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Sample records for reduces surface expression

  1. Introduced Amino Terminal Epitopes Can Reduce Surface Expression of Neuronal Nicotinic Receptors

    PubMed Central

    Bracamontes, John R.; Akk, Gustav; Steinbach, Joe Henry

    2016-01-01

    Epitopes accessible on the surface of intact cells are extremely valuable in studies of membrane proteins, allowing quantification and determination of the distribution of proteins as well as identification of cells expressing large numbers of proteins. However for many membrane proteins there are no suitable antibodies to native sequences, due to lack of availability, low affinity or lack of specificity. In these cases the use of an introduced epitope at specific sites in the protein of interest can often provide a suitable tool for studies. However, the introduction of the epitope sequence has the potential to affect protein expression, the assembly of multisubunit proteins or transport to the surface membrane. We find that surface expression of heteromeric neuronal nicotinic receptors containing the α4 and β4 subunits can be affected by introduced epitopes when inserted near the amino terminus of a subunit. The FLAG epitope greatly reduces surface expression when introduced into either α4 or β4 subunits, the V5 epitope has little effect when placed in either, while the Myc epitope reduces expression more when inserted into β4 than α4. These results indicate that the extreme amino terminal region is important for assembly of these receptors, and demonstrate that some widely used introduced epitopes may severely reduce surface expression. PMID:26963253

  2. Rare TREM2 variants associated with Alzheimer's disease display reduced cell surface expression.

    PubMed

    Sirkis, Daniel W; Bonham, Luke W; Aparicio, Renan E; Geier, Ethan G; Ramos, Eliana Marisa; Wang, Qing; Karydas, Anna; Miller, Zachary A; Miller, Bruce L; Coppola, Giovanni; Yokoyama, Jennifer S

    2016-09-02

    Rare variation in TREM2 has been associated with greater risk for Alzheimer's disease (AD). TREM2 encodes a cell surface receptor expressed on microglia and related cells, and the R47H variant associated with AD appears to affect the ability of TREM2 to bind extracellular ligands. In addition, other rare TREM2 mutations causing early-onset neurodegeneration are thought to impair cell surface expression. Using a sequence kernel association (SKAT) analysis in two independent AD cohorts, we found significant enrichment of rare TREM2 variants not previously characterized at the protein level. Heterologous expression of the identified variants showed that novel variants S31F and R47C displayed significantly reduced cell surface expression. In addition, we identified rare variant R136Q in a patient with language-predominant AD that also showed impaired surface expression. The results suggest rare TREM2 variants enriched in AD may be associated with altered TREM2 function and that AD risk may be conferred, in part, from altered TREM2 surface expression.

  3. Rare TREM2 variants associated with Alzheimer's disease display reduced cell surface expression.

    PubMed

    Sirkis, Daniel W; Bonham, Luke W; Aparicio, Renan E; Geier, Ethan G; Ramos, Eliana Marisa; Wang, Qing; Karydas, Anna; Miller, Zachary A; Miller, Bruce L; Coppola, Giovanni; Yokoyama, Jennifer S

    2016-01-01

    Rare variation in TREM2 has been associated with greater risk for Alzheimer's disease (AD). TREM2 encodes a cell surface receptor expressed on microglia and related cells, and the R47H variant associated with AD appears to affect the ability of TREM2 to bind extracellular ligands. In addition, other rare TREM2 mutations causing early-onset neurodegeneration are thought to impair cell surface expression. Using a sequence kernel association (SKAT) analysis in two independent AD cohorts, we found significant enrichment of rare TREM2 variants not previously characterized at the protein level. Heterologous expression of the identified variants showed that novel variants S31F and R47C displayed significantly reduced cell surface expression. In addition, we identified rare variant R136Q in a patient with language-predominant AD that also showed impaired surface expression. The results suggest rare TREM2 variants enriched in AD may be associated with altered TREM2 function and that AD risk may be conferred, in part, from altered TREM2 surface expression. PMID:27589997

  4. SRC Inhibition Reduces NR2B Surface Expression and Synaptic Plasticity in the Amygdala

    ERIC Educational Resources Information Center

    Sinai, Laleh; Duffy, Steven; Roder, John C.

    2010-01-01

    The Src protein tyrosine kinase plays a central role in the regulation of N-methyl-d-aspartate receptor (NMDAR) activity by regulating NMDAR subunit 2B (NR2B) surface expression. In the amygdala, NMDA-dependent synaptic plasticity resulting from convergent somatosensory and auditory inputs contributes to emotional memory; however, the role of Src…

  5. Reduced plasma membrane surface expression of GLAST mediates decreased glutamate regulation in the aged striatum.

    PubMed

    Nickell, Justin; Salvatore, Michael F; Pomerleau, Francois; Apparsundaram, Subbu; Gerhardt, Greg A

    2007-11-01

    Extracellular L-glutamate poses a severe excitotoxic threat to neurons and glia when unregulated, therefore low synaptic levels of this neurotransmitter must be maintained via a rapid and robust transport system. A recent study from our laboratory showed a reduced glutamate uptake rate in the striatum of the aged Fischer 344 (F344) rat, yet the mechanism underlying this phenomenon is unknown. The current study utilized in vivo electrochemical recordings, immunoblotting and biotinylation in young (6 months), late-middle aged (18 months) and aged (24 months) F344 rats to elucidate the potential role that glutamate transporters (GLT-1, GLAST, and EAAC1) may play in this mechanism. Here we show that the time necessary to clear glutamate from the late-middle aged and aged striatum is significantly prolonged in comparison to the young striatum. In addition, an analysis of various sub-regions of the striatum revealed a marked dorsoventral gradient in terms of glutamate clearance times in the aged striatum, a phenomenon which was not present in the striatum of the animals of the remaining age groups. We also found that the decreased glutamate clearance time observed in the late-middle aged and aged rats is not due to a decrease in the production of total transporter protein among these three transporters. Rather, a significant reduction in the amount of GLAST expressed on the plasma membrane surface in the aged animals (approximately 55% when compared to young rats) may contribute to this phenomenon. These age-related alterations in extracellular l-glutamate regulation may be key contributors to the increased susceptibility of the aged brain to excitotoxic insults such as stroke and hypoxia.

  6. Chronic Morphine Reduces Surface Expression of δ-Opioid Receptors in Subregions of Rostral Striatum.

    PubMed

    Leah, Paul M; Heath, Emily M L; Balleine, Bernard W; Christie, Macdonald J

    2016-03-01

    The delta opioid receptor (DOPr), whilst not the primary target of clinically used opioids, is involved in development of opioid tolerance and addiction. There is growing evidence that DOPr trafficking is involved in drug addiction, e.g., a range of studies have shown increased plasma membrane DOPr insertion during chronic treatment with opioids. The present study used a transgenic mouse model in which the C-terminal of the DOPr is tagged with enhanced-green fluorescence protein to examine the effects of chronic morphine treatment on surface membrane expression in striatal cholinergic interneurons that are implicated in motivated learning following both chronic morphine and morphine sensitization treatment schedules in male mice. A sex difference was noted throughout the anterior striatum, which was most prominent in the nucleus accumbens core region. Incontrast with previous studies in other neurons, chronic exposure to a high dose of morphine for 6 days had no effect, or slightly decreased (anterior dorsolateral striatum) surface DOPr expression. A morphine sensitization schedule produced similar results with a significant decrease in surface DOPr expression in nucleus accumbens shell. These results suggest that chronic morphine and morphine sensitisation treatment may have effects on instrumental reward-seeking behaviours and learning processes related to drug addiction, via effects on striatal DOPr function.

  7. Cognitive decline is associated with reduced surface GluR1 expression in the hippocampus of aged rats.

    PubMed

    Yang, Yuan-Jian; Chen, Hai-Bo; Wei, Bo; Wang, Wei; Zhou, Ping-Liang; Zhan, Jin-Qiong; Hu, Mao-Rong; Yan, Kun; Hu, Bin; Yu, Bin

    2015-03-30

    Individual differences in cognitive aging exist in humans and in rodent populations, yet the underlying mechanisms remain largely unclear. Activity-dependent delivery of GluR1-containing AMPA receptor (AMPARs) plays an essential role in hippocampal synaptic plasticity, learning and memory. We hypothesize that alterations of surface GluR1 expression in the hippocampus might correlate with age-related cognitive decline. To test this hypothesis, the present study evaluated the cognitive function of young adult and aged rats using Morris water maze. After the behavioral test, the surface expression of GluR1 protein in hippocampal CA1 region of rats was determined using Western blotting. The results showed that the surface expression of GluR1 in the hippocampus of aged rats that are cognitively impaired was much lower than that of young adults and aged rats with preserved cognitive abilities. The phosphorylation levels of GluR1 at Ser845 and Ser831 sites, which promote the synaptic delivery of GluR1, were also selectively decreased in the hippocampus of aged-impaired rats. Correlation analysis reveals that greater decrease in surface GluR1 expression was associated with worse behavioral performance. These results suggest that reduced surface GluR1 expression may contribute to cognitive decline that occurs in normal aging, and different pattern of surface GluR1 expression might be responsible for the individual differences in cognitive aging. PMID:25697598

  8. Osteopontin Deficiency Produces Osteoclast Dysfunction Due to Reduced CD44 Surface Expression

    PubMed Central

    Chellaiah, M. A.; Kizer, N.; Biswas, R.; Alvarez, U.; Strauss-Schoenberger, J.; Rifas, L.; Rittling, S. R.; Denhardt, D. T.; Hruska, K. A.

    2003-01-01

    Osteopontin (OPN) was expressed in murine wild-type osteoclasts, localized to the basolateral, clear zone, and ruffled border membranes, and deposited in the resorption pits during bone resorption. The lack of OPN secretion into the resorption bay of avian osteoclasts may be a component of their functional resorption deficiency in vitro. Osteoclasts deficient in OPN were hypomotile and exhibited decreased capacity for bone resorption in vitro. OPN stimulated CD44 expression on the osteoclast surface, and CD44 was shown to be required for osteoclast motility and bone resorption. Exogenous addition of OPN to OPN−/− osteoclasts increased the surface expression of CD44, and it rescued osteoclast motility due to activation of the αvβ3 integrin. Exogenous OPN only partially restored bone resorption because addition of OPN failed to produce OPN secretion into resorption bays as seen in wild-type osteoclasts. As expected with these in vitro findings of osteoclast dysfunction, a bone phenotype, heretofore unappreciated, was characterized in OPN-deficient mice. Delayed bone resorption in metaphyseal trabeculae and diminished eroded perimeters despite an increase in osteoclast number were observed in histomorphometric measurements of tibiae isolated from OPN-deficient mice. The histomorphometric findings correlated with an increase in bone rigidity and moment of inertia revealed by load-to-failure testing of femurs. These findings demonstrate the role of OPN in osteoclast function and the requirement for OPN as an osteoclast autocrine factor during bone remodeling. PMID:12529435

  9. Osteopontin deficiency produces osteoclast dysfunction due to reduced CD44 surface expression.

    PubMed

    Chellaiah, M A; Kizer, N; Biswas, R; Alvarez, U; Strauss-Schoenberger, J; Rifas, L; Rittling, S R; Denhardt, D T; Hruska, K A

    2003-01-01

    Osteopontin (OPN) was expressed in murine wild-type osteoclasts, localized to the basolateral, clear zone, and ruffled border membranes, and deposited in the resorption pits during bone resorption. The lack of OPN secretion into the resorption bay of avian osteoclasts may be a component of their functional resorption deficiency in vitro. Osteoclasts deficient in OPN were hypomotile and exhibited decreased capacity for bone resorption in vitro. OPN stimulated CD44 expression on the osteoclast surface, and CD44 was shown to be required for osteoclast motility and bone resorption. Exogenous addition of OPN to OPN-/- osteoclasts increased the surface expression of CD44, and it rescued osteoclast motility due to activation of the alpha(v)beta(3) integrin. Exogenous OPN only partially restored bone resorption because addition of OPN failed to produce OPN secretion into resorption bays as seen in wild-type osteoclasts. As expected with these in vitro findings of osteoclast dysfunction, a bone phenotype, heretofore unappreciated, was characterized in OPN-deficient mice. Delayed bone resorption in metaphyseal trabeculae and diminished eroded perimeters despite an increase in osteoclast number were observed in histomorphometric measurements of tibiae isolated from OPN-deficient mice. The histomorphometric findings correlated with an increase in bone rigidity and moment of inertia revealed by load-to-failure testing of femurs. These findings demonstrate the role of OPN in osteoclast function and the requirement for OPN as an osteoclast autocrine factor during bone remodeling.

  10. Phosphatidylinositol 4-phosphate 5-kinase reduces cell surface expression of the epithelial sodium channel (ENaC) in cultured collecting duct cells.

    PubMed

    Weixel, Kelly M; Edinger, Robert S; Kester, Lauren; Guerriero, Christopher J; Wang, Huamin; Fang, Liang; Kleyman, Thomas R; Welling, Paul A; Weisz, Ora A; Johnson, John P

    2007-12-14

    Ubiquitination of ENaC subunits has been shown to negatively regulate the cell surface expression of ENaC channels. We have previously demonstrated that epsin links ubiquitinated ENaC to clathrin adaptors for clathrin-mediated endocytosis. Epsin is thought to directly modify the curvature of membranes upon binding to phosphatidylinositol 4,5-bisphosphate (PIP2) where it recruits clathrin and stimulates lattice assembly. Murine phosphatidylinositol 4-phosphate 5-kinase alpha (PI5KIalpha) has been shown to enhance endocytosis in a PIP2-dependent manner. We tested the hypothesis that PI5KIalpha-mediated PIP2 production would negatively regulate ENaC current by enhancing epsin-mediated endocytosis of the channel. Expression of PI5KIalpha decreased ENaC currents in Xenopus oocytes by 80%, entirely because of a decrease in cell surface ENaC levels. Catalytically inactive mutants of PI5Kalpha had no effect on ENaC activity. Expression of the PIP2 binding region of epsin increased ENaC current in oocytes, an effect completely reversed by co-expression of PI5KIalpha. Overexpression of epsin reduced amiloride-sensitive current in CCD cells. Overexpression of PI5KIalpha enhanced membrane PIP2 levels and reduced apical surface expression of ENaC in CCD cells, down-regulating amiloride-sensitive current. Knockdown of PI5KIalpha with isoform-specific siRNA resulted in a 4-fold enhancement of ENaC activity. PI5KIalpha localized exclusively to the apical plasma membrane domain when overexpressed in mouse CCD cells, consistent for a role in regulating PIP2 production at the apical plasma membrane. We conclude that membrane turnover events regulating ENaC surface expression and activity in oocytes and CCD cells can be regulated by PI5KIalpha. PMID:17940289

  11. A shear stress responsive gene product PP1201 protects against Fas-mediated apoptosis by reducing Fas expression on the cell surface.

    PubMed

    Shukla, Sudhanshu; Fujita, Ken-ichi; Xiao, Qi; Liao, Zhiyong; Garfield, Susan; Srinivasula, Srinivasa M

    2011-02-01

    Cells that form vascular system employ different mechanisms to offset deleterious consequences of exposure to cytokines and cells present in blood. Vascular homeostasis is sustained in part by genes, whose expression increases in response to hemodynamic forces in these cells. PP1201 (also known as RECS1) is one such gene whose expression level increases in response to laminar shear stress. Aged mice deficient in PP1201 are prone to develop cystic medial degeneration (CMD), a form of aortic aneurism manifested with loss of smooth muscle cells and accumulation of basophilic substances. Here we found that higher levels of PP1201 can protect against Fas ligand (FasL)-induced apoptosis. PP1201 interacted with the Fas receptor (CD95/Apo1) and colocalized with it in the Golgi compartment. Unlike its homolog lifeguard (LFG), PP1201 overexpression in several types of cells including primary human aortic smooth muscle cells (AoSMC) decreased the expression of Fas on the plasma membrane without changing the total Fas levels. Only high but not constitutive level of PP1201 controls Fas signaling. Our data suggest that PP1201 functions as an anti-apoptotic protein and its increased expression in vascular cells can contribute to homeostasis by reducing Fas trafficking to the cell membrane.

  12. Microenvironmental stresses induce HLA-E/Qa-1 surface expression and thereby reduce CD8(+) T-cell recognition of stressed cells.

    PubMed

    Sasaki, Takanori; Kanaseki, Takayuki; Shionoya, Yosuke; Tokita, Serina; Miyamoto, Sho; Saka, Eri; Kochin, Vitaly; Takasawa, Akira; Hirohashi, Yoshihiko; Tamura, Yasuaki; Miyazaki, Akihiro; Torigoe, Toshihiko; Hiratsuka, Hiroyoshi; Sato, Noriyuki

    2016-04-01

    Hypoxia and glucose deprivation are often observed in the microenvironment surrounding solid tumors in vivo. However, how they interfere with MHC class I antigen processing and CD8(+) T-cell responses remains unclear. In this study, we analyzed the production of antigenic peptides presented by classical MHC class I in mice, and showed that it is quantitatively decreased in the cells exposed to either hypoxia or glucose deprivation. In addition, we unexpectedly found increased surface expression of HLA-E in human and Qa-1 in mouse tumor cells exposed to combined oxygen and glucose deprivation. The induced Qa-1 on the stressed tumor model interacted with an inhibitory NKG2/CD94 receptor on activated CD8(+) T cells and attenuated their specific response to the antigen. Our results thus suggest that microenvironmental stresses modulate not only classical but also nonclassical MHC class I presentation, and confer the stressed cells the capability to escape from the CD8(+) T-cell recognition. PMID:26711740

  13. Mutation Linked to Autosomal Dominant Nocturnal Frontal Lobe Epilepsy Reduces Low-Sensitivity α4β2, and Increases α5α4β2, Nicotinic Receptor Surface Expression

    PubMed Central

    Nichols, Weston A.; Henderson, Brandon J.; Marotta, Christopher B.; Yu, Caroline Y.; Richards, Chris; Dougherty, Dennis A.; Lester, Henry A.

    2016-01-01

    A number of mutations in α4β2-containing (α4β2*) nicotinic acetylcholine (ACh) receptors (nAChRs) are linked to autosomal dominant nocturnal frontal lobe epilepsy (ADNFLE), including one in the β2 subunit called β2V287L. Two α4β2* subtypes with different subunit stoichiometries and ACh sensitivities co-exist in the brain, a high-sensitivity subtype with (α4)2(β2)3 subunit stoichiometry and a low-sensitivity subtype with (α4)3(β2)2 stoichiometry. The α5 nicotinic subunit also co-assembles with α4β2 to form a high-sensitivity α5α4β2 nAChR. Previous studies suggest that the β2V287L mutation suppresses low-sensitivity α4β2* nAChR expression in a knock-in mouse model and also that α5 co-expression improves the surface expression of ADNFLE mutant nAChRs in a cell line. To test these hypotheses further, we expressed mutant and wild-type (WT) nAChRs in oocytes and mammalian cell lines, and measured the effects of the β2V287L mutation on surface receptor expression and the ACh response using electrophysiology, a voltage-sensitive fluorescent dye, and superecliptic pHluorin (SEP). The β2V287L mutation reduced the EC50 values of high- and low-sensitivity α4β2 nAChRs expressed in Xenopus oocytes for ACh by a similar factor and suppressed low-sensitivity α4β2 expression. In contrast, it did not affect the EC50 of α5α4β2 nAChRs for ACh. Measurements of the ACh responses of WT and mutant nAChRs expressed in mammalian cell lines using a voltage-sensitive fluorescent dye and whole-cell patch-clamping confirm the oocyte data. They also show that, despite reducing the maximum response, β2V287L increased the α4β2 response to a sub-saturating ACh concentration (1 μM). Finally, imaging SEP-tagged α5, α4, β2, and β2V287L subunits showed that β2V287L reduced total α4β2 nAChR surface expression, increased the number of β2 subunits per α4β2 receptor, and increased surface α5α4β2 nAChR expression. Thus, the β2V287L mutation alters the subunit

  14. Reduced expression of neurofibromin in human meningiomas.

    PubMed

    Sundaram, V; Lee, J H; Harwalkar, J A; Stein, D J; Roudebush, M; Stacey, D W; Golubic, M

    1997-01-01

    Meningiomas are common, mostly benign, tumours arising from leptomeningeal cells of the meninges, which frequently contain mutations in the neurofibromatosis type 2 (NF2) gene. In this study, we analysed a protein product of the neurofibromatosis type 1 (NF1) gene, neurofibromin, in human established leptomeningeal cells LTAg2B, in 17 sporadic meningiomas and in a meningioma from a patient affected by NF2. The expression level of neurofibromin was determined by immunoblotting and immunoprecipitation with anti-neurofibromin antibodies. The functional status of neurofibromin was analysed through its ability to stimulate the intrinsic GTPase activity of p21 ras. In the cytosolic extracts of four sporadic meningiomas and in the NF2-related meningioma, the expression level and the GTPase stimulatory activity of neurofibromin were drastically reduced compared with the level present in the human brain, human established leptomeningeal cells LTAg2B and the remaining 13 meningiomas. Our results suggest that neurofibromin is expressed in leptomeningeal cells LTAg2B and in most meningiomas, i.e. tumours derived from these cells. The reduced expression and GTPase stimulatory activity of neurofibromin was found in about 23% of meningiomas and in the single NF2-related meningioma analysed. These results suggest that decreased levels of neurofibromin in these tumours may contribute to their tumorigenesis.

  15. Swimming Motility Reduces Deposition to Silica Surfaces

    SciTech Connect

    Lu, Nanxi; Massoudieh, Arash; Liang, Xiaomeng; Hu, Dehong; Kamai, Tamir; Ginn, Timothy R.; Zilles, Julie L.; Nguyen, Thanh H.

    2015-01-01

    The role of swimming motility on bacterial transport and fate in porous media was evaluated. We present microscopic evidence showing that strong swimming motility reduces attachment of Azotobacter vinelandii cells to silica surfaces. Applying global and cluster statistical analyses to microscopic videos taken under non-flow conditions, wild type, flagellated A. vinelandii strain DJ showed strong swimming ability with an average speed of 13.1 μm/s, DJ77 showed impaired swimming averaged at 8.7 μm/s, and both the non-flagellated JZ52 and chemically treated DJ cells were non-motile. Quantitative analyses of trajectories observed at different distances above the collector of a radial stagnation point flow cell (RSPF) revealed that both swimming and non-swimming cells moved with the flow when at a distance of at least 20 μm from the collector surface. Near the surface, DJ cells showed both horizontal and vertical movement diverging them from reaching surfaces, while chemically treated DJ cells moved with the flow to reach surfaces, suggesting that strong swimming reduced attachment. In agreement with the RSPF results, the deposition rates obtained for two-dimensional multiple-collector micromodels were also lowest for DJ, while DJ77 and JZ52 showed similar values. Strong swimming specifically reduced deposition on the upstream surfaces of the micromodel collectors.

  16. Procedures to reduce reflection on polymer surfaces

    NASA Astrophysics Data System (ADS)

    Schulz, Ulrike; Munzert, Peter; Kaless, Antje; Lau, Kerstin; Kaiser, Norbert

    2005-09-01

    Antireflection (AR) properties are required for optical surfaces to avoid disturbing reflections as well as to improve the transmission of optical systems. The common method to reduce the reflection on optics is vacuum deposition of interference coatings. However, special efforts are required for each type of plastic to develop polymer-capable vacuum coating processes due to the manifold chemical and physical properties of optical polymers. An alternative procedure for the antireflection of polymers is the generation of surface structures that decrease the index of refraction in a surface region. In this paper, the suitability of the miscellaneous thermoplastic polymers for plasma-ion assisted deposition processes is evaluated. This comprises the study of damage effects caused by the contact with plasma and high-energy radiation as well as the development of special coating designs and of suitable process conditions. Coating properties achieved are discussed for PMMA and poly-cycloolefines. The same ion source arrangement as used for coating has been applied for etching an antireflective sub-wavelength surface structure into PMMA. In summary, the paper shows the practical application fields for both technologies.

  17. Nanotexturing of surfaces to reduce melting point.

    SciTech Connect

    Garcia, Ernest J.; Zubia, David; Mireles, Jose; Marquez, Noel; Quinones, Stella

    2011-11-01

    This investigation examined the use of nano-patterned structures on Silicon-on-Insulator (SOI) material to reduce the bulk material melting point (1414 C). It has been found that sharp-tipped and other similar structures have a propensity to move to the lower energy states of spherical structures and as a result exhibit lower melting points than the bulk material. Such a reduction of the melting point would offer a number of interesting opportunities for bonding in microsystems packaging applications. Nano patterning process capabilities were developed to create the required structures for the investigation. One of the technical challenges of the project was understanding and creating the specialized conditions required to observe the melting and reshaping phenomena. Through systematic experimentation and review of the literature these conditions were determined and used to conduct phase change experiments. Melting temperatures as low as 1030 C were observed.

  18. Reducing Sliding Friction with Liquid-Impregnated Surfaces

    NASA Astrophysics Data System (ADS)

    Habibi, Mohammad; Collier, C. Patrick; Boreyko, Jonathan; Nature Inspired Fluids; Interfaces Team; CenterNanophase Materials Sciences Team

    2015-11-01

    Liquid-impregnated surfaces are fabricated by infusing a lubricating liquid into the micro/nano roughness of a textured substrate, such that the surface is slippery for any deposited liquid immiscible with the lubricant. To date, liquid-impregnated surfaces have almost exclusively focused on repelling liquids by minimizing the contact angle hysteresis. Here, we demonstrate that liquid-impregnated surfaces are also capable of reducing sliding friction for solid objects. Ordered arrays of silicon micropillars were infused with lubricating liquids varying in viscosity by two orders of magnitude. Five test surfaces were used: two different micropillared surfaces with and without liquid infusion and a smooth, dry control surface. The static and kinetic coefficients of friction were measured using a polished aluminum cube as the sliding object. Compared to the smooth control surface, the sliding friction was reduced by at least a factor of two on the liquid-impregnated surfaces.

  19. Possible rainfall reduction through reduced surface temperatures due to overgrazing

    NASA Technical Reports Server (NTRS)

    Otterman, J.

    1975-01-01

    Surface temperature reduction in terrain denuded of vegetation (as by overgrazing) is postulated to decrease air convection, reducing cloudiness and rainfall probability during weak meteorological disturbances. By reducing land-sea daytime temperature differences, the surface temperature reduction decreases daytime circulation of thermally driven local winds. The described desertification mechanism, even when limited to arid regions, high albedo soils, and weak meteorological disturbances, can be an effective rainfall reducing process in many areas including most of the Mediterranean lands.

  20. The Arabidopsis Abiotic Stress-Induced TSPO-Related Protein Reduces Cell-Surface Expression of the Aquaporin PIP2;7 through Protein-Protein Interactions and Autophagic Degradation[C][W][OPEN

    PubMed Central

    Hachez, Charles; Veljanovski, Vasko; Reinhardt, Hagen; Guillaumot, Damien; Vanhee, Celine; Chaumont, François

    2014-01-01

    The Arabidopsis thaliana multi-stress regulator TSPO is transiently induced by abiotic stresses. The final destination of this polytopic membrane protein is the Golgi apparatus, where its accumulation is strictly regulated, and TSPO is downregulated through a selective autophagic pathway. TSPO-related proteins regulate the physiology of the cell by generating functional protein complexes. A split-ubiquitin screen for potential TSPO interacting partners uncovered a plasma membrane aquaporin, PIP2;7. Pull-down assays and fluorescence imaging approaches revealed that TSPO physically interacts with PIP2;7 at the endoplasmic reticulum and Golgi membranes in planta. Intriguingly, constitutive expression of fluorescently tagged PIP2;7 in TSPO-overexpressing transgenic lines resulted in patchy distribution of the fluorescence, reminiscent of the pattern of constitutively expressed yellow fluorescent protein-TSPO in Arabidopsis. Mutational stabilization of TSPO or pharmacological inhibition of the autophagic pathway affected concomitantly the detected levels of PIP2;7, suggesting that the complex containing both proteins is degraded through the autophagic pathway. Coexpression of TSPO and PIP2;7 resulted in decreased levels of PIP2;7 in the plasma membrane and abolished the membrane water permeability mediated by transgenic PIP2;7. Taken together, these data support a physiological role for TSPO in regulating the cell-surface expression of PIP2;7 during abiotic stress conditions through protein-protein interaction and demonstrate an aquaporin regulatory mechanism involving TSPO. PMID:25538184

  1. The Arabidopsis abiotic stress-induced TSPO-related protein reduces cell-surface expression of the aquaporin PIP2;7 through protein-protein interactions and autophagic degradation.

    PubMed

    Hachez, Charles; Veljanovski, Vasko; Reinhardt, Hagen; Guillaumot, Damien; Vanhee, Celine; Chaumont, François; Batoko, Henri

    2014-12-01

    The Arabidopsis thaliana multi-stress regulator TSPO is transiently induced by abiotic stresses. The final destination of this polytopic membrane protein is the Golgi apparatus, where its accumulation is strictly regulated, and TSPO is downregulated through a selective autophagic pathway. TSPO-related proteins regulate the physiology of the cell by generating functional protein complexes. A split-ubiquitin screen for potential TSPO interacting partners uncovered a plasma membrane aquaporin, PIP2;7. Pull-down assays and fluorescence imaging approaches revealed that TSPO physically interacts with PIP2;7 at the endoplasmic reticulum and Golgi membranes in planta. Intriguingly, constitutive expression of fluorescently tagged PIP2;7 in TSPO-overexpressing transgenic lines resulted in patchy distribution of the fluorescence, reminiscent of the pattern of constitutively expressed yellow fluorescent protein-TSPO in Arabidopsis. Mutational stabilization of TSPO or pharmacological inhibition of the autophagic pathway affected concomitantly the detected levels of PIP2;7, suggesting that the complex containing both proteins is degraded through the autophagic pathway. Coexpression of TSPO and PIP2;7 resulted in decreased levels of PIP2;7 in the plasma membrane and abolished the membrane water permeability mediated by transgenic PIP2;7. Taken together, these data support a physiological role for TSPO in regulating the cell-surface expression of PIP2;7 during abiotic stress conditions through protein-protein interaction and demonstrate an aquaporin regulatory mechanism involving TSPO.

  2. Emotional facial expressions reduce neural adaptation to face identity.

    PubMed

    Gerlicher, Anna M V; van Loon, Anouk M; Scholte, H Steven; Lamme, Victor A F; van der Leij, Andries R

    2014-05-01

    In human social interactions, facial emotional expressions are a crucial source of information. Repeatedly presented information typically leads to an adaptation of neural responses. However, processing seems sustained with emotional facial expressions. Therefore, we tested whether sustained processing of emotional expressions, especially threat-related expressions, would attenuate neural adaptation. Neutral and emotional expressions (happy, mixed and fearful) of same and different identity were presented at 3 Hz. We used electroencephalography to record the evoked steady-state visual potentials (ssVEP) and tested to what extent the ssVEP amplitude adapts to the same when compared with different face identities. We found adaptation to the identity of a neutral face. However, for emotional faces, adaptation was reduced, decreasing linearly with negative valence, with the least adaptation to fearful expressions. This short and straightforward method may prove to be a valuable new tool in the study of emotional processing.

  3. Emotional facial expressions reduce neural adaptation to face identity.

    PubMed

    Gerlicher, Anna M V; van Loon, Anouk M; Scholte, H Steven; Lamme, Victor A F; van der Leij, Andries R

    2014-05-01

    In human social interactions, facial emotional expressions are a crucial source of information. Repeatedly presented information typically leads to an adaptation of neural responses. However, processing seems sustained with emotional facial expressions. Therefore, we tested whether sustained processing of emotional expressions, especially threat-related expressions, would attenuate neural adaptation. Neutral and emotional expressions (happy, mixed and fearful) of same and different identity were presented at 3 Hz. We used electroencephalography to record the evoked steady-state visual potentials (ssVEP) and tested to what extent the ssVEP amplitude adapts to the same when compared with different face identities. We found adaptation to the identity of a neutral face. However, for emotional faces, adaptation was reduced, decreasing linearly with negative valence, with the least adaptation to fearful expressions. This short and straightforward method may prove to be a valuable new tool in the study of emotional processing. PMID:23512931

  4. The processing of coreference for reduced expressions in discourse integration.

    PubMed

    Yang, C L; Gordon, P C; Hendrick, R; Wu, J T; Chou, T L

    2001-01-01

    Three reading-time experiments in Chinese are reported that test contrasting views of how pronominal coreference is achieved. On the one hand, studies of reading time and eye tracking suggest that reduced expressions, such as the pronoun he, serve as critical links to integrate separate utterances into a coherent model of discourse. On the other hand, probe-word recognition studies indicate that full anaphoric expressions, such as a repeated name, are more readily interpreted than reduced expressions due to their rich lexical information, which provides effective cues to match the representation of the appropriate referent in memory. The results indicate that the ease of integrating the critical referent into a model of discourse is a function of the congruence of lexical, semantic, and discourse features conveyed by a syntactically prominent reduced expression within linguistic input. This pattern supports the view that a reduced expression is interpreted on-line and indeed plays a critical role in promoting discourse coherence by facilitating the semantic integration of separate utterances.

  5. Development of antifouling surfaces to reduce bacterial attachment

    NASA Astrophysics Data System (ADS)

    Graham, Mary Viola

    Bacteria are exceptionally good at adhering to surfaces and forming complex structures known as biofilms. This process, known as biofouling, can cause problems for infrastructure (eg, clogging and damaging pipes), for the food industry (eg, contamination of processing surfaces and equipment, and for the medical industry (eg, contamination of indwelling medical devices). Accordingly, multiple strategies have been explored to combat biofouling, including chemical modification of surfaces, development of antibiotic coatings, and more recently, the use of engineered surface topography. When designed properly, engineered surface topographies can significantly reduce bacterial surface attachment, ultimately limiting surface colonization. In this work, we hypothesized that the morphology, size, spacing, and surface pre-treatment of topographical features should directly correlate with the size and shape of target organisms, in order to reduce biofouling. Topographical features with size and spacing from 0.25 to 2 mum were fabricated in silicone elastomer and tested against rod shaped bacteria with an average size of 0.5 x 2 mum and spherical bacteria (cocci) ranging from 0.5 - 1 μm in diameter. Antifouling properties of the different topographical features were tested in both static and flow-based assays, and under oxygen plasma-treated (hydrophilic) and untreated (hydrophobic) surface conditions. We found that surface pre-treatment universally affects the ability bacteria to attach to surfaces, while surface topography limits attachment in a manner dependent on the bacterial size/shape and the size/spacing of the topography.

  6. Surface expression of the Chicxulub crater

    PubMed

    Pope, K O; Ocampo, A C; Kinsland, G L; Smith, R

    1996-06-01

    Analyses of geomorphic, soil, and topographic data from the northern Yucatan Peninsula, Mexico, confirm that the buried Chicxulub impact crater has a distinct surface expression and that carbonate sedimentation throughout the Cenozoic has been influenced by the crater. Late Tertiary sedimentation was mostly restricted to the region within the buried crater, and a semicircular moat existed until at least Pliocene time. The topographic expression of the crater is a series of features concentric with the crater. The most prominent is an approximately 83-km-radius trough or moat containing sinkholes (the Cenote ring). Early Tertiary surfaces rise abruptly outside the moat and form a stepped topography with an outer trough and ridge crest at radii of approximately 103 and approximately 129 km, respectively. Two discontinuous troughs lie within the moat at radii of approximately 41 and approximately 62 km. The low ridge between the inner troughs corresponds to the buried peak ring. The moat corresponds to the outer edge of the crater floor demarcated by a major ring fault. The outer trough and the approximately 62-km-radius inner trough also mark buried ring faults. The ridge crest corresponds to the topographic rim of the crater as modified by postimpact processes. These interpretations support previous findings that the principal impact basin has a diameter of approximately 180 km, but concentric, low-relief slumping extends well beyond this diameter and the eroded crater rim may extend to a diameter of approximately 260 km.

  7. Reduced Ang2 expression in aging endothelial cells.

    PubMed

    Hohensinner, P J; Ebenbauer, B; Kaun, C; Maurer, G; Huber, K; Wojta, J

    2016-06-01

    Aging endothelial cells are characterized by increased cell size, reduced telomere length and increased expression of proinflammatory cytokines. In addition, we describe here that aging reduces the migratory distance of endothelial cells. Furthermore, we observe an increase of the quiescence protein Ang1 and a decrease of the endothelial activation protein Ang2 upon aging. Supplementing Ang2 to aged endothelial cells restored their migratory capacity. We conclude that aging shifts the balance of the Ang1/Ang2 network favouring a quiescent state. Activation of endothelial cells in aging might be necessary to enhance wound healing capacities. PMID:27137842

  8. Zwitteration: Coating Surfaces with Zwitterionic Functionality to Reduce Nonspecific Adsorption

    PubMed Central

    2015-01-01

    Coating surfaces with thin or thick films of zwitterionic material is an effective way to reduce or eliminate nonspecific adsorption to the solid/liquid interface. This review tracks the various approaches to zwitteration, such as monolayer assemblies and polymeric brush coatings, on micro- to macroscopic surfaces. A critical summary of the mechanisms responsible for antifouling shows how zwitterions are ideally suited to this task. PMID:24754399

  9. LIN28A Expression Reduces Sickling of Cultured Human Erythrocytes

    PubMed Central

    de Vasconcellos, Jaira F.; Fasano, Ross M.; Lee, Y. Terry; Kaushal, Megha; Byrnes, Colleen; Meier, Emily R.; Anderson, Molly; Rabel, Antoinette; Braylan, Raul; Stroncek, David F.; Miller, Jeffery L.

    2014-01-01

    Induction of fetal hemoglobin (HbF) has therapeutic importance for patients with sickle cell disease (SCD) and the beta-thalassemias. It was recently reported that increased expression of LIN28 proteins or decreased expression of its target let-7 miRNAs enhances HbF levels in cultured primary human erythroblasts from adult healthy donors. Here LIN28A effects were studied further using erythrocytes cultured from peripheral blood progenitor cells of pediatric subjects with SCD. Transgenic expression of LIN28A was accomplished by lentiviral transduction in CD34(+) sickle cells cultivated ex vivo in serum-free medium. LIN28A over-expression (LIN28A-OE) increased HbF, reduced beta (sickle)-globin, and strongly suppressed all members of the let-7 family of miRNAs. LIN28A-OE did not affect erythroblast differentiation or prevent enucleation, but it significantly reduced or ameliorated the sickling morphologies of the enucleated erythrocytes. PMID:25188417

  10. Mars Express radar collects first surface data

    NASA Astrophysics Data System (ADS)

    2005-08-01

    the middle of August, when the night-time portion of the observations will have almost ended. After that, observation priority will be given to other Mars Express instruments that are best suited to operating in daytime, such as the HRSC camera and Omega mapping spectrometer. However, Marsis will continue its surface and ionospheric investigations in daytime, with ionospheric sounding being reserved for more than 20% of all Mars Express orbits, under all possible Sun illumination conditions. In December, the Mars Express orbit pericentre will enter night-time again. By then, the pericentre will have moved closer to the south pole, allowing Marsis to carry out optimal probing of the subsurface once again, this time in the southern hemisphere. Note to editors The first commissioning phase was given over to testing the Marsis electronics and software and the two 20m-long antennas (dipole). The second commissioning phase, lasting about ten days, will be spent calibrating the 7m ‘monopole’ antenna. This antenna is to be used in conjunction with the Marsis dipole to correct any surface roughness effects caused by the radio waves emitted by the dipole and reflected by an irregular surface. The monopole will find its best use during investigations of areas where surface roughness is greater. The Marsis instrument was developed within the framework of a Memorandum of Understanding between the Italian Space Agency (ASI) and NASA. It was developed by Alenia Spazio under ASI management and the scientific supervision of University of Rome ‘La Sapienza’, in partnership with the Jet Propulsion Laboratory (JPL) and the University of Iowa. JPL provided the antenna manufactured by Astro Aerospace. It is the first instrument designed to actually look below the surface of Mars. Its major goals are to characterise the subsurface layers of sediments and possibly detect underground water or ice, conduct large-scale altimetry mapping and provide data on the planet’s ionosphere. For

  11. Triptolide reduces the viability of osteosarcoma cells by reducing MKP-1 and Hsp70 expression

    PubMed Central

    ZHAO, LEI; JIANG, BO; WANG, DONG; LIU, WEI; ZHANG, HUAWU; LIU, WEISHENG; QIU, ZHEN

    2016-01-01

    Osteosarcoma is the most common type of malignant bone tumor found in adolescents and young adults. The aim of the present study was to determine whether triptolide, a diterpene epoxide extracted from the Tripterygium plant, was able effectively decrease the viability of osteosarcoma cells. The underlying molecular mechanisms are also investigated. The human osteosarcoma cell lines U-2 OS and MG-63 were used in this study. The U-2 OS and MG-63 cells were treated with 0, 5, 10, 25 or 50 nM triptolide. Cells treated with dimethyl sulfoxide only were used as the no drug treatment control. A commercial MTT kit was used to determine the effects of triptolide on cells. Mitogen-activated protein kinase phosphatase-1 (MKP-1) is frequently overexpressed in tumor tissues, possibly related to the failure of a number of chemotherapeutics. Heat shock protein 70 (Hsp70) is a chaperone molecule that is able to increase drug resistance. The protein expression levels of MKP-1 and Hsp70 were determined using western blot analysis. The results indicate that triptolide effectively reduced the viability of the osteosarcoma cells. Furthermore, triptolide was found to effectively reduce MKP-1 expression and Hsp70 levels. Further analysis showed that triptolide reduced MKP-1 mRNA expression in the U-2 OS and MG-63 cells. Triptolide reduced Hsp70 mRNA expression levels in U-2 OS and MG-63 cells. These results suggest that triptolide effectively decreases the viability of osteosarcoma cells. These effects may be associated with the decreased expression of MKP-1 and Hsp70 levels. These results suggest that triptolide may be used in the treatments of osteosarcoma. PMID:27168842

  12. Textured bearing surface in artificial joints to reduce macrophage activation

    NASA Astrophysics Data System (ADS)

    Nakanishi, Yoshitaka; Nishi, Naoki; Chikaura, Hiroto; Nakashima, Yuta; Miura, Hiromasa; Higaki, Hidehiko; Mizuta, Hiroshi; Iwamoto, Yukihide; Fujiwara, Yukio; Komohara, Yoshihiro; Takeya, Motohiro

    2015-12-01

    Micro slurry-jet erosion has been proposed as a precision machining technique for the bearing surfaces of artificial joints in order to reduce the total amount of polyethylene wear and to enlarge the size of the wear debris. The micro slurry-jet erosion method is a wet blasting technique which uses alumina particles as the abrasive medium along with compressed air and water to create an ideal surface. Pin-on-disc wear tests with multidirectional sliding motion on the textured surface of a \\text{Co}-\\text{Cr}-\\text{Mo} alloy counterface for polyethylene resulted in both a reduction of wear as well as enlargement of the polyethylene debris size. In this study, primary human peripheral blood mononuclear phagocytes were incubated with the debris, and it was elucidated that the wear debris generated on the textured surface regulated secretion of the proinflammatory cytokines IL-6 and TNF-α, indicating a reduction in the induced tissue reaction and joint loosening.

  13. Methods for finding transition states on reduced potential energy surfaces

    NASA Astrophysics Data System (ADS)

    Burger, Steven K.; Ayers, Paul W.

    2010-06-01

    Three new algorithms are presented for determining transition state (TS) structures on the reduced potential energy surface, that is, for problems in which a few important degrees of freedom can be isolated. All three methods use constrained optimization to rapidly find the TS without an initial Hessian evaluation. The algorithms highlight how efficiently the TS can be located on a reduced surface, where the rest of the degrees of freedom are minimized. The first method uses a nonpositive definite quasi-Newton update for the reduced degrees of freedom. The second uses Shepard interpolation to fit the Hessian and starts from a set of points that bound the TS. The third directly uses a finite difference scheme to calculate the reduced degrees of freedom of the Hessian of the entire system, and searches for the TS on the full potential energy surface. All three methods are tested on an epoxide hydrolase cluster, and the ring formations of cyclohexane and cyclobutenone. The results indicate that all the methods are able to converge quite rapidly to the correct TS, but that the finite difference approach is the most efficient.

  14. Surface modification of intraocular lenses to reduce corneal endothelial damage.

    PubMed

    Knight, P M; Link, W J

    1979-04-01

    Two methods of surface modification of PMMA, permanent and temporary, were investigated for use on intraocular lenses to reduce corneal endothelial damage due to corneal-IOL touch. Monomer grafting using gamma irradiation was found to produce permanently hydrophilic surfaces. Temporary surface modifications developed and tested were peelable and dissolvable coatings. Test samples were touched to freshly excised rabbit corneas to evaluate the effectiveness of the various surface modifications in reducing endothelial cell damage. This touch testing was performed using static testing in which the test sample was touched to the cornea without movement and dynamic testing in which there was relative movement between the cornea and the test sample. While unmodified PMMA did significant cell damage in both static and dynamic tests perpamently modified (hydrophilic grafted) surfaces were found to perform well in the static, but not in the dynamic tests. Dissolvable coatings performed well in both tests, even with very thin coatings. There was little differentiation between the various water-soluble coatings tested. Due to its characteristics and rate of dissolution, polyvinyl alcohol appears to be an optimum material for coating IOLs. A series of in vitro and in vivo tests performed to assess its safety indicate that PVA is nontoxic and safe in animal eyes. PMID:479004

  15. Reducing measurement scale mismatch to improve surface energy flux estimation

    NASA Astrophysics Data System (ADS)

    Iwema, Joost; Rosolem, Rafael; Rahman, Mostaquimur; Blyth, Eleanor; Wagener, Thorsten

    2016-04-01

    Soil moisture importantly controls land surface processes such as energy and water partitioning. A good understanding of these controls is needed especially when recognizing the challenges in providing accurate hyper-resolution hydrometeorological simulations at sub-kilometre scales. Soil moisture controlling factors can, however, differ at distinct scales. In addition, some parameters in land surface models are still often prescribed based on observations obtained at another scale not necessarily employed by such models (e.g., soil properties obtained from lab samples used in regional simulations). To minimize such effects, parameters can be constrained with local data from Eddy-Covariance (EC) towers (i.e., latent and sensible heat fluxes) and Point Scale (PS) soil moisture observations (e.g., TDR). However, measurement scales represented by EC and PS still differ substantially. Here we use the fact that Cosmic-Ray Neutron Sensors (CRNS) estimate soil moisture at horizontal footprint similar to that of EC fluxes to help answer the following question: Does reduced observation scale mismatch yield better soil moisture - surface fluxes representation in land surface models? To answer this question we analysed soil moisture and surface fluxes measurements from twelve COSMOS-Ameriflux sites in the USA characterized by distinct climate, soils and vegetation types. We calibrated model parameters of the Joint UK Land Environment Simulator (JULES) against PS and CRNS soil moisture data, respectively. We analysed the improvement in soil moisture estimation compared to uncalibrated model simulations and then evaluated the degree of improvement in surface fluxes before and after calibration experiments. Preliminary results suggest that a more accurate representation of soil moisture dynamics is achieved when calibrating against observed soil moisture and further improvement obtained with CRNS relative to PS. However, our results also suggest that a more accurate

  16. Polyelectrolytes Ability in Reducing Atrazine Concentration in Water: Surface Effects

    PubMed Central

    Heijman, S. G. J.; Lopes, S. I. C.; Rietveld, L. C.

    2014-01-01

    This paper reports on the direct ability of two positively charged organic polyelectrolytes (natural-based and synthetic) to reduce the atrazine concentration in water. The adsorption study was set up using multiple glass vessels with different polymer dosing levels followed by ultrafiltration with a 1 kDa membrane. The addition of polymers exhibited a capability in reducing the atrazine concentration up to a maximum of 60% in surface-to-volume ratio experiments. In the beginning, the theoretical L-type of the isotherm of Giles' classification was expected with an increase in the dosage of the polymer. However, in this study, the conventional type of isotherm was not observed. It was found that the adsorption of the cationic polymer on the negatively charged glass surface was necessary and influential for the removal of atrazine. Surface-to-volume ratio adsorption experiments were performed to elucidate the mechanisms and the polymer configuration. The glass surface area was determined to be a limiting parameter in the adsorption mechanism. PMID:25197693

  17. Polyelectrolytes ability in reducing atrazine concentration in water: surface effects.

    PubMed

    Mohd Amin, Mohamad Faiz; Heijman, S G J; Lopes, S I C; Rietveld, L C

    2014-01-01

    This paper reports on the direct ability of two positively charged organic polyelectrolytes (natural-based and synthetic) to reduce the atrazine concentration in water. The adsorption study was set up using multiple glass vessels with different polymer dosing levels followed by ultrafiltration with a 1 kDa membrane. The addition of polymers exhibited a capability in reducing the atrazine concentration up to a maximum of 60% in surface-to-volume ratio experiments. In the beginning, the theoretical L-type of the isotherm of Giles' classification was expected with an increase in the dosage of the polymer. However, in this study, the conventional type of isotherm was not observed. It was found that the adsorption of the cationic polymer on the negatively charged glass surface was necessary and influential for the removal of atrazine. Surface-to-volume ratio adsorption experiments were performed to elucidate the mechanisms and the polymer configuration. The glass surface area was determined to be a limiting parameter in the adsorption mechanism. PMID:25197693

  18. Trifluoperazine reduces the expression of CD69 in phytohemagglutinin-activated lymphocytes.

    PubMed

    Pires, V; Harab, R C; Rumjanek, V M

    1996-04-01

    Trifluoperazine (TFP) is a phenothiazine capable of inhibiting lymphocyte proliferation as well as natural killer cells (NK) and lymphokine-activated killer cells (LAK) cytotoxic activity. CD69 is a surface molecule induced by various mechanisms of cellular activation. In the present work the modulation of CD69 expression by TFP was investigated on PHA-stimulated peripheral blood mononuclear cells and compared to that of CD25 (IL-2 receptor) expression. Determination of surface molecules was performed in an indirect immunofluorescence assay using anti-CD69 or anti-CD25 monoclonal antibodies, and analyzed by flow cytometry. The time course of the expression of these two molecules differed: CD69 expression was already declining at 48 h, whereas CD25 was still increasing at 72 h after stimulation. TFP (10 microM) reduced CD69 expression by 71.8% at 24 h, 68.4% at 48 h and 24% at 72 h following activation. In contrast, the same dose of TFP did not significantly affect CD25 expression at 24 h but showed an inhibitory effect at later times. These results suggest that different activation pathways are involved in the expression of CD25 and CD69.

  19. Reducing Surface Clutter in Cloud Profiling Radar Data

    NASA Technical Reports Server (NTRS)

    Tanelli, Simone; Pak, Kyung; Durden, Stephen; Im, Eastwood

    2008-01-01

    An algorithm has been devised to reduce ground clutter in the data products of the CloudSat Cloud Profiling Radar (CPR), which is a nadir-looking radar instrument, in orbit around the Earth, that measures power backscattered by clouds as a function of distance from the instrument. Ground clutter contaminates the CPR data in the lowest 1 km of the atmospheric profile, heretofore making it impossible to use CPR data to satisfy the scientific interest in studying clouds and light rainfall at low altitude. The algorithm is based partly on the fact that the CloudSat orbit is such that the geodetic altitude of the CPR varies continuously over a range of approximately 25 km. As the geodetic altitude changes, the radar timing parameters are changed at intervals defined by flight software in order to keep the troposphere inside a data-collection time window. However, within each interval, the surface of the Earth continuously "scans through" (that is, it moves across) a few range bins of the data time window. For each radar profile, only few samples [one for every range-bin increment ((Delta)r = 240 m)] of the surface-clutter signature are available around the range bin in which the peak of surface return is observed, but samples in consecutive radar profiles are offset slightly (by amounts much less than (Delta)r) with respect to each other according to the relative change in geodetic altitude. As a consequence, in a case in which the surface area under examination is homogenous (e.g., an ocean surface), a sequence of consecutive radar profiles of the surface in that area contains samples of the surface response with range resolution (Delta)p much finer than the range-bin increment ((Delta)p << r). Once the high-resolution surface response has thus become available, the profile of surface clutter can be accurately estimated by use of a conventional maximum-correlation scheme: A translated and scaled version of the high-resolution surface response is fitted to the observed

  20. Reducing ZnO nanoparticle cytotoxicity by surface modification

    NASA Astrophysics Data System (ADS)

    Luo, Mingdeng; Shen, Cenchao; Feltis, Bryce N.; Martin, Lisandra L.; Hughes, Anthony E.; Wright, Paul F. A.; Turney, Terence W.

    2014-05-01

    Nanoparticulate zinc oxide (ZnO) is one of the most widely used engineered nanomaterials and its toxicology has gained considerable recent attention. A key aspect for controlling biological interactions at the nanoscale is understanding the relevant nanoparticle surface chemistry. In this study, we have determined the disposition of ZnO nanoparticles within human immune cells by measurement of total Zn, as well as the proportions of extra- and intracellular dissolved Zn as a function of dose and surface coating. From this mass balance, the intracellular soluble Zn levels showed little difference in regard to dose above a certain minimal level or to different surface coatings. PEGylation of ZnO NPs reduced their cytotoxicity as a result of decreased cellular uptake arising from a minimal protein corona. We conclude that the key role of the surface properties of ZnO NPs in controlling cytotoxicity is to regulate cellular nanoparticle uptake rather than altering either intracellular or extracellular Zn dissolution.Nanoparticulate zinc oxide (ZnO) is one of the most widely used engineered nanomaterials and its toxicology has gained considerable recent attention. A key aspect for controlling biological interactions at the nanoscale is understanding the relevant nanoparticle surface chemistry. In this study, we have determined the disposition of ZnO nanoparticles within human immune cells by measurement of total Zn, as well as the proportions of extra- and intracellular dissolved Zn as a function of dose and surface coating. From this mass balance, the intracellular soluble Zn levels showed little difference in regard to dose above a certain minimal level or to different surface coatings. PEGylation of ZnO NPs reduced their cytotoxicity as a result of decreased cellular uptake arising from a minimal protein corona. We conclude that the key role of the surface properties of ZnO NPs in controlling cytotoxicity is to regulate cellular nanoparticle uptake rather than

  1. Thermomechanical Mechanisms of Reducing Ice Adhesion on Superhydrophobic Surfaces.

    PubMed

    Cohen, N; Dotan, A; Dodiuk, H; Kenig, S

    2016-09-20

    Superhydrophobic (SH) coatings have been shown to reduce freezing and ice nucleation rates, by means of low surface energy chemistry tailored with nano/micro roughness. Durability enhancement of SH surfaces is a crucial issue. Consequently, the present research on reducing ice adhesion is based on radiation-induced radical reaction for covalently bonding SiO2 nanoparticles to polymer coatings to obtain durable roughness. Results indicated that the proposed approach resulted in SH surfaces having high contact angles (>155°) and low sliding angles (<5°) with improved durability and transparency. In a subsequent stage, the synthesized SH coating was investigated for its icephobic characteristics using a variety of substrates. Results indicated that supercooled water drops bounced back when impinging on SH polycarbonate substrate and froze on SH copper substrate held at -10 to -30 °C and were easily peeled off when coated by ice formed during exposure to air/supercooled water drops at -20 °C. The ice shear adhesion investigation (at -20 °C) demonstrated reduction of shear adhesion to a variety of SH treated substrates having low thermal expansion coefficient (copper and aluminum) and high thermal expansion coefficient (polycarbonate and poly(methyl methacrylate)). It was concluded that the thermal mismatch between the adhering ice and the various substrates and its resultant interfacial thermal stresses affect the adhesion strength of the ice to the respective substrate. PMID:27578298

  2. Dimethylmercury Formation Mediated by Inorganic and Organic Reduced Sulfur Surfaces

    NASA Astrophysics Data System (ADS)

    Jonsson, Sofi; Mazrui, Nashaat M.; Mason, Robert P.

    2016-06-01

    Underlying formation pathways of dimethylmercury ((CH3)2Hg) in the ocean are unknown. Early work proposed reactions of inorganic Hg (HgII) with methyl cobalamin or of dissolved monomethylmercury (CH3Hg) with hydrogen sulfide as possible bacterial mediated or abiotic pathways. A significant fraction (up to 90%) of CH3Hg in natural waters is however adsorbed to reduced sulfur groups on mineral or organic surfaces. We show that binding of CH3Hg to such reactive sites facilitates the formation of (CH3)2Hg by degradation of the adsorbed CH3Hg. We demonstrate that the reaction can be mediated by different sulfide minerals, as well as by dithiols suggesting that e.g. reduced sulfur groups on mineral particles or on protein surfaces could mediate the reaction. The observed fraction of CH3Hg methylated on sulfide mineral surfaces exceeded previously observed methylation rates of CH3Hg to (CH3)2Hg in seawaters and we suggest the pathway demonstrated here could account for much of the (CH3)2Hg found in the ocean.

  3. Dimethylmercury Formation Mediated by Inorganic and Organic Reduced Sulfur Surfaces

    PubMed Central

    Jonsson, Sofi; Mazrui, Nashaat M.; Mason, Robert P.

    2016-01-01

    Underlying formation pathways of dimethylmercury ((CH3)2Hg) in the ocean are unknown. Early work proposed reactions of inorganic Hg (HgII) with methyl cobalamin or of dissolved monomethylmercury (CH3Hg) with hydrogen sulfide as possible bacterial mediated or abiotic pathways. A significant fraction (up to 90%) of CH3Hg in natural waters is however adsorbed to reduced sulfur groups on mineral or organic surfaces. We show that binding of CH3Hg to such reactive sites facilitates the formation of (CH3)2Hg by degradation of the adsorbed CH3Hg. We demonstrate that the reaction can be mediated by different sulfide minerals, as well as by dithiols suggesting that e.g. reduced sulfur groups on mineral particles or on protein surfaces could mediate the reaction. The observed fraction of CH3Hg methylated on sulfide mineral surfaces exceeded previously observed methylation rates of CH3Hg to (CH3)2Hg in seawaters and we suggest the pathway demonstrated here could account for much of the (CH3)2Hg found in the ocean. PMID:27302323

  4. Thermomechanical Mechanisms of Reducing Ice Adhesion on Superhydrophobic Surfaces.

    PubMed

    Cohen, N; Dotan, A; Dodiuk, H; Kenig, S

    2016-09-20

    Superhydrophobic (SH) coatings have been shown to reduce freezing and ice nucleation rates, by means of low surface energy chemistry tailored with nano/micro roughness. Durability enhancement of SH surfaces is a crucial issue. Consequently, the present research on reducing ice adhesion is based on radiation-induced radical reaction for covalently bonding SiO2 nanoparticles to polymer coatings to obtain durable roughness. Results indicated that the proposed approach resulted in SH surfaces having high contact angles (>155°) and low sliding angles (<5°) with improved durability and transparency. In a subsequent stage, the synthesized SH coating was investigated for its icephobic characteristics using a variety of substrates. Results indicated that supercooled water drops bounced back when impinging on SH polycarbonate substrate and froze on SH copper substrate held at -10 to -30 °C and were easily peeled off when coated by ice formed during exposure to air/supercooled water drops at -20 °C. The ice shear adhesion investigation (at -20 °C) demonstrated reduction of shear adhesion to a variety of SH treated substrates having low thermal expansion coefficient (copper and aluminum) and high thermal expansion coefficient (polycarbonate and poly(methyl methacrylate)). It was concluded that the thermal mismatch between the adhering ice and the various substrates and its resultant interfacial thermal stresses affect the adhesion strength of the ice to the respective substrate.

  5. Expressive writing as a brief intervention for reducing drinking intentions.

    PubMed

    Young, Chelsie M; Rodriguez, Lindsey M; Neighbors, Clayton

    2013-12-01

    The present study examined the effectiveness of expressive writing in reducing drinking behavior. We expected that students prompted to write about negative drinking experiences would show greater decreases in future drinking intentions compared to the neutral and the positive writing conditions. We also expected that decreases in drinking intentions following the writing prompts might differ based on current drinking and AUDIT scores. Participants included 200 (76% female) undergraduates who completed measures of their current drinking behavior. They were then randomly assigned to either write about: a time when they had a lot to drink that was a good time (Positive); a time when they had a lot to drink that was a bad time (Negative); or their first day of college (Neutral), followed by measures assessing intended drinking over the next three months. Results revealed that participants intended to drink significantly fewer drinks per week and engage in marginally fewer heavy drinking occasions after writing about a negative drinking occasion when compared to control. Interactions provided mixed findings suggesting that writing about a positive event was associated with higher drinking intentions for heavier drinkers. Writing about a negative event was associated with higher intentions among heavier drinkers, but lower intentions among those with higher AUDIT scores. This research builds on previous expressive writing interventions by applying this technique to undergraduate drinkers. Preliminary results provide some support for this innovative strategy but also suggest the need for further refinement, especially with heavier drinkers.

  6. Expressive writing as a brief intervention for reducing drinking intentions.

    PubMed

    Young, Chelsie M; Rodriguez, Lindsey M; Neighbors, Clayton

    2013-12-01

    The present study examined the effectiveness of expressive writing in reducing drinking behavior. We expected that students prompted to write about negative drinking experiences would show greater decreases in future drinking intentions compared to the neutral and the positive writing conditions. We also expected that decreases in drinking intentions following the writing prompts might differ based on current drinking and AUDIT scores. Participants included 200 (76% female) undergraduates who completed measures of their current drinking behavior. They were then randomly assigned to either write about: a time when they had a lot to drink that was a good time (Positive); a time when they had a lot to drink that was a bad time (Negative); or their first day of college (Neutral), followed by measures assessing intended drinking over the next three months. Results revealed that participants intended to drink significantly fewer drinks per week and engage in marginally fewer heavy drinking occasions after writing about a negative drinking occasion when compared to control. Interactions provided mixed findings suggesting that writing about a positive event was associated with higher drinking intentions for heavier drinkers. Writing about a negative event was associated with higher intentions among heavier drinkers, but lower intentions among those with higher AUDIT scores. This research builds on previous expressive writing interventions by applying this technique to undergraduate drinkers. Preliminary results provide some support for this innovative strategy but also suggest the need for further refinement, especially with heavier drinkers. PMID:24064189

  7. Modulated surface nanostructures for enhanced light trapping and reduced surface reflection of crystalline silicon solar cells

    NASA Astrophysics Data System (ADS)

    Tayagaki, Takeshi; Hoshi, Yusuke; Hirai, Yuji; Matsuo, Yasutaka; Usami, Noritaka

    2016-05-01

    We demonstrated the fabrication of modulated surface nanostructures as a new surface texture design for thin wafer solar cells. Using a combination of conventional alkali etching and colloidal lithography, we fabricated surface textures with micrometer and nanometre scales on a Si substrate. These modulated surface nanostructures exhibit reduced surface reflection in a broad spectral range, compared with conventional micrometer textures. We investigated optical absorption using a rigorous coupled wave analysis simulation, which revealed a significant reduction in surface reflection over a broad spectral range and efficient light trapping (comparable to that of conventional micrometer-scale textures) for the modulated nanostructures. We found that the modulated surface nanostructures have a high potential of improving the performance of thin wafer crystalline Si solar cells.

  8. Towards Reducing the Data Exfiltration Surface for the Insider Threat

    SciTech Connect

    Schlicher, Bob G; MacIntyre, Lawrence Paul; Abercrombie, Robert K

    2016-01-01

    Unauthorized data exfiltrations from both insiders and outsiders are costly and damaging. Network communication resources can be used for transporting data illicitly out of the enterprise or cloud. Combined with built-in malware copying utilities, we define this as comprising the Data Exfiltration Surface (DXS). For securing valuable data, it is desirable to reduce the DXS and maintain controls on the egress points. Our approach is to host the data in a protected enclave that includes novel software Data Diode (SDD) installed on a secured, border gateway. The SDD allows copying data into the enclave systems but denies data from being copied out. Simultaneously, it permits remote access with remote desktop and console applications. Our tests demonstrate that we are able to effectively reduce the DXS and we are able to protect data from being exfiltrated through the use of the SDD.

  9. Reduced expression of sarcospan in muscles of Fukuyama congenital muscular dystrophy.

    PubMed

    Wakayama, Yoshihiro; Inoue, Masahiko; Kojima, Hiroko; Yamashita, Sumimasa; Shibuya, Seiji; Jimi, Takahiro; Hara, Hajime; Matsuzaki, Yoko; Oniki, Hiroaki; Kanagawa, Motoi; Kobayashi, Kazuhiro; Toda, Tatsushi

    2008-12-01

    Expression profiles of sarcospan in muscles with muscular dystrophies are scarcely reported. To examine this, we studied five Fukuyama congenital muscular dystrophy (FCMD) muscles, five Duchenne muscular dystrophy (DMD) muscles, five disease control and five normal control muscles. Immunoblot showed reactions of sarcospan markedly decreased in FCMD and DMD muscle extracts. Immunohistochemistry of FCMD muscles showed that most large diameter myofibers expressed sarcospan discontinuously at their surface membranes. Immature small diameter FCMD myofibers usually did not express sarcospan. Immunoreactivity of sarcospan in DMD muscles was similarly reduced. With regard to dystroglycans and sarcoglycans, immunohistochemistry of FCMD muscles showed selective deficiency of glycosylated alpha-dystroglycan, together with reduced expression of beta-dystroglycan and alpha-, beta-, gamma-, delta-sarcoglycans. Although the expression of glycosylated alpha-dystroglycan was lost, scattered FCMD myofibers showed positive immunoreaction with an antibody against the core protein of alpha-dystroglycan. The group mean ratios of sarcospan mRNA copy number versus GAPDH mRNA copy number by real-time RT-PCR showed that the ratios between FCMD and normal control groups were not significantly different (P>0.1 by the two-tailed t test). This study implied either O-linked glycosylation defects of alpha-dystroglycan in the Golgi apparatus of FCMD muscles may lead to decreased expression of sarcoglycan and sarcospan molecules, or selective deficiency of glycosylated alpha-dystroglycan due to impaired glycosylation in FCMD muscles may affect the molecular integrity of the basal lamina of myofibers. This, in turn, leads to decreased expression of sarcoglycans, and finally of sarcospan at the FCMD myofiber surfaces.

  10. Thrombospondin-4 reduces binding affinity of [(3)H]-gabapentin to calcium-channel α2δ-1-subunit but does not interact with α2δ-1 on the cell-surface when co-expressed.

    PubMed

    Lana, Beatrice; Page, Karen M; Kadurin, Ivan; Ho, Shuxian; Nieto-Rostro, Manuela; Dolphin, Annette C

    2016-01-01

    The α2δ proteins are auxiliary subunits of voltage-gated calcium channels, and influence their trafficking and biophysical properties. The α2δ ligand gabapentin interacts with α2δ-1, and inhibits calcium channel trafficking. However, α2-1 has also been proposed to play a synaptogenic role, independent of calcium channel function. In this regard, α2δ-1 was identified as a ligand of thrombospondins, with the interaction involving the thrombospondin synaptogenic domain and the α2δ-1 von-Willebrand-factor domain. Co-immunoprecipitation between α2δ-1 and the synaptogenic domain of thrombospondin-2 was prevented by gabapentin. We therefore examined whether interaction of thrombospondin with α2δ-1 might reciprocally influence (3)H-gabapentin binding. We concentrated on thrombospondin-4, because, like α2δ-1, it is upregulated in neuropathic pain models. We found that in membranes from cells co-transfected with α2δ-1 and thrombospondin-4, there was a Mg(2+) -dependent reduction in affinity of (3)H-gabapentin binding to α2δ-1. This effect was lost for α2δ-1 with mutations in the von-Willebrand-factor-A domain. However, the effect on (3)H-gabapentin binding was not reproduced by the synaptogenic EGF-domain of thrombospondin-4. Partial co-immunoprecipitation could be demonstrated between thrombospondin-4 and α2δ-1 when co-transfected, but there was no co-immunoprecipitation with thrombospondin-4-EGF domain. Furthermore, we could not detect any association between these two proteins on the cell-surface, indicating the demonstrated interaction occurs intracellularly. PMID:27076051

  11. Thrombospondin-4 reduces binding affinity of [3H]-gabapentin to calcium-channel α2δ-1-subunit but does not interact with α2δ-1 on the cell-surface when co-expressed

    PubMed Central

    Lana, Beatrice; Page, Karen M.; Kadurin, Ivan; Ho, Shuxian; Nieto-Rostro, Manuela; Dolphin, Annette C.

    2016-01-01

    The α2δ proteins are auxiliary subunits of voltage-gated calcium channels, and influence their trafficking and biophysical properties. The α2δ ligand gabapentin interacts with α2δ-1, and inhibits calcium channel trafficking. However, α2-1 has also been proposed to play a synaptogenic role, independent of calcium channel function. In this regard, α2δ-1 was identified as a ligand of thrombospondins, with the interaction involving the thrombospondin synaptogenic domain and the α2δ-1 von-Willebrand-factor domain. Co-immunoprecipitation between α2δ-1 and the synaptogenic domain of thrombospondin-2 was prevented by gabapentin. We therefore examined whether interaction of thrombospondin with α2δ-1 might reciprocally influence 3H-gabapentin binding. We concentrated on thrombospondin-4, because, like α2δ-1, it is upregulated in neuropathic pain models. We found that in membranes from cells co-transfected with α2δ-1 and thrombospondin-4, there was a Mg2+ -dependent reduction in affinity of 3H-gabapentin binding to α2δ-1. This effect was lost for α2δ-1 with mutations in the von-Willebrand-factor-A domain. However, the effect on 3H-gabapentin binding was not reproduced by the synaptogenic EGF-domain of thrombospondin-4. Partial co-immunoprecipitation could be demonstrated between thrombospondin-4 and α2δ-1 when co-transfected, but there was no co-immunoprecipitation with thrombospondin-4-EGF domain. Furthermore, we could not detect any association between these two proteins on the cell-surface, indicating the demonstrated interaction occurs intracellularly. PMID:27076051

  12. Platelets do not express the oxidized or reduced forms of tissue factor

    PubMed Central

    Bouchard, Beth A.; Gissel, Matthew T.; Whelihan, Matthew F.; Mann, Kenneth G.; Butenas, Saulius

    2014-01-01

    Background Expression of tissue factor (TF) antigen and activity in platelets is controversial and dependent upon the laboratory and reagents used. Two forms of TF were described: an oxidized functional form and a reduced nonfunctional form that is converted to the active form through the formation of an allosteric disulfide. This study tests the hypothesis that the discrepancies regarding platelet TF expression are due to differential expression of the two forms. Methods Specific reagents that recognize both oxidized and reduced TF were used in flow cytometry of unactivated and activated platelets and western blotting of whole platelet lysates. TF-dependent activity measurements were used to confirm the results. Results Western blotting analyses of placental TF demonstrated that, in contrast to anti-TF#5, which is directed against the oxidized form of TF, a sheep anti-human TF polyclonal antibody recognizes both the reduced and oxidized forms. Flow cytometric analyses demonstrated that the sheep antibody did not react with the surface of unactivated platelets or platelets activated with thrombin receptor agonist peptide, PAR-1. This observation was confirmed using biotinylated active site-blocked factor (F)VIIa: no binding was observed. Likewise, neither form of TF was detected by western blotting of whole platelet lysates with sheep anti-hTF. Consistent with these observations, no FXa or FIXa generation by FVIIa was detected at the surface of these platelets. Similarly, no TF-related activity was observed in whole blood using thomboelastography. Conclusion and Significance Platelets from healthy donors do not express either oxidized (functional) or reduced (nonfunctional) forms of TF. PMID:24361609

  13. Arterial Shear Stress Reduces Eph-B4 Expression in Adult Human Veins

    PubMed Central

    Model, Lynn S.; Hall, Michael R.; Wong, Daniel J.; Muto, Akihito; Kondo, Yuka; Ziegler, Kenneth R.; Feigel, Amanda; Quint, Clay; Niklason, Laura; Dardik, Alan

    2014-01-01

    Vein graft adaptation to the arterial environment is characterized by loss of venous identity, with reduced Ephrin type-B receptor 4 (Eph-B4) expression but without increased Ephrin-B2 expression. We examined changes of vessel identity of human saphenous veins in a flow circuit in which shear stress could be precisely controlled. Medium circulated at arterial or venous magnitudes of laminar shear stress for 24 hours; histologic, protein, and RNA analyses of vein segments were performed. Vein endothelium remained viable and functional, with platelet endothelial cell adhesion molecule (PECAM)-expressing cells on the luminal surface. Venous Eph-B4 expression diminished (p = .002), Ephrin-B2 expression was not induced (p = .268), and expression of osteopontin (p = .002) was increased with exposure to arterial magnitudes of shear stress. Similar changes were not found in veins placed under venous flow or static conditions. These data show that human saphenous veins remain viable during ex vivo application of shear stress in a bioreactor, without loss of the venous endothelium. Arterial magnitudes of shear stress cause loss of venous identity without gain of arterial identity in human veins perfused ex vivo. Shear stress alone, without immunologic or hormonal influence, is capable of inducing changes in vessel identity and, specifically, loss of venous identity. PMID:25191151

  14. Effective Medium Theory for Drag Reducing Micro-patterned Surfaces in Turbulent Flows

    NASA Astrophysics Data System (ADS)

    Battiato, I.

    2013-12-01

    Inspired by the lotus effect, many studies in the last decade have focused on micro- and nano-patterned surfaces. They revealed that patterns at the micro-scale combined with high contact angles can significantly reduce skin drag. However, the mechanisms and parameters that control drag reduction, e.g. Reynolds number and pattern geometry, are still unclear. We propose an effective medium representation of the micro-features, that treats the latter as a porous medium, and provides a framework to model flow over patterned surfaces in both Cassie and Wenzel states. Our key result is a closed-form expression for the skin friction coefficient in terms of frictional Reynolds (or Karman) number in turbulent regime, the viscosity ratio between the fluid in and above the features, and their geometrical properties. We apply the proposed model to turbulent flows over superhydrophobic ridged surfaces. The model predictions agree with laboratory experiments for Reynolds numbers ranging from 3000 to 10000.

  15. Effective Medium Theory for Drag Reducing Micro-patterned Surfaces in Turbulent Flows

    NASA Astrophysics Data System (ADS)

    Battiato, Ilenia

    2013-11-01

    Inspired by the lotus effect, many studies in the last decade have focused on micro- and nano-patterned surfaces. They revealed that patterns at the micro-scale combined with high contact angles can significantly reduce skin drag. However, the mechanisms and parameters that control drag reduction, e.g. Reynolds number and pattern geometry, are still unclear. We propose an effective medium representation of the micro-features that treats the latter as a porous medium, and provides a framework to model flows over patterned surfaces in both Cassie and Wenzel states. Our key result is a closed-form expression for the skin friction coefficient in terms of frictional Reynolds (or Karman) number in turbulent regime. We apply the proposed model to turbulent flow over superhydrophobic ridged surfaces. The model predictions agree with laboratory experiments for Reynolds numbers ranging from 3000 to 10000.

  16. Imputing gene expression from optimally reduced probe sets

    PubMed Central

    Donner, Yoni; Feng, Ting; Benoist, Christophe; Koller, Daphne

    2012-01-01

    Measuring complete gene expression profiles for a large number of experiments is costly. We propose an approach in which a small subset of probes is selected based on a preliminary set of full expression profiles. In subsequent experiments, only the subset is measured, and the missing values are imputed. We develop several algorithms to simultaneously select probes and impute missing values, and demonstrate that these probe selection for imputation (PSI) algorithms can successfully reconstruct missing gene expression values in a wide variety of applications, as evaluated using multiple metrics of biological importance. We analyze the performance of PSI methods under varying conditions, provide guidelines for choosing the optimal method based on the experimental setting, and indicate how to estimate imputation accuracy. Finally, we apply our approach to a large-scale study of immune system variation. PMID:23064520

  17. Reduced expression of Slit2 in renal cell carcinoma.

    PubMed

    Ma, Wei-Jie; Zhou, Yu; Lu, Dan; Dong, Dong; Tian, Xiao-Jun; Wen, Jie-Xi; Zhang, Jun

    2014-01-01

    Slit2, initially identified as an important axon guidance molecule in the nervous system, was suggested to be involved in multiple cellular processes. Recently, Slit2 was reported to function as a potential tumor suppressor in diverse tumors. In this study, we systematically analyzed the expression level of Slit2 in renal cell carcinoma. Compared to paired adjacent non-malignant tissues, both Slit2 mRNA and protein expression were significantly down-regulated in renal cell carcinoma (RCC). Methylation-specific PCR showed that Slit2 promoter was methylated in two renal carcinoma cell lines. Pharmacologic demethylation dramatically induced Slit2 expression in cancer cell lines with weak expression of Slit2. Besides, bisulfite genomic sequencing confirmed that dense methylation existed in Slit2 promoter. Furthermore, in paired RCC samples, Slit2 methylation was observed in 8 out of 38 patients (21.1 %), which was well correlated with the down-regulation of Slit2 in RCC. Therefore, Slit2 may also be a potential tumor suppressor in RCC, which is down-regulated in RCC partially due to promoter methylation.

  18. Reduced Glucocorticoid Receptor Expression Predicts Bladder Tumor Recurrence and Progression

    PubMed Central

    Ishiguro, Hitoshi; Kawahara, Takashi; Zheng, Yichun; Netto, George J.; Miyamoto, Hiroshi

    2015-01-01

    Objectives To assess the levels of glucocorticoid receptor (GR) expression in bladder tumors because the status and its prognostic value remain largely unknown. Methods We immunohistochemically stained for GR in bladder tumor and matched non-neoplastic bladder tissue specimens. Results Overall, GR was positive in 129 (87%) of 149 urothelial tumors, which was significantly (P = .026) lower than in non-neoplastic urothelium (90 [96%] of 94). Forty-two (79%) of 53 low-grade tumors vs 45 (47%) of 96 high-grade carcinomas (P < .001) and 61 (73%) of 84 non–muscle-invasive (NMI) tumors vs 26 (40%) of 65 muscle-invasive (MI) carcinomas (P < .001) were moderately to strongly immunoreactive for GR. Kaplan-Meier and log-rank tests revealed that loss or weak positivity of GR significantly or marginally correlated with recurrence of NMI tumors (P = .025), progression of MI tumors (P = .082), and cancer-specific survival of MI tumors (P = .067). Multivariate analysis identified low GR expression as a strong predictor for recurrence of NMI tumors (P = .034). Conclusions GR expression was downregulated in bladder tumors compared with nonneoplastic bladder tumors and in high-grade/MI tumors compared with low-grade/NMI tumors. Decreased expression of GR, as an independent prognosticator, predicted recurrence of NMI tumors. These results support experimental evidence suggesting an inhibitory role of GR signals in bladder cancer outgrowth. PMID:25015855

  19. Apolipoprotein A-I expression suppresses COX-2 expression by reducing reactive oxygen species in hepatocytes.

    PubMed

    Mao, Jing; Liu, Wei; Wang, Yutong

    2014-11-21

    Abnormal lipid metabolism may contribute to the increase of reactive oxygen species (ROS) and inflammation in the pathogenesis of non-alcoholic steatohepatitis (NASH). Apolipoprotein A-I (apoA-I) accepts cellular cholesterol and phospholipids transported by ATP-binding cassette transporter A1 to generate nascent high density lipoprotein particles. Previous studies revealed that the overexpression of ABCA1 or apoA-I alleviated hepatic lipid levels by modifying lipid transport. Here, we examined the effect of apoA-I overexpression on ROS and genes involved in inflammation in both BEL-7402 hepatocytes and mice. Human apoA-I was overexpressed by transfection in BEL-7402 hepatocytes and by an adenoviral vector in C57BL/6J mice fed a methionine choline-deficient diet. The overexpression of apoA-I in both models resulted in decreased ROS and lipid peroxidation levels, as well as a reduced MAPK phosphorylation and decreased expression levels of c-Fos and COX-2. These results suggest that apoA-I overexpression can reduce steatosis by decreasing ROS levels and suppressing COX-2-induced inflammation in hepatocytes. MAPK and c-Fos are involved in this regulatory process.

  20. Erythropoietin reduces the expression of myostatin in mdx dystrophic mice.

    PubMed

    Feder, D; Rugollini, M; Santomauro, A; Oliveira, L P; Lioi, V P; Santos, R dos; Ferreira, L G; Nunes, M T; Carvalho, M H; Delgado, P O; Carvalho, A A S; Fonseca, F L A

    2014-11-01

    Erythropoietin (EPO) has been well characterized as a renal glycoprotein hormone regulating red blood cell production by inhibiting apoptosis of erythrocyte progenitors in hematopoietic tissues. EPO exerts regulatory effects in cardiac and skeletal muscles. Duchenne muscular dystrophy is a lethal degenerative disorder of skeletal and cardiac muscle. In this study, we tested the possible therapeutic beneficial effect of recombinant EPO (rhEPO) in dystrophic muscles in mdx mice. Total strength was measured using a force transducer coupled to a computer. Gene expression for myostatin, transforming growth factor-β1 (TGF-β1), and tumor necrosis factor-α (TNF-α) was determined by quantitative real time polymerase chain reaction. Myostatin expression was significantly decreased in quadriceps from mdx mice treated with rhEPO (rhEPO = 0.60 ± 0.11, control = 1.07 ± 0.11). On the other hand, rhEPO had no significant effect on the expression of TGF-β1 (rhEPO = 0.95 ± 0.14, control = 1.05 ± 0.16) and TNF-α (rhEPO = 0.73 ± 0.20, control = 1.01 ± 0.09). These results may help to clarify some of the direct actions of EPO on skeletal muscle. PMID:25296358

  1. MULTIPLE IMAGING TECHNIQUES DEMONSTRATE THE MANIPULATION OF SURFACES TO REDUCE BACTERIAL CONTAMINATION

    EPA Science Inventory

    Surface imaging techniques were combined to determine appropriate manipulation of technologically important surfaces for commercial applications. Stainless steel surfaces were engineered to reduce bacterial contamination, biofilm formation, and corrosion during product processing...

  2. Saccharomyces cerevisiae expressing bacteriophage endolysins reduce Lactobacillus contamination during fermentation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    One of the challenges facing the fuel ethanol industry is the management of bacterial contamination during fermentation. Lactobacillus species are the predominant contaminants that decrease the profitability of biofuel production by reducing ethanol yields and causing “stuck” fermentations, which i...

  3. Effective medium theory for drag-reducing micro-patterned surfaces in turbulent flows

    NASA Astrophysics Data System (ADS)

    Battiato, Ilenia

    2014-11-01

    Many studies in the last decade have revealed that patterns at the microscale can reduce skin drag. Yet, the mechanisms and parameters that control drag reduction, e.g. Reynolds number and pattern geometry, are still unclear. We propose an effective medium representation of the micro-features, that treats the latter as a porous medium, and provides a framework to model turbulent flow over patterned surfaces. Our key result is a closed-form expression for the skin friction coefficient in terms of frictional Reynolds (or Karman) number in turbulent regime, the viscosity ratio between the fluid in and above the features, and their geometrical properties. We apply the proposed model to turbulent flows over superhydrophobic ridged surfaces. The model predictions agree with laboratory experiments for Reynolds numbers ranging from 3000 to 10000.

  4. Glucocorticoids decrease astrocyte numbers by reducing glucocorticoid receptor expression in vitro and in vivo.

    PubMed

    Unemura, Kazuhiro; Kume, Toshiaki; Kondo, Minami; Maeda, Yuki; Izumi, Yasuhiko; Akaike, Akinori

    2012-01-01

    Glucocorticoids are stress hormones released from the adrenal cortex and their concentration is controlled by the hypothalamic-pituitary-adrenal axis. In this study, we investigated the effect of glucocorticoids on the number of astrocytes and glucocorticoid receptor (GR) expression in vitro and in vivo. Proliferation of cultured astrocytes was reduced following treatment with corticosterone and dexamethasone for 72 h. Corticosterone and dexamethasone also reduced GR expression in astrocytes. RU486, a GR antagonist, inhibited the reduction in both astrocyte proliferation and GR expression. Furthermore, GR knockdown by siRNA inhibited astrocyte proliferation. We also examined the effect of excessive glucocorticoid release on GR expression and the number of astrocytes in vivo by administering adrenocorticotropic hormone to rats for 14 days. GR expression was reduced in the prefrontal cortex and hippocampus and the number of astrocytes was reduced in the frontal cortex. Overall, our results suggest that glucocorticoids decrease the number of astrocytes by reducing GR expression.

  5. Reducing Motional Decoherence in Ion Traps with Surface Science Methods

    NASA Astrophysics Data System (ADS)

    Haeffner, Hartmut

    2014-03-01

    Many trapped ions experiments ask for low motional heating rates while trapping the ions close to trapping electrodes. However, in practice small ion-electrode distances lead to unexpected high heating rates. While the mechanisms for the heating is still unclear, it is now evident that surface contamination of the metallic electrodes is at least partially responsible for the elevated heating rates. I will discuss heating rate measurements in a microfabricated surface trap complemented with basic surface science studies. We monitor the elemental surface composition of the Cu-Al alloy trap with an Auger spectrometer. After bake-out, we find a strong Carbon and Oxygen contamination and heating rates of 200 quanta/s at 1 MHz trap frequency. After removing most of the Carbon and Oxygen with Ar-Ion sputtering, the heating rates drop to 4 quanta/s. Interestingly, we still measure the decreased heating rate even after the surface oxidized from the background gas throughout a 40-day waiting time in UHV.

  6. Reduced fouling of ultrafiltration membranes via surface fluorination

    SciTech Connect

    Sedath, R.H.; Yates, S.F.; Li, N.N.

    1993-03-01

    Surface fluorination can affect significantly the performance of an ultrafiltration membrane used to concentrate a food-related stream. Membranes fluorinated and tested as flat sheets exhibit higher initial fluxes, and do not foul as rapidly as untreated membranes. This improvement is linked to increased surface hydrophilicity, as shown in decreased contact angle with water. This increased hydrophilicity, in turn, is linked to the addition of fluorine and oxygen to the surface. The pilot plant study did-not show the difference in membrane flux and fouling observed in the flat sheet study. Instead, fluorinated and unfluorinated modules behaved similarly. Fouling by potato waste feed was severe and resulted in formation of an extensive gel layer within the module on the membrane surface. XPS, SEM and FTIR indicate that buildup of organic material occurred on both fluorinated and unfluorinated membranes, but SEM indicates that a fibrous mat of material was observed only on the nonfluorinated membrane. We conclude that in the pilot study, membrane fouling and gel formation were so extensive that the surface interaction effect was overwhelmed.

  7. Surface protein expression in group B streptococcal invasive isolates.

    PubMed

    Ferrieri, P; Flores, A E

    1997-01-01

    Results from characterization of 211 GBS isolates from early-onset disease indicated that serotypes Ia, III and V accounted for almost 80% of the isolates, and that alpha was the protein most often expressed. Each of the common polysaccharide types had a characteristic predominant protein expression pattern: alpha for Ia, R4 for type III and R1+R4 for type V isolates. Expression of alpha protein was always mutually exclusive of R proteins. The presence of more than one species of R by a given isolate was confirmed by IEP. In addition, PAGE/WB studies verified the multiple MW forms of R1, and the variation from strain to strain in the highest form of R4 that we had previously reported. Our data not only showed the great complexity of the GBS cell surface but also demonstrated the advantage of using both type polysaccharides and surface-localized proteins as markers for characterization of GBS strains.

  8. Expression of the RNase III enzyme DROSHA is reduced during progression of human cutaneous melanoma

    PubMed Central

    Jafarnejad, Seyed Mehdi; Sjoestroem, Cecilia; Martinka, Magdalena; Li, Gang

    2016-01-01

    Aberrant expression of miRNAs and their biogenesis factors has been frequently observed in different types of cancer. We recently reported that expression of DICER1 is reduced in metastatic melanoma. Nevertheless, so far very little is known about the expression pattern of other miRNA biogenesis factors in this type of malignancy. Here, we investigated the expression pattern of DROSHA in a large set of melanocytic lesions by tissue microarray and immunohistochemistry (n = 409). We found that nuclear expression of DROSHA is markedly reduced in the early stages of melanoma progression (P = 0.0001) and is inversely correlated with melanoma thickness (P = 0.0001), AJCC stages (P = 0.0001), and ulceration status (P = 0.002). We also confirmed the reduced expression of nuclear DROSHA by a second specific antibody raised against a different region of the DROSHA protein. In addition, we observed that the reduced nuclear expression of DROSHA during melanoma progression is accompanied by an increased cytoplasmic expression of this protein (P = 0.0001). Finally, we found that expression pattern of DROSHA varies from that of DICER1 and concomitant loss of expression of both DICER1 and DROSHA confers the worse outcome for melanoma patients. Our results demonstrate a reduced nuclear expression of DROSHA which further highlights a perturbed miRNA biogenesis pathway in melanoma. In addition, the aberrant subcellular localization of DROSHA indicates possible deregulation in the mechanisms responsible for its proper localization in the nucleus. PMID:23370771

  9. Downregulation of transferrin receptor surface expression by intracellular antibody

    SciTech Connect

    Peng Jilin; Wu Sha; Zhao Xiaoping; Wang Min; Li Wenhan; Shen Xin; Liu Jing; Lei Ping; Zhu Huifen; Shen Guanxin . E-mail: guanxin_shen@yahoo.com.cn

    2007-03-23

    To deplete cellular iron uptake, and consequently inhibit the proliferation of tumor cells, we attempt to block surface expression of transferrin receptor (TfR) by intracellular antibody technology. We constructed two expression plasmids (scFv-HAK and scFv-HA) coding for intracellular single-chain antibody against TfR with or without endoplasmic reticulum (ER) retention signal, respectively. Then they were transfected tumor cells MCF-7 by liposome. Applying RT-PCR, Western blotting, immunofluorescence microscopy and immunoelectron microscope experiments, we insure that scFv-HAK intrabody was successfully expressed and retained in ER contrasted to the secreted expression of scFv-HA. Flow cytometric analysis confirmed that the TfR surface expression was markedly decreased approximately 83.4 {+-} 2.5% in scFv-HAK transfected cells, while there was not significantly decrease in scFv-HA transfected cells. Further cell growth and apoptosis characteristics were evaluated by cell cycle analysis, nuclei staining and MTT assay. Results indicated that expression of scFv-HAK can dramatically induce cell cycle G1 phase arrest and apoptosis of tumor cells, and consequently significantly suppress proliferation of tumor cells compared with other control groups. For First time this study demonstrates the potential usage of anti-TfR scFv-intrabody as a growth inhibitor of TfR overexpressing tumors.

  10. Surface application of biochar to reduce chloropicrin emissions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Biochar is the carbon-enriched and porous material produced by heating organic material under conditions of limited or no oxygen. As biochar has a large surface area and strong sorption capacity, it can enhance the sequestration of organic contaminants such as pesticides in soil. Chloropicrin (CP) i...

  11. Surface modification of clutch plates to reduce disengaged drag torque

    NASA Astrophysics Data System (ADS)

    Aphale, Chinar R.

    2005-11-01

    Viscous drag torque in disengaged clutches is a significant source of power loss in modern transportation. The main way to reduce this drag torque is to introduce air between the plates when disengaged without reducing the transmission fluid flow eventually needed for reengagement. Six different groove patterns are tested experimentally to determine which have the lowest drag characteristics. Our computations using Fluent showed that the contact angle made by oil with the stationary plate is critical in determining aeration initiation. Experiments coating the stationary plate with an oleophobic substance like Teflon, confirmed these simulations. We will show torque comparisons and visualization through a quartz disk acting as one of the clutch plates.

  12. Reducing dynamin 2 expression rescues X-linked centronuclear myopathy

    PubMed Central

    Cowling, Belinda S.; Chevremont, Thierry; Prokic, Ivana; Kretz, Christine; Ferry, Arnaud; Coirault, Catherine; Koutsopoulos, Olga; Laugel, Vincent; Romero, Norma B.; Laporte, Jocelyn

    2014-01-01

    Centronuclear myopathies (CNM) are congenital disorders associated with muscle weakness and abnormally located nuclei in skeletal muscle. An autosomal dominant form of CNM results from mutations in the gene encoding dynamin 2 (DNM2), and loss-of-function mutations in the gene encoding myotubularin (MTM1) result in X-linked CNM (XLCNM, also called myotubular myopathy), which promotes severe neonatal hypotonia and early death. Currently, no effective treatments exist for XLCNM. Here, we found increased DNM2 levels in XLCNM patients and a mouse model of XLCNM (Mtm1–/y). Generation of Mtm1–/y mice that were heterozygous for Dnm2 revealed that reduction of DNM2 in XLCNM mice restored life span, whole-body strength, and diaphragm function and increased muscle strength. Additionally, classic CNM-associated histological features, including fiber atrophy and nuclei mispositioning, were absent or reduced. Ultrastructural analysis revealed improvement of sarcomere organization and triad structures. Skeletal muscle–specific decrease of Dnm2 during embryogenesis or in young mice after disease onset revealed that the rescue associated with downregulation of Dnm2 is cell autonomous and is able to stop and potentially revert XLCNM progression. These data indicate that MTM1 and DNM2 regulate muscle organization and force through a common pathway. Furthermore, despite DNM2 being a key mechanoenzyme, its reduction is beneficial for XLCNM and represents a potential therapeutic approach for patients. PMID:24569376

  13. Improving MRI surface coil decoupling to reduce B1 distortion

    NASA Astrophysics Data System (ADS)

    Larson, Christian

    As clinical MRI systems continue to advance, larger focus is being given to image uniformity. Good image uniformity begins with generating uniform magnetic fields, which are easily distorted by induced currents on receive-only surface coils. It has become an industry standard to combat these induced currents by placing RF blocking networks on surface coils. This paper explores the effect of blocking network impedance of phased array surface coils on B1 distortion. It has been found and verified, that traditional approaches for blocking network design in complex phased arrays can leave undesirable B1 distortions at 3 Tesla. The traditional approach of LC tank blocking is explored, but shifts from the idea that higher impedance equals better B1 distortion at 3T. The result is a new design principle for a tank with a finite inductive reactance at the Larmor Frequency. The solution is demonstrated via simulation using a simple, single, large tuning loop. The same loop, along with a smaller loop, is used to derive the new design principle, which is then applied to a complex phased array structure.

  14. Elevated expression of ABCB5 in ocular surface squamous neoplasia

    PubMed Central

    Jongkhajornpong, Passara; Nakamura, Takahiro; Sotozono, Chie; Nagata, Maho; Inatomi, Tsutomu; Kinoshita, Shigeru

    2016-01-01

    ATP-binding cassette subfamily B member 5 (ABCB5) is a new member of the ATP-binding cassette superfamily and has been reported as a novel marker for limbal stem cell (LSC), which is essential for corneal homeostasis. ABCB5 expression has also been discovered in the subpopulation of several cancer cells containing the cancer stem cell (CSC). However, the pathogenetic relationship between LSC and CSC and ABCB5 in the ocular surface squamous neoplasm (OSSN) is still entirely unknown. To improve understanding of the role of ABCB5 in OSSN, we performed immunohistochemistry for ABCB5 in nine OSSN case series. While expression of ABCB5 is restricted to the basal epithelial cell layer in the normal limbus, elevated expressions of ABCB5 were clearly observed in all OSSN, and there was some breadth in the range of intensity of ABCB5 expression. Interestingly, the elevated expression patterns of ABCB5 in OSSN could be classified in three categories: perivascular, marginal and diffuse patterns. Our findings demonstrated for the first time that the expression of ABCB5 was upregulated in OSSN and that elevated expression of ABCB5 may be involved in the pathogenesis of OSSN. PMID:26843453

  15. Malaria inhibits surface expression of complement receptor-1 in monocyte/macrophages causing decreased immunecomplex internalization

    PubMed Central

    Fernandez-Arias, Cristina; Lopez, Jean Pierre; Hernandez-Perez, Jean Nikolae; Bautista-Ojeda, Maria Dolores; Branch, OraLee; Rodriguez, Ana

    2013-01-01

    Complement receptor 1 (CR1) expressed on the surface of phagocytic cells binds complement-bound IC playing an important role in the clearance of circulating immunecomplexes (IC). This receptor is critical to prevent accumulation of IC, which can contribute to inflammatory pathology. Accumulation of circulating IC is frequently observed during malaria, although the factors contributing to this accumulation are not clearly understood. We have observed that the surface expression of CR1 on monocyte/macrophages and B cells is strongly reduced in mice infected with Plasmodium yoelii, a rodent malaria model. Monocyte/macrophages from these infected mice present a specific inhibition of complement-mediated internalization of IC caused by the decreased CR1 expression. Accordingly, mice show accumulation of circulating IC and deposition of IC in the kidneys that inversely correlates with the decrease in CR1 surface expression. Our results indicate that malaria induces a significant decrease on surface CR1 expression in the monocyte/macrophage population that results in deficient internalization of IC by monocyte/macrophages. To determine whether this phenomenon is found in human malaria patients, we have analyzed 92 patients infected with either P. falciparum (22) or P. vivax (70), the most prevalent human malaria parasites. The levels of surface CR1 on peripheral monocyte/macrophages and B cells of these patients show a significant decrease compared to uninfected control individuals in the same area. We propose that this decrease in CR1 plays an essential role in impaired IC clearance during malaria. PMID:23440418

  16. On the Use of Surface Porosity to Reduce Unsteady Lift

    NASA Technical Reports Server (NTRS)

    Tinetti, Ana F.; Kelly, Jeffrey J.; Bauer, Steven X. S.; Thomas, Russell H.

    2001-01-01

    An innovative application of existing technology is proposed for attenuating the effects of transient phenomena, such as rotor-stator and rotor-strut interactions, linked to noise and fatigue failure in turbomachinery environments. A computational study was designed to assess the potential of passive porosity technology as a mechanism for alleviating interaction effects by reducing the unsteady lift developed on a stator airfoil subject to wake impingement. The study involved a typical high bypass fan Stator airfoil (solid baseline and several porous configurations), immersed in a free field and exposed to the effects of a transversely moving wake. It was found that, for the airfoil under consideration, the magnitude of the unsteady lift could be reduced more than 18% without incurring significant performance losses.

  17. Venus surface investigation based on VIRTIS measurements on Venus Express

    NASA Astrophysics Data System (ADS)

    Arnold, Gabriele; Haus, Rainer; Döhler, Wolfgang; Kappel, David; Piccioni, Giuseppe; Drossart, Pierre

    The dense atmosphere of Venus prevented systematic studies of its surface at optical wavelengths in the past. The discovery of near infrared nightside atmospheric windows has opened a new challenge for detailed surface studies. The Visible and Infrared Thermal Imaging Spectrometer (VIRTIS) on Venus Express is the first experiment collecting continuously nightside surface emission data from the planet. The observed high variability of measured signatures is mainly due to spatial variations of cloud optical depth and surface elevation. The investigation of surface properties requires a convergent approach of radiative transfer simulations and VIR- TIS data analyses. Therefore, a selection of orbits with well calibrated data over the northern hemisphere was performed for footprints that cover a maximum range of surface elevation variations. Radiative transfer calculations demonstrate that the conservative character of cloud multiple scattering below 2 µm and a strong dependence of radiance ratios on surface elevation in this spectral region allow the mapping of surface topography and a retrieval of the surface temperature. To the first order, the surface temperature is a function of ground elevation. Small deviations from this first order dependence have been identified that are possibly due to different surface materials. 1 Institut f¨r Planetologie, Westf¨lische Wilhelms-Universit¨t M¨nster, Wilhelm-Klemm-Str.10, u a a u 48129 M¨nster, Germany u 2 German PlaceNameAerospace PlaceTypeCenter (DLR), Remote Sensing Technology Institute, Dpt. Marine Remote Sensing, Rutherfordstrasse 2, 12489 CityplaceBerlin, countryregionGermany 3 German PlaceNameAerospace PlaceTypeCenter (DLR), Institute for Planetary Research, Rutherfordstrasse 2, 12489 CityplaceBerlin, country-regionGermany 4 LESIA, Observatoire de Paris, CNRS, UPMC, Université Paris-Diderot, 5 place Jules Janssen, e 92195 Meudon, France 5 INAF-IASF (Instituto di Astrofisica Spaziale e Fisica Cosmica), via

  18. Surface Tension Induced Instabilities in Reduced Gravity: the Benard Problem

    NASA Technical Reports Server (NTRS)

    Koschmieder, E.; Chai, A. T.

    1985-01-01

    A Benard convection experiment has been set up, and the onset of convection in shallow layers of silicone oil two millimeters or less deep has been studied. The onset has been observed visually or has been determined by the break in the heat transfer curve which accompanies the onset of convection. The outcome of these experiments has been very surprising, from the point of view of theoretical expectations. The onset of convection at temperature differences far below the critical value for fluid depths smaller than 2mm was observed. The discrepancy between experiments and theory increases with decreasing fluid depth. According to theoretical considerations, the effects of surface tension become more important as the fluid depth is decreased. Actually, one observes that the onset of convection tales place in two stages. There is first an apparently surface tension driven instability, occuring at subcritical temperature differences according to conventional theory. If then the temperature difference is increased, a second instability occurs which transform the first pattern into conventional strong hexagonal Benard cells. The second instability is in agreement with the critical temperature gradients predicted by Nield.

  19. Real-time absorption reduced surface fluorescence imaging

    PubMed Central

    Yang, Bin; Tunnell, James W.

    2014-01-01

    Abstract. We introduce a technique that limits absorption effects in fluorescence imaging and does not require extensive imaging processing, thus allowing for video rate imaging. The absorption minimization is achieved using spatial frequency domain imaging at a single high spatial frequency with standard three-phase demodulation. At a spatial frequency f=0.5  mm−1, we demonstrated in both in-vitro phantoms and ex-vivo tissue that the absorption can be significantly reduced. In the real-time implementation, we achieved a video rate of 19  frames/s. This technique has potential in cancer visualization and tumor margin detection. PMID:25250826

  20. Real-time absorption reduced surface fluorescence imaging.

    PubMed

    Yang, Bin; Tunnell, James W

    2014-09-01

    We introduce a technique that limits absorption effects in fluorescence imaging and does not require extensive imaging processing, thus allowing for video rate imaging. The absorption minimization is achieved using spatial frequency domain imaging at a single high spatial frequency with standard three-phase demodulation. At a spatial frequency f ¼ 0.5 mm−1, we demonstrated in both in-vitro phantoms and ex-vivo tissue that the absorption can be significantly reduced. In the real-time implementation, we achieved a video rate of 19 frames∕s. This technique has potential in cancer visualization and tumor margin detection. PMID:25250826

  1. Surface Polysaccharide Mutants Reveal that Absence of O Antigen Reduces Biofilm Formation of Actinobacillus pleuropneumoniae

    PubMed Central

    Hathroubi, S.; Hancock, M. A.; Langford, P. R.; Tremblay, Y. D. N.; Labrie, J.

    2015-01-01

    Actinobacillus pleuropneumoniae is a Gram-negative bacterium belonging to the Pasteurellaceae family and the causative agent of porcine pleuropneumonia, a highly contagious lung disease causing important economic losses. Surface polysaccharides, including lipopolysaccharides (LPS) and capsular polysaccharides (CPS), are implicated in the adhesion and virulence of A. pleuropneumoniae, but their role in biofilm formation is still unclear. In this study, we investigated the requirement for these surface polysaccharides in biofilm formation by A. pleuropneumoniae serotype 1. Well-characterized mutants were used: an O-antigen LPS mutant, a truncated core LPS mutant with an intact O antigen, a capsule mutant, and a poly-N-acetylglucosamine (PGA) mutant. We compared the amount of biofilm produced by the parental strain and the isogenic mutants using static and dynamic systems. Compared to the findings for the biofilm of the parental or other strains, the biofilm of the O antigen and the PGA mutants was dramatically reduced, and it had less cell-associated PGA. Real-time PCR analyses revealed a significant reduction in the level of pgaA, cpxR, and cpxA mRNA in the biofilm cells of the O-antigen mutant compared to that in the biofilm cells of the parental strain. Specific binding between PGA and LPS was consistently detected by surface plasmon resonance, but the lack of O antigen did not abolish these interactions. In conclusion, the absence of the O antigen reduces the ability of A. pleuropneumoniae to form a biofilm, and this is associated with the reduced expression and production of PGA. PMID:26483403

  2. Surface Polysaccharide Mutants Reveal that Absence of O Antigen Reduces Biofilm Formation of Actinobacillus pleuropneumoniae.

    PubMed

    Hathroubi, S; Hancock, M A; Bossé, J T; Langford, P R; Tremblay, Y D N; Labrie, J; Jacques, M

    2016-01-01

    Actinobacillus pleuropneumoniae is a Gram-negative bacterium belonging to the Pasteurellaceae family and the causative agent of porcine pleuropneumonia, a highly contagious lung disease causing important economic losses. Surface polysaccharides, including lipopolysaccharides (LPS) and capsular polysaccharides (CPS), are implicated in the adhesion and virulence of A. pleuropneumoniae, but their role in biofilm formation is still unclear. In this study, we investigated the requirement for these surface polysaccharides in biofilm formation by A. pleuropneumoniae serotype 1. Well-characterized mutants were used: an O-antigen LPS mutant, a truncated core LPS mutant with an intact O antigen, a capsule mutant, and a poly-N-acetylglucosamine (PGA) mutant. We compared the amount of biofilm produced by the parental strain and the isogenic mutants using static and dynamic systems. Compared to the findings for the biofilm of the parental or other strains, the biofilm of the O antigen and the PGA mutants was dramatically reduced, and it had less cell-associated PGA. Real-time PCR analyses revealed a significant reduction in the level of pgaA, cpxR, and cpxA mRNA in the biofilm cells of the O-antigen mutant compared to that in the biofilm cells of the parental strain. Specific binding between PGA and LPS was consistently detected by surface plasmon resonance, but the lack of O antigen did not abolish these interactions. In conclusion, the absence of the O antigen reduces the ability of A. pleuropneumoniae to form a biofilm, and this is associated with the reduced expression and production of PGA. PMID:26483403

  3. Analysis of the cell surface expression of cytokine receptors using the surface protein biotinylation method.

    PubMed

    Pavel, Mahmud Arif; Lam, Clarissa; Kashyap, Parul; Salehi-Najafabadi, Zahra; Singh, Gurpreet; Yu, Yong

    2014-01-01

    Cytokines are pleiotropic, low-molecular-weight proteins that regulate the immune responses to infection and inflammation. They stimulate the immune responses by binding to cytokine receptors on the cell plasma membrane. Thus, knowledge of the expression level of particular cytokine receptors on cell surface is crucial for understanding the cytokine function and regulation. One of the techniques to explore the membrane embedded cytokine receptors is cell surface biotinylation. Biotinylated surface proteins can be rapidly purified through the strong interaction between biotin and streptavidin. Here, we describe the procedure for surface biotinylation and purification of biotinylated cytokine receptors for further downstream analysis. PMID:24908305

  4. Analysis of the cell surface expression of cytokine receptors using the surface protein biotinylation method.

    PubMed

    Pavel, Mahmud Arif; Lam, Clarissa; Kashyap, Parul; Salehi-Najafabadi, Zahra; Singh, Gurpreet; Yu, Yong

    2014-01-01

    Cytokines are pleiotropic, low-molecular-weight proteins that regulate the immune responses to infection and inflammation. They stimulate the immune responses by binding to cytokine receptors on the cell plasma membrane. Thus, knowledge of the expression level of particular cytokine receptors on cell surface is crucial for understanding the cytokine function and regulation. One of the techniques to explore the membrane embedded cytokine receptors is cell surface biotinylation. Biotinylated surface proteins can be rapidly purified through the strong interaction between biotin and streptavidin. Here, we describe the procedure for surface biotinylation and purification of biotinylated cytokine receptors for further downstream analysis.

  5. Face in profile view reduces perceived facial expression intensity: an eye-tracking study.

    PubMed

    Guo, Kun; Shaw, Heather

    2015-02-01

    Recent studies measuring the facial expressions of emotion have focused primarily on the perception of frontal face images. As we frequently encounter expressive faces from different viewing angles, having a mechanism which allows invariant expression perception would be advantageous to our social interactions. Although a couple of studies have indicated comparable expression categorization accuracy across viewpoints, it is unknown how perceived expression intensity and associated gaze behaviour change across viewing angles. Differences could arise because diagnostic cues from local facial features for decoding expressions could vary with viewpoints. Here we manipulated orientation of faces (frontal, mid-profile, and profile view) displaying six common facial expressions of emotion, and measured participants' expression categorization accuracy, perceived expression intensity and associated gaze patterns. In comparison with frontal faces, profile faces slightly reduced identification rates for disgust and sad expressions, but significantly decreased perceived intensity for all tested expressions. Although quantitatively viewpoint had expression-specific influence on the proportion of fixations directed at local facial features, the qualitative gaze distribution within facial features (e.g., the eyes tended to attract the highest proportion of fixations, followed by the nose and then the mouth region) was independent of viewpoint and expression type. Our results suggest that the viewpoint-invariant facial expression processing is categorical perception, which could be linked to a viewpoint-invariant holistic gaze strategy for extracting expressive facial cues. PMID:25531122

  6. Detection of CXCR2 cytokine receptor surface expression using immunofluorescence.

    PubMed

    Lam, Clarissa; Pavel, Mahmud Arif; Kashyap, Parul; Salehi-Najafabadi, Zahra; Valentino, Victoria; Yu, Yong

    2014-01-01

    The interleukin-8 (IL-8, CXCL8) chemokine, also known as the neutrophil chemotactic factor, is a cytokine that plays a key role in inflammatory response, cell proliferation, migration, and survival. IL-8 expression is increased not only in inflammatory disorders, but also in many types of cancer, including prostate cancer. IL-8 acts as a ligand for the C-X-C chemokine receptor 2 (CXCR2) protein present on the cell plasma membrane. Binding of the IL-8 ligand to the CXCR2 receptor results in an intracellular signaling pathway mediated by GTP binding proteins coupled to the receptor itself. Knowledge of the CXCR2 expression levels facilitates the understanding of the role and function of IL-8. In this chapter, we describe a protocol that uses the immunofluorescence method and confocal microscopy to analyze the CXCR2 surface expression in human prostate cancer cells. However, this protocol is easily adaptable to analyze the surface expression of other cytokine receptors in different cell types. PMID:24908306

  7. Detection of CXCR2 cytokine receptor surface expression using immunofluorescence.

    PubMed

    Lam, Clarissa; Pavel, Mahmud Arif; Kashyap, Parul; Salehi-Najafabadi, Zahra; Valentino, Victoria; Yu, Yong

    2014-01-01

    The interleukin-8 (IL-8, CXCL8) chemokine, also known as the neutrophil chemotactic factor, is a cytokine that plays a key role in inflammatory response, cell proliferation, migration, and survival. IL-8 expression is increased not only in inflammatory disorders, but also in many types of cancer, including prostate cancer. IL-8 acts as a ligand for the C-X-C chemokine receptor 2 (CXCR2) protein present on the cell plasma membrane. Binding of the IL-8 ligand to the CXCR2 receptor results in an intracellular signaling pathway mediated by GTP binding proteins coupled to the receptor itself. Knowledge of the CXCR2 expression levels facilitates the understanding of the role and function of IL-8. In this chapter, we describe a protocol that uses the immunofluorescence method and confocal microscopy to analyze the CXCR2 surface expression in human prostate cancer cells. However, this protocol is easily adaptable to analyze the surface expression of other cytokine receptors in different cell types.

  8. Bromelain treatment reduces CD25 expression on activated CD4+ T cells in vitro.

    PubMed

    Secor, Eric R; Singh, Anurag; Guernsey, Linda A; McNamara, Jeff T; Zhan, Lijun; Maulik, Nilanjana; Thrall, Roger S

    2009-03-01

    Bromelain (Br), an extract from pineapple stem with cysteine protease activity, exerts anti-inflammatory effects in a number of inflammatory models. We have previously shown that Br treatment decreased activated CD4(+) T cells and has a therapeutic role in an ovalbumin-induced murine model of allergic airway disease. The current study was designed to determine the effect of Br on CD4(+) T cell activation, specifically the expression of CD25 in vitro. CD25 is up regulated upon T cell activation, found as a soluble fraction (sCD25) and is a therapeutic target in inflammation, autoimmunity and allergy. Br treatment of anti-CD3 stimulated CD4(+) T cells reduced CD25 expression in a dose and time dependent manner. This reduction of CD25 was dependent on the proteolytic action of Br as the addition of E64 (a cysteine protease inhibitor) abrogated this response. The concentration of sCD25 was increased in supernatants of Br treated activated CD4(+) T cells as compared to control cells, suggesting that Br proteolytically cleaved cell-surface CD25. This novel mechanism of action identifies how Br may exert its therapeutic benefits in inflammatory conditions.

  9. Insecticides reduce survival and the expression of traits associated with carnivory of carnivorous plants.

    PubMed

    Jennings, David E; Congelosi, Alexandra M; Rohr, Jason R

    2012-03-01

    While agrochemical pollution is thought to be an important conservation threat to carnivorous plants, the effects of insecticides on these taxa have not been quantified previously. Using a combination of lab- and field-based experiments, we tested the effects of commercial and technical grades of three widely used insecticides (carbaryl, lambda-cyhalothrin, and malathion) on survival and the expression of traits associated with carnivory of pink sundews (Drosera capillaris) and Venus flytraps (Dionaea muscipula). Commercial grades were generally more harmful than technical grades under lab and field conditions, but all three insecticides were capable of reducing both survival and the expression of traits associated with carnivory within recommended application rates. However, pink sundews appeared to be more susceptible to insecticides than Venus flytraps, perhaps because of larger numbers of digestive glands on the leaf surfaces. We make several recommendations for future research directions, such as examining the long-term effects of insecticides on carnivorous plant populations, for example in terms of growth rates and fitness. Additionally, future research should include representative species from a wider-range of carnivorous plant growth forms, and explore the mechanism by which insecticides are harming the plants. Given the effects we observed in the present study, we suggest that the use of insecticides should be carefully managed in areas containing vulnerable carnivorous plant species.

  10. Observing the surface of Venus with VIRTIS on Venus Express

    NASA Astrophysics Data System (ADS)

    Helbert, J.; Mariangeli, L.; Baines, K. H.; Garcia, R.; Erard, S.; Piccioni, G.; Drossart, P.; Müller, N.; Hashimoto, G.; Kostama, P.; Virtis Team

    The M channel of VIRTIS will allow the first systematic mapping of the surface and of the near-surface atmosphere of Venus in the near infrared wavelengths range This will be done using the atmospheric windows located at 1 10 1 18 mu m and if possible additionally using the window at 1 02 mu m Wattson and Rothman 1986 Kamp et al 1988 Moroz 2002 The latter is unfortunately right at the low end of the wavelength range of the IR channel and at the upper end of the VIS channel Therefore the usability of this window is unclear until first data from Venus are obtained The atmospheric windows will allow measuring the thermal emission of the surface as was demonstrated by Galileo NIMS Carlson et al 1991 and Cassini VIMS Baines et al 2000 While the atmospheric windows show no or little CO 2 absorption the radiance from the surface is still affected by scattering in the clouds This effect varies based on the optical thickness of the clouds We have developed a quicklook processing procedure which allows deriving surface emissivity variations from nighttime observations correcting for the atmospheric effects We will present the first version of this algorithm During the mission the algorithm will be refined based on the data returned from the different instruments on Venus Express The final goal is to derive maps of the absolute surface emissivity Based on these data two main science tasks for the surface analysis will be pursued Classification of the surface composition and study the interaction between low atmosphere and

  11. Reduced expression of Autographa californica nucleopolyhedrovirus ORF34, an essential gene, enhances heterologous gene expression

    SciTech Connect

    Salem, Tamer Z.; Zhang, Fengrui; Thiem, Suzanne M.

    2013-01-20

    Autographa californica multiple nucleopolyhedrovirus ORF34 is part of a transcriptional unit that includes ORF32, encoding a viral fibroblast growth factor (FGF) and ORF33. We identified ORF34 as a candidate for deletion to improve protein expression in the baculovirus expression system based on enhanced reporter gene expression in an RNAi screen of virus genes. However, ORF34 was shown to be an essential gene. To explore ORF34 function, deletion (KO34) and rescue bacmids were constructed and characterized. Infection did not spread from primary KO34 transfected cells and supernatants from KO34 transfected cells could not infect fresh Sf21 cells whereas the supernatant from the rescue bacmids transfection could recover the infection. In addition, budded viruses were not observed in KO34 transfected cells by electron microscopy, nor were viral proteins detected from the transfection supernatants by western blots. These demonstrate that ORF34 is an essential gene with a possible role in infectious virus production.

  12. GABAA Receptor α1 Subunit Mutation A322D Associated with Autosomal Dominant Juvenile Myoclonic Epilepsy Reduces the Expression and Alters the Composition of Wild Type GABAA Receptors*

    PubMed Central

    Ding, Li; Feng, Hua-Jun; Macdonald, Robert L.; Botzolakis, Emanuel J.; Hu, Ningning; Gallagher, Martin J.

    2010-01-01

    A GABAA receptor (GABAAR) α1 subunit mutation, A322D (AD), causes an autosomal dominant form of juvenile myoclonic epilepsy (ADJME). Previous studies demonstrated that the mutation caused α1(AD) subunit misfolding and rapid degradation, reducing its total and surface expression substantially. Here, we determined the effects of the residual α1(AD) subunit expression on wild type GABAAR expression to determine whether the AD mutation conferred a dominant negative effect. We found that although the α1(AD) subunit did not substitute for wild type α1 subunits on the cell surface, it reduced the surface expression of α1β2γ2 and α3β2γ2 receptors by associating with the wild type subunits within the endoplasmic reticulum and preventing them from trafficking to the cell surface. The α1(AD) subunit reduced surface expression of α3β2γ2 receptors by a greater amount than α1β2γ2 receptors, thus altering cell surface GABAAR composition. When transfected into cultured cortical neurons, the α1(AD) subunit altered the time course of miniature inhibitory postsynaptic current kinetics and reduced miniature inhibitory postsynaptic current amplitudes. These findings demonstrated that, in addition to causing a heterozygous loss of function of α1(AD) subunits, this epilepsy mutation also elicited a modest dominant negative effect that likely shapes the epilepsy phenotype. PMID:20551311

  13. Expression of Plasmodium falciparum surface antigens in Escherichia coli.

    PubMed Central

    Ardeshir, F; Flint, J E; Reese, R T

    1985-01-01

    The asexual blood stages of the human malarial parasite Plasmodium falciparum produce many antigens, only some of which are important for protective immunity. Most of the putative protective antigens are believed to be expressed in schizonts and merozoites, the late stages of the asexual cycle. With the aim of cloning and characterizing genes for important parasite antigens, we used late-stage P. falciparum mRNA to construct a library of cDNA sequences inserted in the Escherichia coli expression vector pUC8. Nine thousand clones from the expression library were immunologically screened in situ with serum from Aotus monkeys immune to P. falciparum, and 95 clones expressing parasite antigens were identified. Mice were immunized with lysates from 49 of the bacterial clones that reacted with Aotus sera, and the mouse sera were tested for their reactivity with parasite antigens by indirect immunofluorescence, immunoprecipitation, and immunoblotting assays. Several different P. falciparum antigens were identified by these assays. Indirect immunofluorescence studies of extracellular merozoites showed that three of these antigens appear to be located on the merozoite surface. Thus, we have identified cDNA clones to three different P. falciparum antigens that may be important in protective immunity. Images PMID:3887406

  14. Surface-based mapping of gene expression and probabilistic expression maps in the mouse cortex.

    PubMed

    Ng, Lydia; Lau, Chris; Sunkin, Susan M; Bernard, Amy; Chakravarty, M Mallar; Lein, Ed S; Jones, Allan R; Hawrylycz, Michael

    2010-02-01

    The Allen Brain Atlas (ABA, www.brain-map.org) is a genome wide, spatially registered collection of cellular resolution in situ hybridization gene expression image data of the C57Bl/6J mouse brain. Derived from the ABA, the Anatomic Gene Expression Atlas (AGEA, http://mouse.brain-map.org/agea) has demonstrated both laminar and areal spatial gene expression correlations in the mouse cortex. While the mouse cortex is lissencephalic, its curvature and substantial bending in boundary areas renders it difficult to visualize and analyze laminar versus areal effects in a rectilinear coordinate framework. In context of human and non-human primate cortex, surface-based representation has proven useful for understanding relative locations of laminar, columnar, and areal features. In this paper, we describe a methodology for constructing surface-based flatmaps of the mouse cortex that enables mapping of gene expression data from individual genes in the ABA, or probabilistic expression maps from the AGEA, to identify and visualize genetic relationships between layers and areas. PMID:19818854

  15. Assessing and reducing sources of gene expression variability in Staphylococcus epidermidis biofilms.

    PubMed

    Sousa, Cármen; França, Angela; Cerca, Nuno

    2014-12-01

    Gene expression quantification can be a useful tool in studying the properties of bacterial biofilms. Unfortunately, techniques such as RNA extraction, cDNA synthesis, and quantitative PCR (qPCR) can introduce variability into mRNA transcript measurements, obscuring biologically relevant results. Here we sought to identify the steps that impair accurate gene expression quantification from Staphylococcus epidermidis biofilm samples. We devised an experimental setup that could be used to determine the contribution of each experimental step to the variability of mRNA transcript measurement. Among factors tested, biofilm growth contributed the most bias to gene expression quantification. Additional experiments demonstrated that pooling biofilms together reduced this variability, resulting in more accurate gene expression analysis results. We therefore recommend pooling in order to reduce the variability associated with gene expression quantification from biofilm samples. PMID:25495729

  16. Expression and surface display of Cellulomonas endoglucanase in the ethanologenic bacterium Zymobacter palmae.

    PubMed

    Kojima, Motoki; Akahoshi, Tomohiro; Okamoto, Kenji; Yanase, Hideshi

    2012-11-01

    In order to reduce the cost of bioethanol production from lignocellulosic biomass, we developed a tool for cell surface display of cellulolytic enzymes on the ethanologenic bacterium Zymobacter palmae. Z. palmae is a novel ethanol-fermenting bacterium capable of utilizing a broad range of sugar substrates, but not cellulose. Therefore, to express and display heterologous cellulolytic enzymes on the Z. palmae cell surface, we utilized the cell-surface display motif of the Pseudomonas ice nucleation protein Ina. The gene encoding Ina from Pseudomonas syringae IFO3310 was cloned, and its product was comprised of three functional domains: an N-terminal domain, a central domain with repeated amino acid residues, and a C-terminal domain. The N-terminal domain of Ina was shown to function as the anchoring motif for a green fluorescence protein fusion protein in Escherichia coli. To express a heterologous cellulolytic enzyme extracellularly in Z. palmae, we fused the N-terminal coding sequence of Ina to the coding sequence of an N-terminal-truncated Cellulomonas endoglucanase. Z. palmae cells carrying the fusion endoglucanase gene were shown to degrade carboxymethyl cellulose. Although a portion of the expressed fusion endoglucanase was released from Z. palmae cells into the culture broth, we confirmed the display of the protein on the cell surface by immunofluorescence microscopy. The results indicate that the N-terminal anchoring motif of Ina from P. syringae enabled the translocation and display of the heterologous cellulase on the cell surface of Z. palmae.

  17. Strongly reduced Si surface recombination by charge injection during etching in diluted HF/HNO3.

    PubMed

    Greil, Stefanie M; Schöpke, Andreas; Rappich, Jörg

    2012-08-27

    Herein, we investigate the behaviour of the surface recombination of light-induced charge carriers during the etching of Si in alkaline (KOH) and acidic etching solutions of HF/HNO(3)/CH(3)COOH (HNA) or HF/HNO(3)/H(3)PO(4) (HNP) at different concentration ratios of HF and HNO(3) by means of photoluminescence (PL) measurements. The surface recombination velocity is strongly reduced during the first stages of etching in HF/HNO(3)-containing solutions pointing to a interface well passivated by the etching process, where a positive surface charge is induced by hole injection from NO-related surface species into the Si near-surface region (back surface field effect). This injected charge leads to a change in band bending by about 150 mV that repulses the light-induced charge carriers from the surface and therefore enhances the photoluminescence intensity, since non-radiative surface recombination is reduced.

  18. Systemic alteration of cell-surface and secreted glycoprotein expression in malignant breast cancer cell lines.

    PubMed

    Timpe, Leslie C; Yen, Roger; Haste, Nicole V; Litsakos-Cheung, Christina; Yen, Ten-Yang; Macher, Bruce A

    2013-11-01

    Breast cancer cell lines express fewer transmembrane and secreted glycoproteins than nonmalignant ones. The objective of these experiments was to characterize the changes in the expression of several hundred glycoproteins quantitatively. Secreted and cell-surface glycoproteins were isolated using a glycoprotein capture protocol and then identified by tandem mass spectrometry. Glycoproteins expressed by a group of cell lines originating from malignant tumors of the breast were compared with those expressed by a nonmalignant set. The average number of spectral counts (proportional to relative protein abundance) and the total number of glycopeptides in the malignant samples were reduced to about two-thirds of the level in the nonmalignant samples. Most glycoproteins were expressed at a different level in the malignant samples, with nearly as many increasing as decreasing. The glycoproteins with reduced expression accounted for a larger change in spectral counts, and hence for the net loss of spectral counts in the malignant lines. Similar results were found when the glycoproteins were studied via identified glycosylation sites only, or through identified sites together with non-glycopeptides. The overall reduction is largely due to the loss of integrins, laminins and other proteins that form or interact with the basement membrane.

  19. Flumazenil decreases surface expression of α4β2δ GABAA receptors by increasing the rate of receptor internalization.

    PubMed

    Kuver, Aarti; Smith, Sheryl S

    2016-01-01

    Increases in expression of α4βδ GABAA receptors (GABARs), triggered by fluctuations in the neurosteroid THP (3α-OH-5α[β]-pregnan-20-one), are associated with changes in mood and cognition. We tested whether α4βδ trafficking and surface expression would be altered by in vitro exposure to flumazenil, a benzodiazepine ligand which reduces α4βδ expression in vivo. We first determined that flumazenil (100 nM-100 μM, IC50=∼1 μM) acted as a negative modulator, reducing GABA (10 μM)-gated current in the presence of 100 nM THP (to increase receptor efficacy), assessed with whole cell patch clamp recordings of recombinant α4β2δ expressed in HEK-293 cells. Surface expression of recombinant α4β2δ receptors was detected using a 3XFLAG reporter at the C-terminus of α4 (α4F) using confocal immunocytochemical techniques following 48 h exposure of cells to GABA (10 μM)+THP (100 nM). Flumazenil (10 μM) decreased surface expression of α4F by ∼60%, while increasing its intracellular accumulation, after 48 h. Reduced surface expression of α4β2δ after flumazenil treatment was confirmed by decreases in the current responses to 100 nM of the GABA agonist gaboxadol. Flumazenil-induced decreases in surface expression of α4β2δ were prevented by the dynamin blocker, dynasore, and by leupeptin, which blocks lysosomal enzymes, suggesting that flumazenil is acting to increase endocytosis and lysosomal degradation of the receptor. Flumazenil increased the rate of receptor removal from the cell surface by 2-fold, assessed using botulinum toxin B to block insertion of new receptors. These findings may suggest new therapeutic strategies for regulation of α4β2δ expression using flumazenil.

  20. Hsc70 regulates cell surface ASIC2 expression and vascular smooth muscle cell migration.

    PubMed

    Grifoni, Samira C; McKey, Susan E; Drummond, Heather A

    2008-05-01

    Recent studies suggest members of the degenerin (DEG)/epithelial Na(+) channel (ENaC)/acid-sensing ion channel (ASIC) protein family play an important role in vascular smooth muscle cell (VSMC) migration. In a previous investigation, we found suppression of a certain DEG/ENaC/ASIC member, ASIC2, increased VSMC chemotactic migration, raising the possibility that ASIC2 may play an inhibitory role. Because ASIC2 protein was retained in the cytoplasm, we reasoned increasing surface expression of ASIC2 might unmask the inhibitory role of ASIC2 in VSMC migration so we could test the hypothesis that ASIC2 inhibits VSMC migration. Therefore, we used the chemical chaperone glycerol to enhance ASIC2 expression. Glycerol 1) increased cytoplasm ASIC2 expression, 2) permitted detection of ASIC2 at the cell surface, and 3) inhibited platelet-derived growth factor (PDGF)-bb mediated VSMC migration. Furthermore, ASIC2 silencing completely abolished the inhibitory effect of glycerol on migration, suggesting upregulation of ASIC2 is responsible for glycerol-induced inhibition of VSMC migration. Because other investigators have shown that glycerol regulates ENaC/ASIC via interactions with a certain heat shock protein, heat shock protein 70 (Hsc70), we wanted to determine the importance of Hsc70 on ASIC2 expression in VSMCs. We found that Hsc70 silencing increases ASIC2 cell surface expression and inhibits VSMC migration, which is abolished by cosilencing ASIC2. These data demonstrate that Hsc70 inhibits ASIC2 expression, and, when the inhibitory effect of Hsc70 is removed, ASIC2 expression increases, resulting in reduced VSMC migration. Because VSMC migration contributes to vasculogenesis and remodeling following vascular injury, our findings raise the possibility that ASIC2-Hsc70 interactions may play a role in these processes. PMID:18310515

  1. Increased NY-ESO-1 expression and reduced infiltrating CD3+ T cells in cutaneous melanoma.

    PubMed

    Giavina-Bianchi, Mara; Giavina-Bianchi, Pedro; Sotto, Mirian Nacagami; Muzikansky, Alona; Kalil, Jorge; Festa-Neto, Cyro; Duncan, Lyn M

    2015-01-01

    NY-ESO-1 is a cancer-testis antigen aberrantly expressed in melanomas, which may serve as a robust and specific target in immunotherapy. NY-ESO-1 antigen expression, tumor features, and the immune profile of tumor infiltrating lymphocytes were assessed in primary cutaneous melanoma. NY-ESO-1 protein was detected in 20% of invasive melanomas (16/79), rarely in in situ melanoma (1/10) and not in benign nevi (0/20). Marked intratumoral heterogeneity of NY-ESO-1 protein expression was observed. NY-ESO-1 expression was associated with increased primary tumor thickness (P = 0.007) and inversely correlated with superficial spreading melanoma (P < 0.02). NY-ESO-1 expression was also associated with reduced numbers and density of CD3+ tumor infiltrating lymphocytes (P = 0.017). When NY-ESO-1 protein was expressed, CD3+ T cells were less diffusely infiltrating the tumor and were more often arranged in small clusters (P = 0.010) or as isolated cells (P = 0.002) than in large clusters of more than five lymphocytes. No correlation of NY-ESO-1 expression with gender, age, tumor site, ulceration, lymph node sentinel status, or survival was observed. NY-ESO-1 expression in melanoma was associated with tumor progression, including increased tumor thickness, and with reduced tumor infiltrating lymphocytes.

  2. Characterization of Staphylococcus aureus mutants expressing reduced susceptibility to common house-cleaners

    PubMed Central

    Davis, A.O.; O’Leary, J.O.; Muthaiyan, A.; Langevin, M.J.; Delgado, A.; Abalos, A.T.; Fajardo, A.R.; Marek, J.; Wilkinson, B.J.; Gustafson, J.E.

    2013-01-01

    Aims To characterize mutants of Staphylococcus aureus expressing reduced susceptibility to house cleaners (HC), assess the impact of the alternative sigma factor SigB on HC susceptibility, and determine the MIC of clinical methicillin-resistant S. aureus (MRSA) to a HC. Methods and Results Susceptibility to HC, HC components, H2O2, vancomycin and oxacillin and physiological parameters were determined for HC-reduced susceptibility (HCRS) mutants, parent strain COL and COLsigB::kan. HCRS mutants selected with three HC expressed reduced susceptibility to multiple HC, HC components, H2O2 and vancomycin. Two unique HCRS mutants also lost the methicillin resistance determinant. In addition, all HCRS mutants exhibited better growth at two temperatures, and one HCRS mutant expressed reduced carotenoid production. COLsigB::kan demonstrated increased susceptibility to all HC and many HC components. sigB operon mutations were not detected in one HCRS mutant background. Of 76 clinical MRSA, 20 exhibited reduced susceptibility to a HC. Conclusions HCRS mutants demonstrate altered susceptibility to multiple antimicrobials. While sigB is required for full HC resistance, one HCRS mechanism does not involve sigB operon mutations. Clinical MRSA expressing reduced susceptibility to a common HC were detected. Significance and Impact of the Study This study suggests that HCRS mutants are not protected against, nor selected by, practical HC concentrations. PMID:15659191

  3. ASIC2 Subunits Facilitate Expression at the Cell Surface and Confer Regulation by PSD-95

    PubMed Central

    Harding, Anne Marie S.; Kusama, Nobuyoshi; Hattori, Tomonori; Gautam, Mamta; Benson, Christopher J.

    2014-01-01

    Acid-sensing ion channels (ASICs) are Na+ channels activated by changes in pH within the peripheral and central nervous systems. Several different isoforms of ASICs combine to form trimeric channels, and their properties are determined by their subunit composition. ASIC2 subunits are widely expressed throughout the brain, where they heteromultimerize with their partnering subunit, ASIC1a. However, ASIC2 contributes little to the pH sensitivity of the channels, and so its function is not well understood. We found that ASIC2 increased cell surface levels of the channel when it is coexpressed with ASIC1a, and genetic deletion of ASIC2 reduced acid-evoked current amplitude in mouse hippocampal neurons. Additionally, ASIC2a interacted with the neuronal synaptic scaffolding protein PSD-95, and PSD-95 reduced cell surface expression and current amplitude in ASICs that contain ASIC2a. Overexpression of PSD-95 also reduced acid-evoked current amplitude in hippocampal neurons. This result was dependent upon ASIC2 since the effect of PSD-95 was abolished in ASIC2−/− neurons. These results lend support to an emerging role of ASIC2 in the targeting of ASICs to surface membranes, and allows for interaction with PSD-95 to regulate these processes. PMID:24699665

  4. Endothelial microparticles reduce ICAM-1 expression in a microRNA-222-dependent mechanism.

    PubMed

    Jansen, Felix; Yang, Xiaoyan; Baumann, Katharina; Przybilla, David; Schmitz, Theresa; Flender, Anna; Paul, Kathrin; Alhusseiny, Adil; Nickenig, Georg; Werner, Nikos

    2015-09-01

    Endothelial microparticles (EMP) are released from activated or apoptotic endothelial cells (ECs) and can be taken up by adjacent ECs, but their effect on vascular inflammation after engulfment is largely unknown. We sought to determine the role of EMP in EC inflammation. In vitro, EMP treatment significantly reduced tumour necrosis factor-α-induced endothelial intercellular adhesion molecule (ICAM)-1 expression on mRNA and protein level, whereas there was no effect on vascular cell adhesion molecule-1 expression. Reduced ICAM-1 expression after EMP treatment resulted in diminished monocyte adhesion in vitro. In vivo, systemic treatment of ApoE-/- mice with EMP significantly reduced murine endothelial ICAM-1 expression. To explore the underlying mechanisms, Taqman microRNA array was performed and microRNA (miR)-222 was identified as the strongest regulated miR between EMP and ECs. Following experiments demonstrated that miR-222 was transported into recipient ECs by EMP and functionally regulated expression of its target protein ICAM-1 in vitro and in vivo. After simulating diabetic conditions, EMP derived from glucose-treated ECs contained significantly lower amounts of miR-222 and showed reduced anti-inflammatory capacity in vitro and in vivo. Finally, circulating miR-222 level was diminished in patients with coronary artery disease (CAD) compared to patients without CAD. EMPs promote anti-inflammatory effects in vitro and in vivo by reducing endothelial ICAM-1 expression via the transfer of functional miR-222 into recipient cells. In pathological hyperglycaemic conditions, EMP-mediated miR-222-dependent anti-inflammatory effects are reduced.

  5. STAT3 Knockdown Reduces Pancreatic Cancer Cell Invasiveness and Matrix Metalloproteinase-7 Expression in Nude Mice

    PubMed Central

    Huang, Ke jian; Wu, Wei dong; Jiang, Tao; Cao, Jun; Feng, Zhen zhong; Qiu, Zheng jun

    2011-01-01

    Aims Transducer and activator of transcription-3 (STAT3) plays an important role in tumor cell invasion and metastasis. The aim of the present study was to investigate the effects of STAT3 knockdown in nude mouse xenografts of pancreatic cancer cells and underlying gene expression. Methods A STAT3 shRNA lentiviral vector was constructed and infected into SW1990 cells. qRT-PCR and western immunoblot were performed to detect gene expression. Nude mouse xenograft assays were used to assess changes in phenotypes of these stable cells in vivo. HE staining was utilized to evaluate tumor cell invasion and immunohistochemistry was performed to analyze gene expression. Results STAT3 shRNA successfully silenced expression of STAT3 mRNA and protein in SW1990 cells compared to control cells. Growth rate of the STAT3-silenced tumor cells in nude mice was significantly reduced compared to in the control vector tumors and parental cells-generated tumors. Tumor invasion into the vessel and muscle were also suppressed in the STAT3-silenced tumors compared to controls. Collagen IV expression was complete and continuous surrounding the tumors of STAT3-silenced SW1990 cells, whereas collagen IV expression was incomplete and discontinuous surrounding the control tumors. Moreover, microvessel density was significantly lower in STAT3-silenced tumors than parental or control tumors of SW1990 cells. In addition, MMP-7 expression was reduced in STAT3-silenced tumors compared to parental SW1990 xenografts and controls. In contrast, expression of IL-1β and IgT7α was not altered. Conclusion These data clearly demonstrate that STAT3 plays an important role in regulation of tumor growth, invasion, and angiogenesis, which could be act by reducing MMP-7 expression in pancreatic cancer cells. PMID:21991388

  6. Reduced LIMK2 expression in colorectal cancer reflects its role in limiting stem cell proliferation

    PubMed Central

    Lourenço, Filipe C; Munro, June; Brown, Jennifer; Cordero, Julia; Stefanatos, Rhoda; Strathdee, Karen; Orange, Clare; Feller, Stephan M; Sansom, Owen J; Vidal, Marcos; Murray, Graeme I; Olson, Michael F

    2014-01-01

    Objective Colorectal cancer (CRC) is a major contributor to cancer mortality and morbidity. LIM kinase 2 (LIMK2) promotes tumour cell invasion and metastasis. The objectives of this study were to determine how LIMK2 expression is associated with CRC progression and patient outcome, and to use genetically modified Drosophila and mice to determine how LIMK2 deletion affects gastrointestinal stem cell regulation and tumour development. Design LIMK2 expression and activity were measured by immunostaining tumours from CRC-prone mice, human CRC cell lines and 650 human tumours. LIMK knockdown in Drosophila or Limk2 deletion in mice allowed for assessment of their contributions to gastrointestinal stem cell homeostasis and tumour development. Results LIMK2 expression was reduced in intestinal tumours of cancer-prone mice, as well as in human CRC cell lines and tumours. Reduced LIMK2 expression and substrate phosphorylation were associated with shorter patient survival. Genetic analysis in Drosophila midgut and intestinal epithelial cells isolated from genetically modified mice revealed a conserved role for LIMK2 in constraining gastrointestinal stem cell proliferation. Limk2 deletion increased colon tumour size in a colitis-associated colorectal mouse cancer model. Conclusions This study revealed that LIMK2 expression and activity progressively decrease with advancing stage, and supports the hypothesis that there is selective pressure for reduced LIMK2 expression in CRC to relieve negative constraints imposed upon gastrointestinal stem cells. PMID:23585469

  7. Leukocyte Pyruvate Kinase Expression is Reduced in Normal Human Pregnancy but not in Preeclampsia

    PubMed Central

    Xu, Yi; Madsen-Bouterse, Sally A.; Romero, Roberto; Hassan, Sonia; Mittal, Pooja; Elfline, Megan; Zhu, Aiping; Petty, Howard R.

    2010-01-01

    Problem Emerging evidence suggests that metabolism influences immune cell signaling and immunoregulation. To examine the immunoregulatory role of glycolysis in pregnancy, we evaluated the properties of pyruvate kinase in leukocytes from non-pregnant women and those with normal pregnancy and pre-eclampsia. Method of study We evaluated pyruvate kinase expression in lymphocytes and neutrophils from non-pregnant, pregnant, and pre-eclampsia patients using fluorescence microscopy and flow cytometry. Leukocyte pyruvate kinase activity and pyruvate concentrations were also evaluated. To study pyruvate’s effect on signaling, we labeled Jurkat T cells with Ca2+ dyes and measured cell responses in the presence of agents influencing intracellular pyruvate. Results The expression of pyruvate kinase is reduced in lymphocytes and neutrophils from normal pregnant women in comparison to those of non-pregnant women and pre-eclampsia patients. Similarly, the activity of pyruvate kinase and the intracellular pyruvate concentration are reduced in leukocytes of normal pregnant women in comparison to non-pregnant women and women with pre-eclampsia. Using Jurkat cells as a model of leukocyte signaling, we have shown that perturbations of intracellular pyruvate influence Ca2+ signals. Conclusion Normal pregnancy is characterized by reduced pyruvate kinase expression within lymphocytes and neutrophils. We speculate that reduced pyruvate kinase expression modifies immune cell responses due to reduced pyruvate concentrations. PMID:20560913

  8. Reduced expression and prognostic implication of inhibitor of growth 4 in human osteosarcoma

    PubMed Central

    ZHAO, DAHANG; LIU, XIANGJIE; ZHANG, YUNGE; DING, ZHAOMING; DONG, FENG; XU, HONGWEI; WANG, BAOXIN; WANG, WENBO

    2016-01-01

    Osteosarcoma is the most prevalent type of primary malignant bone tumor. Inhibitor of growth 4 (ING4) has been demonstrated to function as a tumor suppressor through multiple pathways, and is its expression is understood to be suppressed or reduced in various malignancies. The present study aimed to investigate the expression of ING4 and to determine its prognostic value in osteosarcoma tissue. Formalin-fixed, paraffin-embedded tissue microarrays were analyzed, and contained 41 osteosarcoma specimens and 11 normal bone tissue specimens with duplicate cores. ING4 expression was evaluated by immunohistochemical staining. The association between ING4 expression in the osteosarcoma and normal bone tissues was analyzed, in addition to the association between ING4 expression and Enneking classification of the osteosarcoma tissues. A significant statistical difference was observed in the ING4 immunohistochemical staining score between the osteosarcoma and normal bone tissues (P<0.001). Furthermore, a significant negative correlation was detected between the ING4 immunohistochemical staining scores and the Enneking classification results of the 41 osteosarcoma tissues (P=0.002). Low expression of ING4 was observed in the osteosarcoma specimens, and this reduced expression of ING4 was negatively correlated with Enneking classification. Thus, the results of the present study indicate that ING4 may serve as a promising prognostic marker in osteosarcoma. PMID:27073567

  9. Ontogeny of pig discrete Peyer's patches: expression of surface antigens.

    PubMed

    Makala, L H; Kamada, T; Nagasawa, H; Igarashi, I; Fujisaki, K; Suzuki, N; Mikami, T; Haverson, K; Bailey, M; Stokes, C R; Bland, P W

    2001-06-01

    Leukocyte populations present in the discrete Peyer's patches (PP) of the pig were characterized from birth (Day 0) to day 35 after birth by immunohistochemistry and image analysis. Immediately after birth, cell membrane expression of CD2 and CD3, major histocompatibilty complex (MHC) class 11 (both SLA (swine leukocyte antigen) -DQ+ and SLA-DR+), CD21, 74-22-15 and surface immunoglobulin (sIg) were all demonstrable. Computer assisted morphometric techniques were used to confirm the significant expansion of these cell populations from birth onwards. The distribution of the cell types was not random but suggested a preferential retention of cells at specific sites. This implies a degree of organization of immunological cells within the discrete PP, enhancing the potential to mount immune responses in the most efficient manner.

  10. Reduced tissue osmolarity increases TRPV4 expression and pro-inflammatory cytokines in intervertebral disc cells.

    PubMed

    Walter, B A; Purmessur, D; Moon, A; Occhiogrosso, J; Laudier, D M; Hecht, A C; Iatridis, J C

    2016-01-01

    The mechanical behaviour and cellular metabolism of intervertebral discs (IVDs) and articular cartilage are strongly influenced by their proteoglycan content and associated osmotic properties. This osmotic environment is a biophysical signal that changes with disease and may contribute to the elevated matrix breakdown and altered biologic response to loading observed in IVD degeneration and osteoarthritis. This study tested the hypothesis that changes in osmo-sensation by the transient receptor potential vallinoid-4 (TRPV4) ion channel occur with disease and contribute to the inflammatory environment found during degeneration. Immunohistochemistry on bovine IVDs from an inflammatory organ culture model were used to investigate if TRPV4 is expressed in the IVD and how expression changes with degeneration. Western blot, live-cell calcium imaging, and qRT-PCR were used to investigate whether osmolarity changes or tumour necrosis factor α (TNFα) regulate TRPV4 expression, and how altered TRPV4 expression influences calcium signalling and pro-inflammatory cytokine expression. TRPV4 expression correlated with TNFα expression, and was increased when cultured in reduced medium osmolarity and unaltered with TNFα-stimulation. Increased TRPV4 expression increased the calcium flux following TRPV4 activation and increased interleukin-1β (IL-1β) and IL-6 gene expression in IVD cells. TRPV4 expression was qualitatively elevated in regions of aggrecan depletion in degenerated human IVDs. Collectively, results suggest that reduced tissue osmolarity, likely following proteoglycan degradation, can increase TRPV4 signalling and enhance pro-inflammatory cytokine production, suggesting changes in TRPV4 mediated osmo-sensation may contribute to the progressive matrix breakdown in disease. PMID:27434269

  11. REDUCED TISSUE OSMOLARITY INCREASES TRPV4 EXPRESSION AND PRO-INFLAMMATORY CYTOKINES IN INTERVERTEBRAL DISC CELLS

    PubMed Central

    Walter, B.A.; Purmessur, D; Moon, A.; Occhiogrosso, J.; Laudier, D.M.; Hecht, A.C.; Iatridis, J.C.

    2016-01-01

    The mechanical behaviour and cellular metabolism of intervertebral discs (IVDs) and articular cartilage are strongly influenced by their proteoglycan content and associated osmotic properties. This osmotic environment is a biophysical signal that changes with disease and may contribute to the elevated matrix breakdown and altered biologic response to loading observed in IVD degeneration and osteoarthritis. This study tested the hypothesis that changes in osmo-sensation by the transient receptor potential vallinoid-4 (TRPV4) ion channel occur with disease and contribute to the inflammatory environment found during degeneration. Immunohistochemistry on bovine IVDs from an inflammatory organ culture model were used to investigate if TRPV4 is expressed in the IVD and how expression changes with degeneration. Western blot, live-cell calcium imaging, and qRT-PCR were used to investigate whether osmolarity changes or tumour necrosis factor α (TNFα) regulate TRPV4 expression, and how altered TRPV4 expression influences calcium signalling and pro-inflammatory cytokine expression. TRPV4 expression correlated with TNFα expression, and was increased when cultured in reduced medium osmolarity and unaltered with TNFα-stimulation. Increased TRPV4 expression increased the calcium flux following TRPV4 activation and increased interleukin-1β (IL-1β) and IL-6 gene expression in IVD cells. TRPV4 expression was qualitatively elevated in regions of aggrecan depletion in degenerated human IVDs. Collectively, results suggest that reduced tissue osmolarity, likely following proteoglycan degradation, can increase TRPV4 signalling and enhance pro-inflammatory cytokine production, suggesting changes in TRPV4 mediated osmo-sensation may contribute to the progressive matrix breakdown in disease. PMID:27434269

  12. Neurotrophin-3 significantly reduces sodium channel expression linked to neuropathic pain states.

    PubMed

    Wilson-Gerwing, Tracy D; Stucky, Cheryl L; McComb, Geoffrey W; Verge, Valerie M K

    2008-10-01

    Neuropathic pain resulting from chronic constriction injury (CCI) is critically linked to sensitization of peripheral nociceptors. Voltage gated sodium channels are major contributors to this state and their expression can be upregulated by nerve growth factor (NGF). We have previously demonstrated that neurotrophin-3 (NT-3) acts antagonistically to NGF in modulation of aspects of CCI-induced changes in trkA-associated nociceptor phenotype and thermal hyperalgesia. Thus, we hypothesized that exposure of neurons to increased levels of NT-3 would reduce expression of Na(v)1.8 and Na(v)1.9 in DRG neurons subject to CCI. In adult male rats, Na(v)1.8 and Na(v)1.9 mRNAs are expressed at high levels in predominantly small to medium size neurons. One week following CCI, there is reduced incidence of neurons expressing detectable Na(v)1.8 and Na(v)1.9 mRNA, but without a significant decline in mean level of neuronal expression, and similar findings observed immunohistochemically. There is also increased accumulation/redistribution of channel protein in the nerve most apparent proximal to the first constriction site. Intrathecal infusion of NT-3 significantly attenuates neuronal expression of Na(v)1.8 and Na(v)1.9 mRNA contralateral and most notably, ipsilateral to CCI, with a similar impact on relative protein expression at the level of the neuron and constricted nerve. We also observe reduced expression of the common neurotrophin receptor p75 in response to CCI that is not reversed by NT-3 in small to medium sized neurons and may confer an enhanced ability of NT-3 to signal via trkA, as has been previously shown in other cell types. These findings are consistent with an analgesic role for NT-3. PMID:18601922

  13. Palmitoylation of the β4-subunit regulates surface expression of large conductance calcium-activated potassium channel splice variants.

    PubMed

    Chen, Lie; Bi, Danlei; Tian, Lijun; McClafferty, Heather; Steeb, Franziska; Ruth, Peter; Knaus, Hans Guenther; Shipston, Michael J

    2013-05-01

    Regulatory β-subunits of large conductance calcium- and voltage-activated potassium (BK) channels play an important role in generating functional diversity and control of cell surface expression of the pore forming α-subunits. However, in contrast to α-subunits, the role of reversible post-translational modification of intracellular residues on β-subunit function is largely unknown. Here we demonstrate that the human β4-subunit is S-acylated (palmitoylated) on a juxtamembrane cysteine residue (Cys-193) in the intracellular C terminus of the regulatory β-subunit. β4-Subunit palmitoylation is important for cell surface expression and endoplasmic reticulum (ER) exit of the β4-subunit alone. Importantly, palmitoylated β4-subunits promote the ER exit and surface expression of the pore-forming α-subunit, whereas β4-subunits that cannot be palmitoylated do not increase ER exit or surface expression of α-subunits. Strikingly, however, this palmitoylation- and β4-dependent enhancement of α-subunit surface expression was only observed in α-subunits that contain a putative trafficking motif (… REVEDEC) at the very C terminus of the α-subunit. Engineering this trafficking motif to other C-terminal α-subunit splice variants results in α-subunits with reduced surface expression that can be rescued by palmitoylated, but not depalmitoylated, β4-subunits. Our data reveal a novel mechanism by which palmitoylated β4-subunit controls surface expression of BK channels through masking of a trafficking motif in the C terminus of the α-subunit. As palmitoylation is dynamic, this mechanism would allow precise control of specific splice variants to the cell surface. Our data provide new insights into how complex interplay between the repertoire of post-transcriptional and post-translational mechanisms controls cell surface expression of BK channels.

  14. An Acceptance-Based Psychoeducation Intervention to Reduce Expressed Emotion in Relatives of Bipolar Patients

    ERIC Educational Resources Information Center

    Eisner, Lori R.; Johnson, Sheri L.

    2008-01-01

    Expressed emotion (EE) is a robust predictor of outcome in bipolar disorder. Despite decades of research, interventions to reduce EE levels have had only modest effects. This study used an expanded model of EE to develop an intervention. Research has demonstrated a strong link between attributions and EE in families of patients with psychiatric…

  15. Reduced capacity in automatic processing of facial expression in restrictive anorexia nervosa and obesity.

    PubMed

    Cserjési, Renáta; Vermeulen, Nicolas; Lénárd, László; Luminet, Olivier

    2011-07-30

    There is growing evidence that disordered eating is associated with facial expression recognition and emotion processing problems. In this study, we investigated the question of whether anorexia and obesity occur on a continuum of attention bias towards negative facial expressions in comparison with healthy individuals of normal weight. Thirty-three patients with restrictive anorexia nervosa (AN-R), 30 patients with obesity (OB) and 63 healthy age and social-economic status matched controls were recruited. Our results indicated that AN-R patients were more attentive to angry faces and had difficulties in being attentive to positive expressions, whilst OB patients had problems in looking for or being attentive to negative expressions independently of self-reported depression and anxiety. Our findings did not support the idea that AN-R and OB occur on a continuum. We found that AN-R was associated with a reduced capacity in positive facial expression processing, whereas OB was associated with a reduced capacity in negative facial expressions processing. The social relevance of our findings and a possible explanation based upon neuroscience are discussed.

  16. Hepcidin Bound to α2-Macroglobulin Reduces Ferroportin-1 Expression and Enhances Its Activity at Reducing Serum Iron Levels

    PubMed Central

    Huang, Michael Li-Hsuan; Austin, Christopher J. D.; Sari, Marie-Agnès; Suryo Rahmanto, Yohan; Ponka, Prem; Vyoral, Daniel; Richardson, Des R.

    2013-01-01

    Hepcidin regulates iron metabolism by down-regulating ferroportin-1 (Fpn1). We demonstrated that hepcidin is complexed to the blood transport protein, α2-macroglobulin (α2M) (Peslova, G., Petrak, J., Kuzelova, K., Hrdy, I., Halada, P., Kuchel, P. W., Soe-Lin, S., Ponka, P., Sutak, R., Becker, E., Huang, M. L., Suryo Rahmanto, Y., Richardson, D. R., and Vyoral, D. (2009) Blood 113, 6225–6236). However, nothing is known about the mechanism of hepcidin binding to α2M or the effects of the α2M·hepcidin complex in vivo. We show that decreased Fpn1 expression can be mediated by hepcidin bound to native α2M and also, for the first time, hepcidin bound to methylamine-activated α2M (α2M-MA). Passage of high molecular weight α2M·hepcidin or α2M-MA·hepcidin complexes (≈725 kDa) through a Sephadex G-25 size exclusion column retained their ability to decrease Fpn1 expression. Further studies using ultrafiltration indicated that hepcidin binding to α2M and α2M-MA was labile, resulting in some release from the protein, and this may explain its urinary excretion. To determine whether α2M-MA·hepcidin is delivered to cells via the α2M receptor (Lrp1), we assessed α2M uptake and Fpn1 expression in Lrp1−/− and Lrp1+/+ cells. Interestingly, α2M·hepcidin or α2M-MA·hepcidin demonstrated similar activities at decreasing Fpn1 expression in Lrp1−/− and Lrp1+/+ cells, indicating that Lrp1 is not essential for Fpn1 regulation. In vivo, hepcidin bound to α2M or α2M-MA did not affect plasma clearance of α2M/α2M-MA. However, serum iron levels were reduced to a significantly greater extent in mice treated with α2M·hepcidin or α2M-MA·hepcidin relative to unbound hepcidin. This effect could be mediated by the ability of α2M or α2M-MA to retard kidney filtration of bound hepcidin, increasing its half-life. A model is proposed that suggests that unlike proteases, which are irreversibly bound to activated α2M, hepcidin remains labile and available to down

  17. Association of reduced Connexin 43 expression with retinal vascular lesions in human diabetic retinopathy.

    PubMed

    Tien, Thomas; Muto, Tetsuya; Zhang, Joyce; Sohn, Elliott H; Mullins, Robert F; Roy, Sayon

    2016-05-01

    Connexin 43 (Cx43) downregulation promotes apoptosis in retinal vascular cells of diabetic animal models; however, its relevance to human diabetic retinopathy has not been established. In this study, we investigated whether diabetes alters Cx43 expression and promotes retinal vascular lesions in human retinas. Diabetic human eyes (aged 64-94 years) and non-diabetic human eyes (aged 61-90 years) were analyzed in this study. Retinal protein samples and retinal capillary networks were assessed for Cx43 level by Western blot (WB) analysis and immunostaining. In parallel, retinal capillary networks were stained with hematoxylin and periodic acid Schiff to determine the extent of pericyte loss (PL) and acellular capillaries (AC) in these retinas. Cx43 protein expression was significantly reduced in the diabetic retinas compared to non-diabetic retinas as indicated by WB analysis (81 ± 11% of control). Additionally, a significant decrease in the number of Cx43 plaques per unit length of vessel was observed in the diabetic retinas compared to those of non-diabetic retinas (62 ± 10% of control; p < 0.005). Importantly, a strong inverse relationship was noted between Cx43 expression and the relative number of AC (r = -0.89; p < 0.0005), and between Cx43 expression and number of pericyte loss (r = -0.88; p < 0.0005). Overall, these results show that Cx43 expression is reduced in the human diabetic retinas and Cx43 reduction is associated with increased vascular cell death. These findings suggest that diabetes decreases retinal Cx43 expression and that the development of PL and AC is associated with reduced Cx43 expression in human diabetic retinopathy. PMID:26738943

  18. Improved chemical and electrochemical stability of perovskite oxides with less reducible cations at the surface.

    PubMed

    Tsvetkov, Nikolai; Lu, Qiyang; Sun, Lixin; Crumlin, Ethan J; Yildiz, Bilge

    2016-09-01

    Segregation and phase separation of aliovalent dopants on perovskite oxide (ABO3) surfaces are detrimental to the performance of energy conversion systems such as solid oxide fuel/electrolysis cells and catalysts for thermochemical H2O and CO2 splitting. One key reason behind the instability of perovskite oxide surfaces is the electrostatic attraction of the negatively charged A-site dopants (for example, ) by the positively charged oxygen vacancies () enriched at the surface. Here we show that reducing the surface concentration improves the oxygen surface exchange kinetics and stability significantly, albeit contrary to the well-established understanding that surface oxygen vacancies facilitate reactions with O2 molecules. We take La0.8Sr0.2CoO3 (LSC) as a model perovskite oxide, and modify its surface with additive cations that are more and less reducible than Co on the B-site of LSC. By using ambient-pressure X-ray absorption and photoelectron spectroscopy, we proved that the dominant role of the less reducible cations is to suppress the enrichment and phase separation of Sr while reducing the concentration of and making the LSC more oxidized at its surface. Consequently, we found that these less reducible cations significantly improve stability, with up to 30 times faster oxygen exchange kinetics after 54 h in air at 530 °C achieved by Hf addition onto LSC. Finally, the results revealed a 'volcano' relation between the oxygen exchange kinetics and the oxygen vacancy formation enthalpy of the binary oxides of the additive cations. This volcano relation highlights the existence of an optimum surface oxygen vacancy concentration that balances the gain in oxygen exchange kinetics and the chemical stability loss. PMID:27295099

  19. Improved chemical and electrochemical stability of perovskite oxides with less reducible cations at the surface

    NASA Astrophysics Data System (ADS)

    Tsvetkov, Nikolai; Lu, Qiyang; Sun, Lixin; Crumlin, Ethan J.; Yildiz, Bilge

    2016-09-01

    Segregation and phase separation of aliovalent dopants on perovskite oxide (ABO3) surfaces are detrimental to the performance of energy conversion systems such as solid oxide fuel/electrolysis cells and catalysts for thermochemical H2O and CO2 splitting. One key reason behind the instability of perovskite oxide surfaces is the electrostatic attraction of the negatively charged A-site dopants (for example, ) by the positively charged oxygen vacancies () enriched at the surface. Here we show that reducing the surface concentration improves the oxygen surface exchange kinetics and stability significantly, albeit contrary to the well-established understanding that surface oxygen vacancies facilitate reactions with O2 molecules. We take La0.8Sr0.2CoO3 (LSC) as a model perovskite oxide, and modify its surface with additive cations that are more and less reducible than Co on the B-site of LSC. By using ambient-pressure X-ray absorption and photoelectron spectroscopy, we proved that the dominant role of the less reducible cations is to suppress the enrichment and phase separation of Sr while reducing the concentration of and making the LSC more oxidized at its surface. Consequently, we found that these less reducible cations significantly improve stability, with up to 30 times faster oxygen exchange kinetics after 54 h in air at 530 °C achieved by Hf addition onto LSC. Finally, the results revealed a `volcano' relation between the oxygen exchange kinetics and the oxygen vacancy formation enthalpy of the binary oxides of the additive cations. This volcano relation highlights the existence of an optimum surface oxygen vacancy concentration that balances the gain in oxygen exchange kinetics and the chemical stability loss.

  20. Screening of mRNA Chemical Modification to Maximize Protein Expression with Reduced Immunogenicity

    PubMed Central

    Uchida, Satoshi; Kataoka, Kazunori; Itaka, Keiji

    2015-01-01

    Chemical modification of nucleosides in mRNA is an important technology to regulate the immunogenicity of mRNA. In this study, various previously reported mRNA formulations were evaluated by analyzing in vitro protein expression and immunogenicity in multiple cell lines. For the macrophage-derived cell line, RAW 264.7, modified mRNA tended to have reduced immunogenicity and increased protein expression compared to the unmodified mRNA. In contrast, in some cell types, such as hepatocellular carcinoma cells (HuH-7) and mouse embryonic fibroblasts (MEFs), protein expression was decreased by mRNA modification. Further analyses revealed that mRNA modifications decreased translation efficiency but increased nuclease stability. Thus, mRNA modification is likely to exert both positive and negative effects on the efficiency of protein expression in transfected cells and optimal mRNA formulation should be determined based on target cell types and transfection purposes. PMID:26213960

  1. Screening of mRNA Chemical Modification to Maximize Protein Expression with Reduced Immunogenicity.

    PubMed

    Uchida, Satoshi; Kataoka, Kazunori; Itaka, Keiji

    2015-01-01

    Chemical modification of nucleosides in mRNA is an important technology to regulate the immunogenicity of mRNA. In this study, various previously reported mRNA formulations were evaluated by analyzing in vitro protein expression and immunogenicity in multiple cell lines. For the macrophage-derived cell line, RAW 264.7, modified mRNA tended to have reduced immunogenicity and increased protein expression compared to the unmodified mRNA. In contrast, in some cell types, such as hepatocellular carcinoma cells (HuH-7) and mouse embryonic fibroblasts (MEFs), protein expression was decreased by mRNA modification. Further analyses revealed that mRNA modifications decreased translation efficiency but increased nuclease stability. Thus, mRNA modification is likely to exert both positive and negative effects on the efficiency of protein expression in transfected cells and optimal mRNA formulation should be determined based on target cell types and transfection purposes. PMID:26213960

  2. Inducing a concurrent motor load reduces categorization precision for facial expressions.

    PubMed

    Ipser, Alberta; Cook, Richard

    2016-05-01

    Motor theories of expression perception posit that observers simulate facial expressions within their own motor system, aiding perception and interpretation. Consistent with this view, reports have suggested that blocking facial mimicry induces expression labeling errors and alters patterns of ratings. Crucially, however, it is unclear whether changes in labeling and rating behavior reflect genuine perceptual phenomena (e.g., greater internal noise associated with expression perception or interpretation) or are products of response bias. In an effort to advance this literature, the present study introduces a new psychophysical paradigm for investigating motor contributions to expression perception that overcomes some of the limitations inherent in simple labeling and rating tasks. Observers were asked to judge whether smiles drawn from a morph continuum were sincere or insincere, in the presence or absence of a motor load induced by the concurrent production of vowel sounds. Having confirmed that smile sincerity judgments depend on cues from both eye and mouth regions (Experiment 1), we demonstrated that vowel production reduces the precision with which smiles are categorized (Experiment 2). In Experiment 3, we replicated this effect when observers were required to produce vowels, but not when they passively listened to the same vowel sounds. In Experiments 4 and 5, we found that gender categorizations, equated for difficulty, were unaffected by vowel production, irrespective of the presence of a smiling expression. These findings greatly advance our understanding of motor contributions to expression perception and represent a timely contribution in light of recent high-profile challenges to the existing evidence base.

  3. Defective erythropoiesis in a mouse model of reduced Fbxo7 expression due to decreased p27 expression

    PubMed Central

    Randle, Suzanne J; Nelson, David E; Patel, Shachi P; Laman, Heike

    2015-01-01

    During the final stages of erythropoiesis, lineage-restricted progenitors mature over three to five cell divisions, culminating with withdrawal from the cell cycle and the loss of most organelles, including mitochondria and nuclei. Recent genome-wide association studies in human populations have associated several SNPs near or within FBXO7 with erythrocyte phenotypes. Fbxo7 encodes a multi-functional F-box protein known to bind p27 and participate in selective mitophagy. One SNP causes an amino acid substitution (Met115Ile) and is associated with smaller erythrocytes. We find that the less common IIe115 allele of Fbxo7 binds less efficiently to p27, and cells expressing this allele proliferate faster than cells expressing Met115. We show that an erythroleukaemic cell line with reduced Fbxo7 expression fails to stabilize p27 levels, exit the cell cycle, and produce haemoglobin. In addition, mice deficient in Fbxo7 expression are anaemic due to a reduction in erythrocyte numbers, and this is associated with lower p27 levels, increased numbers of late-stage erythroblasts with greater than 2N DNA content, and delayed mitophagy during terminal differentiation. Collectively, these data support an important physiological, cell cycle regulatory role for Fbxo7 during erythropoiesis. © 2015 Authors. Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland. PMID:26095538

  4. Expression of surface platelet receptors (CD62P and CD41/61) in horses with recurrent airway obstruction (RAO).

    PubMed

    Iwaszko-Simonik, Alicja; Niedzwiedz, Artur; Graczyk, Stanislaw; Slowikowska, Malwina; Pliszczak-Krol, Aleksandra

    2015-03-15

    Recurrent airway obstruction (RAO) is an allergic disease of horses similar to human asthma, which is characterized by airway inflammation and activation of neutrophils, lymphocytes and platelets. Platelet activation and an increase in circulating platelet-leukocyte aggregates may lead to airway remodeling. The aim of this study was to investigate platelet status in RAO-affected horses based on the platelet morphology and platelet surface expression of CD41/61 and CD62P. Ten RAO-affected horses and ten healthy horses were included in this study. Blood samples were obtained to determine the platelet count (PLT), mean platelet volume (MPV) and platelet large cell ratio (P-LCR). Expression of CD62P and CD41/61 was detected by flow cytometry on activated platelets. The median PLT was significantly reduced in horses with RAO compared to the controls. The MPV and the P-LCR values were significantly higher in RAO horses than controls. Expression of CD41/61 on platelets was increased in RAO horses, while CD62P expression was reduced. This study demonstrated the morphological changes in platelets and expression of platelet surface receptors. Despite the decrease of CD62P expression, the observed increased surface expression of CD41/61 on platelets in horses with RAO may contribute to the formation of platelet aggregates in their respiratory system.

  5. Reduced seed germination in Arabidopsis over-expressing SWI/SNF2 ATPase genes.

    PubMed

    Leeggangers, Hendrika A C F; Folta, Adam; Muras, Aleksandra; Nap, Jan-Peter; Mlynarova, Ludmila

    2015-02-01

    In the life of flowering plants, seed germination is a critical step to ensure survival into the next generation. Generally the seed prior to germination has been in a dormant state with a low rate of metabolism. In the transition from a dormant seed to a germinating seed, various epigenetic mechanisms play a regulatory role. Here, we demonstrate that the over-expression of chromatin remodeling ATPase genes (AtCHR12 or AtCHR23) reduced the frequency of seed germination in Arabidopsis thaliana up to 30% relative to the wild-type seeds. On the other hand, single loss-of-function mutations of the two genes did not affect seed germination. The reduction of germination in over-expressing mutants was more pronounced in stress conditions (salt or high temperature), showing the impact of the environment. Reduced germinations upon over-expression coincided with increased transcript levels of seed maturation genes and with reduced degradation of their mRNAs stored in dry seeds. Our results indicate that repression of AtCHR12/23 gene expression in germinating wild-type Arabidopsis seeds is required for full germination. This establishes a functional link between chromatin modifiers and regulatory networks towards seed maturation and germination.

  6. Shear stress reduces protease activated receptor-1 expression in human endothelial cells

    NASA Technical Reports Server (NTRS)

    Nguyen, K. T.; Eskin, S. G.; Patterson, C.; Runge, M. S.; McIntire, L. V.

    2001-01-01

    Shear stress has been shown to regulate several genes involved in the thrombotic and proliferative functions of endothelial cells. Thrombin receptor (protease-activated receptor-1: PAR-1) increases at sites of vascular injury, which suggests an important role for PAR-1 in vascular diseases. However, the effect of shear stress on PAR-1 expression has not been previously studied. This work investigates effects of shear stress on PAR-1 gene expression in both human umbilical vein endothelial cells (HUVECs) and microvascular endothelial cells (HMECs). Cells were exposed to different shear stresses using a parallel plate flow system. Northern blot and flow cytometry analysis showed that shear stress down-regulated PAR-1 messenger RNA (mRNA) and protein levels in both HUVECs and HMECs but with different thresholds. Furthermore, shear-reduced PAR-1 mRNA was due to a decrease of transcription rate, not increased mRNA degradation. Postshear stress release of endothelin-1 in response to thrombin was reduced in HUVECs and HMECs. Moreover, inhibitors of potential signaling pathways applied during shear stress indicated mediation of the shear-decreased PAR-1 expression by protein kinases. In conclusion, shear stress exposure reduces PAR-1 gene expression in HMECs and HUVECs through a mechanism dependent in part on protein kinases, leading to altered endothelial cell functional responses to thrombin.

  7. A Complex Interaction Between Reduced Reelin Expression and Prenatal Organophosphate Exposure Alters Neuronal Cell Morphology

    PubMed Central

    Mullen, Brian R.; Ross, Brennan; Chou, Joan Wang; Khankan, Rana; Khialeeva, Elvira; Bui, Kimberly

    2016-01-01

    Genetic and environmental factors are both likely to contribute to neurodevelopmental disorders including schizophrenia, autism spectrum disorders, and major depressive disorders. Prior studies from our laboratory and others have demonstrated that the combinatorial effect of two factors—reduced expression of reelin protein and prenatal exposure to the organophosphate pesticide chlorpyrifos oxon—gives rise to acute biochemical effects and to morphological and behavioral phenotypes in adolescent and young adult mice. In the current study, we examine the consequences of these factors on reelin protein expression and neuronal cell morphology in adult mice. While the cell populations that express reelin in the adult brain appear unchanged in location and distribution, the levels of full length and cleaved reelin protein show persistent reductions following prenatal exposure to chlorpyrifos oxon. Cell positioning and organization in the hippocampus and cerebellum are largely normal in animals with either reduced reelin expression or prenatal exposure to chlorpyrifos oxon, but cellular complexity and dendritic spine organization is altered, with a skewed distribution of immature dendritic spines in adult animals. Paradoxically, combinatorial exposure to both factors appears to generate a rescue of the dendritic spine phenotypes, similar to the mitigation of behavioral and morphological changes observed in our prior study. Together, our observations support an interaction between reelin expression and chlorpyrifos oxon exposure that is not simply additive, suggesting a complex interplay between genetic and environmental factors in regulating brain morphology. PMID:27364165

  8. Reduced WIF-1 expression stimulates skin hyperpigmentation in patients with melasma.

    PubMed

    Kim, Ji-Young; Lee, Tae-Ryong; Lee, Ai-Young

    2013-01-01

    The expression of Wnt inhibitory factor-1 (WIF-1) gene, which was detected by a microarray analysis of hyperpigmented and normally pigmented skin sets of melasma patients, was significantly reduced in the hyperpigmented skin from melasma patients, but not in healthy controls, regardless of UV irradiation. Wnt signals regulate skin pigmentation; however, WIF-1 is expressed in cultured skin keratinocytes and fibroblasts, but not in melanocytes. Therefore, we examined whether WIF-1 knockdown in neighboring keratinocytes and fibroblasts plays a role in melasma. Additionally, the effect of WIF-1 overexpression on the amelioration of hyperpigmentation was examined. WIF-1 knockdown, either in fibroblasts or in keratinocytes, significantly stimulated tyrosinase expression and melanosome transfer, whereas melanocytes with WIF-1 overexpression significantly reduced those parameters. The WIF-1 knockdown decreased glycogen synthase kinase-3β (GSK-3β), β-catenin, and NFATc2 (nuclear factor of activated T cells, cytoplasmic, calcineurin-dependent 2) phosphorylation and increased microphthalmia-associated transcription factor (MITF) expression as in melanocytes with Wnt-1 overexpression, whereas the WIF-1 overexpression reversed the results. Expression of Wnts, both canonical and noncanonical, was increased in the hyperpigmented skin of melasma patients. Collectively, WIF-1 downregulation, which may occur in epidermal keratinocytes and in dermal fibroblasts, is involved in melasma development because of the stimulation of melanogenesis and melanosome transfer through upregulation of the canonical and the noncanonical Wnt signaling pathway.

  9. Effects of electrolyzed oxidizing water on reducing Listeria monocytogenes contamination on seafood processing surfaces.

    PubMed

    Liu, Chengchu; Duan, Jingyun; Su, Yi-Cheng

    2006-02-15

    The effects of electrolyzed oxidizing (EO) water on reducing Listeria monocytogenes contamination on seafood processing surfaces were studied. Chips (5 x 5 cm(2)) of stainless steel sheet (SS), ceramic tile (CT), and floor tile (FT) with and without crabmeat residue on the surface were inoculated with L. monocytogenes and soaked in tap or EO water for 5 min. Viable cells of L. monocytogenes were detected on all chip surfaces with or without crabmeat residue after being held at room temperature for 1 h. Soaking contaminated chips in tap water resulted in small-degree reductions of the organism (0.40-0.66 log cfu/chip on clean surfaces and 0.78-1.33 log cfu/chip on dirty surfaces). Treatments of EO water significantly (p<0.05) reduced L. monocytogenes on clean surfaces (3.73 log on SS, 4.24 log on CT, and 5.12 log on FT). Presence of crabmeat residue on chip surfaces reduced the effectiveness of EO water on inactivating Listeria cells. However, treatments of EO water also resulted in significant reductions of L. monocytogenes on dirty surfaces (2.33 log on SS and CT and 1.52 log on FT) when compared with tap water treatments. The antimicrobial activity of EO water was positively correlated with its chlorine content. High oxidation-reduction potential (ORP) of EO water also contributed significantly to its antimicrobial activity against L. monocytogenes. EO water was more effective than chlorine water on inactivating L. monocytogenes on surfaces and could be used as a chlorine alternative for sanitation purpose. Application of EO water following a thorough cleaning process could greatly reduce L. monocytogenes contamination in seafood processing environments. PMID:16219378

  10. Recombinant interleukin-16 selectively modulates surface receptor expression and cytokine release in macrophages and dendritic cells

    PubMed Central

    Hermann, E; Darcissac, E; Idziorek, T; Capron, A; Bahr, G M

    1999-01-01

    Interleukin-16 (IL-16), a natural ligand for the CD4 receptor, has been found to modulate T-lymphocyte function and to inhibit human immunodeficiency virus type 1 (HIV-1) replication. Antigen-presenting cells (APC), including macrophages and dendritic cells, are known to express functional surface CD4 molecules, to be susceptible to HIV-1 infection and to play a critical role in different immune processes. Therefore, we evaluated the ability of recombinant IL-16 (rIL-16) to regulate receptor expression and cytokine release in monocyte-derived macrophages (MDM) and monocyte-derived dendritic cells (MDDC). Recombinant IL-16 was found to up-regulate CD25 and CD80 but to down-regulate CD4 and CD86 surface expression in MDM cultures. However, no change could be observed on the level of CD4, CD80 and CD86 expression in IL-16-stimulated MDDC, although a significant up-regulation of CD25 and CD83 was consistently detected. Furthermore, the level of gene expression of the chemokine receptors CCR5 and CXCR4 was significantly reduced in rIL-16-treated MDM and costimulation with IL-2 did not modify the activity of the recombinant cytokine. The effects on chemokine receptor gene expression were less evident in MDDC and only a transient down-regulation of weak intensity could be detected following stimulation with rIL-16. Analysis of supernatants from rIL-16-stimulatedcultures revealed a different profile of released cytokines/chemokines among the two cell populations studied. These findings establish an important role for IL-16 in modulating the activity of APC and may have relevance regarding the protection of reservoir cells against HIV-1 infection. PMID:10447738

  11. Synthesis and characterization of a lubricin mimic (mLub) to reduce friction and adhesion on the articular cartilage surface.

    PubMed

    Lawrence, Alexandra; Xu, Xin; Bible, Melissa D; Calve, Sarah; Neu, Corey P; Panitch, Alyssa

    2015-12-01

    The lubricating proteoglycan, lubricin, facilitates the remarkable low friction and wear properties of articular cartilage in the synovial joints of the body. Lubricin lines the joint surfaces and plays a protective role as a boundary lubricant in sliding contact; decreased expression of lubricin is associated with cartilage degradation and the pathogenesis of osteoarthritis. An unmet need for early osteoarthritis treatment is the development of therapeutic molecules that mimic lubricin function and yet are also resistant to enzymatic degradation common in the damaged joint. Here, we engineered a lubricin mimic (mLub) that is less susceptible to enzymatic degradation and binds to the articular surface to reduce friction. mLub was synthesized using a chondroitin sulfate backbone with type II collagen and hyaluronic acid (HA) binding peptides to promote interaction with the articular surface and synovial fluid constituents. In vitro and in vivo characterization confirmed the binding ability of mLub to isolated type II collagen and HA, and to the cartilage surface. Following trypsin treatment to the cartilage surface, application of mLub, in combination with purified or commercially available hyaluronan, reduced the coefficient of friction, and adhesion, to control levels as assessed over macro-to micro-scales by rheometry and atomic force microscopy. In vivo studies demonstrate an mLub residency time of less than 1 week. Enhanced lubrication by mLub reduces surface friction and adhesion, which may suppress the progression of degradation and cartilage loss in the joint. mLub therefore shows potential for treatment in early osteoarthritis following injury.

  12. Synthesis and characterization of a lubricin mimic (mLub) to reduce friction and adhesion on the articular cartilage surface.

    PubMed

    Lawrence, Alexandra; Xu, Xin; Bible, Melissa D; Calve, Sarah; Neu, Corey P; Panitch, Alyssa

    2015-12-01

    The lubricating proteoglycan, lubricin, facilitates the remarkable low friction and wear properties of articular cartilage in the synovial joints of the body. Lubricin lines the joint surfaces and plays a protective role as a boundary lubricant in sliding contact; decreased expression of lubricin is associated with cartilage degradation and the pathogenesis of osteoarthritis. An unmet need for early osteoarthritis treatment is the development of therapeutic molecules that mimic lubricin function and yet are also resistant to enzymatic degradation common in the damaged joint. Here, we engineered a lubricin mimic (mLub) that is less susceptible to enzymatic degradation and binds to the articular surface to reduce friction. mLub was synthesized using a chondroitin sulfate backbone with type II collagen and hyaluronic acid (HA) binding peptides to promote interaction with the articular surface and synovial fluid constituents. In vitro and in vivo characterization confirmed the binding ability of mLub to isolated type II collagen and HA, and to the cartilage surface. Following trypsin treatment to the cartilage surface, application of mLub, in combination with purified or commercially available hyaluronan, reduced the coefficient of friction, and adhesion, to control levels as assessed over macro-to micro-scales by rheometry and atomic force microscopy. In vivo studies demonstrate an mLub residency time of less than 1 week. Enhanced lubrication by mLub reduces surface friction and adhesion, which may suppress the progression of degradation and cartilage loss in the joint. mLub therefore shows potential for treatment in early osteoarthritis following injury. PMID:26398308

  13. Post-translational regulation of expression and conformation of an immunoglobulin domain in yeast surface display.

    PubMed

    Parthasarathy, Ranganath; Subramanian, Shyamsundar; Boder, Eric T; Discher, Dennis E

    2006-01-01

    Display of heterologous proteins on the surface of Saccharomyces cerevisiae is increasingly being exploited for directed evolution because of straightforward cell screens. However, yeast post-translationally modifies proteins in ways that must be factored into library engineering and refinement. Here, we express the extracellular immunoglobulin domain of an ubiquitous mammalian membrane protein, CD47, which is implicated in cancer, immunocompatibility, and motility. CD47 has multiple sites of glycosylation and a core disulfide bond. We assess the effects of both of these post-translational modifications on expression and antibody binding. CD47's extracellular domain is fused to the yeast mating protein Aga2p on the cell wall, and the resulting fusion protein binds several key antibodies, including a conformation-sensitive antibody. Site-by-site mutagenesis of CD47's five N-linked glycosylation sites progressively decreases expression levels on yeast, but folding appears stable. Cysteine mutations disrupt the expected core disulfide, and also decrease protein expression levels, though not to the extent seen with complete deglycosylation. However, with the core disulfide mutants, antibody binding proves to be lower than expected from expression levels and glycosylation is clearly reduced compared to wild-type. The results indicate that glycosylation regulates heterologous display on yeast more than core disulfides do and thus suggest bounds on directed evolution by post-translational processing.

  14. Developmental abnormalities and reduced fruit softening in tomato plants expressing an antisense Rab11 GTPase gene.

    PubMed

    Lu, C; Zainal, Z; Tucker, G A; Lycett, G W

    2001-08-01

    A cDNA clone from tomato fruit encodes a protein with strong homology with the rab11/YPT3 class of small GTPases that is thought to be involved in the control of protein trafficking within cells. The gene, LeRab11a, showed a pattern consistent with a single copy in DNA gel blots. The corresponding mRNA was developmentally regulated during fruit ripening, and its expression was inhibited in several ripening mutants. Its reduced expression in the Never-ripe mutant indicates that it may be induced by ethylene in fruit. The ripening-induced expression in tissues that are undergoing cell wall loosening immediately suggests a possible role in trafficking of cell wall-modifying enzymes. The message also was produced in leaves and flowers but not in roots. Antisense transformation was used to generate a "mutant phenotype." Antisense fruit changed color as expected but failed to soften normally. This was accompanied by reduced levels of two cell wall hydrolases, pectinesterase and polygalacturonase. There were other phenotypic effects in the plants, including determinate growth, reduced apical dominance, branched inflorescences, abnormal floral structure, and ectopic shoots on the leaves. In some plants, ethylene production was reduced. These data suggest an alternative or additional role in exocytosis or endocytosis of homeotic proteins, hormone carriers, or receptors.

  15. Reduced DOCK4 expression leads to erythroid dysplasia in myelodysplastic syndromes

    PubMed Central

    Sundaravel, Sriram; Duggan, Ryan; Bhagat, Tushar; Ebenezer, David L.; Liu, Hui; Yu, Yiting; Bartenstein, Matthias; Unnikrishnan, Madhu; Karmakar, Subhradip; Liu, Ting-Chun; Torregroza, Ingrid; Quenon, Thomas; Anastasi, John; McGraw, Kathy L.; Pellagatti, Andrea; Boultwood, Jacqueline; Yajnik, Vijay; Artz, Andrew; Le Beau, Michelle M.; Steidl, Ulrich; List, Alan F.; Evans, Todd; Verma, Amit; Wickrema, Amittha

    2015-01-01

    Anemia is the predominant clinical manifestation of myelodysplastic syndromes (MDS). Loss or deletion of chromosome 7 is commonly seen in MDS and leads to a poor prognosis. However, the identity of functionally relevant, dysplasia-causing, genes on 7q remains unclear. Dedicator of cytokinesis 4 (DOCK4) is a GTPase exchange factor, and its gene maps to the commonly deleted 7q region. We demonstrate that DOCK4 is underexpressed in MDS bone marrow samples and that the reduced expression is associated with decreased overall survival in patients. We show that depletion of DOCK4 levels leads to erythroid cells with dysplastic morphology both in vivo and in vitro. We established a novel single-cell assay to quantify disrupted F-actin filament network in erythroblasts and demonstrate that reduced expression of DOCK4 leads to disruption of the actin filaments, resulting in erythroid dysplasia that phenocopies the red blood cell (RBC) defects seen in samples from MDS patients. Reexpression of DOCK4 in −7q MDS patient erythroblasts resulted in significant erythropoietic improvements. Mechanisms underlying F-actin disruption revealed that DOCK4 knockdown reduces ras-related C3 botulinum toxin substrate 1 (RAC1) GTPase activation, leading to increased phosphorylation of the actin-stabilizing protein ADDUCIN in MDS samples. These data identify DOCK4 as a putative 7q gene whose reduced expression can lead to erythroid dysplasia. PMID:26578796

  16. Methamphetamine reduces expression of caveolin-1 in the dorsal striatum: Implication for dysregulation of neuronal function.

    PubMed

    Somkuwar, Sucharita S; Fannon, McKenzie J; Head, Brian P; Mandyam, Chitra D

    2016-07-22

    Role of striatal dopamine D1 receptors (D1Rs) in methamphetamine (Meth) taking and seeking is recognized from contingent Meth self-administration studies. For example, Meth increases levels of D1Rs in the dorsal striatum in animal models of Meth addiction, and blockade of striatal D1Rs decreased responding for Meth and reduced Meth priming-induced drug seeking. However, the mechanism underlying enhanced expression of striatal D1Rs in animals self-administering Meth is unknown and is hypothesized to involve maladaptive intracellular signal transduction mechanism via hyperphosphorylation of extracellular signal-regulated kinase 1/2 (ERK1/2). D1Rs are predominantly localized to detergent-resistant membrane/lipid raft fractions (MLR fraction), and in vitro studies indicate that D1R signaling and recycling is regulated by the MLR-resident protein caveolin-1 (Cav-1), in an endocytotic-dependent manner. Notably, expression of Cav-1 is inversely regulated by ERK1/2 activation, suggesting a signaling interplay among D1Rs, ERK1/2 and Cav-1. We therefore evaluated the effects of extended access Meth self-administration on expression of striatal D1Rs, activated ERK1/2 and Cav-1. We first report that Cav-1 is heavily expressed in neurons located in the dorsal striatum. We also report that extended access Meth produces compulsive-like unregulated intake of the drug, and these behavioral outcomes are associated with enhanced expression of D1Rs, increased activity of ERK1/2, and reduced Cav-1 expression in the dorsal striatum. These data suggest a possible cellular mechanism that involves Cav-1 regulation of D1R expression in response to escalated Meth intake, and how this response of altered D1Rs and enhanced ERK1/2 activation to Meth self-administration contributes to contingent-related processes such as addiction. PMID:27138644

  17. Reduced retinoids and retinoid receptors' expression in pancreatic cancer: A link to patient survival.

    PubMed

    Bleul, Tim; Rühl, Ralph; Bulashevska, Svetlana; Karakhanova, Svetlana; Werner, Jens; Bazhin, Alexandr V

    2015-09-01

    Pancreatic ductal adenocarcinoma (PDAC) represents one of the deadliest cancers in the world. All-trans retinoic acid (ATRA) is the major physiologically active form of vitamin A, regulating expression of many genes. Disturbances of vitamin A metabolism are prevalent in some cancer cells. The main aim of this work was to investigate deeply the components of retinoid signaling in PDAC compared to in the normal pancreas and to prove the clinical importance of retinoid receptor expression. For the study, human tumor tissues obtained from PDAC patients and murine tumors from the orthotopic Panc02 model were used for the analysis of retinoids, using high performance liquid chromatography mass spectrometry and real-time RT-PCR gene expression analysis. Survival probabilities in univariate analysis were estimated using the Kaplan-Meier method and the Cox proportional hazards model was used for the multivariate analysis. In this work, we showed for the first time that the ATRA and all-trans retinol concentration is reduced in PDAC tissue compared to their normal counterparts. The expression of RARα and β as well as RXRα and β are down-regulated in PDAC tissue. This reduced expression of retinoid receptors correlates with the expression of some markers of differentiation and epithelial-to-mesenchymal transition as well as of cancer stem cell markers. Importantly, the expression of RARα and RXRβ is associated with better overall survival of PDAC patients. Thus, reduction of retinoids and their receptors is an important feature of PDAC and is associated with worse patient survival outcomes.

  18. Klotho expression is reduced in COPD airway epithelial cells: effects on inflammation and oxidant injury.

    PubMed

    Gao, Wei; Yuan, Cheng; Zhang, Jingying; Li, Lingling; Yu, Like; Wiegman, Coen H; Barnes, Peter J; Adcock, Ian M; Huang, Mao; Yao, Xin

    2015-12-01

    COPD (chronic obstructive pulmonary disease) is associated with sustained inflammation, excessive injury, and accelerated lung aging. Human Klotho (KL) is an anti-aging protein that protects cells against inflammation and damage. In the present study, we quantified KL expression in the lungs of COPD patients and in an ozone-induced mouse model of COPD, and investigated the mechanisms that control KL expression and function in the airways. KL distribution and levels in human and mouse airways were measured by immunohistochemistry and Western blotting. The effect of CSE (cigarette smoke extract) on KL expression was detected in human bronchial epithelial cells. Moreover, the effect of KL on CSE-mediated inflammation and hydrogen peroxide-induced cellular injury/apoptosis was determined using siRNAs. KL expression was decreased in the lungs of smokers and further reduced in patients with COPD. Similarly, 6 weeks of exposure to ozone decreased KL levels in airway epithelial cells. CSE and TNFα (tumour necrosis factor α) decreased KL expression and release from airway epithelial cells, which was associated with enhanced pro-inflammatory cytokine expression. Moreover, KL depletion increased cell sensitivity to cigarette smoke-induced inflammation and oxidative stress-induced cell damage. These effects involved the NF-κB (nuclear factor κB), MAPK (mitogen-activated protein kinase) and Nrf2 (nuclear factor erythroid 2-related factor 2) pathways. Reduced KL expression in COPD airway epithelial cells was associated with increased oxidative stress, inflammation and apoptosis. These data provide new insights into the mechanisms associated with the accelerated lung aging in COPD development. PMID:26201096

  19. HMA4 expression in tobacco reduces Cd accumulation due to the induction of the apoplastic barrier.

    PubMed

    Siemianowski, Oskar; Barabasz, Anna; Kendziorek, Maria; Ruszczynska, Anna; Bulska, Ewa; Williams, Lorraine Elizabeth; Antosiewicz, Danuta Maria

    2014-03-01

    Ectopic expression in tobacco (Nicotiana tabacum v. Xanthi) of the export protein AtHMA4 (responsible in Arabidopsis for the control of Zn/Cd root to shoot translocation) resulted in decreased Cd uptake/accumulation in roots and shoots. This study contributes to understanding the mechanisms underlying this Cd-dependent phenotype to help predict the consequences of transgene expression for potential phytoremediation/biofortification-based strategies. Microarray analysis was performed to identify metal homeostasis genes that were differentially expressed in roots of Cd-exposed AtHMA4-expressing tobacco relative to the wild type. It was established that down-regulation of genes known to mediate Cd uptake was not responsible for reduced Cd uptake/accumulation in AtHMA4 transformants. The transcript levels of NtIRT1 and NtZIP1 were higher in transgenic plants, indicating an induction of the Fe and Zn deficiency status due to AtHMA4 expression. Interestingly, upon exposure to Cd, genes involved in cell wall lignification (NtHCT, NtOMET, and NtPrx11a) were up-regulated in transformants. Microscopic analysis of roots demonstrated that expression of AtHMA4 caused an induction of cell wall lignification in the external cell layers that was accompanied by enhanced H2O2 accumulation. Further study showed that the concentration of other elements (B, Co, Cu, Ni, Mo, and Zn) was reduced in AtHMA4 transformants in the presence of Cd. In conclusion, due to ectopic expression of 35S::AtHMA4, the physical apoplastic barrier within the external cell layer developed, which is likely to be responsible for the reduction of Cd uptake/accumulation.

  20. HMA4 expression in tobacco reduces Cd accumulation due to the induction of the apoplastic barrier

    PubMed Central

    Antosiewicz, Danuta Maria

    2014-01-01

    Ectopic expression in tobacco (Nicotiana tabacum v. Xanthi) of the export protein AtHMA4 (responsible in Arabidopsis for the control of Zn/Cd root to shoot translocation) resulted in decreased Cd uptake/accumulation in roots and shoots. This study contributes to understanding the mechanisms underlying this Cd-dependent phenotype to help predict the consequences of transgene expression for potential phytoremediation/biofortification-based strategies. Microarray analysis was performed to identify metal homeostasis genes that were differentially expressed in roots of Cd-exposed AtHMA4-expressing tobacco relative to the wild type. It was established that down-regulation of genes known to mediate Cd uptake was not responsible for reduced Cd uptake/accumulation in AtHMA4 transformants. The transcript levels of NtIRT1 and NtZIP1 were higher in transgenic plants, indicating an induction of the Fe and Zn deficiency status due to AtHMA4 expression. Interestingly, upon exposure to Cd, genes involved in cell wall lignification (NtHCT, NtOMET, and NtPrx11a) were up-regulated in transformants. Microscopic analysis of roots demonstrated that expression of AtHMA4 caused an induction of cell wall lignification in the external cell layers that was accompanied by enhanced H2O2 accumulation. Further study showed that the concentration of other elements (B, Co, Cu, Ni, Mo, and Zn) was reduced in AtHMA4 transformants in the presence of Cd. In conclusion, due to ectopic expression of 35S::AtHMA4, the physical apoplastic barrier within the external cell layer developed, which is likely to be responsible for the reduction of Cd uptake/accumulation. PMID:24420575

  1. Study of the surface of reduced lead silicate glasses by electron emission

    SciTech Connect

    Artamonov, O.M.; Kostikov, Y.P.; Novolodskii, V.A.; Redina, I.V.; Sattarov, D.K.

    1986-03-01

    The authors determine the composition of the emitting surface of reduced lead silicate glasses by electron emission and the change in it as a function of the various effects which affect the working of the devices made from RLSG, such as electron multipliers. Preliminary studies were made using an electron spectroscopy for chemical analysis method which showed that the original surface was significantly contaminated by carbon, whose concentration exceeded that of silicon by 7-18 times in different specimens. The surface composition of specimens of reduced lead silicate glasses changes weakly as a function of the reducing regime in hydrogen. Electron bombardment and heating in vaccum at a pressure of 10/sup -9/ torr lead to an increase in the concentration of carbon in the specimen.

  2. Brain SERT Expression of Male Rats Is Reduced by Aging and Increased by Testosterone Restitution

    PubMed Central

    Herrera-Pérez, José Jaime; Fernández-Guasti, Alonso; Martínez-Mota, Lucía

    2013-01-01

    In preclinical and clinical studies aging has been associated with a deteriorated response to antidepressant treatment. We hypothesize that such impairment is explained by an age-related decrease in brain serotonin transporter (SERT) expression associated with low testosterone (T) levels. The objectives of this study were to establish (1) if brain SERT expression is reduced by aging and (2) if the SERT expression in middle-aged rats is increased by T-restitution. Intact young rats (3–5 months) and gonad-intact middle-aged rats with or without T-restitution were used. The identification of the brain SERT expression was done by immunofluorescence in prefrontal cortex, lateral septum, hippocampus, and raphe nuclei. An age-dependent reduction of SERT expression was observed in all brain regions examined, while T-restitution recovered the SERT expression only in the dorsal raphe of middle-aged rats. This last action seems relevant since dorsal raphe plays an important role in the antidepressant action of selective serotonin reuptake inhibitors. All data suggest that this mechanism accounts for the T-replacement usefulness to improve the response to antidepressants in the aged population. PMID:26317087

  3. Atorvastatin reduces CD68, FABP4, and HBP expression in oxLDL-treated human macrophages.

    PubMed

    Llaverias, Gemma; Noé, Véronique; Peñuelas, Silvia; Vázquez-Carrera, Manuel; Sánchez, Rosa M; Laguna, Juan C; Ciudad, Carlos J; Alegret, Marta

    2004-05-21

    With the aim of identifying new target genes that could contribute to limit foam cell formation, we analyzed changes in the pattern of gene expression in human THP-1 macrophages treated with atorvastatin and oxidized-LDL (oxLDL). To this end, we used a human cDNA array containing 588 cardiovascular-related cDNAs. Exposure to oxLDL resulted in differential expression of 26 genes, while coincubation with atorvastatin modified the expression of 29 genes, compared to treatment with oxLDL alone. Changes in the expression of candidate genes, potentially connected to the atherosclerotic process, were confirmed by quantitative RT-PCR and Western blot. We show that atorvastatin prevents the increase in the expression of scavenger receptor CD68 and that of fatty acid binding protein 4 caused by oxLDL. In addition, atorvastatin reduces the expression of HDL-binding protein, apolipoprotein E, and matrix metalloproteinase 9. These findings are relevant to understand the direct antiatherogenic effects of statins on macrophages.

  4. Contributions of feature shapes and surface cues to the recognition of facial expressions.

    PubMed

    Sormaz, Mladen; Young, Andrew W; Andrews, Timothy J

    2016-10-01

    Theoretical accounts of face processing often emphasise feature shapes as the primary visual cue to the recognition of facial expressions. However, changes in facial expression also affect the surface properties of the face. In this study, we investigated whether this surface information can also be used in the recognition of facial expression. First, participants identified facial expressions (fear, anger, disgust, sadness, happiness) from images that were manipulated such that they varied mainly in shape or mainly in surface properties. We found that the categorization of facial expression is possible in either type of image, but that different expressions are relatively dependent on surface or shape properties. Next, we investigated the relative contributions of shape and surface information to the categorization of facial expressions. This employed a complementary method that involved combining the surface properties of one expression with the shape properties from a different expression. Our results showed that the categorization of facial expressions in these hybrid images was equally dependent on the surface and shape properties of the image. Together, these findings provide a direct demonstration that both feature shape and surface information make significant contributions to the recognition of facial expressions. PMID:27425385

  5. Contributions of feature shapes and surface cues to the recognition of facial expressions.

    PubMed

    Sormaz, Mladen; Young, Andrew W; Andrews, Timothy J

    2016-10-01

    Theoretical accounts of face processing often emphasise feature shapes as the primary visual cue to the recognition of facial expressions. However, changes in facial expression also affect the surface properties of the face. In this study, we investigated whether this surface information can also be used in the recognition of facial expression. First, participants identified facial expressions (fear, anger, disgust, sadness, happiness) from images that were manipulated such that they varied mainly in shape or mainly in surface properties. We found that the categorization of facial expression is possible in either type of image, but that different expressions are relatively dependent on surface or shape properties. Next, we investigated the relative contributions of shape and surface information to the categorization of facial expressions. This employed a complementary method that involved combining the surface properties of one expression with the shape properties from a different expression. Our results showed that the categorization of facial expressions in these hybrid images was equally dependent on the surface and shape properties of the image. Together, these findings provide a direct demonstration that both feature shape and surface information make significant contributions to the recognition of facial expressions.

  6. Self-aligned polysilicon MEMS-reduced mask count surface micromachining

    NASA Astrophysics Data System (ADS)

    Noworolski, J. Mark; Sanders, Seth R.

    1998-09-01

    A self-aligned reduced mask count micromachined polysilicon on nitride (SAMPSON) surface micromachining process is introduced. The self-alignment fabrication concept enables rapid fabrication, improves yields, and reduces parasitic capacitance of MEM devices. For many MEM devices the SAMPSON process results in a one mask savings over more conventional approaches. As a demonstration of the fabrication technique a burst-proof surface micromachined polysilicon resonant pressure sensor is fabricated using the SAMPSON process. This pressure sensor does not require a sealed cavity. It is also insensitive to mechanical property variations of the structural material, rendering its response essentially temperature independent.

  7. Fabrication and characterization of stable superhydrophobic surface with good friction-reducing performance on Al foil

    NASA Astrophysics Data System (ADS)

    Li, Peipei; Chen, Xinhua; Yang, Guangbin; Yu, Laigui; Zhang, Pingyu

    2014-05-01

    A lotus-leaf-like hierarchical structure with superhydrophobicity was created on Al foil by a facile three-step solution-immersion method involving etching in hydrochloric acid solution and immersing in hot water as well as surface-modification by stearic acid (denoted as STA). As-prepared etched-immersed Al/STA rough surface was characterized by means of scanning electron microscopy and X-ray photoelectron spectroscopy. Moreover, the water contact angles and water sliding angles of as-prepared etched-immersed Al/STA rough surface were measured, and the friction-reducing performance and self-cleaning ability of the as-prepared surface were also evaluated. Results indicate that the etched-immersed Al/STA rough surface consists of interconnected convex-concave micro-structure and uniformly distributed nano-sheets. Besides, it exhibits stable superhydrophobicity and good friction-reducing ability. Namely, it has a contact angle of water as high as 164.2° and a water sliding angle lower than 5°, while it retains good friction-reducing ability during extended sliding and possesses good self-cleaning ability as well. This demonstrates that the etched-immersed Al/STA rough surface may favor the applications of Al and its alloys in various industrial fields.

  8. Reduced GABAA receptor α6 expression in the trigeminal ganglion alters inflammatory TMJ hypersensitivity

    PubMed Central

    Puri, Jyoti; Vinothini, Priya; Reuben, Jayne; Bellinger, Larry L.; Ailing, Li; Peng, Yuan B.; Kramer, Phillip R.

    2012-01-01

    Trigeminal ganglia neurons express the GABAA receptor subunit alpha 6 (Gabrα6) but the role of this particular subunit in orofacial hypersensitivity is unknown. In this report the function of Gabrα6 was tested by reducing its expression in the trigeminal ganglia and measuring the effect of this reduction on inflammatory temporomandibular joint (TMJ) hypersensitivity. Gabrα6 expression was reduced by infusing the trigeminal ganglia of male Sprague Dawley rats with small interfering RNA (siRNA) having homology to either the Gabrα6 gene (Gabrα6 siRNA) or no known gene (control siRNA). Sixty hours after siRNA infusion the rats received a bilateral TMJ injection of complete Freund’s adjuvant to induce an inflammatory response. Hypersensitivity was then quantitated by measuring meal duration, which lengthens when hypersensitivity increases. Neuronal activity in the trigeminal ganglia was also measured by quantitating the amount of phosphorylated ERK. Rats in a different group that did not have TMJ inflammation had an electrode placed in the spinal cord at the level of C1 sixty hours after siRNA infusion to record extracellular electrical activity of neurons that responded to TMJ stimulation. Our results show that Gabrα6 was expressed in both neurons and satellite glia of the trigeminal ganglia and that Gabrα6 positive neurons within the trigeminal ganglia have afferents in the TMJ. Gabrα6 siRNA infusion reduced Gabrα6 gene expression by 30% and significantly lengthened meal duration in rats with TMJ inflammation. Gabrα6 siRNA infusion also significantly increased p-ERK expression in the trigeminal ganglia of rats with TMJ inflammation and increased electrical activity in the spinal cord of rats without TMJ inflammation. These results suggest that maintaining Gabrα6 expression was necessary to inhibit primary sensory afferents in the trigeminal pathway and reduce inflammatory orofacial nociception. PMID:22521829

  9. Behavioral stress reduces RIP140 expression in astrocyte and increases brain lipid accumulation.

    PubMed

    Feng, Xudong; Lin, Yu-Lung; Wei, Li-Na

    2015-05-01

    Receptor-interacting protein 140 (RIP140) is highly expressed in the brain, and acts in neurons and microglia to affect emotional responses. The present study reveals an additional function of RIP140 in the brain, which is to regulate brain lipid homeostasis via its action in astrocytes. We found forced swim stress (FSS) significantly reduces the expression level of RIP140 and elevates cholesterol content in the brain. Mechanistically, FSS elevates endoplasmic reticulum stress, which suppresses RIP140 expression by increasing microRNA 33 (miR33) that targets RIP140 mRNA's 3'-untranslated region. Consequentially, cholesterol biosynthesis and export are dramatically increased in astrocyte, the major source of brain cholesterol. These results demonstrate that RIP140 plays an important role in maintaining brain cholesterol homeostasis through, partially, regulating cholesterol metabolism in, and mobilization from, astrocyte. Altering RIP140 levels can disrupt brain cholesterol homeostasis, which may contribute to behavioral stress-induced neurological disorders. PMID:25697398

  10. Behavioral stress reduces RIP140 expression in astrocyte and increases brain lipid accumulation.

    PubMed

    Feng, Xudong; Lin, Yu-Lung; Wei, Li-Na

    2015-05-01

    Receptor-interacting protein 140 (RIP140) is highly expressed in the brain, and acts in neurons and microglia to affect emotional responses. The present study reveals an additional function of RIP140 in the brain, which is to regulate brain lipid homeostasis via its action in astrocytes. We found forced swim stress (FSS) significantly reduces the expression level of RIP140 and elevates cholesterol content in the brain. Mechanistically, FSS elevates endoplasmic reticulum stress, which suppresses RIP140 expression by increasing microRNA 33 (miR33) that targets RIP140 mRNA's 3'-untranslated region. Consequentially, cholesterol biosynthesis and export are dramatically increased in astrocyte, the major source of brain cholesterol. These results demonstrate that RIP140 plays an important role in maintaining brain cholesterol homeostasis through, partially, regulating cholesterol metabolism in, and mobilization from, astrocyte. Altering RIP140 levels can disrupt brain cholesterol homeostasis, which may contribute to behavioral stress-induced neurological disorders.

  11. Expertise in video game playing is associated with reduced valence-concordant emotional expressivity.

    PubMed

    Weinreich, André; Strobach, Tilo; Schubert, Torsten

    2015-01-01

    In carefully selected groups of video game playing (VGP) experts and nonexperts, we examined valence-concordant emotional expressivity. We measured electromyographic (EMG) activity over the corrugator supercilii muscle while participants viewed pleasant, neutral, and unpleasant pictures. Potential group differences concerning valence-concordant expressivity may arise from differences concerning the participants' emotional reactivity. To control for such differences, we concomitantly measured skin conductance response (SCR) and, in a separate affect misattribution procedure (AMP), valence transfer from the same set of stimuli. Importantly, we found attenuated valence-concordant EMG activity over the corrugator supercilii muscle in VGP experts compared to nonexperts, but no differences were evident concerning SCR or valence transfer in the AMP. The findings suggest that expertise in VGP is particularly associated with reduced valence-concordant emotional expressivity.

  12. Benzylglucosinolate Derived Isothiocyanate from Tropaeolum majus Reduces Gluconeogenic Gene and Protein Expression in Human Cells

    PubMed Central

    Guzmán-Pérez, Valentina; Bumke-Vogt, Christiane; Schreiner, Monika; Mewis, Inga; Borchert, Andrea; Pfeiffer, Andreas F. H.

    2016-01-01

    Nasturtium (Tropaeolum majus L.) contains high concentrations of benzylglcosinolate. We found that a hydrolysis product of benzyl glucosinolate—the benzyl isothiocyanate (BITC)—modulates the intracellular localization of the transcription factor Forkhead box O 1 (FOXO1). FoxO transcription factors can antagonize insulin effects and trigger a variety of cellular processes involved in tumor suppression, longevity, development and metabolism. The current study evaluated the ability of BITC—extracted as intact glucosinolate from nasturtium and hydrolyzed with myrosinase—to modulate i) the insulin-signaling pathway, ii) the intracellular localization of FOXO1 and, iii) the expression of proteins involved in gluconeogenesis, antioxidant response and detoxification. Stably transfected human osteosarcoma cells (U-2 OS) with constitutive expression of FOXO1 protein labeled with GFP (green fluorescent protein) were used to evaluate the effect of BITC on FOXO1. Human hepatoma HepG2 cell cultures were selected to evaluate the effect on gluconeogenic, antioxidant and detoxification genes and protein expression. BITC reduced the phosphorylation of protein kinase B (AKT/PKB) and FOXO1; promoted FOXO1 translocation from cytoplasm into the nucleus antagonizing the insulin effect; was able to down-regulate the gene and protein expression of gluconeogenic enzymes; and induced the gene expression of antioxidant and detoxification enzymes. Knockdown analyses with specific siRNAs showed that the expression of gluconeogenic genes was dependent on nuclear factor (erythroid derived)-like2 (NRF2) and independent of FOXO1, AKT and NAD-dependent deacetylase sirtuin-1 (SIRT1). The current study provides evidence that BITC might have a role in type 2 diabetes T2D by reducing hepatic glucose production and increasing antioxidant resistance. PMID:27622707

  13. Benzylglucosinolate Derived Isothiocyanate from Tropaeolum majus Reduces Gluconeogenic Gene and Protein Expression in Human Cells.

    PubMed

    Guzmán-Pérez, Valentina; Bumke-Vogt, Christiane; Schreiner, Monika; Mewis, Inga; Borchert, Andrea; Pfeiffer, Andreas F H

    2016-01-01

    Nasturtium (Tropaeolum majus L.) contains high concentrations of benzylglcosinolate. We found that a hydrolysis product of benzyl glucosinolate-the benzyl isothiocyanate (BITC)-modulates the intracellular localization of the transcription factor Forkhead box O 1 (FOXO1). FoxO transcription factors can antagonize insulin effects and trigger a variety of cellular processes involved in tumor suppression, longevity, development and metabolism. The current study evaluated the ability of BITC-extracted as intact glucosinolate from nasturtium and hydrolyzed with myrosinase-to modulate i) the insulin-signaling pathway, ii) the intracellular localization of FOXO1 and, iii) the expression of proteins involved in gluconeogenesis, antioxidant response and detoxification. Stably transfected human osteosarcoma cells (U-2 OS) with constitutive expression of FOXO1 protein labeled with GFP (green fluorescent protein) were used to evaluate the effect of BITC on FOXO1. Human hepatoma HepG2 cell cultures were selected to evaluate the effect on gluconeogenic, antioxidant and detoxification genes and protein expression. BITC reduced the phosphorylation of protein kinase B (AKT/PKB) and FOXO1; promoted FOXO1 translocation from cytoplasm into the nucleus antagonizing the insulin effect; was able to down-regulate the gene and protein expression of gluconeogenic enzymes; and induced the gene expression of antioxidant and detoxification enzymes. Knockdown analyses with specific siRNAs showed that the expression of gluconeogenic genes was dependent on nuclear factor (erythroid derived)-like2 (NRF2) and independent of FOXO1, AKT and NAD-dependent deacetylase sirtuin-1 (SIRT1). The current study provides evidence that BITC might have a role in type 2 diabetes T2D by reducing hepatic glucose production and increasing antioxidant resistance. PMID:27622707

  14. Menthol reduces the anticoagulant effect of warfarin by inducing cytochrome P450 2C expression.

    PubMed

    Hoshino, Motohiro; Ikarashi, Nobutomo; Tsukui, Makoto; Kurokawa, Asako; Naito, Rina; Suzuki, Midori; Yokobori, Kohsuke; Ochiai, Takumi; Ishii, Makoto; Kusunoki, Yoshiki; Kon, Risako; Ochiai, Wataru; Wakui, Nobuyuki; Machida, Yoshiaki; Sugiyama, Kiyoshi

    2014-06-01

    Recently, it was reported that the anticoagulant effect of warfarin was reduced when patients receiving warfarin also took menthol. The purpose of this study is to reveal the mechanism of this reduced anticoagulant effect of warfarin from the pharmacokinetic point of view. Warfarin was orally administered to mice 24h after the administration of menthol for 2 days, and the plasma warfarin concentration was measured. In the menthol administration group, the area under the blood concentration time curve of warfarin was decreased by approximately 25%, while total clearance was increased to 1.3-fold compared to the control group. The hepatic cytochrome P450 (CYP) 2C protein expression level in the menthol administration group was significantly increased compared to that in the control group. An increase in the nuclear translocation of constitutive androstane receptor (CAR) was also observed. The addition of menthol to human hepatic cells, HepaRG cells, caused an increase in the mRNA expression level of CYP2C9. The results of this study revealed that menthol causes an increase in CYP2C expression levels in the liver, which leads to an enhancement of warfarin metabolism, resulting in a decreased anticoagulant effect of warfarin. It was also suggested that menthol acted directly on the liver and increased the expression level of CYP2C by enhancing the nuclear translocation of CAR. PMID:24594507

  15. Gentiana scabra Reduces SR-A Expression and Oxidized-LDL Uptake in Human Macrophages

    PubMed Central

    Lin, Chin-Sheng; Liu, Pang-Yen; Lian, Chen-Hao; Lin, Ching-Heng; Lai, Jenn-Haung; Ho, Ling-Jun; Yang, Shih-Ping; Cheng, Shu-Meng

    2016-01-01

    Background Macrophages can imbibe low-density lipoprotein (LDL) through scavenger receptors to become foam cells, which is critical in the initiation and progression of atherosclerosis. Mounting evidence suggests that the anti-inflammatory nature of Chinese herbs have the capacity to halt the complex mechanisms underlying atherosclerosis. This study examined the effects of Chinese herbs on foam cell formation. Methods Chinese herbs were obtained from the Sun Ten pharmaceutic company. Using oxidized LDL (OxLDL) uptake and a cell toxicity assay, we screened more than 30 types of Chinese herbs. Western blotting was used to determine expressions of scavenger receptors (SRs) and extracellular-signal-regulated kinase (ERK) activities. Results We found that Gentiana scabra reduced oxidized LDL uptake effectively in THP-1 macrophages (p < 0.05 vs. OxLDL treated control). Moreover, treatment with Gentiana scabra in THP-1 macrophages resulted in decreased expression of scavenger receptor- A (SR-A) (p < 0.05 vs. control). Molecular investigation revealed that Gentiana scabra inhibited SR-A protein expression, possibly by regulating ERK signaling pathways (p < 0.05 vs. control). Conclusions By regulating SR-A expression, Gentiana scabra reduced oxidized LDL uptake in human macrophages. These results support the potential use of Gentiana scabra in treating atherosclerosis. PMID:27471359

  16. Promoter mutation and reduced expression of BRCA1 in canine mammary tumors.

    PubMed

    Qiu, H B; Sun, W D; Yang, X; Jiang, Q Y; Chen, S; Lin, D G

    2015-12-01

    Breast cancer 1, early onset (BRCA1) is one of the most important genes in human familial breast cancer, which also plays an important role in canine mammary tumors. The objectives of this study were to determine the promoter sequence of canine BRCA1, to investigate its promoter mutation status and to describe BRCA1 expression pattern in canine mammary tumors. The promoter sequence of canine BRCA1 was acquired by aligning human BRCA1 promoter sequence with canine genomic sequence and confirmed by standard promoter activity analysis. Same as human BRCA1 promoter, the CAAT box and G/C box were found in canine BRCA1 promoter. In order to explore the mutation status of the promoter region and to investigate the expression pattern of this gene, 10 normal canine mammary tissues, 15 benign mammary tumors and 15 malignant mammary tumors were used. By sequencing, 46.7% of the malignant mammary tumors were found with a deletion of one cytosine in the promoter region. The mRNA expression of BRCA1 was significantly reduced in benign and malignant mammary tumors (P<0.05), and the protein expression of BRCA1 was significantly reduced in malignant mammary tumors (P<0.05). This study is the first time to determine the canine BRCA1 promoter sequence and to describe the promoter mutation status in canine mammary tumors. PMID:26679809

  17. Bisdemethoxycurcumin inhibits ovarian cancer via reducing oxidative stress mediated MMPs expressions

    PubMed Central

    Pei, Haifeng; Yang, Yi; Cui, Lin; Yang, Jiong; Li, Xiuchuan; Yang, Yongjian; Duan, Haixia

    2016-01-01

    As one main active compound of curcuminoids, Bisdemethoxycurcumin (BDMC) possesses several biological activities, such as anti-inflammation and anti-cancer activities. However, the detailed mechanism of BDMC’s anti-metastasis activity in ovarian cancer has not been clearly elucidated yet. In the present study, cell proliferation, wound healing motility, cell adhesion and invasion with or without BDMC were determined. In addition, western blot was used to examine proteins expressions. The lucigenin-enhanced luminescence was introduced to assess cellular oxidative stress. The luciferase reporter gene assay was introduced to evaluate the transcriptional activity of NF-κB. Finally, BDMC significantly inhibited the adhesion, migration, invasion and metastasis of SKOV-3 cells. Moreover, BDMC inhibited expressions of several degradation-associated proteins, such as matrix metalloproteinase-2 (MMP-2), matrix metalloproteinase-9 (MMP-9), CD147, urokinase plasminogen activator (uPA), intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1), whereas increased expression of tissue inhibitor of metalloproteinase-1 (TIMP-1), in a dose-dependent manner. In addition, BDMC reduced generation of cellular superoxide in a dose-dependent manner. Furthermore, BDMC inhibited the phosphorylation levels of NF-κB p65 and IκB-α, and consequently reduced NF-κB-driven luciferase expression. Collectively, BDMC serves as a therapeutic medicine to suppress ovarian cancer, perhaps via inhibiting cellular oxidative stress and subsequently inactivating NF-κB pathway. PMID:27349797

  18. Short-chain ceramides depress integrin cell surface expression and function in colorectal cancer cells.

    PubMed

    Morad, Samy A F; Bridges, Lance C; Almeida Larrea, Alex D; Mayen, Anthony L; MacDougall, Matthew R; Davis, Traci S; Kester, Mark; Cabot, Myles C

    2016-07-01

    Colorectal cancer (CRC) is highly metastatic, significantly so to liver, a characteristic that embodies one of the most challenging aspects of treatment. The integrin family of cell-cell and cell-matrix adhesion receptors plays a central role in migration and invasion, functions that underlie metastatic potential. In the present work we sought to determine the impact of ceramide, which plays a key modulatory role in cancer suppression, on integrin cell surface expression and function in CRC cells in order to reveal possible ceramide-centric effects on tumor cell motility. Human CRC cells LoVo, HT-29, and HCT-116 were employed, which represent lines established from primary and metastatic sites. A cell-permeable, short-chain analog, C6-ceramide, was used as ceramide mimic. Exposure of cells to C6-ceramide (24 h) promoted a dose-dependent (2.5-10 µM) decrease in the expression of cell surface β1 and β4 integrin subunits in all cell lines; at 10 µM C6-ceramide, the decreases ranged from 30 to 50% of the control. Expression of cell surface αVβ6 integrin, which is associated with advanced invasion in CRC, was also suppressed by C6-ceramide. Decreases in integrin expression translated to diminished cellular adhesion, 50% of the control at 5 µM C6-ceramide, and markedly reduced cellular migration, approximately 30-40% of the control in all cell lines. Physicochemical examination revealed potent efficacy of nano-formulated C6-ceramide, but inferior activity of dihydro-C6-ceramide and L-C6-ceramide, compared to the unsaturated counterpart and the natural d-enantiomer, respectively. These studies demonstrate novel actions of ceramides that may have application in suppression of tumor metastasis, in addition to their known tumor suppressor effects. PMID:27045476

  19. Methoxychlor and fenvalerate induce neuronal death by reducing GluR2 expression.

    PubMed

    Umeda, Kanae; Kotake, Yaichiro; Miyara, Masatsugu; Ishida, Keishi; Sanoh, Seigo; Ohta, Shigeru

    2016-04-01

    GluR2, an α-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA) receptor subunit, plays important roles in neuronal survival. We previously showed that exposure of cultured rat cortical neurons to several chemicals decreases GluR2 protein expression, leading to neuronal toxicity. Methoxychlor, the bis-p-methoxy derivative of dichlorodiphenyltrichloroethane, and fenvalerate, a synthetic pyrethroid chemical, have been used commercially as agricultural pesticides in several countries. In this study, we investigated the effects of long-term methoxychlor and fenvalerate exposure on neuronal glutamate receptors. Treatment of cultured rat cortical neurons with 1 or 10 µM methoxychlor and fenvalerate for 9 days selectively decreased GluR2 protein expression; the expression of other AMPA receptor subunits GluR1, GluR3, and GluR4 did not change under the same conditions. Importantly, the decreases in GluR2 protein expression were also observed on the cell surface membrane where AMPA receptors typically function. In addition, both chemicals decreased neuronal viability, which was blocked by pretreatment with 1-naphtylacetylspermine, an antagonist of GluR2-lacking AMPA receptors, and MK-801, an N-methyl-d-aspartate (NMDA) receptor antagonist. These results suggest that long-term exposure to methoxychlor and fenvalerate decreases GluR2 protein expression, leading to neuronal death via overactivation of GluR2-lacking AMPA and NMDA receptors.

  20. Arsenic transport between surface and groundwater in a moderately reducing zone: Geochemical approach

    NASA Astrophysics Data System (ADS)

    Khaska, Mahmoud; Le Gal La Salle, Corinne; Verdoux, Patrick

    2015-04-01

    Arsenic contamination represents a major risk to human health as one of the most prominent environmental causes of cancer mortality. Mining activities, particularly those involving arsenic rich ores have an impact on the environment and on human health that may persist for many decades after mine closure. The relationships between As released from alluvial aquifer in the vicinity of the sulfide-rich mine dumps was demonstrated with geochemical and isotopic tracers (major and traces elements, 87Sr/86Sr, 18O, 2H). Strontium isotopes were used to trace the transport of As downstream from a As rich tailing dam. Increasing As and Fe concentrations in surface water are explained by As release associated with alluvial groundwater discharge to the stream. This process occurs in a moderately reduced section of the stream downgradient from the sulfide-rich tailing dam. High As, total Fe and low Eh in groundwater confirm the discharge of alluvial groundwater and explain its impact on surface water. Transport of As between surface and groundwater can be described as follows: 1- Subsurface moderately reducing conditions prevail in groundwater downgradient from the tailing dams. This suggests a flux of reduced water from sulfide-rich tailing dams which is characterized by its high As and Fe content resulting from the reduction of Fe-sulfides. 2- Upon mixing with surface water, oxidizing conditions prevails and precipitate as Fe hydroxide on the stream bed. As and Sr subsequently adsorbed on the Fe -oxyhydroxide surface. This process contributes to the immobilization of As in surface water. Remaining dissolved As in surface water can be re-introduced in alluvial groundwater downstream of the reducing zone.

  1. Reducing Ice Adhesion on Nonsmooth Metallic Surfaces: Wettability and Topography Effects.

    PubMed

    Ling, Edwin Jee Yang; Uong, Victor; Renault-Crispo, Jean-Sébastien; Kietzig, Anne-Marie; Servio, Phillip

    2016-04-01

    The effects of ice formation and accretion on external surfaces range from being mildly annoying to potentially life-threatening. Ice-shedding materials, which lower the adhesion strength of ice to its surface, have recently received renewed research attention as a means to circumvent the problem of icing. In this work, we investigate how surface wettability and surface topography influence the ice adhesion strength on three different surfaces: (i) superhydrophobic laser-inscribed square pillars on copper, (ii) stainless steel 316 Dutch-weave meshes, and (iii) multiwalled carbon nanotube-covered steel meshes. The finest stainless steel mesh displayed the best performance with a 93% decrease in ice adhesion relative to polished stainless steel, while the superhydrophobic square pillars exhibited an increase in ice adhesion by up to 67% relative to polished copper. Comparisons of dynamic contact angles revealed little correlation between surface wettability and ice adhesion. On the other hand, by considering the ice formation process and the fracture mechanics at the ice-substrate interface, we found that two competing mechanisms governing ice adhesion strength arise on nonplanar surfaces: (i) mechanical interlocking of the ice within the surface features that enhances adhesion, and (ii) formation of microcracks that act as interfacial stress concentrators, which reduce adhesion. Our analysis provides insight toward new approaches for the design of ice-releasing materials through the use of surface topographies that promote interfacial crack propagation. PMID:26953827

  2. Reduced ubiquitin C-terminal hydrolase-1 expression levels in dementia with Lewy bodies.

    PubMed

    Barrachina, Marta; Castaño, Esther; Dalfó, Esther; Maes, Tamara; Buesa, Carlos; Ferrer, Isidro

    2006-05-01

    Parkinson disease (PD) and dementia with Lewy bodies (DLB) are characterized by the accumulation of abnormal alpha-synuclein and ubiquitin in protein aggregates conforming Lewy bodies and Lewy neurites. Ubiquitin C-terminal hydrolase-1 (UCHL-1) disassembles polyubiquitin chains to increase the availability of free monomeric ubiquitin to the ubiquitin proteasome system (UPS) thus favoring protein degradation. Since mutations in the UCHL-1 gene, reducing UPS activity by 50%, have been reported in autosomal dominant PD, and UCHL-1 inhibition results in the formation of alpha-synuclein aggregates in mesencephalic cultured neurons, the present study was initiated to test UCHL-1 mRNA and protein levels in post-mortem frontal cortex (area 8) of PD and DLB cases, compared with age-matched controls. TaqMan PCR assays, and Western blots demonstrated down-regulation of UCHL-1 mRNA and UCHL-1 protein in the cerebral cortex in DLB (either in pure forms, not associated with Alzheimer disease: AD, and in common forms, with accompanying AD changes), but not in PD, when compared with age-matched controls. Interestingly, UCHL-1 mRNA and protein expressions were reduced in the medulla oblongata in the same PD cases. Moreover, UCHL-1 protein was decreased in the substantia nigra in cases with Lewy body pathology. UCHL-1 down-regulation was not associated with reduced protein levels of several proteasomal subunits, including 20SX, 20SY, 19S and 11Salpha. Yet UCHL-3 expression was reduced in the cerebral cortex of PD and DLB patients. Together, these observations show reduced UCHL-1 expression as a contributory factor in the abnormal protein aggregation in DLB, and points UCHL-1 as a putative therapeutic target in the treatment of DLB.

  3. Disturbed shear stress reduces Klf2 expression in arterial-venous fistulae in vivo

    PubMed Central

    Yamamoto, Kota; Protack, Clinton D; Kuwahara, Go; Tsuneki, Masayuki; Hashimoto, Takuya; Hall, Michael R; Assi, Roland; Brownson, Kirstyn E; Foster, Trenton R; Bai, Hualong; Wang, Mo; Madri, Joseph A; Dardik, Alan

    2015-01-01

    Laminar shear stress (SS) induces an antiproliferative and anti-inflammatory endothelial phenotype and increases Klf2 expression. We altered the diameter of an arteriovenous fistula (AVF) in the mouse model to determine whether increased fistula diameter produces disturbed SS in vivo and if acutely increased disturbed SS results in decreased Klf2 expression. The mouse aortocaval fistula model was performed with 22, 25, or 28 gauge needles to puncture the aorta and the inferior vena cava. Duplex ultrasound was used to examine the AVF and its arterial inflow and venous outflow, and SS was calculated. Arterial samples were examined with western blot, immunohistochemistry, and immunofluorescence analysis for proteins and qPCR for RNA. Mice with larger diameter fistulae had diminished survival but increased AVF patency. Increased SS magnitudes and range of frequencies were directly proportional to the needle diameter in the arterial limb proximal to the fistula but not in the venous limb distal to the fistula, with 22-gauge needles producing the most disturbed SS in vivo. Klf2 mRNA and protein expression was diminished in the artery proximal to the fistula in proportion to increasing SS. Increased fistula diameter produces increased SS magnitude and frequency, consistent with disturbed SS in vivo. Disturbed SS is associated with decreased mRNA and protein expression of Klf2. Disturbed SS and reduced Klf2 expression near the fistula are potential therapeutic targets to improve AVF maturation. PMID:25780089

  4. Inducing a Concurrent Motor Load Reduces Categorization Precision for Facial Expressions

    PubMed Central

    2015-01-01

    Motor theories of expression perception posit that observers simulate facial expressions within their own motor system, aiding perception and interpretation. Consistent with this view, reports have suggested that blocking facial mimicry induces expression labeling errors and alters patterns of ratings. Crucially, however, it is unclear whether changes in labeling and rating behavior reflect genuine perceptual phenomena (e.g., greater internal noise associated with expression perception or interpretation) or are products of response bias. In an effort to advance this literature, the present study introduces a new psychophysical paradigm for investigating motor contributions to expression perception that overcomes some of the limitations inherent in simple labeling and rating tasks. Observers were asked to judge whether smiles drawn from a morph continuum were sincere or insincere, in the presence or absence of a motor load induced by the concurrent production of vowel sounds. Having confirmed that smile sincerity judgments depend on cues from both eye and mouth regions (Experiment 1), we demonstrated that vowel production reduces the precision with which smiles are categorized (Experiment 2). In Experiment 3, we replicated this effect when observers were required to produce vowels, but not when they passively listened to the same vowel sounds. In Experiments 4 and 5, we found that gender categorizations, equated for difficulty, were unaffected by vowel production, irrespective of the presence of a smiling expression. These findings greatly advance our understanding of motor contributions to expression perception and represent a timely contribution in light of recent high-profile challenges to the existing evidence base. PMID:26618622

  5. Surface adhesive forces: a metric describing the drag-reducing effects of superhydrophobic coatings.

    PubMed

    Cheng, Mengjiao; Song, Mengmeng; Dong, Hongyu; Shi, Feng

    2015-04-01

    Nanomaterials with superhydrophobic properties are promising as drag-reducing coatings. However, debates regarding whether superhydrophobic surfaces are favorable for drag reduction require further clarification. A quantified water adhesive force measurement is proposed as a metric and its effectiveness demonstrated using three typical superhydrophobic coatings on model ships with in situ sailing tests. PMID:25418808

  6. Airfoil-shaped micro-mixers for reducing fouling on membrane surfaces

    SciTech Connect

    Ho, Clifford K; Altman, Susan J; Clem, Paul G; Hibbs, Michael; Cook, Adam W

    2012-10-23

    An array of airfoil-shaped micro-mixers that enhances fluid mixing within permeable membrane channels, such as used in reverse-osmosis filtration units, while minimizing additional pressure drop. The enhanced mixing reduces fouling of the membrane surfaces. The airfoil-shaped micro-mixer can also be coated with or comprised of biofouling-resistant (biocidal/germicidal) ingredients.

  7. Waste Foundry Sand Soil Amendment to Reduce Atrazine Loading to Surface Runoff

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A series of experiments was conducted to evaluate the potential for surface applied foundry sand (FS) waste material to reduce atrazine in runoff water from fields having atrazine-based weed management. In the first experiment, the ability of several FSs to remove atrazine from the water column was ...

  8. Surface adhesive forces: a metric describing the drag-reducing effects of superhydrophobic coatings.

    PubMed

    Cheng, Mengjiao; Song, Mengmeng; Dong, Hongyu; Shi, Feng

    2015-04-01

    Nanomaterials with superhydrophobic properties are promising as drag-reducing coatings. However, debates regarding whether superhydrophobic surfaces are favorable for drag reduction require further clarification. A quantified water adhesive force measurement is proposed as a metric and its effectiveness demonstrated using three typical superhydrophobic coatings on model ships with in situ sailing tests.

  9. Method and apparatus for reducing the drag of flows over surfaces

    NASA Technical Reports Server (NTRS)

    Keefe, Laurence R. (Inventor)

    1998-01-01

    An apparatus, and its accompanying method, for reducing the drag of flows over a surface includes arrays of small disks and sensors. The arrays are embedded in the surface and may extend above, or be depressed below, the surface, provided they remain hydraulically smooth either when operating or when inactive. The disks are arranged in arrays of various shapes, and spaced according to the cruising speed of the vehicle on which the arrays are installed. For drag reduction at speeds of the order of 30 meters/second, preferred embodiments include disks that are 0.2 millimeter in diameter and spaced 0.4 millimeter apart. For drag reduction at speeds of the order of 300 meters/second, preferred embodiments include disks that are 0.045 millimeter in diameter and spaced 0.09 millimeter apart. Smaller and larger dimensions for diameter and spacing are also possible. The disks rotate in the plane of the surface, with their rotation axis substantially perpendicular to the surface. The rotating disks produce velocity perturbations parallel to the surface in the overlying boundary layer. The sensors sense the flow at the surface and connect to control circuitry that adjusts the rotation rates and duty cycles of the disks accordingly. Suction and blowing holes can be interspersed among, or made coaxial with, the disks for creating general three-component velocity perturbations in the near-surface region. The surface can be a flat, planar surface or a nonplanar surface, such as a triangular riblet surface. The present apparatus and method have potential applications in the field of aeronautics for improving performance and efficiency of commercial and military aircraft, and in other industries where drag is an obstacle, including gas and oil delivery through long-haul pipelines.

  10. Acute Heat Stress and Reduced Nutrient Intake Alter Intestinal Proteomic Profile and Gene Expression in Pigs

    PubMed Central

    Pearce, Sarah C.; Lonergan, Steven M.; Huff-Lonergan, Elisabeth; Baumgard, Lance H.; Gabler, Nicholas K.

    2015-01-01

    Heat stress and reduced feed intake negatively affect intestinal integrity and barrier function. Our objective was to compare ileum protein profiles of pigs subjected to 12 hours of HS, thermal neutral ad libitum feed intake, or pair-fed to heat stress feed intake under thermal neutral conditions (pair-fed thermal neutral). 2D-Differential In Gel Electrophoresis and gene expression were performed. Relative abundance of 281 and 138 spots differed due to heat stress, compared to thermal neutral and pair-fed thermal neutral pigs, respectively. However, only 20 proteins were different due to feed intake (thermal neutral versus pair-fed thermal neutral). Heat stress increased mRNA expression of heat shock proteins and protein abundance of heat shock proteins 27, 70, 90-α and β were also increased. Heat stress reduced ileum abundance of several metabolic enzymes, many of which are involved in the glycolytic or TCA pathways, indicating a change in metabolic priorities. Stress response enzymes peroxiredoxin-1 and peptidyl-prolyl cis-trans isomerase A were decreased in pair-fed thermal neutral and thermal neutral pigs compared to heat stress. Heat stress increased mRNA abundance markers of ileum hypoxia. Altogether, these data show that heat stress directly alters intestinal protein and mRNA profiles largely independent of reduced feed intake. These changes may be related to the reduced intestinal integrity associated with heat stress. PMID:26575181

  11. Reduced responses of macrophages on nanometer surface features of altered alumina crystalline phases.

    PubMed

    Khang, Dongwoo; Liu-Snyder, Peishan; Pareta, Rajesh; Lu, Jing; Webster, Thomas J

    2009-06-01

    Extensive prolonged interactions of inflammatory cells (such as macrophages) at the host-implant interface may lead to implant failure. While previous studies have shown increased in vitro and in vivo bone cell adhesion, proliferation and mineralization on nanophase compared to currently implanted ceramics, few studies have been conducted to elucidate inflammatory cell responses on such nanophase ceramics. Controlling surface feature size and corresponding surface roughness on implants may clearly alter immune cell responses, which would be an extremely important consideration for the use of nanostructured materials as improved biomaterials. In this study, reduced macrophage density was observed on alumina (Al(2)O(3)) compacts with greater nanometer surface roughness accompanied by changes in crystallinity for up to 24 h in culture. Since alumina is a commonly used ceramic in orthopedic applications, this in vitro study continues to support the use of nanophase ceramics as improved orthopedic implants by demonstrating reduced macrophage responses.

  12. Ethanol impaired neuronal migration is associated with reduced aspartyl-asparaginyl-beta-hydroxylase expression.

    PubMed

    Carter, Jade J; Tong, Ming; Silbermann, Elizabeth; Lahousse, Stephanie A; Ding, Fei Fei; Longato, Lisa; Roper, Nitin; Wands, Jack R; de la Monte, Suzanne M

    2008-09-01

    Cerebellar hypoplasia in fetal alcohol spectrum disorders (FASD) is associated with inhibition of insulin and insulin-like growth factor (IGF) signaling in the brain. Aspartyl (asparaginyl)-beta-hydroxylase (AAH) is a mediator of neuronal motility, and stimulated by insulin and IGF activation of PI3 kinase-Akt, or inhibition of GSK-3beta. Since ethanol inhibits PI3 Kinase-Akt and increases GSK-3beta activity in brain, we examined the effects of ethanol and GSK-3beta on AAH expression and directional motility in neuronal cells. Control and ethanol-exposed (100 mM x 48 h) human PNET2 cerebellar neuronal cells were stimulated with IGF-1 and used to measure AAH expression and directional motility. Molecular and biochemical approaches were used to characterize GSK-3beta regulation of AAH and neuronal motility. Ethanol reduced IGF-1 stimulated AAH protein expression and directional motility without inhibiting AAH's mRNA. Further analysis revealed that: (1) AAH protein could be phosphorylated by GSK-3beta; (2) high levels of GSK-3beta activity decreased AAH protein; (3) inhibition of GSK-3beta and/or global Caspases increased AAH protein; (4) AAH protein was relatively more phosphorylated in ethanol-treated compared with control cells; and (5) chemical inhibition of GSK-3beta and/or global Caspases partially rescued ethanol-impaired AAH protein expression and motility. Ethanol-impaired neuronal migration is associated with reduced IGF-I stimulated AAH protein expression. This effect may be mediated by increased GSK-3beta phosphorylation and Caspase degradation of AAH. Therapeutic strategies to rectify CNS developmental abnormalities in FASD should target factors underlying the ethanol-associated increases in GSK-3beta and Caspase activation, e.g. IGF resistance and increased oxidative stress. PMID:18478238

  13. Reduced mRNA expression levels of MBD2 and MBD3 in gastric carcinogenesis.

    PubMed

    Pontes, Thaís Brilhante; Chen, Elizabeth Suchi; Gigek, Carolina Oliveira; Calcagno, Danielle Queiroz; Wisnieski, Fernanda; Leal, Mariana Ferreira; Demachki, Samia; Assumpção, Paulo Pimentel; Artigiani, Ricardo; Lourenço, Laércio Gomes; Burbano, Rommel Rodriguez; Arruda Cardoso Smith, Marília

    2014-04-01

    Aberrant methylation has been reported in several neoplasias, including gastric cancer. The methyl-CpG-binding domain (MBD) family proteins have been implicated in the chromatin remodeling process, leading to the modulation of gene expression. To evaluate the role of MBD2 and MBD3 in gastric carcinogenesis and the possible association with clinicopathological characteristics, we assessed the mRNA levels and promoter methylation patterns in gastric tissues. In this study, MBD2 and MBD3 mRNA levels were determined by RT-qPCR in 28 neoplastic and adjacent nonneoplastic and 27 gastritis and non-gastritis samples. The promoter methylation status was determined by bisulfite sequencing, and we found reduced MBD2 and MBD3 levels in the neoplastic samples compared with the other groups. Moreover, a strong correlation between the MBD2 and MBD3 expression levels was observed in each set of paired samples. Our data also showed that the neoplastic tissues exhibited higher MBD2 promoter methylation than the other groups. Interestingly, the non-gastritis group was the only one with positive methylation in the MBD3 promoter region. Furthermore, a weak correlation between gene expression and methylation was observed. Therefore, our data suggest that DNA methylation plays a minor role in the regulation of MBD2 and MBD3 expression, and the presence of methylation at CpGs that interact with transcription factor complexes might also be involved in the modulation of these genes. Moreover, reduced mRNA expression of MBD2 and MBD3 is implicated in gastric carcinogenesis, and thus, further investigations about these genes should be conducted for a better understanding of the role of abnormal methylation involved in this neoplasia. PMID:24338710

  14. Impact of a Reducing Agent on the Dynamic Surface Properties of Lysozyme Solutions.

    PubMed

    Tihonov, Michael M; Kim, Viktoria V; Noskov, Boris A

    2016-05-01

    Disulfide bond shuffling in the presence of the reducing agents dithiothreitol (DTT) or β-mercaptoethanol (BME) strongly affects the surface properties of lysozyme solutions. The addition of 0.32 mM DTT substantially alters the kinetic dependencies of the dynamic surface elasticity and surface tension relative to those of pure protein solutions. The significant increase in the dynamic surface elasticity likely relates to the cross-linking between lysozyme molecules and the formation of a dense layer of protein globules stabilized by intermolecular disulfide bonds at the liquid/gas interface. This effect differs from the previously described influence of chaotropic denaturants, such as guanidine hydrochloride (GuHCl) and urea, on the surface properties of lysozyme solutions. If both chaotropic and reducing agents are added to protein solutions simultaneously, their effects become superimposed. In the case of mixed lysozyme/GuHCl/DTT solutions, the dynamic surface elasticity near equilibrium decreases as the GuHCl concentration increases because of the gradual loosening of the cross-linked layer of protein globules but remains much higher than that of lysozyme/GuHCl solutions. PMID:27086995

  15. Surface properties and reduced biofouling of graft-copolymers that possess oppositely charged groups.

    PubMed

    Herzberg, Moshe; Sweity, Amer; Brami, Matan; Kaufman, Yair; Freger, Viatcheslav; Oron, Gideon; Belfer, Sophia; Kasher, Roni

    2011-04-11

    Microbial biofilms and their components present a major obstacle for ensuring the long-term effectiveness of membrane processes. Graft polymerization on membrane surfaces, in general, and grafting with oppositely charged monomers, have been shown to reduce biofouling significantly. In this study, surface forces and macromolecular properties of graft copolymers that possess oppositely charged groups were related to their potent antibiofouling behavior. Graft polymerization was performed using the negatively charged 3-sulphopropyl methacrylate (SPM) and positively charged [2-(methacryloyloxy)ethyl]-trimethylammonium (MOETMA) monomers to yield a copolymer layer on polyvinylidene fluoride (PVDF) surface. Quartz crystal microbalance with dissipation monitoring (QCM-D) technology was used to monitor the reduced adsorption of extracellular polymeric substances (EPS) extracted from a membrane bioreactor (MBR) wastewater treatment facility. Complemented measurements of attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy provided evaluation of the antifouling properties of the surface. Increase in water content in grafted layer exposed to 100 mM aqueous NaCl solution was observed by QCM-D. Therefore, the grafted copolymer layer is swelled in the presence of 100 mM NaCl because of reversing of polymer self-association by counterions. Force measurements by atomic force microscopy (AFM) showed an increased repulsion between a carboxylate-modified latex (CML) particle probe and a modified PVDF surface, especially in the presence of 100 mM NaCl. The hydration and swelling of the grafted polymer layer are shown to repel EPS and reduce their adsorption. Delineating the surface properties of antifouling grafted layers may lead to the design of novel antifouling surfaces.

  16. Drought response transcriptomes are altered in poplar with reduced tonoplast sucrose transporter expression

    PubMed Central

    Xue, Liang-Jiao; Frost, Christopher J.; Tsai, Chung-Jui; Harding, Scott A.

    2016-01-01

    Transgenic Populus tremula x alba (717-1B4) plants with reduced expression of a tonoplast sucrose efflux transporter, PtaSUT4, exhibit reduced shoot growth compared to wild type (WT) under sustained mild drought. The present study was undertaken to determine whether SUT4-RNAi directly or indirectly altered poplar predisposition and/or response to changes in soil water availability. While sucrose and hexose levels were constitutively elevated in shoot organs, expression responses to drought were most altered in the root tips of SUT4-RNAi plants. Prior to any drought treatment, constitutively elevated transcript levels of abscisic acid biosynthetic genes and bark/vegetative storage proteins suggested altered metabolism in root tips of RNAi plants. Stronger drought-stimulation of stress-inducible genes encoding late-embryogenesis-abundant proteins in transgenic roots was consistent with increased vulnerability to soil drying. Transcript evidence suggested an RNAi effect on intercellular water trafficking by aquaporins in stem xylem during soil drying and recovery. Co-expression network analysis predicted altered integration of abscisic acid sensing/signaling with ethylene and jasmonate sensing/signaling in RNAi compared to WT roots. The overall conclusion is that steepened shoot-root sugar gradient in RNAi plants increased sensitivity of root tips to decreasing soil water availability. PMID:27641356

  17. Drought response transcriptomes are altered in poplar with reduced tonoplast sucrose transporter expression.

    PubMed

    Xue, Liang-Jiao; Frost, Christopher J; Tsai, Chung-Jui; Harding, Scott A

    2016-01-01

    Transgenic Populus tremula x alba (717-1B4) plants with reduced expression of a tonoplast sucrose efflux transporter, PtaSUT4, exhibit reduced shoot growth compared to wild type (WT) under sustained mild drought. The present study was undertaken to determine whether SUT4-RNAi directly or indirectly altered poplar predisposition and/or response to changes in soil water availability. While sucrose and hexose levels were constitutively elevated in shoot organs, expression responses to drought were most altered in the root tips of SUT4-RNAi plants. Prior to any drought treatment, constitutively elevated transcript levels of abscisic acid biosynthetic genes and bark/vegetative storage proteins suggested altered metabolism in root tips of RNAi plants. Stronger drought-stimulation of stress-inducible genes encoding late-embryogenesis-abundant proteins in transgenic roots was consistent with increased vulnerability to soil drying. Transcript evidence suggested an RNAi effect on intercellular water trafficking by aquaporins in stem xylem during soil drying and recovery. Co-expression network analysis predicted altered integration of abscisic acid sensing/signaling with ethylene and jasmonate sensing/signaling in RNAi compared to WT roots. The overall conclusion is that steepened shoot-root sugar gradient in RNAi plants increased sensitivity of root tips to decreasing soil water availability. PMID:27641356

  18. Reduced effects of thyroid hormone on gene expression and metamorphosis in a paedomorphic plethodontid salamander.

    PubMed

    Aran, Robert P; Steffen, Michael A; Martin, Samuel D; Lopez, Olivia I; Bonett, Ronald M

    2014-07-01

    It has been over a century since Gudernatsch (1912, Wilhelm Roux Arch Entwickl Mech Org 35:457-483) demonstrated that mammalian thyroid gland extracts can stimulate tadpole metamorphosis. Despite the tremendous developmental diversity of amphibians, mechanisms of metamorphosis have mostly been studied in a few model systems. This limits our understanding of the processes that influence the evolution of developmental aberrations. Here we isolated thyroid hormone receptors alpha (TRα) and beta (TRβ) from Oklahoma salamanders (Eurycea tynerensis), which exhibit permanently aquatic (paedomorphic) or biphasic (metamorphic) developmental modes in different populations. We found that TRα and TRβ were upregulated by thyroid hormone (T3 ) in tail tissues of larvae from metamorphic populations, but basal levels of TR expression and T3 responsiveness were reduced in larvae from paedomorphic populations. Likewise, we found that T3 treatment resulted in complete loss of larval epibranchials in larvae from metamorphic populations, but little to no epibranchial remodeling occurred in larvae from paedomorphic populations over the same duration. This is the first study to directly demonstrate reduced gene expression and metamorphic responses to T3 in a paedomorphic plethodontid compared to metamorphic conspecifics, and the first salamander system to show differential expression of thyroid hormone receptors associated with alternative developmental patterns.

  19. Reduced expression of PNUTS leads to activation of Rb-phosphatase and caspase-mediated apoptosis.

    PubMed

    De Leon, Gabriel; Sherry, Tara C; Krucher, Nancy A

    2008-06-01

    There is abundant evidence that Retinoblastoma (Rb) activity is important in the control of cell proliferation and apoptosis. Reversible phosphorylation of the Rb protein that is carried out by cyclin dependent kinases and Protein phosphatase 1 (PP1) regulates its functions. A PP1 interacting protein, PNUTS (Phosphatase Nuclear Targeting Subunit) is proposed to be a regulator of Rb phosphorylation. In this study, PNUTS knockdown in MCF7, SKA and HCT116 cancer cells causes a reduction in viability due to increased apoptosis. However, normal cells (MCF10A breast and CCD-18Co colon) do not exhibit reduced viability when PNUTS expression is diminished. PNUTS knockdown has no effect in Rb-null Saos-2 cells. However, when Rb is stably expressed in Saos-2 cells, PNUTS knockdown reduces cell number. Knockdown of PNUTS in p53-/- HCT116 cells indicates that p53 is dispensable for the induction of apoptosis. Loss of PNUTS expression results in increased Rb-phosphatase activity and Rb dephosphorylation. E2F1 dissociates from Rb in cells depleted of PNUTS and the resulting apoptosis is dependent on caspase-8. These results indicate that Rb phosphorylation state can be manipulated by targeting Rb phosphatase activity and suggest that PNUTS may be a potential target for therapeutic pro-apoptotic strategies. PMID:18360108

  20. Dietary lufenuron reduces egg hatch and influences protein expression in the fruit fly Bactrocera latifrons (Hendel).

    PubMed

    Chang, Chiou Ling; Geib, Scott; Cho, Il Kyu; Li, Qing X; Stanley, David

    2014-08-01

    Lufenuron (LFN), a chitin synthase inhibitor, impacts the fertility of Ceratitis capitata, Bactrocera dorsalis, B. cucurbitae, and B. latifrons. We posed the hypothesis that LFN curtails egg hatch in the solanaceous fruit fly, B. latifrons. In this study, newly emerged virgin adults were sexed and fed for 12 days with varying concentrations of LFN-laced agar diets until sexual maturation. Eggs were collected from 12-d-old adults and the egg hatch was assessed. Egg hatch decreased in adults reared on LFN-treated diets. LFN-treated media did not influence fertility after one gender was reared on experimental and the other on control media before mating. Exposure to LFN-treated medium after mating led to reduced egg hatch. We infer that LFN is not a permanent sterilant, and reduced egg hatch depends on continuous exposure to dietary LFN after mating. Proteomic analysis identified two differentially expressed proteins, a pheromone binding protein and a chitin binding protein, between adults maintained on LFN-treated and control diets. Expression of two genes encoding chitin synthase 2, and chitin binding protein, was altered in adults exposed to dietary LFN. LFN treatments also led to increased expression of two odorant binding proteins one in females and one in males. We surmise these data support our hypothesis and provide insight into LFN actions. PMID:24753137

  1. Reduced myelin basic protein and actin-related gene expression in visual cortex in schizophrenia.

    PubMed

    Matthews, Paul R; Eastwood, Sharon L; Harrison, Paul J

    2012-01-01

    Most brain gene expression studies of schizophrenia have been conducted in the frontal cortex or hippocampus. The extent to which alterations occur in other cortical regions is not well established. We investigated primary visual cortex (Brodmann area 17) from the Stanley Neuropathology Consortium collection of tissue from 60 subjects with schizophrenia, bipolar disorder, major depression, or controls. We first carried out a preliminary array screen of pooled RNA, and then used RT-PCR to quantify five mRNAs which the array identified as differentially expressed in schizophrenia (myelin basic protein [MBP], myelin-oligodendrocyte glycoprotein [MOG], β-actin [ACTB], thymosin β-10 [TB10], and superior cervical ganglion-10 [SCG10]). Reduced mRNA levels were confirmed by RT-PCR for MBP, ACTB and TB10. The MBP reduction was limited to transcripts containing exon 2. ACTB and TB10 mRNAs were also decreased in bipolar disorder. None of the transcripts were altered in subjects with major depression. Reduced MBP mRNA in schizophrenia replicates findings in other brain regions and is consistent with oligodendrocyte involvement in the disorder. The decreases in expression of ACTB, and the actin-binding protein gene TB10, suggest changes in cytoskeletal organisation. The findings confirm that the primary visual cortex shows molecular alterations in schizophrenia and extend the evidence for a widespread, rather than focal, cortical pathophysiology.

  2. Reduced Tau protein expression is associated with frontotemporal degeneration with progranulin mutation.

    PubMed

    Papegaey, Anthony; Eddarkaoui, Sabiha; Deramecourt, Vincent; Fernandez-Gomez, Francisco-Jose; Pantano, Pierre; Obriot, Hélène; Machala, Camille; Anquetil, Vincent; Camuzat, Agnès; Brice, Alexis; Maurage, Claude-Alain; Le Ber, Isabelle; Duyckaerts, Charles; Buée, Luc; Sergeant, Nicolas; Buée-Scherrer, Valérie

    2016-07-19

    Reduction of Tau protein expression was described in 2003 by Zhukareva et al. in a variant of frontotemporal lobar degeneration (FTLD) referred to as diagnosis of dementia lacking distinctive histopathology, then re-classified as FTLD with ubiquitin inclusions. However, the analysis of Tau expression in FTLD has not been reconsidered since then. Knowledge of the molecular basis of protein aggregates and genes that are mutated in the FTLD spectrum would enable to determine whether the "Tau-less" is a separate pathological entity or if it belongs to an existing subclass of FTLD. To address this question, we have analyzed Tau expression in the frontal brain areas from control, Alzheimer's disease and FTLD cases, including FTLD- Tau (MAPT), FTLD-TDP (sporadic, FTLD-TDP-GRN, FTLD-TDP-C9ORF72) and sporadic FTLD-FUS, using western blot and 2D-DIGE (Two-Dimensional fluorescence Difference Gel Electrophoresis) approaches. Surprisingly, we found that most of the FTLD-TDP-GRN brains are characterized by a huge reduction of Tau protein expression without any decrease in Tau mRNA levels. Interestingly, only cases affected by point mutations, rather than cases with total deletion of one GRN allele, seem to be affected by this reduction of Tau protein expression. Moreover, proteomic analysis highlighted correlations between reduced Tau protein level, synaptic impairment and massive reactive astrogliosis in these FTLD-GRN cases. Consistent with a recent study, our data also bring new insights regarding the role of progranulin in neurodegeneration by suggesting its involvement in lysosome and synaptic regulation. Together, our results demonstrate a strong association between progranulin deficiency and reduction of Tau protein expression that could lead to severe neuronal and glial dysfunctions. Our study also indicates that this FTLD-TDP-GRN subgroup could be part as a distinct entity of FTLD classification.

  3. Blood-Gene Expression Reveals Reduced Circadian Rhythmicity in Individuals Resistant to Sleep Deprivation

    PubMed Central

    Arnardottir, Erna S.; Nikonova, Elena V.; Shockley, Keith R.; Podtelezhnikov, Alexei A.; Anafi, Ron C.; Tanis, Keith Q.; Maislin, Greg; Stone, David J.; Renger, John J.; Winrow, Christopher J.; Pack, Allan I.

    2014-01-01

    Study Objectives: To address whether changes in gene expression in blood cells with sleep loss are different in individuals resistant and sensitive to sleep deprivation. Design: Blood draws every 4 h during a 3-day study: 24-h normal baseline, 38 h of continuous wakefulness and subsequent recovery sleep, for a total of 19 time-points per subject, with every 2-h psychomotor vigilance task (PVT) assessment when awake. Setting: Sleep laboratory. Participants: Fourteen subjects who were previously identified as behaviorally resistant (n = 7) or sensitive (n = 7) to sleep deprivation by PVT. Intervention: Thirty-eight hours of continuous wakefulness. Measurements and Results: We found 4,481 unique genes with a significant 24-h diurnal rhythm during a normal sleep-wake cycle in blood (false discovery rate [FDR] < 5%). Biological pathways were enriched for biosynthetic processes during sleep. After accounting for circadian effects, two genes (SREBF1 and CPT1A, both involved in lipid metabolism) exhibited small, but significant, linear changes in expression with the duration of sleep deprivation (FDR < 5%). The main change with sleep deprivation was a reduction in the amplitude of the diurnal rhythm of expression of normally cycling probe sets. This reduction was noticeably higher in behaviorally resistant subjects than sensitive subjects, at any given P value. Furthermore, blood cell type enrichment analysis showed that the expression pattern difference between sensitive and resistant subjects is mainly found in cells of myeloid origin, such as monocytes. Conclusion: Individual differences in behavioral effects of sleep deprivation are associated with differences in diurnal amplitude of gene expression for genes that show circadian rhythmicity. Citation: Arnardottir ES, Nikonova EV, Shockley KR, Podtelezhnikov AA, Anafi RC, Tanis KQ, Maislin G, Stone DJ, Renger JJ, Winrow CJ, Pack AI. Blood-gene expression reveals reduced circadian rhythmicity in individuals resistant to

  4. Reduced SIRT1 expression correlates with enhanced oxidative stress in compensated and decompensated heart failure.

    PubMed

    Akkafa, Feridun; Halil Altiparmak, Ibrahim; Erkus, Musluhittin Emre; Aksoy, Nurten; Kaya, Caner; Ozer, Ahmet; Sezen, Hatice; Oztuzcu, Serdar; Koyuncu, Ismail; Umurhan, Berrin

    2015-12-01

    Sirtuin-1 (SIRT1) is a longevity factor in mammals initiating the cell survival mechanisms, and preventing ischemic injury in heart. In the etiopathogenesis of heart failure (HF), impairment in cardiomyocyte survival is a notable factor. Oxidative stress comprises a critical impact on cardiomyocyte lifespan in HF. The aim of the present study was to investigate SIRT1 expression in patients with compensated (cHF) and decompensated HF (dHF), and its correlation with oxidative stress. SIRT1 expression in peripheral leukocytes was examined using quantitative RT-PCR in 163 HF patients and 84 controls. Serum total oxidant status (TOS) and total antioxidant status (TAS) were measured via colorimetric assays, and oxidative stress index (OSI) was calculated. Lipid parameters were also determined by routine laboratory methods. SIRT1 mRNA expression was significantly downregulated in HF with more robust decrease in dHF (p=0.002, control vs cHF; p<0.001, control vs dHF). Markedly increased oxidative stress defined as elevated TOS, OSI and low TAS levels were detected in HF patients comparing with the controls (TAS; p=0.010, control vs cHF, p=0.045 control vs dHF, TOS; p=0.004 control vs cHF; p<0.001 control vs dHF, OSI; p<0.001 for both comparisons, respectively). With SIRT1 expression levels, TAS, TOS, OSI, and high density lipoprotein levels in cHF and dHF were determined correlated. SIRT1 expression were significantly reduced in both HF subtypes, particularly in dHF. SIRT1 expression was correlated with the oxidant levels and antioxidant capacity. Data suggest that SIRT1 may have a significant contribution in regulation of oxidant/antioxidant balance in HF etiology and compensation status. PMID:26233702

  5. Vitamin D improves endothelial dysfunction and restores myeloid angiogenic cell function via reduced CXCL-10 expression in systemic lupus erythematosus.

    PubMed

    Reynolds, John A; Haque, Sahena; Williamson, Kate; Ray, David W; Alexander, M Yvonne; Bruce, Ian N

    2016-01-01

    Patients with systemic lupus erythematosus (SLE) have accelerated cardiovascular disease and dysfunctional endothelial repair mechanisms. Myeloid angiogenic cells (MACs), derived from circulating monocytes, augment vascular repair by paracrine secretion of pro-angiogenic factors. We observed that SLE MACs are dysfunctional and secrete pro-inflammatory cytokines. We also found that the vitamin D receptor was transiently expressed during MAC differentiation and that in vitro, calcitriol increased differentiation of monocytes into MACs in both SLE and in a model using the prototypic SLE cytokine, interferon-alpha. The active form of vitamin D (calcitriol) restored the SLE MAC phenotype towards that of healthy subjects with reduced IL-6 secretion, and normalised surface marker expression. Calcitriol also augmented the angiogenic capacity of MACs via the down-regulation of CXCL-10. In SLE patients treated with cholecalciferol for 12 weeks, the improvement in endothelial function correlated with increase in serum 25(OH)D concentrations independently of disease activity. We also show that MACs were able to positively modulate eNOS expression in human endothelial cells in vitro, an effect further enhanced by calcitriol treatment of SLE MACs. The results demonstrate that vitamin D can positively modify endothelial repair mechanisms and thus endothelial function in a population with significant cardiovascular risk. PMID:26930567

  6. Vitamin D improves endothelial dysfunction and restores myeloid angiogenic cell function via reduced CXCL-10 expression in systemic lupus erythematosus.

    PubMed

    Reynolds, John A; Haque, Sahena; Williamson, Kate; Ray, David W; Alexander, M Yvonne; Bruce, Ian N

    2016-03-01

    Patients with systemic lupus erythematosus (SLE) have accelerated cardiovascular disease and dysfunctional endothelial repair mechanisms. Myeloid angiogenic cells (MACs), derived from circulating monocytes, augment vascular repair by paracrine secretion of pro-angiogenic factors. We observed that SLE MACs are dysfunctional and secrete pro-inflammatory cytokines. We also found that the vitamin D receptor was transiently expressed during MAC differentiation and that in vitro, calcitriol increased differentiation of monocytes into MACs in both SLE and in a model using the prototypic SLE cytokine, interferon-alpha. The active form of vitamin D (calcitriol) restored the SLE MAC phenotype towards that of healthy subjects with reduced IL-6 secretion, and normalised surface marker expression. Calcitriol also augmented the angiogenic capacity of MACs via the down-regulation of CXCL-10. In SLE patients treated with cholecalciferol for 12 weeks, the improvement in endothelial function correlated with increase in serum 25(OH)D concentrations independently of disease activity. We also show that MACs were able to positively modulate eNOS expression in human endothelial cells in vitro, an effect further enhanced by calcitriol treatment of SLE MACs. The results demonstrate that vitamin D can positively modify endothelial repair mechanisms and thus endothelial function in a population with significant cardiovascular risk.

  7. Vitamin D improves endothelial dysfunction and restores myeloid angiogenic cell function via reduced CXCL-10 expression in systemic lupus erythematosus

    PubMed Central

    Reynolds, John A.; Haque, Sahena; Williamson, Kate; Ray, David W.; Alexander, M. Yvonne; Bruce, Ian N.

    2016-01-01

    Patients with systemic lupus erythematosus (SLE) have accelerated cardiovascular disease and dysfunctional endothelial repair mechanisms. Myeloid angiogenic cells (MACs), derived from circulating monocytes, augment vascular repair by paracrine secretion of pro-angiogenic factors. We observed that SLE MACs are dysfunctional and secrete pro-inflammatory cytokines. We also found that the vitamin D receptor was transiently expressed during MAC differentiation and that in vitro, calcitriol increased differentiation of monocytes into MACs in both SLE and in a model using the prototypic SLE cytokine, interferon-alpha. The active form of vitamin D (calcitriol) restored the SLE MAC phenotype towards that of healthy subjects with reduced IL-6 secretion, and normalised surface marker expression. Calcitriol also augmented the angiogenic capacity of MACs via the down-regulation of CXCL-10. In SLE patients treated with cholecalciferol for 12 weeks, the improvement in endothelial function correlated with increase in serum 25(OH)D concentrations independently of disease activity. We also show that MACs were able to positively modulate eNOS expression in human endothelial cells in vitro, an effect further enhanced by calcitriol treatment of SLE MACs. The results demonstrate that vitamin D can positively modify endothelial repair mechanisms and thus endothelial function in a population with significant cardiovascular risk. PMID:26930567

  8. Expression of Arabidopsis Hexokinase in Citrus Guard Cells Controls Stomatal Aperture and Reduces Transpiration.

    PubMed

    Lugassi, Nitsan; Kelly, Gilor; Fidel, Lena; Yaniv, Yossi; Attia, Ziv; Levi, Asher; Alchanatis, Victor; Moshelion, Menachem; Raveh, Eran; Carmi, Nir; Granot, David

    2015-01-01

    Hexokinase (HXK) is a sugar-phosphorylating enzyme involved in sugar-sensing. It has recently been shown that HXK in guard cells mediates stomatal closure and coordinates photosynthesis with transpiration in the annual species tomato and Arabidopsis. To examine the role of HXK in the control of the stomatal movement of perennial plants, we generated citrus plants that express Arabidopsis HXK1 (AtHXK1) under KST1, a guard cell-specific promoter. The expression of KST1 in the guard cells of citrus plants has been verified using GFP as a reporter gene. The expression of AtHXK1 in the guard cells of citrus reduced stomatal conductance and transpiration with no negative effect on the rate of photosynthesis, leading to increased water-use efficiency. The effects of light intensity and humidity on stomatal behavior were examined in rooted leaves of the citrus plants. The optimal intensity of photosynthetically active radiation and lower humidity enhanced stomatal closure of AtHXK1-expressing leaves, supporting the role of sugar in the regulation of citrus stomata. These results suggest that HXK coordinates photosynthesis and transpiration and stimulates stomatal closure not only in annual species, but also in perennial species. PMID:26734024

  9. Expression of Arabidopsis Hexokinase in Citrus Guard Cells Controls Stomatal Aperture and Reduces Transpiration.

    PubMed

    Lugassi, Nitsan; Kelly, Gilor; Fidel, Lena; Yaniv, Yossi; Attia, Ziv; Levi, Asher; Alchanatis, Victor; Moshelion, Menachem; Raveh, Eran; Carmi, Nir; Granot, David

    2015-01-01

    Hexokinase (HXK) is a sugar-phosphorylating enzyme involved in sugar-sensing. It has recently been shown that HXK in guard cells mediates stomatal closure and coordinates photosynthesis with transpiration in the annual species tomato and Arabidopsis. To examine the role of HXK in the control of the stomatal movement of perennial plants, we generated citrus plants that express Arabidopsis HXK1 (AtHXK1) under KST1, a guard cell-specific promoter. The expression of KST1 in the guard cells of citrus plants has been verified using GFP as a reporter gene. The expression of AtHXK1 in the guard cells of citrus reduced stomatal conductance and transpiration with no negative effect on the rate of photosynthesis, leading to increased water-use efficiency. The effects of light intensity and humidity on stomatal behavior were examined in rooted leaves of the citrus plants. The optimal intensity of photosynthetically active radiation and lower humidity enhanced stomatal closure of AtHXK1-expressing leaves, supporting the role of sugar in the regulation of citrus stomata. These results suggest that HXK coordinates photosynthesis and transpiration and stimulates stomatal closure not only in annual species, but also in perennial species.

  10. Expression of Arabidopsis Hexokinase in Citrus Guard Cells Controls Stomatal Aperture and Reduces Transpiration

    PubMed Central

    Lugassi, Nitsan; Kelly, Gilor; Fidel, Lena; Yaniv, Yossi; Attia, Ziv; Levi, Asher; Alchanatis, Victor; Moshelion, Menachem; Raveh, Eran; Carmi, Nir; Granot, David

    2015-01-01

    Hexokinase (HXK) is a sugar-phosphorylating enzyme involved in sugar-sensing. It has recently been shown that HXK in guard cells mediates stomatal closure and coordinates photosynthesis with transpiration in the annual species tomato and Arabidopsis. To examine the role of HXK in the control of the stomatal movement of perennial plants, we generated citrus plants that express Arabidopsis HXK1 (AtHXK1) under KST1, a guard cell-specific promoter. The expression of KST1 in the guard cells of citrus plants has been verified using GFP as a reporter gene. The expression of AtHXK1 in the guard cells of citrus reduced stomatal conductance and transpiration with no negative effect on the rate of photosynthesis, leading to increased water-use efficiency. The effects of light intensity and humidity on stomatal behavior were examined in rooted leaves of the citrus plants. The optimal intensity of photosynthetically active radiation and lower humidity enhanced stomatal closure of AtHXK1-expressing leaves, supporting the role of sugar in the regulation of citrus stomata. These results suggest that HXK coordinates photosynthesis and transpiration and stimulates stomatal closure not only in annual species, but also in perennial species. PMID:26734024

  11. Nandrolone reduces activation of Notch signaling in denervated muscle associated with increased Numb expression

    SciTech Connect

    Liu, Xin-Hua; Yao, Shen; Qiao, Rui-Fang; Levine, Alice C.; Kirschenbaum, Alexander; Pan, Jiangping; Wu, Yong; Qin, Weiping; Bauman, William A.; Cardozo, Christopher P.

    2011-10-14

    Highlights: {yields} Nerve transection increased Notch signaling in paralyzed muscle. {yields} Nandrolone prevented denervation-induced Notch signaling. {yields} Nandrolone induced the expression of an inhibitor of the Notch signaling, Numb. {yields} Reduction of denervation-induced Notch signaling by nandrolone is likely through upregulation of Numb. -- Abstract: Nandrolone, an anabolic steroid, slows denervation-atrophy in rat muscle. The molecular mechanisms responsible for this effect are not well understood. Androgens and anabolic steroids activate Notch signaling in animal models of aging and thereby mitigate sarcopenia. To explore the molecular mechanisms by which nandrolone prevents denervation-atrophy, we investigated the effects of nandrolone on Notch signaling in denervated rat gastrocnemius muscle. Denervation significantly increased Notch activity reflected by elevated levels of nuclear Notch intracellular domain (NICD) and expression of Hey1 (a Notch target gene). Activation was greatest at 7 and 35 days after denervation but remained present at 56 days after denervation. Activation of Notch in denervated muscle was prevented by nandrolone associated with upregulated expression of Numb mRNA and protein. These data demonstrate that denervation activates Notch signaling, and that nandrolone abrogates this response associated with increased expression of Numb, suggesting a potential mechanism by which nandrolone reduces denervation-atrophy.

  12. Effects of reduced frequency of milk removal on gene expression in the bovine mammary gland.

    PubMed

    Littlejohn, M D; Walker, C G; Ward, H E; Lehnert, K B; Snell, R G; Verkerk, G A; Spelman, R J; Clark, D A; Davis, S R

    2010-03-01

    Regulation of milk synthesis and secretion is controlled mostly through local (intramammary) mechanisms. To gain insight into the molecular pathways comprising this response, an analysis of mammary gene expression was conducted in 12 lactating cows shifted from twice daily to once daily milking. Tissues were sampled by biopsy from adjacent mammary quarters of these animals during the two milking frequencies, allowing changes in gene expression to be assessed within each animal. Using bovine-specific, oligonucleotide arrays representing 21,495 unique transcripts, a range of differentially expressed genes were found as a result of less frequent milk removal, constituting transcripts and pathways related to apoptotic signaling (NF-kappaB, JUN, ATF3, IGFBP5, TNFSF12A) mechanical stress and epithelial tight junction synthesis (CYR61, CTGF, THBS1, CLDN4, CLDN8), and downregulated milk synthesis (LALBA, B4GALT1, UGP2, CSN2, GPAM, LPL). Quantitative real-time PCR was used to assess the expression of 13 genes in the study, and all 13 of these were correlated (P < 0.05) with values derived from array analysis. It can be concluded that the physiological changes that occur in the bovine mammary gland as a result of reduced milk removal frequency likely comprise the earliest stages of the involution response and that mechano-signal transduction cascades associated with udder distension may play a role in triggering these events.

  13. Pulsed electromagnetic field stimulates osteoprotegerin and reduces RANKL expression in ovariectomized rats.

    PubMed

    Zhou, Jun; Chen, Shiju; Guo, Hua; Xia, Lu; Liu, Huifang; Qin, Yuxi; He, Chengqi

    2013-05-01

    Pulsed electromagnetic field (PEMF) has been shown to increase bone mineral density in osteoporosis patients and prevent bone loss in ovariectomized rats. But the mechanisms through which PEMF elicits these favorable biological responses are still not fully understood. Receptor activator of nuclear factor κB ligand (RANKL) and osteoprotegerin (OPG) are cytokines predominantly secreted by osteoblasts and play a central role in differentiation and functional activation of osteoclasts. The purpose of this study was to investigate the effects of PEMF on RANKL and OPG expression in ovariectomized rats. Thirty 3-month-old female Sprague-Dawley rats were randomly divided into three groups: sham-operated control (Sham), ovariectomy control (OVX), and ovariectomy with PEMF treatment (PEMF). After 12-week interventions, the results showed that PEMF increased serum 17β-estradiol level, reduced serum tartrate-resistant acid phosphatase level, increased bone mineral density, and inhibited deterioration of bone microarchitecture and strength in OVX rats. Furthermore, PEMF could suppress RANKL expression and improve OPG expression in bone marrow cells of OVX rats. In conclusion, this study suggests that PEMF can prevent ovariectomy-induced bone loss through regulating the expression of RANKL and OPG.

  14. Lack of CD24 expression in mice reduces the number of leukocytes in the colon.

    PubMed

    Bretz, Niko P; Salnikov, Alexei V; Doberstein, Kai; Garbi, Natalio; Kloess, Volker; Joumaa, Safwan; Naumov, Inna; Boon, Louis; Moldenhauer, Gerhard; Arber, Nadir; Altevogt, Peter

    2014-09-01

    CD24 is an extensively glycosylated membrane protein that is linked to the membrane via a glycosyl-phosphatidylinositol (GPI)-anchor. In mice, CD24 is expressed by hematopoietic and non-hematopoietic cells. CD24-/- mice do not have gross immunological defects, but detailed analysis revealed strongly reduced responses in an experimental autoimmune encephalomyelitis (EAE) model and a massive proliferation of T cells under lymphopenic conditions. It was also demonstrated that preB cells from CD24-/- mice are impaired in α4-integrin-mediated cell binding. Here we report that CD24-/- mice have strongly reduced numbers of leukocytes in the colon compared to wildtype mice. The reduction comprized all subpopulations. Leukocyte counts in spleen, mesenteric lymph nodes or small intestine were not significantly different. We find that beside leukocytes, CD24 is widely expressed in EpCAM+ epithelial and CD31+ endothelial cells of colon and small intestine. However, in CD24-/- mice the number of CD31+ endothelial cells in colons was strongly reduced and the number of epithelial cells was augmented. Leukocyte transfer experiments provided evidence that the CD24 status of recipient mice, rather than of the transferred cells, is crucial for leukocyte recruitment to the colon. We hypothesize that CD24 on colonic epithelial and endothelial cells is required for the retention and positioning of leukocytes most likely by affecting integrin function.

  15. Trichomonas vaginalis promotes apoptosis of human neutrophils by activating caspase-3 and reducing Mcl-1 expression.

    PubMed

    Kang, J H; Song, H O; Ryu, J S; Shin, M H; Kim, J M; Cho, Y S; Alderete, J F; Ahn, M H; Min, D Y

    2006-09-01

    Neutrophils are the predominant inflammatory cells found in the vaginal discharge of patients with Trichomonas vaginalis infection. However, it is not known whether neutrophil apoptosis is induced by live T. vaginalis. Therefore, we examined whether T. vaginalis can influence neutrophil apoptosis, and also whether caspase-3 and the Bcl-2 family members are involved in the apoptosis. Thus, human neutrophils were incubated with live T. vaginalis and neutrophil apoptosis was evaluated by Giemsa, annexin V-PI, and DiOC6 stainings. The neutrophil apoptosis was significantly higher in those incubated with T. vaginalis than in the control group. When trichomonads were pre-treated with mAb to AP65 (adhesin protein), or when trophozoites were separated from neutrophils using a Transwell chamber, neutrophil apoptosis was significantly reduced. The activation of caspase-3 was evident in neutrophils undergoing spontaneous apoptosis but was markedly enhanced during T. vaginalis-induced apoptosis. Moreover, the inhibition of caspase-3 effectively reduced T. vaginalis-induced apoptosis. Trichomonad-induced apoptosis was also associated with reduced expression of the neutrophil anti-apoptotic protein, Mcl-1. These results indicate that T. vaginalis alters Mcl-1 expression and caspase-3 activation, thereby inducing apoptosis of human neutrophils. PMID:16916367

  16. Nuclear protein import is reduced in cells expressing nuclear envelopathy-causing lamin A mutants

    SciTech Connect

    Busch, Albert; Kiel, Tilman; Heupel, Wolfgang-M.; Wehnert, Manfred; Huebner, Stefan

    2009-08-15

    Lamins, which form the nuclear lamina, not only constitute an important determinant of nuclear architecture, but additionally play essential roles in many nuclear functions. Mutations in A-type lamins cause a wide range of human genetic disorders (laminopathies). The importance of lamin A (LaA) in the spatial arrangement of nuclear pore complexes (NPCs) prompted us to study the role of LaA mutants in nuclear protein transport. Two mutants, causing prenatal skin disease restrictive dermopathy (RD) and the premature aging disease Hutchinson Gilford progeria syndrome, were used for expression in HeLa cells to investigate their impact on the subcellular localization of NPC-associated proteins and nuclear protein import. Furthermore, dynamics of the LaA mutants within the nuclear lamina were studied. We observed affected localization of NPC-associated proteins, diminished lamina dynamics for both LaA mutants and reduced nuclear import of representative cargo molecules. Intriguingly, both LaA mutants displayed similar effects on nuclear morphology and functions, despite their differences in disease severity. Reduced nuclear protein import was also seen in RD fibroblasts and impaired lamina dynamics for the nucleoporin Nup153. Our data thus represent the first study of a direct link between LaA mutant expression and reduced nuclear protein import.

  17. Demeclocycline attenuates hyponatremia by reducing aquaporin-2 expression in the renal inner medulla.

    PubMed

    Kortenoeven, Marleen L A; Sinke, Anne P; Hadrup, Niels; Trimpert, Christiane; Wetzels, Jack F M; Fenton, Robert A; Deen, Peter M T

    2013-12-15

    Binding of vasopressin to its type 2 receptor in renal collecting ducts induces cAMP signaling, transcription and translocation of aquaporin (AQP)2 water channels to the plasma membrane, and water reabsorption from the prourine. Demeclocycline is currently used to treat hyponatremia in patients with the syndrome of inappropriate antidiuretic hormone secretion (SIADH). Demeclocycline's mechanism of action, which is poorly understood, is studied here. In mouse cortical collecting duct (mpkCCD) cells, which exhibit deamino-8-D-arginine vasopressin (dDAVP)-dependent expression of endogenous AQP2, demeclocycline decreased AQP2 abundance and gene transcription but not its protein stability. Demeclocycline did not affect vasopressin type 2 receptor localization but decreased dDAVP-induced cAMP generation and the abundance of adenylate cyclase 3 and 5/6. The addition of exogenous cAMP partially corrected the demeclocycline effect. As in patients, demeclocycline increased urine volume, decreased urine osmolality, and reverted hyponatremia in an SIADH rat model. AQP2 and adenylate cyclase 5/6 abundances were reduced in the inner medulla but increased in the cortex and outer medulla, in the absence of any sign of toxicity. In conclusion, our in vitro and in vivo data indicate that demeclocycline mainly attenuates hyponatremia in SIADH by reducing adenylate cyclase 5/6 expression and, consequently, cAMP generation, AQP2 gene transcription, and AQP2 abundance in the renal inner medulla, coinciding with a reduced vasopressin escape response in other collecting duct segments.

  18. Lactobacilli Reduce Helicobacter pylori Attachment to Host Gastric Epithelial Cells by Inhibiting Adhesion Gene Expression.

    PubMed

    de Klerk, Nele; Maudsdotter, Lisa; Gebreegziabher, Hanna; Saroj, Sunil D; Eriksson, Beatrice; Eriksson, Olaspers Sara; Roos, Stefan; Lindén, Sara; Sjölinder, Hong; Jonsson, Ann-Beth

    2016-05-01

    The human gastrointestinal tract, including the harsh environment of the stomach, harbors a large variety of bacteria, of which Lactobacillus species are prominent members. The molecular mechanisms by which species of lactobacilli interfere with pathogen colonization are not fully characterized. In this study, we aimed to study the effect of lactobacillus strains upon the initial attachment of Helicobacter pylori to host cells. Here we report a novel mechanism by which lactobacilli inhibit adherence of the gastric pathogen H. pylori In a screen with Lactobacillus isolates, we found that only a few could reduce adherence of H. pylori to gastric epithelial cells. Decreased attachment was not due to competition for space or to lactobacillus-mediated killing of the pathogen. Instead, we show that lactobacilli act on H. pylori directly by an effector molecule that is released into the medium. This effector molecule acts on H. pylori by inhibiting expression of the adhesin-encoding gene sabA Finally, we verified that inhibitory lactobacilli reduced H. pylori colonization in an in vivo model. In conclusion, certain Lactobacillus strains affect pathogen adherence by inhibiting sabA expression and thereby reducing H. pylori binding capacity. PMID:26930708

  19. Trichomonas vaginalis promotes apoptosis of human neutrophils by activating caspase-3 and reducing Mcl-1 expression

    PubMed Central

    KANG, J. H.; SONG, H. O.; RYU, J. S.; SHIN, M. H.; KIM, J. M.; CHO, Y. S.; ALDERETE, J. F.; AHN, M. H.; MIN, D. Y.

    2007-01-01

    SUMMARY Neutrophils are the predominant inflammatory cells found in the vaginal discharge of patients with Trichomonas vaginalis infection. However, it is not known whether neutrophil apoptosis is induced by live T. vaginalis. Therefore, we examined whether T. vaginalis can influence neutrophil apoptosis, and also whether caspase-3 and the Bcl-2 family members are involved in the apoptosis. Thus, human neutrophils were incubated with live T. vaginalis and neutrophil apoptosis was evaluated by Giemsa, annexin V-PI, and DiOC6 stainings. The neutrophil apoptosis was significantly higher in those incubated with T. vaginalis than in the control group. When trichomonads were pre-treated with mAb to AP65 (adhesin protein), or when trophozoites were separated from neutrophils using a Transwell chamber, neutrophil apoptosis was significantly reduced. The activation of caspase-3 was evident in neutrophils undergoing spontaneous apoptosis but was markedly enhanced during T. vaginalis-induced apoptosis. Moreover, the inhibition of caspase-3 effectively reduced T. vaginalis-induced apoptosis. Trichomonad-induced apoptosis was also associated with reduced expression of the neutrophil anti-apoptotic protein, Mcl-1. These results indicate that T. vaginalis alters Mcl-1 expression and caspase-3 activation, thereby inducing apoptosis of human neutrophils. PMID:16916367

  20. Lactobacilli Reduce Helicobacter pylori Attachment to Host Gastric Epithelial Cells by Inhibiting Adhesion Gene Expression.

    PubMed

    de Klerk, Nele; Maudsdotter, Lisa; Gebreegziabher, Hanna; Saroj, Sunil D; Eriksson, Beatrice; Eriksson, Olaspers Sara; Roos, Stefan; Lindén, Sara; Sjölinder, Hong; Jonsson, Ann-Beth

    2016-05-01

    The human gastrointestinal tract, including the harsh environment of the stomach, harbors a large variety of bacteria, of which Lactobacillus species are prominent members. The molecular mechanisms by which species of lactobacilli interfere with pathogen colonization are not fully characterized. In this study, we aimed to study the effect of lactobacillus strains upon the initial attachment of Helicobacter pylori to host cells. Here we report a novel mechanism by which lactobacilli inhibit adherence of the gastric pathogen H. pylori In a screen with Lactobacillus isolates, we found that only a few could reduce adherence of H. pylori to gastric epithelial cells. Decreased attachment was not due to competition for space or to lactobacillus-mediated killing of the pathogen. Instead, we show that lactobacilli act on H. pylori directly by an effector molecule that is released into the medium. This effector molecule acts on H. pylori by inhibiting expression of the adhesin-encoding gene sabA Finally, we verified that inhibitory lactobacilli reduced H. pylori colonization in an in vivo model. In conclusion, certain Lactobacillus strains affect pathogen adherence by inhibiting sabA expression and thereby reducing H. pylori binding capacity.

  1. Mice with reduced NMDA receptor expression: more consistent with autism than schizophrenia?

    PubMed Central

    Gandal, Michael J.; Anderson, Rachel L.; Billingslea, Eddie N.; Carlson, Gregory C.; Roberts, Timothy P.L.; Siegel, Steven J.

    2012-01-01

    Reduced NMDA-receptor (NMDAR) function has been implicated in the pathophysiology of neuropsychiatric disease, most strongly in schizophrenia but also recently in autism spectrum disorders (ASD). To determine the direct contribution of NMDAR dysfunction to disease phenotypes, a mouse model with constitutively reduced expression of the obligatory NR1 subunit has been developed and extensively investigated. Adult NR1neo−/− mice show multiple abnormal behaviors, including reduced social interactions, locomotor hyperactivity, self-injury, deficits in prepulse inhibition, and sensory hypersensitivity, among others. Whereas such phenotypes have largely been interpreted in the context of schizophrenia, these behavioral abnormalities are rather non-specific and are frequently present across models of diseases characterized by negative symptom domains. This study investigated auditory electrophysiological and behavioral paradigms relevant to autism, to determine whether NMDAR hypofunction may be more consistent with adult ASD-like phenotypes. Indeed, transgenic mice demonstrated behavioral deficits relevant to all core ASD symptoms, including decreased social interactions, altered ultrasonic vocalizations, and increased repetitive behaviors. NMDAR disruption recapitulated clinical endophenotypes including reduced prepulse inhibition, auditory-evoked response N1 latency delay, and reduced gamma synchrony. Auditory electrophysiological abnormalities more closely resembled those seen in clinical studies of autism than schizophrenia. These results suggest that NMDA-receptor hypofunction may be associated with a continuum of neuropsychiatric diseases, including schizophrenia and autism. Neural synchrony abnormalities suggest an imbalance of glutamatergic and GABAergic coupling and may provide a target, along with behavioral phenotypes, for preclinical screening of novel therapeutics. PMID:22726567

  2. Huoxue Rongluo Tablet reduces matrix metalloproteinase-9 expression in infarcted brain tissue.

    PubMed

    Zhou, Desheng; Li, Mei; Hu, Hua; Chen, Yao; Yang, Yang; Zhong, Jie; Liu, Lijuan

    2013-12-01

    Huoxue Rongluo Tablet was made of tall gastrodis tuber, dahurian angelica root, honeysuckle stem, grassleaf sweetflag rhizome, common flowering quince fruit, figwort root, red peony root and peach seed at a ratio of 3:2:6:2:3:3:3:3. Huoxue Rongluo Tablet is a well-established and common pre-scription for the treatment of cerebral infarction. In this study, a rat model of cerebral ischemia was established and the animals were intragastrically administered Huoxue Rongluo Tablet. This treat-ment reduced infarct volume, decreased matrix metalloproteinase-9 expression, and improved neurological function. Moreover, the effects of Huoxue Rongluo Tablet were better than those of buflomedil pyridoxal phosphate. These results indicate that Huoxue Rongluo Tablet is effective in treating cerebral infarction by regulating matrix metalloproteinase-9 protein expression.

  3. Huoxue Rongluo Tablet reduces matrix metalloproteinase-9 expression in infarcted brain tissue

    PubMed Central

    Zhou, Desheng; Li, Mei; Hu, Hua; Chen, Yao; Yang, Yang; Zhong, Jie; Liu, Lijuan

    2013-01-01

    Huoxue Rongluo Tablet was made of tall gastrodis tuber, dahurian angelica root, honeysuckle stem, grassleaf sweetflag rhizome, common flowering quince fruit, figwort root, red peony root and peach seed at a ratio of 3:2:6:2:3:3:3:3. Huoxue Rongluo Tablet is a well-established and common pre-scription for the treatment of cerebral infarction. In this study, a rat model of cerebral ischemia was established and the animals were intragastrically administered Huoxue Rongluo Tablet. This treat-ment reduced infarct volume, decreased matrix metalloproteinase-9 expression, and improved neurological function. Moreover, the effects of Huoxue Rongluo Tablet were better than those of buflomedil pyridoxal phosphate. These results indicate that Huoxue Rongluo Tablet is effective in treating cerebral infarction by regulating matrix metalloproteinase-9 protein expression. PMID:25206642

  4. Investigation of water washes suitable for very small meat plants to reduce pathogens on beef surfaces.

    PubMed

    Yoder, Sally Flowers; Henning, William R; Mills, Edward W; Doores, Stephanie; Ostiguy, Nancy; Cutter, Catherine N

    2010-05-01

    Water washing with a handheld hose was performed on beef surfaces to ascertain the most effective combination of methods needed to remove potentially harmful microorganisms. For these experiments, beef brisket surfaces were experimentally inoculated with a fecal slurry containing Escherichia coli O157:H7, Salmonella Typhimurium, Campylobacter coli, and Campylobacter jejuni. In a pilot study, surfaces were washed with cold water (15 degrees C) at various water pressures, spray distances, application times, and drip times, and remaining bacterial populations were determined following the enumeration and isolation of pathogens and naturally occurring hygiene indicators (mesophilic aerobic bacteria, coliforms, and E. coli). The most efficacious combinations of these washing conditions were applied subsequently to artificially contaminated beef brisket surfaces in conjunction with hot (77 degrees C), warm (54 degrees C), and additional cold (15 degrees C) water washes. In the cold water washing pilot study, combinations of physical washing conditions significantly reduced all bacterial populations (P < 0.05). Further studies clearly indicated the superior bactericidal effectiveness of hot water washing; E. coli O157:H7 and Salmonella Typhimurium were reduced by 3.8 and 4.1 log CFU/cm(2), respectively. Overall, higher water temperature, longer application times, and shorter spray distances more effectively removed pathogens from inoculated beef surfaces. These findings will be used to formulate water washing recommendations for very small meat processing establishments. PMID:20501042

  5. Green tea extracts reduce adipogenesis by decreasing expression of transcription factors C/EBPα and PPARγ

    PubMed Central

    Yang, Xiuling; Yin, Lei; Li, Tang; Chen, Zhihong

    2014-01-01

    Objectives: This study is to determine if green tea (Camellia sinensis) extracts (GTE) affects adipogenesis and further investigate the related molecular mechanisms. Methods: Patients with metabolic syndrome were recruited in this study. Of them, 70 patients received GTE and 64 received water to serve as the control group. The human serum adiponectin, visfatin, and leptin concentrations were determined by enzyme-linked immunosorbent assay. Adipogenesis of 3T3-L1 preadipocytes was induced with reagents and then the cells were treated with GTE. The lipids were stained with Oil Red O for analysis of adipogenesis of 3T3-L1 preadipocytes. The 3T3-L1 preadipocytes were treated with increasing concentrations (0.2-0.5%, w/v) of GTE for 2 days and the cell viability was determined by MTT assay. Reverse transcription real-time PCR and immunoblotting assays were performed to determine RNA and protein levels of relative molecules. Results: GTE increases the serum concentrations of adiponectin but decreases visfatin levels in patients received GTE. The leptin concentrations in serum were not significantly affected. The GTE reduces the adipogenesis-induced lipid accumulation in 3T3-L1 preadipocytes. GTE decreases the mRNA and protein expression of adipogenic transcription factors C/EBPα and PPARγ in 3T3-L1 cells. Expression levels of the adipocyte-specific genes encoding adipocyte protein 2, lipoprotein lipase, and glucose transporter 4 were also decreased by GTE. Furthermore, it was found that GTE reduces phosphorylation of Akt during adipocyte differentiation. Conclusions: GTE reduces adipogenesis by decreasing expression of transcription factors C/EBPα and PPARγ by reduction of phosphorylation of Akt during adipocyte differentiation. PMID:25663987

  6. Enhanced photothermal effect of surface oxidized silicon nanocrystals anchored to reduced graphene oxide nanosheets

    NASA Astrophysics Data System (ADS)

    Afshani, Parichehr; Moussa, Sherif; Atkinson, Garrett; Kisurin, Vitaly Y.; Samy El-Shall, M.

    2016-04-01

    We demonstrate the coupling of the photothermal effects of silicon nanocrystals and graphene oxide (GO) dispersed in water. Using laser irradiation (532 nm or 355 nm) of suspended Si nanocrystals in an aqueous solution of GO, the synthesis of surface oxidized Si-reduced GO nanocomposites (SiOx/Si-RGO) is reported. The laser reduction of GO is accompanied by surface oxidation of the Si nanocrystals resulting in the formation of the SiOx/Si-RGO nanocomposites. The SiOx/Si-RGO nanocomposites are proposed as promising materials for photothermal therapy and for the efficient conversion of solar energy into usable heat for a variety of thermal and thermomechanical applications.

  7. Reduced reactivity to air on HF-treated YBa2Cu3O7 - x surfaces

    NASA Astrophysics Data System (ADS)

    Vasquez, R. P.; Hunt, B. D.; Foote, M. C.

    1989-06-01

    Treatment of YBa2Cu3O7-x films with a nonaqueous solution of HF in absolute ethanol results in the formation of an oxyfluoride with relative Y:Ba:Cu concentrations of 1:4:3 on the surface, as determined by x-ray photoelectron spectroscopy. The passivation properties of chemically treated films were tested by monitoring the growth of the high binding energy O 1s peak, associated with nonsuperconducting surface species, as a function of air exposure time, for both HF-treated and untreated films. The native oxyfluoride is shown to reduce the reactivity of the superconductor to air.

  8. Reduced sputum expression of interferon-stimulated genes in severe COPD

    PubMed Central

    Hilzendeger, Clarissa; da Silva, Jane; Henket, Monique; Schleich, Florence; Corhay, Jean Louis; Kebadze, Tatiana; Edwards, Michael R; Mallia, Patrick; Johnston, Sebastian L; Louis, Renaud

    2016-01-01

    Background Exacerbations of COPD are frequent and commonly triggered by respiratory tract infections. The purpose of our study was to investigate innate immunity in stable COPD patients. Methods Induced sputum was collected from 51 stable consecutive COPD patients recruited from the COPD Clinic of CHU Liege and 35 healthy subjects. Expression of interferons beta (IFN-β) and lambda1 (IL-29), IFN-stimulated genes (ISGs) MxA, OAS, and viperin were measured in total sputum cells by reverse transcription quantitative polymerase chain reaction (RT-qPCR). The presence of Picornaviruses was assessed by RT-PCR, while potential pathogenic microorganisms (PPM) were identified by sputum bacteriology. Results Expression of IL-29 was found in 16 of 51 COPD patients (31%) and in nine of 35 healthy subjects (26%), while IFN-β was detected in six of 51 COPD patients (12%) and in two of 35 healthy subjects (6%). ISGs were easily detectable in both groups. In the whole group of COPD patients, OAS expression was decreased (P<0.05), while that of viperin was increased (P<0.01) compared to healthy subjects. No difference was found with respect to MxA. COPD patients from group D of Global Initiative for Chronic Obstructive Lung Disease (GOLD) had reduced expression of all three ISGs (P<0.01 for MxA, P<0.05 for OAS, and P<0.01 for viperin) as compared to those of group B patients. Picornaviruses were detected in eight of 51 (16%) COPD patients vs four of 33 (12%) healthy subjects, while PPM were detected in seven of 39 (18%) COPD patients and associated with raised sputum neutrophil counts. IFN-β expression was raised when either picornavirus or PPM were detected (P=0.06), but no difference was seen regarding IL-29 or ISGs. Conclusion ISGs expression was reduced in severe COPD that may favor exacerbation and contribute to disease progress by altering response to infection. PMID:27418822

  9. Characterization of potato plants with reduced StSYR1 expression

    PubMed Central

    Eschen-Lippold, Lennart; Lübken, Tilo; Smolka, Ulrike; Rosahl, Sabine

    2012-01-01

    Vesicle fusion processes in plants are important for both development and stress responses. Transgenic potato plants with reduced expression of SYNTAXIN-RELATED1 (StSYR1), a gene encoding the potato homolog of Arabidopsis PENETRATION1 (AtPEN1), display spontaneous necrosis and chlorosis at later stages of development. In accordance with this developmental defect, tuber number, weight and overall yield are significantly reduced in StSYR1-RNAi lines. Enhanced resistance of StSYR1-RNAi plants to Phytophthora infestans, the causal agent of late blight disease of potato, correlates with enhanced levels of salicylic acid, whereas levels of 12-oxophytodienoic acid and jasmonic acid are unaltered. Cultured cells of StSYR1-RNAi lines secrete at least two compounds which are not detectable in the supernatant of control cells, suggesting an involvement of StSYR1 in secretion processes to the apoplast. PMID:22516814

  10. Characterization of potato plants with reduced StSYR1 expression.

    PubMed

    Eschen-Lippold, Lennart; Lübken, Tilo; Smolka, Ulrike; Rosahl, Sabine

    2012-05-01

    Vesicle fusion processes in plants are important for both development and stress responses. Transgenic potato plants with reduced expression of SYNTAXIN-RELATED1 (StSYR1), a gene encoding the potato homolog of Arabidopsis PENETRATION1 (AtPEN1), display spontaneous necrosis and chlorosis at later stages of development. In accordance with this developmental defect, tuber number, weight and overall yield are significantly reduced in StSYR1-RNAi lines. Enhanced resistance of StSYR1-RNAi plants to Phytophthora infestans, the causal agent of late blight disease of potato, correlates with enhanced levels of salicylic acid, whereas levels of 12-oxophytodienoic acid and jasmonic acid are unaltered. Cultured cells of StSYR1-RNAi lines secrete at least two compounds which are not detectable in the supernatant of control cells, suggesting an involvement of StSYR1 in secretion processes to the apoplast.

  11. Hepatic AQP9 expression in male rats is reduced in response to PPARα agonist treatment.

    PubMed

    Lebeck, Janne; Cheema, Muhammad Umar; Skowronski, Mariusz T; Nielsen, Søren; Praetorius, Jeppe

    2015-02-01

    The peroxisome proliferator receptor α (PPARα) is a key regulator of the hepatic response to fasting with effects on both lipid and carbohydrate metabolism. A role in hepatic glycerol metabolism has also been found; however, the results are somewhat contradictive. Aquaporin 9 (AQP9) is a pore-forming transmembrane protein that facilitates hepatic uptake of glycerol. Its expression is inversely regulated by insulin in male rodents, with increased expression during fasting. Previous results indicate that PPARα plays a crucial role in the induction of AQP9 mRNA during fasting. In the present study, we use PPARα agonists to explore the effect of PPARα activation on hepatic AQP9 expression and on the abundance of enzymes involved in glycerol metabolism using both in vivo and in vitro systems. In male rats with free access to food, treatment with the PPARα agonist WY 14643 (3 mg·kg(-1)·day(-1)) caused a 50% reduction in hepatic AQP9 abundance with the effect being restricted to AQP9 expressed in periportal hepatocytes. The pharmacological activation of PPARα had no effect on the abundance of GlyK, whereas it caused an increased expression of hepatic GPD1, GPAT1, and L-FABP protein. In WIF-B9 and HepG2 hepatocytes, both WY 14643 and another PPARα agonist GW 7647 reduced the abundance of AQP9 protein. In conclusion, pharmacological PPARα activation results in a marked reduction in the abundance of AQP9 in periportal hepatocytes. Together with the effect on the enzymatic apparatus for glycerol metabolism, our results suggest that PPARα activation in the fed state directs glycerol into glycerolipid synthesis rather than into de novo synthesis of glucose. PMID:25477377

  12. Decreased tumorigenicity correlates with expression of altered cell surface carbohydrates in Lec9 CHO cells.

    PubMed Central

    Ripka, J; Shin, S; Stanley, P

    1986-01-01

    To investigate a role for surface carbohydrates in cellular malignancy, 15 different glycosylation-defective CHO cell mutants were examined for their tumorigenic and metastatic capacities after subcutaneous injection into nude mice. Most of the glycosylation mutants displayed similar or slightly decreased tumorigenicity compared with parental CHO cells. Neither parental CHO cells nor any of the mutants were observed to metastasize. However, independent isolates of one mutant type, Lec9, showed a dramatic reduction in tumor formation. The altered carbohydrates expressed at the surface of Lec9 cells appeared to be responsible for their loss of tumorigenicity, because revertants for lectin resistance were able to form tumors, and a double mutant (Lec9.Lec1) that expressed a Lec1 glycosylation phenotype also formed tumors. Finally, Lec9 cells were able to form tumors in gamma-irradiated nude mice, suggesting that recognition by an irradiation-sensitive host cell(s) was responsible for their reduced tumorigenicity in untreated nude mice. PMID:3785164

  13. The role of soil surface crusting in desertification and strategies to reduce crusting.

    PubMed

    Fox, D M; Bryan, R B; Price, A G

    2004-12-01

    Soil crusting decreases infiltration, increases erosion, and impedes vegetation establishment, so reducing the impact of crusting is of major importance in combating desertification. Although surface crusting has been the subject of considerable research over the past 50 years or more, the practical management of soil crusts remains a challenge for many dryland communities. Crusting occurs in two steps, an initial aggregate breakdown period that occurs under rainfall and a subsequent hardening phase during drying. Several factors influence crust development, but the single most important one is soil aggregate stability. Strategies to reduce crusting can be based either on protecting the surface from raindrop impact or improving aggregate stability, or a combination of both. However, crust control is labor and/or capital intensive and must be thought out clearly in terms of the benefits to be achieved.

  14. Apoptosis is associated with reduced expression of complement regulatory molecules, adhesion molecules and other receptors on polymorphonuclear leucocytes: functional relevance and role in inflammation.

    PubMed Central

    Jones, J; Morgan, B P

    1995-01-01

    Human polymorphonuclear leucocytes (PMN) express proteins that protect them from damage by homologous complement. Protection may be particularly important when these cells migrate to inflammatory sites where complement activation is taking place. Resolution of inflammation involves removal of these PMN. The major mechanism of removal is likely to involve PMN apoptosis followed by recognition and engulfment by macrophages. However, little attention has been paid to the possible relevance of apoptosis to PMN susceptibility to immune effectors. Here we describe a reduction in cell surface expression of two complement regulatory proteins, CD59, an inhibitor of the membrane attack complex and CD55 (decay accelerating factor), an inhibitor of the C3/C5 convertase, on a subpopulation of PMN aged in culture. Loss of these proteins, both attached to the membrane by glycosyl phosphatidylinositol (GPI) anchors, correlated closely with the appearance of apoptotic morphology. We also observed a marked reduction in expression of the GPI-anchored molecule CD16 on apoptotic PMN. Reduced expression of membrane proteins was not confined to those anchored through GPI--several transmembrane molecules including CD11a CD11b and CD18 were also reduced on apoptotic PMN, whilst other were little changed (CD35, CD46). The precipitous fall in CD16 surface expression on PMN was not specific for apoptosis--in vitro incubation of PMN with lipopolysaccharide-inhibited apoptosis but caused a reduction in CD16 expression to 'apoptotic' levels. Images Figure 2 PMID:8567034

  15. Surface modifications of photoanodes in dye sensitized solar cells: enhanced light harvesting and reduced recombination

    NASA Astrophysics Data System (ADS)

    Saxena, Vibha; Aswal, D. K.

    2015-06-01

    In a quest to harvest solar power, dye-sensitized solar cells (DSSCs) have potential for low-cost eco-friendly photovoltaic devices. The major processes which govern the efficiency of a DSSC are photoelectron generation, injection of photo-generated electrons to the conduction band (CB) of the mesoporous nanocrystalline semiconductor (nc-SC); transport of CB electrons through nc-SC and subsequent collection of CB electrons at the counter electrode (CE) through the external circuit; and dye regeneration by redox couple or hole transport layer (HTL). Most of these processes occur at various interfaces of the photoanode. In addition, recombination losses of photo-generated electrons with either dye or redox molecules take place at the interfaces. Therefore, one of the key requirements for high efficiency is to improve light harvesting of the photoanode and to reduce the recombination losses at various interfaces. In this direction, surface modification of the photoanode is the simplest method among the various other approaches available in the literature. In this review, we present a comprehensive discussion on surface modification of the photoanode, which has been adopted in the literature for not only enhancing light harvesting but also reducing recombination. Various approaches towards surface modification of the photoanode discussed are (i) fluorine-doped tin oxide (FTO)/nc-SC interface modified via a compact layer of semiconductor material which blocks exposed sites of FTO to electrolyte (or HTL), (ii) nc-SC/dye interface modification either through acid treatment resulting in enhanced dye loading due to a positively charged surface or by depositing insulating/semiconducting blocking layer on the nc-SC surface, which acts as a tunneling barrier for recombination, (iii) nc-SC/dye interface modified by employing co-adsorbents which helps in reducing the dye aggregation and thereby recombination, and (iv) dye/electrolyte (or dye/HTL) interface modification using

  16. Indoleamine 2,3-dioxygenase (IDO) downregulates the cell surface expression of the CD4 molecule.

    PubMed

    Huang, Guanyou; Zeng, Yaoying; Liang, Peiyan; Zhou, Congrong; Zhao, Shuyun; Huang, Xiuyan; Wu, Lingfei; He, Xianhui

    2012-01-01

    Indoleamine 2,3-dioxygenase (IDO) has been implicated in preventing the fetus from undergoing maternal T cell-mediated immune responses, yet the mechanism underlying these kinds of IDO-mediated immune responses has not been fully elucidated. Since the CD4 molecule plays a central role in the onset and regulation of antigen-specific immune responses, and T cell is sensitive in the absence of tryptophan, we hypothesize that IDO may reduce cell surface CD4 expression. To test this hypothesis, an adenoviral vector-based construct IDO-EGFP was generated and the effect of IDO-EGFP on CD4 expression was determined on recombinant adenoviral infected C8166 and MT-2 cells, by flow cytometry and/or Western blot analysis. The results revealed a significant downregulation of cell membrane CD4 in pAd-IDOEGFP infected cells when compared to that of mock-infected cells or infection with empty vector pAd-EGFP. Further experiments disclosed that either an addition of tryptophan or IDO inhibitor could partly restore CD4 expression in pAd-IDOEGFP infected C8166 cells. Our findings suggest that downregulation of CD4 by IDO might be one of the mechanisms through which IDO regulates T cell-mediated immune responses.

  17. T cell interleukin-15 surface expression in chimpanzees infected with human immunodeficiency virus

    PubMed Central

    Rodriguez, Annette R.; Hodara, Vida; Murthy, Kruthi; Morrow, LaShayla; Sanchez, Melissa; Bienvenu, Amy E.; Murthy, Krishna K.

    2014-01-01

    Interleukin-15 (IL-15) contributes to natural killer cell development and immune regulation. However, IL-15 and interferon-gamma (IFN-γ) production are significantly reduced during progression to AIDS. We have previously reported that HIV infected chimpanzees (Pan troglodytes) express CD3-CD8+ IFN-γ+ natural killer (NK) cells with an inverse correlation to plasma HIV viral load. To expand on our initial study, we examined a larger population of HIV infected chimpanzees (n=10). Whole blood flow cytometry analyses showed that recombinant gp120 (rgp120) or recombinant IL-15 induces specific CD3-CD8+ IFN-γ+ NK cells at higher levels than CD3+CD8+ IFN-γ+ T cells in HIV infected specimens. Interestingly, peripheral blood T cells exhibited 0.5 to 3% IL-15 surface Tcell/NKT cell phenotypes, and rIL-15 stimulation significantly (P<0.007) up-regulated CD4+CD25+ T cell expression. Importantly, these data demonstrate novel T cell interleukin-15 expression and indicate a plausible regulatory mechanism for this cell-type during viral infection. PMID:24565973

  18. Immobilized Silver Nanoparticles on Chitosan with Special Surface State-Enhanced Antimicrobial Efficacy and Reduced Cytotoxicity.

    PubMed

    He, Miao; Lu, Liying; Zhang, Jinchi; Li, Danzhen

    2015-09-01

    Immobilized chitosan-Ag nanoparticles (CTS-Ag NPs) with special surface state have been synthesized successfully through immobilizing Ag NPs on the amino-enriched surface of CTS by reducing Ag (I) in situ. The antimicrobial efficiency and potency of CTS-Ag NPs against Escherichia coli and Staphylococcus aureus were studied. Our results reveal that surface-immobilized CTS-Ag NPs show better antimicrobial efficacy than several other reported monodisperse colloidal Ag NPs, because the unique surface state of our CTS-Ag NPs leads to both "contact killing" and "ion mediated killing" functions. Due to the synergetic effect of CTS and Ag NPs, the immobilized CTS-Ag NPs present a broader antimicrobial spectrum and a more effective antifungal activity against Monilia albican. In addition, CTS as an environment friendly dispersant can help to reduce the cytotoxicity of Ag NPs on higher organisms. The immobilized CTS-Ag NPs are stable and can maintain good disinfection potential after 6 months' shelf-time. PMID:26716197

  19. Reducing bacteria and macrophage density on nanophase hydroxyapatite coated onto titanium surfaces without releasing pharmaceutical agents

    NASA Astrophysics Data System (ADS)

    Bhardwaj, Garima; Yazici, Hilal; Webster, Thomas J.

    2015-04-01

    Reducing bacterial density on titanium implant surfaces has been a major concern because of the increasing number of nosocomial infections. Controlling the inflammatory response post implantation has also been an important issue for medical devices due to the detrimental effects of chronic inflammation on device performance. It has recently been demonstrated that manipulating medical device surface properties including chemistry, roughness and wettability can control both infection and inflammation. Here, we synthesized nanophase (that is, materials with one dimension in the nanoscale) hydroxyapatite coatings on titanium to reduce bacterial adhesion and inflammatory responses (as measured by macrophage functions) and compared such results to bare titanium and plasma sprayed hydroxyapatite titanium coated surfaces used clinically today. This approach is a pharmaceutical-free approach to inhibit infection and inflammation due to the detrimental side effects of any drug released in the body. Here, nanophase hydroxyapatite was synthesized in sizes ranging from 110-170 nm and was subsequently coated onto titanium samples using electrophoretic deposition. Results indicated that smaller nanoscale hydroxyapatite features on titanium surfaces alone decreased bacterial attachment in the presence of gram negative (P. aeruginosa), gram positive (S. aureus) and ampicillin resistant gram-negative (E. coli) bacteria as well as were able to control inflammatory responses; properties which should lead to their further investigation for improved medical applications.

  20. Reducing bacteria and macrophage density on nanophase hydroxyapatite coated onto titanium surfaces without releasing pharmaceutical agents.

    PubMed

    Bhardwaj, Garima; Yazici, Hilal; Webster, Thomas J

    2015-05-14

    Reducing bacterial density on titanium implant surfaces has been a major concern because of the increasing number of nosocomial infections. Controlling the inflammatory response post implantation has also been an important issue for medical devices due to the detrimental effects of chronic inflammation on device performance. It has recently been demonstrated that manipulating medical device surface properties including chemistry, roughness and wettability can control both infection and inflammation. Here, we synthesized nanophase (that is, materials with one dimension in the nanoscale) hydroxyapatite coatings on titanium to reduce bacterial adhesion and inflammatory responses (as measured by macrophage functions) and compared such results to bare titanium and plasma sprayed hydroxyapatite titanium coated surfaces used clinically today. This approach is a pharmaceutical-free approach to inhibit infection and inflammation due to the detrimental side effects of any drug released in the body. Here, nanophase hydroxyapatite was synthesized in sizes ranging from 110-170 nm and was subsequently coated onto titanium samples using electrophoretic deposition. Results indicated that smaller nanoscale hydroxyapatite features on titanium surfaces alone decreased bacterial attachment in the presence of gram negative (P. aeruginosa), gram positive (S. aureus) and ampicillin resistant gram-negative (E. coli) bacteria as well as were able to control inflammatory responses; properties which should lead to their further investigation for improved medical applications.

  1. Surface tension measurements of coal ash slags under reducing conditions at atmospheric pressure

    SciTech Connect

    Tobias Melchior; Gunther Putz; Michael Mueller

    2009-09-15

    The global demand for reduced CO{sub 2} emission from power plants can be answered by coal gasification techniques. To develop integrated gasification combined cycles that incorporate hot syngas cleaning facilities, detailed knowledge of the thermophysical properties of coal ashes is imperative. Currently, the surface tension of liquid coal ash slags in a reducing environment was studied by means of the sessile drop method. Three different algorithms were employed to analyze the acquired drop images. The slags under consideration were obtained from black and brown coals as well as from an experimental gasification reactor. Typically, a sharp surface tension decrease with temperature was found in the melting interval of the ashes. This was followed by a temperature range of smooth drop contours during which a slight rise of the surface tension could mostly be observed. Bubbles at the circumference of the drops started to appear when approaching the measurement temperature limit of 1550{sup o}C. With regard to the temperature regime of uncorrugated drop profiles, coal ash slags exhibited surface tension values between 400 and 700 mN/m. 32 refs., 9 figs., 1 tab.

  2. Decreased Bdnf expression and reduced social behavior in periadolescent rats following prenatal stress.

    PubMed

    Berry, Alessandra; Panetta, Pamela; Luoni, Alessia; Bellisario, Veronica; Capoccia, Sara; Riva, Marco Andrea; Cirulli, Francesca

    2015-04-01

    Prenatal stress (PNS) is a risk factor for the development of neuropsychiatric disorders. This study was aimed at assessing, in a rodent model, changes in gene expression profiles and behavioral output as a result of PNS, during periadolescence, a critical developmental period for the onset of psychopathology. Social behavior was studied in a standardized social interaction paradigm and the expression of Brain-Derived Neurotrophic Factor (Bdnf), a marker of neuronal plasticity, and of inhibitory and excitatory mechanisms (Na(+)-K(+)-2Cl(-) and K(+)-Cl(-) cotransporters ratio, NKCC1/KCC2) was analyzed. Results indicate that PNS reduced Bdnf transcripts while increasing the NKCC1/KCC2 ratio, primarily in the hippocampus. In the prefrontal cortex, changes in Bdnf were found to be gender-dependent. These effects were accompanied by reduced levels of affiliative and investigative social behaviors. Interestingly, interaction with non-stressed subjects was able to improve sociality in PNS rats suggesting that the social environment could be exploited for therapeutic intervention. PMID:25783782

  3. Phenanthrene exposure induces cardiac hypertrophy via reducing miR-133a expression by DNA methylation.

    PubMed

    Huang, Lixing; Xi, Zhihui; Wang, Chonggang; Zhang, Youyu; Yang, Zhibing; Zhang, Shiqi; Chen, Yixin; Zuo, Zhenghong

    2016-01-01

    Growing evidence indicates that there is an emerging link between environmental pollution and cardiac hypertrophy, while the mechanism is unclear. The objective of this study was to examine whether phenanthrene (Phe) could cause cardiac hypertrophy, and elucidate the molecular mechanisms involved. We found that: 1) Phe exposure increased the heart weight and cardiomyocyte size of rats; 2) Phe exposure led to enlarged cell size, and increased protein synthesis in H9C2 cells; 3) Phe exposure induced important markers of cardiac hypertrophy, such as atrial natriuretic peptide, B-type natriuretic peptide, and c-Myc in H9C2 cells and rat hearts; 4) Phe exposure perturbed miR-133a, CdC42 and RhoA, which were key regulators of cardiac hypertrophy, in H9C2 cells and rat hearts; 5) Phe exposure induced DNA methyltransferases (DNMTs) in H9C2 cells and rat hearts; 6) Phe exposure led to methylation of CpG sites within the miR-133a locus and reduced miR-133a expression in H9C2 cells; 7) DNMT inhibition and miR-133a overexpression could both alleviate the enlargement of cell size and perturbation of CdC42 and RhoA caused by Phe exposure. These results indicated that Phe could induce cardiomyocyte hypertrophy in the rat and H9C2 cells. The mechanism might involve reducing miR-133a expression by DNA methylation. PMID:26830171

  4. Phenanthrene exposure induces cardiac hypertrophy via reducing miR-133a expression by DNA methylation

    PubMed Central

    Huang, Lixing; Xi, Zhihui; Wang, Chonggang; Zhang, Youyu; Yang, Zhibing; Zhang, Shiqi; Chen, Yixin; Zuo, Zhenghong

    2016-01-01

    Growing evidence indicates that there is an emerging link between environmental pollution and cardiac hypertrophy, while the mechanism is unclear. The objective of this study was to examine whether phenanthrene (Phe) could cause cardiac hypertrophy, and elucidate the molecular mechanisms involved. We found that: 1) Phe exposure increased the heart weight and cardiomyocyte size of rats; 2) Phe exposure led to enlarged cell size, and increased protein synthesis in H9C2 cells; 3) Phe exposure induced important markers of cardiac hypertrophy, such as atrial natriuretic peptide, B-type natriuretic peptide, and c-Myc in H9C2 cells and rat hearts; 4) Phe exposure perturbed miR-133a, CdC42 and RhoA, which were key regulators of cardiac hypertrophy, in H9C2 cells and rat hearts; 5) Phe exposure induced DNA methyltransferases (DNMTs) in H9C2 cells and rat hearts; 6) Phe exposure led to methylation of CpG sites within the miR-133a locus and reduced miR-133a expression in H9C2 cells; 7) DNMT inhibition and miR-133a overexpression could both alleviate the enlargement of cell size and perturbation of CdC42 and RhoA caused by Phe exposure. These results indicated that Phe could induce cardiomyocyte hypertrophy in the rat and H9C2 cells. The mechanism might involve reducing miR-133a expression by DNA methylation. PMID:26830171

  5. Nonspecific transcription factor binding can reduce noise in the expression of downstream proteins

    NASA Astrophysics Data System (ADS)

    Soltani, M.; Bokes, P.; Fox, Z.; Singh, A.

    2015-10-01

    Transcription factors (TFs) interact with a multitude of binding sites on DNA and partner proteins inside cells. We investigate how nonspecific binding/unbinding to such decoy binding sites affects the magnitude and time-scale of random fluctuations in TF copy numbers arising from stochastic gene expression. A stochastic model of TF gene expression, together with decoy site interactions is formulated. Distributions for the total (bound and unbound) and free (unbound) TF levels are derived by analytically solving the chemical master equation under physiologically relevant assumptions. Our results show that increasing the number of decoy binding sides considerably reduces stochasticity in free TF copy numbers. The TF autocorrelation function reveals that decoy sites can either enhance or shorten the time-scale of TF fluctuations depending on model parameters. To understand how noise in TF abundances propagates downstream, a TF target gene is included in the model. Intriguingly, we find that noise in the expression of the target gene decreases with increasing decoy sites for linear TF-target protein dose-responses, even in regimes where decoy sites enhance TF autocorrelation times. Moreover, counterintuitive noise transmissions arise for nonlinear dose-responses. In summary, our study highlights the critical role of molecular sequestration by decoy binding sites in regulating the stochastic dynamics of TFs and target proteins at the single-cell level.

  6. Surface-layer protein from Caulobacter crescentus: expression, purification and X-ray crystallographic analysis.

    PubMed

    Jones, Michael D; Chan, Anson C K; Nomellini, John F; Murphy, Michael E P; Smit, John

    2016-09-01

    Protein surface layers are self-assembling, paracrystalline lattices on the surface of many prokaryotes. Surface-layer proteins have not benefited from widespread structural analysis owing to their resistance to crystallization. Here, the successful expression of a truncated version of RsaA, the surface-layer protein from Caulobacter crescentus, from a Caulobacter protein-expression system is reported. The purification, crystallization and initial X-ray diffraction analysis of the truncated RsaA, the largest surface-layer protein studied to date and the first from a Gram-negative bacterium, are also reported. PMID:27599857

  7. Reduced GABAA Receptor α6 Expression in The Trigeminal Ganglion Enhanced Myofascial Nociceptive Response

    PubMed Central

    Kramer, P. R.; Bellinger, L. L.

    2013-01-01

    Activation of the GABAA receptor results in inhibition of neuronal activity. One subunit of this multi-subunit receptor termed alpha 6 (Gabrα6) contributed to inflammatory temporomandibular joint (TMJ) nociception but TMJ disorders often include myofascial pain. To address Gabrα6 role in myofascial pain we hypothesized that Gabrα6 has an inhibitory role in myofascial nociceptive responses similar to inflammatory TMJ arthritis. To test this hypothesis a, myofascial nociceptive response was induced by placing a ligature bilaterally on the tendon attachment of the anterior superficial part of a male rat's masseter muscle. Four days after ligature placement Gabrα6 expression was reduced by infusing the trigeminal ganglia (TG) with small interfering RNA (siRNA) having homology to either the Gabrα6 gene (Gabra6 siRNA) or no known gene (control siRNA). After siRNA infusion nociceptive behavioral responses were measured, i.e., feeding behavior and head withdrawal after pressing upon the region above the ligature with von Frey filaments. Neuronal activity in the TG and trigeminal nucleus caudalis and upper cervical region (Vc–C1) was measured by quantitating the amount of phosphorylated extracellular signalregulated kinase (p-ERK). Total Gabrα6 and GABAA receptor contents in the TG and Vc–C1 were determined. Gabrα6 siRNA infusion reduced Gabrα6 and GABAA receptor expression and significantly increased the nociceptive response in both nociceptive assays. Gabra6 siRNA infusion also significantly increased TG p-ERK expression of the ligated rats. From these results we conclude GABAA receptors consisting of the Gabrα6 subunit inhibit TG nociceptive sensory afferents in the trigeminal pathway and have an important role in the regulation of myofascial nociception. PMID:23602886

  8. Chemical Inhibition of Kynureninase Reduces Pseudomonas aeruginosa Quorum Sensing and Virulence Factor Expression.

    PubMed

    Kasper, Stephen H; Bonocora, Richard P; Wade, Joseph T; Musah, Rabi Ann; Cady, Nathaniel C

    2016-04-15

    The opportunistic pathogen Pseudomonas aeruginosa utilizes multiple quorum sensing (QS) pathways to coordinate an arsenal of virulence factors. We previously identified several cysteine-based compounds inspired by natural products from the plant Petiveria alliacea which are capable of antagonizing multiple QS circuits as well as reducing P. aeruginosa biofilm formation. To understand the global effects of such compounds on virulence factor production and elucidate their mechanism of action, RNA-seq transcriptomic analysis was performed on P. aeruginosa PAO1 exposed to S-phenyl-l-cysteine sulfoxide, the most potent inhibitor from the prior study. Exposure to this inhibitor down-regulated expression of several QS-regulated virulence operons (e.g., phenazine biosynthesis, type VI secretion systems). Interestingly, many genes that were differentially regulated pertain to the related metabolic pathways that yield precursors of pyochelin, tricarboxylic acid cycle intermediates, phenazines, and Pseudomonas quinolone signal (PQS). Activation of the MexT-regulon was also indicated, including the multidrug efflux pump encoded by mexEF-oprN, which has previously been shown to inhibit QS and pathogenicity. Deeper investigation of the metabolites involved in these systems revealed that S-phenyl-l-cysteine sulfoxide has structural similarity to kynurenine, a precursor of anthranilate, which is critical for P. aeruginosa virulence. By supplementing exogenous anthranilate, the QS-inhibitory effect was reversed. Finally, it was shown that S-phenyl-l-cysteine sulfoxide competitively inhibits P. aeruginosa kynureninase (KynU) activity in vitro and reduces PQS production in vivo. The kynurenine pathway has been implicated in P. aeruginosa QS and virulence factor expression; however, this is the first study to show that targeted inhibition of KynU affects P. aeruginosa gene expression and QS, suggesting a potential antivirulence strategy.

  9. Chemical Inhibition of Kynureninase Reduces Pseudomonas aeruginosa Quorum Sensing and Virulence Factor Expression.

    PubMed

    Kasper, Stephen H; Bonocora, Richard P; Wade, Joseph T; Musah, Rabi Ann; Cady, Nathaniel C

    2016-04-15

    The opportunistic pathogen Pseudomonas aeruginosa utilizes multiple quorum sensing (QS) pathways to coordinate an arsenal of virulence factors. We previously identified several cysteine-based compounds inspired by natural products from the plant Petiveria alliacea which are capable of antagonizing multiple QS circuits as well as reducing P. aeruginosa biofilm formation. To understand the global effects of such compounds on virulence factor production and elucidate their mechanism of action, RNA-seq transcriptomic analysis was performed on P. aeruginosa PAO1 exposed to S-phenyl-l-cysteine sulfoxide, the most potent inhibitor from the prior study. Exposure to this inhibitor down-regulated expression of several QS-regulated virulence operons (e.g., phenazine biosynthesis, type VI secretion systems). Interestingly, many genes that were differentially regulated pertain to the related metabolic pathways that yield precursors of pyochelin, tricarboxylic acid cycle intermediates, phenazines, and Pseudomonas quinolone signal (PQS). Activation of the MexT-regulon was also indicated, including the multidrug efflux pump encoded by mexEF-oprN, which has previously been shown to inhibit QS and pathogenicity. Deeper investigation of the metabolites involved in these systems revealed that S-phenyl-l-cysteine sulfoxide has structural similarity to kynurenine, a precursor of anthranilate, which is critical for P. aeruginosa virulence. By supplementing exogenous anthranilate, the QS-inhibitory effect was reversed. Finally, it was shown that S-phenyl-l-cysteine sulfoxide competitively inhibits P. aeruginosa kynureninase (KynU) activity in vitro and reduces PQS production in vivo. The kynurenine pathway has been implicated in P. aeruginosa QS and virulence factor expression; however, this is the first study to show that targeted inhibition of KynU affects P. aeruginosa gene expression and QS, suggesting a potential antivirulence strategy. PMID:26785289

  10. Corticosteroids Mediate Heart Failure-Induced Depression through Reduced σ1-Receptor Expression

    PubMed Central

    Bhuiyan, Md. Shenuarin; Hasegawa, Hideyuki; Kanai, Hiroshi; Zhang, Chen; Han, Feng; Fukunaga, Kohji

    2016-01-01

    Cardiovascular diseases are risk factors for depression in humans. We recently proposed that σ1 receptor (σ1R) stimulation rescued cardiac hypertrophy and heart failure induced by transverse aortic constriction (TAC) in mice. Importantly, σ1R stimulation reportedly ameliorates depression-like behaviors in rodents. Thus, we hypothesized that impaired σ1R activity in brain triggers depression-like behaviors in animals with cardiovascular disease. Indeed, here we found that cardiac hypertrophy and heart failure induced by TAC were associated with depression-like behaviors concomitant with downregulation of σ1R expression in brain 6 weeks after surgery. σ1R levels significantly decreased in astrocytes in both the hippocampal CA1 region and dentate gyrus. Oral administration of the specific σ1R agonist SA4503 (0.3–1.0mg/kg) significantly improved TAC-induced depression-like behaviors concomitant with rescued astrocytic σ1R expression in CA1 and the dentate gyrus. Plasma corticosterone levels significantly increased 6 weeks after TAC, and chronic treatment of mice with corticosterone for 3 weeks elicited depression-like behaviors concomitant with reduced astrocytic σ1R expression in hippocampus. Furthermore, the glucocorticoid receptor antagonist mifepristone antagonized depressive-like behaviors and ameliorated decreased hippocampal σ1R expression in TAC mice. We conclude that elevated corticosterone levels trigger hippocampal σ1R downregulation and that σ1R stimulation with SA4503 is an attractive therapy to improve not only cardiac dysfunction but depression-like behaviors associated with heart failure. PMID:27741227

  11. Morphology of gas cavities on patterned hydrophobic surfaces under reduced pressure

    NASA Astrophysics Data System (ADS)

    Xue, Yahui; Lv, Pengyu; Liu, Ying; Shi, Yipeng; Lin, Hao; Duan, Huiling

    2015-09-01

    Gas cavities trapped on structured hydrophobic surfaces play important roles in realizing functionalities such as superhydrophobicity, drag reduction, and surface cleaning. The morphology of the cavities exhibits strong dependence on system parameters which impact the performance of these surfaces. In this work, a complete theoretical analysis is presented to predict cavity morphological change under reduced liquid pressure, on a submerged hydrophobic surface patterned with cylindrical pores. Equilibrium solutions are derived for five different phases, namely, (I) pinned recession, (II) depinned recession, (III) Cassie-Baxter, (IV) expansion, and (V) coalescence; their stabilities are also analyzed. A phase map is developed outlining the different regimes with respect to the gas amount and liquid pressure. Importantly, phase (IV) exhibits a complex stability behavior that leads to two possible routes to coalescence, which lends two different mechanisms of cavitation. Accordingly, the threshold pressure for cavitation can be calculated. The theoretical model is supported by direct experimental measurements via confocal microscopy and demonstrates good quantitative accuracy. This work provides a predictive tool for the design of functional structured hydrophobic surfaces.

  12. Reducing phosphorus loading of surface water using iron-coated sand.

    PubMed

    Groenenberg, Jan E; Chardon, Wim J; Koopmans, Gerwin F

    2013-01-01

    Phosphorus losses from agricultural soils is an important source of P in surface waters leading to surface water quality impairment. In addition to reducing P inputs, mitigation measures are needed to reduce P enrichment of surface waters. Because drainage of agricultural land by pipe drainage is an important pathway of P to surface waters, removing P from drainage water has a large potential to reduce P losses. In a field trial, we tested the performance of a pipe drain enveloped with Fe-coated sand, a side product of the drinking water industry with a high ability to bind P, to remove P from the drainage water. The results of this trial, encompassing more than one hydrological season, are very encouraging because the efficiency of this mitigation measure to remove P amounted to 94%. During the trial, the pipe drains were below the groundwater level for a prolonged time. Nevertheless, no reduction of Fe(III) in the Fe-coated sand occurred, which was most likely prevented by reduction of Mn oxides present in this material. The enveloped pipe drain was estimated to be able to lower the P concentration in the effluent to the desired water quality criterion for about 14 yr. Manganese oxides are expected to be depleted after 5 to 10 yr. The performance of the enveloped pipe drain, both in terms of its ability to remove P to a sufficiently low level and the stability of the Fe-coated sand under submerged conditions in the long term, needs prolonged experimental research.

  13. Shugan-decoction relieves visceral hyperalgesia and reduces TRPV1 and SP colon expression

    PubMed Central

    Shang, Jing-Juan; Yuan, Jian-Ye; Xu, Hui; Tang, Rong-Zhu; Dong, Yue-Bin; Xie, Jian-Qun

    2013-01-01

    AIM: To evaluate the therapeutic effect of Shugan-decoction (SGD) on visceral hyperalgesia and colon gene expressions using a rat model. METHODS: Ninety-six adult male Wistar rats were randomized into six equal groups for assessment of SGD effects on psychological stress-induced changes using the classic water avoidance stress (WAS) test. Untreated model rats were exposed to chronic (1 h/d for 10 d consecutive) WAS conditions; experimental treatment model rats were administered with intragastric SGD at 1 h before WAS on consecutive days 4-10 (low-dose: 0.1 g/mL; mid-dose: 0.2 g/mL; high-dose: 0.4 g/mL); control treatment model rats were similarly administered with the irritable bowel syndrome drug, dicetel (0.0042 g/mL); untreated normal control rats received no drug and were not subjected to the WAS test. At the end of the 10-d WAS testing period, a semi-quantitative measurement of visceral sensitivity was made by assessing the abdominal withdrawal reflex (AWR) to colorectal balloon-induced distension (at 5 mmHg increments) to determine the pain pressure threshold (PPT, evidenced by pain behavior). Subsequently, the animals were sacrificed and colonic tissues collected for assessment of changes in expressions of proteins related to visceral hypersensitivity (transient receptor potential vanilloid 1, TRPV1) and sustained visceral hyperalgesia (substance P, SP) by immunohistochemistry and real-time polymerase chain reaction. Inter-group differences were assessed by paired t test or repeated measures analysis of variance. RESULTS: The WAS test successfully induced visceral hypersensitivity, as evidenced by a significantly reduced AWR pressure in the untreated model group as compared to the untreated normal control group (190.4 ± 3.48 mmHg vs 224.0 ± 4.99 mmHg, P < 0.001). SGD treatments at mid-dose and high-dose and the dicetel treatment significantly increased the WAS-reduced PPT (212.5 ± 2.54, 216.5 ± 3.50 and 217.7 ± 2.83 mmHg respectively, all P < 0

  14. Formation of Random, RIE-Textured Silicon Surfaces with Reduced Reflection and Enhanced Near IR Absorption

    SciTech Connect

    ZAIDI, SALEEM H

    2001-04-01

    The authors have developed novel metal-assisted texturing processes that have led to optically favorable surfaces for solar cells. Large area ({approximately} 200 cm{sup 2}) uniform texturing has been achieved. The physical dimensions of the chamber limited texturing of even larger wafers. Surface contamination and residual RIE-induced damage were removed by incorporation of a complete RCA clean process followed by wet-chemical etching treatments. RIE-textured solar cells with optimized profiles providing performance comparable to the random, wet-chemically etched cells have been demonstrated. A majority of the texture profiles exhibit an enhanced IQE response in the near IR region.using scanning electron microscope measurements, they carried out a detailed analysis of the microstructure of random RIE-textured surfaces. The random microstructure represents a superposition of sub-{micro}m grating structures with a wide distribution of periods, depths, and profiles as determined by the SEM measurements. These structures were modeled using GSOLVER{trademark} software for periodic patterns. The enhanced IR response from random, RIE-textured surfaces is attributed to enhanced coupling of light into the transmitted diffraction orders. These obliquely propagating diffraction orders generate electron-hole pairs closer to the surface, thus, reducing bulk recombination losses relative to a non-scattering, planar surface with identical hemispherical reflection. The optimized texture and damage removal processes have been applied to large area (100--132 cm{sup 2}) multi-crystalline wafers. initial results have demonstrated improved performance relative to planar, control wafers. However, the texture and solar cell fabrication processes require further optimization in the RCA clean, DRE treatments, and emitter formation in order to fully realize the benefits of the low-reflection ({approximately}1-2%) textured surfaces.

  15. Reduced adhesion of macrophages on anodized titanium with select nanotube surface features

    PubMed Central

    Rajyalakshmi, Amancherla; Ercan, Batur; Balasubramanian, K; Webster, Thomas J

    2011-01-01

    One of the important prerequisites for a successful orthopedic implant apart from being osteoconductive is the elicitation of a favorable immune response that does not lead to the rejection of the implant by the host tissue. Anodization is one of the simplest surface modification processes used to create nanotextured and nanotubular features on metal oxides which has been shown to improve bone formation. Anodization of titanium (Ti) leads to the formation of TiO2 nanotubes on the surface, and the presence of these nanotubes mimics the natural nanoscale features of bone, which in turn contributes to improved bone cell attachment, migration, and proliferation. However, inflammatory cell responses on anodized Ti remains to be tested. It is hypothesized that surface roughness and surface feature size on anodized Ti can be carefully manipulated to control immune cell (specifically, macrophages) responses. Here, when Ti samples were anodized at 10 V in the presence of 1% hydrofluoric acid (HF) for 1 minute, nanotextured (nonnanotube) surfaces were created. When anodization of Ti samples was carried out with 1% HF for 10 minutes at 15 V, nanotubes with 40–50 nm diameters were formed, whereas at 20 V with 1% HF for 10 minutes, nanotubes with 60–70 nm diameters were formed. In this study, a reduced density of macrophages was observed after 24 hours of culture on nanotextured and nanotubular Ti samples which were anodized at 10, 15, and 20 V, compared with conventional unmodified Ti samples. This in vitro study thus demonstrated a reduced density of macrophages on anodized Ti, thereby providing further evidence of the greater efficacy of anodized Ti for orthopedic applications. PMID:21980239

  16. Surface expression of the hRSV nucleoprotein impairs immunological synapse formation with T cells

    PubMed Central

    Céspedes, Pablo F.; Bueno, Susan M.; Ramírez, Bruno A.; Gomez, Roberto S.; Riquelme, Sebastián A.; Palavecino, Christian E.; Mackern-Oberti, Juan Pablo; Mora, Jorge E.; Depoil, David; Sacristán, Catarina; Cammer, Michael; Creneguy, Alison; Nguyen, Tuan H.; Riedel, Claudia A.; Dustin, Michael L.; Kalergis, Alexis M.

    2014-01-01

    Human respiratory syncytial virus (hRSV) is the leading cause of bronchiolitis and pneumonia in young children worldwide. The recurrent hRSV outbreaks and reinfections are the cause of a significant public health burden and associate with an inefficient antiviral immunity, even after disease resolution. Although several mouse- and human cell-based studies have shown that hRSV infection prevents naïve T-cell activation by antigen-presenting cells, the mechanism underlying such inhibition remains unknown. Here, we show that the hRSV nucleoprotein (N) could be at least partially responsible for inhibiting T-cell activation during infection by this virus. Early after infection, the N protein was expressed on the surface of epithelial and dendritic cells, after interacting with trans-Golgi and lysosomal compartments. Further, experiments on supported lipid bilayers loaded with peptide-MHC (pMHC) complexes showed that surface-anchored N protein prevented immunological synapse assembly by naive CD4+ T cells and, to a lesser extent, by antigen-experienced T-cell blasts. Synapse assembly inhibition was in part due to reduced T-cell receptor (TCR) signaling and pMHC clustering at the T-cell−bilayer interface, suggesting that N protein interferes with pMHC−TCR interactions. Moreover, N protein colocalized with the TCR independently of pMHC, consistent with a possible interaction with TCR complex components. Based on these data, we conclude that hRSV N protein expression at the surface of infected cells inhibits T-cell activation. Our study defines this protein as a major virulence factor that contributes to impairing acquired immunity and enhances susceptibility to reinfection by hRSV. PMID:25056968

  17. Reduced expression of the complement receptor type 2 (CR2, CD21) by synovial fluid B and T lymphocytes

    PubMed Central

    Illges, H; Braun, M; Peter, H H; Melchers, I

    2000-01-01

    The expression of CR2 (CD21) by synovial B and T lymphocytes of patients suffering from various forms of arthritis was analysed with cytofluorometry and with reverse transcriptase-polymerase chain reaction. CR2 (CD21) cell surface protein was detected in normal quantities on peripheral B cells, but was almost absent on synovial B lymphocytes of the same patients. This reduction was most severe in patients with rheumatoid arthritis, but also observed in all other cases. CR2 (CD21) did not reappear after in vitro culture. CR2 (CD21) mRNA was also strongly reduced in synovial B and T lymphocytes. Synovial fluid B lymphocytes were larger than peripheral blood B lymphocytes, while T cells from the same patients showed no size differences. We conclude that synovial fluid B lymphocytes have undergone an irreversible step towards terminal differentiation. The presence or absence of CR2 (CD21) mRNA in peripheral versus synovial T cells indicates that CR2 (CD21) is also differentially expressed by T lymphocytes. PMID:11091285

  18. Mitigation strategies to reduce pesticide inputs into ground- and surface water and their effectiveness; a review.

    PubMed

    Reichenberger, Stefan; Bach, Martin; Skitschak, Adrian; Frede, Hans-Georg

    2007-10-01

    In this paper, the current knowledge on mitigation strategies to reduce pesticide inputs into surface water and groundwater, and their effectiveness when applied in practice is reviewed. Apart from their effectiveness in reducing pesticide inputs into ground- and surface water, the mitigation measures identified in the literature are evaluated with respect to their practicability. Those measures considered both effective and feasible are recommended for implementing at the farm and catchment scale. Finally, recommendations for modelling are provided using the identified reduction efficiencies. Roughly 180 publications directly dealing with or being somehow related to mitigation of pesticide inputs into water bodies were examined. The effectiveness of grassed buffer strips located at the lower edges of fields has been demonstrated. However, this effectiveness is very variable, and the variability cannot be explained by strip width alone. Riparian buffer strips are most probably much less effective than edge-of-field buffer strips in reducing pesticide runoff and erosion inputs into surface waters. Constructed wetlands are promising tools for mitigating pesticide inputs via runoff/erosion and drift into surface waters, but their effectiveness still has to be demonstrated for weakly and moderately sorbing compounds. Subsurface drains are an effective mitigation measure for pesticide runoff losses from slowly permeable soils with frequent waterlogging. For the pathways drainage and leaching, the only feasible mitigation measures are application rate reduction, product substitution and shift of the application date. There are many possible effective measures of spray drift reduction. While sufficient knowledge exists for suggesting default values for the efficiency of single drift mitigation measures, little information exists on the effect of the drift reduction efficiency of combinations of measures. More research on possible interactions between different drift

  19. Wear-reducing Surface Functionalization of Implant Materials Using Ultrashort Laser Pulses

    NASA Astrophysics Data System (ADS)

    Oldorf, P.; Peters, R.; Reichel, S.; Schulz, A.-P.; Wendlandt, R.

    The aim of the project called "EndoLas" is the development of a reproducible and reliable method for a functionalization of articulating surfaces on hip joint endoprostheses due to a reduction of abrasion and wear by the generation of micro structures using ultrashort laser pulses. On the one hand, the microstructures shall ensure the capture of abraded particles, which cause third-body wear and thereby increase aseptic loosening. On the other hand, the structures shall improve or maintain the tribologically important lubricating film. Thereby, the cavities serve as a reservoir for the body's own synovial fluid. The dry friction, which promotes abrasion and is a part of the mixed friction in the joint, shall therefore be reduced. In experimental setups it was shown, that the abrasive wear can be reduced significantly due to micro-structuring the articulating implant surfaces. To shape the fine and deterministic cavities on the surfaces, an ultra-short pulsed laser, which is integrated in a high-precision, 5-axes micro-machining system, was used. The laser system, based on an Yb:YAG thin-disk regenerative amplifier, has an average output power of 50 W at the fundamental wavelength of 1030 nm, a maximum repetition rate of 400 kHz and a pulse duration of 6 ps. Due to this, a maximum pulse energy of 125 μJ is achievable. Furthermore external second and third harmonic generation enables the usage of wavelengths in the green and violet spectral range.

  20. The expression and distribution of α-Gal gene in various species ocular surface tissue

    PubMed Central

    Shao, Yi; Yu, Yao; Pei, Chong-Gang; Qu, Yangluowa; Gao, Gui-Ping; Yang, Ji-Lin; Zhou, Qiong; Yang, Lu; Liu, Qiu-Ping

    2012-01-01

    AIM To examine the α-Gal gene expression and distribution in the different species/genus and developing phase animal ocular surface tissue. METHODS α-Gal binding assay were carried out on various animal eye sections. Photograph, slit-lamp observation on various eye showed normal corneal transparence. RESULTS A strong α-Gal expression in invertebrates and some vertebrates ocular tissue, but no α-Gal binding in birds, fish and mammal. α-Gal expression change in the development of mice ocular surface tissue (except sclera) and display genus dependency in the different murine ocular surface tissue. CONCLUSION This study identified specific α-Gal epitopes binding area in the ocular surface of several species and may solve the problem that naive ocular surface may be used as natural α-Gal gene knockout model/high risk immunologic rejection model or ocular surface scaffold material. PMID:23166862

  1. Successful Surface Treatments for Reducing Instabilities in Advanced Nickel-base Superalloys for Turbine Blades

    NASA Technical Reports Server (NTRS)

    Locci, Ivan E.; MacKay, Rebecca A.; Garg, Anita; Ritzert, Frank J.

    2004-01-01

    An optimized carburization treatment has been developed to mitigate instabilities that form in the microstructures of advanced turbine airfoil materials. Current turbine airfoils consist of a single crystal superalloy base that provides the mechanical performance of the airfoil, a thermal barrier coating (TBC) that reduces the temperature of the base superalloy, and a bondcoat between the superalloy and the TBC, that improves the oxidation and corrosion resistance of the base superalloy and the spallation resistance of the TBC. Advanced nickel-base superalloys containing high levels of refractory metals have been observed to develop an instability called secondary reaction zone (SRZ), which can form beneath diffusion aluminide bondcoats. This instability between the superalloy and the bondcoat has the potential of reducing the mechanical properties of thin-wall turbine airfoils. Controlled gas carburization treatments combined with a prior stress relief heat treatment and adequate surface preparation have been utilized effectively to minimize the formation of SRZ. These additional processing steps are employed before the aluminide bondcoat is deposited and are believed to change the local chemistry and local stresses of the surface of the superalloy. This paper presents the detailed processing steps used to reduce SRZ between platinum aluminide bondcoats and advanced single crystal superalloys.

  2. Response Surface Energy Modeling of an Electric Vehicle over a Reduced Composite Drive Cycle

    SciTech Connect

    Jehlik, Forrest; LaClair, Tim J.

    2014-04-01

    Response surface methodology (RSM) techniques were applied to develop a predictive model of electric vehicle (EV) energy consumption over the Environmental Protection Agency's (EPA) standardized drive cycles. The model is based on measurements from a synthetic composite drive cycle. The synthetic drive cycle is a minimized statistical composite of the standardized urban (UDDS), highway (HWFET), and US06 cycles. The composite synthetic drive cycle is 20 minutes in length thereby reducing testing time of the three standard EPA cycles by over 55%. Vehicle speed and acceleration were used as model inputs for a third order least squared regression model predicting vehicle battery power output as a function of the drive cycle. The approach reduced three cycles and 46 minutes of drive time to a single test of 20 minutes. Application of response surface modeling to the synthetic drive cycle is shown to predict energy consumption of the three EPA cycles within 2.6% of the actual measured values. Additionally, the response model may be used to predict energy consumption of any cycle within the speed/acceleration envelope of the synthetic cycle. This technique results in reducing test time, which additionally provides a model that may be used to expand the analysis and understanding of the vehicle under consideration.

  3. Reduced cortical thickness, surface area in patients with chronic obstructive pulmonary disease: a surface-based morphometry and neuropsychological study.

    PubMed

    Chen, Ji; Lin, In-Tsang; Zhang, Haiyan; Lin, Jianzhong; Zheng, Shili; Fan, Ming; Zhang, Jiaxing

    2016-06-01

    Neural impairments accompanying chronic obstructive pulmonary disease (COPD) have received growing research attention. Previous neuroimaging studies exclusively used volumetric methods to measure cortical volume as a whole rather than focusing on anatomical and neuropathological distinct indices. Here we decomposed the cortical architecture into cortical thickness (CTh), surface area (SA), and gyrification, for the first time, to provide a more integrative profile of brain damage in COPD. Clinical T1-weighted MRI scans were acquired in 25 stable COPD patients (mean age 69) and 25 age-matched controls. Images were processed using surface-based morphometry to obtain cortical parameters enabling more accurate measurement in deep sulci and localized regional mapping. Demographic, physiological, and cognitive assessments were made and correlated with cortical indices. Compared to controls, COPD patients showed significantly reduced CTh broadly distributed in motor, parietal, and prefrontal cortices, together with more circumscribed SA reduction in dorsomedial prefrontal cortex and Broca's area (cluster-level P < 0.05 corrected). No abnormal gyrification was detected. Decreased CTh in parietofrontal networks strongly correlated with visuospatial construction impairment in COPD patients. Furthermore, thinner dorsolateral prefrontal cortex (DLPFC) best predicted poorer performance (r (2)  = 0.315, P = 0.004), and was associated with lower arterial oxygen saturation. These data indicate that cortical thinning is a key morphologic feature associated with COPD that could be partly attributed to oxygen desaturation and contributes to COPD visual memory and drawing deficits. Surface-based morphometry provides valuable information concerning COPD, and could ultimately help us to characterize the neurodegenerative pattern and to clarify neurologic mechanisms underlying cognitive dysfunction in COPD patients. PMID:25986304

  4. Flunitrazepam rapidly reduces GABAA receptor subunit protein expression via a protein kinase C-dependent mechanism

    PubMed Central

    Johnston, Jonathan D; Price, Sally A; Bristow, David R

    1998-01-01

    Acute flunitrazepam (1 μM) exposure for 1 h reduced GABAA receptor α1 (22±4%, mean±s.e.mean) and β2/3 (21±4%) subunit protein levels in cultured rat cerebellar granule cells. This rapid decrease in subunit proteins was completely prevented by bisindolymaleimide 1 (1 μM), an inhibitor of protein kinase C, but not by N-[2-((p-bromocinnamyl)amino)ethyl]-5-isoquinolinesulfonamide (H-89, 4.8 μM), an inhibitor of protein kinases A and G. These results suggest the existence of a benzodiazepine-induced mechanism to rapidly alter GABAA receptor protein expression, that appears to be dependent on protein kinase C activity. PMID:9723942

  5. Transcriptomic Profiling in Childhood H1N1/09 Influenza Reveals Reduced Expression of Protein Synthesis Genes

    PubMed Central

    Herberg, Jethro A.; Kaforou, Myrsini; Gormley, Stuart; Sumner, Edward R.; Patel, Sanjay; Jones, Kelsey D. J.; Paulus, Stéphane; Fink, Colin; Martinon-Torres, Federico; Montana, Giovanni; Wright, Victoria J.; Levin, Michael

    2013-01-01

    We compared the blood RNA transcriptome of children hospitalized with influenza A H1N1/09, respiratory syncytial virus (RSV) or bacterial infection, and healthy controls. Compared to controls, H1N1/09 patients showed increased expression of inflammatory pathway genes and reduced expression of adaptive immune pathway genes. This was validated on an independent cohort. The most significant function distinguishing H1N1/09 patients from controls was protein synthesis, with reduced gene expression. Reduced expression of protein synthesis genes also characterized the H1N1/09 expression profile compared to children with RSV and bacterial infection, suggesting that this is a key component of the pathophysiological response in children hospitalized with H1N1/09 infection. PMID:23901082

  6. Hyperglycemia reduces functional expression of astrocytic Kir4.1 channels and glial glutamate uptake.

    PubMed

    Rivera-Aponte, D E; Méndez-González, M P; Rivera-Pagán, A F; Kucheryavykh, Y V; Kucheryavykh, L Y; Skatchkov, S N; Eaton, M J

    2015-12-01

    Diabetics are at risk for a number of serious health complications including an increased incidence of epilepsy and poorer recovery after ischemic stroke. Astrocytes play a critical role in protecting neurons by maintaining extracellular homeostasis and preventing neurotoxicity through glutamate uptake and potassium buffering. These functions are aided by the presence of potassium channels, such as Kir4.1 inwardly rectifying potassium channels, in the membranes of astrocytic glial cells. The purpose of the present study was to determine if hyperglycemia alters Kir4.1 potassium channel expression and homeostatic functions of astrocytes. We used q-PCR, Western blot, patch-clamp electrophysiology studying voltage and potassium step responses and a colorimetric glutamate clearance assay to assess Kir4.1 channel levels and homeostatic functions of rat astrocytes grown in normal and high glucose conditions. We found that astrocytes grown in high glucose (25 mM) had an approximately 50% reduction in Kir4.1 mRNA and protein expression as compared with those grown in normal glucose (5mM). These reductions occurred within 4-7 days of exposure to hyperglycemia, whereas reversal occurred between 7 and 14 days after return to normal glucose. The decrease in functional Kir channels in the astrocytic membrane was confirmed using barium to block Kir channels. In the presence of 100-μM barium, the currents recorded from astrocytes in response to voltage steps were reduced by 45%. Furthermore, inward currents induced by stepping extracellular [K(+)]o from 3 to 10mM (reflecting potassium uptake) were 50% reduced in astrocytes grown in high glucose. In addition, glutamate clearance by astrocytes grown in high glucose was significantly impaired. Taken together, our results suggest that down-regulation of astrocytic Kir4.1 channels by elevated glucose may contribute to the underlying pathophysiology of diabetes-induced CNS disorders and contribute to the poor prognosis after stroke

  7. Femtosecond laser full and partial texturing of steel surfaces to reduce friction in lubricated contact

    NASA Astrophysics Data System (ADS)

    Ancona, Antonio; Carbone, Giuseppe; De Filippis, Michele; Volpe, Annalisa; Lugarà, Pietro Mario

    2014-12-01

    Minimizing mechanical losses and friction in vehicle engines would have a great impact on reducing fuel consumption and exhaust emissions, to the benefit of environmental protection. With this scope, laser surface texturing (LST) with femtosecond pulses is an emerging technology, which consists of creating, by laser ablation, an array of high-density microdimples on the surface of a mechanical device. The microtexture decreases the effective contact area and, in case of lubricated contact, acts as oil reservoir and trap for wear debris, leading to an overall friction reduction. Depending on the lubrication regime and on the texture geometry, several mechanisms may concur to modify friction such as the local reduction of the shear stress, the generation of a hydrodynamic lift between the surfaces or the formation of eddy-like flows at the bottom of the dimple cavities. All these effects have been investigated by fabricating and characterizing several LST surfaces by femtosecond laser ablation with different features: partial/full texture, circular/elliptical dimples, variable diameters, and depths but equivalent areal density. More than 85% of friction reduction has been obtained from the circular dimple geometry, but the elliptical texture allows adjusting the friction coefficient by changing its orientation with respect to the sliding direction.

  8. Kefir reduces insulin resistance and inflammatory cytokine expression in an animal model of metabolic syndrome.

    PubMed

    Rosa, Damiana D; Grześkowiak, Łukasz M; Ferreira, Célia L L F; Fonseca, Ana Carolina M; Reis, Sandra A; Dias, Mariana M; Siqueira, Nathane P; Silva, Leticia L; Neves, Clóvis A; Oliveira, Leandro L; Machado, Alessandra B F; Peluzio, Maria do Carmo G

    2016-08-10

    There is growing evidence that kefir can be a promising tool in decreasing the risk of many diseases, including metabolic syndrome (MetS). The aim of the present study was to evaluate the effect of kefir supplementation in the diet of Spontaneously Hypertensive Rats (SHR) in which MetS was induced with monosodium glutamate (MSG), and to determine its effect on metabolic parameters, inflammatory and oxidation marker expression and glycemic index control. Thirty animals were used in this experiment. For the induction of MetS, twenty two-day-old male SHR received five consecutive intradermal injections of MSG. For the Negative Control, ten newborn male SHR received intradermal injections of saline solution (0.9% saline solution). After weaning, animals received standard diet and water ad libitum until reaching 3 months old, for the development of MetS. They were then divided into three groups (n = 10): negative control (NC, 1 mL saline solution per day), positive control (PC, 1 mL saline solution per day) and the Kefir group (1 mL kefir per day). Feeding was carried out by gavage for 10 weeks and the animals received standard food and water ad libitum. Obesity, insulin resistance, pro- and anti-inflammatory markers, and the histology of pancreatic and adipose tissues were among the main variables evaluated. Compared to the PC group, kefir supplementation reduced plasma triglycerides, liver lipids, liver triglycerides, insulin resistance, fasting glucose, fasting insulin, thoracic circumference, abdominal circumference, products of lipid oxidation, pro-inflammatory cytokine expression (IL-1β) and increased anti-inflammatory cytokine expression (IL-10). The present findings indicate that kefir has the potential to benefit the management of MetS. PMID:27384318

  9. An intronic polymorphism associated with increased XRCC1 expression, reduced apoptosis and familial breast cancer.

    PubMed

    Bu, Dawei; Tomlinson, Gail; Lewis, Cheryl M; Zhang, Cindy; Kildebeck, Eric; Euhus, David M

    2006-10-01

    XRCC1 coordinates the activities of DNA polymerase-beta and DNA ligase for base excision repair of oxidative DNA damage. In addition, there is some evidence that XRCC1 is a negative regulator of apoptosis. Single nucleotide polymorphisms in XRCC1 have been inconsistently associated with breast cancer risk. We evaluated XRCC1 gene expression in breast cancer cell lines and carcinogen-induced apoptosis in benign breast epithelial cells in relation to XRCC1 genotypes. XRCC1 IVS10+141G>A was associated with increased expression of XRCC1 mRNA and protein, and reduced apoptosis in response to benzo-[a]-pyrene or ionizing radiation, but XRCC1 R399Q was not. These genotypes were also assessed in a clinic-based sample that included 190 breast cancer patients with a family history of breast cancer and 95 controls with no family history of breast cancer. Heterozygous XRCC1 IVS10+141G>A was associated with an increased breast cancer risk (O.R. = 1.7, 95% C.I. 1.016-2.827, P = 0.04) as was homozygous XRCC1 IVS10+141G>A (O.R. = 4.7, 95% C.I. 1.028-21.444, P = 0.03). XRCC1 R399Q was not associated with breast cancer (O.R. 1.00, 95% C.I. 0.61-1.64). The XRCC1 IVS10+141G>A locus is centered in a sequence that is nearly identical to the consensus binding site for the PLAG1 transcription factor. XRCC1 IVS10+141G>A is an intronic polymorphism that is associated with XRCC1 expression, apoptosis and familial breast cancer. It may occur within an intronic regulatory sequence. PMID:16596326

  10. Reduced kynurenine pathway metabolism and cytokine expression in the prefrontal cortex of depressed individuals

    PubMed Central

    Clark, Sarah M.; Pocivavsek, Ana; Nicholson, James D.; Notarangelo, Francesca M.; Langenberg, Patricia; McMahon, Robert P.; Kleinman, Joel E.; Hyde, Thomas M.; Stiller, John; Postolache, Teodor T.; Schwarcz, Robert; Tonelli, Leonardo H.

    2016-01-01

    Background Neuroinflammatory processes are increasingly believed to participate in the pathophysiology of a number of major psychiatric diseases, including depression. Immune activation stimulates the conversion of the amino acid tryptophan to kynurenine, leading to the formation of neuroactive metabolites, such as quinolinic acid and kynurenic acid. These compounds affect glutamatergic neurotransmission, which plays a prominent role in depressive pathology. Increased tryptophan degradation along the kynurenine pathway (KP) has been proposed to contribute to disease etiology. Methods We used postmortem brain tissue from the ventrolateral prefrontal cortex (VLPFC) to assess tissue levels of tryptophan and KP metabolites, the expression of several KP enzymes and a series of cytokines as well as tissue pathology, including microglial activation. Tissue samples came from nonpsychiatric controls (n = 36) and individuals with depressive disorder not otherwise specified (DD-NOS, n = 45) who died of natural causes, homicide, accident, or suicide. Results We found a reduction in the enzymatic conversion of tryptophan to kynurenine, determined using the kynurenine:tryptophan ratio, and reduced messenger RNA expression of the enzymes indoleamine-2,3-dioxygenase 1 and 2 and tryptophan-2,3-dioxygenase in depressed individuals irrespective of the cause of death. These findings correlated with reductions in the expression of several cytokines, including interferon-γ and tumour necrosis factor-α. Notably, quinolinic acid levels were also lower in depressed individuals than controls. Limitations Information on the use of antidepressants and other psychotropic medications was insufficient for statistical comparisons. Conclusion Contrary to expectations, the present results indicate that depression, in the absence of medical illness or an overt inflammatory process, is associated with compromised, rather than increased, KP metabolism in the VLPFC. PMID:27070351

  11. Reduced expression of galectin-1 and galectin-9 by leucocytes in asthma patients

    PubMed Central

    Sanchez-Cuellar, S; Fuente, H; Cruz-Adalia, A; Lamana, A; Cibrian, D; Giron, R M; Vara, A; Sanchez-Madrid, F; Ancochea, J

    2012-01-01

    Accumulating evidence shows that galectins play roles in the initiation and resolution phases of inflammatory responses by promoting anti- or proinflammatory effects. This study investigated the presence of three members of the galectin family (galectin-1, -3 and -9) in induced sputum samples of asthma patients, as well as their possible implication in the immunopathogenesis of human asthma. Levels of interleukin (IL)-5, IL-13, and galectins were determined in leucocytes isolated from induced sputum samples by reverse transcription–polymerase chain reaction (RT–PCR) immunofluorescence and flow cytometry. High levels of IL-5 and IL-13 mRNA were detected in sputum cells from asthma patients. In parallel, immunoregulatory proteins galectin-1 and galectin-9 showed a reduced expression on macrophages from sputum samples compared with cells from healthy donors. In-vitro immunoassays showed that galectin-1 and galectin-9, but not galectin-3, are able to induce the production of IL-10 by peripheral blood mononuclear cells from healthy donors. These findings indicate that macrophages from sputum samples of asthma patients express low levels of galectin-1 and galectin-9, favouring the exacerbated immune response observed in this disease. PMID:23121677

  12. Disrupting protein expression with Peptide Nucleic Acids reduces infection by obligate intracellular Rickettsia.

    PubMed

    Pelc, Rebecca S; McClure, Jennifer C; Kaur, Simran J; Sears, Khandra T; Rahman, M Sayeedur; Ceraul, Shane M

    2015-01-01

    Peptide Nucleic Acids (PNAs) are single-stranded synthetic nucleic acids with a pseudopeptide backbone in lieu of the phosphodiester linked sugar and phosphate found in traditional oligos. PNA designed complementary to the bacterial Shine-Dalgarno or start codon regions of mRNA disrupts translation resulting in the transient reduction in protein expression. This study examines the use of PNA technology to interrupt protein expression in obligate intracellular Rickettsia sp. Their historically intractable genetic system limits characterization of protein function. We designed PNA targeting mRNA for rOmpB from Rickettsia typhi and rickA from Rickettsia montanensis, ubiquitous factors important for infection. Using an in vitro translation system and competitive binding assays, we determined that our PNAs bind target regions. Electroporation of R. typhi and R. montanensis with PNA specific to rOmpB and rickA, respectively, reduced the bacteria's ability to infect host cells. These studies open the possibility of using PNA to suppress protein synthesis in obligate intracellular bacteria.

  13. Surface antigen expression and complement susceptibility of differentiated neuroblastoma clones.

    PubMed

    Chen, S; Caragine, T; Cheung, N K; Tomlinson, S

    2000-03-01

    Human neuroblastoma cell lines typically consist of heterogenous subpopulations of cells that are morphologically and biochemically distinct. The cell types are characterized as neuroblastic (N-type), substrate-adherent Schwann-like (S-type), or intermediate (I). These cell types can undergo spontaneous or induced transdifferentiation in vitro. We investigated the complement sensitivity of different neuroblastoma cell lines and of matched sets of cloned N- and S-type neuroblastoma cell lines. Human neuroblastoma cell lines that consisted predominantly of a neuroblastic phenotype were shown to be significantly more susceptible to human complement-mediated lysis than cell lines of other cancer types. Complement sensitivity of neuroblastoma cell lines was correlated with low levels of CD59, decay-accelerating factor, and membrane cofactor protein expression. We found that cloned S-type neuroblastoma cells were much more resistant to complement-mediated lysis than cloned N-type cells. The increased complement resistance of S-type cells was shown to be due to increased expression of membrane-bound complement inhibitors. CD59 was the single most important protein in providing S-type cells with protection from complement lysis. S-type cells were also found to express lower levels of GD2, a target antigen for a complement activating monoclonal antibody currently in clinical trials for neuroblastoma immunotherapy. The ability of S-type cells to evade complement, and the ability of S-type cells to differentiate into the more tumorigenic N-type cells, may represent a mechanism of tumor survival and regrowth, a phenomenon often observed with this cancer.

  14. Reduced coupling of water molecules near the surface of reverse micelles.

    PubMed

    Bakulin, Artem A; Pshenichnikov, Maxim S

    2011-11-21

    We report on vibrational dynamics of water near the surface of AOT reverse micelles studied by narrow-band excitation, mid-IR pump-probe spectroscopy. Evidence of OH-stretch frequency splitting into the symmetric and asymmetric modes is clearly observed for the interfacial H(2)O molecules. The polarization memory of interfacial waters is preserved over an exceptionally extended >10 ps timescale which is a factor of 100 longer than in bulk water. These observations point towards negligibly small intermolecular vibrational coupling between the water molecules as well as strongly reduced water rotational mobility within the interfacial water layer. PMID:21959913

  15. Reducing intrinsic loss in superconducting resonators by surface treatment and deep etching of silicon substrates

    SciTech Connect

    Bruno, A.; Lange, G. de; Asaad, S.; Enden, K. L. van der; Langford, N. K.; DiCarlo, L.

    2015-05-04

    We present microwave-frequency NbTiN resonators on silicon, systematically achieving internal quality factors above 1 M in the quantum regime. We use two techniques to reduce losses associated with two-level systems: an additional substrate surface treatment prior to NbTiN deposition to optimize the metal-substrate interface and deep reactive-ion etching of the substrate to displace the substrate-vacuum interfaces away from high electric fields. The temperature and power dependence of resonator behavior indicate that two-level systems still contribute significantly to energy dissipation, suggesting that more interface optimization could further improve performance.

  16. Surface Expression Models for Aqueous Oceanic Activity on Titan

    NASA Astrophysics Data System (ADS)

    Clark, B.

    Drawing upon analogs from the rocky planets with geological features, subsurface acquifers and magmatism, the range of surface manifestations of a subsurface ocean on Titan comprise a series of models. Cryovolcanism of aqueous eutectics will produce flows which may be detectable as sporadic outcrops from the hydrocarbon-rich regolith, exhumed by aeolian and/or fluid processes. Solidification of extruded cryomagma, especially if containing a significant water component, should exhibit fractional crystallization of solutes in late-freeze ponds and flow fronts. Abundant higher- Z elements such as Si, S and Fe, as influenced by the Eh-pH field of the liquid phase, might be in evidence, demonstrating communication among the principal mantle components of such bodies. Consequent availability of potential nutrients and chemical energy sources would be a key indicator for habitability by chemoautolithotrophs on Titan. With near-surface mobility and sensing, LIBS as well as active and passive IR mapping spectrometry are all possible in the environment of Titan's lower atmosphere. Although some remote measurements are infeasible because of the atmosphere, near- surface naturally radioactive rock-forming elements such as K, U, and Th could be detected with gamma ray spectrometry. Touch-and-go techniques developed for small- body sampling can provide material for onboard GC, MS, XRD, microscopy and other miniaturized analytical techniques. Surface dwell times of minutes would enable contact XRF with detection of critical element ratio's such as S/Cl, K/Ca, and Mg/Si/Fe, and Raman spectroscopy for organic and mineralogical analysis, . Longer contact times would permit electromagnetic depth sounding. Many IR and particle- detection sensors operate ideally at or near the low temperatures intrinsic to the Titan atmosphere, simplifying those aspects of instrument development. Exploration of Titan by in situ and mobility techniques would capitalize on the investments and lessons

  17. Effectiveness of UV-C equipped vacuum at reducing culturable surface-bound microorganisms on carpets.

    PubMed

    Lutz, Eric A; Sharma, Smita; Casto, Bruce; Needham, Glen; Buckley, Timothy J

    2010-12-15

    Carpets are both sinks and sources for exposure to chemicals, allergens, and microbes and consequently influence health, including asthma, allergies, and infectious diseases. Asthmatics, children, and the immune-compromised are particularly vulnerable to health risks resulting from exposure to carpet contaminants. To address this risk, a commercial upright vacuum cleaner with an ultraviolet germicidal lamp (λ=253.7 nm, UVC) has been developed for residential and commercial uses. However, its effectiveness in reducing microbial load on real-world carpets has not been previously demonstrated. Accordingly, the purpose of the current study was to evaluate the effectiveness of a UVC-equipped vacuum in reducing the carpet surface-bound microbial load. This was accomplished by comparing the carpet microbial surface load from pre- to post-treatment of 9 ft(2) in-use carpet sections under three treatment scenarios: 1) UVC alone (UV), 2) the beater-bar plus vacuum (BB+Vac), or 3) a combination of all three (COMB). Each treatment was two minutes in duration. Microbial surface loads were measured by pressing contact plates containing Sabourauds Dextrose agar onto the carpet surface. In-use carpets from three locations were tested in place. The treatment effect was evaluated at two levels. First, we considered the mean reduction in CFU from pre- to post-treatment for each 9 ft(2) carpet grid (n = 4 for each treatment). The second level considered each 1 ft(2) section using a paired analysis (n = 40 to 49 for each treatment). A total of 125 pre/post-sample pairs were collected across the three treatments. Results showed that all three treatments were associated with a reduction in carpet microbial load (p < 0.0001). The COMB yielded the largest reduction of 13 CFU/plate (87% reduction) and was approximately the sum of the individual effects of either UVC (6.6 CFU/plate, 60% reduction, p = 0.009) or BB+Vac (7.3 CFU/plate, 78% reduction, p < 0.0001). We therefore conclude that a

  18. Surface expression of subglacial meltwater movement, Bering Glacier, Alaska

    SciTech Connect

    Cadwell, D.H. ); Fleisher, P.J. . Dept. of Earth Sciences); Bailey, P.K. )

    1993-03-01

    Longitudinal topographic profiles (1988--1992) across the thermokarst terminus of the Grindle Hills Ice-tongue and interlobate moraine of the Bering Piedmont Glacier document annual changes in crevasse patterns and fluctuations in surface elevation related to subglacial water movement. A semi-continuous record of aerial photos (1978--1990), plus field observations (1988--1992), reveal the progressive enlargement of two lateral collapse basin on both sides of the thermokarst, connected by a transverse collapse trough. Seasonally generated meltwater at depth rises within the glacier, fills the basins and other depressions and lifts the thermokarst terminus of the ice-tongue a few meters by buoyancy and hydrostatic pressure. The resulting surface tension creates a chaotic crevasse pattern unrelated to normal glacier movement. The crevasses open (2 m wide, 8--10 m deep) in response to increased water accumulation at depth and close during subsidence as the ice-tongue settles following evacuation of subglacier water. A network of open conduits (>10 m diameter), exposed by surface ablation, provides evidence for the scale of englacial passageways beneath the thermokarst and represents a form of subglacial ablation that leads to removal of support and collapse in stagnant glacier masses.

  19. Surface-epitope masking (SEM): an immunological subtraction approach for developing monoclonal antibodies targeting surface-expressed molecules.

    PubMed

    Goldstein, Neil I; Fisher, Paul B

    2007-01-01

    An immunological subtraction approach, surface-epitope masking (SEM), is described that permits the efficient and selective production of monoclonal antibodies (MAbs) reacting with both known and unknown molecules expressed on the cell surface. The tenet underlying SEM involves blocking (masking) of shared antigens between two target populations, a "driver" and a "tester," and using appropriately modified surface-masked "tester" cells to generate MAbs reacting with surface antigens unique to the "tester population" that differentiate the two antigen sources. SEM has been employed to develop MAbs that react with the multidrug resistance surface-expressed P-glycoprotein (MDR-1) and the human interferon-gamma receptor and two potentially novel tumor-associated antigens (TAAs) expressed on the surface of prostate carcinoma and breast carcinoma cells. In principle, the SEM approach provides an uncomplicated and effective means of developing MAbs, which can also be used to identify genes, associated with important cellular processes involved in normal physiology, such as growth, aging, differentiation, and development. In addition, this strategy is amenable to produce MAbs and identify genes associated with specific disease states, including cancer, neurodegeneration, autoimmunity, and infection with pathogenic agents. PMID:18217690

  20. Daily disinfection of high-touch surfaces in isolation rooms to reduce contamination of healthcare workers' hands.

    PubMed

    Kundrapu, Sirisha; Sunkesula, Venkata; Jury, Lucy A; Sitzlar, Brett M; Donskey, Curtis J

    2012-10-01

    In a randomized nonblinded trial, we demonstrated that daily disinfection of high-touch surfaces in rooms of patients with Clostridium difficile infection and methicillin-resistant Staphylococcus aureus colonization reduced acquisition of the pathogens on hands after contacting high-touch surfaces and reduced contamination of hands of healthcare workers caring for the patients.

  1. Reduced FOXO1 Expression Accelerates Skin Wound Healing and Attenuates Scarring

    PubMed Central

    Mori, Ryoichi; Tanaka, Katsuya; de Kerckhove, Maiko; Okamoto, Momoko; Kashiyama, Kazuya; Tanaka, Katsumi; Kim, Sangeun; Kawata, Takuya; Komatsu, Toshimitsu; Park, Seongjoon; Ikematsu, Kazuya; Hirano, Akiyoshi; Martin, Paul; Shimokawa, Isao

    2015-01-01

    The forkhead box O (FOXO) family has been extensively investigated in aging and metabolism, but its role in tissue-repair processes remains largely unknown. Herein, we clarify the molecular aspect of the FOXO family in skin wound healing. We demonstrated that Foxo1 and Foxo3a were both up-regulated during murine skin wound healing. Partial knockout of Foxo1 in Foxo1+/− mice throughout the body led to accelerated skin wound healing with enhanced keratinocyte migration, reduced granulation tissue formation, and decreased collagen density, accompanied by an attenuated inflammatory response, but we observed no wound phenotype in Foxo3a−/− mice. Fibroblast growth factor 2, adiponectin, and notch1 genes were significantly increased at wound sites in Foxo1+/− mice, along with markedly altered extracellular signal–regulated kinase 1/2 and AKT phosphorylation. Similarly, transient knockdown of Foxo1 at the wound site by local delivery of antisense oligodeoxynucleotides enhanced skin wound healing. The link between FOXO1 and scarring extends to patients, in particular keloid scars, where we see FOXO1 expression markedly increased in fibroblasts and inflammatory cells within the otherwise normal dermis. This occurs in the immediate vicinity of the keloid by comparison to the center of the mature keloid, indicating that FOXO1 is associated with the overgrowth of this fibrotic response into adjacent normal skin. Overall, our data indicate that molecular targeting of FOXO1 may improve the quality of healing and reduce pathological scarring. PMID:25010393

  2. Mechanical vibration inhibits osteoclast formation by reducing DC-STAMP receptor expression in osteoclast precursor cells.

    PubMed

    Kulkarni, Rishikesh N; Voglewede, Philip A; Liu, Dawei

    2013-12-01

    It is well known that physical inactivity leads to loss of muscle mass, but it also causes bone loss. Mechanistically, osteoclastogenesis and bone resorption have recently been shown to be regulated by vibration. However, the underlying mechanism behind the inhibition of osteoclast formation is yet unknown. Therefore, we investigated whether mechanical vibration of osteoclast precursor cells affects osteoclast formation by the involvement of fusion-related molecules such as dendritic cell-specific transmembrane protein (DC-STAMP) and P2X7 receptor (P2X7R). RAW264.7 (a murine osteoclastic-like cell line) cells were treated with 20ng/ml receptor activator of NF-κB ligand (RANKL). For 3 consecutive days, the cells were subjected to 1h of mechanical vibration with 20μm displacement at a frequency of 4Hz and compared to the control cells that were treated under the same condition but without the vibration. After 5days of culture, osteoclast formation was determined. Gene expression of DC-STAMP and P2X7R by RAW264.7 cells was determined after 1h of mechanical vibration, while protein production of the DC-STAMP was determined after 6h of postincubation after vibration. As a result, mechanical vibration of RAW264.7 cells inhibited the formation of osteoclasts. Vibration down-regulated DC-STAMP gene expression by 1.6-fold in the presence of RANKL and by 1.4-fold in the absence of RANKL. Additionally, DC-STAMP protein production was also down-regulated by 1.4-fold in the presence of RANKL and by 1.2-fold in the absence of RANKL in RAW264.7 cells in response to mechanical vibration. However, vibration did not affect P2X7R gene expression. Mouse anti-DC-STAMP antibody inhibited osteoclast formation in the absence of vibration. Our results suggest that mechanical vibration of osteoclast precursor cells reduces DC-STAMP expression in osteoclast precursor cells leading to the inhibition of osteoclast formation.

  3. MicroRNA-194 Modulates Glucose Metabolism and Its Skeletal Muscle Expression Is Reduced in Diabetes

    PubMed Central

    Latouche, Celine; Natoli, Alaina; Reddy-Luthmoodoo, Medini; Heywood, Sarah E.; Armitage, James A.; Kingwell, Bronwyn A.

    2016-01-01

    Background The regulation of microRNAs (miRNAs) at different stages of the progression of type 2 diabetes mellitus (T2DM) and their role in glucose homeostasis was investigated. Methods Microarrays were used to assess miRNA expression in skeletal muscle biopsies taken from healthy individuals and patients with pre-diabetes or T2DM, and insulin resistant offspring of rat dams fed a high fat diet during pregnancy. Results Twenty-three miRNAs were differentially expressed in patients with T2DM, and 7 in the insulin resistant rat offspring compared to their controls. Among these, only one miRNA was similarly regulated: miR-194 expression was significantly reduced by 25 to 50% in both the rat model and in human with pre-diabetes and established diabetes. Knockdown of miR-194 in L6 skeletal muscle cells induced an increase in basal and insulin-stimulated glucose uptake and glycogen synthesis. This occurred in conjunction with an increased glycolysis, indicated by elevated lactate production. Moreover, oxidative capacity was also increased as we found an enhanced glucose oxidation in presence of the mitochondrial uncoupler FCCP. When miR-194 was down-regulated in vitro, western blot analysis showed an increased phosphorylation of AKT and GSK3β in response to insulin, and an increase in expression of proteins controlling mitochondrial oxidative phosphorylation. Conclusions Type 2 diabetes mellitus is associated with regulation of several miRNAs in skeletal muscle. Interestingly, miR-194 was a unique miRNA that appeared regulated across different stages of the disease progression, from the early stages of insulin resistance to the development of T2DM. We have shown miR-194 is involved in multiple aspects of skeletal muscle glucose metabolism from uptake, through to glycolysis, glycogenesis and glucose oxidation, potentially via mechanisms involving AKT, GSK3 and oxidative phosphorylation. MiR-194 could be down-regulated in patients with early features of diabetes as an

  4. Involvement of aberrant DNA methylation on reduced expression of lysophosphatidic acid receptor-1 gene in rat tumor cell lines

    SciTech Connect

    Tsujiuchi, Toshifumi . E-mail: ttujiuch@life.kindai.ac.jp; Shimizu, Kyoko; Onishi, Mariko; Sugata, Eriko; Fujii, Hiromasa; Mori, Toshio; Honoki, Kanya; Fukushima, Nobuyuki

    2006-10-27

    Lysophosphatidic acid (LPA) is a bioactive phospholipid that stimulates cell proliferation, migration, and protects cells from apoptosis. It interacts with specific G protein-coupled transmembrane receptors. Recently, it has been reported that alterations of LPA receptor expression might be important in the malignant transformation of tumor cells. Therefore, to assess an involvement of DNA methylation in reduced expression of the LPA receptor-1 (lpa1) gene, we investigated the expression of the lpa1 gene and its DNA methylation patterns in rat tumor cell lines. Both rat brain-derived neuroblastoma B103 and liver-derived hepatoma RH7777 cells used in this study indicated no expression of lpa1. For the analysis of methylation status, bisulfite sequencing was performed with B103 and RH7777 cells, comparing with other lpa1 expressed cells and normal tissues of brain and liver. The lpa1 expressed cells and tissues were all unmethylated in this region of lpa1. In contrast, both B103 and RH7777 cells were highly methylated, correlating with reduced expression of the lpa1. Treatment with 5-aza 2'-deoxycytidine induced expression of lpa1 gene in B103 and RH7777 cells after 24 h. In RH7777 cells treated with 5-aza 2'-deoxycytidine, stress fiber formation was also observed in response to LPA in RH7777 cells, but not in untreated RH7777 cells. These results suggest that aberrant DNA methylation of the lpa1 gene may be involved in its reduced expression in rat tumor cells.

  5. Norepinephrine Reduces Reactive Oxygen Species (ROS) and DNA Damage in Ovarian Surface Epithelial Cells

    PubMed Central

    Patel, Pooja R; Hegde, Muralidhar L; Theruvathu, Jacob; Mitra, Sankar A; Boldogh, Istvan; Sowers, Lawrence

    2015-01-01

    Objective To determine the role of norepinephrine (NE) on DNA damage and reactive oxygen species (ROS) generation in ovarian surface epithelial cells. Method Non-tumorigenic, immortalized ovarian surface epithelial cells were treated with NE, bleomycin, and bleomycin followed by NE. The comet assay was performed on each treatment group to determine the amount of single and double-strand breaks induced by treatments. ROS levels for each treatment group were measured using the H2DCF-DA fluorescence assay. Finally, RNA transcripts were measured for each treatment group with regards to the expression of DNA repair and oxidative stress genes. Results The mean tail moment of untreated cells was significantly greater than that of cells treated with NE (p=0.02). The mean tail moment of cells treated with bleomycin was significantly greater than that of cells treated with bleomycin followed by NE (p<0.01). Treatment with NE resulted in significantly less ROS generation than in untreated cells (p<0.01). NE treatment after hydrogen peroxide treatment resulted in a noticeable decrease in ROS generation. Genes associated with oxidative stress were upregulated in cells treated with bleomycin, however this upregulation was blunted when bleomycin-treated cells were treated subsequently with NE. Conclusion NE is associated with decreased DNA damage and ROS production in ovarian surface epithelial cells. This effect is protective in the presence of the oxidative-damaging agent bleomycin. These results suggest an additional physiologic role for the stress hormone NE, in protecting ovarian surface epithelial cells from oxidative stress. PMID:26167254

  6. Chemokine receptor expression on the surface of peripheral blood mononuclear cells in Chagas disease.

    PubMed

    Talvani, Andre; Rocha, Manoel O C; Ribeiro, Antonio L; Correa-Oliveira, Rodrigo; Teixeira, Mauro M

    2004-01-15

    We evaluated the expression of chemokine receptors (CCR1, CCR2, CCR5, and CXCR4) on the surface of peripheral blood mononuclear cells obtained from patients with chronic chagasic cardiomyopathy (CCC) and noninfected individuals. Only CCR5 and CXCR4 expression was different on the surface of the subsets (CD4, CD8, and CD14) evaluated. Patients with mild CCC had elevated leukocyte expression of CCR5, compared with noninfected individuals or those with severe disease. CXCR4 expression was lower on leukocytes from patients with severe CCC. The differential expression of both receptors on leukocytes of patients with CCC was consistent and clearly correlated with the degree of heart function such that the lower the heart function, the lower the expression of either CCR5 or CXCR4. These results highlight the possible participation of the chemokine system in early forms of chagasic cardiomyopathy and the relevance of heart failure-induced remodeling in modifying immune parameters in infected individuals.

  7. Two Patients with Dry Eye Disease Followed Up Using an Expression Assay of Ocular Surface Mucin

    PubMed Central

    Machida, Yumiko; Shoji, Jun; Harada, Natsuko; Inada, Noriko

    2016-01-01

    Purpose We report 2 patients with dry eye disease followed up using the expression levels of ocular surface mucin. Case Reports Patient 1: a 57-year-old woman with Sjögren's syndrome-associated dry eyes experienced severe dryness and foreign body sensation in both her eyes, and instilled sodium hyaluronate ophthalmic solution 0.3% about 10–15 times daily. We measured the expression levels of MUC5AC mRNA (MUC5AC) and MUC16 mRNA (MUC16) by using real-time reversed transcription polymerase chain reaction for the specimens of modified impression cytology. Expression levels of MUC5AC and MUC16 on her ocular surface were very low. Subjective symptoms and expression levels of ocular surface mucin improved after combined treatment of rebamipide (4 times daily) and fluorometholone (once daily) ophthalmic suspension. Patient 2: a 62-year-old man with chronic graft-versus-host disease-associated dry eye experienced severe foreign body sensation and developed superficial punctate keratopathy with mucous thread and filamentary keratitis. Expression level of MUC5AC was very high at baseline. Subjective symptoms and expression levels of ocular surface mucin improved by combined treatment of rebamipide (4 times daily) and fluorometholone (once daily) ophthalmic suspension. Conclusion Clinical test for MUC gene expression on the ocular surface was found to be useful in the follow-up of dry eye treatment. PMID:27194990

  8. Reduced expression of 15-hydroxy prostaglandin dehydrogenase in chorion during labor is associated with decreased PRB and increased PRA and GR expression.

    PubMed

    Li, Yuan; He, Ping; Sun, Qianqian; Liu, Jie; Gao, Lu; You, Xingji; Gu, Hang; Ni, Xin

    2013-05-01

    The chorion laeve controls the levels of active prostaglandins within the uterus by NAD-dependent 15-hydroxy prostaglandin dehydrogenase (PGDH). The expression of PGDH in chorion is modulated by glucocorticoids and progesterone. In this study, we investigated glucocorticoid receptor (GR) and progesterone receptor A and B (PRA and PRB) in the regulation of PGDH expression in chorion, and we determined whether reduced PGDH expression in chorion during labor is associated with the changes in GR and PR expression by real-time RT-PCR and Western blot analysis. Dexamethasone (DEX) inhibited PGDH expression whereas progesterone stimulated PGDH expression in chorionic trophoblasts. DEX suppressed PGDH expression in GR overexpression and PR knockdown cells. The inhibitory effect of DEX did not occur in GR knockdown cells. Progesterone inhibited PGDH in GR overexpression and PR knockdown cells and it stimulated PGDH in PRB overexpression cells whereas it suppressed PGDH in PRA overexpression cells. Knockdown of c-Jun resulted in a loss of progesterone- and DEX-induced effects. PGDH was down-regulated in chorion tissues during labor. PRB was decreased whereas PRA and GR were increased in chorion during labor. Glucocorticoids inhibit PGDH expression via GR in chorionic trophoblasts. Progesterone enhances PGDH expression through PRB, whereas it inhibits PGDH expression via GR and PRA. Decreased PGDH expression is associated with increased GR and PRA, although decreased PRB, in chorion during labor.

  9. Surface functionalities of gold nanoparticles impact embryonic gene expression responses

    PubMed Central

    Truong, Lisa; Tilton, Susan C.; Zaikova, Tatiana; Richman, Erik; Waters, Katrina M.; Hutchison, James E.; Tanguay, Robert L.

    2012-01-01

    Incorporation of gold nanoparticles (AuNPs) into consumer products is increasing; however, there is a gap in available toxicological data to determine the safety of AuNPs. In this study, we utilised the embryonic zebrafish to investigate how surface functionalisation and charge influence molecular responses. Precisely engineered AuNPs with 1.5 nm cores were synthesised and functionalized with three ligands: 2-mercaptoethanesulfonic acid (MES), N,N,N-trimethylammoniumethanethiol (TMAT), or 2-(2-(2-mercaptoethoxy)ethoxy)ethanol. Developmental assessments revealed differential biological responses when embryos were exposed to the functionalised AuNPs at the same concentration. Using inductively coupled plasma–mass spectrometry, AuNP uptake was confirmed in exposed embryos. Following exposure to MES- and TMAT-AuNPs from 6 to 24 or 6 to 48 h post fertilisation, pathways involved in inflammation and immune response were perturbed. Additionally, transport mechanisms were misregulated after exposure to TMAT and MES-AuNPs, demonstrating that surface functionalisation influences many molecular pathways. PMID:22263968

  10. Shiga Toxin 2 Reduces Complement Inhibitor CD59 Expression on Human Renal Tubular Epithelial and Glomerular Endothelial Cells

    PubMed Central

    Ehrlenbach, Silvia; Rosales, Alejandra; Posch, Wilfried; Wilflingseder, Doris; Hermann, Martin; Brockmeyer, Jens; Karch, Helge; Satchell, Simon C.

    2013-01-01

    Infections with enterohemorrhagic Escherichia coli (EHEC) are a primary cause of hemolytic-uremic syndrome (HUS). Recently, Shiga toxin 2 (Stx2), the major virulence factor of EHEC, was reported to interact with complement, implying that the latter is involved in the pathogenesis of EHEC-induced HUS. The aim of the present study was to investigate the effect of Stx2 on the expression of membrane-bound complement regulators CD46, CD55, and CD59 on proximal tubular epithelial (HK-2) and glomerular endothelial (GEnC) cells derived from human kidney cells that are involved in HUS. Incubation with Stx2 did not influence the amount of CD46 or CD55 on the surface of HK-2 and GEnC cells, as determined by fluorescence-activated cell sorter analysis. In contrast, CD59 was significantly reduced by half on GEnC cells, but the reduction on HK-2 cells was less pronounced. With increasing amounts of Stx2, reduction of CD59 also reached significance in HK-2 cells. Enzyme-linked immunosorbent assay analyses showed that CD59 was not present in the supernatant of Stx2-treated cells, implying that CD59 reduction was not caused by cleavage from the cell surface. In fact, reverse transcription-quantitative PCR analyses showed downregulation of CD59 mRNA as the likely reason for CD59 cell surface reduction. In addition, a significant increase in terminal complement complex deposition on HK-2 cells was observed after treatment with Stx2, as a possible consequence of CD59 downregulation. In summary, Stx2 downregulates CD59 mRNA and protein levels on tubular epithelial and glomerular endothelial cells, and this downregulation likely contributes to complement activation and kidney destruction in EHEC-associated HUS. PMID:23690395

  11. Slotted surface coil with reduced g-factor for SENSE imaging.

    PubMed

    Ocegueda, K; Rodriguez, A O

    2006-01-01

    A new coil design inspired on the slot-and-hole magnetron tube is proposed for SENSE imaging. To investigate its g-factor behaviour: an SNR formula was derived using the quasi-static approach, and combined with the ultimate g-factor formula to compute the ultimate-factor-g-vs-depth plots. A g-factor expression was derived for the circular coil using the same approach for comparison purposes. SNR-vs-depth profiles of an 4-slot coil showed an important improvement over the circular coil. The 4-slot coil g-factor can be up to 58.32% lower than that of a single circular-shaped coil. This improvement makes the slotted surface coil a good choice for SENSE imaging. PMID:17946922

  12. Surface characteristics of coated polyester fabric with reduced graphene oxide and polypyrrole

    NASA Astrophysics Data System (ADS)

    Berendjchi, Amirhosein; Khajavi, Ramin; Yousefi, Ali Akbar; Yazdanshenas, Mohammad Esmail

    2016-03-01

    In this study, the influence of coating polyethylene terephthalate (PET) fabric with reduced graphene oxide (rGO) and polypyrrole (PPy), individually or in combination (rGO-PPy), on surface chemistry and roughness (focusing on wetting behavior), were analyzed systematically. Characterization was carried out by observing the topography (atomic force microscopy - AFM) and stating surface analysis (X-ray photoelectron spectroscopy - XPS), contact angles (goniometry), water shedding angles, and surface energy values of the samples. The results showed that the contact angles of pristine (uncoated), GO and rGO-PPy coated samples were 0°, while it was 92°, 123° and 151° for hot pressed (2nd pristine sample), rGO and PPy samples, respectively. A zero contact angle for PET sample was due to its wicking ability. Results were interpreted with Young, Wenzel and Cassie Baxter equations. It was found that PPy coated samples were consistent with Cassie-Baxter equation, while rGO placed between Wenzel and Cassie-Baxter wetting models.

  13. Tissue Plasminogen Activator Coating on Implant Surfaces Reduces Staphylococcus aureus Biofilm Formation

    PubMed Central

    Na, Manli; Jarneborn, Anders; Jacobsson, Gunnar; Peetermans, Marijke; Verhamme, Peter

    2015-01-01

    Staphylococcus aureus biofilm infections of indwelling medical devices are a major medical challenge because of their high prevalence and antibiotic resistance. As fibrin plays an important role in S. aureus biofilm formation, we hypothesize that coating of the implant surface with fibrinolytic agents can be used as a new method of antibiofilm prophylaxis. The effect of tissue plasminogen activator (tPA) coating on S. aureus biofilm formation was tested with in vitro microplate biofilm assays and an in vivo mouse model of biofilm infection. tPA coating efficiently inhibited biofilm formation by various S. aureus strains. The effect was dependent on plasminogen activation by tPA, leading to subsequent local fibrin cleavage. A tPA coating on implant surfaces prevented both early adhesion and later biomass accumulation. Furthermore, tPA coating increased the susceptibility of biofilm infections to antibiotics. In vivo, significantly fewer bacteria were detected on the surfaces of implants coated with tPA than on control implants from mice treated with cloxacillin. Fibrinolytic coatings (e.g., with tPA) reduce S. aureus biofilm formation both in vitro and in vivo, suggesting a novel way to prevent bacterial biofilm infections of indwelling medical devices. PMID:26519394

  14. Posttranscriptional control is a strong factor enabling exclusive expression of surface antigens in Paramecium tetraurelia.

    PubMed

    Simon, Martin C; Marker, Simone; Schmidt, Helmut J

    2006-01-01

    Variable antigens are large proteins located on the outer membrane of parasitic but also of free-living protists. Multigene families encoding surface antigens demonstrate an exclusive expression of proteins. The resulting presence of just one protein species on the cell surface is required for surface antigen function; therefore, the molecular mechanism of exclusive expression is of main interest. Regulation of gene expression and mechanisms establishing switching of antigens are hardly understood in any organism. Here we report on the reaction of Paramecium to the artificial knock down of surface antigen 51A expression by bacteria-mediated RNAi. This technique involves the feeding of dsRNA-producing bacteria. We analyzed different fragments of the target gene for dsRNA template regarding their specific knock down efficiency and found great differences. Treatment of Paramecia with RNAi against the 51A antigen demonstrated that although a massive amount of mRNA was present, the protein was not detected on the cell surface. Moreover, a minor abundance of 51D transcripts resulted in an exclusive presence of 51D proteins on the cell surface. This posttranscriptional regulation was confirmed by the transcript ratio (51A/51D) determined by real-time (RT) PCR of single cells. Because we were able to document unexclusive transcription also in wild-type cells our results indicate that this posttranscriptional regulation is a main factor of enabling exclusive gene expression. The comparison of serotype shifts, caused by efficient and inefficient knock down, indicates an involvement of full-length transcripts in regulation of gene expression. Thus, our study gives new insights into the mechanism of exclusive expression on the molecular level: (i) exclusive transcription does not occur, (ii) posttranscriptional regulation is a powerful factor enabling exclusive antigen expression, and (iii) surface antigen mRNA is shown to be involved in this mechanism in a regulating way.

  15. Mars Express scientists find a different Mars underneath the surface

    NASA Astrophysics Data System (ADS)

    2006-12-01

    Observations by MARSIS, the first subsurface sounding radar used to explore a planet, strongly suggest that ancient impact craters lie buried beneath the smooth, low plains of Mars' northern hemisphere. The technique uses echoes of radio waves that have penetrated below the surface. MARSIS found evidence that these buried impact craters - ranging from about 130 to 470 kilometres in diameter - are present under much of the northern lowlands. The findings appear in the 14 December 2006 issue of the journal Nature. With MARSIS "it's almost like having X-ray vision," said Thomas R. Watters of the National Air and Space Museum's Center for Earth and Planetary Studies, Washington, and lead author of the results. "Besides finding previously unknown impact basins, we've also confirmed that some subtle, roughly circular, topographic depressions in the lowlands are related to impact features." Studies of how Mars evolved help in understanding early Earth. Some signs of the forces at work a few thousand million years ago are harder to detect on Earth because many of them have been obliterated by tectonic activity and erosion. The new findings bring planetary scientists closer to understanding one of the most enduring mysteries about the geological evolution and history of Mars. In contrast to Earth, Mars shows a striking difference between its northern and southern hemispheres. Almost the entire southern hemisphere has rough, heavily cratered highlands, while most of the northern hemisphere is smoother and lower in elevation. Since the impacts that cause craters can happen anywhere on a planet, the areas with fewer craters are generally interpreted as younger surfaces where geological processes have erased the impact scars. The surface of Mars' northern plains is young and smooth, covered by vast amounts of volcanic lava and sediment. However, the new MARSIS data indicate that the underlying crust is extremely old. “The number of buried impact craters larger than 200

  16. Targeted Surface Expression of an Exogenous Antigen in Stably Transfected Babesia bovis

    PubMed Central

    Laughery, Jacob M.; Knowles, Donald P.; Schneider, David A.; Bastos, Reginaldo G.; McElwain, Terry F.; Suarez, Carlos E.

    2014-01-01

    Babesia bovis is a tick-borne intraerythocytic protozoan responsible for acute disease in cattle which can be controlled by vaccination with attenuated B. bovis strains. Emerging B. bovis transfection technologies may increase the usefulness of these live vaccines. One use of transfected B. bovis parasites may be as a vaccine delivery platform. Previous transfection methods for B. bovis were limited by single expression sites and intracellular expression of transfected antigens. This study describes a novel transfection system in which two exogenous genes are expressed: one for selection and the other for a selected antigen designed to be delivered to the surface of the parasites. The strategy for duplicating the number of transfected genes was based on the use of the putative bidirectional promoter of the B. bovis 1.4 Kb ef-1α intergenic region. The ability of this region to regulate two independent expression sites was demonstrated using a luciferase assay on transiently transfected B. bovis parasites and then incorporated into a stable transfection plasmid to control independent expression of the selectable marker GFP-BSD and another gene of interest. A chimeric gene was synthetized using sequences from the protective B-cell epitopes of Rhipicephalus microplus tick antigen Bm86 along with sequences from the surface exposed B. bovis major surface antigen-1. This chimeric gene was then cloned into the additional expression site of the transfection plasmid. Transfection of the B. bovis Mo7 strain with this plasmid resulted in stable insertion into the ef-1α locus and simultaneous expression of both exogenous genes. Expression of the Bm86 epitopes on the surface of transfected merozoites was demonstrated using immunofluorescence analyses. The ability to independently express multiple genes by the inclusion of a bidirectional promoter and the achievement of surface expression of foreign epitopes advances the potential of transfected B. bovis as a future vaccine

  17. Reduced O-GlcNAcase expression promotes mitotic errors and spindle defects.

    PubMed

    Lanza, Chris; Tan, Ee Phie; Zhang, Zhen; Machacek, Miranda; Brinker, Amanda E; Azuma, Mizuki; Slawson, Chad

    2016-05-18

    Alterations in O-GlcNAc cycling, the addition and removal of O-GlcNAc, lead to mitotic defects and increased aneuploidy. Herein, we generated stable O-GlcNAcase (OGA, the enzyme that removes O-GlcNAc) knockdown HeLa cell lines and characterized the effect of the reduction in OGA activity on cell cycle progression. After release from G1/S, the OGA knockdown cells progressed normally through S phase but demonstrated mitotic exit defects. Cyclin A was increased in the knockdown cells while Cyclin B and D expression was reduced. Retinoblastoma protein (RB) phosphorylation was also increased in the knockdown compared to control. At M phase, the knockdown cells showed more compact spindle chromatids than control cells and had a greater percentage of cells with multipolar spindles. Furthermore, the timing of the inhibitory tyrosine phosphorylation of Cyclin Dependent Kinase 1 (CDK1) was altered in the OGA knockdown cells. Although expression and localization of the chromosomal passenger protein complex (CPC) was unchanged, histone H3 threonine 3 phosphorylation was decreased in one of the OGA knockdown cell lines. The Ewing Sarcoma Breakpoint Region 1 Protein (EWS) participates in organizing the CPC at the spindle and is a known substrate for O-GlcNAc transferase (OGT, the enzyme that adds O-GlcNAc). EWS O-GlcNAcylation was significantly increased in the OGA knockdown cells promoting uneven localization of the mitotic midzone. Our data suggests that O-GlcNAc cycling is an essential mechanism for proper mitotic signaling and spindle formation, and alterations in the rate of O-GlcNAc cycling produces aberrant spindles and promotes aneuploidy.

  18. Reduced O-GlcNAcase expression promotes mitotic errors and spindle defects.

    PubMed

    Lanza, Chris; Tan, Ee Phie; Zhang, Zhen; Machacek, Miranda; Brinker, Amanda E; Azuma, Mizuki; Slawson, Chad

    2016-05-18

    Alterations in O-GlcNAc cycling, the addition and removal of O-GlcNAc, lead to mitotic defects and increased aneuploidy. Herein, we generated stable O-GlcNAcase (OGA, the enzyme that removes O-GlcNAc) knockdown HeLa cell lines and characterized the effect of the reduction in OGA activity on cell cycle progression. After release from G1/S, the OGA knockdown cells progressed normally through S phase but demonstrated mitotic exit defects. Cyclin A was increased in the knockdown cells while Cyclin B and D expression was reduced. Retinoblastoma protein (RB) phosphorylation was also increased in the knockdown compared to control. At M phase, the knockdown cells showed more compact spindle chromatids than control cells and had a greater percentage of cells with multipolar spindles. Furthermore, the timing of the inhibitory tyrosine phosphorylation of Cyclin Dependent Kinase 1 (CDK1) was altered in the OGA knockdown cells. Although expression and localization of the chromosomal passenger protein complex (CPC) was unchanged, histone H3 threonine 3 phosphorylation was decreased in one of the OGA knockdown cell lines. The Ewing Sarcoma Breakpoint Region 1 Protein (EWS) participates in organizing the CPC at the spindle and is a known substrate for O-GlcNAc transferase (OGT, the enzyme that adds O-GlcNAc). EWS O-GlcNAcylation was significantly increased in the OGA knockdown cells promoting uneven localization of the mitotic midzone. Our data suggests that O-GlcNAc cycling is an essential mechanism for proper mitotic signaling and spindle formation, and alterations in the rate of O-GlcNAc cycling produces aberrant spindles and promotes aneuploidy. PMID:27070276

  19. Nell1-deficient mice have reduced expression of extracellular matrix proteins causing cranial and vertebral defects

    SciTech Connect

    Desai, Jayashree; Shannon, Mark E.; Johnson, Mahlon D.; Ruff, David W.; Hughes, Lori A; Kerley, Marilyn K; Carpenter, D A; Johnson, Dabney K; Rinchik, Eugene M.; Culiat, Cymbeline T

    2006-01-01

    The mammalian Nell1 gene encodes a protein kinase C-b1 (PKC-b1) binding protein that belongs to a new class of cell-signaling molecules controlling cell growth and differentiation. Over-expression of Nell1 in the developing cranial sutures in both human and mouse induces craniosynostosis, the premature fusion of the growing cranial bone fronts. Here, we report the generation, positional cloning and characterization of Nell16R, a recessive, neonatal-lethal point mutation in the mouse Nell1 gene, induced by N-ethyl-N-nitrosourea. Nell16R has a T!A base change that converts a codon for cysteine into a premature stop codon [Cys(502)Ter], resulting in severe truncation of the predicted protein product and marked reduction in steady-state levels of the transcript. In addition to the expected alteration of cranial morphology, Nell16R mutants manifest skeletal defects in the vertebral column and ribcage, revealing a hitherto undefined role for Nell1 in signal transduction in endochondral ossification. Real-time quantitative reverse transcription-PCR assays of 219 genes showed an association between the loss of Nell1 function and reduced expression of genes for extracellular matrix (ECM) proteins critical for chondrogenesis and osteogenesis. Several affected genes are involved in the human cartilage disorder Ehlers-Danlos Syndrome and other disorders associated with spinal curvature anomalies. Nell16R mutant mice are a new tool for elucidating basic mechanisms in osteoblast and chrondrocyte differentiation in the developing skull and vertebral column and understanding how perturbations in the production of ECM proteins can lead to anomalies in these structures.

  20. Modeling effectiveness of agricultural BMPs to reduce sediment load and organophosphate pesticides in surface runoff.

    PubMed

    Zhang, Xuyang; Zhang, Minghua

    2011-04-15

    Quantifying effectiveness of agricultural BMPs at the watershed scale is a challenging issue, requiring robust algorithms to simulate not only the agricultural production system but also pollutant transport and fate. This research addresses the challenge to simulate performances of BMPs in reducing organophosphates (OPs) runoff at the watershed scale. The SWAT model is calibrated and validated following a sensitivity analysis combining Latin Hypercube sampling and One-factor-At-a-Time simulation. The calibrated model is then applied in the Orestimba Creek Watershed to simulate BMPs including buffer strips, sediment ponds, vegetated ditches, use reduction, and their combinations. BMP simulation suggested that sediment ponds trap 54-85% of sediment from field runoff, but less than 10% of dissolved diazinon and chlorpyrifos. Use reduction can reduce pesticide load in a close-to-linear fashion. Effectiveness of vegetated ditches and buffers depends on their physical dimension and vegetation cover. Combining individual BMPs provides enhanced mitigation effects. The combination of vegetated ditches, buffer strips and use reduction decreases diazinon and chlorpyrifos load by over 94%. This study has suggested that the SWAT model reasonably predicts BMP effectiveness at the watershed scale. Results will assist decision making in implementing BMPs to reduce pesticide loads in surface runoff. PMID:21377192

  1. Reduced phototropism in pks mutants may be due to altered auxin-regulated gene expression or reduced lateral auxin transport.

    PubMed

    Kami, Chitose; Allenbach, Laure; Zourelidou, Melina; Ljung, Karin; Schütz, Frédéric; Isono, Erika; Watahiki, Masaaki K; Yamamoto, Kotaro T; Schwechheimer, Claus; Fankhauser, Christian

    2014-02-01

    Phototropism allows plants to orient their photosynthetic organs towards the light. In Arabidopsis, phototropins 1 and 2 sense directional blue light such that phot1 triggers phototropism in response to low fluence rates, while both phot1 and phot2 mediate this response under higher light conditions. Phototropism results from asymmetric growth in the hypocotyl elongation zone that depends on an auxin gradient across the embryonic stem. How phototropin activation leads to this growth response is still poorly understood. Members of the phytochrome kinase substrate (PKS) family may act early in this pathway, because PKS1, PKS2 and PKS4 are needed for a normal phototropic response and they associate with phot1 in vivo. Here we show that PKS proteins are needed both for phot1- and phot2-mediated phototropism. The phototropic response is conditioned by the developmental asymmetry of dicotyledonous seedlings, such that there is a faster growth reorientation when cotyledons face away from the light compared with seedlings whose cotyledons face the light. The molecular basis for this developmental effect on phototropism is unknown; here we show that PKS proteins play a role at the interface between development and phototropism. Moreover, we present evidence for a role of PKS genes in hypocotyl gravi-reorientation that is independent of photoreceptors. pks mutants have normal levels of auxin and normal polar auxin transport, however they show altered expression patterns of auxin marker genes. This situation suggests that PKS proteins are involved in auxin signaling and/or lateral auxin redistribution.

  2. VARIABLE BOUND-SITE CHARGING CONTRIBUTIONS TO SURFACE COMPLEXATION MASS ACTION EXPRESSIONS

    EPA Science Inventory

    One and two pK models of surface complexation reactions between reactive surface sites (>SOH) and the proton (H+) use mass action expressions of the form: Ka={[>SOHn-1z-1]g>SOH(0-1)aH+EXP(-xeY/kT)}/{[>SOHnz]g>SOH(n)} where Ka=the acidity constant, [ ]=reactive species concentrati...

  3. Reduced inflammatory activity of RAW 264.7 macrophages on titania nanotube modified Ti surface.

    PubMed

    Neacsu, Patricia; Mazare, Anca; Cimpean, Anisoara; Park, Jung; Costache, Marieta; Schmuki, Patrik; Demetrescu, Ioana

    2014-10-01

    Macrophages play a pivotal role in the hosts response to biomaterials being considered as an essential cell type during both optimal tissue-implant integration and pathologic process of implant failure. Hence, understanding of their cellular activity on biomaterials is important for improving evaluation and design of biomaterials for biomedical applications. In the present study, we have comparatively investigated the interactions of titania nanotubes (78 nm diameter) and commercial pure Ti with RAW 264.7 macrophages in both standard and pro-inflammatory (stimulation with lipopolysaccharide, LPS) culture conditions. In vitro tests showed that TiO2 nanotubes exhibited significantly decreased inflammatory activity of macrophages with respect to cytokine and chemokine gene expression/protein secretion, induction of foreign body giant cells (FBGCs) and nitric oxide (NO) release thereby mitigating the inflammatory response induced by LPS as compared to flat Ti surface. Therefore, our results suggest a novel role of TiO2 nanotubes in modulating macrophage response in biomaterial-associated bacterial infections. Overall, the current study provides new insight into how TiO2 nanotubes can be involved in macrophage activation and supports the great promise of such surface modifications for biomedical applications.

  4. Microbial methanogenesis in the sulfate-reducing zone of surface sediments traversing the Peruvian margin

    NASA Astrophysics Data System (ADS)

    Maltby, J.; Sommer, S.; Dale, A. W.; Treude, T.

    2016-01-01

    We studied the concurrence of methanogenesis and sulfate reduction in surface sediments (0-25 cm below sea floor) at six stations (70, 145, 253, 407, 990 and 1024 m) along the Peruvian margin (12° S). This oceanographic region is characterized by high carbon export to the seafloor creating an extensive oxygen minimum zone (OMZ) on the shelf, both factors that could favor surface methanogenesis. Sediments sampled along the depth transect traversed areas of anoxic and oxic conditions in the bottom-near water. Net methane production (batch incubations) and sulfate reduction (35S-sulfate radiotracer incubation) were determined in the upper 0-25 cm b.s.f. of multiple cores from all stations, while deep hydrogenotrophic methanogenesis (> 30 cm b.s.f., 14C-bicarbonate radiotracer incubation) was determined in two gravity cores at selected sites (78 and 407 m). Furthermore, stimulation (methanol addition) and inhibition (molybdate addition) experiments were carried out to investigate the relationship between sulfate reduction and methanogenesis.

    Highest rates of methanogenesis and sulfate reduction in the surface sediments, integrated over 0-25 cm b.s.f., were observed on the shelf (70-253 m, 0.06-0.1 and 0.5-4.7 mmol m-2 d-1, respectively), while lowest rates were discovered at the deepest site (1024 m, 0.03 and 0.2 mmol m-2 d-1, respectively). The addition of methanol resulted in significantly higher surface methanogenesis activity, suggesting that the process was mostly based on non-competitive substrates - i.e., substrates not used by sulfate reducers. In the deeper sediment horizons, where competition was probably relieved due to the decrease of sulfate, the usage of competitive substrates was confirmed by the detection of hydrogenotrophic activity in the sulfate-depleted zone at the shallow shelf station (70 m).

    Surface methanogenesis appeared to be correlated to the availability of labile organic matter (C / N ratio) and organic carbon

  5. Microbial methanogenesis in the sulfate-reducing zone of surface sediments traversing the Peruvian margin

    NASA Astrophysics Data System (ADS)

    Maltby, J.; Sommer, S.; Dale, A. W.; Treude, T.

    2015-09-01

    We studied the concurrence of methanogenesis and sulfate reduction in surface sediments (0-25 cm below sea floor, cmbsf) at six stations (70, 145, 253, 407, 770 and 1024 m) along the Peruvian margin (12° S). This oceanographic region is characterized by high carbon export to the seafloor, creating an extensive oxygen minimum zone (OMZ) on the shelf, both factors that could favor surface methanogenesis. Sediments sampled along the depth transect traversed areas of anoxic and oxic conditions in the bottom-near water. Net methane production (batch incubations) and sulfate reduction (35S-sulfate radiotracer incubation) were determined in the upper 0-25 cmbsf of multicorer cores from all stations, while deep hydrogenotrophic methanogenesis (> 30 cmbsf, 14C-bicarbonate radiotracer incubation) was determined in two gravity cores at selected sites (78 and 407 m). Furthermore, stimulation (methanol addition) and inhibition (molybdate addition) experiments were carried out to investigate the relationship between sulfate reduction and methanogenesis. Highest rates of methanogenesis and sulfate reduction in the surface sediments, integrated over 0-25 cmbsf, were observed on the shelf (70-253 m, 0.06-0.1 and 0.5-4.7 mmol m-2 d-1, respectively), while lowest rates were discovered at the deepest site (1024 m, 0.03 and 0.2 mmol m-2 d-1, respectively). The addition of methanol resulted in significantly higher surface methanogenesis activity, suggesting that the process was mostly based on non-competitive substrates, i.e., substrates not used by sulfate reducers. In the deeper sediment horizons, where competition was probably relieved due to the decline of sulfate, the usage of competitive substrates was confirmed by the detection of hydrogenotrophic activity in the sulfate-depleted zone at the shallow shelf station (70 m). Surface methanogenesis appeared to be correlated to the availability of labile organic matter (C / N ratio) and organic carbon degradation (DIC production

  6. Targeted deletion of Secisbp2 reduces, but does not abrogate, selenoprotein expression and leads to striatal interneuron loss.

    PubMed

    Seeher, Sandra; Schweizer, Ulrich

    2014-10-01

    Selenoproteins contain the amino acid selenocysteine (Sec). The Sec insertion sequence (SECIS)-binding protein 2 (Secisbp2) binds to SECIS elements in the 3'-UTR of eukaryotic selenoprotein mRNAs. Mutations in SECISBP2 in humans lead to reduced selenoprotein expression thereby affecting thyroid hormone-dependent growth and differentiation processes. The most severe cases also display mental retardation and ataxia. Mouse models are needed to understand selenoprotein-dependent processes underlying the patients' pleiotropic phenotypes. Homozygous Secisbp2 deletion is embryonic lethal. Conditional deletion of Secisbp2 in hepatocytes significantly decreased selenoprotein expression and reduced the abundance of many, but not all, selenoprotein mRNAs. Regarding selenoprotein expression, compensatory Nrf2-dependent gene expression, or embryonic development, phenotypes were always milder in Secisbp2- than in tRNA(Sec)-deficient mice. Neuron-specific inactivation of Secisbp2 reduced cerebral expression of selenoproteins, but allowed to study the development of cortical PVpos interneurons, which are known to depend on selenoproteins. Cre expression spares the cerebellum of these mice, why we suspected that basal ganglia dysfunction may cause the obvious movement phenotype. We observed for the first time that the number of PVpos neurons was reduced by 50% in the caudate putamen of a selenoprotein-deficient mouse model. In situ hybridization for Gad67 showed that selenoprotein deficiency selectively reduced the number of PVpos GABAergic interneurons. We propose that the striatal neuron loss likely causes the movement disorder. The most striking novel finding of this work is the selective damage of PVpos/Gad67pos neurons in the striatum. The second key finding is that selenoprotein expression in hepatocytes and neurons is less dependent on Secisbp2 than on tRNA(Sec). This implies the possibility of Secisbp2-independent selenoprotein expression, albeit on a reduced level. PMID

  7. Modulation of APP Expression Reduces Aβ Deposition in a Mouse Model

    PubMed Central

    Asuni, Ayodeji A.; Guridi, Maitea; Pankiewicz, Joanna E.; Sanchez, Sandrine; Sadowski, Martin J.

    2014-01-01

    Objective Proteolytic cleavage of the amyloid precursor protein (APP) generates β-amyloid (Aβ) peptides. Prolonged accumulation of Aβ in the brain underlies the pathogenesis of Alzheimer’s disease (AD) and is regarded as a principal target for development of disease-modifying therapeutics. Methods Using CHO APP751SW cells we identified and characterized effects of 2-[(pyridine-2-ylmethyl)-amino]-phenol (2-PMAP) on APP steady-state level and Aβ production. Outcomes of 2-PMAP treatment on Aβ accumulation and associated memory deficit were studied in APPSW/PS1dE9 AD transgenic model mice. Results In CHO APP751SW cells, 2-PMAP in a dose-response manner lowered the steady-state APP level and inhibited Aβx-40 and Aβx-42 production with minimum effective concentration ≤0.5μM. The inhibitory effect of 2-PMAP on translational efficiency of APP mRNA into protein was directly confirmed using 35S-methionine/cysteine metabolic labeling technique, while APP mRNA level remained unaltered. Administration of 2-PMAP to APPSW/PS1dE9 mice reduced brain levels of full length APP and its C-terminal fragments along with lowering levels of soluble Aβx-40 and Aβx-42. Four-month chronic treatment of APPSW/PS1dE9 mice revealed no observable toxicity and improved animals’ memory performance. 2-PMAP treatment also caused significant reduction in brain Aβ deposition determined by both unbiased quantification of Aβ plaque load and biochemical analysis of formic acid extracted Aβx-40 and Aβx-42 levels and the level of oligomeric Aβ. Interpretation We demonstrate the potential of modulating APP steady-state expression level as a safe and effective approach for reducing Aβ deposition in AD transgenic model mice. PMID:24687915

  8. Reducing premature KCC2 expression rescues seizure susceptibility and spine morphology in atypical febrile seizures.

    PubMed

    Awad, Patricia N; Sanon, Nathalie T; Chattopadhyaya, Bidisha; Carriço, Josianne Nunes; Ouardouz, Mohamed; Gagné, Jonathan; Duss, Sandra; Wolf, Daniele; Desgent, Sébastien; Cancedda, Laura; Carmant, Lionel; Di Cristo, Graziella

    2016-07-01

    Atypical febrile seizures are considered a risk factor for epilepsy onset and cognitive impairments later in life. Patients with temporal lobe epilepsy and a history of atypical febrile seizures often carry a cortical malformation. This association has led to the hypothesis that the presence of a cortical dysplasia exacerbates febrile seizures in infancy, in turn increasing the risk for neurological sequelae. The mechanisms linking these events are currently poorly understood. Potassium-chloride cotransporter KCC2 affects several aspects of neuronal circuit development and function, by modulating GABAergic transmission and excitatory synapse formation. Recent data suggest that KCC2 downregulation contributes to seizure generation in the epileptic adult brain, but its role in the developing brain is still controversial. In a rodent model of atypical febrile seizures, combining a cortical dysplasia and hyperthermia-induced seizures (LHS rats), we found a premature and sustained increase in KCC2 protein levels, accompanied by a negative shift of the reversal potential of GABA. In parallel, we observed a significant reduction in dendritic spine size and mEPSC amplitude in CA1 pyramidal neurons, accompanied by spatial memory deficits. To investigate whether KCC2 premature overexpression plays a role in seizure susceptibility and synaptic alterations, we reduced KCC2 expression selectively in hippocampal pyramidal neurons by in utero electroporation of shRNA. Remarkably, KCC2 shRNA-electroporated LHS rats show reduced hyperthermia-induced seizure susceptibility, while dendritic spine size deficits were rescued. Our findings demonstrate that KCC2 overexpression in a compromised developing brain increases febrile seizure susceptibility and contribute to dendritic spine alterations. PMID:26875662

  9. Searching for Reduced Carbon on the Surface of Mars: The SAM Combustion Experiment

    NASA Technical Reports Server (NTRS)

    Stern, J. C.; Malespin, C. A.; Mahaffy, P. R.; Webster, C. R.; Eigenbrode, J. L.; Archer, P. D., Jr.; Brunner, A. E.; Freissinet, C.; Franz, H. B.; Glavin, D. P.; Graham, H. V.; McAdam, A. C.; Ming, D. W.; Navarro-Gonzalez, R.; Niles, P. B.; Steele, A.; Sutter, B.; Trainer, M. G.

    2014-01-01

    The search for reduced carbon has been a major focus of past and present missions to Mars. Thermal evolved gas analysis was used by the Viking and Phoenix landers and is currently in use by the Sample Analysis at Mars (SAM) instrument suite on the Mars Science Laboratory (MSL) to characterize volatiles evolved from solid samples, including those associated with reduced organic species. SAM has the additional capability to perform a combustion experiment, in which a sample of Mars regolith is heated in the presence of oxygen and the composition of the evolved gases is measured using quadrupole mass spectrometry (QMS) and tunable laser spectrometry (TLS) [1]. Organics detection on the Martian surface has been complicated by oxidation and destruction during heating by soil oxidants [2], including oxychlorine compounds, and terrestrial organics in the SAM background contributed by one of the SAM wet chemistry reagents MTBSTFA (N-Methyl-N-tertbutyldimethylsilyl- trifluoroacetamide) [3,4]. Thermal Evolved Gas Analysis (TEGA) results from Phoenix show a mid temperature CO2 release between 400 C - 680 C speculated to be carbonate, CO2 adsorbed to grains, or combustion of organics by soil oxidants [5]. Low temperature CO2 evolutions (approx. 200 C - 400 C) were also present at all three sites in Gale Crater where SAM Evolved Gas Analysis (EGA) was performed, and potential sources include combustion of terrestrial organics from SAM, as well as combustion and/or decarboxylation either indigenous martian or exogenous organic carbon [4,6]. By performing an experiment to intentionally combust all reduced materials in the sample, we hope to compare the bulk abundance of CO2 and other oxidized species evolved by combustion to that evolved during an EGA experiment to estimate how much CO2 could be contributed by reduced carbon sources. In addition, C, O, and H isotopic compositions of CO2 and H2O measured by TLS can contribute information regarding the potential sources of these

  10. Surface expression of NMDA receptor changes during memory consolidation in the crab Neohelice granulata.

    PubMed

    Hepp, Yanil; Salles, Angeles; Carbo-Tano, Martin; Pedreira, Maria Eugenia; Freudenthal, Ramiro

    2016-08-01

    The aim of the present study was to analyze the surface expression of the NMDA-like receptors during the consolidation of contextual learning in the crab Neohelice granulata Memory storage is based on alterations in the strength of synaptic connections between neurons. The glutamatergic synapses undergo various forms of N-methyl-D aspartate receptor (NMDAR)-dependent changes in strength, a process that affects the abundance of other receptors at the synapse and underlies some forms of learning and memory. Here we propose a direct regulation of the NMDAR. Changes in NMDAR's functionality might be induced by the modification of the subunit's expression or cellular trafficking. This trafficking does not only include NMDAR's movement between synaptic and extra-synaptic localizations but also the cycling between intracellular compartments and the plasma membrane, a process called surface expression. Consolidation of contextual learning affects the surface expression of the receptor without affecting its general expression. The surface expression of the GluN1 subunit of the NMDAR is down-regulated immediately after training, up-regulated 3 h after training and returns to naïve and control levels 24 h after training. The changes in NMDAR surface expression observed in the central brain are not seen in the thoracic ganglion. A similar increment in surface expression of GluN1 in the central brain is observed 3 h after administration of the competitive GABAA receptor antagonist, bicuculline. These consolidation changes are part of a plasticity event that first, during the down-regulation, stabilizes the trace and later, at 3-h post-training, changes the threshold for synapse activation.

  11. Surface expression of NMDA receptor changes during memory consolidation in the crab Neohelice granulata.

    PubMed

    Hepp, Yanil; Salles, Angeles; Carbo-Tano, Martin; Pedreira, Maria Eugenia; Freudenthal, Ramiro

    2016-08-01

    The aim of the present study was to analyze the surface expression of the NMDA-like receptors during the consolidation of contextual learning in the crab Neohelice granulata Memory storage is based on alterations in the strength of synaptic connections between neurons. The glutamatergic synapses undergo various forms of N-methyl-D aspartate receptor (NMDAR)-dependent changes in strength, a process that affects the abundance of other receptors at the synapse and underlies some forms of learning and memory. Here we propose a direct regulation of the NMDAR. Changes in NMDAR's functionality might be induced by the modification of the subunit's expression or cellular trafficking. This trafficking does not only include NMDAR's movement between synaptic and extra-synaptic localizations but also the cycling between intracellular compartments and the plasma membrane, a process called surface expression. Consolidation of contextual learning affects the surface expression of the receptor without affecting its general expression. The surface expression of the GluN1 subunit of the NMDAR is down-regulated immediately after training, up-regulated 3 h after training and returns to naïve and control levels 24 h after training. The changes in NMDAR surface expression observed in the central brain are not seen in the thoracic ganglion. A similar increment in surface expression of GluN1 in the central brain is observed 3 h after administration of the competitive GABAA receptor antagonist, bicuculline. These consolidation changes are part of a plasticity event that first, during the down-regulation, stabilizes the trace and later, at 3-h post-training, changes the threshold for synapse activation. PMID:27421895

  12. Embryo Microinjection of Selenomethionine Reduces Hatchability and Modifies Oxidant Responsive Gene Expression in Zebrafish

    NASA Astrophysics Data System (ADS)

    Thomas, J. K.; Janz, D. M.

    2016-05-01

    In previous studies we demonstrated that exposure to selenomethionine (SeMet) causes developmental toxicities in zebrafish (Danio rerio). The objectives of this study were to establish a dose-response relationship for developmental toxicities in zebrafish after embryo microinjection of Se (8, 16 or 32 μg/g dry mass of eggs) in the form of SeMet, and to investigate potential underlying mechanism(s) of SeMet-induced developmental toxicities. A dose-dependent increase in frequencies of mortality and total deformities, and reduced hatchability were observed in zebrafish exposed to excess Se via embryo microinjection. The egg Se concentration causing 20% mortality was then used to investigate transcript abundance of proteins involved in antioxidant protection and methylation. Excess Se exposure modified gene expression of oxidant-responsive transcription factors (nuclear factor erythroid 2-related factor nrf2a and nrf2b), and enzymes involved in cellular methylation (methionine adenosyltransferase mat1a and mat2ab) in zebrafish larvae. Notably, excess Se exposure up-regulated transcript abundance of aryl hydrocarbon receptor 2 (ahr2), a signalling pathway involved in the toxicity of dioxin-related compounds. Our findings suggest that oxidative stress or modification of methylation, or a combination of these mechanisms, might be responsible for Se-induced developmental toxicities in fishes.

  13. Protein-poor diet reduces host-specific immune gene expression in Bombus terrestris.

    PubMed

    Brunner, Franziska S; Schmid-Hempel, Paul; Barribeau, Seth M

    2014-07-01

    Parasites infect hosts non-randomly as genotypes of hosts vary in susceptibility to the same genotypes of parasites, but this specificity may be modulated by environmental factors such as nutrition. Nutrition plays an important role for any physiological investment. As immune responses are costly, resource limitation should negatively affect immunity through trade-offs with other physiological requirements. Consequently, nutritional limitation should diminish immune capacity in general, but does it also dampen differences among hosts? We investigated the effect of short-term pollen deprivation on the immune responses of our model host Bombus terrestris when infected with the highly prevalent natural parasite Crithidia bombi. Bumblebees deprived of pollen, their protein source, show reduced immune responses to infection. They failed to upregulate a number of genes, including antimicrobial peptides, in response to infection. In particular, they also showed less specific immune expression patterns across individuals and colonies. These findings provide evidence for how immune responses on the individual-level vary with important elements of the environment and illustrate how nutrition can functionally alter not only general resistance, but also alter the pattern of specific host-parasite interactions. PMID:24850921

  14. Protein-poor diet reduces host-specific immune gene expression in Bombus terrestris.

    PubMed

    Brunner, Franziska S; Schmid-Hempel, Paul; Barribeau, Seth M

    2014-07-01

    Parasites infect hosts non-randomly as genotypes of hosts vary in susceptibility to the same genotypes of parasites, but this specificity may be modulated by environmental factors such as nutrition. Nutrition plays an important role for any physiological investment. As immune responses are costly, resource limitation should negatively affect immunity through trade-offs with other physiological requirements. Consequently, nutritional limitation should diminish immune capacity in general, but does it also dampen differences among hosts? We investigated the effect of short-term pollen deprivation on the immune responses of our model host Bombus terrestris when infected with the highly prevalent natural parasite Crithidia bombi. Bumblebees deprived of pollen, their protein source, show reduced immune responses to infection. They failed to upregulate a number of genes, including antimicrobial peptides, in response to infection. In particular, they also showed less specific immune expression patterns across individuals and colonies. These findings provide evidence for how immune responses on the individual-level vary with important elements of the environment and illustrate how nutrition can functionally alter not only general resistance, but also alter the pattern of specific host-parasite interactions.

  15. Increased Expression of Alpha-Synuclein Reduces Neurotransmitter Release by Inhibiting Synaptic Vesicle Reclustering After Endocytosis

    PubMed Central

    Nemani, Venu M.; Lu, Wei; Berge, Victoria; Nakamura, Ken; Onoa, Bibiana; Lee, Michael K.; Chaudhry, Farrukh A.; Nicoll, Roger A.; Edwards, Robert H.

    2011-01-01

    Summary The protein α-synuclein accumulates in the brain of patients with sporadic Parkinson’s disease (PD), and increased gene dosage causes a severe, dominantly inherited form of PD, but we know little about the effects of synuclein that precede degeneration. α-Synuclein localizes to the nerve terminal, but the knockout has little if any effect on synaptic transmission. In contrast, we now find that the modest over-expression of α-synuclein, in the range predicted for gene multiplication and in the absence of overt toxicity, markedly inhibits neurotransmitter release. The mechanism, elucidated by direct imaging of the synaptic vesicle cycle, involves a specific reduction in size of the synaptic vesicle recycling pool. Ultrastructural analysis demonstrates reduced synaptic vesicle density at the active zone, and imaging further reveals a defect in the reclustering of synaptic vesicles after endocytosis. Increased levels of α-synuclein thus produce a specific, physiological defect in synaptic vesicle recycling that precedes detectable neuropathology. PMID:20152114

  16. Object recognition memory and BDNF expression are reduced in young TgCRND8 mice

    PubMed Central

    Francis, Beverly M.; Kim, John; Barakat, Meredith E.; Fraenkl, Stephan; Yücel, Yeni H.; Peng, Shiyong; Michalski, Bernadeta; Fahnestock, Margaret; McLaurin, JoAnne; Mount, Howard T.J.

    2012-01-01

    The TgCRND8 mouse model of Alzheimer’s disease exhibits progressive cortical and hippocampal β-amyloid accumulation, resulting in plaque pathology and spatial memory impairment by 3 months of age. We tested whether TgCRND8 cognitive function is disrupted prior to the appearance of macroscopic plaques in an object recognition task. We found profound deficits in 8-week-old mice. Animals this age were not impaired on the Morris water maze task. TgCRND8 and littermate controls did not differ in their duration of object exploration or optokinetic responses. Thus, visual and motor dysfunction did not confound the phenotype. Object memory deficits point to the frontal cortex and hippocampus as early targets of functional disruption. Indeed, we observed altered levels of brain-derived neurotrophic factor (BDNF) messenger ribonucleic acid (mRNA) in these brain regions of preplaque TgCRND8 mice. Our findings suggest that object recognition provides an early index of cognitive impairment associated with amyloid exposure and reduced brain-derived neurotrophic factor expression in the TgCRND8 mouse. PMID:20447730

  17. Embryo Microinjection of Selenomethionine Reduces Hatchability and Modifies Oxidant Responsive Gene Expression in Zebrafish

    PubMed Central

    Thomas, J. K.; Janz, D. M.

    2016-01-01

    In previous studies we demonstrated that exposure to selenomethionine (SeMet) causes developmental toxicities in zebrafish (Danio rerio). The objectives of this study were to establish a dose-response relationship for developmental toxicities in zebrafish after embryo microinjection of Se (8, 16 or 32 μg/g dry mass of eggs) in the form of SeMet, and to investigate potential underlying mechanism(s) of SeMet-induced developmental toxicities. A dose-dependent increase in frequencies of mortality and total deformities, and reduced hatchability were observed in zebrafish exposed to excess Se via embryo microinjection. The egg Se concentration causing 20% mortality was then used to investigate transcript abundance of proteins involved in antioxidant protection and methylation. Excess Se exposure modified gene expression of oxidant-responsive transcription factors (nuclear factor erythroid 2-related factor nrf2a and nrf2b), and enzymes involved in cellular methylation (methionine adenosyltransferase mat1a and mat2ab) in zebrafish larvae. Notably, excess Se exposure up-regulated transcript abundance of aryl hydrocarbon receptor 2 (ahr2), a signalling pathway involved in the toxicity of dioxin-related compounds. Our findings suggest that oxidative stress or modification of methylation, or a combination of these mechanisms, might be responsible for Se-induced developmental toxicities in fishes. PMID:27210033

  18. Protein-poor diet reduces host-specific immune gene expression in Bombus terrestris

    PubMed Central

    Brunner, Franziska S.; Schmid-Hempel, Paul; Barribeau, Seth M.

    2014-01-01

    Parasites infect hosts non-randomly as genotypes of hosts vary in susceptibility to the same genotypes of parasites, but this specificity may be modulated by environmental factors such as nutrition. Nutrition plays an important role for any physiological investment. As immune responses are costly, resource limitation should negatively affect immunity through trade-offs with other physiological requirements. Consequently, nutritional limitation should diminish immune capacity in general, but does it also dampen differences among hosts? We investigated the effect of short-term pollen deprivation on the immune responses of our model host Bombus terrestris when infected with the highly prevalent natural parasite Crithidia bombi. Bumblebees deprived of pollen, their protein source, show reduced immune responses to infection. They failed to upregulate a number of genes, including antimicrobial peptides, in response to infection. In particular, they also showed less specific immune expression patterns across individuals and colonies. These findings provide evidence for how immune responses on the individual-level vary with important elements of the environment and illustrate how nutrition can functionally alter not only general resistance, but also alter the pattern of specific host–parasite interactions. PMID:24850921

  19. Carbon monoxide down-modulates Toll-like receptor 4/MD2 expression on innate immune cells and reduces endotoxic shock susceptibility

    PubMed Central

    Riquelme, Sebastián A; Bueno, Susan M; Kalergis, Alexis M

    2015-01-01

    Carbon monoxide (CO) has been recently reported as the main anti-inflammatory mediator of the haem-degrading enzyme haem-oxygenase 1 (HO-1). It has been shown that either HO-1 induction or CO treatment reduces the ability of monocytes to respond to inflammatory stimuli, such as lipopolysaccharide (LPS), due to an inhibition of the signalling pathways leading to nuclear factor-κB, mitogen-activated protein kinases and interferon regulatory factor 3 activation. Hence, it has been suggested that CO impairs the stimulation of the Toll-like receptor 4 (TLR4)/myeloid differentiation factor-2 (MD2) complex located on the surface of immune cells. However, whether CO can negatively modulate the surface expression of the TLR4/MD2 complex in immune cells remains unknown. Here we report that either HO-1 induction or treatment with CO decreases the surface expression of TLR4/MD2 in dendritic cells (DC) and neutrophils. In addition, in a septic shock model of mice intraperitoneally injected with lipopolysaccharide (LPS), prophylactic treatment with CO protected animals from hypothermia, weight loss, mobility loss and death. Further, mice pre-treated with CO and challenged with LPS showed reduced recruitment of DC and neutrophils to peripheral blood, suggesting that this gas causes a systemic tolerance to endotoxin challenge. No differences in the amount of innate cells in lymphoid tissues were observed in CO-treated mice. Our results suggest that CO treatment reduces the expression of the TLR4/MD2 complex on the surface of myeloid cells, which renders them resistant to LPS priming in vitro, as well as in vivo in a model of endotoxic shock. PMID:25179131

  20. Carbon monoxide down-modulates Toll-like receptor 4/MD2 expression on innate immune cells and reduces endotoxic shock susceptibility.

    PubMed

    Riquelme, Sebastián A; Bueno, Susan M; Kalergis, Alexis M

    2015-02-01

    Carbon monoxide (CO) has been recently reported as the main anti-inflammatory mediator of the haem-degrading enzyme haem-oxygenase 1 (HO-1). It has been shown that either HO-1 induction or CO treatment reduces the ability of monocytes to respond to inflammatory stimuli, such as lipopolysaccharide (LPS), due to an inhibition of the signalling pathways leading to nuclear factor-κB, mitogen-activated protein kinases and interferon regulatory factor 3 activation. Hence, it has been suggested that CO impairs the stimulation of the Toll-like receptor 4 (TLR4)/myeloid differentiation factor-2 (MD2) complex located on the surface of immune cells. However, whether CO can negatively modulate the surface expression of the TLR4/MD2 complex in immune cells remains unknown. Here we report that either HO-1 induction or treatment with CO decreases the surface expression of TLR4/MD2 in dendritic cells (DC) and neutrophils. In addition, in a septic shock model of mice intraperitoneally injected with lipopolysaccharide (LPS), prophylactic treatment with CO protected animals from hypothermia, weight loss, mobility loss and death. Further, mice pre-treated with CO and challenged with LPS showed reduced recruitment of DC and neutrophils to peripheral blood, suggesting that this gas causes a systemic tolerance to endotoxin challenge. No differences in the amount of innate cells in lymphoid tissues were observed in CO-treated mice. Our results suggest that CO treatment reduces the expression of the TLR4/MD2 complex on the surface of myeloid cells, which renders them resistant to LPS priming in vitro, as well as in vivo in a model of endotoxic shock.

  1. Chronic intermittent ethanol treatment selectively alters N-methyl-D-aspartate receptor subunit surface expression in cultured cortical neurons.

    PubMed

    Qiang, Mei; Denny, Ashley D; Ticku, Maharaj K

    2007-07-01

    A chronic intermittent ethanol (CIE) exposure regimen consists of repeated episodes of ethanol intoxication and withdrawal. CIE treatment has been reported to result in a significant enhancement of N-methyl-D-aspartate (NMDA) receptor-mediated synaptic responses in vivo, and trafficking of NMDA receptors is emerging a key regulatory mechanism that underlies the channel function. Therefore, in the present study, we examined the effects of CIE on NMDA receptor subunit surface expression. Cultured cortical neurons were exposed to 75 mM ethanol for 14 h followed by 10 h of withdrawal, repeated this cycle five times, and followed by 2 or 5 days of withdrawal. Surface-expressed NMDA receptor subunits and their endocytosis were measured by biotinylation and Western blots. CIE significantly increased NMDA receptor (NR) 1 and NR2B but not NR2A subunit surface expression after 5 days of treatment. However, CIE treatment did not reduce the NMDA receptor endocytosis. Quantification of immunocytochemistry confirmed CIE-induced increase in both the total number of NR1 and NR2B subunit clusters and their targeting to synaptic sites. It is noteworthy that this effect persisted even after ethanol withdrawal with a peak expression occurring between 0 and 2 days after withdrawal, and the expression on the plasma membrane was still at high levels after 5 days of withdrawal. In addition, this was accompanied by significant increases in postsynaptic density protein 95 clusters. Protein kinase A inhibitor completely reversed CIE-induced increase in NR1 and partially in NR2B surface level and a long-lasting effect. These changes may contribute to the development of ethanol-induced neurotoxicity and ethanol dependence.

  2. Evaluating the Performance of a Surface Barrier on Reducing Soil-Water Flow

    SciTech Connect

    Zhang, Z. F.; Strickland, Christopher E.; Field, Jim G.; Parker, Danny L.; Clayton, Ray E.

    2012-08-31

    One of the most common effective techniques for contaminant remediation in the vadose zone is to use a surface barrier to reduce or eliminate soil-water flow to reduce the contaminant flux to the underlying groundwater. Confirming the reduction of the soil-water flux rate is challenging because of the difficulty of determining the very low soil-water flux beneath the barrier. We propose a hydraulic-conductivity factor, fK, as a conservative indicator for quantifying the reduction of soil-water flow. The factor can be calculated using the measured soil-water content or pressure but does not require the knowledge of the saturated hydraulic conductivity or the hydraulic gradient. The formulas were tested by comparing with changes in hydraulic conductivity, K, from a drainage experiment. The pressure-based formula was further applied to evaluate the performance of the interim surface barrier at T Tank Farm on Hanford Site. Three years after barrier emplacement, the hydraulic conductivity decreased by a factor between 3.8 and 13.0 at the 1-, 2- and 5-m depths. The difference between the conductivity-reduction factor and the flux-rate-reduction factor, fq, was quantified with a numerical simulation. With the calculated fK, the numerically determined fK/fq ratio, and the assumed pre-barrier soil-water flux rate of 100 mm yr-1, the estimated soil-water flux rate 3 years after barrier emplacement was no more than 8.5 mm yr-1 at or above the 5-m depth.

  3. PEGylation of microbead surfaces reduces unspecific antibody binding in glycan-based suspension array.

    PubMed

    Pochechueva, Tatiana; Chinarev, Alexander; Bovin, Nicolai; Fedier, André; Jacob, Francis; Heinzelmann-Schwarz, Viola

    2014-10-01

    Glycan-based suspension array (SGA) is an "in-house" developed multi-target immunoassay, employing commercially available fluorescent microbeads as a solid support for unique chemically synthesized glycopolymers which capture naturally occurring human anti-glycan antibodies. SGA is a sensitive and reliable tool for the high-throughput screening of anti-glycan antibody alterations characteristic for a vast number of human diseases including cancer. However, unspecific background binding, for instance binding of non-target antibodies, is a common obstacle in such immunoassays. In an attempt to reduce unspecific background binding of serum (or plasma) antibodies, we prepared glycosylated microbeads modified with linear poly(ethylene glycols) (PEGs) of different lengths. We compared several kinds of PEG modifications: (a) partial side-chain substitution of glycopolymers by PEGs of different lengths, (b) end-point addition of biotin-linked PEGs to glycopolymer-coupled beads, and (c) linking of heterobifunctional PEGs to the bead surface prior to glycopolymer immobilization. Among the various modifications investigated, the direct modification of the bead surface with linear heterobifunctional PEGs, consisting of 23- and 60PEG-units significantly reduced the background binding. The end-point addition of biotin-linked PEGs, especially in the case of PEG consisting from 50PEG-units, helped to repel non-target binding caused by endogenous biotin. We observed unspecific binding predominantly for antibodies of IgG but of IgM class. The novel design of fluorescent microbeads allows the detection of human anti-glycan antibodies with increased specificity and opens new horizons for practical application of SGA as a diagnostic tool.

  4. Reduced surface area chromatography for flow-through purification of viruses and virus like particles.

    PubMed

    Iyer, Ganesh; Ramaswamy, Senthilkumar; Asher, Damon; Mehta, Ushma; Leahy, Anne; Chung, Franklin; Cheng, Kwok-Shun

    2011-07-01

    A method for flow-through purification of viruses and virus like nano-particles using a combination of binding and size-exclusion chromatography was developed. This technique relies on minimizing the external surface area per unit volume available for virus binding by increasing the mean diameter of the beads used in the column. At the same time the impurity binding capacity of the column is maximized by utilizing beads with multiple functionalities of the optimum size. Purification of different types of viruses and virus-like-particles could be achieved using this technique. Flow-through purification of influenza virus using this technique yielded virus recoveries greater than 70-80% coupled with impurity removal greater than 80%. Finally an approach to optimize and facilitate process development using this technology is presented. Since the impurity binding occurs via a non-specific mechanism and virus recovery is achieved through reduced surface area, the technique is not limited to specific types of viruses and offers the potential as a universal purification tool.

  5. High-surface-area nitrogen-doped reduced graphene oxide for electric double-layer capacitors

    SciTech Connect

    Youn, Hee-Chang; Bak, Seong-Min; Kim, Myeong-Seong; Jaye, Cherno; Fischer, Daniel A.; Lee, Chang-Wook; Yang, Xiao-Qing; Roh, Kwang Chul; Kim, Kwang-Bum

    2015-06-08

    A two-step method consisting of solid-state microwave irradiation and heat treatment under NH₃ gas was used to prepare nitrogen-doped reduced graphene oxide (N-RGO) with a high specific surface area (1007m²g⁻¹), high electrical conductivity (1532S m⁻¹), and low oxygen content (1.5 wt%) for electric double-layer capacitor applications. The specific capacitance of N-RGO was 291 Fg⁻¹ at a current density of 1 A g⁻¹, and a capacitance of 261 F g⁻¹ was retained at 50 A g⁻¹, indicating a very good rate capability. N-RGO also showed excellent cycling stability, preserving 96% of the initial specific capacitance after 100,000 cycles. Near-edge X-ray absorption fine-structure spectroscopy evidenced the recover of π-conjugation in the carbon networks with the removal of oxygenated groups and revealed the chemical bonding of the nitrogen atoms in N-RGO. The good electrochemical performance of N-RGO is attributed to its high surface area, high electrical conductivity, and low oxygen content.

  6. High-surface-area nitrogen-doped reduced graphene oxide for electric double-layer capacitors

    DOE PAGES

    Youn, Hee-Chang; Bak, Seong-Min; Kim, Myeong-Seong; Jaye, Cherno; Fischer, Daniel A.; Lee, Chang-Wook; Yang, Xiao-Qing; Roh, Kwang Chul; Kim, Kwang-Bum

    2015-06-08

    A two-step method consisting of solid-state microwave irradiation and heat treatment under NH₃ gas was used to prepare nitrogen-doped reduced graphene oxide (N-RGO) with a high specific surface area (1007m²g⁻¹), high electrical conductivity (1532S m⁻¹), and low oxygen content (1.5 wt%) for electric double-layer capacitor applications. The specific capacitance of N-RGO was 291 Fg⁻¹ at a current density of 1 A g⁻¹, and a capacitance of 261 F g⁻¹ was retained at 50 A g⁻¹, indicating a very good rate capability. N-RGO also showed excellent cycling stability, preserving 96% of the initial specific capacitance after 100,000 cycles. Near-edge X-ray absorptionmore » fine-structure spectroscopy evidenced the recover of π-conjugation in the carbon networks with the removal of oxygenated groups and revealed the chemical bonding of the nitrogen atoms in N-RGO. The good electrochemical performance of N-RGO is attributed to its high surface area, high electrical conductivity, and low oxygen content.« less

  7. High-Surface-Area Nitrogen-Doped Reduced Graphene Oxide for Electric Double-Layer Capacitors.

    PubMed

    Youn, Hee-Chang; Bak, Seong-Min; Kim, Myeong-Seong; Jaye, Cherno; Fischer, Daniel A; Lee, Chang-Wook; Yang, Xiao-Qing; Roh, Kwang Chul; Kim, Kwang-Bum

    2015-06-01

    A two-step method consisting of solid-state microwave irradiation and heat treatment under NH3 gas was used to prepare nitrogen-doped reduced graphene oxide (N-RGO) with a high specific surface area (1007 m(2)  g(-1) ), high electrical conductivity (1532 S m(-1) ), and low oxygen content (1.5 wt %) for electrical double-layer capacitor applications. The specific capacitance of N-RGO was 291 F g(-1) at a current density of 1 A g(-1) , and a capacitance of 261 F g(-1) was retained at 50 A g(-1) , which indicated a very good rate capability. N-RGO also showed excellent cycling stability and preserved 96 % of the initial specific capacitance after 100 000 cycles. Near-edge X-ray absorption fine-structure spectroscopy results provided evidenced for the recovery of π conjugation in the carbon networks with the removal of oxygenated groups and revealed chemical bonding of the nitrogen atoms in N-RGO. The good electrochemical performance of N-RGO is attributed to its high surface area, high electrical conductivity, and low oxygen content.

  8. Multi-resistive Reduced Graphene Oxide Diode with Reversible Surface Electrochemical Reaction induced Carrier Control

    PubMed Central

    Seo, Hyungtak; Ahn, Seungbae; Kim, Jinseo; Lee, Young-Ahn; Chung, Koo-Hyun; Jeon, Ki-Joon

    2014-01-01

    The extended application of graphene-based electronic devices requires a bandgap opening in order to realize the targeted device functionality. Since the bandgap tuning of pristine graphene is limited to 360 meV, the chemical modification of graphene is considered essential to achieve a large bandgap opening at the expense of electrical properties degradation. Reduced graphene oxide (RGO) has attracted significant interest for fabricating graphene-based semiconductors since it has several advantages over other forms of chemically modified graphene; such as tunable bandgap opening, decent electrical properties, and easy synthesis. Because of the reduced bonding nature of RGO, the role of metastable oxygen in the RGO matrix is recently highlighted and it may offer emerging ionic devices. In this study, we show that multi-resistivity RGO/n-Si diodes can be obtained by controlling the RGO thickness at a nanometer scale. This is made possible by (1) a metastable lattice-oxygen drift within bulk RGO and (2) electrochemical ambient hydroxyl (OH) formation at the RGO surface. The effect demonstrated in a p-RGO/n-Si heterojunction diode is equivalent to electrochemically driven reversible electronic manipulation and therefore provides an important basis for the application of O bistability in RGO for chemical sensors and electrocatalysis. PMID:25007942

  9. Infection of vascular endothelial cells with herpes simplex virus enhances tissue factor activity and reduces thrombomodulin expression.

    PubMed Central

    Key, N S; Vercellotti, G M; Winkelmann, J C; Moldow, C F; Goodman, J L; Esmon, N L; Esmon, C T; Jacob, H S

    1990-01-01

    Latent infection of vascular cells with herpes-viruses may play a pathogenic role in the development of human atherosclerosis. In a previous study, we found that cultured human umbilical vein endothelial cells (HUVECs) infected with herpes simplex virus 1 (HSV-1) became procoagulant, exemplified both by their enhanced assembly of the prothrombinase complex and by their inability to reduce adhesion of platelets. We now report two further procoagulant consequences of endothelial HSV infection: loss of surface thrombomodulin (TM) activity and induction of synthesis of tissue factor. Within 4 hr of infection of HUVECs, TM activity measured by thrombin-dependent protein C activation declined 21 +/- 3% (P less than 0.05) and by 18 hr, 48 +/- 5% (P less than 0.001). Similar significant TM decrements accompanied infection of bovine aortic endothelial cells. Identical TM loss was induced with HSV-2 infection but not with adenovirus infection. Decreased surface expression of TM antigen (measured by the specific binding of a polyclonal antibody to bovine TM) closely paralleled the loss of TM activity. As examined by Northern blotting, these losses apparently reflected rapid onset (within 4 hr of HSV infection) loss of mRNA for TM. In contrast, HSV infection induced a viral-dose-dependent increase in synthesis of tissue factor protein, adding to the procoagulant state. The results indicate that loss of endothelial protein-synthetic capacity is not a universal effect of HSV infection. We suggest that the procoagulant state induced by reduction in TM activity and amplified tissue factor activity accompanying HSV infection of endothelium could contribute to deposition of thrombi on atherosclerotic plaques and to the "coagulant-necrosis" state that characterizes HSV-infected mucocutaneous lesions. Images PMID:2169619

  10. Reducing surface water total and methyl mercury concentrations and bioavailability using a coagulation-wetland system

    NASA Astrophysics Data System (ADS)

    Kraus, T. E.; Fleck, J.; Henneberry, Y. K.; Stumpner, E. B.; Krabbenhoft, D. P.; Bachand, P.; Randall, P.

    2013-12-01

    With the recent passage of laws regulating concentrations and loads of mercury (Hg) in surface waters, there is a need to develop management practices that will reduce the export of Hg from both point and non-point sources. Coagulation with metal based salts to remove particles and dissolved organic matter (DOM) from solution is a practice commonly employed by drinking water utilities. Because dissolved Hg is associated with particles and DOM, it follows that Hg should also be removed during the coagulation process and end up associated with the organo-metal precipitate, termed flocculate (floc). The effectiveness of iron- and aluminum-based coagulants for removing both inorganic and methyl mercury (IHg and MeHg, respectively) from solution was demonstrated in laboratory studies conducted on agricultural drainage waters of the Sacramento-San Joaquin Delta: dissolved concentrations of MeHg decreased by 80% while IHg decreased by 97% following coagulation. To test the field application of this technology, samples were collected from the inflows and outflows of wetland treatment cells constructed in the central Delta of California. This replicated field experiment includes three replicates each of three inflow waters treatments: (1) iron sulfate addition, (2) polyaluminum chloride addition, and (3) untreated controls. Water entering and exiting the nine treatment cells was sampled approximately monthly over a 1-year period for total Hg and MeHg in both the dissolved and particulate aqueous phases. Initial results confirm that coagulant addition is removing Hg (total and methyl, particulate and dissolved) from solution and sequestering it in the floc. Seasonal effects on DOM concentration and other factors appear to effect whether passage through the wetland cells alters surface water dissolved organic carbon (DOC) and Hg concentrations. Related studies will examine whether the presence of the floc affects the production and fate of MeHg within the wetland cells. If

  11. Identification of genes affecting expression of phosphoglycerate kinase on the surface of group B streptococcus.

    PubMed

    Boone, Tyler J; Tyrrell, Gregory J

    2012-04-01

    Group B streptococcal phosphoglycerate kinase (GBS-PGK), a glycolytic enzyme, has previously been identified on the surface of group B streptococcus (GBS). To identify genes involved in surface expression of GBS-PGK, we performed Tn917 mutagenesis followed by quantification of PGK expressed on the GBS surface. Tn917 mutagenesis identified 4 genes (sag0966, sag0979, sag0980, and sag1003) that when disrupted, alter expression of GBS-PGK on the bacterial surface. Three of the identified genes were localized to a region of the GBS genome containing genes (sag0973-sag0977) predicted to be involved in resistance to antimicrobial peptides. One mutant isolate, designated NCS13sag1003::Tn917, was found to have increased sensitivity to the antimicrobial peptides bacitracin and nisin. In addition, all of the mutant strains assayed were found to have decreased β-hemolysis. In conclusion, we have identified genes involved in surface expression of GBS-PGK. These genes also appear to be involved in antimicrobial peptide resistance and regulate expression of the β-hemolysin. PMID:22444251

  12. Prime focus architectures for large space telescopes: reduce surfaces to save cost

    NASA Astrophysics Data System (ADS)

    Breckinridge, J. B.; Lillie, C. F.

    2016-07-01

    Conceptual architectures are now being developed to identify future directions for post JWST large space telescope systems to operate in the UV Optical and near IR regions of the spectrum. Here we show that the cost of optical surfaces within large aperture telescope/instrument systems can exceed $100M/reflection when expressed in terms of the aperture increase needed to over come internal absorption loss. We recommend a program in innovative optical design to minimize the number of surfaces by considering multiple functions for mirrors. An example is given using the Rowland circle imaging spectrometer systems for UV space science. With few exceptions, current space telescope architectures are based on systems optimized for ground-based astronomy. Both HST and JWST are classical "Cassegrain" telescopes derived from the ground-based tradition to co-locate the massive primary mirror and the instruments at the same end of the metrology structure. This requirement derives from the dual need to minimize observatory dome size and cost in the presence of the Earth's 1-g gravitational field. Space telescopes, however function in the zero gravity of space and the 1- g constraint is relieved to the advantage of astronomers. Here we suggest that a prime focus large aperture telescope system in space may have potentially have higher transmittance, better pointing, improved thermal and structural control, less internal polarization and broader wavelength coverage than Cassegrain telescopes. An example is given showing how UV astronomy telescopes use single optical elements for multiple functions and therefore have a minimum number of reflections.

  13. Rosiglitazone ameliorates diffuse axonal injury by reducing loss of tau and up-regulating caveolin-1 expression

    PubMed Central

    Zhao, Yong-lin; Song, Jin-ning; Ma, Xu-dong; Zhang, Bin-fei; Li, Dan-dong; Pang, Hong-gang

    2016-01-01

    Rosiglitazone up-regulates caveolin-1 levels and has neuroprotective effects in both chronic and acute brain injury. Therefore, we postulated that rosiglitazone may ameliorate diffuse axonal injury via its ability to up-regulate caveolin-1, inhibit expression of amyloid-beta precursor protein, and reduce the loss and abnormal phosphorylation of tau. In the present study, intraperitoneal injection of rosiglitazone significantly reduced the levels of amyloid-beta precursor protein and hyperphosphorylated tau (phosphorylated at Ser404(p-tau (S404)), and it increased the expression of total tau and caveolin-1 in the rat cortex. Our results show that rosiglitazone inhibits the expression of amyloid-beta precursor protein and lowers p-tau (S404) levels, and it reduces the loss of total tau, possibly by up-regulating caveolin-1. These actions of rosiglitazone may underlie its neuroprotective effects in the treatment of diffuse axonal injury. PMID:27482223

  14. Reduced toxicity of expression, in Escherichia coli, of antipollutant antibody fragments and their use as sensitive diagnostic molecules.

    PubMed

    Strachan, G; Williams, S; Moyle, S P; Harris, W J; Porter, A J

    1999-09-01

    Single-chain antibody fragments (scAb), specific for the chlorophenoxy acid herbicide mecoprop, have been expressed and purified from the bacterium Escherichia coli. Co-expression with the colE1-compatible, arabinose-inducible, skp expression vector pHELP1 prevented bacterial lysis and significantly increased both total and functional expression yield. The periplasmic protein, SKP, may have a role as a generic detoxification protein. Surface plasmon resonance (BIAcore 2000) analysis confirmed that the purified scAb retained similar binding kinetics to the monoclonal antibody (Mab) from which it was cloned. In competition ELISA, the bacterial scAb showed the same specificity for mecoprop and a related herbicide, MCPA, as the Mab but an increase in sensitivity for free antigen in all ELISA formats. Bacterially expressed antibody fragments provide a simple, sensitive and cost-effective alternative to the traditional production of diagnostic Mabs via tissue culture.

  15. Estimation of Land Surface Energy Balance Using Satellite Data of Spatial Reduced Resolution

    NASA Astrophysics Data System (ADS)

    Vintila, Ruxandra; Radnea, Cristina; Savin, Elena; Poenaru, Violeta

    2010-12-01

    The paper presents preliminary results concerning the monitoring at national level of several geo-biophysical variables retrieved by remote sensing, in particular those related to drought or aridisation. The study, which is in progress, represents also an exercise for to the implementation of a Land Monitoring Core Service for Romania, according to the Kopernikus Program and in compliance with the INSPIRE Directive. The SEBS model has been used to retrieve land surface energy balance variables, such as turbulent heat fluxes, evaporative fraction and daily evaporation, based on three information types: (1) surface albedo, emissivity, temperature, fraction of vegetation cover (fCover), leaf area index (LAI) and vegetation height; (2) air pressure, temperature, humidity and wind speed at the planetary boundary layer (PBL) height; (3) downward solar radiation and downward longwave radiation. AATSR and MERIS archived reprocessed images have provided several types of information. Thus, surface albedo, emissivity, and land surface temperature have been retrieved from AATSR, while LAI and fCover have been estimated from MERIS. The vegetation height has been derived from CORINE Land Cover and PELCOM Land Use databases, while the meteorological information at the height of PBL have been estimated from the measurements provided by the national weather station network. Other sources of data used during this study have been the GETASSE30 digital elevation model with 30" spatial resolution, used for satellite image orthorectification, and the SIGSTAR-200 geographical information system of soil resources of Romania, used for water deficit characterisation. The study will continue by processing other AATSR and MERIS archived images, complemented by the validation of SEBS results with ground data collected on the most important biomes for Romania at various phenological stages, and the transformation of evaporation / evapotranspiration into a drought index using the soil texture

  16. Loss of PAX8 in high-grade serous ovarian cancer reduces cell survival despite unique modes of action in the fallopian tube and ovarian surface epithelium.

    PubMed

    Rodgers, Laura H; Ó hAinmhire, Eoghainín; Young, Alexandria N; Burdette, Joanna E

    2016-05-31

    High-grade serous carcinoma (HGSC) is the most common and lethal form of ovarian cancer. PAX8 is a transcription factor expressed in fallopian tube epithelial cells and in 80-96% of HGSC tumors. The ovarian surface epithelium (OSE) only acquires PAX8 expression after malignant transformation. In this study, forced PAX8 expression in OSE cells increased proliferation and migration through upregulation of EMT factors such as N-cadherin and Fibronectin. OSE cells expressing PAX8 also had an increase in the FOXM1 pathway, but PAX8 alone was not sufficient to drive tumorigenesis. PAX8 knockdown in the oviductal epithelium cells did not decrease expression of the FOXM1 pathway and induced only a slight decrease in cell proliferation. No changes in migration, cell cycle, or apoptosis were detected after PAX8 knockdown in oviductal cells. Finally, PAX8 knockdown in HGSC cell lines resulted in increased apoptosis and decreased FOXM1 levels. The results presented here suggest that PAX8 has a cell specific role in governing proliferation and migration in nontransformed ovarian surface epithelium cells compared to the oviductal cells, but its reduction in serous cancer cell lines provides a common mechanism for reducing cell survival.

  17. Systemic neutralization of IL-17A significantly reduces breast cancer associated metastasis in arthritic mice by reducing CXCL12/SDF-1 expression in the metastatic niches

    PubMed Central

    2014-01-01

    Background IL-17A is a pro-inflammatory cytokine that is normally associated with autoimmune arthritis and other pro-inflammatory conditions. Recently, IL-17A has emerged as a critical factor in enhancing breast cancer (BC)-associated metastases. We generated immune competent arthritic mouse models that develop spontaneous BC-associated bone and lung metastasis. Using these models, we have previously shown that neutralization of IL-17A resulted in significant reduction in metastasis. However, the underlying mechanism/s remains unknown. Methods We have utilized two previously published mouse models for this study: 1) the pro-arthritic mouse model (designated SKG) injected with metastatic BC cell line (4T1) in the mammary fat pad, and 2) the PyV MT mice that develop spontaneous mammary gland tumors injected with type II collagen to induce autoimmune arthritis. Mice were treated with anti-IL-17A neutralizing antibody and monitored for metastasis and assessed for pro-inflammatory cytokines and chemokines associated with BC-associated metastasis. Results We first corroborate our previous finding that in vivo neutralization of IL-17A significantly reduced metastasis to the bones and lungs in both models. Next, we report that treatment with anti-IL17A antibody significantly reduced the expression of a key chemokine, CXCL12 (also known as stromal derived factor-1 (SDF - 1)) in the bones and lungs of treated mice. CXCL12 is a ligand for CXCR4 (expressed on BC cells) and their interaction is known to be critical for metastasis. Interestingly, levels of CXCR4 in the tumor remained unchanged with treatment. Consequently, protein lysates derived from the bones and lungs of treated mice were significantly less chemotactic for the BC cells than lysates from untreated mice; and addition of exogenous SDF-1 to the lysates from treated mice completely restored BC cell migration. In addition, cytokines such as IL-6 and M-CSF were significantly reduced in the lung and bone lysates

  18. Mass spectrometry analysis of surface tension reducing substances produced by a pah-degrading Pseudomonas citronellolis strain

    PubMed Central

    Jacques, Rodrigo J. S.; Santos, Eder C.; Haddad, Renato; Catharino, Rodrigo R.; Eberlin, Marcos N.; Bento, Fátima M.; de Oliveira Camargo, Flávio A.

    2008-01-01

    In this work we investigated the structure of the iron-stimulated surface tension reducing substances produced by P. citronellolis 222A isolated from a 17-years old landfarming used for sludge treatment in petrochemical industries and oil refinery. Its mass spectrum differs from P. aeruginosa spectrum, indicating that the surface tension reducing substances produced by P. citronellolis can be a new kind of biosurfactant. PMID:24031229

  19. The vaccinia virus fusion inhibitor proteins SPI-3 (K2) and HA (A56) expressed by infected cells reduce the entry of superinfecting virus.

    PubMed

    Turner, Peter C; Moyer, Richard W

    2008-10-25

    The orthopoxvirus SPI-3 (K2) and A56 (hemagglutinin, HA) proteins interact and together prevent cell-cell fusion. SPI-3/A56 has been proposed to prevent the superinfection of previously infected cells by reducing virus-cell fusion. Binding of mature virions of vaccinia virus (VV) to VV-infected cells was unaffected by SPI-3 or A56 on the surface of infected cells. Entry of VV into infected cells was assessed using VV-P(T7)-luc carrying the luciferase reporter under T7 control. Cells infected with VV or cowpox virus (CPV) expressing T7 RNA polymerase and lacking SPI-3 and/or A56 were superinfected with VV-P(T7)-luc, and luciferase activity was measured. Inactivation of SPI-3 or A56 from the pre-infecting virus resulted in greater luciferase expression from the superinfecting VV-P(T7)-luc. Antibody against SPI-3 present during infection with wild-type CPV-T7 increased luciferase expression from superinfecting VV-P(T7)-luc. The SPI-3/A56 complex on the infected cell surface therefore appears to reduce the entry of virions into infected cells.

  20. The vaccinia virus fusion inhibitor proteins SPI-3 (K2) and HA (A56) expressed by infected cells reduce the entry of superinfecting virus

    SciTech Connect

    Turner, Peter C. Moyer, Richard W.

    2008-10-25

    The orthopoxvirus SPI-3 (K2) and A56 (hemagglutinin, HA) proteins interact and together prevent cell-cell fusion. SPI-3/A56 has been proposed to prevent the superinfection of previously infected cells by reducing virus-cell fusion. Binding of mature virions of vaccinia virus (VV) to VV-infected cells was unaffected by SPI-3 or A56 on the surface of infected cells. Entry of VV into infected cells was assessed using VV-P{sub T7}-luc carrying the luciferase reporter under T7 control. Cells infected with VV or cowpox virus (CPV) expressing T7 RNA polymerase and lacking SPI-3 and/or A56 were superinfected with VV-P{sub T7}-luc, and luciferase activity was measured. Inactivation of SPI-3 or A56 from the pre-infecting virus resulted in greater luciferase expression from the superinfecting VV-P{sub T7}-luc. Antibody against SPI-3 present during infection with wild-type CPV-T7 increased luciferase expression from superinfecting VV-P{sub T7}-luc. The SPI-3/A56 complex on the infected cell surface therefore appears to reduce the entry of virions into infected cells.

  1. Inflammation-Induced Downregulation of Butyrate Uptake and Oxidation Is Not Caused by a Reduced Gene Expression.

    PubMed

    Boesmans, Leen; Ramakers, Meine; Arijs, Ingrid; Windey, Karen; Vanhove, Wiebe; Schuit, Frans; Rutgeerts, Paul; Verbeke, Kristin; De Preter, Vicky

    2015-02-01

    In ulcerative colitis (UC) the butyrate metabolism is impaired, leading to energy-deficiency in the colonic cells. The effect of inflammation on the butyrate metabolism was investigated. HT-29 cells were incubated with pro-inflammatory cytokines (TNF-α and/or IFN-γ) for 1 and 24 h. Cells were additionally stimulated with butyrate to investigate its anti-inflammatory potential. Butyrate uptake and oxidation were measured using (14)C-labeled butyrate. Gene expression of the butyrate metabolism enzymes, interleukin 8 (IL-8; inflammatory marker) and villin-1 (VIL-1; epithelial cell damage marker) was measured via quantitative RT-PCR. Significantly increased IL-8 expression and decreased VIL-1 expression after 24 h incubation with TNF-α and/or IFN-γ confirmed the presence of inflammation. These conditions induced a decrease of both butyrate uptake and oxidation, whereas the gene expression was not reduced. Simultaneous incubation with butyrate counteracted the reduced butyrate oxidation. In contrast, 1 h incubation with TNF-α induced a significant increased IL-8 expression and decreased butyrate uptake. Incubation with TNF-α and/or IFN-γ for 1 h did not induce cell damage nor influence butyrate oxidation. The inflammation-induced downregulation of the butyrate metabolism was not caused by a reduced gene expression, but appeared consequential to a decreased butyrate uptake. Increasing the luminal butyrate levels might have therapeutic potential in UC.

  2. PTEN expression in PTEN-null leukaemic T cell lines leads to reduced proliferation via slowed cell cycle progression.

    PubMed

    Seminario, Maria-Cristina; Precht, Patricia; Wersto, Robert P; Gorospe, Myriam; Wange, Ronald L

    2003-11-01

    The balance of activities between the proto-oncogene phosphoinositide 3-kinase (PI3K) and the tumour suppressor gene PTEN has been shown to affect cellular growth and proliferation, as well as tumorigenesis. Previously, PTEN expression in the PTEN-null Jurkat T cell leukaemia line was shown to cause reduced proliferation without cell cycle arrest. Here, we further these investigations by determining the basis for this phenomenon. By BrdU pulse-chase and cell cycle arrest and release assays, we find that PTEN expression reduced proliferation by slowing progression through all phases of the cell cycle. This was associated with reduced levels of cyclins A, B1 and B2, cdk4, and cdc25A and increased p27KIP1 expression. Apoptosis played no role in the antiproliferative effect of PTEN, since only marginal increases in the rate of apoptosis were detected upon PTEN expression, and inhibitors of effector caspases did not restore proliferative capacity. Active Akt blocked the antiproliferative effects of PTEN, indicating that PTEN mediates its effects through conventional PI3K-linked signalling pathways. Similar results were obtained from a different PTEN-null leukaemia T cell line, CEM. Together, these results show that PTEN expression in leukaemic T cells leads to reduced proliferation via an apoptosis-independent mechanism involving slower passage through the cell cycle.

  3. Identification of novel pancreatic adenocarcinoma cell-surface targets by gene expression profiling and tissue microarray.

    PubMed

    Morse, David L; Balagurunathan, Yoga; Hostetter, Galen; Trissal, Maria; Tafreshi, Narges K; Burke, Nancy; Lloyd, Mark; Enkemann, Steven; Coppola, Domenico; Hruby, Victor J; Gillies, Robert J; Han, Haiyong

    2010-09-01

    Pancreatic cancer has a high mortality rate, which is generally related to the initial diagnosis coming at late stage disease combined with a lack of effective treatment options. Novel agents that selectively detect pancreatic cancer have potential for use in the molecular imaging of cancer, allowing for non-invasive determination of tumor therapeutic response and molecular characterization of the disease. Such agents may also be used for the targeted delivery of therapy to tumor cells while decreasing systemic effects. Using complementary assays of mRNA expression profiling to determine elevated expression in pancreatic cancer tissues relative to normal pancreas tissues, and validation of protein expression by immunohistochemistry on tissue microarray, we have identified cell-surface targets with potential for imaging and therapeutic agent development. Expression profiles of 2177 cell-surface genes for 28 pancreatic tumor specimens and 4 normal pancreas tissue samples were evaluated. Expression in normal tissues was evaluated using array data from 103 samples representing 28 organ sites as well as mining published data. One-hundred seventy unique targets were highly expressed in 2 or more of the pancreatic tumor specimens and were not expressed in the normal pancreas samples. Two targets (TLR2 and ABCC3) were further validated for protein expression by tissue microarray (TMA) based immunohistochemistry. These validated targets have potential for the development of diagnostic imaging and therapeutic agents for pancreatic cancer.

  4. Tyrosine phosphorylation regulates the endocytosis and surface expression of GluN3A-containing NMDA receptors.

    PubMed

    Chowdhury, Dhrubajyoti; Marco, Sonia; Brooks, Ian M; Zandueta, Aitor; Rao, Yijian; Haucke, Volker; Wesseling, John F; Tavalin, Steven J; Pérez-Otaño, Isabel

    2013-02-27

    Selective control of receptor trafficking provides a mechanism for remodeling the receptor composition of excitatory synapses, and thus supports synaptic transmission, plasticity, and development. GluN3A (formerly NR3A) is a nonconventional member of the NMDA receptor (NMDAR) subunit family, which endows NMDAR channels with low calcium permeability and reduced magnesium sensitivity compared with NMDARs comprising only GluN1 and GluN2 subunits. Because of these special properties, GluN3A subunits act as a molecular brake to limit the plasticity and maturation of excitatory synapses, pointing toward GluN3A removal as a critical step in the development of neuronal circuitry. However, the molecular signals mediating GluN3A endocytic removal remain unclear. Here we define a novel endocytic motif (YWL), which is located within the cytoplasmic C-terminal tail of GluN3A and mediates its binding to the clathrin adaptor AP2. Alanine mutations within the GluN3A endocytic motif inhibited clathrin-dependent internalization and led to accumulation of GluN3A-containing NMDARs at the cell surface, whereas mimicking phosphorylation of the tyrosine residue promoted internalization and reduced cell-surface expression as shown by immunocytochemical and electrophysiological approaches in recombinant systems and rat neurons in primary culture. We further demonstrate that the tyrosine residue is phosphorylated by Src family kinases, and that Src-activation limits surface GluN3A expression in neurons. Together, our results identify a new molecular signal for GluN3A internalization that couples the functional surface expression of GluN3A-containing receptors to the phosphorylation state of GluN3A subunits, and provides a molecular framework for the regulation of NMDAR subunit composition with implications for synaptic plasticity and neurodevelopment. PMID:23447623

  5. PALMITATE INHIBITS INSULIN GENE EXPRESSION BY ALTERING PDX-1 NUCLEAR LOCALIZATION AND REDUCING MAFA EXPRESSION IN ISOLATED RAT ISLETS OF LANGERHANS*

    PubMed Central

    Hagman, Derek K.; Hays, Lori B.; Parazzoli, Susan D.; Poitout, Vincent

    2005-01-01

    Abnormalities in lipid metabolism have been proposed as contributing factors to both defective insulin secretion from the pancreatic beta cell and peripheral insulin resistance in type 2 diabetes. Previously, we have shown that prolonged exposure of isolated rat islets of Langerhans to excessive fatty acid levels impairs insulin gene transcription. This study was designed to assess whether palmitate alters the expression and binding activity of the key regulatory factors pancreas-duodenum homeobox-1 (PDX-1), MafA, and Beta2, which respectively bind to the A3, C1, and E1 elements in the proximal region of the insulin promoter. Nuclear extracts of isolated rat islets cultured with 0.5 mM palmitate exhibited reduced binding activity to the A3 and C1 elements, but not the E1 element. Palmitate did not affect the overall expression of PDX-1, but reduced its nuclear localization. In contrast, palmitate blocked the stimulation of MafA mRNA and protein expression by glucose. Combined, adenovirus-mediated, over-expression of PDX-1 and MafA in islets completely prevented the inhibition of insulin gene expression by palmitate. These results demonstrate that prolonged exposure of islets to palmitate inhibits insulin gene transcription by impairing nuclear localization of PDX-1 and cellular expression of MafA. PMID:15944145

  6. Teneligliptin Decreases Uric Acid Levels by Reducing Xanthine Dehydrogenase Expression in White Adipose Tissue of Male Wistar Rats

    PubMed Central

    2016-01-01

    We investigated the effects of teneligliptin on uric acid metabolism in male Wistar rats and 3T3-L1 adipocytes. The rats were fed with a normal chow diet (NCD) or a 60% high-fat diet (HFD) with or without teneligliptin for 4 weeks. The plasma uric acid level was not significantly different between the control and teneligliptin groups under the NCD condition. However, the plasma uric acid level was significantly decreased in the HFD-fed teneligliptin treated rats compared to the HFD-fed control rats. The expression levels of xanthine dehydrogenase (Xdh) mRNA in liver and epididymal adipose tissue of NCD-fed rats were not altered by teneligliptin treatment. On the other hand, Xdh expression was reduced significantly in the epididymal adipose tissue of the HFD-fed teneligliptin treated rats compared with that of HFD-fed control rats, whereas Xdh expression in liver did not change significantly in either group. Furthermore, teneligliptin significantly decreased Xdh expression in 3T3-L1 adipocytes. DPP-4 treatment significantly increased Xdh expression in 3T3-L1 adipocytes. With DPP-4 pretreatment, teneligliptin significantly decreased Xdh mRNA expression compared to the DPP-4-treated 3T3-L1 adipocytes. In conclusion, our studies suggest that teneligliptin reduces uric acid levels by suppressing Xdh expression in epididymal adipose tissue of obese subjects.

  7. Teneligliptin Decreases Uric Acid Levels by Reducing Xanthine Dehydrogenase Expression in White Adipose Tissue of Male Wistar Rats

    PubMed Central

    2016-01-01

    We investigated the effects of teneligliptin on uric acid metabolism in male Wistar rats and 3T3-L1 adipocytes. The rats were fed with a normal chow diet (NCD) or a 60% high-fat diet (HFD) with or without teneligliptin for 4 weeks. The plasma uric acid level was not significantly different between the control and teneligliptin groups under the NCD condition. However, the plasma uric acid level was significantly decreased in the HFD-fed teneligliptin treated rats compared to the HFD-fed control rats. The expression levels of xanthine dehydrogenase (Xdh) mRNA in liver and epididymal adipose tissue of NCD-fed rats were not altered by teneligliptin treatment. On the other hand, Xdh expression was reduced significantly in the epididymal adipose tissue of the HFD-fed teneligliptin treated rats compared with that of HFD-fed control rats, whereas Xdh expression in liver did not change significantly in either group. Furthermore, teneligliptin significantly decreased Xdh expression in 3T3-L1 adipocytes. DPP-4 treatment significantly increased Xdh expression in 3T3-L1 adipocytes. With DPP-4 pretreatment, teneligliptin significantly decreased Xdh mRNA expression compared to the DPP-4-treated 3T3-L1 adipocytes. In conclusion, our studies suggest that teneligliptin reduces uric acid levels by suppressing Xdh expression in epididymal adipose tissue of obese subjects. PMID:27652270

  8. Teneligliptin Decreases Uric Acid Levels by Reducing Xanthine Dehydrogenase Expression in White Adipose Tissue of Male Wistar Rats.

    PubMed

    Moriya, Chihiro; Satoh, Hiroaki

    2016-01-01

    We investigated the effects of teneligliptin on uric acid metabolism in male Wistar rats and 3T3-L1 adipocytes. The rats were fed with a normal chow diet (NCD) or a 60% high-fat diet (HFD) with or without teneligliptin for 4 weeks. The plasma uric acid level was not significantly different between the control and teneligliptin groups under the NCD condition. However, the plasma uric acid level was significantly decreased in the HFD-fed teneligliptin treated rats compared to the HFD-fed control rats. The expression levels of xanthine dehydrogenase (Xdh) mRNA in liver and epididymal adipose tissue of NCD-fed rats were not altered by teneligliptin treatment. On the other hand, Xdh expression was reduced significantly in the epididymal adipose tissue of the HFD-fed teneligliptin treated rats compared with that of HFD-fed control rats, whereas Xdh expression in liver did not change significantly in either group. Furthermore, teneligliptin significantly decreased Xdh expression in 3T3-L1 adipocytes. DPP-4 treatment significantly increased Xdh expression in 3T3-L1 adipocytes. With DPP-4 pretreatment, teneligliptin significantly decreased Xdh mRNA expression compared to the DPP-4-treated 3T3-L1 adipocytes. In conclusion, our studies suggest that teneligliptin reduces uric acid levels by suppressing Xdh expression in epididymal adipose tissue of obese subjects. PMID:27652270

  9. Enkephalins stimulate leukemia cell migration and surface expression of CD9.

    PubMed Central

    Heagy, W; Duca, K; Finberg, R W

    1995-01-01

    Opioid peptides have been implicated in the regulation of tumor growth and biology; however, little attention has been given to the mechanisms that are involved. In this study we show that physiological concentrations of the endogenous opioid neuropeptide methionine-enkephalin (MET-ENK) and the synthetic enkephalins D-Ala2, Me-Phe4, Gly(ol)5 and D-Ala2, D-Leu5 are stimulants for the in vitro migration of pre-B acute lymphoblastoid leukemia (ALL) cells. Activation of the human pre-B ALL cell lines NALM 6 and LAZ 221 with MET-ENK resulted in both an increase in their migration and an augmentation in the surface expression of the leukemia cell marker CD9. The opiate receptor antagonist naloxone reversed these enkephalin-induced effects on the leukemia cells. When the pre-B ALL cells were preincubated with an anti-CD9 mAb before challenge with MET-ENK their migration to the enkephalin was markedly reduced. These studies show that endogenous and synthetic opioid peptides are stimulants for pre-B ALL cell migration and suggest that CD9 is important in the regulation of leukemia cell motility. Images PMID:7657811

  10. Tn5 insertion mutants of Pseudomonas aeruginosa deficient in surface expression of ferripyochelin-binding protein

    SciTech Connect

    Sokol, P.A.

    1987-07-01

    Transposon (Tn5) insertion mutants were isolated in Pseudomonas aeruginosa PAO. These mutants were screened for expression of the ferripyochelin-binding protein with monoclonal antibody in a whole-cell immunoblot assay. Fourteen mutants were identified which did not express ferripyochelin-binding protein on the cell surface. These mutants did not take up /sup 59/Fe-labeled pyochelin and grew slowly in the presence of iron chelators.

  11. Investigation of chemical rinses suitable for very small meat plants to reduce pathogens on beef surfaces.

    PubMed

    Yoder, Sally F; Henning, William R; Mills, Edward W; Doores, Stephanie; Ostiguy, Nancy; Cutter, Catherine N

    2012-01-01

    Numerous antimicrobial interventions are capable of reducing the prevalence of harmful bacteria on raw meat products. There is a need to identify effective and inexpensive antimicrobial interventions that could, in practice, be used in very small meat plants because of limited financial, space, and labor resources. Eight antimicrobial compounds (acetic acid, citric acid, lactic acid, peroxyacetic acid, acidified sodium chlorite, chlorine dioxide, sodium hypochlorite, and aqueous ozone) were applied at various concentrations with small, hand-held spraying equipment, and bactericidal effectiveness was examined. Beef plate pieces were inoculated with fecal slurry containing a pathogen cocktail (Escherichia coli O157:H7, Salmonella Typhimurium, Campylobacter coli, and Campylobacter jejuni) and natural populations of aerobic plate counts, coliforms, and E. coli. Antimicrobial solutions were applied to beef surfaces via a portable, pressurized hand-held spray tank, and treated surfaces were subjected to appropriate methods for the enumeration and isolation of pathogens and hygiene indicators. Relative antimicrobial effectiveness was determined (from greatest to least): (i) organic acids, (ii) peroxyacetic acid, (iii) chlorinated compounds, and (iv) aqueous ozone. Using the equipment described, a 2% lactic acid rinse provided 3.5- to 6.4-log CFU/cm(2) reductions across all bacterial populations studied. Conversely, aqueous ozone yielded 0.02- to 2.9-log CFU/cm(2) reductions in pathogens and hygiene indicators, and did not differ significantly from a control tap water rinse (P = 0.055 to 0.731). This 2% lactic acid rinse will be subsequently combined with a previously described water wash to create a multistep antimicrobial intervention that will be examined under laboratory conditions and validated in very small meat plants. PMID:22221350

  12. Reduced MeCP2 expression is frequent in autism frontal cortex and correlates with aberrant MECP2 promoter methylation

    PubMed Central

    Nagarajan, Raman P.; Hogart, Amber R.; Gwye, Ynnez; Martin, Michelle R.; LaSalle, Janine M.

    2007-01-01

    Mutations in MECP2, encoding methyl CpG binding protein 2 (MeCP2), cause most cases of Rett syndrome (RTT), an X-linked neurodevelopmental disorder. Both RTT and autism are “pervasive developmental disorders” and share a loss of social, cognitive and language skills and a gain in repetitive stereotyped behavior, following apparently normal perinatal development. Although MECP2 coding mutations are a rare cause of autism, MeCP2 expression defects were previously found in autism brain. To further study the role of MeCP2 in autism spectrum disorders (ASDs), we determined the frequency of MeCP2 expression defects in brain samples from autism and other ASDs. We also tested the hypotheses that MECP2 promoter mutations or aberrant promoter methylation correlate with reduced expression in cases of idiopathic autism. MeCP2 immunofluorescence in autism and other neurodevelopmental disorders was quantified by laser scanning cytometry and compared with control postmortem cerebral cortex samples on a large tissue microarray. A significant reduction in MeCP2 expression compared to age-matched controls was found in 11/14 autism (79%), 9/9 RTT (100%), 4/4 Angelman syndrome (100%), 3/4 Prader-Willi syndrome (75%), 3/5 Down syndrome (60%), and 2/2 attention deficit hyperactivity disorder (100%) frontal cortex samples. One autism female was heterozygous for a rare MECP2 promoter variant that correlated with reduced MeCP2 expression. A more frequent occurrence was significantly increased MECP2 promoter methylation in autism male frontal cortex compared to controls. Furthermore, percent promoter methylation of MECP2 significantly correlated with reduced MeCP2 protein expression. These results suggest that both genetic and epigenetic defects lead to reduced MeCP2 expression and may be important in the complex etiology of autism. PMID:17486179

  13. Expression of heat shock protein 90 at the cell surface in human neuroblastoma cells

    PubMed Central

    Cid, Cristina; Regidor, Ignacio; Poveda, Pedro D.

    2008-01-01

    In addition to the activity of heat shock protein 90 (Hsp90/HSPC) as a chaperone, some recent studies have reported expression of Hsp90 at the cell surface in certain types of cancer and nervous system cells. We study the expression of Hsp90 at the cell surface in human neuroblastoma (NB69) cells. Immunofluorescence experiments labeling with anti-Hsp90 antibodies on both nonpermeabilized cells and live cells detected Hsp90 at the cell surface. Hsp90 was also identified in a membrane fraction from subcellular fractionation. Cell-surface Hsp90 was significantly more expressed in undifferentiated proliferative spherical neuroblastoma cells than in differentiated flattened cells. In addition, spherical cells were significantly more sensitive to Hsp90 inhibitor 17-allylamino-17-demethoxygeldanamycin compared to flattened cells. This paper describes the first evidence of cell-surface Hsp90 expression in a cancer cell line from nervous tissue and may indicate a novel target for anti-tumoral agents. PMID:18800240

  14. The transmembrane protein of HIV-1 primary isolates modulates cell surface expression of their envelope glycoproteins.

    PubMed

    Lebigot, S; Roingeard, P; Thibault, G; Lemiale, F; Verrier, B; Barin, F; Brand, D

    2001-11-10

    We have recently shown that the level of cell surface expression of envelope glycoproteins derived from various human immunodeficiency virus type 1 (HIV-1) primary isolates (PI) was lower than those of envelope glycoproteins derived from T-cell laboratory-adapted (TCLA) HIV-1 (D. Brand et al., 2000, Virology 271, 350-362). We investigated this phenomenon by comparing the cell surface expression of chimeric envelope glycoproteins constructed by swapping the gp120 surface and gp41 transmembrane glycoproteins of the TCLA HIV-1MN and the PI HIV-1(133), HIV-1G365, or HIV-1EFRA. We found that each chimeric envelope construct had a cell surface-specific pattern of expression similar to that of the parental envelope glycoproteins corresponding to the gp41. Thus, the difference in cell surface expression observed between TCLA viruses and various PI is probably due to a signal located in gp41. Identification of this signal may be important for the design of PI envelope-derived immunogens and may increase our understanding of the mechanisms by which HIV-1 escapes from the immune system.

  15. Femtosecond laser surface texturing of titanium as a method to reduce the adhesion of Staphylococcus aureus and biofilm formation

    NASA Astrophysics Data System (ADS)

    Cunha, Alexandre; Elie, Anne-Marie; Plawinski, Laurent; Serro, Ana Paula; Botelho do Rego, Ana Maria; Almeida, Amélia; Urdaci, Maria C.; Durrieu, Marie-Christine; Vilar, Rui

    2016-01-01

    The aim of the present work was to investigate the possibility of using femtosecond laser surface texturing as a method to reduce the colonization of Grade 2 Titanium alloy surfaces by Staphylococcus aureus and the subsequent formation of biofilm. The laser treatments were carried out with a Yb:KYW chirped-pulse-regenerative amplification laser system with a central wavelength of 1030 nm and a pulse duration of 500 fs. Two types of surface textures, consisting of laser-induced periodic surface structures (LIPSS) and nanopillars, were produced. The topography, chemical composition and phase constitution of these surfaces were investigated by atomic force microscopy, scanning electron microscopy, X-ray photoelectron spectroscopy, micro-Raman spectroscopy, and X-ray diffraction. Surface wettability was assessed by the sessile drop method using water and diiodomethane as testing liquids. The response of S. aureus put into contact with the laser treated surfaces in controlled conditions was investigated by epifluorescence microscopy and scanning electron microscopy 48 h after cell seeding. The results achieved show that the laser treatment reduces significantly the bacterial adhesion to the surface as well as biofilm formation as compared to a reference polished surfaces and suggest that femtosecond laser texturing is a simple and promising method for endowing dental and orthopedic titanium implants with antibacterial properties, reducing the risk of implant-associated infections without requiring immobilized antibacterial substances, nanoparticles or coatings.

  16. The Hedgehog Inhibitor Cyclopamine Reduces β-Catenin-Tcf Transcriptional Activity, Induces E-Cadherin Expression, and Reduces Invasion in Colorectal Cancer Cells

    PubMed Central

    Qualtrough, David; Rees, Phil; Speight, Beverley; Williams, Ann C.; Paraskeva, Christos

    2015-01-01

    Colorectal cancer is a major global health problem resulting in over 600,000 deaths world-wide every year with the majority of these due to metastatic disease. Wnt signalling, and more specifically β-catenin-related transcription, has been shown to drive both tumorigenesis and the metastatic process in colorectal neoplasia, yet its complex interactions with other key signalling pathways, such as hedgehog, remain to be elucidated. We have previously shown that the Hedgehog (HH) signalling pathway is active in cells from colorectal tumours, and that inhibition of the pathway with cyclopamine induces apoptosis. We now show that cyclopamine treatment reduces β-catenin related transcription in colorectal cancer cell lines, and that this effect can be reversed by addition of Sonic Hedgehog protein. We also show that cyclopamine concomitantly induces expression of the tumour suppressor and prognostic indicator E-cadherin. Consistent with a role for HH in regulating the invasive potential we show that cyclopamine reduces the expression of transcription factors (Slug, Snail and Twist) associated with the epithelial-mesenchymal transition and reduces the invasiveness of colorectal cancer cells in vitro. Taken together, these data show that pharmacological inhibition of the hedgehog pathway has therapeutic potential in the treatment of colorectal cancer. PMID:26393651

  17. Expression of viral EPS-depolymerase reduces fire blight susceptibility in transgenic pear.

    PubMed

    Malnoy, Mickaël; Faize, Mohamed; Venisse, Jean-Stéphane; Geider, Klaus; Chevreau, Elisabeth

    2005-02-01

    Erwinia amylovora is the causal agent of fire blight of Maloideae. One of the main pathogenicity factors of this bacterium is the exopolysaccharide (EPS) of its capsule. In this paper, we used genetic transformation tools to constitutively express an EPS-depolymerase transgene in the pear (Pyrus communis L.) cv. Passe Crassane with the aim of decreasing its high susceptibility to fire blight. Expression of the depolymerase gene in 15 independent transgenic clones led, on average, to low depolymerase activity, although relatively high expression was observed at the transcriptional and translational levels. Only two of the transgenic clones (9X and 10M) consistently showed a decrease in fire blight susceptibility in vitro and in the greenhouse. These clones were also among the highest expressers of depolymerase at the RNA and enzyme activity levels. The correlation observed among all transgenic clones between depolymerase expression and fire blight resistance suggested the potential of this strategy.

  18. High expression of Lifeact in Arabidopsis thaliana reduces dynamic reorganization of actin filaments but does not affect plant development.

    PubMed

    van der Honing, Hannie S; van Bezouwen, Laura S; Emons, Anne Mie C; Ketelaar, Tijs

    2011-10-01

    Lifeact is a novel probe that labels actin filaments in a wide range of organisms. We compared the localization and reorganization of Lifeact:Venus-labeled actin filaments in Arabidopsis root hairs and root epidermal cells of lines that express different levels of Lifeact: Venus with that of actin filaments labeled with GFP:FABD2, a commonly used probe in plants. Unlike GFP:FABD2, Lifeact:Venus labeled the highly dynamic fine F-actin in the subapical region of tip-growing root hairs. Lifeact:Venus expression at varying levels was not observed to affect plant development. However, at expression levels comparable to those of GFP:FABD2 in a well-characterized marker line, Lifeact:Venus reduced reorganization rates of bundles of actin filaments in root epidermal cells. Reorganization rates of cytoplasmic strands, which reflect the reorganization of the actin cytoskeleton, were also reduced in these lines. Moreover, in the same line, Lifeact:Venus-decorated actin filaments were more resistant to depolymerization by latrunculin B than those in an equivalent GFP:FABD2-expressing line. In lines where Lifeact: Venus is expressed at lower levels, these effects are less prominent or even absent. We conclude that Lifeact: Venus reduces remodeling of the actin cytoskeleton in Arabidopsis in a concentration-dependent manner. Since this reduction occurs at expression levels that do not cause defects in plant development, selection of normally growing plants is not sufficient to determine optimal Lifeact expression levels. When correct expression levels of Lifeact have been determined, it is a valuable probe that labels dynamic populations of actin filaments such as fine F-actin, better than FABD2 does.

  19. Analytical evaluation of a surface integral expressing the coupling between interior and exterior volumes in a FE-IE approach

    NASA Technical Reports Server (NTRS)

    Zuffada, C.; Cwik, T.; Jamnejad, V.

    1993-01-01

    Recently an approach which combines the finite element technique and an integral equation to determine the fields scattered by inhomogeneous bodies of complicated shape has been proposed. Basically, a mathematical surface which encloses the scatterers is introduced, thus dividing the space into an interior and an exterior volume, in which the finite element technique and an integral equation for EM scattering, respectively, are applied. The integral equation is set up for the tangential components of the fields at the surface, while the interior volume the unknowns are the total fields. Continuity of the tangential fields at the boundary, as required by Maxwell's equations, is imposed, thus coupling the two methods to obtain a consistent solution. The coupling term is expressed by a surface integral formed by the dot product of a FE basis function and an IE testing function, or viceversa. By choosing the boundary to be a surface of revolution and by making a convenient selection of IE basis (testing) functions, it is possible to evaluate the integrals analytically on surfaces such as curved triangles, curved quadrilaterals and curved pentagons. We will illustrate the salient steps involved in setting up and carrying out these integrals and discuss what class of basis (testing) functions and analytic surfaces of revolution they are applicable to. Analytic calculations offer the advantage of better accuracy than purely numerical ones, and, when combined with them, often shed light on issues of numerical convergence and limiting values. Furthermore, they may reduce computation time and storage requirements.

  20. Laser surface modification of medical grade alloys for reduced heating in a magnetic resonance imaging environment

    SciTech Connect

    Benafan, O. E-mail: raj@ucf.edu; Vaidyanathan, R. E-mail: raj@ucf.edu; Chen, S.-Y.; Kar, A.

    2015-12-15

    Nanoscale surface modification of medical grade metallic alloys was conducted using a neodymium-doped yttrium aluminum garnet laser-based dopant diffusion technique. The objective of this approach was to minimize the induction heating by reducing the absorbed radio frequency field. Such an approach is advantageous in that the dopant is diffused into the alloy and is not susceptible to detachment or spallation as would an externally applied coating, and is expected to not deteriorate the mechanical and electrical properties of the base alloy or device. Experiments were conducted using a controlled environment laser system with the ability to control laser properties (i.e., laser power, spot size, and irradiation time) and dopant characteristics (i.e., temperature, concentration, and pressure). The reflective and transmissive properties of both the doped and untreated samples were measured in a radio frequency (63.86 MHz) magnetic field using a system comprising a high power signal generator, a localized magnetic field source and sensor, and a signal analyzer. The results indicate an increase in the reflectivity of the laser-treated samples compared to untreated samples. The effect of reflectivity on the heating of the alloys is investigated through a mathematical model incorporating Maxwell’s equations and heat conduction.

  1. Variable Source Watershed Model for Reducing Dissolved Phosphorus Concentrations in Surface Waters

    NASA Astrophysics Data System (ADS)

    Steenhuis, T. S.; Hoang, L.; Schneiderman, E. M.; Pacenka, S.; Vermeulen, P. J.; Moore, K. E.; Owens, E. M.

    2015-12-01

    Although established procedures for treatment of point sources have been available for the last fifty years, effective and efficient management procedures for reducing non-point source pollution are still being developed. One of the reasons for the slow development is that the various management practices need to be tailored to the landscape in order to be optimal. Water quality simulation models for watersheds would be ideal for designing these effective practices but in many cases are only validated at the watershed outlet where the monitored data are available which does not guarantee that the spatial distribution of runoff and pollution sources inside the watershed are simulated correctly. Especially, in rural, humid regions where runoff is associated with saturation-excess processes from variable source areas our modeling of the hydrology and water quality is limiting. Recently, we adapted successfully a watershed model El-SWAT that realistically can simulate saturation excess surface runoff and interflow by introducing a perched water table reservoir that can transfer water via the subsurface to the wet areas in the watershed and thereby overcomes one of the major limitation of the SWAT model. For this presentation, we have combined El-SWAT with a set of spatially dependent phosphorus sub routines developed by us for simulating spatially dependent phosphorus losses in upstate New York State. In this presentation we will show its application in designing effective best management practices in the New York City Source Watersheds in the Catskill Mountains.

  2. Laser surface modification of medical grade alloys for reduced heating in a magnetic resonance imaging environment.

    PubMed

    Benafan, O; Chen, S-Y; Kar, A; Vaidyanathan, R

    2015-12-01

    Nanoscale surface modification of medical grade metallic alloys was conducted using a neodymium-doped yttrium aluminum garnet laser-based dopant diffusion technique. The objective of this approach was to minimize the induction heating by reducing the absorbed radio frequency field. Such an approach is advantageous in that the dopant is diffused into the alloy and is not susceptible to detachment or spallation as would an externally applied coating, and is expected to not deteriorate the mechanical and electrical properties of the base alloy or device. Experiments were conducted using a controlled environment laser system with the ability to control laser properties (i.e., laser power, spot size, and irradiation time) and dopant characteristics (i.e., temperature, concentration, and pressure). The reflective and transmissive properties of both the doped and untreated samples were measured in a radio frequency (63.86 MHz) magnetic field using a system comprising a high power signal generator, a localized magnetic field source and sensor, and a signal analyzer. The results indicate an increase in the reflectivity of the laser-treated samples compared to untreated samples. The effect of reflectivity on the heating of the alloys is investigated through a mathematical model incorporating Maxwell's equations and heat conduction. PMID:26724043

  3. High sea surface temperatures driven by a strengthening current reduce foraging success by penguins

    PubMed Central

    Carroll, Gemma; Everett, Jason D.; Harcourt, Robert; Slip, David; Jonsen, Ian

    2016-01-01

    The world’s oceans are undergoing rapid, regionally specific warming. Strengthening western boundary currents play a role in this phenomenon, with sea surface temperatures (SST) in their paths rising faster than the global average. To understand how dynamic oceanography influences food availability in these ocean warming “hotspots”, we use a novel prey capture signature derived from accelerometry to understand how the warm East Australian Current shapes foraging success by a meso-predator, the little penguin. This seabird feeds on low trophic level species that are sensitive to environmental change. We found that in 2012, prey capture success by penguins was high when SST was low relative to the long-term mean. In 2013 prey capture success was low, coincident with an unusually strong penetration of warm water. Overall there was an optimal temperature range for prey capture around 19–21 °C, with lower success at both lower and higher temperatures, mirroring published relationships between commercial sardine catch and SST. Spatially, higher SSTs corresponded to a lower probability of penguins using an area, and lower prey capture success. These links between high SST and reduced prey capture success by penguins suggest negative implications for future resource availability in a system dominated by a strengthening western boundary current. PMID:26923901

  4. Containment of a silicone fluid free surface in reduced gravity using barrier coatings

    NASA Technical Reports Server (NTRS)

    Pline, Alexander D.; Jacobson, Thomas P.

    1988-01-01

    In support of the Surface Tension Driven Convection Experiment planned for flight aboard the Space Shuttle, tests were conducted under reduced gravity in the 2.2-sec Drop Tower and the 5.0-sec Zero-G facility at the NASA Lewis Research Center. The dynamics of controlling the test fluid, a 10-cSt viscosity silicone fluid in a low gravity environment were investigated using different container designs and barrier coatings. Three container edge designs were tested without a barrier coating; a square edge, a sharp edge with a 45-deg slope, and a sawtooth edge. All three edge designs were successful in containing the fluid below the edge. G-jitter experiments were made in scaled down containers subjected to horizontal accelerations. The data showed that a barrier coating is effective in containing silicone fluid under g-levels up to 10 sup -1 sub g sub 0. In addition, a second barrier coating was found which has similar anti-wetting characteristics and is also more durable.

  5. Evaluation of an ATP Assay to Quantify Bacterial Attachment to Surfaces in Reduced Gravity

    NASA Technical Reports Server (NTRS)

    Birmele, Michele N.; Roberson, Luke B.; Roberts, Michael S.

    2010-01-01

    Aim: To develop an assay to quantify the biomass of attached cells and biofilm formed on wetted surfaces in variable-gravity environments. Methods and Results: Liquid cultures of Pseudomonas aeruginosa were exposed to 30-35 brief cycles of hypergravity (< 2-g) followed by free fall (i.e., reduced gravity) equivalent to either lunar-g (i.e., 0.17 normal Earth gravity) or micro-g (i.e., < 0.001 normal Earth gravity) in an aircraft flying a series of parabolas. Over the course of two days of parabolic flight testing, 504 polymer or metal coupons were exposed to a stationary-phase population of P. aeruginosa strain ERC1 at a concentration of 1.0 x 10(exp 5) cells per milliliter. After the final parabola on each flight test day, half of the material coupon samples were treated with either 400 micro-g/L ionic silver fluoride (microgravity-exposed cultures) or 1% formalin (lunar-gravity-exposed cultures). The remaining sample coupons from each flight test day were not treated with a fixative. All samples were returned to the laboratory for analysis within 2 hours of landing, and all biochemical assays were completed within 8 hours of exposure to variable gravity. The intracellular ATP luminescent assay accurately reflected cell physiology compared to both cultivation-based and direct-count microscopy analyses. Cells exposed to variable gravity had more than twice as much intracellular ATP as control cells exposed only to normal Earth gravity.

  6. Roughness distribution of multiple hit and long surface diffusion length noise reduced discrete growth models

    NASA Astrophysics Data System (ADS)

    Disrattakit, P.; Chanphana, R.; Chatraphorn, P.

    2016-11-01

    Conventionally, the universality class of a discrete growth model is identified via the scaling of interface width. This method requires large-scale simulations to minimize finite-size effects on the results. The multiple hit noise reduction techniques (m > 1 NRT) and the long surface diffusion length noise reduction techniques (ℓ > 1 NRT) have been used to promote the asymptotic behaviors of the growth models. Lately, an alternative method involving comparison of roughness distribution in the steady state has been proposed. In this work, the roughness distribution of the (2 +1)-dimensional Das Sarma-Tamborenea (DT), Wolf-Villain (WV), and Larger Curvature (LC) models, with and without NRTs, are calculated in order to investigate effects of the NRTs on the roughness distribution. Additionally, effective growth exponents of the noise reduced (2 +1)-dimensional DT, WV and LC models are also calculated. Our results indicate that the NRTs affect the interface width both in the growth and the saturation regimes. In the steady state, the NRTs do not seem to have any impact on the roughness distribution of the DT model, but it significantly changes the roughness distribution of the WV and LC models to the normal distribution curves.

  7. Surface color perception under two illuminants: the second illuminant reduces color constancy

    NASA Technical Reports Server (NTRS)

    Yang, Joong Nam; Shevell, Steven K.

    2003-01-01

    This study investigates color perception in a scene with two different illuminants. The two illuminants, in opposite corners, simultaneously shine on a (simulated) scene with an opaque dividing wall, which controls how much of the scene is illuminated by each source. In the first experiment, the height of the dividing wall was varied. This changed the amount of each illuminant reaching objects on the opposite side of the wall. Results showed that the degree of color constancy decreased when a region on one side of the wall had cues to both illuminants, suggesting that cues from the second illuminant are detrimental to color constancy. In a later experiment, color constancy was found to improve when the specular highlight cues from the second illuminant were altered to be consistent with the first illuminant. This corroborates the influence of specular highlights in surface color perception, and suggests that the reduced color constancy in the first experiment is due to the inconsistent, though physically correct, cues from the two illuminants.

  8. High sea surface temperatures driven by a strengthening current reduce foraging success by penguins.

    PubMed

    Carroll, Gemma; Everett, Jason D; Harcourt, Robert; Slip, David; Jonsen, Ian

    2016-01-01

    The world's oceans are undergoing rapid, regionally specific warming. Strengthening western boundary currents play a role in this phenomenon, with sea surface temperatures (SST) in their paths rising faster than the global average. To understand how dynamic oceanography influences food availability in these ocean warming "hotspots", we use a novel prey capture signature derived from accelerometry to understand how the warm East Australian Current shapes foraging success by a meso-predator, the little penguin. This seabird feeds on low trophic level species that are sensitive to environmental change. We found that in 2012, prey capture success by penguins was high when SST was low relative to the long-term mean. In 2013 prey capture success was low, coincident with an unusually strong penetration of warm water. Overall there was an optimal temperature range for prey capture around 19-21 °C, with lower success at both lower and higher temperatures, mirroring published relationships between commercial sardine catch and SST. Spatially, higher SSTs corresponded to a lower probability of penguins using an area, and lower prey capture success. These links between high SST and reduced prey capture success by penguins suggest negative implications for future resource availability in a system dominated by a strengthening western boundary current. PMID:26923901

  9. Laser surface modification of medical grade alloys for reduced heating in a magnetic resonance imaging environment.

    PubMed

    Benafan, O; Chen, S-Y; Kar, A; Vaidyanathan, R

    2015-12-01

    Nanoscale surface modification of medical grade metallic alloys was conducted using a neodymium-doped yttrium aluminum garnet laser-based dopant diffusion technique. The objective of this approach was to minimize the induction heating by reducing the absorbed radio frequency field. Such an approach is advantageous in that the dopant is diffused into the alloy and is not susceptible to detachment or spallation as would an externally applied coating, and is expected to not deteriorate the mechanical and electrical properties of the base alloy or device. Experiments were conducted using a controlled environment laser system with the ability to control laser properties (i.e., laser power, spot size, and irradiation time) and dopant characteristics (i.e., temperature, concentration, and pressure). The reflective and transmissive properties of both the doped and untreated samples were measured in a radio frequency (63.86 MHz) magnetic field using a system comprising a high power signal generator, a localized magnetic field source and sensor, and a signal analyzer. The results indicate an increase in the reflectivity of the laser-treated samples compared to untreated samples. The effect of reflectivity on the heating of the alloys is investigated through a mathematical model incorporating Maxwell's equations and heat conduction.

  10. Laser surface modification of medical grade alloys for reduced heating in a magnetic resonance imaging environment

    NASA Astrophysics Data System (ADS)

    Benafan, O.; Chen, S.-Y.; Kar, A.; Vaidyanathan, R.

    2015-12-01

    Nanoscale surface modification of medical grade metallic alloys was conducted using a neodymium-doped yttrium aluminum garnet laser-based dopant diffusion technique. The objective of this approach was to minimize the induction heating by reducing the absorbed radio frequency field. Such an approach is advantageous in that the dopant is diffused into the alloy and is not susceptible to detachment or spallation as would an externally applied coating, and is expected to not deteriorate the mechanical and electrical properties of the base alloy or device. Experiments were conducted using a controlled environment laser system with the ability to control laser properties (i.e., laser power, spot size, and irradiation time) and dopant characteristics (i.e., temperature, concentration, and pressure). The reflective and transmissive properties of both the doped and untreated samples were measured in a radio frequency (63.86 MHz) magnetic field using a system comprising a high power signal generator, a localized magnetic field source and sensor, and a signal analyzer. The results indicate an increase in the reflectivity of the laser-treated samples compared to untreated samples. The effect of reflectivity on the heating of the alloys is investigated through a mathematical model incorporating Maxwell's equations and heat conduction.

  11. Novel SPAST deletion and reduced DPY30 expression in a Spastic Paraplegia type 4 kindred

    PubMed Central

    2014-01-01

    Background The hereditary spastic paraplegias (HSPs) are pleiomorphic disorders of motor pathway and a large number of affected genes have been discovered. Yet, mutations in SPG4/SPAST represent the most frequent molecular etiology in autosomal dominant (AD) patients and sporadic cases. We describe a large, AD-HSP Sardinian family where 5 out of several living members harbored a novel deletion affecting also the 5′UTR of SPAST and resulting in reduced expression of DPY30, the gene located upstream SPAST in a head-to-head manner. Case presentation A 54-year-old woman manifested leg stiffness at age 39 and required a cane to walk at age 50. Neurological examination disclosed mild spasticity and weakness in the legs, hyperreflexia in all limbs, and bilateral Babinski sign. She also complained of urinary urgency, but no additional neurological symptoms or signs were detected at examination. The clinical examination of 24 additional relatives disclosed three further affected individuals, two men and one woman. In the four symptomatic patients the initial manifestations were walking abnormalities and leg stiffness with a mean age at onset (SD) of 46.75 (5.44) years (range 39–51). The mean disease duration was 13.2 (13.4) years (range 6–35), and it correlated well with clinical severity (SPRS score) (r = 0.975, p = 0.005). One patient was confined to bed and displayed knee and ankle contractures, another case needed a cane to walk, and two individuals were able to walk without aids. Interestingly, a patient had also had a miscarriage during her first pregnancy. Gene testing revealed an heterozygous deletion spanning from the 5′-UTR to intron 4 of SPAST in the affected individuals and in one clinically unaffected woman. In three affected patients, the deletion also determined low mRNA levels of SPAST and DPY30, a component of the Set1-like multiprotein histone methyltransferase complex located upstream, head-to-head with SPAST. Conclusion Together with data

  12. Impact of enzymatic tissue disintegration on the level of surface molecule expression and immune cell function

    PubMed Central

    Autengruber, A.; Gereke, M.; Hansen, G.; Hennig, C.; Bruder, D.

    2012-01-01

    Immunological characterization of immune cells that reside in specific anatomic compartments often requires their isolation from the respective tissue on the basis of enzymatic tissue disintegration. Applying enzymatic digestion of primary splenocytes, we evaluated the impact of collagenase and dispase, two enzymes that are commonly used for the liberation of immune cells from tissues, on the detectability of 48 immunologically relevant surface molecules that are frequently used for flow cytometric identification, isolation, and characterization of immune cell subsets. Whereas collagenase treatment had only minor effects on surface expression of most molecules tested, dispase treatment considerably affected antibody-mediated detectability of the majority of surface markers in subsequent FACS analyses. This effect was long lasting and, in case of high-dose dispase treatment, evident for the majority of surface molecules even after 24 h of in vitro culture. Of note, high-dose dispase treatment not only affected surface expression of certain molecules but also impaired antigen-specific proliferation of CD4+ and CD8+ T cells. Together, our data indicate that enzymatic tissue disintegration can have profound effects on the expression of a variety of cell-surface molecules with direct consequences for phenotypic analysis, FACS- and MACS-based target cell isolation, and immune cell function in cell culture experiments. PMID:24672679

  13. Overwintering Is Associated with Reduced Expression of Immune Genes and Higher Susceptibility to Virus Infection in Honey Bees.

    PubMed

    Steinmann, Nadja; Corona, Miguel; Neumann, Peter; Dainat, Benjamin

    2015-01-01

    The eusocial honey bee, Apis mellifera, has evolved remarkable abilities to survive extreme seasonal differences in temperature and availability of resources by dividing the worker caste into two groups that differ in physiology and lifespan: summer and winter bees. Most of the recent major losses of managed honey bee colonies occur during the winter, suggesting that winter bees may have compromised immune function and higher susceptibility to diseases. We tested this hypothesis by comparing the expression of eight immune genes and naturally occurring infection levels of deformed wing virus (DWV), one of the most widespread viruses in A. mellifera populations, between summer and winter bees. Possible interactions between immune response and physiological activity were tested by measuring the expression of vitellogenin and methyl farnesoate epoxidase, a gene coding for the last enzyme involved in juvenile hormone biosynthesis. Our data show that high DWV loads in winter bees correlate with reduced expression of genes involved in the cellular immune response and physiological activity and high expression of humoral immune genes involved in antibacterial defense compared with summer bees. This expression pattern could reflect evolutionary adaptations to resist bacterial pathogens and economize energy during the winter under a pathogen landscape with reduced risk of pathogenic viral infections. The outbreak of Varroa destructor infestation could have overcome these adaptations by promoting the transmission of viruses. Our results suggest that reduced cellular immune function during the winter may have increased honey bee's susceptibility to DWV. These results contribute to our understanding of honey bee colony losses in temperate regions.

  14. Reversing the reduced level of endometrial GLUT4 expression in polycystic ovary syndrome: a mechanistic study of metformin action

    PubMed Central

    Li, Xin; Cui, Peng; Jiang, Hong-Yuan; Guo, Yan-Rong; Pishdari, Bano; Hu, Min; Feng, Yi; Billig, Håkan; Shao, Ruijin

    2015-01-01

    Conflicting results have been reported regarding whether or not insulin-regulated glucose transporter 4 (GLUT4) is expressed in human and rodent endometria. There is an inverse relationship between androgen levels and insulin-dependent glucose metabolism in women. Hyperandrogenemia, hyperinsulinemia, and insulin resistance are believed to contribute to endometrial abnormalities in women with polycystic ovary syndrome (PCOS). However, it has been unclear in previous studies if endometrial GLUT4 expression is regulated by androgen-dependent androgen receptors (ARs) and/or the insulin receptor/Akt/mTOR signaling network. In this study, we demonstrate that GLUT4 is expressed in normal endometrial cells (mainly in the epithelial cells) and is down-regulated under conditions of hyperandrogenemia in tissues from PCOS patients and in a 5α-dihydrotestosterone-induced PCOS-like rat model. Western blot analysis revealed reduced endometrial GLUT4 expression and increased AR expression in PCOS patients. However, the reduced GLUT4 level was not always associated with an increase in AR in PCOS patients when comparing non-hyperplasia with hyperplasia. Using a human tissue culture system, we investigated the molecular basis by which GLUT4 regulation in endometrial hyperplasia tissues is affected by metformin in PCOS patients. We show that specific endogenous organic cation transporter isoforms are regulated by metformin, and this suggests a direct effect of metformin on endometrial hyperplasia. Moreover, we demonstrate that metformin induces GLUT4 expression and inhibits AR expression and blocks insulin receptor/PI3K/Akt/mTOR signaling in the same hyperplasia human tissues. These findings indicate that changes in endometrial GLUT4 expression in PCOS patients involve the androgen-dependent alteration of AR expression and changes in the insulin receptor/PI3K/Akt/mTOR signaling network. PMID:26045896

  15. Reversing the reduced level of endometrial GLUT4 expression in polycystic ovary syndrome: a mechanistic study of metformin action.

    PubMed

    Li, Xin; Cui, Peng; Jiang, Hong-Yuan; Guo, Yan-Rong; Pishdari, Bano; Hu, Min; Feng, Yi; Billig, Håkan; Shao, Ruijin

    2015-01-01

    Conflicting results have been reported regarding whether or not insulin-regulated glucose transporter 4 (GLUT4) is expressed in human and rodent endometria. There is an inverse relationship between androgen levels and insulin-dependent glucose metabolism in women. Hyperandrogenemia, hyperinsulinemia, and insulin resistance are believed to contribute to endometrial abnormalities in women with polycystic ovary syndrome (PCOS). However, it has been unclear in previous studies if endometrial GLUT4 expression is regulated by androgen-dependent androgen receptors (ARs) and/or the insulin receptor/Akt/mTOR signaling network. In this study, we demonstrate that GLUT4 is expressed in normal endometrial cells (mainly in the epithelial cells) and is down-regulated under conditions of hyperandrogenemia in tissues from PCOS patients and in a 5α-dihydrotestosterone-induced PCOS-like rat model. Western blot analysis revealed reduced endometrial GLUT4 expression and increased AR expression in PCOS patients. However, the reduced GLUT4 level was not always associated with an increase in AR in PCOS patients when comparing non-hyperplasia with hyperplasia. Using a human tissue culture system, we investigated the molecular basis by which GLUT4 regulation in endometrial hyperplasia tissues is affected by metformin in PCOS patients. We show that specific endogenous organic cation transporter isoforms are regulated by metformin, and this suggests a direct effect of metformin on endometrial hyperplasia. Moreover, we demonstrate that metformin induces GLUT4 expression and inhibits AR expression and blocks insulin receptor/PI3K/Akt/mTOR signaling in the same hyperplasia human tissues. These findings indicate that changes in endometrial GLUT4 expression in PCOS patients involve the androgen-dependent alteration of AR expression and changes in the insulin receptor/PI3K/Akt/mTOR signaling network. PMID:26045896

  16. CD117 expression in breast phyllodes tumors correlates with adverse pathologic parameters and reduced survival.

    PubMed

    Tan, Wai Jin; Thike, Aye Aye; Tan, Sie Yong; Tse, Gary M-K; Tan, Min-Han; Bay, Boon Huat; Tan, Puay Hoon

    2015-03-01

    CD117 (c-kit) is a type III receptor tyrosine kinase encoded by the KIT gene. Deregulation of expression and mutations in the gene are implicated in various tumors. Reports of CD117 expression in phyllodes tumors have been controversial. We aim to investigate the protein expression of CD117 and mutations in the KIT gene in phyllodes tumors, and correlate the findings with pathological parameters and clinical outcome. A total of 272 cases were included in this study. CD117 expression was investigated by immunohistochemistry on tissue microarray sections. Toluidine blue staining was performed to indicate mast cells. Overall, 28 (10%) cases were CD117 positive. CD117 expression was significantly associated with tumor grade (P<0.001), increased stromal hypercellularity (P=0.003), stromal atypia (P=0.01), and stromal mitotic activity (P<0.001), permeative microscopic margins (P=0.002), and presence of hemorrhage (P=0.001). Expression was also associated with poorer overall survival (P=0.003). Nineteen cases were further selected for mutation screening through the Affymetrix OncoScan platform. No mutation of the KIT gene was found. Despite a lack of mutations in the KIT gene, CD117 protein expression is associated with unfavorable pathological parameters and poorer prognosis, suggesting an underlying role in the biology of phyllodes tumors.

  17. Heparanase Overexpression Reduces Hepcidin Expression, Affects Iron Homeostasis and Alters the Response to Inflammation

    PubMed Central

    Asperti, Michela; Stuemler, Tanja; Poli, Maura; Gryzik, Magdalena; Lifshitz, Lena; Meyron-Holtz, Esther G.; Vlodavsky, Israel

    2016-01-01

    Hepcidin is the key regulator of systemic iron availability that acts by controlling the degradation of the iron exporter ferroportin. It is expressed mainly in the liver and regulated by iron, inflammation, erythropoiesis and hypoxia. The various agents that control its expression act mainly via the BMP6/SMAD signaling pathway. Among them are exogenous heparins, which are strong hepcidin repressors with a mechanism of action not fully understood but that may involve the competition with the structurally similar endogenous Heparan Sulfates (HS). To verify this hypothesis, we analyzed how the overexpression of heparanase, the HS degrading enzyme, modified hepcidin expression and iron homeostasis in hepatic cell lines and in transgenic mice. The results showed that transient and stable overexpression of heparanase in HepG2 cells caused a reduction of hepcidin expression and of SMAD5 phosphorylation. Interestingly, the clones showed also altered level of TfR1 and ferritin, indices of a modified iron homeostasis. The heparanase transgenic mice showed a low level of liver hepcidin, an increase of serum and liver iron with a decrease in spleen iron content. The hepcidin expression remained surprisingly low even after treatment with the inflammatory LPS. The finding that modification of HS structure mediated by heparanase overexpression affects hepcidin expression and iron homeostasis supports the hypothesis that HS participate in the mechanisms controlling hepcidin expression. PMID:27711215

  18. Lifelong expression of apolipoprotein D in the human brainstem: correlation with reduced age-related neurodegeneration.

    PubMed

    Navarro, Ana; Méndez, Elena; Diaz, Celso; del Valle, Eva; Martínez-Pinilla, Eva; Ordóñez, Cristina; Tolivia, Jorge

    2013-01-01

    The lipocalin apolipoprotein D (Apo D) is upregulated in peripheral nerves following injury and in regions of the central nervous system, such as the cerebral cortex, hippocampus, and cerebellum, during aging and progression of certain neurological diseases. In contrast, few studies have examined Apo D expression in the brainstem, a region necessary for survival and generally less prone to age-related degeneration. We measured Apo D expression in whole human brainstem lysates by slot-blot and at higher spatial resolution by quantitative immunohistochemistry in eleven brainstem nuclei (the 4 nuclei of the vestibular nuclear complex, inferior olive, hypoglossal nucleus, oculomotor nucleus, facial motor nucleus, nucleus of the solitary tract, dorsal motor nucleus of the vagus nerve, and Roller`s nucleus). In contrast to cortex, hippocampus, and cerebellum, apolipoprotein D was highly expressed in brainstem tissue from subjects (N = 26, 32-96 years of age) with no history of neurological disease, and expression showed little variation with age. Expression was significantly stronger in somatomotor nuclei (hypoglossal, oculomotor, facial) than visceromotor or sensory nuclei. Both neurons and glia expressed Apo D, particularly neurons with larger somata and glia in the periphery of these brainstem centers. Immunostaining was strongest in the neuronal perinuclear region and absent in the nucleus. We propose that strong brainstem expression of Apo D throughout adult life contributes to resistance against neurodegenerative disease and age-related degeneration, possibly by preventing oxidative stress and ensuing lipid peroxidation.

  19. Lifelong Expression of Apolipoprotein D in the Human Brainstem: Correlation with Reduced Age-Related Neurodegeneration

    PubMed Central

    Navarro, Ana; Méndez, Elena; Diaz, Celso; del Valle, Eva; Martínez-Pinilla, Eva; Ordóñez, Cristina; Tolivia, Jorge

    2013-01-01

    The lipocalin apolipoprotein D (Apo D) is upregulated in peripheral nerves following injury and in regions of the central nervous system, such as the cerebral cortex, hippocampus, and cerebellum, during aging and progression of certain neurological diseases. In contrast, few studies have examined Apo D expression in the brainstem, a region necessary for survival and generally less prone to age-related degeneration. We measured Apo D expression in whole human brainstem lysates by slot-blot and at higher spatial resolution by quantitative immunohistochemistry in eleven brainstem nuclei (the 4 nuclei of the vestibular nuclear complex, inferior olive, hypoglossal nucleus, oculomotor nucleus, facial motor nucleus, nucleus of the solitary tract, dorsal motor nucleus of the vagus nerve, and Roller`s nucleus). In contrast to cortex, hippocampus, and cerebellum, apolipoprotein D was highly expressed in brainstem tissue from subjects (N = 26, 32−96 years of age) with no history of neurological disease, and expression showed little variation with age. Expression was significantly stronger in somatomotor nuclei (hypoglossal, oculomotor, facial) than visceromotor or sensory nuclei. Both neurons and glia expressed Apo D, particularly neurons with larger somata and glia in the periphery of these brainstem centers. Immunostaining was strongest in the neuronal perinuclear region and absent in the nucleus. We propose that strong brainstem expression of Apo D throughout adult life contributes to resistance against neurodegenerative disease and age-related degeneration, possibly by preventing oxidative stress and ensuing lipid peroxidation. PMID:24167586

  20. Ovarian Hormone Deprivation Reduces Oxytocin Expression in Paraventricular Nucleus Preautonomic Neurons and Correlates with Baroreflex Impairment in Rats

    PubMed Central

    De Melo, Vitor U.; Saldanha, Rayssa R. M.; Dos Santos, Carla R.; De Campos Cruz, Josiane; Lira, Vitor A.; Santana-Filho, Valter J.; Michelini, Lisete C.

    2016-01-01

    The prevalence of cardiovascular diseases including hypertension increases dramatically in women after menopause, however the mechanisms involved remain incompletely understood. Oxytocinergic (OTergic) neurons are largely present within the paraventricular nucleus of the hypothalamus (PVN). Several studies have shown that OTergic drive from PVN to brainstem increases baroreflex sensitivity and improves autonomic control of the circulation. Since preautonomic PVN neurons express different types of estrogen receptors, we hypothesize that ovarian hormone deprivation causes baroreflex impairment, autonomic imbalance and hypertension by negatively impacting OTergic drive and oxytocin levels in pre-autonomic neurons. Here, we assessed oxytocin gene and protein expression (qPCR and immunohistochemistry) within PVN subnuclei in sham-operated and ovariectomized Wistar rats. Conscious hemodynamic recordings were used to assess resting blood pressure and heart rate and the autonomic modulation of heart and vessels was estimated by power spectral analysis. We observed that the ovarian hormone deprivation in ovariectomized rats decreased baroreflex sensitivity, increased sympathetic and reduced vagal outflows to the heart and augmented the resting blood pressure. Of note, ovariectomized rats had reduced PVN oxytocin mRNA and protein expression in all pre-autonomic PVN subnuclei. Furthermore, reduced PVN oxytocin protein levels were positively correlated with decreased baroreflex sensitivity and negatively correlated with increased LF/HF ratio. These findings suggest that reduced oxytocin expression in OTergic neurons of the PVN contributes to the baroreflex dysfunction and autonomic dysregulation observed with ovarian hormone deprivation. PMID:27790154

  1. PHTHALATE ESTER-INDUCED GUBERNACULAR LESIONS ARE ASSOCIATED WITH REDUCED INSL-3 GENE EXPRESSION IN THE FETAL RAT TESTIS

    EPA Science Inventory

    Phthalate ester-induced gubernacular ligament lesions are associated with reduced Insl3 gene expression in the fetal rat testis during sexual differentiation.
    VS Wilson, C Lambright, J Furr, J Ostby, C Wood, G Held, LE Gray Jr.
    U.S. EPA, ORD, NHEERL, Reproductive Toxicology...

  2. Hypoxia reduces constitutive and TNF-{alpha}-induced expression of monocyte chemoattractant protein-1 in human proximal renal tubular cells

    SciTech Connect

    Li Xuan; Kimura, Hideki . E-mail: hkimura@fmsrsa.fukui-med.ac.jp; Hirota, Kiichi; Sugimoto, Hidehiro; Yoshida, Haruyoshi

    2005-10-07

    Chronic hypoxia has been reported to be associated with macrophage infiltration in progressive forms of kidney disease. Here, we investigated the regulatory effects of hypoxia on constitutive and TNF-{alpha}-stimulated expression of monocyte chemoattractant protein-1 (MCP-1) in cultured human proximal renal tubular cells (HPTECs). Hypoxia reduced constitutive MCP-1 expression at the mRNA and protein levels in a time-dependent fashion for up to 48 h. Hypoxia also inhibited MCP-1 up-regulation by TNF-{alpha}. Treatment with actinomycin D showed that hypoxic down-regulation of MCP-1 expression resulted mainly from a decrease in the transcription but not the mRNA stability. Immunoblot and immunofluorescence analyses revealed that treatment with hypoxia or an iron chelator, desferrioxamine, induced nuclear accumulation of hypoxia-inducible factor-1{alpha} (HIF-1{alpha}) in HPTECs. Desferrioxamine mimicked hypoxia in the reduction of MCP-1 expression. However, overexpression of a dominant negative form of HIF-1{alpha} did not abolish the hypoxia-induced reduction of MCP-1 expression in HPTECs. These results suggest that hypoxia is an important negative regulator of monocyte chemotaxis to the renal inflamed interstitium, by reducing MCP-1 expression partly via hypoxia-activated signals other than the HIF-1 pathway.

  3. Momilactione B inhibits protein kinase A signaling and reduces tyrosinase-related proteins 1 and 2 expression in melanocytes.

    PubMed

    Lee, Ji Hae; Cho, Boram; Jun, Hee-jin; Seo, Woo-Duck; Kim, Dong-Woo; Cho, Kang-Jin; Lee, Sung-Joon

    2012-05-01

    Momilactone B (MB) is a terpenoid phytoalexin present in rice bran that exhibits several biological activities. MB reduced the melanin content in B16 melanocytes melanin content and inhibited tyrosinase activities. Using transcriptome analysis, the genes involved in protein kinase A (PKA) signaling were found to be markedly altered. B16 cells stimulated with MB had decreased concentrations of cAMP protein kinase A activity, and cAMP-response element-binding protein which is a key transcription factor for microphthalmia-associated transcription factor (MITF) expression. Accordingly, the expression of MITF and its target genes, which are essential for melanogenesis, were reduced. MB thus exhibits anti-melanogenic effects by repressing tyrosinase enzyme activity and inhibiting the PKA signaling pathway which, in turn, decreases melanogenic gene expression.

  4. Cardiac β-Adrenoceptor Expression Is Reduced in Zucker Diabetic Fatty Rats as Type-2 Diabetes Progresses

    PubMed Central

    Haley, James M.; Thackeray, James T.; Thorn, Stephanie L.; DaSilva, Jean N.

    2015-01-01

    Objectives Reduced cardiac β-adrenoceptor (β-AR) expression and cardiovascular dysfunction occur in models of hyperglycemia and hypoinsulinemia. Cardiac β-AR expression in type-2 diabetes models of hyperglycemia and hyperinsulinemia, remain less clear. This study investigates cardiac β-AR expression in type-2 diabetic Zucker diabetic fatty (ZDF) rats. Methods Ex vivo biodistribution experiments with [3H]CGP12177 were performed in Zucker lean (ZL) and ZDF rats at 10 and 16 weeks of age as diabetes develops. Blood glucose, body mass, and diet consumption were measured. Western blotting of β-AR subtypes was completed in parallel. Echocardiography was performed at 10 and 16 weeks to assess systolic and diastolic function. Fasted plasma insulin, free fatty acids (FFA), leptin and fed-state insulin were also measured. Results At 10 weeks, myocardial [3H]CGP12177 was normal in hyperglycemic ZDF (17±4.1mM) compared to ZL, but reduced 16-25% at 16 weeks of age as diabetes and hyperglycemia (22±2.4mM) progressed. Reduced β-AR expression not apparent at 10 weeks also developed by 16 weeks of age in ZDF brown adipose tissue. In the heart, Western blotting at 10 weeks indicated normal β1-AR (98±9%), reduced β2-AR (76±10%), and elevated β3-AR (108±6). At 16 weeks, β1-AR expression became reduced (69±16%), β2-AR expression decreased further (68±14%), and β3-AR remained elevated, similar to 10 weeks (112±9%). While HR was reduced at 10 and 16 weeks in ZDF rats, no significant changes were observed in diastolic or systolic function. Conclusions Cardiac β-AR are reduced over 6 weeks of sustained hyperglycemia in type-2 diabetic ZDF rats. This indicates cardiac [3H]CGP12177 retention and β1- and β2-AR expression are inversely correlated with the progression of type-2 diabetes. PMID:25996498

  5. Surface expression, peptide repertoire, and thermostability of chicken class I molecules correlate with peptide transporter specificity

    PubMed Central

    Tregaskes, Clive A.; Harrison, Michael; Sowa, Anna K.; van Hateren, Andy; Hunt, Lawrence G.; Vainio, Olli; Kaufman, Jim

    2016-01-01

    The chicken major histocompatibility complex (MHC) has strong genetic associations with resistance and susceptibility to certain infectious pathogens. The cell surface expression level of MHC class I molecules varies as much as 10-fold between chicken haplotypes and is inversely correlated with diversity of peptide repertoire and with resistance to Marek’s disease caused by an oncogenic herpesvirus. Here we show that the average thermostability of class I molecules isolated from cells also varies, being higher for high-expressing MHC haplotypes. However, we find roughly the same amount of class I protein synthesized by high- and low-expressing MHC haplotypes, with movement to the cell surface responsible for the difference in expression. Previous data show that chicken TAP genes have high allelic polymorphism, with peptide translocation specific for each MHC haplotype. Here we use assembly assays with peptide libraries to show that high-expressing B15 class I molecules can bind a much wider variety of peptides than are found on the cell surface, with the B15 TAPs restricting the peptides available. In contrast, the translocation specificity of TAPs from the low-expressing B21 haplotype is even more permissive than the promiscuous binding shown by the dominantly expressed class I molecule. B15/B21 heterozygote cells show much greater expression of B15 class I molecules than B15/B15 homozygote cells, presumably as a result of receiving additional peptides from the B21 TAPs. Thus, chicken MHC haplotypes vary in several correlated attributes, with the most obvious candidate linking all these properties being molecular interactions within the peptide-loading complex (PLC). PMID:26699458

  6. Loss of HuR Is Linked to Reduced Expression of Proliferative Genes during Replicative Senescence

    PubMed Central

    Wang, Wengong; Yang, Xiaoling; Cristofalo, Vincent J.; Holbrook, Nikki J.; Gorospe, Myriam

    2001-01-01

    Cellular aging is accompanied by alterations in gene expression patterns. Here, using two models of replicative senescence, we describe the influence of the RNA-binding protein HuR in regulating the expression of several genes whose expression decreases during senescence. We demonstrate that HuR levels, HuR binding to target mRNAs encoding proliferative genes, and the half-lives of such mRNAs are lower in senescent cells. Importantly, overexpression of HuR in senescent cells restored a “younger” phenotype, while a reduction in HuR expression accentuated the senescent phenotype. Our studies highlight a critical role for HuR during the process of replicative senescence. PMID:11486028

  7. Maternal protein restriction reduces expression of angiotensin I-converting enzyme 2 in rat placental labyrinth zone in late pregnancy.

    PubMed

    Gao, Haijun; Yallampalli, Uma; Yallampalli, Chandra

    2012-02-01

    Both the systemic and the uteroplacental renin-angiotensin system (RAS) display dramatic changes during pregnancy. However, whether gestational protein insufficiency affects the expressions of RAS in the placenta remains unknown. In this study, we hypothesized that the expression of Ace2 in the placental labyrinth was reduced by maternal protein restriction. Pregnant Sprague-Dawley rats were fed a normal diet or a low-protein diet (LP) from Day 1 of pregnancy until they were killed at Day 14 or Day 18. The labyrinth zone (LZ) of the placenta was then dissected and snap frozen for expression analysis by quantitative real-time PCR of Ace, Ace2, Agtr1a, Agtr1b, and Agtr2. Formalin-fixed placentas were used for immunohistochemical analysis on ACE and ACE2 proteins. The findings include 1) the expression of Ace2 in rat LZ was reduced by maternal protein restriction in late pregnancy; 2) ACE protein was mainly present in syncytiotrophoblasts, whereas ACE2 protein was found predominantly in fetal mesenchymal tissue and fetal capillaries; 3) Agtr1a was predominant in the rat LZ, and its mRNA levels, but not protein levels, were reduced by LP; 4) expressions of Ace, Ace2, and Agtr1a in the rat LZ and their response to LP occurred in a gender-dependent manner. These results may indicate that a reduced expression of Ace2 and perhaps an associated reduction in angiotensin (1-7) production in the placenta by maternal protein restriction may be responsible for fetal growth restriction and associated programming of adulthood hypertension.

  8. Association of NDRG1 gene promoter methylation with reduced NDRG1 expression in gastric cancer cells and tissue specimens.

    PubMed

    Chang, Xiaojing; Zhang, Shuanglong; Ma, Jinguo; Li, Zhenhua; Zhi, Yu; Chen, Jing; Lu, Yao; Dai, Dongqiu

    2013-05-01

    NDRG1 (N-myc downstream-regulated gene 1) plays a role in cell differentiation and suppression of tumor metastasis. This study aims to determine the expression of NDRG1 mRNA and protein in gastric cancer cell lines and tissue specimens and then assess the possible cause of its aberrant expression. Six gastric cancer cell lines and 20 pairs of normal and gastric cancer tissue samples were used to assess NDRG1 expression using Real-time PCR and Western blot. High-resolution melting analysis (HRM) and methylation-specific PCR (MSP) were performed to detect gene mutation and methylation, respectively, in cell lines and tissues samples. Expression of NDRG1 mRNA and protein was downregulated in gastric cancer cell lines and tissues. Specifically, expression of NDRG1 mRNA and protein was lower in all six gastric cancer cell lines than that of normal gastric cells, while 15 out of 20 cases of gastric cancer tissues had the reduced levels of NDRG1 mRNA and protein. HRM data showed that there was no mutation in NDRG1 gene, but MSP data showed high levels of NDRG1 gene promoter methylation in the CpG islands in both cell lines and tissue samples. Moreover, treatment with the DNA methyltransferase inhibitor 5-Aza-2'-deoxycytidine upregulated NDRG1 expression in gastric cancer HGC27 cells, but not in the histone deacetylase inhibitor trichostatin A-treated HGC27 cells. In conclusion, this study has shown that expression of NDRG1 mRNA and protein was reduced in gastric cancer cell lines and tissues, which is due to methylation of NDRG1 gene promoter. Further study will unearth the clinical significance of the reduced NDRG1 protein in gastric cancer.

  9. Weight-loss changes PPAR expression, reduces atherosclerosis and improves cardiovascular function in obese insulin-resistant mice

    SciTech Connect

    Verreth, Wim; Verhamme, Peter; Pelat, Michael; Ganame, Javier; Bielicki, John K.; Mertens, Ann; Quarck, Rozenn; Benhabiles, Nora; Marguerie, Gerard; Mackness, Bharti; Mackness, Mike; Ninio, Ewa; Herregods, Marie-Christine; Balligand, Jean-Luc; Holvoet, Paul

    2003-09-01

    Weight-loss in obese insulin-resistant, but not in insulin-sensitive, persons reduces CHD risk. It is not known to what extent changes in the adipose gene expression profile are important for reducing CHD risk. We studied the effect of diet restriction-induced weight-loss on gene expression in adipose tissue, atherosclerosis and cardiovascular function in mice with combined leptin and LDL-receptor deficiency. Obesity, hypertriglyceridemia and insulin-resistance are associated with hypertension, impaired left ventricle function and accelerated atherosclerosis in those mice. Diet restriction during 12 weeks caused a 45% weight-loss and changes in the gene expression in adipose tissue of PPARa and PPAR? and of key genes regulating glucose transport and insulin sensitivity, lipid metabolism, oxidative stress and inflammation, most of which are under the transcriptional control of PPARs. These changes were associated with increased insulin-sensitivity, decreased hypertriglyceridemia, reduced mean 24-hour blood pressure and heart rate, restored circadian variations of blood pressure and heart rate, increased ejection fraction, and reduced atherosclerosis. Thus, induction of PPARa and PPAR? in adipose tissue is a key mechanism for reducing atherosclerosis and improving cardiovascular function resulting from weight-loss. Our observations point to the critical role of PPARs in the pathogenesis of cardiovascular features of the metabolic syndrome.

  10. Surface Expression of NMDA Receptor Changes during Memory Consolidation in the Crab "Neohelice granulata"

    ERIC Educational Resources Information Center

    Hepp, Yanil; Salles, Angeles; Carbo-Tano, Martin; Pedreira, Maria Eugenia; Freudenthal, Ramiro

    2016-01-01

    The aim of the present study was to analyze the surface expression of the NMDA-like receptors during the consolidation of contextual learning in the crab "Neohelice granulata". Memory storage is based on alterations in the strength of synaptic connections between neurons. The glutamatergic synapses undergo various forms of…

  11. Reduced Surface Ocean Temperature Variability in the Eastern Equatorial Pacific During the Late Glacial Maximum

    NASA Astrophysics Data System (ADS)

    Ford, H. L.; Ravelo, A. C.; Polissar, P. J.

    2012-12-01

    El Niño-Southern Oscillation is the largest source of global interannual variability with far-reaching climatic effects. Climate model simulations of future warming exhibit widely divergent behavior indicating an incomplete understanding of the factors that dictate tropical climate variability. Generating records of past tropical Pacific variability during times with different climate states is one approach to deepening our understanding of tropical climate change processes and improving predictions of future change. Here we reconstruct tropical Pacific ocean variability from the Last Glacial Maximum (LGM) and from the Holocene at ODP Sites 806 and 849, located in the western equatorial Pacific (WEP) warm pool and eastern equatorial Pacific (EEP) cold tongue, respectively. We reconstruct ocean temperature variability using the intra-sample distribution of Mg/Ca values from individual foraminifera. Sea surface temperature variability is reconstructed from individual specimens of G. sacculifer analyzed for Mg/Ca values with laser ablation ICP-MS (Photon Machines Analyte.193 with HelEx sample cell coupled with a Thermo ElementXS ICP-MS, LA-ICP-MS). Subsurface temperature variability is reconstructed from individual specimens of G. tumida analyzed for Mg/Ca values by ICP-OES. Our results indicate that the cooling of last glacial maximum SSTs was greater in the WEP compared to the EEP. Furthermore, we show this cooling is not an artifact of changes in seasonal or interannual foraminiferal fluxes, but rather, reflects overall cooler temperatures and thus changes in seasonal/interannual heat fluxes. At Site 806 in the WEP, variability during the Holocene and LGM was similar, suggesting the cooling was a direct response to pCO2-radiative forcing. In contrast, at Site 849, sea surface temperature variability during the LGM was greatly diminished in comparison to the Holocene suggesting reduced ENSO and seasonal variability. Therefore conditions in the EEP responded to both

  12. Simulation and preparation of surface EVA in reduced gravity at the Marseilles Bay subsea analogue sites

    NASA Astrophysics Data System (ADS)

    Weiss, P.; Gardette, B.; Chirié, B.; Collina-Girard, J.; Delauze, H. G.

    2012-12-01

    Extravehicular activity (EVA) of astronauts during space missions is simulated nowadays underwater in neutral buoyancy facilities. Certain aspects of weightlessness can be reproduced underwater by adding buoyancy to a diver-astronaut, therefore exposing the subject to the difficulties of working without gravity. Such tests were done at the COMEX' test pool in Marseilles in the 1980s to train for a French-Russian mission to the MIR station, for the development of the European HERMES shuttle and the COLUMBUS laboratory. However, space agencies are currently studying missions to other destinations than the International Space Station in orbit, such as the return to the Moon, NEO (near-Earth objects) or Mars. All these objects expose different gravities: Moon has one sixth of Earth's gravity, Mars has a third of Earth's gravity and asteroids have virtually no surface gravity; the astronaut "floats" above the ground. The preparation of such missions calls for a new concept in neutral buoyancy training, not on man-made structures, but on natural terrain, underwater, to simulate EVA operations such as sampling, locomotion or even anchoring in low gravity. Underwater sites can be used not only to simulate the reduced gravity that astronauts will experience during their field trips, also human factors like stress are more realistically reproduced in such environment. The Bay of Marseille hosts several underwater sites that can be used to simulate various geologic morphologies, such as sink-holes which can be used to simulate astronaut descends into craters, caves where explorations of lava tubes can be trained or monolithic rock structures that can be used to test anchoring devices (e.g., near Earth objects). Marseilles with its aerospace and maritime/offshore heritage hosts the necessary logistics and expertise that is needed to perform such simulations underwater in a safe manner (training of astronaut-divers in local test pools, research vessels, subsea robots and

  13. The development of response surface pathway design to reduce animal numbers in toxicity studies

    PubMed Central

    2014-01-01

    Background This study describes the development of Response Surface Pathway (RSP) design, assesses its performance and effectiveness in estimating LD50, and compares RSP with Up and Down Procedures (UDPs) and Random Walk (RW) design. Methods A basic 4-level RSP design was used on 36 male ICR mice given intraperitoneal doses of Yessotoxin. Simulations were performed to optimise the design. A k-adjustment factor was introduced to ensure coverage of the dose window and calculate the dose steps. Instead of using equal numbers of mice on all levels, the number of mice was increased at each design level. Additionally, the binomial outcome variable was changed to multinomial. The performance of the RSP designs and a comparison of UDPs and RW were assessed by simulations. The optimised 4-level RSP design was used on 24 female NMRI mice given Azaspiracid-1 intraperitoneally. Results The in vivo experiment with basic 4-level RSP design estimated the LD50 of Yessotoxin to be 463 μg/kgBW (95% CI: 383–535). By inclusion of the k-adjustment factor with equal or increasing numbers of mice on increasing dose levels, the estimate changed to 481 μg/kgBW (95% CI: 362–566) and 447 μg/kgBW (95% CI: 378–504 μg/kgBW), respectively. The optimised 4-level RSP estimated the LD50 to be 473 μg/kgBW (95% CI: 442–517). A similar increase in power was demonstrated using the optimised RSP design on real Azaspiracid-1 data. The simulations showed that the inclusion of the k-adjustment factor, reduction in sample size by increasing the number of mice on higher design levels and incorporation of a multinomial outcome gave estimates of the LD50 that were as good as those with the basic RSP design. Furthermore, optimised RSP design performed on just three levels reduced the number of animals from 36 to 15 without loss of information, when compared with the 4-level designs. Simulated comparison of the RSP design with UDPs and RW design demonstrated the superiority of RSP. Conclusion

  14. Imbalanced MHC class II molecule expression at surface of murine B cell lymphomas

    PubMed Central

    1986-01-01

    To study the role of class II MHC expression in mouse lymphomagenesis, we examined the cell surface expression of I-A/E antigens on 24 spontaneous or murine leukemia virus (MuLV)-induced mouse B10.A (I-Ak, I-Ek) B cell lymphomas. Two primary B10.A B cell lymphomas were observed with strong I-Ek expression but with only minimal cell surface I-Ak expression. Both tumors are readily transplantable in syngeneic mice, with maintenance of their I-A-, I-E+ phenotype. Strikingly, one I- A-, I-E+ B cell lymphoma contains a (11; 17) translocation with a breakpoint on chromosome 17 that is localized within or very close to the H-2 complex. DNA of both tumors contains normal restriction enzyme fragments of the A alpha and A beta genes. Northern blot analyses indicated that one I-A-, I-E+ tumor strongly expressed A alpha, E alpha, and E beta mRNAs but possessed only a weak expression of A beta mRNA. The other B cell lymphoma showed A beta, E alpha, and E beta mRNA expression but only minimal A alpha mRNA expression. In 11 primary B10.A B cell lymphomas with a normal I-A+, I-E+ phenotype, no imbalances in A alpha/A beta mRNA levels were observed. The implications of these findings for the role of class II MHC expression in mouse B cell lymphoma-genesis are discussed. PMID:3486245

  15. MicroRNA-142 Reduces Monoamine Oxidase A Expression and Activity in Neuronal Cells by Downregulating SIRT1

    PubMed Central

    Datta Chaudhuri, Amrita; Yelamanchili, Sowmya V.; Fox, Howard S.

    2013-01-01

    Aberrant expression of microRNAs (miRs) has been implicated in the pathogenesis of several neurodegenerative disorders. In HIV-associated neurocognitive disorders (HAND), miR-142 was found to be upregulated in neurons and myeloid cells in the brain. We investigated the downstream effects of chronic miR-142 upregulation in neuronal cells by comparing gene expression in stable clones of the human neuroblastoma cell line BE(2)M17 expressing miR-142 to controls. Microarray analysis revealed that miR-142 expression led to a reduction in monoamine oxidase (MAO) A mRNA, which was validated by qRT-PCR. In addition to the mRNA, the MAOA protein level and enzyme activity were also reduced. Examination of primary human neurons revealed that miR-142 expression indeed resulted in a downregulation of MAOA protein level. Although MAOA is not a direct target of miR-142, SIRT1, a key transcriptional upregulator of MAOA is, thus miR-142 downregulation of MAOA expression is indirect. MiR-142 induced decrease in MAOA expression and activity may contribute to the changes in dopaminergic neurotransmission reported in HAND. PMID:24244526

  16. Maternal High-Fat Feeding Increases Placental Lipoprotein Lipase Activity by Reducing SIRT1 Expression in Mice

    PubMed Central

    Qiao, Liping; Guo, Zhuyu; Bosco, Chris; Guidotti, Stefano; Wang, Yunfeng; Wang, Mingyong; Parast, Mana; Schaack, Jerome; Hay, William W.; Moore, Thomas R.

    2015-01-01

    This study investigated how maternal overnutrition and obesity regulate expression and activation of proteins that facilitate lipid transport in the placenta. To create a maternal overnutrition and obesity model, primiparous C57BL/6 mice were fed a high-fat (HF) diet throughout gestation. Fetuses from HF-fed dams had significantly increased serum levels of free fatty acid and body fat. Despite no significant difference in placental weight, lipoprotein lipase (LPL) protein levels and activity were remarkably elevated in placentas from HF-fed dams. Increased triglyceride content and mRNA levels of CD36, VLDLr, FABP3, FABPpm, and GPAT2 and -3 were also found in placentas from HF-fed dams. Although both peroxisome proliferator–activated receptor-γ (PPARγ) and CCAAT/enhancer binding protein-α protein levels were significantly increased in placentas of the HF group, only PPARγ exhibited a stimulative effect on LPL expression in cultured JEG-3 human trophoblasts. Maternal HF feeding remarkably decreased SIRT1 expression in placentas. Through use of an SIRT1 activator and inhibitor and cultured trophoblasts, an inhibitory effect of SIRT1 on LPL expression was demonstrated. We also found that SIRT1 suppresses PPARγ expression in trophoblasts. Most importantly, inhibition of PPARγ abolished the SIRT1-mediated regulatory effect on LPL expression. Together, these results indicate that maternal overnutrition induces LPL expression in trophoblasts by reducing the inhibitory effect of SIRT1 on PPARγ. PMID:25948680

  17. Improved free-surface expression for frequency-domain elastic optimal mixed-grid modeling

    NASA Astrophysics Data System (ADS)

    Cao, Jian; Chen, Jing-Bo; Dai, Meng-Xue

    2016-07-01

    An accurate and efficient forward modeling is the foundation of full-waveform inversion (FWI). In elastic wave modeling, one of the key problems is how to deal with the free-surface boundary condition appropriately. For the representation of the free-surface boundary condition, conventional displacement-based approaches and staggered-grid approaches are often used in time-domain. In frequency-domain, considering the saving of storage and CPU time, we integrate the idea of physical parameter-modified staggered-grid approach in time-domain with an elastic optimal mixed-grid modeling scheme to design an improved parameter-modified free-surface expression. Accuracy analysis shows that an elastic optimal mixed-grid modeling scheme using the parameter-modified free-surface expression can provide more accurate solutions with only 4 grid points per smallest shear wavelength than conventional displacement-based approaches and is stable for most Poisson ratios. Besides, it also yields smaller condition number of the resulting impedance matrix than conventional displacement-based approaches in laterally varying complex media. These advantages reveal great potential of this free-surface expression in big-data practical application.

  18. Reducing phosphorus flux from organic soils in surface flow treatment wetlands.

    PubMed

    Lindstrom, Susan M; White, John R

    2011-10-01

    Treatment wetlands have a finite period of effective nutrient removal after which treatment efficiency declines. This is due to the accumulation of organic matter which decreases the capacity and hydraulic retention time of the wetland. We investigated four potential solutions to improve the soluble reactive P (SRP) removal of a municipal wastewater treatment wetland soil including; dry down, surface additions of alum or calcium carbonate and physical removal of the accreted organic soil under both aerobic and anaerobic water column conditions. The flux of SRP from the soil to the water column under aerobic conditions was higher for the continuously flooded controls (1.1±0.4 mg P m(-2) d(-1)), dry down (1.5±0.9 mg P m(-2) d(-1)) and CaCO3 (0.8±0.7 mg P m(-2) d(-1)) treatments while the soil removal and alum treatments were significantly lower at 0.02±0.10 and -0.07±0.02 mg P m(-2) d(-1), respectively. These results demonstrate that the two most effective management strategies at sequestering SRP were organic soil removal and alum additions. There are difficulties and costs associated with removal and disposal of soils from a treatment wetland. Therefore our findings suggest that alum addition may be the most cost effective and efficient means of increasing the sequestering of P in aging treatment wetlands experiencing reduced P removal rates. However, more research is needed to determine the longer term effects of alum buildup in the organic soil on the wetland biota, in particular, on the macrophytes and invertebrates. Since alum effectiveness is time limited, a longer term solution to P flux may favor the organic soil removal. PMID:21802114

  19. AlphaII-spectrin participates in the surface expression of cell adhesion molecule L1 and neurite outgrowth.

    PubMed

    Trinh-Trang-Tan, Marie-Marcelle; Bigot, Sylvain; Picot, Julien; Lecomte, Marie-Christine; Kordeli, Ekaterini

    2014-04-01

    AlphaII-spectrin, a basic component of the spectrin-based scaffold which organizes and stabilizes membrane microdomains in most animal cells, has been recently implicated in cell adherence and actin dynamics. Here we investigated the contribution of αΙΙ-spectrin to neuritogenesis, a highly complex cellular process which requires continuous actin cytoskeleton remodeling and cross-talk between extracellular cues and their cell surface receptors, including cell adhesion molecules. Using RNA interference-mediated gene silencing to down-regulate αΙΙ-spectrin expression in human neuroblastoma SH-SY5Y cells, we observed major changes in neurite morphology and cell shape: (1) reduced mean length and a higher number of neurites per cell; occasional long neurites were thinner and displayed abnormal adhesiveness during cell migration resulting in frequent breaks; similar persisting adhesiveness and breaks were also observed in trailing edges of cell bodies; (2) irregular polygonal cell shape in parallel with loss of cortical F-actin from neuronal cell bodies; (3) reduction in protein levels of αΙ- and βΙ-spectrins, but not βΙΙ-spectrin (4) decreased global expression of adhesion molecule L1 and spectrin-binding adapter ankyrin-B, which links L1 to the plasma membrane. Remarkably, αΙΙ-spectrin depletion affected L1 - but not NCAM - cell surface expression, and L1 clustering at growth cones. This study demonstrates that αΙΙ-spectrin is implicated in normal morphology and adhesive properties of neuron cell bodies and neurites, and in cell surface expression and organization of adhesion molecule L1. PMID:24462599

  20. Iron and contact with host cells induce expression of adhesins on surface of Trichomonas vaginalis

    PubMed Central

    Garcia, Ana F.; Chang, Te-Hung; Benchimol, Marlene; Klumpp, David Jichael; Lehker, Michael W.; Alderete, John F.

    2007-01-01

    Summary The proteins AP65, AP51, AP33 and AP23 synthesized by Trichomonas vaginalis organisms in high iron play a role in adherence. Multigene families encode enzymes of the hydrogenosome organelles, which have identity to adhesins. This fact raises questions regarding the compartmentalization of the proteins outside the organelle and about the interactions of adhesins with host cells. Data here demonstrate the presence of the proteins outside the organelle under high-iron conditions. Fluorescence and immunocytochemical experiments show that high-iron-grown organisms coexpressed adhesins on the surface and intracellularly in contrast with low-iron parasites. Furthermore, the AP65 epitopes seen by rabbit anti-AP65 serum that blocks adherence and detects surface proteins were identified, and a mAb reacting to those epitopes recognized the trichomonal surface. Two-dimensional electrophoresis and immunoblot of adhesins from surface-labelled parasites provided evidence that all members of the multigene family were co-ordinately expressed and placed on the trichomonal surface. Similar two-dimensional analysis of proteins from purified hydrogenosomes obtained from iodinated trichomonads confirmed the specific surface labelling of proteins. Contact of trichomonads with vaginal epithelial cells increased the amount of surface-expressed adhesins. Moreover, we found a direct relationship between the levels of adherence and amount of adhesins bound to immortalized vaginal and ureter epithelial cells, further reinforcing specific associations. Finally, trichomonads of MR100, a drug-resistant isolate absent in hydrogenosome proteins and adhesins, were non-adherent. Overall, the results confirm an important role for iron and contact in the surface expression of adhesins of T. vaginalis organisms. PMID:12603729

  1. Mesenchymal Stromal Cells Express GARP/LRRC32 on Their Surface: Effects on Their Biology and Immunomodulatory Capacity

    PubMed Central

    Carrillo-Galvez, Ana Belén; Cobo, Marién; Cuevas-Ocaña, Sara; Gutiérrez-Guerrero, Alejandra; Sánchez-Gilabert, Almudena; Bongarzone, Pierpaolo; García-Pérez, Angélica; Muñoz, Pilar; Benabdellah, Karim; Toscano, Miguel G; Martín, Francisco; Anderson, Per

    2015-01-01

    Mesenchymal stromal cells (MSCs) represent a promising tool for therapy in regenerative medicine, transplantation, and autoimmune disease due to their trophic and immunomodulatory activities. However, we are still far from understanding the mechanisms of action of MSCs in these processes. Transforming growth factor (TGF)-β1 is a pleiotropic cytokine involved in MSC migration, differentiation, and immunomodulation. Recently, glycoprotein A repetitions predominant (GARP) was shown to bind latency-associated peptide (LAP)/TGF-β1 to the cell surface of activated Foxp3+ regulatory T cells (Tregs) and megakaryocytes/platelets. In this manuscript, we show that human and mouse MSCs express GARP which presents LAP/TGF-β1 on their cell surface. Silencing GARP expression in MSCs increased their secretion and activation of TGF-β1 and reduced their proliferative capacity in a TGF-β1-independent manner. Importantly, we showed that GARP expression on MSCs contributed to their ability to inhibit T-cell responses in vitro. In summary, we have found that GARP is an essential molecule for MSC biology, regulating their immunomodulatory and proliferative activities. We envision GARP as a new target for improving the therapeutic efficacy of MSCs and also as a novel MSC marker. Stem Cells 2015;33:183–195 PMID:25182959

  2. Optimization of Recombinant Expression of Synthetic Bacterial Phytase in Pichia pastoris Using Response Surface Methodology

    PubMed Central

    Akbarzadeh, Ali; Dehnavi, Ehsan; Aghaeepoor, Mojtaba; Amani, Jafar

    2015-01-01

    Background: Escherichia coli phytase is an acidic histidine phytase with great specific activity. Pichia pastoris is a powerful system for the heterologous expression of active and soluble proteins which can express recombinant proteins in high cell density fermenter without loss of product yield and efficiently secrete heterologous proteins into the media. Recombinant protein expression is influenced by expression conditions such as temperature, concentration of inducer, and pH. By optimization, the yield of expressed proteins can be increase. Response surface methodology (RSM) has been widely used for the optimization and studying of different parameters in biotechnological processes. Objectives: In this study, the expression of synthetic appA gene in P. pastoris was greatly improved by adjusting the expression condition. Materials and Methods: The appA gene with 410 amino acids was synthesized by P. pastoris codon preference and cloned in expression vector pPinkα-HC, under the control of AOX1 promoter, and it was transformed into P. pastoris GS115 by electroporation. Recombinant phytase was expressed in buffered methanol-complex medium (BMMY) and the expression was analyzed by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and enzymatic assay. To achieve the highest level of expression, methanol concentration, pH and temperature were optimized via RSM. Finally, the optimum pH and temperature for recombinant phytase activity was determined. Results: Escherichia coli phytase was expressed in P. pastoris under different cultivation conditions (post-induction temperature, methanol concentration, and post-induction pH). The optimized conditions by RSM using face centered central composite design were 1% (v/v) methanol, pH = 5.8, and 24.5°C. Under the optimized conditions, appA was successfully expressed in P. pastoris and the maximum phytase activity was 237.2 U/mL after 72 hours of expression. Conclusions: By optimization of recombinant

  3. Zinc-ion implanted and deposited titanium surfaces reduce adhesion of Streptococccus mutans

    NASA Astrophysics Data System (ADS)

    Xu, Juan; Ding, Gang; Li, Jinlu; Yang, Shenhui; Fang, Bisong; Sun, Hongchen; Zhou, Yanmin

    2010-10-01

    While titanium (Ti) is a commonly used dental implant material with advantageous biocompatible and mechanical properties, native Ti surfaces do not have the ability to prevent bacterial colonization. The objective of this study was to evaluate the chemical composition and bacterial adhesive properties of zinc (Zn) ion implanted and deposited Ti surfaces (Zn-PIIID-Ti) as potential dental implant materials. Surfaces of pure Ti (cp-Ti) were modified with increasing concentrations of Zn using plasma immersion ion implantation and deposition (PIIID), and elemental surface compositions were characterized by X-ray photoelectron spectrometry (XPS). To evaluate bacterial responses, Streptococcus mutans were seeded onto the modifiedTi surfaces for 48 h and subsequently observed by scanning electron microscopy. Relative numbers of bacteria on each surface were assessed by collecting the adhered bacteria, reculturing and counting colony forming units after 48 h on bacterial grade plates. Ti, oxygen and carbon elements were detected on all surfaces by XPS. Increased Zn signals were detected on Zn-PIIID-Ti surfaces, correlating with an increase of Zn-deposition time. Substantial numbers of S. mutans adhered to cp-Ti samples, whereas bacterial adhesion on Zn-PIIID-Ti surfaces signficantly decreased as the Zn concentration increased ( p < 0.01). In conclusion, PIIID can successfully introduce Zn onto a Ti surface, forming a modified surface layer bearing Zn ions that consequently deter adhesion of S. mutans, a common bacterium in the oral environment.

  4. Surface expression and rapid internalization of macrosialin (mouse CD68) on elicited mouse peritoneal macrophages.

    PubMed

    Kurushima, H; Ramprasad, M; Kondratenko, N; Foster, D M; Quehenberger, O; Steinberg, D

    2000-01-01

    Macrosialin, the mouse homolog of human CD68, is a heavily glycosylated transmembrane protein found almost exclusively in macrophages. Its function remains uncertain. It has a high affinity for oxidized low-density lipoprotein (LDL) in ligand blots and antibodies against the human homolog, CD68, inhibit the binding of oxidized LDL to a human monocyte-derived cell line (THP-1). However, there is still controversy as to whether macrosialin, found predominantly in late endosomes, is expressed at all on the plasma membrane. The present studies, done in thioglycollate-elicited peritoneal macrophages, confirm that macrosialin is predominantly intracellular but show clearly that 10-15% of it is expressed on the cell surface. Exchange with intracellular pools occurs at an extremely high rate. The results are compatible with a surface function, including internalization of bound ligands or adhesion to surfaces.

  5. Reduced Susceptibility to Xanthomonas citri in Transgenic Citrus Expressing the FLS2 Receptor From Nicotiana benthamiana.

    PubMed

    Hao, Guixia; Pitino, Marco; Duan, Yongping; Stover, Ed

    2016-02-01

    Overexpression of plant pattern-recognition receptors by genetic engineering provides a novel approach to enhance plant immunity and broad-spectrum disease resistance. Citrus canker disease associated with Xanthomonas citri is one of the most important diseases damaging citrus production worldwide. In this study, we cloned the FLS2 gene from Nicotiana benthamiana cDNA and inserted it into the binary vector pBinPlus/ARS to transform Hamlin sweet orange and Carrizo citrange. Transgene presence was confirmed by polymerase chain reaction (PCR) and gene expression of NbFLS2 was compared by reverse transcription quantitative PCR. Reactive oxygen species (ROS) production in response to flg22Xcc was detected in transgenic Hamlin but not in nontransformed controls. Low or no ROS production was detected from nontransformed Hamlin seedlings challenged with flg22Xcc. Transgenic plants highly expressing NbFLS2 were selected and were evaluated for resistance to canker incited by X. citri 3213. Our results showed that the integration and expression of the NbFLS2 gene in citrus can increase canker resistance and defense-associated gene expression when challenged with X. citri. These results suggest that canker-susceptible Citrus genotypes lack strong basal defense induced by X. citri flagellin and the resistance of these genotypes can be enhanced by transgenic expression of the flagellin receptor from a resistant species. PMID:26554734

  6. Fish oil dietary supplementation reduces Ia expression in rat and mouse peritoneal macrophages.

    PubMed

    Mosquera, J; Rodríguez-Iturbe, B; Parra, G

    1990-07-01

    Preliminary studies suggest that administration of fish oil fatty acids may be beneficial in several immunological diseases; therefore, we studied the effect of fish oil dietary supplementation on the expression of Ia in stimulated murine peritoneal macrophages. Rats (n = 19) and mice (n = 27) on standard rodent feeding were separated in experimental (E) and control (C) groups that received fish oil or saline solution, respectively, daily for 4 weeks by esophageal gavage. Cholesterol serum levels were significantly lowered by fish oil (E vs C, P less than 0.01). E and C groups were injected intraperitoneally with Listeria monocytogenes (LM) and peritoneal cells were harvested 4 and 7 days after infection. Decreased expression of Ia induced by LM was found in rats (C = 49.68 +/- 5.09%, E = 16.95 +/- 4.3%, P less than 0.01) and mice (C = 47.38 +/- 7.63%, E = 26.66 +/- 1.92%, P less than 0.01). Animals with a more pronounced depression of serum cholesterol (reduction of 44.04 +/- 1.52% of baseline levels) had more depression of Ia expression (6.47 +/- 1.22%, P less than 0.001 vs control). Reduction of Ia expression was not related to PGE2 production by peritoneal cells. Reduction of Ia expression by fish oil could induce down-regulation of antigen presentation and alloreactivity.

  7. Reduced Expression of GDF-15 Is Associated With Atrophic Inflammatory Lesions of the Prostate

    PubMed Central

    Lambert, James R.; Whitson, Ramon J.; Iczkowski, Kenneth A.; La Rosa, Francisco G.; Smith, Maxwell L.; Wilson, R. Storey; Smith, Elizabeth E.; Torkko, Kathleen C.; Gari, Hamid H.; Lucia, M. Scott

    2015-01-01

    BACKGROUND Accumulating evidence suggests that chronic prostatic inflammation may lead to prostate cancer development. Growth differentiation factor-15 (GDF-15) is highly expressed in the prostate and has been associated with inflammation and tumorigenesis. METHODS To examine the relationship between GDF-15 and prostatic inflammation, GDF-15 expression was measured by immunohistochemical (IHC) staining in human prostatectomy specimens containing inflammation. The relationship between GDF-15 and specific inflammatory cells was determined using non-biased computer image analysis. To provide insight into a potential suppressive role for GDF-15 in inflammation, activation of inflammatory mediator nuclear factor of kappa B (NFκB) was measured in PC3 cells. RESULTS GDF-15 expression in luminal epithelial cells was decreased with increasing inflammation severity, suggesting an inverse association between GDF-15 and inflammation. Quantification of IHC staining by image analysis for GDF-15 and inflammatory cell markers revealed an inverse correlation between GDF-15 and CD3+, CD4+, CD8+, CD68+, and inos+ leukocytes. GDF-15 suppressed NFκB activity in luciferase reporter assays. Expression of the NFκB target, interleukin 8 (IL-8), was downregulated by GDF-15. CONCLUSIONS The inverse relationship between GDF-15 and inflammation demonstrates a novel expression pattern for GDF-15 in the human prostate and suppression of NFκB activity may shed light on a potential mechanism for this inverse correlation. PMID:25327758

  8. Reduced Susceptibility to Xanthomonas citri in Transgenic Citrus Expressing the FLS2 Receptor From Nicotiana benthamiana.

    PubMed

    Hao, Guixia; Pitino, Marco; Duan, Yongping; Stover, Ed

    2016-02-01

    Overexpression of plant pattern-recognition receptors by genetic engineering provides a novel approach to enhance plant immunity and broad-spectrum disease resistance. Citrus canker disease associated with Xanthomonas citri is one of the most important diseases damaging citrus production worldwide. In this study, we cloned the FLS2 gene from Nicotiana benthamiana cDNA and inserted it into the binary vector pBinPlus/ARS to transform Hamlin sweet orange and Carrizo citrange. Transgene presence was confirmed by polymerase chain reaction (PCR) and gene expression of NbFLS2 was compared by reverse transcription quantitative PCR. Reactive oxygen species (ROS) production in response to flg22Xcc was detected in transgenic Hamlin but not in nontransformed controls. Low or no ROS production was detected from nontransformed Hamlin seedlings challenged with flg22Xcc. Transgenic plants highly expressing NbFLS2 were selected and were evaluated for resistance to canker incited by X. citri 3213. Our results showed that the integration and expression of the NbFLS2 gene in citrus can increase canker resistance and defense-associated gene expression when challenged with X. citri. These results suggest that canker-susceptible Citrus genotypes lack strong basal defense induced by X. citri flagellin and the resistance of these genotypes can be enhanced by transgenic expression of the flagellin receptor from a resistant species.

  9. Reduced expression of exocytotic proteins caused by anti-cholinesterase pesticides in Brachionus calyciflorus (Rotifera: Monogononta).

    PubMed

    Pérez-Legaspi, I A; Rico-Martínez, R; Quintanar, J L

    2015-08-01

    The organophosphate and carbamate pesticides methyl-parathion and carbaryl have a common action mechanism: they inhibit acetylcholinesterase enzyme by blocking the transmission of nerve impulses. However, they can alter the expression of exocytotic membrane proteins (SNARE), by modifying release of neurotransmitters and other substances. This study evaluated the adverse effects of the pesticides methyl-parathion and carbaryl on expression of SNARE proteins: Syntaxin-1, Syntaxin-4 and SNAP-23 in freshwater rotifer Brachionus calyciflorus. Protein expression of these three proteins was analyzed before and after exposure to these two pesticides by Western Blot. The expression of Syntaxin-1, Syntaxin-4 and SNAP-23 proteins in B. calyciflorussignificantly decreases with increasing concentration of either pesticides. This suggests that organophosphates and carbamates have adverse effects on expression of membrane proteins of exocytosis by altering the recognition, docking and fusion of presynaptic and vesicular membranes involved in exocytosis of neurotransmitters. Our results demonstrate that the neurotoxic effect of anticholinesterase pesticides influences the interaction of syntaxins and SNAP-25 and the proper assembly of the SNARE complex.

  10. Enhanced expression of multidrug resistance-associated protein 2 and reduced expression of aquaglyceroporin 3 in an arsenic-resistant human cell line.

    PubMed

    Lee, Te-Chang; Ho, I-Ching; Lu, Wen-Jen; Huang, Jin-ding

    2006-07-01

    Arsenic-resistant cells (R15), derived from a human lung adenocarcinoma cell line (CL3), were 10-fold more resistant to sodium arsenite (As(III)). Because R15 cells accumulated less arsenic than parental CL3 cells, this arsenic resistance may be due to higher efflux and/or lower uptake of As(III). We therefore compared expression of the multidrug resistance-associated proteins MRP1, MRP2, and MRP3 in these two cell lines. MRP2 expression was 5-fold higher in R15 cells than in CL3 cells, whereas MRP1 and MRP3 expression levels were similar. Furthermore, verapamil and cyclosporin A, inhibitors of multidrug resistance transporters, significantly reduced the efflux of arsenic from R15. Thus, increased arsenic extrusion by MRP2 may contribute to arsenic resistance in R15 cells. We also examined the expression of several aquaglyceroporins (AQPs), which mediate As(III) uptake by cells. Little AQP7 or AQP9 mRNA was detected by reverse transcription-PCR in either cell line, whereas AQP3 mRNA expression was 2-fold lower in R15 cells than in CL3 cells. When AQP3 expression in CL3 cells was knocked down by RNA interference, CL3 cells accumulated less arsenic and became more resistant to As(III). Conversely, overexpression of AQP3 in human embryonic kidney 293T cells increased arsenic accumulation, and the cells were more susceptible to As(III) than 293T cells transfected with vector alone. These results suggest that AQP3 is involved in As(III) accumulation. Taken together, our results suggest that enhanced expression of MRP2 and lower expression of AQP3 are responsible for lower arsenic accumulation in arsenic-resistant R15 cells.

  11. Reducing acetate excretion from E. coli K-12 by over-expressing the small RNA SgrS.

    PubMed

    Negrete, Alejandro; Majdalani, Nadim; Phue, Je-Nie; Shiloach, Joseph

    2013-01-25

    When exposed to the nonmetabolized glucose derivative alpha methyl glucoside (αMG), both Escherichia coli K-12 (JM109 and MG1655) and E. coli B (BL21) respond by reducing the concentration of the mRNA of the ptsG gene which is responsible for the biosynthesis of the glucose transporter EIICB(glu). This occurs through the over-expression of the noncoding small RNA SgrS, which interacts specifically with the mRNA of the ptsG gene and prevents its translation. However, when these bacteria are exposed to a glucose concentration of 40 g/L, over-expression of SgrS is observed only in E. coli B (BL21). Unlike E. coli K-12 (JM109 and MG1655), which are affected by high glucose concentration and produce higher levels of acetate, E. coli B (BL21) is not affected. Based on this information, it was assumed that over-expression of SgrS enables E. coli B (BL21) to reduce its acetate excretion by controlling the glucose transport. When SgrS was over-expressed in both E. coli K-12 strains from a multicopy plasmid, it was possible to reduce their acetate excretion levels to those seen in E. coli B. This observation opens a new approach towards controlling bacterial metabolism through the use of noncoding RNA.

  12. Reduced SOD2 expression is associated with mortality of hepatocellular carcinoma patients in a mutant p53-dependent manner

    PubMed Central

    Yang, Xian-Zi; Yang, Yang; Zhang, Mei-Yin; Wang, Hui-Yun; Zheng, X.F. Steven

    2016-01-01

    The development and progression of hepatocellular carcinoma (HCC) is accompanied with persistent oxidative stress, but the molecular basis is not well defined. Superoxide dismutase 2 (SOD2) is an important mitochondrial antioxidant and a key aging factor. Here we investigated the expression and clinical significance of SOD2 in a large cohort of HBV-positive HCC tumors. Both SOD2 mRNA and protein are reduced in human primary HCCs compared with matching liver tissues. Consistently, the SOD2 DNA copy numbers are decreased in HCCs, providing a genetic basis for the decrease in SOD2 mRNA expression. Reduced SOD2 expression in HCCs is correlated with older age, larger tumor size, multiple tumor nodules and tumor emboli, and cancer recurrence. Moreover, low SOD2 expression is strongly associated with poor overall survival (OS) and recurrence-free survival (RFS). Univariate and multivariate Cox regression analyses indicates that SOD2 is an independent prognostic predictor for OS and RFS. Intriguingly, reduced SOD2 mRNA is strongly associated with poor survival in a separate cohort of HCC patients carrying mutant p53. Altogether, our results provide clinical evidence for the importance of SOD2 in tumor progression and mortality, and the close relationship of SOD2 and p53 in HCC. PMID:27221200

  13. Reduced expression of plasma membrane calcium ATPase 2 and collapsin response mediator protein 1 promotes death of spinal cord neurons.

    PubMed

    Kurnellas, M P; Li, H; Jain, M R; Giraud, S N; Nicot, A B; Ratnayake, A; Heary, R F; Elkabes, S

    2010-09-01

    The mechanisms underlying neuronal pathology and death in the spinal cord (SC) during inflammation remain elusive. We previously showed the important role of plasma membrane calcium ATPases (PMCAs) in the survival of SC neurons, in vitro. We also postulated that a decrease in PMCA2 expression could cause neuronal death during experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis. The current studies were undertaken to define the specific contribution of PMCA2 to degeneration of SC neurons, the effectors downstream to PMCA2 mediating neuronal death and the triggers that reduce PMCA2 expression. We report that knockdown of PMCA2 in SC neurons decreases collapsin response mediator protein 1 (CRMP1) levels. This is followed by cell death. Silencing of CRMP1 expression also leads to neuronal loss. Kainic acid reduces both PMCA2 and CRMP1 levels and induces neuronal death. Administration of an alpha-amino-3-hydroxyl-5-methyl-4-isoxazole-propionate (AMPA)/kainate receptor antagonist, at onset or peak of EAE, restores the decreased PMCA2 and CRMP1 levels to control values and ameliorates clinical deficits. Thus, our data link the reduction in PMCA2 expression with perturbations in the expression of CRMP1 and the ensuing death of SC neurons. This represents an additional mechanism underlying AMPA/kainate receptor-mediated excitotoxicity with relevance to neurodegeneration in EAE. PMID:20489728

  14. Suberoylanilide Hydroxamic Acid Restores Estrogen Reduced-cTnI Expression in Neonatal Hearts of Mice.

    PubMed

    Peng, Chang; Luo, Xiaomei; Xing, Qianlu; Sun, Huichao; Huang, Xupei

    2016-10-01

    Diastolic cardiac dysfunction can be caused by abnormality in cTnI expression during cardiogenesis. In this study, we investigated the effects of estrogen on the abnormal expression of cTnI in the hearts of neonatal mice and its potential epigenetic mechanisms. We then evaluated suberoylanilide hydroxamic acid (SAHA), a HDAC inhibitor, as a new target treatment of diastolic cardiac dysfunction. Postnatal day 0.5 C57BL/6 mice were injected with estrogen for 1 week, then the hearts of 7-day-old neonatal mice were retrieved for examination. The activities of HDAC and HAT were assayed by colorimetry, and the interaction of cTnI with HDAC5 in mice hearts were examined using chromatin immunoprecipitation assays. The expression of cTnI was tested by quantitative real-time RT-PCR and Western blot. Estrogen treated groups displayed a significantly increased HDAC activity in the hearts of neonatal mice while HAT activity remained unchanged. Additionally, HDAC5 was higher at the cTnI promoter, as compared to the saline treated control groups. The acetylation of histone H3K9ac on cTnI promoter significantly decreased in the hearts of neonatal mice treated with estrogen, and the expression of cTnI at transcriptional and protein levels also decreased. SAHA was shown to increase the acetylation of histone H3K9ac and upregulate the expression of cTnI. The data demonstrated that SAHA can correct cTnI expression abnormality caused by estrogen through inhibiting the binding of HDAC5 to the promoter of cTnI. J. Cell. Biochem. 117: 2377-2384, 2016. © 2016 Wiley Periodicals, Inc. PMID:27379430

  15. Anti-interleukin-33 Reduces Ovalbumin-Induced Nephrotoxicity and Expression of Kidney Injury Molecule-1

    PubMed Central

    2016-01-01

    Purpose: To evaluate the effect of anti-interleukin-33 (anti-IL-33) on a mouse model of ovalbumin (OVA)-induced acute kidney injury (AKI). Methods: Twenty-four female BALB/c mice were assigned to 4 groups: group A (control, n=6) was administered sterile saline intraperitoneally (i.p.) and intranasally (i.n.); group B (allergic, n=6) was administered i.p./i.n. OVA challenge; group C (null treatment, n=6) was administered control IgG i.p. before OVA challenge; and group D (anti-IL-33, n=6) was pretreated with 3.6 µg of anti-IL-33 i.p. before every OVA challenge. The following were evaluated after sacrifice: serum blood urea nitrogen and creatinine levels, Kidney injury molecule-1 gene (Kim-1) and protein (KIM-1) expression in renal parenchyma, and expression of cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS), phosphorylated endothelial NOS (p-eNOS), and phosphorylated AMP kinase (p-AMPK) proteins in renal parenchyma. Results: After OVA injection and intranasal challenge, mice in groups B and C showed significant increases in the expression of Kim-1 at both the mRNA and protein levels. After anti-IL-33 treatment, mice in group D showed significant Kim-1 down-regulation at the mRNA and protein levels. Group D also showed significantly lower COX-2 protein expression, marginally lesser iNOS expression than groups B and C, and p-eNOS and p-AMPK expression at baseline levels. Conclusions: Kim-1 could be a useful marker for detecting early-stage renal injury in mouse models of OVA-induced AKI. Further, anti-IL-33 might have beneficial effects on these mouse models. PMID:27377943

  16. High salt-diet reduces SLC14A1 gene expression in the choroid plexus of Dahl salt sensitive rats.

    PubMed

    Guo, Lirong; Meng, Jie; Xuan, Chengluan; Ge, Jingyan; Sun, Wenzhu; O'Rourke, Stephen T; Sun, Chengwen

    2015-05-29

    Elevated Na(+) concentration ([Na(+)]) in the cerebrospinal fluid (CSF) contributes to the development of salt-sensitive hypertension. CSF is formed by the choroid plexus (CP) in cerebral ventricles, and [Na(+)] in CSF is controlled by transporters in CP. Here, we examined the effect of high salt diet on the expression of urea transporters (UTs) in the CP of Dahl S vs Dahl R rats using real time PCR. High salt intake (8%, for 2 weeks) did not alter the mRNA levels of UT-A (encoded by SLC14A2 gene) in the CP of either Dahl S or Dahl R rats. In contrast, the mRNA levels of UT-B (encoded by SLC14A1 gene) were significantly reduced in the CP of Dahl S rats on high salt diet as compared with Dahl R rats or Dahl S rats on normal salt diet. Reduced UT-B expression was associated with increased [Na(+)] in the CSF and elevated mean arterial pressure (MAP) in Dahl S rats treated with high salt diet, as measured by radiotelemetry. High salt diet-induced reduction in UT-B protein expression in the CP of Dahl S rats was confirmed by Western blot. Immunohistochemistry using UT-B specific antibodies demonstrated that UT-B protein was expressed on the epithelial cells in the CP. These data indicate that high salt diet induces elevations in CSF [Na(+)] and in MAP, both of which are associated with reduced UT-B expression in the CP of Dahl S rats, as compared with Dahl R rats. The results suggest that altered UT-B expression in the CP may contribute to an imbalance of water and electrolytes in the CSF of Dahl S rats on high salt diet, thereby leading to alterations in MAP.

  17. [Topical application of vitamins, phytosterols and ceramides. Protection against increased expression of interstital collagenase and reduced collagen-I expression after single exposure to UVA irradiation].

    PubMed

    Grether-Beck, S; Mühlberg, K; Brenden, H; Krutmann, J

    2008-07-01

    Photoaged skin is characterized by a decrease of dermal collagen fibers, resulting from an increased breakdown and a diminished de novo synthesis. The increased breakdown results from an increased expression of matrix metalloproteinases (MMPs). The main building blocks involved in de novo synthesis of collagen fibers are collagen 1A1 and 1A2, the expression of which is reduced in photoaged skin. We studied the effect of topical application of vitamins, phytosterols and ceramides on UV-induced up-regulation of the expression of MMP-1 and on UV-induced down-regulation of COL1A1 and COL1A2. The study was conducted with 10 subjects with healthy skin who were comparatively treated for 10 days with (i) a basic preparation containing jojoba oil, (ii) the basic preparation supplemented with vitamins, (iii) the basic preparation supplemented with phytosterols and ceramides, and (iv) the basic preparation supplemented with vitamins, phytosterols and ceramides. All four preparations inhibited the UV induced up-regulation of MMP-1. Neither the basic product nor that supplemented with vitamins inhibited down-regulation of COL1A1 and COL1A2, but addition of phytosterols and ceramides caused a decreased down-regulation of the expression of these genes. Our results indicate that phytosterols and ceramides are effective in blocking the reduced collagen synthesis after UV irradiation and even stimulating synthesis. They may be useful additions to anti-aging products.

  18. Reduced thermal sensitivity and Nav1.8 and TRPV1 channel expression in sensory neurons of aged mice.

    PubMed

    Wang, Shuying; Davis, Brian M; Zwick, Melissa; Waxman, Stephen G; Albers, Kathryn M

    2006-06-01

    Sensory neurons in aging mammals undergo changes in anatomy, physiology and gene expression that correlate with reduced sensory perception. In this study we compared young and aged mice to identify proteins that might contribute to this loss of sensation. We first show using behavioral testing that thermal sensitivity in aged male and female mice is reduced. Expression of sodium channel (Nav1.8 and Nav1.9) and transient receptor potential vanilloid (TRPV) channels in DRG and peripheral nerves of young and old male mice was then examined. Immunoblotting and RT-PCR assays showed reduced Nav1.8 levels in aged mice. No change was measured in TRPV1 mRNA levels in DRG though TRPV1 protein appeared reduced in the DRG and peripheral nerves. The GFRalpha3 receptor, which binds the growth factor artemin and is expressed by TRPV1-positive neurons, was also decreased in the DRG of aged animals. These findings indicate that loss of thermal sensitivity in aging animals may result from a decreased level of TRPV1 and Nav1.8 and decreased trophic support that inhibits efficient transport of channel proteins to peripheral afferents. PMID:15979214

  19. Reduced expression of polymeric immunoglobulin receptor (pIgR) in nasopharyngeal carcinoma and its correlation with prognosis.

    PubMed

    Qi, Xuanchang; Li, Xuechang; Sun, Xiuxia

    2016-08-01

    Polymeric immunoglobulin receptor (pIgR) is a key component of the mucosal immune system that mediates epithelial transcytosis of immunoglobulins. The expression of pIgR was reported to be up-regulated and related to the prognosis of several human cancers. However, the clinical significance of pIgR in nasopharyngeal carcinoma (NPC) remains unclear. The purpose of this study was to detect the pIgR expression and its prognostic value in NPC. The expression of serum pIgR was measured in NPC patients and healthy controls by real-time quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR) and western blotting analyses. The relationship between its expression and clinical factors was analyzed by chi-square test. Then, the overall survival of patients was assessed by Kaplan-Meier analysis while the prognostic value of serum pIgR was estimated using univariate and multivariate analyses with cox regression analysis. Serum pIgR was down-regulated in NPC patients compared to that in healthy controls both at messenger RNA (mRNA) and protein levels. Especially, its expression was also significantly lower in patients at advantage stages (III-IV) than those at early stages (I-II). And, the low pIgR expression was strongly associated with advanced clinical stages, T stage, N stage, and distant metastasis. Kaplan-Meier analysis demonstrated that patients with low pIgR expression had a significantly shorter overall survival than those with high expression at any stages. Cox regression analysis suggested that pIgR was closely related to the prognosis of NPC. Serum pIgR expression was reduced in NPC, and it could be an independent prognostic predictor for patients with this cancer. PMID:26910773

  20. Long term exendin-4 treatment reduces food intake and body weight and alters expression of brain homeostatic and reward markers.

    PubMed

    Yang, Yan; Moghadam, Alexander A; Cordner, Zachary A; Liang, Nu-Chu; Moran, Timothy H

    2014-09-01

    Repeated administration of the long-acting glucagon-like peptide 1 receptor agonist exendin-4 (EX-4) has been shown to reduce food intake and body weight and do so without a rebound increase in food intake after treatment termination. The current study examines the neural mechanisms underlying these actions. After 6 weeks of maintenance on a standard chow or a high-fat (HF) diet, male Sprague Dawley rats were treated with EX-4 (3.2 μg/kg, i.p., twice a day) or vehicle for 9 consecutive days. Food intake and body weight (BW) were monitored daily. Expression of the genes for the hypothalamic arcuate nucleus (ARC) peptides proopiomelanocortin (POMC), neuropeptide Y (NPY), and agouti gene-related protein was determined. Expression of the dopamine precursor tyrosine hydroxylase (TH) gene in the ventral tegmental area and genes for dopamine receptors 1 (D1R) and dopamine receptor 2 in the nucleus accumbens were also determined. Pair-fed groups were included to control for the effects of reduced food intake and BW. Treatment with EX-4 significantly decreased food intake and BW over the 9-day period in both the standard chow and HF groups. HF feeding decreased POMC without changing NPY/agouti gene-related protein gene expression in the ARC. Treatment with EX-4 increased POMC and decreased NPY expression independent of the reduction of food intake and BW. Mesolimbic TH and D1R gene expression were decreased significantly in chronic HF diet-fed rats, and these changes were reversed in both EX-4 and pair-fed conditions. These results suggest a role for increased POMC and decreased NPY expression in the ARC in the effects of EX-4 on food intake and BW. Our findings also suggest that EX-4 induced the recovery of mesolimbic TH and D1R expression in HF diet-fed rats may be secondary to HF intake reduction and/or weight loss.

  1. Curcumin inhibits srebp-2 expression in activated hepatic stellate cells in vitro by reducing the activity of specificity protein-1.

    PubMed

    Kang, Qiaohua; Chen, Anping

    2009-12-01

    Elevated levels of cholesterol/low-density lipoprotein (LDL) are a risk factor for the development of nonalcoholic steatohepatitis and its associated hepatic fibrosis. However, underlying mechanisms remain elusive. We previously reported that curcumin induced gene expression of peroxisome proliferator-activated receptor (PPAR)-gamma and stimulated its activity, leading to the inhibition of the activation of hepatic stellate cells (HSCs), the major effector cells during hepatic fibrogenesis. We recently showed that curcumin suppressed gene expression of LDL receptor in activated HSCs in vitro by repressing gene expression of the transcription factor sterol regulatory element binding protein-2 (SREBP-2), leading to the reduction in the level of intracellular cholesterol in HSCs and to the attenuation of the stimulatory effects of LDL on HSCs activation. The current study aimed at exploring molecular mechanisms by which curcumin inhibits srebp-2 expression in HSCs. Promoter deletion assays, mutagenesis assays, and EMSAs localize a specificity protein-1 (SP-1) binding GC-box in the srebp-2 promoter, which is responsible for enhancing the promoter activity and responding to curcumin in HSCs. Curcumin suppresses gene expression of SP-1 and reduces its trans-activation activity, which are mediated by the activation of PPARgamma. The inhibitory effect of curcumin on SP-1 binding to the GC-box is confirmed by chromatin immuno-precipitation. In summary, our results demonstrate that curcumin inhibits srebp-2 expression in cultured HSCs by activating PPARgamma and reducing the SP-1 activity, leading to the repression of ldlr expression. These results provide novel insights into molecular mechanisms by which curcumin inhibits LDL-induced HSC activation.

  2. Expression of a foreign Rubisco small subunit in tobacco with reduced levels of the native protein

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The cDNA, ArRbcS3, for the small subunit of Rubisco from Amaranthus retroflexus (pigweed) was expressed in tobacco (Nicotiana tabacum) under the control of a strong leaf-specific Lhcb promoter. The coding region of the ArRbcS3 was fused to the plastid targeting sequence of the native tobacco rbcS to...

  3. Thymoquinone inhibits cancer metastasis by downregulating TWIST1 expression to reduce epithelial to mesenchymal transition

    PubMed Central

    Khan, Md. Asaduzzaman; Tania, Mousumi; Wei, Chunli; Mei, Zhiqiang; Fu, Shelly; Cheng, Jingliang; Xu, Jianming; Fu, Junjiang

    2015-01-01

    Proteins that promote epithelial to mesenchymal transition (EMT) are associated with cancer metastasis. Inhibition of EMT regulators may be a promising approach in cancer therapy. In this study, Thymoquinone (TQ) was used to treat cancer cell lines to investigate its effects on EMT-regulatory proteins and cancer metastasis. We show that TQ inhibited cancer cell growth, migration and invasion in a dose-dependent manner. At the molecular level, TQ treatment decreased the transcriptional activity of the TWIST1 promoter and the mRNA expression of TWIST1, an EMT-promoting transcription factor. Accordingly, TQ treatment also decreased the expression of TWIST1-upregulated genes such as N-Cadherin and increased the expression of TWIST1-repressed genes such as E-Cadherin, resulting in a reduction of cell migration and invasion. TQ treatment also inhibited the growth and metastasis of cancer cell-derived xenograft tumors in mice but partially attenuated the migration and invasion in TWIST1-overexpressed cell lines. Furthermore, we found that TQ treatment enhanced the promoter DNA methylation of the TWIST1 gene in BT 549 cells. Together, these results demonstrate that TQ treatment inhibits TWIST1 promoter activity and decreases its expression, leading to the inhibition of cancer cell migration, invasion and metastasis. These findings suggest TQ as a potential small molecular inhibitor of cancer growth and metastasis. PMID:26023736

  4. Protostylid expression at the enamel-dentine junction and enamel surface of mandibular molars of Paranthropus robustus and Australopithecus africanus.

    PubMed

    Skinner, Matthew M; Wood, Bernard A; Hublin, Jean-Jacques

    2009-01-01

    Distinctive expressions and incidences of discrete dental traits at the outer enamel surface (OES) contribute to the diagnoses of many early hominin taxa. Examination of the enamel-dentine junction (EDJ), imaged non-destructively using micro-computed tomography, has elucidated the morphological development of dental traits and improved interpretations of their variability within and among taxa. The OES expressions of one of these dental traits, the protostylid, have been found to differ among African Plio-Pleistocene fossil hominin taxa. In this study protostylid expression is examined at the OES and at the EDJ of Paranthropus robustus (n=23) and Australopithecus africanus (n=28) mandibular molars, with the goals of incorporating EDJ morphology into the definition of the protostylid and assessing the relative contribution of the EDJ and enamel cap to its expression in these taxa. The results provide evidence (a) of statistically significant taxon-specific patterns of protostylid morphology at the EDJ that are not evident at the OES; (b) that in P. robustus, thick enamel reduces the morphological correspondence between the form of the protostylid seen at the EDJ and the OES, and (c) that if EDJ images can be obtained, then the protostylid retains its taxonomic value even in worn teeth. PMID:18986683

  5. Myoscape controls cardiac calcium cycling and contractility via regulation of L-type calcium channel surface expression.

    PubMed

    Eden, Matthias; Meder, Benjamin; Völkers, Mirko; Poomvanicha, Montatip; Domes, Katrin; Branchereau, M; Marck, P; Will, Rainer; Bernt, Alexander; Rangrez, Ashraf; Busch, Matthias; Hrabě de Angelis, Martin; Heymes, Christophe; Rottbauer, Wolfgang; Most, Patrick; Hofmann, Franz; Frey, Norbert

    2016-01-01

    Calcium signalling plays a critical role in the pathogenesis of heart failure. Here we describe a cardiac protein named Myoscape/FAM40B/STRIP2, which directly interacts with the L-type calcium channel. Knockdown of Myoscape in cardiomyocytes decreases calcium transients associated with smaller Ca(2+) amplitudes and a lower diastolic Ca(2+) content. Likewise, L-type calcium channel currents are significantly diminished on Myoscape ablation, and downregulation of Myoscape significantly reduces contractility of cardiomyocytes. Conversely, overexpression of Myoscape increases global Ca(2+) transients and enhances L-type Ca(2+) channel currents, and is sufficient to restore decreased currents in failing cardiomyocytes. In vivo, both Myoscape-depleted morphant zebrafish and Myoscape knockout (KO) mice display impairment of cardiac function progressing to advanced heart failure. Mechanistically, Myoscape-deficient mice show reduced L-type Ca(2+)currents, cell capacity and calcium current densities as a result of diminished LTCC surface expression. Finally, Myoscape expression is reduced in hearts from patients suffering of terminal heart failure, implying a role in human disease. PMID:27122098

  6. Improved Electronic Properties of Laser-Doped Emitters by Reducing Surface Roughness

    NASA Astrophysics Data System (ADS)

    Nishimura, Hideki; Hirata, Kenji; Hasegawa, Mitsuhiro; Katagiri, Takuya; Fuyuki, Takashi

    2012-10-01

    Laser doping (LD) can help form emitters at low cost and in high throughput because it operates in air atmosphere and at room temperature. Moreover, LD makes high-efficiency structures in a very simple way by melting and diffusing impurities on selective areas. In this study, evaluation of the relationship between multicrystalline silicon (mc-Si) surface conditions and electric properties is carried out. The results show that the surface electric properties were improved and conversion efficiencies were increased. This was accomplished by changing the surface conditions from rough to smooth by surface etching and vacuum treatment before LD.

  7. Vitamin A supplementation reduces IL-17 and RORc gene expression in atherosclerotic patients.

    PubMed

    Mottaghi, A; Ebrahimof, S; Angoorani, P; Saboor-Yaraghi, A-A

    2014-08-01

    Vitamin A is a potential mediator of T helper cells in atherosclerosis. The purpose of this study was to evaluate the effect of vitamin A supplementation on expression of Th17 cells-related IL-17 and RORc genes in atherosclerotic patients. Thirty one atherosclerotic patients and 15 healthy controls were studied for 4 months. Atherosclerotic patients were randomly divided into vitamin A or placebo groups. Healthy controls and patients in vitamin A group received 25,000 IU retinyl palmitate per day. Peripheral blood mononuclear cells were isolated, cultured and divided into three groups including fresh cells, phytohemagglutinin (PHA)-activated T cells and ox-LDL-activated T cells. Gene expressions of T cells were studied by real-time PCR. In atherosclerotic patients, vitamin A supplementation resulted in significant decrease in IL-17 gene expression by 0.63-fold in fresh cell, 0.82-fold in PHA-activated cells and 0.65-fold in ox-LDL-activated cells (P < 0.05 for all). RORc gene expression in fresh cells as well as ox-LDL-activated cells decreased significantly after vitamin A supplementation in atherosclerotic patients (P = 0.0001 for both). In PHA-activated cells, vitamin A supplementation significantly decreased RORc gene in both atherosclerotic patients and healthy subjects by 0.87-fold and 0.72, respectively, while in placebo group, the RORc gene expression significantly increased by 1.17-fold (P < 0.05 for all). Findings of this study suggest that vitamin A supplementation may be an effective approach to slow progression of atherosclerosis. PMID:24845870

  8. Reduced expression of microenvironmental Th1 cytokines accompanies adenomas-carcinomas sequence of colorectum.

    PubMed

    Cui, Guanglin; Goll, Rasmus; Olsen, Trine; Steigen, Sonja Eriksson; Husebekk, Anne; Vonen, Barthold; Florholmen, Jon

    2007-07-01

    Cytokines have been suggested to be key factors in modulating immune response against tumorigenesis in the microenvironment. Therefore, characterization of cytokine expression along the colorectal adenoma-carcinoma sequence may add important information for understanding the immune-related mechanisms of the development of colorectal carcinoma (CRC). In this study, biopsies from 32 patients with colorectal adenoma (CRA), 20 patients with CRC and 18 healthy controls were examined. Cytokine gene expressions of interleukin-4 (IL-4), IL-10, tumor necrosis factor (TNF)-alpha, interferon (IFN)-gamma and its upstream inducers (IL-12A and IL-18) were measured at messenger RNA (mRNA) level with quantitative real-time PCR (Q-PCR). Cytokine expressing cells were characterized using immunohistochemistry (IHC). A distinct different cytokine profile between adenoma and CRC was observed: the Th1 cytokines (IFN-gamma, TNF-alpha, IL-12A and IL-18) were increased in local tissues of CRA and decreased in CRC. Consistent with the quantitative cytokine data, IHC examinations revealed slightly increased densities of Th1 cytokine-expressing cells in CRA and a remarkably decreased density of the Th1 cells in CRC. In CRA, the cytokine-expressing cells were highly polarized to the subepithelial stroma while the cells were evenly distributed through the stroma in CRC. In conclusion, distinct changes in the Th1 cytokine profile appear along the colorectal adenoma-carcinoma sequence. This may reflect a change in the host immune regulatory function in the adenoma-carcinoma sequence. PMID:17160410

  9. Reduced proximal tubule angiotensin II receptor expression in streptozotocin-induced diabetes mellitus.

    PubMed

    Cheng, H F; Burns, K D; Harris, R C

    1994-12-01

    Diabetes mellitus is characterized by alterations in the intrarenal renin-angiotensin system, including decreases in glomerular angiotensin II (Ang II) receptor density. Since Ang II regulates proximal tubule transport function, the present studies examined whether diabetes altered expression of proximal tubule receptors. In basolateral membranes from 14 day streptozotocin-induced diabetic rats, specific binding of 125I Ang II was decreased to 53 +/- 8% of control (3.2 +/- 0.5 vs. 1.5 +/- 0.2 fmol/mg protein; N = 7; P < 0.02). Similarly, in proximal tubule brush border membranes from diabetic animals, specific binding was decreased to 63 +/- 11% of control (1.1 +/- 0.2 vs 0.6 +/- 0.1 fmol/mg protein; N = 9; P < 0.05). Concomitant insulin treatment reversed the decrease in specific binding of 125I Ang II to basolateral membranes (109 +/- 26% of control; N = 3) and to brush border membranes (85 +/- 17% of control; N = 6). In order to determine if changes in expression of type-1 Ang II receptors (AT1R) accompanied the changes in binding, quantitative polymerase chain reaction of AT1R mRNA was performed and expressed as the ratio of the amplified AT1R to that of an Msc1/Msc1 internal deletion mutant and normalized to that of beta-actin. In total RNA from proximal tubule suspensions of diabetic animals, AT1R mRNA expression decreased by 38% (21 +/- 3 vs. 13 +/- 2 cpm AT1R/cpm deletion mutant/cpm beta actin/10(6); N = 4; P < 0.0025). Insulin treatment reverted AT1R mRNA expression to control levels (22 +/- 3 cpm AT1R/cpm deletion mutant/cpm beta actin/10(6); P < 0.001 compared to the untreated group).(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7700017

  10. Surface EMG-based Sketching Recognition Using Two Analysis Windows and Gene Expression Programming

    PubMed Central

    Yang, Zhongliang; Chen, Yumiao

    2016-01-01

    Sketching is one of the most important processes in the conceptual stage of design. Previous studies have relied largely on the analyses of sketching process and outcomes; whereas surface electromyographic (sEMG) signals associated with sketching have received little attention. In this study, we propose a method in which 11 basic one-stroke sketching shapes are identified from the sEMG signals generated by the forearm and upper arm muscles from 4 subjects. Time domain features such as integrated electromyography, root mean square and mean absolute value were extracted with analysis windows of two length conditions for pattern recognition. After reducing data dimensionality using principal component analysis, the shapes were classified using Gene Expression Programming (GEP). The performance of the GEP classifier was compared to the Back Propagation neural network (BPNN) and the Elman neural network (ENN). Feature extraction with the short analysis window (250 ms with a 250 ms increment) improved the recognition rate by around 6.4% averagely compared with the long analysis window (2500 ms with a 2500 ms increment). The average recognition rate for the eleven basic one-stroke sketching patterns achieved by the GEP classifier was 96.26% in the training set and 95.62% in the test set, which was superior to the performance of the BPNN and ENN classifiers. The results show that the GEP classifier is able to perform well with either length of the analysis window. Thus, the proposed GEP model show promise for recognizing sketching based on sEMG signals. PMID:27790083

  11. Surface expression of ASIC2 inhibits the amiloride-sensitive current and migration of glioma cells.

    PubMed

    Vila-Carriles, Wanda H; Kovacs, Gergely Gy; Jovov, Biljana; Zhou, Zhen-Hong; Pahwa, Amit K; Colby, Garrett; Esimai, Ogenna; Gillespie, G Yancey; Mapstone, Timothy B; Markert, James M; Fuller, Catherine M; Bubien, James K; Benos, Dale J

    2006-07-14

    Gliomas are primary brain tumors with a complex biology characterized by antigenic and genomic heterogeneity and a propensity for invasion into normal brain tissue. High grade glioma cells possess a voltage-independent, amiloride-inhibitable, inward Na+ current. This current does not exist in normal astrocytes or low grade tumor cells. Inhibition of this conductance decreases glioma growth and cell migration making it a potential therapeutic target. Our previous results have shown that the acid-sensing ion channels (ASICs), members of the epithelial Na+ channel (ENaC)/degenerin (DEG) family of ion channels are part of this current pathway. We hypothesized that one member of the ENaC/DEG family, ASIC2, is retained intracellularly and that it is the lack of functional expression of ASIC2 at the cell surface that results in hyperactivity of this conductance in high grade gliomas. In this study we show that the chemical chaperone, glycerol, and the transcriptional regulator, sodium 4-phenylbutyrate, inhibit the constitutively activated inward current and reduce cell growth and migration in glioblastoma multiforme. The results suggest that these compounds induce the movement of ASIC2 to the plasma membrane, and once there, the basally active inward current characteristic of glioma cells is abolished by inherent negative regulatory mechanisms. This in turn compromises the ability of the glioma cell to migrate and proliferate. These results support the hypothesis that the conductance pathway in high grade glioma cells is comprised of ENaC/DEG subunits and that abolishing this channel activity promotes a reversion of a high grade glioma cell to a phenotype resembling that of normal astrocytes. PMID:16704974

  12. Resistance to pathologic cardiac hypertrophy and reduced expression of CaV1.2 in Trpc3-depleted mice.

    PubMed

    Han, Jung Woo; Lee, Young Ho; Yoen, Su-In; Abramowitz, Joel; Birnbaumer, Lutz; Lee, Min Goo; Kim, Joo Young

    2016-10-01

    Sustained elevation of intracellular Ca(2+) concentration ([Ca(2+)]i) reprograms cardiovascular cell fate, leading to cellular hypertrophy via Ca(2+)-calmodulin/calcineurin (Cn)/NFAT activation. Accumulating evidence suggests that transient receptor potential canonical (Trpc) channels play important roles in the development of pathologic cardiac hypertrophy. Here, we demonstrated that Trpc3 mediates pathologic cardiac hypertrophy in neurohumoral elevation via direct regulation of CaV1.2 expressions. Elevated PE (phenylephrine) was maintained in mice by continuous infusion using an osmotic pump. Wild-type (WT) mice, but not Trpc3 (-/-) showed a sudden decrease in blood pressure (BP) or death following elevation of BP under conditions of elevated PE. Trpc3 (-/-) mesenteric artery showed decreased PE-stimulated vasoconstriction. Analysis of morphology, function, and pathologic marker expression revealed that PE elevation caused pathologic cardiac hypertrophy in WT mice, which was prevented by deletion of Trpc3. Interestingly, protection by Trpc3 deletion seemed to be a result of reduced cardiac CaV1.2 expressions. Basal and PE induced increased expression of protein and mRNA of CaV1.2 was decreased in Trpc3 (-/-) heart. Accordingly, altered expression of CaV1.2 was observed by knockdown or stimulation of Trpc3 in cardiomyocytes. These findings suggest that Trpc3 is a mediator of pathologic cardiac hypertrophy not only through mediating part of the Ca(2+) influx, but also through control of CaV1.2 expressions.

  13. Suppressing male spermatogenesis-associated protein 5-like gene expression reduces vitellogenin gene expression and fecundity in Nilaparvata lugens Stål

    PubMed Central

    Ge, Lin-Quan; Xia, Ting; Huang, Bo; Song, Qi-Sheng; Zhang, Hong-Wei; Stanley, David; Yang, Guo-Qing; Wu, Jin-Cai

    2016-01-01

    In our previous study with the brown planthopper (BPH), Nilaparvata lugens, triazophos (tzp) treatments led to substantial up-regulation of a male spermatogenesis-associated protein 5-like gene (NlSPATA5) compared to untreated controls. Mating with tzp-treated males significantly increased fecundity (as numbers of eggs laid), relative to females mated with untreated males. Because SPATA5 acts in mammalian sperm development and is expressed in testes, we posed the hypothesis that NlSPATA5 occurs in BPH seminal fluid and it operates in fecundity via mating. We tested the hypothesis by investigating the influence of suppressing NlSPATA5 expression in BPH males on fecundity. Reduced expression of NlSPATA5 led to decreased male accessory gland protein content and reproductive system development compared to controls. These changes in males led to prolonged pre-oviposition periods and decreased fecundity in females. For both genders, we recorded no difference in the body weight, oviposition periods, and longevity compared to controls. NlSPATA5 suppression in males also led to decreased fat body and ovarian protein content, yeast-like symbionts abundance and ovarian development as well as vitellogenin gene expression in their mating partners. We infer that increased NlSPATA5 expression may be one molecular mechanism of tzp-driven reproduction and population increases in BPH. PMID:27305948

  14. Suppressing male spermatogenesis-associated protein 5-like gene expression reduces vitellogenin gene expression and fecundity in Nilaparvata lugens Stål.

    PubMed

    Ge, Lin-Quan; Xia, Ting; Huang, Bo; Song, Qi-Sheng; Zhang, Hong-Wei; Stanley, David; Yang, Guo-Qing; Wu, Jin-Cai

    2016-01-01

    In our previous study with the brown planthopper (BPH), Nilaparvata lugens, triazophos (tzp) treatments led to substantial up-regulation of a male spermatogenesis-associated protein 5-like gene (NlSPATA5) compared to untreated controls. Mating with tzp-treated males significantly increased fecundity (as numbers of eggs laid), relative to females mated with untreated males. Because SPATA5 acts in mammalian sperm development and is expressed in testes, we posed the hypothesis that NlSPATA5 occurs in BPH seminal fluid and it operates in fecundity via mating. We tested the hypothesis by investigating the influence of suppressing NlSPATA5 expression in BPH males on fecundity. Reduced expression of NlSPATA5 led to decreased male accessory gland protein content and reproductive system development compared to controls. These changes in males led to prolonged pre-oviposition periods and decreased fecundity in females. For both genders, we recorded no difference in the body weight, oviposition periods, and longevity compared to controls. NlSPATA5 suppression in males also led to decreased fat body and ovarian protein content, yeast-like symbionts abundance and ovarian development as well as vitellogenin gene expression in their mating partners. We infer that increased NlSPATA5 expression may be one molecular mechanism of tzp-driven reproduction and population increases in BPH. PMID:27305948

  15. Cdo Regulates Surface Expression of Kir2.1 K+ Channel in Myoblast Differentiation

    PubMed Central

    Koh, Jewoo; Kang, KyeongJin; Bae, Gyu-Un; Cho, Hana; Kang, Jong-Sun

    2016-01-01

    A potassium channel Kir2.1-associated membrane hyperpolarization is required for myogenic differentiation. However the molecular regulatory mechanisms modulating Kir2.1 channel activities in early stage of myogenesis are largely unknown. A cell surface protein, Cdo functions as a component of multiprotein cell surface complexes to promote myogenesis. In this study, we report that Cdo forms a complex with Kir2.1 during myogenic differentiation, and is required for the channel activity by enhancing the surface expression of Kir2.1 in the early stage of differentiation. The expression of a constitutively active form of the upstream kinase for p38MAPK, MKK6(EE) can restore Kir2.1 activities in Cdo-depleted C2C12 cells, while the treatment with a p38MAPK inhibitor, SB203580 exhibits a similar effect of Cdo depletion on Kir2.1 surface expression. Furthermore, Cdo-/- primary myoblasts, which display a defective differentiation program, exhibit a defective Kir2.1 activity. Taken together, our results suggest that a promyogenic Cdo signaling is critical for Kir2.1 activities in the induction of myogenic differentiation. PMID:27380411

  16. Effects of dietary K on cell-surface expression of renal ion channels and transporters.

    PubMed

    Frindt, Gustavo; Palmer, Lawrence G

    2010-10-01

    Changes in apical surface expression of ion channels and transporters in the superficial rat renal cortex were assessed using biotinylation and immunoblotting during alterations in dietary K intake. A high-K diet increased, and a low-K diet decreased, both the overall and surface abundance of the β- and γ-subunits of the epithelial Na channel (ENaC). In the case of γ-ENaC, the effect was specific for the 65-kDa cleaved form of the protein. The overall amount of α-ENAC was also increased with increasing K intake. The total expression of the secretory K(+) channels (ROMK) increased with a high-K diet and decreased with a low-K diet. The surface expression of ROMK increased with high K intake but was not significantly altered by a low-K diet. In contrast, the amounts of total and surface protein representing the thiazide-sensitive NaCl cotransporter (NCC) decreased with increasing K intake. We conclude that modulation of K(+) secretion in response to changes in dietary K intake involves changes in apical K(+) permeability through regulation of K(+) channels and in driving force subsequent to alterations in both Na delivery to the distal nephron and Na(+) uptake across the apical membrane of the K(+) secretory cells. PMID:20702602

  17. Long-term controlled GDNF over-expression reduces dopamine transporter activity without affecting tyrosine hydroxylase expression in the rat mesostriatal system.

    PubMed

    Barroso-Chinea, Pedro; Cruz-Muros, Ignacio; Afonso-Oramas, Domingo; Castro-Hernández, Javier; Salas-Hernández, Josmar; Chtarto, Abdelwahed; Luis-Ravelo, Diego; Humbert-Claude, Marie; Tenenbaum, Liliane; González-Hernández, Tomás

    2016-04-01

    The dopamine (DA) transporter (DAT) is a plasma membrane glycoprotein expressed in dopaminergic (DA-) cells that takes back DA into presynaptic neurons after its release. DAT dysfunction has been involved in different neuro-psychiatric disorders including Parkinson's disease (PD). On the other hand, numerous studies support that the glial cell line-derived neurotrophic factor (GDNF) has a protective effect on DA-cells. However, studies in rodents show that prolonged GDNF over-expression may cause a tyrosine hydroxylase (TH, the limiting enzyme in DA synthesis) decline. The evidence of TH down-regulation suggests that another player in DA handling, DAT, may also be regulated by prolonged GDNF over-expression, and the possibility that this effect is induced at GDNF expression levels lower than those inducing TH down-regulation. This issue was investigated here using intrastriatal injections of a tetracycline-inducible adeno-associated viral vector expressing human GDNF cDNA (AAV-tetON-GDNF) in rats, and doxycycline (DOX; 0.01, 0.03, 0.5 and 3mg/ml) in the drinking water during 5weeks. We found that 3mg/ml DOX promotes an increase in striatal GDNF expression of 12× basal GDNF levels and both DA uptake decrease and TH down-regulation in its native and Ser40 phosphorylated forms. However, 0.5mg/ml DOX promotes a GDNF expression increase of 3× basal GDNF levels with DA uptake decrease but not TH down-regulation. The use of western-blot under non-reducing conditions, co-immunoprecipitation and in situ proximity ligation assay revealed that the DA uptake decrease is associated with the formation of DAT dimers and an increase in DAT-α-synuclein interactions, without changes in total DAT levels or its compartmental distribution. In conclusion, at appropriate GDNF transduction levels, DA uptake is regulated through DAT protein-protein interactions without interfering with DA synthesis. PMID:26777664

  18. Charge transfer and formation of reduced Ce{sup 3+} upon adsorption of metal atoms at the ceria (110) surface

    SciTech Connect

    Nolan, Michael

    2012-04-07

    The modification of cerium dioxide with nanoscale metal clusters is intensely researched for catalysis applications, with gold, silver, and copper having been particularly well studied. The interaction of the metal cluster with ceria is driven principally by a localised interaction between a small number of metal atoms (as small as one) and the surface and understanding the fundamentals of the interaction of metal atoms with ceria surfaces is therefore of great interest. Much attention has been focused on the interaction of metals with the (111) surface of ceria, since this is the most stable surface and can be grown as films, which are probed experimentally. However, nanostructures exposing other surfaces such as (110) show high activity for reactions including CO oxidation and require further study; these nanostructures could be modified by deposition of metal atoms or small clusters, but there is no information to date on the atomic level details of metal-ceria interactions involving the (110) surface. This paper presents the results of density functional theory (DFT) corrected for on-site Coulomb interactions (DFT+U) calculations of the adsorption of a number of different metal atoms at an extended ceria (110) surface; the metals are Au, Ag, Cu, Al, Ga, In, La, Ce, V, Cr, and Fe. Upon adsorption all metals are oxidised, transferring electron(s) to the surface, resulting in localised surface distortions. The precise details depend on the identity of the metal atom. Au, Ag, Cu each transfer one electron to the surface, reducing one Ce ion to Ce{sup 3+}, while of the trivalent metals, Al and La are fully oxidised, but Ga and In are only partially oxidised. Ce and the transition metals are also partially oxidised, with the number of reduced Ce ions possible in this surface no more than three per adsorbed metal atom. The predicted oxidation states of the adsorbed metal atoms should be testable in experiments on ceria nanostructures modified with metal atoms.

  19. Charge transfer and formation of reduced Ce3+ upon adsorption of metal atoms at the ceria (110) surface.

    PubMed

    Nolan, Michael

    2012-04-01

    The modification of cerium dioxide with nanoscale metal clusters is intensely researched for catalysis applications, with gold, silver, and copper having been particularly well studied. The interaction of the metal cluster with ceria is driven principally by a localised interaction between a small number of metal atoms (as small as one) and the surface and understanding the fundamentals of the interaction of metal atoms with ceria surfaces is therefore of great interest. Much attention has been focused on the interaction of metals with the (111) surface of ceria, since this is the most stable surface and can be grown as films, which are probed experimentally. However, nanostructures exposing other surfaces such as (110) show high activity for reactions including CO oxidation and require further study; these nanostructures could be modified by deposition of metal atoms or small clusters, but there is no information to date on the atomic level details of metal-ceria interactions involving the (110) surface. This paper presents the results of density functional theory (DFT) corrected for on-site Coulomb interactions (DFT+U) calculations of the adsorption of a number of different metal atoms at an extended ceria (110) surface; the metals are Au, Ag, Cu, Al, Ga, In, La, Ce, V, Cr, and Fe. Upon adsorption all metals are oxidised, transferring electron(s) to the surface, resulting in localised surface distortions. The precise details depend on the identity of the metal atom. Au, Ag, Cu each transfer one electron to the surface, reducing one Ce ion to Ce(3+), while of the trivalent metals, Al and La are fully oxidised, but Ga and In are only partially oxidised. Ce and the transition metals are also partially oxidised, with the number of reduced Ce ions possible in this surface no more than three per adsorbed metal atom. The predicted oxidation states of the adsorbed metal atoms should be testable in experiments on ceria nanostructures modified with metal atoms.

  20. Phase variation mediates reductions in expression of surface proteins during persistent meningococcal carriage.

    PubMed

    Alamro, Mohamed; Bidmos, Fadil A; Chan, Hannah; Oldfield, Neil J; Newton, Emma; Bai, Xilian; Aidley, Jack; Care, Rory; Mattick, Claire; Turner, David P J; Neal, Keith R; Ala'aldeen, Dlawer A A; Feavers, Ian; Borrow, Ray; Bayliss, Christopher D

    2014-06-01

    Asymptomatic and persistent colonization of the upper respiratory tract by Neisseria meningitidis occurs despite elicitation of adaptive immune responses against surface antigens. A putative mechanism for facilitating host persistence of this bacterial commensal and pathogen is alterations in expression of surface antigens by simple sequence repeat (SSR)-mediated phase variation. We investigated how often phase variation occurs during persistent carriage by analyzing the SSRs of eight loci in multiple isolates from 21 carriers representative of 1 to 6 months carriage. Alterations in repeat number were detected by a GeneScan analysis and occurred at 0.06 mutations/gene/month of carriage. The expression states were determined by Western blotting and two genes, fetA and nadA, exhibited trends toward low expression states. A critical finding from our unique examination of combinatorial expression states, "phasotypes," was for significant reductions in expression of multiple phase-variable surface proteins during persistent carriage of some strains. The immune responses in these carriers were examined by measuring variant-specific PorA IgG antibodies, capsular group Y IgG antibodies and serum bactericidal activity in concomitant serum samples. Persistent carriage was associated with high levels of specific IgG antibodies and serum bactericidal activity while recent strain acquisition correlated with a significant induction of antibodies. We conclude that phase-variable genes are driven into lower expression states during long-term persistent meningococcal carriage, in part due to continuous exposure to antibody-mediated selection, suggesting localized hypermutation has evolved to facilitate host persistence. PMID:24686058

  1. Clonal evolution of myeloma cells leads to quantitative changes in immunoglobulin secretion and surface antigen expression.

    PubMed Central

    Leibson, P J; Loken, M R; Panem, S; Schreiber, H

    1979-01-01

    We report that a cloned population of tumor cells can rapidly produce variants that differ in their quantitative expression of surface proteins and in their rate of immunoglobulin secretion. A fresh clonal isolate of S107 myeloma cells possessing large amounts of surface IgA was continuously passaged in vitro for 2 years. During this period, fluorescence-activated cell sorter analysis indicated the development of subpopulations possessing decreased amounts of surface IgA. Cells from these variant subpopulations were isolated by first using the cell sorter to enrich for cells with decreased amounts of surface IgA and then cloning the selected population in soft agar. The 50 sublines that were isolated showed heritable differences in their levels of surface IgA and H-2 antigens and in their rates of myeloma protein secretion. Sublines having either large amounts, intermediate amounts, or absence of surface IgA also had corresponding large amounts, intermediate amounts, or absence of myeloma protein secretion. In contrast, a decrease or loss of surface Ig did not correlate with a decrease or loss of viral envelope glycoprotein gp71 and H-2 antigens. The variants did not resemble the phenotypes of less-differentiated normal lymphocyte populations of the B-cell lineage. The isolation and characterization of these variants allows us to explore the mechanisms and pathways of tumor cell differentiation as well as to study the regulation and function of cell surface proteins. PMID:288078

  2. VIRTIS on Venus Express: retrieval of real surface emissivity on global scales

    NASA Astrophysics Data System (ADS)

    Arnold, Gabriele E.; Kappel, David; Haus, Rainer; Telléz Pedroza, Laura; Piccioni, Giuseppe; Drossart, Pierre

    2015-09-01

    The extraction of surface emissivity data provides the data base for surface composition analyses and enables to evaluate Venus' geology. The Visible and InfraRed Thermal Imaging Spectrometer (VIRTIS) aboard ESA's Venus Express mission measured, inter alia, the nightside thermal emission of Venus in the near infrared atmospheric windows between 1.0 and 1.2 μm. These data can be used to determine information about surface properties on global scales. This requires a sophisticated approach to understand and consider the effects and interferences of different atmospheric and surface parameters influencing the retrieved values. In the present work, results of a new technique for retrieval of the 1.0 - 1.2 μm - surface emissivity are summarized. It includes a Multi-Window Retrieval Technique, a Multi-Spectrum Retrieval technique (MSR), and a detailed reliability analysis. The MWT bases on a detailed radiative transfer model making simultaneous use of information from different atmospheric windows of an individual spectrum. MSR regularizes the retrieval by incorporating available a priori mean values, standard deviations as well as spatial-temporal correlations of parameters to be retrieved. The capability of this method is shown for a selected surface target area. Implications for geologic investigations are discussed. Based on these results, the work draws conclusions for future Venus surface composition analyses on global scales using spectral remote sensing techniques. In that context, requirements for observational scenarios and instrumental performances are investigated, and recommendations are derived to optimize spectral measurements for Venus' surface studies.

  3. Trypanosomes Expressing a Mosaic Variant Surface Glycoprotein Coat Escape Early Detection by the Immune System

    PubMed Central

    Dubois, Melissa E.; Demick, Karen P.; Mansfield, John M.

    2005-01-01

    Host resistance to African trypanosomiasis is partially dependent on an early and strong T-independent B-cell response against the variant surface glycoprotein (VSG) coat expressed by trypanosomes. The repetitive array of surface epitopes displayed by a monotypic surface coat, in which identical VSG molecules are closely packed together in a uniform architectural display, cross-links cognate B-cell receptors and initiates T-independent B-cell activation events. However, this repetitive array of identical VSG epitopes is altered during the process of antigenic variation, when former and nascent VSG proteins are transiently expressed together in a mosaic surface coat. Thus, T-independent B-cell recognition of the trypanosome surface coat may be disrupted by the introduction of heterologous VSG molecules into the coat structure. To address this hypothesis, we transformed Trypanosoma brucei rhodesiense LouTat 1 with the 117 VSG gene from Trypanosoma brucei brucei MiTat 1.4 in order to produce VSG double expressers; coexpression of the exogenous 117 gene along with the endogenous LouTat 1 VSG gene resulted in the display of a mosaic VSG coat. Results presented here demonstrate that the host's ability to produce VSG-specific antibodies and activate B cells during early infection with VSG double expressers is compromised relative to that during infection with the parental strain, which displays a monotypic coat. These findings suggest a previously unrecognized mechanism of immune response evasion in which coat-switching trypanosomes fail to directly activate B cells until coat VSG homogeneity is achieved. This process affords an immunological advantage to trypanosomes during the process of antigenic variation. PMID:15845470

  4. 40 CFR 52.253 - Metal surface coating thinner and reducer.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 3 2010-07-01 2010-07-01 false Metal surface coating thinner and... PROGRAMS (CONTINUED) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS California § 52.253 Metal surface... described in 40 CFR part 81, dated July 1, 1979, except as follows: (1) In the following portions of...

  5. 40 CFR 52.253 - Metal surface coating thinner and reducer.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 3 2013-07-01 2013-07-01 false Metal surface coating thinner and... PROGRAMS (CONTINUED) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS California § 52.253 Metal surface... described in 40 CFR part 81, dated July 1, 1979, except as follows: (1) In the following portions of...

  6. 40 CFR 52.253 - Metal surface coating thinner and reducer.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 3 2014-07-01 2014-07-01 false Metal surface coating thinner and... PROGRAMS (CONTINUED) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS California § 52.253 Metal surface... described in 40 CFR part 81, dated July 1, 1979, except as follows: (1) In the following portions of...

  7. Liver-specific expression of carboxylesterase 1g/esterase-x reduces hepatic steatosis, counteracts dyslipidemia and improves insulin signaling.

    PubMed

    Bahitham, Wesam; Watts, Russell; Nelson, Randal; Lian, Jihong; Lehner, Richard

    2016-05-01

    Ces1g/Es-x deficiency in mice results in weight gain, insulin resistance, fatty liver and hyperlipidemia through upregulation of de novo lipogenesis and oversecretion of triacylglycerol (TG)-rich lipoproteins. Here, we show that restoration of Ces1g/Es-x expression only in the liver significantly reduced hepatic TG concentration accompanied by decreased size of lipid droplets, reduced secretion of very low-density lipoproteins and improved insulin-mediated signal transduction in the liver. Collectively, these results demonstrate that hepatic Ces1g/Es-x plays a critical role in limiting hepatic steatosis, very low-density lipoprotein assembly and in augmenting insulin sensitivity.

  8. Liver-specific expression of carboxylesterase 1g/esterase-x reduces hepatic steatosis, counteracts dyslipidemia and improves insulin signaling.

    PubMed

    Bahitham, Wesam; Watts, Russell; Nelson, Randal; Lian, Jihong; Lehner, Richard

    2016-05-01

    Ces1g/Es-x deficiency in mice results in weight gain, insulin resistance, fatty liver and hyperlipidemia through upregulation of de novo lipogenesis and oversecretion of triacylglycerol (TG)-rich lipoproteins. Here, we show that restoration of Ces1g/Es-x expression only in the liver significantly reduced hepatic TG concentration accompanied by decreased size of lipid droplets, reduced secretion of very low-density lipoproteins and improved insulin-mediated signal transduction in the liver. Collectively, these results demonstrate that hepatic Ces1g/Es-x plays a critical role in limiting hepatic steatosis, very low-density lipoprotein assembly and in augmenting insulin sensitivity. PMID:26976727

  9. An application of active surface heating for augmenting lift and reducing drag of an airfoil

    NASA Technical Reports Server (NTRS)

    Maestrello, Lucio; Badavi, Forooz F.; Noonan, Kevin W.

    1988-01-01

    Application of active control to separated flow on the RC(6)-08 airfoil at high angle of attack by localized surface heating is numerically simulated by integrating the compressible 2-D nonlinear Navier-Stokes equation solver. Active control is simulated by local modification of the temperature boundary condition over a narrow strip of the upper surface of the airfoil. Both mean and perturbed profiles are favorably altered when excited with the same natural frequency of the shear layer by moderate surface heating for both laminar and turbulent separation. The shear layer is found to be very sensitive to localized surface heating in the vicinity of the separation point. The excitation field at the surface sufficiently altered both the local as well as the global circulation to cause a significant increase in lift and reduction in drag.

  10. Surfaces: a playground for physics with broken symmetry in reduced dimensionality

    SciTech Connect

    Plummer, E.W.

    2001-07-11

    With our crystal ball in front of us, we attempt to articulate the opportunities and challenges for a surface physicist in the beginning of the new millennium. The challenge is quite clear: to use the unique environment of a surface or interface to do fascinating physics, while taking full advantage of the skills the community has developed over the last 30 years. The opportunities appear to be endless! In this age of Nanotechnology where the promise is to shape the world atom by atom, leading to the next industrial revolution [Nanotechnology: shaping the world atom by atom, National Science and Technology Council, Committee on Technology, 1999], surface science should be at the very forefront of both technological and scientific advances. The smaller objects become, the more important their surfaces become. In this article we focus on the role of a surface physicist in the emergence of nanoscale collective phenomena in complex materials.

  11. Differential expression of monocyte surface markers among TB patients with diabetes co-morbidity.

    PubMed

    Stew, Samuel S; Martinez, Perla J; Schlesinger, Larry S; Restrepo, Blanca I

    2013-12-01

    The expression of monocyte surface markers was compared between tuberculosis patients with and without type 2 diabetes (DM2). DM2 was associated with increased CCR2 expression, which may restrain monocyte traffic to the lung. Other host factors associated with baseline monocyte changes were older age (associated with lower CD11b) and obesity (associated with higher RAGE). Given that DM2 patients are more likely to be older and obese, their monocytes are predicted to be altered in function in ways that affect their interaction with Mycobacterium tuberculosis.

  12. Purification, characterization, cloning, and expression of a novel xyloglucan-specific glycosidase, oligoxyloglucan reducing end-specific cellobiohydrolase.

    PubMed

    Yaoi, Katsuro; Mitsuishi, Yasushi

    2002-12-13

    A novel oligoxyloglucan-specific glycosidase, oligoxyloglucan reducing end-specific cellobiohydrolase (OXG-RCBH), with a molecular mass of 97 kDa and a pI of 6.1, was isolated from the fungus Geotrichum sp. M128. Analysis of substrate specificity using various xyloglucan oligosaccharide structures revealed that OXG-RCBH had exoglucanase activity. It recognized the reducing end of oligoxyloglucan and released two glucosyl residue segments from the main chain. The full-length cDNA encoding OXG-RCBH was cloned and sequenced, and it had a 2436-bp open reading frame encoding an 812amino acid protein. The deduced protein showed approximately 35% identity to members of glycoside hydrolase family 74. The cDNA encoding OXG-RCBH was then expressed in Escherichia coli. Although the recombinant protein was expressed as an inclusion body, renaturation was successful, and enzymatically active recombinant OXG-RCBH was obtained. PMID:12374797

  13. Reduced Histone Expression or a Defect in Chromatin Assembly Induces Respiration.

    PubMed

    Galdieri, Luciano; Zhang, Tiantian; Rogerson, Daniella; Vancura, Ales

    2016-01-19

    Regulation of mitochondrial biogenesis and respiration is a complex process that involves several signaling pathways and transcription factors as well as communication between the nuclear and mitochondrial genomes. Here we show that decreased expression of histones or a defect in nucleosome assembly in the yeast Saccharomyces cerevisiae results in increased mitochondrial DNA (mtDNA) copy numbers, oxygen consumption, ATP synthesis, and expression of genes encoding enzymes of the tricarboxylic acid (TCA) cycle and oxidative phosphorylation (OXPHOS). The metabolic shift from fermentation to respiration induced by altered chromatin structure is associated with the induction of the retrograde (RTG) pathway and requires the activity of the Hap2/3/4/5p complex as well as the transport and metabolism of pyruvate in mitochondria. Together, our data indicate that altered chromatin structure relieves glucose repression of mitochondrial respiration by inducing transcription of the TCA cycle and OXPHOS genes carried by both nuclear and mitochondrial DNA.

  14. Reduced sensitivity to both positive and negative reinforcement in mice over-expressing the 5-hydroxytryptamine transporter.

    PubMed

    Line, Samantha J; Barkus, Chris; Rawlings, Nancy; Jennings, Katie; McHugh, Stephen; Sharp, Trevor; Bannerman, David M

    2014-12-01

    The 5-hydroxytryptamine (5-HT) transporter (5-HTT) is believed to play a key role in both normal and pathological psychological states. Much previous data suggest that the s allele of the polymorphic regulatory region of the 5-HTT gene promoter is associated with reduced 5-HTT expression and vulnerability to psychiatric disorders, including anxiety and depression. In comparison, the l allele, which increases 5-HTT expression, is generally considered protective. However, recent data link this allele to both abnormal 5-HT signalling and psychopathic traits. Here, we studied the processing of aversive and rewarding cues in transgenic mice that over-express the 5-HTT (5-HTTOE mice). Compared with wild-type mice, 5-HTTOE mice froze less in response to both a tone that had previously been paired with footshock, and the conditioning context. In addition, on a decision-making T-maze task, 5-HTTOE mice displayed reduced preference for a larger, delayed reward and increased preference for a smaller, immediate reward, suggesting increased impulsiveness compared with wild-type mice. However, further inspection of the data revealed that 5-HTTOE mice displayed a relative insensitivity to reward magnitude, irrespective of delay. In contrast, 5-HTTOE mice appeared normal on tests of spatial working and reference memory, which required an absolute choice between options associated with either reward or no reward. Overall, the present findings suggest that 5-HTT over-expression results in a reduced sensitivity to both positive and negative reinforcers. Thus, these data show that increased 5-HTT expression has some maladaptive effects, supporting recent suggestions that l allele homozygosity may be a potential risk factor for disabling psychiatric traits.

  15. Overwintering Is Associated with Reduced Expression of Immune Genes and Higher Susceptibility to Virus Infection in Honey Bees

    PubMed Central

    Steinmann, Nadja; Corona, Miguel; Neumann, Peter; Dainat, Benjamin

    2015-01-01

    The eusocial honey bee, Apis mellifera, has evolved remarkable abilities to survive extreme seasonal differences in temperature and availability of resources by dividing the worker caste into two groups that differ in physiology and lifespan: summer and winter bees. Most of the recent major losses of managed honey bee colonies occur during the winter, suggesting that winter bees may have compromised immune function and higher susceptibility to diseases. We tested this hypothesis by comparing the expression of eight immune genes and naturally occurring infection levels of deformed wing virus (DWV), one of the most widespread viruses in A. mellifera populations, between summer and winter bees. Possible interactions between immune response and physiological activity were tested by measuring the expression of vitellogenin and methyl farnesoate epoxidase, a gene coding for the last enzyme involved in juvenile hormone biosynthesis. Our data show that high DWV loads in winter bees correlate with reduced expression of genes involved in the cellular immune response and physiological activity and high expression of humoral immune genes involved in antibacterial defense compared with summer bees. This expression pattern could reflect evolutionary adaptations to resist bacterial pathogens and economize energy during the winter under a pathogen landscape with reduced risk of pathogenic viral infections. The outbreak of Varroa destructor infestation could have overcome these adaptations by promoting the transmission of viruses. Our results suggest that reduced cellular immune function during the winter may have increased honey bee’s susceptibility to DWV. These results contribute to our understanding of honey bee colony losses in temperate regions. PMID:26121358

  16. Expressing ScACR3 in rice enhanced arsenite efflux and reduced arsenic accumulation in rice grains.

    PubMed

    Duan, Guilan; Kamiya, Takehiro; Ishikawa, Satoru; Arao, Tomohito; Fujiwara, Toru

    2012-01-01

    Arsenic (As) accumulation in rice grain poses a serious health risk to populations with high rice consumption. Extrusion of arsenite [As(III)] by ScAcr3p is the major arsenic detoxification mechanism in Saccharomyces cerevisiae. However, ScAcr3p homolog is absent in higher plants, including rice. In this study, ScACR3 was introduced into rice and expressed under the control of the Cauliflower mosaic virus (CaMV) 35S promoter. In the transgenic lines, As concentrations in shoots and roots were about 30% lower than in the wild type, while the As translocation factors were similar between transgenic lines and the wild type. The roots of transgenic plants exhibited significantly higher As efflux activities than those of the wild type. Within 24 h exposure to 10 μM arsenate [As(V)], roots of ScACR3-expressing plants extruded 80% of absorbed As(V) to the external solution as As(III), while roots of the wild type extruded 50% of absorbed As(V). Additionally, by exposing the As-containing rice plants to an As-lacking solution for 24 h, about 30% of the total As derived from pre-treatment was extruded to the external solution by ScACR3-expressing plants, while about 15% of As was extruded by wild-type plants. Importantly, ScACR3 expression significantly reduced As accumulation in rice straws and grains. When grown in flooded soil irrigated with As(III)-containing water, the As concentration in husk and brown rice of the transgenic lines was reduced by 30 and 20%, respectively, compared with the wild type. This study reports a potential strategy to reduce As accumulation in the food chain by expressing heterologous genes in crops. PMID:22107880

  17. Reduced sensitivity to both positive and negative reinforcement in mice over-expressing the 5-hydroxytryptamine transporter.

    PubMed

    Line, Samantha J; Barkus, Chris; Rawlings, Nancy; Jennings, Katie; McHugh, Stephen; Sharp, Trevor; Bannerman, David M

    2014-12-01

    The 5-hydroxytryptamine (5-HT) transporter (5-HTT) is believed to play a key role in both normal and pathological psychological states. Much previous data suggest that the s allele of the polymorphic regulatory region of the 5-HTT gene promoter is associated with reduced 5-HTT expression and vulnerability to psychiatric disorders, including anxiety and depression. In comparison, the l allele, which increases 5-HTT expression, is generally considered protective. However, recent data link this allele to both abnormal 5-HT signalling and psychopathic traits. Here, we studied the processing of aversive and rewarding cues in transgenic mice that over-express the 5-HTT (5-HTTOE mice). Compared with wild-type mice, 5-HTTOE mice froze less in response to both a tone that had previously been paired with footshock, and the conditioning context. In addition, on a decision-making T-maze task, 5-HTTOE mice displayed reduced preference for a larger, delayed reward and increased preference for a smaller, immediate reward, suggesting increased impulsiveness compared with wild-type mice. However, further inspection of the data revealed that 5-HTTOE mice displayed a relative insensitivity to reward magnitude, irrespective of delay. In contrast, 5-HTTOE mice appeared normal on tests of spatial working and reference memory, which required an absolute choice between options associated with either reward or no reward. Overall, the present findings suggest that 5-HTT over-expression results in a reduced sensitivity to both positive and negative reinforcers. Thus, these data show that increased 5-HTT expression has some maladaptive effects, supporting recent suggestions that l allele homozygosity may be a potential risk factor for disabling psychiatric traits. PMID:25283165

  18. β-Conglycinin Reduces the Tight Junction Occludin and ZO-1 Expression in IPEC-J2

    PubMed Central

    Zhao, Yuan; Qin, Guixin; Han, Rui; Wang, Jun; Zhang, Xiaodong; Liu, Dandan

    2014-01-01

    Soybean allergy presents a health threat to humans and animals. The mechanism by which food/feed allergen β-conglycinin injures the intestinal barrier has not been well understood. In this study, the changes of epithelial permeability, integrity, metabolic activity, the tight junction (TJ) distribution and expression induced by β-conglycinin were evaluated using IPEC-J2 model. The results showed a significant decrease of trans-epithelial electrical resistance (TEER) (p < 0.001) and metabolic activity (p < 0.001) and a remarkable increase of alkaline phosphatase (AP) activity (p < 0.001) in a dose-dependent manner. The expression levels of tight junction occludin and ZO-1 were decreased (p < 0.05). The reduced fluorescence of targets and change of cellular morphology were recorded. The tight junction occludin and ZO-1 mRNA expression linearly declined with increasing β-conglycinin (p < 0.001). PMID:24473141

  19. Reducing Ventral Tegmental Dopamine D2 Receptor Expression Selectively Boosts Incentive Motivation

    PubMed Central

    de Jong, Johannes W; Roelofs, Theresia J M; Mol, Frédérique M U; Hillen, Anne E J; Meijboom, Katharina E; Luijendijk, Mieneke C M; van der Eerden, Harrie A M; Garner, Keith M; Vanderschuren, Louk J M J; Adan, Roger A H

    2015-01-01

    Altered mesolimbic dopamine signaling has been widely implicated in addictive behavior. For the most part, this work has focused on dopamine within the striatum, but there is emerging evidence for a role of the auto-inhibitory, somatodendritic dopamine D2 receptor (D2R) in the ventral tegmental area (VTA) in addiction. Thus, decreased midbrain D2R expression has been implicated in addiction in humans. Moreover, knockout of the gene encoding the D2R receptor (Drd2) in dopamine neurons has been shown to enhance the locomotor response to cocaine in mice. Therefore, we here tested the hypothesis that decreasing D2R expression in the VTA of adult rats, using shRNA knockdown, promotes addiction-like behavior in rats responding for cocaine or palatable food. Rats with decreased VTA D2R expression showed markedly increased motivation for both sucrose and cocaine under a progressive ratio schedule of reinforcement, but the acquisition or maintenance of cocaine self-administration were not affected. They also displayed enhanced cocaine-induced locomotor activity, but no change in basal locomotion. This robust increase in incentive motivation was behaviorally specific, as we did not observe any differences in fixed ratio responding, extinction responding, reinstatement or conditioned suppression of cocaine, and sucrose seeking. We conclude that VTA D2R knockdown results in increased incentive motivation, but does not directly promote other aspects of addiction-like behavior. PMID:25735756

  20. Reducing Ventral Tegmental Dopamine D2 Receptor Expression Selectively Boosts Incentive Motivation.

    PubMed

    de Jong, Johannes W; Roelofs, Theresia J M; Mol, Frédérique M U; Hillen, Anne E J; Meijboom, Katharina E; Luijendijk, Mieneke C M; van der Eerden, Harrie A M; Garner, Keith M; Vanderschuren, Louk J M J; Adan, Roger A H

    2015-08-01

    Altered mesolimbic dopamine signaling has been widely implicated in addictive behavior. For the most part, this work has focused on dopamine within the striatum, but there is emerging evidence for a role of the auto-inhibitory, somatodendritic dopamine D2 receptor (D2R) in the ventral tegmental area (VTA) in addiction. Thus, decreased midbrain D2R expression has been implicated in addiction in humans. Moreover, knockout of the gene encoding the D2R receptor (Drd2) in dopamine neurons has been shown to enhance the locomotor response to cocaine in mice. Therefore, we here tested the hypothesis that decreasing D2R expression in the VTA of adult rats, using shRNA knockdown, promotes addiction-like behavior in rats responding for cocaine or palatable food. Rats with decreased VTA D2R expression showed markedly increased motivation for both sucrose and cocaine under a progressive ratio schedule of reinforcement, but the acquisition or maintenance of cocaine self-administration were not affected. They also displayed enhanced cocaine-induced locomotor activity, but no change in basal locomotion. This robust increase in incentive motivation was behaviorally specific, as we did not observe any differences in fixed ratio responding, extinction responding, reinstatement or conditioned suppression of cocaine, and sucrose seeking. We conclude that VTA D2R knockdown results in increased incentive motivation, but does not directly promote other aspects of addiction-like behavior.

  1. α(1D)-Adrenergic receptors constitutive activity and reduced expression at the plasma membrane.

    PubMed

    García-Sáinz, J Adolfo; Romero-Ávila, M Teresa; Medina, Luz Del Carmen

    2010-01-01

    Adrenergic receptors are a heterogeneous family of the G protein-coupled receptors that mediate the actions of adrenaline and noradrenaline. Adrenergic receptors comprise three subfamilies (α(1), α(2), and β, with three members each) and the α(1D)-adrenergic receptor is one of the members of the α(1) subfamily with some interesting traits. The α(1D)-adrenergic receptor is difficult to express, seems predominantly located intracellularly, and exhibits constitutive activity. In this chapter, we will describe in detail the conditions and procedures used to determine changes in intracellular free calcium concentration which has been instrumental to define the constitutive activity of these receptors. Taking advantage of the fact that truncation of the first 79 amino acids of α(1D)-adrenergic receptors markedly increased their membrane expression, we were able to show that constitutive activity is present in receptors truncated at the amino and carboxyl termini, which indicates that such domains are dispensable for this action. Constitutive activity could be observed in cells expressing either the rat or human α(1D)-adrenergic receptor orthologs. Such constitutive activity has been observed in native rat arteries and we will discuss the possible functional implications that it might have in the regulation of blood pressure.

  2. Depletion of REF/Aly alters gene expression and reduces RNA polymerase II occupancy

    PubMed Central

    Stubbs, Sarah H.; Conrad, Nicholas K.

    2015-01-01

    Pre-mRNA processing is mechanistically linked to transcription with RNA pol II serving as a platform to recruit RNA processing factors to nascent transcripts. The TREX complex member, REF/Aly, has been suggested to play roles in transcription and nuclear RNA stability in addition to its more broadly characterized role in mRNA export. We employed RNA-seq to identify a subset of transcripts with decreased expression in both nuclear and cytoplasmic fractions upon REF/Aly knockdown, which implies that REF/Aly affects their expression upstream of its role in mRNA export. Transcription inhibition experiments and metabolic labeling assays argue that REF/Aly does not affect stability of selected candidate transcripts. Instead, ChIP assays and nuclear run-on analysis reveal that REF/Aly depletion diminishes the transcription of these candidate genes. Furthermore, we determined that REF/Aly binds directly to candidate transcripts, supporting a direct effect of REF/Aly on candidate gene transcription. Taken together, our data suggest that the importance of REF/Aly is not limited to RNA export, but that REF/Aly is also critical for gene expression at the level of transcription. Our data are consistent with the model that REF/Aly is involved in linking splicing with transcription efficiency. PMID:25477387

  3. Depletion of REF/Aly alters gene expression and reduces RNA polymerase II occupancy.

    PubMed

    Stubbs, Sarah H; Conrad, Nicholas K

    2015-01-01

    Pre-mRNA processing is mechanistically linked to transcription with RNA pol II serving as a platform to recruit RNA processing factors to nascent transcripts. The TREX complex member, REF/Aly, has been suggested to play roles in transcription and nuclear RNA stability in addition to its more broadly characterized role in mRNA export. We employed RNA-seq to identify a subset of transcripts with decreased expression in both nuclear and cytoplasmic fractions upon REF/Aly knockdown, which implies that REF/Aly affects their expression upstream of its role in mRNA export. Transcription inhibition experiments and metabolic labeling assays argue that REF/Aly does not affect stability of selected candidate transcripts. Instead, ChIP assays and nuclear run-on analysis reveal that REF/Aly depletion diminishes the transcription of these candidate genes. Furthermore, we determined that REF/Aly binds directly to candidate transcripts, supporting a direct effect of REF/Aly on candidate gene transcription. Taken together, our data suggest that the importance of REF/Aly is not limited to RNA export, but that REF/Aly is also critical for gene expression at the level of transcription. Our data are consistent with the model that REF/Aly is involved in linking splicing with transcription efficiency.

  4. Liver-specific transgenic expression of cholesteryl ester hydrolase reduces atherosclerosis in Ldlr-/- mice.

    PubMed

    Bie, Jinghua; Wang, Jing; Yuan, Quan; Kakiyama, Genta; Ghosh, Siddhartha S; Ghosh, Shobha

    2014-04-01

    The liver plays a central role in the final elimination of cholesterol from the body either as bile acids or as free cholesterol (FC), and lipoprotein-derived cholesterol is the major source of total biliary cholesterol. HDL is the major lipoprotein responsible for removal and transport of cholesterol, mainly as cholesteryl esters (CEs), from the peripheral tissues to the liver. While HDL-FC is rapidly secreted into bile, the fate of HDL-CE remains unclear. We have earlier demonstrated the role of human CE hydrolase (CEH, CES1) in hepatic hydrolysis of HDL-CE and increasing bile acid synthesis, a process dependent on scavenger receptor BI expression. In the present study, we examined the hypothesis that by enhancing the elimination of HDL-CE into bile/feces, liver-specific transgenic expression of CEH will be anti-atherogenic. Increased CEH expression in the liver significantly increased the flux of HDL-CE to bile acids. In the LDLR(-/-) background, this enhanced elimination of cholesterol led to attenuation of diet-induced atherosclerosis with a consistent increase in fecal sterol secretion primarily as bile acids. Taken together with the observed reduction in atherosclerosis by increasing macrophage CEH-mediated cholesterol efflux, these studies establish CEH as an important regulator in enhancing cholesterol elimination and also as an anti-atherogenic target. PMID:24563511

  5. Reducing Ventral Tegmental Dopamine D2 Receptor Expression Selectively Boosts Incentive Motivation.

    PubMed

    de Jong, Johannes W; Roelofs, Theresia J M; Mol, Frédérique M U; Hillen, Anne E J; Meijboom, Katharina E; Luijendijk, Mieneke C M; van der Eerden, Harrie A M; Garner, Keith M; Vanderschuren, Louk J M J; Adan, Roger A H

    2015-08-01

    Altered mesolimbic dopamine signaling has been widely implicated in addictive behavior. For the most part, this work has focused on dopamine within the striatum, but there is emerging evidence for a role of the auto-inhibitory, somatodendritic dopamine D2 receptor (D2R) in the ventral tegmental area (VTA) in addiction. Thus, decreased midbrain D2R expression has been implicated in addiction in humans. Moreover, knockout of the gene encoding the D2R receptor (Drd2) in dopamine neurons has been shown to enhance the locomotor response to cocaine in mice. Therefore, we here tested the hypothesis that decreasing D2R expression in the VTA of adult rats, using shRNA knockdown, promotes addiction-like behavior in rats responding for cocaine or palatable food. Rats with decreased VTA D2R expression showed markedly increased motivation for both sucrose and cocaine under a progressive ratio schedule of reinforcement, but the acquisition or maintenance of cocaine self-administration were not affected. They also displayed enhanced cocaine-induced locomotor activity, but no change in basal locomotion. This robust increase in incentive motivation was behaviorally specific, as we did not observe any differences in fixed ratio responding, extinction responding, reinstatement or conditioned suppression of cocaine, and sucrose seeking. We conclude that VTA D2R knockdown results in increased incentive motivation, but does not directly promote other aspects of addiction-like behavior. PMID:25735756

  6. Polyphenols from Chilean Propolis and Pinocembrin Reduce MMP-9 Gene Expression and Activity in Activated Macrophages

    PubMed Central

    Saavedra, Nicolás; Cuevas, Alejandro; Cavalcante, Marcela F.; Dörr, Felipe A.; Saavedra, Kathleen; Zambrano, Tomás; Abdalla, Dulcineia S. P.; Salazar, Luis A.

    2016-01-01

    Polyphenols from diverse sources have shown anti-inflammatory activity. In the context of atherosclerosis, macrophages play important roles including matrix metalloproteinases synthesis involved in degradation of matrix extracellular components affecting the atherosclerotic plaque stability. We prepared a propolis extract and pinocembrin in ethanol solution. Propolis extract was chemically characterized using LC-MS. The effect of treatments on gene expression and proteolytic activity was measured in vitro using murine macrophages activated with LPS. Cellular toxicity associated with both treatments and the vehicle was determined using MTT and apoptosis/necrosis detection assays. MMP-9 gene expression and proteolytic activity were measured using qPCR and zymography, respectively. Thirty-two compounds were identified in the propolis extract, including pinocembrin among its major components. Treatment with either ethanolic extract of propolis or pinocembrin inhibits MMP-9 gene expression in a dose-dependent manner. Similarly, an inhibitory effect was observed in proteolytic activity. However, the effect showed by ethanolic extract of propolis was higher than the effect of pinocembrin, suggesting that MMP-9 inhibition results from a joint contribution between the components of the extract. These data suggest a potential role of polyphenols from Chilean propolis in the control of extracellular matrix degradation in atherosclerotic plaques. PMID:27119082

  7. Variation of expression defects in cell surface 190-kDa protein antigen of Streptococcus mutans.

    PubMed

    Lapirattanakul, Jinthana; Nomura, Ryota; Matsumoto-Nakano, Michiyo; Srisatjaluk, Ratchapin; Ooshima, Takashi; Nakano, Kazuhiko

    2015-05-01

    Streptococcus mutans, which consists of four serotypes, c, e, f, and k, possesses a 190-kDa cell surface protein antigen (PA) for initial tooth adhesion. We used Western blot analysis to determine PA expression in 750 S. mutans isolates from 150 subjects and found a significantly higher prevalence of the isolates with PA expression defects in serotypes f and k compared to serotypes c and e. Moreover, the defect patterns could be classified into three types; no PA expression on whole bacterial cells and in their supernatant samples (Type N1), PA expression mainly seen in supernatant samples (Type N2), and only low expression of PA in the samples of whole bacterial cells (Type W). The underlying reasons for the defects were mutations in the gene encoding PA as well as in the transcriptional processing of this gene for Type N1, defects in the sortase gene for Type N2, and low mRNA expression of PA for Type W. Since cellular hydrophobicity and phagocytosis susceptibility of the PA-defective isolates were significantly lower than those of the normal expression isolates, the potential implication of such defective isolates in systemic diseases involving bacteremia other than dental caries was suggested. Additionally, multilocus sequence typing was utilized to characterize S. mutans clones that represented a proportion of isolates with PA defects of 65-100%. Therefore, we described the molecular basis for variation defects in PA expression of S. mutans. Furthermore, we also emphasized the strong association between PA expression defects and serotypes f and k as well as the clonal relationships among these isolates. PMID:25792295

  8. NH125 reduces the level of CPEB3, an RNA binding protein, to promote synaptic GluA2 expression.

    PubMed

    Bender, Crhistian L; Yang, Qian; Sun, Lu; Liu, Siqiong June

    2016-02-01

    Neuronal activity can alter the phosphorylation state of eukaryotic elongation factor 2 (eEF2) and thereby regulates protein synthesis. This is thought to be the underlying mechanism for a form of synaptic plasticity that involves changes in the expression of synaptic AMPA type glutamate receptors. Phosphorylation of eEF2 by Ca/calmodulin-dependent eEF2 kinase reduces the activity of eEF2, and this is prevented by a commonly used eEF2 kinase inhibitor, NH125. Here we show that 10 μM NH125 increased the expression of synaptic GluA2-containing receptors in mouse cerebellar stellate cells and this was prevented by a protein synthesis inhibitor. However NH125 at 10 μM also reduced the level of CPEB3, a protein that is known to bind to GluA2 mRNA and suppress GluA2 (also known as GluR2) synthesis. In contrast, a low concentration of NH125 lowered the peEF2 level, but did not alter CPEB3 expression and also failed to increase synaptic GluA2 receptors. A selective eEF2 kinase inhibitor, A-484954, decreased the level of peEF2, without changing the expression of CPEB3. This suggests that reducing peEF2 does not lead to a decrease in CPEB3 levels and is not sufficient to increase GluA2 synthesis. Thus NH125 at 10 μM reduced the level of CPEB3, and promoted GluA2 translation via a mechanism independent of inhibition of eEF2 kinase. Therefore NH125 does not always alter protein synthesis via selective inhibition of eEF2 kinase and the effects of NH125 on translation of mRNAs should be interpreted with caution.

  9. Mice expressing markedly reduced striatal dopamine transporters exhibit increased locomotor activity, dopamine uptake turnover rate, and cocaine responsiveness.

    PubMed

    Rao, Anjali; Sorkin, Alexander; Zahniser, Nancy R

    2013-10-01

    Variations in the expression levels of the dopamine transporter (DAT) can influence responsiveness to psychostimulant drugs like cocaine. To better understand this relationship, we studied a new DAT-low expresser (DAT-LE) mouse model and performed behavioral and biochemical studies with it. Immunoblotting and [(3) H]WIN 35,428 binding analyses revealed that these mice express ∼35% of wildtype (WT) mouse striatal DAT levels. Compared to WT mice, DAT-LE mice were hyperactive in a novel open-field environment. Despite their higher basal locomotor activity, cocaine (10 or 20 mg/kg, i.p.) induced greater locomotor activation in DAT-LE mice than in WT mice. The maximal velocity (Vmax ) of DAT-mediated [(3) H]DA uptake into striatal synaptosomes was reduced by 46% in DAT-LE mice, as compared to WT. Overall, considering the reduced number of DAT binding sites (Bmax ) along with the reduced Vmax in DAT-LE mice, a 2-fold increase in DA uptake turnover rate (Vmax /Bmax ) was found, relative to WT mice. This suggests that neuroadaptive changes have occurred in the DAT-LE mice that would help to compensate for their low DAT numbers. Interestingly, these changes do not include a reduction in tyrosine hydroxylase levels, as was previously reported in DAT knockout homozygous and heterozygous animals. Further, these changes are not sufficient to prevent elevated novelty- and cocaine-induced locomotor activity. Hence, these mice represent a unique model for studying changes of in vivo DAT function and regulation that result from markedly reduced levels of DAT expression. PMID:23564231

  10. Mice expressing markedly reduced striatal dopamine transporters exhibit increased locomotor activity, dopamine uptake turnover rate, and cocaine responsiveness.

    PubMed

    Rao, Anjali; Sorkin, Alexander; Zahniser, Nancy R

    2013-10-01

    Variations in the expression levels of the dopamine transporter (DAT) can influence responsiveness to psychostimulant drugs like cocaine. To better understand this relationship, we studied a new DAT-low expresser (DAT-LE) mouse model and performed behavioral and biochemical studies with it. Immunoblotting and [(3) H]WIN 35,428 binding analyses revealed that these mice express ∼35% of wildtype (WT) mouse striatal DAT levels. Compared to WT mice, DAT-LE mice were hyperactive in a novel open-field environment. Despite their higher basal locomotor activity, cocaine (10 or 20 mg/kg, i.p.) induced greater locomotor activation in DAT-LE mice than in WT mice. The maximal velocity (Vmax ) of DAT-mediated [(3) H]DA uptake into striatal synaptosomes was reduced by 46% in DAT-LE mice, as compared to WT. Overall, considering the reduced number of DAT binding sites (Bmax ) along with the reduced Vmax in DAT-LE mice, a 2-fold increase in DA uptake turnover rate (Vmax /Bmax ) was found, relative to WT mice. This suggests that neuroadaptive changes have occurred in the DAT-LE mice that would help to compensate for their low DAT numbers. Interestingly, these changes do not include a reduction in tyrosine hydroxylase levels, as was previously reported in DAT knockout homozygous and heterozygous animals. Further, these changes are not sufficient to prevent elevated novelty- and cocaine-induced locomotor activity. Hence, these mice represent a unique model for studying changes of in vivo DAT function and regulation that result from markedly reduced levels of DAT expression.

  11. Morphology, proliferation, and gene expression of gingival fibroblasts on Laser-Lok, titanium, and zirconia surfaces.

    PubMed

    Esfahanizadeh, Nasrin; Motalebi, Sara; Daneshparvar, Niloufar; Akhoundi, Nasrin; Bonakdar, Shahin

    2016-07-01

    Soft tissue seal plays a critical role in long-term success of dental implants, and the effects of implant surface treatments such as laser ablation have been a topic of particular interest in this respect. Considering the existing controversy regarding soft tissue behavior in contact with implant surfaces, this study sought to assess the morphology, proliferation, and gene expression of human gingival fibroblasts (HGFs) on different abutment surfaces. In this in vitro, experimental study, HGFs were cultured on 45 discs (Laser-Lok, titanium, and zirconia). Cell morphology, proliferation rate, and interleukin 10 (IL-10), tumor necrosis factor alpha (TNFα), fibronectin, and integrin gene expressions were assessed by electron microscopy, methyl thiazol tetrazolium (MTT) assay, and real-time polymerase chain reaction (PCR), respectively. Data were analyzed using ANOVA and the Kruskal-Wallis H test. Fibroblast attachment was noted in all the three groups. Spindle-shaped cells with pseudopod-like processes were more frequently seen in the Laser-Lok group. Cell proliferation was significantly higher in the Laser-Lok group compared to those in the other groups (P = 0.0002). Significant differences were found in the expression of IL-10, TNFα, fibronectin, and integrin genes among the groups (P < 0.01). Within the limitations of this study, HGFs on Laser-Lok surfaces had a more mature morphology and greater proliferation and differentiation as compared to those on zirconia and titanium surfaces. This indicates better attachment of these cells to laser-modified surfaces, creating a more efficient soft tissue seal around dental implants. PMID:27025859

  12. Metformin reduces the endotoxin-induced down-regulation of apolipoprotein E gene expression in macrophages

    SciTech Connect

    Stavri, Simona; Trusca, Violeta G.; Simionescu, Maya; Gafencu, Anca V.

    2015-05-29

    The atheroprotective role of macrophage-derived apolipoprotein E (apoE) is well known. Our previous reports demonstrated that inflammatory stress down-regulates apoE expression in macrophages, aggravating atherogenesis. Metformin, extensively used as an anti-diabetic drug, has also anti-inflammatory properties, and thus confers vascular protection. In this study, we questioned whether metformin could have an effect on apoE expression in macrophages in normal conditions or under lipopolysaccharide (LPS)-induced stress. The results showed that metformin slightly increases the apoE expression only at high doses (5–10 mM). Low doses of metformin (1–3 mM) significantly reduce the LPS down-regulatory effect on apoE expression in macrophages. Our experiments demonstrated that LPS-induced NF-κB binds to the macrophage-specific distal regulatory element of apoE gene, namely to the multienhancer 2 (ME.2) and its 5′-deletion fragments. The NF-κB binding on ME.2 and apoE promoter has a down-regulatory effect. In addition, data revealed that metformin impairs NF-κB nuclear translocation, and thus, improves the apoE levels in macrophages under inflammatory stress. The positive effect of metformin in the inflammatory states, its clinical safety and low cost, make this drug a potential adjuvant in the therapeutic strategies for atherosclerosis. - Highlights: • High doses of metformin slightly increase apoE expression in macrophages. • Low doses of metformin up-regulate apoE gene in endotoxin-stressed macrophages. • Metformin reduces the negative effect of LPS on apoE expression by NF-κB inhibition.