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Sample records for abundant cell types

  1. Renal type a intercalated cells contain albumin in organelles with aldosterone-regulated abundance.

    PubMed

    Jensen, Thomas Buus; Cheema, Muhammad Umar; Szymiczek, Agata; Damkier, Helle Hasager; Praetorius, Jeppe

    2015-01-01

    Albumin has been identified in preparations of renal distal tubules and collecting ducts by mass spectrometry. This study aimed to establish whether albumin was a contaminant in those studies or actually present in the tubular cells, and if so, identify the albumin containing cells and commence exploration of the origin of the intracellular albumin. In addition to the expected proximal tubular albumin immunoreactivity, albumin was localized to mouse renal type-A intercalated cells and cells in the interstitium by three anti-albumin antibodies. Albumin did not colocalize with markers for early endosomes (EEA1), late endosomes/lysosomes (cathepsin D) or recycling endosomes (Rab11). Immuno-gold electron microscopy confirmed the presence of albumin-containing large spherical membrane associated bodies in the basal parts of intercalated cells. Message for albumin was detected in mouse renal cortex as well as in a wide variety of other tissues by RT-PCR, but was absent from isolated connecting tubules and cortical collecting ducts. Wild type I MDCK cells showed robust uptake of fluorescein-albumin from the basolateral side but not from the apical side when grown on permeable support. Only a subset of cells with low peanut agglutinin binding took up albumin. Albumin-aldosterone conjugates were also internalized from the basolateral side by MDCK cells. Aldosterone administration for 24 and 48 hours decreased albumin abundance in connecting tubules and cortical collecting ducts from mouse kidneys. We suggest that albumin is produced within the renal interstitium and taken up from the basolateral side by type-A intercalated cells by clathrin and dynamin independent pathways and speculate that the protein might act as a carrier of less water-soluble substances across the renal interstitium from the capillaries to the tubular cells.

  2. Renal Type A Intercalated Cells Contain Albumin in Organelles with Aldosterone-Regulated Abundance

    PubMed Central

    Jensen, Thomas Buus; Cheema, Muhammad Umar; Szymiczek, Agata; Damkier, Helle Hasager; Praetorius, Jeppe

    2015-01-01

    Albumin has been identified in preparations of renal distal tubules and collecting ducts by mass spectrometry. This study aimed to establish whether albumin was a contaminant in those studies or actually present in the tubular cells, and if so, identify the albumin containing cells and commence exploration of the origin of the intracellular albumin. In addition to the expected proximal tubular albumin immunoreactivity, albumin was localized to mouse renal type-A intercalated cells and cells in the interstitium by three anti-albumin antibodies. Albumin did not colocalize with markers for early endosomes (EEA1), late endosomes/lysosomes (cathepsin D) or recycling endosomes (Rab11). Immuno-gold electron microscopy confirmed the presence of albumin-containing large spherical membrane associated bodies in the basal parts of intercalated cells. Message for albumin was detected in mouse renal cortex as well as in a wide variety of other tissues by RT-PCR, but was absent from isolated connecting tubules and cortical collecting ducts. Wild type I MDCK cells showed robust uptake of fluorescein-albumin from the basolateral side but not from the apical side when grown on permeable support. Only a subset of cells with low peanut agglutinin binding took up albumin. Albumin-aldosterone conjugates were also internalized from the basolateral side by MDCK cells. Aldosterone administration for 24 and 48 hours decreased albumin abundance in connecting tubules and cortical collecting ducts from mouse kidneys. We suggest that albumin is produced within the renal interstitium and taken up from the basolateral side by type-A intercalated cells by clathrin and dynamin independent pathways and speculate that the protein might act as a carrier of less water-soluble substances across the renal interstitium from the capillaries to the tubular cells. PMID:25874770

  3. Concise review: alchemy of biology: generating desired cell types from abundant and accessible cells.

    PubMed

    Pournasr, Behshad; Khaloughi, Keynoush; Salekdeh, Ghasem Hosseini; Totonchi, Mehdi; Shahbazi, Ebrahim; Baharvand, Hossein

    2011-12-01

    A major goal of regenerative medicine is to produce cells to participate in the generation, maintenance, and repair of tissues that are damaged by disease, aging, or trauma, such that function is restored. The establishment of induced pluripotent stem cells, followed by directed differentiation, offers a powerful strategy for producing patient-specific therapies. Given how laborious and lengthy this process can be, the conversion of somatic cells into lineage-specific stem/progenitor cells in one step, without going back to, or through, a pluripotent stage, has opened up tremendous opportunities for regenerative medicine. However, there are a number of obstacles to overcome before these cells can be widely considered for clinical applications. Here, we focus on induced transdifferentiation strategies to convert mature somatic cells to other mature cell types or progenitors, and we summarize the challenges that need to be met if the potential applications of transdifferentiation technology are to be achieved.

  4. Abundant expression of HIV target cells and C-type lectin receptors in the foreskin tissue of young Kenyan men.

    PubMed

    Hirbod, Taha; Bailey, Robert C; Agot, Kawango; Moses, Stephen; Ndinya-Achola, Jeckoniah; Murugu, Ruth; Andersson, Jan; Nilsson, Jakob; Broliden, Kristina

    2010-06-01

    A biological explanation for the reduction in HIV-1 (HIV) acquisition after male circumcision may be that removal of the foreskin reduces the number of target cells for HIV. The expression of potential HIV target cells and C-type lectin receptors in foreskin tissue of men at risk of HIV infection were thus analyzed. Thirty-three foreskin tissue samples, stratified by Herpes simplex virus type 2 status, were obtained from a randomized, controlled trial conducted in Kenya. The samples were analyzed by confocal in situ imaging microscopy and mRNA quantification by quantitative RT-qPCR. The presence and location of T cells (CD3(+)CD4(+)), Langerhans cells (CD1a(+)Langerin/CD207(+)), macrophages (CD68(+) or CD14(+)), and submucosal dendritic cells (CD123(+)BDCA-2(+) or CD11c(+)DC-SIGN(+)) were defined. C-type lectin receptor expressing cells were detected in both the epithelium and submucosa, and distinct lymphoid aggregates densely populated with CD3(+)CD4(+) T cells were identified in the submucosa. Although the presence of lymphoid aggregates and mRNA expression of selected markers varied between study subjects, Herpes simplex virus type 2 serostatus was not the major determinant for the detected differences. The detection of abundant and superficially present potential HIV target cells and submucosal lymphoid aggregates in foreskin mucosa from a highly relevant HIV risk group demonstrate a possible anatomical explanation that may contribute to the protective effect of male circumcision on HIV transmission.

  5. Cell type-specific abundance of 4EBP1 primes prostate cancer sensitivity or resistance to PI3K pathway inhibitors

    PubMed Central

    Hsieh, Andrew C.; Nguyen, Hao G.; Wen, Lexiaochuan; Edlind, Merritt P.; Carroll, Peter R.; Kim, Won; Ruggero, Davide

    2016-01-01

    Pharmacological inhibitors against the PI3K-AKT-mTOR pathway, a frequently deregulated signaling pathway in cancer, are clinically promising, but the development of drug resistance is a major limitation. We found that 4EBP1, the central inhibitor of cap-dependent translation, was a critical regulator of both prostate cancer initiation and maintenance downstream of mTOR signaling in a genetic mouse model. 4EBP1 abundance was distinctly different between the epithelial cell types of the normal prostate. Of tumor-prone prostate epithelial cell types, luminal epithelial cells exhibited the highest transcript and protein abundance of 4EBP1 and the lowest protein synthesis rates, which mediated resistance to the PI3K-AKT-mTOR pathway inhibitor MLN0128. Decreasing total 4EBP1 abundance reversed resistance in drug-sensitive cells. Increased 4EBP1 abundance was a common feature in prostate cancer patients that had been treated with the PI3K pathway inhibitor BKM120; thus 4EBP1 may be associated with drug resistance in human tumors. Our findings reveal a molecular program controlling cell type-specific 4EBP1 abundance coupled to the regulation of global protein synthesis rates that renders each epithelial cell type of the prostate uniquely sensitive or resistant to inhibitors of the PI3K-AKT-mTOR signaling pathway. PMID:26577921

  6. Aged Muscle Demonstrates Fiber-Type Adaptations in Response to Mechanical Overload, in the Absence of Myofiber Hypertrophy, Independent of Satellite Cell Abundance.

    PubMed

    Lee, Jonah D; Fry, Christopher S; Mula, Jyothi; Kirby, Tyler J; Jackson, Janna R; Liu, Fujun; Yang, Lin; Dupont-Versteegden, Esther E; McCarthy, John J; Peterson, Charlotte A

    2016-04-01

    Although sarcopenia, age-associated loss of muscle mass and strength, is neither accelerated nor exacerbated by depletion of muscle stem cells, satellite cells, we hypothesized that adaptation in sarcopenic muscle would be compromised. To test this hypothesis, we depleted satellite cells with tamoxifen treatment of Pax7(CreER)-DTA mice at 4 months of age, and 20 months later subjected the plantaris muscle to 2 weeks of mechanical overload. We found myofiber hypertrophy was impaired in aged mice regardless of satellite cell content. Even in the absence of growth, vehicle-treated mice mounted a regenerative response, not apparent in tamoxifen-treated mice. Further, myonuclear accretion occurred in the absence of growth, which was prevented by satellite cell depletion, demonstrating that myonuclear addition is insufficient to drive myofiber hypertrophy. Satellite cell depletion increased extracellular matrix content of aged muscle that was exacerbated by overload, potentially limiting myofiber growth. These results support the idea that satellite cells regulate the muscle environment, and that their loss during aging may contribute to fibrosis, particularly during periods of remodeling. Overload induced a fiber-type composition improvement, independent of satellite cells, suggesting that aged muscle is very responsive to exercise-induced enhancement in oxidative capacity, even with an impaired hypertrophic response.

  7. Determining Mineral Types and Abundances from Reflectance Measurements

    NASA Technical Reports Server (NTRS)

    Smith, M. O.; Adams, J. B.

    1985-01-01

    Mineral types and their abundances were quantitatively determined from laboratory reflectance spectra using principal components analysis (PCA). PCA reduced the measured spectral dimensionality and allowed testing the uniqueness and validity of spectral mixing models. In addition to interpreting absorption bands, in this new approach we interpreted variations in the overall spectral curves in terms of physical processes, namely changes in mixtures of minerals, in particle size and in illumination geometry. Application of this approach to reflectances of planetary surfaces allows interpretation to be extended to quantitative determinations of mineral types and abundances.

  8. Boron Abundances in A and B-type Stars

    NASA Technical Reports Server (NTRS)

    Lambert, David L.

    1997-01-01

    Boron abundances in A- and B-type stars may be a successful way to track evolutionary effects in these hot stars. The light elements - Li, Be, and B - are tracers of exposure to temperatures more moderate than those in which the H-burning CN-cycle operates. Thus, any exposure of surface stellar layers to deeper layers will affect these light element abundances. Li and Be are used in this role in investigations of evolutionary processes in cool stars, but are not observable in hotter stars. An investigation of boron, however, is possible through the B II 1362 A resonance line. We have gathered high resolution spectra from the IUE database of A- and B-type stars near 10 solar mass for which nitrogen abundances have been determined. The B II 1362 A line is blended throughout; the temperature range of this program, requiring spectrum syntheses to recover the boron abundances. For no star could we synthesize the 1362 A region using the meteoritic/solar boron abundance of log e (B) = 2.88; a lower boron abundance was necessary which may reflect evolutionary effects (e.g., mass loss or mixing near the main-sequence), the natal composition of the star forming regions, or a systematic error in the analyses (e.g., non-LTE effects). Regardless of the initial boron abundance, and despite the possibility of non-LTE effects, it seems clear that boron is severely depleted in some stars. It may be that the nitrogen and boron abundances are anticorrelated, as would be expected from mixing between the H-burning and outer stellar layers. If, as we suspect, a residue of boron is present in the A-type supergiants, we may exclude a scenario in which mixing occurs continuously between the surface and the deep layers operating the CN-cycle. Further exploitation of the B II 1362 A line as an indicator of the evolutionary status of A- and B-type stars will require a larger stellar sample to be observed with higher signal-to-noise as attainable with the Hubble Space Telescope.

  9. Types of Stem Cells

    MedlinePlus

    ... Stem Cell Glossary Search Toggle Nav Types of Stem Cells Stem cells are the foundation from which all ... Learn About Stem Cells > Types of Stem Cells Stem cells Stem cells are the foundation for every organ ...

  10. Lithium Abundance Of The Solar-Type Superflare Stars

    NASA Astrophysics Data System (ADS)

    Honda, Satoshi; Notsu, Yuta; Maehara, Hiroyuki; Notsu, Shota; Shibayama, Takuya; Nogami, Daisaku; Shibata, Kazunari

    2016-07-01

    We performed the high dispersion spectroscopy of solar-type superflare stars by Subaru/HDS, and estimate the stellar parameters and lithium abundance of the stars to compare with the Sun. Our spectroscopic analysis of superflare stars show more than half of targets have no evidence of binary system and the stellar parameters are in the range of solar-type stars (Notsu et al. 2015a&b). We also investigate the correlations of Lithium abundance with stellar atmospheric parameters, rotational velocity, and superflare activities to understand the nature of superflare stars and the possibility of the nucleosynthesis of lithium by superflares. The derived lithium abundance in superflare stars do not show the correlation with stellar parameters. As compared with the lithium abundance in Hyades cluster which is younger than the sun, it is suggested that half of observed stars are young. However, there are some objects which show the low lithium and slowly rotate from the estimated v sin(i) and period of brightness variation. These results indicate that the superflare stars are not only young stars but also old stars like our sun. In our observations, we could not find the any evidence of lithium productions by superflare.

  11. DIVERSITY OF TYPE Ia SUPERNOVAE IMPRINTED IN CHEMICAL ABUNDANCES

    SciTech Connect

    Tsujimoto, Takuji; Shigeyama, Toshikazu

    2012-12-01

    A time delay of Type Ia supernova (SN Ia) explosions hinders the imprint of their nucleosynthesis on stellar abundances. However, some occasional cases give birth to stars that avoid enrichment of their chemical compositions by massive stars and thereby exhibit an SN-Ia-like elemental feature including a very low [Mg/Fe] ( Almost-Equal-To - 1). We highlight the elemental feature of Fe-group elements for two low-Mg/Fe objects detected in nearby galaxies, and propose the presence of a class of SNe Ia that yield the low abundance ratios of [Cr, Mn, Ni/Fe]. Our novel models of chemical evolution reveal that our proposed class of SNe Ia (slow SNe Ia) is associated with ones exploding on a long timescale after their stellar birth and give a significant impact on the chemical enrichment in the Large Magellanic Cloud (LMC). In the Galaxy, on the other hand, this effect is unseen due to the overwhelming enrichment by the major class of SNe Ia that explode promptly (prompt SNe Ia) and eject a large amount of Fe-group elements. This nicely explains the different [Cr, Mn, Ni/Fe] features between the two galaxies as well as the puzzling feature seen in the LMC stars exhibiting very low Ca but normal Mg abundances. Furthermore, the corresponding channel of slow SN Ia is exemplified by performing detailed nucleosynthesis calculations in the scheme of SNe Ia resulting from a 0.8 + 0.6 M{sub Sun} white dwarf merger.

  12. Abundances in A-type Horizontal Branch Stars

    NASA Astrophysics Data System (ADS)

    Wilhelm, R.; Smith, V. V.

    1998-12-01

    As part of a program to explore correlations between abundance anomilies and physical parameters (e.g. Teff, vsini) in horizontal branch stars, we present preliminary results from high-resolution (R ~ 18,000) spectral observations of a small sample of A-type, horizontal branch stars. The sample was obtained using the 2.1m telescope and Sandiford Echelle at McDonald Observatory. A total of six standard FHB stars were observed including two, HD 130095 and HD 167105, which have been previously shown by Adleman and Philip to posses anomalously low [Ca/Fe] values. We have also obtained observations of eight of the brighter (B = 11.5-12.5) FHB stars from the HK objective-prism survey and two BHB stars from the globular cluster, M4. We will present abundance results that include [Ca/Fe], [Mg/Fe], and vsini values for the sample along with O and Na results for the two M4 stars. Our findings will be compared to previously published results for cluster BHB and field HB stars.

  13. Chemical abundances in early B-type stars. 5: Metal abundances and LTE/NLTE comparison

    NASA Astrophysics Data System (ADS)

    Kilian, J.

    1994-02-01

    Chemical abundances of neon, magnesium, aluminum, sulfur, and iron are derived for a sample of 21 unevolved B-stars in the local field and nearby associations. While aluminum, sulfur, and iron are underabundant in nearly all stars, near solar abundances are found for magnesium and neon. In agreement with earlier results for carbon, nitrogen, oxygen, and silicon (Kilian 1992), the present results show no correlation with surface gravities or evolutionary states, which indicates that the metal abundances reflect the original composition of the interstellar medium. The results are supplemented by a comparison of local thermodynamic equilibrium (LTE) and non-LTE (NLTE) abundances for C, N, O, Si, Mg, and Al. In most cases the differences amount to +/- (0.1-0.2) dex, which slightly exceeds the estimated accuracy of the NLTE abundance determination. However, a clear temperature gradient is evident for most elements, which indicates systematic LTE abundance errors with a maximum amplitude of 0.4 dex between 21 000 K and 31 000 K.

  14. Rock type identification and abundance estimation from hyperspectral analysis

    NASA Astrophysics Data System (ADS)

    Feng, Jilu

    This study explores the usefulness of hyperspectral data to discriminate rock units and estimate the abundance of sulfides in rocks. Airborne visible-near infrared (VIS-NIR) hyperspectral data collected from northern Cape Smith, Quebec and laboratory thermal infrared reflectance (TIR) data measured on rock samples from eight different mines in the Sudbury Basin, Ontario are involved in the analysis. The study addressed four different geological application scenarios with the aim of retrieving useful lithological information from rock spectra while minimizing the influence of varying environmental factors. The research first examines the effects of topography on the selection of rock endmembers from airborne VIS_NIR spectra and demonstrates how a topographic correction process can improve the discrimination of rock units. It demonstrates that traditional ways of selecting spectral endmembers from hyperspectral data for areas of rugged terrain cannot provide representative rock unit signatures. The second part of the research targeted the mapping of wall rock in an underground environment using TIR spectra. Rock samples from mines of the Sudbury Basin in Ontario were measured using naturally broken surfaces both dry and wet to address environmental conditions encountered underground. An innovative method applying a spectral angle mapper on the 2nd derivative of rock spectra from 700--1300 cm-1 was proved to be robust to remove the effect of liquid water, local geometry and disseminated sulfide ores while preserving diagnostic rock signatures for mapping. The study then focuses on retrieving sulfide information from TIR to estimate ore (total sulfide abundance) grade on naturally broken rock faces and separate ore-bearing rocks from their host rocks in an underground environment regardless of rock types. An important finding is that reflectance at 1319 cm -1, where most silicate rocks demonstrate low reflectance, is related to total sulfide concentration in rocks

  15. Microsystems for the Capture of Low-Abundance Cells

    NASA Astrophysics Data System (ADS)

    Dharmasiri, Udara; Witek, Małgorzata A.; Adams, Andre A.; Soper, Steven A.

    2010-07-01

    Efficient selection and enumeration of low-abundance biological cells are highly important in a variety of applications. For example, the clinical utility of circulating tumor cells (CTCs) in peripheral blood is recognized as a viable biomarker for the management of various cancers, in which the clinically relevant number of CTCs per 7.5 ml of blood is two to five. Although there are several methods for isolating rare cells from a variety of heterogeneous samples, such as immunomagnetic-assisted cell sorting and fluorescence-activated cell sorting, they are fraught with challenges. Microsystem-based technologies are providing new opportunities for selecting and isolating rare cells from complex, heterogeneous samples. Such approaches involve reductions in target-cell loss, process automation, and minimization of contamination issues. In this review, we introduce different application areas requiring rare cell analysis, conventional techniques for their selection, and finally microsystem approaches for low-abundance-cell isolation and enumeration.

  16. Chemical abundances of solar-type dwarfs in open clusters

    NASA Astrophysics Data System (ADS)

    Schuler, Simon C.

    Open clusters have proven continuously to be invaluable tools to the studies of stellar physics and Galactic evolution. Until recently, however, the chemical abundances of the populous and astrophysically important late-F, G, and K open cluster dwarfs have gone largely unanalyzed. In this thesis I report on the study of the chemical abundances derived from high-resolution, moderate-to-high signal-to-noise echelle spectra obtained with the 10-m Keck I, 9.2-m Hobby- Eberly, 8.2-m VLT, 4.0-m KPNO, 2.7-m Harlan J. Smith, and the 2.1-m Otto Struve telescopes of cool dwarfs in the Pleiades, Hyades, and M34 open clusters. The main result of the study is the identification of excitation-related abundance trends found among cool open cluster dwarfs ( T eff <= 5500 K), as well as an overionization of Fe- abundances derived from singly ionized lines are greater than those derived from neutral lines- among the cool Hyades dwarfs; the trends are such that abundances derived from high-excitation (h >= 4.0 eV) spectral lines and using atmospheric models assuming local thermodynamic equilibrium (LTE) increase with decreasing T eff . Particular attention is given to the high-excitation (h = 9.15 eV) near-IR ll7774 O I triplet, a line used often in the derivation of stellar O abundances and known to be susceptible to non-LTE (NLTE) effects. The O I triplet-based abundances show a dramatic increase with decreasing T eff in all three clusters, behavior that is in stark contrast to expectations from canonical NLTE calculations. Other elements with lines of various excitation potentials are also analyzed and are found to exhibit abundance trends that are qualitatively similar to those of the O I triplet. Possible explanations for the observed cool open cluster dwarf abundance anomalies are investigated, and photospheric surface temperature inhomogeneities possibly due to spots, faculae, and/or plages are found to be a plausible culprit. Indeed, multi-component LTE model atmospheres are

  17. Marine debris in central California: quantifying type and abundance of beach litter in Monterey Bay, CA.

    PubMed

    Rosevelt, C; Los Huertos, M; Garza, C; Nevins, H M

    2013-06-15

    Monitoring beach litter is essential for reducing ecological threats towards humans and wildlife. In Monterey Bay, CA information on seasonal and spatial patterns is understudied. Central California's coastal managers require reliable information on debris abundance, distribution, and type, to support policy aimed at reducing litter. We developed a survey method that allowed for trained citizen scientists to quantify the types and abundance of beach litter. Sampling occurred from July 2009-June 2010. Litter abundance ranged from 0.03 to 17.1 items m(-2). Using a mixed model approach, we found season and location have the greatest effect on litter abundance. Styrofoam, the most numerically abundant item, made up 41% of the total amount of litter. Unexpected items included fertilizer pellets. The results of this study provide a baseline on the types and abundance of litter on the central coast and have directly supported policy banning Styrofoam take out containers from local municipalities.

  18. Abundances of sulfur in the Milky Way Disk from Peimbert Type II planetary nebulae

    NASA Astrophysics Data System (ADS)

    Milingo, Jacquelynne Brenda

    2000-08-01

    Sulfur abundance gradients and heavy element ratios for the Milky Way Disk are constructed based upon newly acquired spectrophotometry of Type II planetary nebulae (PN). These spectra extend from 3600-9600 angstroms allowing us to use the [SIII] 9069 and 9532 angstrom lines to improve upon earlier sulfur abundance estimates. Considering a significant portion of sulfur in PN exists in the S(+2) ionization stage (and higher) this method should allow us to extrapolate more reliable total element abundance from ionic abundances. Given the progenitor mass and location of Type II PN (close to the Galactic disk), this sample of objects is free of nucleosynthetic self-contamination and thus their S abundances in particular are expected to reflect levels of these elements in the interstellar medium at the time of PN progenitor formation. These sulfur abundances provide constraints for studying various aspects of GCE such as massive star yields and the distribution of S across the Milky Way disk.

  19. Rapid detection of microbial cell abundance in aquatic systems.

    PubMed

    Rocha, Andrea M; Yuan, Quan; Close, Dan M; O'Dell, Kaela B; Fortney, Julian L; Wu, Jayne; Hazen, Terry C

    2016-11-15

    The detection and quantification of naturally occurring microbial cellular densities is an essential component of environmental systems monitoring. While there are a number of commonly utilized approaches for monitoring microbial abundance, capacitance-based biosensors represent a promising approach because of their low-cost and label-free detection of microbial cells, but are not as well characterized as more traditional methods. Here, we investigate the applicability of enhanced alternating current electrokinetics (ACEK) capacitive sensing as a new application for rapidly detecting and quantifying microbial cellular densities in cultured and environmentally sourced aquatic samples. ACEK capacitive sensor performance was evaluated using two distinct and dynamic systems - the Great Australian Bight and groundwater from the Oak Ridge Reservation in Oak Ridge, TN. Results demonstrate that ACEK capacitance-based sensing can accurately determine microbial cell counts throughout cellular concentrations typically encountered in naturally occurring microbial communities (10(3)-10(6) cells/mL). A linear relationship was observed between cellular density and capacitance change correlations, allowing a simple linear curve fitting equation to be used for determining microbial abundances in unknown samples. This work provides a foundation for understanding the limits of capacitance-based sensing in natural environmental samples and supports future efforts focusing on evaluating the robustness ACEK capacitance-based within aquatic environments.

  20. The relative abundance of hemocyte types in a polyphagous moth larva depends on diet.

    PubMed

    Vogelweith, Fanny; Moret, Yannick; Monceau, Karine; Thiéry, Denis; Moreau, Jérôme

    2016-05-01

    Hemocytes are crucial cells of the insect immune system because of their involvement in multiple immune responses including coagulation, phagocytosis and encapsulation. There are various types of hemocytes, each having a particular role in immunity, such that variation in their relative abundance affects the outcome of the immune response. This study aims to characterize these various types of hemocytes in larvae of the grapevine pest insect Eupoecilia ambiguella, and to assess variation in their concentration as a function of larval diet and immune challenge. Four types of hemocytes were found in the hemolymph of 5th instar larvae: granulocytes, oenocytoids, plasmatocytes and spherulocytes. We found that the total concentration of hemocytes and the concentration of each hemocyte type varied among diets and in response to the immune challenge. Irrespective of the diet, the concentration of granulocytes increased following a bacterial immune challenge, while the concentration of plasmatocytes and spherulocytes differentially varied between larval diets. The concentration of oenocytoids did not vary among diets before the immune challenge but varied between larval diets in response to the challenge. These results suggest that the resistance of insect larvae to different natural enemies critically depends on the effect of larval diet on the larvae's investment into the different types of hemocytes.

  1. The abundance properties of nearby late-type galaxies. II. The relation between abundance distributions and surface brightness profiles

    SciTech Connect

    Pilyugin, L. S.; Grebel, E. K.; Zinchenko, I. A.; Kniazev, A. Y. E-mail: grebel@ari.uni-heidelberg.de E-mail: akniazev@saao.ac.za

    2014-12-01

    The relations between oxygen abundance and disk surface brightness (OH–SB relation) in the infrared W1 band are examined for nearby late-type galaxies. The oxygen abundances were presented in Paper I. The photometric characteristics of the disks are inferred here using photometric maps from the literature through bulge-disk decomposition. We find evidence that the OH–SB relation is not unique but depends on the galactocentric distance r (taken as a fraction of the optical radius R{sub 25}) and on the properties of a galaxy: the disk scale length h and the morphological T-type. We suggest a general, four-dimensional OH–SB relation with the values r, h, and T as parameters. The parametric OH–SB relation reproduces the observed data better than a simple, one-parameter relation; the deviations resulting when using our parametric relation are smaller by a factor of ∼1.4 than that of the simple relation. The influence of the parameters on the OH–SB relation varies with galactocentric distance. The influence of the T-type on the OH–SB relation is negligible at the centers of galaxies and increases with galactocentric distance. In contrast, the influence of the disk scale length on the OH–SB relation is at a maximum at the centers of galaxies and decreases with galactocentric distance, disappearing at the optical edges of galaxies. Two-dimensional relations can be used to reproduce the observed data at the optical edges of the disks and at the centers of the disks. The disk scale length should be used as a second parameter in the OH–SB relation at the center of the disk while the morphological T-type should be used as a second parameter in the relation at optical edge of the disk. The relations between oxygen abundance and disk surface brightness in the optical B and infrared K bands at the center of the disk and at optical edge of the disk are also considered. The general properties of the abundance–surface brightness relations are similar for the

  2. Chemical abundances for A-and F-type supergiant stars

    NASA Astrophysics Data System (ADS)

    Molina, R. E.; Rivera, H.

    2016-10-01

    We present the stellar parameters and elemental abundances of a set of A-F-type supergiant stars HD 45674, HD 180028, HD 194951 and HD 224893 using high resolution (R≈ 42,000) spectra taken from ELODIE library. We present the first results of the abundance analysis for HD 45674 and HD 224893. We reaffirm the abundances for HD 180028 and HD 194951 studied previously by Luck. Alpha-elements indicate that the objects belong to the thin disc population. Their abundances and their location on the Hertzsprung-Russell diagram seem to indicate that HD 45675, HD 194951 and HD 224893 are in the post-first dredge-up (post-1DUP) phase, and that they are moving in the red-blue loop region. HD 180028, on the contary, shows typical abundances of Population I, but its evolutionary status cannot be satisfactorily defined.

  3. Determination of Li abundance in Solar type stars of intermediate brightness

    NASA Astrophysics Data System (ADS)

    Amazo-Gómez, E. M.; Hernandez-Águila, B.; Dagostino, M. C.; Bertone, E.; de la Luz, V.

    2014-10-01

    The determination of the lithium abundance in stellar atmospheres is of fundamental importance in multiple contexts of contemporary astrophysics. On the one hand, the lithium present in stars with global sub-solar metal abundances provides a strong restriction on the abundance of this element as a result of primordial nucleo-synthesis. On the other hand, Li can be an age indicator for stars with convective envelopes. Additionally, Li abundance appears to be correlated with the presence of sub-stellar companions. We present preliminary results of a project aimed at determining the Li abundance in an extended sample of solar-like stars (spectral type G and luminosity class V) of intermediate brightness. High resolution spectroscopic data (R=65000) were obtained with the CanHiS echelle spectrograph on the 2.11m telescope of the Guillermo Haro Observatory in Cananea, Sonora, Mexico. We report the equivalent widths of a first sub-sample of 33 stars.

  4. Abundance patterns in the interstellar medium of early-type galaxies observed with Suzaku

    SciTech Connect

    Konami, Saori; Matsushita, Kyoko; Tamagawa, Toru; Nagino, Ryo

    2014-03-01

    We have analyzed 17 early-type galaxies, 13 ellipticals and 4 S0 galaxies, observed with Suzaku, and investigated metal abundances (O, Mg, Si, and Fe) and abundance ratios (O/Fe, Mg/Fe, and Si/Fe) in the interstellar medium (ISM). The emission from each on-source region, which is four times the effective radius, r {sub e}, is reproduced with one-temperature (1T) or two-temperature (2T) thermal plasma models as well as a multi-temperature model, using APEC plasma code version 2.0.1. The multi-temperature model gave almost the same abundances and abundance ratios with the 1T or 2T models. The weighted averages of the O, Mg, Si, and Fe abundances of all the sample galaxies derived from the multi-temperature model fits are 0.83 ± 0.04, 0.93 ± 0.03, 0.80 ± 0.02, and 0.80 ± 0.02 solar, respectively, in solar units according to the solar abundance table by Lodders in 2003. These abundances show no significant dependence on the morphology and environment. The systematic differences in the derived metal abundances between versions 2.0.1 and 1.3.1 of the APEC plasma codes were investigated. The derived O and Mg abundances in the ISM agree with the stellar metallicity within an aperture with a radius of one r {sub e} derived from optical spectroscopy. From these results, we discuss the past and present Type Ia supernova rates and star formation histories in early-type galaxies.

  5. Dielectrophoretic capture of low abundance cell population using thick electrodes

    PubMed Central

    Marchalot, Julien; Chateaux, Jean-François; Faivre, Magalie; Mertani, Hichem C.; Ferrigno, Rosaria; Deman, Anne-Laure

    2015-01-01

    Enrichment of rare cell populations such as Circulating Tumor Cells (CTCs) is a critical step before performing analysis. This paper presents a polymeric microfluidic device with integrated thick Carbon-PolyDimethylSiloxane composite (C-PDMS) electrodes designed to carry out dielectrophoretic (DEP) trapping of low abundance biological cells. Such conductive composite material presents advantages over metallic structures. Indeed, as it combines properties of both the matrix and doping particles, C-PDMS allows the easy and fast integration of conductive microstructures using a soft-lithography approach while preserving O2 plasma bonding properties of PDMS substrate and avoiding a cumbersome alignment procedure. Here, we first performed numerical simulations to demonstrate the advantage of such thick C-PDMS electrodes over a coplanar electrode configuration. It is well established that dielectrophoretic force (FDEP) decreases quickly as the distance from the electrode surface increases resulting in coplanar configuration to a low trapping efficiency at high flow rate. Here, we showed quantitatively that by using electrodes as thick as a microchannel height, it is possible to extend the DEP force influence in the whole volume of the channel compared to coplanar electrode configuration and maintaining high trapping efficiency while increasing the throughput. This model was then used to numerically optimize a thick C-PDMS electrode configuration in terms of trapping efficiency. Then, optimized microfluidic configurations were fabricated and tested at various flow rates for the trapping of MDA-MB-231 breast cancer cell line. We reached trapping efficiencies of 97% at 20 μl/h and 78.7% at 80 μl/h, for 100 μm thick electrodes. Finally, we applied our device to the separation and localized trapping of CTCs (MDA-MB-231) from a red blood cells sample (concentration ratio of 1:10). PMID:26392836

  6. The Abundance Properties of Nearby Late-type Galaxies. I. The Data

    NASA Astrophysics Data System (ADS)

    Pilyugin, L. S.; Grebel, E. K.; Kniazev, A. Y.

    2014-06-01

    We investigate the oxygen and nitrogen abundance distributions across the optical disks of 130 nearby late-type galaxies using around 3740 published spectra of H II regions. We use these data in order to provide homogeneous abundance determinations for all objects in the sample, including H II regions in which not all of the usual diagnostic lines were measured. Examining the relation between N and O abundances in these galaxies we find that the abundances in their centers and at their isophotal R 25 disk radii follow the same relation. The variation in N/H at a given O/H is around 0.3 dex. We suggest that the observed spread in N/H may be partly caused by the time delay between N and O enrichment and the different star formation histories in galaxies of different morphological types and dimensions. We study the correlations between the abundance properties (central O and N abundances, radial O and N gradients) of a galaxy and its morphological type and dimension.

  7. Cell types, circuits, computation.

    PubMed

    Azeredo da Silveira, Rava; Roska, Botond

    2011-10-01

    How does the connectivity of a neuronal circuit, together with the individual properties of the cell types that take part in it, result in a given computation? We examine this question in the context of retinal circuits. We suggest that the retina can be viewed as a parallel assemblage of many small computational devices, highly stereotypical and task-specific circuits afferent to a given ganglion cell type, and we discuss some rules that govern computation in these devices. Multi-device processing in retina poses conceptual problems when it is contrasted with cortical processing. We lay out open questions both on processing in retinal circuits and on implications for cortical processing of retinal inputs.

  8. Effects of neighboring vascular plants on the abundance of bryophytes in different vegetation types

    NASA Astrophysics Data System (ADS)

    Jägerbrand, Annika K.; Kudo, Gaku; Alatalo, Juha M.; Molau, Ulf

    2012-07-01

    Due to the climate change, vegetation of tundra ecosystems is predicted to shift toward shrub and tree dominance, and this change may influence bryophytes. To estimate how changes in growing environment and the dominance of vascular plants influence bryophyte abundance, we compared the relationship of occurrence of bryophytes among other plant types in a five-year experiment of warming (T), fertilization (F) and T + F in two vegetation types, heath and meadow, in a subarctic-alpine ecosystem. We compared individual leaf area among shrub species to confirm that deciduous shrubs might cause severe shading effect. Effects of neighboring functional types on the performance of Hylocomium splendens was also analyzed. Results show that F and T + F treatments significantly influenced bryophyte abundance negatively. Under natural conditions, bryophytes in the heath site were negatively related to the abundance of shrubs and lichens and the relationship between lichens and bryophytes strengthened after the experimental period. After five years of experimental treatments in the meadow, a positive abundance relationship emerged between bryophytes and deciduous shrubs, evergreen shrubs and forbs. This relationship was not found in the heath site. Our study therefore shows that the abundance relationships between bryophytes and plants in two vegetation types within the same area can be different. Deciduous shrubs had larger leaf area than evergreen shrubs but did not show any shading effect on H. splendens.

  9. Quantitative determination of mineral types and abundances from reflectance spectra using principal components analysis

    NASA Technical Reports Server (NTRS)

    Smith, M. O.; Adams, J. B.; Johnson, P. E.

    1985-01-01

    A procedure was developed for analyzing remote reflectance spectra, including multispectral images, that quantifies parameters such as types of mineral mixtures, the abundances of mixed minerals, and particle sizes. Principal components analysis reduced the spectral dimensionality and allowed testing the uniqueness and validity of spectral mixing models. By analyzing variations in the overall spectral reflectance curves, the type of spectral mixture was identified, mineral abundances quantified and the effects of particle size identified. The results demonstrate an advantage in classification accuracy over classical forms of analysis that ignore effects of particle-size or mineral-mixture systematics on spectra. The approach is applicable to remote sensing data of planetary surfaces for quantitative determinations of mineral abundances.

  10. Future rainfall patterns will reduce arthropod abundance in model arable agroecosystems with different soil types

    NASA Astrophysics Data System (ADS)

    Zaller, Johann; Simmer, Laura; Tabi Tataw, James; Formayer, Herbert; Hösch, Johannes; Baumgarten, Andreas

    2013-04-01

    Climate change scenarios for eastern Austria predict a seasonal shift in precipitation patterns with fewer but heavier rainfall events and longer drought periods during the growing season and more precipitation during winter. This is expected to alter arthropods living in natural and agricultural ecosystems with consequences for several ecosystem functions and services. In order to better understand the effects of future rainfall patterns on aboveground arthropods inhabiting an agroecosystem, we conducted an experiment where we simulated rainfall patterns in model arable systems with three different soil types. Experiments were conducted in winter wheat cultivated in a lysimeter facility near Vienna, Austria, where three different soil types (calcaric phaeozem, calcic chernozem and gleyic phaeozem) were subjected to long-term current vs. predicted rainfall patterns according to regionalized climate change projections for 2071-2100. Aboveground arthropods were assessed by suction sampling in April, May and June 2012. We found significant differences in mean total arthropod abundances between the sampling dates with 20 ± 2 m-2, 90 ± 20 m-2 and 289 ± 54 m-2 in April, May and June, respectively. Across all three sampling dates, future rainfall patterns significantly reduced the abundance of Araneae (-43%), Auchenorrhyncha (-39%), Coleoptera (-48%), Carabidae (-41%), Chrysomelidae (-64%), Collembola (-58%), Diptera (-75%) and Neuroptera (-73%). Generally, different soil types had no effect on the abundance of arthropods. The diversity of arthropod communities was unaffected by rainfall patterns or soil types. Correlation analyses of arthropod abundances with crop biomass, weed density and abundance suggest that rainfall effects indirectly affected arthropods via changes on crops and weeds. In conclusion, these results show that future rainfall patterns will have detrimental effects on the abundance of a variety of aboveground arthropods in winter wheat with potential

  11. Coronal thermal structure and abundances of supermetal-rich solar-type stars

    NASA Technical Reports Server (NTRS)

    Brickhouse, Nancy S. (Principal Investigator); Mushotzky, Richard F. (Technical Monitor)

    2005-01-01

    This observation is for grating spectroscopy of Tau Boo, a late-type star with very high metallicity (about twice solar). Despite the extreme condition of high metallicity in the photosphere, the abundance ratios of the corona appear consistent with the general picture of a coronal abundance/activity relation. The target was obtained by XMM-Newton on 24 June 2003 for 71900 sec. The European PI Antonio Maggio is responsible for data reduction. Members of our team presented at the Cool Stars Workshop 13 held in Hamburg, Germany in July 2004 and conferred at that time on the publication of results. This project is complete except for the final publication.

  12. The metal abundance of circumnuclear star-forming regions in early-type spirals. Spectrophotometric observations

    NASA Astrophysics Data System (ADS)

    Díaz, Ángeles I.; Terlevich, Elena; Castellanos, Marcelo; Hägele, Guillermo F.

    2007-11-01

    We have obtained long-slit observations in the optical and near-infrared of 12 circumnuclear HII regions [circumnuclear star-forming regions (CNSFR)] in the early-type spiral galaxies NGC2903, 3351 and 3504 with the aim of deriving their chemical abundances. Only for one of the regions, the [SIII] λ6312Å was detected providing, together with the nebular [SIII] lines at λλ9069, 9532Å, a value of the electron temperature of . A semi-empirical method for the derivation of abundances in the high metallicity regime is presented. We obtain abundances which are comparable to those found in high metallicity disc HII regions from direct measurements of electron temperatures and consistent with solar values within the errors. The region with the highest oxygen abundance is R3+R4 in NGC3504, 12 + log(O/H) = 8.85, about 1.5 solar if the solar oxygen abundance is set at the value derived by Asplund, Grevesse & Sauval, 12 + log(O/H)solar = 8.66 +/- 0.05. Region R7 in NGC3351 has the lowest oxygen abundance of the sample, about 0.6 times solar. In all the observed CNSFR the O/H abundance is dominated by the O+/H+ contribution, as is also the case for high metallicity disc HII regions. For our observed regions, however, also the S+/S2+ ratio is larger than one, contrary to what is found in high metallicity disc HII regions for which, in general, the sulphur abundances are dominated by S2+/H+. The derived N/O ratios are in average larger than those found in high metallicity disc HII regions and they do not seem to follow the trend of N/O versus O/H which marks the secondary behaviour of nitrogen. On the other hand, the S/O ratios span a very narrow range between 0.6 and 0.8 of the solar value. As compared to high metallicity disc HII regions, CNSFR show values of the O23 and the N2 parameters whose distributions are shifted to lower and higher values, respectively, hence, even though their derived oxygen and sulphur abundances are similar, higher values would in principle be

  13. Coronal Thermal Structure and Abundance of Super-Metal-Rich Late-Type Stars

    NASA Technical Reports Server (NTRS)

    Brickhouse, Nancy; Mushotzky, Richard F. (Technical Monitor)

    2002-01-01

    This report covers the NASA grant NAG5-9943 for Cycle 1 XMM Guest Observer Program. The project is entitled 'Coronal Thermal Structure and Abundances of Super-Metal-Rich Late-Type Stars.' This observation is for grating spectroscopy of 30 Ari, a late-type star with very high metallicity (about twice solar). The goal is to use extreme cases to help understand how abundances change from the photosphere to the corona. The target was obtained by XMM-Newton on 2001 January 16 for 28000 sec. Data processing could not proceed until last fall because the SAS RGS software did not work. A poster was presented at the conference 'New Visions of the X-ray Universe in the XMM-Newton and Chandra Era,' held in Noordwijk 26-30 November 2001. The paper was entitled,'Coronal Abundances and Thermal Structure of the Super-Metal-Rich Star 30 Ari,'. The poster presented analysis of EPIC and RGS data to determine the individual abundances from the star and the emission measure distribution as a function of temperature. Results were compared with previous results on this star by our team using ASCA data.

  14. True Chemical Abundances of Galaxies in the Nearby Universe: A Comparison of Abundance Methods, Interstellar Processes, and Galaxy Types

    NASA Astrophysics Data System (ADS)

    Berg, Danielle Amanda

    2013-12-01

    Peeples et al. (2008) identified low-mass, high oxygen abundance outliers from the mass-metallicity (M-Z) relationship. We present new MMT spectroscopy of four of these dwarf galaxy outliers. We re-examined these anomalous spectra and compared to the parameter space for which standard strong-line methods are calibrated. We discuss the physical nature of these galaxies that leads to their unusual spectra (and previous classification as outliers), finding their low excitation, elevated N/O, and strong Balmer absorption are consistent with the properties expected from galaxies evolving past the "Wolf-Rayet galaxy" phase. To address the issue of securing the low-luminosity end of the M-Z relationship, we present MMT spectroscopic observations of HII regions in 42 low-luminosity galaxies in the Spitzer LVL survey. Direct oxygen abundances were determined based on the temperature sensitive [O III] lambda4363 line, measured at a strength of 4sigma or greater, for 31 of the 42 galaxies in our sample. Combining our results with previous direct abundance studies, we present a further refined sample, requiring reliable distance determinations. We characterize the direct L-Z and M-Z relationships at low-luminosity using the resulting 38 object sample. We show that the luminosity of a low-luminosity galaxy is often a better indicator of metallicity than strong-line methods. Additionally, our results provide the first direct estimates of oxygen abundance for 19 local volume dwarf galaxies. Properties of the ISM of spiral galaxies are known to show radial variations. Motivated by the need to place gradients on the same scale for comparisons amongst galaxies, we present direct oxygen abundance gradients of the nearby spiral galaxies NGC 628 and NGC 2403. A bi-modal N/O gradient pattern is measured for NGC 628. Notably, the N/O ratio plateaus beyond R25, demonstrating that primary nitrogen production is the dominant mechanism in the outer disk. The outer disk beyond R 25 was not

  15. ABUNDANCES OF REFRACTORY ELEMENTS FOR G-TYPE STARS WITH EXTRASOLAR PLANETS

    SciTech Connect

    Kang, Wonseok; Lee, Sang-Gak; Kim, Kang-Min

    2011-08-01

    We confirm the difference in chemical abundance between stars with and without exoplanets and present the relation between chemical abundances and physical properties of exoplanets, such as planetary mass and the semimajor axis of planetary orbit. We obtained the spectra of 52 G-type stars from the Bohyunsan Optical Astronomy Observatory (BOAO) Echelle Spectrograph and carried out abundance analyses for 12 elements: Na, Mg, Al, Si, Ca, Sc, Ti, V, Cr, Mn, Co, and Ni. We first found that the [Mn/Fe] ratios of planet-host stars are higher than those of comparison stars over the entire metallicity range, and we then found that in metal-poor stars of [Fe/H] < -0.4 the abundance difference was larger than in metal-rich samples, especially for the elements of Mg, Al, Sc, Ti, V, and Co. After examining the relation between planet properties and metallicities of planet-host stars, we observed that planet-host stars with low metallicities tend to have several low-mass planets (

  16. Effects of mimosine on Wolbachia in mosquito cells: cell cycle suppression reduces bacterial abundance.

    PubMed

    Fallon, Ann M

    2015-10-01

    The plant allelochemical L-mimosine (β-[N-(3-hydroxy-4-pyridone)]-α-aminopropionic acid; leucenol) resembles the nonessential amino acid, tyrosine. Because the obligate intracellular alphaproteobacterium, Wolbachia pipientis, metabolizes amino acids derived from host cells, the effects of mimosine on infected and uninfected mosquito cells were investigated. The EC50 for mimosine was 6-7 μM with Aedes albopictus C7-10 and C/wStr cell lines, and was not influenced by infection status. Mosquito cells responded to concentrations of mimosine substantially lower than those used to synchronize the mammalian cell cycle; at concentrations of 30-35 μM, mimosine reversibly arrested the mosquito cell cycle at the G1/S boundary and inhibited growth of Wolbachia strain wStr. Although lower concentrations of mimosine slightly increased wStr abundance, concentrations that suppressed the cell cycle reduced Wolbachia levels.

  17. Functional environmental proteomics: elucidating the role of a c-type cytochrome abundant during uranium bioremediation.

    PubMed

    Yun, Jiae; Malvankar, Nikhil S; Ueki, Toshiyuki; Lovley, Derek R

    2016-02-01

    Studies with pure cultures of dissimilatory metal-reducing microorganisms have demonstrated that outer-surface c-type cytochromes are important electron transfer agents for the reduction of metals, but previous environmental proteomic studies have typically not recovered cytochrome sequences from subsurface environments in which metal reduction is important. Gel-separation, heme-staining and mass spectrometry of proteins in groundwater from in situ uranium bioremediation experiments identified a putative c-type cytochrome, designated Geobacter subsurface c-type cytochrome A (GscA), encoded within the genome of strain M18, a Geobacter isolate previously recovered from the site. Homologs of GscA were identified in the genomes of other Geobacter isolates in the phylogenetic cluster known as subsurface clade 1, which predominates in a diversity of Fe(III)-reducing subsurface environments. Most of the gscA sequences recovered from groundwater genomic DNA clustered in a tight phylogenetic group closely related to strain M18. GscA was most abundant in groundwater samples in which Geobacter sp. predominated. Expression of gscA in a strain of Geobacter sulfurreducens that lacked the gene for the c-type cytochrome OmcS, thought to facilitate electron transfer from conductive pili to Fe(III) oxide, restored the capacity for Fe(III) oxide reduction. Atomic force microscopy provided evidence that GscA was associated with the pili. These results demonstrate that a c-type cytochrome with an apparent function similar to that of OmcS is abundant when Geobacter sp. are abundant in the subsurface, providing insight into the mechanisms for the growth of subsurface Geobacter sp. on Fe(III) oxide and suggesting an approach for functional analysis of other Geobacter proteins found in the subsurface.

  18. Photospheric carbon and oxygen abundances of F-G type stars in the Pleiades cluster*

    NASA Astrophysics Data System (ADS)

    Takeda, Yoichi; Hashimoto, Osamu; Honda, Satoshi

    2017-02-01

    In order to investigate the carbon-to-oxygen ratio of the young open cluster M 45 (Pleiades), the C and O abundances of 32 selected F-G type dwarfs (in the effective temperature range of Teff ˜ 5800-7600 K and projected rotational velocity range of vesin i ˜ 10-110 km s-1) belonging to this cluster were determined by applying the synthetic spectrum-fitting technique to C I 5380 and O I 6156-8 lines. The non-local thermodynamical equilibrium corrections for these C I and O I lines were found to be practically negligible (less than a few hundredths dex).The resulting C and O abundances (along with the Fe abundance) turned out nearly uniform without any systematic dependence upon Teff or vesin i. We found, however, in spite of almost solar Fe abundance ([Fe/H] ˜ 0), carbon turned out to be slightly subsolar ([C/H] ˜ -0.1) while that of oxygen was slightly supersolar ([O/H] ˜ +0.1). This leads to a conclusion that the [C/O] ratio was moderately subsolar (˜ -0.2) in the primordial gas from which these Pleiades stars were formed ˜ 120-130 Myr ago. Interestingly, similarly young B-type stars are reported to show just the same result ([C/O] ˜ -0.2), while rather aged (˜ 1-10 Gyr) field F-G stars of near-solar metallicity yield almost the solar value ([C/O] ˜ 0) on average. Such a difference in the C/O ratio between two star groups of distinctly different ages may be explained as a consequence of the orbit migration mechanism which Galactic stars may undergo over a long time.

  19. Bacterial bile metabolising gene abundance in Crohn's, ulcerative colitis and type 2 diabetes metagenomes.

    PubMed

    Labbé, Alain; Ganopolsky, Jorge G; Martoni, Christopher J; Prakash, Satya; Jones, Mitchell L

    2014-01-01

    We performed an analysis to determine the importance of bile acid modification genes in the gut microbiome of inflammatory bowel disease and type 2 diabetic patients. We used publicly available metagenomic datasets from the Human Microbiome Project and the MetaHIT consortium, and determined the abundance of bile salt hydrolase gene (bsh), 7 alpha-dehydroxylase gene (adh) and 7-alpha hydroxysteroid dehydrogenase gene (hsdh) in fecal bacteria in diseased populations of Crohn's disease (CD), Ulcerative Colitis (UC) and Type 2 diabetes mellitus (T2DM). Phylum level abundance analysis showed a significant reduction in Firmicute-derived bsh in UC and T2DM patients but not in CD patients, relative to healthy controls. Reduction of adh and hsdh genes was also seen in UC and T2DM patients, while an increase was observed in the CD population as compared to healthy controls. A further analysis of the bsh genes showed significant differences in the correlations of certain Firmicutes families with disease or healthy populations. From this observation we proceeded to analyse BSH protein sequences and identified BSH proteins clusters representing the most abundant strains in our analysis of Firmicute bsh genes. The abundance of the bsh genes corresponding to one of these protein clusters was significantly reduced in all disease states relative to healthy controls. This cluster includes bsh genes derived from Lachospiraceae, Clostridiaceae, Erysipelotrichaceae and Ruminococcaceae families. This metagenomic analysis provides evidence of the importance of bile acid modifying enzymes in health and disease. It further highlights the importance of identifying gene and protein clusters, as the same gene may be associated with health or disease, depending on the strains expressing the enzyme, and differences in the enzymes themselves.

  20. Amphibian and reptile abundance in riparian and upslope areas of five forest types in western Oregon

    USGS Publications Warehouse

    Gomez, D.M.; Anthony, R.G.

    1996-01-01

    We compared species composition and relative abundance of herpetofauna between riparian and upslope habitats among 5 forest types (shrub, open sapling-pole, large sawtimber and old-growth conifer forests, and deciduous forests) in Western Oregon. Riparian- and upslope- associated species were identified based on capture frequencies from pitfall trapping. Species richness was similar among forest types but slightly greater in the shrub stands. The abundances of 3 species differed among forest types. Total captures was highest in deciduous forests, intermediate in the mature conifer forests, and lowest in the 2 young coniferous forests. Species richness was similar between stream and upslope habitats; however, captures were higher in riparian than upslope habitat. Tailed frogs (Ascaphus truei), Dunn's salamanders (Plethodon dunni), roughskin newts(Tanicha granulosa), Pacific giant salamanders (Dicamptodon tenebrosus) and red-legged frogs(Rana aurora) were captured more frequently in riparian than upslope habitats. Of these species the red-legged frog and Pacific giant salamander may depend on riparian habitat for at least part of their life requirements, while tailed frogs, Dunn's salamanders and roughskin newts appear to be riparian associated species. In addition, we found Oregon salamanders (Ensatina eschscholtzi) were associated with upslope habitats. We suggest riparian management zones should be al least 75-100 m on each side of the stream and that management for upslope/and or old forest associates may be equally as important as for riparian species.

  1. Local Abundance Patterns of Noctuid Moths in Olive Orchards: Life-History Traits, Distribution Type and Habitat Interactions

    PubMed Central

    Pérez-Guerrero, Sergio; Redondo, Alberto José; Yela, José Luis

    2011-01-01

    Local species abundance is related to range size, habitat characteristics, distribution type, body size, and life-history variables. In general, habitat generalists and polyphagous species are more abundant in broad geographical areas. Underlying this, local abundance may be explained from the interactions between life-history traits, chorological pattern, and the local habitat characteristics. The relationship within taxa between life-history traits, distribution area, habitat characteristics, and local abundance of the noctuid moth (Lepidoptera: Noctuidae) assemblage in an olive orchard, one of the most important agro-ecosystems in the Mediterranean basin, was analyzed. A total of 66 species were detected over three years of year-round weekly samplings using the light-trap method. The life-history traits examined and the distribution type were found to be related to the habitat-species association, but none of the biological strategies defined from the association to the different habitats were linked with abundance. In contrast to general patterns, dispersal ability and number of generations per year explained differences in abundance. The relationships were positive, with opportunistic taxa that have high mobility and several generations being locally more abundant. In addition, when the effect of migrant species was removed, the distribution type explained abundance differences, with Mediterranean taxa (whose baricenter is closer to the studied area) being more abundant. PMID:21529251

  2. Mapping impervious surface type and sub-pixel abundance using hyperion hyperspectral imagery

    USGS Publications Warehouse

    Falcone, J.A.; Gomez, R.

    2005-01-01

    Impervious surfaces have been identified as an important and quantifiable indicator of environmental degradation in urban settings. A number of research efforts have been directed at mapping impervious surface type using multispectral imagery. To date, however, no studies have compared equivalent techniques using multispectral and hyperspectral imagery to that end. In this study, data from NASA's 220-channel Hyperion instrument were used to: a) delineate three types of impervious surface, and b) map sub-pixel percent abundance for a study site near Washington, D.C., USA. The results were compared with the results of similar methods using same-spatial-resolution Landsat ETM+ data for mapping impervious surface type, and with the results of the U.S. Geological Survey's National Land Cover Data (NLCD) 2001 impervious surface data layer, which is derived from Landsat and high-resolution Ikonos data. The accuracy of discriminating impervious surface type using Hyperion data was assessed at 88% versus Landsat at 59%. The sub-pixel percent impervious map corresponded well with the NLCD 2001; impervious surface in the study area was calculated at 29.3% for NLCD 2001 and 28.4% for the Hyperion-derived layer. The results suggest that fairly simple techniques using hyperspectral data are effective for quantifying impervious surface type, and that high-spectral- resolution imagery may be a good alternative to high-spatial-resolution data.

  3. Solar Cells from Earth-Abundant Semiconductors with Plasmon-Enhanced Light Absorption

    SciTech Connect

    Atwater, Harry

    2012-04-30

    Progress is reported in these areas: Plasmonic Light Trapping in Thin Film a-Si Solar Cells; Plasmonic Light Trapping in Thin InGaN Quantum Well Solar Cells; and Earth Abundant Cu{sub 2}O and Zn{sub 3}P{sub 2} Solar Cells.

  4. Tailored enrichment strategy detects low abundant small noncoding RNAs in HIV-1 infected cells

    PubMed Central

    2012-01-01

    Background The various classes of small noncoding RNAs (sncRNAs) are important regulators of gene expression across divergent types of organisms. While a rapidly increasing number of sncRNAs has been identified over recent years, the isolation of sncRNAs of low abundance remains challenging. Virally encoded sncRNAs, particularly those of RNA viruses, can be expressed at very low levels. This is best illustrated by HIV-1 where virus encoded sncRNAs represent approximately 0.1-1.0% of all sncRNAs in HIV-1 infected cells or were found to be undetected. Thus, we applied a novel, sequence targeted enrichment strategy to capture HIV-1 derived sncRNAs in HIV-1 infected primary CD4+ T-lymphocytes and macrophages that allows a greater than 100-fold enrichment of low abundant sncRNAs. Results Eight hundred and ninety-two individual HIV-1 sncRNAs were cloned and sequenced from nine different sncRNA libraries derived from five independent experiments. These clones represent up to 90% of all sncRNA clones in the generated libraries. Two hundred and sixteen HIV-1 sncRNAs were distinguishable as unique clones. They are spread throughout the HIV-1 genome, however, forming certain clusters, and almost 10% show an antisense orientation. The length of HIV-1 sncRNAs varies between 16 and 89 nucleotides with an unexpected peak at 31 to 50 nucleotides, thus, longer than cellular microRNAs or short-interfering RNAs (siRNAs). Exemplary HIV-1 sncRNAs were also generated in cells infected with different primary HIV-1 isolates and can inhibit HIV-1 replication. Conclusions HIV-1 infected cells generate virally encoded sncRNAs, which might play a role in the HIV-1 life cycle. Furthermore, the enormous capacity to enrich low abundance sncRNAs in a sequence specific manner highly recommends our selection strategy for any type of investigation where origin or target sequences of the sought-after sncRNAs are known. PMID:22458358

  5. Carbon and nitrogen abundances in F- and G-type stars

    NASA Technical Reports Server (NTRS)

    Clegg, R. E. S.

    1977-01-01

    Carbon and nitrogen abundances have been obtained for a sample of 11-F- and G-type dwarfs covering a range in Fe/H abundance ratio from -0.8 to +0.3. Model atmospheres, which included the effects of convection and line blanketing, were used to calculate synthetic spectra of the CH, CN, and NH molecular bands. Effective oscillator strengths for the bands studied were found by matching synthetic spectra calculated from a model solar atmosphere with the observed solar bands. Many of the metal-poor stars, and particularly the high-velocity stars, were found to have substantial nitrogen over-deficiencies, suggesting that N is manufactured mostly in a secondary manner. The carbon-to-iron ratios were similar to the solar ratio, although there may be slight C over-deficiencies in metal-poor stars. However, the variation in C/Fe is not as marked as that found recently by Hearnshaw (1974). A comprehensive discussion of the theoretical errors is given, and some applications to Galactic evolution are noted.

  6. Effect of Leaf Type and Pesticide Exposure on Abundance of Bacterial Taxa in Mosquito Larval Habitats

    PubMed Central

    Muturi, Ephantus J.; Orindi, Benedict O.; Kim, Chang-Hyun

    2013-01-01

    Lentic freshwater systems including those inhabited by aquatic stages of mosquitoes derive most of their carbon inputs from terrestrial organic matter mainly leaf litter. The leaf litter is colonized by microbial communities that provide the resource base for mosquito larvae. While the microbial biomass associated with different leaf species in container aquatic habitats is well documented, the taxonomic composition of these microbes and their response to common environmental stressors is poorly understood. We used indoor aquatic microcosms to determine the abundances of major taxonomic groups of bacteria in leaf litters from seven plant species and their responses to low concentrations of four pesticides with different modes of action on the target organisms; permethrin, malathion, atrazine and glyphosate. We tested the hypotheses that leaf species support different quantities of major taxonomic groups of bacteria and that exposure to pesticides at environmentally relevant concentrations alters bacterial abundance and community structure in mosquito larval habitats. We found support for both hypotheses suggesting that leaf litter identity and chemical contamination may alter the quality and quantity of mosquito food base (microbial communities) in larval habitats. The effect of pesticides on microbial communities varied significantly among leaf types, suggesting that the impact of pesticides on natural microbial communities may be highly complex and difficult to predict. Collectively, these findings demonstrate the potential for detritus composition within mosquito larval habitats and exposure to pesticides to influence the quality of mosquito larval habitats. PMID:23940789

  7. Terrestrial activity, abundance, diversity of amphibians in differently managed forest types

    SciTech Connect

    Bennett, S.H.; Gibbons, J.W.; Glanville, J.

    1980-04-01

    Diversity indices and relative abundances were determined for amphibians inhabiting three differently managed forest types in South Carolina. Study sites were contiguous around a small lake, and included a slash pine (Pinus ellioti) forest, a loblolly pine (Pinus taeda) forest and a hardwood (predominately oak-hickory) forest. Amphibians were collected using a drift fence and pitfall trap method. Captured animals were marked so that recaptures could be removed from calculations of indices. The dates of study were 30 June-10 August 1977 and 20 June-15 August 1978. The three study sites were similar in species diversity and the evenness component for combined summer data and for the summer of 1978. The hardwood forest had a higher diversity in the summer of 1977. The hardwood forest yielded approximately 50% more individual amphibians than either pine forest during both years.

  8. Relative abundance and flight phenology of two pheromone types of Acrobasis nuxvorella (Lepidoptera: Pyralidae).

    PubMed

    Hartfield, E A; Harris, M K; Medina, R F

    2011-08-01

    Two synthetic sex pheromones have been developed and are currently used to detect the flight of the pecan nut casebearer, Acrobasis nuxvorella Neunzig, the most damaging pest of pecan [Carya illinoinensis (Wangenh.) K. Koch]. One pheromone (referred to as standard) is attractive to moths in the southern United States, but not in Mexico. The other pheromone (referred to as Mexican) is attractive to moths in the southern United States and in Mexico. These two pheromones have been implemented by producers as an important tool in monitoring the activity of this pest and have allowed for more efficient pesticide use. In the future, these pheromones could be used as a means of population reduction through pheromone based control methods. Trapping data taken over a 3-yr period were used to determine if phenological differences exist between pheromone types of pecan nut casebearer. The relative abundance of each pheromone type at several locations in the United States also was evaluated. Results of this study indicate that no phenological differences exist between the two pheromone types studied in the United States and that significantly more males are attracted to field-deployed pheromone traps baited with the standard pheromone than to traps baited with the Mexican pheromone.

  9. Depletion of cells and abundant proteins from biological samples by enhanced dielectrophoresis✩

    PubMed Central

    Gupta, C.; Provine, J.; Davis, R.W.; Howe, R.T.

    2016-01-01

    Platforms that are sensitive and specific enough to assay low-abundance protein biomarkers, in a high throughput multiplex format, within a complex biological fluid specimen, are necessary to enable protein biomarker based diagnostics for diseases such as cancer. The signal from an assay for a low-abundance protein biomarker in a biological fluid sample like blood is typically buried in a background that arises from the presence of blood cells and from high-abundance proteins that make up 90% of the assayed protein mass. We present an automated on-chip platform for the depletion of cells and highly abundant serum proteins in blood. Our platform consists of two components, the first of which is a microfluidic mixer that mixes beads containing antibodies against the highly abundant proteins in the whole blood. This complex mixture (consisting of beads, cells, and serum proteins) is then injected into the second component of our microfluidic platform, which comprises a filter trench to capture all the cells and the beads. The size-based trapping of the cells and beads into the filter trench is significantly enhanced by leveraging additional negative dielectrophoretic forces to push the micron sized particles (cells and beads which have captured the highly abundant proteins) down into the trench, allowing the serum proteins of lower abundance to flow through. In general, dielectrophoresis using bare electrodes is incapable of producing forces beyond the low piconewton range that tend to be insufficient for separation applications. However, by using electrodes passivated with atomic layer deposition, we demonstrate the application of enhanced negative DEP electrodes together with size-based flltration induced by the filter trench, to deplete 100% of the micron sized particles in the mixture. PMID:26924893

  10. Distinguishing cell type using epigenotype

    NASA Astrophysics Data System (ADS)

    Wytock, Thomas; Motter, Adilson E.

    Recently, researchers have proposed that unique cell types are attractors of their epigenetic dynamics including gene expression and chromatin conformation patterns. Traditionally, cell types have been classified by their function, morphology, cytochemistry, and other macroscopically observable properties. Because these properties are the result of many proteins working together, it should be possible to predict cell types from gene expression or chromatin conformation profiles. In this talk, I present a maximum entropy approach to identify and distinguish cell type attractors on the basis of correlations within these profiles. I will demonstrate the flexibility of this method through its separate application to gene expression and chromatin conformation datasets. I show that our method out-performs other machine-learning techniques and uncorrelated benchmarks. We adapt our method to predict growth rate from gene expression in E. coli and S. cerevisiae and compare our predictions with those from metabolic models. In addition, our method identifies a nearly convex region of state-space associated with each cell type attractor basin. Estimates of the growth rate and attractor basin make it possible to rationally control gene regulatory networks independent of a model. This research was supported by NSF-GRFP, NSF-GK12, GAANN, and Northwestern's NIH-NIGMS Molecular Biophysics Training Grant.

  11. Early-type Galaxy Archeology: Ages, Abundance Ratios, and Effective Temperatures from Full-spectrum Fitting

    NASA Astrophysics Data System (ADS)

    Conroy, Charlie; Graves, Genevieve J.; van Dokkum, Pieter G.

    2014-01-01

    The stellar populations of galaxies hold vital clues to their formation histories. In this paper we present results based on modeling stacked spectra of early-type galaxies drawn from the Sloan Digital Sky Survey as a function of velocity dispersion, σ, from 90 km s-1 to 300 km s-1. The spectra are of extremely high quality, with typical signal-to-noise ratio of 1000 Å-1, and a wavelength coverage of 4000 Å -8800 Å. Our population synthesis model includes variation in 16 elements from C to Ba, a two-component star formation history, the shift in effective temperature, Δ T eff, of the stars with respect to a solar metallicity isochrone, and the stellar initial mass function, among other parameters. In our approach we fit the full optical spectra rather than a select number of spectral indices and are able to, for the first time, measure the abundances of the elements V, Cr, Mn, Co, and Ni from the integrated light of distant galaxies. Our main results are as follows: (1) light-weighted stellar ages range from 6-12 Gyr from low to high σ (2) [Fe/H] varies by less than 0.1 dex across the entire sample; (3) Mg closely tracks O, and both increase from ≈0.0 at low σ to ~0.25 at high σ Si and Ti show a shallower rise with σ, and Ca tracks Fe rather than O; (4) the iron peak elements V, Cr, Mn, and Ni track Fe, while Co tracks O, suggesting that Co forms primarily in massive stars; (5) C and N track O over the full sample and [C/Fe] and [N/Fe] exceed 0.2 at high σ and (6) the variation in Δ T eff with total metallicity closely follows theoretical predictions based on stellar evolution theory. This last result is significant because it implies that we are robustly solving not only for the detailed abundance patterns but also the detailed temperature distributions (i.e., isochrones) of the stars in these galaxies. A variety of tests reveal that the systematic uncertainties in our measurements are probably 0.05 dex or less. Our derived [Mg/Fe] and [O

  12. Fluorescent peptide biosensor for probing the relative abundance of cyclin-dependent kinases in living cells.

    PubMed

    Kurzawa, Laetitia; Pellerano, Morgan; Coppolani, J B; Morris, May C

    2011-01-01

    Cyclin-dependant kinases play a central role in coordinating cell growth and division, and in sustaining proliferation of cancer cells, thereby constituting attractive pharmacological targets. However, there are no direct means of assessing their relative abundance in living cells, current approaches being limited to antigenic and proteomic analysis of fixed cells. In order to probe the relative abundance of these kinases directly in living cells, we have developed a fluorescent peptide biosensor with biligand affinity for CDKs and cyclins in vitro, that retains endogenous CDK/cyclin complexes from cell extracts, and that bears an environmentally-sensitive probe, whose fluorescence increases in a sensitive fashion upon recognition of its targets. CDKSENS was introduced into living cells, through complexation with the cell-penetrating carrier CADY2 and applied to assess the relative abundance of CDK/Cyclins through fluorescence imaging and ratiometric quantification. This peptide biosensor technology affords direct and sensitive readout of CDK/cyclin complex levels, and reports on differences in complex formation when tampering with a single CDK or cyclin. CDKSENS further allows for detection of differences between different healthy and cancer cell lines, thereby enabling to distinguish cells that express high levels of these heterodimeric kinases, from cells that present decreased or defective assemblies. This fluorescent biosensor technology provides information on the overall status of CDK/Cyclin complexes which cannot be obtained through antigenic detection of individual subunits, in a non-invasive fashion which does not require cell fixation or extraction procedures. As such it provides promising perspectives for monitoring the response to therapeutics that affect CDK/Cyclin abundance, for cell-based drug discovery strategies and fluorescence-based cancer diagnostics.

  13. Oxygen abundance distributions in six late-type galaxies based on SALT spectra of H II regions

    NASA Astrophysics Data System (ADS)

    Zinchenko, I. A.; Kniazev, A. Y.; Grebel, E. K.; Pilyugin, L. S.

    2015-10-01

    Spectra of 34 H ii regions in the late-type galaxies NGC 1087, NGC 2967, NGC 3023, NGC 4030, NGC 4123, and NGC 4517A were observed with the South African Large Telescope (SALT). In all 34 H ii regions, oxygen abundances were determined through the "counterpart" method (C method). Additionally, in two H ii regions in which we detected auroral lines, we measured oxygen abundances with the classic Te method. We also estimated the abundances in our H ii regions using the O3N2 and N2 calibrations and compared those with the C-based abundances. With these data, we examined the radial abundance distributions in the disks of our target galaxies. We derived surface-brightness profiles and other characteristics of the disks (the surface brightness at the disk center and the disk scale length) in three photometric bands for each galaxy using publicly available photometric imaging data. The radial distributions of the oxygen abundances predicted by the relation between abundance and disk surface brightness in the W1 band obtained for spiral galaxies in our previous study are close to the radial distributions of the oxygen abundances determined from the analysis of the emission line spectra for four galaxies where this relation is applicable. Hence, when the surface-brightness profile of a late-type galaxy is known, this parametric relation can be used to estimate the likely present-day oxygen abundance in the disk of the galaxy. Based on observations made with the Southern African Large Telescope, programs 2012-1-RSA_OTH-001, 2012-2-RSA_OTH-003 and 2013-1-RSA_OTH-005.

  14. Spectra of late type dwarf stars of known abundance for stellar population models

    NASA Technical Reports Server (NTRS)

    Oconnell, R. W.

    1990-01-01

    The project consisted of two parts. The first was to obtain new low-dispersion, long-wavelength, high S/N IUE spectra of F-G-K dwarf stars with previously determined abundances, temperatures, and gravities. To insure high quality, the spectra are either trailed, or multiple exposures are taken within the large aperture. Second, the spectra are assembled into a library which combines the new data with existing IUE Archive data to yield mean spectral energy distributions for each important type of star. My principal responsibility is the construction and maintenance of this UV spectral library. It covers the spectral range 1200-3200A and is maintained in two parts: a version including complete wavelength coverage at the full spectral resolution of the Low Resolution cameras; and a selected bandpass version, consisting of the mean flux in pre-selected 20A bands. These bands are centered on spectral features or continuum regions of special utility - e.g. the C IV lambda 1550 or Mg II lambda 2800 feature. In the middle-UV region, special emphasis is given to those features (including continuum 'breaks') which are most useful in the study of F-G-K star spectra in the integrated light of old stellar populations.

  15. Syncytial-Type Cell Plates

    PubMed Central

    Otegui, Marisa; Staehelin, L. Andrew

    2000-01-01

    Cell wall formation in the syncytial endosperm of Arabidopsis was studied by using high-pressure-frozen/freeze-substituted developing seeds and immunocytochemical techniques. The endosperm cellularization process begins at the late globular embryo stage with the synchronous organization of small clusters of oppositely oriented microtubules (∼10 microtubules in each set) into phragmoplast-like structures termed mini-phragmoplasts between both sister and nonsister nuclei. These mini-phragmoplasts produce a novel kind of cell plate, the syncytial-type cell plate, from Golgi-derived vesicles ∼63 nm in diameter, which fuse by way of hourglass-shaped intermediates into wide (∼45 nm in diameter) tubules. These wide tubules quickly become coated and surrounded by a ribosome-excluding matrix; as they grow, they branch and fuse with each other to form wide tubular networks. The mini-phragmoplasts formed between a given pair of nuclei produce aligned tubular networks that grow centrifugally until they merge into a coherent wide tubular network with the mini-phragmoplasts positioned along the network margins. The individual wide tubular networks expand laterally until they meet and eventually fuse with each other at the sites of the future cell corners. Transformation of the wide tubular networks into noncoated, thin (∼27 nm in diameter) tubular networks begins at multiple sites and coincides with the appearance of clathrin-coated budding structures. After fusion with the syncytial cell wall, the thin tubular networks are converted into fenestrated sheets and cell walls. Immunolabeling experiments show that the cell plates and cell walls of the endosperm differ from those of the embryo and maternal tissue in two features: their xyloglucans lack terminal fucose residues on the side chain, and callose persists in the cell walls after the cell plates fuse with the parental plasma membrane. The lack of terminal fucose residues on xyloglucans suggests that these cell wall

  16. NREL Explores Earth-Abundant Materials for Future Solar Cells (Fact Sheet)

    SciTech Connect

    Not Available

    2012-10-01

    Researchers at the National Renewable Energy Laboratory (NREL) are using a theory-driven technique - sequential cation mutation - to understand the nature and limitations of promising solar cell materials that can replace today's technologies. Finding new materials that use Earth-abundant elements and are easily manufactured is important for large-scale solar electricity deployment.

  17. The origin and evolution of cell types.

    PubMed

    Arendt, Detlev; Musser, Jacob M; Baker, Clare V H; Bergman, Aviv; Cepko, Connie; Erwin, Douglas H; Pavlicev, Mihaela; Schlosser, Gerhard; Widder, Stefanie; Laubichler, Manfred D; Wagner, Günter P

    2016-12-01

    Cell types are the basic building blocks of multicellular organisms and are extensively diversified in animals. Despite recent advances in characterizing cell types, classification schemes remain ambiguous. We propose an evolutionary definition of a cell type that allows cell types to be delineated and compared within and between species. Key to cell type identity are evolutionary changes in the 'core regulatory complex' (CoRC) of transcription factors, that make emergent sister cell types distinct, enable their independent evolution and regulate cell type-specific traits termed apomeres. We discuss the distinction between developmental and evolutionary lineages, and present a roadmap for future research.

  18. Relating species abundance distributions to species-area curves in two Mediterranean-type shrublands

    USGS Publications Warehouse

    Keeley, Jon E.

    2003-01-01

    Based on both theoretical and empirical studies there is evidence that different species abundance distributions underlie different species-area relationships. Here I show that Australian and Californian shrubland communities (at the scale from 1 to 1000 m2) exhibit different species-area relationships and different species abundance patterns. The species-area relationship in Australian heathlands best fits an exponential model and species abundance (based on both density and cover) follows a narrow log normal distribution. In contrast, the species-area relationship in Californian shrublands is best fit with the power model and, although species abundance appears to fit a log normal distribution, the distribution is much broader than in Australian heathlands. I hypothesize that the primary driver of these differences is the abundance of small-stature annual species in California and the lack of annuals in Australian heathlands. Species-area is best fit by an exponential model in Australian heathlands because the bulk of the species are common and thus the species-area curves initially rise rapidly between 1 and 100 m2. Annuals in Californian shrublands generate very broad species abundance distributions with many uncommon or rare species. The power function is a better model in these communities because richness increases slowly from 1 to 100 m2 but more rapidly between 100 and 1000 m2due to the abundance of rare or uncommon species that are more likely to be encountered at coarser spatial scales. The implications of this study are that both the exponential and power function models are legitimate representations of species-area relationships in different plant communities. Also, structural differences in community organization, arising from different species abundance distributions, may lead to different species-area curves, and this may be tied to patterns of life form distribution.

  19. [Cell therapy for type I diabete].

    PubMed

    Sokolova, I B

    2009-01-01

    Cell therapy is a modern and promising approach to type I diabetes mellitus treatment. Nowadays a wide range of cells is used in laboratory experiments and clinical studies, including allogeneic and xenogeneic cells of Langergance islets, bone marrow cells, haematopoietic stem cells, mesenchymal stem cells, and cord blood stem cells. Any type of the cells named could correct the status of the patients to a certain extent. However, full recovery after cell therapy has not been achieved yet.

  20. Predicting the risk of toxic blooms of golden alga from cell abundance and environmental covariates

    USGS Publications Warehouse

    Patino, Reynaldo; VanLandeghem, Matthew M.; Denny, Shawn

    2016-01-01

    Golden alga (Prymnesium parvum) is a toxic haptophyte that has caused considerable ecological damage to marine and inland aquatic ecosystems worldwide. Studies focused primarily on laboratory cultures have indicated that toxicity is poorly correlated with the abundance of golden alga cells. This relationship, however, has not been rigorously evaluated in the field where environmental conditions are much different. The ability to predict toxicity using readily measured environmental variables and golden alga abundance would allow managers rapid assessments of ichthyotoxicity potential without laboratory bioassay confirmation, which requires additional resources to accomplish. To assess the potential utility of these relationships, several a priori models relating lethal levels of golden alga ichthyotoxicity to golden alga abundance and environmental covariates were constructed. Model parameters were estimated using archived data from four river basins in Texas and New Mexico (Colorado, Brazos, Red, Pecos). Model predictive ability was quantified using cross-validation, sensitivity, and specificity, and the relative ranking of environmental covariate models was determined by Akaike Information Criterion values and Akaike weights. Overall, abundance was a generally good predictor of ichthyotoxicity as cross validation of golden alga abundance-only models ranged from ∼ 80% to ∼ 90% (leave-one-out cross-validation). Environmental covariates improved predictions, especially the ability to predict lethally toxic events (i.e., increased sensitivity), and top-ranked environmental covariate models differed among the four basins. These associations may be useful for monitoring as well as understanding the abiotic factors that influence toxicity during blooms.

  1. Abundance anomalies of carbon and nitrogen in the IUE spectra of Algol-type interacting binaries

    NASA Technical Reports Server (NTRS)

    Mccluskey, Carolina P. S.

    1990-01-01

    There are two primary ways in which the products of nucleosynthesis in stellar interiors may appear at the surface of a star. These are mixing and/or loss of the original unburned stellar envelope. In interacting binaries, overflow can contribute dramatically to envelope loss. The simplest abundance anomalies to be expected from nuclear burning of hydrogen, helium, or carbon would be under or over abundances H, He, C, O, Ne, and Mg. In addition, it is expected that carbon is initially severely depleted, while nitrogen is enhanced during hydrogen burning via the CNO cycle in stars above two solar masses. Other, more subtle anomalies are also expected, and elements heavier than magnesium can be created during very late evolution by nuclear burning in massive stars. Consequently, it is expected that abundance anomalies of various kinds should occur in interacting binaries where one or both stars have lost significant amounts of mass.

  2. Genetics of single-cell protein abundance variation in large yeast populations

    NASA Astrophysics Data System (ADS)

    Albert, Frank W.; Treusch, Sebastian; Shockley, Arthur H.; Bloom, Joshua S.; Kruglyak, Leonid

    2014-02-01

    Variation among individuals arises in part from differences in DNA sequences, but the genetic basis for variation in most traits, including common diseases, remains only partly understood. Many DNA variants influence phenotypes by altering the expression level of one or several genes. The effects of such variants can be detected as expression quantitative trait loci (eQTL). Traditional eQTL mapping requires large-scale genotype and gene expression data for each individual in the study sample, which limits sample sizes to hundreds of individuals in both humans and model organisms and reduces statistical power. Consequently, many eQTL are probably missed, especially those with smaller effects. Furthermore, most studies use messenger RNA rather than protein abundance as the measure of gene expression. Studies that have used mass-spectrometry proteomics reported unexpected differences between eQTL and protein QTL (pQTL) for the same genes, but these studies have been even more limited in scope. Here we introduce a powerful method for identifying genetic loci that influence protein expression in the yeast Saccharomyces cerevisiae. We measure single-cell protein abundance through the use of green fluorescent protein tags in very large populations of genetically variable cells, and use pooled sequencing to compare allele frequencies across the genome in thousands of individuals with high versus low protein abundance. We applied this method to 160 genes and detected many more loci per gene than previous studies. We also observed closer correspondence between loci that influence protein abundance and loci that influence mRNA abundance of a given gene. Most loci that we detected were clustered in `hotspots' that influence multiple proteins, and some hotspots were found to influence more than half of the proteins that we examined. The variants that underlie these hotspots have profound effects on the gene regulatory network and provide insights into genetic variation in cell

  3. Cell abundance and microbial community composition along a complete oil sand mining and reclamation process

    NASA Astrophysics Data System (ADS)

    Lappé, M.; Schneider, B.; Kallmeyer, J.

    2012-12-01

    Hydrocarbons constitute an important energy source for microbes but can also be of environmental concern. Microbial activity causes hydrocarbon degradation and thereby loss of economical value, but also helps to remove hydrocarbons from the environment. The present study characterizes the abundance of microbes along the oil sand mining process in Alberta, Canada, as a first approach to assess the impact of mining and oil extraction on the microbial population. After mining the oil is extracted from the sediment by a hot-water extraction (50-60°C), resulting in three major fractions: crude oil, tailings sand and fine tailings. The tailings sand is used as substratum for newly developing soils on the reclamation areas. The very liquid fine tailings still have a TOC content of about 4.3% and are pumped into tailings ponds, where they need up to three decades to settle and solidify. After deposition, these mature fine tailings (MFTs) are enriched in organics (TOC content between 9.6 and 16.8%) and dredged out of the ponds and put on dumps for several years for dewatering. Finally they are brought out onto the reclamation sites and deposited below the sand layer. Cells were extracted from oily sediments according to the protocol of Lappé and Kallmeyer (2011), stained with SYBR Green I and counted by fluorescence microscopy. Cell abundance in the unprocessed oil sand is around 1.6 x 107 cells cm-3. After processing the fresh fine tailings still contain around 1.6 x 107 cells cm-3. Cell counts in the processed MFTs are 5.8 x 107 cells cm-3, whereas in the sand used as substratum for newly developing soils, they are twice as high (1.4 x 108). In root-bearing horizons, cell counts reach 1.1 x 109 cell cm-3. Cell numbers calculated from cultivation experiments are in the same range. Higher cell counts in the tailings sand are probably due to a higher nitrogen supply through the addition of a 35 cm top layer of a peat-mineral mix. In the sand nitrate concentrations are high

  4. Single-cell messenger RNA sequencing reveals rare intestinal cell types.

    PubMed

    Grün, Dominic; Lyubimova, Anna; Kester, Lennart; Wiebrands, Kay; Basak, Onur; Sasaki, Nobuo; Clevers, Hans; van Oudenaarden, Alexander

    2015-09-10

    Understanding the development and function of an organ requires the characterization of all of its cell types. Traditional methods for visualizing and isolating subpopulations of cells are based on messenger RNA or protein expression of only a few known marker genes. The unequivocal identification of a specific marker gene, however, poses a major challenge, particularly if this cell type is rare. Identifying rare cell types, such as stem cells, short-lived progenitors, cancer stem cells, or circulating tumour cells, is crucial to acquire a better understanding of normal or diseased tissue biology. To address this challenge we first sequenced the transcriptome of hundreds of randomly selected cells from mouse intestinal organoids, cultured self-organizing epithelial structures that contain all cell lineages of the mammalian intestine. Organoid buds, like intestinal crypts, harbour stem cells that continuously differentiate into a variety of cell types, occurring at widely different abundances. Since available computational methods can only resolve more abundant cell types, we developed RaceID, an algorithm for rare cell type identification in complex populations of single cells. We demonstrate that this algorithm can resolve cell types represented by only a single cell in a population of randomly sampled organoid cells. We use this algorithm to identify Reg4 as a novel marker for enteroendocrine cells, a rare population of hormone-producing intestinal cells. Next, we use Reg4 expression to enrich for these rare cells and investigate the heterogeneity within this population. RaceID confirmed the existence of known enteroendocrine lineages, and moreover discovered novel subtypes, which we subsequently validated in vivo. Having validated RaceID we then applied the algorithm to ex vivo-isolated Lgr5-positive stem cells and their direct progeny. We find that Lgr5-positive cells represent a homogenous abundant population of stem cells mixed with a rare population of Lgr5

  5. Constraining the Abundances of Complex Organics in the Inner Regions of Solar-type Protostars

    NASA Astrophysics Data System (ADS)

    Taquet, Vianney; López-Sepulcre, Ana; Ceccarelli, Cecilia; Neri, Roberto; Kahane, Claudine; Charnley, Steven B.

    2015-05-01

    The high abundances of Complex Organic Molecules (COMs) with respect to methanol, the most abundant COM, detected toward low-mass protostars, tend to be underpredicted by astrochemical models. This discrepancy might come from the large beam of the single-dish telescopes, encompassing several components of the studied protostar, commonly used to detect COMs. To address this issue, we have carried out multi-line observations of methanol and several COMs toward the two low-mass protostars NGC 1333-IRAS 2A and -IRAS 4A with the Plateau de Bure interferometer at an angular resolution of 2″, resulting in the first multi-line detection of the O-bearing species glycolaldehyde and ethanol and of the N-bearing species ethyl cyanide toward low-mass protostars other than IRAS 16293. The high number of detected transitions from COMs (more than 40 methanol transitions for instance) allowed us to accurately derive the source size of their emission and the COM column densities. The COM abundances with respect to methanol derived toward IRAS 2A and IRAS 4A are slightly, but not substantitally, lower than those derived from previous single-dish observations. The COM abundance ratios do not vary significantly with the protostellar luminosity, over five orders of magnitude, implying that low-mass hot corinos are quite chemically rich as high-mass hot cores. Astrochemical models still underpredict the abundances of key COMs, such as methyl formate or di-methyl ether, suggesting that our understanding of their formation remains incomplete.

  6. A monoallelic-to-biallelic T-cell transcriptional switch regulates GATA3 abundance

    PubMed Central

    Ku, Chia-Jui; Lim, Kim-Chew; Kalantry, Sundeep; Maillard, Ivan; Engel, James Douglas; Hosoya, Tomonori

    2015-01-01

    Protein abundance must be precisely regulated throughout life, and nowhere is the stringency of this requirement more evident than during T-cell development: A twofold increase in the abundance of transcription factor GATA3 results in thymic lymphoma, while reduced GATA3 leads to diminished T-cell production. GATA3 haploinsufficiency also causes human HDR (hypoparathyroidism, deafness, and renal dysplasia) syndrome, often accompanied by immunodeficiency. Here we show that loss of one Gata3 allele leads to diminished expansion (and compromised development) of immature T cells as well as aberrant induction of myeloid transcription factor PU.1. This effect is at least in part mediated transcriptionally: We discovered that Gata3 is monoallelically expressed in a parent of origin-independent manner in hematopoietic stem cells and early T-cell progenitors. Curiously, half of the developing cells switch to biallelic Gata3 transcription abruptly at midthymopoiesis. We show that the monoallelic-to-biallelic transcriptional switch is stably maintained and therefore is not a stochastic phenomenon. This unique mechanism, if adopted by other regulatory genes, may provide new biological insights into the rather prevalent phenomenon of monoallelic expression of autosomal genes as well as into the variably penetrant pathophysiological spectrum of phenotypes observed in many human syndromes that are due to haploinsufficiency of the affected gene. PMID:26385963

  7. Songbird abundance in native and planted grassland varies with type and amount of grassland in the surrounding landscape

    USGS Publications Warehouse

    Davis, Stephen K.; Fisher, Ryan; Skinner, Susan; Shaffer, Terry L.; Brigham, R. Mark

    2013-01-01

    Agriculture and wildlife conservation programs have converted vast amounts of cropland into grasslands planted with exotic species. Understanding how landscape context influences avian use of native and planted grasslands is essential for developing effective conservation strategies in agricultural landscapes. Our primary objective was to determine the extent to which the amount and type of grassland in the surrounding landscape influences the abundance of grassland songbird species on native and planted grassland parcels in southern Saskatchewan and Alberta, Canada. Bird abundance was more strongly influenced by the amount and type of grassland within 400 m of breeding parcels than at larger spatial scales. Grassland specialists responded similarly to habitat and landscape type over both years and provinces. Sprague's pipit (Anthus spragueii) and Baird's sparrow (Ammodramus bairdii) were most common in native grassland parcels surrounded by native grassland and were more likely to occur in planted grasslands surrounded by native grassland. Bobolinks (Dolichonyx oryzivorus) were most common in planted grassland parcels, but their abundance increased with the amount of native grassland surrounding these parcels. Our findings indicate that the suitability of planted grasslands for these species is influenced by their proximity to native grassland. Grassland generalists showed mixed responses to habitat and landscape type over the 2 years (Le Conte's sparrow [Ammodramus leconteii]) and between provinces (Savannah sparrow [Passerculus sandwichensis] and western meadowlark [Sturnella neglecta]). Management to benefit grassland specialists should therefore consider the landscape context when seeding cultivated land to non-native grassland and conserve extant native grassland.

  8. Fiber type effects on contraction-stimulated glucose uptake and GLUT4 abundance in single fibers from rat skeletal muscle.

    PubMed

    Castorena, Carlos M; Arias, Edward B; Sharma, Naveen; Bogan, Jonathan S; Cartee, Gregory D

    2015-02-01

    To fully understand skeletal muscle at the cellular level, it is essential to evaluate single muscle fibers. Accordingly, the major goals of this study were to determine if there are fiber type-related differences in single fibers from rat skeletal muscle for: 1) contraction-stimulated glucose uptake and/or 2) the abundance of GLUT4 and other metabolically relevant proteins. Paired epitrochlearis muscles isolated from Wistar rats were either electrically stimulated to contract (E-Stim) or remained resting (No E-Stim). Single fibers isolated from muscles incubated with 2-deoxy-d-[(3)H]glucose (2-DG) were used to determine fiber type [myosin heavy chain (MHC) isoform protein expression], 2-DG uptake, and abundance of metabolically relevant proteins, including the GLUT4 glucose transporter. E-Stim, relative to No E-Stim, fibers had greater (P < 0.05) 2-DG uptake for each of the isolated fiber types (MHC-IIa, MHC-IIax, MHC-IIx, MHC-IIxb, and MHC-IIb). However, 2-DG uptake for E-Stim fibers was not significantly different among these five fiber types. GLUT4, tethering protein containing a UBX domain for GLUT4 (TUG), cytochrome c oxidase IV (COX IV), and filamin C protein levels were significantly greater (P < 0.05) in MHC-IIa vs. MHC-IIx, MHC-IIxb, or MHC-IIb fibers. TUG and COX IV in either MHC-IIax or MHC-IIx fibers exceeded values for MHC-IIxb or MHC-IIb fibers. GLUT4 levels for MHC-IIax fibers exceeded MHC-IIxb fibers. GLUT4, COX IV, filamin C, and TUG abundance in single fibers was significantly (P < 0.05) correlated with each other. Differences in GLUT4 abundance among the fiber types were not accompanied by significant differences in contraction-stimulated glucose uptake.

  9. Abundances of TC and related elements in stars of type M, MS, and S

    NASA Astrophysics Data System (ADS)

    Vanture, Andrew D.; Wallerstein, George; Brown, Jeffrey A.; Bazan, Grant

    1991-11-01

    Abundances of Co, Zr, Nb, and Tc relative to V have been derived for a sample of ten M and MS stars from 0.10 A/pixel and 0.04 A/pixel Reticon spectra. On a scale with log N(H) = 12.0 and log N(V) = 4.0, it is found that log N(Tc) is about 1.4 for M stars 1.0 MS stars with Tc. It has been suggested by Dominy and Wallerstein that the presence of Tc in M stars which show no enhancements of other s-process elements can be explained by a 'mini s-process'. Detailed calculations and the observed abundances and Tc and related elements presented in this study put this interpretation in doubt. The observations also fail to support the alternative hypothesis suggested by Malaney and Lattanzio that Tc is produced by the photofission of Th and U.

  10. Purification and Characterization of Abundant Secreted Protein in Suspension-Cultured Pumpkin Cells 1

    PubMed Central

    Esaka, Muneharu; Enoki, Keiko; Kouchi, Bonko; Sasaki, Takuji

    1990-01-01

    The abundant secreted protein with molecular weight of 32,000 was purified from the culture medium of suspension-cultured pumpkin (Cucurbita sp.) cells. Two steps, ammonium sulfate fractionation and Sepharose 6B column chromatography, were sufficient for purification to homogeneity. Antibodies against the pure protein were used to show that a protein of the same size is made by callus cells. There is considerable homology between the amino-terminal amino acid sequence of this secreted protein and chitinase isolated from tobacco (Nicotiana tabacum L.) or bean (Phaseolus vulgaris L.). Images Figure 1 Figure 2 Figure 3 Figure 4 PMID:16667554

  11. Oxygen abundance determination of B-type stars with the O I 7771-5 Å lines*

    NASA Astrophysics Data System (ADS)

    Takeda, Yoichi; Honda, Satoshi

    2016-06-01

    Oxygen abundances of 34 B-type stars in the effective temperature range of Teff ˜ 10000-28000 K with diversified rotational velocities (vesin i ˜ 0-250 km s-1) were determined from the O I triplet lines at 7771-5 Å, with an aim of examining whether this O I feature can be a reliable abundance indicator for such high-temperature stars including rapid rotators. It revealed that the required non-local thermodynamic equilibrium (LTE) abundance correction is distinctly large (ranging from ˜-0.6 dex to ˜-1.7 dex) and its consideration is indispensable. On the condition that the non-LTE effect is taken into account, this triplet is a useful O abundance indicator (with a precision of ≲ 0.2 dex) up to Teff ≲ 25000 K, since its total equivalent width is sufficiently large ( ≳ 200 mÅ). In contrast, it is not adequate for abundance derivation for stars at Teff ≳ 25000 K, where its strength rapidly drops down toward a hardly detectable level (except for sharp-lined stars) and its sensitivity to Teff or log g becomes considerably large. The resulting non-LTE oxygen abundances turned out to be almost normal (i.e., near-solar around ˜8.7-8.8 within ˜±0.2 dex) for most stars without any dependence upon projected rotational velocity as well as luminosity (or mass), which is consistent with the prediction of recent stellar evolution calculations.

  12. Pericyte abundance affects sucrose permeability in cultures of rat brain microvascular endothelial cells.

    PubMed

    Parkinson, Fiona E; Hacking, Cindy

    2005-07-05

    The blood-brain barrier is a physical and metabolic barrier that restricts diffusion of blood-borne substances into brain. In vitro models of the blood-brain barrier are used to characterize this structure, examine mechanisms of damage and repair and measure permeability of test substances. The core component of in vitro models of the blood-brain barrier is brain microvascular endothelial cells. We cultured rat brain microvascular endothelial cells (RBMEC) from isolated rat cortex microvessels. After 2-14 days in vitro (DIV), immunohistochemistry of these cells showed strong labeling for zona occludens 1 (ZO-1), a tight junction protein expressed in endothelial cells. Pericytes were also present in these cultures, as determined by expression of alpha-actin. The present study was performed to test different cell isolation methods and to compare the resulting cell cultures for abundance of pericytes and for blood-brain barrier function, as assessed by 14C-sucrose flux. Two purification strategies were used. First, microvessels were preabsorbed onto uncoated plastic for 4 h, then unattached microvessels were transferred to coated culture ware. Second, microvessels were incubated with an antibody to platelet-endothelial cell adhesion molecule 1 (PECAM-1; CD31) precoupled to magnetic beads, and a magnetic separation procedure was performed. Our results indicate that immunopurification, but not preadsorption, was an effective method to purify microvessels and reduce pericyte abundance in the resulting cultures. This purification significantly reduced 14C-sucrose fluxes across cell monolayers. These data indicate that pericytes can interfere with the development of blood-brain barrier properties in in vitro models that utilize primary cultures of RBMECs.

  13. Identifying Type Ia Supernova Mechanisms in Dwarf Spheroidal Galaxies through Analysis of Iron-peak Elemental Abundances

    NASA Astrophysics Data System (ADS)

    Guo, Rachel; Xie, Justin Long; Kirby, Evan N.

    2017-01-01

    Through the fusion of nucleons to produce elements heavier than hydrogen and helium, stellar nucleosynthesis produces most of the elements in the universe. Such is the case in a supernova explosion, which creates most of the elements on the periodic table—including iron-peak elements, atomic numbers 21 through 30—through nucleosynthesis and ejects them into the interstellar medium. In this study, we determine the best theoretical supernova model appropriate for the stars in the dwarf spheroidal galaxies Sculptor, Fornax, Ursa Minor, and Leo II by calculating the abundances of iron-peak elements in these stars. To determine iron-peak elemental abundances, we compare synthesized spectra with observed spectra from medium-resolution spectroscopy and determine the best-fitting spectrum by way of a chi-squared minimization. Through inspecting the relationship between the iron-peak element abundances and the abundance of iron itself and by comparing them to previously hypothesized supernova model theories, we discover that the near-Chandrasekhar mass “n1” model, as predicted by Seitenzahl et al., most accurately represents the trends and patterns within our data, presenting new insight into Type Ia supernovae mechanisms within the Milky Way and beyond.

  14. Effects of forest type and management on native wood wasp abundance (Hymenoptera: Siricidae) in Mississippi, United States.

    PubMed

    Chase, Kevin D; Gandhi, Kamal J K; Riggins, John J

    2014-06-01

    The United States has a rich fauna of native Siricidae (wood wasps), but they are rarely studied because they have limited economic impact. In 2004, a non-native wood-boring pest, Sirex noctilio F., was found established in North America. Because S. noctilio is an economically important pest in pine plantations throughout the Southern Hemisphere, interest in the ecology of American native wood wasp populations has increased. A study was conducted during fall 2011 to investigate the effects of forest stand type and characteristics on native wood wasp abundance, and to describe their flight phenology in northeastern Mississippi. In total, 609 native wood wasps were captured, consisting of 608 Sirex nigricornis F. and one Urocerus cressoni Norton. There were significant treatment and location effects that influenced wood wasp abundance. The flight period of wood wasps captured in our study (October-December) was similar to studies in the southeastern United States, but differed from results in Minnesota and the northeastern United States (June-October). Wood wasp abundance was significantly correlated with higher basal area, smaller tree diameter at breast height, and shorter trees, all indicators of forest stand stress. It appears proper silvicultural management of pine plantations may reduce native wood wasp population abundance in the southeastern United States, as it does to S. noctilio in the Southern Hemisphere. We propose implementing management models used for the southern pine beetle to reduce stand hazard of future infestations of native and invasive wood wasps.

  15. Abundant primary piRNAs, endo-siRNAs, and microRNAs in a Drosophila ovary cell line

    PubMed Central

    Lau, Nelson C.; Robine, Nicolas; Martin, Raquel; Chung, Wei-Jen; Niki, Yuzo; Berezikov, Eugene; Lai, Eric C.

    2009-01-01

    Piwi proteins, a subclass of Argonaute-family proteins, carry ∼24–30-nt Piwi-interacting RNAs (piRNAs) that mediate gonadal defense against transposable elements (TEs). We analyzed the Drosophila ovary somatic sheet (OSS) cell line and found that it expresses miRNAs, endogenous small interfering RNAs (endo-siRNAs), and piRNAs in abundance. In contrast to intact gonads, which contain mixtures of germline and somatic cell types that express different Piwi-class proteins, OSS cells are a homogenous somatic cell population that expresses only PIWI and primary piRNAs. Detailed examination of its TE-derived piRNAs and endo-siRNAs revealed aspects of TE defense that do not rely upon ping-pong amplification. In particular, we provide evidence that a subset of piRNA master clusters, including flamenco, are specifically expressed in OSS and ovarian follicle cells. These data indicate that the restriction of certain TEs in somatic gonadal cells is largely mediated by a primary piRNA pathway. PMID:19541914

  16. Elemental abundance analysis of the early-type members of the open cluster M6: Preliminary results

    NASA Astrophysics Data System (ADS)

    Kılıçoǧlu, T.; Monier, R.; Fossati, L.

    2014-11-01

    Differences in chemical composition among main sequence stars within a given cluster are probably due to differences in their masses and other effects such as radiative diffusion, magnetic field, rotation, mixing mechanisms, mass loss, accretion and multiplicity. The early type main-sequence members of open clusters of different ages support studies of the competition between radiative diffusion and mixing mechanisms. We have analysed low- and high-resolution spectra covering the spectral range λ 4500-5840 Å of late B-, A- and F-type members of the open cluster M6 (age ˜100 Myr). The spectra were obtained with the FLAMES/GIRAFFE spectrograph mounted at UT2, the 8-m VLT telescope. The effective temperatures, surface gravities and microturbulent velocities of the stars were derived from both photometric and spectral methods. We have also performed a chemical abundance analysis using synthetic spectra. Abundances were determined for the elements C, O, Mg, Si, Ca, Sc, Ti, Cr, Mn, Fe, Ni, Y and Ba. The star-to-star variations in element abundances among the members of M6 are discussed.

  17. Sensing Small Changes in Protein Abundance: Stimulation of Caco-2 Cells by Human Whey Proteins.

    PubMed

    Cundiff, Judy K; McConnell, Elizabeth J; Lohe, Kimberly J; Maria, Sarah D; McMahon, Robert J; Zhang, Qiang

    2016-01-04

    Mass spectrometry (MS)-based proteomic approaches have largely facilitated our systemic understanding of cellular processes and biological functions. Cutoffs in protein expression fold changes (FCs) are often arbitrarily determined in MS-based quantification with no demonstrable determination of small magnitude changes in protein expression. Therefore, many biological insights may remain veiled due to high FC cutoffs. Herein, we employ the intestinal epithelial cell (IEC) line Caco-2 as a model system to demonstrate the dynamicity of tandem-mass-tag (TMT) labeling over a range of 5-40% changes in protein abundance, with the variance controls of ± 5% FC for around 95% of TMT ratios when sampling 9-12 biological replicates. We further applied this procedure to examine the temporal proteome of Caco-2 cells upon exposure to human whey proteins (WP). Pathway assessments predict subtle effects due to WP in moderating xenobiotic metabolism, promoting proliferation and various other cellular functions in differentiating enterocyte-like Caco-2 cells. This demonstration of a sensitive MS approach may open up new perspectives in the system-wide exploration of elusive or transient biological effects by facilitating scrutiny of narrow windows of proteome abundance changes. Furthermore, we anticipate this study will encourage more investigations of WP on infant gastrointestinal tract development.

  18. The VLT-FLAMES Tarantula Survey. XXV. Surface nitrogen abundances of O-type giants and supergiants

    NASA Astrophysics Data System (ADS)

    Grin, N. J.; Ramírez-Agudelo, O. H.; de Koter, A.; Sana, H.; Puls, J.; Brott, I.; Crowther, P. A.; Dufton, P. L.; Evans, C. J.; Gräfener, G.; Herrero, A.; Langer, N.; Lennon, D. J.; van Loon, J. Th.; Markova, N.; de Mink, S. E.; Najarro, F.; Schneider, F. R. N.; Taylor, W. D.; Tramper, F.; Vink, J. S.; Walborn, N. R.

    2017-04-01

    Context. Theoretically, rotation-induced chemical mixing in massive stars has far reaching evolutionary consequences, affecting the sequence of morphological phases, lifetimes, nucleosynthesis, and supernova characteristics. Aims: Using a sample of 72 presumably single O-type giants to supergiants observed in the context of the VLT-FLAMES Tarantula Survey (VFTS), we aim to investigate rotational mixing in evolved core-hydrogen burning stars initially more massive than 15 M⊙ by analysing their surface nitrogen abundances. Methods: Using stellar and wind properties derived in a previous VFTS study we computed synthetic spectra for a set of up to 21 N ii-v lines in the optical spectral range, using the non-LTE atmosphere code FASTWIND. We constrained the nitrogen abundance by fitting the equivalent widths of relatively strong lines that are sensitive to changes in the abundance of this element. Given the quality of the data, we constrained the nitrogen abundance in 38 cases; for 34 stars only upper limits could be derived, which includes almost all stars rotating at νesini> 200 km s-1. Results: We analysed the nitrogen abundance as a function of projected rotation rate νesini and confronted it with predictions of rotational mixing. We found a group of N-enhanced slowly-spinning stars that is not in accordance with predictions of rotational mixing in single stars. Among O-type stars with (rotation-corrected) gravities less than log gc = 3.75 this group constitutes 30-40 percent of the population. We found a correlation between nitrogen and helium abundance which is consistent with expectations, suggesting that, whatever the mechanism that brings N to the surface, it displays CNO-processed material. For the rapidly-spinning O-type stars we can only provide upper limits on the nitrogen abundance, which are not in violation with theoretical expectations. Hence, the data cannot be used to test the physics of rotation induced mixing in the regime of high spin rates

  19. Late embryogenesis abundant proteins protect human hepatoma cells during acute desiccation.

    PubMed

    Li, Shumin; Chakraborty, Nilay; Borcar, Apurva; Menze, Michael A; Toner, Mehmet; Hand, Steven C

    2012-12-18

    Expression of late embryogenesis abundant (LEA) proteins is highly correlated with desiccation tolerance in anhydrobiotic animals, selected land plants, and bacteria. Genes encoding two LEA proteins, one localized to the cytoplasm/nucleus (AfrLEA2) and one targeted to mitochondria (AfrLEA3m), were stably transfected into human HepG2 cells. A trehalose transporter was used for intracellular loading of this disaccharide. Cells were rapidly and uniformly desiccated to low water content (<0.12 g H(2)O/g dry weight) with a recently developed spin-drying technique. Immediately on rehydration, control cells without LEA proteins or trehalose exhibited 0% membrane integrity, compared with 98% in cells loaded with trehalose and expressing AfrLEA2 or AfrLEA3m; surprisingly, AfrLEA3m without trehalose conferred 94% protection. Cell proliferation across 7 d showed an 18-fold increase for cells dried with AfrLEA3m and trehalose, compared with 27-fold for nondried controls. LEA proteins dramatically enhance desiccation tolerance in mammalian cells and offer the opportunity for engineering biostability in the dried state.

  20. Virus-specific CD4+ memory phenotype T cells are abundant in unexposed adults

    PubMed Central

    Su, Laura F.; Kidd, Brian A.; Han, Arnold; Kotzin, Jonathan J.; Davis, Mark M.

    2013-01-01

    While T cell memory is generally thought to require direct antigen exposure, we find an abundance of memory phenotype cells (20–90%, averaging over 50%) of CD4+ T cells specific for viral antigens in adults that have never been infected. These cells express the appropriate memory markers and genes, rapidly produce cytokines, and have clonally expanded. This contrasts with newborns where the same T cell receptor (TCR) specificities are almost entirely naïve, which may explain the vulnerability of young children to infections. One mechanism for this phenomenon is TCR cross-reactivity to environmental antigens and in support of this we find extensive cross-recognition by HIV-1 and influenza-reactive T lymphocytes to other microbial peptides and the expansion of one of these following influenza vaccination. Thus the presence of these memory phenotype T cells has significant implications for immunity to novel pathogens, child and adult health, and the influence of pathogen-rich versus hygienic environments. PMID:23395677

  1. Modelling epigenetic regulation of gene expression in 12 human cell types reveals combinatorial patterns of cell-type-specific genes.

    PubMed

    Lu, Yiming; Qu, Wubin; Min, Bo; Liu, Zheyan; Chen, Changsheng; Zhang, Chenggang

    2014-06-01

    The maintenance of the diverse cell types in a multicellular organism is one of the fundamental mysteries of biology. Modelling the dynamic regulatory relationships between the histone modifications and the gene expression across the diverse cell types is essential for the authors to understand the mechanisms of the epigenetic regulation. Here, the authors thoroughly assessed the histone modification enrichment profiles at the promoters and constructed quantitative models between the histone modification abundances and the gene expression in 12 human cell types. The author's results showed that the histone modifications at the promoters exhibited remarkably cell-type-dependent variability in the cell-type-specific (CTS) genes. They demonstrated that the variable profiles of the modifications are highly predictive for the dynamic changes of the gene expression across all the cell types. Their findings revealed the close relationship between the combinatorial patterns of the histone modifications and the CTS gene expression. They anticipate that the findings and the methods they used in this study could provide useful information for the future studies of the regulatory roles of the histone modifications in the CTS genes.

  2. Variation in Plant Traits Explains Global Biogeographic Variation in the Abundance of Major Forest Functional Types

    NASA Astrophysics Data System (ADS)

    Wang, Y.

    2015-12-01

    Contrasting leaf types (needle vs. broadleaf) with different lifespans (annual vs. perennial) represent different adaptive strategies of plants under different environmental conditions. Previous studies explained adaptive advantages of different strategies using empirical models but cannot adequately explain the co-dominance of multiple plant functional types (PFTs) as observed in many parts of the world. Here we used a process-based model to explore whether observed inter- and intra-PFT variation in key plant traits can explain global biogeographic variation in co-dominance of major forest functional types. Using a parameter screening method, we identified the four most important plant traits for simulating annual net primary production (NPP) using the Australian Community Atmosphere-Biosphere-Land Exchange model (CABLE). Using ensemble CABLE simulations, we estimated the fraction of global land cover attributed to each PFT by comparing the simulated NPP for all three PFTs at each land point, globally. Our results were consistent with land area cover fractions of major forest types estimated from remote sensing data products; i.e., evergreen needle-leaf forests dominate in boreal regions, evergreen broadleaf forests dominate in tropical regions, and deciduous broadleaf forests are distributed widely across a broad range of environmental conditions. More importantly our approach successfully explained a paradox that has puzzled ecologists for over a century: why evergreen leaf types dominate in both boreal and tropical regions. We conclude that variation in and co-variation between key plant traits can explain significant fractions of global biogeographic variation of three major forest types, and should be taken into account when simulating global vegetation dynamics.

  3. Quantitative Comparison of Abundance Structures of Generalized Communities: From B-Cell Receptor Repertoires to Microbiomes

    PubMed Central

    Saeedghalati, Mohammadkarim; Farahpour, Farnoush; Lange, Anja; Westendorf, Astrid M.; Seifert, Marc; Küppers, Ralf

    2017-01-01

    The community, the assemblage of organisms co-existing in a given space and time, has the potential to become one of the unifying concepts of biology, especially with the advent of high-throughput sequencing experiments that reveal genetic diversity exhaustively. In this spirit we show that a tool from community ecology, the Rank Abundance Distribution (RAD), can be turned by the new MaxRank normalization method into a generic, expressive descriptor for quantitative comparison of communities in many areas of biology. To illustrate the versatility of the method, we analyze RADs from various generalized communities, i.e. assemblages of genetically diverse cells or organisms, including human B cells, gut microbiomes under antibiotic treatment and of different ages and countries of origin, and other human and environmental microbial communities. We show that normalized RADs enable novel quantitative approaches that help to understand structures and dynamics of complex generalized communities. PMID:28114391

  4. Difference in hydrogen abundance between two classes of type I X-ray bursts

    SciTech Connect

    Ebisuzaki, T.; Nakamura, N.

    1988-05-01

    The hypothesis that the bright type I X-ray bursts differ from faint bursts in that a hydrogen-rich envelope is ejected in the former type and not in the latter is theoretically discussed and experimentally investigated. Color-temperature versus luminosity diagrams of X-ray bursts from MXB 1636-536 and MXB 1608-522 are constructed based on observations from the Tenma satellite and are used to study the hydrogen richness of the surface of the neutron stars resulting from the outbursts. Systematic differences between the bright and faint class diagrams are found which confirm the hypothesis. 28 references.

  5. The difference in hydrogen abundance between two classes of type I X-ray bursts

    NASA Technical Reports Server (NTRS)

    Ebisuzaki, Toshikazu; Nakamura, Norio

    1988-01-01

    The hypothesis that the bright type I X-ray bursts differ from faint bursts in that a hydrogen-rich envelope is ejected in the former type and not in the latter is theoretically discussed and experimentally investigated. Color-temperature versus luminosity diagrams of X-ray bursts from MXB 1636-536 and MXB 1608-522 are constructed based on observations from the Tenma satellite and are used to study the hydrogen richness of the surface of the neutron stars resulting from the outbursts. Systematic differences between the bright and faint class diagrams are found which confirm the hypothesis.

  6. TAZ Protein Accumulation Is Negatively Regulated by YAP Abundance in Mammalian Cells*

    PubMed Central

    Finch-Edmondson, Megan L.; Strauss, Robyn P.; Passman, Adam M.; Sudol, Marius; Yeoh, George C.; Callus, Bernard A.

    2015-01-01

    The mammalian Hippo signaling pathway regulates cell growth and survival and is frequently dysregulated in cancer. YAP and TAZ are transcriptional coactivators that function as effectors of this signaling pathway. Aberrant YAP and TAZ activity is reported in several human cancers, and normally the expression and nuclear localization of these proteins is tightly regulated. We sought to establish whether a direct relationship exists between YAP and TAZ. Using knockdown and overexpression experiments we show YAP inversely regulates the abundance of TAZ protein by proteasomal degradation. Interestingly this phenomenon was uni-directional since TAZ expression did not affect YAP abundance. Structure/function analyses suggest that YAP-induced TAZ degradation is a consequence of YAP-targeted gene transcription involving TEAD factors. Subsequent investigation of known regulators of TAZ degradation using specific inhibitors revealed a role for heat shock protein 90 and glycogen synthase kinase 3 but not casein kinase 1 nor LATS in YAP-mediated TAZ loss. Importantly, this phenomenon is conserved from mouse to human; however, interestingly, different YAP isoforms varied in their ability to degrade TAZ. Since shRNA-mediated TAZ depletion in HeLa and D645 cells caused apoptotic cell death, we propose that isoform-specific YAP-mediated TAZ degradation may contribute to the contradicting roles reported for YAP overexpression. This study identifies a novel mechanism of TAZ regulation by YAP, which has significant implications for our understanding of Hippo pathway regulation, YAP-isoform specific signaling, and the role of these proteins in cell proliferation, apoptosis, and tumorigenesis. PMID:26432639

  7. T cell abundance in blood predicts acute organ toxicity in chemoradiotherapy for head and neck cancer

    PubMed Central

    Reichardt, Sybille D.; Rave-Fränk, Margret; Schirmer, Markus A.; Stadelmann, Christine; Canis, Martin; Wolff, Hendrik A.

    2016-01-01

    Treatment of head and neck squamous cell carcinoma (HNSCC) by chemoradiotherapy (CRT) often results in high-grade acute organ toxicity (HGAOT). As these adverse effects impair the patients' quality of life and the feasibility of the planned therapy, we sought to analyze immunological parameters in tumor material and blood samples obtained from 48 HNSCC patients in order to assess the potential to predict the individual acute organ toxicity. T cells in the tumor stroma were enriched in patients developing HGAOT whereas levels of soluble factors in the plasma and gene expression in whole blood did not coincide with the occurrence of acute organ toxicity. In contrast, the frequency and absolute numbers of selected leukocyte subpopulations measured in samples of peripheral blood mononuclear cells (PBMCs) directly before the beginning of CRT were significantly different in patients with HGAOT as compared to those without. When we validated several potential markers including the abundance of T cells in a small prospective study with 16 HNSCC patients, we were able to correctly predict acute organ toxicity in up to 81% of the patients. We conclude that analysis of PBMCs by fluorescence-activated cell sorting (FACS) might be a convenient strategy to identify patients at risk of developing HGAOT caused by CRT, which might allow to adapt the treatment regimen and possibly improve disease outcome. PMID:27589568

  8. Studies on microperoxisomes. VII. Pigment epithelial cells and other cell types in the retina of rodents

    PubMed Central

    1975-01-01

    The pigment epithelial cell of the retina actively participates in two aspects of lipid metabolism: (a) the fatty acid esterification of vitamin A and its storage and transport to the photoreceptors, and (b) the phagocytosis and degradation of the lipoprotein membrane disks shed from the photoreceptor cells. Study of the pigment epithelial cells of adult albino and pigmented rodents has revealed the abundance of an organelle, microperoxisomes, not previously known to exist in this cell type. The metabolism, transport, and storage of lipids are major functions of other cell types which possess large numbers of microperoxisomes associated with a highly developed smooth endoplasmic reticulum. Microperoxisomes were encountered, but relatively rarely, in Muller cells and vascular endothelial cells. A tubular system in photoreceptor terminals is reactive in the cytochemical procedure used to visualize microperoxisomes. PMID:1168648

  9. Supernovae 1983i and 1983v - Evidence for abundance variations in type Ib supernovae

    NASA Technical Reports Server (NTRS)

    Wheeler, J. C.; Harkness, R. P.; Barker, E. S.; Cochran, A. L.; Wills, D.

    1987-01-01

    Spectra are presented of SN 1983i 5 days after discovery and of SN 1983v 13 days after discovery. The similarity of these two spectra argues that they are of similar origin and phase. Theoretical atmosphere calculations provide evidence for a connection to the type Ib supernovae 1983n and 1984l, with SN 1983i and 1983v having a similar structure but less helium and more carbon and oxygen. Available photometry suggests that the spectra correspond to a phase about 20 days after maximum light. These spectra are consistent with an interpretation of type Ib supernovae arising in the bare cores of moderately massive stars, with individual events showing a range in He/O mass ratio from approximately 10 to less than 1.

  10. Relative abundances of chondrule primary textural types in ordinary chondrites and their bearing on conditions of chondrule formation

    NASA Astrophysics Data System (ADS)

    Gooding, J. L.; Keil, K.

    1981-03-01

    A petrographic survey of > 1600 chondrules in thin-sections of 12 different mildly to highly unequilibrated H-, L-, and Li-chondrites, as well as morphological and textural study of 141 whole chondrules separated from 11 of the same chondrites, was used to determine the relative abundances of definable chondrule primary textural types. Percentage abundances of various chondrule types are remarkably similar in all chondrites studied and are ˜47-52 porphyritic olivine-pyroxene (POP), 15-27 porphyritic olivine (P 0), 9-11 porphyritic pyroxene (PP), 34 barred olivine (BO), 7-9 radial pyroxene (RP), 2-5 granular olivine-pyroxene (GOP), 3-5 cryptocrystalline (C), and ≥ 1 metallic (M). Neither chondrule size nor shape is strongly correlated with textural type. Compound and cratered chondrules, which are interpreted as products of collisions between plastic chondrules, comprise ˜2-28% of non-porphyritic (RP, GOP, C) but only ˜2-9% of porphyritic (POP, PO, PP, BO) chondrules, leading to a model-dependent implication that non-porphyritic chondrules evolved at number densities (chondrules per unit volume of space) which were 102 to 104 times greater than those which prevailed during porphyritic chondrule formation (total range of ˜1 to ˜106 m-3. Distinctive "rims" of fine-grained sulfides and/or silicates occur on both porphyritic and non-porphyritic types and appear to post-date chondrule formation. Apparently, either the same process(es) contributed chondrules to all unequilibrated ordinary chondrites or, if genetically different, the various chondrule types were well mixed before incorporation into chondrites. Melting of pre-existing materials is the mechanism favored for chondrule formation.

  11. The Gaia-ESO Survey: detailed abundances for thousands of FGK-type stars

    NASA Astrophysics Data System (ADS)

    Smiljanic, R.

    2014-10-01

    The Gaia-ESO Survey is using FLAMES at the VLT to observe more than 10^{5} stars. Giraffe medium-resolution spectra is being obtained for ˜ 10^{5} stars and high-resolution UVES spectra is being obtained for ˜ 5000 stars. Here I present a short summary of the Survey with emphasis on the sample of FGK-type stars being observed with UVES.

  12. Enzymatic passaging of human embryonic stem cells alters central carbon metabolism and glycan abundance

    PubMed Central

    Badur, Mehmet G.; Zhang, Hui; Metallo, Christian M.

    2016-01-01

    To realize the potential of human embryonic stem cells (hESCs) in regenerative medicine and drug discovery applications, large numbers of cells that accurately recapitulate cell and tissue function must be robustly produced. Previous studies have suggested that genetic instability and epigenetic changes occur as a consequence of enzymatic passaging. However, the potential impacts of such passaging methods on the metabolism of hESCs have not been described. Using stable isotope tracing and mass spectrometry-based metabolomics, we have explored how different passaging reagents impact hESC metabolism. Enzymatic passaging caused significant decreases in glucose utilization throughout central carbon metabolism along with attenuated de novo lipogenesis. In addition, we developed and validated a method for rapidly quantifying glycan abundance and isotopic labeling in hydrolyzed biomass. Enzymatic passaging reagents significantly altered levels of glycans immediately after digestion but surprisingly glucose contribution to glycans was not affected. These results demonstrate that there is an immediate effect on hESC metabolism after enzymatic passaging in both central carbon metabolism and biosynthesis. HESCs subjected to enzymatic passaging are routinely placed in a state requiring re-synthesis of biomass components, subtly influencing their metabolic needs in a manner that may impact cell performance in regenerative medicine applications. PMID:26289220

  13. Enzymatic passaging of human embryonic stem cells alters central carbon metabolism and glycan abundance.

    PubMed

    Badur, Mehmet G; Zhang, Hui; Metallo, Christian M

    2015-10-01

    To realize the potential of human embryonic stem cells (hESCs) in regenerative medicine and drug discovery applications, large numbers of cells that accurately recapitulate cell and tissue function must be robustly produced. Previous studies have suggested that genetic instability and epigenetic changes occur as a consequence of enzymatic passaging. However, the potential impacts of such passaging methods on the metabolism of hESCs have not been described. Using stable isotope tracing and mass spectrometry-based metabolomics, we have explored how different passaging reagents impact hESC metabolism. Enzymatic passaging caused significant decreases in glucose utilization throughout central carbon metabolism along with attenuated de novo lipogenesis. In addition, we developed and validated a method for rapidly quantifying glycan abundance and isotopic labeling in hydrolyzed biomass. Enzymatic passaging reagents significantly altered levels of glycans immediately after digestion but surprisingly glucose contribution to glycans was not affected. These results demonstrate that there is an immediate effect on hESC metabolism after enzymatic passaging in both central carbon metabolism and biosynthesis. HESCs subjected to enzymatic passaging are routinely placed in a state requiring re-synthesis of biomass components, subtly influencing their metabolic needs in a manner that may impact cell performance in regenerative medicine applications.

  14. Evolution of eyes and photoreceptor cell types.

    PubMed

    Arendt, Detlev

    2003-01-01

    The evolution of the eye is a matter of debate ever since Darwin's Origin of Species. While morphological comparisons of eye anatomy and photoreceptor cell types led to the view that animal eyes evolved multiple times independently, the molecular conservation of the pax6 eye-specifying cascade has indicated the contrary - that animal eyes evolved from a common, simple precursor, the proto-eye. Morphological and molecular comparative approaches are combined here in a novel Evo-Devo approach, the molecular comparison of cell types ("comparative molecular cell biology"). In the eye, the various types of photoreceptor cells, as well as pigment and lens cells, each require distinct combinations of specifying transcription factors that control their particular differentiation programmes, such as opsin expression in photoreceptors, specific neurotransmitter metabolism, or axonal outgrowth. Comparing the molecular combinatorial codes of cell types of animal extant eyes, their evolutionary histories can be reconstructed. This is exemplified here on the evolution of ciliary and rhabdomeric photoreceptor cells in bilaterian eyes and on the evolution of cell type diversity in the vertebrate retina. I propose that the retinal ganglion, amacrine and horizontal cells are evolutionary sister cell types that evolved from a common rhabdomeric photoreceptor cell precursor.

  15. GRLD-1 regulates cell-wide abundance of glutamate receptor through post-transcriptional regulation

    PubMed Central

    Wang, George J.; Kang, Lijun; Kim, Julie E.; Maro, Géraldine S.; Xu, X. Z. Shawn; Shen, Kang

    2011-01-01

    AMPA receptors mediate most of the fast postsynaptic response at glutamatergic synapses. The abundance of AMPA receptors in neurons and at postsynaptic membranes is tightly regulated. Changes in synaptic AMPA receptor levels have been proposed to be a key regulatory event in synaptic plasticity and learning and memory. While the local, synapse-specific regulation of AMPA receptors has been intensely studied, the global, cell-wide control is less well understood. Using a forward genetic approach, we identified Glutamate Receptor Level Decreased-1 (GRLD-1), a putative RNA-binding protein that is required for efficient production of GLR-1 in the AVE interneurons in the nematode Caenorhabditis elegans. In grld-1 mutants, GLR-1 levels were drastically reduced. Consistently, both glutamate-induced currents in AVE and glr-1-dependent nose-touch avoidance behavior were defective in grld-1 mutants. We propose that this evolutionarily conserved family of proteins controls the abundance of GLR-1 by regulating glr-1 transcript splicing. PMID:21037582

  16. WIYN OPEN CLUSTER STUDY. LVII. OXYGEN ABUNDANCES OF SOLAR-TYPE DWARFS IN THE HYADES AND NGC 752

    SciTech Connect

    Maderak, Ryan M.; Deliyannis, Constantine P.; Cummings, Jeffery D.; King, Jeremy R. E-mail: con@astro.indiana.edu E-mail: jcummings@astro-udec.cl

    2013-12-01

    Oxygen has been proposed to be a superior tracer, compared to iron, for studying galactic chemical evolution. In the context of improving our understanding of the evolution of Galactic oxygen using open clusters, we present a spectroscopic analysis of oxygen and iron abundances in the 650 Myr old Hyades cluster and in the 1.45 Gyr old cluster NGC 752, using high-dispersion 7774 Å O I triplet region spectra of dwarfs in these clusters acquired with the Hydra MOS on the WIYN 3.5 m telescope. Motivated by recent improvements in analysis of the triplet, we use a strictly differential analysis in solar-type stars to obtain reliable O abundances. Using stars whose radial velocities and spectral cross-correlation analyses are consistent with single-star membership, we report Hyades cluster averages of [O/H] = 0.195 ± 0.010 and [Fe/H] = 0.130 ± 0.009 based on 22 stars, and NGC 752 cluster averages of [O/H] = –0.077 ± 0.02 and [Fe/H] = –0.063 ± 0.013 based on 36 stars (where the errors are σ{sub μ}; we discuss possible additional systematic errors). These cluster abundance averages are in very good agreement with most previous determinations. Whereas the [O/H] cluster averages utilize only stars found in the ''prime'' T {sub eff} range straddling the solar T {sub eff}, the [Fe/H] cluster averages come from stars exhibiting a flat [Fe/H]-T {sub eff} relation of over 1000 K for the Hyades and nearly 2000 K for NGC 752. Previous studies of open clusters younger than NGC 752 have reported oxygen triplet over abundances in cool dwarfs, as compared to oxygen abundances of the prime-T {sub eff} range. We report that NGC 752 also shows such overabundances, at a higher level than the Hyades overabundances, and thus contradicts the idea of a decline of such overabundances with increasing age. We discuss evidence for and against correlations of the oxygen overabundances with rotation, X-ray luminosity, chromospheric activity, and metallicity.

  17. A conserved abundant cytoplasmic long noncoding RNA modulates repression by Pumilio proteins in human cells

    PubMed Central

    Tichon, Ailone; Gil, Noa; Lubelsky, Yoav; Havkin Solomon, Tal; Lemze, Doron; Itzkovitz, Shalev; Stern-Ginossar, Noam; Ulitsky, Igor

    2016-01-01

    Thousands of long noncoding RNA (lncRNA) genes are encoded in the human genome, and hundreds of them are evolutionarily conserved, but their functions and modes of action remain largely obscure. Particularly enigmatic lncRNAs are those that are exported to the cytoplasm, including NORAD—an abundant and highly conserved cytoplasmic lncRNA. Here we show that most of the sequence of NORAD is comprised of repetitive units that together contain at least 17 functional binding sites for the two mammalian Pumilio homologues. Through binding to PUM1 and PUM2, NORAD modulates the mRNA levels of their targets, which are enriched for genes involved in chromosome segregation during cell division. Our results suggest that some cytoplasmic lncRNAs function by modulating the activities of RNA-binding proteins, an activity which positions them at key junctions of cellular signalling pathways. PMID:27406171

  18. 13C and 15N natural isotope abundance reflects breast cancer cell metabolism

    NASA Astrophysics Data System (ADS)

    Tea, Illa; Martineau, Estelle; Antheaume, Ingrid; Lalande, Julie; Mauve, Caroline; Gilard, Francoise; Barillé-Nion, Sophie; Blackburn, Anneke C.; Tcherkez, Guillaume

    2016-09-01

    Breast cancer is the most common cancer in women worldwide. Despite the information provided by anatomopathological assessment and molecular markers (such as receptor expression ER, PR, HER2), breast cancer therapies and prognostics depend on the metabolic properties of tumor cells. However, metabolomics have not provided a robust and congruent biomarker yet, likely because individual metabolite contents are insufficient to encapsulate all of the alterations in metabolic fluxes. Here, we took advantage of natural 13C and 15N isotope abundance to show there are isotopic differences between healthy and cancer biopsy tissues or between healthy and malignant cultured cell lines. Isotope mass balance further suggests that these differences are mostly related to lipid metabolism, anaplerosis and urea cycle, three pathways known to be impacted in malignant cells. Our results demonstrate that the isotope signature is a good descriptor of metabolism since it integrates modifications in C partitioning and N excretion altogether. Our present study is thus a starting point to possible clinical applications such as patient screening and biopsy characterization in every cancer that is associated with metabolic changes.

  19. 13C and 15N natural isotope abundance reflects breast cancer cell metabolism

    PubMed Central

    Tea, Illa; Martineau, Estelle; Antheaume, Ingrid; Lalande, Julie; Mauve, Caroline; Gilard, Francoise; Barillé-Nion, Sophie; Blackburn, Anneke C.; Tcherkez, Guillaume

    2016-01-01

    Breast cancer is the most common cancer in women worldwide. Despite the information provided by anatomopathological assessment and molecular markers (such as receptor expression ER, PR, HER2), breast cancer therapies and prognostics depend on the metabolic properties of tumor cells. However, metabolomics have not provided a robust and congruent biomarker yet, likely because individual metabolite contents are insufficient to encapsulate all of the alterations in metabolic fluxes. Here, we took advantage of natural 13C and 15N isotope abundance to show there are isotopic differences between healthy and cancer biopsy tissues or between healthy and malignant cultured cell lines. Isotope mass balance further suggests that these differences are mostly related to lipid metabolism, anaplerosis and urea cycle, three pathways known to be impacted in malignant cells. Our results demonstrate that the isotope signature is a good descriptor of metabolism since it integrates modifications in C partitioning and N excretion altogether. Our present study is thus a starting point to possible clinical applications such as patient screening and biopsy characterization in every cancer that is associated with metabolic changes. PMID:27678172

  20. IDENTIFICATION OF A NOVEL CELL TYPE IN PERIPHERAL LYMPHOID ORGANS OF MICE

    PubMed Central

    Steinman, Ralph M.; Cohn, Zanvil A.

    1973-01-01

    A novel cell type has been identified in adherent cell populations prepared from mouse peripheral lymphoid organs (spleen, lymph node, Peyer's patch). Though present in small numbers (0.1–1.6% of the total nucleated cells) the cells have distinct morphological features. The nucleus is large, retractile, contorted in shape, and contains small nucleoli (usually two). The abundant cytoplasm is arranged in processes of varying length and width and contains many large spherical mitochondria. In the living state, the cells undergo characteristic movements, and unlike macrophages, do not appear to engage in active endocytosis. The term, dendritic cell, is proposed for this novel cell type. PMID:4573839

  1. A Cell-type-resolved Liver Proteome*

    PubMed Central

    Ding, Chen; Li, Yanyan; Guo, Feifei; Jiang, Ying; Ying, Wantao; Li, Dong; Yang, Dong; Xia, Xia; Liu, Wanlin; Zhao, Yan; He, Yangzhige; Li, Xianyu; Sun, Wei; Liu, Qiongming; Song, Lei; Zhen, Bei; Zhang, Pumin; Qian, Xiaohong; Qin, Jun; He, Fuchu

    2016-01-01

    Parenchymatous organs consist of multiple cell types, primarily defined as parenchymal cells (PCs) and nonparenchymal cells (NPCs). The cellular characteristics of these organs are not well understood. Proteomic studies facilitate the resolution of the molecular details of different cell types in organs. These studies have significantly extended our knowledge about organogenesis and organ cellular composition. Here, we present an atlas of the cell-type-resolved liver proteome. In-depth proteomics identified 6000 to 8000 gene products (GPs) for each cell type and a total of 10,075 GPs for four cell types. This data set revealed features of the cellular composition of the liver: (1) hepatocytes (PCs) express the least GPs, have a unique but highly homogenous proteome pattern, and execute fundamental liver functions; (2) the division of labor among PCs and NPCs follows a model in which PCs make the main components of pathways, but NPCs trigger the pathways; and (3) crosstalk among NPCs and PCs maintains the PC phenotype. This study presents the liver proteome at cell resolution, serving as a research model for dissecting the cell type constitution and organ features at the molecular level. PMID:27562671

  2. Abundance stratification in Type Ia supernovae - V. SN 1986G bridging the gap between normal and subluminous SNe Ia

    NASA Astrophysics Data System (ADS)

    Ashall, C.; Mazzali, P. A.; Pian, E.; James, P. A.

    2016-12-01

    A detailed spectroscopic analysis of SN 1986G has been performed. SN 1986G `bridges the gap' between normal and subluminous Type Ia supernovae (SNe Ia). The abundance tomography technique is used to determine the abundance distribution of the elements in the ejecta. SN 1986G was found to be a low-energy Chandrasekhar mass explosion. Its kinetic energy was 70 per cent of the standard W7 model (0.9 × 1051 erg). Oxygen dominates the ejecta from the outermost layers down to ˜9000 km s-1, intermediate mass elements (IMEs) dominate from ˜9000 to ˜3500 km s-1 with Ni and Fe dominating the inner layers < ˜3500 km s-1. The final masses of the main elements in the ejecta were found to be, O = 0.33 M⊙, IME = 0.69 M⊙, stable NSE = 0.21 M⊙, 56Ni = 0.14 M⊙. An upper limit of the carbon mass is set at C = 0.02 M⊙. The spectra of SN 1986G consist of almost exclusively singly ionized species. SN 1986G can be thought of as a low-luminosity extension of the main population of SN Ia, with a large deflagration phase that produced more IMEs than a standard SN Ia.

  3. Supergiants and the Galactic metallicity gradient. II - Spectroscopic abundances for 64 distant F- to M-type supergiants

    NASA Astrophysics Data System (ADS)

    Luck, R. Earle; Bond, Howard E.

    1989-11-01

    The metallicity gradient in the Galactic disk from in situ stars with visual magnitude ranging from 6 to 10 is analyzed. Atmospheric parameters and detailed chemical abundances for 64 Population I supergiants of spectral types F through M and luminosity classes Ia through II have been determined. The derived Fe/H ratios ranging from -0.5 to + 0.7 show a mean value of +0.13 with an estimated uncertainty of + or - 0.2. A subset of 25 supergiants fainter than 7th magnitude lying in the direction of the Galactic center shows a Fe/H mean of +0.18 + or - 0.04, while a similar sample of 15 faint supergiants lying in the direction of the Galactic anticenter shows a lower Fe/H mean of +0.07 + or - 0.06. For a sample of bright supergiants analyzed by Luck and Lambert (1985), the mean abundance pattern for all 64 stars showed the following: deficient C and O along with enhancement of N, indicating mixing of CNO-cycled material to the stellar surfaces; an apparent Sr enhancement attributed to departures from LTE; and an essentially solar pattern of other chemical elements.

  4. Monolithic cascade-type solar cells

    NASA Technical Reports Server (NTRS)

    Yamamoto, S.; Shibukawa, A.; Yamaguchi, M.

    1985-01-01

    Solar cells consist of a semiconductor base, a bottom cell with a band-gap energy of E1, and a top cell with a band-gap energy of E2, and 0.96 E1 1.36 eV and (0.80 E + 0.77) eV E2 (0.80 E1 + 0.92) eV. A monolithic cascade-type solar cell was prepared with an n(+)-type GaAs base, a GaInAs bottom solar cell, and a GaAiInAs top solar cell. The surface of the cell is coated with a SiO antireflection film. The efficiency of the cell is 32%.

  5. Computational Model Reveals Limited Correlation between Germinal Center B-Cell Subclone Abundancy and Affinity: Implications for Repertoire Sequencing

    PubMed Central

    Reshetova, Polina; van Schaik, Barbera D. C.; Klarenbeek, Paul L.; Doorenspleet, Marieke E.; Esveldt, Rebecca E. E.; Tak, Paul-Peter; Guikema, Jeroen E. J.; de Vries, Niek; van Kampen, Antoine H. C.

    2017-01-01

    Immunoglobulin repertoire sequencing has successfully been applied to identify expanded antigen-activated B-cell clones that play a role in the pathogenesis of immune disorders. One challenge is the selection of the Ag-specific B cells from the measured repertoire for downstream analyses. A general feature of an immune response is the expansion of specific clones resulting in a set of subclones with common ancestry varying in abundance and in the number of acquired somatic mutations. The expanded subclones are expected to have BCR affinities for the Ag higher than the affinities of the naive B cells in the background population. For these reasons, several groups successfully proceeded or suggested selecting highly abundant subclones from the repertoire to obtain the Ag-specific B cells. Given the nature of affinity maturation one would expect that abundant subclones are of high affinity but since repertoire sequencing only provides information about abundancies, this can only be verified with additional experiments, which are very labor intensive. Moreover, this would also require knowledge of the Ag, which is often not available for clinical samples. Consequently, in general we do not know if the selected highly abundant subclone(s) are also the high(est) affinity subclones. Such knowledge would likely improve the selection of relevant subclones for further characterization and Ag screening. Therefore, to gain insight in the relation between subclone abundancy and affinity, we developed a computational model that simulates affinity maturation in a single GC while tracking individual subclones in terms of abundancy and affinity. We show that the model correctly captures the overall GC dynamics, and that the amount of expansion is qualitatively comparable to expansion observed from B cells isolated from human lymph nodes. Analysis of the fraction of high- and low-affinity subclones among the unexpanded and expanded subclones reveals a limited correlation between

  6. New method for estimating bacterial cell abundances in natural samples by use of sublimation.

    PubMed

    Glavin, Daniel P; Cleaves, H James; Schubert, Michael; Aubrey, Andrew; Bada, Jeffrey L

    2004-10-01

    We have developed a new method based on the sublimation of adenine from Escherichia coli to estimate bacterial cell counts in natural samples. To demonstrate this technique, several types of natural samples, including beach sand, seawater, deep-sea sediment, and two soil samples from the Atacama Desert, were heated to a temperature of 500 degrees C for several seconds under reduced pressure. The sublimate was collected on a cold finger, and the amount of adenine released from the samples was then determined by high-performance liquid chromatography with UV absorbance detection. Based on the total amount of adenine recovered from DNA and RNA in these samples, we estimated bacterial cell counts ranging from approximately 10(5) to 10(9) E. coli cell equivalents per gram. For most of these samples, the sublimation-based cell counts were in agreement with total bacterial counts obtained by traditional DAPI (4,6-diamidino-2-phenylindole) staining.

  7. New method for estimating bacterial cell abundances in natural samples by use of sublimation

    NASA Technical Reports Server (NTRS)

    Glavin, Daniel P.; Cleaves, H. James; Schubert, Michael; Aubrey, Andrew; Bada, Jeffrey L.

    2004-01-01

    We have developed a new method based on the sublimation of adenine from Escherichia coli to estimate bacterial cell counts in natural samples. To demonstrate this technique, several types of natural samples, including beach sand, seawater, deep-sea sediment, and two soil samples from the Atacama Desert, were heated to a temperature of 500 degrees C for several seconds under reduced pressure. The sublimate was collected on a cold finger, and the amount of adenine released from the samples was then determined by high-performance liquid chromatography with UV absorbance detection. Based on the total amount of adenine recovered from DNA and RNA in these samples, we estimated bacterial cell counts ranging from approximately 10(5) to 10(9) E. coli cell equivalents per gram. For most of these samples, the sublimation-based cell counts were in agreement with total bacterial counts obtained by traditional DAPI (4,6-diamidino-2-phenylindole) staining.

  8. Diffraction pattern study for cell type identification.

    PubMed

    Mihailescu, M; Costescu, J

    2012-01-16

    This paper presents our study regarding diffracted intensity distribution in Fresnel and Fraunhofer approximation from different cell types. Starting from experimental information obtained through digital holographic microscopy, we modeled the cell shapes as oblate spheroids and built their phase-only transmission functions. In Fresnel approximation, the experimental and numerical diffraction patterns from mature and immature red blood cells have complementary central intensity values at different distances. The Fraunhofer diffraction patterns of deformed red blood cells were processed in the reciprocal space where, the isoamplitude curves were formed independently for each degree of cell deformation present within every sample; the values on each separate isoamplitude curve are proportional with the percentage of the respective cell type within the sample.

  9. Radial Trends in IMF-sensitive Absorption Features in Two Early-type Galaxies: Evidence for Abundance-driven Gradients

    NASA Astrophysics Data System (ADS)

    McConnell, Nicholas J.; Lu, Jessica R.; Mann, Andrew W.

    2016-04-01

    Samples of early-type galaxies show a correlation between stellar velocity dispersion and the stellar initial mass function (IMF) as inferred from gravity-sensitive absorption lines in the galaxies’ central regions. To search for spatial variations in the IMF, we have observed two early-type galaxies with Keck/LRIS and measured radial gradients in the strengths of absorption features from 4000-5500 Å and 8000-10000 Å. We present spatially resolved measurements of the dwarf-sensitive spectral indices {Na} {{I}} (8190 Å) and Wing-Ford {{FeH}} (9915 Å), as well as indices for species of H, C2, CN, Mg, Ca, {{TiO}}, and Fe. Our measurements show a metallicity gradient in both objects, and Mg/Fe consistent with a shallow gradient in α-enhancement, matching widely observed trends for massive early-type galaxies. The {Na} {{I}} index and the CN1 index at 4160 Å exhibit significantly steeper gradients, with a break at r˜ 0.1 {r}{{eff}} (r˜ 300 pc). Inside this radius, {Na} {{I}} strength increases sharply toward the galaxy center, consistent with a rapid central rise in [Na/Fe]. In contrast, the ratio of the {{FeH}} to Fe index strength decreases toward the galaxy center. This behavior cannot be reproduced by a steepening IMF inside of 0.1 {r}{{eff}} if the IMF is a single power law. While gradients in the mass function above ˜ 0.4 {M}⊙ may occur, exceptional care is required to disentangle these IMF variations from the extreme variations in individual element abundances near the galaxies’ centers.

  10. Container Type Influences the Relative Abundance, Body Size, and Susceptibility of Ochlerotatus triseriatus (Diptera: Culicidae) to La Crosse Virus.

    PubMed

    Bara, Jeffrey J; Muturi, Ephantus J

    2015-05-01

    Ochlerotatus triseriatus (Say), the primary vector of La Crosse virus (LAC), develops in a variety of natural and artificial aquatic containers where it often co-occurs with larvae of other mosquito species. We conducted a field study at two woodlots (South Farms and Trelease Woods) in Urbana, IL, to examine how container type influences vector abundance, body size, and susceptibility to LAC. Mosquito pupae were collected from tree holes, plastic bins, and waste tires, and eclosing adults were identified to species morphologically. Oc. triseriatus and Ochlerotatus japonicus (Theobald) females were orally challenged with LAC and midgut infection rate, disseminated infection rate, and body titer were determined by reverse-transcriptase real-time PCR. Oc. triseriatus was the dominant species collected in tree holes while Oc. japonicus and Culex restuans (Theobald) were mostly dominant in artificial containers. Female Oc. triseriatus and Oc. japonicus collected from plastic bins were significantly larger than those collected from tree holes or waste tires. Oc. japonicus females from South Farms were also significantly larger than those from Trelease Woods. Oc. triseriatus females collected from plastic bins and waste tires were significantly more susceptible to LAC infection relative to females collected from tree holes. In addition, Oc. triseriatus females from waste tires had significantly higher LAC titer relative to Oc. triseriatus from tree holes. For each container type and study site, wing length was not correlated to infection or dissemination rates. These findings suggest that the container type in which Oc.triseriatus develop may contribute to the spatial and temporal dynamics of LAC transmission.

  11. Genomic Typing of Red Cell Antigens

    DTIC Science & Technology

    2011-09-01

    Antigen‐Matched  Red  Cells   for  Sickle   Cell   Anemia  Patients  Using  Molecular Typing to Augment Testing: Meghan Delaney, Prashant Gaur, Askale...H, Constans J, Quilici JC, Lefevre‐Witier P, Sevin J, Stevens M: Study of red blood  cell  and serum enzymes in  five  Pyrenean communities and in a...Antigen‐Matched Red  Cells  for  Sickle   Cell  Anemia Patients  Using Molecular Typing to Augment Testing: AABB (poster) 2009.  Background: Patients with  sickle

  12. The cell walls of syncytia formed by Heterodera schachtii in Arabidopsis thaliana are abundant in methyl-esterified pectin.

    PubMed

    Davies, Laura Jane; Urwin, Peter E

    2012-11-01

    Plant-parasitic cyst nematodes form a specialized feeding site, termed a syncytium, in the roots of host plants. Monoclonal antibodies to defined glycans, in addition to a cellulose-binding module, were used to characterize the cell walls of a functioning syncytia in situ. Cell walls of syncytia were found to contain cellulose, xyloglucan and mannan. Analysis of the pectin network revealed syncytial cell walls are abundant in homogalacturonan, which was heavily methyl-esterified. Arabinan was also detected and the results suggest the cell walls of syncytia are highly flexible.

  13. Conformation of a group 2 late embryogenesis abundant protein from soybean. Evidence of poly (L-proline)-type II structure.

    PubMed

    Soulages, Jose L; Kim, Kangmin; Arrese, Estela L; Walters, Christina; Cushman, John C

    2003-03-01

    Late embryogenesis abundant (LEA) proteins are members of a large group of hydrophilic, glycine-rich proteins found in plants, algae, fungi, and bacteria known collectively as hydrophilins that are preferentially expressed in response to dehydration or hyperosmotic stress. Group 2 LEA (dehydrins or responsive to abscisic acid) proteins are postulated to stabilize macromolecules against damage by freezing, dehydration, ionic, or osmotic stress. However, the structural and physicochemical properties of group 2 LEA proteins that account for such functions remain unknown. We have analyzed the structural properties of a recombinant form of a soybean (Glycine max) group 2 LEA (rGmDHN1). Differential scanning calorimetry of purified rGmDHN1 demonstrated that the protein does not display a cooperative unfolding transition upon heating. Ultraviolet absorption and circular dichroism spectroscopy revealed that the protein is in a largely hydrated and unstructured conformation in solution. However, ultraviolet absorption and circular dichroism measurements collected at different temperatures showed that the protein exists in equilibrium between two extended conformational states: unordered and left-handed extended helical or poly (L-proline)-type II structures. It is estimated that 27% of the residues of rGmDHN1 adopt or poly (L-proline)-type II-like helical conformation at 12 degrees C. The content of extended helix gradually decreases to 15% as the temperature is increased to 80 degrees C. Studies of the conformation of the protein in solution in the presence of liposomes, trifluoroethanol, and sodium dodecyl sulfate indicated that rGmDHN1 has a very low intrinsic ability to adopt alpha-helical structure and to interact with phospholipid bilayers through amphipathic alpha-helices. The ability of the protein to remain in a highly extended conformation at low temperatures could constitute the basis of the functional role of GmDHN1 in the prevention of freezing, desiccation

  14. High abundance of CD271+ multipotential stromal cells (MSCs) in intramedullary cavities of long bones

    PubMed Central

    Cox, George; Boxall, Sally A.; Giannoudis, Peter V.; Buckley, Conor T.; Roshdy, Tarek; Churchman, Sarah M.; McGonagle, Dennis; Jones, Elena

    2012-01-01

    Aspiration of iliac crest bone marrow (ICBM) remains the most frequent technique used in harvesting multipotential stromal cells (MSCs) for bone regeneration. Although this tissue type is easily accessed by a surgeon, it has a low frequency of MSCs, which is significant given the high cell numbers required for bone regeneration strategies. Lipoaspirates possess higher MSC frequencies, albeit cells with a differentiation profile less suited to orthopaedic interventions. Intra-medullary cavities of long bones have previously been shown to harbour MSCs in animals, however evaluation of their frequency, differentiation capacity and phenotype in humans had not previously been performed. Long bone fatty bone marrow (LBFBM) was collected prior to harvesting bone graft. Basic cellular compositions of donor-matched LBFBM and ICBM aspirates, including the numbers of CD34+ hematopoietic stem cells and CD31+ endothelial cells, were similar. MSCs were enumerated using colony-forming-unit-fibroblast assays and flow cytometry for the presence of a resident LBFBM CD45−/low CD271+ MSC population and revealed a trend for higher MSC numbers (average 5 fold, n = 6) per millilitre of LBFBM compared to donor-matched ICBM. Functional characteristics of resident MSCs, including their growth rates, differentiation potentials and surface phenotypes (CD73+CD105+CD90+) before and after culture-amplification, were similar. Enhanced numbers of MSCs could be recovered following brief enzymatic treatment of solid fragments of LBFBM. Our findings therefore reveal that the intramedullary cavity of the human femur is a depot of MSCs, which, although closely associated with fat, have a differentiation profile equivalent to ICBM. This anatomical site is frequently accessed by the orthopaedic/trauma surgeon and aspiration of the intramedullary cavity represents a ‘low-tech’ method of harvesting potentially large numbers of MSCs for regenerative therapies and research. This article is part of a

  15. Abundances of microRNAs in human cells can be estimated as a function of the abundances of YRHB and RHHK tetranucleotides in these microRNAs as an ill-posed inverse problem solution.

    PubMed

    Ponomarenko, Mikhail P; Suslov, Valentin V; Ponomarenko, Petr M; Gunbin, Konstantin V; Stepanenko, Irina L; Vishnevsky, Oleg V; Kolchanov, Nikolay A

    2013-01-01

    Mature microRNAs (miRNAs) are small endogenous non-coding RNAs 18-25 nt in length. They program the RNA Induced Silencing Complex (RISC) to make it inhibit either messenger RNAs or promoter DNAs. We have found that the mean abundance of miRNAs in Arabidopsis is correlated with the abundance of DRYD tetranucleotides near the 3'-end and the abundance of WRHB tetranucleotides in the center of the miRNA sequence. Based on this correlation, we have estimated miRNA abundances in seven organs of this plant, namely: inflorescences, stems, siliques, seedlings, roots, cauline, and rosette leaves. We have also found that the mean affinity of miRNAs for two proteins in the Argonaute family (Ago2 and Ago3) in man is correlated with the abundance of YRHB tetranucleotides near the 3'-end and that the preference of miRNAs for Ago2 is correlated with the abundance of RHHK tetranucleotides in the center of the miRNA sequence. This allowed us to obtain statistically significant estimates of miRNA abundances in human embryonic kidney cells, HEK293T. These findings in relation to two taxonomically distant entities (man and Arabidopsis) fit one another like pieces of a jigsaw puzzle, which allowed us to heuristically generalize them and state that the miRNA abundance in the human brain may be determined by the abundance of YRHB and RHHK tetranucleotides in these miRNAs.

  16. Fuel cells - Fundamentals and types: Unique features

    NASA Astrophysics Data System (ADS)

    Selman, J. R.

    An overview of the working principles, thermodynamic efficiencies, types, and engineering aspects of fuel cells is presented. It is noted that fuel cells are distinguished from other direct energy conversion devices by the existence of charge separation at the electrodes involving ions in an electrolyte. The electrical energy produced by a fuel cell is shown to be equal to the change in the free energy of the reactants, and thermodynamic balances of reactions in different fuel cells are provided. The production of electricity in the discharge mode involves a spontaneous reaction of overproduction of electrons at the anode and consumption of the electrons at the cathode, with the total ionic current being equal to the electronic current in the external circuit. Attention is given to the operations and problems of acid, alkaline, molten carbonate, and solid oxide fuel cells, in addition to applications of electro-organic fuel cells.

  17. High throughput screening for compounds that alter muscle cell glycosylation identifies new role for N-glycans in regulating sarcolemmal protein abundance and laminin binding.

    PubMed

    Cabrera, Paula V; Pang, Mabel; Marshall, Jamie L; Kung, Raymond; Nelson, Stanley F; Stalnaker, Stephanie H; Wells, Lance; Crosbie-Watson, Rachelle H; Baum, Linda G

    2012-06-29

    Duchenne muscular dystrophy is an X-linked disorder characterized by loss of dystrophin, a cytoskeletal protein that connects the actin cytoskeleton in skeletal muscle cells to extracellular matrix. Dystrophin binds to the cytoplasmic domain of the transmembrane glycoprotein β-dystroglycan (β-DG), which associates with cell surface α-dystroglycan (α-DG) that binds laminin in the extracellular matrix. β-DG can also associate with utrophin, and this differential association correlates with specific glycosylation changes on α-DG. Genetic modification of α-DG glycosylation can promote utrophin binding and rescue dystrophic phenotypes in mouse dystrophy models. We used high throughput screening with the plant lectin Wisteria floribunda agglutinin (WFA) to identify compounds that altered muscle cell surface glycosylation, with the goal of finding compounds that increase abundance of α-DG and associated sarcolemmal glycoproteins, increase utrophin usage, and increase laminin binding. We identified one compound, lobeline, from the Prestwick library of Food and Drug Administration-approved compounds that fulfilled these criteria, increasing WFA binding to C2C12 cells and to primary muscle cells from wild type and mdx mice. WFA binding and enhancement by lobeline required complex N-glycans but not O-mannose glycans that bind laminin. However, inhibiting complex N-glycan processing reduced laminin binding to muscle cell glycoproteins, although O-mannosylation was intact. Glycan analysis demonstrated a general increase in N-glycans on lobeline-treated cells rather than specific alterations in cell surface glycosylation, consistent with increased abundance of multiple sarcolemmal glycoproteins. This demonstrates the feasibility of high throughput screening with plant lectins to identify compounds that alter muscle cell glycosylation and identifies a novel role for N-glycans in regulating muscle cell function.

  18. High Throughput Screening for Compounds That Alter Muscle Cell Glycosylation Identifies New Role for N-Glycans in Regulating Sarcolemmal Protein Abundance and Laminin Binding*

    PubMed Central

    Cabrera, Paula V.; Pang, Mabel; Marshall, Jamie L.; Kung, Raymond; Nelson, Stanley F.; Stalnaker, Stephanie H.; Wells, Lance; Crosbie-Watson, Rachelle H.; Baum, Linda G.

    2012-01-01

    Duchenne muscular dystrophy is an X-linked disorder characterized by loss of dystrophin, a cytoskeletal protein that connects the actin cytoskeleton in skeletal muscle cells to extracellular matrix. Dystrophin binds to the cytoplasmic domain of the transmembrane glycoprotein β-dystroglycan (β-DG), which associates with cell surface α-dystroglycan (α-DG) that binds laminin in the extracellular matrix. β-DG can also associate with utrophin, and this differential association correlates with specific glycosylation changes on α-DG. Genetic modification of α-DG glycosylation can promote utrophin binding and rescue dystrophic phenotypes in mouse dystrophy models. We used high throughput screening with the plant lectin Wisteria floribunda agglutinin (WFA) to identify compounds that altered muscle cell surface glycosylation, with the goal of finding compounds that increase abundance of α-DG and associated sarcolemmal glycoproteins, increase utrophin usage, and increase laminin binding. We identified one compound, lobeline, from the Prestwick library of Food and Drug Administration-approved compounds that fulfilled these criteria, increasing WFA binding to C2C12 cells and to primary muscle cells from wild type and mdx mice. WFA binding and enhancement by lobeline required complex N-glycans but not O-mannose glycans that bind laminin. However, inhibiting complex N-glycan processing reduced laminin binding to muscle cell glycoproteins, although O-mannosylation was intact. Glycan analysis demonstrated a general increase in N-glycans on lobeline-treated cells rather than specific alterations in cell surface glycosylation, consistent with increased abundance of multiple sarcolemmal glycoproteins. This demonstrates the feasibility of high throughput screening with plant lectins to identify compounds that alter muscle cell glycosylation and identifies a novel role for N-glycans in regulating muscle cell function. PMID:22570487

  19. IMF and [Na/Fe] abundance ratios from optical and NIR spectral features in early-type galaxies

    NASA Astrophysics Data System (ADS)

    La Barbera, F.; Vazdekis, A.; Ferreras, I.; Pasquali, A.; Allende Prieto, C.; Röck, B.; Aguado, D. S.; Peletier, R. F.

    2017-01-01

    We present a joint analysis of the four most prominent sodium-sensitive features (Na D, Na I λ8190Å, Na I λ1.14 μm, and Na I λ2.21 μm), in the optical and near-infrared spectral ranges, of two nearby, massive (σ ˜ 300 km s-1), early-type galaxies (named XSG1 and XSG2). Our analysis relies on deep Very Large Telescope/X-Shooter long-slit spectra, along with newly developed stellar population models, allowing for [Na/Fe] variations, up to ˜1.2 dex, over a wide range of age, total metallicity, and initial mass function (IMF) slope. The new models show that the response of the Na-dependent spectral indices to [Na/Fe] is stronger when the IMF is bottom heavier. For the first time, we are able to match all four Na features in the central regions of massive early-type galaxies finding an overabundance of [Na/Fe] in the range 0.5-0.7 dex and a bottom-heavy IMF. Therefore, individual abundance variations cannot be fully responsible for the trends of gravity-sensitive indices, strengthening the case towards a non-universal IMF. Given current limitations of theoretical atmosphere models, our [Na/Fe] estimates should be taken as upper limits. For XSG1, where line strengths are measured out to ˜0.8 Re, the radial trend of [Na/Fe] is similar to [α/Fe] and [C/Fe], being constant out to ˜0.5 Re, and decreasing by ˜0.2-0.3 dex at ˜0.8 Re, without any clear correlation with local metallicity. Such a result seems to be in contrast to the predicted increase of Na nucleosynthetic yields from asymptotic giant branch stars and Type II supernovae. For XSG1, the Na-inferred IMF radial profile is consistent, within the errors, with that derived from TiO features and the Wing-Ford band presented in a recent paper.

  20. RNA cell typing and DNA profiling of mixed samples: can cell types and donors be associated?

    PubMed

    Harteveld, Joyce; Lindenbergh, Alexander; Sijen, Titia

    2013-09-01

    Forensic samples regularly involve mixtures, which are readily recognised in forensic analyses. Combined DNA and mRNA profiling is an upcoming forensic practice to examine donors and cell types from the exact same sample. From DNA profiles individual genotypes may be deconvoluted, but to date no studies have established whether the cell types identified in corresponding RNA profiles can be associated with individual donors. Although RNA expression levels hold many variables from which an association may not be expected, proof of concept is important to forensic experts who may be cross examined about this possible correlation in court settings. Clearly, the gender-specificity of certain body fluids (semen, vaginal mucosa, menstrual secretion) can be instructive. However, when donors of the same gender or gender-neutral cell types are involved, alternatives are needed. Here we analyse basic two-component mixtures (two cell types provided by different donors) composed of six different cell types, and assess whether the heights of DNA and RNA peaks may guide association of donor and cell type. Divergent results were obtained; for some mixtures RNA peak heights followed the DNA results, but for others the major DNA component did not present higher RNA peaks. Also, variation in mixture ratios was observed for RNA profiling replicates and when different donor couples gave the same two body fluids. As sample degradation may affect the two nucleic acids and/or distinct cell types differently (and thus influence donor and cell type association), mixtures were subjected to elevated temperature or UV-light. Variation in DNA and RNA stability was observed both between and within cell types and depended on the method inducing degradation. Taken together, we discourage to associate cell types and donors from peak heights when performing RNA and DNA profiling.

  1. Versatile UHV compatible Knudsen type effusion cell

    SciTech Connect

    Shukla, A.K.; Banik, S.; Dhaka, R.S.; Biswas, C.; Barman, S.R.; Haak, H.

    2004-11-01

    A versatile Knudsen type effusion cell has been fabricated for growing nanostructures and epitaxial layers of metals and semiconductors. The cell provides excellent vacuum compatibility (10{sup -10} mbar range during operation), efficient water cooling, uniform heating, and moderate input power consumption (100 W at 1000 deg. C). The thermal properties of the cell have been determined. The performance of the cell has been assessed by x-ray photoemission spectroscopy (XPS) for Mn adlayer growth on Al(111). We find that this Knudsen cell has a stable deposition rate of 0.17 monolayer per minute at 550 deg. C. From the XPS spectra, we show that the Mn adlayers are completely clean, i.e., devoid of any surface contamination.

  2. Using fluorescence activated cell sorting to examine cell-type-specific gene expression in rat brain tissue.

    PubMed

    Schwarz, Jaclyn M

    2015-05-28

    The brain is comprised of four primary cell types including neurons, astrocytes, microglia and oligodendrocytes. Though they are not the most abundant cell type in the brain, neurons are the most widely studied of these cell types given their direct role in impacting behaviors. Other cell types in the brain also impact neuronal function and behavior via the signaling molecules they produce. Neuroscientists must understand the interactions between the cell types in the brain to better understand how these interactions impact neural function and disease. To date, the most common method of analyzing protein or gene expression utilizes the homogenization of whole tissue samples, usually with blood, and without regard for cell type. This approach is an informative approach for examining general changes in gene or protein expression that may influence neural function and behavior; however, this method of analysis does not lend itself to a greater understanding of cell-type-specific gene expression and the effect of cell-to-cell communication on neural function. Analysis of behavioral epigenetics has been an area of growing focus which examines how modifications of the deoxyribonucleic acid (DNA) structure impact long-term gene expression and behavior; however, this information may only be relevant if analyzed in a cell-type-specific manner given the differential lineage and thus epigenetic markers that may be present on certain genes of individual neural cell types. The Fluorescence Activated Cell Sorting (FACS) technique described below provides a simple and effective way to isolate individual neural cells for the subsequent analysis of gene expression, protein expression, or epigenetic modifications of DNA. This technique can also be modified to isolate more specific neural cell types in the brain for subsequent cell-type-specific analysis.

  3. NLTE carbon abundance determination in selected A- and B-type stars and the interpretation of C I emission lines

    NASA Astrophysics Data System (ADS)

    Alexeeva, S. A.; Ryabchikova, T. A.; Mashonkina, L. I.

    2016-10-01

    We constructed a comprehensive model atom for C I-C II using the most up-to-date atomic data available and evaluated the non-local thermodynamic equilibrium (NLTE) line formation for C I and C II in classical 1D models representing the atmospheres of A- and late B-type stars. Our NLTE calculations predict the emission that appears at effective temperature of 9250 to 10 500 K depending on log g in the C I 8335, 9405 Å singlet lines and at Teff> 15 000 K (log g = 4) in the C I 9061-9111 Å, 9603-9658 Å triplet lines. A pre-requisite of the emission phenomenon is the overionization-recombination mechanism resulting in a depopulation of the lower levels of C I to a greater extent than the upper levels. Extra depopulation of the lower levels of the transitions corresponding to the near-infrared lines, is caused by photon loss in the UV lines C I 2479, 1930, and 1657 Å. We analysed the lines of C I and C II in Vega, HD 73666, Sirius, 21 Peg, π Cet, HD 22136, and ι Her taking advantage of their observed high-resolution spectra. The C I emission lines were detected in the four hottest stars, and they were well reproduced in our NLTE calculations. For each star, the mean NLTE abundances from lines of the two ionization stages, C I and C II, including the C I emission lines, were found to be consistent. We show that the predicted C I emission phenomenon depends strongly on whether accurate or approximate electron-impact excitation rates are applied.

  4. Stem cell treatment for type 1 diabetes

    PubMed Central

    Li, Ming; Ikehara, Susumu

    2014-01-01

    Type 1 diabetes mellitus (T1DM) is a common chronic disease in children, characterized by a loss of β cells, which results in defects in insulin secretion and hyperglycemia. Chronic hyperglycemia causes diabetic complications, including diabetic nephropathy, neuropathy, and retinopathy. Curative therapies mainly include diet and insulin administration. Although hyperglycemia can be improved by insulin administration, exogenous insulin injection cannot successfully mimic the insulin secretion from normal β cells, which keeps blood glucose levels within the normal range all the time. Islet and pancreas transplantation achieves better glucose control, but there is a lack of organ donors. Cell based therapies have also been attempted to treat T1DM. Stem cells such as embryonic stem cells, induced pluripotent stem cells and tissue stem cells (TSCs) such as bone marrow-, adipose tissue-, and cord blood-derived stem cells, have been shown to generate insulin-producing cells. In this review, we summarize the most-recently available information about T1DM and the use of TSCs to treat T1DM. PMID:25364717

  5. Zooplankton abundance in relation to state and type of intrusions onto the southeastern United States shelf during summer

    SciTech Connect

    Paffenhoefer, G.A.; Wester, B.T.; Nicholas, W.D.

    1984-01-01

    The vertical distribution of zooplankton on the continental shelf of northeastern Florida was determined in and around upwelling events and related to concentrations of particulate matter. Doliolida and the cladoceran Penilia avirostris were significantly more abundant in upwelled water < 22/sup 0/C and the cyclopoid genus Oncaea more abundant at warmer temperatures. The abundance of doliolida, Oithona and Oncaea in intrusions and the thermocline was significantly higher in older than in recently upwelled waters. The vertical sequences of the abundance of zooplankton and particulate matter (2-114 ..mu..m ESD) were identical. Zooplankton maxima co-occurred primarily with maxima in phytoplankton biomass (chlorophyll a) and only partly with primary productivity. 27 references, 16 figures, 6 tables.

  6. Light differentially regulates cell division and the mRNA abundance of pea nucleolin during de-etiolation

    NASA Technical Reports Server (NTRS)

    Reichler, S. A.; Balk, J.; Brown, M. E.; Woodruff, K.; Clark, G. B.; Roux, S. J.

    2001-01-01

    The abundance of plant nucleolin mRNA is regulated during de-etiolation by phytochrome. A close correlation between the mRNA abundance of nucleolin and mitosis has also been previously reported. These results raised the question of whether the effects of light on nucleolin mRNA expression were a consequence of light effects on mitosis. To test this we compared the kinetics of light-mediated increases in cell proliferation with that of light-mediated changes in the abundance of nucleolin mRNA using plumules of dark-grown pea (Pisum sativum) seedlings. These experiments show that S-phase increases 9 h after a red light pulse, followed by M-phase increases in the plumule leaves at 12 h post-irradiation, a time course consistent with separately measured kinetics of red light-induced increases in the expression of cell cycle-regulated genes. These increases in cell cycle-regulated genes are photoreversible, implying that the light-induced increases in cell proliferation are, like nucleolin mRNA expression, regulated via phytochrome. Red light stimulates increases in the mRNA for nucleolin at 6 h post-irradiation, prior to any cell proliferation changes and concurrent with the reported timing of phytochrome-mediated increases of rRNA abundance. After a green light pulse, nucleolin mRNA levels increase without increasing S-phase or M-phase. Studies in animals and yeast indicate that nucleolin plays a significant role in ribosome biosynthesis. Consistent with this function, pea nucleolin can rescue nucleolin deletion mutants of yeast that are defective in rRNA synthesis. Our data show that during de-etiolation, the increased expression of nucleolin mRNA is more directly regulated by light than by mitosis.

  7. Effect of oocyte quality on the relative abundance of specific gene transcripts in bovine mature oocytes and 16-cell embryos

    PubMed Central

    Bilodeau-Goeseels, Sylvie

    2003-01-01

    Although the developmental potential of oocytes is related to oocyte quality, whether the expression of specific genes is altered in oocytes of different quality and in resulting embryos is not known. Semi-quantitative reverse transcription-polymerase chain reaction was used to compare the relative abundance of 2 transcripts for housekeeping proteins (β-actin and ribosomal protein L30) and 3 transcripts for growth factor ligand or receptors (platelet derived growth factor receptor α (PDGFRα), basic fibroblast growth factor (bFGF)), in mature bovine oocytes of high versus low developmental potential. The transcripts for L30, PDGFRα, and bFGF in 16-cell embryos originating from these oocytes were also examined. No significant effect of oocyte quality was detected for any of the transcripts examined from oocytes or 16-cell embryos. In conclusion, a lower developmental potential of oocytes with advanced signs of atresia, was not associated with a lower level of abundance of the transcripts examined. PMID:12760483

  8. LITHIUM ABUNDANCE IN SOLAR-TYPE STARS WITH LOW CHROMOSPHERIC ACTIVITY: APPLICATION TO THE SEARCH FOR MAUNDER MINIMUM ANALOGS

    SciTech Connect

    Lubin, Dan; Tytler, David; Kirkman, David

    2010-06-10

    We use measurements of lithium abundance to examine the evolutionary history of stars frequently believed to be in a Maunder minimum (MM) state due to their low chromospheric activity. In a sample whose main-sequence membership has been verified using Hipparcos parallax data, we find that stars with very low chromospheric activity log R'{sub HK} {<=} -5.0 have substantially depleted lithium compared with the full sample, with half of these lithium abundances lying more than one standard deviation below the sample mean for their range of color index. One interpretation is that these stars are near the end of their main-sequence lifetime, and therefore their low activity does not necessarily signify a transient MM state in a solar-age star. Conversely, using information in published activity time series for some stars, and combined lithium and activity measurements from the Ursa Major moving group and M67, we find limited evidence that a low-activity star having lithium abundance in the normal range for its color index may be a viable MM candidate. Thus, lithium abundance, which can be readily observed or even retrieved from some of the spectroscopic data collected by recent planet-search surveys, may have value for expanding and refining the program star lists for long-term MM searches. Finally, we find that the use of Hipparcos parallax data to ascertain main-sequence membership sharpens the distinction in sample-mean lithium abundance between stars with planet detections and comparison stars.

  9. Identification of Vulnerable Cell Types in Major Brain Disorders Using Single Cell Transcriptomes and Expression Weighted Cell Type Enrichment.

    PubMed

    Skene, Nathan G; Grant, Seth G N

    2016-01-01

    The cell types that trigger the primary pathology in many brain diseases remain largely unknown. One route to understanding the primary pathological cell type for a particular disease is to identify the cells expressing susceptibility genes. Although this is straightforward for monogenic conditions where the causative mutation may alter expression of a cell type specific marker, methods are required for the common polygenic disorders. We developed the Expression Weighted Cell Type Enrichment (EWCE) method that uses single cell transcriptomes to generate the probability distribution associated with a gene list having an average level of expression within a cell type. Following validation, we applied EWCE to human genetic data from cases of epilepsy, Schizophrenia, Autism, Intellectual Disability, Alzheimer's disease, Multiple Sclerosis and anxiety disorders. Genetic susceptibility primarily affected microglia in Alzheimer's and Multiple Sclerosis; was shared between interneurons and pyramidal neurons in Autism and Schizophrenia; while intellectual disabilities and epilepsy were attributable to a range of cell-types, with the strongest enrichment in interneurons. We hypothesized that the primary cell type pathology could trigger secondary changes in other cell types and these could be detected by applying EWCE to transcriptome data from diseased tissue. In Autism, Schizophrenia and Alzheimer's disease we find evidence of pathological changes in all of the major brain cell types. These findings give novel insight into the cellular origins and progression in common brain disorders. The methods can be applied to any tissue and disorder and have applications in validating mouse models.

  10. Modulation of Na(+)-K(+)-ATPase cell surface abundance through structural determinants on the α1-subunit.

    PubMed

    Pierre, Sandrine V; Belliard, Aude; Sottejeau, Yoann

    2011-01-01

    Through their ion-pumping and non-ion-pumping functions, Na(+)-K(+)-ATPase protein complexes at the plasma membrane are critical to intracellular homeostasis and to the physiological and pharmacological actions of cardiotonic steroids. Alteration of the abundance of Na(+)-K(+)-ATPase units at the cell surface is one of the mechanisms for Na(+)-K(+)-ATPase regulation in health and diseases that has been closely examined over the past few decades. We here summarize these findings, with emphasis on studies that explicitly tested the involvement of defined regions or residues on the Na(+)-K(+)-ATPase α1 polypeptide. We also report new findings on the effect of manipulating Na(+)-K(+)-ATPase membrane abundance by targeting one of these defined regions: a dileucine motif of the form [D/E]XXXL[L/I]. In this study, opossum kidney cells stably expressing rat α1 Na(+)-K(+)-ATPase or a mutant where the motif was disrupted (α1-L499V) were exposed to 30 min of substrate/coverslip-induced-ischemia followed by reperfusion (I-R). Biotinylation studies suggested that I-R itself acted as an inducer of Na(+)-K(+)-ATPase internalization and that surface expression of the mutant was higher than the native Na(+)-K(+)-ATPase before and after ischemia. Annexin V/propidium iodide staining and lactate dehydrogenase release suggested that I-R injury was reduced in α1-L499V-expressing cells compared with α1-expressing cells. Hence, modulation of Na(+)-K(+)-ATPase cell surface abundance through structural determinants on the α-subunit is an important mechanism of regulation of cellular Na(+)-K(+)-ATPase in various physiological and pathophysiological conditions, with a significant impact on cell survival in face of an ischemic stress.

  11. HETEROGENEITY IN {sup 12}CO/{sup 13}CO ABUNDANCE RATIOS TOWARD SOLAR-TYPE YOUNG STELLAR OBJECTS

    SciTech Connect

    Smith, Rachel L.; Pontoppidan, Klaus M.; Young, Edward D.; Morris, Mark R. E-mail: smithrl2@appstate.edu

    2015-11-10

    This study reports an unusual heterogeneity in [{sup 12}C{sup 16}O]/[{sup 13}C{sup 16}O] abundance ratios of carbon monoxide observed in the gas phase toward seven ∼solar-mass young stellar objects (YSOs) and three dense foreground clouds in the nearby star-forming regions, Ophiuchus, Corona Australis, Orion, and Vela, and an isolated core, L43. Robust isotope ratios were derived using infrared absorption spectroscopy of the 4.7 μm fundamental and 2.3 μm overtone rovibrational bands of CO at very high spectral resolution (λ/Δλ ≈ 95,000), observed with the Cryogenic Infrared Echelle Spectrograph (CRIRES) on the Very Large Telescope. We find [{sup 12}C{sup 16}O]/[{sup 13}C{sup 16}O] values ranging from ∼85 to 165, significantly higher than those of the local interstellar medium (ISM) (∼65–69). These observations are evidence for isotopic heterogeneity in carbon reservoirs in solar-type YSO environments, and encourage the need for refined galactic chemical evolution models to explain the {sup 12}C/{sup 13}C discrepancy between the solar system and local ISM. The oxygen isotope ratios are consistent with isotopologue-specific photodissociation by CO self-shielding toward the disks, VV CrA N and HL Tau, further substantiating models predicting CO self-shielding on disk surfaces. However, we find that CO self-shielding is an unlikely general explanation for the high [{sup 12}C{sup 16}O]/[{sup 13}C{sup 16}O] ratios observed in this study. Comparison of the solid CO against gas-phase [{sup 12}C{sup 16}O]/[{sup 13}C{sup 16}O] suggests that interactions between CO ice and gas reservoirs need to be further investigated as at least a partial explanation for the unusually high [{sup 12}C{sup 16}O]/[{sup 13}C{sup 16}O] observed.

  12. X-RAY PROPERTIES OF YOUNG EARLY-TYPE GALAXIES. II. ABUNDANCE RATIO IN THE HOT INTERSTELLAR MATTER

    SciTech Connect

    Kim, Dong-Woo; Fabbiano, Giuseppina; Pipino, Antonio

    2012-05-20

    Using Chandra X-ray observations of young, post-merger elliptical galaxies, we present X-ray characteristics of age-related observational results by comparing them with typical old elliptical galaxies in terms of metal abundances in the hot interstellar matter (ISM). While the absolute element abundances may be uncertain because of unknown systematic errors and partly because of the smaller amount of hot gas in young ellipticals, the relative abundance ratios (e.g., the {alpha}-element to Fe ratio, and most importantly the Si/Fe ratio) can be relatively well constrained. In two young elliptical galaxies (NGC 720 and NGC 3923) we find that the Si to Fe abundance ratio is super-solar (at a 99% significance level), in contrast to typical old elliptical galaxies where the Si to Fe abundance ratio is close to solar. Also, the O/Mg ratio is close to solar in the two young elliptical galaxies, as opposed to the sub-solar O/Mg ratio reported in old elliptical galaxies. Both features appear to be less significant outside the effective radius (roughly 30'' for the galaxies under study), consistent with the observations that confine to the centermost regions the signatures of recent star formation in elliptical galaxies. Observed differences between young and old elliptical galaxies can be explained by the additional contribution from SNe II ejecta in the former. In young elliptical galaxies, the later star formation associated with recent mergers would have a dual effect, resulting both in galaxy scale winds-and therefore smaller observed amounts of hot ISM-because of the additional SN II heating, and in different metal abundances, because of the additional SN II yields.

  13. Monitoring cell physiology by expression profiles and discovering cell type-specific genes by compiled expression profiles

    SciTech Connect

    Okubo, Kousaku; Itoh, Kouichi; Fukushima, Atsushi; Yoshii, Junji; Matsubara, Kenichi

    1995-11-20

    A gene expression profile is the list showing the expressed gene species and the abundance of their transcripts in a given cell or tissue. This list is made by constructing 3{prime}-directed cDNA libraries consisting of only the 3{prime}-termini of mRNA and sequencing randomly selected clones from such libraries: genes are identified by the sequences, and the composition of mRNA, which reflects gene activities, is measured from the frequency of appearance of the gene transcripts. For practical reasons, the number of sequenced clones has been limited to approximately 1000 per library at present, but the resulting profile covers almost all highly or moderately expressed genes, along with many less active genes. We constructed expression profiles from the HL60 human promyelocytic cell line and two of its derivatives, granulocytoids induced by DMSO and monocytoids induced by TPA. In HL60, a significant fraction of the abundantly expressed genes was for protein synthesis. Upon induction, these genes were partially or totally silenced; transcripts for proteins that characterize the granulocytes and monocyte-macrophages became abundant. By compiling and comparing different expression profiles, genes can be categorized into those expressed in diverse cell types and those active only in limited cell types. Although at present, the number of expression profiles that can be compiled is limited and this categorization is applicable only to abundantly expressed genes, 13 novel genes that may represent granulocyte- or monocyte-specific functions have been discovered. 37 refs., 1 fig., 2 tabs.

  14. Synthesis of Earth-abundant Cu2SnS3 for Solar Cells

    NASA Astrophysics Data System (ADS)

    Tiwari, D.; Chaudhuri, T. K.

    2011-07-01

    Cu2SnS3 (CTS) is an emerging semiconducting absorber layer material for solar cells having energy band gap of around 1 eV. In this work CTS powders has been synthesized from metal salts using different sulphur sources. It is found that thiourea yielded pure CTS. The composition of the prepared material has been confirmed by X-ray diffraction (XRD), which shows the CTS powder to be nanocrystalline with triclinic phase. Also the time of the completion of reaction has been optimized by studying the XRD pattern of the product at different time interval of reaction. The diffuse reflectance spectrum of CTS depicts the energy band gap for the sample to be 1.1 eV. The electrical measurement of the pellet of the CTS powders proves the material to have p-type conduction with thermoelectric coefficient of 95μV/K as determined from hot-probe method. The electrical conductivity of the pellet is 10-32 mho/cm.

  15. Deep-sequencing method for quantifying background abundances of symbiodinium types: exploring the rare symbiodinium biosphere in reef-building corals.

    PubMed

    Quigley, Kate M; Davies, Sarah W; Kenkel, Carly D; Willis, Bette L; Matz, Mikhail V; Bay, Line K

    2014-01-01

    The capacity of reef-building corals to associate with environmentally-appropriate types of endosymbionts from the dinoflagellate genus Symbiodinium contributes significantly to their success at local scales. Additionally, some corals are able to acclimatize to environmental perturbations by shuffling the relative proportions of different Symbiodinium types hosted. Understanding the dynamics of these symbioses requires a sensitive and quantitative method of Symbiodinium genotyping. Electrophoresis methods, still widely utilized for this purpose, are predominantly qualitative and cannot guarantee detection of a background type below 10% of the total Symbiodinium population. Here, the relative abundances of four Symbiodinium types (A13, C1, C3, and D1) in mixed samples of known composition were quantified using deep sequencing of the internal transcribed spacer of the ribosomal RNA gene (ITS-2) by means of Next Generation Sequencing (NGS) using Roche 454. In samples dominated by each of the four Symbiodinium types tested, background levels of the other three types were detected when present at 5%, 1%, and 0.1% levels, and their relative abundances were quantified with high (A13, C1, D1) to variable (C3) accuracy. The potential of this deep sequencing method for resolving fine-scale genetic diversity within a symbiont type was further demonstrated in a natural symbiosis using ITS-1, and uncovered reef-specific differences in the composition of Symbiodinium microadriaticum in two species of acroporid corals (Acropora digitifera and A. hyacinthus) from Palau. The ability of deep sequencing of the ITS locus (1 and 2) to detect and quantify low-abundant Symbiodinium types, as well as finer-scale diversity below the type level, will enable more robust quantification of local genetic diversity in Symbiodinium populations. This method will help to elucidate the role that background types have in maximizing coral fitness across diverse environments and in response to

  16. Enteropathy-type T-cell lymphoma.

    PubMed

    Zettl, Andreas; deLeeuw, Ron; Haralambieva, Eugenia; Mueller-Hermelink, Hans-Konrad

    2007-05-01

    Session 7 of the Society for Hematopathology/European Association for Haematopathology Workshop was devoted to case presentations and discussion of enteropathy-type T-cell lymphoma (ETL) and other T-cell lymphomas involving the gastrointestinal tract. ETL is a rare type of T-cell lymphoma, often associated with a history of celiac disease, that usually arises in the jejunum but can involve other gastrointestinal tract sites (eg, stomach and colon). As the cases submitted illustrate, there are 2 histologic groups of ETL that correlate with clinical and immunophenotypic features. Pleomorphic-anaplastic ETL is usually associated with a history of celiac disease and histologic evidence of enteropathy and is most often CD56-. Monomorphic ETL often occurs without a history of celiac disease, has variable histologic evidence of enteropathy, and is usually CD56+. Comparative genomic hybridization has shown recurrent chromosomal gains and losses that are characteristic of ETL and uncommon in other T-cell lymphomas, providing useful ancillary data for the diagnosis of ETL.

  17. Cell type-dependent regulation of free ISG15 levels and ISGylation.

    PubMed

    Tecalco Cruz, Angeles C; Mejía-Barreto, Karen

    2017-03-11

    Interferon-stimulated gene 15 (ISG15) is an ubiquitin-like protein, which can either be found as a free protein or covalently-bound to target proteins via ISGylation. The functions of free and conjugated ISG15 are ambiguous in tumorigenesis owing to its roles as an oncogene and a tumour suppressor gene. This dual role for ISG15 could be a result of the cancer cell type and the cellular context. Here, we report that ISG15 expression is upregulated in different cancer cells compared to normal cells. Furthermore, we found higher endogenous, free ISG15 protein levels in MCF7 breast cancer cells than in other cells, suggesting that non-conjugated ISG15 levels are cell type-specific. Additionally, we demonstrated that interferon gamma (IFN-Ɣ) increased both free and conjugated levels of ISG15 in MCF7 cells. Interestingly, endogenous conjugated and free ISG15 levels were differentially regulated by IFN-Ɣ in several cell lines. On characterisation of the subcellular distribution of ISG15 in several cell types, our results indicated that free ISG15 was mainly localised to the cytoplasm of MCF7 cells, whereas ISGylation marks were also found in the cytoplasm, but mainly in the nucleus, with a specific distribution pattern in each cell type. Thus, free and conjugated ISG15 protein levels and their subcellular distribution are cell type-dependent, whereas IFN-Ɣ signalling may differentially control the abundance of both ISG15 forms in transformed and normal cells.

  18. The Future of Using Earth-Abundant Elements in Counter Electrodes for Dye-Sensitized Solar Cells.

    PubMed

    Briscoe, Joe; Dunn, Steve

    2016-05-01

    With limited global resources for many of the elements that are found in some of the most common renewable energy technologies, there is a growing need to use "Earth-abundant" elements as a long-term solution to growing energy demands. The dye-sensitized solar cell has the potential to produce low-cost renewable energy, with inexpensive production and most components using Earth-abundant elements. However, the most commonly used material for the cell counter electrode (CE) is platinum, an extremely expensive and rare element. A selection of the materials investigated as alternative CEs are discussed, including metal sulfides, oxides, carbides, and nitrides and carbon-based materials such as carbon nanotubes, graphene, and conductive polymers. As well as having the potential for lower cost, these materials can also produce more-efficient devices due to their high surface area and catalytic activity. Therefore, once issues such as stability have been studied in more detail and scale-up of production methods are considered, there is a very promising future for the replacement of Pt in DSSCs with lower-cost, Earth-abundant alternatives.

  19. Plant single-cell and single-cell-type metabolomics.

    PubMed

    Misra, Biswapriya B; Assmann, Sarah M; Chen, Sixue

    2014-10-01

    In conjunction with genomics, transcriptomics, and proteomics, plant metabolomics is providing large data sets that are paving the way towards a comprehensive and holistic understanding of plant growth, development, defense, and productivity. However, dilution effects from organ- and tissue-based sampling of metabolomes have limited our understanding of the intricate regulation of metabolic pathways and networks at the cellular level. Recent advances in metabolomics methodologies, along with the post-genomic expansion of bioinformatics knowledge and functional genomics tools, have allowed the gathering of enriched information on individual cells and single cell types. Here we review progress, current status, opportunities, and challenges presented by single cell-based metabolomics research in plants.

  20. Low abundance of mitochondrial DNA changes mitochondrial status and renders cells resistant to serum starvation and sodium nitroprusside insult.

    PubMed

    Lee, Sung Ryul; Heo, Hye Jin; Jeong, Seung Hun; Kim, Hyoung Kyu; Song, In Sung; Ko, Kyung Soo; Rhee, Byoung Doo; Kim, Nari; Han, Jin

    2015-07-01

    Mutation or depletion of mitochondrial DNA (mtDNA) can cause severe mitochondrial malfunction, originating from the mitochondrion itself, or from the crosstalk between nuclei and mitochondria. However, the changes that would occur if the amount of mtDNA is diminished are less known. Thus, we generated rat myoblast H9c2 cells containing lower amounts of mtDNA via ethidium bromide and uridine supplementation. After confirming the depletion of mtDNA by quantitative PCR and gel electrophoresis analysis, we investigated the changes in mitochondrial physical parameters by using flow cytometry. We also evaluated the resistance of these cells to serum starvation and sodium nitroprusside. H9c2 cells with diminished mtDNA contents showed decreased mitochondrial membrane potential, mass, free calcium, and zinc ion contents as compared to naïve H9c2 cells. Furthermore, cytosolic and mitochondrial reactive oxygen species levels were significantly higher in mtDNA-lowered H9c2 cells than in the naïve cells. Although the oxygen consumption rate and cell proliferation were decreased, mtDNA-lowered H9c2 cells were more resistant to serum deprivation and nitroprusside insults than the naïve H9c2 cells. Taken together, we conclude that the low abundance of mtDNA cause changes in cellular status, such as changes in reactive oxygen species, calcium, and zinc ion levels inducing resistance to stress.

  1. [Influences of long-term application of organic and inorganic fertilizers on the composition and abundance of nirS-type denitrifiers in black soil].

    PubMed

    Yin, Chang; Fan, Fen-Liang; Li, Zhao-Jun; Song, A-Lin; Zhu, Ping; Peng, Chang; Liang, Yong-Chao

    2012-11-01

    The objectives of this study were to explore the effects of long-term organic and inorganic fertilizations on the composition and abundance of nirS-type denitrifiers in black soil. Soil samples were collected from 4 treatments (i. e. no fertilizer treatment, CK; organic manure treatment, OM; chemical fertilizer treatment (NPK) and combination of organic and chemical fertilizers treatment (MNPK)) in Gongzhuling Long-term Fertilization Experiment Station. Composition and abundance of nirS-type denitrifiers were analyzed with terminal restriction fragment length polymorphism (T-RFLP) and real-time quantitative PCR (Q-PCR), respectively. Denitrification enzyme activity (DEA) and soil properties were also measured. Application of organic fertilizers (OM and MNPK) significantly increased the DEAs of black soil, with the DEAs in OM and MNPK being 5.92 and 6.03 times higher than that in CK treatment, respectively, whereas there was no significant difference between NPK and CK. OM and MNPK treatments increased the abundances of nirS-type denitrifiers by 2.73 and 3.83 times relative to that of CK treatment, respectively. The abundance of nirS-type denitrifiers in NPK treatment was not significantly different from that of CK. The T-RFLP analysis of nirS genes showed significant differences in community composition between organic and inorganic treatments, with the emergence of a 79 bp T-RF, a significant decrease in relative abundance of the 84 bp T-RF and a loss of the 99 bp T-RF in all organic treatments. Phylogenetic analysis indicated that the airS-type denitrifiers in the black soil were mainly composed of alpha, beta and gamma-Proteobacteria. The 79 bp-type denitrifiers inhabiting exclusively in organic treatments (OM and MNPK) were affiliated to Pseudomonadaceae in gamma-Proteobacteria and Burkholderiales in beta-Proteobacteria. The 84 bp-types were related to Burkholderiales and Rhodocyclales. Correlation analysis indicated that pH, concentrations of total nitrogen

  2. Defining cell types and states with single-cell genomics

    PubMed Central

    Trapnell, Cole

    2015-01-01

    A revolution in cellular measurement technology is under way: For the first time, we have the ability to monitor global gene regulation in thousands of individual cells in a single experiment. Such experiments will allow us to discover new cell types and states and trace their developmental origins. They overcome fundamental limitations inherent in measurements of bulk cell population that have frustrated efforts to resolve cellular states. Single-cell genomics and proteomics enable not only precise characterization of cell state, but also provide a stunningly high-resolution view of transitions between states. These measurements may finally make explicit the metaphor that C.H. Waddington posed nearly 60 years ago to explain cellular plasticity: Cells are residents of a vast “landscape” of possible states, over which they travel during development and in disease. Single-cell technology helps not only locate cells on this landscape, but illuminates the molecular mechanisms that shape the landscape itself. However, single-cell genomics is a field in its infancy, with many experimental and computational advances needed to fully realize its full potential. PMID:26430159

  3. Bovine herpesvirus type 1 induces cell death by a cell-type-dependent fashion.

    PubMed

    Geiser, Vicki; Rose, Suzanne; Jones, Clinton

    2008-06-01

    Bovine herpesvirus 1 (BHV-1), a member of the alpha-herpesvirinae sub-family, causes significant losses to the cattle industry. BHV-1 establishes latency in trigeminal ganglionic sensory neurons, but periodically reactivates from latency. Previous studies suggested that infection with BHV-1-induced novel morphological changes in rabbit skin (RS) cells versus bovine kidney cells (MDBK). Consequently, we hypothesized that viral infection led to a novel form of cell death in RS cells compared to MDBK cells. To test this hypothesis, we examined the levels of apoptosis in these cell types following infection with BHV-1. Infection of RS, but not MDBK, cells leads to high levels of apoptosis compared to mock-infected cells. Previous studies indicated that a BHV-1 recombinant virus that does not express the bICP0 protein grows poorly in permissive cells and induces a persistent-like infection. This suggested that bICP0 played an important role in regulating cell death following infection. To test this hypothesis, we compared the levels of apoptosis in cells infected with the bICP0 null mutant versus viral strains that expressed bICP0. The bICP0 null mutant induces low levels of apoptosis in RS or MDBK cells. When MDBK cells are treated with UV light prior to infection, bICP0 expressing viral strains, but not the bICP0 null mutant, inhibited UV-induced apoptosis. Infection of MDBK cells with the bICP0 null mutant, leads to an accumulation of autophagosomes that are not detected following infection with bICP0 expressing viruses. These studies suggest that the bICP0 null mutant induces autophagy in MDBK cells, and bICP0 protein expression mediates cell-type specific cytotoxicity.

  4. Single-cell transcriptomes identify human islet cell signatures and reveal cell-type–specific expression changes in type 2 diabetes

    PubMed Central

    Bolisetty, Mohan; Kursawe, Romy; Sun, Lili; Sivakamasundari, V.; Kycia, Ina

    2017-01-01

    Blood glucose levels are tightly controlled by the coordinated action of at least four cell types constituting pancreatic islets. Changes in the proportion and/or function of these cells are associated with genetic and molecular pathophysiology of monogenic, type 1, and type 2 (T2D) diabetes. Cellular heterogeneity impedes precise understanding of the molecular components of each islet cell type that govern islet (dys)function, particularly the less abundant delta and gamma/pancreatic polypeptide (PP) cells. Here, we report single-cell transcriptomes for 638 cells from nondiabetic (ND) and T2D human islet samples. Analyses of ND single-cell transcriptomes identified distinct alpha, beta, delta, and PP/gamma cell-type signatures. Genes linked to rare and common forms of islet dysfunction and diabetes were expressed in the delta and PP/gamma cell types. Moreover, this study revealed that delta cells specifically express receptors that receive and coordinate systemic cues from the leptin, ghrelin, and dopamine signaling pathways implicating them as integrators of central and peripheral metabolic signals into the pancreatic islet. Finally, single-cell transcriptome profiling revealed genes differentially regulated between T2D and ND alpha, beta, and delta cells that were undetectable in paired whole islet analyses. This study thus identifies fundamental cell-type–specific features of pancreatic islet (dys)function and provides a critical resource for comprehensive understanding of islet biology and diabetes pathogenesis. PMID:27864352

  5. Decreased abundance of type III secretion system-inducing signals in Arabidopsis mkp1 enhances resistance against Pseudomonas syringae

    SciTech Connect

    Anderson, Jeffrey C.; Wan, Ying; Kim, Young-Mo; Pasa-Tolic, Ljiljana; Metz, Thomas O.; Peck, Scott C.

    2014-04-21

    Many phytopathogenic bacteria use a type III secretion system (T3SS) to inject defense-suppressing effector proteins into host cells. Genes encoding the T3SS are induced at the start of infection, yet host signals that initiate T3SS gene expression are poorly understood. Here we identify several plant-derived metabolites that induce the T3SS in the bacterial pathogen Pseudomonas syringae pv tomato DC3000. In addition, we report that mkp1 (mapk phosphatase 1), an Arabidopsis mutant that is more resistant to bacterial infection, produces decreased levels of these T3SS-inducing metabolites. Consistent with the observed decrease in these metabolites, T3SS effector delivery by DC3000 was impaired in mkp1. Addition of the bioactive metabolites to the mkp1-DC3000 interaction fully restored T3SS effector delivery and suppressed enhanced resistance in mkp1. Together, these results demonstrate that DC3000 perceives multiple signals derived from plants to initiate their virulence program, and reveal a new layer of molecular communication between plants and these pathogenic bacteria.

  6. Abundance and composition of ammonia-oxidizing bacteria and archaea in different types of soil in the Yangtze River estuary*

    PubMed Central

    Li, Xiao-ran; Xiao, Yi-ping; Ren, Wen-wei; Liu, Zeng-fu; Shi, Jin-huan; Quan, Zhe-xue

    2012-01-01

    Tidal flats are soil resources of great significance. Nitrification plays a central role in the nitrogen cycle and is often a critical first step in nitrogen removal from estuarine and coastal environments. We determined the abundance as well as composition of ammonia-oxidizing bacteria (AOB) and ammonia-oxidizing archaea (AOA) in different soils during land reclamation process. The abundance of AOA was higher than that of AOB in farm land and wild land while AOA was not detected in tidal flats using real-time polymerase chain reaction (PCR). The different abundances of AOB and AOA were negatively correlated with the salinity. The diversities of AOB and AOA were also investigated using clone libraries by amplification of amoA gene. Among AOB, nearly all sequences belonged to the Nitrosomonas lineage in the initial land reclamation process, i.e., tidal flats, while both Nitrosomonas and Nitrosospira lineages were detected in later and transition phases of land reclamation process, farm land and wild land. The ratio of the numbers of sequences of Nitrosomonas and Nitrosospira lineages was positively correlated with the salinity and the net nitrification rate. As for AOA, there was no obvious correlation with the changes in the physicochemical properties of the soil. This study suggests that AOB may be more import than AOA with respect to influencing the different land reclamation process stages. PMID:23024044

  7. Increased Abundance of M Cells in the Gut Epithelium Dramatically Enhances Oral Prion Disease Susceptibility.

    PubMed

    Donaldson, David S; Sehgal, Anuj; Rios, Daniel; Williams, Ifor R; Mabbott, Neil A

    2016-12-01

    Many natural prion diseases of humans and animals are considered to be acquired through oral consumption of contaminated food or pasture. Determining the route by which prions establish host infection will identify the important factors that influence oral prion disease susceptibility and to which intervention strategies can be developed. After exposure, the early accumulation and replication of prions within small intestinal Peyer's patches is essential for the efficient spread of disease to the brain. To replicate within Peyer's patches, the prions must first cross the gut epithelium. M cells are specialised epithelial cells within the epithelia covering Peyer's patches that transcytose particulate antigens and microorganisms. M cell-development is dependent upon RANKL-RANK-signalling, and mice in which RANK is deleted only in the gut epithelium completely lack M cells. In the specific absence of M cells in these mice, the accumulation of prions within Peyer's patches and the spread of disease to the brain was blocked, demonstrating a critical role for M cells in the initial transfer of prions across the gut epithelium in order to establish host infection. Since pathogens, inflammatory stimuli and aging can modify M cell-density in the gut, these factors may also influence oral prion disease susceptibility. Mice were therefore treated with RANKL to enhance M cell density in the gut. We show that prion uptake from the gut lumen was enhanced in RANKL-treated mice, resulting in shortened survival times and increased disease susceptibility, equivalent to a 10-fold higher infectious titre of prions. Together these data demonstrate that M cells are the critical gatekeepers of oral prion infection, whose density in the gut epithelium directly limits or enhances disease susceptibility. Our data suggest that factors which alter M cell-density in the gut epithelium may be important risk factors which influence host susceptibility to orally acquired prion diseases.

  8. Increased Abundance of M Cells in the Gut Epithelium Dramatically Enhances Oral Prion Disease Susceptibility

    PubMed Central

    Sehgal, Anuj; Rios, Daniel

    2016-01-01

    Many natural prion diseases of humans and animals are considered to be acquired through oral consumption of contaminated food or pasture. Determining the route by which prions establish host infection will identify the important factors that influence oral prion disease susceptibility and to which intervention strategies can be developed. After exposure, the early accumulation and replication of prions within small intestinal Peyer’s patches is essential for the efficient spread of disease to the brain. To replicate within Peyer’s patches, the prions must first cross the gut epithelium. M cells are specialised epithelial cells within the epithelia covering Peyer’s patches that transcytose particulate antigens and microorganisms. M cell-development is dependent upon RANKL-RANK-signalling, and mice in which RANK is deleted only in the gut epithelium completely lack M cells. In the specific absence of M cells in these mice, the accumulation of prions within Peyer’s patches and the spread of disease to the brain was blocked, demonstrating a critical role for M cells in the initial transfer of prions across the gut epithelium in order to establish host infection. Since pathogens, inflammatory stimuli and aging can modify M cell-density in the gut, these factors may also influence oral prion disease susceptibility. Mice were therefore treated with RANKL to enhance M cell density in the gut. We show that prion uptake from the gut lumen was enhanced in RANKL-treated mice, resulting in shortened survival times and increased disease susceptibility, equivalent to a 10-fold higher infectious titre of prions. Together these data demonstrate that M cells are the critical gatekeepers of oral prion infection, whose density in the gut epithelium directly limits or enhances disease susceptibility. Our data suggest that factors which alter M cell-density in the gut epithelium may be important risk factors which influence host susceptibility to orally acquired prion diseases

  9. The types of endocrine cells in the pancreas of Sunda porcupine (Hystrix javanica)

    PubMed Central

    Budipitojo, Teguh; Fibrianto, Yuda Heru; Mulyani, Guntari Titik

    2016-01-01

    Aim: To identify the types of endocrine cells in the pancreas of the Sunda porcupine (Hystrix javanica) and its immunolocalization. Materials and Methods: Five adult H. javanica were used without sexual distinction. The presences of endocrine cells (glucagon, insulin, somatostatin, and pancreatic polypeptide [PP]) in pancreatic tissues were detected using the avidin-biotin-peroxidase complex method. Results: The fusiform, round, and oval form endocrine cells were detected in the islets of Langerhans and exocrine parts. Most of the insulin cells were found in the central area, glucagon cells were identified in the central and peripheral areas, and somatostatin and PP cells were detected in the mantle area of the islets of Langerhans. Glucagon and somatostatin cells were also detected in smaller numbers of peripheral parts of the islet. In all of the islet parts, glucagon endocrine cells were most prevalent cell type and then, somatostatin, insulin, and PP. In the exocrine parts, PP, somatostatin, glucagon, and insulin endocrine cells were found in the inter-acinus part with moderate, moderate, a few and rare numbers, in that order. In the pancreatic duct, glucagon and somatostatin cells were found between epithelial cells in rare numbers. Conclusion: The pancreas of Sunda porcupine (H. javanica) contains four types of major pancreatic endocrine cells with approximately similar distribution patterns to the other rodents, except for abundant glucagon cells in the peripheral area of the islets of Langerhans. PMID:27397977

  10. CDK-Dependent Hsp70 Phosphorylation Controls G1 Cyclin Abundance and Cell-Cycle Progression

    PubMed Central

    Truman, Andrew W.; Kristjansdottir, Kolbrun; Wolfgeher, Donald; Hasin, Naushaba; Polier, Sigrun; Zhang, Hong; Perrett, Sarah; Prodromou, Chrisostomos; Jones, Gary W.; Kron, Stephen J.

    2012-01-01

    Summary In budding yeast, the essential functions of Hsp70 chaperones Ssa1–4 are regulated through expression level, isoform specificity, and cochaperone activity. Suggesting a novel regulatory paradigm, we find that phosphorylation of Ssa1 T36 within a cyclin-dependent kinase (CDK) consensus site conserved among Hsp70 proteins alters cochaperone and client interactions. T36 phosphorylation triggers displacement of Ydj1, allowing Ssa1 to bind the G1 cyclin Cln3 and promote its degradation. The stress CDK Pho85 phosphorylates T36 upon nitrogen starvation or pheromone stimulation, destabilizing Cln3 to delay onset of S phase. In turn, the mitotic CDK Cdk1 phosphorylates T36 to block Cln3 accumulation in G2/M. Suggesting broad conservation from yeast to human, CDK-dependent phosphorylation of Hsc70 T38 similarly regulates Cyclin D1 binding and stability. These results establish an active role for Hsp70 chaperones as signal transducers mediating growth control of G1 cyclin abundance and activity. PMID:23217712

  11. Abundance of the Multiheme c-Type Cytochrome OmcB Increases in Outer Biofilm Layers of Electrode-Grown Geobacter sulfurreducens

    PubMed Central

    Stephen, Camille S.; LaBelle, Edward V.; Brantley, Susan L.; Bond, Daniel R.

    2014-01-01

    When Geobacter sulfurreducens utilizes an electrode as its electron acceptor, cells embed themselves in a conductive biofilm tens of microns thick. While environmental conditions such as pH or redox potential have been shown to change close to the electrode, less is known about the response of G. sulfurreducens to growth in this biofilm environment. To investigate whether respiratory protein abundance varies with distance from the electrode, antibodies against an outer membrane multiheme cytochrome (OmcB) and cytoplasmic acetate kinase (AckA) were used to determine protein localization in slices spanning ∼25 µm-thick G. sulfurreducens biofilms growing on polished electrodes poised at +0.24 V (vs. Standard Hydrogen Electrode). Slices were immunogold labeled post-fixing, imaged via transmission electron microscopy, and digitally reassembled to create continuous images allowing subcellular location and abundance per cell to be quantified across an entire biofilm. OmcB was predominantly localized on cell membranes, and 3.6-fold more OmcB was detected on cells 10–20 µm distant from the electrode surface compared to inner layers (0–10 µm). In contrast, acetate kinase remained constant throughout the biofilm, and was always associated with the cell interior. This method for detecting proteins in intact conductive biofilms supports a model where the utilization of redox proteins changes with depth. PMID:25090411

  12. Direct Correlation between Motile Behavior and Protein Abundance in Single Cells

    PubMed Central

    Gillet, Sébastien; Frankel, Nicholas W.; Weibel, Douglas B.

    2016-01-01

    Understanding how stochastic molecular fluctuations affect cell behavior requires the quantification of both behavior and protein numbers in the same cells. Here, we combine automated microscopy with in situ hydrogel polymerization to measure single-cell protein expression after tracking swimming behavior. We characterized the distribution of non-genetic phenotypic diversity in Escherichia coli motility, which affects single-cell exploration. By expressing fluorescently tagged chemotaxis proteins (CheR and CheB) at different levels, we quantitatively mapped motile phenotype (tumble bias) to protein numbers using thousands of single-cell measurements. Our results disagreed with established models until we incorporated the role of CheB in receptor deamidation and the slow fluctuations in receptor methylation. Beyond refining models, our central finding is that changes in numbers of CheR and CheB affect the population mean tumble bias and its variance independently. Therefore, it is possible to adjust the degree of phenotypic diversity of a population by adjusting the global level of expression of CheR and CheB while keeping their ratio constant, which, as shown in previous studies, confers functional robustness to the system. Since genetic control of protein expression is heritable, our results suggest that non-genetic diversity in motile behavior is selectable, supporting earlier hypotheses that such diversity confers a selective advantage. PMID:27599206

  13. Specific and Abundant Secretion of a Novel Hydroxyproline-Rich Glycoprotein from Salt-Adapted Winged Bean Cells 1

    PubMed Central

    Esaka, Muneharu; Hayakawa, Hiromi; Hashimoto, Mami; Matsubara, Naomi

    1992-01-01

    Winged bean callus was adapted to increasing concentrations of NaCl by sequential transfer to medium with 0, 0.5, 1.0, 1.5, and 2.0% (w/v) NaCl. When the culture media, after cell suspension cultures of callus adapted to 0.5 (SA-0.5), 1.0 (SA-1.0), 1.5 (SA-1.5), or 2.0% (w/v) NaCl (SA-2.0), were analyzed by sodium dodecylsulfate-polyacrylamide gel electrophoresis, six specific or enhanced polypeptide bands (SAP1, -2, -3, -4, -5, and -6) were observed. SAP1, with a molecular weight of 84,000, was abundantly secreted in suspension cultures of SA-1.0 and SA-1.5, and was observed as the most striking polypeptide band. The SAP1 yield was about 4 mg/g cells fresh weight. SAP1 was abundantly secreted after the suspension culture of SA-1.0 in the presence of AlCl3, but little was secreted in the presence of KCl, LiCl, CaCl2, MgCl2, mannitol, sucrose, or abscisic acid. SAP1 was purified from the culture medium after suspension culture of SA-1.0 in the presence of 1.0% (w/v) NaCl. Two steps, ammonium sulfate fractionation and CM-cellulose chromatography, were sufficient for purification to homogeneity. Finally, about 5 mg of SAP1 could be isolated from 7 g of fresh callus cells. Of the amino-terminal 32 amino acid residues of SAP1, 10 and 5 were found to be hydroxyproline and proline, respectively. SAP1 on an acrylamide gel was stained by the periodic acid-Schiff method. It is interesting that SAP1 has pentahydroxyproline blocks (Hyp5) instead of tetrahydroxyproline blocks (Hyp4) common to many hydroxyproline-rich glycoproteins in dicotyledons. Thus, this novel hydroxyproline-rich glycoprotein was shown to be abundantly secreted from NaCl-adapted winged bean cells. Images Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 PMID:16653126

  14. Chemical abundances and kinematics of 257 G-, K-type field giants. Setting a base for further analysis of giant-planet properties orbiting evolved stars

    NASA Astrophysics Data System (ADS)

    Adibekyan, V. Zh.; Benamati, L.; Santos, N. C.; Alves, S.; Lovis, C.; Udry, S.; Israelian, G.; Sousa, S. G.; Tsantaki, M.; Mortier, A.; Sozzetti, A.; De Medeiros, J. R.

    2015-06-01

    We performed a uniform and detailed abundance analysis of 12 refractory elements (Na, Mg, Al, Si, Ca, Ti, Cr, Ni, Co, Sc, Mn, and V) for a sample of 257 G- and K-type evolved stars from the CORALIE planet search programme. To date, only one of these stars is known to harbour a planetary companion. We aimed to characterize this large sample of evolved stars in terms of chemical abundances and kinematics, thus setting a solid base for further analysis of planetary properties around giant stars. This sample, being homogeneously analysed, can be used as a comparison sample for other planet-related studies, as well as for different type of studies related to stellar and Galaxy astrophysics. The abundances of the chemical elements were determined using an local thermodynamic equilibrium (LTE) abundance analysis relative to the Sun, with the spectral synthesis code MOOG and a grid of Kurucz ATLAS9 atmospheres. To separate the Galactic stellar populations, both a purely kinematical approach and a chemical method were applied. We confirm the overabundance of Na in giant stars compared to the field FGK dwarfs. This enhancement might have a stellar evolutionary character, but departures from LTE may also produce a similar enhancement. Our chemical separation of stellar populations also suggests a `gap' in metallicity between the thick-disc and high-α metal-rich stars, as previously observed in dwarfs sample from HARPS. The present sample, as most of the giant star samples, also suffers from the B - V colour cut-off, which excludes low-log g stars with high metallicities, and high-log g star with low [Fe/H]. For future studies of planet occurrence dependence on stellar metallicity around these evolved stars, we suggest to use a subsample of stars in a `cut-rectangle' in the log g-[Fe/H] diagram to overcome the aforementioned issue.

  15. Activation of Type II Cells into Regenerative Stem Cell Antigen-1+ Cells during Alveolar Repair

    PubMed Central

    Kumar, Varsha Suresh; Zhang, Wei; Rehman, Jalees; Malik, Asrar B.

    2015-01-01

    The alveolar epithelium is composed of two cell types: type I cells comprise 95% of the gas exchange surface area, whereas type II cells secrete surfactant, while retaining the ability to convert into type I cells to induce alveolar repair. Using lineage-tracing analyses in the mouse model of Pseudomonas aeruginosa–induced lung injury, we identified a population of stem cell antigen (Sca)-1–expressing type II cells with progenitor cell properties that mediate alveolar repair. These cells were shown to be distinct from previously reported Sca-1–expressing bronchioalveolar stem cells. Microarray and Wnt reporter studies showed that surfactant protein (Sp)-C+Sca-1+ cells expressed Wnt signaling pathway genes, and inhibiting Wnt/β-catenin signaling prevented the regenerative function of Sp-C+Sca-1+ cells in vitro. Thus, P. aeruginosa–mediated lung injury induces the generation of a Sca-1+ subset of type II cells. The progenitor phenotype of the Sp-C+Sca-1+ cells that mediates alveolar epithelial repair might involve Wnt signaling. PMID:25474582

  16. Glucose Transporters are Abundant in Cells with "Occluding" Junctions at the Blood-Eye Barriers

    NASA Astrophysics Data System (ADS)

    Harik, Sami I.; Kalaria, Rajesh N.; Whitney, Paul M.; Andersson, Lars; Lundahl, Per; Ledbetter, Steven R.; Perry, George

    1990-06-01

    We studied the distribution of the "erythroid/brain" glucose transporter protein in the human and rat eye by immunocytochemistry with monoclonal and polyclonal antibodies to the C terminus of the human erythrocyte glucose transporter. We found intense immunocytochemical staining in the endothelium of microvessels of the retina, optic nerve, and iris but not in microvessels of the choroid, ciliary body, sclera, and other retro-orbital tissues. In addition, we found marked immunocytochemical staining of retinal pigment epithelium, ciliary body epithelium, and posterior epithelium of the iris. The common feature of all those endothelial and epithelial cells that stained intensely for the glucose transporter is the presence of "occluding" intercellular junctions, which constitute the anatomical bases of the blood-eye barriers. We propose that a high density of the glucose transporter is a biochemical concomitant of epithelial and endothelial cells with barrier characteristics, at least in tissues that have a high metabolic requirement for glucose.

  17. Classification of lattice defects in the kesterite Cu2ZnSnS4 and Cu2ZnSnSe4 earth-abundant solar cell absorbers.

    PubMed

    Chen, Shiyou; Walsh, Aron; Gong, Xin-Gao; Wei, Su-Huai

    2013-03-20

    The kesterite-structured semiconductors Cu2ZnSnS4 and Cu2ZnSnSe4 are drawing considerable attention recently as the active layers in earth-abundant low-cost thin-film solar cells. The additional number of elements in these quaternary compounds, relative to binary and ternary semiconductors, results in increased flexibility in the material properties. Conversely, a large variety of intrinsic lattice defects can also be formed, which have important influence on their optical and electrical properties, and hence their photovoltaic performance. Experimental identification of these defects is currently limited due to poor sample quality. Here recent theoretical research on defect formation and ionization in kesterite materials is reviewed based on new systematic calculations, and compared with the better studied chalcopyrite materials CuGaSe2 and CuInSe2 . Four features are revealed and highlighted: (i) the strong phase-competition between the kesterites and the coexisting secondary compounds; (ii) the intrinsic p-type conductivity determined by the high population of acceptor CuZn antisites and Cu vacancies, and their dependence on the Cu/(Zn+Sn) and Zn/Sn ratio; (iii) the role of charge-compensated defect clusters such as [2CuZn +SnZn ], [VCu +ZnCu ] and [ZnSn +2ZnCu ] and their contribution to non-stoichiometry; (iv) the electron-trapping effect of the abundant [2CuZn +SnZn ] clusters, especially in Cu2ZnSnS4. The calculated properties explain the experimental observation that Cu poor and Zn rich conditions (Cu/(Zn+Sn) ≈ 0.8 and Zn/Sn ≈ 1.2) result in the highest solar cell efficiency, as well as suggesting an efficiency limitation in Cu2ZnSn(S,Se)4 cells when the S composition is high.

  18. Effects of heat stress on proliferation, protein turnover, and abundance of heat shock protein messenger ribonucleic acid in cultured porcine muscle satellite cells.

    PubMed

    Kamanga-Sollo, E; Pampusch, M S; White, M E; Hathaway, M R; Dayton, W R

    2011-11-01

    It is well established that heat stress (HS) negatively affects growth rate in swine. Although reduced feed intake undoubtedly plays a significant role in this reduction, studies in laboratory animals and other nonswine species indicate muscle growth also is affected by HS-related alterations in muscle physiology. Evidence is now emerging that heat shock proteins (Hsp), produced in response to HS and other types of cellular stress, may play an important role in regulating the rate and efficiency of muscle growth. Because muscle satellite cells play a crucial role in postnatal muscle growth, the effects of HS on rates of satellite cell proliferation, protein synthesis, and protein degradation play an important role in determining the rate and extent of muscle growth. Consequently, in the current study we have examined the effects of mild HS (40.5°C for 48 h) on the rates of proliferation, protein synthesis, and protein degradation and on quantities of Hsp90, Hsp70, and Hsp25/27 mRNA and protein in cultured porcine muscle satellite cells (PSC). Mild HS of PSC cultures resulted in 2.5-, 1.4-, and 6.5-fold increases (P < 0.05) in the abundance of Hsp90, Hsp70, and Hsp25/27 mRNA, respectively, relative to control cultures. Abundance of Hsp 90, 70, and 25/27 proteins was also increased in HS PSC cultures compared with those in control cultures. Proliferation rates in HS PSC cultures were 35% less (P < 0.05) than those in control cultures. Protein synthesis rates in HS-fused PSC cultures were 85% greater (P < 0.05) than those in control cultures, and protein degradation rates in HS-fused PSC were 23% less (P < 0.05) than those in control cultures. In light of the crucial role satellite cells play in postnatal muscle growth, the HS-induced changes we have observed in rates of proliferation, protein turnover, and abundance of Hsp mRNA and Hsp protein in PSC cultures indicate that mild HS affects the physiology of PSC in ways that could affect muscle growth in swine.

  19. Association between ferritin, high sensitivity C-reactive protein (hsCRP) and relative abundance of Hepcidin mRNA with the risk of type 2 diabetes in obese subjects.

    PubMed

    Andrews Guzmán, Mónica; Arredondo Olguín, Miguel

    2014-09-01

    Obesity and Type 2 diabetes mellitus share a strong pro-inflammatory profile. It has been observed that iron is a risk factor in the development of type 2 diabetes. The aim of this study was to evaluate the relationship between iron nutritional status and inflammation with the risk of type 2 diabetes development in obese subjects. We studied 30 obese men with type 2 diabetes (OBDM); 30 obese subjects without diabetes (OB) and 30 healthy subjects (Cn). We isolated peripheral mononuclear cells (PMCs) and challenged them with high Fe concentrations. Total mRNA was isolated and relative abundance of TNF-, IL-6 and hepcidin were determined by qPCR. Iron status, biochemical, inflammatory and oxidative stress parameters were also characterized. OBDM and OB patients showed increased hsCRP levels compared to the Cn group. OBDM subjects showed higher levels of ferritin than the Cn group. TNF-α and IL-6 mRNA relative abundances were increased in OBDM PMCs treated with high/Fe. Hepcidin mRNA was increased with basal and high iron concentration. We found that the highest quartile of ferritin was associated with an increased risk of type 2 diabetes when it was adjusted to BMI and HOMA-IR; this association was independent of the inflammatory status. The highest level of hepcidin gene expression also showed a trend of increased risk of diabetes, however it was not significant. Levels of hsCRP over 2 mg/L showed a significant trend of increasing the risk of diabetes. In conclusion, iron may stimulate the expression of pro-inflammatory genes (TNF-α and IL- 6), and both hepcidin and ferritin gene expression levels could be a risk factor for the development of type 2 diabetes. Subjects that have an increased cardiovascular risk also have a major risk to develop type 2 diabetes, which is independent of the BMI and insulin resistance state.

  20. Microdissected double-minute DNA detects variable patterns of chromosomal localizations and multiple abundantly expressed transcripts in normal and leukemic cells

    SciTech Connect

    Sen, S.; Zhou, Hongyi; Stass, S.A.; Sen, P. ); Mulac-Jericevic, B.; Pirrotta, V. )

    1994-02-01

    Double-minute (dm) chromosomes are cytogenetically resolvable DNA amplification-mediating acentric extrachromosomal structures that are commonly seen in primary tumors, tumor cell lines, and drug-resistant cells grown in vitro. Selective isolation of dm DNAs with standard molecular biological techniques is difficult, and thus, detailed studies to elucidate their structure, site of chromosomal origin, and chromosomal reintegration patterns have been limited. In those instances in which a gene has been localized on dms, characterization of the remainder of the DNA, which far exceeds the size of the gene identified, has remained inconclusive. dms seen in the acute myeloid leukemia cell line HL-60 have been shown to harbor the c-myc protooncogene. In this paper, the authors report the successful isolation of the dm-specific DNAs from these cells by the microdissection/polymerase chain reaction technique and demonstrate that the dm DNAs derived from a single discrete normal chromosome segment 8q24.1-q24.2 reintegrate at various specific locations in the leukemic cells. The microdissected dm DNA detects multiple abundantly expressed transcripts distinct from c-myc mRNA on Northern blots. By devising a [open quotes]transcript selection[close quotes] strategy, they cloned the partial genomic sequence of a gene from the microdissected DNA that encodes two of these RNAs. This strategy will be generally applicable for rapid cloning of unknown amplified genes harbored on dms. With DNA from 20 microdissected dms, they constructed a genomic library of about 20,000 recombinant microclones with an average insert size of about 450 bp. The microclones should help in isolating corresponding yeast artificial chromosome clones for high-resolution physical mapping of dms in HL-60 cells. Furthermore, application of the microdissection technique appears to be an extremely feasible approach to characterization of dms in other cell types. 42 refs., 6 figs., 1 tab.

  1. Anodic biofilms in microbial fuel cells harbor low numbers of higher-power-producing bacteria than abundant genera.

    PubMed

    Kiely, Patrick D; Call, Douglas F; Yates, Matthew D; Regan, John M; Logan, Bruce E

    2010-09-01

    Microbial fuel cell (MFC) anode communities often reveal just a few genera, but it is not known to what extent less abundant bacteria could be important for improving performance. We examined the microbial community in an MFC fed with formic acid for more than 1 year and determined using 16S rRNA gene cloning and fluorescent in situ hybridization that members of the Paracoccus genus comprised most (approximately 30%) of the anode community. A Paracoccus isolate obtained from this biofilm (Paracoccus denitrificans strain PS-1) produced only 5.6 mW/m(2), whereas the original mixed culture produced up to 10 mW/m(2). Despite the absence of any Shewanella species in the clone library, we isolated a strain of Shewanella putrefaciens (strain PS-2) from the same biofilm capable of producing a higher-power density (17.4 mW/m(2)) than the mixed culture, although voltage generation was variable. Our results suggest that the numerical abundance of microorganisms in biofilms cannot be assumed a priori to correlate to capacities of these predominant species for high-power production. Detailed screening of bacterial biofilms may therefore be needed to identify important strains capable of high-power generation for specific substrates.

  2. A Lithium Abundance Study of Solar-type Stars in Blanco 1 using the 2.1m McDonald Telescope: Developing Undergraduate Research Experiences.

    NASA Astrophysics Data System (ADS)

    Cargile, Phillip; James, D. J.; Villalon, K.; Girgenti, S.; Mermilliod, J.

    2007-12-01

    We present a new catalog of lithium equivalent widths for 20 solar-type stars in the young (60-100 Myr), nearby (250 pc) open cluster Blanco 1, measured from high-resolution spectra (R 30,000), taken during an observing run on the 2.1m telescope at McDonald Observatory. These new lithium data, coupled with the 20 or so extant measurements in the literature, are used in combination with the results of a recently completed standardized BVIc CCD survey, and corresponding 2MASS near-infrared colors, to derive precise lithium abundances for solar-type stars in Blanco 1. Comparing these new results with the existing lithium dataset for other open clusters, we investigate the mass- and age-dependent lithium depletion distribution among early-epoch (< 1Gyr) solar-type stars, and specifically, the lithium abundance scatter as a function of mass in Blanco 1. Our scientific project is highly synergystic with a pedagogical philosophy. We have instituted a program whereby undergraduate students - typically majoring in Liberal Arts and performing an independent study in Astronomy - receive hands-on research experience observing with the 2.1m telescope at the McDonald Observatory. After their observing run, these undergraduates take part in the reduction and analysis of the acquired spectra, and their research experience typically culminates in writing an undergraduate thesis and/or giving a professional seminar to the Astronomy group at Vanderbilt University.

  3. Breakdown of Chlorophyll in Higher Plants—Phyllobilins as Abundant, Yet Hardly Visible Signs of Ripening, Senescence, and Cell Death

    PubMed Central

    2016-01-01

    Abstract Fall colors have always been fascinating and are still a remarkably puzzling phenomenon associated with the breakdown of chlorophyll (Chl) in leaves. As discovered in recent years, nongreen bilin‐type Chl catabolites are generated, which are known as the phyllobilins. Collaborative chemical‐biological efforts have led to the elucidation of the key Chl‐breakdown processes in senescent leaves and in ripening fruit. Colorless and largely photoinactive phyllobilins are rapidly produced from Chl, apparently primarily as part of a detoxification program. However, fluorescent Chl catabolites accumulate in some senescent leaves and in peels of ripe bananas and induce a striking blue glow. The structural features, chemical properties, and abundance of the phyllobilins in the biosphere suggest biological roles, which still remain to be elucidated. PMID:26919572

  4. P2-type Nax[Fe1/2Mn1/2]O2 made from earth-abundant elements for rechargeable Na batteries

    NASA Astrophysics Data System (ADS)

    Yabuuchi, Naoaki; Kajiyama, Masataka; Iwatate, Junichi; Nishikawa, Heisuke; Hitomi, Shuji; Okuyama, Ryoichi; Usui, Ryo; Yamada, Yasuhiro; Komaba, Shinichi

    2012-06-01

    Rechargeable lithium batteries have risen to prominence as key devices for green and sustainable energy development. Electric vehicles, which are not equipped with an internal combustion engine, have been launched in the market. Manganese- and iron-based positive-electrode materials, such as LiMn2O4 and LiFePO4, are used in large-scale batteries for electric vehicles. Manganese and iron are abundant elements in the Earth’s crust, but lithium is not. In contrast to lithium, sodium is an attractive charge carrier on the basis of elemental abundance. Recently, some layered materials, where sodium can be electrochemically and reversibly extracted/inserted, have been reported. However, their reversible capacity is typically limited to 100 mAh g-1. Herein, we report a new electrode material, P2-Na2/3[Fe1/2Mn1/2]O2, that delivers 190 mAh g-1 of reversible capacity in the sodium cells with the electrochemically active Fe3+/Fe4+ redox. These results will contribute to the development of rechargeable batteries from the earth-abundant elements operable at room temperature.

  5. Packed Red Blood Cells Are an Abundant and Proximate Potential Source of Nitric Oxide Synthase Inhibition

    PubMed Central

    Zwemer, Charles F.; Davenport, Robertson D.; Gomez-Espina, Juan; Blanco-Gonzalez, Elisa; Whitesall, Steven E.; D'Alecy, Louis G.

    2015-01-01

    Objective We determined, for packed red blood cells (PRBC) and fresh frozen plasma, the maximum content, and ability to release the endogenous nitric oxide synthase (NOS) inhibitors asymmetric dimethylarginine (ADMA) and monomethylarginine (LNMMA). Background ADMA and LNMMA are near equipotent NOS inhibitors forming blood’s total NOS inhibitory content. The balance between removal from, and addition to plasma determines their free concentrations. Removal from plasma is by well-characterized specific hydrolases while formation is restricted to posttranslational protein methylation. When released into plasma they can readily enter endothelial cells and inhibit NOS. Fresh rat and human whole blood contain substantial protein incorporated ADMA however; the maximum content of ADMA and LNMMA in PRBC and fresh frozen plasma has not been determined. Methods We measured total (free and protein incorporated) ADMA and LNMMA content in PRBCs and fresh frozen plasma, as well as their incubation induced release, using HPLC with fluorescence detection. We tested the hypothesis that PRBC and fresh frozen plasma contain substantial inhibitory methylarginines that can be released chemically by complete in vitro acid hydrolysis or physiologically at 37°C by enzymatic blood proteolysis. Results In vitro strong-acid-hydrolysis revealed a large PRBC reservoir of ADMA (54.5 ± 9.7 µM) and LNMMA (58.9 ± 28.9 μM) that persisted over 42-d at 6° or -80°C. In vitro 5h incubation at 37°C nearly doubled free ADMA and LNMMNA concentration from PRBCs while no change was detected in fresh frozen plasma. Conclusion The compelling physiological ramifications are that regardless of storage age, 1) PRBCs can rapidly release pathologically relevant quantities of ADMA and LNMMA when incubated and 2) PRBCs have a protein-incorporated inhibitory methylarginines reservoir 100 times that of normal free inhibitory methylarginines in blood and thus could represent a clinically relevant and proximate

  6. Sensitive detection using microfluidics technology of single cell PCR products from high and low abundance IgH VDJ templates in multiple myeloma.

    PubMed

    Pilarski, Linda M; Lauzon, Jana; Strachan, Erin; Adamia, Sophia; Atrazhev, Alexey; Belch, Andrew R; Backhouse, Christopher J

    2005-10-20

    Human cancer is inherently heterogeneous, so the ability to monitor individual cancer cells at every clinic visit would be a valuable tool. This work describes the first step towards developing handheld and automated devices for molecular and phenotypic analysis of cancer cells. Here, we show that use of capillary electrophoresis to detect PCR product amplified from either transcripts (high abundance template) or genomic DNA (low abundance template) encoding clonotypic immunoglobulin heavy chain VDJ of plasma cells from patients with multiple myeloma. High abundance IgH VDJ transcripts amplified in conventional systems or by capillary electrophoresis through channels on microfluidic chips or, alternatively, PCR product amplified from individual myeloma plasma cells in a single stage RT-PCR reaction was readily detectable on microfluidic chips. For low abundance templates, a nested PCR strategy was needed to detect PCR product by any method. Using microfluidic chips, PCR products amplified from genomic IgH VDJ DNA were detected in six out of eight plasma cells. Comparison of the ABI3100 and the microfluidic chip indicates that approximately 20 times more sample is injected into the ABI 3100 capillary than for the microfluidics chip. Overall, for high and low abundance template in individual cells, the microfluidic separation/detection system is at least as sensitive as the ABI 3100. In the future, integrated microfluidic platforms that incorporate both PCR cycling and product detection on the same chip are likely to exceed conventional systems in sensitivity and speed of genetic analysis by RT-PCR or PCR.

  7. Influence of Trap Height and Bait Type on Abundance and Species Diversity of Cerambycid Beetles Captured in Forests of East-Central Illinois.

    PubMed

    Schmeelk, Thomas C; Millar, Jocelyn G; Hanks, Lawrence M

    2016-08-01

    We assessed how height of panel traps above the forest floor, and the type of trap bait used, influenced the abundance and diversity of cerambycid beetles caught in forested areas of east-central Illinois. Panel traps were suspended from branches of hardwood trees at three heights above the ground: understory (∼1.5 m), lower canopy (∼6 m), and midcanopy (∼12 m). Traps were baited with either a multispecies blend of synthesized cerambycid pheromones or a fermenting bait mixture. Traps captured a total of 848 beetles of 50 species in the cerambycid subfamilies Cerambycinae, Lamiinae, Lepturinae, and Parandrinae, and one species in the closely related family Disteniidae. The species caught in highest numbers was the cerambycine Anelaphus pumilus (Newman), represented by 349 specimens. The 17 most abundant species (mean ± 1 SD: 45 ± 80 specimens per species) included 12 cerambycine and five lamiine species. Of these most abundant species, 13 (77%) were attracted to traps baited with the pheromone blend. Only the cerambycine Eburia quadrigeminata (Say) was attracted by the fermenting bait. Three species were captured primarily in understory traps, and another five species primarily in midcanopy traps. Variation among cerambycid species in their vertical distribution in forests accounted for similar overall abundances and species richness across trap height treatments. These findings suggest that trapping surveys of native communities of cerambycids, and quarantine surveillance for newly introduced exotic species, would be optimized by including a variety of trap baits and distributing traps across vertical strata of forests.

  8. Umbilical Cord Wharton’s Jelly Repeated Culture System: A New Device and Method for Obtaining Abundant Mesenchymal Stem Cells for Bone Tissue Engineering

    PubMed Central

    Xing, Junchao; Wu, Xuehui; Jin, Huiyong; Li, Zhiqiang; Deng, Moyuan; Xie, Zhao; Xu, Jianzhong

    2014-01-01

    To date, various types of cells for seeding regenerative scaffolds have been used for bone tissue engineering. Among seed cells, the mesenchymal stem cells derived from human umbilical cord Wharton’s jelly (hUCMSCs) represent a promising candidate and hold potential for bone tissue engineering due to the the lack of ethical controversies, accessibility, sourced by non-invasive procedures for donors, a reduced risk of contamination, osteogenic differentiation capacities, and higher immunomodulatory capacity. However, the current culture methods are somewhat complicated and inefficient and often fail to make the best use of the umbilical cord (UC) tissues. Moreover, these culture processes cannot be performed on a large scale and under strict quality control. As a result, only a small quantity of cells can be harvested using the current culture methods. To solve these problems, we designed and evaluated an UC Wharton’s jelly repeated culture device. Using this device, hUCMSCs were obtained from the repeated cultures and their quantities and biological characteristics were compared. We found that using our culture device, which retained all tissue blocks on the bottom of the dish, the total number of obtained cells increased 15–20 times, and the time required for the primary passage was reduced. Moreover, cells harvested from the repeated cultures exhibited no significant difference in their immunophenotype, potential for multilineage differentiation, or proliferative, osteoinductive capacities, and final osteogenesis. The application of the repeated culture frame (RCF) not only made full use of the Wharton’s jelly but also simplified and specified the culture process, and thus, the culture efficiency was significantly improved. In summary, abundant hUCMSCs of dependable quality can be acquired using the RCF. PMID:25329501

  9. Umbilical cord Wharton's jelly repeated culture system: a new device and method for obtaining abundant mesenchymal stem cells for bone tissue engineering.

    PubMed

    Chang, Zhengqi; Hou, Tianyong; Xing, Junchao; Wu, Xuehui; Jin, Huiyong; Li, Zhiqiang; Deng, Moyuan; Xie, Zhao; Xu, Jianzhong

    2014-01-01

    To date, various types of cells for seeding regenerative scaffolds have been used for bone tissue engineering. Among seed cells, the mesenchymal stem cells derived from human umbilical cord Wharton's jelly (hUCMSCs) represent a promising candidate and hold potential for bone tissue engineering due to the the lack of ethical controversies, accessibility, sourced by non-invasive procedures for donors, a reduced risk of contamination, osteogenic differentiation capacities, and higher immunomodulatory capacity. However, the current culture methods are somewhat complicated and inefficient and often fail to make the best use of the umbilical cord (UC) tissues. Moreover, these culture processes cannot be performed on a large scale and under strict quality control. As a result, only a small quantity of cells can be harvested using the current culture methods. To solve these problems, we designed and evaluated an UC Wharton's jelly repeated culture device. Using this device, hUCMSCs were obtained from the repeated cultures and their quantities and biological characteristics were compared. We found that using our culture device, which retained all tissue blocks on the bottom of the dish, the total number of obtained cells increased 15-20 times, and the time required for the primary passage was reduced. Moreover, cells harvested from the repeated cultures exhibited no significant difference in their immunophenotype, potential for multilineage differentiation, or proliferative, osteoinductive capacities, and final osteogenesis. The application of the repeated culture frame (RCF) not only made full use of the Wharton's jelly but also simplified and specified the culture process, and thus, the culture efficiency was significantly improved. In summary, abundant hUCMSCs of dependable quality can be acquired using the RCF.

  10. A web-server of cell type discrimination system.

    PubMed

    Wang, Anyou; Zhong, Yan; Wang, Yanhua; He, Qianchuan

    2014-01-01

    Discriminating cell types is a daily request for stem cell biologists. However, there is not a user-friendly system available to date for public users to discriminate the common cell types, embryonic stem cells (ESCs), induced pluripotent stem cells (iPSCs), and somatic cells (SCs). Here, we develop WCTDS, a web-server of cell type discrimination system, to discriminate the three cell types and their subtypes like fetal versus adult SCs. WCTDS is developed as a top layer application of our recent publication regarding cell type discriminations, which employs DNA-methylation as biomarkers and machine learning models to discriminate cell types. Implemented by Django, Python, R, and Linux shell programming, run under Linux-Apache web server, and communicated through MySQL, WCTDS provides a friendly framework to efficiently receive the user input and to run mathematical models for analyzing data and then to present results to users. This framework is flexible and easy to be expended for other applications. Therefore, WCTDS works as a user-friendly framework to discriminate cell types and subtypes and it can also be expended to detect other cell types like cancer cells.

  11. The abundance and stability of “water” in type 1 and 2 carbonaceous chondrites (CI, CM and CR)

    NASA Astrophysics Data System (ADS)

    Garenne, A.; Beck, P.; Montes-Hernandez, G.; Chiriac, R.; Toche, F.; Quirico, E.; Bonal, L.; Schmitt, B.

    2014-07-01

    Carbonaceous chondrites record processes of aqueous alteration in the presence of hydrated and hydroxylated minerals, which could have provided a source of water in the inner solar system (Alexander et al., 2012, 2013). In this study, thermogravimetric analysis (TGA) was performed on 26 CM chondrites, which cover a range of degree of aqueous alteration from 2.0, such as Meteorite Hills (MET) 01070, to 2.6, such as Queen Alexandra Range (QUE) 97990, in order to quantify their water content. In addition, by measuring the release of volatile elements as a function of temperature, we obtained information on the mineralogy of water-bearing phases and provide indicators of aqueous alteration based on water released by phyllosilicates. These analyses are combined with infrared spectroscopy (IR) made on meteorite pellets heated up to 300 °C. The infrared features (-OH band at 3-μm and SiO4 around 10-μm) revealed a correlation with TGA. The two techniques are in agreement with the scheme of aqueous alteration proposed by Rubin et al. (2007) and Alexander et al. (2013) based on phyllosilicate abundance. The low temperature (200-400 °C) mass loss observed in TGA is attributed to Fe-oxy-hydroxydes (ferrihydrite, goethite). However, the proportion of these minerals formed by terrestrial alteration remains unknown. TGA also revealed two anomalous CM chondrites, Pecora Escarpment (PCA) 02012 and PCA 02010. Their TGA curves are significantly different from those of “regular” CMs with little mass loss, which can be related to the dehydration history of these meteorites in response to a heating event (Raman measurements also point toward a thermal event, Quirico et al., 2013). In the case of more mildly heated chondrites, such as with Wisconsin Range (WIS) 91600, the TGA curve presents similar mass loss to the other CMs. Seven bulk measurements of CR chondrites and 3 measurements of matrix-enriched parts of CR meteorites were also studied by TGA, and confirm the low

  12. The microbes we eat: abundance and taxonomy of microbes consumed in a day's worth of meals for three diet types.

    PubMed

    Lang, Jenna M; Eisen, Jonathan A; Zivkovic, Angela M

    2014-01-01

    Far more attention has been paid to the microbes in our feces than the microbes in our food. Research efforts dedicated to the microbes that we eat have historically been focused on a fairly narrow range of species, namely those which cause disease and those which are thought to confer some "probiotic" health benefit. Little is known about the effects of ingested microbial communities that are present in typical American diets, and even the basic questions of which microbes, how many of them, and how much they vary from diet to diet and meal to meal, have not been answered. We characterized the microbiota of three different dietary patterns in order to estimate: the average total amount of daily microbes ingested via food and beverages, and their composition in three daily meal plans representing three different dietary patterns. The three dietary patterns analyzed were: (1) the Average American (AMERICAN): focused on convenience foods, (2) USDA recommended (USDA): emphasizing fruits and vegetables, lean meat, dairy, and whole grains, and (3) Vegan (VEGAN): excluding all animal products. Meals were prepared in a home kitchen or purchased at restaurants and blended, followed by microbial analysis including aerobic, anaerobic, yeast and mold plate counts as well as 16S rRNA PCR survey analysis. Based on plate counts, the USDA meal plan had the highest total amount of microbes at 1.3 × 10(9) CFU per day, followed by the VEGAN meal plan and the AMERICAN meal plan at 6 × 10(6) and 1.4 × 10(6) CFU per day respectively. There was no significant difference in diversity among the three dietary patterns. Individual meals clustered based on taxonomic composition independent of dietary pattern. For example, meals that were abundant in Lactic Acid Bacteria were from all three dietary patterns. Some taxonomic groups were correlated with the nutritional content of the meals. Predictive metagenome analysis using PICRUSt indicated differences in some functional KEGG categories

  13. Present-day cosmic abundances. A comprehensive study of nearby early B-type stars and implications for stellar and Galactic evolution and interstellar dust models

    NASA Astrophysics Data System (ADS)

    Nieva, M.-F.; Przybilla, N.

    2012-03-01

    Context. Early B-type stars are ideal indicators for present-day cosmic abundances since they preserve their pristine abundances and typically do not migrate far beyond their birth environments over their short lifetimes, in contrast to older stars like the Sun. They are also unaffected by depletion onto dust grains, unlike the cold/warm interstellar medium (ISM) or H ii regions. Aims: A carefully selected sample of early B-type stars in OB associations and the field within the solar neighbourhood is studied comprehensively. Quantitative spectroscopy is used to characterise their atmospheric properties in a self-consistent way. Present-day abundances for the astrophysically most interesting chemical elements are derived in order to investigate whether a present-day cosmic abundance standard can be established. Methods: High-resolution and high-S/N FOCES, FEROS and ELODIE spectra of well-studied sharp-lined early B-type stars are analysed in non-LTE. Line-profile fits based on extensive model grids and an iterative analysis methodology are used to constrain stellar parameters and elemental abundances at high accuracy and precision. Atmospheric parameters are derived from the simultaneous establishment of independent indicators, from multiple ionization equilibria and the Stark-broadened hydrogen Balmer lines, and they are confirmed by reproduction of the stars' global spectral energy distributions. Results: Effective temperatures are constrained to 1-2% and surface gravities to less than 15% uncertainty, along with accurate rotational, micro- and macroturbulence velocities. Good agreement of the resulting spectroscopic parallaxes with those from the new reduction of the Hipparcos catalogue is obtained. Absolute values for abundances of He, C, N, O, Ne, Mg, Si and Fe are determined to better than 25% uncertainty. The synthetic spectra match the observations reliably over almost the entire visual spectral range. Three sample stars, γ Ori, o Per and θ1 Ori D, are

  14. HERV-H RNA is abundant in human embryonic stem cells and a precise marker for pluripotency

    PubMed Central

    2012-01-01

    Background Certain post-translational modifications to histones, including H3K4me3, as well as binding sites for the transcription factor STAT1, predict the site of integration of exogenous gamma-retroviruses with great accuracy and cell-type specificity. Statistical methods that were used to identify chromatin features that predict exogenous gamma-retrovirus integration site selection were exploited here to determine whether cell type-specific chromatin markers are enriched in the vicinity of endogenous retroviruses (ERVs). Results Among retro-elements in the human genome, the gamma-retrovirus HERV-H was highly associated with H3K4me3, though this association was only observed in embryonic stem (ES) cells (p < 10-300) and, to a lesser extent, in induced pluripotent stem (iPS) cells. No significant association was observed in nearly 40 differentiated cell types, nor was any association observed with other retro-elements. Similar strong association was observed between HERV-H and the binding sites within ES cells for the pluripotency transcription factors NANOG, OCT4, and SOX2. NANOG binding sites were located within the HERV-H 5′LTR itself. OCT4 and SOX2 binding sites were within 1 kB and 2 kB of the 5′LTR, respectively. In keeping with these observations, HERV-H RNA constituted 2% of all poly A RNA in ES cells. As ES cells progressed down a differentiation pathway, the levels of HERV-H RNA decreased progressively. RNA-Seq datasets showed HERV-H transcripts to be over 5 kB in length and to have the structure 5′LTR-gag-pro-3′LTR, with no evidence of splicing and no intact open reading frames. Conclusion The developmental regulation of HERV-H expression, the association of HERV-H with binding sites for pluripotency transcription factors, and the extremely high levels of HERV-H RNA in human ES cells suggest that HERV-H contributes to pluripotency in human cells. Proximity of HERV-H to binding sites for pluripotency transcription factors within ES cells

  15. Comparison of Types of Cell Death: Apoptosis and Necrosis.

    ERIC Educational Resources Information Center

    Manning, Francis; Zuzel, Katherine

    2003-01-01

    Cell death is an essential factor in many biological processes including development. Discusses two types of cell death: (1) necrosis (induced by sodium azide); and (2) apoptosis (induced by sodium chromate). Illustrates key features that differ between these two types of cells death including loss of membrane integrity and internucleosomal DNA…

  16. Polo-like kinase 2 acting as a promoter in human tumor cells with an abundance of TAp73

    PubMed Central

    Hu, ZhengBo; Xu, ZunYing; Liao, XiaoHong; Yang, Xiao; Dong, Cao; Luk, KuaDi; Jin, AnMin; Lu, Hai

    2015-01-01

    Background TAp73, a member of the p53 tumor suppressor family, is frequently overexpressed in malignant tumors in humans. TAp73 abundance and phosphorylation modification result in variations in transcriptional activity. In a previous study, we found that the antitumor function of TAp73 was reactivated by dephosphorylation in head and neck squamous cell carcinomas. Polo-like kinase 2 (PLK2) displayed a close relationship with the p53 family in affecting the fate of cells. Herein, we investigate the hypothesis that PLK2 phosphorylates TAp73 and inhibits TAp73 function. Materials and methods Head and neck squamous cell carcinoma cell lines and osteosarcoma cell lines were used as natural models of the different expression levels of TAp73. Phosphorylation predictor software Scansite 3.0 and the predictor GPS-polo 1.0 were used to analyze the phosphorylation sites. Coimmunoprecipitation, phosphor-tag Western blot, metabolic labeling, and indirect immunofluorescence assays were used to determine the interactions between PLK2 and TAp73. TAp73 activity was assessed by Western blot and reverse transcription polymerase chain reaction, which we used to detect P21 and PUMA, both downstream genes of TAp73. The physiological effects of PLK2 cross talk with TAp73 on cell cycle progress and apoptosis were observed by flow cytometry and terminal deoxynucleotidyl transferase dUTP nick end labeling assays. Results PLK2 binds to and phosphorylates TAp73. PLK2 phosphorylates TAp73 at residue Ser48 and prohibits TAp73 translocation to the nucleus. Additionally, PLK2 inhibition combined with a DNA-damaging drug upregulated p21 and PUMA mRNA expression to a greater extent than DNA-damaging drug treatment alone. Inhibiting PLK2 in TAp73-enriched cells strengthened the effects of the DNA-damaging drug on both G1 phase arrest and apoptosis. Pretreatment with TAp73-siRNA weakened these effects. Conclusion These findings reveal a novel PLK2 function (catalyzed phosphorylation of TAp73) which

  17. Differences in Abundances of Cell-Signalling Proteins in Blood Reveal Novel Biomarkers for Early Detection Of Clinical Alzheimer's Disease

    PubMed Central

    Rocha de Paula, Mateus; Gómez Ravetti, Martín; Berretta, Regina; Moscato, Pablo

    2011-01-01

    Background In November 2007 a study published in Nature Medicine proposed a simple test based on the abundance of 18 proteins in blood to predict the onset of clinical symptoms of Alzheimer's Disease (AD) two to six years before these symptoms manifest. Later, another study, published in PLoS ONE, showed that only five proteins (IL-1, IL-3, EGF, TNF- and G-CSF) have overall better prediction accuracy. These classifiers are based on the abundance of 120 proteins. Such values were standardised by a Z-score transformation, which means that their values are relative to the average of all others. Methodology The original datasets from the Nature Medicine paper are further studied using methods from combinatorial optimisation and Information Theory. We expand the original dataset by also including all pair-wise differences of z-score values of the original dataset (“metafeatures”). Using an exact algorithm to solve the resulting Feature Set problem, used to tackle the feature selection problem, we found signatures that contain either only features, metafeatures or both, and evaluated their predictive performance on the independent test set. Conclusions It was possible to show that a specific pattern of cell signalling imbalance in blood plasma has valuable information to distinguish between NDC and AD samples. The obtained signatures were able to predict AD in patients that already had a Mild Cognitive Impairment (MCI) with up to 84% of sensitivity, while maintaining also a strong prediction accuracy of 90% on a independent dataset with Non Demented Controls (NDC) and AD samples. The novel biomarkers uncovered with this method now confirms ANG-2, IL-11, PDGF-BB, CCL15/MIP-1; and supports the joint measurement of other signalling proteins not previously discussed: GM-CSF, NT-3, IGFBP-2 and VEGF-B. PMID:21479255

  18. Mast Cells Are Abundant in Primary Cutaneous T-Cell Lymphomas: Results from a Computer-Aided Quantitative Immunohistological Study

    PubMed Central

    Eder, Johanna; Rogojanu, Radu; Jerney, Waltraud; Erhart, Friedrich; Dohnal, Alexander; Kitzwögerer, Melitta; Steiner, Georg; Moser, Julia; Trautinger, Franz

    2016-01-01

    Background Mast cells (MC) are bone marrow derived haematopoetic cells playing a crucial role not only in immune response but also in the tumor microenvironment with protumorigenic and antitumorigenic functions. The role of MC in primary cutaneous T-cell lymphomas (CTCL), a heterogeneous group of non-Hodgkin lymphomas with initial presentation in the skin, is largely unknown. Objective To gain more accurate information about presence, number, distribution and state of activation (degranulated vs. non-degranulated) of MC in CTCL variants and clinical stages. Materials and Methods We established a novel computer-aided tissue analysis method on digitized skin sections. Immunohistochemistry with an anti-MC tryptase antibody was performed on 34 biopsies of different CTCL subtypes and on control skin samples. An algorithm for the automatic detection of the epidermis and of cell density based CTCL areas was developed. Cells were stratified as being within the CTCL infiltrate, in P1 (a surrounding area 0–30 μm away from CTCL), or in P2 (30–60 μm away from CTCL) area. Results We found high MC counts within CTCL infiltrates and P1 and a decreased MC number in the surrounding dermis P2. Higher MC numbers were found in MF compared to all other CTCL subgroups. Regarding different stages of MF, we found significantly higher mast cell counts in stages IA and IB than in stages IIA and IIB. Regarding MC densities, we found a higher density of MC in MF compared to all other CTCL subgroups. More MC were non-degranulated than degranulated. Conclusion Here for the first time an automated method for MC analysis on tissue sections and its use in CTCL is described. Eliminating error from investigator bias, the method allows for precise cell identification and counting. Our results provide new insights on MC distribution in CTCL reappraising their role in the pathophysiology of CTCL. PMID:27893746

  19. Circular RNA profiling reveals an abundant circHIPK3 that regulates cell growth by sponging multiple miRNAs

    PubMed Central

    Zheng, Qiupeng; Bao, Chunyang; Guo, Weijie; Li, Shuyi; Chen, Jie; Chen, Bing; Luo, Yanting; Lyu, Dongbin; Li, Yan; Shi, Guohai; Liang, Linhui; Gu, Jianren; He, Xianghuo; Huang, Shenglin

    2016-01-01

    Circular RNAs (circRNAs) represent a class of widespread and diverse endogenous RNAs that may regulate gene expression in eukaryotes. However, the regulation and function of human circRNAs remain largely unknown. Here we generate ribosomal-depleted RNA sequencing data from six normal tissues and seven cancers, and detect at least 27,000 circRNA candidates. Many of these circRNAs are differently expressed between the normal and cancerous tissues. We further characterize one abundant circRNA derived from Exon2 of the HIPK3 gene, termed circHIPK3. The silencing of circHIPK3 but not HIPK3 mRNA significantly inhibits human cell growth. Via a luciferase screening assay, circHIPK3 is observed to sponge to 9 miRNAs with 18 potential binding sites. Specifically, we show that circHIPK3 directly binds to miR-124 and inhibits miR-124 activity. Our results provide evidence that circular RNA produced from precursor mRNA may have a regulatory role in human cells. PMID:27050392

  20. Functional identification of islet cell types by electrophysiological fingerprinting

    PubMed Central

    Zhang, Quan; Vergari, Elisa; Kellard, Joely A.; Rodriguez, Blanca; Ashcroft, Frances M.; Rorsman, Patrik

    2017-01-01

    The α-, β- and δ-cells of the pancreatic islet exhibit different electrophysiological features. We used a large dataset of whole-cell patch-clamp recordings from cells in intact mouse islets (N = 288 recordings) to investigate whether it is possible to reliably identify cell type (α, β or δ) based on their electrophysiological characteristics. We quantified 15 electrophysiological variables in each recorded cell. Individually, none of the variables could reliably distinguish the cell types. We therefore constructed a logistic regression model that included all quantified variables, to determine whether they could together identify cell type. The model identified cell type with 94% accuracy. This model was applied to a dataset of cells recorded from hyperglycaemic βV59M mice; it correctly identified cell type in all cells and was able to distinguish cells that co-expressed insulin and glucagon. Based on this revised functional identification, we were able to improve conductance-based models of the electrical activity in α-cells and generate a model of δ-cell electrical activity. These new models could faithfully emulate α- and δ-cell electrical activity recorded experimentally. PMID:28275121

  1. GABAergic cell types in the lizard hippocampus.

    PubMed

    Guirado, S; Dávila, J C

    1999-04-01

    The neurochemical classification of GABAergic cells in the lizard hippocampus resulted in a further division into four major, non-overlapping subtypes. Each GABAergic cell subtype displays specific targets on the principal hippocampal neurons. The synaptic targets of the GABA/neuropeptide subtype are the distal apical dendrites of principal neurons. Calretinin- and parvalbumin-containing GABAergic cells synapse on the cell body and proximal dendrites of principal cells. Calbindin is expressed in a distinct group of interneurons, the synapses of which are directed to the dendrites of principal neurons. Finally, another subtype displays NADPH-diaphorase activity, but its synaptic target has not been established.

  2. Decreased abundance of type III secretion system-inducing signals in Arabidopsis mkp1 enhances resistance against Pseudomonas syringae

    PubMed Central

    Anderson, Jeffrey C.; Wan, Ying; Kim, Young-Mo; Pasa-Tolic, Ljiljana; Metz, Thomas O.; Peck, Scott C.

    2014-01-01

    Genes encoding the virulence-promoting type III secretion system (T3SS) in phytopathogenic bacteria are induced at the start of infection, indicating that recognition of signals from the host plant initiates this response. However, the precise nature of these signals and whether their concentrations can be altered to affect the biological outcome of host–pathogen interactions remain speculative. Here we use a metabolomic comparison of resistant and susceptible genotypes to identify plant-derived metabolites that induce T3SS genes in Pseudomonas syringae pv tomato DC3000 and report that mapk phosphatase 1 (mkp1), an Arabidopsis mutant that is more resistant to bacterial infection, produces decreased levels of these bioactive compounds. Consistent with these observations, T3SS effector expression and delivery by DC3000 was impaired when infecting the mkp1 mutant. The addition of bioactive metabolites fully restored T3SS effector delivery and suppressed the enhanced resistance in the mkp1 mutant. Pretreatment of plants with pathogen-associated molecular patterns (PAMPs) to induce PAMP-triggered immunity (PTI) also restricts T3SS effector delivery and enhances resistance by unknown mechanisms, and the addition of the bioactive metabolites similarly suppressed both aspects of PTI. Together, these results demonstrate that DC3000 perceives multiple signals derived from plants to initiate its T3SS and that the level of these host-derived signals impacts bacterial pathogenesis. PMID:24753604

  3. Star cell type core configuration for structural sandwich materials

    DOEpatents

    Christensen, Richard M.

    1995-01-01

    A new pattern for cellular core material used in sandwich type structural materials. The new pattern involves star shaped cells intermixed with hexagonal shaped cells. The new patterned cellular core material includes star shaped cells interconnected at points thereof and having hexagonal shape cells positioned adjacent the star points. The new pattern allows more flexibility and can conform more easily to curved shapes.

  4. Alveolar type II cell-fibroblast interactions, synthesis and secretion of surfactant and type I collagen.

    PubMed

    Griffin, M; Bhandari, R; Hamilton, G; Chan, Y C; Powell, J T

    1993-06-01

    During alveolar development and alveolar repair close contacts are established between fibroblasts and lung epithelial cells through gaps in the basement membrane. Using co-culture systems we have investigated whether these close contacts influence synthesis and secretion of the principal surfactant apoprotein (SP-A) by cultured rat lung alveolar type II cells and the synthesis and secretion of type I collagen by fibroblasts. The alveolar type II cells remained cuboidal and grew in colonies on fibroblast feeder layers and on Matrigel-coated cell culture inserts but were progressively more flattened on fixed fibroblast monolayers and plastic. Alveolar type II cells cultured on plastic released almost all their SP-A into the medium by 4 days. Alveolar type II cells cultured on viable fibroblasts or Matrigel-coated inserts above fibroblasts accumulated SP-A in the medium at a constant rate for the first 4 days, and probably recycle SP-A by endocytosis. The amount of mRNA for SP-A was very low after 4 days of culture of alveolar type II cells on plastic, Matrigel-coated inserts or fixed fibroblast monolayers: relatively, the amount of mRNA for SP-A was increased 4-fold after culture of alveolar type II cells on viable fibroblasts. Co-culture of alveolar type II cells with confluent human dermal fibroblasts stimulated by 2- to 3-fold the secretion of collagen type I into the culture medium, even after the fibroblasts' growth had been arrested with mitomycin C. Collagen secretion, by fibroblasts, also was stimulated 2-fold by conditioned medium from alveolar type II cells cultured on Matrigel. The amount of mRNA for type I collagen increased only modestly when fibroblasts were cultured in this conditioned medium. This stimulation of type I collagen secretion diminished as the conditioned medium was diluted out, but at high dilutions further stimulation occurred, indicating that a factor that inhibited collagen secretion also was being diluted out. The conditioned medium

  5. Identification of the Abundant Hydroxyproline-Rich Glycoproteins in the Root Walls of Wild-Type Arabidopsis, an ext3 Mutant Line, and Its Phenotypic Revertant

    PubMed Central

    Chen, Yuning; Ye, Dening; Held, Michael A.; Cannon, Maura C.; Ray, Tui; Saha, Prasenjit; Frye, Alexandra N.; Mort, Andrew J.; Kieliszewski, Marcia J.

    2015-01-01

    Extensins are members of the cell wall hydroxyproline-rich glycoprotein (HRGP) superfamily that form covalently cross-linked networks in primary cell walls. A knockout mutation in EXT3 (AT1G21310), the gene coding EXTENSIN 3 (EXT3) in Arabidopsis Landsberg erecta resulted in a lethal phenotype, although about 20% of the knockout plants have an apparently normal phenotype (ANP). In this study the root cell wall HRGP components of wild-type, ANP and the ext3 mutant seedlings were characterized by peptide fractionation of trypsin digested anhydrous hydrogen fluoride deglycosylated wall residues and by sequencing using LC-MS/MS. Several HRGPs, including EXT3, were identified in the wild-type root walls but not in walls of the ANP and lethal mutant. Indeed the ANP walls and walls of mutants displaying the lethal phenotype possessed HRGPs, but the profiles suggest that changes in the amount and perhaps type may account for the corresponding phenotypes. PMID:27135319

  6. Increased abundance of translation machinery in stem cell-derived neural progenitor cells from four schizophrenia patients.

    PubMed

    Topol, A; English, J A; Flaherty, E; Rajarajan, P; Hartley, B J; Gupta, S; Desland, F; Zhu, S; Goff, T; Friedman, L; Rapoport, J; Felsenfeld, D; Cagney, G; Mackay-Sim, A; Savas, J N; Aronow, B; Fang, G; Zhang, B; Cotter, D; Brennand, K J

    2015-10-20

    The genetic and epigenetic factors contributing to risk for schizophrenia (SZ) remain unresolved. Here we demonstrate, for the first time, perturbed global protein translation in human-induced pluripotent stem cell (hiPSC)-derived forebrain neural progenitor cells (NPCs) from four SZ patients relative to six unaffected controls. We report increased total protein levels and protein synthesis, together with two independent sets of quantitative mass spectrometry evidence indicating markedly increased levels of ribosomal and translation initiation and elongation factor proteins, in SZ hiPSC NPCs. We posit that perturbed levels of global protein synthesis in SZ hiPSC NPCs represent a novel post-transcriptional mechanism that might contribute to disease progression.

  7. Improved fuel-cell-type hydrogen sensor

    NASA Technical Reports Server (NTRS)

    Rudek, F. P.; Rutkowski, M. D.

    1968-01-01

    Modified hydrogen sensor replaces oxygen cathode with a cathode consisting of a sealed paste of gold hydroxide and a pure gold current collector. The net reaction which occurs during cell operation is the reduction of the gold hydroxide to gold and water, with a half-cell potential of 1.4 volts.

  8. Abundances of La138 and Ta180 Through ν-Nucleosynthesis in 20 M ⊙ Type II Supernova Progenitor, Guided by Stellar Models for Seeds

    NASA Astrophysics Data System (ADS)

    Lahkar, N.; Kalita, S.; Duorah, H. L.; Duorah, K.

    2017-03-01

    Yields of nature's rarest isotopes La138 and Ta180 are calculated by neutrino processes in the Ne-shell of density ρ ≈ 104 g/cc in a type II supernova (SN II) progenitor of mass 20 M ⊙. Two extended sets of neutrino temperature - T ν e = 3, 4, 5, 6 MeV and T ν( μ/ τ)= 4, 6, 8, 10, 12 MeV respectively for charged and neutral current processes are taken. Solar mass fractions of the seeds La 139, Ta 181, Ba 138 and Hf 180 are taken for calculation. They are assumed to be produced in some s-processing events of earlier generation massive `seed stars' with average interior density range < ρ>≈103-106 g/cc. The abundances of these two elements are calculated relative to O 16 and are found to be sensitive to the neutrino temperature. For neutral current processes with the neutron emission branching ratio, b n = 3.81 × 10-4 and b n = 9.61 × 10-1, the relative abundances of La138 lie in the ranges 4.48 × 10-14-2.94 × 10-13 and 1.13 × 10-10-7.43 × 10-10 respectively. Similarly, the relative abundances of Ta180 lie in the ranges 1.80 × 10-15-1.17 × 10-14 and 4.53 × 10-12-2.96 × 10-11 respectively for the lower and higher values of the neutron emission branching ratio. For charged current processes, the relative abundances of La138 and Ta180 are found to be in the ranges 1.38 × 10-9-7.62 × 10-9 and 2.09 × 10-11-1.10 × 10-10 respectively. Parametrized by density of the `seed stars', the yields are found to be consistent with recent supernova simulation results throughout the range of neutrino temperatures. La138 and Ta180 are found to be efficiently produced in charged current interaction.

  9. Heterologous expression of rab4 reduces glucose transport and GLUT4 abundance at the cell surface in oocytes.

    PubMed Central

    Mora, S; Monden, I; Zorzano, A; Keller, K

    1997-01-01

    To evaluate the role of the small rab GTP-binding proteins in glucose transporter trafficking, we have heterologously co-expressed rab4 or rab5 and GLUT4 or GLUT1 glucose transporters in Xenopus oocytes. Co-injection of rab4 and GLUT4 cRNAs resulted in a dose-dependent decrease in glucose transport; this effect was specific for rab4, since co-injection of an inactive rab4 mutant or rab5 cRNA did not have any effect on glucose transport. The effect of rab4 was selective for GLUT4, since no effect was detected in GLUT1-expressing oocytes. The inhibitory effect of rab4 on GLUT4-induced glucose transport was not the result of a change in overall cellular levels of GLUT4 glucose transporters. However, rab4 expression caused a marked decrease in the abundance of GLUT4 transporters present at the cell surface. Finally, rab4 and inhibitors of PtdIns 3-kinase showed additive effects in decreasing glucose transport in GLUT4-expressing oocytes. We conclude that rab4 plays an important role in the regulation of the intracellular GLUT4 trafficking pathway, by contributing to the intracellular retention of GLUT4 through a PtdIns 3-kinase-independent mechanism. PMID:9182703

  10. A realistic bi-hemispheric model of the cerebellum uncovers the purpose of the abundant granule cells during motor control.

    PubMed

    Pinzon-Morales, Ruben-Dario; Hirata, Yutaka

    2015-01-01

    The cerebellar granule cells (GCs) have been proposed to perform lossless, adaptive spatio-temporal coding of incoming sensory/motor information required by downstream cerebellar circuits to support motor learning, motor coordination, and cognition. Here we use a physio-anatomically inspired bi-hemispheric cerebellar neuronal network (biCNN) to selectively enable/disable the output of GCs and evaluate the behavioral and neural consequences during three different control scenarios. The control scenarios are a simple direct current motor (1 degree of freedom: DOF), an unstable two-wheel balancing robot (2 DOFs), and a simulation model of a quadcopter (6 DOFs). Results showed that adequate control was maintained with a relatively small number of GCs (< 200) in all the control scenarios. However, the minimum number of GCs required to successfully govern each control plant increased with their complexity (i.e., DOFs). It was also shown that increasing the number of GCs resulted in higher robustness against changes in the initialization parameters of the biCNN model (i.e., synaptic connections and synaptic weights). Therefore, we suggest that the abundant GCs in the cerebellar cortex provide the computational power during the large repertoire of motor activities and motor plants the cerebellum is involved with, and bring robustness against changes in the cerebellar microcircuit (e.g., neuronal connections).

  11. A realistic bi-hemispheric model of the cerebellum uncovers the purpose of the abundant granule cells during motor control

    PubMed Central

    Pinzon-Morales, Ruben-Dario; Hirata, Yutaka

    2015-01-01

    The cerebellar granule cells (GCs) have been proposed to perform lossless, adaptive spatio-temporal coding of incoming sensory/motor information required by downstream cerebellar circuits to support motor learning, motor coordination, and cognition. Here we use a physio-anatomically inspired bi-hemispheric cerebellar neuronal network (biCNN) to selectively enable/disable the output of GCs and evaluate the behavioral and neural consequences during three different control scenarios. The control scenarios are a simple direct current motor (1 degree of freedom: DOF), an unstable two-wheel balancing robot (2 DOFs), and a simulation model of a quadcopter (6 DOFs). Results showed that adequate control was maintained with a relatively small number of GCs (< 200) in all the control scenarios. However, the minimum number of GCs required to successfully govern each control plant increased with their complexity (i.e., DOFs). It was also shown that increasing the number of GCs resulted in higher robustness against changes in the initialization parameters of the biCNN model (i.e., synaptic connections and synaptic weights). Therefore, we suggest that the abundant GCs in the cerebellar cortex provide the computational power during the large repertoire of motor activities and motor plants the cerebellum is involved with, and bring robustness against changes in the cerebellar microcircuit (e.g., neuronal connections). PMID:25983678

  12. The effect of decrease in salinity on the dynamics of abundance and the cell size of Corethron Hystrix (Bacillariophyta) in laboratory culture

    NASA Astrophysics Data System (ADS)

    Aizdaicher, Nina A.; Markina, Zhanna V.

    2010-03-01

    Effect of salinity on abundance dynamics and cell size of microalga Corethron hystrix Hensen (Bacillariophyta) were studied. C. hystrix can normally grow within a rather narrow salinity range between 32 and 28‰. The viable cells of this microalga change their morphological characters at a salinity of 24‰. This salinity level probably marks the beginning of cell division restriction, because the general number of cells by the end of the experiment was lower than in the control. The decrease of salinity to 16‰ caused pronounced irreversible morphological changes: cell height increased, chloroplasts compressed, protoplasm became granular, cytoplasm retracted, and spines shortened.

  13. Mitochondria single nucleotide variation across six blood cell types.

    PubMed

    Zhang, Pan; Samuels, David C; Wang, Jing; Zhao, Shilin; Shyr, Yu; Guo, Yan

    2016-05-01

    It has been shown that heteroplasmic mitochondrial DNA variants can be tissue specific. However, whether mitochondrial DNA variants are specific by blood cell types has not been investigated. Motivated by this question and using mitochondria sequences extracted from RNAseq data from six distinct blood cell types (neutrophil, monocyte, myeloid dendritic, natural killer, T and B), we thoroughly compared SNPs and heteroplasmies among these cell types. Each cell type from each subject was sequenced at four time points used as biological replicates. We found that mitochondria content is low in neutrophil compared to the other five blood cell types. Subsequent analysis on the other five blood cell types showed that at the SNP level, there was no discrepancy. At the heteroplasmy level, we observed good concordances among all blood cell types. However, the allele frequencies of the heteroplasmy differed between blood cell types for certain heteroplasmic sites. Furthermore, we identified five tri-allelic sites (1610, 2617, 8303, 12146, 13710) that are likely caused by RNA editing. Three out of these five sites are located at the ninth position of tRNA genes, and are likely resulting from post-transcriptional methylation.

  14. Epidermal cells adhere preferentially to type IV (basement membrane) collagen

    PubMed Central

    1979-01-01

    Epidermal cells from adult guinea pig skin attach and differentiate preferentially on substrates of type IV (basement membrane) collagen, compared to those of types I--III collagen. In contrast, guinea pig dermal fibroblasts attach equally well to all four collagen substrates. Fibronectin mediates the attachment of fibroblasts but not of epidermal cells to collagen. PMID:422650

  15. Abundance and single-cell activity of heterotrophic bacterial groups in the western Arctic Ocean in summer and winter.

    PubMed

    Nikrad, Mrinalini P; Cottrell, M T; Kirchman, D L

    2012-04-01

    Environmental conditions in the western Arctic Ocean range from constant light and nutrient depletion in summer to complete darkness and sea ice cover in winter. This seasonal environmental variation is likely to have an effect on the use of dissolved organic matter (DOM) by heterotrophic bacteria in surface water. However, this effect is not well studied and we know little about the activity of specific bacterial clades in the surface oceans. The use of DOM by three bacterial subgroups in both winter and summer was examined by microautoradiography combined with fluorescence in situ hybridization. We found selective use of substrates by these groups, although the abundances of Ant4D3 (Antarctic Gammaproteobacteria), Polaribacter (Bacteroidetes), and SAR11 (Alphaproteobacteria) were not different between summer and winter in the Beaufort and Chukchi Seas. The number of cells taking up glucose within all three bacterial groups decreased significantly from summer to winter, while the percentage of cells using leucine did not show a clear pattern between seasons. The uptake of the amino acid mix increased substantially from summer to winter by the Ant4D3 group, although such a large increase in uptake was not seen for the other two groups. Use of glucose by bacteria, but not use of leucine or the amino acid mix, related strongly to inorganic nutrients, chlorophyll a, and other environmental factors. Our results suggest a switch in use of dissolved organic substrates from summer to winter and that the three phylogenetic subgroups examined fill different niches in DOM use in the two seasons.

  16. Phospholipase D1 decreases type I collagen levels in hepatic stellate cells via induction of autophagy.

    PubMed

    Seo, H-Y; Jang, B-K; Jung, Y-A; Lee, E-J; Kim, H-S; Jeon, J-H; Kim, J-G; Lee, I-K; Kim, M-K; Park, K-G

    2014-06-20

    Hepatic stellate cells (HSCs) are major players in liver fibrogenesis. Accumulating evidence shows that suppression of autophagy plays an important role in the development and progression of liver disease. Phospholipase D1 (PLD1), which catalyzes the hydrolysis of phosphatidylcholine to yield phosphatidic acid (PA) and choline, was recently shown to modulate autophagy. However, little is known about the effects of PLD1 on the production of type I collagen that characterizes liver fibrosis. Here, we examined whether PLD1 regulates type I collagen levels in HSCs through induction of autophagy. Adenovirus-mediated overexpression of PLD-1 (Ad-PLD1) reduced type I collagen levels in the activated human HSC lines, hTERT and LX2. Overexpression of PLD1 in HSCs led to induction of autophagy as demonstrated by increased LC3-II conversion and formation of LC3 puncta, and decreased p62 abundance. Moreover, inhibiting the induction of autophagy by treating cells with bafilomycin or a small interfering (si)RNA for ATG7 rescued Ad-PLD1-induced suppression of type I collagen accumulation in HSCs. The effects of PLD on type I collagen levels were not related to TGF-β/Smad signaling. Furthermore, treatment of cells with PA induced autophagy and inhibited type I collagen accumulation. The present study indicates that PLD1 plays a role in regulating type I collagen accumulation through induction of autophagy.

  17. Myosin types in cultured muscle cells

    PubMed Central

    1980-01-01

    Fluorescent antibodies against fast skeletal, slow skeletal, and ventricular myosins were applied to muscle cultures from embryonic pectoralis and ventricular myocadium of the chicken. A number of spindle-shaped mononucleated cells, presumably myoblasts, and all myotubes present in skeletal muscle cultures were labeled by all three antimyosin antisera. In contrast, in cultures from ventricular myocardium all muscle cells were labeled by anti-ventricular myosin, whereas only part of them were stained by anti-slow skeletal myosin and rare cells reacted with anti-fast skeletal myosin. The findings indicate that myosin(s) present in cultured embryonic skeletal muscle cells contains antigenic determinants similar to those present in adult fast skeletal, slow skeletal, and ventricular myosins. PMID:6156177

  18. Extinct type of human parvovirus B19 persists in tonsillar B cells.

    PubMed

    Pyöriä, Lari; Toppinen, Mari; Mäntylä, Elina; Hedman, Lea; Aaltonen, Leena-Maija; Vihinen-Ranta, Maija; Ilmarinen, Taru; Söderlund-Venermo, Maria; Hedman, Klaus; Perdomo, Maria F

    2017-04-04

    Parvovirus B19 (B19V) DNA persists lifelong in human tissues, but the cell type harbouring it remains unclear. We here explore B19V DNA distribution in B, T and monocyte cell lineages of recently excised tonsillar tissues from 77 individuals with an age range of 2-69 years. We show that B19V DNA is most frequent and abundant among B cells, and within them we find a B19V genotype that vanished from circulation >40 years ago. Since re-infection or re-activation are unlikely with this virus type, this finding supports the maintenance of pathogen-specific humoral immune responses as a consequence of B-cell long-term survival rather than continuous replenishment of the memory pool. Moreover, we demonstrate the mechanism of B19V internalization to be antibody dependent in two B-cell lines as well as in ex vivo isolated tonsillar B cells. This study provides direct evidence for a cell type accountable for B19V DNA tissue persistence.

  19. Characterization of cloned cells from an immortalized fetal pulmonary type II cell line

    SciTech Connect

    Henderson, R.F.; Waide, J.J.; Lechner, J.F.

    1995-12-01

    A cultured cell line that maintained expression of pulmonary type II cell markers of differentiation would be advantageous to generate a large number of homogenous cells in which to study the biochemical functions of type II cells. Type II epithelial cells are the source of pulmonary surfactant and a cell of origin for pulmonary adenomas. Last year our laboratory reported the induction of expression of two phenotypic markers of pulmonary type II cells (alkaline phosphatase activity and surfactant lipid synthesis) in cultured fetal rat lung epithelial (FRLE) cells, a spontaneously immortalized cell line of fetal rat lung type II cell origin. Subsequently, the induction of the ability to synthesize surfactant lipid became difficult to repeat. We hypothesized that the cell line was heterogenuous and some cells were more like type II cells than others. The purpose of this study was to test this hypothesis and to obtain a cultured cell line with type II cell phenotypic markers by cloning several FRLE cells and characterizing them for phenotypic markers of type II cells (alkaline phosphatase activity and presence of surfactant lipids). Thirty cloned cell lines were analyzed for induced alkaline phosphatase activity (on x-axis) and for percent of phospholipids that were disaturated (i.e., surfactant).

  20. DNA methylation of cord blood cell types: Applications for mixed cell birth studies.

    PubMed

    Bakulski, Kelly M; Feinberg, Jason I; Andrews, Shan V; Yang, Jack; Brown, Shannon; L McKenney, Stephanie; Witter, Frank; Walston, Jeremy; Feinberg, Andrew P; Fallin, M Daniele

    2016-05-03

    Epigenome-wide association studies of disease widely use DNA methylation measured in blood as a surrogate tissue. Cell proportions can vary between people and confound associations of exposure or outcome. An adequate reference panel for estimating cell proportions from adult whole blood for DNA methylation studies is available, but an analogous cord blood cell reference panel is not yet available. Cord blood has unique cell types and the epigenetic signatures of standard cell types may not be consistent throughout the life course. Using magnetic bead sorting, we isolated cord blood cell types (nucleated red blood cells, granulocytes, monocytes, natural killer cells, B cells, CD4(+)T cells, and CD8(+)T cells) from 17 live births at Johns Hopkins Hospital. We confirmed enrichment of the cell types using fluorescence assisted cell sorting and ran DNA from the separated cell types on the Illumina Infinium HumanMethylation450 BeadChip array. After filtering, the final analysis was on 104 samples at 429,794 probes. We compared cell type specific signatures in cord to each other and methylation at 49.2% of CpG sites on the array differed by cell type (F-test P < 10(-8)). Differences between nucleated red blood cells and the remainder of the cell types were most pronounced (36.9% of CpG sites at P < 10(-8)) and 99.5% of these sites were hypomethylated relative to the other cell types. We also compared the mean-centered sorted cord profiles to the available adult reference panel and observed high correlation between the overlapping cell types for granulocytes and monocytes (both r=0.74), and poor correlation for CD8(+)T cells and NK cells (both r=0.08). We further provide an algorithm for estimating cell proportions in cord blood using the newly developed cord reference panel, which estimates biologically plausible cell proportions in whole cord blood samples.

  1. Identification and quantitation of morphological cell types in electrophoretically separated human embryonic kidney cell cultures

    NASA Technical Reports Server (NTRS)

    Williams, K. B.; Kunze, M. E.; Todd, P. W.

    1985-01-01

    Four major cell types were identified by phase microscopy in early passage human embryonic kidney cell cultures. They are small and large epithelioid, domed, and fenestrated cells. Fibroblasts are also present in some explants. The percent of each cell type changes with passage number as any given culture grows. As a general rule, the fraction of small epithelioid cells increases, while the fraction of fenestrated cells, always small, decreases further. When fibroblasts are present, they always increase in percentage of the total cell population. Electrophoretic separation of early passage cells showed that the domed cells have the highest electrophoretic mobility, fibroblasts have an intermediate high mobility, small epithelioid cells have a low mobility, broadly distributed, and fenestrated cells have the lowest mobility. All cell types were broadly distributed among electrophoretic subfractions, which were never pure but only enriched with respect to a given cell type.

  2. OXYGEN ABUNDANCES IN CEPHEIDS

    SciTech Connect

    Luck, R. E.; Andrievsky, S. M.; Korotin, S. N.; Kovtyukh, V. V. E-mail: serkor@skyline.od.ua E-mail: scan@deneb1.odessa.ua

    2013-07-01

    Oxygen abundances in later-type stars, and intermediate-mass stars in particular, are usually determined from the [O I] line at 630.0 nm, and to a lesser extent, from the O I triplet at 615.7 nm. The near-IR triplets at 777.4 nm and 844.6 nm are strong in these stars and generally do not suffer from severe blending with other species. However, these latter two triplets suffer from strong non-local thermodynamic equilibrium (NLTE) effects and thus see limited use in abundance analyses. In this paper, we derive oxygen abundances in a large sample of Cepheids using the near-IR triplets from an NLTE analysis, and compare those abundances to values derived from a local thermodynamic equilibrium (LTE) analysis of the [O I] 630.0 nm line and the O I 615.7 nm triplet as well as LTE abundances for the 777.4 nm triplet. All of these lines suffer from line strength problems making them sensitive to either measurement complications (weak lines) or to line saturation difficulties (strong lines). Upon this realization, the LTE results for the [O I] lines and the O I 615.7 nm triplet are in adequate agreement with the abundance from the NLTE analysis of the near-IR triplets.

  3. Analysis of the cGMP/cAMP interactome using a chemical proteomics approach in mammalian heart tissue validates sphingosine kinase type 1-interacting protein as a genuine and highly abundant AKAP.

    PubMed

    Scholten, Arjen; Poh, Mee Kian; van Veen, Toon A B; van Breukelen, Bas; Vos, Marc A; Heck, Albert J R

    2006-06-01

    The cyclic nucleotide monophosphates cAMP and cGMP play an essential role in many signaling pathways. To analyze which proteins do interact with these second messenger molecules, we developed a chemical proteomics approach using cAMP and cGMP immobilized onto agarose beads, via flexible linkers in the 2- and 8-position of the nucleotide. Optimization of the affinity pull-down procedures in lysates of HEK293 cells revealed that a large variety of proteins could be pulled down specifically. Identification of these proteins by mass spectrometry showed that many of these proteins were indeed genuine cAMP or cGMP binding proteins. However, additionally many of the pulled-down proteins were more abundant AMP/ADP/ATP, GMP/GDP/GTP, or general DNA/RNA binding proteins. Therefore, a sequential elution protocol was developed, eluting proteins from the beads using solutions containing ADP, GDP, cGMP, and/or cAMP, respectively. Using this protocol, we were able to sequentially and selectively elute ADP, GDP, and DNA binding proteins. The fraction left on the beads was further enriched, for cAMP/cGMP binding proteins. Transferring this protocol to the analysis of the cGMP/cAMP "interactome" in rat heart ventricular tissue enabled the specific pull-down of known cAMP/cGMP binding proteins such as cAMP and cGMP dependent protein kinases PKA and PKG, several phosphodiesterases and 6 AKAPs, that interact with PKA. Among the latter class of proteins was the highly abundant sphingosine kinase type1-interating protein (SKIP), recently proposed to be a potential AKAP. Further bioinformatics analysis endorses that SKIP is indeed a genuine PKA interacting protein, which is highly abundant in heart ventricular tissue.

  4. Intracellular SERS Nanoprobes For Distinction Of Different Neuronal Cell Types

    PubMed Central

    2013-01-01

    Distinction between closely related and morphologically similar cells is difficult by conventional methods especially without labeling. Using nuclear-targeted gold nanoparticles (AuNPs) as intracellular probes we demonstrate the ability to distinguish between progenitor and differentiated cell types in a human neuroblastoma cell line using surface-enhanced Raman spectroscopy (SERS). SERS spectra from the whole cell area as well as only the nucleus were analyzed using principal component analysis that allowed unambiguous distinction of the different cell types. SERS spectra from the nuclear region showed the developments during cellular differentiation by identifying an increase in DNA/RNA ratio and proteins transcribed. Our approach using nuclear-targeted AuNPs and SERS imaging provides label-free and noninvasive characterization that can play a vital role in identifying cell types in biomedical stem cell research. PMID:23638825

  5. The GalNAc-type O-Glycoproteome of CHO cells characterized by the SimpleCell strategy.

    PubMed

    Yang, Zhang; Halim, Adnan; Narimatsu, Yoshiki; Jitendra Joshi, Hiren; Steentoft, Catharina; Schjoldager, Katrine Ter-Borch Gram; Alder Schulz, Morten; Sealover, Natalie R; Kayser, Kevin J; Paul Bennett, Eric; Levery, Steven B; Vakhrushev, Sergey Y; Clausen, Henrik

    2014-12-01

    The Chinese hamster ovary cell (CHO) is the major host cell factory for recombinant production of biological therapeutics primarily because of its "human-like" glycosylation features. CHO is used for production of several O-glycoprotein therapeutics including erythropoietin, coagulation factors, and chimeric receptor IgG1-Fc-fusion proteins, however, some O-glycoproteins are not produced efficiently in CHO. We have previously shown that the capacity for O-glycosylation of proteins can be one limiting parameter for production of active proteins in CHO. Although the capacity of CHO for biosynthesis of glycan structures (glycostructures) on glycoproteins are well established, our knowledge of the capacity of CHO cells for attaching GalNAc-type O-glycans to proteins (glycosites) is minimal. This type of O-glycosylation is one of the most abundant forms of glycosylation, and it is differentially regulated in cells by expression of a subset of homologous polypeptide GalNAc-transferases. Here, we have genetically engineered CHO cells to produce homogeneous truncated O-glycans, so-called SimpleCells, which enabled lectin enrichment of O-glycoproteins and characterization of the O-glycoproteome. We identified 738 O-glycoproteins (1548 O-glycosites) in cell lysates and secretomes providing the first comprehensive insight into the O-glycosylation capacity of CHO (http://glycomics.ku.dk/o-glycoproteome_db/).

  6. Type II alveolar epithelial cell in vitro culture in aerobiosis.

    PubMed

    Aerts, C; Voisin, C; Wallaert, B

    1988-08-01

    A method of Type II alveolar epithelial cell culture in aerobiosis has been developed. Isolation of Type II cells was performed by digesting guinea-pig lung tissue with crude trypsin and elastase and using discontinuous Percoll density gradients. The Type II cells, as identified by light and electron microscopy, were cultured in aerobiosis for up to six days, in direct contact with the atmosphere in conditions mimicking those present in the lower respiratory tract. Significant activities of cellular superoxide dismutase (SOD), manganese dependent superoxide dismutase (Mn-SOD), catalase and glutathione peroxidase (GSH-Px) were found at the time of isolation. In contrast, cell glutathione content varied widely from one experiment to another. Changes of antioxidant enzymes were evaluated during cell culture in aerobiosis. SOD, Mn-SOD and catalase were significantly decreased after three days but were not significantly different between a three day and six day culture. Antioxidant changes did not influence the cell culture. In marked contrast, decrease in cell glutathione was associated with rapid cell death, whereas good cell survival was obtained at high levels of cell glutathione. Cell culture in aerobiosis will permit a precise evaluation of the effects of gases, particularly oxidant gases, on a primary culture of Type II alveolar epithelial cells.

  7. Therapeutic application of cardiac stem cells and other cell types.

    PubMed

    Hayashi, Emiko; Hosoda, Toru

    2013-01-01

    Various researches on regenerative medicine were carried out experimentally, and selected modalities have been introduced to the clinical arena. Meanwhile, the presence of resident stem cells in the heart and their role in physiological cell turnover were demonstrated. So far skeletal myoblasts, bone marrow-derived cells, mesenchymal stromal cells, and resident cardiac cells have been applied for therapeutic myocardial regeneration. Among them, autologous transplantation of c-kit-positive cardiac stem cells in congestive heart failure patients resulted in an outstanding outcome, with long-lasting beneficial effects without major adverse events. By reviewing these clinical trials, an endeavor was made to seek for an ideal cellular therapy for cardiovascular diseases.

  8. Molecular events in the cell types of the olfactory epithelium during adult neurogenesis

    PubMed Central

    2013-01-01

    Background Adult neurogenesis, fundamental for cellular homeostasis in the mammalian olfactory epithelium, requires major shifts in gene expression to produce mature olfactory sensory neurons (OSNs) from multipotent progenitor cells. To understand these dynamic events requires identifying not only the genes involved but also the cell types that express each gene. Only then can the interrelationships of the encoded proteins reveal the sequences of molecular events that control the plasticity of the adult olfactory epithelium. Results Of 4,057 differentially abundant mRNAs at 5 days after lesion-induced OSN replacement in adult mice, 2,334 were decreased mRNAs expressed by mature OSNs. Of the 1,723 increased mRNAs, many were expressed by cell types other than OSNs and encoded proteins involved in cell proliferation and transcriptional regulation, consistent with increased basal cell proliferation. Others encoded fatty acid metabolism and lysosomal proteins expressed by infiltrating macrophages that help scavenge debris from the apoptosis of mature OSNs. The mRNAs of immature OSNs behaved dichotomously, increasing if they supported early events in OSN differentiation (axon initiation, vesicular trafficking, cytoskeletal organization and focal adhesions) but decreasing if they supported homeostatic processes that carry over into mature OSNs (energy production, axon maintenance and protein catabolism). The complexity of shifts in gene expression responsible for converting basal cells into neurons was evident in the increased abundance of 203 transcriptional regulators expressed by basal cells and immature OSNs. Conclusions Many of the molecular changes evoked during adult neurogenesis can now be ascribed to specific cellular events in the OSN cell lineage, thereby defining new stages in the development of these neurons. Most notably, the patterns of gene expression in immature OSNs changed in a characteristic fashion as these neurons differentiated. Initial patterns

  9. Replication of adenovirus type 4 DNA by a purified fraction from infected cells.

    PubMed Central

    Temperley, S M; Hay, R T

    1991-01-01

    An extract from Adenovirus type 4 infected HeLa cells was fractionated by ion-exchange and DNA affinity chromatography. One fraction, which bound tightly to single stranded DNA, contained predominantly a protein of apparent molecular weight 65,000 and three less abundant proteins. Immunological cross-reactivity with adenovirus type 2 proteins confirmed the presence of preterminal protein and indicated that the abundant species was the virus coded DNA binding protein. This fraction contained an aphidicolin resistant DNA polymerase activity and in the presence of a linearised plasmid containing the adenovirus type 4 origin of DNA replication efficient transfer of dCMP onto preterminal protein, indicative of initiation, was observed. Furthermore, addition of all four deoxyribonucleotide triphosphates and an ATP regenerating system resulted in the elongation of initiated molecules to generate plasmid molecules covalently attached to preterminal protein. Adenovirus type 4 DNA binding protein was extensively purified from crude adenovirus-4 infected HeLa extract by immunoaffinity chromatography using a monoclonal antibody raised against adenovirus type 2 DNA binding protein. A low level of initiation of DNA replication was detected in the fraction depleted of DNA binding protein but activity was restored by addition of purified DNA binding protein. DNA binding protein therefore plays an important role in the initiation of Ad4 DNA replication. Images PMID:1829516

  10. High-resolution metabolic mapping of cell types in plant roots.

    PubMed

    Moussaieff, Arieh; Rogachev, Ilana; Brodsky, Leonid; Malitsky, Sergey; Toal, Ted W; Belcher, Heather; Yativ, Merav; Brady, Siobhan M; Benfey, Philip N; Aharoni, Asaph

    2013-03-26

    Metabolite composition offers a powerful tool for understanding gene function and regulatory processes. However, metabolomics studies on multicellular organisms have thus far been performed primarily on whole organisms, organs, or cell lines, losing information about individual cell types within a tissue. With the goal of profiling metabolite content in different cell populations within an organ, we used FACS to dissect GFP-marked cells from Arabidopsis roots for metabolomics analysis. Here, we present the metabolic profiles obtained from five GFP-tagged lines representing core cell types in the root. Fifty metabolites were putatively identified, with the most prominent groups being glucosinolates, phenylpropanoids, and dipeptides, the latter of which is not yet explored in roots. The mRNA expression of enzymes or regulators in the corresponding biosynthetic pathways was compared with the relative metabolite abundance. Positive correlations suggest that the rate-limiting steps in biosynthesis of glucosinolates in the root are oxidative modifications of side chains. The current study presents a work flow for metabolomics analyses of cell-type populations.

  11. Nickel isotope abundances of type I deep-sea spheres and of iron-nickel spherules from sediments in Alberta, Canada

    NASA Astrophysics Data System (ADS)

    Xue, S.; Herzog, G. F.; Hall, G. S.; Bi, D.; Brownlee, D. E.

    1995-12-01

    Nickel isotope abundances were measured by ICP-MS in twenty-one whole, type I deep-sea spheres, in Ni-rich cores and oxide shells separated from three others, and in Fe-Ni alloy spherules from Alberta, Canada. The nickel isotopes in the whole deep-sea spheres are mass fractionated from 0.4 to 2.4%/ AMU. These: values correspond to open system vaporization losses of Ni as high as 94% (relative). The degree of mass fractionation correlates well with bulk nickel content in most cases. Taken together with published iron isotope data, the nickel isotope results indicate a pre-loss Fe/Ni ratio of about 12 for many spheres. Similar ratios are observed in the following types of meteoritic material: EL-chondrite metal; IA, IIE, IIIA, and IVA iron meteorites; and metal from pallasites and mesosiderites. Metal cores separated from three deep-sea spheres contain between 40 and 52% Ni, with mass fractionations ranging from undetectable to a high of 0.8%/AMU. Within experimental error, the degree of Ni mass fractionation in each oxide shell was the same as that in the corresponding core. No mass-dependent isotopic fractionation of nickel was observed in Ni-rich spherules recovered from Alberta sands of Pleistocene age. In general, Ni-rich samples have low degrees of isotopic fractionation which suggests that the most rapid vaporization of Ni occurs when both Fe and Ni have been oxidized.

  12. Nebular spectra and abundance tomography of the Type Ia supernova SN 2011fe: a normal SN Ia with a stable Fe core

    NASA Astrophysics Data System (ADS)

    Mazzali, P. A.; Sullivan, M.; Filippenko, A. V.; Garnavich, P. M.; Clubb, K. I.; Maguire, K.; Pan, Y.-C.; Shappee, B.; Silverman, J. M.; Benetti, S.; Hachinger, S.; Nomoto, K.; Pian, E.

    2015-07-01

    A series of optical and one near-infrared nebular spectra covering the first year of the Type Ia supernova SN 2011fe are presented and modelled. The density profile that proved best for the early optical/ultraviolet spectra, `ρ-11fe', was extended to lower velocities to include the regions that emit at nebular epochs. Model ρ-11fe is intermediate between the fast deflagration model W7 and a low-energy delayed-detonation. Good fits to the nebular spectra are obtained if the innermost ejecta are dominated by neutron-rich, stable Fe-group species, which contribute to cooling but not to heating. The correct thermal balance can thus be reached for the strongest [Fe II] and [Fe III] lines to be reproduced with the observed ratio. The 56Ni mass thus obtained is ˜0.47 ± 0.05 M⊙. The bulk of 56Ni has an outermost velocity of ˜8500 km s-1. The mass of stable iron is ˜0.23 ± 0.03 M⊙. Stable Ni has low abundance, ˜10-2 M⊙. This is sufficient to reproduce an observed emission line near 7400 Å. A sub-Chandrasekhar explosion model with mass 1.02 M⊙ and no central stable Fe does not reproduce the observed line ratios. A mock model where neutron-rich Fe-group species are located above 56Ni following recent suggestions is also shown to yield spectra that are less compatible with the observations. The densities and abundances in the inner layers obtained from the nebular analysis, combined with those of the outer layers previously obtained, are used to compute a synthetic bolometric light curve, which compares favourably with the light curve of SN 2011fe.

  13. Stellar laboratories. V. The Xe vi ultraviolet spectrum and the xenon abundance in the hot DO-type white dwarf RE 0503-289

    NASA Astrophysics Data System (ADS)

    Rauch, T.; Hoyer, D.; Quinet, P.; Gallardo, M.; Raineri, M.

    2015-05-01

    Context. For the spectral analysis of spectra of hot stars with a high resolution and high signal-to-noise ratio (S/N), advanced non-local thermodynamic equilibrium (NLTE) model atmospheres are mandatory. These are strongly dependent on the reliability of the atomic data that are used for their calculation. Aims: Reliable Xe vi oscillator strengths are used to identify Xe lines in the ultraviolet spectrum of the DO-type white dwarf RE 0503-289 and to determine its photospheric Xe abundance. Methods: We publish newly calculated oscillator strengths that are based on a recently measured Xe vi laboratory line spectrum. These strengths were used to consider their radiative and collisional bound-bound transitions in detail in our NLTE stellar-atmosphere models to analyze Xe vi lines exhibited in high-resolution and high S/N UV observations of RE 0503-289. Results: We identify three hitherto unknown Xe vi lines in the ultraviolet spectrum of RE 0503-289 and confirm the previously measured photospheric Xe abundance of this white dwarf (log Xe = -4.2 ± 0.6 by mass). Conclusions: Reliable measurements and calculations of atomic data are prerequisite for stellar-atmosphere modeling. Observed Xe vi line profiles in the ultraviolet spectrum of the white dwarf RE 0503-289 were well reproduced with the newly calculated Xe vi oscillator strengths. Based on observations made with the NASA-CNES-CSA Far Ultraviolet Spectroscopic Explorer.Based on observations with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26666.

  14. Mucosal-associated invariant T cell alterations in obese and type 2 diabetic patients

    PubMed Central

    Magalhaes, Isabelle; Pingris, Karine; Poitou, Christine; Bessoles, Stéphanie; Venteclef, Nicolas; Kiaf, Badr; Beaudoin, Lucie; Da Silva, Jennifer; Allatif, Omran; Rossjohn, Jamie; Kjer-Nielsen, Lars; McCluskey, James; Ledoux, Séverine; Genser, Laurent; Torcivia, Adriana; Soudais, Claire; Lantz, Olivier; Boitard, Christian; Aron-Wisnewsky, Judith; Larger, Etienne; Clément, Karine; Lehuen, Agnès

    2015-01-01

    Obesity and type 2 diabetes (T2D) are associated with low-grade inflammation, activation of immune cells, and alterations of the gut microbiota. Mucosal-associated invariant T (MAIT) cells, which are innate-like T cells that recognize bacterial ligands, are present in blood and enriched in mucosal and inflamed tissues. Here, we analyzed MAIT cells in the blood and adipose tissues of patients with T2D and/or severe obesity. We determined that circulating MAIT cell frequency was dramatically decreased in both patient groups, and this population was even undetectable in some obese patients. Moreover, in both patient groups, circulating MAIT cells displayed an activated phenotype that was associated with elevated Th1 and Th17 cytokine production. In obese patients, MAIT cells were more abundant in adipose tissue than in the blood and exhibited a striking IL-17 profile. Bariatric surgery in obese patients not only improved their metabolic parameters but also increased circulating MAIT cell frequency at 3 months after surgery. Similarly, cytokine production by blood MAIT cells was strongly decreased after surgery. This study reveals profound MAIT cell abnormalities in patients harboring metabolic disorders, suggesting their potential role in these pathologies. PMID:25751065

  15. Type I Interferons and Natural Killer Cell Regulation in Cancer

    PubMed Central

    Müller, Lena; Aigner, Petra; Stoiber, Dagmar

    2017-01-01

    Type I interferons (IFNs) are known to mediate antitumor effects against several tumor types and have therefore been commonly used in clinical anticancer treatment. However, how IFN signaling exerts its beneficial effects is only partially understood. The clinically relevant activity of type I IFNs has been mainly attributed to their role in tumor immune surveillance. Different mechanisms have been postulated to explain how type I IFNs stimulate the immune system. On the one hand, they modulate innate immune cell subsets such as natural killer (NK) cells. On the other hand, type I IFNs also influence adaptive immune responses. Here, we review evidence for the impact of type I IFNs on immune surveillance against cancer and highlight the role of NK cells therein.

  16. Overexpression of two cambium-abundant Chinese fir (Cunninghamia lanceolata) α-expansin genes ClEXPA1 and ClEXPA2 affect growth and development in transgenic tobacco and increase the amount of cellulose in stem cell walls.

    PubMed

    Wang, Guifeng; Gao, Yan; Wang, Jinjun; Yang, Liwei; Song, Rentao; Li, Xiaorong; Shi, Jisen

    2011-05-01

    Expansins are unique plant cell wall proteins that possess the ability to induce immediately cell wall extension in vitro and cell expansion in vivo. To investigate the biological functions of expansins that are abundant in wood-forming tissues, we cloned two expansin genes from the differentiating xylem of Chinese fir (Cunninghamia lanceolata (Lamb.) Hook). Phylogenetic reconstruction indicated that they belong to α-expansin (EXPA), named ClEXPA1 and ClEXPA2. Expression pattern analysis demonstrated that they are preferentially expressed in the cambium region. Overexpression of ClEXPA1 and ClEXPA2 in tobacco plants yielded pleiotropic phenotypes of plant height, stem diameter, leaf number and seed pod. The height and diameter growth of the 35S(pro) :ClEXPA1 and 35S(pro) :ClEXPA2 transgenic plants were increased drastically, exhibiting an enlargement of pith parenchyma cell size. Isolated cell walls of ClEXPA1 and ClEXPA2 overexpressors contained 30%-50% higher cellulose contents than the wild type, accompanied by a thickening of the cell walls in the xylem region. Both ClEXPA1 and ClEXPA2 are involved in plant growth and development, with a partially functional overlap. Expansins are not only able to induce cell expansion in different tissues/organs in vivo, but they also can act as a potential activator during secondary wall formation by directly or indirectly affecting cellulose metabolism, probably in a cell type-dependent manner.

  17. Star cell type core configuration for structural sandwich materials

    DOEpatents

    Christensen, R.M.

    1995-08-01

    A new pattern for cellular core material used in sandwich type structural materials is disclosed. The new pattern involves star shaped cells intermixed with hexagonal shaped cells. The new patterned cellular core material includes star shaped cells interconnected at points thereof and having hexagonal shape cells positioned adjacent the star points. The new pattern allows more flexibility and can conform more easily to curved shapes. 3 figs.

  18. C-type lectin receptor DCIR modulates immunity to tuberculosis by sustaining type I interferon signaling in dendritic cells

    PubMed Central

    Troegeler, Anthony; Mercier, Ingrid; Cougoule, Céline; Pietretti, Danilo; Colom, André; Duval, Carine; Vu Manh, Thien-Phong; Capilla, Florence; Poincloux, Renaud; Pingris, Karine; Nigou, Jérôme; Rademann, Jörg; Dalod, Marc; Verreck, Frank A. W.; Al Saati, Talal; Lugo-Villarino, Geanncarlo; Lepenies, Bernd; Hudrisier, Denis; Neyrolles, Olivier

    2017-01-01

    Immune response against pathogens is a tightly regulated process that must ensure microbial control while preserving integrity of the infected organs. Tuberculosis (TB) is a paramount example of a chronic infection in which antimicrobial immunity is protective in the vast majority of infected individuals but can become detrimental if not finely tuned. Here, we report that C-type lectin dendritic cell (DC) immunoreceptor (DCIR), a key component in DC homeostasis, is required to modulate lung inflammation and bacterial burden in TB. DCIR is abundantly expressed in pulmonary lesions in Mycobacterium tuberculosis-infected nonhuman primates during both latent and active disease. In mice, we found that DCIR deficiency impairs STAT1-mediated type I IFN signaling in DCs, leading to increased production of IL-12 and increased differentiation of T lymphocytes toward Th1 during infection. As a consequence, DCIR-deficient mice control M. tuberculosis better than WT animals but also develop more inflammation characterized by an increased production of TNF and inducible NOS (iNOS) in the lungs. Altogether, our results reveal a pathway by which a C-type lectin modulates the equilibrium between infection-driven inflammation and pathogen’s control through sustaining type I IFN signaling in DCs. PMID:28069953

  19. The Transcriptomes of Two Heritable Cell Types Illuminate the Circuit Governing Their Differentiation

    PubMed Central

    Homann, Oliver R.; Hernday, Aaron D.; Monighetti, Cinna K.; De La Vega, Francisco M.; Johnson, Alexander D.

    2010-01-01

    The differentiation of cells into distinct cell types, each of which is heritable for many generations, underlies many biological phenomena. White and opaque cells of the fungal pathogen Candida albicans are two such heritable cell types, each thought to be adapted to unique niches within their human host. To systematically investigate their differences, we performed strand-specific, massively-parallel sequencing of RNA from C. albicans white and opaque cells. With these data we first annotated the C. albicans transcriptome, finding hundreds of novel differentially-expressed transcripts. Using the new annotation, we compared differences in transcript abundance between the two cell types with the genomic regions bound by a master regulator of the white-opaque switch (Wor1). We found that the revised transcriptional landscape considerably alters our understanding of the circuit governing differentiation. In particular, we can now resolve the poor concordance between binding of a master regulator and the differential expression of adjacent genes, a discrepancy observed in several other studies of cell differentiation. More than one third of the Wor1-bound differentially-expressed transcripts were previously unannotated, which explains the formerly puzzling presence of Wor1 at these positions along the genome. Many of these newly identified Wor1-regulated genes are non-coding and transcribed antisense to coding transcripts. We also find that 5′ and 3′ UTRs of mRNAs in the circuit are unusually long and that 5′ UTRs often differ in length between cell-types, suggesting UTRs encode important regulatory information and that use of alternative promoters is widespread. Further analysis revealed that the revised Wor1 circuit bears several striking similarities to the Oct4 circuit that specifies the pluripotency of mammalian embryonic stem cells. Additional characteristics shared with the Oct4 circuit suggest a set of general hallmarks characteristic of heritable

  20. The transcriptomes of two heritable cell types illuminate the circuit governing their differentiation.

    PubMed

    Tuch, Brian B; Mitrovich, Quinn M; Homann, Oliver R; Hernday, Aaron D; Monighetti, Cinna K; De La Vega, Francisco M; Johnson, Alexander D

    2010-08-19

    The differentiation of cells into distinct cell types, each of which is heritable for many generations, underlies many biological phenomena. White and opaque cells of the fungal pathogen Candida albicans are two such heritable cell types, each thought to be adapted to unique niches within their human host. To systematically investigate their differences, we performed strand-specific, massively-parallel sequencing of RNA from C. albicans white and opaque cells. With these data we first annotated the C. albicans transcriptome, finding hundreds of novel differentially-expressed transcripts. Using the new annotation, we compared differences in transcript abundance between the two cell types with the genomic regions bound by a master regulator of the white-opaque switch (Wor1). We found that the revised transcriptional landscape considerably alters our understanding of the circuit governing differentiation. In particular, we can now resolve the poor concordance between binding of a master regulator and the differential expression of adjacent genes, a discrepancy observed in several other studies of cell differentiation. More than one third of the Wor1-bound differentially-expressed transcripts were previously unannotated, which explains the formerly puzzling presence of Wor1 at these positions along the genome. Many of these newly identified Wor1-regulated genes are non-coding and transcribed antisense to coding transcripts. We also find that 5' and 3' UTRs of mRNAs in the circuit are unusually long and that 5' UTRs often differ in length between cell-types, suggesting UTRs encode important regulatory information and that use of alternative promoters is widespread. Further analysis revealed that the revised Wor1 circuit bears several striking similarities to the Oct4 circuit that specifies the pluripotency of mammalian embryonic stem cells. Additional characteristics shared with the Oct4 circuit suggest a set of general hallmarks characteristic of heritable

  1. Barrier Epithelial Cells and the Control of Type 2 Immunity.

    PubMed

    Hammad, Hamida; Lambrecht, Bart N

    2015-07-21

    Type-2-cell-mediated immunity, rich in eosinophils, basophils, mast cells, CD4(+) T helper 2 (Th2) cells, and type 2 innate lymphoid cells (ILC2s), protects the host from helminth infection but also drives chronic allergic diseases like asthma and atopic dermatitis. Barrier epithelial cells (ECs) represent the very first line of defense and express pattern recognition receptors to recognize type-2-cell-mediated immune insults like proteolytic allergens or helminths. These ECs mount a prototypical response made up of chemokines, innate cytokines such as interleukin-1 (IL-1), IL-25, IL-33, and thymic stromal lymphopoietin (TSLP), as well as the alarmins uric acid, ATP, HMGB1, and S100 proteins. These signals program dendritic cells (DCs) to mount Th2-cell-mediated immunity and in so doing boost ILC2, basophil, and mast cell function. Here we review the general mechanisms of how different stimuli trigger type-2-cell-mediated immunity at mucosal barriers and how this leads to protection or disease.

  2. Generation of human-induced pluripotent stem cells to model spinocerebellar ataxia type 2 in vitro.

    PubMed

    Xia, Guangbin; Santostefano, Katherine; Hamazaki, Takashi; Liu, Jilin; Subramony, S H; Terada, Naohiro; Ashizawa, Tetsuo

    2013-10-01

    Spinocerebellar ataxia type 2 (SCA2) is caused by triple nucleotide repeat (CAG) expansion in the coding region of the ATAXN2 gene on chromosome 12, which produces an elongated, toxic polyglutamine tract, leading to Purkinje cell loss. There is currently no effective therapy. One of the main obstacles that hampers therapeutic development is lack of an ideal disease model. In this study, we have generated and characterized SCA2-induced pluripotent stem (iPS) cell lines as an in vitro cell model. Dermal fibroblasts (FBs) were harvested from primary cultures of skin explants obtained from a SCA2 subject and a healthy subject. For reprogramming, hOct4, hSox2, hKlf4, and hc-Myc were transduced to passage-3 FBs by retroviral infection. Both SCA2 iPS and control iPS cells were successfully generated and showed typical stem cell growth patterns with normal karyotype. All iPS cell lines expressed stem cell markers and differentiated in vitro into cells from three embryonic germ layers. Upon in vitro neural differentiation, SCA2 iPS cells showed abnormality in neural rosette formation but successfully differentiated into neural stem cells (NSCs) and subsequent neural cells. SCA2 and normal FBs showed a comparable level of ataxin-2 expression; whereas SCA2 NSCs showed less ataxin-2 expression than normal NSCs and SCA2 FBs. Within the neural lineage, neurons had the most abundant expression of ataxin-2. Time-lapsed neural growth assay indicated terminally differentiated SCA2 neural cells were short-lived compared with control neural cells. The expanded CAG repeats of SCA2 were stable throughout reprogramming and neural differentiation. In conclusion, we have established the first disease-specific human SCA2 iPS cell line. These mutant iPS cells have the potential for neural differentiation. These differentiated neural cells harboring mutations are invaluable for the study of SCA2 pathogenesis and therapeutic drug development.

  3. Human laryngeal ganglia contain both sympathetic and parasympathetic cell types.

    PubMed

    Ibanez, Marta; Valderrama-Canales, Francisco J; Maranillo, Eva; Vazquez, Teresa; Pascual-Font, Arán; McHanwell, Stephen; Sanudo, Jose

    2010-09-01

    The presence of ganglia associated with the laryngeal nerves is well documented. In man, these ganglia have been less well studied than in other species and, in particular, the cell types within these ganglia are less well characterized. Using a panel of antibodies to a variety of markers found in the paraganglion cells of other species, we were able to show the existence of at least two populations of cells within human laryngeal paraganglia. One population contained chromogranin and tyrosine hydroxylase representing a neurosecretory population possibly secreting dopamine. A second population of choline acetyltransferase positive cells would appear to have a putative parasympathetic function. Further work is needed to characterize these cell populations more fully before it will be possible to assign functions to these cell types but our results are consistent with the postulated functions of these ganglia as chemoreceptors, neurosecretory cells, and regulators of laryngeal mucus secretion.

  4. The Rho pathway mediates transition to an alveolar type I cell phenotype during static stretch of alveolar type II cells

    PubMed Central

    Foster, Cherie D; Varghese, Linda S; Gonzales, Linda W.; Margulies, Susan S.; Guttentag, Susan H.

    2011-01-01

    Stretch is an essential mechanism for lung growth and development. Animal models in which fetal lungs have been chronically over- or under-distended demonstrate a disrupted mix of type II and type I cells, with static overdistention typically promoting a type I cell phenotype. The Rho GTPase family, key regulators of cytoskeletal signaling, are known to mediate cellular differentiation in response to stretch in other organs. Using a well-described model of alveolar epithelial cell differentiation and a validated stretch device, we investigated the effects of supraphysiologic stretch on human fetal lung (HFL) alveolar epithelial cell phenotype. Static stretch applied to epithelial cells suppressed type II cell markers (SP-B and Pepsinogen C, PGC), and induced type I cell markers (Caveolin-1, Claudin 7 and Plasminogen Activator Inhibitor-1, PAI-1) as predicted. Static stretch was also associated with Rho A activation. Furthermore, the Rho kinase (ROCK) inhibitor Y27632 decreased Rho A activation, and blunted the stretch-induced changes in alveolar epithelial cell marker expression. Together these data provide further evidence that mechanical stimulation of the cytoskeleton and Rho activation are key upstream events in mechanotransduction-associated alveolar epithelial cell differentiation. PMID:20220547

  5. Partial characterization of cell-type X collagen interactions.

    PubMed Central

    Luckman, Steven P; Rees, Elaine; Kwan, Alvin P L

    2003-01-01

    Type X collagen is a short-chain non-fibrillar collagen that is deposited exclusively at sites of new bone formation. Although this collagen has been implicated in chondrocyte hypertrophy and endochondral ossification, its precise function remains unclear. One possible function could be to regulate the processes of chondrocyte hypertrophy through direct cell-type X collagen interactions. Adhesions of embryonic chick chondrocytes, and cell lines with known expression of collagen-binding integrins (MG63 and HOS), were assayed on chick type X collagen substrates, including the native, heat-denatured and pepsin-digested collagen, and the isolated C-terminal non-collagenous (NC1) domain. Type X collagen supported the greatest level of adhesion for all cell types tested. The involvement of the alpha2beta1 integrin in type X collagen-cell interaction was demonstrated by adhesion studies in the presence of Mg(2+) and Ca(2+) ions and integrin-function-blocking antibodies. Cells expressing alpha2beta1 integrin (chick chondrocytes and MG63 cells) also adhered to heat-denatured type X collagen and the isolated NC1 domain; however, removal of the non-collagenous domains by limited pepsinization of type X collagen resulted in very low levels of adhesion. Both focal contacts and actin stress-fibre formation were apparent in cells plated on type X collagen. The presence of alpha2 and beta1 integrin subunits in isolated chondrocytes and epiphyseal cartilage was also confirmed by immunolocalization. Our results demonstrate, for the first time, that type X collagen is capable of interacting directly with chondrocytes and other cells, primarily via alpha2beta1 integrin. These findings are atypical from the fibrillar collagen-cell interactions via collagen binding integrins in that: (1) the triple-helical conformation is not strictly required for cell adhesion; (2) the NC1 domain is also involved in the adhesion of alpha2beta1-expressing cells. These data form the basis for further

  6. Chitin recognition via chitotriosidase promotes pathologic type-2 helper T cell responses to cryptococcal infection.

    PubMed

    Wiesner, Darin L; Specht, Charles A; Lee, Chrono K; Smith, Kyle D; Mukaremera, Liliane; Lee, S Thera; Lee, Chun G; Elias, Jack A; Nielsen, Judith N; Boulware, David R; Bohjanen, Paul R; Jenkins, Marc K; Levitz, Stuart M; Nielsen, Kirsten

    2015-03-01

    Pulmonary mycoses are often associated with type-2 helper T (Th2) cell responses. However, mechanisms of Th2 cell accumulation are multifactorial and incompletely known. To investigate Th2 cell responses to pulmonary fungal infection, we developed a peptide-MHCII tetramer to track antigen-specific CD4+ T cells produced in response to infection with the fungal pathogen Cryptococcus neoformans. We noted massive accruement of pathologic cryptococcal antigen-specific Th2 cells in the lungs following infection that was coordinated by lung-resident CD11b+ IRF4-dependent conventional dendritic cells. Other researchers have demonstrated that this dendritic cell subset is also capable of priming protective Th17 cell responses to another pulmonary fungal infection, Aspergillus fumigatus. Thus, higher order detection of specific features of fungal infection by these dendritic cells must direct Th2 cell lineage commitment. Since chitin-containing parasites commonly elicit Th2 responses, we hypothesized that recognition of fungal chitin is an important determinant of Th2 cell-mediated mycosis. Using C. neoformans mutants or purified chitin, we found that chitin abundance impacted Th2 cell accumulation and disease. Importantly, we determined Th2 cell induction depended on cleavage of chitin via the mammalian chitinase, chitotriosidase, an enzyme that was also prevalent in humans experiencing overt cryptococcosis. The data presented herein offers a new perspective on fungal disease susceptibility, whereby chitin recognition via chitotriosidase leads to the initiation of harmful Th2 cell differentiation by CD11b+ conventional dendritic cells in response to pulmonary fungal infection.

  7. FACS purification of immunolabeled cell types from adult rat brain.

    PubMed

    Guez-Barber, Danielle; Fanous, Sanya; Harvey, Brandon K; Zhang, Yongqing; Lehrmann, Elin; Becker, Kevin G; Picciotto, Marina R; Hope, Bruce T

    2012-01-15

    Molecular analysis of brain tissue is greatly complicated by having many different classes of neurons and glia interspersed throughout the brain. Fluorescence-activated cell sorting (FACS) has been used to purify selected cell types from brain tissue. However, its use has been limited to brain tissue from embryos or transgenic mice with promoter-driven reporter genes. To overcome these limitations, we developed a FACS procedure for dissociating intact cell bodies from adult wild-type rat brains and sorting them using commercially available antibodies against intracellular and extracellular proteins. As an example, we isolated neurons using a NeuN antibody and confirmed their identity using microarray and real time PCR of mRNA from the sorted cells. Our FACS procedure allows rapid, high-throughput, quantitative assays of molecular alterations in identified cell types with widespread applications in neuroscience.

  8. Application of FLIM-FIDSAM for the in vivo analysis of hormone competence of different cell types.

    PubMed

    Elgass, Kirstin; Caesar, Katharina; Wanke, Dierk; Harter, Klaus; Meixner, Alfred J; Schleifenbaum, Frank

    2010-11-01

    Background fluorescence derived from subcellular compartments is a major drawback in high-resolution live imaging, especially of plant cells. A novel technique for contrast enhancement of fluorescence images of living cells expressing fluorescent fusion proteins termed fluorescence intensity decay shape analysis microscopy (FIDSAM) has been recently published and is applied here to plant cells expressing wild-type levels of a low-abundant membrane protein (BRI1-EGFP), demonstrating the applicability of FIDSAM to samples exhibiting about 80% autofluorescence. Furthermore, the combination of FIDSAM and fluorescence lifetime imaging microscopy enables the simultaneous determination and quantification of different ligand-specific responses in living cells with high spatial and temporal resolution even in samples with high autofluorescence background. Correlation of different responses can be used to determine the hormone ligand competence of different cell types as demonstrated here in BRI1-EGFP-expressing root and hypocotyl cells.

  9. Murine Coronavirus Cell Type Dependent Interaction with the Type I Interferon Response

    PubMed Central

    Rose, Kristine M.; Weiss, Susan R.

    2009-01-01

    Coronaviruses infect many species of animal including humans, causing acute and chronic diseases of many organ systems. Murine coronavirus, mouse hepatitis virus (MHV) infection of the mouse, provides animal models for the study of central nervous system disease, including encephalitis and demyelinating diseases such as Multiple Sclerosis and for hepatitis. While there are many studies of the adaptive immune response to MHV, there has until recently been scant information on the type I interferon (IFN) response to MHV. The relationship between MHV and the IFN-α/β response is paradoxical. While the type I IFN response is a crucial aspect of host defense against MHV in its natural host, there is little if any induction of IFN following infection of mouse fibroblast cell lines in vitro. Furthermore, MHV is relatively resistant to the antiviral effects of IFN-α/β in mouse fibroblast cell lines and in human 293T cells. MHV can, under some circumstances, compromise the antiviral effects of IFN signaling. The nucleocapsid protein as well as the nsp1 and nsp3 proteins of MHV has been reported to have IFN antagonist activity. However, in primary cell types such as plasmacytoid dendritic cells (pDC) and macrophages, IFN is induced by MHV infection and an antiviral state is established. Other primary cell types such as neurons, astrocytes and hepatocytes fail to produce IFN following infection and, in vivo, likely depend on IFN produced by pDCs and macrophages for protection from MHV. Thus MHV induction of IFN-α/β and the ability to induce an antiviral state in response to interferon is extremely cell type dependent. IFN induced protection from MHV pathogenesis likely requires the orchestrated activities of several cell types, however, the cell types involved in limiting MHV replication may be different in the liver and in the immune privileged CNS. PMID:20221421

  10. A secretory cell type develops alongside multiciliated cells, ionocytes and goblet cells, and provides a protective, anti-infective function in the frog embryonic mucociliary epidermis

    PubMed Central

    Dubaissi, Eamon; Rousseau, Karine; Lea, Robert; Soto, Ximena; Nardeosingh, Siddarth; Schweickert, Axel; Amaya, Enrique; Thornton, David J.; Papalopulu, Nancy

    2014-01-01

    The larval epidermis of Xenopus is a bilayered epithelium, which is an excellent model system for the study of the development and function of mucosal and mucociliary epithelia. Goblet cells develop in the outer layer while multiciliated cells and ionocytes sequentially intercalate from the inner to the outer layer. Here, we identify and characterise a fourth cell type, the small secretory cell (SSC). We show that the development of these cells is controlled by the transcription factor Foxa1 and that they intercalate into the outer layer of the epidermis relatively late, at the same time as embryonic hatching. Ultrastructural and molecular characterisation shows that these cells have an abundance of large apical secretory vesicles, which contain highly glycosylated material, positive for binding of the lectin, peanut agglutinin, and an antibody to the carbohydrate epitope, HNK-1. By specifically depleting SSCs, we show that these cells are crucial for protecting the embryo against bacterial infection. Mass spectrometry studies show that SSCs secrete a glycoprotein similar to Otogelin, which may form the structural component of a mucus-like protective layer, over the surface of the embryo, and several potential antimicrobial substances. Our study completes the characterisation of all the epidermal cell types in the early tadpole epidermis and reinforces the suitability of this system for the in vivo study of complex epithelia, including investigation of innate immune defences. PMID:24598166

  11. Thermoelectrics with earth abundant elements: high performance p-type PbS nanostructured with SrS and CaS.

    PubMed

    Zhao, Li-Dong; He, Jiaqing; Wu, Chun-I; Hogan, Timothy P; Zhou, Xiaoyuan; Uher, Ctirad; Dravid, Vinayak P; Kanatzidis, Mercouri G

    2012-05-09

    We report high thermoelectric performance in nanostructured p-type PbS, a material consisting of highly earth abundant and inexpensive elements. The high level of Na doping switched intrinsic n-type PbS to p-type and substantially raised the power factor maximum for pure PbS to ~9.0 μW cm(-1) K(-2) at >723 K using 2.5 at. % Na as the hole dopant. Contrary to that of PbTe, no enhancement in the Hall coefficient occurs at high temperature for heavily doped p-type PbS, indicating a single band model and no heavy hole band. We also report that the lattice thermal conductivity of PbS can be greatly reduced by adding SrS or CaS, which form a combination of a nanostructured/solid solution material as determined by transmission electron microscopy. We find that both nanoscale precipitates and point defects play an important role in reducing the lattice thermal conductivity, but the contribution from nanoscale precipitates of SrS is greater than that of CaS, whereas the contribution from point defects in the case of CaS is greater than that of SrS. Theoretical calculations of the lattice thermal conductivity based on the modified Callaway model reveal that both nanostructures and point defects (solid solution) effectively scatter phonons in this system. The lattice thermal conductivity at 723 K can be reduced by ~50% by introducing up to 4.0 at. % of either SrS or CaS. As a consequence, ZT values as high as 1.22 and 1.12 at 923 K can be achieved for nominal Pb(0.975)Na(0.025)S with 3.0 at. % SrS and CaS, respectively. No deterioration was observed after a 15 d annealing treatment of the samples, indicating the excellent thermal stability for these high performance thermoelectrics. The promising thermoelectric properties of nanostructured PbS point to a robust low cost alternative to other high performance thermoelectric materials.

  12. MANF silencing, immunity induction or autophagy trigger an unusual cell type in metamorphosing Drosophila brain.

    PubMed

    Stratoulias, Vassilis; Heino, Tapio I

    2015-05-01

    Glia are abundant cells in the brain of animals ranging from flies to humans. They perform conserved functions not only in neural development and wiring, but also in brain homeostasis. Here we show that by manipulating gene expression in glia, a previously unidentified cell type appears in the Drosophila brain during metamorphosis. More specifically, this cell type appears in three contexts: (1) after the induction of either immunity, or (2) autophagy, or (3) by silencing of neurotrophic factor DmMANF in glial cells. We call these cells MANF immunoreactive Cells (MiCs). MiCs are migratory based on their shape, appearance in brain areas where no cell bodies exist and the nuclear localization of dSTAT. They are labeled with a unique set of molecular markers including the conserved neurotrophic factor DmMANF and the transcription factor Zfh1. They possess the nuclearly localized protein Relish, which is the hallmark of immune response activation. They also express the conserved engulfment receptor Draper, therefore indicating that they are potentially phagocytic. Surprisingly, they do not express any of the common glial and neuronal markers. In addition, ultrastructural studies show that MiCs are extremely rich in lysosomes. Our findings reveal critical molecular and functional components of an unusual cell type in the Drosophila brain. We suggest that MiCs resemble macrophages/hemocytes and vertebrate microglia based on their appearance in the brain upon genetically challenged conditions and the expression of molecular markers. Interestingly, macrophages/hemocytes or microglia-like cells have not been reported in the fly nervous system before.

  13. Optimization of low cost, non toxic, earth abundant p-type Cu2SnS3 thin film for Photovoltaic application

    NASA Astrophysics Data System (ADS)

    Chaudhari, J. J.; Patel, S.; Joshi, U. S.

    2016-09-01

    Cu2SnS3 (CTS) is one of promising candidate as an absorber material for thin film solar cell. Because of relatively higher prize of Indium and hazardous environmental impact of processing of Gallium, CTS is suitable alternative candidate to Cu2SnS3 (CIGS) based solar cell as its constituent elements such as copper, tin and sulphur are abundantly available in earth's crust. CTS is ternary semiconductor and its energy band gap is 1.5eV, which is perfectly matched with solar energy spectrum for maximum transfer of solar energy into electrical energy through photovoltaic action. The primary methods for the synthesis of CTS are Thermal evaporation, electrochemical, sputtering and wet chemical methods. Here in this paper we have optimized a low cost non-vacuum solution process method for the synthesis of CTS without any external sulfurization. The X-ray diffraction studies showed the formation of phase with the peaks corresponding to (112), (220) and (312) planes. Chemical Solution Deposition (CSD) for the synthesis of CTS is suitable for large area deposition and it includes several routes like solvothermal methods, direct liquid coating and nano ink based technique. The metal Chloride salts and thiourea is used as a source of sulphur to synthesize CTS solution and homogeneous thin films of CTS deposited on glass substrate using spin coating method. Use of abrasive solvent like hydrazine and hydrogen sulphide gas which are used to synthesize CTS thin film have detrimental effect on environment, we report eco friendly solvent based approach to synthesize CTS at low temperature 200 °C.

  14. Cell Based Therapeutics in Type 1 Diabetes Mellitus.

    PubMed

    Zamboni, Fernanda; Collins, Maurice N

    2017-02-24

    This review focuses on Type 1 diabetes mellitus (T1DM) and the role of bioengineering, nanotechnology and cell therapy in its treatment. T1DM is discussed in terms of its prevalence as well as the role of the extra cellular matrix (ECM) of the pancreas in its development and mode of action. Surface engineering strategies and the chemistries behind important cell encapsulation techniques, which are emerging from recent research in immunosuppression, are described. Key enabling technologies such as therapeutic agent immobilisation on cells, oxygen releasing systems, gene delivery and bio imaging are assessed with respect to T1DM. These latest cell surface technologies provide unlimited possibilities for control of cell/cell and cell/ECM interactions, allowing the ability to confer "immune camouflage". Finally, we provide an outlook to the future of cell-based technologies for T1DM treatment and their likely deployment in clinical trials.

  15. Mast Cells in Lung Homeostasis: Beyond Type I Hypersensitivity.

    PubMed

    Campillo-Navarro, Marcia; Chávez-Blanco, Alma D; Wong-Baeza, Isabel; Serafín-López, Jeanet; Flores-Mejía, Raúl; Estrada-Parra, Sergio; Estrada-García, Iris; Chacón-Salinas, Rommel

    2014-06-01

    Lungs are indispensable organs for the respiratory process, and maintaining their homeostasis is essential for human health and survival. However, during the lifetime of an individual, the lungs suffer countless insults that put at risk their delicate organization and function. Many cells of the immune system participate to maintain this equilibrium and to keep functional lungs. Among these cells, mast cells have recently attracted attention because of their ability to rapidly secrete many chemical and biological mediators that modulate different processes like inflammation, angiogenesis, cell proliferation, etc. In this review, we focus on recent advances in the understanding of the role that mast cells play in lung protection during infections, and of the relation of mast cell responses to type I hypersensitivity-associated pathologies. Furthermore, we discuss the potential role of mast cells during wound healing in the lung and its association with lung cancer, and how mast cells could be exploited as therapeutic targets in some diseases.

  16. [Functional properties of taste bud cells. Mechanisms of afferent neurotransmission in Type II taste receptor cells].

    PubMed

    Romanov, R A

    2013-01-01

    Taste Bud cells are heterogeneous in their morphology and functionality. These cells are responsible for sensing a wide variety of substances and for associating detected compounds with a different taste: bitter, sweet, salty, sour and umami. Today we know that each of the five basic tastes corresponds to distinct cell populations organized into three basic morpho-functional cell types. In addition, some receptor cells of the taste bud demonstrate glia-related functions. In this article we expand on some properties of these three morphological receptor cell types. Main focus is devoted to the Type II cells and unusual mechanism for afferent neurotransmission in these cells. Taste cells of the Type II consist of three populations detecting bitter, sweet and umami tastes, and, thus, evoke a serious scientific interest.

  17. Development of low-cost technology for the next generation of high efficiency solar cells composed of earth abundant elements

    SciTech Connect

    Agrawal, Rakesh

    2014-09-28

    The development of renewable, affordable, and environmentally conscious means of generating energy on a global scale represents a grand challenge of our time. Due to the “permanence” of radiation from the sun, solar energy promises to remain a viable and sustainable power source far into the future. Established single-junction photovoltaic technologies achieve high power conversion efficiencies (pce) near 20% but require complicated manufacturing processes that prohibit the marriage of large-scale throughput (e.g. on the GW scale), profitability, and quality control. Our approach to this problem begins with the synthesis of nanocrystals of semiconductor materials comprising earth abundant elements and characterized by material and optoelectronic properties ideal for photovoltaic applications, namely Cu2ZnSn(S,Se)4 (CZTSSe). Once synthesized, such nanocrystals are formulated into an ink, coated onto substrates, and processed into completed solar cells in such a way that enables scale-up to high throughput, roll-to-roll manufacturing processes. This project aimed to address the major limitation to CZTSSe solar cell pce’s – the low open-circuit voltage (Voc) reported throughout literature for devices comprised of this material. Throughout the project significant advancements have been made in fundamental understanding of the CZTSSe material and device limitations associated with this material system. Additionally, notable improvements have been made to our nanocrystal based processing technique to alleviate performance limitations due to the identified device limitations. Notably, (1) significant improvements have been made in reducing intra- and inter-nanoparticle heterogeneity, (2) improvements in device performance have been realized with novel cation substitution in Ge-alloyed CZTGeSSe absorbers, (3) systematic analysis of absorber sintering has been conducted to optimize the selenization process for large grain CZTSSe absorbers, (4) novel electrical

  18. Extensive determination of glycan heterogeneity reveals an unusual abundance of high mannose glycans in enriched plasma membranes of human embryonic stem cells.

    PubMed

    An, Hyun Joo; Gip, Phung; Kim, Jaehan; Wu, Shuai; Park, Kun Wook; McVaugh, Cheryl T; Schaffer, David V; Bertozzi, Carolyn R; Lebrilla, Carlito B

    2012-04-01

    Most cell membrane proteins are known or predicted to be glycosylated in eukaryotic organisms, where surface glycans are essential in many biological processes including cell development and differentiation. Nonetheless, the glycosylation on cell membranes remains not well characterized because of the lack of sensitive analytical methods. This study introduces a technique for the rapid profiling and quantitation of N- and O-glycans on cell membranes using membrane enrichment and nanoflow liquid chromatography/mass spectrometry of native structures. Using this new method, the glycome analysis of cell membranes isolated from human embryonic stem cells and somatic cell lines was performed. Human embryonic stem cells were found to have high levels of high mannose glycans, which contrasts with IMR-90 fibroblasts and a human normal breast cell line, where complex glycans are by far the most abundant and high mannose glycans are minor components. O-Glycosylation affects relatively minor components of cell surfaces. To verify the quantitation and localization of glycans on the human embryonic stem cell membranes, flow cytometry and immunocytochemistry were performed. Proteomics analyses were also performed and confirmed enrichment of plasma membrane proteins with some contamination from endoplasmic reticulum and other membranes. These findings suggest that high mannose glycans are the major component of cell surface glycosylation with even terminal glucoses. High mannose glycans are not commonly presented on the surfaces of mammalian cells or in serum yet may play important roles in stem cell biology. The results also mean that distinguishing stem cells from other mammalian cells may be facilitated by the major difference in the glycosylation of the cell membrane. The deep structural analysis enabled by this new method will enable future mechanistic studies on the biological significance of high mannose glycans on stem cell membranes and provide a general tool to examine

  19. Generation of diverse neural cell types through direct conversion

    PubMed Central

    Petersen, Gayle F; Strappe, Padraig M

    2016-01-01

    A characteristic of neurological disorders is the loss of critical populations of cells that the body is unable to replace, thus there has been much interest in identifying methods of generating clinically relevant numbers of cells to replace those that have been damaged or lost. The process of neural direct conversion, in which cells of one lineage are converted into cells of a neural lineage without first inducing pluripotency, shows great potential, with evidence of the generation of a range of functional neural cell types both in vitro and in vivo, through viral and non-viral delivery of exogenous factors, as well as chemical induction methods. Induced neural cells have been proposed as an attractive alternative to neural cells derived from embryonic or induced pluripotent stem cells, with prospective roles in the investigation of neurological disorders, including neurodegenerative disease modelling, drug screening, and cellular replacement for regenerative medicine applications, however further investigations into improving the efficacy and safety of these methods need to be performed before neural direct conversion becomes a clinically viable option. In this review, we describe the generation of diverse neural cell types via direct conversion of somatic cells, with comparison against stem cell-based approaches, as well as discussion of their potential research and clinical applications. PMID:26981169

  20. Monomeric, porous type II collagen scaffolds promote chondrogenic differentiation of human bone marrow mesenchymal stem cells in vitro

    NASA Astrophysics Data System (ADS)

    Tamaddon, M.; Burrows, M.; Ferreira, S. A.; Dazzi, F.; Apperley, J. F.; Bradshaw, A.; Brand, D. D.; Czernuszka, J.; Gentleman, E.

    2017-03-01

    Osteoarthritis (OA) is a common cause of pain and disability and is often associated with the degeneration of articular cartilage. Lesions to the articular surface, which are thought to progress to OA, have the potential to be repaired using tissue engineering strategies; however, it remains challenging to instruct cell differentiation within a scaffold to produce tissue with appropriate structural, chemical and mechanical properties. We aimed to address this by driving progenitor cells to adopt a chondrogenic phenotype through the tailoring of scaffold composition and physical properties. Monomeric type-I and type-II collagen scaffolds, which avoid potential immunogenicity associated with fibrillar collagens, were fabricated with and without chondroitin sulfate (CS) and their ability to stimulate the chondrogenic differentiation of human bone marrow-derived mesenchymal stem cells was assessed. Immunohistochemical analyses showed that cells produced abundant collagen type-II on type-II scaffolds and collagen type-I on type-I scaffolds. Gene expression analyses indicated that the addition of CS – which was released from scaffolds quickly – significantly upregulated expression of type II collagen, compared to type-I and pure type-II scaffolds. We conclude that collagen type-II and CS can be used to promote a more chondrogenic phenotype in the absence of growth factors, potentially providing an eventual therapy to prevent OA.

  1. Monomeric, porous type II collagen scaffolds promote chondrogenic differentiation of human bone marrow mesenchymal stem cells in vitro

    PubMed Central

    Tamaddon, M.; Burrows, M.; Ferreira, S. A.; Dazzi, F.; Apperley, J. F.; Bradshaw, A.; Brand, D. D.; Czernuszka, J.; Gentleman, E.

    2017-01-01

    Osteoarthritis (OA) is a common cause of pain and disability and is often associated with the degeneration of articular cartilage. Lesions to the articular surface, which are thought to progress to OA, have the potential to be repaired using tissue engineering strategies; however, it remains challenging to instruct cell differentiation within a scaffold to produce tissue with appropriate structural, chemical and mechanical properties. We aimed to address this by driving progenitor cells to adopt a chondrogenic phenotype through the tailoring of scaffold composition and physical properties. Monomeric type-I and type-II collagen scaffolds, which avoid potential immunogenicity associated with fibrillar collagens, were fabricated with and without chondroitin sulfate (CS) and their ability to stimulate the chondrogenic differentiation of human bone marrow-derived mesenchymal stem cells was assessed. Immunohistochemical analyses showed that cells produced abundant collagen type-II on type-II scaffolds and collagen type-I on type-I scaffolds. Gene expression analyses indicated that the addition of CS – which was released from scaffolds quickly – significantly upregulated expression of type II collagen, compared to type-I and pure type-II scaffolds. We conclude that collagen type-II and CS can be used to promote a more chondrogenic phenotype in the absence of growth factors, potentially providing an eventual therapy to prevent OA. PMID:28256634

  2. Dietary Yeast Cell Wall Extract Alters the Proteome of the Skin Mucous Barrier in Atlantic Salmon (Salmo salar): Increased Abundance and Expression of a Calreticulin-Like Protein.

    PubMed

    Micallef, Giulia; Cash, Phillip; Fernandes, Jorge M O; Rajan, Binoy; Tinsley, John W; Bickerdike, Ralph; Martin, Samuel A M; Bowman, Alan S

    2017-01-01

    In order to improve fish health and reduce use of chemotherapeutants in aquaculture production, the immunomodulatory effect of various nutritional ingredients has been explored. In salmon, there is evidence that functional feeds can reduce the abundance of sea lice. This study aimed to determine if there were consistent changes in the skin mucus proteome that could serve as a biomarker for dietary yeast cell wall extract. The effect of dietary yeast cell wall extract on the skin mucus proteome of Atlantic salmon was examined using two-dimensional gel electrophoresis. Forty-nine spots showed a statistically significant change in their normalised volumes between the control and yeast cell wall diets. Thirteen spots were successfully identified by peptide fragment fingerprinting and LC-MS/MS and these belonged to a variety of functions and pathways. To assess the validity of the results from the proteome approach, the gene expression of a selection of these proteins was studied in skin mRNA from two different independent feeding trials using yeast cell wall extracts. A calreticulin-like protein increased in abundance at both the protein and transcript level in response to dietary yeast cell wall extract. The calreticulin-like protein was identified as a possible biomarker for yeast-derived functional feeds since it showed the most consistent change in expression in both the mucus proteome and skin transcriptome. The discovery of such a biomarker is expected to quicken the pace of research in the application of yeast cell wall extracts.

  3. Dietary Yeast Cell Wall Extract Alters the Proteome of the Skin Mucous Barrier in Atlantic Salmon (Salmo salar): Increased Abundance and Expression of a Calreticulin-Like Protein

    PubMed Central

    Micallef, Giulia; Cash, Phillip; Fernandes, Jorge M. O.; Rajan, Binoy; Tinsley, John W.; Bickerdike, Ralph

    2017-01-01

    In order to improve fish health and reduce use of chemotherapeutants in aquaculture production, the immunomodulatory effect of various nutritional ingredients has been explored. In salmon, there is evidence that functional feeds can reduce the abundance of sea lice. This study aimed to determine if there were consistent changes in the skin mucus proteome that could serve as a biomarker for dietary yeast cell wall extract. The effect of dietary yeast cell wall extract on the skin mucus proteome of Atlantic salmon was examined using two-dimensional gel electrophoresis. Forty-nine spots showed a statistically significant change in their normalised volumes between the control and yeast cell wall diets. Thirteen spots were successfully identified by peptide fragment fingerprinting and LC-MS/MS and these belonged to a variety of functions and pathways. To assess the validity of the results from the proteome approach, the gene expression of a selection of these proteins was studied in skin mRNA from two different independent feeding trials using yeast cell wall extracts. A calreticulin-like protein increased in abundance at both the protein and transcript level in response to dietary yeast cell wall extract. The calreticulin-like protein was identified as a possible biomarker for yeast-derived functional feeds since it showed the most consistent change in expression in both the mucus proteome and skin transcriptome. The discovery of such a biomarker is expected to quicken the pace of research in the application of yeast cell wall extracts. PMID:28046109

  4. Infection of nonlymphoid cells by human immunodeficiency virus type 1 or type 2.

    PubMed Central

    Ikeuchi, K; Kim, S; Byrn, R A; Goldring, S R; Groopman, J E

    1990-01-01

    Human epithelial cells (L132) derived from embryonic lung and human lung fibroblasts (MRC5) were infected by human immunodeficiency virus type 1 (HIV-1) or type 2 (HIV-2). Surface CD4 protein was detected on these cells, and recombinant soluble CD4 (sCD4) blocked infection, indicating that HIV infection was mediated by the cell surface CD4 protein. In contrast, infection of human primary chondrocyte cells (C23), synovial cells (HSA), and foreskin fibroblasts (F13) was apparently independent of cell CD4-mediated mechanisms. Surface CD4 protein could not be detected on these cells, and sCD4 did not block the infection. F13 cells could be infected only by HIV-2, not by HIV-1, under our experimental conditions. In cells of mesenchymal orgin, viral production could be detected only after cocultivation with the human T-lymphoid H9 cells but not by conventional viral assays, including reverse transcriptase and p24 antigen assays in cell culture supernatant and immunofluorescence of host cells. Our DNA transfection studies indicated that this lack of detectable viral production was not due to the inefficient use of the HIV long terminal repeat or the Tat protein in these cells. These mesenchymal and epithelial cells were susceptible to HIV infection but differed in mechanism of virus entry compared with hematopoietic cells such as T lymphocytes. These observations may provide insights into clinical syndromes such as lung dysfunction in HIV-infected newborns and connective tissue disorders in HIV-infected adults. Images PMID:2384919

  5. The development and plasticity of alveolar type 1 cells

    PubMed Central

    Yang, Jun; Hernandez, Belinda J.; Martinez Alanis, Denise; Narvaez del Pilar, Odemaris; Vila-Ellis, Lisandra; Akiyama, Haruhiko; Evans, Scott E.; Ostrin, Edwin J.; Chen, Jichao

    2016-01-01

    Alveolar type 1 (AT1) cells cover >95% of the gas exchange surface and are extremely thin to facilitate passive gas diffusion. The development of these highly specialized cells and its coordination with the formation of the honeycomb-like alveolar structure are poorly understood. Using new marker-based stereology and single-cell imaging methods, we show that AT1 cells in the mouse lung form expansive thin cellular extensions via a non-proliferative two-step process while retaining cellular plasticity. In the flattening step, AT1 cells undergo molecular specification and remodel cell junctions while remaining connected to their epithelial neighbors. In the folding step, AT1 cells increase in size by more than 10-fold and undergo cellular morphogenesis that matches capillary and secondary septa formation, resulting in a single AT1 cell spanning multiple alveoli. Furthermore, AT1 cells are an unexpected source of VEGFA and their normal development is required for alveolar angiogenesis. Notably, a majority of AT1 cells proliferate upon ectopic SOX2 expression and undergo stage-dependent cell fate reprogramming. These results provide evidence that AT1 cells have both structural and signaling roles in alveolar maturation and can exit their terminally differentiated non-proliferative state. Our findings suggest that AT1 cells might be a new target in the pathogenesis and treatment of lung diseases associated with premature birth. PMID:26586225

  6. Cell wall polysaccharides from fern leaves: evidence for a mannan-rich Type III cell wall in Adiantum raddianum.

    PubMed

    Silva, Giovanna B; Ionashiro, Mari; Carrara, Thalita B; Crivellari, Augusto C; Tiné, Marco A S; Prado, Jefferson; Carpita, Nicholas C; Buckeridge, Marcos S

    2011-12-01

    Primary cell walls from plants are composites of cellulose tethered by cross-linking glycans and embedded in a matrix of pectins. Cell wall composition varies between plant species, reflecting in some instances the evolutionary distance between them. In this work the monosaccharide compositions of isolated primary cell walls of nine fern species and one lycophyte were characterized and compared with those from Equisetum and an angiosperm dicot. The relatively high abundance of mannose in these plants suggests that mannans may constitute the major cross-linking glycan in the primary walls of pteridophytes and lycophytes. Pectin-related polysaccharides contained mostly rhamnose and uronic acids, indicating the presence of rhamnogalacturonan I highly substituted with galactose and arabinose. Structural and fine-structural analyses of the hemicellulose fraction of leaves of Adiantum raddianum confirmed this hypothesis. Linkage analysis showed that the mannan contains mostly 4-Man with very little 4,6-Man, indicating a low percentage of branching with galactose. Treatment of the mannan-rich fractions with endo-β-mannanase produced characteristic mannan oligosaccharides. Minor amounts of xyloglucan and xylans were also detected. These data and those of others suggest that all vascular plants contain xyloglucans, arabinoxylans, and (gluco)mannans, but in different proportions that define cell wall types. Whereas xyloglucan and pectin-rich walls define Type I walls of dicots and many monocots, arabinoxylans and lower proportion of pectin define the Type II walls of commelinoid monocots. The mannan-rich primary walls with low pectins of many ferns and a lycopod indicate a fundamentally different wall type among land plants, the Type III wall.

  7. Microbial abundance in surface ice on the Greenland Ice Sheet

    PubMed Central

    Stibal, Marek; Gözdereliler, Erkin; Cameron, Karen A.; Box, Jason E.; Stevens, Ian T.; Gokul, Jarishma K.; Schostag, Morten; Zarsky, Jakub D.; Edwards, Arwyn; Irvine-Fynn, Tristram D. L.; Jacobsen, Carsten S.

    2015-01-01

    Measuring microbial abundance in glacier ice and identifying its controls is essential for a better understanding and quantification of biogeochemical processes in glacial ecosystems. However, cell enumeration of glacier ice samples is challenging due to typically low cell numbers and the presence of interfering mineral particles. We quantified for the first time the abundance of microbial cells in surface ice from geographically distinct sites on the Greenland Ice Sheet (GrIS), using three enumeration methods: epifluorescence microscopy (EFM), flow cytometry (FCM), and quantitative polymerase chain reaction (qPCR). In addition, we reviewed published data on microbial abundance in glacier ice and tested the three methods on artificial ice samples of realistic cell (102–107 cells ml−1) and mineral particle (0.1–100 mg ml−1) concentrations, simulating a range of glacial ice types, from clean subsurface ice to surface ice to sediment-laden basal ice. We then used multivariate statistical analysis to identify factors responsible for the variation in microbial abundance on the ice sheet. EFM gave the most accurate and reproducible results of the tested methodologies, and was therefore selected as the most suitable technique for cell enumeration of ice containing dust. Cell numbers in surface ice samples, determined by EFM, ranged from ~ 2 × 103 to ~ 2 × 106 cells ml−1 while dust concentrations ranged from 0.01 to 2 mg ml−1. The lowest abundances were found in ice sampled from the accumulation area of the ice sheet and in samples affected by fresh snow; these samples may be considered as a reference point of the cell abundance of precipitants that are deposited on the ice sheet surface. Dust content was the most significant variable to explain the variation in the abundance data, which suggests a direct association between deposited dust particles and cells and/or by their provision of limited nutrients to microbial communities on the GrIS. PMID:25852678

  8. Regulation of adeno-associated virus gene expression in 293 cells: control of mRNA abundance and translation

    SciTech Connect

    Trempe, J.P.; Carter, B.J.

    1988-01-01

    The authors studied the effects of the adeno-associated virus (AAV) rep gene on the control of gene expression from the AAV p/sub 40/ promoter in 293 cells in the absence of an adenovirus coinfection. AAV vectors containing the chloramphenicol acetyltransferase (cat) gene were used to measure the levels of cat expression and steady-state mRNA from p/sub 40/. When the rep gene was present in cis or in trans, cat expression from p/sub 40/ was decreased 3- to 10-fold, but there was a 2- to 10-fold increase in the level of p/sub 40/ mRNA. Conversely, cat expression increased and the p/sub 40/ mRNA level decreased in the absence of the rep gene. Both wild-type and carboxyl-terminal truncated Rep proteins were capable of eliciting both effects. These data suggest two roles for the pleiotropic AAV rep gene: as a translational inhibitor and as a positive regulator of p/sub 40/ mRNA levels. They also provide additional evidence for a cis-acting negative regulatory region which decreases RNA from the AAV p/sub 5/ promoter in a fashion independent of rep.

  9. Cardiac stem cell therapy: Have we put too much hype in which cell type to use?

    PubMed

    Ye, Jianqin; Yeghiazarians, Yerem

    2015-09-01

    Injection of various stem cells has been tested with the hopes of improving cardiac function after a myocardial infarction (MI). However, there is continued controversy as to which cell type is best for repair. Due to technical differences in cell isolation, processing, delivery, and cardiac functional assessment by various investigators, it has been difficult to directly compare the results of different cells. Using same techniques to evaluate the efficacy of different cell types, we have separately delivered bone marrow cells (BMCs), cardiospheres (CSs), CS-derived Sca-1(+)/CD45(-) cells, human embryonic stem cell-derived cardiomyocytes, and BMC extract into infarcted murine myocardium and found that all of these treatments reduce infarct size and improve cardiac function post-MI similarly without one regimen being superior to another. The beneficial effects appear to be via paracrine influences. Different progenitors lead to improved cardiac function post-MI, but it is premature to hype any specific cell type at this time.

  10. Connectivity between the OFF bipolar type DB3a and six types of ganglion cell in the marmoset retina.

    PubMed

    Masri, Rania A; Percival, Kumiko A; Koizumi, Amane; Martin, Paul R; Grünert, Ulrike

    2016-06-15

    Parallel visual pathways originate at the first synapse in the retina, where cones make connections with cone bipolar cells that in turn contact ganglion cells. There are more ganglion cell types than bipolar types, suggesting that there must be divergence from bipolar to ganglion cells. Here we analyze the contacts between an OFF bipolar type (DB3a) and six ganglion cell types in the retina of the marmoset monkey (Callithrix jacchus). Ganglion cells were transfected via particle-mediated gene transfer of an expression plasmid for the postsynaptic density 95-green fluorescent protein (PSD95-GFP), and DB3a cells were labeled via immunohistochemistry. Ganglion cell types that fully or partially costratified with DB3a cells included OFF parasol, OFF midget, broad thorny, recursive bistratified, small bistratified, and large bistratified cells. On average, the number of DB3a contacts to parasol cells (18 contacts per axon terminal) is higher than that to other ganglion cell types (between four and seven contacts). We estimate that the DB3a output to OFF parasol cells accounts for at least 30% of the total DB3a output. Furthermore, we found that OFF parasol cells receive approximately 20% of their total bipolar input from DB3a cells, suggesting that other diffuse bipolar types also provide input to OFF parasol cells. We conclude that DB3a cells preferentially contact OFF parasol cells but also provide input to other ganglion cell types.

  11. Is Transforming Stem Cells to Pancreatic Beta Cells Still the Holy Grail for Type 2 Diabetes?

    PubMed

    Kahraman, Sevim; Okawa, Erin R; Kulkarni, Rohit N

    2016-08-01

    Diabetes is a progressive disease affecting millions of people worldwide. There are several medications and treatment options to improve the life quality of people with diabetes. One of the strategies for the treatment of diabetes could be the use of human pluripotent stem cells or induced pluripotent stem cells. The recent advances in differentiation of stem cells into insulin-secreting beta-like cells in vitro make the transplantation of the stem cell-derived beta-like cells an attractive approach for treatment of type 1 and type 2 diabetes. While stem cell-derived beta-like cells provide an unlimited cell source for beta cell replacement therapies, these cells can also be used as a platform for drug screening or modeling diseases.

  12. Common glycoproteins expressing polylactosamine-type glycans on matched patient primary and metastatic melanoma cells show different glycan profiles.

    PubMed

    Kinoshita, Mitsuhiro; Mitsui, Yosuke; Kakoi, Naotaka; Yamada, Keita; Hayakawa, Takao; Kakehi, Kazuaki

    2014-02-07

    Recently, we reported comparative analysis of glycoproteins which express cancer-specific N-glycans on various cancer cells and identified 24 glycoproteins having polylactosamine (polyLacNAc)-type N-glycans that are abundantly present in malignant cells [ Mitsui et al., J. Pharm. Biomed. Anal. 2012 , 70 , 718 - 726 ]. In the present study, we applied the technique to comparative studies on common glycoproteins present in the matched patient primary and metastatic melanoma cell lines. Metastatic melanoma cells (WM266-4) contained a large amount of polyLacNAc-type N-glycans in comparison with primary melanoma cells (WM115). To identify the glycoproteins expressing these N-glycans, glycopeptides having polyLacNAc-type N-glycans were captured by a Datura stramonium agglutinin (DSA)-immobilized agarose column. The captured glycopeptides were analyzed by LC/MS after removing N-glycans, and some glycoproteins such as basigin, lysosome-associated membrane protein-1 (LAMP-1), and chondroitin sulfate proteoglycan 4 (CSPG4) were identified in both WM115 and WM266-4 cells. The expression level of polyLacNAc of CSPG4 in WM266-4 cells was significantly higher than that in WM115 cells. In addition, sulfation patterns of chondroitin sulfate (CS) chains in CSPG4 showed dramatic changes between these cell lines. These data show that characteristic glycans attached to common proteins observed in different stages of cancer cells will be useful markers for determining degree of malignancies of tumor cells.

  13. Contributions of photosynthetic and non-photosynthetic cell types to leaf respiration in Vicia faba L. and their responses to growth temperature.

    PubMed

    Long, Benedict M; Bahar, Nur H A; Atkin, Owen K

    2015-11-01

    In intact leaves, mitochondrial populations are highly heterogeneous among contrasting cell types; how such contrasting populations respond to sustained changes in the environment remains, however, unclear. Here, we examined respiratory rates, mitochondrial protein composition and response to growth temperature in photosynthetic (mesophyll) and non-photosynthetic (epidermal) cells from fully expanded leaves of warm-developed (WD) and cold-developed (CD) broad bean (Vicia faba L.). Rates of respiration were significantly higher in mesophyll cell protoplasts (MCPs) than epidermal cell protoplasts (ECPs), with both protoplast types exhibiting capacity for cytochrome and alternative oxidase activity. Compared with ECPs, MCPs contained greater relative quantities of porin, suggesting higher mitochondrial surface area in mesophyll cells. Nevertheless, the relative quantities of respiratory proteins (normalized to porin) were similar in MCPs and ECPs, suggesting that ECPs have lower numbers of mitochondria yet similar protein complement to MCP mitochondria (albeit with lower abundance serine hydroxymethyltransferase). Several mitochondrial proteins (both non-photorespiratory and photorespiratory) exhibited an increased abundance in response to cold in both protoplast types. Based on estimates of individual protoplast respiration rates, combined with leaf cell abundance data, epidermal cells make a small but significant (2%) contribution to overall leaf respiration which increases twofold in the cold. Taken together, our data highlight the heterogeneous nature of mitochondrial populations in leaves, both among contrasting cell types and in how those populations respond to growth temperature.

  14. Single-cell transcriptome analysis of fish immune cells provides insight into the evolution of vertebrate immune cell types

    PubMed Central

    Ferreira, Lauren; Macaulay, Iain C.; Stubbington, Michael J.T.

    2017-01-01

    The immune system of vertebrate species consists of many different cell types that have distinct functional roles and are subject to different evolutionary pressures. Here, we first analyzed conservation of genes specific for all major immune cell types in human and mouse. Our results revealed higher gene turnover and faster evolution of trans-membrane proteins in NK cells compared with other immune cell types, and especially T cells, but similar conservation of nuclear and cytoplasmic protein coding genes. To validate these findings in a distant vertebrate species, we used single-cell RNA sequencing of lck:GFP cells in zebrafish and obtained the first transcriptome of specific immune cell types in a nonmammalian species. Unsupervised clustering and single-cell TCR locus reconstruction identified three cell populations, T cells, a novel type of NK-like cells, and a smaller population of myeloid-like cells. Differential expression analysis uncovered new immune-cell–specific genes, including novel immunoglobulin-like receptors, and neofunctionalization of recently duplicated paralogs. Evolutionary analyses confirmed the higher gene turnover of trans-membrane proteins in NK cells compared with T cells in fish species, suggesting that this is a general property of immune cell types across all vertebrates. PMID:28087841

  15. Type-2 innate lymphoid cells in asthma and allergy.

    PubMed

    McKenzie, Andrew N J

    2014-12-01

    Type-2 innate lymphoid cells (ILC2) belong to an expanding family of innate lymphocytes that provide a potent source of immune effector cytokines at the initiation of immune responses. ILC2 arise, under the control of the transcription factors RORα and GATA3, from lymphoid progenitors in the bone marrow, to secrete type-2 cytokines including IL-5 and IL-13. Using experimental models, ILC2 have been implicated in allergic diseases, such as asthma and atopic dermatitis, but also in metabolic homeostasis. Furthermore, recent reports have indicated that ILC2 not only play roles at the initiation of type-2 immunity but can also contribute to chronic pathology, such as fibrosis, and can impact on the priming of the adaptive T-cell response. The identification of ILC2 in patients with allergic dermatitis and allergic rhinitis indicates that these cells may represent new therapeutic targets.

  16. Cell-Type Specific Four-Component Hydrogel

    PubMed Central

    Aberle, Timo; Franke, Katrin; Rist, Elke; Benz, Karin; Schlosshauer, Burkhard

    2014-01-01

    In the field of regenerative medicine we aim to develop implant matrices for specific tissue needs. By combining two per se, cell-permissive gel systems with enzymatic crosslinkers (gelatin/transglutaminase and fibrinogen/thrombin) to generate a blend (technical term: quattroGel), an unexpected cell-selectivity evolved. QuattroGels were porous and formed cavities in the cell diameter range, possessed gelation kinetics in the minute range, viscoelastic properties and a mechanical strength appropriate for general cell adhesion, and restricted diffusion. Cell proliferation of endothelial cells, chondrocytes and fibroblasts was essentially unaffected. In contrast, on quattroGels neither endothelial cells formed vascular tubes nor did primary neurons extend neurites in significant amounts. Only chondrocytes differentiated properly as judged by collagen isoform expression. The biophysical quattroGel characteristics appeared to leave distinct cell processes such as mitosis unaffected and favored differentiation of sessile cells, but hampered differentiation of migratory cells. This cell-type selectivity is of interest e.g. during articular cartilage or invertebral disc repair, where pathological innervation and angiogenesis represent adverse events in tissue engineering. PMID:24475174

  17. Targeting memory T cells in type 1 diabetes.

    PubMed

    Ehlers, Mario R; Rigby, Mark R

    2015-11-01

    Type 1 diabetes (T1D) is a chronic autoimmune disease that leads to progressive destruction of pancreatic beta cells. Compared to healthy controls, a characteristic feature of patients with T1D is the presence of self-reactive T cells with a memory phenotype. These autoreactive memory T cells in both the CD4(+) and CD8(+) compartments are likely to be long-lived, strongly responsive to antigenic stimulation with less dependence on costimulation for activation and clonal expansion, and comparatively resistant to suppression by regulatory T cells (Tregs) or downregulation by immune-modulating agents. Persistence of autoreactive memory T cells likely contributes to the difficulty in preventing disease progression in new-onset T1D and maintaining allogeneic islet transplants by regular immunosuppressive regimens. The majority of immune interventions that have demonstrated some success in preserving beta cell function in the new-onset period have been shown to deplete or modulate memory T cells. Based on these and other considerations, preservation of residual beta cells early after diagnosis or restoration of beta cell mass by use of stem cell or transplantation technology will require a successful strategy to control the autoreactive memory T cell compartment, which could include depletion, inhibition of homeostatic cytokines, induction of hyporesponsiveness, or a combination of these approaches.

  18. Early effects of altered gravity environments on plant cell growth and cell proliferation: Characterization of morphofunctional nucleolar types in an Arabidopsis cell culture system

    NASA Astrophysics Data System (ADS)

    Manzano, Ana Isabel; Herranz, Raul; Manzano, Aránzazu; Van Loon, Jack; Medina, Francisco Javier

    2016-02-01

    Changes in the cell growth rate of an in vitro cellular system in Arabidopsis thaliana induced by short exposure to an altered gravity environment have been estimated by a novel approach. The method consisted of defining three structural nucleolar types which are easy and reliable indicators of the ribosome biogenesis activity and, consequently, of protein biosynthesis, a parameter strictly correlated to cell growth in this cellular system. The relative abundance of each nucleolar type was statistically assessed in different conditions of gravity. Samples exposed to simulated microgravity for 200 min showed a significant decrease in nucleolar activity compared to 1g controls, whereas samples exposed to hypergravity (2g) for the same period showed nucleolar activity slightly increased,. These effects could be considered as an early cellular response to the environmental alteration, given the short duration of the treatment. The functional significance of the structural data was validated by a combination of several different well-known parameters, using microscopical, flow cytometry, qPCR and proteomic approaches, which showed that the decreased cell growth rate was decoupled from an increased cell proliferation rate under simulated microgravity, and the opposite trend was observed under hypergravity. Actually, not all parameters tested showed the same quantitative changes, indicating that the response to the environmental alteration is time-dependent. These results are in agreement with previous observations in root meristematic cells and they show the ability of plant cells to produce a response to gravity changes, independently of their integration into plant organs.

  19. Silicification in Grasses: Variation between Different Cell Types

    PubMed Central

    Kumar, Santosh; Soukup, Milan; Elbaum, Rivka

    2017-01-01

    Plants take up silicon as mono-silicic acid, which is released to soil by the weathering of silicate minerals. Silicic acid can be taken up by plant roots passively or actively, and later it is deposited in its polymerized form as amorphous hydrated silica. Major silica depositions in grasses occur in root endodermis, leaf epidermal cells, and outer epidermal cells of inflorescence bracts. Debates are rife about the mechanism of silica deposition, and two contrasting scenarios are often proposed to explain it. According to the passive mode of silicification, silica deposition is a result of silicic acid condensation due to dehydration, such as during transpirational loss of water from the aboveground organs. In general, silicification and transpiration are positively correlated, and continued silicification is sometimes observed after cell and tissue maturity. The other mode of silicification proposes the involvement of some biological factors, and is based on observations that silicification is not necessarily coupled with transpiration. Here, we review evidence for both mechanisms of silicification, and propose that the deposition mechanism is specific to the cell type. Considering all the cell types together, our conclusion is that grass silica deposition can be divided into three modes: spontaneous cell wall silicification, directed cell wall silicification, and directed paramural silicification in silica cells.

  20. Avian and Human Seasonal Influenza Hemagglutinin Proteins Elicit CD4 T Cell Responses That Are Comparable in Epitope Abundance and Diversity.

    PubMed

    DiPiazza, Anthony; Richards, Katherine; Poulton, Nicholas; Sant, Andrea J

    2017-03-01

    Avian influenza viruses remain a significant concern due to their pandemic potential. Vaccine trials have suggested that humans respond poorly to avian influenza vaccines relative to seasonal vaccines. It is important to understand, first, if there is a general deficiency in the ability of avian hemagglutinin (HA) proteins to generate immune responses and, if so, what underlies this defect. This question is of particular interest because it has been suggested that in humans, the poor immunogenicity of H7 vaccines may be due to a paucity of CD4 T cell epitopes. Because of the generally high levels of cross-reactive CD4 T cells in humans, it is not possible to compare the inherent immunogenicities of avian and seasonal HA proteins in an unbiased manner. Here, we empirically examine the epitope diversity and abundance of CD4 T cells elicited by seasonal and avian HA proteins. HLA-DR1 and HLA-DR4 transgenic mice were vaccinated with purified HA proteins, and CD4 T cells to specific epitopes were identified and quantified. These studies revealed that the diversity and abundance of CD4 T cells specific for HA do not segregate on the basis of whether the HA was derived from human seasonal or avian influenza viruses. Therefore, we conclude that failure in responses to avian vaccines in humans is likely due to a lack of cross-reactive CD4 T cell memory perhaps coupled with competition with or suppression of naive, HA-specific CD4 T cells by memory CD4 T cells specific for more highly conserved proteins.

  1. Cell type specific DNA methylation in cord blood: A 450K-reference data set and cell count-based validation of estimated cell type composition.

    PubMed

    Gervin, Kristina; Page, Christian Magnus; Aass, Hans Christian D; Jansen, Michelle A; Fjeldstad, Heidi Elisabeth; Andreassen, Bettina Kulle; Duijts, Liesbeth; van Meurs, Joyce B; van Zelm, Menno C; Jaddoe, Vincent W; Nordeng, Hedvig; Knudsen, Gunn Peggy; Magnus, Per; Nystad, Wenche; Staff, Anne Cathrine; Felix, Janine F; Lyle, Robert

    2016-09-01

    Epigenome-wide association studies of prenatal exposure to different environmental factors are becoming increasingly common. These studies are usually performed in umbilical cord blood. Since blood comprises multiple cell types with specific DNA methylation patterns, confounding caused by cellular heterogeneity is a major concern. This can be adjusted for using reference data consisting of DNA methylation signatures in cell types isolated from blood. However, the most commonly used reference data set is based on blood samples from adult males and is not representative of the cell type composition in neonatal cord blood. The aim of this study was to generate a reference data set from cord blood to enable correct adjustment of the cell type composition in samples collected at birth. The purity of the isolated cell types was very high for all samples (>97.1%), and clustering analyses showed distinct grouping of the cell types according to hematopoietic lineage. We explored whether this cord blood and the adult peripheral blood reference data sets impact the estimation of cell type composition in cord blood samples from an independent birth cohort (MoBa, n = 1092). This revealed significant differences for all cell types. Importantly, comparison of the cell type estimates against matched cell counts both in the cord blood reference samples (n = 11) and in another independent birth cohort (Generation R, n = 195), demonstrated moderate to high correlation of the data. This is the first cord blood reference data set with a comprehensive examination of the downstream application of the data through validation of estimated cell types against matched cell counts.

  2. Cell proliferation in type C gastritis affecting the intact stomach

    PubMed Central

    Mac, D; Willis, P; Prescott, R; Lamonby, S; Lynch, D

    2000-01-01

    Aims—Type C gastritis caused by bile reflux has a characteristic appearance, similar to that seen in other forms of chemical gastritis, such as those associated with NSAIDs or alcohol. An increase in mucosal cell proliferation increases the likelihood of a neoplastic clone of epithelial cells emerging, particularly where there is chronic epithelial injury associated with bile reflux. It has been shown previously that type C gastritis is associated with increased cell proliferation in the postsurgical stomach. The aim of this study was to determine cell proliferation in type C gastritis caused by bile reflux affecting the intact stomach. Methods—Specimens from 15 patients with a histological diagnosis of type C gastritis on antral biopsy were obtained from the pathology archives between 1994 and 1997. A control group of nine normal antral biopsies was also selected and all underwent MIB-1 immunostaining. The gastric glands were divided into three zones (zone 1, gastric pit; zone 2, isthmus; and zone 3, gland base) and the numbers of positively staining nuclei for 500 epithelial cell nuclei were counted in each zone to determine the percentage labelling index (LI%). Results—Cell proliferation was significantly higher in all three zones of the gastric glands with type C gastritis compared with controls as follows: zone 1, median LI% in type C gastritis 64.7 (range, 7.8–99.2), controls 4.7 (range, 2.0–11.3); zone 2, median LI% in type C gastritis 94.7 (range, 28.8–98.7), controls 40.2 (range, 23.1–70.3); and zone 3, median LI% in type C gastritis 20.0 (range, 1.3–96.0), controls 2.6 (range, 0.9–8.7). Conclusions—Bile reflux is thought to act as a promoter of gastric carcinogenesis in the postsurgical stomach. The same may be true in the intact stomach. Key Words: cell proliferation • epithelial kinetics • chemical gastritis PMID:11064674

  3. Absolute Quantification of Endogenous Ras Isoform Abundance

    PubMed Central

    Mageean, Craig J.; Griffiths, John R.; Smith, Duncan L.; Clague, Michael J.; Prior, Ian A.

    2015-01-01

    Ras proteins are important signalling hubs situated near the top of networks controlling cell proliferation, differentiation and survival. Three almost identical isoforms, HRAS, KRAS and NRAS, are ubiquitously expressed yet have differing biological and oncogenic properties. In order to help understand the relative biological contributions of each isoform we have optimised a quantitative proteomics method for accurately measuring Ras isoform protein copy number per cell. The use of isotopic protein standards together with selected reaction monitoring for diagnostic peptides is sensitive, robust and suitable for application to sub-milligram quantities of lysates. We find that in a panel of isogenic SW48 colorectal cancer cells, endogenous Ras proteins are highly abundant with ≥260,000 total Ras protein copies per cell and the rank order of isoform abundance is KRAS>NRAS≥HRAS. A subset of oncogenic KRAS mutants exhibit increased total cellular Ras abundance and altered the ratio of mutant versus wild type KRAS protein. These data and methodology are significant because Ras protein copy number is required to parameterise models of signalling networks and informs interpretation of isoform-specific Ras functional data. PMID:26560143

  4. Type I IFN promotes NK cell expansion during viral infection by protecting NK cells against fratricide.

    PubMed

    Madera, Sharline; Rapp, Moritz; Firth, Matthew A; Beilke, Joshua N; Lanier, Lewis L; Sun, Joseph C

    2016-02-08

    Type I interferon (IFN) is crucial in host antiviral defense. Previous studies have described the pleiotropic role of type I IFNs on innate and adaptive immune cells during viral infection. Here, we demonstrate that natural killer (NK) cells from mice lacking the type I IFN-α receptor (Ifnar(-/-)) or STAT1 (which signals downstream of IFNAR) are defective in expansion and memory cell formation after mouse cytomegalovirus (MCMV) infection. Despite comparable proliferation, Ifnar(-/-) NK cells showed diminished protection against MCMV infection and exhibited more apoptosis compared with wild-type NK cells. Furthermore, we show that Ifnar(-/-) NK cells express increased levels of NK group 2 member D (NKG2D) ligands during viral infection and are susceptible to NK cell-mediated fratricide in a perforin- and NKG2D-dependent manner. Adoptive transfer of Ifnar(-/-) NK cells into NK cell-deficient mice reverses the defect in survival and expansion. Our study reveals a novel type I IFN-dependent mechanism by which NK cells evade mechanisms of cell death after viral infection.

  5. Twelve chromatically opponent ganglion cell types in turtle retina.

    PubMed

    Rocha, F A F; Saito, C A; Silveira, L C L; de Souza, J M; Ventura, D F

    2008-01-01

    The turtle retina has been extensively used for the study of chromatic processing mechanisms. Color opponency has been previously investigated with trichromatic paradigms, but behavioral studies show that the turtle has an ultraviolet (UV) channel and a tetrachromatic visual system. Our laboratory has been working in the characterization of neuronal responses in the retina of vertebrates using stimuli in the UV-visible range of the electromagnetic spectrum. In the present investigation, we recorded color-opponent responses from turtle amacrine and ganglion cells to UV and visible stimuli and extended our previous results that UV color-opponency is present at the level of the inner nuclear layer. We recorded from 181 neurons, 36 of which were spectrally opponent. Among these, there were 10 amacrine (5%), and 26 ganglion cells (15%). Morphological identification of color-opponent neurons was possible for two ganglion cell classes (G17 and G22) and two amacrine cell classes (A22 and A23b). There was a variety of cell response types and a potential for complex processing of chromatic stimuli, with intensity- and wavelength-dependent response components. Ten types of color opponency were found in ganglion cells and by adding previous results from our laboratory, 12 types of opponent responses have been found. The majority of the ganglion cells were R+UVBG- and RG+UVB-color-opponents but there were other less frequent types of chromatic opponency. This study confirms the participation of a UV channel in the processing of color opponency in the turtle inner retina and shows that the turtle visual system has the retinal mechanisms to allow many possible chromatic combinations.

  6. Cation Type Specific Cell Remodeling Regulates Attachment Strength

    PubMed Central

    Fuhrmann, Alexander; Li, Julie; Chien, Shu; Engler, Adam J.

    2014-01-01

    Single-molecule experiments indicate that integrin affinity is cation-type-dependent, but in spread cells integrins are engaged in complex focal adhesions (FAs), which can also regulate affinity. To better understand cation-type-dependent adhesion in fully spread cells, we investigated attachment strength by application of external shear. While cell attachment strength is indeed modulated by cations, the regulation of integrin-mediated adhesion is also exceedingly complex, cell specific, and niche dependent. In the presence of magnesium only, fibroblasts and fibrosarcoma cells remodel their cytoskeleton to align in the direction of applied shear in an α5-integrin/fibronectin-dependent manner, which allows them to withstand higher shear. In the presence of calcium or on collagen in modest shear, fibroblasts undergo piecewise detachment but fibrosarcoma cells exhibit increased attachment strength. These data augment the current understanding of force-mediated detachment by suggesting a dynamic interplay in situ between cell adhesion and integrins depending on local niche cation conditions. PMID:25014042

  7. Type I collagen gel protects murine fibrosarcoma L929 cells from TNFα-induced cell death

    SciTech Connect

    Wang, Hong-Ju; He, Wen-Qi; Chen, Ling; Liu, Wei-Wei; Xu, Qian; Xia, Ming-Yu; Hayashi, Toshihiko; Fujisaki, Hitomi; Hattori, Shunji; Tashiro, Shin-ichi; Onodera, Satoshi; Ikejima, Takashi

    2015-02-20

    Murine fibrosarcoma L929 cells have been used to test efficacy of proinflammatory cytokine TNFα. In the present study, we reported on protective effect of type I collagen gel used as L929 cell culture. L929 cell grew and proliferated well on collagen gel. However, the L929 cells exhibited cobblestone-like morphology which was much different from the spread fusiform shape when cultured on conventional cell dishes as well as the cells tended to aggregate. On conventional cell culture dishes, the cells treated with TNFα became round in shape and eventually died in a necroptotic manner. The cells cultured on collagen gel, however, were completely unaffected. TNFα treatment was reported to induce autophagy in L929 cells on the plastic dish, and therefore we investigated the effect of collagen gel on induction of autophagy. The results indicated that autophagy induced by TNFα treatment was much reduced when the cells were cultured on collagen gel. In conclusion, type I collagen gel protected L929 cell from TNFα-induced cell death. - Highlights: • Collagen gel culture changed the morphology of L929 cells. • L929 cell cultured on collagen gel were resistant to TNFα-induced cell death. • Collagen gel culture inhibited TNFα-induced autophagy in L929 cells.

  8. Common pathways regulate Type III TGFβ receptor-dependent cell invasion in epicardial and endocardial cells.

    PubMed

    Clark, Cynthia R; Robinson, Jamille Y; Sanchez, Nora S; Townsend, Todd A; Arrieta, Julian A; Merryman, W David; Trykall, David Z; Olivey, Harold E; Hong, Charles C; Barnett, Joey V

    2016-06-01

    Epithelial-Mesenchymal Transformation (EMT) and the subsequent invasion of epicardial and endocardial cells during cardiac development is critical to the development of the coronary vessels and heart valves. The transformed cells give rise to cardiac fibroblasts and vascular smooth muscle cells or valvular interstitial cells, respectively. The Type III Transforming Growth Factor β (TGFβR3) receptor regulates EMT and cell invasion in both cell types, but the signaling mechanisms downstream of TGFβR3 are not well understood. Here we use epicardial and endocardial cells in in vitro cell invasion assays to identify common mechanisms downstream of TGFβR3 that regulate cell invasion. Inhibition of NF-κB activity blocked cell invasion in epicardial and endocardial cells. NF-κB signaling was found to be dysregulated in Tgfbr3(-/-) epicardial cells which also show impaired cell invasion in response to ligand. TGFβR3-dependent cell invasion is also dependent upon Activin Receptor-Like Kinase (ALK) 2, ALK3, and ALK5 activity. A TGFβR3 mutant that contains a threonine to alanine substitution at residue 841 (TGFβR3-T841A) induces ligand-independent cell invasion in both epicardial and endocardial cells in vitro. These findings reveal a role for NF-κB signaling in the regulation of epicardial and endocardial cell invasion and identify a mutation in TGFβR3 which stimulates ligand-independent signaling.

  9. IPC: professional type 1 interferon-producing cells and plasmacytoid dendritic cell precursors.

    PubMed

    Liu, Yong-Jun

    2005-01-01

    Type 1 interferon-(alpha, beta, omega)-producing cells (IPCs), also known as plasmacytoid dendritic cell precursors (pDCs), represent 0.2%-0.8% of peripheral blood mononuclear cells in both humans and mice. IPCs display plasma cell morphology, selectively express Toll-like receptor (TLR)-7 and TLR9, and are specialized in rapidly secreting massive amounts of type 1 interferon following viral stimulation. IPCs can promote the function of natural killer cells, B cells, T cells, and myeloid DCs through type 1 interferons during an antiviral immune response. At a later stage of viral infection, IPCs differentiate into a unique type of mature dendritic cell, which directly regulates the function of T cells and thus links innate and adaptive immune responses. After more than two decades of effort by researchers, IPCs finally claim their place in the hematopoietic chart as the most important cell type in antiviral innate immunity. Understanding IPC biology holds future promise for developing cures for infectious diseases, cancer, and autoimmune diseases.

  10. Fourier Transform Infrared spectroscopy discloses different types of cell death in flow cytometrically sorted cells.

    PubMed

    Le Roux, K; Prinsloo, L C; Meyer, D

    2015-10-01

    Fourier Transform Infrared (FTIR) spectroscopy is a label free methodology showing promise in characterizing different types of cell death. Cervical adenocarcinoma (HeLa) and African monkey kidney (Vero) cells were treated with a necrosis inducer (methanol), novel apoptotic inducers (diphenylphosphino gold (I) complexes) and positive control, auranofin. Following treatment, cells stained with annexin-V and propidium iodide were sorted using a Fluorescence Activated Cell Sorter (FACS Aria) to obtain populations consisting of either viable, necrotic or apoptotic cells. Transmission Electron Microscopy confirmed successful sorting of all three populations. Four bands were identified which could discriminate between viable and necrotic cells namely 989 cm(-1), 2852 cm(-1), 2875 cm(-1) and 2923 cm(-1). In HeLa cells viable and induced apoptosis could be distinguished by 1294 cm(-1), while four bands were different in Vero cells namely; 1626 cm(-1), 1741 cm(-1), 2852 cm(-1) 2923 cm(-1). Principal Component Analysis showed separation between the different types of cell death and the loadings plots indicated an increase in an additional band at 1623 cm(-1) in dead cells. FTIR spectroscopy can be developed into an invaluable tool for the assessment of specific types of chemically induced cell death with notably different molecular signatures depending on whether the cells are cancerous and mechanism of cell death.

  11. Protein Expression Profile of Rat Type Two Alveolar Epithelial Cells During Hyperoxic Stress and Recovery

    NASA Astrophysics Data System (ADS)

    Bhargava, Maneesh

    Rationale: In rodent model systems, the sequential changes in lung morphology resulting from hyperoxic injury are well characterized, and are similar to changes in human acute respiratory distress syndrome (ARDS). In the injured lung, alveolar type two (AT2) epithelial cells play a critical role restoring the normal alveolar structure. Thus characterizing the changes in AT2 cells will provide insights into the mechanisms underpinning the recovery from lung injury. Methods: We applied an unbiased systems level proteomics approach to elucidate molecular mechanisms contributing to lung repair in a rat hyperoxic lung injury model. AT2 cells were isolated from rat lungs at predetermined intervals during hyperoxic injury and recovery. Protein expression profiles were determined by using iTRAQRTM with tandem mass spectrometry. Results: Of 959 distinct proteins identified, 183 significantly changed in abundance during the injury-recovery cycle. Gene Ontology enrichment analysis identified cell cycle, cell differentiation, cell metabolism, ion homeostasis, programmed cell death, ubiquitination, and cell migration to be significantly enriched by these proteins. Gene Set Enrichment Analysis of data acquired during lung repair revealed differential expression of gene sets that control multicellular organismal development, systems development, organ development, and chemical homeostasis. More detailed analysis identified activity in two regulatory pathways, JNK and miR 374. A Short Time-series Expression Miner (STEM) algorithm identified protein clusters with coherent changes during injury and repair. Conclusion: Coherent changes occur in the AT2 cell proteome in response to hyperoxic stress. These findings offer guidance regarding the specific molecular mechanisms governing repair of the injured lung.

  12. Folate metabolite profiling of different cell types and embryos suggests variation in folate one-carbon metabolism, including developmental changes in human embryonic brain.

    PubMed

    Leung, Kit-Yi; De Castro, Sandra C P; Cabreiro, Filipe; Gustavsson, Peter; Copp, Andrew J; Greene, Nicholas D E

    2013-06-01

    Folates act as co-factors for transfer of one-carbon units for nucleotide production, methylation and other biosynthetic reactions. Comprehensive profiling of multiple folates can be achieved using liquid chromatography tandem mass spectrometry, enabling determination of their relative abundance that may provide an indication of metabolic differences between cell types. For example, cell lines exposed to methotrexate showed a dose-dependent elevation of dihydrofolate, consistent with inhibition of dihydrofolate reductase. We analysed the folate profile of E. coli sub-types as well as cell lines and embryonic tissue from both human and mouse. The folate profile of bacteria differed markedly from those of all the mammalian samples, most notably in the greater abundance of formyl tetrahydrofolate. The overall profiles of mouse and human fibroblasts and mid-gestation mouse embryos were broadly similar, with specific differences. The major folate species in these cell types was 5-methyl tetrahydrofolate, in contrast to lymphoblastoid cell lines in which the predominant form was tetrahydrofolate. Analysis of embryonic human brain revealed a shift in folate profile with increasing developmental stage, with a decline in relative abundance of dihydrofolate and increase in 5-methyl tetrahydrofolate. These cell type-specific and developmental changes in folate profile may indicate differential requirements for the various outputs of folate metabolism.

  13. Identifying Cell Types from Spatially Referenced Single-Cell Expression Datasets

    PubMed Central

    Achim, Kaia; Richardson, Sylvia; Azizi, Lamiae; Marioni, John

    2014-01-01

    Complex tissues, such as the brain, are composed of multiple different cell types, each of which have distinct and important roles, for example in neural function. Moreover, it has recently been appreciated that the cells that make up these sub-cell types themselves harbour significant cell-to-cell heterogeneity, in particular at the level of gene expression. The ability to study this heterogeneity has been revolutionised by advances in experimental technology, such as Wholemount in Situ Hybridizations (WiSH) and single-cell RNA-sequencing. Consequently, it is now possible to study gene expression levels in thousands of cells from the same tissue type. After generating such data one of the key goals is to cluster the cells into groups that correspond to both known and putatively novel cell types. Whilst many clustering algorithms exist, they are typically unable to incorporate information about the spatial dependence between cells within the tissue under study. When such information exists it provides important insights that should be directly included in the clustering scheme. To this end we have developed a clustering method that uses a Hidden Markov Random Field (HMRF) model to exploit both quantitative measures of expression and spatial information. To accurately reflect the underlying biology, we extend current HMRF approaches by allowing the degree of spatial coherency to differ between clusters. We demonstrate the utility of our method using simulated data before applying it to cluster single cell gene expression data generated by applying WiSH to study expression patterns in the brain of the marine annelid Platynereis dumereilii. Our approach allows known cell types to be identified as well as revealing new, previously unexplored cell types within the brain of this important model system. PMID:25254363

  14. Single-cell RNA sequencing identifies distinct mouse medial ganglionic eminence cell types

    PubMed Central

    Chen, Ying-Jiun J.; Friedman, Brad A.; Ha, Connie; Durinck, Steffen; Liu, Jinfeng; Rubenstein, John L.; Seshagiri, Somasekar; Modrusan, Zora

    2017-01-01

    Many subtypes of cortical interneurons (CINs) are found in adult mouse cortices, but the mechanism generating their diversity remains elusive. We performed single-cell RNA sequencing on the mouse embryonic medial ganglionic eminence (MGE), the major birthplace for CINs, and on MGE-like cells differentiated from embryonic stem cells. Two distinct cell types were identified as proliferating neural progenitors and immature neurons, both of which comprised sub-populations. Although lineage development of MGE progenitors was reconstructed and immature neurons were characterized as GABAergic, cells that might correspond to precursors of different CINs were not identified. A few non-neuronal cell types were detected, including microglia. In vitro MGE-like cells resembled bona fide MGE cells but expressed lower levels of Foxg1 and Epha4. Together, our data provide detailed understanding of the embryonic MGE developmental program and suggest how CINs are specified. PMID:28361918

  15. Type I interferon promotes cell-to-cell spread of Listeria monocytogenes.

    PubMed

    Osborne, Suzanne E; Sit, Brandon; Shaker, Andrew; Currie, Elissa; Tan, Joël M J; van Rijn, Jorik; Higgins, Darren E; Brumell, John H

    2017-03-01

    Type I interferons (IFNs) play a critical role in antiviral immune responses, but can be deleterious to the host during some bacterial infections. Listeria monocytogenes (Lm) induces a type I IFN response by activating cytosolic antiviral surveillance pathways. This is beneficial to the bacteria as mice lacking the type I IFN receptor (IFNAR1(-/-) ) are resistant to systemic infection by Lm. The mechanisms by which type I IFNs promote Lm infection are unclear. Here, we show that IFNAR1 is required for dissemination of Lm within infection foci in livers of infected mice and for efficient cell-to-cell spread in vitro in macrophages. IFNAR1 promotes ActA polarization and actin-based motility in the cytosol of host cells. Our studies suggest type I IFNs directly impact the intracellular life cycle of Lm and provide new insight into the mechanisms used by bacterial pathogens to exploit the type I IFN response.

  16. Inducible human immunodeficiency virus type 1 packaging cell lines.

    PubMed Central

    Yu, H; Rabson, A B; Kaul, M; Ron, Y; Dougherty, J P

    1996-01-01

    Packaging cell lines are important tools for transferring genes into eukaryotic cells. Human immunodeficiency virus type 1 (HIV-1)-based packaging cell lines are difficult to obtain, in part owing to the problem that some HIV-1 proteins are cytotoxic in a variety of cells. To overcome this, we have developed an HIV-1-based packaging cell line which has an inducible expression system. The tetracycline-inducible expression system was utilized to control the expression of the Rev regulatory protein, which in turn controls the expression of the late proteins including Gag, Pol, and Env. Western blotting (immunoblotting) demonstrated that the expression of p24gag and gp120env from the packaging cells peaked on days 6 and 7 postinduction. Reverse transcriptase activity could be detected by day 4 after induction and also peaked on days 6 and 7. Defective vector virus could be propagated, yielding titers as high as 7 x 10(3) CFU/ml, while replication-competent virus was not detectable at any time. Thus, the cell line should enable the transfer of specific genes into CD4+ cells and should be a useful tool for studying the biology of HIV-1. We have also established an inducible HIV-1 Env-expressing cell line which could be used to propagate HIV-1 vectors that require only Env in trans. The env-minus vector virus titer produced from the Env-expressing cells reached 2 x 10(4) CFU/ml. The inducible HIV-1 Env-expressing cell line should be a useful tool for the study of HIV-1 Env as well. PMID:8676479

  17. Promoter for the late gene encoding Vp5 of herpes simplex virus type 1 is recognized by cell extracts derived from uninfected cells

    SciTech Connect

    Chisholm, G.E.; Summers, W.C.

    1986-11-01

    The ability of whole-cell extracts from unidentified HeLa cells to recognize the promoter for the herpes simplex virus type 1 late gene encoding the major capsid protein Vp5 was investigated by using both in vitro transcriptional and S1 nuclease protection analysis. This gene promoter was recognized by the cell extracts and produced abundant amounts of transcript in the absence of any other virus-encoded factors. This transcript was shown to arise, in vitro, from specific initiation at or very near the physiological mRNA start site. Thus, it appears that cell extracts from uninfected HeLa cells can efficiently recognize both early- and late-gene promoters.

  18. Inferring cell type innovations by phylogenetic methods-concepts, methods, and limitations.

    PubMed

    Kin, Koryu

    2015-12-01

    Multicellular organisms are composed of distinct cell types that have specific roles in the body. Each cell type is a product of two kinds of historical processes-development and evolution. Although the concept of a cell type is difficult to define, the cell type concept based on the idea of the core regulatory network (CRN), a gene regulatory network that determines the identity of a cell type, illustrates the essential aspects of the cell type concept. The first step toward elucidating cell type evolution is to reconstruct the evolutionary relationships of cell types, or the cell type tree. The sister cell type model assumes that a new cell type evolves through divergence from a multifunctional ancestral cell type, creating tree-like evolutionary relationships between cell types. The process of generating a cell type tree can also be understood as the sequential addition of a new branching point on an ancestral cell differentiation hierarchy in evolution. A cell type tree thus represents an intertwined history of cell type evolution and development. Cell type trees can be reconstructed from high-throughput sequencing data, and the reconstruction of a cell type tree leads to the discovery of genes that are functionally important for a cell type. Although many issues including the lack of cross-species comparisons and the lack of a proper model for cell type evolution remain, the study of the origin of a new cell type using phylogenetic methods offers a promising new research avenue in developmental evolution. J. Exp. Zool. (Mol. Dev. Evol.) 324B: 653-661, 2015. © 2015 Wiley Periodicals, Inc.

  19. Microscopic elucidation of abundant endophytic bacteria colonizing the cell wall–plasma membrane peri-space in the shoot-tip tissue of banana

    PubMed Central

    Thomas, Pious; Reddy, Krishna M.

    2013-01-01

    This study was aimed at generating microscopic evidence of intra-tissue colonization in banana in support of the previous findings on widespread association of endophytic bacteria with the shoot tips of field-grown plants and micropropagated cultures, and to understand the extent of tissue colonization. Leaf-sheath tissue sections (∼50–100 µm) from aseptically gathered shoot tips of cv. Grand Naine were treated with Live/Dead bacterial viability kit components SYTO 9 (S9) and propidium iodide (PI) followed by epifluorescence or confocal laser scanning microscopy (CLSM). The S9, which targets live bacteria, showed abundant green-fluorescing particles along the host cell periphery in CLSM, apparently in between the plasma membrane and the cell wall. These included non-motile and occasional actively motile single bacterial cells seen in different x–y planes and z-stacks over several cell layers, with the fluorescence signal similar to that of pure cultures of banana endophytes. Propidium iodide, which stains dead bacteria, did not detect any, but post-ethanol treatment, both PI and 4′,6-diamidino-2-phenylindole detected abundant bacteria. Propidium iodide showed clear nuclear staining, as did S9 to some extent, and the fluorophores appeared to detect bacteria at the exclusion of DNA-containing plant organelles as gathered from bright-field and phase-contrast microscopy. The S9–PI staining did not work satisfactorily with formalin- or paraformaldehyde-fixed tissue. The extensive bacterial colonization in fresh tissue was further confirmed with the suckers of different cultivars, and was supported by transmission electron microscopy. This study thus provides clear microscopic evidence of the extensive endophytic bacterial inhabitation in the confined cell wall–plasma membrane peri-space in shoot tissue of banana with the organisms sharing an integral association with the host. The abundant tissue colonization suggests a possible involvement of endophytes in

  20. Increased DNA methylation variability in type 1 diabetes across three immune effector cell types

    PubMed Central

    Paul, Dirk S.; Teschendorff, Andrew E.; Dang, Mary A.N.; Lowe, Robert; Hawa, Mohammed I.; Ecker, Simone; Beyan, Huriya; Cunningham, Stephanie; Fouts, Alexandra R.; Ramelius, Anita; Burden, Frances; Farrow, Samantha; Rowlston, Sophia; Rehnstrom, Karola; Frontini, Mattia; Downes, Kate; Busche, Stephan; Cheung, Warren A.; Ge, Bing; Simon, Marie-Michelle; Bujold, David; Kwan, Tony; Bourque, Guillaume; Datta, Avik; Lowy, Ernesto; Clarke, Laura; Flicek, Paul; Libertini, Emanuele; Heath, Simon; Gut, Marta; Gut, Ivo G; Ouwehand, Willem H.; Pastinen, Tomi; Soranzo, Nicole; Hofer, Sabine E.; Karges, Beate; Meissner, Thomas; Boehm, Bernhard O.; Cilio, Corrado; Elding Larsson, Helena; Lernmark, Åke; Steck, Andrea K.; Rakyan, Vardhman K.; Beck, Stephan; Leslie, R. David

    2016-01-01

    The incidence of type 1 diabetes (T1D) has substantially increased over the past decade, suggesting a role for non-genetic factors such as epigenetic mechanisms in disease development. Here we present an epigenome-wide association study across 406,365 CpGs in 52 monozygotic twin pairs discordant for T1D in three immune effector cell types. We observe a substantial enrichment of differentially variable CpG positions (DVPs) in T1D twins when compared with their healthy co-twins and when compared with healthy, unrelated individuals. These T1D-associated DVPs are found to be temporally stable and enriched at gene regulatory elements. Integration with cell type-specific gene regulatory circuits highlight pathways involved in immune cell metabolism and the cell cycle, including mTOR signalling. Evidence from cord blood of newborns who progress to overt T1D suggests that the DVPs likely emerge after birth. Our findings, based on 772 methylomes, implicate epigenetic changes that could contribute to disease pathogenesis in T1D. PMID:27898055

  1. The statistical geometry of transcriptome divergence in cell-type evolution and cancer.

    PubMed

    Liang, Cong; Forrest, Alistair R R; Wagner, Günter P

    2015-01-14

    In evolution, body plan complexity increases due to an increase in the number of individualized cell types. Yet, there is very little understanding of the mechanisms that produce this form of organismal complexity. One model for the origin of novel cell types is the sister cell-type model. According to this model, each cell type arises together with a sister cell type through specialization from an ancestral cell type. A key prediction of the sister cell-type model is that gene expression profiles of cell types exhibit tree structure. Here we present a statistical model for detecting tree structure in transcriptomic data and apply it to transcriptomes from ENCODE and FANTOM5. We show that transcriptomes of normal cells harbour substantial amounts of hierarchical structure. In contrast, cancer cell lines have less tree structure, suggesting that the emergence of cancer cells follows different principles from that of evolutionary cell-type origination.

  2. Ultrastructural and functional characterization of circulating hemocytes from Galleria mellonella larva: Cell types and their role in the innate immunity.

    PubMed

    Wu, Gongqing; Liu, Yi; Ding, Ying; Yi, Yunhong

    2016-08-01

    Galleria mellonella larvae have been widely used as a model to study the virulence of various human pathogens. Hemocytes play important roles in the innate immune response of G. mellonella. In this study, the hemocytes of G. mellonella larvae were analyzed by transmission electron microscope, light microscope, and cytochemistry. The cytological and morphological analyses revealed four types of hemocytes; Plasmatocytes, granular cells, spherule cells and oenocytoids. Differential hemocyte counts showed that under our conditions plasmatocytes and granular cells were the most abundant circulating cell types in the hemolymph. We also investigated the role of different types of hemocytes in the cellular and humoral immune defenses. The in-vivo experiment showed that plasmatocytes, granular cells and oenocytoids phagocytized FITC-labelled Escherichia coli bacteria in larvae of G. mellonella, whereas the granular cells exhibited the strongest phagocytic ability against these microbial cells. After incubation with L-DOPA, plasmatocytes, granular cells and oenocytoids are stained brown, indicating the presence of phenoloxidase activity. These results shed new light on our understanding of the immune function of G. mellonella hemocytes.

  3. Human mast cells decrease SLPI levels in type II – like alveolar cell model, in vitro

    PubMed Central

    Hollander, Camilla; Nyström, Max; Janciauskiene, Sabina; Westin, Ulla

    2003-01-01

    Background Mast cells are known to accumulate at sites of inflammation and upon activation to release their granule content, e.g. histamine, cytokines and proteases. The secretory leukocyte protease inhibitor (SLPI) is produced in the respiratory mucous and plays a role in regulating the activity of the proteases. Result We have used the HMC-1 cell line as a model for human mast cells to investigate their effect on SLPI expression and its levels in cell co-culture experiments, in vitro. In comparison with controls, we found a significant reduction in SLPI levels (by 2.35-fold, p < 0.01) in a SLPI-producing, type II-like alveolar cell line, (A549) when co-cultured with HMC-1 cells, but not in an HMC-1-conditioned medium, for 96 hours. By contrast, increased SLPI mRNA expression (by 1.58-fold, p < 0.05) was found under the same experimental conditions. Immunohistochemical analysis revealed mast cell transmigration in co-culture with SLPI-producing A549 cells for 72 and 96 hours. Conclusion These results indicate that SLPI-producing cells may assist mast cell migration and that the regulation of SLPI release and/or consumption by mast cells requires interaction between these cell types. Therefore, a "local relationship" between mast cells and airway epithelial cells might be an important step in the inflammatory response. PMID:12952550

  4. Mesenchymal stem cell-based therapy for type 1 diabetes.

    PubMed

    Wu, Hao; Mahato, Ram I

    2014-03-01

    Diabetes has increasingly become a worldwide health problem, causing huge burden on healthcare system and economy. Type 1 diabetes (T1D), traditionally termed "juvenile diabetes" because of an early onset age, is affecting 5-10% of total diabetic population. Insulin injection, the predominant treatment for T1D, is effective to ameliorate the hyperglycemia but incompetent to relieve the autoimmunity and to regenerate lost islets. Islet transplantation, an experimental treatment for T1D, also suffers from limited supply of human islets and poor immunosuppression. The recent progress in regenerative medicine, especially stem cell therapy, has suggested several novel and potential cures for T1D. Mesenchymal stem cell (MSC) based cell therapy is among one of them. MSCs are a type of adult stem cells residing in bone marrow, adipose tissue, umbilical cord blood, and many other tissues. MSCs, with self-renewal potential and transdifferentiation capability, can be expanded in vitro and directed to various cell lineages with relatively less efforts. MSCs have well-characterized hypoimmunogenicity and immunomodulatory effect. All these features make MSCs attractive for treating T1D. Here, we review the properties of MSCs and some of the recent progress using MSCs as a new therapeutic in the treatment of T1D. We also discuss the strength and limitations of using MSC therapy in human trials.

  5. Caveolin-1 Expression and Membrane Cholesterol Content Modulate N-Type Calcium Channel Activity in NG108-15 Cells

    PubMed Central

    Toselli, M.; Biella, G.; Taglietti, V.; Cazzaniga, E.; Parenti, M.

    2005-01-01

    Caveolins are the main structural proteins of glycolipid/cholesterol-rich plasmalemmal invaginations, termed caveolae. In addition, caveolin-1 isoform takes part in membrane remodelling as it binds and transports newly synthesized cholesterol from endoplasmic reticulum to the plasma membrane. Caveolin-1 is expressed in many cell types, including hippocampal neurons, where an abundant SNAP25-caveolin-1 complex is detected after induction of persistent synaptic potentiation. To ascertain whether caveolin-1 influences neuronal voltage-gated Ca2+ channel basal activity, we stably expressed caveolin-1 into transfected neuroblastoma × glioma NG108-15 hybrid cells [cav1(+) clone] that lack endogenous caveolins but express N-type Ca2+ channels upon cAMP-induced neuronal differentiation. Whole-cell patch-clamp recordings of cav1(+) cells demonstrated that N-type current density was reduced in size by ∼70% without any significant change in the time course of activation and inactivation and voltage dependence. Moreover, the cav1(+) clone exhibited a significantly increased proportion of membrane cholesterol compared to wild-type NG108-15 cells. To gain insight into the mechanism underlying caveolin-1 lowering of N-current density, and more precisely to test whether this was indirectly caused by caveolin-1-induced enhancement of membrane cholesterol, we compared single N-type channel activities in cav1(+) clone and wild-type NG108-15 cells enriched with cholesterol after exposure to a methyl-β-cyclodextrin-cholesterol complex. A lower Ca2+ channel activity was recorded from cell-attached patches of both cell types, thus supporting the view that the increased proportion of membrane cholesterol is ultimately responsible for the effect. This is due to a reduction in the probability of channel opening caused by a significant decrease of channel mean open time and by an increase of the frequency of null sweeps. PMID:16040758

  6. Theoretical Evaluation of Cu-Sn-S and Cu-Sb-S Based Solar Absorbers for Earth-Abundant Thin-Film Solar Cells

    NASA Astrophysics Data System (ADS)

    Zawadzki, Pawel; Peng, Haowei; Zakutayev, Andriy; Lany, Stephan

    2013-03-01

    Current thin-film solar absorbers such as Cu(In/Ga)Se2 or CdTe, although remarkably efficient, incorporate limited-supply elements like indium or tellurium. Meeting the cost competiveness criterion necessary for a large-scale deployment of thin-film PV technologies requires development of new earth-abundant solar absorbers. In an effort to accelerate such development we combine first principles theory and high throughput experiments to explore In-free ternary copper chalcogenides. As part of the theoretical evaluation, we study the Cu2SnS3, Cu4SnS4, CuSbS2 and Cu3SbS3 based compounds formed by isovalent alloying on Sn, Sb, and S sites. For this set of materials we predict band-structures and optical absorption coefficients and demonstrate the feasibility of achieving the optimal band gap of 1.3 eV for a single junction cell and a high optical absorption of ~104 cm-1 at Eg+0.2 eV. We additionally perform defect studies to elucidate the doping trends within this class of materials. The project ``Rapid Development of Earth-abundant Thin Film Solar Cells'' is supported as a part of the SunShot initiative by the U. S. Department of Energy, Office of Energy Efficiency and Renewable Energy under Contract No. DE-AC36-08GO28308 to NREL.

  7. Sea lamprey mark type, wounding rate, and parasite-host preference and abundance relationships for lake trout and other species in Lake Ontario

    USGS Publications Warehouse

    Lantry, Brian F.; Adams, Jean; Christie, Gavin; Schaner, Teodore; Bowlby, James; Keir, Michael; Lantry, Jana; Sullivan, Paul; Bishop, Daniel; Treska, Ted; Morrison, Bruce

    2015-01-01

    We examined how attack frequency by sea lampreys on fishes in Lake Ontario varied in response to sea lamprey abundance and preferred host abundance (lake trout > 433 mm). For this analysis we used two gill net assessment surveys, one angler creel survey, three salmonid spawning run datasets, one adult sea lamprey assessment, and a bottom trawl assessment of dead lake trout. The frequency of fresh sea lamprey marks observed on lake trout from assessment surveys was strongly related to the frequency of sea lamprey attacks observed on salmon and trout from the creel survey and spawning migrations. Attack frequencies on all salmonids examined were related to the ratio between the abundances of adult sea lampreys and lake trout. Reanalysis of the susceptibility to sea lamprey attack for lake trout strains stocked into Lake Ontario reaffirmed that Lake Superior strain lake trout were among the most and Seneca Lake strain among the least susceptible and that Lewis Lake strain lake trout were even more susceptible than the Superior strain. Seasonal attack frequencies indicated that as the number of observed sea lamprey attacks decreased during June–September, the ratio of healing to fresh marks also decreased. Simulation of the ratios of healing to fresh marks indicated that increased lethality of attacks by growing sea lampreys contributed to the decline in the ratios and supported laboratory studies about wound healing duration.

  8. SIGNS OF ACCRETION IN THE ABUNDANCE PATTERNS OF THE COMPONENTS OF THE RS CVn-TYPE ECLIPSING BINARY STAR LX PERSEI

    SciTech Connect

    Kang, Young-Woon; Yushchenko, Alexander V.; Hong, Kyeongsoo; Guinan, Edward F.; Gopka, Vira F. E-mail: yua@sejong.ac.kr

    2013-06-01

    We present spectroscopic observations of LX Per carried out using the Korean Bohyunsan Observatory Echelle Spectrograph (BOES) with spectral resolving power R = 80, 000. The spectrograph was attached to the 1.8 m telescope. The fit of synthetic spectra to the observed spectrum of the system allowed us to find the component parameters and the abundances of chemical elements in the atmospheres of the components. The strong Ca II H and K emissions are confirmed; we also found emission lines in the Ca II reversals' triplet absorptions at the wavelengths of 8498, 8542, and 8662 A in the spectrum of the cooler component of LX Per. A unique photometric solution using the distorted light curves of three different epochs was made. The spot model light curves were fitted to the 1981, 1982, and 1983 observations successfully by adjusting only spot parameters. We could infer that the variation of spot location and size was the main reason for the changing shape of light curves. The main feature of the abundance patterns of both components was the apparent deficiency of heavy (Z > 30) elements. Only elements with strong lines, namely Y and Ba, were detected. Correlations of relative abundances of chemical elements with condensation temperatures and second ionization potentials of these elements, which can be explained by the accretion of dust and gas, were found.

  9. CHEMICAL ABUNDANCE EVIDENCE OF ENDURING HIGH STAR FORMATION RATES IN AN EARLY-TYPE GALAXY: HIGH [Ca/Fe] IN NGC 5128 GLOBULAR CLUSTERS

    SciTech Connect

    Colucci, Janet E.; Duran, Maria Fernanda; Bernstein, Rebecca A.

    2013-08-20

    We present [Fe/H], ages, and Ca abundances for an initial sample of 10 globular clusters in NGC 5128 obtained from high-resolution, high signal-to-noise ratio echelle spectra of their integrated light. All abundances and ages are obtained using our original technique for high-resolution integrated light abundance analysis of globular clusters. The clusters have a range in [Fe/H] between -1.6 and -0.2. In this sample, the average [Ca/Fe] for clusters with [Fe/H] <-0.4 is +0.37 {+-} 0.07, while the average [Ca/Fe] in our Milky Way (MW) and M31 GC samples is +0.29 {+-} 0.09 and +0.24 {+-} 0.10, respectively. This may imply a more rapid chemical enrichment history for NGC 5128 than for either the MW or M31. This sample provides the first quantitative picture of the chemical history of NGC 5128 that is directly comparable to what is available for the MW. Data presented here were obtained with the MIKE echelle spectrograph on the Magellan Clay Telescope.

  10. Cu2ZnSnS4 (CZTS) nanoparticle based nontoxic and earth-abundant hybrid pn-junction solar cells.

    PubMed

    Saha, Sudip K; Guchhait, Asim; Pal, Amlan J

    2012-06-14

    A heterojunction between a layer of CZTS nanoparticles and a layer of fullerene derivatives forms a pn-junction. We have used such an inorganic-organic hybrid pn-junction device for solar cell applications. As routes to optimize device performance, interdot separation has been reduced by replacing long-chain ligands of the quantum dots with short-chain ligands and thickness of the CZTS layer has been varied. We have shown that the CZTS-fullerene interface could dissociate photogenerated excitons due to the depletion region formed at the pn-junction. From capacitance-voltage characteristics, we have determined the width of the depletion region, and compared it with the parameters of devices based on the components of the heterojunction. The results demonstrate solar cell applications based on nontoxic and earth-abundant materials.

  11. [Enteropathy type T-cell lymphomas: pathology and pathogenesis].

    PubMed

    Zettl, A; Rüdiger, T; Müller-Hermelink, H K

    2007-02-01

    Enteropathy type T-cell lymphomas (ETL) are the most frequent T-cell lymphomas arising in the gastrointestinal tract. Commonly, the neoplasm is clinically associated with symptoms of malabsorption, and it frequently manifests as a spontaneous bowel perforation. Among ETL, two types can be distinguished by morphology, immunophenotype and, possibly, by pathogenesis. A total of 80% of ETL are characterized by a close association with celiac disease, pleomorphic cytomorphology and the rare expression of CD8 and CD56. In contrast, 20% of ETL show a monomorphic small to medium size cytomorphology and frequent expression of CD8 and CD56, an association with celiac disease is rare in the latter cases. Genetically, ETL is characterized by frequent and recurrent chromosomal gains of 9q33-q34.

  12. Oral administration of banana lectin modulates cytokine profile and abundance of T-cell populations in mice.

    PubMed

    Sansone, Ana Claudia Miranda Brito; Sansone, Marcelo; Dos Santos Dias, Carlos Tadeu; Oliveira do Nascimento, João Roberto

    2016-08-01

    Banana lectin (BanLec) is a dimeric protein occurring in fruit pulp that modulates immune cell functioning in vitro. In order to assess the immune response in vivo, BanLec from ripe banana (Musa acuminata) fruit was purified and orally given to mice for seven days. The analysis of cytokines in the mice peripheral blood revealed increased IL-10, IL-17 and TNFα, and a reduction of IFNγ and IL-6. In the thymus, an increase of CD4+ and a decrease of CD8+ T-cells were observed after oral administration of BanLec. The modulation of pro- and anti-inflammatory cytokines and T-cells in the peripheral blood and thymus of mice demonstrated the immunomodulatory properties of natural BanLec in vivo. This research brings new data on a protein from a fresh fruit consumed worldwide that may act as an immunomodulator, potentially affecting the host response to infections, immune diseases and cancer.

  13. Automatic discovery of cell types and microcircuitry from neural connectomics

    PubMed Central

    Jonas, Eric; Kording, Konrad

    2015-01-01

    Neural connectomics has begun producing massive amounts of data, necessitating new analysis methods to discover the biological and computational structure. It has long been assumed that discovering neuron types and their relation to microcircuitry is crucial to understanding neural function. Here we developed a non-parametric Bayesian technique that identifies neuron types and microcircuitry patterns in connectomics data. It combines the information traditionally used by biologists in a principled and probabilistically coherent manner, including connectivity, cell body location, and the spatial distribution of synapses. We show that the approach recovers known neuron types in the retina and enables predictions of connectivity, better than simpler algorithms. It also can reveal interesting structure in the nervous system of Caenorhabditis elegans and an old man-made microprocessor. Our approach extracts structural meaning from connectomics, enabling new approaches of automatically deriving anatomical insights from these emerging datasets. DOI: http://dx.doi.org/10.7554/eLife.04250.001 PMID:25928186

  14. Diagnostic challenges of composite colorectal tumors of adenoma-mantle cell lymphoma type.

    PubMed

    Handra-Luca, Adriana

    2013-12-01

    Composite intestinal tumors of adenoma-lymphoma type are rare. To our knowledge 1 tumor showing this association has been previously reported, the histologic diagnosis being made retrospectively. We report the case of an 80-year old male patient complaining for epigastric pain, rectorrhagia, diarrhea, and weight loss. At endoscopy, a rectal lesion (3 cm) of villous low-grade dysplasia adenoma type was detected. Due to persistence of symptoms, new gastro- and coloscopies were performed, the biopsies showing low-grade dysplasia adenomas (right colon, and rectum) and an abundant lymphoid infiltrate (gastroduodenal anastomosis, small intestine, sigmoid, right and left colon, transverse colon, and rectum) of mantle cell lymphoma type, the rectal polyp being composed of both tumor types. The muscularis mucosa was focally infiltrated by the lymphoma, the bulk of the lymphoma being submucosal. After the treatment of 8 mini-cyclophosphamide, hydroxydaunorubicin, oncovin, prednisone cures, lymphoma persisted. On endoscopic ultrasound examination, after the 6 cures of bendamustine following the cyclophosphamide, hydroxydaunorubicin, oncovin, prednisone treatment, the signal of the rectal villous lesion disappeared in the peripheral layers, including of the muscular layer, suggestive of an invasive lesion or persistence of lymphoma. Biopsies confirmed the persistence of the rectal adenoma with low and high-grade adenoma, without lymphoma. In conclusion, the biopsic diagnosis of composite intestinal tumors of adenoma-mantle cell lymphoma type may be challenging, the bulk of the lymphoma being submucosal as in the present case. Although the malignant tumor treatment is the priority in such cases, the effects of chemotherapy on the evolution of benign tumors such as adenomas should be carefully assessed.

  15. Different types of cell death induced by enterotoxins.

    PubMed

    Lin, Chiou-Feng; Chen, Chia-Ling; Huang, Wei-Ching; Cheng, Yi-Lin; Hsieh, Chia-Yuan; Wang, Chi-Yun; Hong, Ming-Yuan

    2010-08-01

    The infection of bacterial organisms generally causes cell death to facilitate microbial invasion and immune escape, both of which are involved in the pathogenesis of infectious diseases. In addition to the intercellular infectious processes, pathogen-produced/secreted enterotoxins (mostly exotoxins) are the major weapons that kill host cells and cause diseases by inducing different types of cell death, particularly apoptosis and necrosis. Blocking these enterotoxins with synthetic drugs and vaccines is important for treating patients with infectious diseases. Studies of enterotoxin-induced apoptotic and necrotic mechanisms have helped us to create efficient strategies to use against these well-characterized cytopathic toxins. In this article, we review the induction of the different types of cell death from various bacterial enterotoxins, such as staphylococcal enterotoxin B, staphylococcal alpha-toxin, Panton-Valentine leukocidin, alpha-hemolysin of Escherichia coli, Shiga toxins, cytotoxic necrotizing factor 1, heat-labile enterotoxins, and the cholera toxin, Vibrio cholerae. In addition, necrosis caused by pore-forming toxins, apoptotic signaling through cross-talk pathways involving mitochondrial damage, endoplasmic reticulum stress, and lysosomal injury is discussed.

  16. Interleukin 18 stimulates HIV type 1 in monocytic cells

    PubMed Central

    Shapiro, Leland; Puren, Adrian J.; Barton, Hazel A.; Novick, Daniela; Peskind, Robert L.; Shenkar, Robert; Gu, Yong; Su, Michael S.-S.; Dinarello, Charles A.

    1998-01-01

    The cytokine interleukin (IL) 18 (formerly interferon γ-inducing factor) induces the T helper type 1 response. In the present studies, IL-18 increased HIV type 1 (HIV-1) production from 5- to 30-fold in the chronically infected U1 monocytic cell line. Inhibition of tumor necrosis factor (TNF) activity by the addition of TNF-binding protein reduced IL-18-stimulated HIV-1 production by 48%. In the same cultures, IL-18-induced IL-8 was inhibited by 96%. Also, a neutralizing anti-IL-6 mAb reduced IL-18-induced HIV-1 by 63%. Stimulation of U1 cells with IL-18 resulted in increased production of IL-6, and exogenous IL-6 added to U1 cells increased HIV-1 production 4-fold over control. A specific inhibitor of the p38 mitogen-activated protein kinase reduced IL-18-induced HIV-1 by 73%, and a 50% inhibition was observed at 0.05 μM. In the same cultures, IL-8 was inhibited by 87%. By gel-shift and supershift analyses, increased binding activity of the transcription factor NF-κB was measured in nuclear extracts from U1 cells 1 h after exposure to IL-18. These results demonstrate induction of HIV-1 by IL-18 in a monocyte target associated with an intermediate role for TNF and IL-6, activation of p38 mitogen-activated protein kinase, and nuclear translocation of NF-κB. PMID:9770523

  17. Interleukin 18 stimulates HIV type 1 in monocytic cells.

    PubMed

    Shapiro, L; Puren, A J; Barton, H A; Novick, D; Peskind, R L; Shenkar, R; Gu, Y; Su, M S; Dinarello, C A

    1998-10-13

    The cytokine interleukin (IL) 18 (formerly interferon gamma-inducing factor) induces the T helper type 1 response. In the present studies, IL-18 increased HIV type 1 (HIV-1) production from 5- to 30-fold in the chronically infected U1 monocytic cell line. Inhibition of tumor necrosis factor (TNF) activity by the addition of TNF-binding protein reduced IL-18-stimulated HIV-1 production by 48%. In the same cultures, IL-18-induced IL-8 was inhibited by 96%. Also, a neutralizing anti-IL-6 mAb reduced IL-18-induced HIV-1 by 63%. Stimulation of U1 cells with IL-18 resulted in increased production of IL-6, and exogenous IL-6 added to U1 cells increased HIV-1 production 4-fold over control. A specific inhibitor of the p38 mitogen-activated protein kinase reduced IL-18-induced HIV-1 by 73%, and a 50% inhibition was observed at 0.05 microM. In the same cultures, IL-8 was inhibited by 87%. By gel-shift and supershift analyses, increased binding activity of the transcription factor NF-kappaB was measured in nuclear extracts from U1 cells 1 h after exposure to IL-18. These results demonstrate induction of HIV-1 by IL-18 in a monocyte target associated with an intermediate role for TNF and IL-6, activation of p38 mitogen-activated protein kinase, and nuclear translocation of NF-kappaB.

  18. Development and Testing of Shingle-type Solar Cell Modules

    NASA Technical Reports Server (NTRS)

    Shepard, N. F., Jr.

    1979-01-01

    The design, development, fabrication and testing of a shingle-type terrestrial solar cell module which produces 98 watts/sq m of exposed module area at 1 kW/sq m insolation and 61 C are reported. These modules make it possible to easily incorporate photovoltaic power generation into the sloping roofs of residential or commercial buildings by simply nailing the modules to the plywood roof sheathing. This design consists of nineteen series-connected 53 mm diameter solar cells arranged in a closely packed hexagon configuration. These cells are individually bonded to the embossed surface of a 3 mm thick thermally tempered hexagon-shaped piece of glass. Polyvinyl butyral is used as the laminating adhesive.

  19. Induction of Human Squamous Cell-Type Carcinomas by Arsenic

    PubMed Central

    Martinez, Victor D.; Becker-Santos, Daiana D.; Vucic, Emily A.; Lam, Stephen; Lam, Wan L.

    2011-01-01

    Arsenic is a potent human carcinogen. Around one hundred million people worldwide have potentially been exposed to this metalloid at concentrations considered unsafe. Exposure occurs generally through drinking water from natural geological sources, making it difficult to control this contamination. Arsenic biotransformation is suspected to have a role in arsenic-related health effects ranging from acute toxicities to development of malignancies associated with chronic exposure. It has been demonstrated that arsenic exhibits preference for induction of squamous cell carcinomas in the human, especially skin and lung cancer. Interestingly, keratins emerge as a relevant factor in this arsenic-related squamous cell-type preference. Additionally, both genomic and epigenomic alterations have been associated with arsenic-driven neoplastic process. Some of these aberrations, as well as changes in other factors such as keratins, could explain the association between arsenic and squamous cell carcinomas in humans. PMID:22175027

  20. Products of cells cultured from gliomas. VI. Immunofluorescent, morphometric, and ultrastructural characterization of two different cell types growing from explants of human gliomas.

    PubMed Central

    McKeever, P. E.; Smith, B. H.; Taren, J. A.; Wahl, R. L.; Kornblith, P. L.; Chronwall, B. M.

    1987-01-01

    Explants derived from human gliomas have been characterized with respect to their cellular outgrowth pattern after 1-22 weeks in culture. A mat of cells which were fibronectin (FN)-positive and glial fibrillary acidic protein (GFAP)-negative (hereafter designated FN+ cells) with a polygonal, flat morphology covered the growth substrate in a swirling pattern for a mean diameter of 9.2 mm around FN+ explants. FN+ cells showed ruffled plasmalemma, dilated rough endoplasmic reticulin (RDR), and extracellular filamentous strands. Rare desmosomes were compatible with at most minor leptomeningeal components or differentiation. FN+ cells predominated in six of seven cultures at passage 2, and their features were the same from various high-grade gliomas and gliosarcoma. Around other explants, elongated or stellate cells which were GFAP+ and FN- grew in a netlike pattern with little cell-to-cell contact. These GFAP+ cells surrounded explants at a mean diameter of 2 mm, substantially less than FN+ cells (P less than 0.005), and they grew more slowly than FN+ cells around explants. GFAP+ cells had an area/perimeter ratio which was less than that of FN+ cells. GFAP+ cells contained abundant intracellular filaments, rare desmosomes, and narrow RER cisternae. In mixed explants, GFAP+ cells often grew on top of FN+ cells. Individual cells which stained for both GFAP and FN were evident only from one glioma (8% doubly positive). Cells negative for both proteins resembled FN+ cells morphologically. Frozen sections of original glioma tissue showed FN+ vessel walls and GFAP+ parenchyma. Results are evidence for very early overgrowth of a preexistent FN+ cell type distinct from the GFAP+ parenchymal cell. The features of this distinct cell type are mesenchymal and resemble the proliferating vascular elements of gliomas in situ. The tendency for GFAP+ cells to grow on top of these FN+ cells suggests a feeder layer interaction. More knowledge of the origins and interactions of these two

  1. Botulinum neurotoxin type A inhibits synaptic vesicle 2 expression in breast cancer cell lines

    PubMed Central

    Bandala, C; Cortés-Algara, AL; Mejía-Barradas, CM; Ilizaliturri-Flores, I; Dominguez-Rubio, R; Bazán-Méndez, CI; Floriano-Sánchez, E; Luna-Arias, JP; Anaya-Ruiz, M; Lara-Padilla, E

    2015-01-01

    Aim: It is known that botulinum neurotoxin type A (BoNTA) improves some kinds of cancer (e.g. prostate) and that synaptic vesicle glycoprotein 2 (SV2) is the molecular target of this neurotoxin. Besides having potential therapeutic value, this glycoprotein has recently been proposed as a molecular marker for several types of cancer. Although the mechanisms of cancer development and the improvement found with botulinum treatment are not well understood, the formation of the botulinum-SV2 complex may influence the presence and distribution of SV2 and the function of vesicles. To date, there are no reports on the possible effect of botulinum on breast cancer of unknown causes, which have a great impact on women’s health. Thus we determined the presence of SV2 in three breast cancer cell lines and the alterations found with botulinum application. Materials and methods: With and without adding 10 units of botulinum, SV2 protein expression was determined by optical densitometry in T47D, MDA-MB-231 and MDA-MB-453 cell lines and the distribution of SV2 was observed with immunochemistry (hematoxylin staining). Results: The SV2 protein was abundant in the cancer cells herein tested, and maximally so in T47D. In all three cancer cell lines botulinum diminished SV2 expression, which was found mostly in the cell periphery. Conclusion: SV2 could be a molecular marker in breast cancer. Its expression and distribution is regulated by botulinum, suggesting an interesting control mechanism for SV2 expression and a possible alternative therapy. Further studies are needed in this sense. PMID:26339411

  2. AtMYB41 activates ectopic suberin synthesis and assembly in multiple plant species and cell types

    PubMed Central

    Kosma, Dylan K; Murmu, Jhadeswar; Razeq, Fakhria M; Santos, Patricia; Bourgault, Richard; Molina, Isabel; Rowland, Owen

    2014-01-01

    Suberin is a lipid and phenolic cell wall heteropolymer found in the roots and other organs of all vascular plants. Suberin plays a critical role in plant water relations and in protecting plants from biotic and abiotic stresses. Here we describe a transcription factor, AtMYB41 (At4g28110), that can activate the steps necessary for aliphatic suberin synthesis and deposition of cell wall-associated suberin-like lamellae in both Arabidopsis thaliana and Nicotiana benthamiana. Overexpression of AtMYB41 increased the abundance of suberin biosynthetic gene transcripts by orders of magnitude and resulted in the accumulation of up to 22 times more suberin-type than cutin-type aliphatic monomers in leaves. Overexpression of AtMYB41 also resulted in elevated amounts of monolignols in leaves and an increase in the accumulation of phenylpropanoid and lignin biosynthetic gene transcripts. Surprisingly, ultrastructural data indicated that overexpression led to the formation of suberin-like lamellae in both epidermal and mesophyll cells of leaves. We further implicate AtMYB41 in the production of aliphatic suberin under abiotic stress conditions. These results provide insight into the molecular-genetic mechanisms of the biosynthesis and deposition of a ubiquitous cell wall-associated plant structure and will serve as a basis for discovering the transcriptional network behind one of the most abundant lipid-based polymers in nature. PMID:25060192

  3. β-Cell function in type 2 diabetes.

    PubMed

    Ferrannini, Ele; Mari, Andrea

    2014-10-01

    Different in vivo tests explore different aspects of β-cell function. Because intercorrelation of insulin secretion indices is modest, no single in vivo test allows β-cell function to be assessed with accuracy and specificity comparable to insulin sensitivity. Physiologically-based mathematical modeling is necessary to interpret insulin secretory responses in terms of relevant parameters of β-cell function. Models can be used to analyze intravenous glucose tests, but secretory responses to intravenous glucose may be paradoxical in subjects with diabetes. Use of oral glucose (or mixed meal) data may be preferable not only for simplicity but also for physiological interpretation. While the disposition index focuses on the relationship between insulin secretion and insulin resistance, secretion parameters reflecting the dynamic response to changing glucose levels over a time frame of minutes or hours--such as β-cell glucose sensitivity--are key to explain changes in glucose tolerance and are largely independent of insulin sensitivity. Pathognomonic of the β-cell defect of type 2 diabetes is a reduced glucose sensitivity, which is accompanied by normal or raised absolute insulin secretion rates--compensatory to the attendant insulin resistance--and impaired incretin-induced potentiation. As β-cell mass is frequently within the range of nondiabetic individuals, these defects are predominantly functional and potentially reversible. Any intervention, on lifestyle or with drugs, that improves glucose tolerance does so primarily through increased β-cell glucose sensitivity. So far, however, no intervention has proven unequivocally capable of modifying the natural course of β-cell dysfunction.

  4. Increased abundance of translation machinery in stem cell–derived neural progenitor cells from four schizophrenia patients

    PubMed Central

    Topol, A; English, J A; Flaherty, E; Rajarajan, P; Hartley, B J; Gupta, S; Desland, F; Zhu, S; Goff, T; Friedman, L; Rapoport, J; Felsenfeld, D; Cagney, G; Mackay-Sim, A; Savas, J N; Aronow, B; Fang, G; Zhang, B; Cotter, D; Brennand, K J

    2015-01-01

    The genetic and epigenetic factors contributing to risk for schizophrenia (SZ) remain unresolved. Here we demonstrate, for the first time, perturbed global protein translation in human-induced pluripotent stem cell (hiPSC)-derived forebrain neural progenitor cells (NPCs) from four SZ patients relative to six unaffected controls. We report increased total protein levels and protein synthesis, together with two independent sets of quantitative mass spectrometry evidence indicating markedly increased levels of ribosomal and translation initiation and elongation factor proteins, in SZ hiPSC NPCs. We posit that perturbed levels of global protein synthesis in SZ hiPSC NPCs represent a novel post-transcriptional mechanism that might contribute to disease progression. PMID:26485546

  5. Isolation of cell type-specific apoptotic bodies by fluorescence-activated cell sorting

    PubMed Central

    Atkin-Smith, Georgia K.; Paone, Stephanie; Zanker, Damien J.; Duan, Mubing; Phan, Than K.; Chen, Weisan; Hulett, Mark D.; Poon, Ivan K. H.

    2017-01-01

    Apoptotic bodies (ApoBDs) are membrane-bound extracellular vesicles that can mediate intercellular communication in physiological and pathological settings. By combining recently developed analytical strategies with fluorescence-activated cell sorting (FACS), we have developed a method that enables the isolation of ApoBDs from cultured cells to 99% purity. In addition, this approach also enables the identification and isolation of cell type-specific ApoBDs from tissue, bodily fluid and blood-derived samples. PMID:28057919

  6. Enterococcus faecalis Produces Abundant Extracellular Structures Containing DNA in the Absence of Cell Lysis during Early Biofilm Formation

    PubMed Central

    Barnes, Aaron M. T.; Ballering, Katie S.; Leibman, Rachel S.; Wells, Carol L.; Dunny, Gary M.

    2012-01-01

    ABSTRACT Enterococcus faecalis is a common Gram-positive commensal bacterium of the metazoan gastrointestinal tract capable of biofilm formation and an opportunistic pathogen of increasing clinical concern. Dogma has held that biofilms are slow-growing structures, often taking days to form mature microcolonies. Here we report that extracellular DNA (eDNA) is an integral structural component of early E. faecalis biofilms (≤4 h postinoculation). Combining cationic dye-based biofilm matrix stabilization techniques with correlative immuno-scanning electron microscopy (SEM) and fluorescent techniques, we demonstrate that—in early E. faecalis biofilms—eDNA localizes to previously undescribed intercellular filamentous structures, as well as to thick mats of extruded extracellular matrix material. Both of these results are consistent with previous reports that early biofilms are exquisitely sensitive to exogenous DNase treatment. High-resolution SEM demonstrates a punctate labeling pattern in both structures, suggesting the presence of an additional, non-DNA constituent. Notably, the previously described fratricidal or lytic mechanism reported as the source of eDNA in older (≥24 h) E. faecalis biofilms does not appear to be at work under these conditions; extensive visual examination by SEM revealed a striking lack of lysed cells, and bulk biochemical assays also support an absence of significant lysis at these early time points. In addition, some cells demonstrated eDNA labeling localized at the septum, suggesting the possibility of DNA secretion from metabolically active cells. Overall, these data are consistent with a model in which a subpopulation of viable E. faecalis cells secrete or extrude DNA into the extracellular matrix. PMID:22829679

  7. Characterization of the abundant ≤0.2 μm cell-like particles inhabiting Lake Vida brine, McMurdo Dry Valleys, Antarctica

    NASA Astrophysics Data System (ADS)

    Kuhn, E.; Ichimura, A.; Peng, V.; Fritsen, C. H.; Murray, A. E.

    2011-12-01

    0.2 μm filtrate clone library includes genera not detected in the 2005 clone library like Pseudoalteromonas and β-Proteobacteria genera Herbaspirillum and Naxibacter. Confocal microscopy observations showed that DNA stains bind to the NP, suggesting that NP have a genomic component. SEM and STEM images show that the NP presents coccoid morphology, cell division behavior, and an extracellular matrix connecting cells to each other. Energy-dispersive x-ray microanalyses (EDS) detected C, O and Fe in the NP and cells >0.2 μm. Preliminary results suggest: (1) the NP presents a community composition different from the whole community, including the most abundant genera detected in the whole brine (Pscychrobacter and Marinobacter); (2) NP and some >0.2 μm cells contain Fe in their composition, suggesting an iron oxide external layer; and (3) the microbial community is connected by an uncharacterized matrix (likely comprised of an extracellular polymeric substance) linking cells to cells and cells to particles. Thus, the most abundant constituents inhabiting the unusual cryoenvironment of Lake Vida appear to be of biological origin, though their growth state and means for survival remain to be known.

  8. The boron abundance of Procyon

    NASA Technical Reports Server (NTRS)

    Lemke, Michael; Lambert, David L.; Edvardsson, Bengt

    1993-01-01

    The B I 2496.8 A resonance line and HST/GHRS echelle spectra are used with model atmospheres and synthetic spectra to derive the B abundance of the F dwarfs Procyon (Alpha Canis Minoris), Theta Ursae Majoris, and Iota Pegasi. The B abundance of Theta UMa and Iota Peg is similar to that derived by Boesgaard and Heacox (1978) from the B II resonance line in spectra of A- and B-type stars. These two dwarfs show normal abundances of Li, Be, and B. Procyon, which is highly depleted in Li and Be, is depleted in B by a factor of at least 3. Comparison of the spectra of Procyon and the halo dwarf HD 140283 shows that the B abundance assigned by Duncan et al. (1992) to three halo dwarfs is not greatly overestimated as a result of contamination of the B I line by an unidentified line.

  9. The boron abundance of Procyon

    NASA Astrophysics Data System (ADS)

    Lemke, Michael; Lambert, David L.; Edvardsson, Bengt

    1993-05-01

    The B I 2496.8 A resonance line and HST/GHRS echelle spectra are used with model atmospheres and synthetic spectra to derive the B abundance of the F dwarfs Procyon (Alpha Canis Minoris), Theta Ursae Majoris, and Iota Pegasi. The B abundance of Theta UMa and Iota Peg is similar to that derived by Boesgaard and Heacox (1978) from the B II resonance line in spectra of A- and B-type stars. These two dwarfs show normal abundances of Li, Be, and B. Procyon, which is highly depleted in Li and Be, is depleted in B by a factor of at least 3. Comparison of the spectra of Procyon and the halo dwarf HD 140283 shows that the B abundance assigned by Duncan et al. (1992) to three halo dwarfs is not greatly overestimated as a result of contamination of the B I line by an unidentified line.

  10. Activated Type 2 Innate Lymphoid Cells regulate Beige Fat Biogenesis

    PubMed Central

    Lee, Min-Woo; Odegaard, Justin I.; Mukundan, Lata; Qiu, Yifu; Molofsky, Ari B.; Nussbaum, Jesse C.; Yun, Karen; Locksley, Richard M.; Chawla, Ajay

    2014-01-01

    SUMMARY Type 2 innate lymphoid cells (ILC2s), an innate source of the type 2 cytokines interleukin (IL)-5 and -13, participate in the maintenance of tissue homeostasis. Although type 2 immunity is critically important for mediating metabolic adaptations to environmental cold, the functions of ILC2s in beige or brown fat development are poorly defined. We report here that activation of ILC2s by IL-33 is sufficient to promote the growth of functional beige fat in thermoneutral mice. Mechanistically, ILC2 activation results in the proliferation of bipotential adipocyte precursors (APs) and their subsequent commitment to the beige fat lineage. Loss- and gain-of-function studies reveal that ILC2-and eosinophil-derived type 2 cytokines stimulate signaling via the IL-4Rα in PDGFRα+ APs to promote beige fat biogenesis. Together, our results highlight a critical role for ILC2s and type 2 cytokines in the regulation of adipocyte precursor numbers and fate, and as a consequence, adipose tissue homeostasis. PMID:25543153

  11. Chrna2-Martinotti Cells Synchronize Layer 5 Type A Pyramidal Cells via Rebound Excitation

    PubMed Central

    Leão, Richardson N.; Edwards, Steven J.

    2017-01-01

    Martinotti cells are the most prominent distal dendrite–targeting interneurons in the cortex, but their role in controlling pyramidal cell (PC) activity is largely unknown. Here, we show that the nicotinic acetylcholine receptor α2 subunit (Chrna2) specifically marks layer 5 (L5) Martinotti cells projecting to layer 1. Furthermore, we confirm that Chrna2-expressing Martinotti cells selectively target L5 thick-tufted type A PCs but not thin-tufted type B PCs. Using optogenetic activation and inhibition, we demonstrate how Chrna2-Martinotti cells robustly reset and synchronize type A PCs via slow rhythmic burst activity and rebound excitation. Moreover, using optical feedback inhibition, in which PC spikes controlled the firing of surrounding Chrna2-Martinotti cells, we found that neighboring PC spike trains became synchronized by Martinotti cell inhibition. Together, our results show that L5 Martinotti cells participate in defined cortical circuits and can synchronize PCs in a frequency-dependent manner. These findings suggest that Martinotti cells are pivotal for coordinated PC activity, which is involved in cortical information processing and cognitive control. PMID:28182735

  12. Type 1 diabetes immunotherapy using polyclonal regulatory T cells

    PubMed Central

    Bluestone, Jeffrey A.; Buckner, Jane H.; Fitch, Mark; Gitelman, Stephen E.; Gupta, Shipra; Hellerstein, Marc K.; Herold, Kevan C.; Lares, Angela; Lee, Michael R.; Li, Kevin; Liu, Weihong; Long, S. Alice; Masiello, Lisa M.; Nguyen, Vinh; Putnam, Amy L.; Rieck, Mary; Sayre, Peter; Tang, Qizhi

    2016-01-01

    Type 1 diabetes (T1D) is an autoimmune disease that occurs in genetically susceptible individuals. Regulatory T cells (Tregs) have been shown to be defective in the autoimmune disease setting. Thus, efforts to repair or replace Tregs in T1D may reverse autoimmunity and protect the remaining insulin-producing β cells. On the basis of this premise, a robust technique has been developed to isolate and expand Tregs from patients with T1D. The expanded Tregs retained their T cell receptor diversity and demonstrated enhanced functional activity. We report on a phase 1 trial to assess safety of Treg adoptive immunotherapy in T1D. Fourteen adult subjects with T1D, in four dosing cohorts, received ex vivo–expanded autologous CD4+CD127lo/−CD25+ polyclonal Tregs (0.05 × 108 to 26 × 108 cells). A subset of the adoptively transferred Tregs was long-lived, with up to 25% of the peak level remaining in the circulation at 1 year after transfer. Immune studies showed transient increases in Tregs in recipients and retained a broad Treg FOXP3+CD4+CD25hiCD127lo phenotype long-term. There were no infusion reactions or cell therapy–related high-grade adverse events. C-peptide levels persisted out to 2+ years after transfer in several individuals. These results support the development of a phase 2 trial to test efficacy of the Treg therapy. PMID:26606968

  13. Staphylococcus epidermidis Affinity for Fibrinogen-Coated Surfaces Correlates with the Abundance of the SdrG Adhesin on the Cell Surface.

    PubMed

    Vanzieleghem, Thomas; Herman-Bausier, Philippe; Dufrene, Yves F; Mahillon, Jacques

    2015-04-28

    Staphylococcus epidermidis is a world-leading pathogen in healthcare facilities, mainly causing medical device-associated infections. These nosocomial diseases often result in complications such as bacteremia, fibrosis, or peritonitis. The virulence of S. epidermidis relies on its ability to colonize surfaces and develop thereupon in the form of biofilms. Bacterial adherence on biomaterials, usually covered with plasma proteins after implantation, is a critical step leading to biofilm infections. The cell surface protein SdrG mediates adhesion of S. epidermidis to fibrinogen (Fg) through a specific "dock, lock, and latch" mechanism, which results in greatly stabilized protein-ligand complexes. Here, we combine single-molecule, single-cell, and whole population assays to investigate the extent to which the surface density of SdrG determines the ability of S. epidermidis clinical strains HB, ATCC 35984, and ATCC 12228 to bind to Fg-coated surfaces. Strains that showed enhanced adhesion on Fg-coated polydimethylsiloxane (PDMS) were characterized by increased amounts of SdrG proteins on the cell surface, as observed by single-molecule analysis. Consistent with previous reports showing increased expression of SdrG following in vivo exposure, this work provides direct evidence that abundance of SdrG on the cell surface of S. epidermidis strains dramatically improves their ability to bind to Fg-coated implanted medical devices.

  14. Global methylation profiles in DNA from different blood cell types.

    PubMed

    Wu, Hui-Chen; Delgado-Cruzata, Lissette; Flom, Julie D; Kappil, Maya; Ferris, Jennifer S; Liao, Yuyan; Santella, Regina M; Terry, Mary Beth

    2011-01-01

    DNA methylation measured in white blood cell DNA is increasingly being used as in studies of cancer susceptibility. However, little is known about the correlation between different assays to measure global methylation and whether the source of DNA matters when examining methylation profiles in different blood cell types. Using information from 620 women, 217 and 403 women with DNA available from granulocytes (Gran), and total white blood cells (WBC), respectively, and 48 women with DNA available from four different sources (WBC, Gran, mononuclear (MN), and lymphoblastoid cell lines (LCL)), we compared DNA methylation for three repetitive elements (LINE1, Sat2, Alu) by MethyLight, luminometric methylation assay (LUMA), and [(3)H]-methyl acceptance assay. For four of the five assays, DNA methylation levels measured in Gran were not correlated with methylation in LBC, MN, or WBC; the exception was Sat2. DNA methylation in LCL was correlated with methylation in MN and WBC for the [(3)H]-methyl acceptance, LINE1, and Alu assays. Methylation in MN was correlated with methylation in WBC for the [(3)H]-methyl acceptance and LUMA assays. When we compared the five assays to each other by source of DNA, we observed statistically significant positive correlations ranging from 0.3-0.7 for each cell type with one exception (Sat2 and Alu in MN). Among the 620 women stratified by DNA source, correlations among assays were highest for the three repetitive elements (range 0.39-0.64). Results from the LUMA assay were modestly correlated with LINE1 (0.18-0.20). These results suggest that both assay and source of DNA are critical components in the interpretation of global DNA methylation patterns from WBC.

  15. Single-Cell mRNA Profiling Reveals Cell-Type Specific Expression of Neurexin Isoforms

    PubMed Central

    Fuccillo, Marc V.; Földy, Csaba; Gökce, Özgün; Rothwell, Patrick E.; Sun, Gordon L.; Malenka, Robert C.; Südhof, Thomas C.

    2016-01-01

    Summary Neurexins are considered central organizers of synapse architecture that are implicated in neuropsychiatric disorders. Expression of neurexins in hundreds of alternatively spliced isoforms suggested that individual neurons might exhibit a cell type-specific neurexin expression pattern (a neurexin code). To test this hypothesis, we quantified the single-cell levels of neurexin isoforms and other trans-synaptic cell-adhesion molecules by microfluidics-based RT-PCR. We show that the neurexin repertoire displays pronounced cell-type specificity that is remarkably consistent within each type of neuron. Furthermore, we uncovered region-specific regulation of neurexin transcription and splice-site usage. Finally, we demonstrate that the transcriptional profiles of neurexins can be altered in an experience-dependent fashion by exposure to a drug of abuse. Our data provide evidence of cell type-specific expression patterns of multiple neurexins at the single-cell level, and suggest that expression of synaptic cell-adhesion molecules overlaps with other key features of cellular identity and diversity. PMID:26182417

  16. Is human T-cell lymphotropic virus type I really silent?

    PubMed Central

    Asquith, B; Hanon, E; Taylor, G P; Bangham, C R

    2000-01-01

    The role of the cellular immune response to human T-cell lymphotropic virus type I (HTLV-I) is not fully understood. The low level of HTLV-I protein expression in peripheral blood lymphocytes has led to the widely held belief that HTLV-I is transcriptionally silent in vivo. However, most HTLV-I-infected individuals mount a strong and persistently activated cytotoxic T-lymphocyte (CTL) response to the virus; this observation implies that there is abundant chronic transcription of HTLV-I genes. Here we show that HTLV-I Tax protein expression rises quickly in freshly isolated peripheral blood lymphocytes, but that expressing cells are rapidly killed by CTLs. Mathematical analysis of these results indicates that the CTL response is extremely efficient and that the half-life of a Tax-expressing cell is less than a day. We propose that HTLV-I protein expression in circulating lymphocytes is undetectable by current techniques because of the efficiency of the CTL-mediated immune surveillance in vivo. PMID:11186302

  17. Absent and abundant MET immunoreactivity is associated with poor prognosis of patients with oral and oropharyngeal squamous cell carcinoma

    PubMed Central

    De Herdt, Maria J.; Willems, Stefan M.; van der Steen, Berdine; Noorlag, Rob; Verhoef, Esther I.; van Leenders, Geert J.L.H.; van Es, Robert J.J.; Koljenović, Senada; de Jong, Robert J. Baatenburg; Looijenga, Leendert H.J.

    2016-01-01

    Although the receptor tyrosine kinase (RTK) MET is widely expressed in head and neck squamous cell carcinoma (HNSCC), its prognostic value remains unclear. This might be due to the use of a variety of antibodies and scoring systems. Here, the reliability of five commercial C-terminal MET antibodies (D1C2, CVD13, SP44, C-12 and C-28) was evaluated before examining the prognostic value of MET immunoreactivity in HNSCC. Using cancer cell lines, it was shown that D1C2 and CVD13 specifically detect MET under reducing, native and formalin-fixed paraffin-embedded (FFPE) conditions. Immunohistochemical staining of routinely FFPE oral SCC with D1C2 and CVD13 demonstrated that D1C2 is most sensitive in the detection of membranous MET. Examination of membranous D1C2 immunoreactivity with 179 FFPE oral and oropharyngeal SCC – represented in a tissue microarray – illustrated that staining is either uniform (negative or positive) across tumors or differs between a tumor's center and periphery. Ultimately, statistical analysis revealed that D1C2 uniform staining is significantly associated with poor 5-year overall and disease free survival of patients lacking vasoinvasive growth (HR = 3.019, p < 0.001; HR = 2.559, p < 0.001). These findings might contribute to reliable stratification of patients eligible for treatment with biologicals directed against MET. PMID:26909606

  18. Gamma-Retrovirus Integration Marks Cell Type-Specific Cancer Genes: A Novel Profiling Tool in Cancer Genomics

    PubMed Central

    Gilroy, Kathryn L.; Terry, Anne; Naseer, Asif; de Ridder, Jeroen; Wang, Weiwei; Carpenter, Eric; Mason, Andrew; Wong, Gane K-S.; Kilbey, Anna; Neil, James C.

    2016-01-01

    Retroviruses have been foundational in cancer research since early studies identified proto-oncogenes as targets for insertional mutagenesis. Integration of murine gamma-retroviruses into the host genome favours promoters and enhancers and entails interaction of viral integrase with host BET/bromodomain factors. We report that this integration pattern is conserved in feline leukaemia virus (FeLV), a gamma-retrovirus that infects many human cell types. Analysis of FeLV insertion sites in the MCF-7 mammary carcinoma cell line revealed strong bias towards active chromatin marks with no evidence of significant post-integration growth selection. The most prominent FeLV integration targets had little overlap with the most abundantly expressed transcripts, but were strongly enriched for annotated cancer genes. A meta-analysis based on several gamma-retrovirus integration profiling (GRIP) studies in human cells (CD34+, K562, HepG2) revealed a similar cancer gene bias but also remarkable cell-type specificity, with prominent exceptions including a universal integration hotspot at the long non-coding RNA MALAT1. Comparison of GRIP targets with databases of super-enhancers from the same cell lines showed that these have only limited overlap and that GRIP provides unique insights into the upstream drivers of cell growth. These observations elucidate the oncogenic potency of the gamma-retroviruses and support the wider application of GRIP to identify the genes and growth regulatory circuits that drive distinct cancer types. PMID:27097319

  19. PAX6 maintains β cell identity by repressing genes of alternative islet cell types

    PubMed Central

    Swisa, Avital; Avrahami, Dana; Eden, Noa; Zhang, Jia; Feleke, Eseye; Dahan, Tehila; Cohen-Tayar, Yamit; Stolovich-Rain, Miri; Kaestner, Klaus H.; Glaser, Benjamin; Ashery-Padan, Ruth

    2016-01-01

    Type 2 diabetes is thought to involve a compromised β cell differentiation state, but the mechanisms underlying this dysfunction remain unclear. Here, we report a key role for the TF PAX6 in the maintenance of adult β cell identity and function. PAX6 was downregulated in β cells of diabetic db/db mice and in WT mice treated with an insulin receptor antagonist, revealing metabolic control of expression. Deletion of Pax6 in β cells of adult mice led to lethal hyperglycemia and ketosis that were attributed to loss of β cell function and expansion of α cells. Lineage-tracing, transcriptome, and chromatin analyses showed that PAX6 is a direct activator of β cell genes, thus maintaining mature β cell function and identity. In parallel, we found that PAX6 binds promoters and enhancers to repress alternative islet cell genes including ghrelin, glucagon, and somatostatin. Chromatin analysis and shRNA-mediated gene suppression experiments indicated a similar function of PAX6 in human β cells. We conclude that reduced expression of PAX6 in metabolically stressed β cells may contribute to β cell failure and α cell dysfunction in diabetes. PMID:27941241

  20. Development and characterization of a Mantle Cell Lymphoma Cell Bank in the American Type Culture Collection.

    PubMed

    Fogli, Laura K; Williams, Michael E; Connors, Joseph M; Reid, Yvonne; Brown, Kathleen; O'Connor, Owen A

    2015-07-01

    Mantle cell lymphoma (MCL) is a rare B-cell malignancy that carries a relatively poor prognosis compared to other forms of non-Hodgkin lymphoma. Standardized preclinical tools are desperately required to hasten the discovery and translation of promising new treatments for MCL. Via an initiative organized through the Mantle Cell Lymphoma Consortium and the Lymphoma Research Foundation, we gathered MCL cell lines from laboratories around the world to create a characterized MCL Cell Bank at the American Type Culture Collection (ATCC). Initiated in 2006, this collection now contains eight cell lines, all of which have been rigorously characterized and are now stored and available for distribution to the general scientific community. We believe the awareness and use of these standardized cell lines will decrease variability between investigators, harmonize international research efforts, improve our understanding of the pathogenesis of the disease and hasten the development of novel treatment strategies.

  1. Alternatively spliced type II procollagen mRNAs define distinct populations of cells during vertebral development: differential expression of the amino-propeptide

    PubMed Central

    1991-01-01

    Type II collagen is a major component of cartilage providing structural integrity to the tissue. Type II procollagen can be expressed in two forms by differential splicing of the primary gene transcript. The two mRNAs either include (type IIA) or exclude (type IIB) an exon (exon 2) encoding the major portion of the amino (NH2)-propeptide (Ryan, M. C., and L. J. Sandell. 1990. J. Biol. Chem. 265:10334-10339). The expression of the two procollagens was examined in order to establish a potential functional significance for the two type II procollagen mRNAs. First, to establish whether the two mRNAs are functional, we showed that both mRNAs can be translated and the proteins secreted into the extracellular environment. Both proteins were identified as type II procollagens. Secondly, to test the hypothesis that differential expression of type II procollagens may be a marker for a distinct population of cells, specific procollagen mRNAs were localized in tissue by in situ hybridization to oligonucleotides spanning the exon junctions. Embryonic vertebral column was chosen as a source of tissue undergoing rapid chondrogenesis, allowing the examination of a variety of cell types related to cartilage. In this issue, each procollagen mRNA had a distinct tissue distribution during chondrogenesis with type IIB expressed in chondrocytes and type IIA expressed in cells surrounding cartilage in prechondrocytes. The morphology of the cells expressing the two collagen types was distinct: the cells expressing type IIA are narrow, elongated, and "fibroblastic" in appearance while the cells expressing type IIB are large and round. The expression of type IIB appears to be correlated with abundant synthesis and accumulation of cartilagenous extracellular matrix. The expression of type IIB is spatially correlated with the high level expression of the cartilage proteoglycan, aggrecan, establishing type IIB procollagen and aggrecan as markers for the chondrocyte phenotype. Transcripts of

  2. Optically characterizing collagen gels made with different cell types

    NASA Astrophysics Data System (ADS)

    Levitz, David; Choudhury, Niloy; Vartanian, Keri; Hinds, Monica T.; Hanson, Stephen R.; Jacques, Steven L.

    2009-02-01

    The ability of optical imaging techniques such as optical coherence tomography (OCT) to non-destructively characterize tissue-engineered constructs has generated enormous interest recently. Collagen gels are 3D structures that represent a simple common model of many engineered tissues that contain 2 primary scatterers: collagen and cells. We are testing the ability of OCT data to characterize the remodeling of such collagen-based constructs by 3 different types of cells: vascular smooth muscle cells (SMCs), endothelial cells (ECs), and osteoblasts (OBs). Collagen gels were prepared with SMCs, ECs, and OBs with a seeding density of 1×106 cells/ml; additionally, acellular controls were also prepared. The disk-shaped constructs were allowed to remodel in the incubator for 5 days, with OCT imaging occurring on days 1 and 5. From the OCT data, the attenuation and reflectivity were evaluated by fitting the data to a theoretical model that relates the tissue optical properties (scattering coefficient and anisotropy factor) and imaging conditions to the OCT signal. The degree of gel compaction was determined from the volume of the culture medium that feeds the constructs. We found that gel compaction (relative to the acellular control) occurred in the SMC constructs, but not in the OB or EC constructs. The optical property data showed that at day 5 the SMC constructs had an overall higher reflectivity (lower g) relative to day 1, whereas there was no obvious change in reflectivity of the EC, OB constructs and acellular controls relative to day 1. Moreover, there was a difference in the attenuation of the OB constructs on day 5 relative to day 1, but not in the other constructs. The apparent decrease in anisotropy observed in the SMC constructs, but not in the OB and EC constructs and acellular controls, suggests that OCT is sensitive to the remodeling of the collagen matrix that accompanies gel compaction, and can offer highly localized information on the construct

  3. Clear cell renal cell carcinoma with a syncytial-type multinucleated giant tumor cell component: implications for differential diagnosis.

    PubMed

    Williamson, Sean R; Kum, Jennifer B; Goheen, Michael P; Cheng, Liang; Grignon, David J; Idrees, Muhammad T

    2014-04-01

    A component of syncytial-type multinucleated tumor giant cells is uncommon in clear cell renal cell carcinoma, and the histogenesis, incidence, and clinical implications of this finding are not well understood. We retrieved 13 such tumors from our pathology archives in patients with a median age of 60years, comprising 1.5% of clear cell renal cell carcinomas. Stage was typically pT4 or pT3 (each 38%). Microscopically, all tumors included a component of low-grade clear cell renal cell carcinoma with usual features. Syncytial-type giant tumor cells possessed voluminous cytoplasm, usually granular and eosinophilic, and numerous nuclei similar to those of the mononuclear tumor cells. Transition between areas of mononuclear and multinucleated cells was sometimes abrupt. Other findings included necrosis (77%), hyaline globules (46%), emperipolesis (46%), and intranuclear cytoplasmic invaginations (23%). Immunohistochemical staining typically revealed both mononuclear and multinucleated cells to be positive for carbonic anhydrase IX, CD10, epithelial membrane antigen, vimentin, and cytokeratin AE1/AE3 and negative for β human chorionic gonadotropin, TFE3, cathepsin K, cytokeratin 7, cytokeratin 20, HMB45, CD68, smooth muscle actin, and S100. Most patients with available information (7/9) were alive with metastatic disease at the most recent follow-up. Syncytial-type giant cells are an uncommon finding associated with aggressive clear cell renal cell carcinomas. Despite the unusual appearance of this tumor component, its immunoprofile supports an epithelial lineage and argues against trophoblastic, osteoclast-like, or histiocytic differentiation. Reactivity for typical clear cell renal cell carcinoma antigens facilitates discrimination from giant cells of epithelioid angiomyolipoma or other tumors, particularly in a biopsy specimen or a metastatic tumor.

  4. Transplantation of mesenchymal stem cells improves type 1 diabetes mellitus.

    PubMed

    Li, Lisha; Li, Furong; Gao, Feng; Yang, Yali; Liu, Yuanyuan; Guo, Pingping; Li, Yulin

    2016-05-01

    Bone-marrow-derived stem cells can regenerate pancreatic tissue in a model of type 1 diabetes mellitus. Mesenchymal stem cells (MSCs) form the main part of bone marrow. We show that the intrapancreatic transplantation of MSCs elevates serum insulin and C-peptide, while decreasing blood glucose. MSCs engrafted into the damaged rat pancreas become distributed into the blood vessels, acini, ducts, and islets. Renascent islets, islet-like clusters, and a small number of MSCs expressing insulin protein have been observed in the pancreas of diabetic rats. Intrapancreatic transplantation of MSCs triggers a series of molecular and cellular events, including differentiation towards the pancreas directly and the provision of a niche to start endogenous pancreatic regeneration, which ameliorates hypoinsulinemia and hyperglycemia caused by streptozotocin. These data establish the many roles of MSCs in the restoration of the function of an injured organ.

  5. Functionalized fullerenes mediate photodynamic killing of cancer cells: Type I versus Type II photochemical mechanism

    PubMed Central

    Mroz, Pawel; Pawlak, Anna; Satti, Minahil; Lee, Haeryeon; Wharton, Tim; Gali, Hariprasad; Sarna, Tadeusz; Hamblin, Michael R.

    2007-01-01

    Photodynamic therapy (PDT) employs the combination of non-toxic photosensitizers (PS) and harmless visible light to generate reactive oxygen species (ROS) and kill cells. Most clinically studied PS are based on the tetrapyrrole structure of porphyrins, chlorins and related molecules, but new non-tetrapyrrole PS are being sought. Fullerenes are soccer-ball shaped molecules composed of sixty or seventy carbon atoms and have attracted interest in connection with the search for biomedical applications of nanotechnology. Fullerenes are biologically inert unless derivatized with functional groups, whereupon they become soluble and can act as PS. We have compared the photodynamic activity of six functionalized fullerenes with 1, 2, or 3 hydrophilic or 1, 2, or 3 cationic groups. The octanol-water partition coefficients were determined and the relative contributions of Type I photochemistry (photogeneration of superoxide in the presence of NADH) and Type II photochemistry (photogeneration of singlet oxygen) were studied by measurement of oxygen consumption, 1270-nm luminescence and EPR spin-trapping of the superoxide product. We studied three mouse cancer cell lines: (J774, LLC and CT26) incubated for 24 h with fullerenes and illuminated with white light. The order of effectiveness as PS was inversely proportional to the degree of substitution of the fullerene nucleus for both the neutral and cationic series. The mono-pyrrolidinium fullerene was the most active PS against all cell lines and induced apoptosis 4–6 hours after illumination. It produced diffuse intracellular fluorescence when dichlorodihydrofluorescein was added as an ROS probe suggesting a Type I mechanism for phototoxicity. We conclude that certain functionalized fullerenes have potential as novel PDT agents and phototoxicity may be mediated both by superoxide and by singlet oxygen. PMID:17664135

  6. Isolation of Highly Pure Primary Mouse Alveolar Epithelial Type II Cells by Flow Cytometric Cell Sorting

    PubMed Central

    Lowell, Clifford A.

    2017-01-01

    In this protocol, we describe the method for isolating highly pure primary alveolar epithelial type II (ATII) cells from lungs of naïve mice. The method combines negative selection for a variety of lineage markers along with positive selection for EpCAM, a pan-epithelial cell marker. This method yields 2-3 × 106 ATII cells per mouse lung. The cell preps are highly pure and viable and can be used for genomic or proteomic analyses or cultured ex vivo to understand their roles in various biological processes. PMID:28180137

  7. Transdifferentiation between Luminal- and Basal-Type Cancer Cells

    DTIC Science & Technology

    2013-12-01

    mesenchymal transition (EMT) by inhibitory phosphorylation of transcription factor Snail , a master switch of EMT. Supported by this award, we have... Snail -wild type (WT), Snail -S11E and –S11V. Snail , a well-known transcription repressor of the key epithelial adherens junction protein E-cadherin...CD24hiCD44lo phenotype (Fig 1A). The resulting cell lines MCF7/ Snail -WT and Snail -S11E (mimics constant phosphorylation) did not display a significant

  8. Single-cell-type Proteomics: Toward a Holistic Understanding of Plant Function*

    PubMed Central

    Dai, Shaojun; Chen, Sixue

    2012-01-01

    Multicellular organisms such as plants contain different types of cells with specialized functions. Analyzing the protein characteristics of each type of cell will not only reveal specific cell functions, but also enhance understanding of how an organism works. Most plant proteomics studies have focused on using tissues and organs containing a mixture of different cells. Recent single-cell-type proteomics efforts on pollen grains, guard cells, mesophyll cells, root hairs, and trichomes have shown utility. We expect that high resolution proteomic analyses will reveal novel functions in single cells. This review provides an overview of recent developments in plant single-cell-type proteomics. We discuss application of the approach for understanding important cell functions, and we consider the technical challenges of extending the approach to all plant cell types. Finally, we consider the integration of single-cell-type proteomics with transcriptomics and metabolomics with the goal of providing a holistic understanding of plant function. PMID:22982375

  9. Single-cell-type proteomics: toward a holistic understanding of plant function.

    PubMed

    Dai, Shaojun; Chen, Sixue

    2012-12-01

    Multicellular organisms such as plants contain different types of cells with specialized functions. Analyzing the protein characteristics of each type of cell will not only reveal specific cell functions, but also enhance understanding of how an organism works. Most plant proteomics studies have focused on using tissues and organs containing a mixture of different cells. Recent single-cell-type proteomics efforts on pollen grains, guard cells, mesophyll cells, root hairs, and trichomes have shown utility. We expect that high resolution proteomic analyses will reveal novel functions in single cells. This review provides an overview of recent developments in plant single-cell-type proteomics. We discuss application of the approach for understanding important cell functions, and we consider the technical challenges of extending the approach to all plant cell types. Finally, we consider the integration of single-cell-type proteomics with transcriptomics and metabolomics with the goal of providing a holistic understanding of plant function.

  10. Age-related changes in transcriptional abundance and circulating levels of anti-Mullerian hormone and Sertoli cell count in crossbred and Zebu bovine males.

    PubMed

    Rajak, S K; Kumaresan, A; Attupuram, N M; Chhillar, S; Baithalu, R K; Nayak, S; Sreela, L; Singh, Raushan K; Tripathi, U K; Mohanty, T K; Yadav, Savita

    2017-02-01

    Age-related changes in peripheral anti-Mullerian hormone (AMH) concentrations and transcriptional abundance of AMH gene in testicular tissue were studied in crossbred (Holstein Friesian × Tharparkar) and Zebu (Tharparkar) males. In both the breeds, basal AMH concentrations were estimated using ELISA method in blood plasma obtained from six males each at 1, 6, 12, 18, and 24 months age. After blood collection at respective ages, all the males were castrated and expression and immunolocalization of AMH was performed in the testicular tissue. The concentration of AMH in blood plasma was found to be highest at 1 month of age in both crossbred and Zebu males, which subsequently decreased with advancing age. Significantly (P < 0.05) lower concentration of AMH was observed in crossbred as compared with Zebu males at 24 months of age. In line with peripheral AMH concentrations, the expression of AMH gene was also higher (P < 0.05) at 1 month of age, which thereafter declined significantly with advancement of age in crossbred males. Furthermore, the expression of AMH gene differed significantly between Zebu and crossbred males at all the age groups studied. Immunolocalization of AMH in testicular tissue also revealed a stronger expression at 1 month age, which gradually decreased till 24 months of age. The true Sertoli cell count was significantly higher in Zebu compared with crossbred males at all age groups studied except at 6 months age. The relationship between Sertoli cell count and circulating AMH concentrations was negative and significant (r = -0.81; P = 0.004). In conclusion, expression of AMH gene in testicular tissue and peripheral blood concentrations of AMH were higher in young compared with adults in both crossbred and Zebu males; however, the transcriptional abundance and circulating levels of AMH were higher in Zebu compared with crossbred males.

  11. Circulating Osteogenic Precursor Cells in Type 2 Diabetes Mellitus

    PubMed Central

    Manavalan, J. S.; Cremers, S.; Dempster, D. W.; Zhou, H.; Dworakowski, E.; Kode, A.; Kousteni, S.

    2012-01-01

    Context: Type 2 diabetes mellitus (T2D) is associated with an increased risk of fractures and low bone formation. However, the mechanism for the low bone formation is not well understood. Recently, circulating osteogenic precursor (COP) cells, which contribute to bone formation, have been characterized in the peripheral circulation. Objective: Our objective was to characterize the number and maturity of COP cells in T2D. Patients, Design, and Setting: Eighteen postmenopausal women with T2D and 27 controls participated in this cross-sectional study at a clinical research center. Main Outcome Measures: COP cells were characterized using flow cytometry and antibodies against osteocalcin (OCN) and early stem cell markers. Histomorphometric (n = 9) and molecular (n=14) indices of bone turnover and oxidative stress were also measured. Results: The percentage of OCN+ cells in peripheral blood mononuclear cells was lower in T2D (0.8 ± 0.2 vs. 1.6 ± 0.4%; P < 0.0001), whereas the percentage of OCN+ cells coexpressing the early marker CD146 was increased (OCN+/CD146+: 33.3 ± 7 vs. 12.0 ± 4%; P < 0.0001). Reduced histomorphometric indices of bone formation were observed in T2D subjects, including mineralizing surface (2.65 ± 1.9 vs. 7.58 ± 2.4%, P = 0.02), bone formation rate (0.01 ± 0.1 vs. 0.05 ±0.2 μm3/um2 · d, P = 0.02), and osteoblast surface (1.23 ±0.9 vs. 4.60 ± 2.5%, P = 0.03). T2D subjects also had reduced molecular expression of the osteoblast regulator gene Runx2 but increased expression of the oxidative stress markers p66Shc and SOD2. Conclusions: Circulating OCN+ cells were decreased in T2D, whereas OCN+/CD146+ cells were increased. Histomorphometric indices of bone formation were decreased in T2D, as was molecular expression of osteoblastic activity. Stimulation of bone formation may have beneficial therapeutic skeletal consequences in T2D. PMID:22740707

  12. Dynamics of Immune Cell Types Within the Macaque Corpus Luteum During the Menstrual Cycle: Role of Progesterone1

    PubMed Central

    Bishop, Cecily V.; Xu, Fuhua; Molskness, Theodore A.; Stouffer, Richard L.; Hennebold, Jon D.

    2015-01-01

    The goal of the current study was to characterize the immune cell types within the primate corpus luteum (CL). Luteal tissue was collected from rhesus females at discrete intervals during the luteal phase of the natural menstrual cycle. Dispersed cells were incubated with fluorescently labeled antibodies specific for the immune cell surface proteins CD11b (neutrophils and monocytes/macrophages), CD14 (monocytes/macrophages), CD16 (natural killer [NK] cells), CD20 (B-lymphocytes), and CD3epsilon (T-lymphocytes) for analysis by flow cytometry. Numbers of CD11b-positive (CD11b+) and CD14+ cells increased significantly 3 to 4 days after serum progesterone (P4) concentrations declined below 0.3 ng/ml. CD16+ cells were the most abundant immune cell type in CL during the mid and mid-late luteal phases and were 3-fold increased 3 to 4 days after serum P4 decreased to baseline levels. CD3epsilon+ cells tended to increase 3 to 4 days after P4 decline. To determine whether immune cells were upregulated by the loss of luteotropic (LH) support or through loss of LH-dependent steroid milieu, monkeys were assigned to 4 groups: control (no treatment), the GnRH antagonist Antide, Antide plus synthetic progestin (R5020), or Antide plus the estrogen receptor agonists diarylpropionitrile (DPN)/propyl-pyrazole-triol (PPT) during the mid-late luteal phase. Antide treatment increased the numbers of CD11b+ and CD14+ cells, whereas progestin, but not estrogen, replacement suppressed the numbers of CD11b+, CD14+, and CD16+ cells. Neither Antide nor steroid replacement altered numbers of CD3epsilon+ cells. These data suggest that increased numbers of innate immune cells in primate CL after P4 synthesis declines play a role in onset of structural regression of primate CL. PMID:26400401

  13. Islet transplantation versus stem cells for the cell therapy of type 1 diabetes mellitus.

    PubMed

    Basta, G; Montanucci, P; Calafiore, R

    2015-12-01

    Pancreatic islet cell transplantation has represented the mainstay of cell therapy for the potential, final cure of type 1 diabetes mellitus (T1D), along the past two decades. Unfortunately, the restricted availability of cadaveric human donor pancreases coupled with heavy side effects of the recipient's general immunosuppression, have severely crippled progress of this approach into clinical trials. Only a few excellence centers, worldwide, have thus far accrued still quite marginal clinical success. In an attempt to overcome the limits of islet transplantation new technologies for use of several stem cell lineages are being under investigation, with initial experimental evidence of success. Essentially, the actual lines of research involve attempts to either activate native endogenous stem cells that replace diseased/dead cells, by a cell regeneration process, or condition other stem cells to acquire the functional properties of the targeted cells to be substituted (i.e., beta-cell-like elements associated with insulin secretory competence). A wide array of stem cells may fulfill this task, from embryonic (whose use still faces strong ethical barriers), to adult, to induced pluripotent stem cells. Mesenchymal adult stem cells, retrievable from many different sites, including adipose tissue, bone marrow and post-partum umbilical cord Wharton Jelly, seem to couple plastic to immunoregulatory properties that might greatly help progress for the disease cure.

  14. A general water-based precursor solution approach to deposit earth abundant Cu2ZnSn(S,Se)4 thin film solar cells

    NASA Astrophysics Data System (ADS)

    Yang, Yanchun; Kang, Xiaojiao; Huang, Lijian; Wei, Song; Pan, Daocheng

    2016-05-01

    Earth abundant Cu2ZnSn(S,Se)4 (CZTSSe) has been considered as one of the most promising thin film solar cell absorber candidates. Here, we develop a facile water-based precursor solution approach for depositing high-efficiency Cu2ZnSn(S,Se)4 thin film solar cells. In this environmentally friendly approach, inexpensive elemental Cu, Zn, Sn and S powders are used as the starting materials and are dissolved in the aqueous solution of thioglycolic acid and methylamine, forming a homogeneous precursor solution for depositing Cu2ZnSnS4 nanocrystal thin film. As-deposited CZTS nanocrystal thin films are selenized to form the large-grain CZTSSe absorber layers. It was found that Na doping plays an important role in the formation of the extremely dense and flat CZTSSe absorber layer, and fill factor can be significantly improved for Na-doped CZTSSe solar cells, which lead to a photoelectric conversion efficiency of 6.96% with an open-circuit voltage of 378 mV, a short current density of 28.17 mA cm-2, and a fill factor of 65.4%.

  15. 1,25-Dihydroxyvitamin D3 and fetal lung maturation: immunogold detection of VDR expression in pneumocytes type II cells and effect on fructose 1,6 bisphosphatase.

    PubMed

    Nguyen, M; Trubert, C L; Rizk-Rabin, M; Rehan, V K; Besançon, F; Cayre, Y E; Garabédian, M

    2004-05-01

    Lung maturation before birth includes type II pneumocyte differentiation with progressive disappearance of glycogen content and onset of surfactant synthesis. We have shown previously that 1,25-(OH)2D3 increases surfactant synthesis and secretion by type II cells and decreases their glycogen content in fetal rat lung explants. Recently, the gene coding fructose 1,6 bisphosphatase (F1,6BP), a regulatory enzyme of gluconeogenesis, has been identified in type II cells and its promoter bears a Vitamin D response element. Present results show:The coexistence of type II cells at different stages of maturation. in rat fetal lung on day 21 of gestation (electron microscopy), and the association between maturation of type II cells and disappearance of their glycogen content. The immunogold labeling of all type II cells when using the 9A7g VDR-antibody, with significantly more abundant gold particles in cells exhibiting an intermediate glycogen content. The expression of F1,6BP mRNA in a human type II cell line (NCI-H441) and the increase of this expression after 18h incubation with 1,25-(OH)2D3 (10(-8)M). These results bring further evidence for a physiological role of 1,25-(OH)2D3 during type II pneumocyte maturation. Activation of F1,6BP may participate to the 1,25-(OH)2D3 action on surfactant synthesis via the gluconeogenesis pathway.

  16. Integrated proteomic and N-glycoproteomic analyses of doxorubicin sensitive and resistant ovarian cancer cells reveal glycoprotein alteration in protein abundance and glycosylation.

    PubMed

    Ji, Yanlong; Wei, Shasha; Hou, Junjie; Zhang, Chengqian; Xue, Peng; Wang, Jifeng; Chen, Xiulan; Guo, Xiaojing; Yang, Fuquan

    2017-01-06

    Ovarian cancer is one of the most common cancer among women in the world, and chemotherapy remains the principal treatment for patients. However, drug resistance is a major obstacle to the effective treatment of ovarian cancers and the underlying mechanism is not clear. An increased understanding of the mechanisms that underline the pathogenesis of drug resistance is therefore needed to develop novel therapeutics and diagnostic. Herein, we report the comparative analysis of the doxorubicin sensitive OVCAR8 cells and its doxorubicin-resistant variant NCI/ADR-RES cells using integrated global proteomics and N-glycoproteomics. A total of 1525 unique N-glycosite-containing peptides from 740 N-glycoproteins were identified and quantified, of which 253 N-glycosite-containing peptides showed significant change in the NCI/ADR-RES cells. Meanwhile, stable isotope labeling by amino acids in cell culture (SILAC) based comparative proteomic analysis of the two ovarian cancer cells led to the quantification of 5509 proteins. As about 50% of the identified N-glycoproteins are low-abundance membrane proteins, only 44% of quantified unique N-glycosite-containing peptides had corresponding protein expression ratios. The comparison and calibration of the N-glycoproteome versus the proteome classified 14 change patterns of N-glycosite-containing peptides, including 8 up-regulated N-glycosite-containing peptides with the increased glycosylation sites occupancy, 35 up-regulated N-glycosite-containing peptides with the unchanged glycosylation sites occupancy, 2 down-regulated N-glycosite-containing peptides with the decreased glycosylation sites occupancy, 46 down-regulated N-glycosite-containing peptides with the unchanged glycosylation sites occupancy. Integrated proteomic and N-glycoproteomic analyses provide new insights, which can help to unravel the relationship of N-glycosylation and multidrug resistance (MDR), understand the mechanism of MDR, and discover the new diagnostic and

  17. Expression of intracisternal A-type particles is increased when a B-cell lymphoma differentiates into an immunoglobulin-secreting cell.

    PubMed Central

    Wiest, D L; Burkhardt, J K; Stockdale, A M; Argon, Y

    1989-01-01

    The murine B-cell lymphoma CH12, like many other murine cells, expresses intracisternal A-type particles (IAPs). When CH12 cells are treated with lipopolysaccharide, the cells differentiate and secrete immunoglobulin M. The expression of IAP genes was also increased, in parallel with the increased expression of immunoglobulin genes. The amount of IAP mRNA increased within 48 h of lipopolysaccharide treatment and reached a level fivefold higher than that in unactivated CH12 cells. The two major IAP transcripts (7.2 and 5.4 kilobases) were induced to similar extents. The increased level of mRNA was reflected in higher levels of the major IAP structural protein p70, whose abundance increased 3.6-fold. The number of IAP particles per cell also increased upon activation of CH12, from 67 in nonsecreting CH12 to 290 in secreting cells. All of the IAPs were confined to the cisternae of the endoplasmic reticulum (ER), regardless of the differentiation state of the cell. Accompanying the induction of p70 was the induction of the related IAP polypeptide p102. A third viral polypeptide, p120, was also made in CH12; its abundance was almost unchanged. Localization of the IAP proteins on ultrathin frozen sections showed that most were assembled into particles in the ER. However, there were small pools of unassembled proteins both in the ER and on the plasma membrane. p70 and p120 could be detected, by iodination, on the surfaces of both secreting and nonsecreting CH12 cells. Unlike p70 and p120, p102 did not seem to be membrane associated. Taken together, these observations show that IAP expression is regulated developmentally in B lymphocytes. Also, these observations point to possible interactions between IAP genes and other cellular genes. Images PMID:2492059

  18. Abundance of phosphorylated Apis mellifera CREB in the honeybee's mushroom body inner compact cells varies with age.

    PubMed

    Gehring, Katrin B; Heufelder, Karin; Kersting, Isabella; Eisenhardt, Dorothea

    2016-04-15

    Hymenopteran eusociality has been proposed to be associated with the activity of the transcription factor CREB (cAMP-response element binding protein). The honeybee (Apis mellifera) is a eusocial insect displaying a pronounced age-dependent division of labor. In honeybee brains, CREB-dependent genes are regulated in an age-dependent manner, indicating that there might be a role for neuronal honeybee CREB (Apis mellifera CREB, or AmCREB) in the bee's division of labor. In this study, we further explore this hypothesis by asking where in the honeybee brain AmCREB-dependent processes might take place and whether they vary with age in these brain regions. CREB is activated following phosphorylation at a conserved serine residue. An increase of phosphorylated CREB is therefore regarded as an indicator of CREB-dependent transcriptional activation. Thus, we here examine the localization of phosphorylated AmCREB (pAmCREB) in the brain and its age-dependent variability. We report prominent pAmCREB staining in a subpopulation of intrinsic neurons of the mushroom bodies. In these neurons, the inner compact cells (IC), pAmCREB is located in the nuclei, axons, and dendrites. In the central bee brain, the IC somata and their dendritic region, we observed an age-dependent increase of pAmCREB. Our results demonstrate the IC to be candidate neurons involved in age-dependent division of labor. We hypothesize that the IC display a high level of CREB-dependent transcription that might be related to neuronal and behavioral plasticity underlying a bee's foraging behavior.

  19. Solid type clear cell carcinoma of the pancreas: differential diagnosis of an unusual case and review of the literature.

    PubMed

    Loos, Martin; Bergmann, Frank; Bauer, Andrea; Hoheisel, Jörg D; Esposito, Irene; Kleeff, Jörg; Schirmacher, Peter; Büchler, Markus W; Klöppel, Günter; Friess, Helmut

    2007-06-01

    Pancreatic neoplasms have been reliably classified on the basis of their histopathology and immunophenotype. In this study, we report on a pancreatic tumor whose phenotype and genotype could not be assigned to any known tumor entity. The tumor was observed in the pancreatic head of a 54-year-old woman. It was found to be a solid infiltrating carcinoma with abundant clear cells. Apart from cytokeratin, the tumor cells expressed vimentin, S100, and MUC-1. DNA microarray analysis revealed a transcription profile clearly differing from that of normal pancreatic tissue and pancreatic ductal adenocarcinoma. Despite metastatic behavior, the tumor displayed a more favorable course than conventional pancreatic ductal adenocarcinoma. We suggest that this tumor be called solid type clear cell carcinoma of the pancreas.

  20. Membrane Targeting of P-type ATPases in Plant Cells

    SciTech Connect

    Jeffrey F. Harper, Ph.D.

    2004-06-30

    How membrane proteins are targeted to specific subcellular locations is a very complex and poorly understood area of research. Our long-term goal is to use P-type ATPases (ion pumps), in a model plant system Arabidopsis, as a paradigm to understand how members of a family of closely related membrane proteins can be targeted to different subcellular locations. The research is divided into two specific aims. The first aim is focused on determining the targeting destination of all 10 ACA-type calcium pumps (Arabidopsis Calcium ATPase) in Arabidopsis. ACAs represent a plant specific-subfamily of plasma membrane-type calcium pumps. In contrast to animals, the plant homologs have been found in multiple membrane systems, including the ER (ACA2), tonoplast (ACA4) and plasma membrane (ACA8). Their high degree of similarity provides a unique opportunity to use a comparative approach to delineate the membrane specific targeting information for each pump. One hypothesis to be tested is that an endomembrane located ACA can be re-directed to the plasma membrane by including targeting information from a plasma membrane isoform, ACA8. Our approach is to engineer domain swaps between pumps and monitor the targeting of chimeric proteins in plant cells using a Green Fluorescence Protein (GFP) as a tag. The second aim is to test the hypothesis that heterologous transporters can be engineered into plants and targeted to the plasma membrane by fusing them to a plasma membrane proton pump. As a test case we are evaluating the targeting properties of fusions made between a yeast sodium/proton exchanger (Sod2) and a proton pump (AHA2). This fusion may potentially lead to a new strategy for engineering salt resistant plants. Together these aims are designed to provide fundamental insights into the biogenesis and function of plant cell membrane systems.

  1. Choline Deficiency Causes Colonic Type II Natural Killer T (NKT) Cell Loss and Alleviates Murine Colitis under Type I NKT Cell Deficiency

    PubMed Central

    Sagami, Shintaro; Ueno, Yoshitaka; Tanaka, Shinji; Fujita, Akira; Niitsu, Hiroaki; Hayashi, Ryohei; Hyogo, Hideyuki; Hinoi, Takao; Kitadai, Yasuhiko; Chayama, Kazuaki

    2017-01-01

    Serum levels of choline and its derivatives are lower in patients with inflammatory bowel disease (IBD) than in healthy individuals. However, the effect of choline deficiency on the severity of colitis has not been investigated. In the present study, we investigated the role of choline deficiency in dextran sulfate sodium (DSS)-induced colitis in mice. Methionine-choline-deficient (MCD) diet lowered the levels of type II natural killer T (NKT) cells in the colonic lamina propria, peritoneal cavity, and mesenteric lymph nodes, and increased the levels of type II NKT cells in the livers of wild-type B6 mice compared with that in mice fed a control (CTR) diet. The gene expression pattern of the chemokine receptor CXCR6, which promotes NKT cell accumulation, varied between colon and liver in a manner dependent on the changes in the type II NKT cell levels. To examine the role of type II NKT cells in colitis under choline-deficient conditions, we assessed the severity of DSS-induced colitis in type I NKT cell-deficient (Jα18-/-) or type I and type II NKT cell-deficient (CD1d-/-) mice fed the MCD or CTR diets. The MCD diet led to amelioration of inflammation, decreases in interferon (IFN)-γ and interleukin (IL)-4 secretion, and a decrease in the number of IFN-γ and IL-4-producing NKT cells in Jα18-/- mice but not in CD1d-/- mice. Finally, adaptive transfer of lymphocytes with type II NKT cells exacerbated DSS-induced colitis in Jα18-/- mice with MCD diet. These results suggest that choline deficiency causes proinflammatory type II NKT cell loss and alleviates DSS-induced colitis. Thus, inflammation in DSS-induced colitis under choline deficiency is caused by type II NKT cell-dependent mechanisms, including decreased type II NKT cell and proinflammatory cytokine levels. PMID:28095507

  2. Cell types and synaptic organization of the medullary electromotor nucleus in a constant frequency weakly electric fish, Sternarchus albifrons.

    PubMed

    Tokunaga, A; Akert, K; Sandri, C; Bennett, M V

    1980-08-01

    The medullary electromotor nucleus (EMN) of Sternarchus albifrons was studied at the light and electron microscopic levels. The EMN consists of a dense meshwork of myelinated axons and glial elements with interposed large neurons; it is provided with an abundant supply of capillaries. Two types of essentially adrendritic nerve cells were distinguished on the basis of size: giant neurons (approx. 70 micrometers in diameter) and large neurons (approx. 30 micrometers in diameter). Their population ratio is 1:4. Only giant cells are labelled following the injection of retrograde tracer into the spinal cord; they are therefore identified with the so-called "relay cells" of other gymnotids. Tracer experiments further suggest that the descending axons of these relay cells give off collateral branches throughout the elongated spinal electromotor nucleus. In contrast, the large cells remain unlabelled and therefore lack spinal projections; they most likely correspond to "pacemaker cells." The perikaryal surface, including axon hillock and proximal part of initial segment of both types of EMN cells, is contacted by clusters of synaptic terminals and astrocytic processes. Two main varieties of synaptic terminals occur: (1) large endings and (2) ordinary end feet with standard size (S-type) and variable size (Sv-type) clear, spherical vesicles. The junction between large endings and EMN cells is characterized by the combination of gap junctions and surrounding intermediate junctions whose freeze-fracture characteristics were morphometrically analyzed. The large endings were formed by nodes of Ranvier as well as by fiber terminations, and synchronization within the EMN may be achieved by presynaptic fibers. Some of the contacts occur directly on the initial segment, which could allow activity to bypass the soma. It is concluded that the elctromotor system of Sternarchus is comprised of a rapid conduction pathway where medullary pacemaker and relay cells as well as spinal

  3. T regulatory cells distinguish two types of primary hypophysitis.

    PubMed

    Mirocha, S; Elagin, R B; Salamat, S; Jaume, J C

    2009-03-01

    Numerous cases of primary hypophysitis have been described over the past 25 years with, however, little insight into the cause(s) of this disease. In order to guide treatment, a better understanding of the pathogenesis is needed. We studied the pathogenesis of primary hypophysitis by analysing systematically the immune response at the pituitary tissue level of consecutive cases of 'lymphocytic' hypophysitis who underwent pituitary biopsy. In order to investigate further the pathogenesis of their diseases we characterized two cases at clinical, cellular and molecular levels. We show here, for the first time, that lymphocytic hypophysitis probably encompasses at least two separate entities. One entity, in agreement with the classical description of lymphocytic hypophysitis, demonstrates an autoimmune process with T helper 17 cell dominance and lack of T regulatory cells. The other entity represents a process in which T regulatory cells seem to control the immune response, which may not be self- but foreign-targeted. Our data suggest that it may be necessary to biopsy suspected primary hypophysitis and to analyse pituitary tissue with immune markers to guide treatment. Based on our results, hypophysitis driven by an immune homeostatic process should not be treated with immunosuppression, while autoimmune-defined hypophysitis may benefit from it. We show here for the first time two different pathogenic processes classified under one disease type and how to distinguish them. Because of our findings, changes in current diagnostic and therapeutic approaches may need to be considered.

  4. Massively parallel single-cell RNA-seq for marker-free decomposition of tissues into cell types.

    PubMed

    Jaitin, Diego Adhemar; Kenigsberg, Ephraim; Keren-Shaul, Hadas; Elefant, Naama; Paul, Franziska; Zaretsky, Irina; Mildner, Alexander; Cohen, Nadav; Jung, Steffen; Tanay, Amos; Amit, Ido

    2014-02-14

    In multicellular organisms, biological function emerges when heterogeneous cell types form complex organs. Nevertheless, dissection of tissues into mixtures of cellular subpopulations is currently challenging. We introduce an automated massively parallel single-cell RNA sequencing (RNA-seq) approach for analyzing in vivo transcriptional states in thousands of single cells. Combined with unsupervised classification algorithms, this facilitates ab initio cell-type characterization of splenic tissues. Modeling single-cell transcriptional states in dendritic cells and additional hematopoietic cell types uncovers rich cell-type heterogeneity and gene-modules activity in steady state and after pathogen activation. Cellular diversity is thereby approached through inference of variable and dynamic pathway activity rather than a fixed preprogrammed cell-type hierarchy. These data demonstrate single-cell RNA-seq as an effective tool for comprehensive cellular decomposition of complex tissues.

  5. Revisiting human natural killer cell subset function revealed cytolytic CD56dimCD16+ NK cells as rapid producers of abundant IFN-γ on activation

    PubMed Central

    De Maria, Andrea; Bozzano, Federica; Cantoni, Claudia; Moretta, Lorenzo

    2011-01-01

    The two major functions of human natural killer (NK) cells are conventionally associated with distinct cell subsets. Thus, cytolytic activity is mostly confined to the CD56dimCD16+ subset, whereas cytokine production is generally assigned to CD56brightCD16+/− cells. In this study, we reevaluated the functional capabilities of these NK subsets with regard to the production of IFN-γ at different time points after cell triggering via NKp46 and NKp30 activating receptors. Different from previous studies, cytokine production was also assessed at early intervals. We show that CD56dim NK cells produce IFN-γ already at 2 to 4 h, whereas no cytokine production is detected beyond 16 h. In contrast, CD56bright cells release IFN-γ only at late time intervals (>16 h after stimulation). The rapid IFN-γ production by CD56dim NK cells is in line with the presence of IFN-γ mRNA in freshly isolated cells. Rapid IFN-γ production was also induced by combinations of IL-2, IL-12, and IL-15. Our data indicate that not only cytolytic activity but also early IFN-γ production is a functional property of CD56dim NK cells. Thus, this subset can assure a rapid and comprehensive NK cell intervention during the early phases of innate responses. PMID:21187373

  6. β-cell replacement sources for type 1 diabetes: a focus on pancreatic ductal cells

    PubMed Central

    Corritore, Elisa; Lee, Yong-Syu; Sokal, Etienne M.; Lysy, Philippe A.

    2016-01-01

    Thorough research on the capacity of human islet transplantation to cure type 1 diabetes led to the achievement of 3- to 5-year-long insulin independence in nearly half of transplanted patients. Yet, translation of this technique to clinical routine is limited by organ shortage and the need for long-term immunosuppression, restricting its use to adults with unstable disease. The production of new bona fide β cells in vitro was thus investigated and finally achieved with human pluripotent stem cells (PSCs). Besides ethical concerns about the use of human embryos, studies are now evaluating the possibility of circumventing the spontaneous tumor formation associated with transplantation of PSCs. These issues fueled the search for cell candidates for β-cell engineering with safe profiles for clinical translation. In vivo studies revealed the regeneration capacity of the exocrine pancreas after injury that depends at least partially on facultative progenitors in the ductal compartment. These stimulated subpopulations of pancreatic ductal cells (PDCs) underwent β-cell transdifferentiation through reactivation of embryonic signaling pathways. In vitro models for expansion and differentiation of purified PDCs toward insulin-producing cells were described using cocktails of growth factors, extracellular-matrix proteins and transcription factor overexpression. In this review, we will describe the latest findings in pancreatic β-cell mass regeneration due to adult ductal progenitor cells. We will further describe recent advances in human PDC transdifferentiation to insulin-producing cells with potential for clinical translational studies. PMID:27540464

  7. Extranodal natural killer/T-cell lymphoma, nasal-type.

    PubMed

    Chorianopoulos, Dimitrios; Samitas, Konstantinos; Vittorakis, Stylianos; Kiriazi, Vasiliki; Rondoyianni, Dimitra; Tsaousis, Georgios; Skoutelis, Athanasios

    2010-01-01

    expressed the cytotoxic proteins T-cell intracellular antigen and granzyme B (Figure 3) They lacked TdT, CD34, CD7, CD8, TCL-1, and CD123. Findings from an in situ hybridization study for Epstein-Barr virus were negative. Give this result, molecular analysis ofT-cell receptor (TCR) gene rearrangements was performed using polymerase chain reaction-based TCR-gamma gene, wit negative results. The morphology and the immunophenotype were consistent with natural killer/T-cell lymphoma, nasal-type. Nasal involvement must be first excluded to proceed to the diagnosis of nasal-type natural killer-cell lymphoma. Indeed, histologic examination of the nasal mass revealed its polypoid nature. Thus, the authors were led to the diagnosis of extranodal extranasal natural killer/T-cell lymphoma, nasal-type, CD56-positive, Ep stein-Barr virus-negative, TCR-negative. The patient received combination chemotherapy and completed 4 cycles of cyclophosphamide, doxorubicin vincristine, and prednisone every 14 days for 2 months. Skin lesions improved, and there was no fever soon after the initiation of therapy. Reevaluatio after the fourth cycle, however, disclosed pulmonary infiltrations as well as leukemic infiltration of the central nervous system. The patient had receive systemic salvage chemotherapy and intrathecal infusions of methotrexate. Although the lung lesions had diminished at that time, the patient develope paraplegia, his clinical course rapidly deteriorated, and he eventually died.

  8. Stem cell approaches for the treatment of type 1 diabetes mellitus.

    PubMed

    Wagner, Ryan T; Lewis, Jennifer; Cooney, Austin; Chan, Lawrence

    2010-09-01

    Type 1 diabetes is characterized by near total absence of pancreatic b cells. Current treatments consisting of insulin injections and islet transplantation are clinically unsatisfactory. In order to develop a cure for type 1 diabetes, we must find a way to reverse autoimmunity, which underlies b cell destruction, as well as an effective strategy to generate new b cells. This article reviews the different approaches that are being taken to produce new b cells. Much emphasis has been placed on selecting the right non-b cell population, either in vivo or in vitro, as the starting material. Different cell types, including adult stem cells, other types of progenitor cells in situ, and even differentiated cell populations, as well as embryonic stem cells and induced pluripotent stem cells, will require different methods for islet and b cell induction. We discussed the pros and cons of the different strategies that are being used to re-invent the pancreatic b cell.

  9. Cell type-specific regulation of von Willebrand factor expression by the E4BP4 transcriptional repressor.

    PubMed

    Hough, Christine; Cuthbert, Carla D; Notley, Colleen; Brown, Christine; Hegadorn, Carol; Berber, Ergul; Lillicrap, David

    2005-02-15

    Mechanisms of tissue-restricted patterns of von Willebrand factor (VWF) expression involve activators and repressors that limit expression to endothelial cells and megakaryocytes. The relative transcriptional activity of the proximal VWF promoter was assessed in VWF-producing and -nonproducing cells, and promoter activity was highest in endothelial cells followed by megakaryocytes. Only basal VWF promoter activity was seen in nonendothelial cells. Here we identify a negative response element located at nucleotides (nts) +96/+105 and demonstrate, using chromatin immunoprecipitation (ChIP) analysis, that in vivo this sequence interacts with the E4BP4 transcriptional repressor. Differences in size and relative abundance of nuclear E4BP4 were observed. In HepG2 cells, low levels of larger forms of E4BP4 are present that directly interact with the negative response element. In VWF-expressing cells, high levels of smaller forms predominate with no evidence of direct DNA binding. However, in endothelial cells, mutation of the VWF E4BP4 binding motif not only restores but also further elevates VWF promoter activity, suggesting that E4BP4 may be part of a coordinated binding complex. These observations implicate this binding motif in repressing both activated and basal levels of VWF transcription by different cell type-specific mechanisms, and support the hypothesis that E4BP4 sequesters negative regulators of transcription, thereby enhancing activated gene expression.

  10. LagC is required for cell-cell interactions that are essential for cell-type differentiation in Dictyostelium.

    PubMed

    Dynes, J L; Clark, A M; Shaulsky, G; Kuspa, A; Loomis, W F; Firtel, R A

    1994-04-15

    Strain AK127 is a developmental mutant of Dictyostelium discoideum that was isolated by restriction enzyme-mediated integration (REMI). Mutant cells aggregate normally but are unable to proceed past the loose aggregate stage. The cloned gene, lagC (loose aggregate C), encodes a novel protein of 98 kD that contains an amino-terminal signal sequence and a putative carboxy-terminal transmembrane domain. The mutant strain AK127 shows no detectable lagC transcript upon Northern analysis, indicating that the observed phenotype is that of a null allele. Expression of the lagC cDNA in AK127 cells complements the arrest at the loose aggregate stage, indicating that the mutant phenotype results from disruption of the lagC gene. In wild-type cells, lagC mRNA is induced at the loose aggregate stage and is expressed through the remainder of development. lagC- null cells aggregate but then disaggregate and reaggregate to form small granular mounds. Mature spores are produced at an extremely low efficiency (< 0.1% of wild type), appearing only after approximately 72 hr, whereas wild-type strains produce mature spores by 26 hr. lagC- null cells accumulate reduced levels of transcripts for the prestalk-enriched genes rasD and CP2 and do not express the DIF-induced prestalk-specific gene ecmA or the cAMP-induced prespore-specific gene SP60 to significant levels. In chimeric organisms resulting from the coaggregation of lagC- null and wild-type cells, cell-type-specific gene expression is rescued in the lagC- null cells; however, lagC- prespore cells are localized to the posterior of the prespore region and do not form mature spores, suggesting that LagC protein has both no cell-autonomous and cell-autonomous functions. Overexpression of lagC from an actin promoter in both wild-type and lagC- cells causes a delay at the tight aggregate stage, the first stage requiring LagC activity. These results suggest that the LagC protein functions as a nondiffusible cell-cell signaling molecule

  11. Demonstration of different modes of cell death upon herpes simplex virus 1 infection in different types of oral cells.

    PubMed

    Huang, C R; Lin, S S; Chou, M Y; Ho, C C; Wang, L; Lee, Y L; Chen, C S; Yang, C C

    2005-01-01

    The effects of Herpes simplex virus 1 (HSV-1) infection on five different types of oral cancerous cells (neck metastasis of gingival carcinoma (GNM) cells and tongue squamous cells of carcinoma (TSCCa) and non-cancerous cells (buccal mucosal fibroblasts (BF), gingival fibroblasts (GF), oral submucosal fibrosis cells (OSF)) and one type of non-oral cancerous cells (KB cells) were investigated. In HSV-1-infected cells the cell viability, CPE, viral antigens accumulation, caspase-3 activity, annexin V binding and DNA fragmentation were estimated. Three different forms or pathways of cell death were considered: apoptosis (the presence or rise of caspase-3 activity, DNA fragmentation and annexin V binding), slow cell death (the presence or rise of DNA fragmentation, the absence or decline of caspase-3 activity and annexin V binding), and necrosis (the absence of decline of caspase-3 activity, DNA fragmentation and annexin V binding). The viability of all cell types, except for KB cells, was reduced by the infection. CPE and viral antigens data demonstrated that all six types of cells could be infected with HSV-1. Upon HSV-1 infection there occurred (i) a classical apoptosis in GF cells, (ii) apoptosis in the early phase of infection and necrosis in the late phase of infection in GNM and TSCCa cells, (iii) slow cell death followed by necrosis in BF and OSF cells (however, these cells showed a different type of CPE), (iv) a classical slow cell death in KB cells. It is hypothesized that HSV-1 infection has a potential to induce several distinct pathways leading to cell death or several forms of cell death. Moreover, more than one pathway may be involved in the death of particular cell type. As HSV-1 was demonstrated to infect different oral and non-oral cells and cause different pathways or forms of cell death, the safety of using HSV-1 as a vector for gene therapy should be re-considered.

  12. Fluorescence-Activated Cell Sorting for Analysis of Cell Type-Specific Responses to Salinity Stress in Arabidopsis and Rice

    PubMed Central

    Evrard, Aurelie; Bargmann, Bastiaan O.R.; Birnbaum, Kenneth D.; Tester, Mark; Baumann, Ute; Johnson, Alexander A.T.

    2014-01-01

    Fluorescence-activated cell sorting (FACS) provides a rapid means of isolating large numbers of fluorescently tagged cells from a heterogeneous mixture of cells. Collections of transgenic plants with cell type-specific expression of fluorescent marker genes such as green fluorescent protein (GFP) are ideally suited for FACS-assisted studies of individual cell types. Here we describe the use of Arabidopsis and rice enhancer trap lines with tissue-specific GFP expression patterns in the root to isolate specific cell types of root tissues using FACS. Additionally, protocols are provided to impose a ramped salinity stress for 48 h prior to cell sorting. PMID:22895766

  13. Metal-sulfur type cell having improved positive electrode

    NASA Astrophysics Data System (ADS)

    Dejonghe, Lutgard C.; Visco, Steven J.; Mailhe, Catherine C.; Armand, Michel B.

    1988-03-01

    A novel metal-sulfur type cell operable at a temperature of 200 C or less with an energy density of 150 Whrs/Kg or better is disclosed characterized by an organo-sulfur cathode formed from an organic-sulfur compound having the general formula, in its charged state, of (R(S) sub y) n wherein y = 1 to 6; n = 2 to 20; and R is one or more different aliphatic or aromatic organic moieties having 1 to 20 carbon atoms, which may include one or more oxygen, sulfur, or nitrogen heteroatoms when R comprises one or more aromatic rings, or one or more oxygen, sulfur, nitrogen, or fluorine atoms associated with the chain when R comprises an aliphatic chain, wherein the aliphatic group may be linear or branched, saturated or unsaturated, and wherein either the aliphatic chain or the aromatic ring may have substituted groups thereon.

  14. Thermal stability of porcine circovirus type 2 in cell culture.

    PubMed

    O'Dea, Mark A; Hughes, Andrew P; Davies, Linda J; Muhling, Jillian; Buddle, Ross; Wilcox, G E

    2008-01-01

    International trade in pig meat has resulted in some countries placing restrictions on the importation of pig meat, with requirements for cooking of imported meat to destroy viral agents. This study investigated the in vitro resistance of an Australian strain of porcine circovirus type 2 (PCV2), the causative agent of post-weaning multisystemic wasting syndrome (PMWS), to heat treatment. The viability of the virus in cell cultures was determined by a combination of reverse transcriptase polymerase chain reaction (RT-PCR) to detect viral transcripts, and immunohistochemistry (IHC) to visualize viral capsid antigen. PCV2 retained infectivity when heated at 75 degrees C for 15 min but was inactivated by heating at 80 degrees C and above for 15 min. The results provide important information on the thermal tolerance of PCV2, which can be taken into account in risk assessments for trade in pig meat and porcine-derived biological products.

  15. Cell-type homologies and the origins of the neocortex

    PubMed Central

    Dugas-Ford, Jennifer; Rowell, Joanna J.; Ragsdale, Clifton W.

    2012-01-01

    The six-layered neocortex is a uniquely mammalian structure with evolutionary origins that remain in dispute. One long-standing hypothesis, based on similarities in neuronal connectivity, proposes that homologs of the layer 4 input and layer 5 output neurons of neocortex are present in the avian forebrain, where they contribute to specific nuclei rather than to layers. We devised a molecular test of this hypothesis based on layer-specific gene expression that is shared across rodent and carnivore neocortex. Our findings establish that the layer 4 input and the layer 5 output cell types are conserved across the amniotes, but are organized into very different architectures, forming nuclei in birds, cortical areas in reptiles, and cortical layers in mammals. PMID:23027930

  16. Metal-sulfur type cell having improved positive electrode

    DOEpatents

    DeJonghe, L.C.; Visco, S.J.; Mailhe, C.C.; Armand, M.B.

    1988-03-31

    A novel metal-sulfur type cell operable at a temperature of 200/degree/C or less with an energy density of 150 Whrs/Kg or better is disclosed characterized by an organo-sulfur cathode formed from an organic-sulfur compound having the general formula, in its charged state, of (R(S)/sub y/)n wherein y = 1 to 6; n = 2 to 20; and R is one or more different aliphatic or aromatic organic moieties having 1 to 20 carbon atoms, which may include one or more oxygen, sulfur, or nitrogen heteroatoms when R comprises one or more aromatic rings, or one or more oxygen, sulfur, nitrogen, or fluorine atoms associated with the chain when R comprises an aliphatic chain, wherein the aliphatic group may be linear or branched, saturated or unsaturated, and wherein either the aliphatic chain or the aromatic ring may have substituted groups thereon. 4 figs.

  17. Metal-sulfur type cell having improved positive electrode

    DOEpatents

    Dejonghe, Lutgard C.; Visco, Steven J.; Mailhe, Catherine C.; Armand, Michel B.

    1989-01-01

    An novel metal-sulfur type cell operable at a temperature of 200.degree. C. or less with an energy density of 150 Whrs/Kg or better is disclosed characterized by an organo-sulfur cathode formed from an organic-sulfur compound having the general formula, in its charged state, of (R(S).sub.y).sub.n wherein y=1 to 6; n=2 to 20; and R is one or more different aliphatic or aromatic organic moieties having 1 to 20 carbon atoms, which may include one or more oxygen, sulfur, or nitrogen heteroatoms when R comprisises one of more aromatic rings, or one or more oxygen, sulfur, nitrogen, or fluorine atoms associtated with the chain when R comprises an aliphatic chain, wherein the aliphatic group may be linear or branched, saturated or unsaturated, and wherein either the aliphatic chain or the aromatic ring may have substituted groups thereon.

  18. In vitro endothelial cell susceptibility to xenobiotics: comparison of three cell types.

    PubMed

    L'Azou, B; Fernandez, P; Bareille, R; Beneteau, M; Bourget, C; Cambar, J; Bordenave, L

    2005-03-01

    In three different endothelial cell (EC) cultures (primary human umbilical cord vein, so-called HUVEC; and immortalized cell lines HBMEC and EA-hy-926), the effects of different xenobiotics were studied in order to standardize vascular EC models for in vitro pharmacotoxicological studies. Cell characteristics were first investigated by the production and the mRNA levels of known endothelial markers in the three EC culture models. EC secretory products, tissue plasminogen activator (tPA) and von Willebrand factor (vWF), were present in the supernatant of the immortalized cell lines. The mRNA levels of vWF, tPA, platelet endothelial cell adhesion molecule-1 (PECAM-1/CD31), and beta -integrin subunit, which are involved in the control of platelet function, coagulation, and fibrinolysis as well as in cell-matrix interactions, were investigated in all EC types. For at least three parameters, cultured cells provided marked characteristics of EC phenotype, in HUVEC and in immortalized cell lines, regardless of their origin from the macro- or microcirculation. Toxicity experiments were assessed after 24 h exposure to cadmium, cyclosporin A and cisplatin by MTT assay. These experiments show nonsignificant difference in susceptibility to cyclosporin A and cadmium on HUVEC, HBMEC, and EA-hy-926. However, HBMEC, seems to be highly susceptible to cisplatin compared to HUVEC, the latter being more sensitive than EA-hy-926. For experiments conducted with cyclosporin and cadmium, cell lines could constitute an alternative material for routine cytotoxicity studies.

  19. Type of cell death induced by seven metals in cultured mouse osteoblastic cells.

    PubMed

    Contreras, René García; Vilchis, José Rogelio Scougall; Sakagami, Hiroshi; Nakamura, Yuko; Nakamura, Yukio; Hibino, Yasushi; Nakajima, Hiroshi; Shimada, Jun

    2010-01-01

    The use of dental metal alloys in the daily clinic makes it necessary to evaluate the cytotoxicity of eluted metal components against oral cells. However, the cytotoxic mechanism and the type of cell death induced by dental metals in osteoblasts have not been well characterized. This study investigated the cytotoxicity of seven metals against the mouse osteoblastic cell line MC3T3-E1. alpha-MEM was used as a culture medium, since this medium provided much superior proliferation of MC3T3-E1 cells over DMEM. Ag (NH(3))(2)F was the most cytotoxic, followed by CuCl>CuCl(2) >CoCl(2), NiCl(2)>FeCl(3) and FeCl(2) (least toxic). None of the metals showed any apparent growth stimulating effect (so-called 'hormesis') at lower concentrations. A time course study demonstrated that two hours of contact between oral cells and Ag (NH(3))(2)F, CuCl, CoCl(2) or NiCl(2) induced irreversible cell death. Contact with these metals induced a smear pattern of DNA fragmentation without activation of caspase-3. Preincubation of MC3T3-E1 cells with either a caspase inhibitor (Z-VAD-FMK) or autophagy inhibitors (3-methyladenine, bafilomycin) failed to rescue them from metal cytotoxicity. These data suggest the induction of necrotic cell death rather than apoptosis and autophagy by metals in this osteoblastic cell line.

  20. Solar and stellar photospheric abundances

    NASA Astrophysics Data System (ADS)

    Allende Prieto, Carlos

    2016-12-01

    The determination of photospheric abundances in late-type stars from spectroscopic observations is a well-established field, built on solid theoretical foundations. Improving those foundations to refine the accuracy of the inferred abundances has proven challenging, but progress has been made. In parallel, developments on instrumentation, chiefly regarding multi-object spectroscopy, have been spectacular, and a number of projects are collecting large numbers of observations for stars across the Milky Way and nearby galaxies, promising important advances in our understanding of galaxy formation and evolution. After providing a brief description of the basic physics and input data involved in the analysis of stellar spectra, a review is made of the analysis steps, and the available tools to cope with large observational efforts. The paper closes with a quick overview of relevant ongoing and planned spectroscopic surveys, and highlights of recent research on photospheric abundances.

  1. Silver nanowire interactions with primary human alveolar type-II epithelial cell secretions: contrasting bioreactivity with human alveolar type-I and type-II epithelial cells

    PubMed Central

    Sweeney, Sinbad; Theodorou, Ioannis G.; Zambianchi, Martina; Chen, Shu; Gow, Andrew; Schwander, Stephan; Zhang, Junfeng (Jim); Chung, Kian Fan; Shaffer, Milo S.; Ryan, Mary P.; Porter, Alexandra E.; Tetley, Teresa D.

    2015-01-01

    Inhaled nanoparticles have a high deposition rate in the alveolar units of the deep lung. The alveolar epithelium is composed of type-I and type-II epithelial cells (ATI and ATII respectively) and is bathed in pulmonary surfactant. The effect of native human ATII cell secretions on nanoparticle toxicity is not known. We investigated the cellular uptake and toxicity of silver nanowires (AgNWs; 70 nm diameter, 1.5 μm length) with human ATI-like cells (TT1), in the absence or presence of Curosurf® (a natural porcine pulmonary surfactant with a low amount of protein) or harvested primary human ATII cell secretions (HAS; containing both the complete lipid as well as the full protein complement of human pulmonary surfactant i.e. SP-A, SP-B, SP-C and SP-D). We hypothesised that Curosurf® or HAS would confer improved protection for TT1 cells, limiting the toxicity of AgNWs. In agreement with our hypothesis, HAS reduced the inflammatory and reactive oxygen species (ROS)-generating potential of AgNWs with exposed TT1 cells. For example, IL-8 release and ROS generation was reduced by 38% and 29%, respectively, resulting in similar levels to that of the non-treated controls. However in contrast to our hypothesis, Curosurf® had no effect. We found a significant reduction in AgNW uptake by TT1 cells in the presence of HAS but not Curosurf. Furthermore, we show that the SP-A and SP-D are likely to be involved in this process as they were found to be specifically bound to the AgNWs. While ATI cells appear to be protected by HAS, evidence suggested that ATII cells, despite no uptake, were vulnerable to AgNW exposure (indicated by increased IL-8 release and ROS generation and decreased intracellular SP-A levels one day post-exposure). This study provides unique findings that may be important for the study of lung epithelial-endothelial translocation of nanoparticles in general and associated toxicity within the alveolar unit. PMID:25996248

  2. Crosstalk on cell behavior in interactive cocultures of hMSCs with various oral cell types.

    PubMed

    Proksch, Susanne; Steinberg, Thorsten; Stampf, Susanne; Schwarz, Ulrich; Hellwig, Elmar; Tomakidi, Pascal

    2012-12-01

    When prospectively applied for regenerative therapies, human bone-marrow-derived mesenchymal stem cells (hMSCs) interact with the locally residing host cells. With respect to the developmentally particular origin of oral cells, little is known about the putatively discriminative behavioral responses of hMSCs in interaction with various oral cell types, including human alveolar bone osteoblasts (hOAs), periodontal ligament fibroblasts (hPDLs), and gingival fibroblasts (hGFs). To assess the crosstalk between hMSCs and oral cells, interactive cocultures were established by combining well-characterized hMSCs with hOAs, hPDLs, or hGFs, and the behavioral hMSC aspects, that is, proliferation and gene expression, were measured by employing a 5-bromo-2'-deoxyuridine assay and real-time polymerase chain reaction, while apoptosis was quantified by in situ cell death detection kit. hMSCs expressed the typical antigen spectrum lacking CD34, CD45, CD14, CD19, and HLA-DR, while expressing CD73, CD90, and CD105, and could successfully be transformed into adipocytes, osteocytes, and chondrocytes. Monocultured control hMSCs proliferated readily, whereas a general reduction of BrdU-labeled cells was observed in cocultures. Globally, upon extending time periods, interactive coculture combinations of hMSCs with hOAs reduced both osteogenic gene and stem cell marker transcription in hMSCs, a phenomenon appearing less pronounced by combining hMSCs with hPDLs, such that the observed effects in terms of proliferation and gene expression followed the same ranking: hOAs>hGFs>hPDLs. Vice versa, in interactive hMSC cocultures, the cell survival rate was significantly increased, irrespective from the combined coculture cell counterpart. Our results show for the first time that behavior of hMSCs reflected by proliferation and gene expression was governed by interaction with various oral cells in a cell-type-discriminative manner. In addition, hMSC coculture restrains apoptosis, such that

  3. Defining stem cell types: understanding the therapeutic potential of ESCs, ASCs, and iPS cells.

    PubMed

    Alvarez, Clara V; Garcia-Lavandeira, Montserrat; Garcia-Rendueles, Maria E R; Diaz-Rodriguez, Esther; Garcia-Rendueles, Angela R; Perez-Romero, Sihara; Vila, Tania Vila; Rodrigues, Joana S; Lear, Pamela V; Bravo, Susana B

    2012-10-01

    Embryonic, adult, artificially reprogrammed, and cancer…- there are various types of cells associated with stemness. Do they have something fundamental in common? Are we applying a common name to very different entities? In this review, we will revisit the characteristics that define 'pluripotency', the main property of stem cells (SCs). For each main type of physiological (embryonic and adult) or synthetic (induced pluripotent) SCs, markers and functional behavior in vitro and in vivo will be described. We will review the pioneering work that has led to obtaining human SC lines, together with the problems that have arisen, both in a biological context (DNA alterations, heterogeneity, tumors, and immunogenicity) and with regard to ethical concerns. Such problems have led to proposals for new operative procedures for growing human SCs of sufficiently high quality for use as models of disease and in human therapy. Finally, we will review the data from the first clinical trials to use various types of SCs.

  4. Relative stability of major types of beta-turns as a function of amino acid composition: a study based on Ab initio energetic and natural abundance data.

    PubMed

    Perczel, András; Jákli, Imre; McAllister, Michael A; Csizmadia, Imre G

    2003-06-06

    Folding properties of small globular proteins are determined by their amino acid sequence (primary structure). This holds both for local (secondary structure) and for global conformational features of linear polypeptides and proteins composed from natural amino acid derivatives. It thus provides the rational basis of structure prediction algorithms. The shortest secondary structure element, the beta-turn, most typically adopts either a type I or a type II form, depending on the amino acid composition. Herein we investigate the sequence-dependent folding stability of both major types of beta-turns using simple dipeptide models (-Xxx-Yyy-). Gas-phase ab initio properties of 16 carefully selected and suitably protected dipeptide models (for example Val-Ser, Ala-Gly, Ser-Ser) were studied. For each backbone fold most probable side-chain conformers were considered. Fully optimized 321G RHF molecular structures were employed in medium level [B3LYP/6-311++G(d,p)//RHF/3-21G] energy calculations to estimate relative populations of the different backbone conformers. Our results show that the preference for beta-turn forms as calculated by quantum mechanics and observed in Xray determined proteins correlates significantly.

  5. The microbes we eat: abundance and taxonomy of microbes consumed in a day’s worth of meals for three diet types

    PubMed Central

    Lang, Jenna M.; Eisen, Jonathan A.

    2014-01-01

    Far more attention has been paid to the microbes in our feces than the microbes in our food. Research efforts dedicated to the microbes that we eat have historically been focused on a fairly narrow range of species, namely those which cause disease and those which are thought to confer some “probiotic” health benefit. Little is known about the effects of ingested microbial communities that are present in typical American diets, and even the basic questions of which microbes, how many of them, and how much they vary from diet to diet and meal to meal, have not been answered. We characterized the microbiota of three different dietary patterns in order to estimate: the average total amount of daily microbes ingested via food and beverages, and their composition in three daily meal plans representing three different dietary patterns. The three dietary patterns analyzed were: (1) the Average American (AMERICAN): focused on convenience foods, (2) USDA recommended (USDA): emphasizing fruits and vegetables, lean meat, dairy, and whole grains, and (3) Vegan (VEGAN): excluding all animal products. Meals were prepared in a home kitchen or purchased at restaurants and blended, followed by microbial analysis including aerobic, anaerobic, yeast and mold plate counts as well as 16S rRNA PCR survey analysis. Based on plate counts, the USDA meal plan had the highest total amount of microbes at 1.3 × 109 CFU per day, followed by the VEGAN meal plan and the AMERICAN meal plan at 6 × 106 and 1.4 × 106 CFU per day respectively. There was no significant difference in diversity among the three dietary patterns. Individual meals clustered based on taxonomic composition independent of dietary pattern. For example, meals that were abundant in Lactic Acid Bacteria were from all three dietary patterns. Some taxonomic groups were correlated with the nutritional content of the meals. Predictive metagenome analysis using PICRUSt indicated differences in some functional KEGG categories

  6. Comparison of elastic properties of open-cell metallic biomaterials with different unit cell types.

    PubMed

    Hedayati, Reza; Sadighi, Mojtaba; Mohammadi-Aghdam, Mohammad; Hosseini-Toudeshky, Hossein

    2017-02-06

    Additive manufacturing techniques have made it possible to create open-cell porous structures with arbitrary micro-geometrical characteristics. Since a wide range of micro-geometrical features is available for making an implant, having a comprehensive knowledge of the mechanical response of cellular structures is very useful. In this study, finite element simulations have been carried out to investigate the effect of structure unit cell type (cube, rhombic dodecahedron, Kelvin, Weaire-Phelan, and diamond), cross-section type (circular, square, and triangular), strut length, and relative density on the Young's modulus, shear modulus, yield stress, shear yield stress, and Poisson's ratio of open-cell tessellated cellular structures. It was desired to see whether or not and to what extent each of the aforementioned parameters affect the mechanical properties of a porous structure. It was seen that the strut cross-section type does not have a considerable effect on the structure Young's modulus while its effect on the structure yield stress is significant. The strut length was not effective on the mechanical properties if the relative density was kept constant. It was also observed that the structure unit cell type and relative density have a considerable effect on the elastic properties. The highest and the lowest stiffness and strength belonged to the cube and diamond unit cell types, respectively. The rhombic dodecahedron structure with circular cross-section had a high yielding strength (second among all the cases) while its Young's modulus was relatively low. Therefore, it is the best choice for applications with low stiffness requirements, such as biomedical implants. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2017.

  7. Galvanic Cell Type Sensor for Soil Moisture Analysis.

    PubMed

    Gaikwad, Pramod; Devendrachari, Mruthyunjayachari Chattanahalli; Thimmappa, Ravikumar; Paswan, Bhuneshwar; Raja Kottaichamy, Alagar; Makri Nimbegondi Kotresh, Harish; Thotiyl, Musthafa Ottakam

    2015-07-21

    Here we report the first potentiometric sensor for soil moisture analysis by bringing in the concept of Galvanic cells wherein the redox energies of Al and conducting polyaniline are exploited to design a battery type sensor. The sensor consists of only simple architectural components, and as such they are inexpensive and lightweight, making it suitable for on-site analysis. The sensing mechanism is proved to be identical to a battery type discharge reaction wherein polyaniline redox energy changes from the conducting to the nonconducting state with a resulting voltage shift in the presence of soil moisture. Unlike the state of the art soil moisture sensors, a signal derived from the proposed moisture sensor is probe size independent, as it is potentiometric in nature and, hence, can be fabricated in any shape or size and can provide a consistent output signal under the strong aberration conditions often encountered in soil moisture analysis. The sensor is regenerable by treating with 1 M HCl and can be used for multiple analysis with little read out hysteresis. Further, a portable sensor is fabricated which can provide warning signals to the end user when the moisture levels in the soil go below critically low levels, thereby functioning as a smart device. As the sensor is inexpensive, portable, and potentiometric, it opens up avenues for developing effective and energy efficient irrigation strategies, understanding the heat and water transfer at the atmosphere-land interface, understanding soil mechanics, forecasting the risk of natural calamities, and so on.

  8. Relationship between asbestos exposure and lung cancer cell type

    SciTech Connect

    Stewart, W.F.

    1984-01-01

    A nested case-control study was undertaken to investigate the relationship between asbestos exposure and lung cancer cell type. Cases were former employees of two Virginia shipyards, and were identified from the Virginia Tumor Registry. All cases were diagnosed with lung cancer between 1975-82. A stratified random sample of controls was selected from among former shipyard workers from the same two yards as the cases. Job histories were abstracted from shipyard personnel records on all cases and controls and were the primary source of data used to derive measures of asbestos exposure. Analyses were conducted using the conditional maximum likelihood estimate of the odds ratio an logistic regression. The results from the analysis showed that adenocarcinoma had the strongest association with asbestos exposure and the only case group to be associated with a multiplicative interaction effect between asbestos exposure and smoking. The most significant associations were found for adenocarcinoma cases employed before 1950. Strikingly negative dose-response relationships were found for the other three case groups. The results suggest indirectly that squamous and small cell cancer may have shorter latency from exposure to diagnosis and that proportionately more of these cases were not captured in this study. Problems which are related to a calendar time criteria for case ascertainment, i.e., diagnosis between 1975-82, limit the conclusiveness of these findings.

  9. Boron implanted emitter for n-type silicon solar cell

    NASA Astrophysics Data System (ADS)

    Liang, Peng; Han, Pei-De; Fan, Yu-Jie; Xing, Yu-Peng

    2015-03-01

    The effects of ion doses on the properties of boron implanted Si for n-type solar cell application were investigated with doses ranging from 5× 1014 cm- 2 to 2× 1015 cm- 2 and a subsequent two-step annealing process in a tube furnace. With the help of the TCAD process simulation tool, knowledge on diffusion kinetics of dopants and damage evolution was obtained by fitting SIMS measured boron profiles. Due to insufficient elimination of the residual damage, the implanted emitter was found to have a higher saturation current density (J0e) and a poorer crystallographic quality. Consistent with this observation, Voc, Jsc, and the efficiency of the all-implanted p+-n-n+ solar cells followed a decreasing trend with an increase of the implantation dose. The obtained maximum efficiency was 19.59% at a low dose of 5× 1014 cm- 2. The main efficiency loss under high doses came not only from increased recombination of carriers in the space charge region revealed by double-diode parameters of dark I-V curves, but also from the degraded minority carrier diffusion length in the emitter and base evidenced by IQE data. These experimental results indicated that clusters and dislocation loops had appeared at high implantation doses, which acted as effective recombination centers for photogenerated carriers. Project supported by the National Natural Science Foundation of China (Grant Nos. 61275040, 60976046, and 61021003) and the National Basic Research Program of China (Grant No. 2012CB934200).

  10. Cell-type specific posttranslational processing of peptides by different pituitary cell lines.

    PubMed

    Dickerson, I M; Mains, R E

    1990-07-01

    In order to compare prohormone processing in two distinct pituitary cell types, somatomammotrope cells (GH3) and corticotrope cells (AtT-20) were stably transfected with vectors encoding preproneuropeptide Y (preproNPY) containing four different pairs of basic amino acids at the single endoproteolytic cleavage site: wildtype or KR (lysine-arginine), RR, RK, and KK. The GH-NPY cell lines cleaved proNPY to a similar extent, regardless of the sequence of the basic amino acids at the cleavage site (KR = RR = RK = KK). AtT-20-NPY cells are known to exhibit a strong hierarchy of cleavage site preference when processing wildtype and mutated proNPY forms (KR = RR greater than RK much greater than KK). All four types of GH-NPY and AtT-NPY cells faithfully produced NPY (1-36) NH2 from proNPY (1-69), regardless of the amino acid sequence at the cleavage site. All four types of GH-NPY cells produced some of the expected proNPY-COOH-terminal peptide with Ser40 at its NH2-terminal [proNPY (40-69)]. GH3 cells expressing the RR, RK, and KK forms of proNPY yielded in addition some proNPY-COOH-terminal peptide retaining the amino terminals Lys39 or Arg39 residue. In contrast, AtT-NPY-RK cells produced only the Lys39 form of proNPY-COOH-terminal peptide while the other three AtT-NPY lines (KR, RR, and KK) produced only the Ser40 form of proNPY-COOH-terminal peptide. The residence time of proNPY and NPY in GH3 cells was dramatically increased by treatment with insulin, estradiol, and epidermal growth factor, in concert with the expected increase in PRL synthesis and decrease in GH synthesis; increased residence time in the cells did not result in an increase in the extent of cleavage of proNPY to NPY. AtT-20 cells did not respond to the somatomammotrope-specific set of hormones. Thus, there are several important differences in the posttranslational processing and storage of peptide hormones in corticotropes and somatomammotropes.

  11. Lithium, Sodium, and Potassium Abundances in Sharp-Lined A-Type Stars Takeda, Yoichi; Kang, Dong-Il; Han, Inwoo; Lee, Byeong-Cheol; Kim, Kang-Min; Kawanomoto, Satoshi; Ohishi, Naoko;

    NASA Astrophysics Data System (ADS)

    2012-04-01

    The abundances of alkali elements (Li, Na, and K) were determined from the Li I 6708, Na I 5682/5688, and K I 7699 lines by taking into account the non-LTE effect for 24 sharp-lined A-type stars (ve sin i ≲ 50 km s-1, 7000 K &lesssim Teff &lessim 10000 K, many showing Am peculiarities to different degrees), based on high-dispersion and high-S/N spectral data secured at BOAO (Korea) and OAO (Japan). We found a significant trend that A(Na) tightly scales with A(Fe) irrespective of Teff, which means that Na becomes enriched similarly to Fe in accordance with the degree of Am peculiarity. Regarding lithium, A(Li) mostly ranges between ˜ 3 and ˜ 3.5 (i.e., almost the same as or slightly less than the solar system abundance of 3.3) with a weak decreasing tendency with a lowering of Teff at Teff &lesssim 8000 K, though several stars exceptionally show distinctly larger depletion. The abundances of potassium also revealed an apparent Teff-dependence in the sense that A(K) in late-A stars tends to be mildly subsolar [possibly with a weak anti-correlation with A(Fe)] systematically decreasing from ˜ 5.0 (Teff ˜ 8500 K) to ˜ 4.6 (Teff ˜ 7500 K), while those for early-A stars remain near-solar around ˜ 5.0-5.2. These observational facts may serve as important constraints for any theory aiming to explain chemical anomalies of A-type stars.

  12. Stem cell sources for clinical islet transplantation in type 1 diabetes: embryonic and adult stem cells.

    PubMed

    Miszta-Lane, Helena; Mirbolooki, Mohammadreza; James Shapiro, A M; Lakey, Jonathan R T

    2006-01-01

    Lifelong immunosuppressive therapy and inadequate sources of transplantable islets have led the islet transplantation benefits to less than 0.5% of type 1 diabetics. Whereas the potential risk of infection by animal endogenous viruses limits the uses of islet xeno-transplantation, deriving islets from stem cells seems to be able to overcome the current problems of islet shortages and immune compatibility. Both embryonic (derived from the inner cell mass of blastocysts) and adult stem cells (derived from adult tissues) have shown controversial results in secreting insulin in vitro and normalizing hyperglycemia in vivo. ESCs research is thought to have much greater developmental potential than adult stem cells; however it is still in the basic research phase. Existing ESC lines are not believed to be identical or ideal for generating islets or beta-cells and additional ESC lines have to be established. Research with ESCs derived from humans is controversial because it requires the destruction of a human embryo and/or therapeutic cloning, which some believe is a slippery slope to reproductive cloning. On the other hand, adult stem cells are already in some degree specialized, recipients may receive their own stem cells. They are flexible but they have shown mixed degree of availability. Adult stem cells are not pluripotent. They may not exist for all organs. They are difficult to purify and they cannot be maintained well outside the body. In order to draw the future avenues in this field, existent discrepancies between the results need to be clarified. In this study, we will review the different aspects and challenges of using embryonic or adult stem cells in clinical islet transplantation for the treatment of type 1 diabetes.

  13. An Efficient Antipodal Cell Isolation Method for Screening of Cell Type-Specific Genes in Arabidopsis thaliana

    PubMed Central

    Sun, Meng-xiang

    2016-01-01

    In flowering plants, the mature embryo sac consists of seven cells, namely two synergid cells and an egg cell at the micropylar end, one central cell, and three antipodal cells at the chalazal end. Excluding the antipodal cell, as a model for the study of cell fate determination and cell type specification, the roles of these embryo sac component cells in fertilization and seed formation have been widely investigated. At this time, little is known regarding the function of antipodal cells and their cell type-specific gene expression patterns. One reason for this is difficulties related to the observation and isolation of cells for detailed functional analyses. Here, we report a method for antipodal cell isolation and transcriptome analysis. We identified antipodal cell-specific marker line K44-1, and based on this marker line, established a procedure allowing us to isolate antipodal cells with both high quality and quantity. PCR validation of antipodal-specific genes from antipodal cell cDNA showed that the isolated cells are qualified and can be used for transcriptome analysis and screening of cell type-specific marker genes. The isolated cells could keep viable for a week in culture condition. This method can be used to efficiently isolate antipodal cells of high quality and will promote the functional investigation of antipodal cells in Arabidopsis thaliana. This increases our understanding of the molecular regulatory mechanism of antipodal cell specification. PMID:27875553

  14. When is an Alveolar Type 2 Cell an Alveolar Type 2 Cell? A Conundrum for Lung Stem Cell Biology and Regenerative Medicine.

    PubMed

    Beers, Michael F; Moodley, Yuben

    2017-03-22

    Generating mature, differentiated, adult lung cells from pluripotent cells such as induced pluripotent cells (iPS) and embryonic stem cells (ES) offers the hope of both generating disease specific in vitro models and creating definitive and personalized therapies for a host of debilitating lung parenchymal and airway diseases. With the goal of advancing lung regenerative medicine, several groups have developed and reported on protocols utilizing either defined media, co-culture with mesenchymal components, or sequential treatments mimicking lung development, to obtain distal lung epithelial cells from stem cell precursors. However, there remains significant controversy about the degree of differentiation of these cells compared to their primary counterparts coupled with a lack of consistency or uniformity in assessing the resultant phenotypes. Given the inevitable, exponential expansion of these approaches and the probable but yet to emerge 2nd and higher generation techniques to create such assets, we were prompted to pose the question: "What makes a lung epithelial cell a lung epithelial cell?" and more specifically for this Perspective "What are the minimum features that constitute an alveolar type II epithelial cell (AT2)". In addressing this, we summarize a body of work spanning nearly five decades amassed by a series of "lung epithelial cell biology pioneers" which carefully describes well characterized molecular, functional, and morphological features critical for discriminate assessment of an AT2 phenotype. Armed with this we propose a series of core criteria to assist the field in confirming that cells obtained following a differentiating protocol are indeed mature and functional AT2 epithelial cells.

  15. Protein covalent immobilization via its scarce thiol versus abundant amine groups: Effect on orientation, cell binding domain exposure and conformational lability.

    PubMed

    Ba, O M; Hindie, M; Marmey, P; Gallet, O; Anselme, K; Ponche, A; Duncan, A C

    2015-10-01

    Quantity, orientation, conformation and covalent linkage of naturally cell adhesive proteins adsorbed or covalently linked to a surface, are known to influence the preservation of their subsequent long term cell adhesion properties and bioactivity. In the present work, we explore two different strategies for the covalent linking of plasma fibronectin (pFN) - used as a cell adhesive model protein, onto a polystyrene (PS) surface. One is aimed at tethering the protein to the surface in a semi-oriented fashion (via one of the 4 free thiol reactive groups on the protein) with a heterofunctional coupling agent (SSMPB method). The other aims to immobilize the protein in a more random fashion by reaction between the abundant pendant primary amine bearing amino acids of the pFN and activated carboxylic surface functions obtained after glutaric anhydride surface treatment (GA method). The overall goal will be to verify the hypothesis of a correlation between covalent immobilization of a model cell adhesive protein to a PS surface in a semi-oriented configuration (versus randomly oriented) with promotion of enhanced exposure of the protein's cell binding domain. This in turn would lead to enhanced cell adhesion. Ideally the goal is to elaborate substrates exhibiting a long term stable protein monolayer with preserved cell adhesive properties and bioactivity for biomaterial and/or cell adhesion commercial plate applications. However, the initial restrictive objective of this paper is to first quantitatively and qualitatively investigate the reversibly (merely adsorbed) versus covalently irreversibly bound protein to the surface after the immobilization procedure. Although immobilized surface amounts were similar (close to the monolayer range) for all immobilization approaches, covalent grafting showed improved retention and stronger "tethering" of the pFN protein to the surface (roughly 40%) after SDS rinsing compared to that for mere adsorption (0%) suggesting an added value

  16. Nonsense but not missense mutations can decrease the abundance of nuclear mRNA for the mouse major urinary protein, while both types of mutations can facilitate exon skipping.

    PubMed Central

    Belgrader, P; Maquat, L E

    1994-01-01

    In an effort to understand the mechanisms by which nonsense codons affect RNA metabolism in mammalian cells, nonsense mutations were generated within the gene for the secretory major urinary protein (MUP) of mice. The translation of MUP mRNA normally begins within exon 1 and terminates within exon 6, the penultimate exon. Through the use of Northern (RNA) blot hybridization and assays that couple reverse transcription and PCR, a nonsense mutation within codon 50 of exon 2 or codon 143 of exon 5 was found to reduce the abundance of fully spliced, nuclear MUP mRNA to 10 to 20% of normal without an additional reduction in the abundance of cytoplasmic mRNA. In contrast, a nonsense mutation within codon 172 of exon 5 was found to have no effects on the abundance of MUP mRNA. These findings suggest that a boundary between nonsense mutations that do and do not reduce the abundance of nuclear mRNA exists within the exon preceding the exon that harbors the normal site of translation termination. In this way, the boundary is analogous to the boundary that exists within the penultimate exon of the human gene for the cytosolic enzyme triosephosphate isomerase. Assays for exon skipping, i.e., the removal of an exon as a part of the flanking introns during the process of splicing, reveal that 0.1, 2.0, and 0.1% of MUP mRNA normally lack exon 5, exon 6, and exons 5 plus 6, respectively. Relative to normal, the two nonsense mutations within exon 5 increase the abundance of RNA lacking exon 5 on average 20-fold and increase the abundance of RNA lacking exons 5 plus 6 on average 5-fold. Since only one of these nonsense mutations also reduces the abundance of fully spliced nuclear mRNA to 10 to 20% of normal, the two mechanisms by which a nonsense mutation can alter nuclear RNA metabolism must be distinct. The analysis of missense mutations within codons 143 and 172, some of which retain the nonsense mutation, indicates that the reduction in the abundance of fully spliced nuclear m

  17. Precision Automation of Cell Type Classification and Sub-Cellular Fluorescence Quantification from Laser Scanning Confocal Images

    PubMed Central

    Hall, Hardy C.; Fakhrzadeh, Azadeh; Luengo Hendriks, Cris L.; Fischer, Urs

    2016-01-01

    While novel whole-plant phenotyping technologies have been successfully implemented into functional genomics and breeding programs, the potential of automated phenotyping with cellular resolution is largely unexploited. Laser scanning confocal microscopy has the potential to close this gap by providing spatially highly resolved images containing anatomic as well as chemical information on a subcellular basis. However, in the absence of automated methods, the assessment of the spatial patterns and abundance of fluorescent markers with subcellular resolution is still largely qualitative and time-consuming. Recent advances in image acquisition and analysis, coupled with improvements in microprocessor performance, have brought such automated methods within reach, so that information from thousands of cells per image for hundreds of images may be derived in an experimentally convenient time-frame. Here, we present a MATLAB-based analytical pipeline to (1) segment radial plant organs into individual cells, (2) classify cells into cell type categories based upon Random Forest classification, (3) divide each cell into sub-regions, and (4) quantify fluorescence intensity to a subcellular degree of precision for a separate fluorescence channel. In this research advance, we demonstrate the precision of this analytical process for the relatively complex tissues of Arabidopsis hypocotyls at various stages of development. High speed and robustness make our approach suitable for phenotyping of large collections of stem-like material and other tissue types. PMID:26904081

  18. Silver nanowire interactions with primary human alveolar type-II epithelial cell secretions: contrasting bioreactivity with human alveolar type-I and type-II epithelial cells

    NASA Astrophysics Data System (ADS)

    Sweeney, Sinbad; Theodorou, Ioannis G.; Zambianchi, Marta; Chen, Shu; Gow, Andrew; Schwander, Stephan; Zhang, Junfeng (Jim); Chung, Kian Fan; Shaffer, Milo S. P.; Ryan, Mary P.; Porter, Alexandra E.; Tetley, Teresa D.

    2015-06-01

    Inhaled nanoparticles have a high deposition rate in the alveolar units of the deep lung. The alveolar epithelium is composed of type-I and type-II epithelial cells (ATI and ATII respectively) and is bathed in pulmonary surfactant. The effect of native human ATII cell secretions on nanoparticle toxicity is not known. We investigated the cellular uptake and toxicity of silver nanowires (AgNWs; 70 nm diameter, 1.5 μm length) with human ATI-like cells (TT1), in the absence or presence of Curosurf® (a natural porcine pulmonary surfactant with a low amount of protein) or harvested primary human ATII cell secretions (HAS; containing both the complete lipid as well as the full protein complement of human pulmonary surfactant i.e. SP-A, SP-B, SP-C and SP-D). We hypothesised that Curosurf® or HAS would confer improved protection for TT1 cells, limiting the toxicity of AgNWs. In agreement with our hypothesis, HAS reduced the inflammatory and reactive oxygen species (ROS)-generating potential of AgNWs with exposed TT1 cells. For example, IL-8 release and ROS generation was reduced by 38% and 29%, respectively, resulting in similar levels to that of the non-treated controls. However in contrast to our hypothesis, Curosurf® had no effect. We found a significant reduction in AgNW uptake by TT1 cells in the presence of HAS but not Curosurf. Furthermore, we show that the SP-A and SP-D are likely to be involved in this process as they were found to be specifically bound to the AgNWs. While ATI cells appear to be protected by HAS, evidence suggested that ATII cells, despite no uptake, were vulnerable to AgNW exposure (indicated by increased IL-8 release and ROS generation and decreased intracellular SP-A levels one day post-exposure). This study provides unique findings that may be important for the study of lung epithelial-endothelial translocation of nanoparticles in general and associated toxicity within the alveolar unit.Inhaled nanoparticles have a high deposition rate in

  19. A Chandrasekhar mass progenitor for the Type Ia supernova remnant 3C 397 from the enhanced abundances of nickel and manganese

    DOE PAGES

    Yamaguchi, Hiroya; Badenes, Carles; Foster, Adam R.; ...

    2015-03-12

    Despite decades of intense efforts, many fundamental aspects of Type Ia supernovae (SNe Ia) remain elusive. One of the major open questions is whether the mass of an exploding white dwarf (WD) is close to the Chandrasekhar limit. Here, we report the detection of strong K-shell emission from stable Fe-peak elements in the Suzaku X-ray spectrum of the Type Ia supernova remnant (SNR) 3C 397. The high Ni/Fe and Mn/Fe mass ratios (0.11–0.24 and 0.018–0.033, respectively) in the hot plasma component that dominates the K-shell emission lines indicate a degree of neutronization in the supernova ejecta that can only bemore » achieved by electron capture in the dense cores of exploding WDs with a near-Chandrasekhar mass. This suggests a single-degenerate origin for 3C 397, since Chandrasekhar mass progenitors are expected naturally if the WD accretes mass slowly from a companion. Altogether with other results supporting the double-degenerate scenario, our work adds to the mounting evidence that both progenitor channels make a significant contribution to the SN Ia rate in star-forming galaxies.« less

  20. A Chandrasekhar mass progenitor for the Type Ia supernova remnant 3C 397 from the enhanced abundances of nickel and manganese

    SciTech Connect

    Yamaguchi, Hiroya; Badenes, Carles; Foster, Adam R.; Bravo, Eduardo; Williams, Brian J.; Maeda, Keiichi; Nobukawa, Masayoshi; Eriksen, Kristoffer A.; Brickhouse, Nancy S.; Petre, Robert; Koyama, Katsuji

    2015-03-12

    Despite decades of intense efforts, many fundamental aspects of Type Ia supernovae (SNe Ia) remain elusive. One of the major open questions is whether the mass of an exploding white dwarf (WD) is close to the Chandrasekhar limit. Here, we report the detection of strong K-shell emission from stable Fe-peak elements in the Suzaku X-ray spectrum of the Type Ia supernova remnant (SNR) 3C 397. The high Ni/Fe and Mn/Fe mass ratios (0.11–0.24 and 0.018–0.033, respectively) in the hot plasma component that dominates the K-shell emission lines indicate a degree of neutronization in the supernova ejecta that can only be achieved by electron capture in the dense cores of exploding WDs with a near-Chandrasekhar mass. This suggests a single-degenerate origin for 3C 397, since Chandrasekhar mass progenitors are expected naturally if the WD accretes mass slowly from a companion. Altogether with other results supporting the double-degenerate scenario, our work adds to the mounting evidence that both progenitor channels make a significant contribution to the SN Ia rate in star-forming galaxies.

  1. A CHANDRASEKHAR MASS PROGENITOR FOR THE TYPE Ia SUPERNOVA REMNANT 3C 397 FROM THE ENHANCED ABUNDANCES OF NICKEL AND MANGANESE

    SciTech Connect

    Yamaguchi, Hiroya; Williams, Brian J.; Petre, Robert; Badenes, Carles; Foster, Adam R.; Brickhouse, Nancy S.; Bravo, Eduardo; Maeda, Keiichi; Nobukawa, Masayoshi; Koyama, Katsuji; Eriksen, Kristoffer A.

    2015-03-10

    Despite decades of intense efforts, many fundamental aspects of Type Ia supernovae (SNe Ia) remain elusive. One of the major open questions is whether the mass of an exploding white dwarf (WD) is close to the Chandrasekhar limit. Here, we report the detection of strong K-shell emission from stable Fe-peak elements in the Suzaku X-ray spectrum of the Type Ia supernova remnant (SNR) 3C 397. The high Ni/Fe and Mn/Fe mass ratios (0.11–0.24 and 0.018–0.033, respectively) in the hot plasma component that dominates the K-shell emission lines indicate a degree of neutronization in the supernova ejecta that can only be achieved by electron capture in the dense cores of exploding WDs with a near-Chandrasekhar mass. This suggests a single-degenerate origin for 3C 397, since Chandrasekhar mass progenitors are expected naturally if the WD accretes mass slowly from a companion. Together with other results supporting the double-degenerate scenario, our work adds to the mounting evidence that both progenitor channels make a significant contribution to the SN Ia rate in star-forming galaxies.

  2. A Chandrasekhar Mass Progenitor for the Type Ia Supernova Remnant 3C 397 from the Enhanced Abundances of Nickel and Manganese

    NASA Astrophysics Data System (ADS)

    Yamaguchi, Hiroya; Badenes, Carles; Foster, Adam R.; Bravo, Eduardo; Williams, Brian J.; Maeda, Keiichi; Nobukawa, Masayoshi; Eriksen, Kristoffer A.; Brickhouse, Nancy S.; Petre, Robert; Koyama, Katsuji

    2015-03-01

    Despite decades of intense efforts, many fundamental aspects of Type Ia supernovae (SNe Ia) remain elusive. One of the major open questions is whether the mass of an exploding white dwarf (WD) is close to the Chandrasekhar limit. Here, we report the detection of strong K-shell emission from stable Fe-peak elements in the Suzaku X-ray spectrum of the Type Ia supernova remnant (SNR) 3C 397. The high Ni/Fe and Mn/Fe mass ratios (0.11-0.24 and 0.018-0.033, respectively) in the hot plasma component that dominates the K-shell emission lines indicate a degree of neutronization in the supernova ejecta that can only be achieved by electron capture in the dense cores of exploding WDs with a near-Chandrasekhar mass. This suggests a single-degenerate origin for 3C 397, since Chandrasekhar mass progenitors are expected naturally if the WD accretes mass slowly from a companion. Together with other results supporting the double-degenerate scenario, our work adds to the mounting evidence that both progenitor channels make a significant contribution to the SN Ia rate in star-forming galaxies.

  3. Internalisation of engineered nanoparticles into mammalian cells in vitro: influence of cell type and particle properties

    NASA Astrophysics Data System (ADS)

    Busch, Wibke; Bastian, Susanne; Trahorsch, Ulrike; Iwe, Maria; Kühnel, Dana; Meißner, Tobias; Springer, Armin; Gelinsky, Michael; Richter, Volkmar; Ikonomidou, Chrysanthy; Potthoff, Annegret; Lehmann, Irina; Schirmer, Kristin

    2011-01-01

    Cellular internalisation of industrial engineered nanoparticles is undesired and a reason for concern. Here we investigated and compared the ability of seven different mammalian cell cultures in vitro to incorporate six kinds of engineered nanoparticles, focussing on the role of cell type and particle properties in particle uptake. Uptake was examined using light and electron microscopy coupled with energy dispersive X-ray spectroscopy (EDX) for particle element identification. Flow cytometry was applied for semi-quantitative analyses of particle uptake and for exploring the influence on uptake by the phagocytosis inhibitor Cytochalasin D (CytoD). All particles studied were found to enter each kind of cultured cells. Yet, particles were never found within cell nuclei. The presence of the respective particles within the cells was confirmed by EDX. Live-cell imaging revealed the time-dependent process of internalisation of technical nanoparticles, which was exemplified by tungsten carbide particle uptake into the human skin cells, HaCaT. Particles were found to co-localise with lysosomal structures within the cells. The incorporated nanoparticles changed the cellular granularity, as measured by flow cytometry, already after 3 h of exposure in a particle specific manner. By correlating particle properties with flow cytometry data, only the primary particle size was found to be a weakly influential property for particle uptake. CytoD, an inhibitor of actin filaments and therewith of phagocytosis, significantly inhibited the internalisation of particle uptake in only two of the seven investigated cell cultures. Our study, therefore, supports the notion that nanoparticles can enter mammalian cells quickly and easily, irrespective of the phagocytic ability of the cells.

  4. Phospholipid-transfer activities in cytosols from lung, isolated alveolar type II cells and alveolar type II cell-derived adenomas.

    PubMed Central

    Pool, G L; Bubacz, D G; Lumb, R H; Mason, R J

    1983-01-01

    We have examined phospholipid-transfer activities in cytosols from rat and mouse whole lung, isolated rat alveolar type II cells and alveolar type II cell-derived mouse pulmonary adenomas. We report an enrichment in phosphatidylcholine and phosphatidylglycerol (but not phosphatidylinositol) protein-catalysed transfer in the type II cell and adenoma cytosols compared with the whole-lung cytosols. The activities from these cytosols were resolved using column chromatofocusing, which clearly demonstrated the presence of a phosphatidylcholine-specific transfer protein in each of the four tissues. In addition, two proteins (rat) or three proteins (mouse) catalysing both phosphatidylcholine and phosphatidylglycerol transfer were resolved from whole lung, whereas in both the rat isolated alveolar type II cells and the mouse type II cell-derived adenomas one of these less specific proteins is not present. PMID:6661189

  5. Cell-cell signalling in sexual chemotaxis: a basis for gametic differentiation, mating types and sexes.

    PubMed

    Hadjivasiliou, Zena; Iwasa, Yoh; Pomiankowski, Andrew

    2015-08-06

    While sex requires two parents, there is no obvious need for them to be differentiated into distinct mating types or sexes. Yet this is the predominate state of nature. Here, we argue that mating types could play a decisive role because they prevent the apparent inevitability of self-stimulation during sexual signalling. We rigorously assess this hypothesis by developing a model for signaller-detector dynamics based on chemical diffusion, chemotaxis and cell movement. Our model examines the conditions under which chemotaxis improves partner finding. Varying parameter values within ranges typical of protists and their environments, we show that simultaneous secretion and detection of a single chemoattractant can cause a multifold movement impediment and severely hinder mate finding. Mutually exclusive roles result in faster pair formation, even when cells conferring the same roles cannot pair up. This arrangement also allows the separate mating types to optimize their signalling or detecting roles, which is effectively impossible for cells that are both secretors and detectors. Our findings suggest that asymmetric roles in sexual chemotaxis (and possibly other forms of sexual signalling) are crucial, even without morphological differences, and may underlie the evolution of gametic differentiation among both mating types and sexes.

  6. Expressed sequence tag analysis of adult human optic nerve for NEIBank: Identification of cell type and tissue markers

    PubMed Central

    Bernstein, Steven L; Guo, Yan; Peterson, Katherine; Wistow, Graeme

    2009-01-01

    Background The optic nerve is a pure white matter central nervous system (CNS) tract with an isolated blood supply, and is widely used in physiological studies of white matter response to various insults. We examined the gene expression profile of human optic nerve (ON) and, through the NEIBANK online resource, to provide a resource of sequenced verified cDNA clones. An un-normalized cDNA library was constructed from pooled human ON tissues and was used in expressed sequence tag (EST) analysis. Location of an abundant oligodendrocyte marker was examined by immunofluorescence. Quantitative real time polymerase chain reaction (qRT-PCR) and Western analysis were used to compare levels of expression for key calcium channel protein genes and protein product in primate and rodent ON. Results Our analyses revealed a profile similar in many respects to other white matter related tissues, but significantly different from previously available ON cDNA libraries. The previous libraries were found to include specific markers for other eye tissues, suggesting contamination. Immune/inflammatory markers were abundant in the new ON library. The oligodendrocyte marker QKI was abundant at the EST level. Immunofluorescence revealed that this protein is a useful oligodendrocyte cell-type marker in rodent and primate ONs. L-type calcium channel EST abundance was found to be particularly low. A qRT-PCR-based comparative mammalian species analysis reveals that L-type calcium channel expression levels are significantly lower in primate than in rodent ON, which may help account for the class-specific difference in responsiveness to calcium channel blocking agents. Several known eye disease genes are abundantly expressed in ON. Many genes associated with normal axonal function, mRNAs associated with axonal transport, inflammation and neuroprotection are observed. Conclusion We conclude that the new cDNA library is a faithful representation of human ON and EST data provide an initial overview

  7. Mammalian non-CG methylations are conserved and cell-type specific and may have been involved in the evolution of transposon elements.

    PubMed

    Guo, Weilong; Zhang, Michael Q; Wu, Hong

    2016-08-30

    Although non-CG methylations are abundant in several mammalian cell types, their biological significance is sparsely characterized. We gathered 51 human and mouse DNA methylomes from brain neurons, embryonic stem cells and induced pluripotent stem cells, primordial germ cells and oocytes. We utilized an unbiased sub-motif prediction method and reported CW as the representative non-CG methylation context, which is distinct from CC methylation in terms of sequence context and genomic distribution. A two-dimensional comparison of non-CG methylations across cell types and species was performed. Unambiguous studies of sequence preferences and genomic region enrichment showed that CW methylation is cell-type specific and is also conserved between humans and mice. In brain neurons, it was found that active long interspersed nuclear element-1 (LINE-1) lacked CW methylations but not CG methylations. Coincidentally, both human Alu and mouse B1 elements preferred high CW methylations at specific loci during their respective evolutionary development. Last, the strand-specific distributions of CW methylations in introns and long interspersed nuclear elements are also cell-type specific and conserved. In summary, our results illustrate that CW methylations are highly conserved among species, are dynamically regulated in each cell type, and are potentially involved in the evolution of transposon elements.

  8. Mammalian non-CG methylations are conserved and cell-type specific and may have been involved in the evolution of transposon elements

    PubMed Central

    Guo, Weilong; Zhang, Michael Q.; Wu, Hong

    2016-01-01

    Although non-CG methylations are abundant in several mammalian cell types, their biological significance is sparsely characterized. We gathered 51 human and mouse DNA methylomes from brain neurons, embryonic stem cells and induced pluripotent stem cells, primordial germ cells and oocytes. We utilized an unbiased sub-motif prediction method and reported CW as the representative non-CG methylation context, which is distinct from CC methylation in terms of sequence context and genomic distribution. A two-dimensional comparison of non-CG methylations across cell types and species was performed. Unambiguous studies of sequence preferences and genomic region enrichment showed that CW methylation is cell-type specific and is also conserved between humans and mice. In brain neurons, it was found that active long interspersed nuclear element-1 (LINE-1) lacked CW methylations but not CG methylations. Coincidentally, both human Alu and mouse B1 elements preferred high CW methylations at specific loci during their respective evolutionary development. Last, the strand-specific distributions of CW methylations in introns and long interspersed nuclear elements are also cell-type specific and conserved. In summary, our results illustrate that CW methylations are highly conserved among species, are dynamically regulated in each cell type, and are potentially involved in the evolution of transposon elements. PMID:27573482

  9. Cell-Type-Specific Chromatin States Differentially Prime Squamous Cell Carcinoma Tumor-Initiating Cells for Epithelial to Mesenchymal Transition.

    PubMed

    Latil, Mathilde; Nassar, Dany; Beck, Benjamin; Boumahdi, Soufiane; Wang, Li; Brisebarre, Audrey; Dubois, Christine; Nkusi, Erwin; Lenglez, Sandrine; Checinska, Agnieszka; Vercauteren Drubbel, Alizée; Devos, Michael; Declercq, Wim; Yi, Rui; Blanpain, Cédric

    2017-02-02

    Epithelial to mesenchymal transition (EMT) in cancer cells has been associated with metastasis, stemness, and resistance to therapy. Some tumors undergo EMT while others do not, which may reflect intrinsic properties of their cell of origin. However, this possibility is largely unexplored. By targeting the same oncogenic mutations to discrete skin compartments, we show that cell-type-specific chromatin and transcriptional states differentially prime tumors to EMT. Squamous cell carcinomas (SCCs) derived from interfollicular epidermis (IFE) are generally well differentiated, while hair follicle (HF) stem cell-derived SCCs frequently exhibit EMT, efficiently form secondary tumors, and possess increased metastatic potential. Transcriptional and epigenomic profiling revealed that IFE and HF tumor-initiating cells possess distinct chromatin landscapes and gene regulatory networks associated with tumorigenesis and EMT that correlate with accessibility of key epithelial and EMT transcription factor binding sites. These findings highlight the importance of chromatin states and transcriptional priming in dictating tumor phenotypes and EMT.

  10. Decipher the Molecular Response of Plant Single Cell Types to Environmental Stresses

    PubMed Central

    2016-01-01

    The analysis of the molecular response of entire plants or organs to environmental stresses suffers from the cellular complexity of the samples used. Specifically, this cellular complexity masks cell-specific responses to environmental stresses and logically leads to the dilution of the molecular changes occurring in each cell type composing the tissue/organ/plant in response to the stress. Therefore, to generate a more accurate picture of these responses, scientists are focusing on plant single cell type approaches. Several cell types are now considered as models such as the pollen, the trichomes, the cotton fiber, various root cell types including the root hair cell, and the guard cell of stomata. Among them, several have been used to characterize plant response to abiotic and biotic stresses. In this review, we are describing the various -omic studies performed on these different plant single cell type models to better understand plant cell response to biotic and abiotic stresses. PMID:27088086

  11. Decipher the Molecular Response of Plant Single Cell Types to Environmental Stresses

    SciTech Connect

    Nourbakhsh-Rey, Mehrnoush; Libault, Marc

    2016-01-01

    The analysis of the molecular response of entire plants or organs to environmental stresses suffers from the cellular complexity of the samples used. Specifically, this cellular complexity masks cell-specific responses to environmental stresses and logically leads to the dilution of the molecular changes occurring in each cell type composing the tissue/organ/plant in response to the stress. Therefore, to generate a more accurate picture of these responses, scientists are focusing on plant single cell type approaches. Several cell types are now considered as models such as the pollen, the trichomes, the cotton fiber, various root cell types including the root hair cell, and the guard cell of stomata. Among them, several have been used to characterize plant response to abiotic and biotic stresses. Lastly, in this review, we are describing the various -omic studies performed on these different plant single cell type models to better understand plant cell response to biotic and abiotic stresses.

  12. Transcription Factors CTCF and Pax6 Are Segregated to Different Cell Types During Retinal Cell Differentiation

    PubMed Central

    Canto-Soler, M. Valeria; Huang, Hu; Romero, M. Soledad; Adler, Ruben

    2008-01-01

    We have hypothesized that the transcription factor CTCF may influence retinal cell differentiation by controlling Pax6 expression, because (1) CTCF has been shown to repress Pax6 expression in some tissues, and (2) Pax6 blocks the differentiation of retinal progenitor cells as photoreceptors and promotes their differentiation as nonphotoreceptor neurons. Our results show that, as predicted by this hypothesis, CTCF and Pax6 become segregated to different retinal cell types. The factors are initially coexpressed in the undifferentiated neuroepithelium, but already at that time they show complementary periphery-to-fundus gradients of distribution. As the retina laminates, Pax6 becomes restricted to ganglion and amacrine cells, and CTCF to the bipolar/Muller cell layer and the outer nuclear layer. Polymerase chain reaction analysis of laser capture microdissection samples and dissociated cells showed that both immature and differentiated photoreceptors are CTCF (+)/Pax6 (−). Functional studies are now under way to further analyze the role of CTCF in retinal cell differentiation. PMID:18224715

  13. Abundances in Przybylski's star

    NASA Astrophysics Data System (ADS)

    Cowley, C. R.; Ryabchikova, T.; Kupka, F.; Bord, D. J.; Mathys, G.; Bidelman, W. P.

    2000-09-01

    We have derived abundances for 54 elements in the extreme roAp star HD101065. ESO spectra with a resolution of about 80000, and S/N of 200 or more were employed. The adopted model has Teff=6600K, and log(g)=4.2. Because of the increased line opacity and consequent low gas pressure, convection plays no significant role in the temperature structure. Lighter elemental abundances through the iron group scatter about standard abundance distribution (SAD) (solar) values. Iron and nickel are about one order of magnitude deficient while cobalt is enhanced by 1.5dex. Heavier elements, including the lanthanides, generally follow the solar pattern but enhanced by 3 to 4dex. Odd-Z elements are generally less abundant than their even-Z neighbours. With a few exceptions (e.g. Yb), the abundance pattern among the heavy elements is remarkably coherent, and resembles a displaced solar distribution.

  14. Brain structure. Cell types in the mouse cortex and hippocampus revealed by single-cell RNA-seq.

    PubMed

    Zeisel, Amit; Muñoz-Manchado, Ana B; Codeluppi, Simone; Lönnerberg, Peter; La Manno, Gioele; Juréus, Anna; Marques, Sueli; Munguba, Hermany; He, Liqun; Betsholtz, Christer; Rolny, Charlotte; Castelo-Branco, Gonçalo; Hjerling-Leffler, Jens; Linnarsson, Sten

    2015-03-06

    The mammalian cerebral cortex supports cognitive functions such as sensorimotor integration, memory, and social behaviors. Normal brain function relies on a diverse set of differentiated cell types, including neurons, glia, and vasculature. Here, we have used large-scale single-cell RNA sequencing (RNA-seq) to classify cells in the mouse somatosensory cortex and hippocampal CA1 region. We found 47 molecularly distinct subclasses, comprising all known major cell types in the cortex. We identified numerous marker genes, which allowed alignment with known cell types, morphology, and location. We found a layer I interneuron expressing Pax6 and a distinct postmitotic oligodendrocyte subclass marked by Itpr2. Across the diversity of cortical cell types, transcription factors formed a complex, layered regulatory code, suggesting a mechanism for the maintenance of adult cell type identity.

  15. Rabbit somatic cell cloning: effects of donor cell type, histone acetylation status and chimeric embryo complementation.

    PubMed

    Yang, Feikun; Hao, Ru; Kessler, Barbara; Brem, Gottfried; Wolf, Eckhard; Zakhartchenko, Valeri

    2007-01-01

    The epigenetic status of a donor nucleus has an important effect on the developmental potential of embryos produced by somatic cell nuclear transfer (SCNT). In this study, we transferred cultured rabbit cumulus cells (RCC) and fetal fibroblasts (RFF) from genetically marked rabbits (Alicia/Basilea) into metaphase II oocytes and analyzed the levels of histone H3-lysine 9-lysine 14 acetylation (acH3K9/14) in donor cells and cloned embryos. We also assessed the correlation between the histone acetylation status of donor cells and cloned embryos and their developmental potential. To test whether alteration of the histone acetylation status affects development of cloned embryos, we treated donor cells with sodium butyrate (NaBu), a histone deacetylase inhibitor. Further, we tried to improve cloning efficiency by chimeric complementation of cloned embryos with blastomeres from in vivo fertilized or parthenogenetic embryos. The levels of acH3K9/14 were higher in RCCs than in RFFs (P<0.05). Although the type of donor cells did not affect development to blastocyst, after transfer into recipients, RCC cloned embryos induced a higher initial pregnancy rate as compared to RFF cloned embryos (40 vs 20%). However, almost all pregnancies with either type of cloned embryos were lost by the middle of gestation and only one fully developed, live RCC-derived rabbit was obtained. Treatment of RFFs with NaBu significantly increased the level of acH3K9/14 and the proportion of nuclear transfer embryos developing to blastocyst (49 vs 33% with non-treated RFF, P<0.05). The distribution of acH3K9/14 in either group of cloned embryos did not resemble that in in vivo fertilized embryos suggesting that reprogramming of this epigenetic mark is aberrant in cloned rabbit embryos and cannot be corrected by treatment of donor cells with NaBu. Aggregation of embryos cloned from NaBu-treated RFFs with blastomeres from in vivo derived embryos improved development to blastocyst, but no cloned

  16. Morphine biosynthesis in opium poppy involves two cell types: sieve elements and laticifers.

    PubMed

    Onoyovwe, Akpevwe; Hagel, Jillian M; Chen, Xue; Khan, Morgan F; Schriemer, David C; Facchini, Peter J

    2013-10-01

    Immunofluorescence labeling and shotgun proteomics were used to establish the cell type-specific localization of morphine biosynthesis in opium poppy (Papaver somniferum). Polyclonal antibodies for each of six enzymes involved in converting (R)-reticuline to morphine detected corresponding antigens in sieve elements of the phloem, as described previously for all upstream enzymes transforming (S)-norcoclaurine to (S)-reticuline. Validated shotgun proteomics performed on whole-stem and latex total protein extracts generated 2031 and 830 distinct protein families, respectively. Proteins corresponding to nine morphine biosynthetic enzymes were represented in the whole stem, whereas only four of the final five pathway enzymes were detected in the latex. Salutaridine synthase was detected in the whole stem, but not in the latex subproteome. The final three enzymes converting thebaine to morphine were among the most abundant active latex proteins despite a limited occurrence in laticifers suggested by immunofluorescence labeling. Multiple charge isoforms of two key O-demethylases in the latex were revealed by two-dimensional immunoblot analysis. Salutaridine biosynthesis appears to occur only in sieve elements, whereas conversion of thebaine to morphine is predominant in adjacent laticifers, which contain morphine-rich latex. Complementary use of immunofluorescence labeling and shotgun proteomics has substantially resolved the cellular localization of morphine biosynthesis in opium poppy.

  17. Effects of abnormal cell-to-cell interference on p-type floating gate and control gate NAND flash memory

    NASA Astrophysics Data System (ADS)

    Kim, Yong Jun; Kang, Jun Geun; Lee, Byungin; Cho, Gyu-Seog; Park, Sung-Kye; Choi, Woo Young

    2014-01-01

    Abnormal cell-to-cell interference occurring in NAND flash memory has been investigated. In the case of extremely downscaled NAND flash memory, cell-to-cell interference increases abnormally. The abnormal cell-to-cell interference has been observed in a p-type floating gate (FG)/control gate (CG) cells for the first time. It has been found that the depletion region variation leads to the abnormal cell-to-cell interference. The depletion region variation of FG and CG is determined by state of neighbor cells. The depletion region variation affects CG-to-FG coupling capacitance and threshold voltage variation (ΔVT). Finally, it is observed that there is a symmetrical relationship between n- and p-type FG/CG NAND flash memory in terms of cell-to-cell interference.

  18. Cell type-specific and common characteristics of exosomes derived from mouse cell lines: Yield, physicochemical properties, and pharmacokinetics.

    PubMed

    Charoenviriyakul, Chonlada; Takahashi, Yuki; Morishita, Masaki; Matsumoto, Akihiro; Nishikawa, Makiya; Takakura, Yoshinobu

    2017-01-01

    Exosomes are small membrane vesicles secreted from cells and are expected to be used as drug delivery systems. Important characteristics of exosomes, such as yield, physicochemical properties, and pharmacokinetics, may be different among different cell types. However, there is limited information about the effect of cell type on these characteristics. In the present study, we evaluated these characteristics of exosomes derived from five different types of mouse cell lines: B16BL6 murine melanoma cells, C2C12 murine myoblast cells, NIH3T3 murine fibroblasts cells, MAEC murine aortic endothelial cells, and RAW264.7 murine macrophage-like cells. Exosomes were collected using a differential ultracentrifugation method. The exosomes collected from all the cell types were negatively charged globular vesicles with a diameter of approximately 100nm. C2C12 and RAW264.7 cells produced more exosomes than the other types of cells. The exosomes were labeled with a fusion protein of Gaussia luciferase and lactadherin to evaluate their pharmacokinetics. After intravenous injection into mice, all the exosomes rapidly disappeared from the systemic circulation and mainly distributed to the liver. In conclusion, the exosome yield was significantly different among the cell types, and all the exosomes evaluated in this study showed comparable physicochemical and pharmacokinetic properties.

  19. Differential volume regulation and calcium signaling in two ciliary body cell types is subserved by TRPV4 channels

    PubMed Central

    Jo, Andrew O.; Lakk, Monika; Frye, Amber M.; Phuong, Tam T. T.; Redmon, Sarah N.; Roberts, Robin; Berkowitz, Bruce A.; Yarishkin, Oleg; Križaj, David

    2016-01-01

    Fluid secretion by the ciliary body plays a critical and irreplaceable function in vertebrate vision by providing nutritive support to the cornea and lens, and by maintaining intraocular pressure. Here, we identify TRPV4 (transient receptor potential vanilloid isoform 4) channels as key osmosensors in nonpigmented epithelial (NPE) cells of the mouse ciliary body. Hypotonic swelling and the selective agonist GSK1016790A (EC50 ∼33 nM) induced sustained transmembrane cation currents and cytosolic [Ca2+]i elevations in dissociated and intact NPE cells. Swelling had no effect on [Ca2+]i levels in pigment epithelial (PE) cells, whereas depolarization evoked [Ca2+]i elevations in both NPE and PE cells. Swelling-evoked [Ca2+]i signals were inhibited by the TRPV4 antagonist HC067047 (IC50 ∼0.9 μM) and were absent in Trpv4−/− NPE. In NPE, but not PE, swelling-induced [Ca2+]i signals required phospholipase A2 activation. TRPV4 localization to NPE was confirmed with immunolocalization and excitation mapping approaches, whereas in vivo MRI analysis confirmed TRPV4-mediated signals in the intact mouse ciliary body. Trpv2 and Trpv4 were the most abundant vanilloid transcripts in CB. Overall, our results support a model whereby TRPV4 differentially regulates cell volume, lipid, and calcium signals in NPE and PE cell types and therefore represents a potential target for antiglaucoma medications. PMID:27006502

  20. Types of HLA in the bladder transitional cell carcinoma (TCC).

    PubMed

    Yılmaz, Erkan; Uğur Özalp, Ali; Cekmen, Arman; Eren, Bülent; Onal, Bülent; Akkuş, Emre; Erdoğan, Ergun

    2013-02-01

    HLA plays a complementary role in the interaction between tumor and body immunology. The aim of this study was to determine the existence of the association between the HLA system and transitional cell carcinoma (TCC). Using standard micro-lymphocytotoxic method of Terasaki, HLA-A, B, DR and DQ antigen types of 30 patients with TCC of the bladder were compared with the control group (30 healthy people). In the TCC patient group, HLA -DQ6(1) and HLA -DQ7(3) antigens were detected with a significantly higher frequency than in the control group (p=0.018 and p=0.038, respectively), whereas HLA-A10, B4, DR53 and DQ1 antigens were detected with significantly higher frequency in the control group (p less 0.05 in all). It suggests that patients who had the antigens detected were at higher risk of TCC, and the ones who had the antigens displaying protective features as were detected in the control group, were at lesser risk.

  1. Steviol glycosides modulate glucose transport in different cell types.

    PubMed

    Rizzo, Benedetta; Zambonin, Laura; Angeloni, Cristina; Leoncini, Emanuela; Dalla Sega, Francesco Vieceli; Prata, Cecilia; Fiorentini, Diana; Hrelia, Silvana

    2013-01-01

    Extracts from Stevia rebaudiana Bertoni, a plant native to Central and South America, have been used as a sweetener since ancient times. Currently, Stevia extracts are largely used as a noncaloric high-potency biosweetener alternative to sugar, due to the growing incidence of type 2 diabetes mellitus, obesity, and metabolic disorders worldwide. Despite the large number of studies on Stevia and steviol glycosides in vivo, little is reported concerning the cellular and molecular mechanisms underpinning the beneficial effects on human health. The effect of four commercial Stevia extracts on glucose transport activity was evaluated in HL-60 human leukaemia and in SH-SY5Y human neuroblastoma cells. The extracts were able to enhance glucose uptake in both cellular lines, as efficiently as insulin. Our data suggest that steviol glycosides could act by modulating GLUT translocation through the PI3K/Akt pathway since treatments with both insulin and Stevia extracts increased the phosphorylation of PI3K and Akt. Furthermore, Stevia extracts were able to revert the effect of the reduction of glucose uptake caused by methylglyoxal, an inhibitor of the insulin receptor/PI3K/Akt pathway. These results corroborate the hypothesis that Stevia extracts could mimic insulin effects modulating PI3K/Akt pathway.

  2. Steviol Glycosides Modulate Glucose Transport in Different Cell Types

    PubMed Central

    Rizzo, Benedetta; Zambonin, Laura; Leoncini, Emanuela; Vieceli Dalla Sega, Francesco; Prata, Cecilia; Fiorentini, Diana; Hrelia, Silvana

    2013-01-01

    Extracts from Stevia rebaudiana Bertoni, a plant native to Central and South America, have been used as a sweetener since ancient times. Currently, Stevia extracts are largely used as a noncaloric high-potency biosweetener alternative to sugar, due to the growing incidence of type 2 diabetes mellitus, obesity, and metabolic disorders worldwide. Despite the large number of studies on Stevia and steviol glycosides in vivo, little is reported concerning the cellular and molecular mechanisms underpinning the beneficial effects on human health. The effect of four commercial Stevia extracts on glucose transport activity was evaluated in HL-60 human leukaemia and in SH-SY5Y human neuroblastoma cells. The extracts were able to enhance glucose uptake in both cellular lines, as efficiently as insulin. Our data suggest that steviol glycosides could act by modulating GLUT translocation through the PI3K/Akt pathway since treatments with both insulin and Stevia extracts increased the phosphorylation of PI3K and Akt. Furthermore, Stevia extracts were able to revert the effect of the reduction of glucose uptake caused by methylglyoxal, an inhibitor of the insulin receptor/PI3K/Akt pathway. These results corroborate the hypothesis that Stevia extracts could mimic insulin effects modulating PI3K/Akt pathway. PMID:24327825

  3. Clostridium botulinum type A progenitor toxin binds to Intestine-407 cells via N-acetyllactosamine moiety.

    PubMed

    Kojima, Shoudou; Eguchi, Hironobu; Ookawara, Tomomi; Fujiwara, Noriko; Yasuda, Jun; Nakagawa, Kazuhiko; Yamamura, Takehira; Suzuki, Keiichiro

    2005-06-03

    Botulism is a highly fatal disease caused by the botulinum progenitor toxin. In this study, the role of oligosaccharides for the binding of botulinum type A progenitor toxin (type A PTX) to human intestinal cells was investigated. The binding of type A PTX to Intestine-407 cells was inhibited by the addition of N-acetyllactosamine, lactose, and galactose. Treatment of Intestine-407 cells with neuraminidase led to a significant increase in the binding of type A PTX, while further digestion of cell surface oligosaccharides by beta-galactosidase and beta-N-acetylhexosaminidase decreased the binding. These results indicate that the N-acetyllactosamine moiety is responsible for the binding of type A PTX. These findings were further confirmed by a binding assay using synthesized oligosaccharides. Interestingly, sialylation or fucosylation of oligosaccharides inhibited the binding of type A PTX. These data suggest that the type A PTX binds to intestinal cells via cell surface N-acetyllactosamine moiety.

  4. Red blood cells of sickle cell disease patients exhibit abnormally high abundance of N-methyl D-aspartate receptors mediating excessive calcium uptake.

    PubMed

    Hänggi, Pascal; Makhro, Asya; Gassmann, Max; Schmugge, Markus; Goede, Jeroen S; Speer, Oliver; Bogdanova, Anna

    2014-10-01

    Recently we showed that N-methyl D-aspartate receptors (NMDARs) are expressed in erythroid precursors (EPCs) and present in the circulating red blood cells (RBCs) of healthy humans, regulating intracellular Ca(2+) in these cells. This study focuses on investigating the possible role of NMDARs in abnormally high Ca(2+) permeability in the RBCs of patients with sickle cell disease (SCD). Protein levels of the NMDAR subunits in the EPCs of SCD patients did not differ from those in EPCs of healthy humans. However, the number and activity of the NMDARs in circulating SCD-RBCs was substantially up-regulated, being particularly high during haemolytic crises. The number of active NMDARs correlated negatively with haematocrit and haemoglobin levels in the blood of SCD patients. Calcium uptake via these non-selective cation channels was induced by RBC treatment with glycine, glutamate and homocysteine and was facilitated by de-oxygenation of SCD-RBCs. Oxidative stress and RBC dehydration followed receptor stimulation and Ca(2+) uptake. Inhibition of the NMDARs with an antagonist memantine caused re-hydration and largely prevented hypoxia-induced sickling. The EPCs of SCD patients showed higher tolerance to memantine than those of healthy subjects. Consequently, NMDARs in the RBCs of SCD patients appear to be an attractive target for pharmacological intervention.

  5. SMARCA4-deficient undifferentiated carcinoma of the ovary (small cell carcinoma, hypercalcemic type): clinicopathologic and immunohistochemical study of 3 cases.

    PubMed

    Agaimy, Abbas; Thiel, Falk; Hartmann, Arndt; Fukunaga, Masaharu

    2015-10-01

    Small cell carcinoma of the ovary, hypercalcemic type is a very rare aggressive neoplasm of unknown histogenesis, affecting mainly girls and young women. Recently, inactivating mutations in SMARCA4 (BRG1), a member of the switch/sucrose nonfermenting chromatin remodeling complex, has been identified as driver events in most cases. We herein describe 3 cases in 34, 34, and 37-year-old women. Symptoms were mainly abdominal pain and mass. One patient was normocalcemic, and the other 2 had no preoperative serum calcium values available. All patients received radical hysterectomy with salpingo-oophorectomy, lymphadenectomy, and variable multimodality therapy. Two developed abdominal recurrences/metastases and died of disease at 4 and 12 months. One patient was alive without disease 17 months after surgery and radiochemotherapy. Histologic examination showed undifferentiated neoplasms composed of diffuse sheets, nests and cords of noncohesive monomorphic small blue/basaloid cells (classic variant, 1 case), and large undifferentiated/rhabdoid cells with abundant cytoplasm (large cell/rhabdoid variant, 2 case) admixed with minor small cell areas. One case contained rare isolated goblet cells, but true glandular component was absent. All tumors expressed vimentin and variably pancytokeratin and WT1. Nuclear SMARCB1 was intact in all cases (1 case showed small foci with mosaic loss). All tumors showed complete loss of SMARCA4. In conclusion, SMARCA4 immunohistochemistry represents a highly valuable emerging tool in identifying small cell carcinoma of the ovary, hypercalcemic type in routine practice. Distinguishing this aggressive neoplasm from juvenile granulosa cell tumor and other undifferentiated ovarian cancers is mandatory in selecting appropriate chemotherapeutic regimens and would allow better characterization of this entity, for which targeted molecular therapy still remains to be established.

  6. THE RELATIVE ABUNDANCE OF COMPACT AND NORMAL MASSIVE EARLY-TYPE GALAXIES AND ITS EVOLUTION FROM REDSHIFT z {approx} 2 TO THE PRESENT

    SciTech Connect

    Cassata, P.; Giavalisco, M.; Guo Yicheng; Salimbeni, S.; Renzini, A.; Ferguson, H.; Koekemoer, A. M.; Grogin, N. A.; Dahlen, T.; Lotz, J. M.; Scarlata, C.; Conselice, C. J.; Dickinson, M.; Lin Lihwai

    2011-12-10

    We report on the evolution of the number density and size of early-type galaxies (ETGs) from z {approx} 2 to z {approx} 0. We select a sample of 563 massive (M > 10{sup 10} M{sub Sun }), passively evolving (specific star formation rate <10{sup -2} Gyr{sup -1}), and morphologically spheroidal galaxies at 0 < z < 2.5, using the panchromatic photometry and spectroscopic redshifts available in the Great Observatories Origins Deep Surveys fields. We combine Advanced Camera for Surveys and Wide Field Camera 3 Hubble Space Telescope images to study the morphology of our galaxies in their optical rest frame in the entire 0 < z < 2.5 range. We find that throughout the explored redshift range the passive galaxies selected with our criteria have weak morphological K-correction, with size being slightly smaller in the optical than in the UV rest frame (by {approx}20% and {approx}10% at z > 1.2 and z < 1.2, respectively). We measure a significant evolution of the mass-size relation of ETGs, with a fractional increment that is almost independent of the stellar mass. ETGs formed at z > 1 appear to be preferentially small, and the evolution of the mass-size relation at z < 1 is driven by both the continuous size growth of the compact galaxies and the appearance of new ETGs with large sizes. We also find that the number density of all passive ETGs increases rapidly, by a factor of five, from z {approx} 2 to z {approx} 1, and then more mildly by another factor of 1.5 from z {approx} 1 to z {approx} 0. We interpret these results as evidence that the bulk of the ETGs are formed at 1 < z < 3 through a mechanism that leaves very compact remnants. At z < 1 the compact ETGs grow gradually in size, becoming normal-size galaxies, and at the same time new ETGs with normal-large sizes are formed.

  7. The Relative Abundance of Compact and Normal Massive Early-type Galaxies and Its Evolution from Redshift z ~ 2 to the Present

    NASA Astrophysics Data System (ADS)

    Cassata, P.; Giavalisco, M.; Guo, Yicheng; Renzini, A.; Ferguson, H.; Koekemoer, A. M.; Salimbeni, S.; Scarlata, C.; Grogin, N. A.; Conselice, C. J.; Dahlen, T.; Lotz, J. M.; Dickinson, M.; Lin, Lihwai

    2011-12-01

    We report on the evolution of the number density and size of early-type galaxies (ETGs) from z ~ 2 to z ~ 0. We select a sample of 563 massive (M > 1010 M ⊙), passively evolving (specific star formation rate <10-2 Gyr-1), and morphologically spheroidal galaxies at 0 < z < 2.5, using the panchromatic photometry and spectroscopic redshifts available in the Great Observatories Origins Deep Surveys fields. We combine Advanced Camera for Surveys and Wide Field Camera 3 Hubble Space Telescope images to study the morphology of our galaxies in their optical rest frame in the entire 0 < z < 2.5 range. We find that throughout the explored redshift range the passive galaxies selected with our criteria have weak morphological K-correction, with size being slightly smaller in the optical than in the UV rest frame (by ~20% and ~10% at z > 1.2 and z < 1.2, respectively). We measure a significant evolution of the mass-size relation of ETGs, with a fractional increment that is almost independent of the stellar mass. ETGs formed at z > 1 appear to be preferentially small, and the evolution of the mass-size relation at z < 1 is driven by both the continuous size growth of the compact galaxies and the appearance of new ETGs with large sizes. We also find that the number density of all passive ETGs increases rapidly, by a factor of five, from z ~ 2 to z ~ 1, and then more mildly by another factor of 1.5 from z ~ 1 to z ~ 0. We interpret these results as evidence that the bulk of the ETGs are formed at 1 < z < 3 through a mechanism that leaves very compact remnants. At z < 1 the compact ETGs grow gradually in size, becoming normal-size galaxies, and at the same time new ETGs with normal-large sizes are formed. Based on data obtained with the Hubble Space Telescope operated by AURA, Inc. for NASA under contract NAS5-26555.

  8. Type 1 Diabetes Candidate Genes Linked to Pancreatic Islet Cell Inflammation and Beta-Cell Apoptosis

    PubMed Central

    Størling, Joachim; Pociot, Flemming

    2017-01-01

    Type 1 diabetes (T1D) is a chronic immune-mediated disease resulting from the selective destruction of the insulin-producing pancreatic islet β-cells. Susceptibility to the disease is the result of complex interactions between environmental and genetic risk factors. Genome-wide association studies (GWAS) have identified more than 50 genetic regions that affect the risk of developing T1D. Most of these susceptibility loci, however, harbor several genes, and the causal variant(s) and gene(s) for most of the loci remain to be established. A significant part of the genes located in the T1D susceptibility loci are expressed in human islets and β cells and mounting evidence suggests that some of these genes modulate the β-cell response to the immune system and viral infection and regulate apoptotic β-cell death. Here, we discuss the current status of T1D susceptibility loci and candidate genes with focus on pancreatic islet cell inflammation and β-cell apoptosis. PMID:28212332

  9. Type 1 Diabetes Candidate Genes Linked to Pancreatic Islet Cell Inflammation and Beta-Cell Apoptosis.

    PubMed

    Størling, Joachim; Pociot, Flemming

    2017-02-16

    Type 1 diabetes (T1D) is a chronic immune-mediated disease resulting from the selective destruction of the insulin-producing pancreatic islet β-cells. Susceptibility to the disease is the result of complex interactions between environmental and genetic risk factors. Genome-wide association studies (GWAS) have identified more than 50 genetic regions that affect the risk of developing T1D. Most of these susceptibility loci, however, harbor several genes, and the causal variant(s) and gene(s) for most of the loci remain to be established. A significant part of the genes located in the T1D susceptibility loci are expressed in human islets and β cells and mounting evidence suggests that some of these genes modulate the β-cell response to the immune system and viral infection and regulate apoptotic β-cell death. Here, we discuss the current status of T1D susceptibility loci and candidate genes with focus on pancreatic islet cell inflammation and β-cell apoptosis.

  10. Concise Review: Methods and Cell Types Used to Generate Down Syndrome Induced Pluripotent Stem Cells

    PubMed Central

    Hibaoui, Youssef; Feki, Anis

    2015-01-01

    Down syndrome (DS, trisomy 21), is the most common viable chromosomal disorder, with an incidence of 1 in 800 live births. Its phenotypic characteristics include intellectual impairment and several other developmental abnormalities, for the majority of which the pathogenetic mechanisms remain unknown. Several models have been used to investigate the mechanisms by which the extra copy of chromosome 21 leads to the DS phenotype. In the last five years, several laboratories have been successful in reprogramming patient cells carrying the trisomy 21 anomaly into induced pluripotent stem cells, i.e., T21-iPSCs. In this review, we summarize the different T21-iPSCs that have been generated with a particular interest in the technical procedures and the somatic cell types used for the reprogramming. PMID:26239351

  11. Dye-Sensitized Solar Cells: The Future of Using Earth-Abundant Elements in Counter Electrodes for Dye-Sensitized Solar Cells (Adv. Mater. 20/2016).

    PubMed

    Briscoe, Joe; Dunn, Steve

    2016-05-01

    Sustainability is an important concept generating traction in the research community. To be really sustainable the full life cycle of a product needs to be carefully considered. A key aspect of this is using elements that are either readily recycled or accessible in the Earth's biosphere. Jigsawing these materials together in compounds to address our future energy needs represents a great opportunity for the current generation of researchers. On page 3802, S. Dunn and J. Briscoe summarize the performance of a selection of alternative materials to replace platinum in the counter electrodes of dye-sensitized solar cells.

  12. The reduction in small ribosomal subunit abundance in ethanol-stressed cells of Bacillus subtilis is mediated by a SigB-dependent antisense RNA.

    PubMed

    Mars, Ruben A T; Mendonça, Karoline; Denham, Emma L; van Dijl, Jan Maarten

    2015-10-01

    One of the best-characterized general stress responses in bacteria is the σB-mediated stress response of the Gram-positive soil bacterium Bacillus subtilis. The σB regulon contains approximately 200 protein-encoding genes and 136 putative regulatory RNAs. One of these σB-dependent RNAs, named S1136-S1134, was recently mapped as being transcribed from the S1136 promoter on the opposite strand of the essential rpsD gene, which encodes the ribosomal primary-binding protein S4. Accordingly, S1136-S1134 transcription results in an rpsD-overlapping antisense RNA (asRNA). Upon exposure of B. subtilis to ethanol, the S1136 promoter was found to be induced, while rpsD transcription was downregulated. By quantitative PCR, we show that the activation of transcription from the S1136 promoter is directly responsible for the downregulation of rpsD upon ethanol exposure. We also show that this downregulation of rpsD leads to a reduced level of the small (30S) ribosomal subunit upon ethanol stress. The activation of the S1136 promoter thus represents the first example of antisense transcription-mediated regulation in the general stress response of B. subtilis and implicates the reduction of ribosomal protein abundance as a new aspect in the σB-dependent stress response. We propose that the observed reduction in the level of the small ribosomal subunit, which contains the ribosome-decoding center, may protect B. subtilis cells against misreading and spurious translation of possibly toxic aberrant peptides under conditions of ethanol stress.

  13. Differential diagnosis of ovarian tumors based primarily on their patterns and cell types.

    PubMed

    Young, R H; Scully, R E

    2001-08-01

    The differential diagnosis of ovarian tumors is reviewed based on their patterns and cell types. This approach, which differs from the standard textbook discussion of each neoplasm as an entity, has practical value as differential diagnosis depends largely on the pattern or patterns and cell type or types of tumors. Awareness of the broad range of lesions that may exhibit particular patterns or contain one or more cell types is crucial in formulating a differential diagnosis. The following patterns are considered: moderate-to-large-glandular and hollow-tubular; solid tubular and pseudotubular; cords and ribbons; insular; trabecular; slit-like and reticular spaces; microglandular and microfollicular; macrofollicular and pseudomacrofollicular; papillary; diffuse; fibromatous-thecomatous; and biphasic and pseudobiphasic. The following cell types are considered: small round cells; spindle cells; mucinous cells, comprising columnar, goblet cell and signet ring cell subtypes; clear cells; hobnail cells; oxyphil cells; and transitional cells. The morphologic diversity of ovarian tumors poses many challenges; knowledge of the occurrence and frequency of these patterns and cell types in various tumors and tumor-like lesions is of paramount diagnostic importance. A specific diagnosis can usually be made by evaluating routinely stained slides, but much less often, special staining, immunohistochemical staining or, very rarely, ultrastructural examination is also required. Finally, clinical data, operative findings, and gross features of the lesions may provide important, and at times decisive diagnostic clues.

  14. Amide-type local anesthetics and human mesenchymal stem cells: clinical implications for stem cell therapy.

    PubMed

    Dregalla, Ryan C; Lyons, Nicolette F; Reischling, Patrick D; Centeno, Christopher J

    2014-03-01

    In the realm of regenerative medicine, human mesenchymal stem cells (hMSCs) are gaining attention as a cell source for the repair and regeneration of tissues spanning an array of medical disciplines. In orthopedics, hMSCs are often delivered in a site-specific manner at the area of interest and may require the concurrent application of local anesthetics (LAs). To address the implications of using hMSCs in combination with anesthetics for intra-articular applications, we investigated the effect that clinically relevant doses of amide-type LAs have on the viability of bone marrow-derived hMSCs and began to characterize the mechanism of LA-induced hMSC death. In our study, culture-expanded hMSCs from three donors were exposed to the amide-type LAs ropivacaine, lidocaine, bupivacaine, and mepivacaine. To replicate the physiological dilution of LAs once injected into the synovial capsule, each anesthetic was reduced to 12.5%, 25%, and 50% of the stock solution and incubated with each hMSC line for 40 minutes, 120 minutes, 360 minutes, and 24 hours. At each time point, cell viability assays were performed. We found that extended treatment with LAs for 24 hours had a significant impact on both hMSC viability and adhesion. In addition, hMSC treatment with three of the four anesthetics resulted in cell death via apoptosis following brief exposures. Ultimately, we concluded that amide-type LAs induce hMSC apoptosis in a time- and dose-dependent manner that may threaten clinical outcomes, following a similar trend that has been established between these particular anesthetics and articular chondrocytes both in vitro and in vivo.

  15. The 3 major types of innate and adaptive cell-mediated effector immunity.

    PubMed

    Annunziato, Francesco; Romagnani, Chiara; Romagnani, Sergio

    2015-03-01

    The immune system has tailored its effector functions to optimally respond to distinct species of microbes. Based on emerging knowledge on the different effector T-cell and innate lymphoid cell (ILC) lineages, it is clear that the innate and adaptive immune systems converge into 3 major kinds of cell-mediated effector immunity, which we propose to categorize as type 1, type 2, and type 3. Type 1 immunity consists of T-bet(+) IFN-γ-producing group 1 ILCs (ILC1 and natural killer cells), CD8(+) cytotoxic T cells (TC1), and CD4(+) TH1 cells, which protect against intracellular microbes through activation of mononuclear phagocytes. Type 2 immunity consists of GATA-3(+) ILC2s, TC2 cells, and TH2 cells producing IL-4, IL-5, and IL-13, which induce mast cell, basophil, and eosinophil activation, as well as IgE antibody production, thus protecting against helminthes and venoms. Type 3 immunity is mediated by retinoic acid-related orphan receptor γt(+) ILC3s, TC17 cells, and TH17 cells producing IL-17, IL-22, or both, which activate mononuclear phagocytes but also recruit neutrophils and induce epithelial antimicrobial responses, thus protecting against extracellular bacteria and fungi. On the other hand, type 1 and 3 immunity mediate autoimmune diseases, whereas type 2 responses can cause allergic diseases.

  16. Type 3 innate lymphoid cells maintain intestinal epithelial stem cells after tissue damage.

    PubMed

    Aparicio-Domingo, Patricia; Romera-Hernandez, Monica; Karrich, Julien J; Cornelissen, Ferry; Papazian, Natalie; Lindenbergh-Kortleve, Dicky J; Butler, James A; Boon, Louis; Coles, Mark C; Samsom, Janneke N; Cupedo, Tom

    2015-10-19

    Disruption of the intestinal epithelial barrier allows bacterial translocation and predisposes to destructive inflammation. To ensure proper barrier composition, crypt-residing stem cells continuously proliferate and replenish all intestinal epithelial cells within days. As a consequence of this high mitotic activity, mucosal surfaces are frequently targeted by anticancer therapies, leading to dose-limiting side effects. The cellular mechanisms that control tissue protection and mucosal healing in response to intestinal damage remain poorly understood. Type 3 innate lymphoid cells (ILC3s) are regulators of homeostasis and tissue responses to infection at mucosal surfaces. We now demonstrate that ILC3s are required for epithelial activation and proliferation in response to small intestinal tissue damage induced by the chemotherapeutic agent methotrexate. Multiple subsets of ILC3s are activated after intestinal tissue damage, and in the absence of ILC3s, epithelial activation is lost, correlating with increased pathology and severe damage to the intestinal crypts. Using ILC3-deficient Lgr5 reporter mice, we show that maintenance of intestinal stem cells after damage is severely impaired in the absence of ILC3s or the ILC3 signature cytokine IL-22. These data unveil a novel function of ILC3s in limiting tissue damage by preserving tissue-specific stem cells.

  17. Coordinating cell proliferation and differentiation: Antagonism between cell cycle regulators and cell type-specific gene expression

    PubMed Central

    Ruijtenberg, Suzan; van den Heuvel, Sander

    2016-01-01

    ABSTRACT Cell proliferation and differentiation show a remarkable inverse relationship. Precursor cells continue division before acquiring a fully differentiated state, while terminal differentiation usually coincides with proliferation arrest and permanent exit from the division cycle. Mechanistic insight in the temporal coordination between cell cycle exit and differentiation has come from studies of cells in culture and genetic animal models. As initially described for skeletal muscle differentiation, temporal coordination involves mutual antagonism between cyclin-dependent kinases that promote cell cycle entry and transcription factors that induce tissue-specific gene expression. Recent insights highlight the contribution of chromatin-regulating complexes that act in conjunction with the transcription factors and determine their activity. In particular SWI/SNF chromatin remodelers contribute to dual regulation of cell cycle and tissue-specific gene expression during terminal differentiation. We review the concerted regulation of the cell cycle and cell type-specific transcription, and discuss common mutations in human cancer that emphasize the clinical importance of proliferation versus differentiation control. PMID:26825227

  18. An indirect role for NK cells in a CD4(+) T-cell-dependent mouse model of type I diabetes.

    PubMed

    Angstetra, Eveline; Graham, Kate L; Zhao, Yuxing; Irvin, Allison E; Elkerbout, Lorraine; Santamaria, Pere; Slattery, Robyn M; Kay, Thomas W; Thomas, Helen E

    2012-02-01

    CD8(+) T cells kill pancreatic β-cells in a cell-cell contact-dependent mechanism in the non-obese diabetic mouse. CD4(+) T lymphocytes are also able to kill pancreatic β-cells, but they do not directly contact β-cells and may use another cell type as the actual cytotoxic cell. Natural killer (NK) cells could have this role but it is uncertain whether they are cytotoxic towards β-cells. Therefore, the requirement for NK cells in β-cell destruction in the CD4-dependent T-cell antigen receptor transgenic NOD4.1 mice was examined. NK cells failed to kill β-cells in vitro, even in the absence of major histocompatibility complex class I. We observed only 9.7±1.1% of islet infiltrating NK cells from NOD4.1 mice expressing the degranulation marker CD107a. Diabetogenic CD4(+) T cells transferred disease to NODscid.IL2Rγ(-/-) mice lacking NK cells, indicating that NK cells do not contribute to β-cell death in vitro or in vivo. However, depletion of NK cells reduced diabetes incidence in NOD4.1 mice, suggesting that NK cells may help to maintain the right environment for cytotoxicity of effector cells.

  19. Hippocampal pyramidal neurons comprise two distinct cell types that are countermodulated by metabotropic receptors

    PubMed Central

    Graves, Austin R; Moore, Shannon J; Bloss, Erik B; Mensh, Brett D; Kath, William L; Spruston, Nelson

    2012-01-01

    Summary Relating the function of neuronal cell types to information processing and behavior is a central goal of neuroscience. In the hippocampus, pyramidal cells in CA1 and the subiculum process sensory and motor cues to form a cognitive map encoding spatial, contextual, and emotional information, which they transmit throughout the brain. Do these cells constitute a single class, or are there multiple cell types with specialized functions? Using unbiased cluster analysis, we show that there are two morphologically and electrophysiologically distinct principal cell types that carry hippocampal output. We show further that these two cell types are inversely modulated by the synergistic action of glutamate and acetylcholine acting on metabotropic receptors that are central to hippocampal function. Combined with prior connectivity studies, our results support a model of hippocampal processing in which the two pyramidal cell types are predominantly segregated into two parallel pathways that process distinct modalities of information. PMID:23177962

  20. N-type and L-type calcium channels mediate glycinergic synaptic inputs to retinal ganglion cells of tiger salamanders.

    PubMed

    Bieda, Mark C; Copenhagen, David R

    2004-01-01

    Synaptically localized calcium channels shape the timecourse of synaptic release, are a prominent site for neuromodulation, and have been implicated in genetic disease. In retina, it is well established that L-type calcium channels play a major role in mediating release of glutamate from the photoreceptors and bipolar cells. However, little is known about which calcium channels are coupled to synaptic exocytosis of glycine, which is primarily released by amacrine cells. A recent report indicates that glycine release from spiking AII amacrine cells relies exclusively upon L-type calcium channels. To identify calcium channel types controlling neurotransmitter release from the population of glycinergic neurons that drive retinal ganglion cells, we recorded electrical and potassium evoked inhibitory synaptic currents (IPSCs) from these postsynaptic neurons in retinal slices from tiger salamanders. The L-channel antagonist nifedipine strongly inhibited release and FPL64176, an L-channel agonist, greatly enhanced it, indicating a significant role for L-channels. omega-Conotoxin MVIIC, an N/P/Q-channel antagonist, strongly inhibited release, indicating an important role for non-L channels. While the P/Q-channel blocker omega-Aga IVA produced only small effects, the N-channel blocker omega-conotoxin GVIA strongly inhibited release. Hence, N-type and L-type calcium channels appear to play major roles, overall, in mediating synaptic release of glycine onto retinal ganglion cells.

  1. Estimation of Cell-Type Composition Including T and B Cell Subtypes for Whole Blood Methylation Microarray Data.

    PubMed

    Waite, Lindsay L; Weaver, Benjamin; Day, Kenneth; Li, Xinrui; Roberts, Kevin; Gibson, Andrew W; Edberg, Jeffrey C; Kimberly, Robert P; Absher, Devin M; Tiwari, Hemant K

    2016-01-01

    DNA methylation levels vary markedly by cell-type makeup of a sample. Understanding these differences and estimating the cell-type makeup of a sample is an important aspect of studying DNA methylation. DNA from leukocytes in whole blood is simple to obtain and pervasive in research. However, leukocytes contain many distinct cell types and subtypes. We propose a two-stage model that estimates the proportions of six main cell types in whole blood (CD4+ T cells, CD8+ T cells, monocytes, B cells, granulocytes, and natural killer cells) as well as subtypes of T and B cells. Unlike previous methods that only estimate overall proportions of CD4+ T cell, CD8+ T cells, and B cells, our model is able to estimate proportions of naïve, memory, and regulatory CD4+ T cells as well as naïve and memory CD8+ T cells and naïve and memory B cells. Using real and simulated data, we are able to demonstrate that our model is able to reliably estimate proportions of these cell types and subtypes. In studies with DNA methylation data from Illumina's HumanMethylation450k arrays, our estimates will be useful both for testing for associations of cell type and subtype composition with phenotypes of interest as well as for adjustment purposes to prevent confounding in epigenetic association studies. Additionally, our method can be easily adapted for use with whole genome bisulfite sequencing (WGBS) data or any other genome-wide methylation data platform.

  2. Advances in understanding the cell types and approaches used for generating induced pluripotent stem cells.

    PubMed

    Li, Jun; Song, Wei; Pan, Guangjin; Zhou, Jun

    2014-07-19

    Successfully reprogramming somatic cells to a pluripotent state generates induced pluripotent stem (iPS) cells (or iPSCs), which have extensive self-renewal capacity like embryonic stem cells (ESCs). iPSCs can also generate daughter cells that can further undergo differentiation into various lineages or terminally differentiate to reach their final functional state. The discovery of how to produce iPSCs opened a new field of stem cell research with both intellectual and therapeutic benefits. The huge potential implications of disease-specific or patient-specific iPSCs have impelled scientists to solve problems hindering their applications in clinical medicine, especially the issues of convenience and safety. To determine the range of tissue types amenable to reprogramming as well as their particular characteristics, cells from three embryonic germ layers have been assessed, and the advantages that some tissue origins have over fibroblast origins concerning efficiency and accessibility have been elucidated. To provide safe iPSCs in an efficient and convenient way, the delivery systems and combinations of inducing factors as well as the chemicals used to generate iPSCs have also been significantly improved in addition to the efforts on finding better donor cells. Currently, iPSCs can be generated without c-Myc and Klf4 oncogenes, and non-viral delivery integration-free chemically mediated reprogramming methods have been successfully employed with relatively satisfactory efficiency. This paper will review recent advances in iPS technology by highlighting tissue origin and generation of iPSCs. The obstacles that need to be overcome for clinical applications of iPSCs are also discussed.

  3. Photovoltaic Cell Having A P-Type Polycrystalline Layer With Large Crystals

    DOEpatents

    Albright, Scot P.; Chamberlin, Rhodes R.

    1996-03-26

    A photovoltaic cell has an n-type polycrystalline layer and a p-type polycrystalline layer adjoining the n-type polycrystalline layer to form a photovoltaic junction. The p-type polycrystalline layer comprises a substantially planar layer portion having relatively large crystals adjoining the n-type polycrystalline layer. The planar layer portion includes oxidized impurities which contribute to obtainment of p-type electrical properties in the planar layer portion.

  4. Cell-Type-Specific Genome-wide Expression Profiling after Laser Capture Microdissection of Living Tissue

    SciTech Connect

    Marchetti, F; Manohar, C F

    2005-02-09

    The purpose of this technical feasibility study was to develop and evaluate robust microgenomic tools for investigations of genome-wide expression of very small numbers of cells isolated from whole tissue sections. Tissues contain large numbers of cell-types that play varied roles in organ function and responses to endogenous and exogenous toxicants whether bacterial, viral, chemical or radiation. Expression studies of whole tissue biopsy are severely limited because heterogeneous cell-types result in an averaging of molecular signals masking subtle but important changes in gene expression in any one cell type(s) or group of cells. Accurate gene expression analysis requires the study of specific cell types in their tissue environment but without contamination from surrounding cells. Laser capture microdissection (LCM) is a new technology to isolate morphologically distinct cells from tissue sections. Alternative methods are available for isolating single cells but not yet for their reliable genome-wide expression analyses. The tasks of this feasibility project were to: (1) Develop efficient protocols for laser capture microdissection of cells from tissues identified by antibody label, or morphological stain. (2) Develop reproducible gene-transcript analyses techniques for single cell-types and determine the numbers of cells needed for reliable genome-wide analyses. (3) Validate the technology for epithelial and endothelial cells isolated from the gastrointestinal tract of mice.

  5. Different GATA factors dictate CCR3 transcription in allergic inflammatory cells in a cell type-specific manner.

    PubMed

    Kong, Su-Kang; Kim, Byung Soo; Uhm, Tae Gi; Lee, Wonyong; Lee, Gap Ryol; Park, Choon-Sik; Lee, Chul-Hoon; Chung, Il Yup

    2013-06-01

    The chemokine receptor CCR3 is expressed in prominent allergic inflammatory cells, including eosinophils, mast cells, and Th2 cells. We previously identified a functional GATA element within exon 1 of the CCR3 gene that is responsible for GATA-1-mediated CCR3 transcription. Because allergic inflammatory cells exhibit distinct expression patterns of different GATA factors, we investigated whether different GATA factors dictate CCR3 transcription in a cell type-specific manner. GATA-2 was expressed in EoL-1 eosinophilic cells, GATA-1 and GATA-2 were expressed in HMC-1 mast cells, and GATA-3 was preferentially expressed in Jurkat cells. Unlike a wild-type CCR3 reporter, reporters lacking the functional GATA element were not active in any of the three cell types, implying the involvement of different GATA factors in CCR3 transcription. RNA interference assays showed that small interfering RNAs specific for different GATA factors reduced CCR3 reporter activity in a cell type-specific fashion. Consistent with these findings, chromatin immunoprecipitation and EMSA analyses demonstrated cell type-specific binding of GATA factors to the functional GATA site. More importantly, specific inhibition of the CCR3 reporter activity by different GATA small interfering RNAs was well preserved in respective cell types differentiated from cord blood; in particular, GATA-3 was entirely responsible for reporter activity in Th2 cells and replaced the role predominantly played by GATA-1 and GATA-2. These results highlight a mechanistic role of GATA factors in which cell type-specific expression is the primary determinant of transcription of the CCR3 gene in major allergic inflammatory cells.

  6. A Comprehensive Proteomic View of Responses of A549 Type II Alveolar Epithelial Cells to Human Respiratory Syncytial Virus Infection*

    PubMed Central

    Dave, Keyur A.; Norris, Emma L.; Bukreyev, Alexander A.; Headlam, Madeleine J.; Buchholz, Ursula J.; Singh, Toshna; Collins, Peter L.; Gorman, Jeffrey J.

    2014-01-01

    Human respiratory syncytial virus is a major respiratory pathogen for which there are no suitable antivirals or vaccines. A better understanding of the host cell response to this virus may redress this problem. The present report concerns analysis of multiple independent biological replicates of control and 24 h infected lysates of A549 cells by two different proteomic workflows. One workflow involved fractionation of lysates by in-solution protein IEF and individual fractions were digested using trypsin prior to capillary HPLC-LTQ-OrbitrapXL-MS/MS. A second workflow involved digestion of whole cell lysates and analysis by nanoUltraHPLC-LTQ-OrbitrapElite-MS/MS. Both workflows resulted in the quantification of viral proteins exclusively in lysates of infected cells in the relative abundances anticipated from previous studies. Unprecedented numbers (3247 - 5010) of host cell protein groups were also quantified and the infection-specific regulation of a large number (191) of these protein groups was evident based on a stringent false discovery rate cut-off (<1%). Bioinformatic analyses revealed that most of the regulated proteins were potentially regulated by type I, II, and III interferon, TNF-α and noncanonical NF-κB2 mediated antiviral response pathways. Regulation of specific protein groups by infection was validated by quantitative Western blotting and the cytokine-/key regulator-specific nature of their regulation was confirmed by comparable analyses of cytokine treated A549 cells. Overall, it is evident that the workflows described herein have produced the most comprehensive proteomic characterization of host cell responses to human respiratory syncytial virus published to date. These workflows will form the basis for analysis of the impacts of specific genes of human respiratory syncytial virus responses of A549 and other cell lines using a gene-deleted version of the virus. They should also prove valuable for the analysis of the impact of other infectious

  7. A comprehensive proteomic view of responses of A549 type II alveolar epithelial cells to human respiratory syncytial virus infection.

    PubMed

    Dave, Keyur A; Norris, Emma L; Bukreyev, Alexander A; Headlam, Madeleine J; Buchholz, Ursula J; Singh, Toshna; Collins, Peter L; Gorman, Jeffrey J

    2014-12-01

    Human respiratory syncytial virus is a major respiratory pathogen for which there are no suitable antivirals or vaccines. A better understanding of the host cell response to this virus may redress this problem. The present report concerns analysis of multiple independent biological replicates of control and 24 h infected lysates of A549 cells by two different proteomic workflows. One workflow involved fractionation of lysates by in-solution protein IEF and individual fractions were digested using trypsin prior to capillary HPLC-LTQ-OrbitrapXL-MS/MS. A second workflow involved digestion of whole cell lysates and analysis by nanoUltraHPLC-LTQ-OrbitrapElite-MS/MS. Both workflows resulted in the quantification of viral proteins exclusively in lysates of infected cells in the relative abundances anticipated from previous studies. Unprecedented numbers (3247 - 5010) of host cell protein groups were also quantified and the infection-specific regulation of a large number (191) of these protein groups was evident based on a stringent false discovery rate cut-off (<1%). Bioinformatic analyses revealed that most of the regulated proteins were potentially regulated by type I, II, and III interferon, TNF-α and noncanonical NF-κB2 mediated antiviral response pathways. Regulation of specific protein groups by infection was validated by quantitative Western blotting and the cytokine-/key regulator-specific nature of their regulation was confirmed by comparable analyses of cytokine treated A549 cells. Overall, it is evident that the workflows described herein have produced the most comprehensive proteomic characterization of host cell responses to human respiratory syncytial virus published to date. These workflows will form the basis for analysis of the impacts of specific genes of human respiratory syncytial virus responses of A549 and other cell lines using a gene-deleted version of the virus. They should also prove valuable for the analysis of the impact of other infectious

  8. Chondrocytes expressing intracellular collagen type II enter the cell cycle and co-express collagen type I in monolayer culture.

    PubMed

    Tekari, Adel; Luginbuehl, Reto; Hofstetter, Willy; Egli, Rainer J

    2014-11-01

    For autologous chondrocyte transplantation, articular chondrocytes are harvested from cartilage tissue and expanded in vitro in monolayer culture. We aimed to characterize with a cellular resolution the synthesis of col