NOTCH1/VEGFA/VEGFR2 signaling axis, these angiogenic cells generate mature coronary arteries. The NOTCH modulator POFUT1 critically regulates this signaling axis. POFUT1 inactivation disrupts signaling events and results in excessive angiogenic cell proliferation and plexus formation, leading to anomalous coronary arteries, myocardial infarction and heart failure. Simultaneous VEGFR2 inactivation fully rescues these defects. These findings show that dysregulated angiogenic precursors link coronary anomalies to ischemic heart disease.Though coronary arteries are crucial for heart function, the mechanisms guiding their formation are largely unknown. Here, Wang et al. identify a unique, endocardially-derived angiogenic precursor cell population for coronary artery formation in mice and show that a DLL4/NOTCH1/VEGFA/VEGFR2 signaling axis is key for coronary artery development.

Molecular mechanism of central nervous system repair by the Drosophila NG2 homologue kon-tiki

PubMed Central

Harrison, Neale

2016-01-01

Neuron glia antigen 2 (NG2)–positive glia are repair cells that proliferate upon central nervous system (CNS) damage, promoting functional recovery. However, repair is limited because of the failure of the newly produced glial cells to differentiate. It is a key goal to discover how to regulate NG2 to enable glial proliferation and differentiation conducive to repair. Drosophila has an NG2 homologue called kon-tiki (kon), of unknown CNS function. We show that kon promotes repair and identify the underlying mechanism. Crush injury up-regulates kon expression downstream of Notch. Kon in turn induces glial proliferation and initiates glial differentiation by activating glial genes and prospero (pros). Two negative feedback loops with Notch and Pros allow Kon to drive the homeostatic regulation required for repair. By modulating Kon levels in glia, we could prevent or promote CNS repair. Thus, the functional links between Kon, Notch, and Pros are essential for, and can drive, repair. Analogous mechanisms could promote CNS repair in mammals. PMID:27551055

A Novel Approach to Photonic Generation and Modulation of Ultra-Wideband Pulses

NASA Astrophysics Data System (ADS)

Xiang, Peng; Guo, Hao; Chen, Dalei; Zhu, Huatao

2016-01-01

A novel approach to photonic generation of ultra-wideband (UWB) signals is proposed in this paper. The proposed signal generator is capable of generating UWB doublet pulses with flexible reconfigurability, and many different pulse modulation formats, including the commonly used pulse-position modulation (PPM) and bi-phase modulation (BPM) can be realized. Moreover, the photonic UWB pulse generator is capable of generating UWB signals with a tunable spectral notch-band, which is desirable to realize the interference avoidance between UWB and other narrow band systems, such as Wi-Fi. A mathematical model describing the proposed system is developed and the generation of UWB signals with different modulation formats is demonstrated via computer simulations.

Lin28 induces resistance to anti-androgens via promotion of AR splice variant generation.

PubMed

Tummala, Ramakumar; Nadiminty, Nagalakshmi; Lou, Wei; Evans, Christopher P; Gao, Allen C

2016-04-01

Prostate cancer (PCa) is androgen-dependent initially and progresses to a castration-resistant state after androgen deprivation therapy. Treatment options for castration-resistant PCa include the potent second-generation anti-androgen enzalutamide or CYP17A1 inhibitor abiraterone. Recent clinical observations point to the development of resistance to these therapies which may be mediated by constitutively active alternative splice variants of the androgen receptor (AR). Sensitivity of LNCaP cells overexpressing Lin28 (LN-Lin28) to enzalutamide, abiraterone, or bicalutamide was compared to that of control LN-neo cells using cell growth assays, proliferation assays using MTT, anchorage-dependent clonogenic ability assays and soft agar assays. Ability of LN-Lin28 cells to maintain AR activation after treatment with enzalutamide, abiraterone, or bicalutamide was tested using immunofluorescence, Western blotting, ChIP assays, and qRT-PCR. Importance of Lin28 in enzalutamide resistance was assessed by the downregulation of Lin28 expression in C4-2B and 22Rv1 cells chronically treated with enzalutamide. Requirement for sustained AR signaling in LN-Lin28 cells was examined by the downregulation of either full length AR or AR-V7 using siRNA. We show that Lin28 promotes the development of resistance to currently used targeted therapeutics by enhancing the expression of AR splice variants such as AR-V7. PCa cells overexpressing Lin28 exhibit resistance to treatment with enzalutamide, abiraterone, or bicalutamide. Downregulation of Lin28 resensitizes enzalutamide-resistant PCa cells to enzalutamide treatment. We also show that the upregulation of splicing factors such as hnRNPA1 by Lin28 may mediate the enhanced generation of AR splice variants in Lin28-expressing cells. Our findings suggest that Lin28 plays a key role in the acquisition of resistance to AR-targeted therapies by PCa cells and establish the importance of Lin28 in PCa progression. © 2015 Wiley Periodicals, Inc.

The Lin28 Expression in Stallion Testes.

PubMed

Lee, Geumhui; Jung, Heejun; Yoon, Minjung

2016-01-01

The molecular markers for specific germ cell stages can be utilized for identifying, monitoring, and separating a particular stage of germ cells. The RNA-binding protein Lin28 is expressed in gonocytes of human fetal testes. The Lin28 expression is restricted to a very small population of spermatogonial cells in human, mice, and monkey. The main objective of this study was to investigate the expression pattern of Lin28 in stallion testes at different reproductive stages. Based on the presence or absence of full spermatogenesis and lumina in seminiferous tubules, the testicular samples were categorized into two reproductive stages pre-pubertal and post-pubertal. We performed a reverse transcription polymerase chain reaction to confirm the presence of Lin28 mRNA in the testicular tissues and a western blot analysis to verify the cross-reactivity of rabbit Lin28 antibody with horse testicular tissue. For immunohistochemistry, Lin28 (rabbit anti-human), GATA4 (goat anti-human) or DAZL (goat anti-human) antibodies were used. The results of RT-PCR confirmed the expression of Lin28 mRNA in the stallion testes. The western blot analysis showed that the expression of 28 kDa Lin28 protein was localized in the cytoplasm of spermatogonia at both reproductive stages. The numbers of Lin28-positive germ cells per 1000 Sertoli cells in pre- and post-pubertal stages were 253 ± 8.66 and 29.67 ± 2.18, respectively. At both reproductive stages, all Lin28 positive cells showed no co-stained with GATA4 antibody, whereas only some of the Lin28-positive germ cells showed co-staining with DAZL antibody. The results from whole-mount staining showed that the Lin28 expression was limited to Asingle (As) and Apaired (Apr) spermatogonia. In conclusion, Lin28 might be utilized as a molecular marker for undifferentiated spermatogonial stem cells when used with DAZL antibody.

The Lin28 Expression in Stallion Testes

PubMed Central

Yoon, Minjung

2016-01-01

The molecular markers for specific germ cell stages can be utilized for identifying, monitoring, and separating a particular stage of germ cells. The RNA-binding protein Lin28 is expressed in gonocytes of human fetal testes. The Lin28 expression is restricted to a very small population of spermatogonial cells in human, mice, and monkey. The main objective of this study was to investigate the expression pattern of Lin28 in stallion testes at different reproductive stages. Based on the presence or absence of full spermatogenesis and lumina in seminiferous tubules, the testicular samples were categorized into two reproductive stages pre-pubertal and post-pubertal. We performed a reverse transcription polymerase chain reaction to confirm the presence of Lin28 mRNA in the testicular tissues and a western blot analysis to verify the cross-reactivity of rabbit Lin28 antibody with horse testicular tissue. For immunohistochemistry, Lin28 (rabbit anti-human), GATA4 (goat anti-human) or DAZL (goat anti-human) antibodies were used. The results of RT-PCR confirmed the expression of Lin28 mRNA in the stallion testes. The western blot analysis showed that the expression of 28 kDa Lin28 protein was localized in the cytoplasm of spermatogonia at both reproductive stages. The numbers of Lin28-positive germ cells per 1000 Sertoli cells in pre- and post-pubertal stages were 253 ± 8.66 and 29.67 ± 2.18, respectively. At both reproductive stages, all Lin28 positive cells showed no co-stained with GATA4 antibody, whereas only some of the Lin28-positive germ cells showed co-staining with DAZL antibody. The results from whole-mount staining showed that the Lin28 expression was limited to Asingle (As) and Apaired (Apr) spermatogonia. In conclusion, Lin28 might be utilized as a molecular marker for undifferentiated spermatogonial stem cells when used with DAZL antibody. PMID:27798668

Lin-28 binds IGF-2 mRNA and participates in skeletal myogenesis by increasing translation efficiency.

PubMed

Polesskaya, Anna; Cuvellier, Sylvain; Naguibneva, Irina; Duquet, Arnaud; Moss, Eric G; Harel-Bellan, Annick

2007-05-01

Lin-28 is a highly conserved, RNA-binding, microRNA-regulated protein that is involved in regulation of developmental timing in Caenorhabditis elegans. In mammals, Lin-28 is stage-specifically expressed in embryonic muscle, neurons, and epithelia, as well as in embryonic carcinoma cells, but is suppressed in most adult tissues, with the notable exception of skeletal and cardiac muscle. The specific function and mechanism of action of Lin-28 are not well understood. Here we used loss-of-function and gain-of-function assays in cultured myoblasts to show that expression of Lin-28 is essential for skeletal muscle differentiation in mice. In order to elucidate the specific function of Lin-28, we used a combination of biochemical and functional assays, which revealed that, in differentiating myoblasts, Lin-28 binds to the polysomes and increases the efficiency of protein synthesis. An important target of Lin-28 is IGF-2, a crucial growth and differentiation factor for muscle tissue. Interaction of Lin-28 with translation initiation complexes in skeletal myoblasts and in the embryonic carcinoma cell line P19 was confirmed by localization of Lin-28 to the stress granules, temporary structures that contain stalled mRNA-protein translation complexes. Our results unravel novel mechanisms of translational regulation in skeletal muscle and suggest that Lin-28 performs the role of "translational enhancer" in embryonic and adult cells and tissues.

Dynamic gene expression of Lin-28 during embryonic development in mouse and chicken.

PubMed

Yokoyama, Shigetoshi; Hashimoto, Megumi; Shimizu, Hirohito; Ueno-Kudoh, Hiroe; Uchibe, Kenta; Kimura, Ichiro; Asahara, Hiroshi

2008-02-01

The Caenorhabditis elegans heterochronic gene lin-28 regulates developmental timing in the nematode trunk. We report the dynamic expression patterns of Lin-28 homologues in mouse and chick embryos. Whole mount in situ hybridization revealed specific and intriguing expression patterns of Lin-28 in the developing mouse and chick limb bud. Mouse Lin-28 expression was detected in both the forelimb and hindlimb at E9.5, but disappeared from the forelimb at E10.5, and finally from the forelimb and hindlimb at E11.5. Chicken Lin-28, which was first detected in the limb primordium at stage 15/16, was also downregulated as the stage proceeded. The amino acid sequences of mouse and chicken Lin-28 genes are highly conserved and the similar expression patterns of Lin-28 during limb development in mouse and chicken suggest that this heterochronic gene is also conserved during vertebrate limb development.

Monocyte to macrophage differentiation-associated (MMD) positively regulates ERK and Akt activation and TNF-α and NO production in macrophages.

PubMed

Liu, Qiang; Zheng, Jin; Yin, Dan-Dan; Xiang, Jie; He, Fei; Wang, Yao-Chun; Liang, Liang; Qin, Hong-Yan; Liu, Li; Liang, Ying-Min; Han, Hua

2012-05-01

Macrophage activation is modulated by both environmental cues and endogenous programs. In the present study, we investigated the role of a PAQR family protein, monocyte to macrophage differentiation-associated (MMD), in macrophage activation and unveiled its underlying molecular mechanism. Our results showed that while MMD expression could be detected in all tissues examined, its expression level is significantly up-regulated upon monocyte differentiation. Within cells, EGFP-MMD fusion protein could be co-localized to endoplasmic reticulum, mitochondria, Golgi apparatus, but not lysosomes and cytoplasm. MMD expression is up-regulated in macrophages after LPS stimulation, and this might be modulated by RBP-J, the critical transcription factor of Notch signaling. Overexpression of MMD in macrophages increased the production of TNF-α and NO upon LPS stimulation. We found that MMD overexpression enhanced ERK1/2 and Akt phosphorylation in macrophages after LPS stimulation. Blocking Erk or Akt by pharmacological agent reduced TNF-α or NO production in MMD-overexpressing macrophages, respectively. These results suggested that MMD modulates TNF-α and NO production in macrophages, and this process might involves Erk or Akt.

Increased leukemia-associated gene expression in benzene-exposed workers

PubMed Central

Li, Keqiu; Jing, Yaqing; Yang, Caihong; Liu, Shasha; Zhao, Yuxia; He, Xiaobo; Li, Fei; Han, Jiayi; Li, Guang

2014-01-01

Long-term exposure to benzene causes several adverse health effects, including an increased risk of acute myeloid leukemia. This study was to identify genetic alternations involved in pathogenesis of leukemia in benzene-exposed workers without clinical symptoms of leukemia. This study included 33 shoe-factory workers exposed to benzene at levels from 1 ppm to 10 ppm. These workers were divided into 3 groups based on the benzene exposure time, 1- < 7, 7- < 12, and 12- < 24 years. 17 individuals without benzene exposure history were recruited as controls. Cytogenetic analysis using Affymetrix Cytogenetics Array found copy-number variations (CNVs) in several chromosomes of benzene-exposed workers. Expression of targeted genes in these altered chromosomes, NOTCH1 and BSG, which play roles in leukemia pathogenesis, was further examined using real-time PCR. The NOTCH1 mRNA level was significantly increased in all 3 groups of workers, and the NOTCH1 mRNA level in the 12- < 24 years group was significantly higher than that in 1- < 7 and 7- < 12 years groups. Compared to the controls, the BSG mRNA level was significantly increased in 7- < 12 and 12- < 24 years groups, but not in the 1- < 7 years group. These results suggest that CNVs and leukemia-related gene expression might play roles in leukemia development in benzene-exposed workers. PMID:24993241

Multiple transcription factors directly regulate Hox gene lin-39 expression in ventral hypodermal cells of the C. elegans embryo and larva, including the hypodermal fate regulators LIN-26 and ELT-6.

PubMed

Liu, Wan-Ju; Reece-Hoyes, John S; Walhout, Albertha J M; Eisenmann, David M

2014-05-13

Hox genes encode master regulators of regional fate specification during early metazoan development. Much is known about the initiation and regulation of Hox gene expression in Drosophila and vertebrates, but less is known in the non-arthropod invertebrate model system, C. elegans. The C. elegans Hox gene lin-39 is required for correct fate specification in the midbody region, including the Vulval Precursor Cells (VPCs). To better understand lin-39 regulation and function, we aimed to identify transcription factors necessary for lin-39 expression in the VPCs, and in particular sought factors that initiate lin-39 expression in the embryo. We used the yeast one-hybrid (Y1H) method to screen for factors that bound to 13 fragments from the lin-39 region: twelve fragments contained sequences conserved between C. elegans and two other nematode species, while one fragment was known to drive reporter gene expression in the early embryo in cells that generate the VPCs. Sixteen transcription factors that bind to eight lin-39 genomic fragments were identified in yeast, and we characterized several factors by verifying their physical interactions in vitro, and showing that reduction of their function leads to alterations in lin-39 levels and lin-39::GFP reporter expression in vivo. Three factors, the orphan nuclear hormone receptor NHR-43, the hypodermal fate regulator LIN-26, and the GATA factor ELT-6 positively regulate lin-39 expression in the embryonic precursors to the VPCs. In particular, ELT-6 interacts with an enhancer that drives GFP expression in the early embryo, and the ELT-6 site we identified is necessary for proper embryonic expression. These three factors, along with the factors ZTF-17, BED-3 and TBX-9, also positively regulate lin-39 expression in the larval VPCs. These results significantly expand the number of factors known to directly bind and regulate lin-39 expression, identify the first factors required for lin-39 expression in the embryo, and hint at a positive feedback mechanism involving GATA factors that maintains lin-39 expression in the vulval lineage. This work indicates that, as in other organisms, the regulation of Hox gene expression in C. elegans is complicated, redundant and robust.

Fetal deficiency of Lin28 programs life-long aberrations in growth and glucose metabolism

PubMed Central

Shinoda, Gen; Shyh-Chang, Ng; de Soysa, T. Yvanka; Zhu, Hao; Seligson, Marc T.; Shah, Samar P.; Abo-Sido, Nora; Yabuuchi, Akiko; Hagan, John P.; Gregory, Richard I.; Asara, John M.; Cantley, Lewis C.; Moss, Eric G.; Daley, George Q.

2013-01-01

LIN28A/B are RNA binding proteins implicated by genetic association studies in human growth and glucose metabolism. Mice with ectopic over-expression of Lin28a have shown related phenotypes. Here we describe the first comprehensive analysis of the physiologic consequences of Lin28a and Lin28b deficiency in knockout (KO) mice. Lin28a/b-deficiency led to dwarfism starting at different ages, and compound gene deletions showed a cumulative dosage effect on organismal growth. Conditional gene deletion at specific developmental stages revealed that fetal but neither neonatal nor adult deficiency resulted in growth defects and aberrations in glucose metabolism. Tissue-specific KO mice implicated skeletal muscle-deficiency in the abnormal programming of adult growth and metabolism. The effects of Lin28b KO can be rescued by Tsc1 haplo-insufficiency in skeletal muscles. Our data implicate fetal expression of Lin28a/b in the regulation of life-long effects on metabolism and growth, and demonstrate that fetal Lin28b acts at least in part via mTORC1 signaling. PMID:23666760

The parameters effect on the structural performance of damaged steel box beam using Taguchi method

NASA Astrophysics Data System (ADS)

El-taly, Boshra A.; Abd El Hameed, Mohamed F.

2018-03-01

In the current study, the influence of notch or opening parameters and the positions of the applied load on the structural performance of steel box beams up to failure was investigated using Finite Element analysis program, ANSYS. The Taguchi-based design of experiments technique was used to plan the current study. The plan included 12 box steel beams; three intact beams, and nine damaged beams (with opening) in the beams web. The numerical studies were conducted under varying the spacing between the two concentrated point loads (location of applied loads), the notch (opening) position, and the ratio between depth and width of the notch with a constant notch area. According to Taguchi analysis, factor X (location of the applied loads) was found the highest contributing parameters for the variation of the ultimate load, vertical deformation, shear stresses, and the compressive normal stresses.

Ikaros-Notch axis in host hematopoietic cells regulates experimental graft-versus-host disease

PubMed Central

Toubai, Tomomi; Sun, Yaping; Tawara, Isao; Friedman, Ann; Liu, Chen; Evers, Rebecca; Nieves, Evelyn; Malter, Chelsea; Chockley, Peter; Maillard, Ivan; Winandy, Susan

2011-01-01

Host hematopoietically derived APCs play a vital role in the initiation of GVH responses. However, the APC autonomous molecular mechanisms that are critical for the induction of GVHD are not known. We report here that the Ikaros-Notch axis in host hematopoietically derived APCs regulates the severity of acute GVHD across multiple clinically relevant murine models of experimental bone marrow transplantation. In the present study, Ikaros deficiency (Ik−/−) limited to host hematopoietically derived APCs enhanced donor T-cell expansion and intensified acute GVHD, as determined by survival and other GVHD-specific parameters. The Ik−/− conventional CD8+ and CD8−CD11c+ dendritic cells (DCs), the most potent APCs, showed no increase in the expression of activation markers or in response to TLR stimulation compared with wild-type controls. However, Ik−/− DCs demonstrated an enhanced stimulation of allogeneic T cells. Deficiency of Ikaros in the conventional CD8+ and CD8−CD11c+ DCs was associated with an increase in Notch signaling, the blockade of which mitigated the enhanced in vitro and in vivo allostimulatory capacity. Therefore, the Ikaros-Notch axis is a novel pathway that modulates DC biology in general, and targeting this pathway in host hematopoietically derived APCs may reduce GVHD. PMID:21471527

A team of heterochromatin factors collaborates with small RNA pathways to combat repetitive elements and germline stress

PubMed Central

McMurchy, Alicia N; Stempor, Przemyslaw; Gaarenstroom, Tessa; Wysolmerski, Brian; Dong, Yan; Aussianikava, Darya; Appert, Alex; Huang, Ni; Kolasinska-Zwierz, Paulina; Sapetschnig, Alexandra; Miska, Eric A; Ahringer, Julie

2017-01-01

Repetitive sequences derived from transposons make up a large fraction of eukaryotic genomes and must be silenced to protect genome integrity. Repetitive elements are often found in heterochromatin; however, the roles and interactions of heterochromatin proteins in repeat regulation are poorly understood. Here we show that a diverse set of C. elegans heterochromatin proteins act together with the piRNA and nuclear RNAi pathways to silence repetitive elements and prevent genotoxic stress in the germ line. Mutants in genes encoding HPL-2/HP1, LIN-13, LIN-61, LET-418/Mi-2, and H3K9me2 histone methyltransferase MET-2/SETDB1 also show functionally redundant sterility, increased germline apoptosis, DNA repair defects, and interactions with small RNA pathways. Remarkably, fertility of heterochromatin mutants could be partially restored by inhibiting cep-1/p53, endogenous meiotic double strand breaks, or the expression of MIRAGE1 DNA transposons. Functional redundancy among factors and pathways underlies the importance of safeguarding the genome through multiple means. DOI: http://dx.doi.org/10.7554/eLife.21666.001 PMID:28294943

Lin28a protects against postinfarction myocardial remodeling and dysfunction through Sirt1 activation and autophagy enhancement.

PubMed

Hao, Yuanyuan; Lu, Qun; Yang, Guodong; Ma, Aiqun

2016-10-28

Myocardial remodeling and cardiac dysfunction prevention may represent a therapeutic approach to reduce mortality in patients with myocardial infarction (MI). We investigated the effects of Lin28a in experimental MI models, as well as the mechanisms underlying these effects. Left anterior descending (LAD) coronary artery ligation was used to construct an MI-induced injury model. Neonatal cardiomyocytes were isolated and cultured to investigate the mechanisms underlying the protective effects of Lin28a against MI-induced injury. Lin28a significantly inhibited left ventricular remodeling and cardiac dysfunction after MI, as demonstrated via echocardiography and hemodynamic measurements. Lin28a reduced cardiac enzyme and inflammatory marker release in mice subjected to MI-induced injury. The mechanisms underlying the protective effects of Lin28a against MI-induced injury were associated with autophagy enhancements and apoptosis inhibition. Consistent with these findings, Lin28a knockdown aggravated cardiac remodeling and dysfunction after MI-induced injury. Lin28a knockdown also inhibited cardiomyocyte autophagy and increased cardiomyocyte apoptosis in mice subjected to MI-induced injury. Interestingly, Sirt1 knockdown abolished the protective effects of Lin28a against cardiac remodeling and dysfunction after MI, and Lin28a failed to increase the numbers of GFP-LC3-positive punctae and decrease aggresome and p62 accumulation in Sirt1-knockdown neonatal cardiomyocytes subjected to hypoxia-induced injury. Lin28a inhibits cardiac remodeling, improves cardiac function, and reduces cardiac enzyme and inflammatory marker release after MI. Lin28a also up-regulates cardiomyocyte autophagy and inhibits cardiomyocyte apoptosis through Sirt1 activation. Copyright © 2016 Elsevier Inc. All rights reserved.

Regulation of cortical contractility and spindle positioning by the protein phosphatase 6 PPH-6 in one-cell stage C. elegans embryos

PubMed Central

Afshar, Katayoun; Werner, Michael E.; Tse, Yu Chung; Glotzer, Michael; Gönczy, Pierre

2010-01-01

Modulation of the microtubule and the actin cytoskeleton is crucial for proper cell division. Protein phosphorylation is known to be an important regulatory mechanism modulating these cytoskeletal networks. By contrast, there is a relative paucity of information regarding how protein phosphatases contribute to such modulation. Here, we characterize the requirements for protein phosphatase PPH-6 and its associated subunit SAPS-1 in one-cell stage C. elegans embryos. We establish that the complex of PPH-6 and SAPS-1 (PPH-6/SAPS-1) is required for contractility of the actomyosin network and proper spindle positioning. Our analysis demonstrates that PPH-6/SAPS-1 regulates the organization of cortical non-muscle myosin II (NMY-2). Accordingly, we uncover that PPH-6/SAPS-1 contributes to cytokinesis by stimulating actomyosin contractility. Furthermore, we demonstrate that PPH-6/SAPS-1 is required for the proper generation of pulling forces on spindle poles during anaphase. Our results indicate that this requirement is distinct from the role in organizing the cortical actomyosin network. Instead, we uncover that PPH-6/SAPS-1 contributes to the cortical localization of two positive regulators of pulling forces, GPR-1/2 and LIN-5. Our findings provide the first insights into the role of a member of the PP6 family of phosphatases in metazoan development. PMID:20040490

Vibration Based Crack Detection in a Rotating Disk. Part 2; Experimental Results

NASA Technical Reports Server (NTRS)

Gyekenyesi, Andrew L.; Sawicki, Jerzy T.; Martin, Richard E.; Haase, Wayne C.; Baaklini, George

2005-01-01

This paper describes the experimental results concerning the detection of a crack in a rotating disk. The goal was to utilize blade tip clearance and shaft vibration measurements to monitor changes in the system's center of mass and/or blade deformation behaviors. The concept of the approach is based on the fact that the development of a disk crack results in a distorted strain field within the component. As a result, a minute deformation in the disk's geometry as well as a change in the system's center of mass occurs. Here, a notch was used to simulate an actual crack. The vibration based experimental results failed to identify the existence of a notch when utilizing the approach described above, even with a rather large, circumferential notch (l.2 in.) located approximately mid-span on the disk (disk radius = 4.63 in. with notch at r = 2.12 in.). This was somewhat expected, since the finite element based results in Part 1 of this study predicted changes in blade tip clearance as well as center of mass shifts due to a notch to be less than 0.001 in. Therefore, the small changes incurred by the notch could not be differentiated from the mechanical and electrical noise of the rotor system. Although the crack detection technique of interest failed to identify the existence ofthe notch, the vibration data produced and captured here will be utilized in upcoming studies that will focus on different data mining techniques concerning damage detection in a disk.

IRF4 controls the positioning of mature B cells in the lymphoid microenvironments by regulating NOTCH2 expression and activity

PubMed Central

Simonetti, Giorgia; Carette, Amanda; Silva, Kathryn; Wang, Haowei; De Silva, Nilushi S.; Heise, Nicole; Siebel, Christian W.; Shlomchik, Mark J.

2013-01-01

The transcription factor interferon regulatory factor-4 (IRF4) is expressed in B cells at most developmental stages. In antigen-activated B cells, IRF4 controls germinal center formation, class-switch recombination, and the generation of plasma cells. Here we describe a novel function for IRF4 in the homeostasis of mature B cells. Inducible deletion of irf4 specifically in B cells in vivo led to the aberrant accumulation of irf4-deleted follicular B cells in the marginal zone (MZ) area. IRF4-deficient B cells showed elevated protein expression and activation of NOTCH2, a transmembrane receptor and transcriptional regulator known to be required for MZ B cell development. Administration of a NOTCH2-inhibitory antibody abolished nuclear translocation of NOTCH2 in B cells within 12 h and caused a rapid and progressive disintegration of the MZ that was virtually complete 48 h after injection. The disappearance of the MZ was accompanied by a transient increase of MZ-like B cells in the blood rather than increased B cell apoptosis, demonstrating that continued NOTCH2 activation is critical for the retention of B cells in the MZ. Our results suggest that IRF4 controls the positioning of mature B cells in the lymphoid microenvironments by regulating NOTCH2 expression. These findings may have implications for the understanding of B cell malignancies with dysregulated IRF4 and NOTCH2 activity. PMID:24323359

Assessment of Ductile-to-Brittle Transition Behavior of Localized Microstructural Regions in a Friction-Stir Welded X80 Pipeline Steel with Miniaturized Charpy V-Notch Testing

NASA Astrophysics Data System (ADS)

Avila, Julian A.; Lucon, Enrico; Sowards, Jeffrey; Mei, Paulo Roberto; Ramirez, Antonio J.

2016-06-01

Friction-stir welding (FSW) is an alternative welding process for pipelines. This technology offers sound welds, good repeatability, and excellent mechanical properties. However, it is of paramount importance to determine the toughness of the welds at low temperatures in order to establish the limits of this technology. Ductile-to-brittle transition curves were generated in the present study by using a small-scale instrumented Charpy machine and miniaturized V-notch specimens (Kleinstprobe, KLST); notches were located in base metal, heat-affected, stirred, and hard zones within a FSW joint of API-5L X80 Pipeline Steel. Specimens were tested at temperatures between 77 K (-196 °C) and 298 K (25 °C). Based on the results obtained, the transition temperatures for the base material and heat-affected zone were below 173 K (-100 °C); conversely, for the stirred and hard zones, it was located around 213 K (-60 °C). Fracture surfaces were characterized and showed a ductile fracture mechanism at high impact energies and a mixture of ductile and brittle mechanisms at low impact energies.

Modulators of Fish Immune Responses. Volume 1. Models for Environmental Toxicology/Biomarkers Immunostimulators

DTIC Science & Technology

1994-01-01

Immunity in Invertebrates. (M. Breh~lin, editor). Springer-Verlag, Berlin, Heidelberg. pp 112-124. Smith, V.J. and K. Soderhall. (1983). Beta -1-3- glucan ...resistance of carp Cyprinus carpio to experimental Edwardsiella tarda infection, by some beta - 1, 3- glucan . Nippon Suisan Gakkaishi 55:1815-1819. Yoshida...inhibitory and anti-bacterial activity of soluble and particulate glucan . Intl. J. Cancer 24: 773-779. Ellsaesser, C.F. (1989). Identification and

LIN9, a Subunit of the DREAM Complex, Regulates Mitotic Gene Expression and Proliferation of Embryonic Stem Cells

PubMed Central

Esterlechner, Jasmina; Reichert, Nina; Iltzsche, Fabian; Krause, Michael; Finkernagel, Florian; Gaubatz, Stefan

2013-01-01

The DREAM complex plays an important role in regulation of gene expression during the cell cycle. We have previously shown that the DREAM subunit LIN9 is required for early embryonic development and for the maintenance of the inner cell mass in vitro. In this study we examined the effect of knocking down LIN9 on ESCs. We demonstrate that depletion of LIN9 alters the cell cycle distribution of ESCs and results in an accumulation of cells in G2 and M and in an increase of polyploid cells. Genome-wide expression studies showed that the depletion of LIN9 results in downregulation of mitotic genes and in upregulation of differentiation-specific genes. ChIP-on chip experiments showed that mitotic genes are direct targets of LIN9 while lineage specific markers are regulated indirectly. Importantly, depletion of LIN9 does not alter the expression of pluripotency markers SOX2, OCT4 and Nanog and LIN9 depleted ESCs retain alkaline phosphatase activity. We conclude that LIN9 is essential for proliferation and genome stability of ESCs by activating genes with important functions in mitosis and cytokinesis. PMID:23667535

Characterization of two Listeria innocua chitinases of different sizes that were expressed in Escherichia coli.

PubMed

Honda, Shotaro; Wakita, Satoshi; Sugahara, Yasusato; Kawakita, Masao; Oyama, Fumitaka; Sakaguchi, Masayoshi

2016-09-01

Two putative chitinase genes, lin0153 and lin1996, from the nonpathogenic bacterium Listeria innocua were expressed in Escherichia coli, and the gene products were characterized. The genes were close homologs of chitinases from the pathogenic bacterium Listeria monocytogenes, in which chitinases and chitin-binding proteins play important roles in pathogenesis in mice-infection models. The purified recombinant enzymes that are different in size, LinChi78 (lin0153 product) and LinChi35 (lin1996 product)-with molecular masses of 82 and 38 kDa, including vector-derived additional sequences, respectively-exhibited optimum catalytic activity under neutral and acidic conditions at 50 °C, respectively, and were stable over broad pH (4-11) and temperature (4-40 °C) ranges. LinChi35 displayed higher k cat and K M values for 4-nitrophenyl N,N-diacetyl-β-D-chitobioside [4NP-(GlcNAc)2] than LinChi78. Both enzymes produced primarily dimers from colloidal chitin as a substrate. However, LinChi78 and LinChi35 could hydrolyze oligomeric substrates in a processive exo- and nonprocessive endo-manner, respectively, and showed different reactivity toward oligomeric substrates. Both enzymes could bind chitin beads but were different in their binding ability toward crystalline α-chitin and cellulose. The structure-function relationships of these chitinases are discussed in reference to other bacterial chitinases.

Mouse model of CADASIL reveals novel insights into Notch3 function in adult hippocampal neurogenesis.

PubMed

Ehret, Fanny; Vogler, Steffen; Pojar, Sherin; Elliott, David A; Bradke, Frank; Steiner, Barbara; Kempermann, Gerd

2015-03-01

Could impaired adult hippocampal neurogenesis be a relevant mechanism underlying CADASIL (cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy)? Memory symptoms in CADASIL, the most common hereditary form of vascular dementia, are usually thought to be primarily due to vascular degeneration and white matter lacunes. Since adult hippocampal neurogenesis, a process essential for the integration of new spatial memory occurs in a highly vascularized niche, we considered dysregulation of adult neurogenesis as a potential mechanism for the manifestation of dementia in CADASIL. Analysis in aged mice overexpressing Notch3 with a CADASIL mutation, revealed vascular deficits in arteries of the hippocampal fissure but not in the niche of the dentate gyrus. At 12 months of age, cell proliferation and survival of newborn neurons were reduced not only in CADASIL mice but also in transgenic controls overexpressing wild type Notch3. At 6 months, hippocampal neurogenesis was altered in CADASIL mice independent of overt vascular abnormalities in the fissure. Further, we identified Notch3 expression in hippocampal precursor cells and maturing neurons in vivo as well as in cultured hippocampal precursor cells. Overexpression and knockdown experiments showed that Notch3 signaling negatively regulated precursor cell proliferation. Notch3 overexpression also led to deficits in KCl-induced precursor cell activation. This suggests a cell-autonomous effect of Notch3 signaling in the regulation of precursor proliferation and activation and a loss-of-function effect in CADASIL. Consequently, besides vascular damage, aberrant precursor cell proliferation and differentiation due to Notch3 dysfunction might be an additional independent mechanism for the development of hippocampal dysfunction in CADASIL. Copyright © 2014. Published by Elsevier Inc.

DPL-1 DP, LIN-35 Rb and EFL-1 E2F act with the MCD-1 zinc-finger protein to promote programmed cell death in Caenorhabditis elegans.

PubMed

Reddien, Peter W; Andersen, Erik C; Huang, Michael C; Horvitz, H Robert

2007-04-01

The genes egl-1, ced-9, ced-4, and ced-3 play major roles in programmed cell death in Caenorhabditis elegans. To identify genes that have more subtle activities, we sought mutations that confer strong cell-death defects in a genetically sensitized mutant background. Specifically, we screened for mutations that enhance the cell-death defects caused by a partial loss-of-function allele of the ced-3 caspase gene. We identified mutations in two genes not previously known to affect cell death, dpl-1 and mcd-1 (modifier of cell death). dpl-1 encodes the C. elegans homolog of DP, the human E2F-heterodimerization partner. By testing genes known to interact with dpl-1, we identified roles in cell death for four additional genes: efl-1 E2F, lin-35 Rb, lin-37 Mip40, and lin-52 dLin52. mcd-1 encodes a novel protein that contains one zinc finger and that is synthetically required with lin-35 Rb for animal viability. dpl-1 and mcd-1 act with efl-1 E2F and lin-35 Rb to promote programmed cell death and do so by regulating the killing process rather than by affecting the decision between survival and death. We propose that the DPL-1 DP, MCD-1 zinc finger, EFL-1 E2F, LIN-35 Rb, LIN-37 Mip40, and LIN-52 dLin52 proteins act together in transcriptional regulation to promote programmed cell death.

Forging T-Lymphocyte Identity: Intersecting Networks of Transcriptional Control

PubMed Central

Rothenberg, Ellen V.; Ungerbäck, Jonas; Champhekar, Ameya

2016-01-01

T lymphocyte development branches off from other lymphoid developmental programs through its requirement for sustained environmental signals through the Notch pathway. In the thymus, Notch signaling induces a succession of T-lineage regulatory factors that collectively create the T-cell identity through distinct steps. This process involves both the staged activation of T-cell identity genes and the staged repression of progenitor-cell-inherited regulatory genes once their roles in self-renewal and population expansion are no longer needed. With the recent characterization of Innate Lymphoid Cells (ILCs) that share transcriptional regulation programs extensively with T cell subsets, T-cell identity can increasingly be seen as defined in modular terms, as the processes selecting and actuating effector function are potentially detachable from the processes generating and selecting clonally unique T-cell receptor structures. The developmental pathways of different classes of T cells and ILCs are distinguished by the numbers of prerequisites of gene rearrangement, selection, and antigen contact before the cells gain access to nearly-common regulatory mechanisms for choosing effector function. Here, the major classes of transcription factors that interact with Notch signals during T-lineage specification are discussed in terms of their roles in these programs, the evidence for their spectra of target genes at different stages, and their cross-regulatory and cooperative actions with each other. Specific topics include Notch modulation of PU.1 and GATA-3, PU.1-Notch competition, the relationship between PU.1 and GATA-3, and the roles of E proteins, Bcl11b, and GATA-3 in guiding acquisition of T-cell identity while avoiding redirection to an ILC fate. PMID:26791859

Si-rich SiNx based Kerr switch enables optical data conversion up to 12 Gbit/s

PubMed Central

Lin, Gong-Ru; Su, Sheng-Pin; Wu, Chung-Lun; Lin, Yung-Hsiang; Huang, Bo-Ji; Wang, Huai-Yung; Tsai, Cheng-Ting; Wu, Chih-I; Chi, Yu-Chieh

2015-01-01

Silicon photonic interconnection on chip is the emerging issue for next-generation integrated circuits. With the Si-rich SiNx micro-ring based optical Kerr switch, we demonstrate for the first time the wavelength and format conversion of optical on-off-keying data with a bit-rate of 12 Gbit/s. The field-resonant nonlinear Kerr effect enhances the transient refractive index change when coupling the optical data-stream into the micro-ring through the bus waveguide. This effectively red-shifts the notched dip wavelength to cause the format preserved or inversed conversion of data carried by the on-resonant or off-resonant probe, respectively. The Si quantum dots doped Si-rich SiNx strengthens its nonlinear Kerr coefficient by two-orders of magnitude higher than that of bulk Si or Si3N4. The wavelength-converted and cross-amplitude-modulated probe data-stream at up to 12-Gbit/s through the Si-rich SiNx micro-ring with penalty of −7 dB on transmission has shown very promising applicability to all-optical communication networks. PMID:25923653

Si-rich SiNx based Kerr switch enables optical data conversion up to 12 Gbit/s.

PubMed

Lin, Gong-Ru; Su, Sheng-Pin; Wu, Chung-Lun; Lin, Yung-Hsiang; Huang, Bo-Ji; Wang, Huai-Yung; Tsai, Cheng-Ting; Wu, Chih-I; Chi, Yu-Chieh

2015-04-29

Silicon photonic interconnection on chip is the emerging issue for next-generation integrated circuits. With the Si-rich SiNx micro-ring based optical Kerr switch, we demonstrate for the first time the wavelength and format conversion of optical on-off-keying data with a bit-rate of 12 Gbit/s. The field-resonant nonlinear Kerr effect enhances the transient refractive index change when coupling the optical data-stream into the micro-ring through the bus waveguide. This effectively red-shifts the notched dip wavelength to cause the format preserved or inversed conversion of data carried by the on-resonant or off-resonant probe, respectively. The Si quantum dots doped Si-rich SiNx strengthens its nonlinear Kerr coefficient by two-orders of magnitude higher than that of bulk Si or Si3N4. The wavelength-converted and cross-amplitude-modulated probe data-stream at up to 12-Gbit/s through the Si-rich SiNx micro-ring with penalty of -7 dB on transmission has shown very promising applicability to all-optical communication networks.

Evidence of functional cross talk between the Notch and NF-κB pathways in nonneoplastic hyperproliferating colonic epithelium.

PubMed

Ahmed, Ishfaq; Roy, Badal; Chandrakesan, Parthasarathy; Venugopal, Anand; Xia, Lijun; Jensen, Roy; Anant, Shrikant; Umar, Shahid

2013-02-15

The Notch and NF-κB signaling pathways regulate stem cell function and inflammation in the gut, respectively. We investigate whether a functional cross talk exists between the two pathways during transmissible murine colonic hyperplasia (TMCH) caused by Citrobacter rodentium (CR). During TMCH, NF-κB activity and subunit phosphorylation in colonic crypts of NIH Swiss mice at days 6 and 12 were associated with increases in downstream target CXC chemokine ligand (CXCL)-1/keratinocyte-derived chemokine (KC) expression. Blocking Notch signaling acutely for 5 days with the Notch blocker dibenzazepine (DBZ) failed to inhibit crypt NF-κB activity or CXCL-1/KC expression. Chronic DBZ administration for 10 days, however, blocked Notch and NF-κB signaling in the crypts and abrogated hyperplasia. Intriguingly, chronic Notch inhibition was associated with significant increases in IL-1α, granulocyte colony-stimulating factor, monocyte chemoattractant protein 1, macrophage inflammatory protein 2, and KC in the crypt-denuded lamina propria or whole distal colon, with concomitant increases in myeloperoxidase activity. In core-3(-/-) mice, which are defective in intestinal mucin, DBZ administration replicated the results of NIH Swiss mice; in Apc(Min/+) mice, which are associated with CR-induced elevation of NF-κB-p65(276) expression, DBZ reversed the increase in NF-κB-p65(276), which may have blocked rapid proliferation of the mutated crypts. DBZ further blocked reporter activities involving the NF-κB-luciferase reporter plasmid or the Toll-like receptor 4/NF-κB/SEAPorter HEK-293 reporter cell line, while ectopic expression of Notch-N(ICD) reversed the inhibitory effect. Dietary bael (Aegle marmelos) extract (4%) and curcumin (4%) restored Notch and NF-κB cross talk in NIH Swiss mice, inhibited CR/DBZ-induced apoptosis in the crypts, and promoted crypt regeneration. Thus functional cross talk between the Notch and NF-κB pathways during TMCH regulates hyperplasia and/or inflammation in response to CR infection.

Detecting inflammation in inflammatory bowel disease - how does ultrasound compare to magnetic resonance enterography using standardised scoring systems?

PubMed

Barber, Joy L; Zambrano-Perez, Alexsandra; Olsen, Øystein E; Kiparissi, Fevronia; Baycheva, Mila; Knaflez, Daniela; Shah, Neil; Watson, Tom A

2018-06-01

Magnetic resonance enterography (MRE) is the current gold standard for imaging in inflammatory bowel disease, but ultrasound (US) is a potential alternative. To determine whether US is as good as MRE for the detecting inflamed bowel, using a combined consensus score as the reference standard. We conducted a retrospective cohort study in children and adolescents <18 years with inflammatory bowel disease (IBD) at a tertiary and quaternary centre. We included children who underwent MRE and US within 4 weeks. We scored MRE using the London score and US using a score adapted from the METRIC (MR Enterography or Ultrasound in Crohn's Disease) trial. Four gastroenterologists assessed an independent clinical consensus score. A combined consensus score using the imaging and clinical scores was agreed upon and used as the reference standard to compare MRE with US. We included 53 children. At a whole-patient level, MRE scores were 2% higher than US scores. We used Lin coefficient to assess inter-observer variability. The repeatability of MRE scores was poor (Lin 0.6). Agreement for US scoring was substantial (Lin 0.95). There was a significant positive correlation between MRE and clinical consensus scores (Spearman's rho = 0.598, P=0.0053) and US and clinical consensus scores (Spearman's rho = 0.657, P=0.0016). US detects as much clinically significant bowel disease as MRE. It is possible that MRE overestimates the presence of disease when using a scoring system. This study demonstrates the feasibility of using a clinical consensus reference standard in paediatric IBD imaging studies.

Notched-noise precursors improve detection of low-frequency amplitude modulationa)

PubMed Central

Almishaal, Ali; Bidelman, Gavin M.; Jennings, Skyler G.

2017-01-01

Amplitude modulation (AM) detection was measured with a short (50 ms), high-frequency carrier as a function of carrier level (Experiment I) and modulation frequency (Experiment II) for conditions with or without a notched-noise precursor. A longer carrier (500 ms) was also included in Experiment I. When the carrier was preceded by silence (no precursor condition) AM detection thresholds worsened for moderate-level carriers compared to lower- or higher-level carriers, resulting in a “mid-level hump.” AM detection thresholds with a precursor were better than those without a precursor, primarily for moderate-to-high level carriers, thus eliminating the mid-level hump in AM detection. When the carrier was 500 ms, AM thresholds improved by a constant (across all levels) relative to AM thresholds with a precursor, consistent with the longer carrier providing more “looks” to detect the AM signal. Experiment II revealed that improved AM detection with compared to without a precursor is limited to low-modulation frequencies (<60 Hz). These results are consistent with (1) a reduction in cochlear gain over the course of the precursor perhaps via the medial olivocochlear reflex or (2) a form of perceptual enhancement which may be mediated by adaptation of inhibition. PMID:28147582

A simple system for 160GHz optical terahertz wave generation and data modulation

NASA Astrophysics Data System (ADS)

Li, Yihan; He, Jingsuo; Sun, Xueming; Shi, Zexia; Wang, Ruike; Cui, Hailin; Su, Bo; Zhang, Cunlin

2018-01-01

A simple system based on two cascaded Mach-Zehnder modulators, which can generate 160GHz optical terahertz waves from 40GHz microwave sources, is simulated and tested in this paper. Fiber grating filter is used in the system to filter out optical carrier. By properly adjusting the modulator DC bias voltages and the signal voltages and phases, 4-tupling optical terahertz wave can be generated with fiber grating. This notch fiber grating filter is greatly suitable for terahertz over fiber (TOF) communication system. This scheme greatly reduces the cost of long-distance terahertz communication. Furthermore, 10Gbps digital signal is modulated in the 160GHz optical terahertz wave.

Androgens Up-regulate Transcription of the Notch Inhibitor Numb in C2C12 Myoblasts via Wnt/β-Catenin Signaling to T Cell Factor Elements in the Numb Promoter*

PubMed Central

Liu, Xin-Hua; Wu, Yong; Yao, Shen; Levine, Alice C.; Kirschenbaum, Alexander; Collier, Lauren; Bauman, William A.; Cardozo, Christopher P.

2013-01-01

Androgen signaling via the androgen receptor is a key pathway that contributes to development, cell fate decisions, and differentiation, including that of myogenic progenitors. Androgens and synthetic steroids have well established anabolic actions on skeletal muscle. Wnt and Notch signaling pathways are also essential to myogenic cell fate decisions during development and tissue repair. However, the interactions among these pathways are largely unknown. Androgenic regulation of Wnt signaling has been reported. Nandrolone, an anabolic steroid, has been shown to inhibit Notch signaling and up-regulate Numb, a Notch inhibitor. To elucidate the mechanisms of interaction between nandrolone and Wnt/Notch signaling, we investigated the effects of nandrolone on Numb expression and Wnt signaling and determined the roles of Wnt signaling in nandrolone-induced Numb expression in C2C12 myoblasts. Nandrolone increased Numb mRNA and protein levels and T cell factor (Tcf) transcriptional activity via inhibition of glycogen synthase kinase 3β. Up-regulation of Numb expression by nandrolone was blocked by the Wnt inhibitors, sFRP1 and DKK1, whereas Wnt3a increased Numb mRNA and protein expression. In addition, we observed that the proximal promoter of the Numb gene had functional Tcf binding elements to which β-catenin was recruited in a manner enhanced by both nandrolone and Wnt3a. Moreover, site-directed mutagenesis indicated that the Tcf binding sites in the Numb promoter are required for the nandrolone-induced Numb transcriptional activation in this cell line. These results reveal a novel molecular mechanism underlying up-regulation of Numb transcription with a critical role for increased canonical Wnt signaling. In addition, the data identify Numb as a novel target gene of the Wnt signaling pathway by which Wnts would be able to inhibit Notch signaling. PMID:23649620

Improved knowledge retention among clinical pharmacy students using an anthropology classroom assessment technique.

PubMed

Whitley, Heather P; Parton, Jason M

2014-09-15

To adapt a classroom assessment technique (CAT) from an anthropology course to a diabetes module in a clinical pharmacy skills laboratory and to determine student knowledge retention from baseline. Diabetes item stems, focused on module objectives, replaced anthropology terms. Answer choices, coded to Bloom's Taxonomy, were expanded to include higher-order thinking. Students completed the online 5-item probe 4 times: prelaboratory lecture, postlaboratory, and at 6 months and 12 months after laboratory. Statistical analyses utilized a single factor, repeated measures design using rank transformations of means with a Mann-Whitney-Wilcoxon test. The CAT revealed a significant increase in knowledge from prelaboratory compared to all postlaboratory measurements (p<0.0001). Significant knowledge retention was maintained with basic terms, but declined with complex terms between 6 and 12 months. The anthropology assessment tool was effectively adapted using Bloom's Taxonomy as a guide and, when used repeatedly, demonstrated knowledge retention. Minimal time was devoted to application of the probe making it an easily adaptable CAT.

The Effect of Compressive Loading on the Fatigue Lifetime of Graphite/ Epoxy Laminates

DTIC Science & Technology

1979-10-01

Un-notched 11 3 Specimen Configuration, Notched 12 4 Location of Thickness and Width Measurements 14 5 Overall View of Composite Compression Test...Grips in Universal Testing Machine 24 8 Specimen Positioning Device 26 9 "Full-Fixity" Apparatus, Showing Auxiliary Platens 26 10 Specimen and Restraint...the accumu- lation of a statistically significant data base. * IA previous research study [11 showed that graphite/epoxy composites under constant

Assessment and Treatment of Blast-Induced Auditory and Vestibular Injuries

DTIC Science & Technology

2017-06-01

that originates from damage to mechanosensory hair cells. Using a compression driven shock tube, we seek to : 1) determine whether exposure to a...determine the cell-type-specific changes in gene expression that occur within auditory supporting cells and hair cells after repeated blast exposure...and 4) determine whether overexpression of Atoh1, inhibition of Notch signaling, or a combination of the two can induce meaningful hair cell

Adaptive Same Frequency Repeater (SFR) Study

DTIC Science & Technology

1976-03-01

Formulation 13 (2) Evaluation of the Steady State Weights!.’.’.’!.*!!."!! 21 (3) Evaluation of the Composite Transfer Function.... 2^ (4) Simplified...well as possible the amplitude and phase of the composite coupling path. Because the coupling paths have frequency-dependent transfer functions...34), (35) and the notch filter and channel transfer .’unctions (3fi) and (39). The composite transfer function Hc(f ’ ^’.f) is then found and

The ubiquitin ligase LIN41/TRIM71 targets p53 to antagonize cell death and differentiation pathways during stem cell differentiation

PubMed Central

Nguyen, Duong Thi Thuy; Richter, Daniel; Michel, Geert; Mitschka, Sibylle; Kolanus, Waldemar; Cuevas, Elisa; Gregory Wulczyn, F

2017-01-01

Rapidity and specificity are characteristic features of proteolysis mediated by the ubiquitin-proteasome system. Therefore, the UPS is ideally suited for the remodeling of the embryonic stem cell proteome during the transition from pluripotent to differentiated states and its inverse, the generation of inducible pluripotent stem cells. The Trim-NHL family member LIN41 is among the first E3 ubiquitin ligases to be linked to stem cell pluripotency and reprogramming. Initially discovered in C. elegans as a downstream target of the let-7 miRNA, LIN41 is now recognized as a critical regulator of stem cell fates as well as the timing of neurogenesis. Despite being indispensable for embryonic development and neural tube closure in mice, the underlying mechanisms for LIN41 function in these processes are poorly understood. To better understand the specific contributions of the E3 ligase activity for the stem cell functions of LIN41, we characterized global changes in ubiquitin or ubiquitin-like modifications using Lin41-inducible mouse embryonic stem cells. The tumor suppressor protein p53 was among the five most strongly affected proteins in cells undergoing neural differentiation in response to LIN41 induction. We show that LIN41 interacts with p53, controls its abundance by ubiquitination and antagonizes p53-dependent pro-apoptotic and pro-differentiation responses. In vivo, the lack of LIN41 is associated with upregulation of Grhl3 and widespread caspase-3 activation, two downstream effectors of p53 with essential roles in neural tube closure. As Lin41-deficient mice display neural tube closure defects, we conclude that LIN41 is critical for the regulation of p53 functions in cell fate specification and survival during early brain development. PMID:28430184

Effects of consecutive trials and test-retest reliability of 1000-Hz tympanometry in adults.

PubMed

Carazo, Carla Dominguez; Sun, Xiao-Ming

2015-04-01

To investigate the effect of consecutive 1000-Hz tympanometry testing on admittance measures, and examine test-retest reliability. Repeated measures with eight trials of 1000-Hz Y(a) and B(a)/G(a) tympanometry, respectively, in two ears of each subject, followed by repeated 226-Hz tympanometry. Twenty-seven normal-hearing young adults. For single-peak tympanograms, peak Y(tm) and G(tm) systematically increased across trials with a mean change of 8% and 15% at Trial 8, respectively, whereas B(tm) increased marginally. For notched tympanograms, peak Y(tm) and B(tm) decreased by 23% and 162% at Trial 8, and G(tm) in two cases also decreased (10% on average). Trial 2 and 3 contributed 50% to 70% of the total changes. Test-retest differences of subsequently acquired 1000- and 226-Hz tympanograms were smaller than previously reported. Consecutive testing significantly alters middle-ear admittance in 1000-Hz tympanometry. The outcome is contingent on tympanogram pattern and admittance component: Increase of peak Y(tm) and G(tm) in single-peak tympanograms and decrease of all measures in notched tympanograms. The present results complement previous studies on our understanding of the mechanism underlying this effect: a decrease of middle-ear stiffness. The effect of repetitive tympanometry should be accounted for in research involving sequential testing.

The role of lin-22, a hairy/enhancer of split homolog, in patterning the peripheral nervous system of C. elegans.

PubMed

Wrischnik, L A; Kenyon, C J

1997-08-01

In C. elegans, six lateral epidermal stem cells, the seam cells V1-V6, are located in a row along the anterior-posterior (A/P) body axis. Anterior seam cells (V1-V4) undergo a fairly simple sequence of stem cell divisions and generate only epidermal cells. Posterior seam cells (V5 and V6) undergo a more complicated sequence of cell divisions that include additional rounds of stem cell proliferation and the production of neural as well as epidermal cells. In the wild type, activity of the gene lin-22 allows V1-V4 to generate their normal epidermal lineages rather than V5-like lineages. lin-22 activity is also required to prevent additional neurons from being produced by one branch of the V5 lineage. We find that the lin-22 gene exhibits homology to the Drosophila gene hairy, and that lin-22 activity represses neural development within the V5 lineage by blocking expression of the posterior-specific Hox gene mab-5 in specific cells. In addition, in order to prevent anterior V cells from generating V5-like lineages, wild-type lin-22 gene activity must inhibit (directly or indirectly) at least five downstream regulatory gene activities. In anterior body regions, lin-22(+) inhibits expression of the Hox gene mab-5. It also inhibits the activity of the achaete-scute homolog lin-32 and an unidentified gene that we postulate regulates stem cell division. Each of these three genes is required for the expression of a different piece of the ectopic V5-like lineages generated in lin-22 mutants. In addition, lin-22 activity prevents two other Hox genes, lin-39 and egl-5, from acquiring new activities within their normal domains of function along the A/P body axis. Some, but not all, of the patterning activities of lin-22 in C. elegans resemble those of hairy in Drosophila.

Regulation of differentiation flux by Notch signalling influences the number of dopaminergic neurons in the adult brain

PubMed Central

Trujillo-Paredes, Niurka; Valencia, Concepción; Guerrero-Flores, Gilda; Arzate, Dulce-María; Baizabal, José-Manuel; Guerra-Crespo, Magdalena; Fuentes-Hernández, Ayari; Zea-Armenta, Iván; Covarrubias, Luis

2016-01-01

ABSTRACT Notch signalling is a well-established pathway that regulates neurogenesis. However, little is known about the role of Notch signalling in specific neuronal differentiation. Using Dll1 null mice, we found that Notch signalling has no function in the specification of mesencephalic dopaminergic neural precursor cells (NPCs), but plays an important role in regulating their expansion and differentiation into neurons. Premature neuronal differentiation was observed in mesencephalons of Dll1-deficient mice or after treatment with a Notch signalling inhibitor. Coupling between neurogenesis and dopaminergic differentiation was indicated from the coincident emergence of neuronal and dopaminergic markers. Early in differentiation, decreasing Notch signalling caused a reduction in NPCs and an increase in dopaminergic neurons in association with dynamic changes in the proportion of sequentially-linked dopaminergic NPCs (Msx1/2+, Ngn2+, Nurr1+). These effects in differentiation caused a significant reduction in the number of dopaminergic neurons produced. Accordingly, Dll1 haploinsufficient adult mice, in comparison with their wild-type littermates, have a consistent reduction in neuronal density that was particularly evident in the substantia nigra pars compacta. Our results are in agreement with a mathematical model based on a Dll1-mediated regulatory feedback loop between early progenitors and their dividing precursors that controls the emergence and number of dopaminergic neurons. PMID:26912775

Regulation of differentiation flux by Notch signalling influences the number of dopaminergic neurons in the adult brain.

PubMed

Trujillo-Paredes, Niurka; Valencia, Concepción; Guerrero-Flores, Gilda; Arzate, Dulce-María; Baizabal, José-Manuel; Guerra-Crespo, Magdalena; Fuentes-Hernández, Ayari; Zea-Armenta, Iván; Covarrubias, Luis

2016-02-24

Notch signalling is a well-established pathway that regulates neurogenesis. However, little is known about the role of Notch signalling in specific neuronal differentiation. Using Dll1 null mice, we found that Notch signalling has no function in the specification of mesencephalic dopaminergic neural precursor cells (NPCs), but plays an important role in regulating their expansion and differentiation into neurons. Premature neuronal differentiation was observed in mesencephalons of Dll1-deficient mice or after treatment with a Notch signalling inhibitor. Coupling between neurogenesis and dopaminergic differentiation was indicated from the coincident emergence of neuronal and dopaminergic markers. Early in differentiation, decreasing Notch signalling caused a reduction in NPCs and an increase in dopaminergic neurons in association with dynamic changes in the proportion of sequentially-linked dopaminergic NPCs (Msx1/2+, Ngn2+, Nurr1+). These effects in differentiation caused a significant reduction in the number of dopaminergic neurons produced. Accordingly, Dll1 haploinsufficient adult mice, in comparison with their wild-type littermates, have a consistent reduction in neuronal density that was particularly evident in the substantia nigra pars compacta. Our results are in agreement with a mathematical model based on a Dll1-mediated regulatory feedback loop between early progenitors and their dividing precursors that controls the emergence and number of dopaminergic neurons. © 2016. Published by The Company of Biologists Ltd.

Atypical fibroxanthoma and pleomorphic dermal sarcoma harbor frequent NOTCH1/2 and FAT1 mutations and similar DNA copy number alteration profiles.

PubMed

Griewank, Klaus G; Wiesner, Thomas; Murali, Rajmohan; Pischler, Carina; Müller, Hansgeorg; Koelsche, Christian; Möller, Inga; Franklin, Cindy; Cosgarea, Ioana; Sucker, Antje; Schadendorf, Dirk; Schaller, Jörg; Horn, Susanne; Brenn, Thomas; Mentzel, Thomas

2018-03-01

Atypical fibroxanthomas and pleomorphic dermal sarcomas are tumors arising in sun-damaged skin of elderly patients. They have differing prognoses and are currently distinguished using histological criteria, such as invasion of deeper tissue structures, necrosis and lymphovascular or perineural invasion. To investigate the as-yet poorly understood genetics of these tumors, 41 atypical fibroxanthomas and 40 pleomorphic dermal sarcomas were subjected to targeted next-generation sequencing approaches as well as DNA copy number analysis by comparative genomic hybridization. In an analysis of the entire coding region of 341 oncogenes and tumor suppressor genes in 13 atypical fibroxanthomas using an established hybridization-based next-generation sequencing approach, we found that these tumors harbor a large number of mutations. Gene alterations were identified in more than half of the analyzed samples in FAT1, NOTCH1/2, CDKN2A, TP53, and the TERT promoter. The presence of these alterations was verified in 26 atypical fibroxanthoma and 35 pleomorphic dermal sarcoma samples by targeted amplicon-based next-generation sequencing. Similar mutation profiles in FAT1, NOTCH1/2, CDKN2A, TP53, and the TERT promoter were identified in both atypical fibroxanthoma and pleomorphic dermal sarcoma. Activating RAS mutations (G12 and G13) identified in 3 pleomorphic dermal sarcoma were not found in atypical fibroxanthoma. Comprehensive DNA copy number analysis demonstrated a wide array of different copy number gains and losses, with similar profiles in atypical fibroxanthoma and pleomorphic dermal sarcoma. In summary, atypical fibroxanthoma and pleomorphic dermal sarcoma are highly mutated tumors with recurrent mutations in FAT1, NOTCH1/2, CDKN2A, TP53, and the TERT promoter, and a range of DNA copy number alterations. These findings suggest that atypical fibroxanthomas and pleomorphic dermal sarcomas are genetically related, potentially representing two ends of a common tumor spectrum and distinguishing these entities is at present still best performed using histological criteria.

Delta-like 1 regulates Bergmann glial monolayer formation during cerebellar development.

PubMed

Hiraoka, Yuichi; Komine, Okiru; Nagaoka, Mai; Bai, Ning; Hozumi, Katsuto; Tanaka, Kohichi

2013-05-21

Bergmann glia (BG) are unipolar cerebellar astrocytes. The somata of mature BG reside in the Purkinje cell layer and extend radially arranged processes to the pial surface. BG have multiple branched processes, which enwrap the synapses of Purkinje cell dendrites. They migrate from the ventricular zone and align next to the Purkinje cell layer during development. Previously, we reported that Notch1, Notch2, and RBPj genes in the BG play crucial roles in the monolayer formation and morphogenesis of BG. However, it remains to be determined which ligand activates Nocth1 and Notch 2 on BG. Delta-like 1 (Dll1) is a major ligand of Notch receptors that is expressed in the developing cerebellum. In this study, we used human glial fibrillary acidic protein (hGFAP) promoter-driven Cre-mediated recombination to delete Dll1 in BG. Dll1-conditional mutant mice showed disorganization of Bergmann fibers, ectopic localization of BG in the molecular layer and a reduction in the number of BG. These results suggest that Dll1 is required for the formation of the BG layer and its morphological maturation, apparently through a Notch1/2-RBPj dependent signaling pathway.

Correlation of eddy current responses between fatigue cracks and electrical-discharge-machining notches

NASA Astrophysics Data System (ADS)

Seo, Sukho; Choi, Gyudong; Eom, Tae Jhoun; Lee, Bokwon; Lee, Soo Yeol

2017-07-01

The eddy current responses of Electrical Discharge Machining (EDM) notches and fatigue cracks are directly compared to verify the reliability of eddy current inspection. The fatigue crack growth tests using a constant load range control mode were conducted to obtain a variety of edge crack sizes, ranging from 0.9 to 6.6 mm for Al alloy and from 0.1 to 3 mm for Ti alloy. EDM notch specimens of Al and Ti alloys were accordingly prepared in lengths similar to that of the fatigued specimen. The crack length was determined by optical microscope and scanning electron microscope. The eddy current responses between the EDM and fatigued specimens with varying notch/crack length were examined using probe sensors at (100-500) kHz and (1-2) MHz for Al and Ti alloys, respectively. The results show a significant difference in the eddy current signal between the two specimens, based on the correlation between the eddy current response and notch/crack length. This suggests that eddy current inspection using the EDM reference specimen is inaccurate in determining the precise crack size, unless the eddy current response data base is obtained from a fatigue-cracked specimen.

A CPW-fed circular wide-slot UWB antenna with wide tunable and flexible reconfigurable dual notch bands.

PubMed

Li, Yingsong; Li, Wenxing; Ye, Qiubo

2013-01-01

A coplanar waveguide (CPW)-fed circular slot antenna with wide tunable dual band-notched function and frequency reconfigurable characteristic is designed, and its performance is verified experimentally for ultra-wideband (UWB) communication applications. The dual band-notched function is achieved by using a T-shaped stepped impedance resonator (T-SIR) inserted inside the circular ring radiation patch and by etching a parallel stub loaded resonator (PSLR) in the CPW transmission line, while the wide tunable bands can be implemented by adjusting the dimensions of the T-SIR and the PSLR. The notch band reconfigurable characteristic is realized by integrating three switches into the T-SIR and the PSLR. The numerical and experimental results show that the proposed antenna has a wide bandwidth ranging from 2.7 GHz to 12 GHz with voltage standing wave ratio (VSWR) less than 2, except for the two notch bands operating at 3.8-5.9 GHz and 7.7-9.2 GHz, respectively. In addition, the proposed antenna has been optimized to a compact size and can provide omnidirectional radiation patterns, which are suitable for UWB communication applications.

A CPW-Fed Circular Wide-Slot UWB Antenna with Wide Tunable and Flexible Reconfigurable Dual Notch Bands

PubMed Central

Li, Yingsong; Li, Wenxing; Ye, Qiubo

2013-01-01

A coplanar waveguide (CPW)-fed circular slot antenna with wide tunable dual band-notched function and frequency reconfigurable characteristic is designed, and its performance is verified experimentally for ultra-wideband (UWB) communication applications. The dual band-notched function is achieved by using a T-shaped stepped impedance resonator (T-SIR) inserted inside the circular ring radiation patch and by etching a parallel stub loaded resonator (PSLR) in the CPW transmission line, while the wide tunable bands can be implemented by adjusting the dimensions of the T-SIR and the PSLR. The notch band reconfigurable characteristic is realized by integrating three switches into the T-SIR and the PSLR. The numerical and experimental results show that the proposed antenna has a wide bandwidth ranging from 2.7 GHz to 12 GHz with voltage standing wave ratio (VSWR) less than 2, except for the two notch bands operating at 3.8–5.9 GHz and 7.7–9.2 GHz, respectively. In addition, the proposed antenna has been optimized to a compact size and can provide omnidirectional radiation patterns, which are suitable for UWB communication applications. PMID:24222733

In vitro expansion of Lin+ and Lin- mononuclear cells from human peripheral blood

NASA Astrophysics Data System (ADS)

Norhaiza, H. Siti; Rohaya, M. A. W.; Zarina, Z. A. Intan; Hisham, Z. A. Shahrul

2013-11-01

Haematopoietic stem cells (HSCs) are used in the therapy of blood disorders due to the ability of these cells to reconstitute haematopoietic lineage cells when transplanted into myeloablative recipients. However, substantial number of cells is required in order for the reconstitution to take place. Since HSCs present in low frequency, larger number of donor is required to accommodate the demand of transplantable HSCs. Therefore, in vitro expansion of HSCs will have profound impact on clinical purposes. The aim of this study was to expand lineage negative (Lin-) stem cells from human peripheral blood. Total peripheral blood mononuclear cells (PBMNCs) were fractionated from human blood by density gradient centrifugation. Subsequently, PBMNCs were subjected to magnetic assisted cell sorter (MACS) which depletes lineage positive (Lin+) mononuclear cells expressing lineage positive markers such as CD2, CD3, CD11b, CD14, CD15, CD16, CD19, CD56, CD123, and CD235a to obtained Lin- cell population. The ability of Lin+ and Lin- to survive in vitro was explored by culturing both cell populations in complete medium consisting of Alpha-Minimal Essential Medium (AMEM) +10% (v/v) Newborn Calf Serum (NBCS)+ 2% (v/v) pen/strep. In another experiment, Lin+ and Lin- were cultured with complete medium supplemented with 10ng/mL of the following growth factors: stem cell factor (SCF), interleukin (IL)-3, granulocyte-macrophage colony stimulating factor (GM-CSF), 2IU/mL of Erythropoietin (Epo) and 20ng/mL of IL-6. Three samples were monitored in static culture for 22 days. The expansion potential was assessed by the number of total viable cells, counted by trypan blue exclusion assay. It was found that Lin+ mononuclear cells were not able to survive either in normal proliferation medium or proliferation medium supplemented with cytokines. Similarly, Lin- stem cells were not able to survive in proliferation medium however, addition of cytokines into the proliferation medium support Lin- stem cells for at least 18 days. The Lin- stem cells started to response to the cytokines added as early as Day 2 of culture. It is concluded that Lin- stem cells can be expanded in vitro by culturing in proliferation medium supplemented with cytokines.

Audiometric notch and extended high-frequency hearing threshold shift in relation to total leisure noise exposure: An exploratory analysis.

PubMed

Wei, Wenjia; Heinze, Stefanie; Gerstner, Doris G; Walser, Sandra M; Twardella, Dorothee; Reiter, Christina; Weilnhammer, Veronika; Perez-Alvarez, Carmelo; Steffens, Thomas; Herr, Caroline E W

2017-01-01

Studies investigating leisure noise effect on extended high frequency hearing are insufficient and they have inconsistent results. The aim of this study was to investigate if extended high-frequency hearing threshold shift is related to audiometric notch, and if total leisure noise exposure is associated with extended high-frequency hearing threshold shift. A questionnaire of the Ohrkan cohort study was used to collect information on demographics and leisure time activities. Conventional and extended high-frequency audiometry was performed. We did logistic regression between extended high-frequency hearing threshold shift and audiometric notch as well as between total leisure noise exposure and extended high-frequency hearing threshold shift. Potential confounders (sex, school type, and firecrackers) were included. Data from 278 participants (aged 18-23 years, 53.2% female) were analyzed. Associations between hearing threshold shift at 10, 11.2, 12.5, and 14 kHz with audiometric notch were observed with a higher prevalence of threshold shift at the four frequencies, compared to the notch. However, we found no associations between total leisure noise exposure and hearing threshold shift at any extended high frequency. This exploratory analysis suggests that while extended high-frequency hearing threshold shifts are not related to total leisure noise exposure, they are strongly associated with audiometric notch. This leads us to further explore the hypothesis that extended high-frequency threshold shift might be indicative of the appearance of audiometric notch at a later time point, which can be investigated in the future follow-ups of the Ohrkan cohort.

Illegitimate V(D)J recombination-mediated deletions in Notch1 and Bcl11b are not sufficient for extensive clonal expansion and show minimal age or sex bias in frequency or junctional processing

PubMed Central

Champagne, Devin P.; Shockett, Penny E.

2014-01-01

Illegitimate V(D)J recombination at oncogenes and tumor suppressor genes is implicated in formation of several T cell malignancies. Notch1 and Bcl11b, genes involved in developing T cell specification, selection, proliferation, and survival, were previously shown to contain hotspots for deletional illegitimate V(D)J recombination associated with radiation-induced thymic lymphoma. Interestingly, these deletions were also observed in wild-type animals. In this study, we conducted frequency, clonality, and junctional processing analyses of Notch1 and Bcl11b deletions during mouse development and compared results to published analyses of authentic V(D)J rearrangements at the T cell receptor beta (TCRβ) locus and illegitimate V(D)J deletions observed at the human, nonimmune HPRT1 locus not involved in T cell malignancies. We detect deletions in Notch1 and Bcl11b in thymic and splenic T cell populations, consistent with cells bearing deletions in the circulating lymphocyte pool. Deletions in thymus can occur in utero, increase in frequency between fetal and postnatal stages, are detected at all ages examined between fetal and 7 months, exhibit only limited clonality (contrasting with previous results in radiation-sensitive mouse strains), and consistent with previous reports are more frequent in Bcl11b, partially explained by relatively high Recombination Signal Information Content (RIC) scores. Deletion junctions in Bcl11b exhibit greater germline nucleotide loss, while in Notch1 palindromic (P) nucleotides are more abundant, although average P nucleotide length is similar for both genes and consistent with results at the TCRβ locus. Non-templated (N) nucleotide insertions appear to increase between fetal and postnatal stages for Notch1, consistent with normal terminal deoxynucleotidyl transferase (TdT) activity; however, neonatal Bcl11b junctions contain elevated levels of N insertions. Finally, contrasting with results at the HPRT1 locus, we find no obvious age or gender bias in junctional processing, and inverted repeats at recessed coding ends (Pr nucleotides) correspond mostly to single-base additions consistent with normal TdT activity. PMID:24530429

WaveNet: A Web-Based Metocean Data Access, Processing, and Analysis Tool. Part 3 - CDIP Database

DTIC Science & Technology

2014-06-01

and Analysis Tool; Part 3 – CDIP Database by Zeki Demirbilek, Lihwa Lin, and Derek Wilson PURPOSE: This Coastal and Hydraulics Engineering...Technical Note (CHETN) describes coupling of the Coastal Data Information Program ( CDIP ) database to WaveNet, the first module of MetOcnDat (Meteorological...provides a step-by-step procedure to access, process, and analyze wave and wind data from the CDIP database. BACKGROUND: WaveNet addresses a basic

A Cross-Grade Study Validating the Evolutionary Pathway of Student Mental Models in Electric Circuits

ERIC Educational Resources Information Center

Lin, Jing-Wen

2017-01-01

Cross-grade studies are valuable for the development of sequential curriculum. However such studies are time and resource intensive and fail to provide a clear representation to integrate different levels of representational complexity. Lin (Lin, 2006; Lin & Chiu, 2006; Lin, Chiu, & Hsu, 2006) proposed a cladistics approach in conceptual…

Integrated β-catenin, BMP, PTEN, and Notch signalling patterns the nephron

PubMed Central

Lindström, Nils O; Lawrence, Melanie L; Burn, Sally F; Johansson, Jeanette A; Bakker, Elvira RM; Ridgway, Rachel A; Chang, C-Hong; Karolak, Michele J; Oxburgh, Leif; Headon, Denis J; Sansom, Owen J; Smits, Ron; Davies, Jamie A; Hohenstein, Peter

2015-01-01

The different segments of the nephron and glomerulus in the kidney balance the processes of water homeostasis, solute recovery, blood filtration, and metabolite excretion. When segment function is disrupted, a range of pathological features are presented. Little is known about nephron patterning during embryogenesis. In this study, we demonstrate that the early nephron is patterned by a gradient in β-catenin activity along the axis of the nephron tubule. By modifying β-catenin activity, we force cells within nephrons to differentiate according to the imposed β-catenin activity level, thereby causing spatial shifts in nephron segments. The β-catenin signalling gradient interacts with the BMP pathway which, through PTEN/PI3K/AKT signalling, antagonises β-catenin activity and promotes segment identities associated with low β-catenin activity. β-catenin activity and PI3K signalling also integrate with Notch signalling to control segmentation: modulating β-catenin activity or PI3K rescues segment identities normally lost by inhibition of Notch. Our data therefore identifies a molecular network for nephron patterning. DOI: http://dx.doi.org/10.7554/eLife.04000.001 PMID:25647637

A nanobiosensor for dynamic single cell analysis during microvascular self-organization.

PubMed

Wang, S; Sun, J; Zhang, D D; Wong, P K

2016-10-14

The formation of microvascular networks plays essential roles in regenerative medicine and tissue engineering. Nevertheless, the self-organization mechanisms underlying the dynamic morphogenic process are poorly understood due to a paucity of effective tools for mapping the spatiotemporal dynamics of single cell behaviors. By establishing a single cell nanobiosensor along with live cell imaging, we perform dynamic single cell analysis of the morphology, displacement, and gene expression during microvascular self-organization. Dynamic single cell analysis reveals that endothelial cells self-organize into subpopulations with specialized phenotypes to form microvascular networks and identifies the involvement of Notch1-Dll4 signaling in regulating the cell subpopulations. The cell phenotype correlates with the initial Dll4 mRNA expression level and each subpopulation displays a unique dynamic Dll4 mRNA expression profile. Pharmacological perturbations and RNA interference of Notch1-Dll4 signaling modulate the cell subpopulations and modify the morphology of the microvascular network. Taken together, a nanobiosensor enables a dynamic single cell analysis approach underscoring the importance of Notch1-Dll4 signaling in microvascular self-organization.

Exercise differentially affects metabolic functions and white adipose tissue in female letrozole- and dihydrotestosterone-induced mouse models of polycystic ovary syndrome.

PubMed

Marcondes, Rodrigo R; Maliqueo, Manuel; Fornes, Romina; Benrick, Anna; Hu, Min; Ivarsson, Niklas; Carlström, Mattias; Cushman, Samuel W; Stenkula, Karin G; Maciel, Gustavo A R; Stener-Victorin, Elisabet

2017-06-15

Here we hypothesized that exercise in dihydrotestosterone (DHT) or letrozole (LET)-induced polycystic ovary syndrome mouse models improves impaired insulin and glucose metabolism, adipose tissue morphology, and expression of genes related to adipogenesis, lipid metabolism, Notch pathway and browning in inguinal and mesenteric fat. DHT-exposed mice had increased body weight, increased number of large mesenteric adipocytes. LET-exposed mice displayed increased body weight and fat mass, decreased insulin sensitivity, increased frequency of small adipocytes and increased expression of genes related to lipolysis in mesenteric fat. In both models, exercise decreased fat mass and inguinal and mesenteric adipose tissue expression of Notch pathway genes, and restored altered mesenteric adipocytes morphology. In conclusion, exercise restored mesenteric adipocytes morphology in DHT- and LET-exposed mice, and insulin sensitivity and mesenteric expression of lipolysis-related genes in LET-exposed mice. Benefits could be explained by downregulation of Notch, and modulation of browning and lipolysis pathways in the adipose tissue. Copyright © 2017 Elsevier B.V. All rights reserved.

Molecular mechanism of central nervous system repair by the Drosophila NG2 homologue kon-tiki.

PubMed

Losada-Perez, Maria; Harrison, Neale; Hidalgo, Alicia

2016-08-29

Neuron glia antigen 2 (NG2)-positive glia are repair cells that proliferate upon central nervous system (CNS) damage, promoting functional recovery. However, repair is limited because of the failure of the newly produced glial cells to differentiate. It is a key goal to discover how to regulate NG2 to enable glial proliferation and differentiation conducive to repair. Drosophila has an NG2 homologue called kon-tiki (kon), of unknown CNS function. We show that kon promotes repair and identify the underlying mechanism. Crush injury up-regulates kon expression downstream of Notch. Kon in turn induces glial proliferation and initiates glial differentiation by activating glial genes and prospero (pros). Two negative feedback loops with Notch and Pros allow Kon to drive the homeostatic regulation required for repair. By modulating Kon levels in glia, we could prevent or promote CNS repair. Thus, the functional links between Kon, Notch, and Pros are essential for, and can drive, repair. Analogous mechanisms could promote CNS repair in mammals. © 2016 Losada-Perez et al.

Cell and matrix modulation in prenatal and postnatal equine growth cartilage, zones of Ranvier and articular cartilage

PubMed Central

Löfgren, Maria; Ekman, Stina; Svala, Emilia; Lindahl, Anders; Ley, Cecilia; Skiöldebrand, Eva

2014-01-01

Formation of synovial joints includes phenotypic changes of the chondrocytes and the organisation of their extracellular matrix is regulated by different factors and signalling pathways. Increased knowledge of the normal processes involved in joint development may be used to identify similar regulatory mechanisms during pathological conditions in the joint. Samples of the distal radius were collected from prenatal and postnatal equine growth plates, zones of Ranvier and articular cartilage with the aim of identifying Notch signalling components and cells with stem cell-like characteristics and to follow changes in matrix protein localisation during joint development. The localisation of the Notch signalling components Notch1, Delta4, Hes1, Notch dysregulating protein epidermal growth factor-like domain 7 (EGFL7), the stem cell-indicating factor Stro-1 and the matrix molecules cartilage oligomeric matrix protein (COMP), fibromodulin, matrilin-1 and chondroadherin were studied using immunohistochemistry. Spatial changes in protein localisations during cartilage maturation were observed for Notch signalling components and matrix molecules, with increased pericellular localisation indicating new synthesis and involvement of these proteins in the formation of the joint. However, it was not possible to characterise the phenotype of the chondrocytes based on their surrounding matrix during normal chondrogenesis. The zone of Ranvier was identified in all horses and characterised as an area expressing Stro-1, EGFL7 and chondroadherin with an absence of COMP and Notch signalling. Stro-1 was also present in cells close to the perichondrium, in the articular cartilage and in the fetal resting zone, indicating stem cell-like characteristics of these cells. The presence of stem cells in the articular cartilage will be of importance for the repair of damaged cartilage. Perivascular chondrocytes and hypertrophic cells of the cartilage bone interface displayed positive staining for EGFL7, which is a novel finding and suggests a role of EGFL7 in the vascular infiltration of growth cartilage. PMID:25175365

Evolution of the Chordate Regeneration Blastema: Differential Gene Expression and Conserved Role of Notch Signaling During Siphon Regeneration in the Ascidian Ciona

PubMed Central

Hamada, Mayuko; Goricki, Spela; Byerly, Mardi S.; Satoh, Noriyuki; Jeffery, William R.

2015-01-01

The regeneration of the oral siphon (OS) and other distal structures in the ascidian Ciona intestinalis occurs by epimorphosis involving the formation of a blastema of proliferating cells. Despite the longstanding use of Ciona as a model in molecular developmental biology, regeneration in this system has not been previously explored by molecular analysis. Here we have employed microarray analysis and quantitative real time RT-PCR to identify genes with differential expression profiles during OS regeneration. The majority of differentially expressed genes were downregulated during OS regeneration, suggesting roles in normal growth and homeostasis. However, a subset of differentially expressed genes was upregulated in the regenerating OS, suggesting functional roles during regeneration. Among the upregulated genes were key members of the Notch signaling pathway, including those encoding the delta and jagged ligands, two fringe modulators, and to a lesser extent the notch receptor. In situ hybridization showed a complementary pattern of delta1 and notch gene expression in the blastema of the regenerating OS. Chemical inhibition of the Notch signaling pathway reduced the levels of cell proliferation in the branchial sac, a stem cell niche that contributes progenitor cells to the regenerating OS, and in the OS regeneration blastema, where siphon muscle fibers eventually re-differentiate. Chemical inhibition also prevented the replacement of oral siphon pigment organs, sensory receptors rimming the entrance of the OS, and siphon muscle fibers, but had no effects on the formation of the wound epidermis. Since Notch signaling is involved in the maintenance of proliferative activity in both the Ciona and vertebrate regeneration blastema, the results suggest a conserved evolutionary role of this signaling pathway in chordate regeneration. The genes identified in this investigation provide the foundation for future molecular analysis of OS regeneration. PMID:26206613

Effect of notch position on fracture energy for foamed concrete

NASA Astrophysics Data System (ADS)

Naqiuddin Zamri, Mohd; Rahman, Norashidah Abd; Jaini, Zainorizuan Mohd; Shamila Bahador, Nurul

2017-11-01

Foamed concrete is one of the lightweight concrete used to replace normal concrete. Foamed concrete has potential as a building construction material in Malaysia due to low density range. However, the behavior of fracture energy on foamed concrete still under investigation. Therefore, a study to determine the fracture energy of foamed concrete was conducted. In this study, foamed concrete fracture energy was obtained using the three-point bending test methods develop by RILEM and Hillerborg. A total of 12 beams with different types of notch and positions of notch were tested on the load-deflection condition. In addition, a total of 9 cube samples were cast to support the result of fracture energy by using model from Bazant and Becq-Giraudon and Comite Euro-International du Beton (CEB). Results showed the far the position of the notch from midpoint, the higher the value of fracture energy. In this study, the value of fracture energy ranges between 15 N/m and 40 N/m.

Dynamic changes in global microRNAome and transcriptome reveal complex miRNA-mRNA regulated host response to Japanese Encephalitis Virus in microglial cells

PubMed Central

Kumari, Bharti; Jain, Pratistha; Das, Shaoli; Ghosal, Suman; Hazra, Bibhabasu; Trivedi, Ashish Chandra; Basu, Anirban; Chakrabarti, Jayprokas; Vrati, Sudhanshu; Banerjee, Arup

2016-01-01

Microglia cells in the brain play essential role during Japanese Encephalitis Virus (JEV) infection and may lead to change in microRNA (miRNA) and mRNA profile. These changes may together control disease outcome. Using Affymetrix microarray platform, we profiled cellular miRNA and mRNA expression at multiple time points during viral infection in human microglial (CHME3) cells. In silico analysis of microarray data revealed a phased pattern of miRNAs expression, associated with JEV replication and provided unique signatures of infection. Target prediction and pathway enrichment analysis identified anti correlation between differentially expressed miRNA and the gene expression at multiple time point which ultimately affected diverse signaling pathways including Notch signaling pathways in microglia. Activation of Notch pathway during JEV infection was demonstrated in vitro and in vivo. The expression of a subset of miRNAs that target multiple genes in Notch signaling pathways were suppressed and their overexpression could affect JEV induced immune response. Further analysis provided evidence for the possible presence of cellular competing endogenous RNA (ceRNA) associated with innate immune response. Collectively, our data provide a uniquely comprehensive view of the changes in the host miRNAs induced by JEV during cellular infection and identify Notch pathway in modulating microglia mediated inflammation. PMID:26838068

Dynamic changes in global microRNAome and transcriptome reveal complex miRNA-mRNA regulated host response to Japanese Encephalitis Virus in microglial cells.

PubMed

Kumari, Bharti; Jain, Pratistha; Das, Shaoli; Ghosal, Suman; Hazra, Bibhabasu; Trivedi, Ashish Chandra; Basu, Anirban; Chakrabarti, Jayprokas; Vrati, Sudhanshu; Banerjee, Arup

2016-02-03

Microglia cells in the brain play essential role during Japanese Encephalitis Virus (JEV) infection and may lead to change in microRNA (miRNA) and mRNA profile. These changes may together control disease outcome. Using Affymetrix microarray platform, we profiled cellular miRNA and mRNA expression at multiple time points during viral infection in human microglial (CHME3) cells. In silico analysis of microarray data revealed a phased pattern of miRNAs expression, associated with JEV replication and provided unique signatures of infection. Target prediction and pathway enrichment analysis identified anti correlation between differentially expressed miRNA and the gene expression at multiple time point which ultimately affected diverse signaling pathways including Notch signaling pathways in microglia. Activation of Notch pathway during JEV infection was demonstrated in vitro and in vivo. The expression of a subset of miRNAs that target multiple genes in Notch signaling pathways were suppressed and their overexpression could affect JEV induced immune response. Further analysis provided evidence for the possible presence of cellular competing endogenous RNA (ceRNA) associated with innate immune response. Collectively, our data provide a uniquely comprehensive view of the changes in the host miRNAs induced by JEV during cellular infection and identify Notch pathway in modulating microglia mediated inflammation.

Modélisation des charges d'espace dans les isolants solides par une analyse spectrale

NASA Astrophysics Data System (ADS)

Haas, V.; Scouarnec, Ch.; Franceschi, J. L.

1998-01-01

A mathematical method based on spectral algebra is developped for the thermal modulation method. These methods permit to measure the space charge distribution in solid insulators. The modelling presented permits to evaluate the performances and the limitations of the measurement method. Une linéarisation par l'algèbre spectrale a été développée dans une méthode de modulation thermique pour mesurer la distribution des charges électriques dans les isolants solides. La modélisation présentée permet d'évaluer les performances et les limites tant numériques que physiques de la méthode de mesure.

Importance of the pluripotency factor LIN28 in the mammalian nucleolus during early embryonic development.

PubMed

Vogt, Edgar J; Meglicki, Maciej; Hartung, Kristina Ilka; Borsuk, Ewa; Behr, Rüdiger

2012-12-01

The maternal nucleolus is required for proper activation of the embryonic genome (EGA) and early embryonic development. Nucleologenesis is characterized by the transformation of a nucleolar precursor body (NPB) to a mature nucleolus during preimplantation development. However, the function of NPBs and the involved molecular factors are unknown. We uncover a novel role for the pluripotency factor LIN28, the biological significance of which was previously demonstrated in the reprogramming of human somatic cells to induced pluripotent stem (iPS) cells. Here, we show that LIN28 accumulates at the NPB and the mature nucleolus in mouse preimplantation embryos and embryonic stem cells (ESCs), where it colocalizes with the nucleolar marker B23 (nucleophosmin 1). LIN28 has nucleolar localization in non-human primate (NHP) preimplantation embryos, but is cytoplasmic in NHP ESCs. Lin28 transcripts show a striking decline before mouse EGA, whereas LIN28 protein localizes to NPBs at the time of EGA. Following knockdown with a Lin28 morpholino, the majority of embryos arrest between the 2- and 4-cell stages and never develop to morula or blastocyst. Lin28 morpholino-injected embryos arrested at the 2-cell stage were not enriched with nucleophosmin at presumptive NPB sites, indicating that functional NPBs were not assembled. Based on these results, we propose that LIN28 is an essential factor of nucleologenesis during early embryonic development.

The NCU Lu-Lin Observatory Survived the Taiwan 921 Earthquake

NASA Astrophysics Data System (ADS)

Tsay, W. S.; Chang, K. H.; Li, H. H.

1999-12-01

The NCU (National Central University) Lu-Lin Observatory is located at Mt. Front Lu-Lin, 120o 52' 25" E and 23o 28' 07" N, a 2862-m peak in the Yu-Shan National Park. The construction of Lu-Lin Observatory was finished in January 1999. Fortunately the Lu-Lin Observatory survived the Taiwan 921 Earthquake that was 7.3 on the Ritcher scale. We are proud of the design of Lu-Lin Observatory adopted H-beam and steel wall even the center of earthquake was only 40 km away. The initial study of Lu-Lin site was started since late 1989. Later on, a three-year project was founded by the National Science Council , which supported the development of a modern seeing monitor for this site survey study from 1990 through 1993. The average seeing of Lu-Lin site is about 1.39 arc-second with average 200 clear nights annually. The sky background of this site is 20.72 mag/arcsec2 in V band and 21.22 mag/arcsec2 in B band. The Lu-Lin observatory is developed for both research and education activity. A homemade 76-cm Super Light Telescope (SLT) and three TAOS's 50-cm robotic telescopes will be the two major research facilities. This work is supported by the National Science Council of Taiwan.

Clinicopathological Characteristics of Patients with Gastric Cancer according to the Expression of LIN28A.

PubMed

Park, Chan Hyuk; Lee, Jung Hwa; Lee, Na Keum; Lee, Yong Chan; Lee, Sang Kil

2016-09-15

Although LIN28A is known to potentially play a role in the oncogenesis of various cancers, whether LIN28A expression is a predictor of poor prognosis in patients with gastric cancer has not been fully explored. We sought to evaluate clinicopathological characteristics according to the expression of LIN28A in numerous gastric cancer tissue samples. LIN28A expression was evaluated by immunohistochemical (IHC) analysis of a tissue microarray comprising 288 gastric cancer tissues and 288 adjacent normal tissues. Clinicopathological characteristics, including overall survival, were compared according to LIN28A expression. The IHC staining score was lower for the cancer tissues than the normal tissues (p<0.001). However, no significant differences were observed in the clinicopathological characteristics between the low and high LIN28A expression groups. In addition, the 5-year overall survival rate did not differ between the two groups: 75.3% (95% confidence interval [CI], 69.3% to 81.7%) versus 71.6% (95% CI, 63.3% to 80.9%) for low versus high expression, respectively. The expression of LIN28A did not appear to play a distinct role in predicting the clinicopathological characteristics of patients with gastric cancer. In addition, LIN28A expression was not an independently associated factor for overall survival in patients with gastric cancer.

The Lin28/let-7 axis regulates glucose metabolism

PubMed Central

Zhu, Hao; Shyh-Chang, Ng; Segrè, Ayellet V.; Shinoda, Gen; Shah, Samar P.; Einhorn, William S.; Takeuchi, Ayumu; Engreitz, Jesse M.; Hagan, John P.; Kharas, Michael G; Urbach, Achia; Thornton, James E.; Triboulet, Robinson; Gregory, Richard I.; Altshuler, David; Daley, George Q.

2012-01-01

SUMMARY The let-7 tumor suppressor microRNAs are known for their regulation of oncogenes, while the RNA-binding proteins Lin28a/b promote malignancy by blocking let-7 biogenesis. In studies of the Lin28/let-7 pathway, we discovered unexpected roles in regulating metabolism. When overexpressed in mice, both Lin28a and LIN28B promoted an insulin-sensitized state that resisted high fat diet-induced diabetes, whereas muscle-specific loss of Lin28a and overexpression of let-7 resulted in insulin resistance and impaired glucose tolerance. These phenomena occurred in part through let-7-mediated repression of multiple components of the insulin-PI3K-mTOR pathway, including IGF1R, INSR, and IRS2. The mTOR inhibitor rapamycin abrogated the enhanced glucose uptake and insulin-sensitivity conferred by Lin28a in vitro and in vivo. In addition, we found that let-7 targets were enriched for genes that contain SNPs associated with type 2 diabetes and fasting glucose in human genome-wide association studies. These data establish the Lin28/let-7 pathway as a central regulator of mammalian glucose metabolism. PMID:21962509

Prediction of the mid-tracheal level using surface anatomical landmarks in adults

PubMed Central

Jang, Young-Eun; Kim, Eun-Hee; Song, In-Kyung; Lee, Ji-Hyun; Ryu, Ho-Geoul; Kim, Hee-Soo; Kim, Jin-Tae

2017-01-01

Abstract Endotracheal tube (ETT) should be placed at the optimal level to avoid single lung ventilation or accidental extubation. This study was performed to estimate the mid-tracheal level by using surface anatomical landmarks in adult patients. Neck computed tomography images of 329 adult patients between the ages of 16 and 79 years were reviewed. In the midline sagittal plane, the levels corresponding to the vocal cords, cricoid cartilage, suprasternal notch, manubriosternal junction, and carina were identified. The surface distances from the cricoid cartilage to the suprasternal notch (extCC-SSN) and that from the suprasternal notch to the manubriosternal junction (extSSN-MSJ) were measured. The relationship between mid-tracheal level and the surface distances was analyzed using Bland–Altman plot. The difference between the extCC-SSN and the mid-tracheal level was −6.6 (12.5) mm, and the difference between the extSSN-MSJ and the mid-tracheal level was −19.2 (6.1) mm. The difference between the extCC-SSN and the mid-tracheal level was smaller in females compared with males [−1.7 (11.7) mm vs −12.8 (10.7) mm; P < 0.001]. The mid-tracheal level, which is helpful in planning the insertion depth of an ETT, can be predicted by the surface distance between the cricoid cartilage and suprasternal notch in adults, especially in females. PMID:28328810

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

O-Fucose Monosaccharide of Drosophila Notch Has a Temperature-sensitive Function and Cooperates with O-Glucose Glycan in Notch Transport and Notch Signaling Activation*

PubMed Central

Ishio, Akira; Sasamura, Takeshi; Ayukawa, Tomonori; Kuroda, Junpei; Ishikawa, Hiroyuki O.; Aoyama, Naoki; Matsumoto, Kenjiroo; Gushiken, Takuma; Okajima, Tetsuya; Yamakawa, Tomoko; Matsuno, Kenji

2015-01-01

Notch (N) is a transmembrane receptor that mediates the cell-cell interactions necessary for many cell fate decisions. N has many epidermal growth factor-like repeats that are O-fucosylated by the protein O-fucosyltransferase 1 (O-Fut1), and the O-fut1 gene is essential for N signaling. However, the role of the monosaccharide O-fucose on N is unclear, because O-Fut1 also appears to have O-fucosyltransferase activity-independent functions, including as an N-specific chaperon. Such an enzymatic activity-independent function could account for the essential role of O-fut1 in N signaling. To evaluate the role of the monosaccharide O-fucose modification in N signaling, here we generated a knock-in mutant of O-fut1 (O-fut1R245A knock-in), which expresses a mutant protein that lacks O-fucosyltransferase activity but maintains the N-specific chaperon activity. Using O-fut1R245A knock-in and other gene mutations that abolish the O-fucosylation of N, we found that the monosaccharide O-fucose modification of N has a temperature-sensitive function that is essential for N signaling. The O-fucose monosaccharide and O-glucose glycan modification, catalyzed by Rumi, function redundantly in the activation of N signaling. We also showed that the redundant function of these two modifications is responsible for the presence of N at the cell surface. Our findings elucidate how different forms of glycosylation on a protein can influence the protein's functions. PMID:25378397

Myeloid dendritic cells frequencies are increased in children with autism spectrum disorder and associated with amygdala volume and repetitive behaviors

PubMed Central

Breece, Elizabeth; Paciotti, Brian; Nordahl, Christine Wu; Ozonoff, Sally; Van de Water, Judy A.; Rogers, Sally J.; Amaral, David; Ashwood, Paul

2012-01-01

The pathophysiology of Autism Spectrum Disorder (ASD) is not yet known; however, studies suggest that dysfunction of the immune system affects many children with ASD. Increasing evidence points to dysfunction of the innate immune system including activation of microglia and perivascular macrophages, increases in inflammatory cytokines/chemokines in brain tissue and CSF, and abnormal peripheral monocyte cell function. Dendritic cells are major players in innate immunity and have important functions in the phagocytosis of pathogens or debris, antigen presentation, activation of naïve T cells, induction of tolerance and cytokine/chemokine production. In this study, we assessed circulating frequencies of myeloid dendritic cells (defined as Lin-1−BDCA1+CD11c+ and Lin-1−BDCA3+CD123−) and plasmacytoid dendritic cells (Lin-1− BDCA2+CD123+ or Lin-1−BDCA4+ CD11c−) in 57 children with ASD, and 29 typically developing controls of the same age, all of who were enrolled as part of the Autism Phenome Project (APP). The frequencies of dendritic cells and associations with behavioral assessment and MRI measurements of amygdala volume were compared in the same participants. The frequencies of myeloid dendritic cells were significantly increased in children with ASD compared to typically developing controls (p < 0.03). Elevated frequencies of myeloid dendritic cells were positively associated with abnormal right and left amygdala enlargement, severity of gastrointestinal symptoms and increased repetitive behaviors. The frequencies of plasmacytoid dendritic cells were also associated with amygdala volumes as well as developmental regression in children with ASD. Dendritic cells play key roles in modulating immune responses and differences in frequencies or functions of these cells may result in immune dysfunction in children with ASD. These data further implicate innate immune cells in the complex pathophysiology of ASD. PMID:23063420

Modulation between high- and low-frequency transcutaneous electric nerve stimulation delays the development of analgesic tolerance in arthritic rats.

PubMed

Desantana, Josimari M; Santana-Filho, Valter J; Sluka, Kathleen A

2008-04-01

To investigate whether repeated administration of modulating frequency transcutaneous electric nerve stimulation (TENS) prevents development of analgesic tolerance. Knee joint inflammation (3% carrageenan and kaolin) was induced in rats. Either mixed or alternating frequency was administered daily (20min) for 2 weeks to the inflamed knee under light halothane anesthesia (1%-2%). Laboratory. Adult male Sprague-Dawley rats (N=36). Mixed- (4Hz and 100Hz) or alternating- (4Hz on 1 day; 100Hz on the next day) frequency TENS at sensory intensity and 100micros pulse duration. Paw and joint withdrawal thresholds to mechanical stimuli were assessed before induction of inflammation, and before and after daily application of TENS. The reduced paw and joint withdrawal thresholds that occur 24 hours after the induction of inflammation were significantly reversed by the first administration of TENS when compared with sham treatment or to the condition before TENS treatment, which was observed through day 9. By the tenth day, repeated daily administration of either mixed- or alternating-frequency TENS did not reverse the decreased paw and joint withdrawal thresholds. These data suggest that repeated administration of modulating frequency TENS leads to a development of opioid tolerance. However, this tolerance effect is delayed by approximately 5 days compared with administration of low- or high-frequency TENS independently. Clinically, we can infer that a treatment schedule of repeated daily TENS administration will result in a tolerance effect. Moreover, modulating low and high frequency TENS seems to produce a better analgesic effect and tolerance is slower to develop.

In vitro expansion of Lin{sup +} and Lin{sup −} mononuclear cells from human peripheral blood

DOE Office of Scientific and Technical Information (OSTI.GOV)

Norhaiza, H. Siti; Zarina, Z. A. Intan; Hisham, Z. A. Shahrul

2013-11-27

Haematopoietic stem cells (HSCs) are used in the therapy of blood disorders due to the ability of these cells to reconstitute haematopoietic lineage cells when transplanted into myeloablative recipients. However, substantial number of cells is required in order for the reconstitution to take place. Since HSCs present in low frequency, larger number of donor is required to accommodate the demand of transplantable HSCs. Therefore, in vitro expansion of HSCs will have profound impact on clinical purposes. The aim of this study was to expand lineage negative (Lin{sup −}) stem cells from human peripheral blood. Total peripheral blood mononuclear cells (PBMNCs)more » were fractionated from human blood by density gradient centrifugation. Subsequently, PBMNCs were subjected to magnetic assisted cell sorter (MACS) which depletes lineage positive (Lin{sup +}) mononuclear cells expressing lineage positive markers such as CD2, CD3, CD11b, CD14, CD15, CD16, CD19, CD56, CD123, and CD235a to obtained Lin{sup −} cell population. The ability of Lin{sup +} and Lin{sup −} to survive in vitro was explored by culturing both cell populations in complete medium consisting of Alpha-Minimal Essential Medium (AMEM) +10% (v/v) Newborn Calf Serum (NBCS)+ 2% (v/v) pen/strep. In another experiment, Lin{sup +} and Lin{sup −} were cultured with complete medium supplemented with 10ng/mL of the following growth factors: stem cell factor (SCF), interleukin (IL)-3, granulocyte-macrophage colony stimulating factor (GM-CSF), 2IU/mL of Erythropoietin (Epo) and 20ng/mL of IL-6. Three samples were monitored in static culture for 22 days. The expansion potential was assessed by the number of total viable cells, counted by trypan blue exclusion assay. It was found that Lin{sup +} mononuclear cells were not able to survive either in normal proliferation medium or proliferation medium supplemented with cytokines. Similarly, Lin{sup −} stem cells were not able to survive in proliferation medium however, addition of cytokines into the proliferation medium support Lin{sup −} stem cells for at least 18 days. The Lin{sup −} stem cells started to response to the cytokines added as early as Day 2 of culture. It is concluded that Lin{sup −} stem cells can be expanded in vitro by culturing in proliferation medium supplemented with cytokines.« less

Modulation of Cholinergic Pathways and Inflammatory Mediators in Blast-Induced Traumatic Brain Injury

DTIC Science & Technology

2013-01-01

matic brain injury (TBI). Centrally acting acetylcholinesterase (AChE) inhibitors are also being considered as potential therapeutic candidates...repeated blast exposures [12]. AChE inhibitors are possible therapeutic candidates against Alzheimer’s disease and TBI [13–15]. In this study, we...esterase inhibitor , as described earlier [12,17–19]. Brain AChE activity was expressed as milliunits/mg protein. 2.3. Microarray analysis Various

Transient gamma-secretase inhibition accelerates and enhances fracture repair likely via Notch signaling modulation

PubMed Central

Wang, Cuicui; Shen, Jie; Yukata, Kiminori; Inzana, Jason A.; O'Keefe, Regis J.; Awad, Hani A.; Hilton, Matthew J.

2014-01-01

Approximately 10% of skeletal fractures result in healing complications and non-union, while most fractures repair with appropriate stabilization and without pharmacologic intervention. It is the latter injuries that cannot be underestimated as the expenses associated with their treatment and subsequent lost productivity are predicted to increase to over $74 billion by 2015. During fracture repair, local mesenchymal stem/progenitor cells (MSCs) differentiate to form new cartilage and bone, reminiscent of events during skeletal development. We previously demonstrated that permanent loss of gamma-secretase activity and Notch signaling accelerates bone and cartilage formation from MSC progenitors during skeletal development, leading to pathologic acquisition of bone and depletion of bone marrow derived MSCs. Here, we investigated whether transient and systemic gamma-secretase and Notch inhibition is capable of accelerating and enhancing fracture repair by promoting controlled MSC differentiation near the fracture site. Our radiographic, microCT, histological, cell and molecular analyses reveal that single and intermittent gamma-secretase inhibitor (GSI) treatments significantly enhance cartilage and bone callus formation via the promotion of MSC differentiation, resulting in only a moderate reduction of local MSCs. Biomechanical testing further demonstrates that GSI treated fractures exhibit superior strength earlier in the healing process, with single dose GSI treated fractures exhibiting bone strength approaching that of un-fractured tibiae. These data further establish that transient inhibition of gamma-secretase activity and Notch signaling temporarily increases osteoclastogenesis and accelerates bone remodeling, which coupled with the effects on MSCs likely explains the accelerated and enhanced fracture repair. Therefore, we propose that the Notch pathway serves as an important therapeutic target during skeletal fracture repair. PMID:25527421

Modulation of notch signaling pathway to prevent H2O2/menadione-induced SK-N-MC cells death by EUK134.

PubMed

Kamarehei, Maryam; Yazdanparast, Razieh

2014-10-01

The brain in Alzheimer's disease is under increased oxidative stress, and this may have a role in the pathogenesis and neural death in this disorder. It has been verified that numerous signaling pathways involved in neurodegenerative disorders are activated in response to reactive oxygen species (ROS). EUK134, a synthetic salen-manganese antioxidant complex, has been found to possess many interesting pharmacological activities awaiting exploration. The present study is to characterize the role of Notch signaling in apoptotic cell death of SK-N-MC cells. The cells were treated with hydrogen peroxide (H2O2) or menadione to induce oxidative stress. The free-radical scavenging capabilities of EUK134 were studied through the MTT assay, glutathione peroxidase (GPx) enzyme activity assay, and glutathione (GSH) Levels. The extents of lipid peroxidation, protein carbonyl formation, and intracellular ROS levels, as markers of oxidative stress, were also studied. Our results showed that H2O2/menadione reduced GSH levels and GPx activity. However, EUK134 protected cells against ROS-induced cell death by down-regulation of lipid peroxidation and protein carbonyl formation as well as restoration of antioxidant enzymes activity. ROS induced apoptosis and increased NICD and HES1 expression. Inhibition of NICD production proved that Notch signaling is involved in apoptosis through p53 activation. Moreover, H2O2/menadione led to Numb protein down-regulation which upon EUK134 pretreatment, its level increased and subsequently prevented Notch pathway activation. We indicated that EUK134 can be a promising candidate in designing natural-based drugs for ROS-induced neurodegenerative diseases. Collectively, ROS activated Notch signaling in SK-N-MC cells leading to cell apoptosis.

Forging T-Lymphocyte Identity: Intersecting Networks of Transcriptional Control.

PubMed

Rothenberg, Ellen V; Ungerbäck, Jonas; Champhekar, Ameya

2016-01-01

T-lymphocyte development branches off from other lymphoid developmental programs through its requirement for sustained environmental signals through the Notch pathway. In the thymus, Notch signaling induces a succession of T-lineage regulatory factors that collectively create the T-cell identity through distinct steps. This process involves both the staged activation of T-cell identity genes and the staged repression of progenitor-cell-inherited regulatory genes once their roles in self-renewal and population expansion are no longer needed. With the recent characterization of innate lymphoid cells (ILCs) that share transcriptional regulation programs extensively with T-cell subsets, T-cell identity can increasingly be seen as defined in modular terms, as the processes selecting and actuating effector function are potentially detachable from the processes generating and selecting clonally unique T-cell receptor structures. The developmental pathways of different classes of T cells and ILCs are distinguished by the numbers of prerequisites of gene rearrangement, selection, and antigen contact before the cells gain access to nearly common regulatory mechanisms for choosing effector function. Here, the major classes of transcription factors that interact with Notch signals during T-lineage specification are discussed in terms of their roles in these programs, the evidence for their spectra of target genes at different stages, and their cross-regulatory and cooperative actions with each other. Specific topics include Notch modulation of PU.1 and GATA-3, PU.1-Notch competition, the relationship between PU.1 and GATA-3, and the roles of E proteins, Bcl11b, and GATA-3 in guiding acquisition of T-cell identity while avoiding redirection to an ILC fate. © 2016 Elsevier Inc. All rights reserved.

Targeted next generation sequencing identifies novel NOTCH3 gene mutations in CADASIL diagnostics patients.

PubMed

Maksemous, Neven; Smith, Robert A; Haupt, Larisa M; Griffiths, Lyn R

2016-11-24

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is a monogenic, hereditary, small vessel disease of the brain causing stroke and vascular dementia in adults. CADASIL has previously been shown to be caused by varying mutations in the NOTCH3 gene. The disorder is often misdiagnosed due to its significant clinical heterogeneic manifestation with familial hemiplegic migraine and several ataxia disorders as well as the location of the currently identified causative mutations. The aim of this study was to develop a new, comprehensive and efficient single assay strategy for complete molecular diagnosis of NOTCH3 mutations through the use of a custom next-generation sequencing (NGS) panel for improved routine clinical molecular diagnostic testing. Our custom NGS panel identified nine genetic variants in NOTCH3 (p.D139V, p.C183R, p.R332C, p.Y465C, p.C597W, p.R607H, p.E813E, p.C977G and p.Y1106C). Six mutations were stereotypical CADASIL mutations leading to an odd number of cysteine residues in one of the 34 NOTCH3 gene epidermal growth factor (EGF)-like repeats, including three new typical cysteine mutations identified in exon 11 (p.C597W; c.1791C>G); exon 18 (p.C977G; c.2929T>G) and exon 20 (p.Y1106C; c.3317A>G). Interestingly, a novel missense mutation in the CACNA1A gene was also identified in one CADASIL patient. All variants identified (novel and known) were further investigated using in silico bioinformatic analyses and confirmed through Sanger sequencing. NGS provides an improved and effective methodology for the diagnosis of CADASIL. The NGS approach reduced time and cost for comprehensive genetic diagnosis, placing genetic diagnostic testing within reach of more patients.

Modulation of Brain Activity during Phonological Familiarization

ERIC Educational Resources Information Center

Majerus, S.; Van der Linden, M.; Collette, F.; Laureys, S.; Poncelet, M.; Degueldre, C.; Delfiore, G.; Luxen, A.; Salmon, E.

2005-01-01

We measured brain activity in 12 adults for the repetition of auditorily presented words and nonwords, before and after repeated exposure to their phonological form. The nonword phoneme combinations were either of high (HF) or low (LF) phonotactic frequency. After familiarization, we observed, for both word and nonword conditions, decreased…

Germline Genetic Variants Disturbing the Let-7/LIN28 Double-Negative Feedback Loop Alter Breast Cancer Susceptibility

PubMed Central

Fan, Lei; Li, Ji-Yu; Yang, Chen; Huang, A-Ji; Shao, Zhi-Ming

2011-01-01

Previous studies have shown that let-7 can repress the post-transcriptional translation of LIN28, and LIN28 in turn could block the maturation of let-7, forming a double-negative feedback loop. In this study, we investigated the effect of germline genetic variants on regulation of the homeostasis of the let-7/LIN28 loop and breast cancer risk. We initially demonstrated that the T/C variants of rs3811463, a single nucleotide polymorphism (SNP) located near the let-7 binding site in LIN28, could lead to differential regulation of LIN28 by let-7. Specifically, the C allele of rs3811463 weakened let-7–induced repression of LIN28 mRNA, resulting in increased production of LIN28 protein, which could in turn down-regulate the level of mature let-7. This effect was then validated at the tissue level in that the normal breast tissue of individuals with the rs3811463-TC genotype expressed significantly lower levels of let-7 and higher levels of LIN28 protein than those individuals with the rs3811463-TT genotype. Because previous in vitro and ex vivo experiments have consistently suggested that LIN28 could promote cellular transformation, we then systematically evaluated the relationship between rs3811463 as well as other common LIN28 SNPs and the risk of breast cancer in a stepwise manner. The first hospital-based association study (n = 2,300) demonstrated that two SNPs were significantly associated with breast cancer risk, one of which was rs3811463, while the other was rs6697410. The C allele of the rs3811463 SNP corresponded to an increased risk of breast cancer with an odds ratio (OR) of 1.25 (P = 0.0091), which was successfully replicated in a second independent study (n = 1,156) with community-based controls. The combined P-value of the two studies was 8.0×10−5. Taken together, our study demonstrates that host genetic variants could disturb the regulation of the let-7/LIN28 double-negative feedback loop and alter breast cancer risk. PMID:21912531

Let-7 miRNA Precursors Co-express with LIN28B in Cervical Cells.

PubMed

Zamora-Contreras, Aida Margarita; Alvarez-Salas, Luis Marat

2018-01-01

The let-7 microRNAs (miRNAs) are frequently dysregulated in carcinogenic processes, including cervical cancer. LIN28 proteins regulate let-7 biogenesis by binding to conserved sequences within the pre-miRNA structure. Nevertheless, recent research has shown that some let-7 miRNAs may escape LIN28 regulation. Correlate pre-let-7 miRNAs and LIN28B levels in cervical cell lines with different malignancy and HPV content. Pre-let-7 levels were determined by RTqPCR. LIN28B and other let-7 targets were analyzed by immunoblot. In silico tools were used to correlate let-7 and LIN28B expression and to analyze prelet- 7 sequences and structures. Lin28B protein was detected in all tested cell lines although it was more expressed in tumor cell lines. High levels of pre-let-7c/f-1 and pre-miR-98 were present in almost all cell lines regardless malignancy and LIN28B expression. Pre-let-7g/i were mainly expressed in tumor cell lines, pre-let-7e and pre-let-7-a3 were absent in all cell lines and pre-let-7a-2 showed indistinct expression. LIN28B showed positive correlation with pre-let-7i/g/f-1 and pre-miR-98 in tumor cell lines, suggesting escape from regulation. Sequence alignment and analysis of pre-let-7 miRNAs showed distinctive structural features within the preE region that may influence the ideal pre-let-7 structuring for LIN28B interaction. Short preE-stems were present in pre-let-7 that may escape LIN28B regulation, but long preEstems were mostly associated with high-level pre-let-7 miRNAs. The observed differences of pre-let-7 levels in cervical cell lines may be the result of alternative preE structuring affecting interaction with LIN28B thus resulting in differential let-7 regulation. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Overexpression of Lin28 inhibits the proliferation, migration and cell cycle progression and induces apoptosis of BGC-823 gastric cancer cells.

PubMed

Song, Hu; Xu, Wei; Song, Jun; Liang, Yong; Fu, Wei; Zhu, Xiao-Cheng; Li, Chao; Peng, Jun-Sheng; Zheng, Jun-Nian

2015-02-01

Lin28 plays important roles in the development, maintenance of pluripotency and progression of various types of cancers. Lin28 represses the biogenesis of let-7 microRNAs and is implicated in both development and tumorigenesis. Oncogenic regulation of let-7 microRNAs has been demonstrated in several human malignancies, yet their correlation with Lin28 has not yet been studied in gastric cancer. Therefore, in the present study, we explored the possible mechanisms involved in the effects by Lin28 on the proliferation, migration, cell cycle arrest and apoptosis in gastric cancer cells via alteration of let-7 miRNA. The expression levels of Lin28 and let-7 were detected by real-time PCR in gastric cancer cell lines in vitro. Lin28 was overexpressed in the BGC-823 cells via lentiviral transfection, and let-7 expression was assessed. Cell proliferation and migration capabilities were investigated by MTT and Transwell assays, while cell cycle distribution and the apoptosis rate were detected using flow cytometry. The expression of Lin28 was moderately expressed in the GES cells while underexpressed in the BGC-823, SGC-7901 and HGC-27 cells. Let-7a miRNA was highly expressed in the GES, BGC-823, SGC-7901 and HGC-27 cells. Overexpression of Lin28 was inversely correlated with the downregulated expression of let-7a, and markedly suppressed the proliferation, migration, cell cycle progression and induced apoptosis in the BGC-823 cells. These findings demonstrated that overexpression of Lin28 can suppress the biological behavior of gastric cancer in vitro, and let-7 miRNA may play an important role in the process. We suggest that Lin28 may be a candidate predictor or an anticancer therapeutic target for gastric cancer patients.

Hematopoietic stem cells found in lineage-positive subsets in the bone marrow of 5-fluorouracil-treated mice.

PubMed

Nishi, N; Osawa, M; Ishikawa, R; Nishikawa, M; Tsumura, H; Inoue, H; Sudo, T

1995-09-01

It is known that treatment of mice with 5-fluorouracil (5-FU, 150 mg/kg) confers radioprotection. To investigate this effect, we performed bone marrow transplantation (BMT) using C57BL/6-Ly5 congenic mice treated with 5-FU five days prior to experiments. The mononuclear cells (MNC) in 5-FU-treated bone marrow (BM) were 10 times more radioprotective than those in untreated BM. Moreover, the number of BM MNC expressing c-kit on their surface from 5-FU-treated mice was markedly decreased relative to those from untreated controls. These results showed that the surface characteristics of cells that contributed to this radio-protective effect differ from those of stem cells as reported recently. BM MNC of mice treated with 5-FU were separated on the basis of expression of the lineage-specific antigens (Lin), c-kit, and Ly6A/E. When injected into lethally irradiated mice, 1,000 Lin+ and Lin-c-kit+Ly6A/E+ cells showed radioprotective effects such that 100% and 60% survived, respectively. Flow cytometric analysis 165 days after BMT showed that 88.8% and 65.1% of peripheral blood (PB) in mice transplanted with Lin+ and Lin-c-kit+Ly6A/E+ was derived from donor mice, respectively. After six months, donor-derived Lin-c-kit+Ly6A/E+ cells which showed radioprotective effects on a secondary irradiated host were detected from mice transplanted with Lin+ cells from 5-FU-treated mice. Taken together, these findings demonstrated that stem cells expressing Lin+ present in the BM of mice treated with 5-FU other than Lin-c-kit+Ly6A/E+ cells and these Lin+ cells play an important role in the recovery of myeloablative mice.

Remote Field Eddy Curent Signal Modeling for the Gap Measurement of Neighboring Tubes

NASA Astrophysics Data System (ADS)

Jung, H. K.; Lee, D. H.; Lee, Y. S.

2005-04-01

The fuel channels in the Canadian Deuterium Uranium (CANDU) reactor consist of the coaxial pressure tube (PT) and the calandria tube (CT). The Liquid injection nozzle (LIN) is cross aligned with the fuel channel to control the reactor by injecting poison. For a safe operation, the gap between the LIN and CT should be maintained in order to prevent a contact of the neighboring tubes. The remote field eddy current (RFEC) method was applied to measure the gap between a nonmagnetic Zircaloy-2 liquid injection nozzle (LIN) and a Zircaloy-2 calandria tube. Under the condition of inserting the RFEC probe into the coaxial tubes and of crossing a LIN above or under the CT, the modeling of a LIN signal is needed to check the possibility of a gap measurement. The Volume Integral Code S/W which covers the axi-symmetric 3D configuration has been very rarely applied to obtain a LIN signal. This problem was solved by assuming a LIN as a flaw which can be described as a complete 3D object. This simulated LIN signal was verified by performing the laboratory experiment. The gap between the LIN and CT can be correlated with the amplitude of the LIN signals in the voltage plane. Typical noises in the fuel channel were the relative constriction, the change in the pressure tube diameter (fill-factor), thickness variation, and so on. These noise signals were simulated by using the modeling and were analyzed by considering their dependency on the phase angle and amplitude of the voltage plane in order to separate the gap signal from them. It could be concluded that the voltage plane analysis of the simulated RFEC signals were effective for obtaining the gap measurement of the neighboring tube.

The Autism Diagnostic Observation Schedule, Toddler Module: Standardized Severity Scores

PubMed Central

Esler, Amy N.; Bal, Vanessa Hus; Guthrie, Whitney; Wetherby, Amy; Weismer, Susan Ellis; Lord, Catherine

2016-01-01

Standardized calibrated severity scores (CSS) have been created for Autism Diagnostic Observation Schedule, 2nd edition (ADOS-2) Modules 1–4 as a metric of the relative severity of autism-specific behaviors. Total and domain CSS were created for the Toddler Module to facilitate comparison to other modules. Analyses included 388 children with ASD age 12 to 30 months and were replicated on 435 repeated assessments from 127 children with ASD. Compared to raw scores, associations between total and domain CSS and participant characteristics were reduced in the original sample. Verbal IQ effects on Social Affect-CSS were not reduced in the replication sample. Toddler Module CSS increases comparability of ADOS-2 scores across modules and allows studies of symptom trajectories to extend to earlier ages. PMID:25832801

Audiometric Notch and Extended High-Frequency Hearing Threshold Shift in Relation to Total Leisure Noise Exposure: An Exploratory Analysis

PubMed Central

Wei, Wenjia; Heinze, Stefanie; Gerstner, Doris G.; Walser, Sandra M.; Twardella, Dorothee; Reiter, Christina; Weilnhammer, Veronika; Perez-Alvarez, Carmelo; Steffens, Thomas; Herr, Caroline E.W.

2017-01-01

Background: Studies investigating leisure noise effect on extended high frequency hearing are insufficient and they have inconsistent results. The aim of this study was to investigate if extended high-frequency hearing threshold shift is related to audiometric notch, and if total leisure noise exposure is associated with extended high-frequency hearing threshold shift. Materials and Methods: A questionnaire of the Ohrkan cohort study was used to collect information on demographics and leisure time activities. Conventional and extended high-frequency audiometry was performed. We did logistic regression between extended high-frequency hearing threshold shift and audiometric notch as well as between total leisure noise exposure and extended high-frequency hearing threshold shift. Potential confounders (sex, school type, and firecrackers) were included. Results: Data from 278 participants (aged 18–23 years, 53.2% female) were analyzed. Associations between hearing threshold shift at 10, 11.2, 12.5, and 14 kHz with audiometric notch were observed with a higher prevalence of threshold shift at the four frequencies, compared to the notch. However, we found no associations between total leisure noise exposure and hearing threshold shift at any extended high frequency. Conclusion: This exploratory analysis suggests that while extended high-frequency hearing threshold shifts are not related to total leisure noise exposure, they are strongly associated with audiometric notch. This leads us to further explore the hypothesis that extended high-frequency threshold shift might be indicative of the appearance of audiometric notch at a later time point, which can be investigated in the future follow-ups of the Ohrkan cohort. PMID:29319010

Efficient method to create integration-free, virus-free, Myc and Lin28-free human induced pluripotent stem cells from adherent cells.

PubMed

Kamath, Anant; Ternes, Sara; McGowan, Stephen; English, Anthony; Mallampalli, Rama; Moy, Alan B

2017-08-01

Nonviral induced pluripotent stem cell (IPSC) reprogramming is not efficient without the oncogenes, Myc and Lin28 . We describe a robust Myc and Lin28 -free IPSC reprogramming approach using reprogramming molecules. IPSC colony formation was compared in the presence and absence of Myc and Lin28 by the mixture of reprogramming molecules and episomal vectors. While more colonies were observed in cultures transfected with the aforementioned oncogenes, the Myc and Lin28 -free method achieved the same reprogramming efficiency as reports that used these oncogenes. Further, all colonies were fully reprogrammed based on expression of SSEA4, even in the absence of Myc and Lin28 . This approach satisfies an important regulatory pathway for developing IPSC cell therapies with lower clinical risk.

Biochemistry of Microbial Degradation of Hexachlorocyclohexane and Prospects for Bioremediation

PubMed Central

Lal, Rup; Pandey, Gunjan; Sharma, Pooja; Kumari, Kirti; Malhotra, Shweta; Pandey, Rinku; Raina, Vishakha; Kohler, Hans-Peter E.; Holliger, Christof; Jackson, Colin; Oakeshott, John G.

2010-01-01

Summary: Lindane, the γ-isomer of hexachlorocyclohexane (HCH), is a potent insecticide. Purified lindane or unpurified mixtures of this and α-, β-, and δ-isomers of HCH were widely used as commercial insecticides in the last half of the 20th century. Large dumps of unused HCH isomers now constitute a major hazard because of their long residence times in soil and high nontarget toxicities. The major pathway for the aerobic degradation of HCH isomers in soil is the Lin pathway, and variants of this pathway will degrade all four of the HCH isomers although only slowly. Sequence differences in the primary LinA and LinB enzymes in the pathway play a key role in determining their ability to degrade the different isomers. LinA is a dehydrochlorinase, but little is known of its biochemistry. LinB is a hydrolytic dechlorinase that has been heterologously expressed and crystallized, and there is some understanding of the sequence-structure-function relationships underlying its substrate specificity and kinetics, although there are also some significant anomalies. The kinetics of some LinB variants are reported to be slow even for their preferred isomers. It is important to develop a better understanding of the biochemistries of the LinA and LinB variants and to use that knowledge to build better variants, because field trials of some bioremediation strategies based on the Lin pathway have yielded promising results but would not yet achieve economic levels of remediation. PMID:20197499

Context- and Cell-Dependent Effects of Delta-Like 4 Targeting in the Bone Marrow Microenvironment

PubMed Central

Remédio, Leonor; Carvalho, Tânia; Caiado, Francisco; Bastos-Carvalho, Ana; Martins, Diana; Duarte, António; Yagita, Hideo; Dias, Sergio

2012-01-01

Delta-like 4 (Dll4) is a ligand of the Notch pathway family which has been widely studied in the context of tumor angiogenesis, its blockade shown to result in non-productive angiogenesis and halted tumor growth. As Dll4 inhibitors enter the clinic, there is an emerging need to understand their side effects, namely the systemic consequences of Dll4:Notch blockade in tissues other than tumors. The present study focused on the effects of systemic anti-Dll4 targeting in the bone marrow (BM) microenvironment. Here we show that Dll4 blockade with monoclonal antibodies perturbs the BM vascular niche of sub-lethally irradiated mice, resulting in increased CD31+, VE-Cadherin+ and c-kit+ vessel density, and also increased megakaryocytes, whereas CD105+, VEGFR3+, SMA+ and lectin+ vessel density remained unaltered. We investigated also the expression of angiocrine genes upon Dll4 treatment in vivo, and demonstrate that IGFbp2, IGFbp3, Angpt2, Dll4, DHH and VEGF-A are upregulated, while FGF1 and CSF2 are reduced. In vitro treatment of endothelial cells with anti-Dll4 reduced Akt phosphorylation while maintaining similar levels of Erk 1/2 phosphorylation. Besides its effects in the BM vascular niche, anti-Dll4 treatment perturbed hematopoiesis, as evidenced by increased myeloid (CD11b+), decreased B (B220+) and T (CD3+) lymphoid BM content of treated mice, with a corresponding increase in myeloid circulating cells. Moreover, anti-Dll4 treatment also increased the number of CFU-M and -G colonies in methylcellulose assays, independently of Notch1. Finally, anti-Dll4 treatment of donor BM improved the hematopoietic recovery of lethally irradiated recipients in a transplant setting. Together, our data reveals the hematopoietic (BM) effects of systemic anti-Dll4 treatment result from qualitative vascular changes and also direct hematopoietic cell modulation, which may be favorable in a transplant setting. PMID:23285048

Notch1 stimulation induces a vascularization switch with pericyte-like cell differentiation of glioblastoma stem cells.

PubMed

Guichet, Pierre-Olivier; Guelfi, Sophie; Teigell, Marisa; Hoppe, Liesa; Bakalara, Norbert; Bauchet, Luc; Duffau, Hugues; Lamszus, Katrin; Rothhut, Bernard; Hugnot, Jean-Philippe

2015-01-01

Glioblastoma multiforms (GBMs) are highly vascularized brain tumors containing a subpopulation of multipotent cancer stem cells. These cells closely interact with endothelial cells in neurovascular niches. In this study, we have uncovered a close link between the Notch1 pathway and the tumoral vascularization process of GBM stem cells. We observed that although the Notch1 receptor was activated, the typical target proteins (HES5, HEY1, and HEY2) were not or barely expressed in two explored GBM stem cell cultures. Notch1 signaling activation by expression of the intracellular form (NICD) in these cells was found to reduce their growth rate and migration, which was accompanied by the sharp reduction in neural stem cell transcription factor expression (ASCL1, OLIG2, and SOX2), while HEY1/2, KLF9, and SNAI2 transcription factors were upregulated. Expression of OLIG2 and growth were restored after termination of Notch1 stimulation. Remarkably, NICD expression induced the expression of pericyte cell markers (NG2, PDGFRβ, and α-smooth muscle actin [αSMA]) in GBM stem cells. This was paralleled with the induction of several angiogenesis-related factors most notably cytokines (heparin binding epidermal growth factor [HB-EGF], IL8, and PLGF), matrix metalloproteinases (MMP9), and adhesion proteins (vascular cell adhesion molecule 1 [VCAM1], intercellular adhesion molecule 1 [ICAM1], and integrin alpha 9 [ITGA9]). In xenotransplantation experiments, contrasting with the infiltrative and poorly vascularized tumors obtained with control GBM stem cells, Notch1 stimulation resulted in poorly disseminating but highly vascularized grafts containing large vessels with lumen. Notch1-stimulated GBM cells expressed pericyte cell markers and closely associated with endothelial cells. These results reveal an important role for the Notch1 pathway in regulating GBM stem cell plasticity and angiogenic properties. © 2014 AlphaMed Press.

Music-induced cortical plasticity and lateral inhibition in the human auditory cortex as foundations for tonal tinnitus treatment.

PubMed

Pantev, Christo; Okamoto, Hidehiko; Teismann, Henning

2012-01-01

Over the past 15 years, we have studied plasticity in the human auditory cortex by means of magnetoencephalography (MEG). Two main topics nurtured our curiosity: the effects of musical training on plasticity in the auditory system, and the effects of lateral inhibition. One of our plasticity studies found that listening to notched music for 3 h inhibited the neuronal activity in the auditory cortex that corresponded to the center-frequency of the notch, suggesting suppression of neural activity by lateral inhibition. Subsequent research on this topic found that suppression was notably dependent upon the notch width employed, that the lower notch-edge induced stronger attenuation of neural activity than the higher notch-edge, and that auditory focused attention strengthened the inhibitory networks. Crucially, the overall effects of lateral inhibition on human auditory cortical activity were stronger than the habituation effects. Based on these results we developed a novel treatment strategy for tonal tinnitus-tailor-made notched music training (TMNMT). By notching the music energy spectrum around the individual tinnitus frequency, we intended to attract lateral inhibition to auditory neurons involved in tinnitus perception. So far, the training strategy has been evaluated in two studies. The results of the initial long-term controlled study (12 months) supported the validity of the treatment concept: subjective tinnitus loudness and annoyance were significantly reduced after TMNMT but not when notching spared the tinnitus frequencies. Correspondingly, tinnitus-related auditory evoked fields (AEFs) were significantly reduced after training. The subsequent short-term (5 days) training study indicated that training was more effective in the case of tinnitus frequencies ≤ 8 kHz compared to tinnitus frequencies >8 kHz, and that training should be employed over a long-term in order to induce more persistent effects. Further development and evaluation of TMNMT therapy are planned. A goal is to transfer this novel, completely non-invasive and low-cost treatment approach for tonal tinnitus into routine clinical practice.

Music-induced cortical plasticity and lateral inhibition in the human auditory cortex as foundations for tonal tinnitus treatment

PubMed Central

Pantev, Christo; Okamoto, Hidehiko; Teismann, Henning

2012-01-01

Over the past 15 years, we have studied plasticity in the human auditory cortex by means of magnetoencephalography (MEG). Two main topics nurtured our curiosity: the effects of musical training on plasticity in the auditory system, and the effects of lateral inhibition. One of our plasticity studies found that listening to notched music for 3 h inhibited the neuronal activity in the auditory cortex that corresponded to the center-frequency of the notch, suggesting suppression of neural activity by lateral inhibition. Subsequent research on this topic found that suppression was notably dependent upon the notch width employed, that the lower notch-edge induced stronger attenuation of neural activity than the higher notch-edge, and that auditory focused attention strengthened the inhibitory networks. Crucially, the overall effects of lateral inhibition on human auditory cortical activity were stronger than the habituation effects. Based on these results we developed a novel treatment strategy for tonal tinnitus—tailor-made notched music training (TMNMT). By notching the music energy spectrum around the individual tinnitus frequency, we intended to attract lateral inhibition to auditory neurons involved in tinnitus perception. So far, the training strategy has been evaluated in two studies. The results of the initial long-term controlled study (12 months) supported the validity of the treatment concept: subjective tinnitus loudness and annoyance were significantly reduced after TMNMT but not when notching spared the tinnitus frequencies. Correspondingly, tinnitus-related auditory evoked fields (AEFs) were significantly reduced after training. The subsequent short-term (5 days) training study indicated that training was more effective in the case of tinnitus frequencies ≤ 8 kHz compared to tinnitus frequencies >8 kHz, and that training should be employed over a long-term in order to induce more persistent effects. Further development and evaluation of TMNMT therapy are planned. A goal is to transfer this novel, completely non-invasive and low-cost treatment approach for tonal tinnitus into routine clinical practice. PMID:22754508

Novel therapeutic Strategies for Targeting Liver Cancer Stem Cells

PubMed Central

Oishi, Naoki; Wang, Xin Wei

2011-01-01

The cancer stem cell (CSC) hypothesis was first proposed over 40 years ago. Advances in CSC isolation were first achieved in hematological malignancies, with the first CSC demonstrated in acute myeloid leukemia. However, using similar strategies and technologies, and taking advantage of available surface markers, CSCs have been more recently demonstrated in a growing range of epithelial and other solid organ malignancies, suggesting that the majority of malignancies are dependent on such a compartment. Primary liver cancer consists predominantly of hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma (ICC). It is believed that hepatic progenitor cells (HPCs) could be the origin of some HCCs and ICCs. Furthermore, stem cell activators such as Wnt/β-catenin, TGF-β, Notch and Hedgehog signaling pathways also expedite tumorigenesis, and these pathways could serve as molecular targets to assist in designing cancer prevention strategies. Recent studies indicate that additional factors such as EpCAM, Lin28 or miR-181 may also contribute to HCC progression by targeting HCC CSCs. Various therapeutic drugs that directly modulate CSCs have been examined in vivo and in vitro. However, CSCs clearly have a complex pathogenesis, with a considerable crosstalk and redundancy in signaling pathways, and hence targeting single molecules or pathways may have a limited benefit for treatment. Many of the key signaling molecules are shared by both CSCs and normal stem cells, which add further challenges for designing molecularly targeted strategies specific to CSCs but sparing normal stem cells to avoid side effects. In addition to the direct control of CSCs, many other factors that are needed for the maintenance of CSCs, such as angiogenesis, vasculogenesis, invasion and migration, hypoxia, immune evasion, multiple drug resistance, and radioresistance, should be taken into consideration when designing therapeutic strategies for HCC. Here we provide a brief review of molecular signaling in liver CSCs and present insights into new therapeutic strategies for targeting liver CSCs. PMID:21552419

The heterochronic gene Lin28 regulates amphibian metamorphosis through disturbance of thyroid hormone function.

PubMed

Faunes, Fernando; Gundermann, Daniel G; Muñoz, Rosana; Bruno, Renzo; Larraín, Juan

2017-05-15

Metamorphosis is a classic example of developmental transition, which involves important morphological and physiological changes that prepare the organism for the adult life. It has been very well established that amphibian metamorphosis is mainly controlled by Thyroid Hormone (TH). Here, we show that the heterochronic gene Lin28 is downregulated during Xenopus laevis metamorphosis. Lin28 overexpression before activation of TH signaling delays metamorphosis and inhibits the expression of TH target genes. The delay in metamorphosis is rescued by incubation with exogenous TH, indicating that Lin28 works upstream or parallel to TH. High-throughput analyses performed before any delay on metamorphosis or change in TH signaling showed that overexpression of Lin28 reduces transcript levels of several hormones secreted by the pituitary, including the Thyroid-Stimulating Hormone (TSH), and regulates the expression of proteins involved in TH transport, metabolism and signaling, showing that Lin28 disrupts TH function at different levels. Our data demonstrates that the role of Lin28 in controlling developmental transitions is evolutionary conserved and establishes a functional interaction between Lin28 and thyroid hormone function introducing a new regulatory step in perinatal development with implications for our understanding of endocrine disorders. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Atomic force microscopy captures length phenotypes in single proteins

PubMed Central

Carrion-Vazquez, Mariano; Marszalek, Piotr E.; Oberhauser, Andres F.; Fernandez, Julio M.

1999-01-01

We use single-protein atomic force microscopy techniques to detect length phenotypes in an Ig module. To gain amino acid resolution, we amplify the mechanical features of a single module by engineering polyproteins composed of up to 12 identical repeats. We show that on mechanical unfolding, mutant polyproteins containing five extra glycine residues added to the folded core of the module extend 20 Å per module farther than the wild-type polyproteins. By contrast, similar insertions near the N or C termini have no effect. Hence, our atomic force microscopy measurements readily discriminate the location of the insert and measure its size with a resolution similar to that of NMR and x-ray crystallography. PMID:10500169

Photonic Quantum Networks formed from NV− centers

PubMed Central

Nemoto, Kae; Trupke, Michael; Devitt, Simon J.; Scharfenberger, Burkhard; Buczak, Kathrin; Schmiedmayer, Jörg; Munro, William J.

2016-01-01

In this article we present a simple repeater scheme based on the negatively-charged nitrogen vacancy centre in diamond. Each repeater node is built from modules comprising an optical cavity containing a single NV−, with one nuclear spin from 15N as quantum memory. The module uses only deterministic processes and interactions to achieve high fidelity operations (>99%), and modules are connected by optical fiber. In the repeater node architecture, the processes between modules by photons can be in principle deterministic, however current limitations on optical components lead the processes to be probabilistic but heralded. Our resource-modest repeater architecture contains two modules at each node, and the repeater nodes are then connected by entangled photon pairs. We discuss the performance of such a quantum repeater network with modest resources and then incorporate more resource-intense strategies step by step. Our architecture should allow large-scale quantum information networks with existing or near future technology. PMID:27215433

Photonic Quantum Networks formed from NV(-) centers.

PubMed

Nemoto, Kae; Trupke, Michael; Devitt, Simon J; Scharfenberger, Burkhard; Buczak, Kathrin; Schmiedmayer, Jörg; Munro, William J

2016-05-24

In this article we present a simple repeater scheme based on the negatively-charged nitrogen vacancy centre in diamond. Each repeater node is built from modules comprising an optical cavity containing a single NV(-), with one nuclear spin from (15)N as quantum memory. The module uses only deterministic processes and interactions to achieve high fidelity operations (>99%), and modules are connected by optical fiber. In the repeater node architecture, the processes between modules by photons can be in principle deterministic, however current limitations on optical components lead the processes to be probabilistic but heralded. Our resource-modest repeater architecture contains two modules at each node, and the repeater nodes are then connected by entangled photon pairs. We discuss the performance of such a quantum repeater network with modest resources and then incorporate more resource-intense strategies step by step. Our architecture should allow large-scale quantum information networks with existing or near future technology.

miR-188 promotes senescence of lineage-negative bone marrow cells by targeting MAP3K3 expression.

PubMed

Zheng, Yue; Liu, Hua; Kong, Ye

2017-08-01

Lineage-negative bone marrow cells (lin-BMCs) have reparative potential for overcoming endothelial dysfunction and reducing cardiovascular risk. Here, we found that miR-188 is upregulated and mitogen-activated protein kinase kinase kinase 3 (MAP3K3) is downregulated in aged lin-BMCs, whereas their expression is reversed in young lin-BMCs. We identified and confirmed MAP3K3 as a direct target of miR-188. MiR-188 overexpression or MAP3K3 silencing in young lin-BMCs increases p16 and p21 expression, enhances cell senescence, and decreases the ability for cell proliferation, migration, and tube formation. Conversely, miR-188 suppression in aged lin-BMCs yields the opposite results. We further found that MAP3K3 is involved in miR-188-induced promotion of lin-BMC senescence. All data reveal that miR-188 induces lin-BMC senescence by targeting MAP3K3 expression, thus, providing new theoretical basis for the prevention and treatment of cardiovascular diseases. © 2017 Federation of European Biochemical Societies.

RNA binding protein Lin28B confers gastric cancer cells stemness via directly binding to NRP-1.

PubMed

Wang, Xiaocong; Hu, Huihua; Liu, Hebo

2018-05-19

This work aims to explore the roles and related mechanisms of RNA binding protein Lin28B in gastric cancer cells stemness. We found that Lin28B expression was negatively correlated with the overall survival (OS) of gastric cancer patients, and significantly increased in gastric cancer cells compared with that in gastric epithelial cells. Lin28B overexpression increased spheroid formation, expression of gastric cancer stemness-related markers, and decreased cisplatin sensitivity in gastric cancer cells. Mechanistically, Lin28B could directly bind to NRP-1 3'UTR, thus increasing NRP-1 mRNA stability and expression, and activate the downstream Wnt/β-catenin signaling. Knockdown of NRP-1 or treatment with Wnt/β-catenin antagonist could rescue the promotive effects of Lin28B on gastric cancer stemness. Thus, thes results indicate that Lin28B could facilitate gastric cancer stemness via directly binding to NRP-1 3'UTR and activating the downstream Wnt/β-catenin signaling. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

Biochemical Characterization and Cellular Effects of CADASIL Mutants of NOTCH3

PubMed Central

Meng, He; Zhang, Xiaojie; Yu, Genggeng; Lee, Soo Jung; Chen, Y. Eugene; Prudovsky, Igor; Wang, Michael M.

2012-01-01

Cerebral Autosomal Dominant Arteriopathy with Subcortical Infarcts and Leukoencephalopathy (CADASIL) is the best understood cause of dominantly inherited stroke and results from NOTCH3 mutations that lead to NOTCH3 protein accumulation and selective arterial smooth muscle degeneration. Previous studies show that NOTCH3 protein forms multimers. Here, we investigate protein interactions between NOTCH3 and other vascular Notch isoforms and characterize the effects of elevated NOTCH3 on smooth muscle gene regulation. We demonstrate that NOTCH3 forms heterodimers with NOTCH1, NOTCH3, and NOTCH4. R90C and C49Y mutant NOTCH3 form complexes which are more resistant to detergents than wild type NOTCH3 complexes. Using quantitative NOTCH3-luciferase clearance assays, we found significant inhibition of mutant NOTCH3 clearance. In coculture assays of NOTCH function, overexpressed wild type and mutant NOTCH3 significantly repressed NOTCH-regulated smooth muscle transcripts and potently impaired the activity of three independent smooth muscle promoters. Wildtype and R90C recombinant NOTCH3 proteins applied to cell cultures also blocked canonical Notch fuction. We conclude that CADASIL mutants of NOTCH3 complex with NOTCH1, 3, and 4, slow NOTCH3 clearance, and that overexpressed wild type and mutant NOTCH3 protein interfere with key NOTCH-mediated functions in smooth muscle cells. PMID:23028706

O-linked-N-acetylglucosamine modification of mammalian Notch receptors by an atypical O-GlcNAc transferase Eogt1

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sakaidani, Yuta; Ichiyanagi, Naoki; Saito, Chika

2012-03-02

Highlights: Black-Right-Pointing-Pointer We characterized A130022J15Rik (Eogt1)-a mouse gene homologous to Drosophila Eogt. Black-Right-Pointing-Pointer Eogt1 encodes EGF domain O-GlcNAc transferase. Black-Right-Pointing-Pointer Expression of Eogt1 in Drosophila rescued the cell-adhesion defect in the Eogt mutant. Black-Right-Pointing-Pointer O-GlcNAcylation reaction in the secretory pathway is conserved through evolution. -- Abstract: O-linked-{beta}-N-acetylglucosamine (O-GlcNAc) modification is a unique cytoplasmic and nuclear protein modification that is common in nearly all eukaryotes, including filamentous fungi, plants, and animals. We had recently reported that epidermal growth factor (EGF) repeats of Notch and Dumpy are O-GlcNAcylated by an atypical O-GlcNAc transferase, EOGT, in Drosophila. However, no study has yet shownmore » whether O-GlcNAcylation of extracellular proteins is limited to insects such as Drosophila or whether it occurs in other organisms, including mammals. Here, we report the characterization of A130022J15Rik, a mouse gene homolog of Drosophila Eogt (Eogt 1). Enzymatic analysis revealed that Eogt1 has a substrate specificity similar to that of Drosophila EOGT, wherein the Thr residue located between the fifth and sixth conserved cysteines of the folded EGF-like domains is modified. This observation is supported by the fact that the expression of Eogt1 in Drosophila rescued the cell-adhesion defect caused by Eogt downregulation. In HEK293T cells, Eogt1 expression promoted modification of Notch1 EGF repeats by O-GlcNAc, which was further modified, at least in part, by galactose to generate a novel O-linked-N-acetyllactosamine structure. These results suggest that Eogt1 encodes EGF domain O-GlcNAc transferase and that O-GlcNAcylation reaction in the secretory pathway is a fundamental biochemical process conserved through evolution.« less

Rbpj-κ mediated Notch signaling plays a critical role in development of hypothalamic Kisspeptin neurons

PubMed Central

Biehl, Matthew J; Raetzman, Lori T

2015-01-01

The mammalian arcuate nucleus (ARC) houses neurons critical for energy homeostasis and sexual maturation. Proopiomelanocortin (POMC) and Neuropeptide Y (NPY) neurons function to balance energy intake and Kisspeptin neurons are critical for the onset of puberty and reproductive function. While the physiological roles of these neurons have been well established, their development remains unclear. We have previously shown that Notch signaling plays an important role in cell fate within the ARC of mice. Active Notch signaling prevented neural progenitors from differentiating into feeding circuit neurons, whereas conditional loss of Notch signaling lead to a premature differentiation of these neurons. Presently, we hypothesized that Kisspeptin neurons would similarly be affected by Notch manipulation. To address this, we utilized mice with a conditional deletion of the Notch signaling co-factor Rbpj-κ (Rbpj cKO), or mice persistently expressing the Notch1 intracellular domain (NICD tg) within Nkx2.1 expressing cells of the developing hypothalamus. Interestingly, we found that in both models, a lack of Kisspeptin neurons are observed. This suggests that Notch signaling must be properly titrated for formation of Kisspeptin neurons. These results led us to hypothesize that Kisspeptin neurons of the ARC may arise from a different lineage of intermediate progenitors than NPY neurons and that Notch was responsible for the fate choice between these neurons. To determine if Kisspeptin neurons of the ARC differentiate similarly through a Pomc intermediate, we utilized a genetic model expressing the tdTomato fluorescent protein in all cells that have ever expressed Pomc. We observed some Kisspeptin expressing neurons labeled with the Pomc reporter similar to NPY neurons, suggesting that these distinct neurons can arise from a common progenitor. Finally, we hypothesized that temporal differences leading to premature depletion of progenitors in cKO mice lead to our observed phenotype. Using a BrdU birthdating paradigm, we determined the percentage of NPY and Kisspeptin neurons born on embryonic days 11.5, 12.5, and 13.5. We found no difference in the timing of differentiation of either neuronal subtype, with a majority occurring at e11.5. Taken together, our findings suggest that active Notch signaling is an important molecular switch involved in instructing subpopulations of progenitor cells to differentiate into Kisspeptin neurons. PMID:26318021

A simulation method for combining hydrodynamic data and acoustic tag tracks to predict the entrainment of juvenile salmonids onto the Yolo Bypass under future engineering scenarios

USGS Publications Warehouse

Blake, Aaron R.; Stumpner, Paul; Burau, Jon R.

2017-01-01

During water year 2016 the U.S. Geological Survey California Water Science Center (USGS) collaborated with the California Department of Water Resources (DWR) to conduct a joint hydrodynamic and fisheries study to acquire data that could be used to evaluate the effects of proposed modifications to the Fremont Weir on outmigrating juvenile Chinook salmon. During this study the USGS surgically implanted acoustic tags in juvenile late fall run Chinook salmon from the Coleman National Fish Hatchery, released the acoustically tagged juvenile salmon into the Sacramento River upstream of the Fremont Weir, and tracked their movements as they emigrated past the western end of the Fremont Weir.The USGS analyzed tracking data from the acoustically tagged juvenile salmon along with detailed hydrodynamic data collected in the Sacramento River during the winter/spring of water year 2016 in the vicinity of the western end of the Fremont Weir to assess the potential for enhancing the entrainment of Sacramento River Chinook salmon onto the Yolo Bypass under six different Fremont Weir modification scenarios. Each modification scenario consists of a notch or multiple notches in the Fremont Weir which are designed to divert a portion of the Sacramento River onto the Yolo Bypass when the Sacramento River is below the crest of the Fremont Weir. The primary goal of this entrainment analysis was to investigate how the location of the notch or notches in each scenario affected the entrainment of juvenile Chinook salmon onto the Yolo Bypass, and to predict the notch location or locations that would result in maximum entrainment under each modification scenario. Stumpner et al.’s (in review) analysis of hydraulic data collected during the 2016 study period showed that backwater effects in the Sacramento River created significant variability in the relationship between Sacramento River stage and the proportion of the Sacramento River flow that we expect to be diverted onto the Yolo Bypass under the modification scenarios. Because of this variability, accurately evaluating the entrainment potential of possible notch locations for each scenario required combining historic abundance data for juvenile Sacramento River Chinook salmon with historic hydraulic data for the Sacramento River in the vicinity of the Fremont Weir, so that the entrainment estimates would reflect the covariance between Sacramento River stage, Sacramento River discharge, and juvenile salmon abundance within the historic record.We used a Monte Carlo simulation framework to combine the high resolution hydrodynamic data and acoustic tag track data collected in 2016 with historic juvenile salmon abundance, Sacramento River stage, and Sacramento River discharge data from a period spanning water years 1996-2010 to assess the entrainment potential of different weir modification scenarios under historic conditions. The scenarios we simulated consisted of four single notch configurations, and two multiple notch configurations in the vicinity of the western end of the Fremont Weir. For each notch configuration the 15-water-year entrainment simulation was repeated for 63 possible notch locations in the vicinity of the western end of the Fremont Weir. This approach allowed us to assess the effect of notch location on the entrainment of juvenile salmonids onto the Yolo Bypass for each of the six notch configurations that we evaluated.The entrainment simulations showed that the location of each notch configuration had a major impact on the entrainment for each scenario; the predicted entrainment of some scenarios varied by as much as 400% based on where the notch (or notches) was (were) located in the study area. All of the single notch scenarios performed best when they were located within a 330 ft (100 meter) long section of the Sacramento River bank adjacent to the western terminus of the Fremont Weir (Table 1). Both of the multiple notch scenarios performed best when their upstream notches were located about 660 ft (200 meters) upstream of the western terminus of the Fremont Weir (Table 1). The results of the entrainment simulations indicated that for each notch configuration the same notch location produced near-maximum entrainment regardless of run abundance timing; this result suggests that there are areas within the study are where a notch (or notches) can be sited to achieve maximum entrainment for all runs (barring significant behavioral or physiological differences between runs). In addition, the simulation results indicate that for each notch configuration the same location is expected to produce nearmaximum entrainment for both wet water years and dry water years.Based on the results of the entrainment simulation we make three general recommendations for strategies to improve the entrainment potential of a notch in the Fremont Weir:1) Comparisons between the maximum entrainment potential for each scenario suggested that total entrainment of winter run, spring run, and fall run salmon onto the Yolo Bypass can be increased by increasing the amount of water entering a notch when the Sacramento River stage is between 19 ft and 22 ft NAVD88; this could be accomplished by lowering notch invert elevations or by adding a control section to the Sacramento River to raise stage for a given discharge.2) The relationship between Sacramento River stage and entrainment for each scenario indicated that entrainment efficiency for each scenario declined significantly once Sacramento River stage exceeded bankfull (approximately 28.5 ft NAVD88). This effect was likely due to inundation of the floodplain between the Sacramento River and the Fremont Weir; Stumpner et. al (In Review) have documented a reduction in the strength of the secondary circulation and centralization of the downwelling zone in the Sacramento River when this floodplain is inundated. Therefore, increasing the height of the river right bank of the Sacramento River to coincide with the height of the Fremont Weir is recommended to increase entrainment at higher stages. 3) Bathymetric features upstream of notch openings appeared to have a major impact on the entrainment potential of the simulated notches. For this reason we recommend taking care to avoid siting notches immediately downstream of bank features that alter the sidewall boundary layer, and we expect that smoothing the bank bathymetry upstream of a notch will enhance entrainment. Finally, we caution that the entrainment simulation was based on the behavior of large hatchery smolts, so it is likely that our results will be sensitive to any differences in behavior and physiology between these hatchery surrogates and naturally migrating juvenile salmon.

Weighted Lin-Wang Tests for Crossing Hazards

PubMed Central

Koziol, James A.; Jia, Zhenyu

2014-01-01

Lin and Wang have introduced a quadratic version of the logrank test, appropriate for situations in which the underlying survival distributions may cross. In this note, we generalize the Lin-Wang procedure to incorporate weights and investigate the performance of Lin and Wang's test and weighted versions in various scenarios. We find that weighting does increase statistical power in certain situations; however, none of the procedures was dominant under every scenario. PMID:24795776

Taxonomic notes on the armored spiders of the families Pacullidae and Tetrablemmidae (Arachnida, Araneae) from Singapore.

PubMed

Lin, Yucheng; Koh, Joseph K H; Koponen, Seppo; Li, Shuqiang

2017-01-01

Eight species of armored spiders belonging to two families, Pacullidae Simon, 1894 and Tetrablemmidae O. Pickard-Cambridge, 1873, are reported from Singapore. Five species are documented as new to science: Paculla bukittimahensis Lin & Li, sp. n. (male and female), Paculla globosa Lin & Li, sp. n. (male and female), Ablemma malacca Lin & Li, sp. n. (male and female), Singaporemma lenachanae Lin & Li, sp. n. (male and female), and Sulaimania brevis Lin & Li, sp. n. (male). The three known species are Brignoliella besutensis Lin, Li & Jäger, 2012, Brignoliella michaeli Lehtinen, 1981, and Singaporemma singulare Shear, 1978, of which the female of Brignoliella besutensis is described for the first time. For comparison, types of Singaporemma adjacens Lehtinen, 1981 from Vietnam, Singaporemma halongense Lehtinen, 1981 from Vietnam, Singaporemma singulare from Singapore and Sulaimania vigelandi Lehtinen, 1981 from Malaysia are studied and photographed.

Taxonomic notes on the armored spiders of the families Pacullidae and Tetrablemmidae (Arachnida, Araneae) from Singapore

PubMed Central

Lin, Yucheng; Koh, Joseph K. H.; Koponen, Seppo; Li, Shuqiang

2017-01-01

Abstract Eight species of armored spiders belonging to two families, Pacullidae Simon, 1894 and Tetrablemmidae O. Pickard-Cambridge, 1873, are reported from Singapore. Five species are documented as new to science: Paculla bukittimahensis Lin & Li, sp. n. (male and female), Paculla globosa Lin & Li, sp. n. (male and female), Ablemma malacca Lin & Li, sp. n. (male and female), Singaporemma lenachanae Lin & Li, sp. n. (male and female), and Sulaimania brevis Lin & Li, sp. n. (male). The three known species are Brignoliella besutensis Lin, Li & Jäger, 2012, Brignoliella michaeli Lehtinen, 1981, and Singaporemma singulare Shear, 1978, of which the female of Brignoliella besutensis is described for the first time. For comparison, types of Singaporemma adjacens Lehtinen, 1981 from Vietnam, Singaporemma halongense Lehtinen, 1981 from Vietnam, Singaporemma singulare from Singapore and Sulaimania vigelandi Lehtinen, 1981 from Malaysia are studied and photographed. PMID:28769602

Bacterial diversity and real-time PCR based assessment of linA and linB gene distribution at hexachlorocyclohexane contaminated sites.

PubMed

Lal, Devi; Jindal, Swati; Kumari, Hansi; Jit, Simran; Nigam, Aeshna; Sharma, Pooja; Kumari, Kirti; Lal, Rup

2015-03-01

The disposal of hexachlorocyclohexane (HCH) muck has created large number of HCH dumpsites all over the world from where the harmful HCH isomers are leaking into the environment. Bacteria have evolved at such contaminated sites that have the ability to degrade HCH. Degradation of various HCH isomers in bacterial strains is mediated primarily by two genes: linA and linB which encode dehydrochlorinase and haloalkane dehalogenase respectively. In this study we explored one such highly contaminated HCH dumpsite located in Lucknow, Uttar Pradesh, India. To assess the biostimulation potential of the contaminated site, microbial diversity study and real-time PCR based quantification of lin genes was carried out. The soil samples from dumpsite and surrounding areas were found to be highly contaminated with HCH residue levels as high as 1.8 × 10(5)  mg kg(-1). The residues were detected in areas upto 13 km from the dumpsite. Sphingomonads, Chromohalobacter, and Marinobacter were the dominant genera present at the dump-site. Role of Sphingomonads in HCH degradation has been well documented. The highest copy numbers of linA and linB genes as determined using real-time PCR were 6.2 × 10(4) and 5.3 × 10(5), respectively, were found in sample from the dump site. The presence of Sphingomonads, linA, and linB genes from HCH contaminated soil indicates the presence of indigenous bacterial communities capable of HCH degradation. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Selection based on CD133 and high aldehyde dehydrogenase activity isolates long-term reconstituting human hematopoietic stem cells

PubMed Central

Hess, David A.; Wirthlin, Louisa; Craft, Timothy P.; Herrbrich, Phillip E.; Hohm, Sarah A.; Lahey, Ryan; Eades, William C.; Creer, Michael H.; Nolta, Jan A.

2006-01-01

The development of novel cell-based therapies requires understanding of distinct human hematopoietic stem and progenitor cell populations. We recently isolated reconstituting hematopoietic stem cells (HSCs) by lineage depletion and purification based on high aldehyde dehydrogenase activity (ALDHhiLin- cells). Here, we further dissected the ALDHhi-Lin- population by selection for CD133, a surface molecule expressed on progenitors from hematopoietic, endothelial, and neural lineages. ALDHhiCD133+Lin- cells were primarily CD34+, but also included CD34-CD38-CD133+ cells, a phenotype previously associated with repopulating function. Both ALDHhiCD133-Lin- and ALDHhiCD133+Lin- cells demonstrated distinct clonogenic progenitor function in vitro, whereas only the ALDHhiCD133+Lin- population seeded the murine bone marrow 48 hours after transplantation. Significant human cell repopulation was observed only in NOD/SCID and NOD/SCID β2M-null mice that received transplants of ALDHhiCD133+Lin- cells. Limiting dilution analysis demonstrated a 10-fold increase in the frequency of NOD/SCID repopulating cells compared with CD133+Lin- cells, suggesting that high ALDH activity further purified cells with repopulating function. Transplanted ALDHhiCD133+Lin- cells also maintained primitive hematopoietic phenotypes (CD34+CD38-) and demonstrated enhanced repopulating function in recipients of serial, secondary transplants. Cell selection based on ALDH activity and CD133 expression provides a novel purification of HSCs with long-term repopulating function and may be considered an alternative to CD34 cell selection for stem cell therapies. PMID:16269619

Y Chromosome Regulation of Autism Susceptibility Genes

DTIC Science & Technology

2009-06-01

with human -like spontaneous mutation. Neuroreport, 2008. 19(7): p. 739-43. 60. Lin, Y.M., et al., Association analysis of monoamine oxidase A gene and...susceptibility genes, including the monoamine oxidase A (MOAA), mediator complex subunit 12 (MED12), homeobox B1 (HOXB1) gastrin-releasing peptide...autism susceptibility genes, the RET proto- oncogene and monoamine oxidase A (MAOA) gene for detail studies. MAOA deaminates monoamines and is involved

Photovoltaic array mounting apparatus, systems, and methods

DOEpatents

West, John Raymond; Atchley, Brian; Hudson, Tyrus Hawkes; Johansen, Emil

2014-12-02

An apparatus for mounting a photovoltaic (PV) module on a surface, including a support with an upper surface, a lower surface, tabs, one or more openings, and a clip comprising an arm and a notch, where the apparatus resists wind forces and seismic forces and creates a grounding electrical bond between the PV module, support, and clip. The invention further includes a method for installing PV modules on a surface that includes arranging supports in rows along an X axis and in columns along a Y axis on a surface such that in each row the distance between two neighboring supports does not exceed the length of the longest side of a PV module and in each column the distance between two neighboring supports does not exceed the length of the shortest side of a PV module.

Mitotic Spindle Positioning in the EMS Cell of Caenorhabditis elegans Requires LET-99 and LIN-5/NuMA.

PubMed

Liro, Małgorzata J; Rose, Lesilee S

2016-11-01

Asymmetric divisions produce daughter cells with different fates, and thus are critical for animal development. During asymmetric divisions, the mitotic spindle must be positioned on a polarized axis to ensure the differential segregation of cell fate determinants into the daughter cells. In many cell types, a cortically localized complex consisting of Gα, GPR-1/2, and LIN-5 (Gαi/Pins/Mud, Gαi/LGN/NuMA) mediates the recruitment of dynactin/dynein, which exerts pulling forces on astral microtubules to physically position the spindle. The conserved PAR polarity proteins are known to regulate both cytoplasmic asymmetry and spindle positioning in many cases. However, spindle positioning also occurs in response to cell signaling cues that appear to be PAR-independent. In the four-cell Caenorhabditis elegans embryo, Wnt and Mes-1/Src-1 signaling pathways act partially redundantly to align the spindle on the anterior/posterior axis of the endomesodermal (EMS) precursor cell. It is unclear how those extrinsic signals individually contribute to spindle positioning and whether either pathway acts via conserved spindle positioning regulators. Here, we genetically test the involvement of Gα, LIN-5, and their negative regulator LET-99, in transducing EMS spindle positioning polarity cues. We also examined whether the C. elegans ortholog of another spindle positioning regulator, DLG-1, is required. We show that LET-99 acts in the Mes-1/Src-1 pathway for spindle positioning. LIN-5 is also required for EMS spindle positioning, possibly through a Gα- and DLG-1-independent mechanism. Copyright © 2016 by the Genetics Society of America.

Mitotic Spindle Positioning in the EMS Cell of Caenorhabditis elegans Requires LET-99 and LIN-5/NuMA

PubMed Central

Liro, Małgorzata J.; Rose, Lesilee S.

2016-01-01

Asymmetric divisions produce daughter cells with different fates, and thus are critical for animal development. During asymmetric divisions, the mitotic spindle must be positioned on a polarized axis to ensure the differential segregation of cell fate determinants into the daughter cells. In many cell types, a cortically localized complex consisting of Gα, GPR-1/2, and LIN-5 (Gαi/Pins/Mud, Gαi/LGN/NuMA) mediates the recruitment of dynactin/dynein, which exerts pulling forces on astral microtubules to physically position the spindle. The conserved PAR polarity proteins are known to regulate both cytoplasmic asymmetry and spindle positioning in many cases. However, spindle positioning also occurs in response to cell signaling cues that appear to be PAR-independent. In the four-cell Caenorhabditis elegans embryo, Wnt and Mes-1/Src-1 signaling pathways act partially redundantly to align the spindle on the anterior/posterior axis of the endomesodermal (EMS) precursor cell. It is unclear how those extrinsic signals individually contribute to spindle positioning and whether either pathway acts via conserved spindle positioning regulators. Here, we genetically test the involvement of Gα, LIN-5, and their negative regulator LET-99, in transducing EMS spindle positioning polarity cues. We also examined whether the C. elegans ortholog of another spindle positioning regulator, DLG-1, is required. We show that LET-99 acts in the Mes-1/Src-1 pathway for spindle positioning. LIN-5 is also required for EMS spindle positioning, possibly through a Gα- and DLG-1-independent mechanism. PMID:27672093

Kynurenine promotes the goblet cell differentiation of HT-29 colon carcinoma cells by modulating Wnt, Notch and AhR signals.

PubMed

Park, Joo-Hung; Lee, Jeong-Min; Lee, Eun-Jin; Kim, Da-Jeong; Hwang, Won-Bhin

2018-04-01

Various amino acids regulate cell growth and differentiation. In the present study, we examined the ability of HT-29 cells to differentiate into goblet cells in RPMI and DMEM which are largely different in the amounts of numerous amino acids. Most of the HT-29 cells differentiated into goblet cells downregulating the stem cell marker Lgr5 when cultured in DMEM, but remained undifferentiated in RPMI. The goblet cell differentiation in DMEM was inhibited by 1-methyl-tryptophan (1-MT), an inhibitor of indoleamine 2,3 dioxygenase-1 which is the initial enzyme in tryptophan metabolism along the kynurenine (KN) pathway, whereas tryptophan and KN induced goblet cell differentiation in RPMI. The levels of Notch1 and its activation product Notch intracytoplasmic domain in HT-29 cells were lower in DMEM than those in RPMI and were increased by 1-MT in both media. HT-29 cells grown in both media expressed β-catenin at the same level on day 2 when goblet cell differentiation was not observed. β-catenin expression, which was increased by 1-MT in both media, was decreased by KN. DMEM reduced Hes1 expression while enhancing Hath1 expression. Finally, aryl hydrocarbon receptor (AhR) activation moderately induced goblet cell differentiation. Our results suggest that KN promotes goblet cell differentiation by regulating Wnt, Notch, and AhR signals and expression of Hes1 and Hath1.

Rescue of Notch signaling in cells incapable of GDP-L-fucose synthesis by gap junction transfer of GDP-L-fucose in Drosophila.

PubMed

Ayukawa, Tomonori; Matsumoto, Kenjiroo; Ishikawa, Hiroyuki O; Ishio, Akira; Yamakawa, Tomoko; Aoyama, Naoki; Suzuki, Takuya; Matsuno, Kenji

2012-09-18

Notch (N) is a transmembrane receptor that mediates cell-cell interactions to determine many cell-fate decisions. N contains EGF-like repeats, many of which have an O-fucose glycan modification that regulates N-ligand binding. This modification requires GDP-L-fucose as a donor of fucose. The GDP-L-fucose biosynthetic pathways are well understood, including the de novo pathway, which depends on GDP-mannose 4,6 dehydratase (Gmd) and GDP-4-keto-6-deoxy-D-mannose 3,5-epimerase/4-reductase (Gmer). However, the potential for intercellularly supplied GDP-L-fucose and the molecular basis of such transportation have not been explored in depth. To address these points, we studied the genetic effects of mutating Gmd and Gmer on fucose modifications in Drosophila. We found that these mutants functioned cell-nonautonomously, and that GDP-L-fucose was supplied intercellularly through gap junctions composed of Innexin-2. GDP-L-fucose was not supplied through body fluids from different isolated organs, indicating that the intercellular distribution of GDP-L-fucose is restricted within a given organ. Moreover, the gap junction-mediated supply of GDP-L-fucose was sufficient to support the fucosylation of N-glycans and the O-fucosylation of the N EGF-like repeats. Our results indicate that intercellular delivery is a metabolic pathway for nucleotide sugars in live animals under certain circumstances.

Improved Knowledge Retention Among Clinical Pharmacy Students Using an Anthropology Classroom Assessment Technique

PubMed Central

Parton, Jason M.

2014-01-01

Objective. To adapt a classroom assessment technique (CAT) from an anthropology course to a diabetes module in a clinical pharmacy skills laboratory and to determine student knowledge retention from baseline. Design. Diabetes item stems, focused on module objectives, replaced anthropology terms. Answer choices, coded to Bloom’s Taxonomy, were expanded to include higher-order thinking. Students completed the online 5-item probe 4 times: prelaboratory lecture, postlaboratory, and at 6 months and 12 months after laboratory. Statistical analyses utilized a single factor, repeated measures design using rank transformations of means with a Mann-Whitney-Wilcoxon test. Assessment. The CAT revealed a significant increase in knowledge from prelaboratory compared to all postlaboratory measurements (p<0.0001). Significant knowledge retention was maintained with basic terms, but declined with complex terms between 6 and 12 months. Conclusion. The anthropology assessment tool was effectively adapted using Bloom’s Taxonomy as a guide and, when used repeatedly, demonstrated knowledge retention. Minimal time was devoted to application of the probe making it an easily adaptable CAT. PMID:25258445

Biodegradation of γ-hexachlorocyclohexane by transgenic hairy root cultures of Cucurbita moschata that accumulate recombinant bacterial LinA.

PubMed

Nanasato, Yoshihiko; Namiki, Sayuri; Oshima, Masao; Moriuchi, Ryota; Konagaya, Ken-Ichi; Seike, Nobuyasu; Otani, Takashi; Nagata, Yuji; Tsuda, Masataka; Tabei, Yutaka

2016-09-01

γ-HCH was successfully degraded using LinA-expressed transgenic hairy root cultures of Cucurbita moschata . Fusing an endoplasmic reticulum-targeting signal peptide to LinA was essential for stable accumulation in the hairy roots. The pesticide γ-hexachlorocyclohexane (γ-HCH) is a persistent organic pollutant (POP) that raises public health and environmental pollution concerns worldwide. Although several isolates of γ-HCH-degrading bacteria are available, inoculating them directly into γ-HCH-contaminated soil is ineffective because of the bacterial survival rate. Cucurbita species incorporate significant amounts of POPs from soils compared with other plant species. Here, we describe a novel bioremediation strategy that combines the bacterial degradation of γ-HCH and the efficient uptake of γ-HCH by Cucurbita species. We produced transgenic hairy root cultures of Cucurbita moschata that expressed recombinant bacterial linA, isolated from the bacterium Sphingobium japonicum UT26. The LinA protein was accumulated stably in the hairy root cultures by fusing an endoplasmic reticulum (ER)-targeting signal peptide to LinA. Then, we demonstrated that the cultures degraded more than 90 % of γ-HCH (1 ppm) overnight and produced the γ-HCH metabolite 1,2,4-trichlorobenzene, indicating that LinA degraded γ-HCH. These results indicate that the gene linA has high potential for phytoremediation of environmental γ-HCH.

HOXB7 overexpression in lung cancer is a hallmark of acquired stem-like phenotype.

PubMed

Monterisi, Simona; Lo Riso, Pietro; Russo, Karin; Bertalot, Giovanni; Vecchi, Manuela; Testa, Giuseppe; Di Fiore, Pier Paolo; Bianchi, Fabrizio

2018-03-26

HOXB7 is a homeodomain (HOX) transcription factor involved in regional body patterning of invertebrates and vertebrates. We previously identified HOXB7 within a ten-gene prognostic signature for lung adenocarcinoma, where increased expression of HOXB7 was associated with poor prognosis. This raises the question of how HOXB7 overexpression can influence the metastatic behavior of lung adenocarcinoma. Here, we analyzed publicly available microarray and RNA-seq lung cancer expression datasets and found that HOXB7-overexpressing tumors are enriched in gene signatures characterizing adult and embryonic stem cells (SC), and induced pluripotent stem cells (iPSC). Experimentally, we found that HOXB7 upregulates several canonical SC/iPSC markers and sustains the expansion of a subpopulation of cells with SC characteristics, through modulation of LIN28B, an emerging cancer gene and pluripotency factor, which we discovered to be a direct target of HOXB7. We validated this new circuit by showing that HOXB7 enhances reprogramming to iPSC with comparable efficiency to LIN28B or its target c-MYC, which is a canonical reprogramming factor.

The algorithmic performance of J-Tpeak for drug safety clinical trial.

PubMed

Chien, Simon C; Gregg, Richard E

The interval from J-point to T-wave peak (JTp) in ECG is a new biomarker able to identify drugs that prolong the QT interval but have different ion channel effects. If JTp is not prolonged, the prolonged QT may be associated with multi ion channel block that may have low torsade de pointes risk. From the automatic ECG measurement perspective, accurate and repeatable measurement of JTp involves different challenges than QT. We evaluated algorithm performance and JTp challenges using the Philips DXL diagnostic 12/16/18-lead algorithm. Measurement of JTp represents a different use model. Standard use of corrected QT interval is clinical risk assessment on patients with cardiac disease or suspicion of heart disease. Drug safety trials involve a very different population - young healthy subjects - who commonly have J-waves, notches and slurs. Drug effects include difficult and unusual morphology such as flat T-waves, gentle notches, and multiple T-wave peaks. The JTp initiative study provided ECGs collected from 22 young subjects (11 males and females) in randomized testing of dofetilide, quinidine, ranolazine, verapamil and placebo. We compare the JTp intervals between DXL algorithm and the FDA published measurements. The lead wise, vector-magnitude (VM), root-mean-square (RMS) and principal-component-analysis (PCA) representative beats were used to measure JTp and QT intervals. We also implemented four different methods for T peak detection for comparison. We found that JTp measurements were closer to the reference for combined leads RMS and PCA than individual leads. Differences in J-point location led to part of the JTp measurement difference because of the high prevalence of J-waves, notches and slurs. Larger differences were noted for drug effect causing multiple distinct T-wave peaks (Tp). The automated algorithm chooses the later peak while the reference was the earlier peak. Choosing among different algorithmic strategies in T peak measurement results in the tradeoff between stability and the accurate detection of calcium or sodium channel block. Measurement of JTp has different challenges than QT measurement. JTp measurement accuracy improved with combined leads RMS and PCA over lead II or V5. Copyright © 2017 Elsevier Inc. All rights reserved.

Modulation of hematopoietic progenitor cell fate in vitro by varying collagen oligomer matrix stiffness in the presence or absence of osteoblasts.

PubMed

Chitteti, Brahmananda Reddy; Kacena, Melissa A; Voytik-Harbin, Sherry L; Srour, Edward F

2015-10-01

To recreate the in vivo hematopoietic cell microenvironment or niche and to study the impact of extracellular matrix (ECM) biophysical properties on hematopoietic progenitor cell (HPC) proliferation and function, mouse bone-marrow derived HPC (Lin-Sca1+cKit+/(LSK) were cultured within three-dimensional (3D) type I collagen oligomer matrices. To generate a more physiologic milieu, 3D cultures were established in both the presence and absence of calvariae-derived osteoblasts (OB). Collagen oligomers were polymerized at varying concentration to give rise to matrices of different fibril densities and therefore matrix stiffness (shear storage modulus, 50-800 Pa). Decreased proliferation and increased clonogenicity of LSK cells was associated with increase of matrix stiffness regardless of whether OB were present or absent from the 3D culture system. Also, regardless of whether OB were or were not added to the 3D co-culture system, LSK within 800 Pa collagen oligomer matrices maintained the highest percentage of Lin-Sca1+ cells as well as higher percentage of cells in quiescent state (G0/G1) compared to 50 Pa or 200Pa matrices. Collectively, these data illustrate that biophysical features of collagen oligomer matrices, specifically fibril density-induced modulation of matrix stiffness, provide important guidance cues in terms of LSK expansion and differentiation and therefore maintenance of progenitor cell function. Copyright © 2015. Published by Elsevier B.V.

Integrated optic single-ring filter for narrowband phase demodulation

NASA Astrophysics Data System (ADS)

Madsen, C. K.

2017-05-01

Integrated optic notch filters are key building blocks for higher-order spectral filter responses and have been demonstrated in many technology platforms from dielectrics (such as Si3N4) to semiconductors (Si photonics). Photonic-assisted RF processing applications for notch filters include identifying and filtering out high-amplitude, narrowband signals that may be interfering with the desired signal, including undesired frequencies detected in radar and free-space optical links. The fundamental tradeoffs for bandwidth and rejection depth as a function of the roundtrip loss and coupling coefficient are investigated along with the resulting spectral phase response for minimum-phase and maximum-phase responses compared to the critical coupling condition and integration within a Mach Zehnder interferometer. Based on a full width at half maximum criterion, it is shown that maximum-phase responses offer the smallest bandwidths for a given roundtrip loss. Then, a new role for passive notch filters in combination with high-speed electro-optic phase modulation is explored around narrowband phase-to-amplitude demodulation using a single ring operating on one sideband. Applications may include microwave processing and instantaneous frequency measurement (IFM) for radar, space and defense applications.

Overexpression of Lin28b in Neural Stem Cells is Insufficient for Brain Tumor Formation, but Induces Pathological Lobulation of the Developing Cerebellum.

PubMed

Wefers, Annika K; Lindner, Sven; Schulte, Johannes H; Schüller, Ulrich

2017-02-01

LIN28B is a homologue of the RNA-binding protein LIN28A and regulates gene expression during development and carcinogenesis. It is strongly upregulated in a variety of brain tumors, such as medulloblastoma, embryonal tumor with multilayered rosettes (ETMR), atypical teratoid/rhabdoid tumor (AT/RT), or glioblastoma, but the effect of an in vivo overexpression of LIN28B on the developing central nervous system is unknown. We generated transgenic mice that either overexpressed Lin28b in Math1-positive cerebellar granule neuron precursors or in a broad range of Nestin-positive neural precursors. Sections of the cerebellar vermis from adult Math1-Cre::lsl-Lin28b mice had an additional subfissure in lobule IV. Vermes from p0 and p7 Nestin-Cre::lsl-Lin28b mice appeared normal, but we found a pronounced vermal hypersublobulation at p15 and p21 in these mice. Also, the external granule cell layer (EGL) was thicker at p15 than in controls, contained more proliferating cells, and persisted up to p21. Consistently, some Pax6- and NeuN-positive cells were present in the EGL of Nestin-Cre::lsl-Lin28b mice even at p21, and we detected more NeuN-positive granule neuron precursors in the molecular layer (ML) as compared to control. Finally, we found some residual Pax2-positive precursors of inhibitory interneurons in the ML of Nestin-Cre::lsl-Lin28b mice at p21, which have already disappeared in controls. We conclude that while overexpression of LIN28B in Nestin-positive cells does not lead to tumor formation, it results in a protracted development of granule cells and inhibitory interneurons and leads to a hypersublobulation of the cerebellar vermis.

Suppressor Mutations for Presenilin 1 Familial Alzheimer Disease Mutants Modulate γ-Secretase Activities.

PubMed

Futai, Eugene; Osawa, Satoko; Cai, Tetsuo; Fujisawa, Tomoya; Ishiura, Shoichi; Tomita, Taisuke

2016-01-01

γ-Secretase is a multisubunit membrane protein complex containing presenilin (PS1) as a catalytic subunit. Familial Alzheimer disease (FAD) mutations within PS1 were analyzed in yeast cells artificially expressing membrane-bound substrate, amyloid precursor protein, or Notch fused to Gal4 transcriptional activator. The FAD mutations, L166P and G384A (Leu-166 to Pro and Gly-384 to Ala substitution, respectively), were loss-of-function in yeast. We identified five amino acid substitutions that suppress the FAD mutations. The cleavage of amyloid precursor protein or Notch was recovered by the secondary mutations. We also found that secondary mutations alone activated the γ-secretase activity. FAD mutants with suppressor mutations, L432M or S438P within TMD9 together with a missense mutation in the second or sixth loops, regained γ-secretase activity when introduced into presenilin null mouse fibroblasts. Notably, the cells with suppressor mutants produced a decreased amount of Aβ42, which is responsible for Alzheimer disease. These results indicate that the yeast system is useful to screen for mutations and chemicals that modulate γ-secretase activity. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

Effects of Notch2 and Notch3 on Cell Proliferation and Apoptosis of Trophoblast Cell Lines.

PubMed

Zhao, Wei-Xiu; Zhuang, Xu; Huang, Tao-Tao; Feng, Ran; Lin, Jian-Hua

2015-01-01

To investigate the effect of Notch2 and Notch3 on cell proliferation and apoptosis of two trophoblast cell lines, BeWo and JAR. Notch2 and Notch3 expression in BeWo and JAR cells was upregulated or downregulated using lentivirus-mediated overexpression or RNA interference. The effect of Notch2 and Notch3 on cell proliferation was assessed by the CCK-8 assay. The effect of Notch2 and Notch3 on the apoptosis of BeWo and JAR cells was evaluated by flow cytometry using the Annexin V-PE Apoptosis kit. Lentivirus-based overexpression vectors were constructed by cloning the full-length coding sequences of human Notch2 and Notch3 C-terminally tagged with GFP or GFP alone (control) into a lentivirus-based expression vector. Lentivirus-based gene silencing vectors were prepared by cloning small interfering sequences targeting human Notch2 and Notch3 and scrambled control RNA sequence into a lentivirus-based gene knockdown vector. The effect of Notch2 and Notch3 on cell proliferation was assessed by the CCK-8 assay. And the effect of Notch2 and Notch3 on the apoptosis of BeWo and JAR cells was evaluated by flow cytometry using the Annexin V PE Apoptosis kit. We found that the downregulation of Notch2 and Notch3 gene expression in BeWo and JAR cells resulted in an increase in cell proliferation, while upregulation of Notch3 and Notch2 expression led to a decrease in cell proliferation. Moreover, the overexpression of Notch3 and Notch2 in BeWo and JAR cells reduced apoptosis in these trophoblast cell lines, whereas apoptosis was increased in the cells in which the expression of Notch3 and Notch2 was downregulated. Notch2 and Notch3 inhibited both cell proliferation and cell apoptosis in BeWo and JAR trophoblast cell lines.

Repeated Exposure to Taekwondo Combat Modulates the Physiological and Hormonal Responses to Subsequent Bouts and Recovery Periods.

PubMed

Bridge, Craig A; Sparks, Andy S; McNaughton, Lars R; Close, Graeme L; Hausen, Matheus; Gurgel, Jonas; Drust, Barry

2018-05-17

Bridge, CA, Sparks, SA, McNaughton, LR, Close, GL, Hausen, M, Gurgel, J, and Drust, B. Repeated exposure to taekwondo combat modulates the physiological and hormonal responses to subsequent bouts and recovery periods. J Strength Cond Res XX(X): 000-000, 2018-This study examined the physiological and hormonal responses to successive taekwondo combats using an ecologically valid competition time structure. Ten elite male international taekwondo competitors (age 19 ± 3 years) took part in a simulated championship event. The competitors performed 4 combats that were interspersed with different recovery intervals (63 ± 4, 31 ± 3 and 156 ± 5 minutes, respectively). Heart rate (HR) was measured during the combats and venous blood samples were obtained both before and after each combat to determine the plasma metabolite and hormone concentrations. The plasma noradrenaline (21.8 ± 12.8 vs. 15.0 ± 7.0 nmol·l) and lactate (13.9 ± 4.2 vs. 10.5 ± 3.2 mmol·l) responses were attenuated (p < 0.05) between combat 1 and 4. Higher (p < 0.05) HR responses were evident in the final combat when compared with the earlier combats. Higher (p < 0.05) resting HR (139 ± 10 vs. 127 ± 12 b·min), plasma lactate (3.1 ± 1.2 vs. 2.0 ± 0.7 mmol·l), glycerol (131 ± 83 vs. 56 ± 38 μmol·l) and nonesterified free fatty acid (0.95 ± 0.29 vs. 0.71 ± 0.28 mmol·l) concentrations were measured before combat 3 compared with combat 1. Repeated exposure to taekwondo combat using an ecologically valid time structure modulates the physiological and hormonal responses to subsequent bouts and recovery periods. Strategies designed to assist competitors to effectively manage the metabolic changes associated with the fight schedule and promote recovery between the bouts may be important during championship events.

Phosphatase and tensin homolog-β-catenin signaling modulates regulatory T cells and inflammatory responses in mouse liver ischemia/reperfusion injury.

PubMed

Zhu, Qiang; Li, Changyong; Wang, Kunpeng; Yue, Shi; Jiang, Longfeng; Ke, Michael; Busuttil, Ronald W; Kupiec-Weglinski, Jerzy W; Zhang, Feng; Lu, Ling; Ke, Bibo

2017-06-01

The phosphatase and tensin homolog (PTEN) deleted on chromosome 10 plays an important role in regulating T cell activation during inflammatory response. Activation of β-catenin is crucial for maintaining immune homeostasis. This study investigates the functional roles and molecular mechanisms by which PTEN-β-catenin signaling promotes regulatory T cell (Treg) induction in a mouse model of liver ischemia/reperfusion injury (IRI). We found that mice with myeloid-specific phosphatase and tensin homolog knockout (PTEN M-KO ) exhibited reduced liver damage as evidenced by decreased levels of serum alanine aminotransferase, intrahepatic macrophage trafficking, and proinflammatory mediators compared with the PTEN-proficient (floxed phosphatase and tensin homolog [PTEN FL/FL ]) controls. Disruption of myeloid PTEN-activated b-catenin promoted peroxisome proliferator-activated receptor gamma (PPARγ)-mediated Jagged-1/Notch signaling and induced forkhead box P3 (FOXP3)1 Tregs while inhibiting T helper 17 cells. However, blocking of Notch signaling by inhibiting γ-secretase reversed myeloid PTEN deficiency-mediated protection in ischemia/reperfusion-triggered liver inflammation with reduced FOXP3 + and increased retinoid A receptor-related orphan receptor gamma t-mediated interleukin 17A expression in ischemic livers. Moreover, knockdown of β-catenin or PPARγ in PTEN-deficient macrophages inhibited Jagged-1/Notch activation and reduced FOXP3 + Treg induction, leading to increased proinflammatory mediators in macrophage/T cell cocultures. In conclusion, our findings demonstrate that PTEN-β-catenin signaling is a novel regulator involved in modulating Treg development and provides a potential therapeutic target in liver IRI. Liver Transplantation 23 813-825 2017 AASLD. © 2017 by the American Association for the Study of Liver Diseases.

Visual ModuleOrganizer: a graphical interface for the detection and comparative analysis of repeat DNA modules

PubMed Central

2014-01-01

Background DNA repeats, such as transposable elements, minisatellites and palindromic sequences, are abundant in sequences and have been shown to have significant and functional roles in the evolution of the host genomes. In a previous study, we introduced the concept of a repeat DNA module, a flexible motif present in at least two occurences in the sequences. This concept was embedded into ModuleOrganizer, a tool allowing the detection of repeat modules in a set of sequences. However, its implementation remains difficult for larger sequences. Results Here we present Visual ModuleOrganizer, a Java graphical interface that enables a new and optimized version of the ModuleOrganizer tool. To implement this version, it was recoded in C++ with compressed suffix tree data structures. This leads to less memory usage (at least 120-fold decrease in average) and decreases by at least four the computation time during the module detection process in large sequences. Visual ModuleOrganizer interface allows users to easily choose ModuleOrganizer parameters and to graphically display the results. Moreover, Visual ModuleOrganizer dynamically handles graphical results through four main parameters: gene annotations, overlapping modules with known annotations, location of the module in a minimal number of sequences, and the minimal length of the modules. As a case study, the analysis of FoldBack4 sequences clearly demonstrated that our tools can be extended to comparative and evolutionary analyses of any repeat sequence elements in a set of genomic sequences. With the increasing number of sequences available in public databases, it is now possible to perform comparative analyses of repeated DNA modules in a graphic and friendly manner within a reasonable time period. Availability Visual ModuleOrganizer interface and the new version of the ModuleOrganizer tool are freely available at: http://lcb.cnrs-mrs.fr/spip.php?rubrique313. PMID:24678954

The common oncogenomic program of NOTCH1 and NOTCH3 signaling in T-cell acute lymphoblastic leukemia.

PubMed

Choi, Sung Hee; Severson, Eric; Pear, Warren S; Liu, Xiaole S; Aster, Jon C; Blacklow, Stephen C

2017-01-01

Notch is a major oncogenic driver in T cell acute lymphoblastic leukemia (T-ALL), in part because it binds to an enhancer that increases expression of MYC. Here, we exploit the capacity of activated NOTCH1 and NOTCH3 to induce T-ALL, despite substantial divergence in their intracellular regions, as a means to elucidate a broad, common Notch-dependent oncogenomic program through systematic comparison of the transcriptomes and Notch-bound genomic regulatory elements of NOTCH1- and NOTCH3-dependent T-ALL cells. ChIP-seq studies show a high concordance of functional NOTCH1 and NOTCH3 genomic binding sites that are enriched in binding motifs for RBPJ, the transcription factor that recruits activated Notch to DNA. The interchangeability of NOTCH1 and NOTCH3 was confirmed by rescue of NOTCH1-dependent T-ALL cells with activated NOTCH3 and vice versa. Despite remarkable overall similarity, there are nuanced differences in chromatin landscapes near critical common Notch target genes, most notably at a Notch-dependent enhancer that regulates MYC, which correlates with responsiveness to Notch pathway inhibitors. Overall, a common oncogenomic program driven by binding of either Notch is sufficient to maintain T-ALL cell growth, whereas cell-context specific differences appear to influence the response of T-ALL cells to Notch inhibition.

The common oncogenomic program of NOTCH1 and NOTCH3 signaling in T-cell acute lymphoblastic leukemia

PubMed Central

Pear, Warren S.; Liu, Xiaole S.; Aster, Jon C.

2017-01-01

Notch is a major oncogenic driver in T cell acute lymphoblastic leukemia (T-ALL), in part because it binds to an enhancer that increases expression of MYC. Here, we exploit the capacity of activated NOTCH1 and NOTCH3 to induce T-ALL, despite substantial divergence in their intracellular regions, as a means to elucidate a broad, common Notch-dependent oncogenomic program through systematic comparison of the transcriptomes and Notch-bound genomic regulatory elements of NOTCH1- and NOTCH3-dependent T-ALL cells. ChIP-seq studies show a high concordance of functional NOTCH1 and NOTCH3 genomic binding sites that are enriched in binding motifs for RBPJ, the transcription factor that recruits activated Notch to DNA. The interchangeability of NOTCH1 and NOTCH3 was confirmed by rescue of NOTCH1-dependent T-ALL cells with activated NOTCH3 and vice versa. Despite remarkable overall similarity, there are nuanced differences in chromatin landscapes near critical common Notch target genes, most notably at a Notch-dependent enhancer that regulates MYC, which correlates with responsiveness to Notch pathway inhibitors. Overall, a common oncogenomic program driven by binding of either Notch is sufficient to maintain T-ALL cell growth, whereas cell-context specific differences appear to influence the response of T-ALL cells to Notch inhibition. PMID:29023469

Comparison of the complete genome sequences of four γ-hexachlorocyclohexane-degrading bacterial strains: insights into the evolution of bacteria able to degrade a recalcitrant man-made pesticide.

PubMed

Tabata, Michiro; Ohhata, Satoshi; Nikawadori, Yuki; Kishida, Kouhei; Sato, Takuya; Kawasumi, Toru; Kato, Hiromi; Ohtsubo, Yoshiyuki; Tsuda, Masataka; Nagata, Yuji

2016-12-01

γ-Hexachlorocyclohexane (γ-HCH) is a recalcitrant man-made chlorinated pesticide. Here, the complete genome sequences of four γ-HCH-degrading sphingomonad strains, which are most unlikely to have been derived from one ancestral γ-HCH degrader, were compared. Together with several experimental data, we showed that (i) all the four strains carry almost identical linA to linE genes for the conversion of γ-HCH to maleylacetate (designated "specific" lin genes), (ii) considerably different genes are used for the metabolism of maleylacetate in one of the four strains, and (iii) the linKLMN genes for the putative ABC transporter necessary for γ-HCH utilization exhibit structural divergence, which reflects the phylogenetic relationship of their hosts. Replicon organization and location of the lin genes in the four genomes are significantly different with one another, and that most of the specific lin genes are located on multiple sphingomonad-unique plasmids. Copies of IS6100, the most abundant insertion sequence in the four strains, are often located in close proximity to the specific lin genes. Analysis of the footprints of target duplication upon IS6100 transposition and the experimental detection of IS6100 transposition strongly suggested that the IS6100 transposition has caused dynamic genome rearrangements and the diversification of lin-flanking regions in the four strains. © The Author 2016. Published by Oxford University Press on behalf of Kazusa DNA Research Institute.

A role for Lin-28 in growth and metamorphosis in Drosophila melanogaster.

PubMed

González-Itier, Sergio; Contreras, Esteban G; Larraín, Juan; Glavic, Álvaro; Faunes, Fernando

2018-06-13

Insect metamorphosis has been a classic model to understand the role of hormones in growth and timing of developmental transitions. In addition to hormones, transitions in some species are regulated by genetic programs, such as the heterochronic gene network discovered in C. elegans. However, the functional link between hormones and heterochronic genes is not clear. The heterochronic gene lin-28 is involved in the maintenance of stem cells, growth and developmental timing in vertebrates. In this work, we used gain-of-function and loss-of-function experiments to study the role of Lin-28 in larval growth and the timing of metamorphosis of Drosophila melanogaster. During the late third instar stage, Lin-28 is mainly expressed in neurons of the central nervous system and in the intestine. Loss-of-function lin-28 mutant larvae are smaller and the larval-to-pupal transition is accelerated. This faster transition correlates with increased levels of ecdysone direct target genes such as Broad-Complex (BR-C) and Ecdysone Receptor (EcR). Overexpression of Lin-28 does not affect the timing of pupariation but most animals are not able to eclose, suggesting defects in metamorphosis. Overexpression of human Lin-28 results in delayed pupariation and the death of animals during metamorphosis. Altogether, these results suggest that Lin-28 is involved in the control of growth during larval development and in the timing and progression of metamorphosis. Copyright © 2017. Published by Elsevier B.V.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhao, Chen; Tao, Zui; Xue, Langyue

In lower-order vertebrates, Müller glia exhibit characteristics of retinal progenitor cells, while in higher vertebrates, such as mammals, the regenerative capacity of Müller glia is limited. Recently, we reported that Lin28b promoted the trans-differentiation of Müller cells to rod photoreceptor and bipolar cells in the retina of retinitis pigmentosa rat model, whereas it is unclear whether Lin28b can stimulate the reprogramming of Müller glia in vitro for transplantation into a damaged retina. In the present study, Long-Evens rat Müller glia were infected with Adeno-Lin28b or Adeno-GFP. Over-expression of Lin28b in isolated rat Müller glia resulted in the suppression of GFAP expression,more » enhancement of cell proliferation and a significant increase of the expression of retinal progenitor markers 5 days after infection. Moreover, Lin28b caused a significant reduction of the Let-7 family of microRNAs. Following sub-retinal space transplantation, Müller glia-derived retinal progenitors improved b-wave amplification of 30d Royal College of Surgeons retinitis pigmentosa model (RCS-P+) rats, as detected by electroretinography (ERG) recordings. Taken together, these data suggest that the up-regulation of Lin28b expression facilitated the reprogramming of Müller cells toward characteristics of retinal progenitors. - Highlights: • Lin28b reprograms Müller glia to retinal progenitors. • Let-7 micrRNAs are suppressed by Lin28b. • Transplantation of reprogrammed Müller glia restores retinal function.« less

Comparative genomic analysis of nine Sphingobium strains: Insights into their evolution and hexachlorocyclohexane (HCH) degradation pathways

DOE PAGES

Verma, Helianthous; Kumar, Roshan; Oldach, Phoebe; ...

2014-11-23

Background: Sphingobium spp. are efficient degraders of a wide range of chlorinated and aromatic hydrocarbons. In particular, strains which harbour the lin pathway genes mediating the degradation of hexachlorocyclohexane (HCH) isomers are of interest due to the widespread persistence of this contaminant. Here, we examined the evolution and diversification of the lin pathway under the selective pressure of HCH, by comparing the draft genomes of six newly-sequenced Sphingobium spp. (strains LL03, DS20, IP26, HDIPO4, P25 and RL3) isolated from HCH dumpsites, with three existing genomes ( S. indicum B90A, S. japonicum UT26S and Sphingobium sp. SYK6). Results: Efficient HCH degradersmore » phylogenetically clustered in a closely related group comprising of UT26S, B90A, HDIPO4 and IP26, where HDIPO4 and IP26 were classified as subspecies with ANI value >98%. Less than 10% of the total gene content was shared among all nine strains, but among the eight HCH-associated strains, that is all except SYK6, the shared gene content jumped to nearly 25%. Genes associated with nitrogen stress response and two-component systems were found to be enriched. The strains also housed many xenobiotic degradation pathways other than HCH, despite the absence of these xenobiotics from isolation sources. In addition, these strains, although non-motile, but posses flagellar assembly genes. While strains HDIPO4 and IP26 contained the complete set of lin genes, DS20 was entirely devoid of lin genes (except linKLMN) whereas, LL03, P25 and RL3 were identified as lin deficient strains, as they housed incomplete lin pathways. Further, in HDIPO4, linA was found as a hybrid of two natural variants i.e., linA1 and linA2 known for their different enantioselectivity. In conclusion, the bacteria isolated from HCH dumpsites provide a natural testing ground to study variations in the lin system and their effects on degradation efficacy. Further, the diversity in the lin gene sequences and copy number, their arrangement with respect to IS 6100 and evidence for potential plasmid content elucidate possible evolutionary acquisition mechanisms for this pathway. This study further opens the horizon for selection of bacterial strains for inclusion in an HCH bioremediation consortium and suggests that HDIPO4, IP26 and B90A would be appropriate candidates for inclusion.« less

Combined deficiency of Notch1 and Notch3 causes pericyte dysfunction, models CADASIL, and results in arteriovenous malformations

PubMed Central

Kofler, Natalie M.; Cuervo, Henar; Uh, Minji K.; Murtomäki, Aino; Kitajewski, Jan

2015-01-01

Pericytes regulate vessel stability and pericyte dysfunction contributes to retinopathies, stroke, and cancer. Here we define Notch as a key regulator of pericyte function during angiogenesis. In Notch1+/−; Notch3−/− mice, combined deficiency of Notch1 and Notch3 altered pericyte interaction with the endothelium and reduced pericyte coverage of the retinal vasculature. Notch1 and Notch3 were shown to cooperate to promote proper vascular basement membrane formation and contribute to endothelial cell quiescence. Accordingly, loss of pericyte function due to Notch deficiency exacerbates endothelial cell activation caused by Notch1 haploinsufficiency. Mice mutant for Notch1 and Notch3 develop arteriovenous malformations and display hallmarks of the ischemic stroke disease CADASIL. Thus, Notch deficiency compromises pericyte function and contributes to vascular pathologies. PMID:26563570

Multiple diagnostic tests to identify cattle with Bovine viral diarrhea virus and duration of positive test results in persistently infected cattle

PubMed Central

Fulton, Robert W.; Hessman, Bill E.; Ridpath, Julia F.; Johnson, Bill J.; Burge, Lurinda J.; Kapil, Sanjay; Braziel, Barbara; Kautz, Kira; Reck, Amy

2009-01-01

Several tests for Bovine viral diarrhea virus (BVDV) were applied to samples collected monthly from December 20, 2005, through November 27, 2006 (day 0 to day 342) from 12 persistently infected (PI) cattle with BVDV subtypes found in US cattle: BVDV-1a, BVDV-1b, and BVDV-2a. The samples included clotted blood for serum, nasal swabs, and fresh and formalin-fixed ear notches. The tests were as follows: titration of infectious virus in serum and nasal swabs; antigen-capture (AC) enzyme-linked immunosorbent assay (ELISA), or ACE, on serum, nasal swabs, and fresh ear notches; gel-based polymerase chain reaction (PCR) testing of serum, nasal swabs, and fresh ear notches; immunohistochemical (IHC) testing of formalin-fixed ear notches; and serologic testing for BVDV antibodies in serum. Of the 12 animals starting the study, 3 died with mucosal disease. The ACE and IHC tests on ear notches had positive results throughout the study, as did the ACE and PCR tests on serum. There was detectable virus in nasal swabs from all the cattle throughout the study except for a few samples that were toxic to cell cultures. The serum had a virus titer ≥ log10 1.60 in all samples from all the cattle except for 3 collections from 1 animal. Although there were several equivocal results, the PCR test most often had positive results. The BVDV antibodies were due to vaccination or exposure to heterologous strains and did not appear to interfere with any BVDV test. These findings illustrate that PI cattle may be identified by several tests, but differentiation of PI cattle from cattle with acute BVDV infection requires additional testing, especially of blood samples and nasal swabs positive on initial testing. Also, calves PI with BVDV are continual shedders of infectious virus, as shown by the infectivity of nasal swabs over the 11-mo study. PMID:19436580

Effect of Fatigue-Stressing Short of Failure on Some Typical Aircraft Metals

DTIC Science & Technology

1945-10-01

of the fractures .. .,. . ....:,:..;.-.,: ,: TTqm c,on~~~’~rktion of such resultb it seemed worth while ~“~arn+ning the effects of repeated strese:on...fatigue-stz’~$sed short 015:: fracture . ; Tli~ impact behavior of normalized SAE X 4130 staal was studied[’YoTlotiing” fatigue-stressing .under”a...conduc&ed in the conventional manner on a group of notched specimens t-o determine the S-N curve and the fatigue limit (tests to fracture ). Four

The Case for Pedagogical Action Research in Psychology Learning and Teaching

ERIC Educational Resources Information Center

Norton, Lin

2014-01-01

It is just over 12 years since "Psychology Teaching Review"'s first Special Issue on action research psychology. In the guest editorial for that issue Lin Norton suggested that pedagogical action research can be controversial, and that for some academic psychologists it appears to be more than curriculum development rather than…

Laser cooling of nuclear spin 0 alkali 78Rb

NASA Astrophysics Data System (ADS)

Behr, J. A.; Gorelov, A.; Anholm, M.

2015-05-01

The textbook example for sub-Doppler cooling is a J = 1/2 I = 0 alkali atom in lin ⊥ lin molasses. In the σ+ σ- configuration of a standard MOT, the main sub-Doppler cooling mechanism relies on changing alignment (MF2 population) with the summed linear polarization orientation, but there is no such variation in AC Stark shift for F = 1/2. We have nevertheless looked for signs of sub-Doppler cooling by trapping I = 0 78Rb in a standard MOT and measuring the cloud size as a function of laser detuning and intensity. The 78Rb cloud size does not change significantly with lowered intensity, and expands slightly with detuning, consistent with minimal to no sub-Doppler cooling. Our geometry does show the well-known substantially smaller cloud size with detuning and intensity for I = 3/2 87Rb. Maintaining an I = 0 alkali cloud size with lowered intensity will help our planned β- ν correlation experiments in 38mK decay by suppressing possible production of photoassisted dimers. Supported by NSERC and NRC Canada through TRIUMF.

Silicon Nanotips and Related Nano-Systems Involving Fluid and Carrier Transport and Their Micro-Devices for Power and Sensing Applications

DTIC Science & Technology

2011-05-10

Methanol’, Chien-Cheng Li, Ran-Jin Lin, Hong-Ping Lin, Ching-Chun Chang, Yu - Kai Lin, Li-Chyong Chen*, Kuei-Hsien Chen*, Chem. Comm. 47, 1473 (2011). (5...CuO-ZnO Inverse Opals as High-performance Methanol Microreformer’, Yan-Gu Lin, Yu -Kuei Hsu, San-Yuan Chen, Li-Chyong Chen* and Kuei-Hsien Chen*, J...Chun Lo, Hsin-I Hsiung, Surojit Chattopadhyay*, Hsieh -Cheng Han, Chia-Fu Chen*, Jih Perng Leu, Kuei-Hsien Chen and Li-Chyong Chen*, Biosens

Sb-Based n- and p-Channel Heterostructure FETs for High-Speed, Low-Power Applications

DTIC Science & Technology

2008-07-01

Laboratory are presented. 2. InAlSb/InAs HEMTs The HEMT material was grown by solid-source molecu- lar beam epitaxy (MBE) on a semi-insulating (100) GaAs...and S.Y. Lin, “Strained quantum well modulation-doped InGaSb/AlGaSb struc- tures grown by molecular beam epitaxy ,” J. Electron. Mater., vol.22, no.3...where he majored in solid state physics and researched growth by molecular - beam epitaxy (MBE) of certain compound semiconductor ma- terials. Since

Notched strength of beryllium powder and ingot sheets.

NASA Technical Reports Server (NTRS)

Moss, R. G.

1972-01-01

The effects of notches in thin beryllium sheets were studied as functions of material variables and notch severity. Double edge notched samples having stress concentration factors of 1.0 to 15.4 were prepared by milling to size, etching, and electrical discharge machining the notches. Strength was not reduced greatly by sharp notches, and duller notches were more deleterious than sharp notches. The trend was for reduced strength for dull notches, increased strength for sharper notches, and reduced strength for very sharp notches. Differences in material purity or source of the sheet had little affect on notch sensitivity. The most important factors appear to be oxide content and directionality of the sheet microstructure; high oxide content and highly directional microstructure tend to give more notch sensitivity than low oxide content, and more bidirectional microstructure. Postulated causes of the change in notched/unnotched strength are given.

Differential Regulation of NOTCH2 and NOTCH3 Contribute to Their Unique Functions in Vascular Smooth Muscle Cells*

PubMed Central

Baeten, Jeremy T.; Lilly, Brenda

2015-01-01

Notch signaling is a key regulator of vascular smooth muscle cell (VSMC) phenotypes, including differentiation, proliferation, and cell survival. However, the exact contribution of the individual Notch receptors has not been thoroughly delineated. In this study, we identify unique roles for NOTCH2 and NOTCH3 in regulating proliferation and cell survival in cultured VSMCs. Our results indicate that NOTCH2 inhibits PDGF-B-dependent proliferation and its expression is decreased by PDGF-B. In contrast, NOTCH3 promotes proliferation and receptor expression is increased by PDGF-B. Additionally, data show that NOTCH3, but not NOTCH2 protects VSMCs from apoptosis and apoptosis mediators degrade NOTCH3 protein. We identified three pro-survival genes specifically regulated by NOTCH3 in cultured VSMCs and in mouse aortas. This regulation is mediated through MAP kinase signaling, which we demonstrate can be activated by NOTCH3, but not NOTCH2. Overall, this study highlights discrete roles for NOTCH2 and NOTCH3 in VSMCs and connects these roles to specific upstream regulators that control their expression. PMID:25957400

Damage tolerance and arrest characteristics of pressurized graphite/epoxy tape cylinders

NASA Technical Reports Server (NTRS)

Ranniger, Claudia U.; Lagace, Paul A.; Graves, Michael J.

1993-01-01

An investigation of the damage tolerance and damage arrest characteristics of internally-pressurized graphite/epoxy tape cylinders with axial notches was conducted. An existing failure prediction methodology, developed and verified for quasi-isotropic graphite/epoxy fabric cylinders, was investigated for applicability to general tape layups. In addition, the effect of external circumferential stiffening bands on the direction of fracture path propagation and possible damage arrest was examined. Quasi-isotropic (90/0/plus or minus 45)s and structurally anisotropic (plus or minus 45/0)s and (plus or minus 45/90)s coupons and cylinders were constructed from AS4/3501-6 graphite/epoxy tape. Notched and unnotched coupons were tested in tension and the data correlated using the equation of Mar and Lin. Cylinders with through-thickness axial slits were pressurized to failure achieving a far-field two-to-one biaxial stress state. Experimental failure pressures of the (90/0/plus or minus 45)s cylinders agreed with predicted values for all cases but the specimen with the smallest slit. However, the failure pressures of the structurally anisotropic cylinders, (plus or minus 45/0)s and (plus or minus 45/90)s, were above the values predicted utilizing the predictive methodology in all cases. Possible factors neglected by the predictive methodology include structural coupling in the laminates and axial loading of the cylindrical specimens. Furthermore, applicability of the predictive methodology depends on the similarity of initial fracture modes in the coupon specimens and the cylinder specimens of the same laminate type. The existence of splitting which may be exacerbated by the axial loading in the cylinders, shows that this condition is not always met. The circumferential stiffeners were generally able to redirect fracture propagation from longitudinal to circumferential. A quantitative assessment for stiffener effectiveness in containing the fracture, based on cylinder radius, slit size, and bending stiffnesses of the laminates, is proposed.

Upregulation of ASCL1 and inhibition of Notch signaling pathway characterize progressive astrocytoma.

PubMed

Somasundaram, Kumaravel; Reddy, Sreekanth P; Vinnakota, Katyayni; Britto, Ramona; Subbarayan, Madhavan; Nambiar, Sandeep; Hebbar, Aparna; Samuel, Cini; Shetty, Mitesh; Sreepathi, Hari Kishore; Santosh, Vani; Hegde, Alangar Sathyaranjandas; Hegde, Sridevi; Kondaiah, Paturu; Rao, M R S

2005-10-27

Astrocytoma is the most common type of brain cancer constituting more than half of all brain tumors. With an aim to identify markers describing astrocytoma progression, we have carried out microarray analysis of astrocytoma samples of different grades using cDNA microarray containing 1152 cancer-specific genes. Data analysis identified several differentially regulated genes between normal brain tissue and astrocytoma as well as between grades II/III astrocytoma and glioblastoma multiforme (GBM; grade IV). We found several genes known to be involved in malignancy including Achaete-scute complex-like 1 (Drosophila) (ASCL1; Hash 1). As ASCL has been implicated in neuroendocrine, medullary thyroid and small-cell lung cancers, we chose to examine the role of ASCL1 in the astrocytoma development. Our data revealed that ASCL1 is overexpressed in progressive astrocytoma as evidenced by increased levels of ASCL1 transcripts in 85.71% (6/7) of grade II diffuse astrocytoma (DA), 90% (9/10) of grade III anaplastic astrocytoma (AA) and 87.5% (7/8) of secondary GBMs, while the majority of primary de novo GBMs expressed similar to or less than normal brain levels (66.67%; 8/12). ASCL1 upregulation in progressive astrocytoma is accompanied by inhibition of Notch signaling as seen by uninduced levels of HES1, a transcriptional target of Notch1, increased levels of HES6, a dominant-negative inhibitor of HES1-mediated repression of ASCL1, and increased levels of Notch ligand Delta1, which is capable of inhibiting Notch signaling by forming intracellular Notch ligand autonomous complexes. Our results imply that inhibition of Notch signaling may be an important early event in the development of grade II DA and subsequent progression to grade III AA and secondary GBM. Furthermore, ASCL1 appears to be a putative marker to distinguish primary GBM from secondary GBM.

Innovative tidal notch detection using TLS and fuzzy logic: Implications for palaeo-shorelines from compressional (Crete) and extensional (Gulf of Corinth) tectonic settings

NASA Astrophysics Data System (ADS)

Schneiderwind, S.; Boulton, S. J.; Papanikolaou, I.; Reicherter, K.

2017-04-01

Tidal notches are a generally accepted sea-level marker and maintain particular interest for palaeoseismic studies since coastal seismic activity potentially displaces them from their genetic position. The result of subsequent seismic events is a notch sequence reflecting the cumulative coastal uplift. In order to evaluate preserved notch sequences, an innovative and interdisciplinary workflow is presented that accurately highlights evidence for palaeo-sea-level markers. The workflow uses data from terrestrial laser scanning and iteratively combines high-resolution curvature analysis, high performance edge detection, and feature extraction. Based on the assumptions that remnants, such as the roof of tidal notches, form convex patterns, edge detection is performed on principal curvature images. In addition, a standard algorithm is compared to edge detection results from a custom Fuzzy logic approach. The results pass through a Hough transform in order to extract continuous line features of an almost horizontal orientation. The workflow was initially developed on a single, distinct, and sheltered exposure in southern Crete and afterwards successfully tested on laser scans of different coastal cliffs from the Perachora Peninsula. This approach allows a detailed examination of otherwise inaccessible locations and the evaluation of lateral and 3D geometries, thus evidence for previously unrecognised sea-level markers can be identified even when poorly developed. High resolution laser scans of entire cliff exposures allow local variations to be quantified. Edge detection aims to reduce information on the surface curvature and Hough transform limits the results towards orientation and continuity. Thus, the presented objective methodology enhances the recognition of tidal notches and supports palaeoseismic studies by contributing spatial information and accurate measurements of horizontal movements, beyond that recognised during traditional surveys. This is especially useful for the identification of palaeo-shorelines in extensional tectonic environments where coseismic footwall uplift (only 1/2 to 1/4 of net slip per event) is unlikely to raise an entire notch above the tidal range.

Mid-wave infrared narrow bandwidth guided mode resonance notch filter.

PubMed

Zhong, Y; Goldenfeld, Z; Li, K; Streyer, W; Yu, L; Nordin, L; Murphy, N; Wasserman, D

2017-01-15

We have designed, fabricated, and characterized a guided mode resonance notch filter operating in the technologically vital mid-wave infrared (MWIR) region of the electromagnetic spectrum. The filter provides a bandstop at λ≈4.1  μm, with a 12 dB extinction on resonance. In addition, we demonstrate a high transmission background (>80%), less than 6% transmission on resonance, and an ultra-narrow bandwidth transmission notch (10  cm^-1). Our filter is optically characterized using angle- and polarization-dependent Fourier transform infrared spectroscopy, and simulated using rigorous coupled-wave analysis (RCWA) with excellent agreement between simulations and our experimental results. Using our RCWA simulations, we are able to identify the optical modes associated with the transmission dips of our filter. The presented structure offers a potential route toward narrow-band laser filters in the MWIR.

A 25-Gbps high-sensitivity optical receiver with 10-Gbps photodiode using inductive input coupling for optical interconnects

NASA Astrophysics Data System (ADS)

Oku, Hideki; Narita, Kiyomi; Shiraishi, Takashi; Ide, Satoshi; Tanaka, Kazuhiro

2012-01-01

A 25-Gbps high-sensitivity optical receiver with a 10-Gbps photodiode (PD) using inductive input coupling has been demonstrated for optical interconnects. We introduced the inductive input coupling technique to achieve the 25-Gbps optical receiver using a 10-Gbps PD. We implemented an input inductor (Lin) between the PD and trans-impedance amplifier (TIA), and optimized inductance to enhance the bandwidth and reduce the input referred noise current through simulation with the RF PD-model. Near the resonance frequency of the tank circuit formed by PD capacitance, Lin, and TIA input capacitance, the PD photo-current through Lin into the TIA is enhanced. This resonance has the effects of enhancing the bandwidth at TIA input and reducing the input equivalent value of the noise current from TIA. We fabricated the 25-Gbps optical receiver with the 10-Gbps PD using an inductive input coupling technique. Due to the application of an inductor, the receiver bandwidth is enhanced from 10 GHz to 14.2 GHz. Thanks to this wide-band and low-noise performance, we were able to improve the sensitivity at an error rate of 1E-12 from non-error-free to -6.5 dBm. These results indicate that our technique is promising for cost-effective optical interconnects.

Regulation of C. elegans L4 cuticle collagen genes by the heterochronic protein LIN-29.

PubMed

Abete-Luzi, Patricia; Eisenmann, David M

2018-05-01

The cuticle, the outer covering of the nematode C. elegans, is synthesized five times during the worm's life by the underlying hypodermis. Cuticle collagens, the major cuticle component, are encoded by a large family of col genes and, interestingly, many of these genes express predominantly at a single developmental stage. This temporal preference motivated us to investigate the mechanisms underlying col gene expression and here we focus on a subset of col genes expressed in the L4 stage. We identified minimal promoter regions of <300 bp for col-38, col-49, and col-63. In these regions, we predicted cis-regulatory sequences and evaluated their function in vivo via mutagenesis of a col-38p::yfp reporter. We used RNAi to study the requirement for candidate transcription regulators ELT-1 and ELT-3, LIN-29, and the LIN-29 co-factor MAB-10, and found LIN-29 to be necessary for the expression of four L4-specific genes (col-38, col-49, col-63, and col-138). Temporal misexpression of LIN-29 was also sufficient to activate these genes at a different developmental stage. The LIN-29 DNA-binding domain bound the col-38, col-49, and col-63 minimal promoters in vitro. For col-38 we showed that the LIN-29 sites necessary for reporter expression in vivo are also bound in vitro: this is the first identification of specific binding sites for LIN-29 necessary for in vivo target gene expression. © 2018 Wiley Periodicals, Inc.

Analysis of the microvascular morphology and hemodynamics of breast cancer in mice using SPring-8 synchrotron radiation microangiography

PubMed Central

Torii, Masae; Fukui, Toshifumi; Inoue, Masashi; Umetani, Keiji; Shirai, Mikiyasu; Inagaki, Tadakatsu; Tsuchimochi, Hirotsugu; Toi, Masakazu

2017-01-01

Tumor vasculature is characterized by morphological and functional abnormalities. However, analysis of the dynamics in blood flow is still challenging because of limited spatial and temporal resolution. Synchrotron radiation (SR) microangiography above the K-edge of the iodine contrast agent can provide high-contrast imaging of microvessels in time orders of milliseconds. In this study, mice bearing the human breast cancer cell lines MDAMB231 and NOTCH4 overexpression in MDAMB231 (MDAMB231NOTCH4+) and normal mice were assessed using SR microangiography. NOTCH is transmembrane protein that has crucial roles for vasculogenesis, angiogenesis and tumorigenesis, and NOTCH4 is considered to be a cause of high-flow arteriovenous shunting. A subgroup of mice received intravenous eribulin treatment, which is known to improve intratumor core circulation (MDAMB231_eribulin). Microvessel branches from approximately 200 µm to less than 20 µm in diameter were observed within the same visual field. The mean transition time (MTT) was measured as a dynamic parameter and quantitative analysis was performed. MTT in MDAMB231 was longer than that in normal tissue, and MDAMB231NOTCH4+ showed shorter MTT [5.0 ± 1.4 s, 3.6 ± 1.0 s and 3.6 ± 1.1 s (mean ± standard deviation), respectively]. After treatment, average MTT was correlated to tumor volume (r = 0.999) in MDAMB231_eribulin, while in contrast there was no correlation in MDAMB231 (r = −0.026). These changes in MTT profile are considered to be driven by the modulation of intratumoral circulation dynamics. These results demonstrate that a SR microangiography approach enables quantitative analysis of morphological and dynamic characteristics of tumor vasculature in vivo. Further studies will reveal new findings concerning vessel function in tumors. PMID:28862627

Absence of post-translational aspartyl beta-hydroxylation of epidermal growth factor domains in mice leads to developmental defects and an increased incidence of intestinal neoplasia.

PubMed

Dinchuk, Joseph E; Focht, Richard J; Kelley, Jennifer A; Henderson, Nancy L; Zolotarjova, Nina I; Wynn, Richard; Neff, Nicola T; Link, John; Huber, Reid M; Burn, Timothy C; Rupar, Mark J; Cunningham, Mark R; Selling, Bernard H; Ma, Jianhong; Stern, Andrew A; Hollis, Gregory F; Stein, Robert B; Friedman, Paul A

2002-04-12

The BAH genomic locus encodes three distinct proteins: junctin, humbug, and BAH. All three proteins share common exons, but differ significantly based upon the use of alternative terminal exons. The biological roles of BAH and humbug and their functional relationship to junctin remain unclear. To evaluate the role of BAH in vivo, the catalytic domain of BAH was specifically targeted such that the coding regions of junctin and humbug remained undisturbed. BAH null mice lack measurable BAH protein in several tissues, lack aspartyl beta-hydroxylase activity in liver preparations, and exhibit no hydroxylation of the epidermal growth factor (EGF) domain of clotting Factor X. In addition to reduced fertility in females, BAH null mice display several developmental defects including syndactyly, facial dysmorphology, and a mild defect in hard palate formation. The developmental defects present in BAH null mice are similar to defects observed in knock-outs and hypomorphs of the Notch ligand Serrate-2. In this work, beta-hydroxylation of Asp residues in EGF domains is demonstrated for a soluble form of a Notch ligand, human Jagged-1. These results along with recent reports that another post-translational modification of EGF domains in Notch gene family members (glycosylation by Fringe) alters Notch pathway signaling, lends credence to the suggestion that aspartyl beta-hydroxylation may represent another post-translational modification of EGF domains that can modulate Notch pathway signaling. Previous work has demonstrated increased levels of BAH in certain tumor tissues and a role for BAH in tumorigenesis has been proposed. The role of hydroxylase in tumor formation was tested directly by crossing BAH KO mice with an intestinal tumor model, APCmin mice. Surprisingly, BAH null/APCmin mice show a statistically significant increase in both intestinal polyp size and number when compared with BAH wild-type/APCmin controls. These results suggest that, in contrast to expectations, loss of BAH catalytic activity may promote tumor formation.

Two-Stage Processing of Sounds Explains Behavioral Performance Variations due to Changes in Stimulus Contrast and Selective Attention: An MEG Study

PubMed Central

Kauramäki, Jaakko; Jääskeläinen, Iiro P.; Hänninen, Jarno L.; Auranen, Toni; Nummenmaa, Aapo; Lampinen, Jouko; Sams, Mikko

2012-01-01

Selectively attending to task-relevant sounds whilst ignoring background noise is one of the most amazing feats performed by the human brain. Here, we studied the underlying neural mechanisms by recording magnetoencephalographic (MEG) responses of 14 healthy human subjects while they performed a near-threshold auditory discrimination task vs. a visual control task of similar difficulty. The auditory stimuli consisted of notch-filtered continuous noise masker sounds, and of 1020-Hz target tones occasionally () replacing 1000-Hz standard tones of 300-ms duration that were embedded at the center of the notches, the widths of which were parametrically varied. As a control for masker effects, tone-evoked responses were additionally recorded without masker sound. Selective attention to tones significantly increased the amplitude of the onset M100 response at 100 ms to the standard tones during presence of the masker sounds especially with notches narrower than the critical band. Further, attention modulated sustained response most clearly at 300–400 ms time range from sound onset, with narrower notches than in case of the M100, thus selectively reducing the masker-induced suppression of the tone-evoked response. Our results show evidence of a multiple-stage filtering mechanism of sensory input in the human auditory cortex: 1) one at early (100 ms) latencies bilaterally in posterior parts of the secondary auditory areas, and 2) adaptive filtering of attended sounds from task-irrelevant background masker at longer latency (300 ms) in more medial auditory cortical regions, predominantly in the left hemisphere, enhancing processing of near-threshold sounds. PMID:23071654

Effe0cts of porcine acellular dermal matrix treatment on wound healing and scar formation: role of Jag1 expression in epidermal stem cells.

PubMed

Chen, Xiao-Dong; Ruan, Shu-Bin; Lin, Ze-Peng; Zhou, Ziheng; Zhang, Feng-Gang; Yang, Rong-Hua; Xie, Ju-Lin

2018-02-08

Skin wound healing involves Notch/Jagged1 signaling. However, little is known how Jag1 expression level in epidermal stem cells (ESCs) contributes to wound healing and scar formation. We applied multiple cellular and molecular techniques to examine how Jag1 expression in ESCs modulates ESCs differentiation to myofibroblasts (MFB) in vitro, interpret how Jag1 expression in ESCs is involved in wound healing and scar formation in mice, and evaluate the effects of porcine acellular dermal matrix (ADM) treatment on wound healing and scar formation. We found that Jag1, Notch1 and Hes1 expression was up-regulated in the wound tissue during the period of wound healing. Furthermore, Jag1 expression level in the ESCs was positively associated with the level of differentiation to MFB. ESC-specific knockout of Jag1 delayed wound healing and promoted scar formation in vivo. In addition, we reported that porcine ADM treatment after skin incision could accelerate wound closure and reduce scar formation in vivo. This effect was associated with decreased expression of MFB markers, including α-SMA Col-1 and Col-III in wound tissues. Finally, we confirmed that porcine ADM treatment could increase Jag1, Notch1 and Hesl expression in wound tissues. Taken together, our results suggested that ESC-specific Jag1 expression levels are critical for wound healing and scar formation, and porcine ADM treatment would be beneficial in promoting wound healing and preventing scar formation by enhancing Notch/Jagged1 signaling pathway in ESCs.

Development of the Lupus Interactive Navigator as an Empowering Web-Based eHealth Tool to Facilitate Lupus Management: Users Perspectives on Usability and Acceptability.

PubMed

Neville, Carolyn; Da Costa, Deborah; Rochon, Murray; Peschken, Christine A; Pineau, Christian A; Bernatsky, Sasha; Keeling, Stephanie; Avina-Zubieta, Antonio; Lye, Elizabeth; Eng, Davy; Fortin, Paul R

2016-05-30

Systemic Lupus Erythematosus (SLE) is a serious, complex, and chronic illness. Similar to most other chronic illness states, there is great interest in helping persons with SLE engage in their disease management. The objectives of this study were to (1) develop the Lupus Interactive Navigator (LIN), a web-based self-management program for persons with SLE, and (2) test the LIN for usability and acceptability. The LIN development platform was based on the results of preliminary comprehensive needs assessments and adapted from the Oncology Interactive Navigator, a web-based tool developed for persons with cancer. Medical researchers, writers, designers, and programmers worked with clinical experts and persons with SLE to develop content for the LIN. Usability and acceptability of the LIN was tested on individuals with SLE meeting American College of Rheumatology criteria, who were recruited from five Canadian SLE clinics. Participants were provided with access to the LIN and were asked to use it over a two-week period. Following the testing period, participants were contacted for a 30-minute telephone interview to assess usability and acceptability. The content for the LIN was subdivided into six primary information topics with interview videos featuring rheumatologists, allied health professionals, and persons with SLE. Usability and acceptability of the LIN was tested on 43 females with SLE. Of these, 37 (86%) completed telephone interviews. The average age was 43.6 (SD 15.9) years and disease duration averaged 14.1 (SD 10.8) years. Median time spent on LIN was 16.3 (interquartile range [IQR]:13.7, 53.5) minutes and median number of sessions was 2 (IQR: 1, 3). Overall, Likert ratings (0=strongly disagree; 7=strongly agree) of website usability and content were very high, with 75% scoring >6 out of 7 on all items. All participants agreed that LIN was easy to use, would recommend it to others with SLE, and would refer to it for future questions about SLE. Very high ratings were also given to relevancy, credibility, and usefulness of the information provided. Overall, 73% of the participants rated all topics helpful to very helpful. Participants who reported more prior knowledge about SLE rated items regarding improvement in knowledge and helpfulness relatively lower than persons with less prior knowledge. Most participants commented that the LIN would be very useful to those newly diagnosed with SLE. Minor revisions were recommended. This study furthers the understanding of the needs in the SLE community and delivers a unique eHealth tool to promote self-management in persons with SLE. The LIN was found to be highly acceptable in content and usability. The information provided on LIN may be most helpful for individuals with less experience with the disease, such as those newly diagnosed, indicating the need to tailor the content for persons with more SLE experience.

Epigenetic regulation of NOTCH1 and NOTCH3 by KMT2A inhibits glioma proliferation.

PubMed

Huang, Yin-Cheng; Lin, Sheng-Jia; Shih, Hung-Yu; Chou, Chung-Han; Chu, Hsiao-Han; Chiu, Ching-Chi; Yuh, Chiou-Hwa; Yeh, Tu-Hsueh; Cheng, Yi-Chuan

2017-09-08

Glioblastomas are among the most fatal brain tumors; however, the molecular determinants of their tumorigenic behavior are not adequately defined. In this study, we analyzed the role of KMT2A in the glioblastoma cell line U-87 MG. KMT2A knockdown promoted cell proliferation. Moreover, it increased the DNA methylation of NOTCH1 and NOTCH3 and reduced the expression of NOTCH1 and NOTCH3 . NOTCH1 or NOTCH3 activation inhibited U-87 MG cell proliferation, whereas NOTCH1 and NOTCH3 inhibition by shRNAs induced cell proliferation, thus demonstrating the tumor-suppressive ability of NOTCH1 and NOTCH3 in U-87 MG cells. The induced cell proliferation caused by KMT2A knockdown could be nullified by using either constitutively active NOTCH1 or constitutively active NOTCH3. This result demonstrates that KMT2A positively regulates NOTCH1 and NOTCH3 and that this mechanism is essential for inhibiting the U-87 MG cell proliferation. The role of KMT2A knockdown in promoting tumor growth was further confirmed in vivo by transplanting U-87 MG cells into the brains of zebrafish larvae. In conclusion, we identified KMT2A-NOTCH as a negative regulatory cascade for glioblastoma cell proliferation, and this result provides important information for KMT2A- or NOTCH-targeted therapeutic strategies for brain tumors.

Novel Roles for Notch3 and Notch4 Receptors in Gene Expression and Susceptibility to Ozone-Induced Lung Inflammation in Mice.

PubMed

Verhein, Kirsten C; McCaw, Zachary; Gladwell, Wesley; Trivedi, Shweta; Bushel, Pierre R; Kleeberger, Steven R

2015-08-01

Ozone is a highly toxic air pollutant and global health concern. Mechanisms of genetic susceptibility to ozone-induced lung inflammation are not completely understood. We hypothesized that Notch3 and Notch4 are important determinants of susceptibility to ozone-induced lung inflammation. Wild-type (WT), Notch3 (Notch3-/-), and Notch4 (Notch4-/-) knockout mice were exposed to ozone (0.3 ppm) or filtered air for 6-72 hr. Relative to air-exposed controls, ozone increased bronchoalveolar lavage fluid (BALF) protein, a marker of lung permeability, in all genotypes, but significantly greater concentrations were found in Notch4-/- compared with WT and Notch3-/- mice. Significantly greater mean numbers of BALF neutrophils were found in Notch3-/- and Notch4-/- mice compared with WT mice after ozone exposure. Expression of whole lung Tnf was significantly increased after ozone in Notch3-/- and Notch4-/- mice, and was significantly greater in Notch3-/- compared with WT mice. Statistical analyses of the transcriptome identified differentially expressed gene networks between WT and knockout mice basally and after ozone, and included Trim30, a member of the inflammasome pathway, and Traf6, an inflammatory signaling member. These novel findings are consistent with Notch3 and Notch4 as susceptibility genes for ozone-induced lung injury, and suggest that Notch receptors protect against innate immune inflammation.

Nonoverlapping functions for Notch1 and Notch3 during murine steady-state thymic lymphopoiesis

PubMed Central

Shi, Jianjun; Fallahi, Mohammad; Luo, Jun-Li

2011-01-01

Notch1 signaling is absolutely essential for steady-state thymic lymphopoiesis, but the role of other Notch receptors, and their potential overlap with the function of Notch1, remains unclear. Here we show that like Notch1, Notch3 is differentially expressed by progenitor thymocytes, peaking at the DN3 progenitor stage. Using mice carrying a gene-trapped allele, we show that thymic cellularity is slightly reduced in the absence of Notch3, although progression through the defined sequence of TCR-αβ development is normal, as are NKT and TCRγδ cell production. The absence of a profound effect from Notch3 deletion is not explained by residual function of the gene-trapped allele because insertion mapping suggests that the targeted allele would not encode functional signaling domains. We also show that although Notch1 and Notch3 are coexpressed on some early intrathymic progenitors, the relatively mild phenotype seen after Notch3 deletion does not result from the compensatory function of Notch1, nor does Notch3 function explain the likewise mild phenotype seen after conditional (intrathymic) deletion of Notch1. Our studies indicate that Notch1 and Notch3 carry out nonoverlapping functions during thymocyte differentiation, and that while Notch1 is absolutely required early in the lymphopoietic process, neither receptor is essential at later stages. PMID:21768299

Long non-coding RNA GAS5 aggravates hypoxia injury in PC-12 cells via down-regulating miR-124.

PubMed

Hu, Xiaoli; Liu, Juan; Zhao, Gang; Zheng, Jiaping; Qin, Xia

2018-05-08

One important feature of cerebral ischemia is hypoxia injury in nerve cells. Growth arrest-specific transcript 5 (GAS5) is widely reported as a tumor suppressor gene; however, the investigations about its role in cerebrovascular disease are relatively rare. This study was aimed to explore the impact of GAS5 on hypoxia response in nervous cells. PC-12 cells were incubated under anoxic condition to induce hypoxia injury. Regulatory effects of GAS5 on miR-124 and miR-124 on ICAM-1 expression were assessed by qRT-PCR and/or Western blot. Targeting effect of miR-124 on ICAM-1 3'-untranslated regions (UTR) was evaluated through dual luciferase activity assay. The potential regulatory mechanism on hypoxia injury in PC-12 cells was assessed by detecting key elements of NF-κB and Notch signaling pathways using Western blot. GAS5 ectopic expression accentuated hypoxia injury in PC-12 cells. miR-124 expression was negatively regulated by GAS5 expression. Cells with overexpressions of GAS5 and miR-124 alleviated hypoxia injury as in compassion with cells only with GAS5 overexpression. ICAM-1 expression was negatively regulated by miR-124 expression. ICAM-1 was a functional target of miR-124. ICAM-1 overexpression aggravated hypoxia injury, but inversely, ICAM-1 silence diminished hypoxia damage. Besides, ICAM-1 expression was negatively related with activation of NF-κB and Notch pathways. GAS5-miR-124-ICAM-1 axis could regulate hypoxia injury in PC-12 cells. GAS5 might aggravate hypoxia injury via down-regulating miR-124, then up-regulating ICAM-1, and further enhancing activations of NF-κB and Notch pathways. © 2018 Wiley Periodicals, Inc.

Lin28a uses distinct mechanisms of binding to RNA and affects miRNA levels positively and negatively.

PubMed

Nowak, Jakub Stanislaw; Hobor, Fruzsina; Downie Ruiz Velasco, Angela; Choudhury, Nila Roy; Heikel, Gregory; Kerr, Alastair; Ramos, Andres; Michlewski, Gracjan

2017-03-01

Lin28a inhibits the biogenesis of let-7 miRNAs by triggering the polyuridylation and degradation of their precursors by terminal uridylyltransferases TUT4/7 and 3'-5' exoribonuclease Dis3l2, respectively. Previously, we showed that Lin28a also controls the production of neuro-specific miRNA-9 via a polyuridylation-independent mechanism. Here we reveal that the sequences and structural characteristics of pre-let-7 and pre-miRNA-9 are eliciting two distinct modes of binding to Lin28a. We present evidence that Dis3l2 controls miRNA-9 production. Finally, we show that the constitutive expression of untagged Lin28a during neuronal differentiation in vitro positively and negatively affects numerous other miRNAs. Our findings shed light on the role of Lin28a in differentiating cells and on the ways in which one RNA-binding protein can perform multiple roles in the regulation of RNA processing. © 2017 Nowak et al.; Published by Cold Spring Harbor Laboratory Press for the RNA Society.

Differential Regulation of NOTCH2 and NOTCH3 Contribute to Their Unique Functions in Vascular Smooth Muscle Cells.

PubMed

Baeten, Jeremy T; Lilly, Brenda

2015-06-26

Notch signaling is a key regulator of vascular smooth muscle cell (VSMC) phenotypes, including differentiation, proliferation, and cell survival. However, the exact contribution of the individual Notch receptors has not been thoroughly delineated. In this study, we identify unique roles for NOTCH2 and NOTCH3 in regulating proliferation and cell survival in cultured VSMCs. Our results indicate that NOTCH2 inhibits PDGF-B-dependent proliferation and its expression is decreased by PDGF-B. In contrast, NOTCH3 promotes proliferation and receptor expression is increased by PDGF-B. Additionally, data show that NOTCH3, but not NOTCH2 protects VSMCs from apoptosis and apoptosis mediators degrade NOTCH3 protein. We identified three pro-survival genes specifically regulated by NOTCH3 in cultured VSMCs and in mouse aortas. This regulation is mediated through MAP kinase signaling, which we demonstrate can be activated by NOTCH3, but not NOTCH2. Overall, this study highlights discrete roles for NOTCH2 and NOTCH3 in VSMCs and connects these roles to specific upstream regulators that control their expression. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

Tangeretin enhances radiosensitivity and inhibits the radiation-induced epithelial-mesenchymal transition of gastric cancer cells.

PubMed

Zhang, Xukui; Zheng, Luming; Sun, Yinggang; Wang, Tianxiao; Wang, Baocheng

2015-07-01

Irradiation has been reported to increase radioresistance and epithelial-mesenchymal transition (EMT) in gastric cancer (GC) cells. The Notch pathway is critically implicated in cancer EMT and radioresistance. In the present study, we investigated the use of a Notch-1 inhibiting compound as a novel therapeutic candidate to regulate radiation-induced EMT in GC cells. According to previous screening, tangeretin, a polymethoxylated flavonoid from citrus fruits was selected as a Notch-1 inhibitor. Tangeretin enhanced the radiosensitivity of GC cells as demonstrated by MTT and colony formation assays. Tangeretin also attenuated radiation-induced EMT, invasion and migration in GC cells, accompanied by a decrease in Notch-1, Jagged1/2, Hey-1 and Hes-1 expressions. Tangeretin triggered the upregulation of miR-410, a tumor-suppressive microRNA. Furthermore, re-expression of miR-410 prevented radiation-induced EMT and cell invasion. An in vivo tumor xenograft model confirmed the antimetastasis effect of tangeretin as we observed in vitro. In nude mice, tumor size was considerably diminished by radiation plus tangeretin co-treatment. Tangeretin almost completely inhibited lung metastasis induced by irradiation. Tangeretin may be a novel antimetastatic agent for radiotherapy.

Analysis of audiometric notch as a noise-induced hearing loss phenotype in US youth: data from the National Health And Nutrition Examination Survey, 2005-2010.

PubMed

Bhatt, Ishan S; Guthrie, O'neil

2017-06-01

Bilateral audiometric notch (BN) at 4000-6000 Hz was identified as a noise-induced hearing loss (NIHL) phenotype for genetic association analysis in college-aged musicians. This study analysed BN in a sample of US youth. Prevalence of the BN within the study sample was determined and logistic-regression analyses were performed to identify audiologic and other demographic factors associated with BN. Computer-simulated "flat" audiograms were used to estimate potential influence of false-positive rates in estimating the prevalence of the BN. 2348 participants (12-19 years) following the inclusion criteria were selected from the National Health and Nutrition Examination Survey data (2005-2010). The prevalence of BN was 16.6%. Almost 55.6% of the participants showed notch in at least one ear. Noise exposure, gender, ethnicity and age showed significant relationship with the BN. Computer simulation revealed that 5.5% of simulated participants with "flat" audiograms showed BN. Association of noise exposure with BN suggests that it is a useful NIHL phenotype for genetic association analyses. However, further research is necessary to reduce false-positive rates in notch identification.

Word Frequency Analysis. MOS: 75C. Skill Levels 1 & 2.

DTIC Science & Technology

1981-05-01

A4Fi j, A REAS . I --- - ., ARISS 12 ARMY I A~K1h ’.-L ARRANGED 64 AS I ASCERTAIN 2 .L~u Ip ASSEMBLE 12 ASSEMBLED 1 ASSEMPLY I ASSI----------------2...GOVERNING .16 GRADE ’G.; S GRAA!TET I GRfATEST I GREEN I GFEP.I .4 ( AriSS I GROUPS s GUIDANCE I G lIn (;UItES V 1 E I GUIVIS/ 3 GWPM 1-’ 1 I.AO 1 HAE

Lin28 Mediates Cancer Chemotherapy Resistance via Regulation of miRNA Signaling.

PubMed

Xu, Chaoyang; Xie, Shuduo; Song, Chunjiao; Huang, Liming; Jiang, Zhinong

2014-06-01

Chemotherapy resistance is one of the major obstacles limiting the success of cancer drug treatment. Among the mechanisms of resistance to chemotherapy treatment, there are those closely related to P-Glycoprotein, multidrug resistance-related protein, glutathione S-transferase pi and topoisomerase-II. Lin28 is a highly conserved RNA-binding protein, it consists of a cold shock domain and retroviral-type (CCHC) zinc finger motifs. In previous preclinical and clinical studies, positive Lin28 expression in cancer cells was correlated with decreased sensitivity to chemotherapy. And Lin28 could mediate cancer chemotherapy resistance via regulation of miR107 and Let-7 MiRNA. This article reviews current knowledge on predictive value of Lin28 in response to chemotherapy. Better understanding of its role may facilitate patient's selection of therapeutic regimen and lead to optimal clinical outcome.

Selective blockade of microRNA processing by Lin-28

PubMed Central

Viswanathan, Srinivas R.; Daley, George Q.; Gregory, Richard I.

2012-01-01

MicroRNAs (miRNAs) play critical roles in development, and dysregulation of miRNA expression has been observed in human malignancies. Recent evidence suggests that the processing of several primary miRNA transcripts (pri-miRNAs) is blocked post-transcriptionally in embryonic stem (ES) cells, embryonal carcinoma (EC) cells, and primary tumors. Here we show that Lin-28, a developmentally regulated RNA-binding protein, selectively blocks the processing of pri-let-7 miRNAs in embryonic cells. Using in vitro and in vivo studies, we demonstrate that Lin-28 is necessary and sufficient for blocking Microprocessor-mediated cleavage of pri-let-7 miRNAs. Our results identify Lin-28 as a negative regulator of miRNA biogenesis and suggest that Lin-28 may play a central role in blocking miRNA-mediated differentiation in stem cells and certain cancers. PMID:18292307

LIN-39/Hox triggers cell division and represses EFF-1/fusogen-dependent vulval cell fusion

PubMed Central

Shemer, Gidi; Podbilewicz, Benjamin

2002-01-01

General mechanisms by which Hox genes establish cell fates are known. However, a few Hox effectors mediating cell behaviors have been identified. Here we found the first effector of LIN-39/HoxD4/Dfd in Caenorhabditis elegans. In specific vulval precursor cells (VPCs), LIN-39 represses early and late expression of EFF-1, a membrane protein essential for cell fusion. Repression of eff-1 is also achieved by the activity of CEH-20/Exd/Pbx, a known cofactor of Hox proteins. Unfused VPCs in lin-39(−);eff-1(−) double mutants fail to divide but migrate, executing vulval fates. Thus, lin-39 is essential for inhibition of EFF-1-dependent cell fusion and stimulation of cell proliferation during vulva formation. Supplemental material is available at http://www.genesdev.org. PMID:12502736

Lin Receives 2010 Natural Hazards Focus Group Award for Graduate Research

NASA Astrophysics Data System (ADS)

2010-11-01

Ning Lin has been awarded the Natural Hazards Focus Group Award for Graduate Research, given annually to a recent Ph.D. recipient for outstanding contributions to natural hazards research. Lin's thesis is entitled “Multi-hazard risk analysis related to hurricanes.” She is scheduled to present an invited talk in the Extreme Natural Events: Modeling, Prediction, and Mitigation session (NH20) during the 2010 AGU Fall Meeting, held 13-17 December in San Francisco, Calif. Lin will be formally presented with the award at the Natural Hazards focus group reception on 14 December 2010.

Bone Marrow Mesenchymal Stromal Cells Stimulate Skeletal Myoblast Proliferation through the Paracrine Release of VEGF

PubMed Central

Chellini, Flaminia; Mazzanti, Benedetta; Nistri, Silvia; Nosi, Daniele; Saccardi, Riccardo; Quercioli, Franco; Zecchi-Orlandini, Sandra; Formigli, Lucia

2012-01-01

Mesenchymal stromal cells (MSCs) are the leading cell candidates in the field of regenerative medicine. These cells have also been successfully used to improve skeletal muscle repair/regeneration; however, the mechanisms responsible for their beneficial effects remain to be clarified. On this basis, in the present study, we evaluated in a co-culture system, the ability of bone-marrow MSCs to influence C2C12 myoblast behavior and analyzed the cross-talk between the two cell types at the cellular and molecular level. We found that myoblast proliferation was greatly enhanced in the co-culture as judged by time lapse videomicroscopy, cyclin A expression and EdU incorporation. Moreover, myoblasts immunomagnetically separated from MSCs after co-culture expressed higher mRNA and protein levels of Notch-1, a key determinant of myoblast activation and proliferation, as compared with the single culture. Notch-1 intracellular domain and nuclear localization of Hes-1, a Notch-1 target gene, were also increased in the co-culture. Interestingly, the myoblastic response was mainly dependent on the paracrine release of vascular endothelial growth factor (VEGF) by MSCs. Indeed, the addition of MSC-derived conditioned medium (CM) to C2C12 cells yielded similar results as those observed in the co-culture and increased the phosphorylation and expression levels of VEGFR. The treatment with the selective pharmacological VEGFR inhibitor, KRN633, resulted in a marked attenuation of the receptor activation and concomitantly inhibited the effects of MSC-CM on C2C12 cell growth and Notch-1 signaling. In conclusion, this study provides novel evidence for a role of MSCs in stimulating myoblast cell proliferation and suggests that the functional interaction between the two cell types may be exploited for the development of new and more efficient cell-based skeletal muscle repair strategies. PMID:22815682

[Heavy metal pollution characteristics and ecological risk analysis for soil in Phyllostachys praecox stands of Lin'an].

PubMed

Fang, Xiao-bo; Shi, Han; Liao, Xin-feng; Lou, Zhong; Zhou, Lyu-yan; Yu, Hai-xia; Yao, Lin; Sun, Li-ping

2015-06-01

An investigation was carried out in an attempt to reveal the characteristics of heavy metals contamination in the soils of Phyllostachys praecox forest in Lin' an. Based on the concentrations of Hg, As, Cu, Pb, Zn, Cd, Cr, Ni, Co and Mn in 160 topsoil samples, the pollution status and ecological risks of heavy metals in the soils were assessed by single factor pollution index, Nemerow integrated pollution index and Hankanson potential ecological risk index. The spatial variability of heavy metal concentrations in the soils closely related to the distribution of traffic, industrial and livestock pollution sources. The average concentrations of Hg, As, Cu, Pb, Zn, Cd, Cr, Ni, Co and Mn in the soils were 0.16, 7.41, 34.36, 87.98, 103.98, 0.26, 59.12, 29.56, 11.44 and 350.26 mg · kg(-1), respectively. Pb, Cd, Zn and Cu concentrations were as 2.89, 1.70, 1.12 and 1.12 times as the background values of soil in Zhejiang Province, respectively. But their concentrations were all lower than the threshold values of the National Environmental Quality Standard for Soil (GB 15618-1995). The average single factor pollution index revealed that the level of heavy metal pollution in the soils was in order of Pb>Cd>Cu= Zn>Hg>As>Ni>Co>Cr>Mn. Pb pollution was of moderate level while Cd, Cu and Zn pollutions were slight. There was no soil pollution caused by the other heavy metals. However, the Nemerow integrated pollution index showed that all the 160 soil samples were contaminated by heavy metals to a certain extent. Among total 160 soil samples, slight pollution level, moderate pollution level and heavy pollution level accounted for 55.6%, 29.4% and 15.0%, respectively. The average single factor potential ecological risk index (Er(i)) implied that the potential ecological risk related to Cd reached moderate level, while the others were of slight level. Furthermore, Cd and Hg showed higher potential ecological risk indices which reached up to 256.82 and 187.33 respectively, indicating Cd and Hg had a strong ecological risk and therefore might pose the most serious ecological risk in the soils of P. praecox standsin Lin' an. In addition, the integrated factor potential ecological risk analysis suggested a slight risk to local ecosystem originated from heavy metal contamination in the soils of P. praecox stands in Lin'an.

Smart Methods for Linezolid Determination in the Presence of Alkaline and Oxidative Degradation Products Utilizing Their Overlapped Spectral Bands

NASA Astrophysics Data System (ADS)

Abd El-Monem Hegazy, M.; Shaaban Eissa, M.; Abd El-Sattar, O. I.; Abd El-Kawy, M. M.

2014-09-01

Linezolid (LIN) is considered the first available oxazolidinone antibacterial agent. It is susceptible to hydrolysis and oxidation. Five simple, accurate, sensitive and validated UV spectrophotometric methods were developed for LIN determination in the presence of its alkaline (ALK) and oxidative (OXD) degradation products in bulk powder and pharmaceutical formulation. Method A is a second derivative one (D2) in which LIN is determined at 240.9 nm. Method B is a pH-induced differential derivative one where LIN is determined using the fourth derivative (D4) of the difference spectra (ΔA) at 285.3 nm. Methods C, D, and E are manipulating ratio spectra, where C is the double divisor-ratio difference spectrophotometric one (DD-RD) in which LIN was determined by calculating the amplitude difference at 243.7 and 267.6 nm of the ratio spectra. Method D is the double divisor-first derivative of ratio spectra (DD-DD1) in which LIN was determined at 270.2 nm. Method E is a mean centering of ratio spectra one (MCR) in which LIN was determined at 318.0 nm. The developed methods have been validated according to ICH guidelines. The results were statistically compared to that of a reported HPLC method and there was no significant difference regarding both accuracy and precision.

Hypoxia-driven angiogenesis: role of tip cells and extracellular matrix scaffolding.

PubMed

Germain, Stéphane; Monnot, Catherine; Muller, Laurent; Eichmann, Anne

2010-05-01

Angiogenesis is a highly coordinated tissue remodeling process leading to blood vessel formation. Hypoxia triggers angiogenesis via induction of expression of growth factors such as vascular endothelial growth factor (VEGF). VEGF instructs endothelial cells to form tip cells, which lead outgrowing capillary sprouts, whereas Notch signaling inhibits sprout formation. Basement membrane deposition and mechanical cues from the extracellular matrix (ECM) induced by hypoxia may participate to coordinated vessel sprouting in conjunction with the VEGF and Notch signaling pathways. Hypoxia regulates ECM composition, deposition, posttranslational modifications and rearrangement. In particular, hypoxia-driven vascular remodeling is dynamically regulated through modulation of ECM-modifying enzyme activities that eventually affect both matricellular proteins and growth factor availability. Better understanding of the complex interplay between endothelial cells and soluble growth factors and mechanical factors from the ECM will certainly have significant implications for understanding the regulation of developmental and pathological angiogenesis driven by hypoxia.

A Dual Role for NOTCH Signaling in Joint Cartilage Maintenance and Osteoarthritis

PubMed Central

Liu, Zhaoyang; Chen, Jianquan; Mirando, Anthony; Wang, Cuicui; Zuscik, Michael J.; O’Keefe, Regis J.; Hilton, Matthew J.

2015-01-01

Loss of NOTCH signaling in postnatal murine joints results in osteoarthritis (OA), indicating a requirement for NOTCH during joint cartilage maintenance. Unexpectedly, NOTCH components are significantly up-regulated in human and murine post-traumatic OA, suggesting either a reparative or pathological role for NOTCH activation in OA. Here we investigated the potential dual role for NOTCH in joint maintenance and OA by generating two mouse models overexpressing the NOTCH1 intracellular domain within postnatal joint cartilage; one with sustained NOTCH activation that likely resembles pathological NOTCH signaling and one with transient NOTCH activation that more closely reflects physiological NOTCH signaling. Sustained NOTCH signaling in joint cartilage leads to an early and progressive OA pathology, while on the contrary, transient NOTCH activation enhances cartilage matrix synthesis and promotes joint maintenance under normal physiological conditions. Using RNA-seq, immunohistochemical, and biochemical approaches we identified several novel targets potentially responsible for NOTCH-mediated cartilage degradation, fibrosis, and OA progression, including components of the IL6/STAT3 and ERK/p38 MAPK pathways; factors that may also contribute to post-traumatic OA development. Collectively, these data demonstrate a dual role for the NOTCH pathway in joint cartilage and identify important downstream NOTCH effectors as potential targets for disease modifying osteoarthritis drugs (DMOADs). PMID:26198357

Loss of Notch2 and Notch3 in vascular smooth muscle causes patent ductus arteriosus.

PubMed

Baeten, Jeremy T; Jackson, Ashley R; McHugh, Kirk M; Lilly, Brenda

2015-12-01

The overlapping roles of the predominant Notch receptors in vascular smooth muscle cells, Notch2 and Notch3, have not been clearly defined in vivo. In this study, we use a smooth muscle-specific deletion of Notch2 together with a global Notch3 deletion to produce mice with combinations of mutant and wild-type Notch2/3 alleles in vascular smooth muscle cells. Mice with complete loss of Notch3 and smooth muscle-expressed Notch2 display late embryonic lethality and subcutaneous hemorrhage. Mice without smooth muscle-Notch2 and only one wild-type copy of Notch3 die within one day of birth and present with vascular defects, most notably patent ductus arteriosus (DA) and aortic dilation. These defects were associated with decreased expression of contractile markers in both the DA and aorta. These results demonstrate that Notch2 and Notch3 have overlapping roles in promoting development of vascular smooth muscle cells, and together contribute to functional closure of the DA. © 2015 Wiley Periodicals, Inc.

Notch1 Signaling Regulates the Th17/Treg Immune Imbalance in Patients with Psoriasis Vulgaris.

PubMed

Ma, Lei; Xue, HaiBo; Gao, Tianqin; Gao, MeiLan; Zhang, YuJie

2018-01-01

To evaluate the regulating effect of Notch1 signaling on Th17/Treg immune imbalance in psoriasis vulgaris (PV). Notch1, Hes-1, ROR γ t, Foxp3, IL-17, and IL-10 mRNA expression, as well as Th17 and Treg cell percentages in peripheral CD4 + T cells, were detected by real-time quantitative RT-PCR and flow cytometry, and serum concentrations of IL-17 and IL-10 were detected by ELISA in 36 PV patients and 32 healthy controls. Additionally, CD4 + T cells from 12 PV patients were treated with γ -secretase inhibitor DAPT, and the above indexes were measured. PV patients presented distinct Th17/Treg immune imbalance and highly expressed Notch1 and Hes-1 mRNA levels, which were positively correlated with psoriasis area and severity index (PASI) and the ratios of Th17/Treg and ROR γ t/Foxp3. DAPT treatment resulted in the obvious downregulation of Th17 cell percentage in cocultured CD4 + T cells, ROR γ t and IL-17 mRNA levels, and IL-17 concentration in cell-free supernatant from cocultured CD4 + T cells of PV patients in a dose-dependent manner, while there was no significant influence on Treg cell percentage, Foxp3, and IL-10 expression, therefore leading to the recovery of Th17/Treg immune imbalance. Notch1 signaling may contribute to the pathogenesis of PV by regulating Th17/Treg immune imbalance.

Interplay between Notch1 and Notch3 promotes EMT and tumor initiation in squamous cell carcinoma.

PubMed

Natsuizaka, Mitsuteru; Whelan, Kelly A; Kagawa, Shingo; Tanaka, Koji; Giroux, Veronique; Chandramouleeswaran, Prasanna M; Long, Apple; Sahu, Varun; Darling, Douglas S; Que, Jianwen; Yang, Yizeng; Katz, Jonathan P; Wileyto, E Paul; Basu, Devraj; Kita, Yoshiaki; Natsugoe, Shoji; Naganuma, Seiji; Klein-Szanto, Andres J; Diehl, J Alan; Bass, Adam J; Wong, Kwok-Kin; Rustgi, Anil K; Nakagawa, Hiroshi

2017-11-24

Notch1 transactivates Notch3 to drive terminal differentiation in stratified squamous epithelia. Notch1 and other Notch receptor paralogs cooperate to act as a tumor suppressor in squamous cell carcinomas (SCCs). However, Notch1 can be stochastically activated to promote carcinogenesis in murine models of SCC. Activated form of Notch1 promotes xenograft tumor growth when expressed ectopically. Here, we demonstrate that Notch1 activation and epithelial-mesenchymal transition (EMT) are coupled to promote SCC tumor initiation in concert with transforming growth factor (TGF)-β present in the tumor microenvironment. We find that TGFβ activates the transcription factor ZEB1 to repress Notch3, thereby limiting terminal differentiation. Concurrently, TGFβ drives Notch1-mediated EMT to generate tumor initiating cells characterized by high CD44 expression. Moreover, Notch1 is activated in a small subset of SCC cells at the invasive tumor front and predicts for poor prognosis of esophageal SCC, shedding light upon the tumor promoting oncogenic aspect of Notch1 in SCC.

Cancer Health Disparities Research: Where have we been and where should we go? | Division of Cancer Prevention

Cancer.gov

Speaker | Scarlett Lin Gomez, PhD, MPH will present the next CPFP Colloquia lecture entitled, "Cancer Health Disparities Research: Where have we been and where should we go?" Date: May 15, 2018; Time: 11:00 am - 12:00 pm; Location: NCI Shady Grove campus, Conference Room: 2W-910/912.

Translations on Red Flag No. 12, 5 December 1977

DTIC Science & Technology

1978-01-25

counterrevolutionary nature, the "gang of four," who were but Jackals in the same lair as the Lin Piao antiparty clique, panicked. The gang did...said that I was an ambitious man daring to think and act. But the class enemies accused me of "wanting to become a golden phoenix and an official

Knockdown of miR-128a induces Lin28a expression and reverts myeloid differentiation blockage in acute myeloid leukemia

PubMed Central

De Luca, Luciana; Trino, Stefania; Laurenzana, Ilaria; Tagliaferri, Daniela; Falco, Geppino; Grieco, Vitina; Bianchino, Gabriella; Nozza, Filomena; Campia, Valentina; D'Alessio, Francesca; La Rocca, Francesco; Caivano, Antonella; Villani, Oreste; Cilloni, Daniela; Musto, Pellegrino; Del Vecchio, Luigi

2017-01-01

Lin28A is a highly conserved RNA-binding protein that concurs to control the balance between stemness and differentiation in several tissue lineages. Here, we report the role of miR-128a/Lin28A axis in blocking cell differentiation in acute myeloid leukemia (AML), a genetically heterogeneous disease characterized by abnormally controlled proliferation of myeloid progenitor cells accompanied by partial or total inability to undergo terminal differentiation. First, we found Lin28A underexpressed in blast cells from AML patients and AML cell lines as compared with CD34+ normal precursors. In vitro transfection of Lin28A in NPM1-mutated OCI-AML3 cell line significantly triggered cell-cycle arrest and myeloid differentiation, with increased expression of macrophage associate genes (EGR2, ZFP36 and ANXA1). Furthermore, miR-128a, a negative regulator of Lin28A, was found overexpressed in AML cells compared with normal precursors, especially in acute promyelocytic leukemia (APL) and in ‘AML with maturation’ (according to 2016 WHO classification of myeloid neoplasms and acute leukemia). Its forced overexpression by lentiviral infection in OCI-AML3 downregulated Lin28A with ensuing repression of macrophage-oriented differentiation. Finally, knockdown of miR-128a in OCI-AML3 and in APL/AML leukemic cells (by transfection and lentiviral infection, respectively) induced myeloid cell differentiation and increased expression of Lin28A, EGR2, ZFP36 and ANXA1, reverting myeloid differentiation blockage. In conclusion, our findings revealed a new mechanism for AML differentiation blockage, suggesting new strategies for AML therapy based upon miR-128a inhibition. PMID:28569789

Gender differences in cardiac autonomic modulation during medical internship.

PubMed

Lin, Yu-Hsuan; Chen, Ching-Yen; Lin, Sheng-Hsuan; Liu, Chun-Hao; Weng, Wei-Hung; Kuo, Terry B J; Yang, Cheryl C H

2013-06-01

Medical internship is known to be a time of high stress and long working hours, which increases the risk of depression and cardiovascular disease. Gender differences in medical interns' cardiovascular risk have not been reported previously. Thirty-eight medical interns (29 males) were repeatedly tested for depressive symptoms using the Hospital Anxiety and Depression Scale and 5-min spectral analysis of heart rate variability (HRV) at 3-month intervals during their internship. Among the male interns, the variance of the heart rate decreased at 6, 9, 12 months, and a reduced high frequency, which suggests reduced cardiac parasympathetic modulation, was found at 9 and 12 months into their internship. Increased depressive symptoms were also identified at 12 months in the male group. No significant differences in depression or any of the HRV indices were identified among the female interns during their internship. Copyright © 2013 Society for Psychophysiological Research.

Taxonomic review of the plant bug subfamily Isometopinae for Taiwan and Japanese Southwest Islands, with descriptions of new taxa (Hemiptera: Heteroptera: Miridae: Isometopinae).

PubMed

Yasunaga, Tomohide; Yamada, Kazutaka; Tsai, Jing-Fu

2017-12-19

The fauna of plant bug subfamily Isometopinae in Taiwan and Japanese Southwest (Nansei) Islands is reviewed. Twenty-five species are recognized, including two new species of Myiomma Puton, M. austroccidens sp. nov. and M. kentingense sp. nov., which are herein diagnosed and described. In addition, Isometopus yehi Lin, 2004 is synonymized with I. bipunctatus Lin; Isometopidea yangi Lin is transferred to Kohnometopus; and a substitute name, Alcecoris linyangorum, is proposed for A. formosanus (Lin Yang) (= a junior secondary homonym of Alcecoris formosanus Lin). An annotated checklist, with updated distributional record and biological information, is provided for all treated taxa. A new tribe Sophianini is proposed for two genera, Alcecoris and Sophianus, characterized principally by the conspicuously modified antennal structures. An additional new species, Alcecoris cochlearatus sp. nov., found during examination of related Oriental specimens, is described from the Malay Peninsula.

Reduced fatty acid synthesis and desaturation due to exogenous trans10,cis12-CLA in cows fed oleic or linoleic oil.

PubMed

Loor, J J; Herbein, J H

2003-04-01

To determine effects of an elevated supply of cis9,trans11-18:2 (9/11CLA) or trans10,cis12-18:2 (10/12CLA) on de novo synthesis and desaturation of long-chain fatty acids, four Holstein cows fed high-oleic sunflower (OLE) or high-linoleic safflower oil (LIN) at 2.5% of DM were infused (0.625 g/h) with 9/11CLA or 10/12CLA for 48 h via the abomasum. Treatments were assigned in a 2 x 2 factorial design. The assigned diets were fed for 11 d before each 48-h infusion period. Milk samples were obtained at 12 and 0 h before infusion and at 12-h intervals from 0 to 96 h. Concentrations of trans11-18:1 and 18:2n-6 in arterial plasma phospholipid, triglyceride, and FFA fractions were greater due to feeding LIN compared with OLE. Infused 9/11CLA and 10/12CLA were incorporated into plasma triglycerides and FFA primarily. Exogenous 10/12CLA also was found in plasma phospholipids. Milk yield and DMI were not affected by treatments. Percentages and yields of protein, lactose, and SNF in milk also were not affected by treatments. Milk fat percentage and yield, however, decreased 25% from 0 to 96 h in response to infusion of 10/12CLA compared with 9/11CLA. Yields of trans11-18:1, 9/11CLA and 18:2n-6 in milk fat before infusion were higher when LIN was fed compared with OLE. Infusion of 9/11CLA, regardless of diet, increased 9/11CLA in milk fat by 44%. Although 10/12CLA was not detectable in milk fat before infusion, it averaged 6 mg/g of total fatty acids and 2 g/d after 48 h. At 48 h, recovery in milk of infused 9/11CLA was 16% compared with 8% for 10/12CLA. Yields of saturated 6:0 to 16:0, cis9-18:1, 9/11CLA, and 20:4n-6 were reduced by 10/12CLA infusion. Due to a 40% increase in the concentration of 18:0 by 48 h of 10/12CLA infusion, however, yield of 18:0 was not affected. Ratios of cis9-18:1/18:0, 9/11CLA/trans11-18:1, and 20:4n-6/18:2n-6 in milk fat decreased in response to infusion of 10/12CLA, regardless of diet. At peak concentration of 10/12CLA, reductions in cis9-18:1 and saturated 4:0-16:0 yields accounted for 36% and 53% of the decrease in total fatty acid yield. Results indicated 10/12CLA alters lipid metabolism in the bovine mammary gland by simultaneously reducing de novo synthesis and desaturation. Furthermore, milk triglyceride synthesis may have a stringent requirement for endogenously synthesized oleic acid.

The contribution of Notch1 to nephron segmentation in the developing kidney is revealed in a sensitized Notch2 background and can be augmented by reducing Mint dosage

PubMed Central

Surendran, Kameswaran; Boyle, Scott; Barak, Hila; Kim, Mijin; Stromberski, Colin; McCright, Brent; Kopan, Raphael

2009-01-01

We previously determined that Notch2, and not Notch1 was required for forming proximal nephron segments. The dominance of Notch2 may be conserved in humans, since Notch2 mutations occur in Alagille syndrome (ALGS) 2 patients, which includes renal complications. To test whether mutations in Notch1 could increase the severity of renal complications in ALGS, we inactivated conditional Notch1 and Notch2 alleles in mice using a Six2-GFP∷Cre. This BAC transgene is expressed mosaically in renal epithelial progenitors but uniformly in cells exiting the progenitor pool to undergo mesenchymal to epithelial transition. Although delaying Notch2 inactivation had a marginal effect on nephron numbers, it created a sensitized background in which the inactivation of Notch1 severely compromised nephron formation, function and survival. These and additional observations indicate that Notch1 in concert with Notch2 contributes to the morphogenesis of renal vesicles into S-shaped bodies in a RBP-J dependent manner. A significant implication is that elevating Notch1 activity could improve renal functions in ALGS2 patients. As proof of principle, we determined that conditional inactivation of Mint, an inhibitor of Notch-RBP-J interaction, resulted in a moderate rescue of Notch2 null kidneys, implying that temporal blockage of Notch signaling inhibitors downstream of receptor activation may have therapeutic benefits for ALGS patients. PMID:19914235

Alternative mode of presentation of Kanizsa figures sheds new light on the chronometry of the mechanisms underlying the perception of illusory figures.

PubMed

Brodeur, M; Lepore, F; Lepage, M; Bacon, B A; Jemel, B; Debruille, J B

2008-01-31

The mechanisms responsible for the perception of illusory modal figures are usually studied by presenting entire Kanizsa figures at stimulus onset. However, with this mode of presentation, the brain activity generated by the inducers (the 'pacmen') is difficult to differentiate from the activity underlying the perception of the illusory figure. Therefore, in addition to this usual presentation mode, we used an alternative presentation mode. Inducer disks remained permanently on the screen and the illusory figure was induced by just removing the notches from the disks. The results support the heuristic value of this alternative mode of presentation. The P1 deflection of the visual evoked potentials (VEPs) was found to be greater for the illusory modal figure than for its control and for an amodal figure. This modulation is one of the earliest direct evidences for a low-level processing of illusory forms in the human brain. Meanwhile, larger N1s were obtained for the control figures than for the illusory figures in the notch mode of presentation. While this new type of N1 modulation could shed some light on the stage of processing indexed by this deflection, several propositions are put forward to account for the P1 and N1 variations found.

MiR-146a modulates macrophage polarization by inhibiting Notch1 pathway in RAW264.7 macrophages.

PubMed

Huang, Cheng; Liu, Xue-Jiao; QunZhou; Xie, Juan; Ma, Tao-Tao; Meng, Xiao-Ming; Li, Jun

2016-03-01

Macrophages are heterogeneous and plastic cells which are able to undergo dynamic transition between M1 and M2 polarized phenotypes in response to the microenvironment signals. However, the underlying molecular mechanisms of macrophage polarization are still obscure. In the current study, it was revealed that miR-146a might play a pivotal role in macrophage polarization. As our results indicated, miR-146a was highly expressed in M2 macrophages rather than M1 macrophages. Over-expression of miR-146a resulted in significantly decreased production of pro-inflammatory cytokines including iNOS and TNF-α in M1 macrophages, while increased production of M2 marker genes such as Arg1 and CD206 in M2 macrophages. In contrast, knockdown of miR-146a promoted M1 macrophage polarization but diminished M2 macrophage polarization. Mechanistically, it was revealed that miR-146a modulated macrophage polarization by targeting Notch1. Of note, PPARγ was responsible as another target for miR-146a-mediated macrophage polarization. Taken together, it was suggested that miR-146a might serve as a molecular regulator in macrophage polarization and is a potential therapeutic target for inflammatory diseases. Copyright © 2016 Elsevier B.V. All rights reserved.

NOTCH2 signaling confers immature morphology and aggressiveness in human hepatocellular carcinoma cells

PubMed Central

HAYASHI, YOSHIHIRO; OSANAI, MAKOTO; LEE, GANG-HONG

2015-01-01

The NOTCH family of membranous receptors plays key roles during development and carcinogenesis. Since NOTCH2, yet not NOTCH1 has been shown essential for murine hepatogenesis, NOTCH2 rather than NOTCH1 may be more relevant to human hepatocarcinogenesis; however, no previous studies have supported this hypothesis. We therefore assessed the role of NOTCH2 in human hepatocellular carcinoma (HCC) by immunohistochemistry and cell culture. Immunohistochemically, 19% of primary HCCs showed nuclear staining for NOTCH2, indicating activated NOTCH2 signaling. NOTCH2-positive HCCs were on average in more advanced clinical stages, and exhibited more immature cellular morphology, i.e. higher nuclear-cytoplasmic ratios and nuclear densities. Such features were not evident in NOTCH1-positive HCCs. In human HCC cell lines, abundant NOTCH2 expression was associated with anaplasia, represented by loss of E-cadherin. When NOTCH2 signaling was stably downregulated in HLF cells, an anaplastic HCC cell line, the cells were attenuated in potential for in vitro invasiveness and migration, as well as in vivo tumorigenicity accompanied by histological maturation. Generally, inverse results were obtained for a differentiated HCC cell line, Huh7, manipulated to overexpress activated NOTCH2. These findings suggested that the NOTCH2 signaling may confer aggressive behavior and immature morphology in human HCC cells. PMID:26252838

NOTCH2 signaling confers immature morphology and aggressiveness in human hepatocellular carcinoma cells.

PubMed

Hayashi, Yoshihiro; Osanai, Makoto; Lee, Gang-Hong

2015-10-01

The NOTCH family of membranous receptors plays key roles during development and carcinogenesis. Since NOTCH2, yet not NOTCH1 has been shown essential for murine hepatogenesis, NOTCH2 rather than NOTCH1 may be more relevant to human hepatocarcinogenesis; however, no previous studies have supported this hypothesis. We therefore assessed the role of NOTCH2 in human hepatocellular carcinoma (HCC) by immunohistochemistry and cell culture. Immunohistochemically, 19% of primary HCCs showed nuclear staining for NOTCH2, indicating activated NOTCH2 signaling. NOTCH2-positive HCCs were on average in more advanced clinical stages, and exhibited more immature cellular morphology, i.e. higher nuclear-cytoplasmic ratios and nuclear densities. Such features were not evident in NOTCH1‑positive HCCs. In human HCC cell lines, abundant NOTCH2 expression was associated with anaplasia, represented by loss of E-cadherin. When NOTCH2 signaling was stably downregulated in HLF cells, an anaplastic HCC cell line, the cells were attenuated in potential for in vitro invasiveness and migration, as well as in vivo tumorigenicity accompanied by histological maturation. Generally, inverse results were obtained for a differentiated HCC cell line, Huh7, manipulated to overexpress activated NOTCH2. These findings suggested that the NOTCH2 signaling may confer aggressive behavior and immature morphology in human HCC cells.

Genetics and Prognostication in Splenic Marginal Zone Lymphoma: Revelations from Deep Sequencing

PubMed Central

Gibson, Jane; Wang, Jun; Walewska, Renata; Parker, Helen; Parker, Anton; Davis, Zadie; Gardiner, Anne; McIver-Brown, Neil; Kalpadakis, Christina; Xochelli, Aliki; Anagnostopoulos, Achilles; Fazi, Claudia; de Castro, David Gonzalez; Dearden, Claire; Pratt, Guy; Rosenquist, Richard; Ashton-Key, Margaret; Forconi, Francesco; Collins, Andrew; Ghia, Paolo; Matutes, Estella; Pangalis, Gerassimos; Stamatopoulos, Kostas; Oscier, David; Strefford, Jonathan C

2015-01-01

Purpose Mounting evidence supports the clinical significance of gene mutations and immunogenetic features in common mature B-cell malignancies. Experimental Design We undertook a detailed characterization of the genetic background of splenic marginal zone lymphoma (SMZL), using targeted re-sequencing and explored potential clinical implications in a multinational cohort of 175 SMZL patients. Results We identified recurrent mutations in TP53 (16%), KLF2 (12%), NOTCH2 (10%), TNFAIP3 (7%), MLL2 (11%), MYD88 (7%) and ARID1A (6%), all genes known to be targeted by somatic mutation in SMZL. KLF2 mutations were early, clonal events, enriched in patients with del(7q) and IGHV1-2*04 B-cell receptor immunoglobulins, and were associated with a short median time-to-first-treatment (0.12 vs. 1.11 yrs; P=0.01). In multivariate analysis mutations in NOTCH2 (HR 2.12, 95%CI 1.02-4.4, P=0.044) and 100% germline IGHV gene identity (HR 2.19, 95%CI 1.05-4.55, P=0.036) were independent markers of short time-to-first-treatment, while TP53 mutations were an independent marker of short overall survival (HR 2.36, 95% CI 1.08-5.2, P=0.03). Conclusion We identify key associations between gene mutations and clinical outcome, demonstrating for the first time that NOTCH2 and TP53 gene mutations are independent markers of reduced treatment-free and overall survival, respectively. PMID:25779943

Novel Roles for Notch3 and Notch4 Receptors in Gene Expression and Susceptibility to Ozone-Induced Lung Inflammation in Mice

PubMed Central

McCaw, Zachary; Gladwell, Wesley; Trivedi, Shweta; Bushel, Pierre R.; Kleeberger, Steven R.

2015-01-01

Background Ozone is a highly toxic air pollutant and global health concern. Mechanisms of genetic susceptibility to ozone-induced lung inflammation are not completely understood. We hypothesized that Notch3 and Notch4 are important determinants of susceptibility to ozone-induced lung inflammation. Methods Wild-type (WT), Notch3 (Notch3–/–), and Notch4 (Notch4–/–) knockout mice were exposed to ozone (0.3 ppm) or filtered air for 6–72 hr. Results Relative to air-exposed controls, ozone increased bronchoalveolar lavage fluid (BALF) protein, a marker of lung permeability, in all genotypes, but significantly greater concentrations were found in Notch4–/– compared with WT and Notch3–/– mice. Significantly greater mean numbers of BALF neutrophils were found in Notch3–/– and Notch4–/– mice compared with WT mice after ozone exposure. Expression of whole lung Tnf was significantly increased after ozone in Notch3–/– and Notch4–/– mice, and was significantly greater in Notch3–/– compared with WT mice. Statistical analyses of the transcriptome identified differentially expressed gene networks between WT and knockout mice basally and after ozone, and included Trim30, a member of the inflammasome pathway, and Traf6, an inflammatory signaling member. Conclusions These novel findings are consistent with Notch3 and Notch4 as susceptibility genes for ozone-induced lung injury, and suggest that Notch receptors protect against innate immune inflammation. Citation Verhein KC, McCaw Z, Gladwell W, Trivedi S, Bushel PR, Kleeberger SR. 2015. Novel roles for Notch3 and Notch4 receptors in gene expression and susceptibility to ozone-induced lung inflammation in mice. Environ Health Perspect 123:799–805; http://dx.doi.org/10.1289/ehp.1408852 PMID:25658374

Discrete Notch signaling requirements in the specification of hematopoietic stem cells

PubMed Central

Kim, Albert D; Melick, Chase H; Clements, Wilson K; Stachura, David L; Distel, Martin; Panáková, Daniela; MacRae, Calum; Mork, Lindsey A; Crump, J Gage; Traver, David

2014-01-01

Hematopoietic stem cells (HSCs) require multiple molecular inputs for proper specification, including activity of the Notch signaling pathway. A requirement for the Notch1 and dispensability of the Notch2 receptor has been demonstrated in mice, but the role of the remaining Notch receptors has not been investigated. Here, we demonstrate that three of the four Notch receptors are independently required for the specification of HSCs in the zebrafish. The orthologues of the murine Notch1 receptor, Notch1a and Notch1b, are each required intrinsically to fate HSCs, just prior to their emergence from aortic hemogenic endothelium. By contrast, the Notch3 receptor is required earlier within the developing somite to regulate HSC emergence in a non-cell-autonomous manner. Epistatic analyses demonstrate that Notch3 function lies downstream of Wnt16, which is required for HSC specification through its regulation of two Notch ligands, dlc and dld. Collectively, these findings demonstrate for the first time that multiple Notch signaling inputs are required to specify HSCs and that Notch3 performs a novel role within the somite to regulate the neighboring precursors of hemogenic endothelium. PMID:25230933

The Keap1/Nrf2 pathway in health and disease: from the bench to the clinic.

PubMed

O'Connell, Maria A; Hayes, John D

2015-08-01

The transcription factor nuclear factor-erythroid 2 p45-related factor 2 (Nrf2, with gene called NFE2L2) is a master regulator of the antioxidant response. In the last decade, interest has intensified in this research area as its importance in several physiological and pathological processes has become widely recognized; these include redox signalling and redox homoeostasis, drug metabolism and disposition, intermediary metabolism, cellular adaptation to stress, chemoprevention and chemoresistance, toxicity, inflammation, neurodegeneration, lipogenesis and aging. Regulation of Nrf2 is complex and although much attention has focussed on its repression by Kelch-like ECH-associated protein-1 (Keap1), recently it has become increasingly apparent that it is also controlled by cross-talk with other signalling pathways including the glycogen synthase kinase-3 (GSK-3)-β-transducin repeat-containing protein (β-TrCP) axis, ERAD (endoplasmic reticulum-associated degradation)-associated E3 ubiquitin-protein ligase (Hrd1, also called synoviolin), nuclear factor-kappa B (NF-κB), Notch and AMP kinase. Due to its beneficial role in several diseases, Nrf2 has become a major therapeutic target, with novel natural, synthetic and targeted small molecules currently under investigation to modulate the pathway and in clinical trials. © 2015 Authors; published by Portland Press Limited.

COMBINED ENDOCRINE EFFECTS OF IN UTERO EXPOSURE TO THE ANTIANDROGENS BUTYLBENZYL PHTHALATE (BBP) AND LINURON (LIN) ON FETAL TESTOSTERONE (T) SYNTHESIS AND REPRODUCTIVE TRACT DEVELOPMENT

EPA Science Inventory

COMBINED ENDOCRINE EFFECTS OF IN UTERO EXPOSURE TO THE ANTIANDROGENS BUTYLBENZYL PHTHALATE (BBP) AND LINURON (Lin) ON FETAL TESTOSTERONE (T) SYNTHESIS AND REPRODUCTIVE TRACT DEVELOPMENT
Parks LG , Hotchkiss AK, Ostby J, Lambright C and Gray LE, Jr.

Lin and BBP are toxic...

Beta-cyclodextrin enhanced gastroprotective effect of (-)-linalool, a monoterpene present in rosewood essential oil, in gastric lesion models.

PubMed

da Silva, Francilene Vieira; de Barros Fernandes, Hélio; Oliveira, Irisdalva Sousa; Viana, Ana Flávia Seraine Custódio; da Costa, Douglas Soares; Lopes, Miriam Teresa Paz; de Lira, Kamila Lopes; Quintans-Júnior, Lucindo José; de Sousa, Adriano Antunes; de Cássia Meneses Oliveira, Rita

2016-11-01

(-)-Linalool is a monoterpene constituent of many essential oils. This particular monoterpene has both anti-inflammatory and antimicrobial activity. Moreover, this compound has been shown to be antinociceptive. However, the poor chemical stability and short half-life prevents the clinical application of (-)-linalool and many other essential oils. Important to the topic of this study, β-cyclodextrin (β-CD) has been used to increase the solubility, stability, and pharmacological effects of numerous lipophilic compounds in vivo. In this study, the gastroprotective activities of (-)-linalool (LIN) and linalool incorporated into inclusion complex containing β-cyclodextrin (LIN-βCD) were evaluated using models of acute and chronic gastric ulcers in rodents. LIN and LIN-βCD showed strong gastroprotective activity (p < 0.001). The LIN-βCD complex revealed that the gastroprotective effect was significantly improved compared with LIN uncomplexed, suggesting that this improvement is related to increased solubility and stability. Taking together the potentiation of the antioxidant profile of this monoterpene, our results suggest that β-CD may represent an important tool for improved gastroprotective activity of (-)-linalool and other water-insoluble compounds.

Clinical application of Lin's biopsy grasper for intrauterine targeted biopsy and polypectomy during office hysteroscopy.

PubMed

Cheng, Hsin-Yi; Lin, Bao-Liang; Tseng, Jen-Yu; Ueno, Kazunori; Nakada, Sakura

2018-06-01

Hysteroscopy has widely been used for diagnosis of the uterine cavity; however, target biopsy has often been difficult in part to the inherent limitations of ancillary instruments. Lin's biopsy grasper was specifically designed to work in conjunction with a flexible hysteroscope to obtain intrauterine biopsy under transabdominal sonography. Herein, we share our clinical experience in the management of endometrial abnormalities with the use of Lin's biopsy grasper during office-based hysteroscopy. From February 2006 to November 2016, the use of Lin's biopsy grasper for tissue biopsy was attempted on 126 cases. We retrospectively recorded and analyzed the patients' preoperative characteristics and biopsy outcomes to demonstrate the feasibility and efficacy of Lin's biopsy grasper. Out of the one hundred and twenty-six enrolled patients, satisfactory targeted biopsies were achieved; including high diagnostic rate (92.1%, with 116 cases confirmed histologically) and adequate tissue retrieval (77.8%, with 98 cases obtaining optimal specimen volume). All patients tolerated the procedure without analgesics or anesthesia. Diagnostic flexible hysteroscopy combined with the use of Lin's biopsy grasper has proven to be an effective tool for intrauterine evaluation and obtaining tissue sample. Copyright © 2018. Published by Elsevier B.V.

Transmembrane protein MIG-13 links the Wnt signaling and Hox genes to the cell polarity in neuronal migration

PubMed Central

Wang, Xiangming; Zhou, Fanli; Lv, Sijing; Yi, Peishan; Zhu, Zhiwen; Yang, Yihong; Feng, Guoxin; Li, Wei; Ou, Guangshuo

2013-01-01

Directional cell migration is a fundamental process in neural development. In Caenorhabditis elegans, Q neuroblasts on the left (QL) and right (QR) sides of the animal generate cells that migrate in opposite directions along the anteroposterior body axis. The homeobox (Hox) gene lin-39 promotes the anterior migration of QR descendants (QR.x), whereas the canonical Wnt signaling pathway activates another Hox gene, mab-5, to ensure the QL descendants’ (QL.x) posterior migration. However, the regulatory targets of LIN-39 and MAB-5 remain elusive. Here, we showed that MIG-13, an evolutionarily conserved transmembrane protein, cell-autonomously regulates the asymmetric distribution of the actin cytoskeleton in the leading migratory edge. We identified mig-13 as a cellular target of LIN-39 and MAB-5. LIN-39 establishes QR.x anterior polarity by binding to the mig-13 promoter and promoting mig-13 expression, whereas MAB-5 inhibits QL.x anterior polarity by associating with the lin-39 promoter and downregulating lin-39 and mig-13 expression. Thus, MIG-13 links the Wnt signaling and Hox genes that guide migrations, to the actin cytoskeleton, which executes the motility response in neuronal migration. PMID:23784779

Drosophila Lin-52 Acts in Opposition to Repressive Components of the Myb-MuvB/dREAM Complex

PubMed Central

Lewis, Peter W.; Sahoo, Debashis; Geng, Cuiyun; Bell, Maren

2012-01-01

The Drosophila melanogaster Myb-MuvB/dREAM complex (MMB/dREAM) participates in both the activation and repression of developmentally regulated genes and origins of DNA replication. Mutants in MMB subunits exhibit diverse phenotypes, including lethality, eye defects, reduced fecundity, and sterility. Here, we used P-element excision to generate mutations in lin-52, which encodes the smallest subunit of the MMB/dREAM complex. lin-52 is required for viability, as null mutants die prior to pupariation. The generation of somatic and germ line mutant clones indicates that lin-52 is required for adult eye development and for early embryogenesis via maternal effects. Interestingly, the maternal-effect embryonic lethality, larval lethality, and adult eye defects could be suppressed by mutations in other subunits of the MMB/dREAM complex. These results suggest that a partial MMB/dREAM complex is responsible for the lethality and eye defects of lin-52 mutants. Furthermore, these findings support a model in which the Lin-52 and Myb proteins counteract the repressive activities of the other members of the MMB/dREAM complex at specific genomic loci in a developmentally controlled manner. PMID:22688510

Stress Survival Islet 2, Predominantly Present in Listeria monocytogenes Strains of Sequence Type 121, Is Involved in the Alkaline and Oxidative Stress Responses

PubMed Central

Harter, Eva; Wagner, Eva Maria; Zaiser, Andreas; Halecker, Sabrina; Wagner, Martin

2017-01-01

ABSTRACT The foodborne pathogen Listeria monocytogenes is able to survive a variety of stress conditions leading to the colonization of different niches like the food processing environment. This study focuses on the hypervariable genetic hot spot lmo0443 to lmo0449 haboring three inserts: the stress survival islet 1 (SSI-1), the single-gene insert LMOf2365_0481, and two homologous genes of the nonpathogenic species Listeria innocua: lin0464, coding for a putative transcriptional regulator, and lin0465, encoding an intracellular PfpI protease. Our prevalence study revealed a different distribution of the inserts between human and food-associated isolates. The lin0464-lin0465 insert was predominantly found in food-associated strains of sequence type 121 (ST121). Functional characterization of this insert showed that the putative PfpI protease Lin0465 is involved in alkaline and oxidative stress responses but not in acidic, gastric, heat, cold, osmotic, and antibiotic stresses. In parallel, deletion of lin0464 decreased survival under alkaline and oxidative stresses. The expression of both genes increased significantly under oxidative stress conditions independently of the alternative sigma factor σB. Furthermore, we showed that the expression of the protease gene lin0465 is regulated by the transcription factor lin0464 under stress conditions, suggesting that lin0464 and lin0465 form a functional unit. In conclusion, we identified a novel stress survival islet 2 (SSI-2), predominantly present in L. monocytogenes ST121 strains, beneficial for survival under alkaline and oxidative stresses, potentially supporting adaptation and persistence of L. monocytogenes in food processing environments. IMPORTANCE Listeria monocytogenes strains of ST121 are known to persist for months and even years in food processing environments, thereby increasing the risk of food contamination and listeriosis. However, the molecular mechanism underlying this remarkable niche-specific adaptation is still unknown. Here, we demonstrate that the genomic islet SSI-2, predominantly present in L. monocytogenes ST121 strains, is beneficial for survival under alkaline and oxidative stress conditions, which are routinely encountered in food processing environments. Our findings suggest that SSI-2 is part of a diverse set of molecular determinants contributing to niche-specific adaptation and persistence of L. monocytogenes ST121 strains in food processing environments. PMID:28625982

Stress Survival Islet 2, Predominantly Present in Listeria monocytogenes Strains of Sequence Type 121, Is Involved in the Alkaline and Oxidative Stress Responses.

PubMed

Harter, Eva; Wagner, Eva Maria; Zaiser, Andreas; Halecker, Sabrina; Wagner, Martin; Rychli, Kathrin

2017-08-15

The foodborne pathogen Listeria monocytogenes is able to survive a variety of stress conditions leading to the colonization of different niches like the food processing environment. This study focuses on the hypervariable genetic hot spot lmo0443 to lmo0449 haboring three inserts: the stress survival islet 1 (SSI-1), the single-gene insert LMOf2365_0481 , and two homologous genes of the nonpathogenic species Listeria innocua : lin0464 , coding for a putative transcriptional regulator, and lin0465 , encoding an intracellular PfpI protease. Our prevalence study revealed a different distribution of the inserts between human and food-associated isolates. The lin0464-lin0465 insert was predominantly found in food-associated strains of sequence type 121 (ST121). Functional characterization of this insert showed that the putative PfpI protease Lin0465 is involved in alkaline and oxidative stress responses but not in acidic, gastric, heat, cold, osmotic, and antibiotic stresses. In parallel, deletion of lin0464 decreased survival under alkaline and oxidative stresses. The expression of both genes increased significantly under oxidative stress conditions independently of the alternative sigma factor σ B Furthermore, we showed that the expression of the protease gene lin0465 is regulated by the transcription factor lin0464 under stress conditions, suggesting that lin0464 and lin0465 form a functional unit. In conclusion, we identified a novel stress survival islet 2 (SSI-2), predominantly present in L. monocytogenes ST121 strains, beneficial for survival under alkaline and oxidative stresses, potentially supporting adaptation and persistence of L. monocytogenes in food processing environments. IMPORTANCE Listeria monocytogenes strains of ST121 are known to persist for months and even years in food processing environments, thereby increasing the risk of food contamination and listeriosis. However, the molecular mechanism underlying this remarkable niche-specific adaptation is still unknown. Here, we demonstrate that the genomic islet SSI-2, predominantly present in L. monocytogenes ST121 strains, is beneficial for survival under alkaline and oxidative stress conditions, which are routinely encountered in food processing environments. Our findings suggest that SSI-2 is part of a diverse set of molecular determinants contributing to niche-specific adaptation and persistence of L. monocytogenes ST121 strains in food processing environments. Copyright © 2017 Harter et al.

The Challenge of Targeting Notch in Hematologic Malignancies

PubMed Central

Hernandez Tejada, Fiorela N.; Galvez Silva, Jorge R.; Zweidler-McKay, Patrick A.

2014-01-01

Notch signaling can play oncogenic and tumor suppressor roles depending on cell type. Hematologic malignancies encompass a wide range of transformed cells, and consequently the roles of Notch are diverse in these diseases. For example Notch is a potent T-cell oncogene, with >50% of T-cell acute lymphoblastic leukemia (T-ALL) cases carry activating mutations in the Notch1 receptor. Targeting Notch signaling in T-ALL with gamma-secretase inhibitors, which prevent Notch receptor activation, has shown pre-clinical activity, and is under evaluation clinically. In contrast, Notch signaling inhibits acute myeloblastic leukemia growth and survival, and although targeting Notch signaling in AML with Notch activators appears to have pre-clinical activity, no Notch agonists are clinically available at this time. As such, despite accumulating evidence about the biology of Notch signaling in different hematologic cancers, which provide compelling clinical promise, we are only beginning to target this pathway clinically, either on or off. In this review, we will summarize the evidence for oncogenic and tumor suppressor roles of Notch in a wide range of leukemias and lymphomas, and describe therapeutic opportunities for now and the future. PMID:24959528

The archetypal R90C CADASIL-NOTCH3 mutation retains NOTCH3 function in vivo.

PubMed

Monet, Marie; Domenga, Valérie; Lemaire, Barbara; Souilhol, Céline; Langa, Francina; Babinet, Charles; Gridley, Thomas; Tournier-Lasserve, Elisabeth; Cohen-Tannoudji, Michel; Joutel, Anne

2007-04-15

Cerebral Autosomal Dominant Arteriopathy with Subcortical infarcts and Leukoencephalopathy (CADASIL) is the most prominent known cause of inherited stroke and vascular dementia in human adult. The disease gene, NOTCH3, encodes a transmembrane receptor primarily expressed in arterial smooth muscle cells (SMC). Pathogenic mutations lead to an odd number of cysteine residues within the NOTCH3 extracellular domain (NOTCH3(ECD)), and are associated with progressive accumulation of NOTCH3(ECD) at the SMC plasma membrane. The murine homolog, Notch3, is dispensable for viability but required post-natally for the elaboration and maintenance of arteries. How CADASIL-associated mutations impact NOTCH3 function remains a fundamental, yet unresolved issue. Particularly, whether NOTCH3(ECD) accumulation may titrate the ligand and inhibit the normal pathway is unknown. Herein, using genetic analyses in the mouse, we assessed the functional significance of an archetypal CADASIL-associated mutation (R90C), in vivo, in brain arteries. We show that transgenic mouse lines expressing either the wild-type human NOTCH3 or the mutant R90C human NOTCH3, at comparable and physiological levels, can rescue the arterial defects of Notch3-/- mice to similar degrees. In vivo assessment of NOTCH3/RBP-Jk activity provides evidence that the mutant NOTCH3 protein exhibits normal level of activity in brain arteries. Remarkably, the mutant NOTCH3 protein remains functional and does not exhibit dominant negative interfering activity, even when NOTCH3(ECD) accumulates. Collectively, these data suggest a model that invokes novel pathogenic roles for the mutant NOTCH3 protein rather than compromised NOTCH3 function as the primary determinant of the CADASIL arteriopathy.

An Antibody to Notch2 Reverses the Osteopenic Phenotype of Hajdu-Cheney Mutant Male Mice

PubMed Central

Sanjay, Archana; Yu, Jungeun; Zanotti, Stefano

2017-01-01

Notch receptors play a central role in skeletal development and bone remodeling. Hajdu-Cheney syndrome (HCS), a disease characterized by osteoporosis and fractures, is associated with gain-of-NOTCH2 function mutations. To study HCS, we created a mouse model harboring a point 6955C>T mutation in the Notch2 locus upstream of the proline, glutamic acid, serine, and threonine domain, leading to a Q2319X change at the amino acid level. Notch2Q2319X heterozygous mutants exhibited cancellous and cortical bone osteopenia. Microcomputed tomography demonstrated that the cancellous and cortical osteopenic phenotype was reversed by the administration of antibodies generated against the negative regulatory region (NRR) of Notch2, previously shown to neutralize Notch2 activity. Bone histomorphometry revealed that anti-Notch2 NRR antibodies decreased the osteoclast number and eroded surface in cancellous bone of Notch2Q2319X mice. An increase in osteoclasts on the endocortical surface of Notch2Q2319X mice was not observed in the presence of anti-Notch2 NRR antibodies. The anti-Notch2 NRR antibody decreased the induction of Notch target genes and Tnfsf11 messenger RNA levels in bone extracts and osteoblasts from Notch2Q2319X mice. In vitro experiments demonstrated increased osteoclastogenesis in Notch2Q2319X mutants in response to macrophage colony-stimulating factor and receptor activator of nuclear factor–κB ligand, and these effects were suppressed by the anti-Notch2 NRR. In conclusion, Notch2Q2319X mice exhibit cancellous and cortical bone osteopenia that can be corrected by the administration of anti-Notch2 NRR antibodies. PMID:28323963

Whistlers observed outside the plasmasphere: Correlation to plasmaspheric/plasmapause features

NASA Astrophysics Data System (ADS)

Adrian, M. L.; Fung, S. F.; Gallagher, D. L.; Green, J. L.

2015-09-01

Whistlers observed outside the plasmasphere by Cluster have been correlated with the global plasmasphere using Imager for Magnetopause-to-Aurora Global Exploration-Extreme Ultraviolet Imager (IMAGE-EUV) observations. Of the 12 Cluster-observed whistler events reported, EUV is able to provide global imaging of the plasmasphere for every event and demonstrates a direct correlation between the detection of lightning-generated whistlers beyond the plasmapause and the presence of a global perturbation of the local plasmapause. Of these 12 correlated events, seven of the Cluster-observed whistlers (or 58%) are associated with the Cluster spacecraft lying radially outward from a plasmaspheric notch. Two of the Cluster-observed whistlers (17%) are associated with the low-density region between the late afternoon plasmapause and the western wall of a plasmaspheric drainage plume. The final three Cluster-observed whistler events (25%) are associated with a nonradial, nonazimuthal depletion in plasmaspheric He+ emission that are termed "notch-like" crenulations. In one of these cases, the notch-like crenulations appear to be manifestations entrained within the plasmasphere boundary layer of a standing wave on the surface of the plasmasphere. The correlated Cluster/IMAGE-EUV observations suggest that the depleted flux tubes that connect the ionosphere to the low-density regions of plasmaspheric trough and inner magnetosphere facilitate the escape of whistler waves from the plasmasphere.

CONNECTIVE TISSUE GROWTH FACTOR IS A TARGET OF NOTCH SIGNALING IN CELLS OF THE OSTEOBLASTIC LINEAGE

PubMed Central

Canalis, Ernesto; Zanotti, Stefano; Smerdel-Ramoya, Anna

2014-01-01

Connective tissue growth factor (Ctgf) or CCN2 is a protein synthesized by osteoblasts necessary for skeletal homeostasis, although its overexpression inhibits osteogenic signals and bone formation. Ctgf is induced by bone morphogenetic proteins, transforming growth factor β and Wnt; and in the present studies, we explored whether Notch regulated Ctgf expression in osteoblasts. We employed RosaNotch mice, where the Notch intracellular domain (NICD) is expressed following the excision of a STOP cassette, placed between the Rosa26 promoter and NICD. Notch was activated by transduction of adenoviral vectors expressing Cre recombinase (Ad-CMV-Cre). Notch induced Ctgf mRNA levels in a time dependent manner and increased Ctgf heterogeneous nuclear RNA. Notch also destabilized Ctgf mRNA shortening its half-life from 13 h to 3 h. The effect of Notch on Ctgf expression was lost following Rbpjκ downregulation, demonstrating that it was mediated by Notch canonical signaling. However, downregulation of the classic Notch target genes Hes1, Hey1 and Hey2 did not modify the effect of Notch on Ctgf expression. Wild type osteoblasts exposed to immobilized Delta-like 1 displayed enhanced Notch signaling and increased Ctgf expression. In addition to the effects of Notch in vitro, Notch induced Ctgf in vivo, and calvariae and femurs from RosaNotch mice mated with transgenics expressing the Cre recombinase in cells of the osteoblastic lineage exhibited increased expression of Ctgf. In conclusion, Ctgf is a target of Notch canonical signaling in osteoblasts, and may act in concert with Notch to regulate skeletal homeostasis. PMID:24792956

Notch2 blockade enhances hematopoietic stem cell mobilization and homing.

PubMed

Wang, Weihuan; Yu, Shuiliang; Myers, Jay; Wang, Yiwei; Xin, William W; Albakri, Marwah; Xin, Alison W; Li, Ming; Huang, Alex Y; Xin, Wei; Siebel, Christian W; Lazarus, Hillard M; Zhou, Lan

2017-10-01

Despite use of newer approaches, some patients being considered for autologous hematopoietic cell transplantation (HCT) may only mobilize limited numbers of hematopoietic progenitor cells (HPCs) into blood, precluding use of the procedure, or being placed at increased risk of complications due to slow hematopoietic reconstitution. Developing more efficacious HPC mobilization regimens and strategies may enhance the mobilization process and improve patient outcome. Although Notch signaling is not essential for homeostasis of adult hematopoietic stem cells (HSCs), Notch-ligand adhesive interaction maintains HSC quiescence and niche retention. Using Notch receptor blocking antibodies, we report that Notch2 blockade, but not Notch1 blockade, sensitizes hematopoietic stem cells and progenitors (HSPCs) to mobilization stimuli and leads to enhanced egress from marrow to the periphery. Notch2 blockade leads to transient myeloid progenitor expansion without affecting HSC homeostasis and self-renewal. We show that transient Notch2 blockade or Notch2-loss in mice lacking Notch2 receptor lead to decreased CXCR4 expression by HSC but increased cell cycling with CXCR4 transcription being directly regulated by the Notch transcriptional protein RBPJ. In addition, we found that Notch2-blocked or Notch2-deficient marrow HSPCs show an increased homing to the marrow, while mobilized Notch2-blocked, but not Notch2-deficient stem cells and progenitors, displayed a competitive repopulating advantage and enhanced hematopoietic reconstitution. These findings suggest that blocking Notch2 combined with the current clinical regimen may further enhance HPC mobilization and improve engraftment during HCT. Copyright© 2017 Ferrata Storti Foundation.

Cigarette smoke induces the expression of Notch3, not Notch1, protein in lung adenocarcinoma.

PubMed

Cheng, Zhenshun; Tan, Qiuyue; Tan, Weijun; Zhang, L I

2015-08-01

The aim of the present study was to determine the effect of cigarette smoke on the expression of Notch proteins in lung adenocarcinoma (LAC). Protein expression levels of Notch1 and Notch3 were analyzed using immunohistochemistry in 102 human LAC specimens. Of these, 52 were obtained from smokers and 50 from non-smokers. In addition, cigarette smoke extract (CSE) at varying concentrations (1, 2.5 and 5%) was administered to A549 cells. The expression of Notch1 and Notch3 protein was then detected by western blot analysis at different time points (0, 8, 24 and 48 h). Of the 102 LAC specimens, 42 (41.2%) were positive for Notch1 and 63 (61.8%) were positive for Notch3. There was no significant difference in the level of Notch1 expression between smokers and non-smokers with LAC (P>0.05). The positive rate and staining intensity of Notch3 expression were increased in the smokers compared with the non-smokers (P<0.05). The expression of Notch3 protein in A549 cells increased in a time- and dose-dependent manner following treatment with CSE, whilst the expression of Notch1 protein appeared stable. The results suggested that cigarette smoke was able to induce the expression of Notch3, not Notch1, protein in LAC. The data revealed an upregulation of Notch3 in LAC following cigarette smoke exposure. Such findings may provide a novel therapeutic target for the treatment of LAC.

Notch Inhibitors for Cancer Treatment

PubMed Central

Espinoza, Ingrid; Miele, Lucio

2013-01-01

Notch signaling is an evolutionarily conserved cell signaling pathway involved in cell fate during development, stem cell renewal and differentiation in postnatal tissues. Roles for Notch in carcinogenesis, in the biology of cancer stem cells and tumor angiogenesis have been reported. These features identify Notch as a potential therapeutic target in oncology. Based on the molecular structure of Notch receptor, Notch ligands and Notch activators, a set of Notch pathway inhibitors have been developed. Most of these inhibitors had shown anti-tumor effects in preclinical studies. At the same time, the combinatorial effect of these inhibitors with current chemotherapeutical drugs still under study in different clinical trials. In this review, we describe the basics of Notch signaling and the role of Notch in normal and cancer stem cells as a logic way to develop different Notch inhibitors and their current stage of progress for cancer patient’s treatment. PMID:23458608

Epithelial transformation by KLF4 requires Notch1 but not canonical Notch1 signaling

PubMed Central

Liu, Zhaoli; Teng, Lihong; Bailey, Sarah K.; Frost, Andra R.; Bland, Kirby I.; LoBuglio, Albert F.; Ruppert, J. Michael; Lobo-Ruppert, Susan M.

2009-01-01

The transcription factors Notch1 and KLF4 specify epithelial cell fates and confer stem cell properties. suggesting a functional relationship, each gene can act to promote or suppress tumorigenesis in a context-dependent manner, and alteration of KLF4 or Notch pathway genes in mice gives rise to similar phenotypes. Activation of a conditional allele of KLF4 in RK3E epithelial cells rapidly induces expression of Notch1 mRNA and the active, intracellular form of Notch1. KLF4-induced transformation was suppressed by knockdown of endogenous Notch1 using siRNA or an inhibitor of γ-secretase. Chromatin immunoprecipitation assay shows that KLF4 binds to the proximal Notch1 promoter in human mammary epithelial cells, and siRNA-mediated suppression of KLF4 in human mammary cancer cells results in reduced expression of Notch1. Furthermore, KLF4 and Notch1 expression are correlated in primary human breast tumors (N = 89; pearson analysis, r > 0.5, p < 0.0001). Like KLF4, Notch1 was previously shown to induce transformation of rat cells immortalized with adenovirus E1A, similar to RK3E cells. We therefore compared the signaling requirements for Notch1- or KLF4-induced malignant transformation of RK3E. As expected, transformation by Notch1 was suppressed by dominant-negative CSL or MaML1, inhibitors of canonical Notch1 signaling. However, these inhibitors did not suppress transformation by KLF4. Therefore, while KLF4-induced transformation requires Notch1, canonical Notch1 signaling is not required, and Notch1 may signal through a distinct pathway in cells with increased KLF4 activity. These results suggest that KLF4 could contribute to breast tumor progression by activating synthesis of Notch1 and by promoting signaling through a non-canonical Notch1 pathway. PMID:19717984

Histone deacetylase 6 controls Notch3 trafficking and degradation in T-cell acute lymphoblastic leukemia cells.

PubMed

Pinazza, Marica; Ghisi, Margherita; Minuzzo, Sonia; Agnusdei, Valentina; Fossati, Gianluca; Ciminale, Vincenzo; Pezzè, Laura; Ciribilli, Yari; Pilotto, Giorgia; Venturoli, Carolina; Amadori, Alberto; Indraccolo, Stefano

2018-04-12

Several studies have revealed that endosomal sorting controls the steady-state levels of Notch at the cell surface in normal cells and prevents its inappropriate activation in the absence of ligands. However, whether this highly dynamic physiologic process can be exploited to counteract dysregulated Notch signaling in cancer cells remains unknown. T-ALL is a malignancy characterized by aberrant Notch signaling, sustained by activating mutations in Notch1 as well as overexpression of Notch3, a Notch paralog physiologically subjected to lysosome-dependent degradation in human cancer cells. Here we show that treatment with the pan-HDAC inhibitor Trichostatin A (TSA) strongly decreases Notch3 full-length protein levels in T-ALL cell lines and primary human T-ALL cells xenografted in mice without substantially reducing NOTCH3 mRNA levels. Moreover, TSA markedly reduced the levels of Notch target genes, including pTα, CR2, and DTX-1, and induced apoptosis of T-ALL cells. We further observed that Notch3 was post-translationally regulated following TSA treatment, with reduced Notch3 surface levels and increased accumulation of Notch3 protein in the lysosomal compartment. Surface Notch3 levels were rescued by inhibition of dynein with ciliobrevin D. Pharmacologic studies with HDAC1, 6, and 8-specific inhibitors disclosed that these effects were largely due to inhibition of HDAC6 in T-ALL cells. HDAC6 silencing by specific shRNA was followed by reduced Notch3 expression and increased apoptosis of T-ALL cells. Finally, HDAC6 silencing impaired leukemia outgrowth in mice, associated with reduction of Notch3 full-length protein in vivo. These results connect HDAC6 activity to regulation of total and surface Notch3 levels and suggest HDAC6 as a potential novel therapeutic target to lower Notch signaling in T-ALL and other Notch3-addicted tumors.

Scapular Notching on Kinematic Simulated Range of Motion After Reverse Shoulder Arthroplasty Is Not the Result of Impingement in Adduction

PubMed Central

Lädermann, Alexandre; Gueorguiev, Boyko; Charbonnier, Caecilia; Stimec, Bojan V.; Fasel, Jean H.D.; Zderic, Ivan; Hagen, Jennifer; Walch, Gilles

2015-01-01

Abstract Impingement after reverse shoulder arthroplasty (RSA) is believed to occur from repetitive contact in adduction between the humeral component and the inferior scapular pillar. The primary purpose of this biomechanical study was to confirm the presence of different types of impingement and to examine which daily-life movements are responsible for them. A secondary aim was to provide recommendations on the type of components that would best minimize notching and loss of range of motion (ROM). The study included 12 fresh frozen shoulder specimens; each had a computed tomography (CT) image of the entire scapula and humerus in order to acquire topological information of the bones before RSA implantation. Cyclic tests were run postimplantation with 3 shoulders in each modalities. To quantify bone loss due to impingement, 3-dimensional anatomical models of the scapula were reconstructed from the CT scans and compared to their intact states. We found 8 bony impingements in 7 specimens: 2 at the lateral acromion, 1 at the inferior acromion, 4 scapular notching, and 1 with the glenoid resulting to wear at the 3:00 to 6:00 clock-face position. Impingements occurred in all kinds of tested motions, except for the internal/external rotation at 90° of abduction. The 3 specimens tested in abduction/adduction presented bone loss on the acromion side only. Scapular notching was noted in flexion/extension and in internal/external rotation at 0° of abduction. The humeral polyethylene liner was worn in 2 specimens—1 at the 6:00 to 8:00 clock-face position during internal/external rotation at 0° of abduction and 1 at the 4:00 clock-face position during flexion/extension. The present study revealed that 2 types of impingement interactions coexist and correspond to a frank abutment or lead to a scapular notching (friction-type impingement). Scapular notching seems to be caused by more movements or combination of movements than previously considered, and in particular by movements of flexion/extension and internal/external rotation with the arm at the side. Polyethylene cups with a notch between 3 and 9 o’clock and lower neck-shaft angle (145° or 135°) may play an important role in postoperative ROM limiting scapular notching. PMID:26402829

In-situ scanning electron microscope studies of crack growth in an aluminum metal-matrix composite

NASA Technical Reports Server (NTRS)

Manoharan, M.; Lewandowski, J. J.

1990-01-01

Edge-notched specimens of a cast and extruded Al alloy-based, alumina particulate-reinforced composite in the annealed condition were tested in situ in a SEM apparatus equipped with a deformation stage permitting the direct observation of crack growth phenomena. Fracture in this composite is seen to proceed by initiation of microcracks ahead of the macrocrack; as deformation proceeds, the microcracks lengthen, and crack propagation occurs when the region of intense plastic straining becomes comparable to the macrocrack-microcrack distance. The sequence is then repeated.

A critical role of Notch signaling in osteosarcoma invasion and metastasis

PubMed Central

Zhang, Pingyu; Yang, Yanwen; Zweidler-McKay, Patrick A.; Hughes, Dennis P.M.

2010-01-01

Purpose Notch signaling is an important mediator of growth and survival in several cancer types, with Notch pathway genes functioning as oncogenes or tumor suppressors in different cancers. However, the role of Notch in osteosarcoma is unknown. Experimental Design We assessed the expression of Notch pathway genes in human osteosarcoma cell lines and patient samples. We then employed pharmacologic and retroviral manipulation of the Notch pathway and studied the impact on osteosarcoma cell proliferation, survival, anchorage-independent growth, invasion and metastasis in vitro and in vivo. Results Notch pathway genes, including Notch ligand DLL1, Notch 1 and 2, and the Notch target gene HES1 were expressed in osteosarcoma cells, and expression of HES1 was associated with invasive and metastatic potential. Blockade of Notch pathway signaling with a small molecule inhibitor of gamma secretase eliminated invasion in matrigel without affecting cell proliferation, survival, or anchorage-independent growth. Manipulation of Notch and HES1 signaling demonstrated a crucial role for HES1 in osteosarcoma invasiveness and metastasis in vivo. Conclusion These studies identify a new invasion and metastasis-regulating pathway in osteosarcoma and define a novel function for the Notch pathway: regulation of metastasis. Since the Notch pathway can be inhibited pharmacologically, these findings point toward possible new treatments to reduce invasion and metastasis in osteosarcoma. PMID:18483362

An Analysis of Navy Nurse Corps Accession Sources

DTIC Science & Technology

2014-03-01

1 I. INTRODUCTION A. BACKGROUND Since 1998, the United States has experienced a nationwide nursing shortage (Juraschek, Zhang, Ranganathan ...supply of RNs in the civilian workforce (Juraschek, Zhang, Ranganathan , & Lin, 2012). A study by Juraschek, Zhang, Ranganathan , & Lin (2012...Postgraduate School, Monterey, CA. Retrieved from www.dtic.mil/cgi- bin/GetTRDoc?AD=ADA344570 Juraschek, S. P., Zhang, X., Ranganathan , V. K., & Lin, V

Notch Receptor Expression in Neurogenic Regions of the Adult Zebrafish Brain

PubMed Central

de Oliveira-Carlos, Vanessa; Ganz, Julia; Hans, Stefan; Kaslin, Jan; Brand, Michael

2013-01-01

The adult zebrash brain has a remarkable constitutive neurogenic capacity. The regulation and maintenance of its adult neurogenic niches are poorly understood. In mammals, Notch signaling is involved in stem cell maintenance both in embryonic and adult CNS. To better understand how Notch signaling is involved in stem cell maintenance during adult neurogenesis in zebrafish we analysed Notch receptor expression in five neurogenic zones of the adult zebrafish brain. Combining proliferation and glial markers we identified several subsets of Notch receptor expressing cells. We found that 90 of proliferating radial glia express notch1a, notch1b and notch3. In contrast, the proliferating non-glial populations of the dorsal telencephalon and hypothalamus rarely express notch3 and about half express notch1a/1b. In the non-proliferating radial glia notch3 is the predominant receptor throughout the brain. In the ventral telencephalon and in the mitotic area of the optic tectum, where cells have neuroepithelial properties, notch1a/1b/3 are expressed in most proliferating cells. However, in the cerebellar niche, although progenitors also have neuroepithelial properties, only notch1a/1b are expressed in a high number of PCNA cells. In this region notch3 expression is mostly in Bergmann glia and at low levels in few PCNA cells. Additionally, we found that in the proliferation zone of the ventral telencephalon, Notch receptors display an apical high to basal low gradient of expression. Notch receptors are also expressed in subpopulations of oligodendrocytes, neurons and endothelial cells. We suggest that the partial regional heterogeneity observed for Notch expression in progenitor cells might be related to the cellular diversity present in each of these neurogenic niches. PMID:24039926

Therapeutic antibody targeting of individual Notch receptors.

PubMed

Wu, Yan; Cain-Hom, Carol; Choy, Lisa; Hagenbeek, Thijs J; de Leon, Gladys P; Chen, Yongmei; Finkle, David; Venook, Rayna; Wu, Xiumin; Ridgway, John; Schahin-Reed, Dorreyah; Dow, Graham J; Shelton, Amy; Stawicki, Scott; Watts, Ryan J; Zhang, Jeff; Choy, Robert; Howard, Peter; Kadyk, Lisa; Yan, Minhong; Zha, Jiping; Callahan, Christopher A; Hymowitz, Sarah G; Siebel, Christian W

2010-04-15

The four receptors of the Notch family are widely expressed transmembrane proteins that function as key conduits through which mammalian cells communicate to regulate cell fate and growth. Ligand binding triggers a conformational change in the receptor negative regulatory region (NRR) that enables ADAM protease cleavage at a juxtamembrane site that otherwise lies buried within the quiescent NRR. Subsequent intramembrane proteolysis catalysed by the gamma-secretase complex liberates the intracellular domain (ICD) to initiate the downstream Notch transcriptional program. Aberrant signalling through each receptor has been linked to numerous diseases, particularly cancer, making the Notch pathway a compelling target for new drugs. Although gamma-secretase inhibitors (GSIs) have progressed into the clinic, GSIs fail to distinguish individual Notch receptors, inhibit other signalling pathways and cause intestinal toxicity, attributed to dual inhibition of Notch1 and 2 (ref. 11). To elucidate the discrete functions of Notch1 and Notch2 and develop clinically relevant inhibitors that reduce intestinal toxicity, we used phage display technology to generate highly specialized antibodies that specifically antagonize each receptor paralogue and yet cross-react with the human and mouse sequences, enabling the discrimination of Notch1 versus Notch2 function in human patients and rodent models. Our co-crystal structure shows that the inhibitory mechanism relies on stabilizing NRR quiescence. Selective blocking of Notch1 inhibits tumour growth in pre-clinical models through two mechanisms: inhibition of cancer cell growth and deregulation of angiogenesis. Whereas inhibition of Notch1 plus Notch2 causes severe intestinal toxicity, inhibition of either receptor alone reduces or avoids this effect, demonstrating a clear advantage over pan-Notch inhibitors. Our studies emphasize the value of paralogue-specific antagonists in dissecting the contributions of distinct Notch receptors to differentiation and disease and reveal the therapeutic promise in targeting Notch1 and Notch2 independently.

Notch2 and Notch3 suppress the proliferation and mediate invasion of trophoblast cell lines

PubMed Central

Zhao, Wei-Xiu; Wu, Zhen-Ming; Liu, Wei

2017-01-01

ABSTRACT Notch signaling pathways play important roles in cell fate and many diseases, including preeclampsia, the dysregulation of which may be the main cause of maternal mortality. This study aimed to investigate the roles of Notch2 and Notch3 in proliferation and invasion in trophoblast cell lines (BeWo and JAR). Small hairpin RNAs targeting Notch2/Notch3 and Notch2/Notch3-overexpression vectors were designed, constructed and transfected into BeWo and JAR cells. Quantitative real-time polymerase chain reaction (qRT-PCR) and western blotting were then used to detect Notch2 and Notch3 mRNA and protein levels, and confirm the efficiency of silence and overexpression. Flow cytometry assays were conducted to evaluate the cell cycle of the two cell lines, and transwell assays were used to detect migration and invasion. Western blot analysis was also performed to show the alteration of the cell lines' physiological activities at protein level. When Notch2 was downregulated in BeWo cells, proliferation was dramatically promoted, while migration and invasion were significantly inhibited. When Notch2 was upregulated in JAR cells, proliferation was inhibited, but migration and invasion were promoted. After overexpression of Notch3 in BeWo cells, proliferation was downregulated, but migration and invasion were both upregulated. By contrast, the silencing of Notch3 expression in JAR cells significantly enhanced proliferation, but suppressed migration and invasion. These data indicated that Notch2 and Notch3 mediate the invasion and migration of BeWo and JAR cells, and may play a potential role in early onset severe preeclampsia. PMID:28606936

Notch2 and Notch3 suppress the proliferation and mediate invasion of trophoblast cell lines.

PubMed

Zhao, Wei-Xiu; Wu, Zhen-Ming; Liu, Wei; Lin, Jian-Hua

2017-08-15

Notch signaling pathways play important roles in cell fate and many diseases, including preeclampsia, the dysregulation of which may be the main cause of maternal mortality. This study aimed to investigate the roles of Notch2 and Notch3 in proliferation and invasion in trophoblast cell lines (BeWo and JAR). Small hairpin RNAs targeting Notch2/Notch3 and Notch2/Notch3-overexpression vectors were designed, constructed and transfected into BeWo and JAR cells. Quantitative real-time polymerase chain reaction (qRT-PCR) and western blotting were then used to detect Notch2 and Notch3 mRNA and protein levels, and confirm the efficiency of silence and overexpression. Flow cytometry assays were conducted to evaluate the cell cycle of the two cell lines, and transwell assays were used to detect migration and invasion. Western blot analysis was also performed to show the alteration of the cell lines' physiological activities at protein level.When Notch2 was downregulated in BeWo cells, proliferation was dramatically promoted, while migration and invasion were significantly inhibited. When Notch2 was upregulated in JAR cells, proliferation was inhibited, but migration and invasion were promoted. After overexpression of Notch3 in BeWo cells, proliferation was downregulated, but migration and invasion were both upregulated. By contrast, the silencing of Notch3 expression in JAR cells significantly enhanced proliferation, but suppressed migration and invasion. These data indicated that Notch2 and Notch3 mediate the invasion and migration of BeWo and JAR cells, and may play a potential role in early onset severe preeclampsia. © 2017. Published by The Company of Biologists Ltd.

Transcription factor RBP-J-mediated signalling regulates basophil immunoregulatory function in mouse asthma model.

PubMed

Qu, Shuo-Yao; He, Ya-Long; Zhang, Jian; Wu, Chang-Gui

2017-09-01

Basophils (BA) play an important role in the promotion of aberrant T helper type 2 (Th2) immune responses in asthma. It is not only the effective cell, but also modulates the initiation of Th2 immune responses. We earlier demonstrated that Notch signalling regulates the biological function of BAin vitro. However, whether this pathway plays the same role in vivo is not clear. The purpose of the present study was to investigate the effect of Notch signalling on BA function in the regulation of allergic airway inflammation in a murine model of asthma. Bone marrow BA were prepared by bone marrow cell culture in the presence of recombinant interleukin-3 (rIL-3; 300 pg/ml) for 7 days, followed by isolation of the CD49b + microbeads. The recombination signal binding protein J (RBP-J -/- ) BA were co-cultured with T cells, and the supernatant and the T-cell subtypes were examined. The results indicated disruption of the capacity of BA for antigen presentation alongside an up-regulation of the immunoregulatory function. This was possibly due to the low expression of OX40L in the RBP-J -/- BA. Basophils were adoptively transferred to ovalbumin-sensitized recipient mice, to establish an asthma model. Lung pathology, cytokine profiles of brobchoalveolar fluid, airway hyperactivity and the absolute number of Th1/Th2 cells in lungs were determined. Overall, our results indicate that the RBP-J-mediated Notch signalling is critical for BA-dependent immunoregulation. Deficiency of RBP-J influences the immunoregulatory functions of BA, which include activation of T cells and their differentiation into T helper cell subtypes. The Notch signalling pathway is a potential therapeutic target for BA-based immunotherapy against asthma. © 2017 John Wiley & Sons Ltd.

Sertoli Cell Wt1 Regulates Peritubular Myoid Cell and Fetal Leydig Cell Differentiation during Fetal Testis Development.

PubMed

Wen, Qing; Wang, Yuqian; Tang, Jixin; Cheng, C Yan; Liu, Yi-Xun

2016-01-01

Sertoli cells play a significant role in regulating fetal testis compartmentalization to generate testis cords and interstitium during development. The Sertoli cell Wilms' tumor 1 (Wt1) gene, which encodes ~24 zinc finger-containing transcription factors, is known to play a crucial role in fetal testis cord assembly and maintenance. However, whether Wt1 regulates fetal testis compartmentalization by modulating the development of peritubular myoid cells (PMCs) and/or fetal Leydig cells (FLCs) remains unknown. Using a Wt1-/flox; Amh-Cre mouse model by deleting Wt1 in Sertoli cells (Wt1SC-cKO) at embryonic day 14.5 (E14.5), Wt1 was found to regulate PMC and FLC development. Wt1 deletion in fetal testis Sertoli cells caused aberrant differentiation and proliferation of PMCs, FLCs and interstitial progenitor cells from embryo to newborn, leading to abnormal fetal testis interstitial development. Specifically, the expression of PMC marker genes α-Sma, Myh11 and Des, and interstitial progenitor cell marker gene Vcam1 were down-regulated, whereas FLC marker genes StAR, Cyp11a1, Cyp17a1 and Hsd3b1 were up-regulated, in neonatal Wt1SC-cKO testes. The ratio of PMC:FLC were also reduced in Wt1SC-cKO testes, concomitant with a down-regulation of Notch signaling molecules Jag 1, Notch 2, Notch 3, and Hes1 in neonatal Wt1SC-cKO testes, illustrating changes in the differentiation status of FLC from their interstitial progenitor cells during fetal testis development. In summary, Wt1 regulates the development of FLC and interstitial progenitor cell lineages through Notch signaling, and it also plays a role in PMC development. Collectively, these effects confer fetal testis compartmentalization.

The Role of Notch3 in Cancer.

PubMed

Aburjania, Zviadi; Jang, Samuel; Whitt, Jason; Jaskula-Stzul, Renata; Chen, Herbert; Rose, J Bart

2018-04-05

The Notch family is a highly conserved gene group that regulates cell-cell interaction, embryogenesis, and tissue commitment. This review article focuses on the third Notch family subtype, Notch3. Regulation via Notch3 signaling was first implicated in vasculogenesis. However, more recent findings suggest that Notch3 signaling may play an important role in oncogenesis, tumor maintenance, and resistance to chemotherapy. Its role is mainly oncogenic, although in some cancers it appears to be tumor suppressive. Despite the wealth of published literature, it remains relatively underexplored and requires further research to shed more light on its role in cancer development, determine its tissue-specific function, and elaborate novel treatment strategies. Herein we summarize the role of Notch3 in cancer, possible mechanisms of its action, and current cancer treatment strategies targeting Notch3 signaling. The Notch family is a highly conserved gene group that regulates cell-cell interaction, embryogenesis, and tissue commitment. This review summarizes the existing data on the third subtype of the Notch family, Notch3. The role of Notch3 in different types of cancers is discussed, as well as implications of its modification and new strategies to affect Notch3 signaling activity. © AlphaMed Press 2018.

Accumulate Repeat Accumulate Coded Modulation

NASA Technical Reports Server (NTRS)

Abbasfar, Aliazam; Divsalar, Dariush; Yao, Kung

2004-01-01

In this paper we propose an innovative coded modulation scheme called 'Accumulate Repeat Accumulate Coded Modulation' (ARA coded modulation). This class of codes can be viewed as serial turbo-like codes, or as a subclass of Low Density Parity Check (LDPC) codes that are combined with high level modulation. Thus at the decoder belief propagation can be used for iterative decoding of ARA coded modulation on a graph, provided a demapper transforms the received in-phase and quadrature samples to reliability of the bits.

NOTCH1 and FBXW7 mutations have a favorable impact on early response to treatment, but not on outcome, in children with T-cell acute lymphoblastic leukemia (T-ALL) treated on EORTC trials 58881 and 58951.

PubMed

Clappier, E; Collette, S; Grardel, N; Girard, S; Suarez, L; Brunie, G; Kaltenbach, S; Yakouben, K; Mazingue, F; Robert, A; Boutard, P; Plantaz, D; Rohrlich, P; van Vlierberghe, P; Preudhomme, C; Otten, J; Speleman, F; Dastugue, N; Suciu, S; Benoit, Y; Bertrand, Y; Cavé, H

2010-12-01

Risk-adjusted treatment stratification in T-cell acute lymphoblastic leukemias (T-ALLs) is currently based only on early response to chemotherapy. We investigated the prognostic implication of hyperactivation of NOTCH pathway resulting from mutations of NOTCH1 or FBXW7 in children with T-ALL enrolled in EORTC-CLG trials. Overall, 80 out of 134 (60%) patients were NOTCH+ (NOTCH1 and/or FBXW7 mutated). Although clinical presentations were not significantly associated with NOTCH status, NOTCH+ patients showed a better early response to chemotherapy as compared with NOTCH- patients, according to the rate of poor pre-phase 'responders' (25% versus 44%; P=0.02) and the incidence of high minimal residual disease (MRD) levels (11% (7/62) versus 32% (10/31); P=0.01) at completion of induction. However, the outcome of NOTCH+ patients was similar to that of NOTCH- patients, with a 5-year event-free survival (EFS) of 73% and 70% (P=0.82), and 5-year overall survival of 82% and 79% (P=0.62), respectively. In patients with high MRD levels, the 5-year EFS rate was 0% (NOTCH+) versus 42% (NOTCH-), whereas in those with low MRD levels, the outcome was similar: 76% (NOTCH+) versus 78% (NOTCH-). The incidence of isolated central nervous system (CNS) relapses was relatively high in NOTCH1+ patients (8.3%), which could be related to a higher propensity of NOTCH+ leukemic blasts to target the CNS.

Correlation of ALDH1 and Notch3 Expression: Clinical implication in Ovarian Carcinomas.

PubMed

Kim, Mi Joung; Kim, A-Ram; Jeong, Ju-Yeon; Kim, Kwang-Il; Kim, Tae-Heon; Lee, Chan; Chung, Kwanghoe; Ko, Young-Hyeh; An, Hee-Jung

2017-01-01

Purpose : ALDH1 is a putative cancer stem cell marker, while the Notch signaling pathway is involved in regulation of cancer stem cell (CSC)s. This study aims to determine the expression of Notch signaling genes in ovarian CSCs, and to assess the clinical impact of expression of ALDH1 and Notch signaling genes in ovarian cancers. Methods : We examined expression of Notch signaling genes in FACS-sorted ALDH1(+) putative ovarian CSCs and expression of ALDH1 and Notch signaling genes in 86 ovarian epithelial tumors and various ovarian cancer cell lines by real-time RT-PCR, including Notch receptors ( Notch1-4 ), Notch ligands ( Jagged1 and Jagged2 ), and the downstream molecule, Hes1 . Furthermore, we correlated their expression with clinicopathological parameters and patient's survival in ovarian serous carcinoma (OSC)s, the most prevalent type of ovarian cancer. Results : The higher expression levels of ALDH1 and Notch related genes, especially Notch3 were associated with CSCs and with chemoresistant OSCs and paclitaxel-resistant SKpac ovarian cancer cells. Among the Notch signaling genes, high Notch3 expression was significantly associated with all the parameters of poor prognosis, i.e., advanced stage, lymph node and distant metastases, and chemoresistance, whereas other genes were less correlated with these parameters. A combined upregulation of ALDH1 and Notch3 was an independent poor prognostic factor in OSCs. Conclusions : ALDH1 correlates with Notch3 expression in ovarian carcinomas. ALDH1 and Notch3 overexpression is an independent poor prognostic indicator for worse patient's survival in this subset of OSCs.

Multi-Objective Optimization for Trustworthy Tactical Networks: A Survey and Insights

DTIC Science & Technology

2013-06-01

existing data sources, gathering and maintaining the data needed , and completing and reviewing the collection of information. Send comments regarding...problems: using repeated cooperative games [12], hedonic games [25], and nontransferable utility cooperative games [27]. It should be noted that trust...examined an optimal task allocation problem in a distributed computing system where program modules need to be allocated to different processors to

A kinetic formulation of piezoresistance in N-type silicon: Application to non-linear effects

NASA Astrophysics Data System (ADS)

Charbonnieras, A. R.; Tellier, C. R.

1999-07-01

This paper is devoted to the theoretical study of the influence of the temperature and of the doping on the piezoresistance of N-type silicon. In the first step the fractional change in the resistivity caused by stresses is calculated in the framework of a multivalley model using a kinetic transport formulation based on the Boltzmann transport equation. In the second step shifts in the minima of the conduction band and the resulting shift of the Fermi level are expressed in terms of deformation potentials and of stresses. General expressions for the fundamental linear, π_{11} and π_{12}, and non-linear, π_{111}, π_{112}, π_{122} and π_{123}, piezoresistance coefficients are then derived. Plots of the non-linear piezoresistance coefficients against the reduced shift of the Fermi level or against temperature allow us to characterize the influence of doping and temperature. Finally some attempts are made to estimate the non-linearity for heavily doped semiconductor gauges. Cette publication est consacrée à l'étude théorique de l'influence de la température et du dopage sur la piezorésistivité du silicium type N. Dans une première étape nous adoptons le modèle de vallées et nous utilisons une formulation cinétique du transport électronique faisant appel à l'équation de transport de Boltzmann pour calculer la variation de la résistivité du semiconducteur sous contrainte. Dans la deuxième étape nous exprimons les déplacements des minima de la bande de conduction et du niveau de Fermi en termes de potentiels de déformation et de contraintes. Nous proposons ensuite des expressions générales pour les coefficients piezorésistifs fondamentaux linéaires, π_{11} et π_{12}, et non-linéaires, π_{111}, π_{112}, π_{122} et π_{123}. Des représentations graphiques des variations des coefficients non-linéaires permettent de caractériser l'influence du dopage et de la température. Enfin nous fournissons une première pré-estimation des effets non-linéaires pour des jauges en silicium N dégénéré.

Identification of molecular species of polyol oils produced from soybean oil by Pseudomonas aeruginosa e03-12 nrrl b-59991

USDA-ARS?s Scientific Manuscript database

The objective of this study is to develop a bioprocess for the production of polyol oils directly from soybean oil. We reported earlier methods for microbial screening and production of polyol oils from soybean oil (Hou and Lin, 2013). The polyol oil produced by Acinetobacter haemolyticus A01-35 (NR...

Deficiency of Suppressor Enhancer Lin12 1 Like (SEL1L) in Mice Leads to Systemic Endoplasmic Reticulum Stress and Embryonic Lethality*

PubMed Central

Francisco, Adam B.; Singh, Rajni; Li, Shuai; Vani, Anish K.; Yang, Liu; Munroe, Robert J.; Diaferia, Giuseppe; Cardano, Marina; Biunno, Ida; Qi, Ling; Schimenti, John C.; Long, Qiaoming

2010-01-01

Stress in the endoplasmic reticulum (ER) plays an important causal role in the pathogenesis of several chronic diseases such as Alzheimer, Parkinson, and diabetes mellitus. Insight into the genetic determinants responsible for ER homeostasis will greatly facilitate the development of therapeutic strategies for the treatment of these debilitating diseases. Suppressor enhancer Lin12 1 like (SEL1L) is an ER membrane protein and was thought to be involved in the quality control of secreted proteins. Here we show that the mice homozygous mutant for SEL1L were embryonic lethal. Electron microscopy studies revealed a severely dilated ER in the fetal liver of mutant embryos, indicative of alteration in ER homeostasis. Consistent with this, several ER stress responsive genes were significantly up-regulated in the mutant embryos. Mouse embryonic fibroblast cells deficient in SEL1L exhibited activated unfolded protein response at the basal state, impaired ER-associated protein degradation, and reduced protein secretion. Furthermore, markedly increased apoptosis was observed in the forebrain and dorsal root ganglions of mutant embryos. Taken together, our results demonstrate an essential role for SEL1L in protein quality control during mouse embryonic development. PMID:20197277

Deficiency of suppressor enhancer Lin12 1 like (SEL1L) in mice leads to systemic endoplasmic reticulum stress and embryonic lethality.

PubMed

Francisco, Adam B; Singh, Rajni; Li, Shuai; Vani, Anish K; Yang, Liu; Munroe, Robert J; Diaferia, Giuseppe; Cardano, Marina; Biunno, Ida; Qi, Ling; Schimenti, John C; Long, Qiaoming

2010-04-30

Stress in the endoplasmic reticulum (ER) plays an important causal role in the pathogenesis of several chronic diseases such as Alzheimer, Parkinson, and diabetes mellitus. Insight into the genetic determinants responsible for ER homeostasis will greatly facilitate the development of therapeutic strategies for the treatment of these debilitating diseases. Suppressor enhancer Lin12 1 like (SEL1L) is an ER membrane protein and was thought to be involved in the quality control of secreted proteins. Here we show that the mice homozygous mutant for SEL1L were embryonic lethal. Electron microscopy studies revealed a severely dilated ER in the fetal liver of mutant embryos, indicative of alteration in ER homeostasis. Consistent with this, several ER stress responsive genes were significantly up-regulated in the mutant embryos. Mouse embryonic fibroblast cells deficient in SEL1L exhibited activated unfolded protein response at the basal state, impaired ER-associated protein degradation, and reduced protein secretion. Furthermore, markedly increased apoptosis was observed in the forebrain and dorsal root ganglions of mutant embryos. Taken together, our results demonstrate an essential role for SEL1L in protein quality control during mouse embryonic development.

Pleiotrophin regulates the expansion and regeneration of hematopoietic stem cells.

PubMed

Himburg, Heather A; Muramoto, Garrett G; Daher, Pamela; Meadows, Sarah K; Russell, J Lauren; Doan, Phuong; Chi, Jen-Tsan; Salter, Alice B; Lento, William E; Reya, Tannishtha; Chao, Nelson J; Chute, John P

2010-04-01

Hematopoietic stem cell (HSC) self-renewal is regulated by both intrinsic and extrinsic signals. Although some of the pathways that regulate HSC self-renewal have been uncovered, it remains largely unknown whether these pathways can be triggered by deliverable growth factors to induce HSC growth or regeneration. Here we show that pleiotrophin, a neurite outgrowth factor with no known function in hematopoiesis, efficiently promotes HSC expansion in vitro and HSC regeneration in vivo. Treatment of mouse bone marrow HSCs with pleiotrophin caused a marked increase in long-term repopulating HSC numbers in culture, as measured in competitive repopulating assays. Treatment of human cord blood CD34(+)CDCD38(-)Lin(-) cells with pleiotrophin also substantially increased severe combined immunodeficient (SCID)-repopulating cell counts in culture, compared to input and cytokine-treated cultures. Systemic administration of pleiotrophin to irradiated mice caused a pronounced expansion of bone marrow stem and progenitor cells in vivo, indicating that pleiotrophin is a regenerative growth factor for HSCs. Mechanistically, pleiotrophin activated phosphoinositide 3-kinase (PI3K) signaling in HSCs; antagonism of PI3K or Notch signaling inhibited pleiotrophin-mediated expansion of HSCs in culture. We identify the secreted growth factor pleiotrophin as a new regulator of both HSC expansion and regeneration.

Induction of the Hajdu-Cheney Syndrome Mutation in CD19 B Cells in Mice Alters B-Cell Allocation but Not Skeletal Homeostasis.

PubMed

Yu, Jungeun; Zanotti, Stefano; Schilling, Lauren; Schoenherr, Chris; Economides, Aris N; Sanjay, Archana; Canalis, Ernesto

2018-06-01

Mice harboring Notch2 mutations replicating Hajdu-Cheney syndrome (Notch2 tm1.1ECan ) have osteopenia and exhibit an increase in splenic marginal zone B cells with a decrease in follicular B cells. Whether the altered B-cell allocation is responsible for the osteopenia of Notch2 tm1.1ECan mutants is unknown. To determine the effect of NOTCH2 activation in B cells on splenic B-cell allocation and skeletal phenotype, a conditional-by-inversion (COIN) Hajdu-Cheney syndrome allele of Notch2 (Notch2 [ΔPEST]COIN ) was used. Cre recombination generates a permanent Notch2 ΔPEST allele expressing a transcript for which sequences coding for the proline, glutamic acid, serine, and threonine-rich (PEST) domain are replaced by a stop codon. CD19-Cre drivers were backcrossed into Notch2 [ΔPEST]COIN/[ΔPEST]COIN to generate CD19-specific Notch2 ΔPEST/ΔPEST mutants and control Notch2 [ΔPEST]COIN/[ΔPEST]COIN littermates. There was an increase in marginal zone B cells and a decrease in follicular B cells in the spleen of CD19 Cre/WT ;Notch2 ΔPEST/ΔPEST mice, recapitulating the splenic phenotype of Notch2 tm1.1ECan mice. The effect was reproduced when the NOTCH1 intracellular domain was induced in CD19-expressing cells (CD19 Cre/WT ;Rosa Notch1/WT mice). However, neither CD19 Cre/WT ;Notch2 ΔPEST/ΔPEST nor CD19 Cre/WT ;Rosa Notch1/WT mice had a skeletal phenotype. Moreover, splenectomies in Notch2 tm1.1ECan mice did not reverse their osteopenic phenotype. In conclusion, Notch2 activation in CD19-expressing cells determines B-cell allocation in the spleen but has no skeletal consequences. Copyright © 2018 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

The DREAM complex through its subunit Lin37 cooperates with Rb to initiate quiescence

PubMed Central

Mages, Christina FS; Wintsche, Axel; Bernhart, Stephan H

2017-01-01

The retinoblastoma Rb protein is an important factor controlling the cell cycle. Yet, mammalian cells carrying Rb deletions are still able to arrest under growth-limiting conditions. The Rb-related proteins p107 and p130, which are components of the DREAM complex, had been suggested to be responsible for a continued ability to arrest by inhibiting E2f activity and by recruiting chromatin-modifying enzymes. Here, we show that p130 and p107 are not sufficient for DREAM-dependent repression. We identify the MuvB protein Lin37 as an essential factor for DREAM function. Cells not expressing Lin37 proliferate normally, but DREAM completely loses its ability to repress genes in G0/G1 while all remaining subunits, including p130/p107, still bind to target gene promoters. Furthermore, cells lacking both Rb and Lin37 are incapable of exiting the cell cycle. Thus, Lin37 is an essential component of DREAM that cooperates with Rb to induce quiescence. PMID:28920576

Evolutionary plasticity of the NHL domain underlies distinct solutions to RNA recognition.

PubMed

Kumari, Pooja; Aeschimann, Florian; Gaidatzis, Dimos; Keusch, Jeremy J; Ghosh, Pritha; Neagu, Anca; Pachulska-Wieczorek, Katarzyna; Bujnicki, Janusz M; Gut, Heinz; Großhans, Helge; Ciosk, Rafal

2018-04-19

RNA-binding proteins regulate all aspects of RNA metabolism. Their association with RNA is mediated by RNA-binding domains, of which many remain uncharacterized. A recently reported example is the NHL domain, found in prominent regulators of cellular plasticity like the C. elegans LIN-41. Here we employ an integrative approach to dissect the RNA specificity of LIN-41. Using computational analysis, structural biology, and in vivo studies in worms and human cells, we find that a positively charged pocket, specific to the NHL domain of LIN-41 and its homologs (collectively LIN41), recognizes a stem-loop RNA element, whose shape determines the binding specificity. Surprisingly, the mechanism of RNA recognition by LIN41 is drastically different from that of its more distant relative, the fly Brat. Our phylogenetic analysis suggests that this reflects a rapid evolution of the domain, presenting an interesting example of a conserved protein fold that acquired completely different solutions to RNA recognition.