CAMKII and calcineurin regulate the lifespan of Caenorhabditis elegans through the FOXO transcription factor DAF-16.

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Tao, Li; Xie, Qi; Ding, Yue-He; Li, Shang-Tong; Peng, Shengyi; Zhang, Yan-Ping; Tan, Dan; Yuan, Zengqiang; Dong, Meng-Qiu

2013-06-25

The insulin-like signaling pathway maintains a relatively short wild-type lifespan in Caenorhabditis elegans by phosphorylating and inactivating DAF-16, the ortholog of the FOXO transcription factors of mammalian cells. DAF-16 is phosphorylated by the AKT kinases, preventing its nuclear translocation. Calcineurin (PP2B phosphatase) also limits the lifespan of C. elegans, but the mechanism through which it does so is unknown. Herein, we show that TAX-6•CNB-1 and UNC-43, the C. elegans Calcineurin and Ca(2+)/calmodulin-dependent kinase type II (CAMKII) orthologs, respectively, also regulate lifespan through DAF-16. Moreover, UNC-43 regulates DAF-16 in response to various stress conditions, including starvation, heat or oxidative stress, and cooperatively contributes to lifespan regulation by insulin signaling. However, unlike insulin signaling, UNC-43 phosphorylates and activates DAF-16, thus promoting its nuclear localization. The phosphorylation of DAF-16 at S286 by UNC-43 is removed by TAX-6•CNB-1, leading to DAF-16 inactivation. Mammalian FOXO3 is also regulated by CAMKIIA and Calcineurin. DOI:http://dx.doi.org/10.7554/eLife.00518.001.

An Expanded Role for the RFX Transcription Factor DAF-19, with Dual Functions in Ciliated and Nonciliated Neurons.

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De Stasio, Elizabeth A; Mueller, Katherine P; Bauer, Rosemary J; Hurlburt, Alexander J; Bice, Sophie A; Scholtz, Sophie L; Phirke, Prasad; Sugiaman-Trapman, Debora; Stinson, Loraina A; Olson, Haili B; Vogel, Savannah L; Ek-Vazquez, Zabdiel; Esemen, Yagmur; Korzynski, Jessica; Wolfe, Kelsey; Arbuckle, Bonnie N; Zhang, He; Lombard-Knapp, Gaelen; Piasecki, Brian P; Swoboda, Peter

2018-03-01

Regulatory Factor X (RFX) transcription factors (TFs) are best known for activating genes required for ciliogenesis in both vertebrates and invertebrates. In humans, eight RFX TFs have a variety of tissue-specific functions, while in the worm Caenorhabditis elegans , the sole RFX gene, daf-19 , encodes a set of nested isoforms. Null alleles of daf-19 confer pleiotropic effects including altered development with a dauer constitutive phenotype, complete absence of cilia and ciliary proteins, and defects in synaptic protein maintenance. We sought to identify RFX/ daf-19 target genes associated with neuronal functions other than ciliogenesis using comparative transcriptome analyses at different life stages of the worm. Subsequent characterization of gene expression patterns revealed one set of genes activated in the presence of DAF-19 in ciliated sensory neurons, whose activation requires the daf-19c isoform, also required for ciliogenesis. A second set of genes is downregulated in the presence of DAF-19, primarily in nonsensory neurons. The human orthologs of some of these neuronal genes are associated with human diseases. We report the novel finding that daf-19a is directly or indirectly responsible for downregulation of these neuronal genes in C. elegans by characterizing a new mutation affecting the daf-19a isoform ( tm5562 ) and not associated with ciliogenesis, but which confers synaptic and behavioral defects. Thus, we have identified a new regulatory role for RFX TFs in the nervous system. The new daf-19 candidate target genes we have identified by transcriptomics will serve to uncover the molecular underpinnings of the pleiotropic effects that daf-19 exerts on nervous system function. Copyright © 2018 by the Genetics Society of America.

Decay accelerating factor (DAF) is anchored to membranes by a C-terminal glycolipid

International Nuclear Information System (INIS)

Medof, M.E.; Haas, R.; Walter, E.I.; Rosenberry, T.L.

1986-01-01

Purified 70 kDa membrane (m) DAF incorporates into cells when added in vitro. A 2 kDa smaller DAF form which functions extrinsically like C4bp but is unable to incorporate can be isolated from urine (u). Because of common deficits of mDAF and acetylcholinesterase (AChE) in erythrocytes (E) of patients with paroxysmal nocturnal hemoglobinuria (PNH), mDAF was analyzed for a O-terminal glycolipid membrane anchor similar to that in E AChE. Incubation of E with phosphatidylinositol-specific phospholipase C, an enzyme which cleaves a similar glycolipid anchor in trypanosome variant surface glycoproteins (mfVSGs), released 20% of the DAF antigen. The released DAF species resembled uDAF in size, extrinsic model of C4b2a decay, and lack of hydrophobicity. Reductive radiomethylation of mDAF with [ 14 C]HCHO and NaCNBH 3 revealed ethanolamine and glucosamine in proportions similar to those in the E AChE glycolipid anchor. Papain cleavage of radiomethylated mDAF released the labeled ethanolamine and glucosamine in small O-terminal fragments from the residual DAF that retained N-terminal Asp. Following labeling of the anchors of mDAF and E AChE with the lipophilic photoreagent 3-trifluoromethyl-3-(m-[ 125 I]iodophenyl)diazirine, cleavage at the glucosamine residue by deamination quantitatively released the label from both proteins. Biosynthetic labeling of Hela cells with [ 3 H]ethanolamine resulted in rapid 3 H incorporation into both 48 kDa proDAF and 70 kDa mDAF. These data indicate that mDAF is anchored by a glycolipid similar to that in E AChE, mfVSGs and Thy-1 antigen and raise the possibility that a defect in the assembly or attachment of this structure could account for the deficits of mDAF and E AChE in PNH

Data Analysis Facility (DAF)

Science.gov (United States)

1991-01-01

NASA-Dryden's Data Analysis Facility (DAF) provides a variety of support services to the entire Dryden community. It provides state-of-the-art hardware and software systems, available to any Dryden engineer for pre- and post-flight data processing and analysis, plus supporting all archival and general computer use. The Flight Data Access System (FDAS) is one of the advanced computer systems in the DAF, providing for fast engineering unit conversion and archival processing of flight data delivered from the Western Aeronautical Test Range. Engineering unit conversion and archival formatting of flight data is performed by the DRACO program on a Sun 690MP and an E-5000 computer. Time history files produced by DRACO are then moved to a permanent magneto-optical archive, where they are network-accessible 24 hours a day, 7 days a week. Pertinent information about the individual flights is maintained in a relational (Sybase) database. The DAF also houses all general computer services, including; the Compute Server 1 and 2 (CS1 and CS2), the server for the World Wide Web, overall computer operations support, courier service, a CD-ROM Writer system, a Technical Support Center, the NASA Dryden Phone System (NDPS), and Hardware Maintenance.

Transcriptional regulation of Caenorhabditis elegans FOXO/DAF-16 modulates lifespan.

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Bansal, Ankita; Kwon, Eun-Soo; Conte, Darryl; Liu, Haibo; Gilchrist, Michael J; MacNeil, Lesley T; Tissenbaum, Heidi A

2014-01-01

Insulin/IGF-1 signaling plays a central role in longevity across phylogeny. In C. elegans, the forkhead box O (FOXO) transcription factor, DAF-16, is the primary target of insulin/IGF-1 signaling, and multiple isoforms of DAF-16 (a, b, and d/f) modulate lifespan, metabolism, dauer formation, and stress resistance. Thus far, across phylogeny modulation of mammalian FOXOs and DAF-16 have focused on post-translational regulation with little focus on transcriptional regulation. In C. elegans, we have previously shown that DAF-16d/f cooperates with DAF-16a to promote longevity. In this study, we generated transgenic strains expressing near-endogenous levels of either daf-16a or daf-16d/f, and examined temporal expression of the isoforms to further define how these isoforms contribute to lifespan regulation. Here, we show that DAF-16a is sensitive both to changes in gene dosage and to alterations in the level of insulin/IGF-1 signaling. Interestingly, we find that as worms age, the intestinal expression of daf-16d/f but not daf-16a is dramatically upregulated at the level of transcription. Preventing this transcriptional upregulation shortens lifespan, indicating that transcriptional regulation of daf-16d/f promotes longevity. In an RNAi screen of transcriptional regulators, we identify elt-2 (GATA transcription factor) and swsn-1 (core subunit of SWI/SNF complex) as key modulators of daf-16d/f gene expression. ELT-2 and another GATA factor, ELT-4, promote longevity via both DAF-16a and DAF-16d/f while the components of SWI/SNF complex promote longevity specifically via DAF-16d/f. Our findings indicate that transcriptional control of C. elegans FOXO/daf-16 is an essential regulatory event. Considering the conservation of FOXO across species, our findings identify a new layer of FOXO regulation as a potential determinant of mammalian longevity and age-related diseases such as cancer and diabetes.

The crystal structure of a coxsackievirus B3-RD variant and a refined 9-angstrom cryo-electron microscopy reconstruction of the virus complexed with decay-accelerating factor (DAF) provide a new footprint of DAF on the virus surface.

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Yoder, Joshua D; Cifuente, Javier O; Pan, Jieyan; Bergelson, Jeffrey M; Hafenstein, Susan

2012-12-01

The coxsackievirus-adenovirus receptor (CAR) and decay-accelerating factor (DAF) have been identified as cellular receptors for coxsackievirus B3 (CVB3). The first described DAF-binding isolate was obtained during passage of the prototype strain, Nancy, on rhabdomyosarcoma (RD) cells, which express DAF but very little CAR. Here, the structure of the resulting variant, CVB3-RD, has been solved by X-ray crystallography to 2.74 Å, and a cryo-electron microscopy reconstruction of CVB3-RD complexed with DAF has been refined to 9.0 Å. This new high-resolution structure permits us to correct an error in our previous view of DAF-virus interactions, providing a new footprint of DAF that bridges two adjacent protomers. The contact sites between the virus and DAF clearly encompass CVB3-RD residues recently shown to be required for binding to DAF; these residues interact with DAF short consensus repeat 2 (SCR2), which is known to be essential for virus binding. Based on the new structure, the mode of the DAF interaction with CVB3 differs significantly from the mode reported previously for DAF binding to echoviruses.

Strongyloides stercoralis daf-2 encodes a divergent ortholog of Caenorhabditis elegans DAF-2.

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Massey, Holman C; Ranjit, Najju; Stoltzfus, Jonathan D; Lok, James B

2013-06-01

We hypothesise that developmental arrest in infectious larvae of parasitic nematodes is regulated by signalling pathways homologous to Caenorhabditis elegans DAF (dauer formation) pathways. Alignment of Strongyloides stercoralis (Ss) DAF-2 with DAF-2 of C. elegans and homologs of other species shows that most structural motifs in these insulin-like receptors are conserved. However, the catalytic domain of Ss-DAF-2 contains two substitutions (Q1242 and Q1256), that would result in constitutive dauer formation in C. elegans or diabetes in vertebrate animals. Ss-daf-2 also shows two alternately spliced isoforms, the constitutively expressed Ss-daf-2a, and Ss-daf-2b, which is only expressed in stages leading to parasitism. Copyright © 2013 Australian Society for Parasitology Inc. Published by Elsevier Ltd. All rights reserved.

dbl-1/TGF-β and daf-12/NHR Signaling Mediate Cell-Nonautonomous Effects of daf-16/FOXO on Starvation-Induced Developmental Arrest.

Directory of Open Access Journals (Sweden)

Rebecca E W Kaplan

2015-12-01

Full Text Available Nutrient availability has profound influence on development. In the nematode C. elegans, nutrient availability governs post-embryonic development. L1-stage larvae remain in a state of developmental arrest after hatching until they feed. This "L1 arrest" (or "L1 diapause" is associated with increased stress resistance, supporting starvation survival. Loss of the transcription factor daf-16/FOXO, an effector of insulin/IGF signaling, results in arrest-defective and starvation-sensitive phenotypes. We show that daf-16/FOXO regulates L1 arrest cell-nonautonomously, suggesting that insulin/IGF signaling regulates at least one additional signaling pathway. We used mRNA-seq to identify candidate signaling molecules affected by daf-16/FOXO during L1 arrest. dbl-1/TGF-β, a ligand for the Sma/Mab pathway, daf-12/NHR and daf-36/oxygenase, an upstream component of the daf-12 steroid hormone signaling pathway, were up-regulated during L1 arrest in a daf-16/FOXO mutant. Using genetic epistasis analysis, we show that dbl-1/TGF-β and daf-12/NHR steroid hormone signaling pathways are required for the daf-16/FOXO arrest-defective phenotype, suggesting that daf-16/FOXO represses dbl-1/TGF-β, daf-12/NHR and daf-36/oxygenase. The dbl-1/TGF-β and daf-12/NHR pathways have not previously been shown to affect L1 development, but we found that disruption of these pathways delayed L1 development in fed larvae, consistent with these pathways promoting development in starved daf-16/FOXO mutants. Though the dbl-1/TGF-β and daf-12/NHR pathways are epistatic to daf-16/FOXO for the arrest-defective phenotype, disruption of these pathways does not suppress starvation sensitivity of daf-16/FOXO mutants. This observation uncouples starvation survival from developmental arrest, indicating that DAF-16/FOXO targets distinct effectors for each phenotype and revealing that inappropriate development during starvation does not cause the early demise of daf-16/FOXO mutants. Overall

dbl-1/TGF-β and daf-12/NHR Signaling Mediate Cell-Nonautonomous Effects of daf-16/FOXO on Starvation-Induced Developmental Arrest.

Science.gov (United States)

Kaplan, Rebecca E W; Chen, Yutao; Moore, Brad T; Jordan, James M; Maxwell, Colin S; Schindler, Adam J; Baugh, L Ryan

2015-12-01

Nutrient availability has profound influence on development. In the nematode C. elegans, nutrient availability governs post-embryonic development. L1-stage larvae remain in a state of developmental arrest after hatching until they feed. This "L1 arrest" (or "L1 diapause") is associated with increased stress resistance, supporting starvation survival. Loss of the transcription factor daf-16/FOXO, an effector of insulin/IGF signaling, results in arrest-defective and starvation-sensitive phenotypes. We show that daf-16/FOXO regulates L1 arrest cell-nonautonomously, suggesting that insulin/IGF signaling regulates at least one additional signaling pathway. We used mRNA-seq to identify candidate signaling molecules affected by daf-16/FOXO during L1 arrest. dbl-1/TGF-β, a ligand for the Sma/Mab pathway, daf-12/NHR and daf-36/oxygenase, an upstream component of the daf-12 steroid hormone signaling pathway, were up-regulated during L1 arrest in a daf-16/FOXO mutant. Using genetic epistasis analysis, we show that dbl-1/TGF-β and daf-12/NHR steroid hormone signaling pathways are required for the daf-16/FOXO arrest-defective phenotype, suggesting that daf-16/FOXO represses dbl-1/TGF-β, daf-12/NHR and daf-36/oxygenase. The dbl-1/TGF-β and daf-12/NHR pathways have not previously been shown to affect L1 development, but we found that disruption of these pathways delayed L1 development in fed larvae, consistent with these pathways promoting development in starved daf-16/FOXO mutants. Though the dbl-1/TGF-β and daf-12/NHR pathways are epistatic to daf-16/FOXO for the arrest-defective phenotype, disruption of these pathways does not suppress starvation sensitivity of daf-16/FOXO mutants. This observation uncouples starvation survival from developmental arrest, indicating that DAF-16/FOXO targets distinct effectors for each phenotype and revealing that inappropriate development during starvation does not cause the early demise of daf-16/FOXO mutants. Overall, this study shows

A functional SNP in the regulatory region of the decay-accelerating factor gene associates with extraocular muscle pareses in myasthenia gravis

KAUST Repository

Heckmann, J M

2009-08-13

Complement activation in myasthenia gravis (MG) may damage muscle endplate and complement regulatory proteins such as decay-accelerating factor (DAF) or CD55 may be protective. We hypothesize that the increased prevalence of severe extraocular muscle (EOM) dysfunction among African MG subjects reported earlier may result from altered DAF expression. To test this hypothesis, we screened the DAF gene sequences relevant to the classical complement pathway and found an association between myasthenics with EOM paresis and the DAF regulatory region c.-198CG SNP (odds ratio8.6; P0.0003). This single nucleotide polymorphism (SNP) results in a twofold activation of a DAF 5?-flanking region luciferase reporter transfected into three different cell lines. Direct matching of the surrounding SNP sequence within the DAF regulatory region with the known transcription factor-binding sites suggests a loss of an Sp1-binding site. This was supported by the observation that the c.-198CG SNP did not show the normal lipopolysaccharide-induced DAF transcriptional upregulation in lymphoblasts from four patients. Our findings suggest that at critical periods during autoimmune MG, this SNP may result in inadequate DAF upregulation with consequent complement-mediated EOM damage. Susceptible individuals may benefit from anti-complement therapy in addition to immunosuppression. © 2010 Macmillan Publishers Limited. All rights reserved.

Production of multiple transgenic Yucatan miniature pigs expressing human complement regulatory factors, human CD55, CD59, and H-transferase genes.

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Young-Hee Jeong

Full Text Available The present study was conducted to generate transgenic pigs coexpressing human CD55, CD59, and H-transferase (HT using an IRES-mediated polycistronic vector. The study focused on hyperacute rejection (HAR when considering clinical xenotransplantation as an alternative source for human organ transplants. In total, 35 transgenic cloned piglets were produced by somatic cell nuclear transfer (SCNT and were confirmed for genomic integration of the transgenes from umbilical cord samples by PCR analysis. Eighteen swine umbilical vein endothelial cells (SUVEC were isolated from umbilical cord veins freshly obtained from the piglets. We observed a higher expression of transgenes in the transgenic SUVEC (Tg SUVEC compared with the human umbilical vein endothelial cells (HUVEC. Among these genes, HT and hCD59 were expressed at a higher level in the tested Tg organs compared with non-Tg control organs, but there was no difference in hCD55 expression between them. The transgenes in various organs of the Tg clones revealed organ-specific and spatial expression patterns. Using from 0 to 50% human serum solutions, we performed human complement-mediated cytolysis assays. The results showed that, overall, the Tg SUVEC tested had greater survival rates than did the non-Tg SUVEC, and the Tg SUVEC with higher HT expression levels tended to have more down-regulated α-Gal epitope expression, resulting in greater protection against cytotoxicity. By contrast, several Tg SUVEC with low CD55 expression exhibited a decreased resistance response to cytolysis. These results indicated that the levels of HT expression were inversely correlated with the levels of α-Gal epitope expression and that the combined expression of hCD55, hCD59, and HT proteins in SUVECs markedly enhances a protective response to human serum-mediated cytolysis. Taken together, these results suggest that combining a polycistronic vector system with SCNT methods provides a fast and efficient alternative

Deletion of Crry and DAF on murine platelets stimulates thrombopoiesis and increases factor H-dependent resistance of peripheral platelets to complement attack.

Science.gov (United States)

Barata, Lidia; Miwa, Takashi; Sato, Sayaka; Kim, David; Mohammed, Imran; Song, Wen-Chao

2013-03-15

Complement receptor 1-related gene/protein y (Crry) and decay-accelerating factor (DAF) are two murine membrane C3 complement regulators with overlapping functions. Crry deletion is embryonically lethal whereas DAF-deficient mice are generally healthy. Crry(-/-)DAF(-/-) mice were viable on a C3(-/-) background, but platelets from such mice were rapidly destroyed when transfused into C3-sufficient mice. In this study, we used the cre-lox system to delete platelet Crry in DAF(-/-) mice and studied Crry/DAF-deficient platelet development in vivo. Rather than displaying thrombocytopenia, Pf4-Cre(+)-Crry(flox/flox) mice had normal platelet counts and their peripheral platelets were resistant to complement attack. However, chimera mice generated with Pf4-Cre(+)-Crry(flox/flox) bone marrows showed platelets from C3(-/-) but not C3(+/+) recipients to be sensitive to complement activation, suggesting that circulating platelets in Pf4-Cre(+)-Crry(flox/flox) mice were naturally selected in a complement-sufficient environment. Notably, Pf4-Cre(+)-Crry(flox/flox) mouse platelets became complement susceptible when factor H function was blocked. Examination of Pf4-Cre(+)-Crry(flox/flox) mouse bone marrows revealed exceedingly active thrombopoiesis. Thus, under in vivo conditions, Crry/DAF deficiency on platelets led to abnormal platelet turnover, but peripheral platelet count was compensated for by increased thrombopoiesis. Selective survival of Crry/DAF-deficient platelets aided by factor H protection and compensatory thrombopoiesis demonstrates the cooperation between membrane and fluid phase complement inhibitors and the body's ability to adaptively respond to complement regulator deficiencies.

DAF-16: FOXO in the Context of C. elegans.

Science.gov (United States)

Tissenbaum, Heidi A

2018-01-01

In Caenorhabditis elegans, there is a single FOXO transcription factor homolog, encoded by the gene, daf-16. As a central regulator for multiple signaling pathways, DAF-16 integrates these signals which results in modulation of several biological processes including longevity, development, fat storage, stress resistance, innate immunity, and reproduction. Using C. elegans allows for studies of FOXO in the context of the whole animal. Therefore, manipulating levels or the activity of daf-16 results in phenotypic changes. Genetic and molecular analysis revealed that similar to other systems, DAF-16 is the downstream target of the conserved insulin/IGF-1 signaling (IIS) pathway; a PI 3-kinase/AKT signaling cascade that ultimately controls the regulation of DAF-16 nuclear localization. In this chapter, I will focus on understanding how a single gene daf-16 can incorporate signals from multiple upstream pathways and in turn modulate different phenotypes as well as the study of FOXO in the context of a whole organism. © 2018 Elsevier Inc. All rights reserved.

Decay-accelerating factor 1 deficiency exacerbates Trypanosoma cruzi-induced murine chronic myositis.

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Solana, María E; Ferrer, María F; Novoa, María Mercedes; Song, Wen-Chao; Gómez, Ricardo M

2012-10-01

Murine infection with Trypanosoma cruzi (Tc) has been used to study the role of T-cells in the pathogenesis of human inflammatory idiopathic myositis. Absence of decay-accelerating factor 1 (Daf1) has been shown to enhance murine T-cell responses and autoimmunity. To determine whether Daf1 deficiency can exacerbate Tc-induced myositis, C57BL/6 DAF(+/+) and DAF(-/-) mice were inoculated with 5 × 10(4) trypomastigotes, and their morbidity, parasitemia, parasite burden, histopathology, and T-cell expansion were studied in the acute and chronic stages. DAF(-/-) mice had lower parasitemia and parasite burden but higher morbidity, muscle histopathology, and increased number of CD44(+) (activated/memory phenotype) splenic CD4(+) and CD8(+) T-cells. An enhanced CD8(+) T-cell immune-specific response may explain the lower parasitemia and parasite burden levels and the increase in histopathological lesions. We propose that Tc-inoculated DAF(-/-) mice are a useful model to study T-cell mediated immunity in skeletal muscle tissues. Copyright © 2012 Wiley Periodicals, Inc.

Calycosin promotes lifespan in Caenorhabditis elegans through insulin signaling pathway via daf-16, age-1 and daf-2.

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Lu, Lulu; Zhao, Xuan; Zhang, Jianyong; Li, Miao; Qi, Yonghao; Zhou, Lijun

2017-07-01

The naturally occurring calycosin is a known antioxidant that prevents redox imbalance in organisms. However, calycosin's effect on lifespan and its physiological molecular mechanisms are not yet well understood. In this study, we demonstrated that calycosin could prolong the lifespan of Caenorhabditis elegans, and that such extension was associated with its antioxidant capability as well as its ability to enhance stress resistance and reduce ROS (reactive oxygen species) accumulation. To explore mechanisms of this longevity effect, we assessed the impact of calycosin on lifespans of insulin-signaling impaired worms: daf-2, age-1, and daf-16 mutants. We found that calycosin did not alter the lifespan of all three mutants, thereby suggesting that calycosin requires insulin signaling to promote lifespan extension. On the other hand, we observed that calycosin could enhance the nuclear translocation of the core transcription factor DAF-16/FoXO instead of the conserved stress-responsive transcription factor SKN-1/Nrf-2. This observation is consistent with the understanding that the nuclear localized DAF-16 up-regulates its downstream targets sod-3, ctl-1, and hsp-16.2. Lastly, it is also noteworthy that the longevity effect of calycosin is likely not associated with the calorie restriction mechanism. Collectively, our results strongly suggest that calycosin could function as an antioxidant to extend the lifespan of C. elegans by enhancing nucleus translocation of DAF-16 through the insulin-signaling pathway. Copyright © 2017 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Sterol-derived hormone(s controls entry into diapause in Caenorhabditis elegans by consecutive activation of DAF-12 and DAF-16.

Directory of Open Access Journals (Sweden)

Vitali Matyash

2004-10-01

Full Text Available Upon starvation or overcrowding, Caenorhabditis elegans interrupts its reproductive cycle and forms a specialised larva called dauer (enduring. This process is regulated by TGF-beta and insulin-signalling pathways and is connected with the control of life span through the insulin pathway components DAF-2 and DAF-16. We found that replacing cholesterol with its methylated metabolite lophenol induced worms to form dauer larvae in the presence of food and low population density. Our data indicate that methylated sterols do not actively induce the dauer formation but rather that the reproductive growth requires a cholesterol-derived hormone that cannot be produced from methylated sterols. Using the effect of lophenol on growth, we have partially purified activity, named gamravali, which promotes the reproduction. In addition, the effect of lophenol allowed us to determine the role of sterols during dauer larva formation and longevity. In the absence of gamravali, the nuclear hormone receptor DAF-12 is activated and thereby initiates the dauer formation program. Active DAF-12 triggers in neurons the nuclear import of DAF-16, a forkhead domain transcription factor that contributes to dauer differentiation. This hormonal control of DAF-16 activation is, however, independent of insulin signalling and has no influence on life span.

FoxO/Daf-16 restored thrashing movement reduced by heat stress in Caenorhabditis elegans.

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Furuhashi, Tsubasa; Sakamoto, Kazuichi

2014-04-01

Many studies on thermotolerance have been done in Caenorhabditis elegans in order to extend survival under heat stress; Daf-16, a homolog of FoxO in C. elegans, was detected as the key factor in thermotolerance. However, the recovery process from heat stress damage has been seldom discussed. In this study, we analyzed the roles of FoxO/Daf-16 on the recovery from heat stress damage by monitoring thrashing movement. Heat shock reduced the movement, which was restored by culturing at 20°C. Thrashing movement was not restored in the daf-16 mutant, which suggests that Daf-16 is one of the essential factors in repairing the damage. Movement restoration was promoted in the daf-2 mutant, a homolog of insulin/IGF-1-like receptor, in a daf-16-dependent manner. In addition, heat stress decreased the expression of daf-28 and ins-7, agonists of Daf-2. Taken together, these results revealed that FoxO/Daf-16 removes heat stress damage and restores movement via inhibition of the insulin-like signaling pathway in C. elegans, suggesting that FoxO/Daf-16 plays a critical role in thermotolerance. Copyright © 2014 Elsevier Inc. All rights reserved.

RFX Transcription Factor DAF-19 Regulates 5-HT and Innate Immune Responses to Pathogenic Bacteria in Caenorhabditis elegans

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Choi, Sunju; Xu, Lu; Sze, Ji Ying

2013-01-01

In Caenorhabditis elegans the Toll-interleukin receptor domain adaptor protein TIR-1 via a conserved mitogen-activated protein kinase (MAPK) signaling cascade induces innate immunity and upregulates serotonin (5-HT) biosynthesis gene tph-1 in a pair of ADF chemosensory neurons in response to infection. Here, we identify transcription factors downstream of the TIR-1 signaling pathway. We show that common transcription factors control the innate immunity and 5-HT biosynthesis. We demonstrate that a cysteine to tyrosine substitution in an ARM motif of the HEAT/Arm repeat region of the TIR-1 protein confers TIR-1 hyperactivation, leading to constitutive tph-1 upregulation in the ADF neurons, increased expression of intestinal antimicrobial genes, and enhanced resistance to killing by the human opportunistic pathogen Pseudomonas aeruginosa PA14. A forward genetic screen for suppressors of the hyperactive TIR-1 led to the identification of DAF-19, an ortholog of regulatory factor X (RFX) transcription factors that are required for human adaptive immunity. We show that DAF-19 concerts with ATF-7, a member of the activating transcription factor (ATF)/cAMP response element-binding B (CREB) family of transcription factors, to regulate tph-1 and antimicrobial genes, reminiscent of RFX-CREB interaction in human immune cells. daf-19 mutants display heightened susceptibility to killing by PA14. Remarkably, whereas the TIR-1-MAPK-DAF-19/ATF-7 pathway in the intestinal immunity is regulated by DKF-2/protein kinase D, we found that the regulation of tph-1 expression is independent of DKF-2 but requires UNC-43/Ca2+/calmodulin-dependent protein kinase (CaMK) II. Our results suggest that pathogenic cues trigger a common core-signaling pathway via tissue-specific mechanisms and demonstrate a novel role for RFX factors in neuronal and innate immune responses to infection. PMID:23505381

Isoxanthohumol, a constituent of hop (Humulus lupulus L.), increases stress resistance in Caenorhabditis elegans dependent on the transcription factor DAF-16.

Science.gov (United States)

Büchter, Christian; Havermann, Susannah; Koch, Karoline; Wätjen, Wim

2016-02-01

The flavanone isoxanthohumol (IX) has gained attention as antioxidative and chemopreventive agent, but the molecular mechanism of action remains unclear. We investigated effects of this secondary plant compound in vivo using the model organism Caenorhabditis elegans. Adult C. elegans nematodes were incubated with IX, and then, the stress resistance was analysed in the SYTOX assay; lifespan was monitored by touch-provoked movement method, the amount of reactive oxygen species (ROS) was measured in the DCF assay, and the nuclear localisation of the transcription factor DAF-16 was analysed by using a transgenic strain. By the use of a DAF-16 loss-of-function strain, we analysed whether the effects are dependent on DAF-16. IX increases the resistance of the nematode against thermal stress. Additionally, a reduction in ROS in vivo was caused by IX. Since the flavanone only has a marginal radical-scavenging capacity (TEAC assay), we suggest that IX mediates its antioxidative effects indirectly via activation of DAF-16 (homologue to mammalian FOXO proteins). The nuclear translocation of this transcription factor is increased by IX. In the DAF-16-mutated strain, the IX-mediated increase in stress resistance was completely abolished; furthermore, an increased formation of ROS and a reduced lifespan was mediated by IX. IX or a bacterial metabolite of IX causes antioxidative effects as well as an increased stress resistance in C. elegans via activation of DAF-16. The homologous pathway may have implications in the molecular mechanism of IX in mammals.

Longevity Genes Revealed by Integrative Analysis of Isoform-Specific daf-16/FoxO Mutants of Caenorhabditis elegans.

Science.gov (United States)

Chen, Albert Tzong-Yang; Guo, Chunfang; Itani, Omar A; Budaitis, Breane G; Williams, Travis W; Hopkins, Christopher E; McEachin, Richard C; Pande, Manjusha; Grant, Ana R; Yoshina, Sawako; Mitani, Shohei; Hu, Patrick J

2015-10-01

FoxO transcription factors promote longevity across taxa. How they do so is poorly understood. In the nematode Caenorhabditis elegans, the A- and F-isoforms of the FoxO transcription factor DAF-16 extend life span in the context of reduced DAF-2 insulin-like growth factor receptor (IGFR) signaling. To elucidate the mechanistic basis for DAF-16/FoxO-dependent life span extension, we performed an integrative analysis of isoform-specific daf-16/FoxO mutants. In contrast to previous studies suggesting that DAF-16F plays a more prominent role in life span control than DAF-16A, isoform-specific daf-16/FoxO mutant phenotypes and whole transcriptome profiling revealed a predominant role for DAF-16A over DAF-16F in life span control, stress resistance, and target gene regulation. Integration of these datasets enabled the prioritization of a subset of 92 DAF-16/FoxO target genes for functional interrogation. Among 29 genes tested, two DAF-16A-specific target genes significantly influenced longevity. A loss-of-function mutation in the conserved gene gst-20, which is induced by DAF-16A, reduced life span extension in the context of daf-2/IGFR RNAi without influencing longevity in animals subjected to control RNAi. Therefore, gst-20 promotes DAF-16/FoxO-dependent longevity. Conversely, a loss-of-function mutation in srr-4, a gene encoding a seven-transmembrane-domain receptor family member that is repressed by DAF-16A, extended life span in control animals, indicating that DAF-16/FoxO may extend life span at least in part by reducing srr-4 expression. Our discovery of new longevity genes underscores the efficacy of our integrative strategy while providing a general framework for identifying specific downstream gene regulatory events that contribute substantially to transcription factor functions. As FoxO transcription factors have conserved functions in promoting longevity and may be dysregulated in aging-related diseases, these findings promise to illuminate fundamental

Triggering of the dsRNA sensors TLR3, MDA5, and RIG-I induces CD55 expression in synovial fibroblasts.

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Olga N Karpus

Full Text Available CD55 (decay-accelerating factor is a complement-regulatory protein highly expressed on fibroblast-like synoviocytes (FLS. CD55 is also a ligand for CD97, an adhesion-type G protein-coupled receptor abundantly present on leukocytes. Little is known regarding the regulation of CD55 expression in FLS.FLS isolated from arthritis patients were stimulated with pro-inflammatory cytokines and Toll-like receptor (TLR ligands. Transfection with polyinosinic-polycytidylic acid (poly(I:C and 5'-triphosphate RNA were used to activate the cytoplasmic double-stranded (dsRNA sensors melanoma differentiation-associated gene 5 (MDA5 and retinoic acid-inducible gene-I (RIG-I. CD55 expression, cell viability, and binding of CD97-loaded beads were quantified by flow cytometry.CD55 was expressed at equal levels on FLS isolated from patients with rheumatoid arthritis (RA, osteoarthritis, psoriatic arthritis and spondyloarthritis. CD55 expression in RA FLS was significantly induced by IL-1β and especially by the TLR3 ligand poly(I:C. Activation of MDA5 and RIG-I also enhanced CD55 expression. Notably, activation of MDA5 dose-dependently induced cell death, while triggering of TLR3 or RIG-I had a minor effect on viability. Upregulation of CD55 enhanced the binding capacity of FLS to CD97-loaded beads, which could be blocked by antibodies against CD55.Activation of dsRNA sensors enhances the expression of CD55 in cultured FLS, which increases the binding to CD97. Our findings suggest that dsRNA promotes the interaction between FLS and CD97-expressing leukocytes.

Coating of human decay accelerating factor (hDAF) onto medical devices to improve biocompatibility.

Science.gov (United States)

Watkins, N J; Braidley, P; Bray, C J; Savill, C M; White, D J

1997-12-01

In passing blood through an artificial circulatory system, the blood is exposed to surfaces that result in activation of the complement system. The consequences of the activation of complement can be extremely serious for the patient ranging from mild discomfort to respiratory distress and even anaphylaxis. An entirely novel approach was to express recombinant GPI anchored human decay accelerating factor (hDAF) using the baculovirus system and then coat the recombinant protein onto the surfaces of these materials to reduce complement activation. Expression of hDAF in Sf9 cells was shown by ELISA, FACS analysis, and Western blot. Functional activity was tested by CH50 assay. For the coating experiments a small scale model of a cardiovascular bypass circuit constructed from COBE tubing was used. hDAF was either coated onto the circuit using adsorption or covalently linked via the photoreactive crosslinker, p-azidobenzoyl hydrazide. After coating, heparinised human blood was pumped around the circuit and samples were collected into EDTA collection tubes at different time points. Complement activation was measured using a Quidel C3a-des-arg EIA. The photolinked circuits gave a reduction in C3a production of 20-50%, compared to 10-20% seen with an absorbed hDAF circuit. Furthermore, the inhibition of complement was seen over the whole time scale of the photolinked circuit, 60-90 min, whilst in the adsorbed circuit inhibition was not seen to a significant degree after 60 min. The time scale of a standard cardiac bypass is 45-90 min, therefore, the photolinked circuit results are encouraging, as significant inhibition of complement activation is seen within this time frame.

Transgenic C. elegans dauer larvae expressing hookworm phospho null DAF-16/FoxO exit dauer.

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Verena Gelmedin

Full Text Available Parasitic hookworms and the free-living model nematode Caenorhabtidis elegans share a developmental arrested stage, called the dauer stage in C. elegans and the infective third-stage larva (L3 in hookworms. One of the key transcription factors that regulate entrance to and exit from developmental arrest is the forkhead transcription factor DAF-16/FoxO. During the dauer stage, DAF-16 is activated and localized in the nucleus. DAF-16 is negatively regulated by phosphorylation by the upstream kinase AKT, which causes DAF-16 to localize out of the nucleus and the worm to exit from dauer. DAF-16 is conserved in hookworms, and hypothesized to control recovery from L3 arrest during infection. Lacking reverse genetic techniques for use in hookworms, we used C. elegans complementation assays to investigate the function of Ancylostoma caninum DAF-16 during entrance and exit from L3 developmental arrest. We performed dauer switching assays and observed the restoration of the dauer phenotype when Ac-DAF-16 was expressed in temperature-sensitive dauer defective C. elegans daf-2(e1370;daf-16(mu86 mutants. AKT phosphorylation site mutants of Ac-DAF-16 were also able to restore the dauer phenotype, but surprisingly allowed dauer exit when temperatures were lowered. We used fluorescence microscopy to localize DAF-16 during dauer and exit from dauer in C. elegans DAF-16 mutant worms expressing Ac-DAF-16, and found that Ac-DAF-16 exited the nucleus during dauer exit. Surprisingly, Ac-DAF-16 with mutated AKT phosphorylation sites also exited the nucleus during dauer exit. Our results suggest that another mechanism may be involved in the regulation DAF-16 nuclear localization during recovery from developmental arrest.

Daf-2, Daf-16 and Daf-23: Genetically Interacting Genes Controlling Dauer Formation in Caenorhabditis Elegans

OpenAIRE

Gottlieb, S.; Ruvkun, G.

1994-01-01

Under conditions of high population density and low food, Caenorhabditis elegans forms an alternative third larval stage, called the dauer stage, which is resistant to desiccation and harsh environments. Genetic analysis of some dauer constitutive (Daf-c) and dauer defective (Daf-d) mutants has revealed a complex pathway that is likely to function in particular neurons and/or responding tissues. Here we analyze the genetic interactions between three genes which comprise a branch of the dauer ...

CD55 deposited on synovial collagen fibers protects from immune complex-mediated arthritis

NARCIS (Netherlands)

Karpus, Olga N.; Kiener, Hans P.; Niederreiter, Birgit; Yilmaz-Elis, A. Seda; van der Kaa, Jos; Ramaglia, Valeria; Arens, Ramon; Smolen, Josef S.; Botto, Marina; Tak, Paul P.; Verbeek, J. Sjef; Hamann, Jörg

2015-01-01

CD55, a glycosylphosphatidylinositol-anchored, complement-regulating protein (decay-accelerating factor), is expressed by fibroblast-like synoviocytes (FLS) with high local abundance in the intimal lining layer. We here explored the basis and consequences of this uncommon presence. Synovial tissue,

Analysis list: daf-16 [Chip-atlas[Archive

Lifescience Database Archive (English)

Full Text Available daf-16 Adult + ce10 http://dbarchive.biosciencedbc.jp/kyushu-u/ce10/target/daf-16.1....tsv http://dbarchive.biosciencedbc.jp/kyushu-u/ce10/target/daf-16.5.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/ce10/target/daf...-16.10.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/ce10/colo/daf-16.Adult.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/ce10/colo/Adult.gml ...

Analysis list: daf-12 [Chip-atlas[Archive

Lifescience Database Archive (English)

Full Text Available daf-12 Larvae + ce10 http://dbarchive.biosciencedbc.jp/kyushu-u/ce10/target/daf-12....1.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/ce10/target/daf-12.5.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/ce10/target/daf...-12.10.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/ce10/colo/daf-12.Larvae.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/ce10/colo/Larvae.gml ...

Redox-dependent control of FOXO/DAF-16 by transportin-1.

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Putker, Marrit; Madl, Tobias; Vos, Harmjan R; de Ruiter, Hesther; Visscher, Marieke; van den Berg, Maaike C W; Kaplan, Mohammed; Korswagen, Hendrik C; Boelens, Rolf; Vermeulen, Michiel; Burgering, Boudewijn M T; Dansen, Tobias B

2013-02-21

Forkhead box O (FOXO; DAF-16 in worms) transcription factors, which are of vital importance in cell-cycle control, stress resistance, tumor suppression, and organismal lifespan, are largely regulated through nucleo-cytoplasmic shuttling. Insulin signaling keeps FOXO/DAF-16 cytoplasmic, and hence transcriptionally inactive. Conversely, as in loss of insulin signaling, reactive oxygen species (ROS) can activate FOXO/DAF-16 through nuclear accumulation. How ROS regulate the nuclear translocation of FOXO/DAF-16 is largely unknown. Cysteine oxidation can stabilize protein-protein interactions through the formation of disulfide-bridges when cells encounter ROS. Using a proteome-wide screen that identifies ROS-induced mixed disulfide-dependent complexes, we discovered several interaction partners of FOXO4, one of which is the nuclear import receptor transportin-1. We show that disulfide formation with transportin-1 is required for nuclear localization and the activation of FOXO4/DAF-16 induced by ROS, but not by the loss of insulin signaling. This molecular mechanism for nuclear shuttling is conserved in C. elegans and directly connects redox signaling to the longevity protein FOXO/DAF-16. Copyright © 2013 Elsevier Inc. All rights reserved.

Relative Contribution of Cellular Complement Inhibitors CD59, CD46, and CD55 to Parainfluenza Virus 5 Inhibition of Complement-Mediated Neutralization

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Yujia Li

2018-04-01

Full Text Available The complement system is a part of the innate immune system that viruses need to face during infections. Many viruses incorporate cellular regulators of complement activation (RCA to block complement pathways and our prior work has shown that Parainfluenza virus 5 (PIV5 incorporates CD55 and CD46 to delay complement-mediated neutralization. In this paper, we tested the role of a third individual RCA inhibitor CD59 in PIV5 interactions with complement pathways. Using a cell line engineered to express CD59, we show that small levels of functional CD59 are associated with progeny PIV5, which is capable of blocking assembly of the C5b-C9 membrane attack complex (MAC. PIV5 containing CD59 (PIV5-CD59 showed increased resistance to complement-mediated neutralization in vitro comparing to PIV5 lacking regulators. Infection of A549 cells with PIV5 and RSV upregulated CD59 expression. TGF-beta treatment of PIV5-infected cells also increased cell surface CD59 expression and progeny virions were more resistant to complement-mediated neutralization. A comparison of individual viruses containing only CD55, CD46, or CD59 showed a potency of inhibiting complement-mediated neutralization, which followed a pattern of CD55 > CD46 > CD59.

Interaction of hookworm 14-3-3 with the forkhead transcription factor DAF-16 requires intact Akt phosphorylation sites

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Hawdon John M

2009-04-01

Full Text Available Abstract Background Third-stage infective larvae (L3 of hookworms are in an obligatory state of developmental arrest that ends upon entering the definitive host, where they receive a signal that re-activates development. Recovery from the developmentally arrested dauer stage of Caenorhabditis elegans is analogous to the resumption of development during hookworm infection. Insulin-like signaling (ILS mediates recovery from arrest in C. elegans and activation of hookworm dauer L3. In C. elegans, phosphorylation of the forkhead transcription factor DAF-16 in response to ILS creates binding cites for the 14-3-3 protein Ce-FTT-2, which translocates DAF-16 out of the nucleus, resulting in resumption of reproductive development. Results To determine if hookworm 14-3-3 proteins play a similar role in L3 activation, hookworm FTT-2 was identified and tested for its ability to interact with A. caninum DAF-16 in vitro. The Ac-FTT-2 amino acid sequence was 91% identical to the Ce-FTT-2, and was most closely related to FTT-2 from other nematodes. Ac-FTT-2 was expressed in HEK 293T cells, and was recognized by an antibody against human 14-3-3β isoform. Reciprocal co-immunoprecipitations using anti-epitope tag antibodies indicated that Ac-FTT-2 interacts with Ac-DAF-16 when co-expressed in serum-stimulated HEK 293T cells. This interaction requires intact Akt consensus phosphorylation sites at serine107 and threonine312, but not serine381. Ac-FTT-2 was undetectable by Western blot in excretory/secretory products from serum-stimulated (activated L3 or adult A. caninum. Conclusion The results indicate that Ac-FTT-2 interacts with DAF-16 in a phosphorylation-site dependent manner, and suggests that Ac-FTT-2 mediates activation of L3 by binding Ac-DAF-16 during hookworm infection.

Structural and functional characterisation of FOXO/Acan-DAF-16 from the parasitic nematode Angiostrongylus cantonensis.

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Yan, Baolong; Sun, Weiwei; Yan, Lanzhu; Zhang, Liangliang; Zheng, Yuan; Zeng, Yuzhen; Huang, Huicong; Liang, Shaohui

2016-12-01

Fork head box transcription factors subfamily O (FoxO) is regarded to be significant in cell-cycle control, cell differentiation, ageing, stress response, apoptosis, tumour formation and DNA damage repair. In the free-living nematode Caenorhabditis elegans, the FoxO transcription factor is encoded by Ce-daf-16, which is negatively regulated by insulin-like signaling (IIS) and involved in promoting dauer formation through bringing about its hundreds of downstream genes expression. In nematode parasites, orthologues of daf-16 from several species have been identified, with functions in rescue of dauer phenotypes determined in a surrogate system C. elegans. In this study, we identified the FoxO encoding gene, Acan-daf-16, from the parasitic nematode Angiostrongylus cantonensis, and determined the genomic structures, transcripts and functions far more thorough in longevity, stress resistance and dauer formation. Acan-daf-16 encodes two proteins, Acan-DAF-16A and Acan-DAF-16B, consisting of 555 and 491 amino acids, respectively. Both isoforms possess the highly conserved fork head domains. Acan-daf-16A and Acan-daf-16B are expressed from distinct promoters. The expression patterns of Acan-daf-16 isoforms in the C. elegans surrogate system showed that p Acan-daf-16a:gfp was expressed in all cells of C. elegans, including the pharynx, and the expression of p Acan-daf-16b:gfp was restricted to the pharynx. In addition to the same genomic organization to the orthologue in C. elegans, Ce-daf-16, both Acan-DAF-16 isoforms could restore the C. elegans daf-16(mg54) mutation in longevity, dauer formation and stress resistance, in spite of the partial complementation of Acan-DAF-16B isoform in longevity. These findings provide further evidence of the functional conservation of DAF-16s between parasitic nematodes and the free-living nematode C. elegans. Copyright © 2016. Published by Elsevier B.V.

Identification of hookworm DAF-16/FOXO response elements and direct gene targets.

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Xin Gao

2010-08-01

Full Text Available The infective stage of the parasitic nematode hookworm is developmentally arrested in the environment and needs to infect a specific host to complete its life cycle. The canine hookworm (Ancylostoma caninum is an excellent model for investigating human hookworm infections. The transcription factor of A. caninum, Ac-DAF-16, which has a characteristic fork head or "winged helix" DNA binding domain (DBD, has been implicated in the resumption of hookworm development in the host. However, the precise roles of Ac-DAF-16 in hookworm parasitism and its downstream targets are unknown. In the present study, we combined molecular techniques and bioinformatics to identify a group of Ac-DAF-16 binding sites and target genes.The DNA binding domain of Ac-DAF-16 was used to select genomic fragments by in vitro genomic selection. Twenty four bound genomic fragments were analyzed for the presence of the DAF-16 family binding element (DBE and possible alternative Ac-DAF-16 bind motifs. The 22 genes linked to these genomic fragments were identified using bioinformatics tools and defined as candidate direct gene targets of Ac-DAF-16. Their developmental stage-specific expression patterns were examined. Also, a new putative DAF-16 binding element was identified.Our results show that Ac-DAF-16 is involved in diverse biological processes throughout hookworm development. Further investigation of these target genes will provide insights into the molecular basis by which Ac-DAF-16 regulates its downstream gene network in hookworm infection.

The MYST family histone acetyltransferase complex regulates stress resistance and longevity through transcriptional control of DAF-16/FOXO transcription factors.

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Ikeda, Takako; Uno, Masaharu; Honjoh, Sakiko; Nishida, Eisuke

2017-08-09

The well-known link between longevity and the Sir2 histone deacetylase family suggests that histone deacetylation, a modification associated with repressed chromatin, is beneficial to longevity. However, the molecular links between histone acetylation and longevity remain unclear. Here, we report an unexpected finding that the MYST family histone acetyltransferase complex (MYS-1/TRR-1 complex) promotes rather than inhibits stress resistance and longevity in Caenorhabditis elegans Our results show that these beneficial effects are largely mediated through transcriptional up-regulation of the FOXO transcription factor DAF-16. MYS-1 and TRR-1 are recruited to the promoter regions of the daf-16 gene, where they play a role in histone acetylation, including H4K16 acetylation. Remarkably, we also find that the human MYST family Tip60/TRRAP complex promotes oxidative stress resistance by up-regulating the expression of FOXO transcription factors in human cells. Tip60 is recruited to the promoter regions of the foxo1 gene, where it increases H4K16 acetylation levels. Our results thus identify the evolutionarily conserved role of the MYST family acetyltransferase as a key epigenetic regulator of DAF-16/FOXO transcription factors. © 2017 The Authors.

ASM-3 acid sphingomyelinase functions as a positive regulator of the DAF-2/AGE-1 signaling pathway and serves as a novel anti-aging target.

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Yongsoon Kim

Full Text Available In C. elegans, the highly conserved DAF-2/insulin/insulin-like growth factor 1 receptor signaling (IIS pathway regulates longevity, metabolism, reproduction and development. In mammals, acid sphingomyelinase (ASM is an enzyme that hydrolyzes sphingomyelin to produce ceramide. ASM has been implicated in CD95 death receptor signaling under certain stress conditions. However, the involvement of ASM in growth factor receptor signaling under physiological conditions is not known. Here, we report that in vivo ASM functions as a positive regulator of the DAF-2/IIS pathway in C. elegans. We have shown that inactivation of asm-3 extends animal lifespan and promotes dauer arrest, an alternative developmental process. A significant cooperative effect on lifespan is observed between asm-3 deficiency and loss-of-function alleles of the age-1/PI 3-kinase, with the asm-3; age-1 double mutant animals having a mean lifespan 259% greater than that of the wild-type animals. The lifespan extension phenotypes caused by the loss of asm-3 are dependent on the functions of daf-16/FOXO and daf-18/PTEN. We have demonstrated that inactivation of asm-3 causes nuclear translocation of DAF-16::GFP protein, up-regulates endogenous DAF-16 protein levels and activates the downstream targeting genes of DAF-16. Together, our findings reveal a novel role of asm-3 in regulation of lifespan and diapause by modulating IIS pathway. Importantly, we have found that two drugs known to inhibit mammalian ASM activities, desipramine and clomipramine, markedly extend the lifespan of wild-type animals, in a manner similar to that achieved by genetic inactivation of the asm genes. Our studies illustrate a novel strategy of anti-aging by targeting ASM, which may potentially be extended to mammals.

ASM-3 acid sphingomyelinase functions as a positive regulator of the DAF-2/AGE-1 signaling pathway and serves as a novel anti-aging target.

Science.gov (United States)

Kim, Yongsoon; Sun, Hong

2012-01-01

In C. elegans, the highly conserved DAF-2/insulin/insulin-like growth factor 1 receptor signaling (IIS) pathway regulates longevity, metabolism, reproduction and development. In mammals, acid sphingomyelinase (ASM) is an enzyme that hydrolyzes sphingomyelin to produce ceramide. ASM has been implicated in CD95 death receptor signaling under certain stress conditions. However, the involvement of ASM in growth factor receptor signaling under physiological conditions is not known. Here, we report that in vivo ASM functions as a positive regulator of the DAF-2/IIS pathway in C. elegans. We have shown that inactivation of asm-3 extends animal lifespan and promotes dauer arrest, an alternative developmental process. A significant cooperative effect on lifespan is observed between asm-3 deficiency and loss-of-function alleles of the age-1/PI 3-kinase, with the asm-3; age-1 double mutant animals having a mean lifespan 259% greater than that of the wild-type animals. The lifespan extension phenotypes caused by the loss of asm-3 are dependent on the functions of daf-16/FOXO and daf-18/PTEN. We have demonstrated that inactivation of asm-3 causes nuclear translocation of DAF-16::GFP protein, up-regulates endogenous DAF-16 protein levels and activates the downstream targeting genes of DAF-16. Together, our findings reveal a novel role of asm-3 in regulation of lifespan and diapause by modulating IIS pathway. Importantly, we have found that two drugs known to inhibit mammalian ASM activities, desipramine and clomipramine, markedly extend the lifespan of wild-type animals, in a manner similar to that achieved by genetic inactivation of the asm genes. Our studies illustrate a novel strategy of anti-aging by targeting ASM, which may potentially be extended to mammals.

ASM-3 Acid Sphingomyelinase Functions as a Positive Regulator of the DAF-2/AGE-1 Signaling Pathway and Serves as a Novel Anti-Aging Target

Science.gov (United States)

Kim, Yongsoon; Sun, Hong

2012-01-01

In C. elegans, the highly conserved DAF-2/insulin/insulin-like growth factor 1 receptor signaling (IIS) pathway regulates longevity, metabolism, reproduction and development. In mammals, acid sphingomyelinase (ASM) is an enzyme that hydrolyzes sphingomyelin to produce ceramide. ASM has been implicated in CD95 death receptor signaling under certain stress conditions. However, the involvement of ASM in growth factor receptor signaling under physiological conditions is not known. Here, we report that in vivo ASM functions as a positive regulator of the DAF-2/IIS pathway in C. elegans. We have shown that inactivation of asm-3 extends animal lifespan and promotes dauer arrest, an alternative developmental process. A significant cooperative effect on lifespan is observed between asm-3 deficiency and loss-of-function alleles of the age-1/PI 3-kinase, with the asm-3; age-1 double mutant animals having a mean lifespan 259% greater than that of the wild-type animals. The lifespan extension phenotypes caused by the loss of asm-3 are dependent on the functions of daf-16/FOXO and daf-18/PTEN. We have demonstrated that inactivation of asm-3 causes nuclear translocation of DAF-16::GFP protein, up-regulates endogenous DAF-16 protein levels and activates the downstream targeting genes of DAF-16. Together, our findings reveal a novel role of asm-3 in regulation of lifespan and diapause by modulating IIS pathway. Importantly, we have found that two drugs known to inhibit mammalian ASM activities, desipramine and clomipramine, markedly extend the lifespan of wild-type animals, in a manner similar to that achieved by genetic inactivation of the asm genes. Our studies illustrate a novel strategy of anti-aging by targeting ASM, which may potentially be extended to mammals. PMID:23049887

DAF-16 employs the chromatin remodeller SWI/SNF to promote stress resistance and longevity.

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Riedel, Christian G; Dowen, Robert H; Lourenco, Guinevere F; Kirienko, Natalia V; Heimbucher, Thomas; West, Jason A; Bowman, Sarah K; Kingston, Robert E; Dillin, Andrew; Asara, John M; Ruvkun, Gary

2013-05-01

Organisms are constantly challenged by stresses and privations and require adaptive responses for their survival. The forkhead box O (FOXO) transcription factor DAF-16 (hereafter referred to as DAF-16/FOXO) is a central nexus in these responses, but despite its importance little is known about how it regulates its target genes. Proteomic identification of DAF-16/FOXO-binding partners in Caenorhabditis elegans and their subsequent functional evaluation by RNA interference revealed several candidate DAF-16/FOXO cofactors, most notably the chromatin remodeller SWI/SNF. DAF-16/FOXO and SWI/SNF form a complex and globally co-localize at DAF-16/FOXO target promoters. We show that specifically for gene activation, DAF-16/FOXO depends on SWI/SNF, facilitating SWI/SNF recruitment to target promoters, to activate transcription by presumed remodelling of local chromatin. For the animal, this translates into an essential role for SWI/SNF in DAF-16/FOXO-mediated processes, in particular dauer formation, stress resistance and the promotion of longevity. Thus, we give insight into the mechanisms of DAF-16/FOXO-mediated transcriptional regulation and establish a critical link between ATP-dependent chromatin remodelling and lifespan regulation.

Cell-nonautonomous signaling of FOXO/DAF-16 to the stem cells of Caenorhabditis elegans.

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Wenjing Qi

Full Text Available In Caenorhabditis elegans (C. elegans, the promotion of longevity by the transcription factor DAF-16 requires reduced insulin/IGF receptor (IIR signaling or the ablation of the germline, although the reason for the negative impact of germ cells is unknown. FOXO/DAF-16 activity inhibits germline proliferation in both daf-2 mutants and gld-1 tumors. In contrast to its function as a germline tumor suppressor, we now provide evidence that somatic DAF-16 in the presence of IIR signaling can also result in tumorigenic activity, which counteracts robust lifespan extension. In contrast to the cell-autonomous IIR signaling, which is required for larval germline proliferation, activation of DAF-16 in the hypodermis results in hyperplasia of the germline and disruption of the surrounding basement membrane. SHC-1 adaptor protein and AKT-1 kinase antagonize, whereas AKT-2 and SGK-1 kinases promote, this cell-nonautonomous DAF-16 function. Our data suggest that a functional balance of DAF-16 activities in different tissues determines longevity and reveals a novel, cell-nonautonomous role of FOXO/DAF-16 to affect stem cells.

Cell-Nonautonomous Signaling of FOXO/DAF-16 to the Stem Cells of Caenorhabditis elegans

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Qi, Wenjing; Huang, Xu; Neumann-Haefelin, Elke; Schulze, Ekkehard; Baumeister, Ralf

2012-01-01

In Caenorhabditis elegans (C. elegans), the promotion of longevity by the transcription factor DAF-16 requires reduced insulin/IGF receptor (IIR) signaling or the ablation of the germline, although the reason for the negative impact of germ cells is unknown. FOXO/DAF-16 activity inhibits germline proliferation in both daf-2 mutants and gld-1 tumors. In contrast to its function as a germline tumor suppressor, we now provide evidence that somatic DAF-16 in the presence of IIR signaling can also result in tumorigenic activity, which counteracts robust lifespan extension. In contrast to the cell-autonomous IIR signaling, which is required for larval germline proliferation, activation of DAF-16 in the hypodermis results in hyperplasia of the germline and disruption of the surrounding basement membrane. SHC-1 adaptor protein and AKT-1 kinase antagonize, whereas AKT-2 and SGK-1 kinases promote, this cell-nonautonomous DAF-16 function. Our data suggest that a functional balance of DAF-16 activities in different tissues determines longevity and reveals a novel, cell-nonautonomous role of FOXO/DAF-16 to affect stem cells. PMID:22916022

The Deubiquitylase MATH-33 Controls DAF-16 Stability and Function in Metabolism and Longevity.

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Heimbucher, Thomas; Liu, Zheng; Bossard, Carine; McCloskey, Richard; Carrano, Andrea C; Riedel, Christian G; Tanasa, Bogdan; Klammt, Christian; Fonslow, Bryan R; Riera, Celine E; Lillemeier, Bjorn F; Kemphues, Kenneth; Yates, John R; O'Shea, Clodagh; Hunter, Tony; Dillin, Andrew

2015-07-07

FOXO family transcription factors are downstream effectors of Insulin/IGF-1 signaling (IIS) and major determinants of aging in organisms ranging from worms to man. The molecular mechanisms that actively promote DAF16/FOXO stability and function are unknown. Here we identify the deubiquitylating enzyme MATH-33 as an essential DAF-16 regulator in IIS, which stabilizes active DAF-16 protein levels and, as a consequence, influences DAF-16 functions, such as metabolism, stress response, and longevity in C. elegans. MATH-33 associates with DAF-16 in cellulo and in vitro. MATH-33 functions as a deubiquitylase by actively removing ubiquitin moieties from DAF-16, thus counteracting the action of the RLE-1 E3-ubiquitin ligase. Our findings support a model in which MATH-33 promotes DAF-16 stability in response to decreased IIS by directly modulating its ubiquitylation state, suggesting that regulated oscillations in the stability of DAF-16 protein play an integral role in controlling processes such as metabolism and longevity. Copyright © 2015 Elsevier Inc. All rights reserved.

RNA helicase HEL-1 promotes longevity by specifically activating DAF-16/FOXO transcription factor signaling in Caenorhabditis elegans

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Seo, Mihwa; Seo, Keunhee; Hwang, Wooseon; Koo, Hee Jung; Hahm, Jeong-Hoon; Yang, Jae-Seong; Han, Seong Kyu; Hwang, Daehee; Kim, Sanguk; Jang, Sung Key; Lee, Yoontae; Nam, Hong Gil; Lee, Seung-Jae V.

2015-01-01

The homeostatic maintenance of the genomic DNA is crucial for regulating aging processes. However, the role of RNA homeostasis in aging processes remains unknown. RNA helicases are a large family of enzymes that regulate the biogenesis and homeostasis of RNA. However, the functional significance of RNA helicases in aging has not been explored. Here, we report that a large fraction of RNA helicases regulate the lifespan of Caenorhabditis elegans. In particular, we show that a DEAD-box RNA helicase, helicase 1 (HEL-1), promotes longevity by specifically activating the DAF-16/forkhead box O (FOXO) transcription factor signaling pathway. We find that HEL-1 is required for the longevity conferred by reduced insulin/insulin-like growth factor 1 (IGF-1) signaling (IIS) and is sufficient for extending lifespan. We further show that the expression of HEL-1 in the intestine and neurons contributes to longevity. HEL-1 enhances the induction of a large fraction of DAF-16 target genes. Thus, the RNA helicase HEL-1 appears to promote longevity in response to decreased IIS as a transcription coregulator of DAF-16. Because HEL-1 and IIS are evolutionarily well conserved, a similar mechanism for longevity regulation via an RNA helicase-dependent regulation of FOXO signaling may operate in mammals, including humans. PMID:26195740

The C. elegans Ortholog of USP7 controls DAF-16 stability in Insulin/IGF-1-like signaling.

Science.gov (United States)

Heimbucher, Thomas; Hunter, Tony

2015-01-01

FOXO family transcription factors are downstream effectors of Insulin/IGF-1 signaling (IIS) and are regulated by posttranslational modification and coregulators, including components of the ubiquitin-proteasome system (UPS). Cofactors promoting DAF-16/FOXO protein stability and function in IIS have not been described yet. In a recent study, we have identified the deubiquitylating enzyme MATH-33, the ortholog of mammalian USP7/HAUSP, as an essential DAF-16 coregulator. We found that MATH-33 actively stabilizes DAF-16 protein levels when IIS is downregulated. Here we discuss how DAF-16/FOXO transcription factors are regulated by the UPS, in particular by the interplay of E3-ubiquitin ligases and deubiquitylating enzymes, which is critical for balancing DAF-16/FOXO activity and degradation. Recent findings raise the intriguing possibility that regulated oscillations in DAF-16/FOXO steady state levels play an integral role in mechanisms controlling healthspan and lifespan extension.

Reversible reprotoxic effects of manganese through DAF-16 transcription factor activation and vitellogenin downregulation in Caenorhabditis elegans.

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Gubert, Priscila; Puntel, Bruna; Lehmen, Tassia; Bornhorst, Julia; Avila, Daiana S; Aschner, Michael; Soares, Felix A A

2016-04-15

Vitellogenesis is the yolk production process which provides the essential nutrients for the developing embryos. Yolk is a lipoprotein particle that presents lipids and lipid-binding proteins, referred to as vitellogenins (VIT). The Caenorhabditis elegans nematode has six genes encoding VIT lipoproteins. Several pathways are known to regulate vitellogenesis, including the DAF-16 transcription factor. Some reports have shown that heavy metals, such as manganese (Mn), impair brood size in C. elegans; however the mechanisms associated with this effect have yet to be identified. Our aim was to evaluate Mn's effects on C. elegans reproduction and better understand the pathways related to these effects. Young adult larval stage worms were treated for 4h with Mn in 85mM NaCl and Escherichia coli OP50 medium. Mn reduced egg-production and egg-laying during the first 24h after the treatment, although the total number of progenies were indistinguishable from the control group levels. This delay may have occurred due to DAF-16 activation, which was noted only after the treatment and was not apparent 24h later. Moreover, the expression, protein levels and green fluorescent protein (GFP) fluorescence associated with VIT were decreased soon after Mn treatment and recovered after 24h. Combined, these data suggest that the delay in egg-production is likely regulated by DAF-16 and followed by the inhibition of VIT transport activity. Further studies are needed to clarify the mechanisms associated with Mn-induced DAF-16 activation. Copyright © 2016 Elsevier Inc. All rights reserved.

Difference in Ulex europaeus agglutinin I-binding activity of decay-accelerating factor detected in the stools of patients with colorectal cancer and ulcerative colitis.

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Okazaki, Hiroaki; Mizuno, Motowo; Nasu, Junichirou; Makidono, Chiho; Hiraoka, Sakiko; Yamamoto, Kazuhide; Okada, Hiroyuki; Fujita, Teizo; Tsuji, Takao; Shiratori, Yasushi

2004-03-01

Expression of decay-accelerating factor (DAF, CD55), a complement-regulatory glycoprotein, is enhanced in colorectal-cancer (CC) cells and colonic epithelium in ulcerative colitis (UC), and stools from these patients contain increased amounts of DAF. Carbohydrate chains of glycoproteins are often altered during malignant transformation or inflammation. In this study, we investigated whether DAF molecules in patients with CC and those with UC differ with respect to oligosaccharide side chains. We analyzed DAF in stools and homogenates of colonic-tissue specimens obtained from patients with CC or UC using solid-phase enzyme-linked assay and Western blotting for reactivity with the lectins Ulex europaeus agglutinin I (UEA-I), wheat-germ agglutinin, peanut agglutinin, and concanavalin A. UEA-I bound to DAF in stools from patients with UC but not in that from the stools of CC patients, as demonstrated on the solid-phase enzyme-linked assay (P <.05, Mann-Whitney U test) and Western blotting. Binding of UEA-I was specifically inhibited by the addition of fucose. The difference in UEA-I reactivity with DAF was observed also in colonic-tissue homogenates from patients with UC and those with CC. DAF expressed in the mucosa and excreted into the stools of UC patients is different from that expressed in CC with regard to UEA-I reactivity. Future studies should be directed toward determining whether a qualitatively unique isoform of DAF is present, of which sugar chains are specific to CC in UC patients.

DAF-16/FOXO employs the chromatin remodeller SWI/SNF to promote stress resistance and longevity

Science.gov (United States)

Riedel, Christian G.; Dowen, Robert H.; Lourenco, Guinevere F.; Kirienko, Natalia V.; Heimbucher, Thomas; West, Jason A.; Bowman, Sarah K.; Kingston, Robert E.; Dillin, Andrew; Asara, John M.; Ruvkun, Gary

2013-01-01

Organisms are constantly challenged by stresses and privations and require adaptive responses for their survival. The transcription factor DAF-16/FOXO is central nexus in these responses, but despite its importance little is known about how it regulates its target genes. Proteomic identification of DAF-16/FOXO binding partners in Caenorhabditis elegans and their subsequent functional evaluation by RNA interference (RNAi) revealed several candidate DAF-16/FOXO cofactors, most notably the chromatin remodeller SWI/SNF. DAF-16/FOXO and SWI/SNF form a complex and globally colocalize at DAF-16/FOXO target promoters. We show that specifically for gene-activation, DAF-16/FOXO depends on SWI/SNF, facilitating SWI/SNF recruitment to target promoters, in order to activate transcription by presumed remodelling of local chromatin. For the animal, this translates into an essential role of SWI/SNF for DAF-16/FOXO-mediated processes, i.e. dauer formation, stress resistance, and the promotion of longevity. Thus we give insight into the mechanisms of DAF-16/FOXO-mediated transcriptional regulation and establish a critical link between ATP-dependent chromatin remodelling and lifespan regulation. PMID:23604319

DAF-16/FOXO and EGL-27/GATA promote developmental growth in response to persistent somatic DNA damage.

Science.gov (United States)

Mueller, Michael M; Castells-Roca, Laia; Babu, Vipin; Ermolaeva, Maria A; Müller, Roman-Ulrich; Frommolt, Peter; Williams, Ashley B; Greiss, Sebastian; Schneider, Jennifer I; Benzing, Thomas; Schermer, Bernhard; Schumacher, Björn

2014-12-01

Genome maintenance defects cause complex disease phenotypes characterized by developmental failure, cancer susceptibility and premature ageing. It remains poorly understood how DNA damage responses function during organismal development and maintain tissue functionality when DNA damage accumulates with ageing. Here we show that the FOXO transcription factor DAF-16 is activated in response to DNA damage during development, whereas the DNA damage responsiveness of DAF-16 declines with ageing. We find that in contrast to its established role in mediating starvation arrest, DAF-16 alleviates DNA-damage-induced developmental arrest and even in the absence of DNA repair promotes developmental growth and enhances somatic tissue functionality. We demonstrate that the GATA transcription factor EGL-27 co-regulates DAF-16 target genes in response to DNA damage and together with DAF-16 promotes developmental growth. We propose that EGL-27/GATA activity specifies DAF-16-mediated DNA damage responses to enable developmental progression and to prolong tissue functioning when DNA damage persists.

L1 arrest, daf-16/FoxO and nonautonomous control of post-embryonic development.

Science.gov (United States)

Kaplan, Rebecca E W; Baugh, L Ryan

2016-01-01

Post-embryonic development is governed by nutrient availability. L1 arrest, dauer formation and aging illustrate how starvation, anticipation of starvation and caloric restriction have profound influence on C. elegans development, respectively. Insulin-like signaling through the Forkhead box O transcription factor daf-16/FoxO regulates each of these processes. We recently reported that ins-4, ins-6 and daf-28 promote L1 development from the intestine and chemosensory neurons, similar to their role in dauer development. daf-16 functions cell-nonautonomously in regulation of L1 arrest, dauer development and aging. Discrepancies in daf-16 sites of action have been reported in each context, but the consensus implicates epidermis, intestine and nervous system. We suggest technical limitations of the experimental approach responsible for discrepant results. Steroid hormone signaling through daf-12/NHR is known to function downstream of daf-16 in control of dauer development, but signaling pathways mediating cell-nonautonomous effects of daf-16 in aging and L1 arrest had not been identified. We recently showed that daf-16 promotes L1 arrest by inhibiting daf-12/NHR and dbl-1/TGF-β Sma/Mab signaling, two pathways that promote L1 development in fed larvae. We will review these results on L1 arrest and speculate on why there are so many signals and signaling centers regulating post-embryonic development.

Baicalein modulates stress-resistance and life span in C. elegans via SKN-1 but not DAF-16.

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Havermann, Susannah; Humpf, Hans-Ulrich; Wätjen, Wim

2016-09-01

The flavonoid baicalein has been demonstrated to be an activator of the transcription factor Nrf2 in mammalian cell lines. We show that it further modulates the Nrf2 homolog SKN-1 in Caenorhabditis elegans and by this pathway mediates beneficial effects in the nematode: baicalein enhances the resistance of C. elegans against lethal thermal and sodium arsenite stress and dose-dependently prolongs the life span of the nematode. Using RNA interference against SKN-1 we were able to show that the induction of longevity and the enhanced stress-resistance were dependent on this transcription factor. DAF-16 (homolog to mammalian FOXO) is another pivotal aging-related transcription factor in the nematode. We demonstrate that DAF-16 does not participate in the beneficial effects of baicalein: since baicalein causes no increase in the nuclear translocation of DAF-16 (DAF-16::GFP expressing strain, incubation time: 1h) and it still induces longevity even in a DAF-16 loss-of-function strain, we conclude, that baicalein increases stress-resistance and life span in C. elegans via SKN-1 but not DAF-16. Copyright © 2016 Elsevier B.V. All rights reserved.

Synthetic DAF-12 modulators with potential use in controlling the nematode life cycle.

Science.gov (United States)

Dansey, María V; Alvarez, Lautaro D; Samaja, Gisela; Escudero, Daiana S; Veleiro, Adriana S; Pecci, Adalí; Castro, Olga A; Burton, Gerardo

2015-01-01

Dafachronic acids (DAs) are 3-keto cholestenoic acids bearing a carboxylic acid moiety at the end of the steroid side chain. These compounds interact with the DAF-12 receptor, a ligand-dependent transcription factor that acts as a molecular switch mediating the choice between arrest at diapause or progression to reproductive development and adult lifespan in different nematodes. Recently, we reported that the 27-nor-Δ4-DA was able to directly activate DAF-12 in a transactivation cell-based luciferase assay and rescued the Mig phenotype of daf-9(rh50) Caenorhabditis elegans mutants. In the present paper, to investigate further the relationship between the structure of the steroid side chain and DAF-12 activity, we evaluated the in vitro and in vivo activity of Δ4-DA analogues with modified side chains using transactivation cell-based assays and daf-9(dh6) C. elegans mutants. Our results revealed that introduction of a 24,25-double bond on the cholestenoic acid side chain did not affect DAF-12 activity, whereas shortening the side chain lowered the activity. Most interestingly, the C24 alcohol 24-hydroxy-4-cholen-3-one (6) was an antagonist of the DAF-12 receptor both in vitro and in vivo.

The DAF-16 FOXO transcription factor regulates natc-1 to modulate stress resistance in Caenorhabditis elegans, linking insulin/IGF-1 signaling to protein N-terminal acetylation.

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Warnhoff, Kurt; Murphy, John T; Kumar, Sandeep; Schneider, Daniel L; Peterson, Michelle; Hsu, Simon; Guthrie, James; Robertson, J David; Kornfeld, Kerry

2014-10-01

The insulin/IGF-1 signaling pathway plays a critical role in stress resistance and longevity, but the mechanisms are not fully characterized. To identify genes that mediate stress resistance, we screened for C. elegans mutants that can tolerate high levels of dietary zinc. We identified natc-1, which encodes an evolutionarily conserved subunit of the N-terminal acetyltransferase C (NAT) complex. N-terminal acetylation is a widespread modification of eukaryotic proteins; however, relatively little is known about the biological functions of NATs. We demonstrated that loss-of-function mutations in natc-1 cause resistance to a broad-spectrum of physiologic stressors, including multiple metals, heat, and oxidation. The C. elegans FOXO transcription factor DAF-16 is a critical target of the insulin/IGF-1 signaling pathway that mediates stress resistance, and DAF-16 is predicted to directly bind the natc-1 promoter. To characterize the regulation of natc-1 by DAF-16 and the function of natc-1 in insulin/IGF-1 signaling, we analyzed molecular and genetic interactions with key components of the insulin/IGF-1 pathway. natc-1 mRNA levels were repressed by DAF-16 activity, indicating natc-1 is a physiological target of DAF-16. Genetic studies suggested that natc-1 functions downstream of daf-16 to mediate stress resistance and dauer formation. Based on these findings, we hypothesize that natc-1 is directly regulated by the DAF-16 transcription factor, and natc-1 is a physiologically significant effector of the insulin/IGF-1 signaling pathway that mediates stress resistance and dauer formation. These studies identify a novel biological function for natc-1 as a modulator of stress resistance and dauer formation and define a functionally significant downstream effector of the insulin/IGF-1 signaling pathway. Protein N-terminal acetylation mediated by the NatC complex may play an evolutionarily conserved role in regulating stress resistance.

The Transcription Factor DAF-16 is Essential for Increased Longevity in C. elegans Exposed to Bifidobacterium longum BB68.

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Zhao, Liang; Zhao, Yang; Liu, Ruihai; Zheng, Xiaonan; Zhang, Min; Guo, Huiyuan; Zhang, Hao; Ren, Fazheng

2017-08-07

The longevity-promoting benefits of lactobacilli were hypothesized as early as 1907. Although the anti-aging effects of lactic acid bacteria (LAB) have been observed in nematodes, rodents and humans for over a century, the mechanisms underlying the effects of probiotics on aging have rarely been assessed. Using the Caenorhabditis elegans (C. elegans) model, various studies have elucidated the role of different signaling cascades, especially the DAF-16 cascade, on lifespan extension by LAB. In this study, the mechanisms through which Bifidobacterium longum strain BB68 affects the longevity of C. elegans were assessed. The lifespan of nematodes increased by 28% after worms were fed BB68, and this extension of lifespan was completely lost in backgrounds containing a mutated DAF-16 gene. High levels of DAF-16 (in the daf-16 (mu86); muIs61 strain) nuclear accumulation and high expression of the SOD-3 gene (a DAF-16-specific target gene) were observed as a result of BB68 treatment. Immunofluorescence microscopy revealed that TIR-1 and JNK-1 are involved in the phosphorylation and activation of DAF-16. Thus, BB68 increased the longevity of nematodes by activating the TIR-1 - JNK-1 - DAF-16 signaling pathway, and the cell wall component of BB68 contributed to longevity.

daf-31 encodes the catalytic subunit of N alpha-acetyltransferase that regulates Caenorhabditis elegans development, metabolism and adult lifespan.

Science.gov (United States)

Chen, Di; Zhang, Jiuli; Minnerly, Justin; Kaul, Tiffany; Riddle, Donald L; Jia, Kailiang

2014-10-01

The Caenorhabditis elegans dauer larva is a facultative state of diapause. Mutations affecting dauer signal transduction and morphogenesis have been reported. Of these, most that result in constitutive formation of dauer larvae are temperature-sensitive (ts). The daf-31 mutant was isolated in genetic screens looking for novel and underrepresented classes of mutants that form dauer and dauer-like larvae non-conditionally. Dauer-like larvae are arrested in development and have some, but not all, of the normal dauer characteristics. We show here that daf-31 mutants form dauer-like larvae under starvation conditions but are sensitive to SDS treatment. Moreover, metabolism is shifted to fat accumulation in daf-31 mutants. We cloned the daf-31 gene and it encodes an ortholog of the arrest-defective-1 protein (ARD1) that is the catalytic subunit of the major N alpha-acetyltransferase (NatA). A daf-31 promoter::GFP reporter gene indicates daf-31 is expressed in multiple tissues including neurons, pharynx, intestine and hypodermal cells. Interestingly, overexpression of daf-31 enhances the longevity phenotype of daf-2 mutants, which is dependent on the forkhead transcription factor (FOXO) DAF-16. We demonstrate that overexpression of daf-31 stimulates the transcriptional activity of DAF-16 without influencing its subcellular localization. These data reveal an essential role of NatA in controlling C. elegans life history and also a novel interaction between ARD1 and FOXO transcription factors, which may contribute to understanding the function of ARD1 in mammals.

Simulation environment architecture development using the DoDAF

NARCIS (Netherlands)

Berg, T. van den; Lutz, R.

2015-01-01

The US Department of Defense (DoD) Architecture Framework (DoDAF) provides a common approach for architecture description development. The primary use of DoDAF is capability development and system acquisition in the military domain. Although DoDAF was not designed to support the development of

DAF-16 employs the chromatin remodeller SWI/SNF to promote stress resistance and longevity

NARCIS (Netherlands)

Riedel, Christian G; Dowen, Robert H; Lourenco, Guinevere F; Kirienko, Natalia V; Heimbucher, Thomas; West, Jason A; Bowman, Sarah K; Kingston, Robert E; Dillin, Andrew; Asara, John M; Ruvkun, Gary

Organisms are constantly challenged by stresses and privations and require adaptive responses for their survival. The forkhead box O (FOXO) transcription factor DAF-16 (hereafter referred to as DAF-16/FOXO) is a central nexus in these responses, but despite its importance little is known about how

Insulin Signaling-independent Activation of DAF-16 Shapes the Transcriptome during Normal Aging

OpenAIRE

Zhang, Yan-Ping; Liang, Chung-Yi; Hsu, Ao-Lin; Li, Shang-Tong; Zhang, Pan; Dong, Meng-Qiu; Zhao, Han-Qing

2018-01-01

The roles and regulatory mechanisms of transriptome changes during aging are unclear. It has been proposed that the transcriptome suffers decay during aging owing to age-associated down-regulation of transcription factors. In this study, we characterized the role of a transcription factor DAF-16, which is a highly conserved lifespan regulator, in the normal aging process of Caenorhabditis elegans. We found that DAF-16 translocates into the nucleus in aged wild-type worms and activates the exp...

daf-31 encodes the catalytic subunit of N alpha-acetyltransferase that regulates Caenorhabditis elegans development, metabolism and adult lifespan.

Directory of Open Access Journals (Sweden)

Di Chen

2014-10-01

Full Text Available The Caenorhabditis elegans dauer larva is a facultative state of diapause. Mutations affecting dauer signal transduction and morphogenesis have been reported. Of these, most that result in constitutive formation of dauer larvae are temperature-sensitive (ts. The daf-31 mutant was isolated in genetic screens looking for novel and underrepresented classes of mutants that form dauer and dauer-like larvae non-conditionally. Dauer-like larvae are arrested in development and have some, but not all, of the normal dauer characteristics. We show here that daf-31 mutants form dauer-like larvae under starvation conditions but are sensitive to SDS treatment. Moreover, metabolism is shifted to fat accumulation in daf-31 mutants. We cloned the daf-31 gene and it encodes an ortholog of the arrest-defective-1 protein (ARD1 that is the catalytic subunit of the major N alpha-acetyltransferase (NatA. A daf-31 promoter::GFP reporter gene indicates daf-31 is expressed in multiple tissues including neurons, pharynx, intestine and hypodermal cells. Interestingly, overexpression of daf-31 enhances the longevity phenotype of daf-2 mutants, which is dependent on the forkhead transcription factor (FOXO DAF-16. We demonstrate that overexpression of daf-31 stimulates the transcriptional activity of DAF-16 without influencing its subcellular localization. These data reveal an essential role of NatA in controlling C. elegans life history and also a novel interaction between ARD1 and FOXO transcription factors, which may contribute to understanding the function of ARD1 in mammals.

The DAF-7/TGF-β signaling pathway regulates abundance of the C. elegans glutamate receptor GLR-1

Science.gov (United States)

McGehee, Annette M.; Moss, Benjamin J.; Juo, Peter

2015-01-01

Transforming growth factor-β (TGF-β) family signaling pathways have roles in both neuronal development and the regulation of synaptic function. Here we identify a novel role for the C. elegans DAF-7/TGF-β signaling pathway in the regulation of the AMPA-type glutamate receptor GLR-1. We found that the abundance of GLR-1 increases at synapses in the ventral nerve cord (VNC) of animals with loss-of-function mutations in multiple DAF-7/TGF-β pathway components including the TGF-β ligand DAF-7, the type I receptor DAF-1, and the Smads DAF-8 and DAF-14. The GLR-1 defect can be rescued by expression of daf-8 specifically in glr-1-expressing interneurons. The effect on GLR-1 was specific for the DAF-7 pathway because mutations in the DBL-1/TGF-β family pathway did not increase GLR-1 levels in the VNC. Immunoblot analysis indicates that total levels of GLR-1 protein are increased in neurons of DAF-7/TGF-β pathway mutants. The increased abundance of GLR-1 in the VNC of daf-7 pathway mutants is dependent on the transcriptional regulator DAF-3/Smad suggesting that DAF-3-dependent transcription controls GLR-1 levels. Furthermore, we found that glr-1 transcription is increased in daf-7 mutants based on a glr-1 transcriptional reporter. Together these results suggest that the DAF-7/TGF-β signaling pathway functions in neurons and negatively regulates the abundance of GLR-1, in part, by controlling transcription of the receptor itself. Finally, DAF-7/TGF-β pathway mutants exhibit changes in spontaneous locomotion that are dependent on endogenous GLR-1 and consistent with increased glutamatergic signaling. These results reveal a novel mechanism by which TGF-β signaling functions in the nervous system to regulate behavior. PMID:26054666

The DAF-7/TGF-β signaling pathway regulates abundance of the Caenorhabditis elegans glutamate receptor GLR-1.

Science.gov (United States)

McGehee, Annette M; Moss, Benjamin J; Juo, Peter

2015-07-01

Transforming growth factor-β (TGF-β) family signaling pathways have roles in both neuronal development and the regulation of synaptic function. Here we identify a novel role for the Caenorhabditis elegans DAF-7/TGF-β signaling pathway in the regulation of the AMPA-type glutamate receptor GLR-1. We found that the abundance of GLR-1 increases at synapses in the ventral nerve cord (VNC) of animals with loss-of-function mutations in multiple DAF-7/TGF-β pathway components including the TGF-β ligand DAF-7, the type I receptor DAF-1, and the Smads DAF-8 and DAF-14. The GLR-1 defect can be rescued by expression of daf-8 specifically in glr-1-expressing interneurons. The effect on GLR-1 was specific for the DAF-7 pathway because mutations in the DBL-1/TGF-β family pathway did not increase GLR-1 levels in the VNC. Immunoblot analysis indicates that total levels of GLR-1 protein are increased in neurons of DAF-7/TGF-β pathway mutants. The increased abundance of GLR-1 in the VNC of daf-7 pathway mutants is dependent on the transcriptional regulator DAF-3/Smad suggesting that DAF-3-dependent transcription controls GLR-1 levels. Furthermore, we found that glr-1 transcription is increased in daf-7 mutants based on a glr-1 transcriptional reporter. Together these results suggest that the DAF-7/TGF-β signaling pathway functions in neurons and negatively regulates the abundance of GLR-1, in part, by controlling transcription of the receptor itself. Finally, DAF-7/TGF-β pathway mutants exhibit changes in spontaneous locomotion that are dependent on endogenous GLR-1 and consistent with increased glutamatergic signaling. These results reveal a novel mechanism by which TGF-β signaling functions in the nervous system to regulate behavior. Copyright © 2015 Elsevier Inc. All rights reserved.

The protein kinase MBK-1 contributes to lifespan extension in daf-2 mutant and germline-deficient Caenorhabditis elegans.

Science.gov (United States)

Mack, Hildegard I D; Zhang, Peichuan; Fonslow, Bryan R; Yates, John R

2017-05-25

In Caenorhabditis elegans , reduction of insulin/IGF-1 like signaling and loss of germline stem cells both increase lifespan by activating the conserved transcription factor DAF-16 (FOXO). While the mechanisms that regulate DAF-16 nuclear localization in response to insulin/IGF-1 like signaling are well characterized, the molecular pathways that act in parallel to regulate DAF-16 transcriptional activity, and the pathways that couple DAF-16 activity to germline status, are not fully understood at present. Here, we report that inactivation of MBK-1, the C. elegans ortholog of the human FOXO1-kinase DYRK1A substantially shortens the prolonged lifespan of daf-2 and glp-1 mutant animals while decreasing wild-type lifespan to a lesser extent. On the other hand, lifespan-reduction by mutation of the MBK-1-related kinase HPK-1 was not preferential for long-lived mutants. Interestingly, mbk-1 loss still allowed for DAF-16 nuclear accumulation but reduced expression of certain DAF-16 target genes in germline-less, but not in daf-2 mutant animals. These findings indicate that mbk-1 and daf-16 functionally interact in the germline- but not in the daf-2 pathway. Together, our data suggest mbk-1 as a novel regulator of C. elegans longevity upon both, germline ablation and DAF-2 inhibition, and provide evidence for mbk-1 regulating DAF-16 activity in germline-deficient animals.

The DAF-16 FOXO transcription factor regulates natc-1 to modulate stress resistance in Caenorhabditis elegans, linking insulin/IGF-1 signaling to protein N-terminal acetylation.

Directory of Open Access Journals (Sweden)

Kurt Warnhoff

2014-10-01

Full Text Available The insulin/IGF-1 signaling pathway plays a critical role in stress resistance and longevity, but the mechanisms are not fully characterized. To identify genes that mediate stress resistance, we screened for C. elegans mutants that can tolerate high levels of dietary zinc. We identified natc-1, which encodes an evolutionarily conserved subunit of the N-terminal acetyltransferase C (NAT complex. N-terminal acetylation is a widespread modification of eukaryotic proteins; however, relatively little is known about the biological functions of NATs. We demonstrated that loss-of-function mutations in natc-1 cause resistance to a broad-spectrum of physiologic stressors, including multiple metals, heat, and oxidation. The C. elegans FOXO transcription factor DAF-16 is a critical target of the insulin/IGF-1 signaling pathway that mediates stress resistance, and DAF-16 is predicted to directly bind the natc-1 promoter. To characterize the regulation of natc-1 by DAF-16 and the function of natc-1 in insulin/IGF-1 signaling, we analyzed molecular and genetic interactions with key components of the insulin/IGF-1 pathway. natc-1 mRNA levels were repressed by DAF-16 activity, indicating natc-1 is a physiological target of DAF-16. Genetic studies suggested that natc-1 functions downstream of daf-16 to mediate stress resistance and dauer formation. Based on these findings, we hypothesize that natc-1 is directly regulated by the DAF-16 transcription factor, and natc-1 is a physiologically significant effector of the insulin/IGF-1 signaling pathway that mediates stress resistance and dauer formation. These studies identify a novel biological function for natc-1 as a modulator of stress resistance and dauer formation and define a functionally significant downstream effector of the insulin/IGF-1 signaling pathway. Protein N-terminal acetylation mediated by the NatC complex may play an evolutionarily conserved role in regulating stress resistance.

[The significances of peripheral neutrophils CD(55) and myeloperoxidase expression in patients with myeloperoxidase-specific anti-neutrophil cytoplasmic antibody associated vasculitis].

Science.gov (United States)

Zhou, X L; Zheng, M J; Shuai, Z W; Zhang, L; Zhang, M M; Chen, S Y

2017-06-01

Objective: To investigate the expression of CD(55) and myeloperoxidase (MPO) on neutrophils in patients with MPO-specific anti-neutrophil cytoplasmic antibody associated vasculitis(MPO-AAV), and analyze the relationship between the expression and clinical manifestation. Methods: Forty untreated patients with active MPO-AAV (patient group) and 30 healthy volunteers (control group) were enrolled in this study. The CD(55) on neutrophils and both membrane and cytoplasmic MPO were detected by flow cytometry. Serum fragment-from the activated complement factor B(Ba) and MPO were measured by ELISA. The clinical activity of vasculitis was valued by Birmingham vasculitis activity score-version 3(BVAS-V3). The significance of laboratory data was evaluated by Spearman correlation test and multivariate linear regression analysis. Results: (1)The mean fluorescence intensity(MFI) of CD(55) expressed on neutrophils was significantly higher than that in control group[4 068.6±2 306.0 vs 2 999.5±1 504.9, P =0.033]. Similar results of serum MPO and Ba in patient group were found compared to controls [500.0(381.0, 612.7) IU/L vs 286.9(225.5, 329.1) IU/L, P <0.001; 35.2(25.2, 79.5) ng/L vs 18.0(15.0, 28.0) ng/L, P <0.001], respectively. However, MIF of cytoplasmic MPO in patients was significantly lower than that of control group(1 577.1±1 175.9 vs 3 105.3±2 323.0, P =0.003) . (2) In patient group, cytoplasmic intensity of MPO was negatively associated with the serum levels of MPO( r =-0.710, P <0.001) and Ba ( r =-0.589, P =0.001). Moreover, serum MPO was positively associated with serum Ba( r =0.691, P <0.001). Membrane intensity of CD(55) on neutrophils was positively correlated with patient age ( r =0.514, P =0.001), C reactive protein ( r =0.376, P =0.018), peripheral neutrophils count ( r =0.485, P =0.001) and BVAS-V3 ( r =0.484, P =0.002), whereas negative correlation between membrane CD(55) and disease duration was seen ( r =-0.403, P =0.01). (3) The result of multiple

Ida-1, the Caenorhabditis elegans orthologue of mammalian diabetes autoantigen IA-2, potentially acts as a common modulator between Parkinson's disease and Diabetes: role of Daf-2/Daf-16 insulin like signalling pathway.

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Fatima, Soobiya; Haque, Rizwanul; Jadiya, Pooja; Shamsuzzama; Kumar, Lalit; Nazir, Aamir

2014-01-01

The lack of cure to age associated Parkinson's disease (PD) has been challenging the efforts of researchers as well as health care providers. Recent evidences suggest that diabetic patients tend to show a higher future risk for PD advocating a strong correlation between PD and Diabetes, thus making it intriguing to decipher common genetic cues behind these ailments. We carried out studies on ida-1, the C. elegans orthologue of mammalian type-1 diabetes auto-antigen IA-2 towards achieving its functional workup vis-à-vis various associated endpoints of PD and Diabetes. Employing transgenic C. elegans strain expressing "human" alpha synuclein (NL5901) under normal and increased glucose concentrations, we studied aggregation of alpha synuclein, content of dopamine, expression of dopamine transporter, content of reactive oxygen species, locomotor activity, nuclear translocation of FOXO transcription factor Daf-16, and quantification of Daf2/Daf-16 mRNA. Our findings indicate that ida-1 affords protection in the studied disease conditions as absence of ida-1 resulted in higher alpha-synuclein aggregation under conditions that mimic the blood glucose levels of diabetic patients. We also observed reduced dopamine content, decreased motility, defective Daf-16 translocation and reduced expression of Daf-2 and Daf-16. Our studies establish important function of ida-1 as a modulator in Daf-2/Daf-16 insulin like signalling pathway thus possibly being a common link between PD and Diabetes.

Genome-wide endogenous DAF-16/FOXO recruitment dynamics during lowered insulin signalling in C. elegans.

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Kumar, Neeraj; Jain, Vaibhav; Singh, Anupama; Jagtap, Urmila; Verma, Sonia; Mukhopadhyay, Arnab

2015-12-08

Lowering insulin-IGF-1-like signalling (IIS) activates FOXO transcription factors (TF) to extend life span across species. To study the dynamics of FOXO chromatin occupancy under this condition in C. elegans, we report the first recruitment profile of endogenous DAF-16 and show that the response is conserved. DAF-16 predominantly acts as a transcriptional activator and binding within the 0.5 kb promoter-proximal region results in maximum induction of downstream targets that code for proteins involved in detoxification and longevity. Interestingly, genes that are activated under low IIS already have higher DAF-16 recruited to their promoters in WT. DAF-16 binds to variants of the FOXO consensus sequence in the promoter proximal regions of genes that are exclusively targeted during low IIS. We also define a set of 'core' direct targets, after comparing multiple studies, which tend to co-express and contribute robustly towards IIS-associated phenotypes. Additionally, we show that nuclear hormone receptor DAF-12 as well as zinc-finger TF EOR-1 may bind DNA in close proximity to DAF-16 and distinct TF classes that are direct targets of DAF-16 may be instrumental in regulating its indirect targets. Together, our study provides fundamental insights into the transcriptional biology of FOXO/DAF-16 and gene regulation downstream of the IIS pathway.

C. elegans SIRT6/7 homolog SIR-2.4 promotes DAF-16 relocalization and function during stress.

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Chiang, Wei-Chung; Tishkoff, Daniel X; Yang, Bo; Wilson-Grady, Joshua; Yu, Xiaokun; Mazer, Travis; Eckersdorff, Mark; Gygi, Steven P; Lombard, David B; Hsu, Ao-Lin

2012-09-01

FoxO transcription factors and sirtuin family deacetylases regulate diverse biological processes, including stress responses and longevity. Here we show that the Caenorhabditis elegans sirtuin SIR-2.4--homolog of mammalian SIRT6 and SIRT7 proteins--promotes DAF-16-dependent transcription and stress-induced DAF-16 nuclear localization. SIR-2.4 is required for resistance to multiple stressors: heat shock, oxidative insult, and proteotoxicity. By contrast, SIR-2.4 is largely dispensable for DAF-16 nuclear localization and function in response to reduced insulin/IGF-1-like signaling. Although acetylation is known to regulate localization and activity of mammalian FoxO proteins, this modification has not been previously described on DAF-16. We find that DAF-16 is hyperacetylated in sir-2.4 mutants. Conversely, DAF-16 is acetylated by the acetyltransferase CBP-1, and DAF-16 is hypoacetylated and constitutively nuclear in response to cbp-1 inhibition. Surprisingly, a SIR-2.4 catalytic mutant efficiently rescues the DAF-16 localization defect in sir-2.4 null animals. Acetylation of DAF-16 by CBP-1 in vitro is inhibited by either wild-type or mutant SIR-2.4, suggesting that SIR-2.4 regulates DAF-16 acetylation indirectly, by preventing CBP-1-mediated acetylation under stress conditions. Taken together, our results identify SIR-2.4 as a critical regulator of DAF-16 specifically in the context of stress responses. Furthermore, they reveal a novel role for acetylation, modulated by the antagonistic activities of CBP-1 and SIR-2.4, in modulating DAF-16 localization and function.

Towards understanding the lifespan extension by reduced insulin signaling: bioinformatics analysis of DAF-16/FOXO direct targets in Caenorhabditis elegans.

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Li, Yan-Hui; Zhang, Gai-Gai

2016-04-12

DAF-16, the C. elegans FOXO transcription factor, is an important determinant in aging and longevity. In this work, we manually curated FOXODB http://lyh.pkmu.cn/foxodb/, a database of FOXO direct targets. It now covers 208 genes. Bioinformatics analysis on 109 DAF-16 direct targets in C. elegans found interesting results. (i) DAF-16 and transcription factor PQM-1 co-regulate some targets. (ii) Seventeen targets directly regulate lifespan. (iii) Four targets are involved in lifespan extension induced by dietary restriction. And (iv) DAF-16 direct targets might play global roles in lifespan regulation.

Selenite protects Caenorhabditis elegans from oxidative stress via DAF-16 and TRXR-1.

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Li, Wen-Hsuan; Shi, Yeu-Ching; Chang, Chun-Han; Huang, Chi-Wei; Hsiu-Chuan Liao, Vivian

2014-04-01

Selenium is an essential micronutrient. In the present study, trace amount of selenite (0.01 μM) was evaluated for oxidative stress resistance and potential associated factors in Caenorhabditis elegans. Selenite-treated C. elegans showed an increased survival under oxidative stress and thermal stress compared to untreated controls. Further studies demonstrated that the significant stress resistance of selenite on C. elegans could be attributed to its in vivo free radical-scavenging ability. We also found that the oxidative and thermal stress resistance phenotypes by selenite were absent from the forkhead transcription factor daf-16 mutant worms. Moreover, selenite influenced the subcellular distribution of DAF-16 in C. elegans. Furthermore, selenite increased mRNA levels of stress-resistance-related proteins, including superoxide dismutase-3 and heat shock protein-16.2. Additionally, selenite (0.01 μM) upregulated expressions of transgenic C. elegans carrying sod-3::green fluorescent protein (GFP) and hsp-16.2::GFP, whereas this effect was abolished by feeding daf-16 RNA interference in C. elegans. Finally, unlike the wild-type N2 worms, the oxidative stress resistance phenotypes by selenite were both absent from the C. elegans selenoprotein trxr-1 mutant worms and trxr-1 mutants feeding with daf-16 RNA interference. These findings suggest that the antioxidant effects of selenite in C. elegans are mediated via DAF-16 and TRXR-1. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Nonautonomous Regulation of Neuronal Migration by Insulin Signaling, DAF-16/FOXO, and PAK-1

Directory of Open Access Journals (Sweden)

Lisa M. Kennedy

2013-09-01

Full Text Available Neuronal migration is essential for nervous system development in all organisms and is regulated in the nematode, C. elegans, by signaling pathways that are conserved in humans. Here, we demonstrate that the insulin/IGF-1-PI3K signaling pathway modulates the activity of the DAF-16/FOXO transcription factor to regulate the anterior migrations of the hermaphrodite-specific neurons (HSNs during embryogenesis of C. elegans. When signaling is reduced, DAF-16 is activated and promotes migration; conversely, when signaling is enhanced, DAF-16 is inactivated, and migration is inhibited. We show that DAF-16 acts nonautonomously in the hypodermis to promote HSN migration. Furthermore, we identify PAK-1, a p21-activated kinase, as a downstream mediator of insulin/IGF-1-DAF-16 signaling in the nonautonomous control of HSN migration. Because a FOXO-Pak1 pathway was recently shown to regulate mammalian neuronal polarity, our findings indicate that the roles of FOXO and Pak1 in neuronal migration are most likely conserved from C. elegans to higher organisms.

Porcine Knock-in Fibroblasts Expressing hDAF on α-1,3-Galactosyltransferase (GGTA1) Gene Locus.

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Kim, Ji Woo; Kim, Hye-Min; Lee, Sang Mi; Kang, Man-Jong

2012-10-01

The Galactose-α1,3-galactose (α1,3Gal) epitope is responsible for hyperacute rejection in pig-to-human xenotransplantation. Human decay-accelerating factor (hDAF) is a cell surface regulatory protein that serves as a complement inhibitor to protect self cells from complement attack. The generation of α1,3-galactosyltransferase (GGTA1) knock-out pigs expressing DAF is a necessary step for their use as organ donors for humans. In this study, we established GGTA1 knock-out cell lines expressing DAF from pig ear fibroblasts for somatic cell nuclear transfer. hDAF expression was detected in hDAF knock-in heterozygous cells, but not in normal pig cells. Expression of the GGTA1 gene was lower in the knock-in heterozygous cell line compared to the normal pig cell. Knock-in heterozygous cells afforded more effective protection against cytotoxicity with human serum than with GGTA1 knock-out heterozygous and control cells. These cell lines may be used in the production of GGTA1 knock-out and DAF expression pigs for xenotransplantation.

Acoustic sensitivity of the saccule and daf music.

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Emami, Seyede Faranak

2014-04-01

The daf is a large Persian frame drum used as a musical instrument in both popular and classical music which can induce a percussive sound at low frequencies (146-290 Hz) with peaks of up to 130 dBspl. The percussive sounds have a power distribution in the region of saccular sensitivity. In view of the saccular stimulation by sound in humans, we decided to use cervical vestibular-evoked myogenic potentials (cVEMPs) to evaluate the possibility that the daf music may have a disturbing effect on saccular function. During this case-control study, 18 daf musicians were compared with 20 healthy individuals evaluated in the audiology department of the Hamadan University of Medical Sciences. Assessment consisted of pure tone audiometry, tympanometry, and cVEMPs. Multiple comparisons of mean the cVEMPs and mean hearing loss at 250 Hz among the three groups (affected, unaffected, and normal ears) were significant. There were no significant differences between all daf players on high-tone loss at 3000 Hz. The daf musicians had bilateral unsymmetrical sensorineural hearing loss (SNHL), with hearing loss at 250 Hz (low-tone loss) and notched audiogram at 3000 Hz (high-tone loss). Eleven musicians with decreased vestibular excitability as detected by abnormal cVEMPs had mild (26-40 dBHL) low-tone loss and significant abnormal cVEMPs findings. In contrast, the others had slight (16-25 dBHL) low-tone loss with normal cVEMPs. Exposure to daf music is related to both saccular and cochlear dysfunction. Exposure to daf music is related to both saccular and cochlear dysfunction.

Glycosyl-phosphatidylinositol (GPI)-anchored membrane association of the porcine reproductive and respiratory syndrome virus GP4 glycoprotein and its co-localization with CD163 in lipid rafts

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Du, Yijun [Department of Pathobiology, University of Illinois at Urbana-Champaign, 2001 South Lincoln Ave, Urbana, IL 61802 (United States); Shandong Key Laboratory of Animal Disease Control and Breeding, Institute of Animal Science and Veterinary Medicine, Shandong Academy of Agricultural Sciences, Jinan (China); Pattnaik, Asit K. [School of Veterinary Medicine and Biomedical Sciences and the Nebraska Center for Virology, University of Nebraska-Lincoln, Lincoln, NE 68583-0900 (United States); Song, Cheng [Department of Pathobiology, University of Illinois at Urbana-Champaign, 2001 South Lincoln Ave, Urbana, IL 61802 (United States); Yoo, Dongwan, E-mail: dyoo@illinois.edu [Department of Pathobiology, University of Illinois at Urbana-Champaign, 2001 South Lincoln Ave, Urbana, IL 61802 (United States); Li, Gang, E-mail: dyoo@illinois.edu [Department of Pathobiology, University of Illinois at Urbana-Champaign, 2001 South Lincoln Ave, Urbana, IL 61802 (United States); Institute of Animal Science and Veterinary Medicine, Chinese Academy of Agricultural Sciences, Beijing (China)

2012-03-01

The porcine reproductive and respiratory syndrome virus (PRRSV) glycoprotein 4 (GP4) resembles a typical type I membrane protein in its structure but lacks a hydrophilic tail at the C-terminus, suggesting that GP4 may be a lipid-anchored membrane protein. Using the human decay-accelerating factor (DAF; CD55), a known glycosyl-phosphatidylinositol (GPI) lipid-anchored protein, chimeric constructs were made to substitute the GPI-anchor domain of DAF with the putative lipid-anchor domain of GP4, and their membrane association and lipase cleavage were determined in cells. The DAF-GP4 fusion protein was transported to the plasma membrane and was cleaved by phosphatidylinositol-specific phospholipase C (PI-PLC), indicating that the C-terminal domain of GP4 functions as a GPI anchor. Mutational studies for residues adjacent to the GPI modification site and characterization of respective mutant viruses generated from infectious cDNA clones show that the ability of GP4 for membrane association corresponded to virus viability and growth characteristics. The residues T158 ({omega} - 2, where {omega} is the GPI moiety at E160), P159 ({omega} - 1), and M162 ({omega} + 2) of GP4 were determined to be important for virus replication, with M162 being of particular importance for virus infectivity. The complete removal of the peptide-anchor domain in GP4 resulted in a complete loss of virus infectivity. The depletion of cholesterol from the plasma membrane of cells reduced the virus production, suggesting a role of lipid rafts in PRRSV infection. Remarkably, GP4 was found to co-localize with CD163 in the lipid rafts on the plasma membrane. Since CD163 has been reported as a cellular receptor for PRRSV and GP4 has been shown to interact with this receptor, our data implicates an important role of lipid rafts during entry of the virus.

Glycosyl-phosphatidylinositol (GPI)-anchored membrane association of the porcine reproductive and respiratory syndrome virus GP4 glycoprotein and its co-localization with CD163 in lipid rafts

International Nuclear Information System (INIS)

Du, Yijun; Pattnaik, Asit K.; Song, Cheng; Yoo, Dongwan; Li, Gang

2012-01-01

The porcine reproductive and respiratory syndrome virus (PRRSV) glycoprotein 4 (GP4) resembles a typical type I membrane protein in its structure but lacks a hydrophilic tail at the C-terminus, suggesting that GP4 may be a lipid-anchored membrane protein. Using the human decay-accelerating factor (DAF; CD55), a known glycosyl-phosphatidylinositol (GPI) lipid-anchored protein, chimeric constructs were made to substitute the GPI-anchor domain of DAF with the putative lipid-anchor domain of GP4, and their membrane association and lipase cleavage were determined in cells. The DAF-GP4 fusion protein was transported to the plasma membrane and was cleaved by phosphatidylinositol-specific phospholipase C (PI-PLC), indicating that the C-terminal domain of GP4 functions as a GPI anchor. Mutational studies for residues adjacent to the GPI modification site and characterization of respective mutant viruses generated from infectious cDNA clones show that the ability of GP4 for membrane association corresponded to virus viability and growth characteristics. The residues T158 (ω − 2, where ω is the GPI moiety at E160), P159 (ω − 1), and M162 (ω + 2) of GP4 were determined to be important for virus replication, with M162 being of particular importance for virus infectivity. The complete removal of the peptide–anchor domain in GP4 resulted in a complete loss of virus infectivity. The depletion of cholesterol from the plasma membrane of cells reduced the virus production, suggesting a role of lipid rafts in PRRSV infection. Remarkably, GP4 was found to co-localize with CD163 in the lipid rafts on the plasma membrane. Since CD163 has been reported as a cellular receptor for PRRSV and GP4 has been shown to interact with this receptor, our data implicates an important role of lipid rafts during entry of the virus.

Regulation of Lysosomal Function by the DAF-16 Forkhead Transcription Factor Couples Reproduction to Aging in Caenorhabditis elegans.

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Baxi, Kunal; Ghavidel, Ata; Waddell, Brandon; Harkness, Troy A; de Carvalho, Carlos E

2017-09-01

Aging in eukaryotes is accompanied by widespread deterioration of the somatic tissue. Yet, abolishing germ cells delays the age-dependent somatic decline in Caenorhabditis elegans In adult worms lacking germ cells, the activation of the DAF-9/DAF-12 steroid signaling pathway in the gonad recruits DAF-16 activity in the intestine to promote longevity-associated phenotypes. However, the impact of this pathway on the fitness of normally reproducing animals is less clear. Here, we explore the link between progeny production and somatic aging and identify the loss of lysosomal acidity-a critical regulator of the proteolytic output of these organelles-as a novel biomarker of aging in C. elegans The increase in lysosomal pH in older worms is not a passive consequence of aging, but instead is timed with the cessation of reproduction, and correlates with the reduction in proteostasis in early adult life. Our results further implicate the steroid signaling pathway and DAF-16 in dynamically regulating lysosomal pH in the intestine of wild-type worms in response to the reproductive cycle. In the intestine of reproducing worms, DAF-16 promotes acidic lysosomes by upregulating the expression of v-ATPase genes. These findings support a model in which protein clearance in the soma is linked to reproduction in the gonad via the active regulation of lysosomal acidification. Copyright © 2017 by the Genetics Society of America.

Non-transcriptional Function of FOXO1/DAF-16 Contributes to Translesion DNA Synthesis.

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Daitoku, Hiroaki; Kaneko, Yuta; Yoshimochi, Kenji; Matsumoto, Kaori; Araoi, Sho; Sakamaki, Jun-Ichi; Takahashi, Yuta; Fukamizu, Akiyoshi

2016-08-22

Forkhead box O (FOXO; DAF-16 in nematode) transcription factors activate a program of genes that control stress resistance, metabolism, and lifespan. Given the adverse impact of the stochastic DNA damage on organismal development and ageing, we examined the role of FOXO/DAF-16 in UV-induced DNA-damage response. Knockdown of FOXO1, but not FOXO3a, increases sensitivity to UV irradiation when exposed during S phase, suggesting a contribution of FOXO1 to translesion DNA synthesis (TLS), a replicative bypass of UV-induced DNA lesions. Actually, FOXO1 depletion results in a sustained activation of the ATR-Chk1 signaling and a reduction of PCNA monoubiquitination following UV irradiation. FOXO1 does not alter the expression of TLS-related genes but binds to the protein replication protein A (RPA1) that coats single-stranded DNA and acts as a scaffold for TLS. In Caenorhabditis elegans, daf-16 null mutants show UV-induced retardation in larval development and are rescued by overexpressing DAF-16 mutant lacking transactivation domain, but not substitution mutant unable to interact with RPA-1. Thus, our findings demonstrate that FOXO1/DAF-16 is a functional component in TLS independently of its transactivation activity. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

Non-autonomous Regulation of Neuronal Migration by Insulin Signaling, DAF-16/FOXO and PAK-1

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Kennedy, Lisa M.; Pham, Steven C.D.L.; Grishok, Alla

2013-01-01

SUMMARY Neuronal migration is essential for nervous system development in all organisms and is regulated in the nematode, C. elegans, by signaling pathways that are conserved in humans. Here, we demonstrate that the Insulin/IGF-1-PI3K signaling pathway modulates the activity of the DAF-16/FOXO transcription factor to promote the anterior migrations of the hermaphrodite-specific neurons (HSNs) during embryogenesis of C. elegans. When signaling is reduced, DAF-16 is activated and promotes migration, conversely, when signaling is enhanced, DAF-16 is inactivated and migration is inhibited. We show that DAF-16 acts non-autonomously in the hypodermis to promote HSN migration. Furthermore, we identify PAK-1, a p21-activated kinase, as a downstream mediator of Insulin/IGF-1-DAF-16 signaling in the non-autonomous control of HSN migration. As a FOXO-Pak1 pathway was recently shown to regulate mammalian neuronal polarity, our findings indicate that the roles of FOXO and Pak1 in neuronal migration are likely conserved from C. elegans to higher organisms. PMID:23994474

Functional Conservation and Divergence of daf-22 Paralogs in Pristionchus pacificus Dauer Development.

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Markov, Gabriel V; Meyer, Jan M; Panda, Oishika; Artyukhin, Alexander B; Claaßen, Marc; Witte, Hanh; Schroeder, Frank C; Sommer, Ralf J

2016-10-01

Small-molecule signaling in nematode dauer formation has emerged as a major model to study chemical communication in development and evolution. Developmental arrest as nonfeeding and stress-resistant dauer larvae represents the major survival and dispersal strategy. Detailed studies in Caenorhabditis elegans and Pristionchus pacificus revealed that small-molecule communication changes rapidly in evolution resulting in extreme structural diversity of small-molecule compounds. In C. elegans, a blend of ascarosides constitutes the dauer pheromone, whereas the P. pacificus dauer pheromone includes additional paratosides and integrates building blocks from diverse primary metabolic pathways. Despite this complexity of small-molecule structures and functions, little is known about the biosynthesis of small molecules in nematodes outside C. elegans Here, we show that the genes encoding enzymes of the peroxisomal β-oxidation pathway involved in small-molecule biosynthesis evolve rapidly, including gene duplications and domain switching. The thiolase daf-22, the most downstream factor in C. elegans peroxisomal β-oxidation, has duplicated in P. pacificus, resulting in Ppa-daf-22.1, which still contains the sterol-carrier-protein (SCP) domain that was lost in C. elegans daf-22, and Ppa-daf-22.2. Using the CRISPR/Cas9 system, we induced mutations in both P. pacificus daf-22 genes and identified an unexpected complexity of functional conservation and divergence. Under well-fed conditions, ascaroside biosynthesis proceeds exclusively via Ppa-daf-22.1 In contrast, starvation conditions induce Ppa-daf-22.2 activity, resulting in the production of a specific subset of ascarosides. Gene expression studies indicate a reciprocal up-regulation of both Ppa-daf-22 genes, which is, however, independent of starvation. Thus, our study reveals an unexpected functional complexity of dauer development and evolution. © The Author 2016. Published by Oxford University Press on behalf of the

Complementary information on CdSe/ZnSe quantum dot local structure from extended X-ray absorption fine structure and diffraction anomalous fine structure measurements

International Nuclear Information System (INIS)

Piskorska-Hommel, E.; Holý, V.; Caha, O.; Wolska, A.; Gust, A.; Kruse, C.; Kröncke, H.; Falta, J.; Hommel, D.

2012-01-01

The extended X-ray absorption fine structure (EXAFS) and diffraction anomalous fine structure (DAFS) have been applied to investigate a local structure for the CdSe/ZnSe quantum dots grown by molecular beam epitaxy (MBE) and migration-enhanced epitaxy (MEE). The aim was to study the intermixing of Cd and Zn atoms, chemical compositions and strain induced by cap-layer. The EXAFS at the Cd K-edge and DAFS at the Se K-edge proved the intermixing of Cd and Zn atoms. The distances Cd–Se (2.61 Å) found from EXAFS and DAFS analysis for h 1 region is closer to that in bulk CdSe (2.62 Å). The DAFS analysis revealed the differences in the local structure in two investigated regions (i.e. different iso-strain volumes) on the quantum dots. It was found that the investigated areas differ in the Cd concentration. To explain the experimental results the theoretical calculation based on a full valence-force field (VFF) model was performed. The theoretical VFF model fully explains the experimental data.

Dianxianning improved amyloid β-induced pathological characteristics partially through DAF-2/DAF-16 insulin like pathway in transgenic C. elegans.

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Zhi, Dejuan; Wang, Dong; Yang, Wenqi; Duan, Ziyun; Zhu, Shuqian; Dong, Juan; Wang, Na; Wang, Ningbo; Fei, Dongqing; Zhang, Zhanxin; Wang, Xin; Wang, Meizhu; Li, Hongyu

2017-09-12

Dianxianning (DXN) is a traditional Chinese formula, and has been approved in China for treating epilepsy since 1996. Here anti-Alzheimer's disease activity of DXN has been reported. DXN improved AD-like symptoms of paralysis and 5-HT sensitivity of transgenic Aβ 1-42 C. elegans. In worms, DXN significantly increased Aβ monomers and decreased the toxic Aβ oligomers, thus reducing Aβ toxicity. DXN significantly suppressed the expression of hsp-16.2 induced by juglone, and up-regulated sod-3 expression. These results indicated that DXN increased stress resistance and protected C. elegans against oxidative stress. Furthermore, DXN could significantly promote DAF-16 nuclear translocation, but it did not activate SKN-1. The inhibitory effect of DXN on the Aβ toxicity was significantly reverted by daf-16 RNAi, rather than skn-1 RNAi or hsf-1 RNAi. These results indicated that DAF-16 is at least partially required for the anti-AD effect of DXN. In conclusion, DXN improved Aβ-induced pathological characteristics partially through DAF-2/DAF-16 insulin like pathway in transgenic worms. Together with our data obtained by Morris water maze test, the results showed that DXN markedly ameliorated cognitive performance impairment induced by scopolamine in mice. All the results support that DXN is a potential drug candidate to treat Alzheimer's diseases.

DAF-12 Regulates a Connected Network of Genes to Ensure Robust Developmental Decisions

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Stuckenholz, Carsten; Labhart, Paul; Alexiadis, Vassili; Martin, René; Knölker, Hans-Joachim; Fisher, Alfred L.

2011-01-01

The nuclear receptor DAF-12 has roles in normal development, the decision to pursue dauer development in unfavorable conditions, and the modulation of adult aging. Despite the biologic importance of DAF-12, target genes for this receptor are largely unknown. To identify DAF-12 targets, we performed chromatin immunoprecipitation followed by hybridization to whole-genome tiling arrays. We identified 1,175 genomic regions to be bound in vivo by DAF-12, and these regions are enriched in known DAF-12 binding motifs and act as DAF-12 response elements in transfected cells and in transgenic worms. The DAF-12 target genes near these binding sites include an extensive network of interconnected heterochronic and microRNA genes. We also identify the genes encoding components of the miRISC, which is required for the control of target genes by microRNA, as a target of DAF-12 regulation. During reproductive development, many of these target genes are misregulated in daf-12(0) mutants, but this only infrequently results in developmental phenotypes. In contrast, we and others have found that null daf-12 mutations enhance the phenotypes of many miRISC and heterochronic target genes. We also find that environmental fluctuations significantly strengthen the weak heterochronic phenotypes of null daf-12 alleles. During diapause, DAF-12 represses the expression of many heterochronic and miRISC target genes, and prior work has demonstrated that dauer formation can suppress the heterochronic phenotypes of many of these target genes in post-dauer development. Together these data are consistent with daf-12 acting to ensure developmental robustness by committing the animal to adult or dauer developmental programs despite variable internal or external conditions. PMID:21814518

Effects of non-latching blast valves on the source term and consequences of the design-basis accidents in the Device Assembly Facility (DAF)

International Nuclear Information System (INIS)

Nguyen, D.H.

1993-08-01

The analysis of the Design-Basis Accidents (DBA) involving high explosives (HE) and Plutonium (Pu) in the assembly cell of the Device Assembly Facility (DAF), which was completed earlier, assumed latching blast valves in the ventilation system of the assembly cell. Latching valves effectively sealed a release path through the ventilation duct system. However, the blast valves in the assembly cell, as constructed are actually non-latching valves, and would reopen when the gas pressure drops to 0.5 psi above one atmosphere. Because the reopening of the blast valves provides an additional release path to the environment, and affects the material transport from the assembly cell to other DAF buildings, the DOE/NV DAF management has decided to support an additional analysis of the DAF's DBA to account for the effects of non-latching valves. Three cases were considered in the DAF's DBA, depending on the amount of HE and Pu involved, as follows: Case 1 -- 423 number-sign HE, 16 kg Pu; Case 2 -- 150 number-sign HE 10 kg Pu; Case 3 -- 55 number-sign HE 5 kg Pu. The results of the analysis with non-latching valves are summarized

Effects of Caenorhabditis elegans sgk-1 mutations on lifespan, stress resistance, and DAF-16/FoxO regulation.

Science.gov (United States)

Chen, Albert Tzong-Yang; Guo, Chunfang; Dumas, Kathleen J; Ashrafi, Kaveh; Hu, Patrick J

2013-10-01

The AGC family serine-threonine kinases Akt and Sgk are similar in primary amino acid sequence and in vitro substrate specificity, and both kinases are thought to directly phosphorylate and inhibit FoxO transcription factors. In the nematode Caenorhabditis elegans, it is well established that AKT-1 controls dauer arrest and lifespan by regulating the subcellular localization of the FoxO transcription factor DAF-16. SGK-1 is thought to act similarly to AKT-1 in lifespan control by phosphorylating and inhibiting the nuclear translocation of DAF-16/FoxO. Using sgk-1 null and gain-of-function mutants, we now provide multiple lines of evidence indicating that AKT-1 and SGK-1 influence C. elegans lifespan, stress resistance, and DAF-16/FoxO activity in fundamentally different ways. Whereas AKT-1 shortens lifespan, SGK-1 promotes longevity in a DAF-16-/FoxO-dependent manner. In contrast to AKT-1, which reduces resistance to multiple stresses, SGK-1 promotes resistance to oxidative stress and ultraviolet radiation but inhibits thermotolerance. Analysis of several DAF-16/FoxO target genes that are repressed by AKT-1 reveals that SGK-1 represses a subset of these genes while having little influence on the expression of others. Accordingly, unlike AKT-1, which promotes the cytoplasmic sequestration of DAF-16/FoxO, SGK-1 does not influence DAF-16/FoxO subcellular localization. Thus, in spite of their similar in vitro substrate specificities, Akt and Sgk influence longevity, stress resistance, and FoxO activity through distinct mechanisms in vivo. Our findings highlight the need for a re-evaluation of current paradigms of FoxO regulation by Sgk. © 2013 The Authors. Aging Cell published by the Anatomical Society and John Wiley & Sons Ltd.

RNAi screen of DAF-16/FOXO target genes in C. elegans links pathogenesis and dauer formation.

Directory of Open Access Journals (Sweden)

Victor L Jensen

2010-12-01

Full Text Available The DAF-16/FOXO transcription factor is the major downstream output of the insulin/IGF1R signaling pathway controlling C. elegans dauer larva development and aging. To identify novel downstream genes affecting dauer formation, we used RNAi to screen candidate genes previously identified to be regulated by DAF-16. We used a sensitized genetic background [eri-1(mg366; sdf-9(m708], which enhances both RNAi efficiency and constitutive dauer formation (Daf-c. Among 513 RNAi clones screened, 21 displayed a synthetic Daf-c (SynDaf phenotype with sdf-9. One of these genes, srh-100, was previously identified to be SynDaf, but twenty have not previously been associated with dauer formation. Two of the latter genes, lys-1 and cpr-1, are known to participate in innate immunity and six more are predicted to do so, suggesting that the immune response may contribute to the dauer decision. Indeed, we show that two of these genes, lys-1 and clc-1, are required for normal resistance to Staphylococcus aureus. clc-1 is predicted to function in epithelial cohesion. Dauer formation exhibited by daf-8(m85, sdf-9(m708, and the wild-type N2 (at 27°C were all enhanced by exposure to pathogenic bacteria, while not enhanced in a daf-22(m130 background. We conclude that knockdown of the genes required for proper pathogen resistance increases pathogenic infection, leading to increased dauer formation in our screen. We propose that dauer larva formation is a behavioral response to pathogens mediated by increased dauer pheromone production.

Myricetin-Mediated Lifespan Extension in Caenorhabditis elegans Is Modulated by DAF-16

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Wim Wätjen

2013-06-01

Full Text Available Myricetin is a naturally occurring flavonol found in many plant based food sources. It increases the lifespan of Caenorhabditis elegans, but the molecular mechanisms are not yet fully understood. We have investigated the impact of this flavonoid on the transcription factors DAF-16 (C. elegans FoxO homologue and SKN-1 (Nrf2 homologue, which have crucial functions in the regulation of ageing. Myricetin is rapidly assimilated by the nematode, causes a nuclear translocation of DAF-16 but not of SKN-1, and finally prolongs the mean adult lifespan of C. elegans by 32.9%. The lifespan prolongation was associated with a decrease in the accumulation of reactive oxygen species (ROS detected by DCF. Myricetin also decreases the formation of lipofuscin, a pigment consisting of highly oxidized and cross-linked proteins that is considered as a biomarker of ageing in diverse species. The lifespan extension was completely abolished in a daf-16 loss-of-function mutant strain (CF1038. Consistently with this result, myricetin was also not able to diminish stress-induced ROS accumulation in the mutant. These results strongly indicate that the pro-longevity effect of myricetin is dependent on DAF-16 and not on direct anti-oxidative effects of the flavonoid.

Localization of Nitric Oxide in Wheat Roots by DAF Fluorescence.

Science.gov (United States)

Wany, Aakanksha; Gupta, Kapuganti Jagadis

2016-01-01

Nitric oxide is a free radical signal molecule. Various methods are available for measurement of NO. Out of all methods, fluorescent probes to localize NO is very widely used method. Diaminofluorescein in diacetate form (DAF-2DA) is most widely probe for NO measurement. This method is based on application of 4,5-diaminofluorescein diacetate (DAF-2DA) which is actively diffused into cells, once taken up by cells cytoplasmic esterases cleave the acetate groups to generate 4,5-diaminofluorescein; DAF-2. The generated DAF-2 can readily react with N2O3, which is an oxidation product of NO to generate the highly fluorescent DAF-2T (triazolofluorescein). There are various advantages and disadvantages associated with this method, but to its advantage in diffusion closely to NO producing sites, it is widely used for localization studies. Here, we describe method to make sections of the roots and localization of NO in roots subjected to hypoxic stress.

Lack of Association of CD55 Receptor Genetic Variants and Severe Malaria in Ghanaian Children

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Kathrin Schuldt

2017-03-01

Full Text Available In a recent report, the cellular receptor CD55 was identified as a molecule essential for the invasion of human erythrocytes by Plasmodium falciparum, the causal agent of the most severe form of malaria. As this invasion process represents a critical step during infection with the parasite, it was hypothesized that genetic variants in the gene could affect severe malaria (SM susceptibility. We performed high-resolution variant discovery of rare and common genetic variants in the human CD55 gene. Association testing of these variants in over 1700 SM cases and unaffected control individuals from the malaria-endemic Ashanti Region in Ghana, West Africa, were performed on the basis of single variants, combined rare variant analyses, and reconstructed haplotypes. A total of 26 genetic variants were detected in coding and regulatory regions of CD55. Five variants were previously unknown. None of the single variants, rare variants, or haplotypes showed evidence for association with SM or P. falciparum density. Here, we present the first comprehensive analysis of variation in the CD55 gene in the context of SM and show that genetic variants present in a Ghanaian study group appear not to influence susceptibility to the disease.

Angiostrongylus cantonensis daf-2 regulates dauer, longevity and stress in Caenorhabditis elegans.

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Yan, Baolong; Sun, Weiwei; Shi, Xiaomeng; Huang, Liyang; Chen, Lingzi; Wang, Suhua; Yan, Lanzhu; Liang, Shaohui; Huang, Huicong

2017-06-15

The insulin-like signaling (IIS) pathway is considered to be significant in regulating fat metabolism, dauer formation, stress response and longevity in Caenorhabditis elegans. "Dauer hypothesis" indicates that similar IIS transduction mechanism regulates dauer development in free-living nematode C. elegans and the development of infective third-stage larvae (iL3) in parasitic nematodes, and this is bolstered by a few researches on structures and functions of the homologous genes in the IIS pathway cloned from several parasitic nematodes. In this study, we identified the insulin-like receptor encoding gene, Acan-daf-2, from the parasitic nematode Angiostrongylus cantonensis, and determined the genomic structures, transcripts and functions far more thorough in longevity, stress resistance and dauer formation. The sequence of Acan-DAF-2, consisting of 1413 amino acids, contained all of the characteristic domains of insulin-like receptors from other taxa. The expression patterns of Acan-daf-2 in the C. elegans surrogate system showed that pAcan-daf-2:gfp was only expressed in intestine, compared with the orthologue in C. elegans, Ce-daf-2 in both intestine and neurons. In addition to the similar genomic organization to Ce-daf-2, Acan-DAF-2 could also negatively regulate Ce-DAF-16A through nuclear/cytosolic translocation and partially restore the C. elegans daf-2(e1370) mutation in longevity, dauer formation and stress resistance. These findings provided further evidence of the functional conservation of DAF-2 between parasitic nematodes and the free-living nematode C. elegans, and might be significant in understanding the developmental biology of nematode parasites, particularly in the infective process and the host-specificity. Copyright © 2017. Published by Elsevier B.V.

C. elegans DAF-16/FOXO interacts with TGF-ß/BMP signaling to induce germline tumor formation via mTORC1 activation.

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Wenjing Qi

2017-05-01

Full Text Available Activation of the FOXO transcription factor DAF-16 by reduced insulin/IGF signaling (IIS is considered to be beneficial in C. elegans due to its ability to extend lifespan and to enhance stress resistance. In the germline, cell-autonomous DAF-16 activity prevents stem cell proliferation, thus acting tumor-suppressive. In contrast, hypodermal DAF-16 causes a tumorous germline phenotype characterized by hyperproliferation of the germline stem cells and rupture of the adjacent basement membrane. Here we show that cross-talk between DAF-16 and the transforming growth factor ß (TGFß/bone morphogenic protein (BMP signaling pathway causes germline hyperplasia and results in disruption of the basement membrane. In addition to activating MADM/NRBP/hpo-11 gene alone, DAF-16 also directly interacts with both R-SMAD proteins SMA-2 and SMA-3 in the nucleus to regulate the expression of mTORC1 pathway. Knocking-down of BMP genes or each of the four target genes in the hypodermis was sufficient to inhibit germline proliferation, indicating a cell-non-autonomously controlled regulation of stem cell proliferation by somatic tissues. We propose the existence of two antagonistic DAF-16/FOXO functions, a cell-proliferative somatic and an anti-proliferative germline activity. Whereas germline hyperplasia under reduced IIS is inhibited by DAF-16 cell-autonomously, activation of somatic DAF-16 in the presence of active IIS promotes germline proliferation and eventually induces tumor-like germline growth. In summary, our results suggest a novel pathway crosstalk of DAF-16 and TGF-ß/BMP that can modulate mTORC1 at the transcriptional level to cause stem-cell hyperproliferation. Such cell-type specific differences may help explaining why human FOXO activity is considered to be tumor-suppressive in most contexts, but may become oncogenic, e.g. in chronic and acute myeloid leukemia.

C. elegans DAF-16/FOXO interacts with TGF-ß/BMP signaling to induce germline tumor formation via mTORC1 activation.

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Qi, Wenjing; Yan, Yijian; Pfeifer, Dietmar; Donner V Gromoff, Erika; Wang, Yimin; Maier, Wolfgang; Baumeister, Ralf

2017-05-01

Activation of the FOXO transcription factor DAF-16 by reduced insulin/IGF signaling (IIS) is considered to be beneficial in C. elegans due to its ability to extend lifespan and to enhance stress resistance. In the germline, cell-autonomous DAF-16 activity prevents stem cell proliferation, thus acting tumor-suppressive. In contrast, hypodermal DAF-16 causes a tumorous germline phenotype characterized by hyperproliferation of the germline stem cells and rupture of the adjacent basement membrane. Here we show that cross-talk between DAF-16 and the transforming growth factor ß (TGFß)/bone morphogenic protein (BMP) signaling pathway causes germline hyperplasia and results in disruption of the basement membrane. In addition to activating MADM/NRBP/hpo-11 gene alone, DAF-16 also directly interacts with both R-SMAD proteins SMA-2 and SMA-3 in the nucleus to regulate the expression of mTORC1 pathway. Knocking-down of BMP genes or each of the four target genes in the hypodermis was sufficient to inhibit germline proliferation, indicating a cell-non-autonomously controlled regulation of stem cell proliferation by somatic tissues. We propose the existence of two antagonistic DAF-16/FOXO functions, a cell-proliferative somatic and an anti-proliferative germline activity. Whereas germline hyperplasia under reduced IIS is inhibited by DAF-16 cell-autonomously, activation of somatic DAF-16 in the presence of active IIS promotes germline proliferation and eventually induces tumor-like germline growth. In summary, our results suggest a novel pathway crosstalk of DAF-16 and TGF-ß/BMP that can modulate mTORC1 at the transcriptional level to cause stem-cell hyperproliferation. Such cell-type specific differences may help explaining why human FOXO activity is considered to be tumor-suppressive in most contexts, but may become oncogenic, e.g. in chronic and acute myeloid leukemia.

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Lifescience Database Archive (English)

Full Text Available Oth.ALL.10.daf-16.AllCell ce10 TFs and others daf-16 All cell types SRX005634,SRX00...5631 http://dbarchive.biosciencedbc.jp/kyushu-u/ce10/assembled/Oth.ALL.10.daf-16.AllCell.bed ...

Hc-daf-2 encodes an insulin-like receptor kinase in the barber's pole worm, Haemonchus contortus, and restores partial dauer regulation.

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Li, Facai; Lok, James B; Gasser, Robin B; Korhonen, Pasi K; Sandeman, Mark R; Shi, Deshi; Zhou, Rui; Li, Xiangrui; Zhou, Yanqin; Zhao, Junlong; Hu, Min

2014-06-01

Infective L3s (iL3s) of parasitic nematodes share common behavioural, morphological and developmental characteristics with the developmentally arrested (dauer) larvae of the free-living nematode Caenorhabditis elegans. It is proposed that similar molecular mechanisms regulate entry into or exit from the dauer stage in C. elegans, and the transition from free-living to parasitic forms of parasitic nematodes. In C. elegans, one of the key factors regulating the dauer transition is the insulin-like receptor (designated Ce-DAF-2) encoded by the gene Ce-daf-2. However, nothing is known about DAF-2 homologues in most parasitic nematodes. Here, using a PCR-based approach, we identified and characterised a gene (Hc-daf-2) and its inferred product (Hc-DAF-2) in Haemonchus contortus (a socioeconomically important parasitic nematode of ruminants). The sequence of Hc-DAF-2 displays significant sequence homology to insulin receptors (IR) in both vertebrates and invertebrates, and contains conserved structural domains. A sequence encoding an important proteolytic motif (RKRR) identified in the predicted peptide sequence of Hc-DAF-2 is consistent with that of the human IR, suggesting that it is involved in the formation of the IR complex. The Hc-daf-2 gene was transcribed in all life stages of H. contortus, with a significant up-regulation in the iL3 compared with other stages. To compare patterns of expression between Hc-daf-2 and Ce-daf-2, reporter constructs fusing the Ce-daf-2 or Hc-daf-2 promoter to sequence encoding GFP were microinjected into the N2 strain of C. elegans, and transgenic lines were established and examined. Both genes showed similar patterns of expression in amphidial (head) neurons, which relate to sensation and signal transduction. Further study by heterologous genetic complementation in a daf-2-deficient strain of C. elegans (CB1370) showed partial rescue of function by Hc-daf-2. Taken together, these findings provide a first insight into the roles of Hc-daf

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Dominant negative mutations of Caenorhabditis elegans daf-7 confer a novel developmental phenotype.

Science.gov (United States)

Crook, Matt; Grant, Warwick N

2013-06-01

TGF-β signaling pathways are involved in the control of development in every member of the animal kingdom. As such, TGF-β ligands are widely divergent yet retain a set of core conserved features, specifically, a pre-protein cleavage site and several conserved ligand domain residues, the disruption of which produces a dominant negative phenotype. We have extended these observations into an invertebrate system by creating a series of loss-of-function Caenorhabditis elegans daf-7 transgenes. When we tested these mutant transgenes in a daf-7/+ background, we saw a molting and excretory canal phenotype. Members of both pathways downstream of daf-4 were required for this phenotype. Our results show that the basic mechanisms of TGF-β function are conserved across the animal kingdom. A subset of our daf-7 mutations also produced an unexpected and novel phenotype. Epistasis experiments demonstrated that both daf-3/-5 and sma-4/-9 were downstream of our mutant daf-7 transgenes, which suggests not only a role for DAF-7 in the control of molting and the development of the excretory system but also that daf-7 and dbl-1 signaling may converge downstream of their shared Type II receptor, daf-4. Our approach may unveil new roles in development for other invertebrate TGF-β ligands. Copyright © 2013 Wiley Periodicals, Inc.

Activation of DAF-16/FOXO by reactive oxygen species contributes to longevity in long-lived mitochondrial mutants in Caenorhabditis elegans.

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Senchuk, Megan M; Dues, Dylan J; Schaar, Claire E; Johnson, Benjamin K; Madaj, Zachary B; Bowman, Megan J; Winn, Mary E; Van Raamsdonk, Jeremy M

2018-03-01

Mild deficits in mitochondrial function have been shown to increase lifespan in multiple species including worms, flies and mice. Here, we study three C. elegans mitochondrial mutants (clk-1, isp-1 and nuo-6) to identify overlapping genetic pathways that contribute to their longevity. We find that genes regulated by the FOXO transcription factor DAF-16 are upregulated in all three strains, and that the transcriptional changes present in these worms overlap significantly with the long-lived insulin-IGF1 signaling pathway mutant daf-2. We show that DAF-16 and multiple DAF-16 interacting proteins (MATH-33, IMB-2, CST-1/2, BAR-1) are required for the full longevity of all three mitochondrial mutants. Our results suggest that the activation of DAF-16 in these mutants results from elevated levels of reactive oxygen species. Overall, this work reveals an overlapping genetic pathway required for longevity in three mitochondrial mutants, and, combined with previous work, demonstrates that DAF-16 is a downstream mediator of lifespan extension in multiple pathways of longevity.

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Dansk Almenmedicinsk Forskningsdag - DAF 2015

DEFF Research Database (Denmark)

Geyti, Christine Ladegaard

2015-01-01

Den 18. marts blev Dansk Almenmedicinsk Forskningsdag (DAF) afholdt i København. Arrangementet foregik i Domus Medicas flotte adelspalæ med prægtige lysekroner og hyggelige opholdsrum med bløde lænestole og gamle bøger op og ned ad væggene. Der blev nu ikke megen tid til at slænge sig, for progra......Den 18. marts blev Dansk Almenmedicinsk Forskningsdag (DAF) afholdt i København. Arrangementet foregik i Domus Medicas flotte adelspalæ med prægtige lysekroner og hyggelige opholdsrum med bløde lænestole og gamle bøger op og ned ad væggene. Der blev nu ikke megen tid til at slænge sig...

Regulation of Caenorhabditis elegans vitellogenesis by DAF-2/IIS through separable transcriptional and posttranscriptional mechanisms.

Science.gov (United States)

DePina, Ana S; Iser, Wendy B; Park, Sung-Soo; Maudsley, Stuart; Wilson, Mark A; Wolkow, Catherine A

2011-07-12

Evolutionary theories of aging propose that longevity evolves as a competition between reproduction and somatic maintenance for a finite pool of resources. Reproduction is thought to shorten lifespan by depleting resources from processes promoting somatic maintenance. Maternal yolk production, vitellogenesis, represents a significant maternal cost for reproduction and is suppressed under genetic and environmental conditions that extend lifespan. However, little is known about the pathways regulating vitellogenesis in response to prolongevity cues. In order to identify mechanisms that suppress vitellogenesis under prolongevity conditions, we studied factors regulating vitellogenesis in C. elegans nematodes. In C. elegans, vitellogenesis is depressed in the absence of insulin-like signaling (IIS). We found that the C. elegans daf-2/IIS pathway regulates vitellogenesis through two mechanisms. vit-2 transcript levels in daf-2 mutants were indirectly regulated through a germline-dependent signal, and could be rescued by introduction of daf-2(+) sperm. However, yolk protein (YP) levels in daf-2 mutants were also regulated by germline-independent posttranscriptional mechanisms. C. elegans vitellogenesis is regulated transcriptionally and posttranscriptionally in response to environmental and reproductive cues. The daf-2 pathway suppressed vitellogenesis through transcriptional mechanisms reflecting reproductive phenotypes, as well as distinct posttranscriptional mechanisms. This study reveals that pleiotropic effects of IIS pathway mutations can converge on a common downstream target, vitellogenesis, as a mechanism to modulate longevity.

Regulation of Caenorhabditis elegans vitellogenesis by DAF-2/IIS through separable transcriptional and posttranscriptional mechanisms

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Wilson Mark A

2011-07-01

Full Text Available Abstract Background Evolutionary theories of aging propose that longevity evolves as a competition between reproduction and somatic maintenance for a finite pool of resources. Reproduction is thought to shorten lifespan by depleting resources from processes promoting somatic maintenance. Maternal yolk production, vitellogenesis, represents a significant maternal cost for reproduction and is suppressed under genetic and environmental conditions that extend lifespan. However, little is known about the pathways regulating vitellogenesis in response to prolongevity cues. Results In order to identify mechanisms that suppress vitellogenesis under prolongevity conditions, we studied factors regulating vitellogenesis in C. elegans nematodes. In C. elegans, vitellogenesis is depressed in the absence of insulin-like signaling (IIS. We found that the C. elegans daf-2/IIS pathway regulates vitellogenesis through two mechanisms. vit-2 transcript levels in daf-2 mutants were indirectly regulated through a germline-dependent signal, and could be rescued by introduction of daf-2(+ sperm. However, yolk protein (YP levels in daf-2 mutants were also regulated by germline-independent posttranscriptional mechanisms. Conclusions C. elegans vitellogenesis is regulated transcriptionally and posttranscriptionally in response to environmental and reproductive cues. The daf-2 pathway suppressed vitellogenesis through transcriptional mechanisms reflecting reproductive phenotypes, as well as distinct posttranscriptional mechanisms. This study reveals that pleiotropic effects of IIS pathway mutations can converge on a common downstream target, vitellogenesis, as a mechanism to modulate longevity.

A 44 bp intestine-specific hermaphrodite-specific enhancer from the C. elegans vit-2 vitellogenin gene is directly regulated by ELT-2, MAB-3, FKH-9 and DAF-16 and indirectly regulated by the germline, by daf-2/insulin signaling and by the TGF-β/Sma/Mab pathway.

Science.gov (United States)

Goszczynski, Barbara; Captan, Vasile V; Danielson, Alicia M; Lancaster, Brett R; McGhee, James D

2016-05-01

The Caenorhabditis elegans vitellogenin genes are transcribed in the intestine of adult hermaphrodites but not of males. A 44-bp region from the vit-2 gene promoter is able largely to reconstitute this tissue-, stage- and sex-specific-expression. This "enhancer" contains a binding site for the DM-domain factor MAB-3, the male-specific repressor of vitellogenesis, as well as an activator site that we show is the direct target of the intestinal GATA factor ELT-2. We further show that the enhancer is directly activated by the winged-helix/forkhead-factor FKH-9, (whose gene has been shown by others to be a direct target of DAF-16), by an unknown activator binding to the MAB-3 site, and by the full C. elegans TGF-β/Sma/Mab pathway acting within the intestine. The vit-2 gene has been shown by others to be repressed by the daf-2/daf-16 insulin signaling pathway, which so strongly influences aging and longevity in C. elegans. We show that the activity of the 44 bp vit-2 enhancer is abolished by loss of daf-2 but is restored by simultaneous loss of daf-16. DAF-2 acts from outside of the intestine but DAF-16 acts both from outside of the intestine and from within the intestine where it binds directly to the same non-canonical target site that interacts with FKH-9. Activity of the 44 bp vit-2 enhancer is also inhibited by loss of the germline, in a manner that is only weakly influenced by DAF-16 but that is strongly influenced by KRI-1, a key downstream effector in the pathway by which germline loss increases C. elegans lifespan. The complex behavior of this enhancer presumably allows vitellogenin gene transcription to adjust to demands of body size, germline proliferation and nutritional state but we suggest that the apparent involvement of this enhancer in aging and longevity "pathways" could be incidental. Copyright © 2016 Elsevier Inc. All rights reserved.

Study of local structure by DAFS

International Nuclear Information System (INIS)

Mizuki, Jun-ichiro

1997-01-01

We will describe a rather new X-ray structural technique, Diffraction Anomalous Fine Structure (DAFS), in which the Bragg diffraction intensities of a fixed momentum transfer is measured as a function of the incident X-ray energy. This technique can provide the same short-range structural information as XAFS. Because DAFS combines the capabilities of diffraction and XAFS into a single technique, it has two enhanced sensitivities compared to the separate technique. These are 'spatial selectivity' and 'site selectivity'. In this chapter semiconductor interface structure study as an example for spatial selectivity and structural study of high Tc superconductor as an example for site selectivity will be shown. (author)

A splice acceptor mutation in C. elegans daf-19/Rfx disrupts functional specialization of male-specific ciliated neurons but does not affect ciliogenesis.

Science.gov (United States)

Wells, Kristen L; Rowneki, Mazhgan; Killian, Darrell J

2015-04-01

RFX transcription factors are master regulators of ciliogenesis in diverse animal species. The sole Caenorhabditis elegans RFX homolog, DAF-19, plays at least two roles in the formation of functional cilia. The DAF-19(C) isoform is required for ciliogenesis and the DAF-19(M) isoform is required for the functional specialization of a subset of male-specific ciliated neurons called PKD neurons. Here we report the identification of a novel mutation, daf-19(sm129), which disrupts the functional specification of PKD neurons and thus suggests that daf-19m activity is compromised. However, ciliogenesis is not disrupted in daf-19(sm129) mutants suggesting that daf-19c activity is retained. The sm129 mutation disrupts a splice acceptor site adjacent to an exon common to the daf-19c and daf-19m isoforms resulting in aberrant splicing in a proportion of transcripts. While aberrant splicing of daf-19c to upstream cryptic sites results in in-frame and functional products, a large proportion of daf-19m mRNAs include the entire upstream intron, which introduces a frameshift and stop codons. At least 15% of disease-causing mutations affect splicing of the gene bearing the mutation, thus it is important to understand the consequences of splice site mutations on gene function. However, predicting the effects of a splice site mutation remains difficult and experimental determination is still required. Using daf-19(sm129) as a model, our results suggest that this problem is exacerbated when a splice acceptor mutation is used by multiple isoforms of the same gene because the effects on each isoform can be dramatically different. Copyright © 2015 Elsevier B.V. All rights reserved.

Lowbush cranberry acts through DAF-16/FOXO signaling to promote increased lifespan and axon branching in aging posterior touch receptor neurons.

Science.gov (United States)

Scerbak, Courtney; Vayndorf, Elena; Hernandez, Alicia; McGill, Colin; Taylor, Barbara

2018-05-01

Medicinal berries are appreciated for their health benefits, in traditional ecological knowledge and nutrition science. Determining the cellular mechanisms underlying the effects of berry supplementation may contribute to our understanding of aging. Here, we report that lowbush cranberry (Vaccinium vitis-idaea) treatment causes marked nuclear localization of the central aging-related transcription factor DAF-16/FOXO in aged Caenorhabditis elegans. Further, functional DAF-16 is required for the lifespan extension, improved mechanosensation, and posterior touch receptor neuron morphological changes induced by lowbush cranberry treatments. DAF-16 is not observed in nuceli nor required for lifespan extension in lifespan-extending Alaskan blueberry treatments and, while DAF-16 is not visibly induced into the nucleus in lifespan-extending Alaskan chaga treatments, it is required for chaga-induced lifespan extension. These findings underscore the importance of DAF-16 in the aging of whole organisms and touch receptor neurons and also, importantly, indicate that this critical pathway is not always activated upon consumption of functional foods that impact aging.

Application of the pothole DAF method to vehicles traversing periodic roadway irregularities

Science.gov (United States)

Pesterev, A. V.; Bergman, L. A.; Tan, C. A.; Yang, B.

2005-01-01

This paper is a sequel to the work discussed in Pesterev et al. (Journal of Sound and Vibration, in press). In that paper, it was suggested that the technique to determine the effect of a local road surface irregularity on the dynamics of a vehicle modelled as a linear multi-degree-of-freedom system relies on the so-called pothole dynamic amplification factor (DAF), which is a complex-valued function specific to the irregularity shape. This paper discusses the companion problem of how to determine the DAF function for an irregularity represented as a superposition of simpler ones. Another purpose of this paper is to demonstrate the application of the pothole DAF functions technique to finding a priori estimates of the effect of irregularities with a repeated structure. Specifically, we solve the problem of finding the conditions under which the dynamic effect of two identical potholes located one after another is greater than that due to the single pothole. We also find the estimate for the number of periods of a periodic irregularity that are sufficient in order to consider the oscillator response as steady state. The discussions are illustrated by numerical examples.

Selective expression of a splice variant of decay-accelerating factor in c-erbB-2-positive mammary carcinoma cells showing increased transendothelial invasiveness

International Nuclear Information System (INIS)

Brandt, Burkhard; Mikesch, Jan-Hendrik; Simon, Ronald; Roetger, Antje; Kemming, Dirk; Schier, Katrin; Sauter, Guido; Buerger, Horst

2005-01-01

By differential-display-PCR a subclone of the SK-BR-3 cell line with high in vitro transendothelial invasiveness was identified to express increased levels of a new alternative splice variant of decay-accelerating factor (DAF). DAF seems to play an important role in some malignant tumours since on the one hand the expression of complement inhibitors on the surface of tumour cells prevents the accumulation of complement factors and in consequence cell lysis. On the other hand, DAF has been identified as a ligand for the CD97 surface receptor which induces cell migration. Immunofluorescence procedures, Western blot analyses, and cDNA clone sequencing were employed to confirm the expression of DAF restricted to invasive tumour cells. Using a radioactive RNA-in situ hybridisation on freshly frozen tissue microarrays and RT-PCR on native tumour tissue, the expression of alternative spliced DAF mRNA was demonstrated in invasive breast cancer. Due to the fact that it could thereby not be detected in normal mammary tissues, it has to be confirmed in larger studies that the DAF splice variant might be a specific tumour marker for invasive breast cancer

Identification of ligands for DAF-12 that govern dauer formation and reproduction in C. elegans.

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Motola, Daniel L; Cummins, Carolyn L; Rottiers, Veerle; Sharma, Kamalesh K; Li, Tingting; Li, Yong; Suino-Powell, Kelly; Xu, H Eric; Auchus, Richard J; Antebi, Adam; Mangelsdorf, David J

2006-03-24

In response to environmental and dietary cues, the C. elegans orphan nuclear receptor, DAF-12, regulates dauer diapause, reproductive development, fat metabolism, and life span. Despite strong evidence for hormonal control, the identification of the DAF-12 ligand has remained elusive. In this work, we identified two distinct 3-keto-cholestenoic acid metabolites of DAF-9, a cytochrome P450 involved in hormone production, that function as ligands for DAF-12. At nanomolar concentrations, these steroidal ligands (called dafachronic acids) bind and transactivate DAF-12 and rescue the hormone deficiency of daf-9 mutants. Interestingly, DAF-9 has a biochemical activity similar to mammalian CYP27A1 catalyzing addition of a terminal acid to the side chain of sterol metabolites. Together, these results define the first steroid hormones in nematodes as ligands for an invertebrate orphan nuclear receptor and demonstrate that steroidal regulation of reproduction, from biology to molecular mechanism, is conserved from worms to humans.

Decay accelerating factor of complement is anchored to cells by a C-terminal glycolipid

International Nuclear Information System (INIS)

Medof, M.E.; Walter, E.I.; Roberts, W.L.; Haas, R.; Rosenberry, T.L.

1986-01-01

Membrane-associated decay accelerating factor (DAF) of human erythrocytes (E/sup hu/) was analyzed for a C-terminal glycolipid anchoring structure. Automated amino acid analysis of DAF following reductive radiomethylation revealed ethanolamine and glucosamine residues in proportions identical with those present in the E/sup hu/ acetylcholinesterase (AChE) anchor. Cleavage of radiomethylated 70-kilodalton (kDa) DAF with papain released the labeled ethanolamine and glucosamine and generated 61- and 55-kDa DAF products that retained all labeled Lys and labeled N-terminal Asp. Incubation of intact E/sup hu/ with phosphatidylinositol-specific phospholipase C (PI-PLC), which cleaves the anchors in trypanosome membrane form variant surface glycoproteins (mfVSGs) and murine thymocyte Thy-1 antigen, released 15% of the cell-associated DAF antigen. The released 67-kDa PI-PLC DAF derivative retained its ability to decay the classical C3 convertase C4b2a but was unable to membrane-incorporate and displayed physicochemical properties similar to urine DAF, a hydrophilic DAF form that can be isolated for urine. Nitrous acid deamination cleavage of E/sup hu/ DAF at glucosamine following labeling with the lipophilic photoreagent 3-(trifluoromethyl)-3-(m-[ 125 I]iodophenyl)diazirine ([ 125 I]TID) released the [ 125 I]TID label in a parallel fashion as from [ 125 I]TID-labeled AChE. Biosynthetic labeling of HeLa cells with [ 3 H] ethanolamine resulted in rapid 3 H incorporation into both 48-kDa pro-DAF and 72-kDa mature epithelial cell DAF. The findings indicate that DAF and AChE are anchored in E/sup hu/ by the same or a similar glycolipid structure and that, like VSGs, this structure is incorporated into DAF early in DAF biosynthesis prior to processing of pro-DAF in the Golgi

Piceatannol extends the lifespan of Caenorhabditis elegans via DAF-16.

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Shen, Peiyi; Yue, Yiren; Sun, Quancai; Kasireddy, Nandita; Kim, Kee-Hong; Park, Yeonhwa

2017-05-06

Piceatannol is a natural stilbene with many beneficial effects, such as antioxidative, anti-inflammatory, antiatherogenic activities; however, its role on aging is not known. In this study, we used Caenorhabditis elegans as an animal model to study the effect of piceatannol on its lifespan and investigated the underlying mechanisms. The results showed that 50 and 100 µM piceatannol significantly extended the lifespan of C. elegans without altering the growth rate, worm size and progeny production. Piceatannol delayed the age-related decline of pumping rate and locomotive activity, and protected the worms from heat and oxidative stress. This study further indicated that lifespan extension and enhanced stress resistance induced by piceatannol requires DAF-16. Since DAF-16 is conserved from nematodes to mammals, our study may have important implications in utilizing piceatannol to promote healthy aging and combat age-related disease in humans. © 2016 BioFactors, 43(3):379-387, 2017. © 2017 International Union of Biochemistry and Molecular Biology.

RNA surveillance via nonsense-mediated mRNA decay is crucial for longevity in daf-2/insulin/IGF-1 mutant C. elegans.

Science.gov (United States)

Son, Heehwa G; Seo, Mihwa; Ham, Seokjin; Hwang, Wooseon; Lee, Dongyeop; An, Seon Woo A; Artan, Murat; Seo, Keunhee; Kaletsky, Rachel; Arey, Rachel N; Ryu, Youngjae; Ha, Chang Man; Kim, Yoon Ki; Murphy, Coleen T; Roh, Tae-Young; Nam, Hong Gil; Lee, Seung-Jae V

2017-03-09

Long-lived organisms often feature more stringent protein and DNA quality control. However, whether RNA quality control mechanisms, such as nonsense-mediated mRNA decay (NMD), which degrades both abnormal as well as some normal transcripts, have a role in organismal aging remains unexplored. Here we show that NMD mediates longevity in C. elegans strains with mutations in daf-2/insulin/insulin-like growth factor 1 receptor. We find that daf-2 mutants display enhanced NMD activity and reduced levels of potentially aberrant transcripts. NMD components, including smg-2/UPF1, are required to achieve the longevity of several long-lived mutants, including daf-2 mutant worms. NMD in the nervous system of the animals is particularly important for RNA quality control to promote longevity. Furthermore, we find that downregulation of yars-2/tyrosyl-tRNA synthetase, an NMD target transcript, by daf-2 mutations contributes to longevity. We propose that NMD-mediated RNA surveillance is a crucial quality control process that contributes to longevity conferred by daf-2 mutations.

Structural and functional characterization of a novel gene, Hc-daf-22, from the strongylid nematode Haemonchus contortus.

Science.gov (United States)

Guo, Xiaolu; Zhang, Hongli; Zheng, Xiuping; Zhou, Qianjin; Yang, Yi; Chen, Xueqiu; Du, Aifang

2016-07-29

The strongylid nematode Haemonchus contortus is a parasite of major concern for modern livestock husbandry because hostile environmental conditions may induce diapause in the early fourth-stage larvae. A new gene Hc-daf-22 was identified which is the homologue of Ce-daf-22 and human SCPx. Genome walking and RACE were performed to obtain the whole cDNA and genomic sequence of this gene. Using qRT-PCR with all developmental stages as templates to explore the transcription level and micro-injection was applied to confirm the promoter activity of the 5'-flanking region. Overexpression, rescue and RNA interference experiments were performed in N2, daf-22 mutant (ok 693) strains of C. elegans to study the gene function of Hc-daf-22. The full length gene of Hc-daf-22 (6,939 bp) contained 16 exons separated by 15 introns, and encoded a cDNA of 1,602 bp (533 amino acids, estimated at about 59.3 kDa) with a peak in L3 and L4 in transcriptional level. The Hc-DAF-22 protein was consisted of a 3-oxoacyl-CoA thiolase domain and a SCP2 domain and evolutionarily conserved. The 1,548 bp fragment upstream of the 5'-flanking region was confirmed to have promoter activity compared with 5'-flanking region of Ce-daf-22. The rescue experiment by micro-injection of daf-22 (ok693) mutant strain showed significant increase in body size and brood size in the rescued worms with significantly reduced or completely absent fat granules confirmed by Oil red O staining, indicating that Hc-daf-22 could partially rescue the function of Ce-daf-22. Furthermore, RNAi with Hc-daf-22 could partially silence the endogenous Ce-daf-22 in N2 worms and mimic the phenotype of daf-22 (ok693) mutants. The gene Hc-daf-22 was isolated and its function identified using C. elegans as a model organism. Our results indicate that Hc-daf-22 shared similar characteristics and function with Ce-daf-22 and may play an important role in peroxisomal β-oxidation and the development in H. contortus.

Germline signaling mediates the synergistically prolonged longevity produced by double mutations in daf-2 and rsks-1 in C. elegans.

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Chen, Di; Li, Patrick Wai-Lun; Goldstein, Benjamin A; Cai, Waijiao; Thomas, Emma Lynn; Chen, Fen; Hubbard, Alan E; Melov, Simon; Kapahi, Pankaj

2013-12-26

Inhibition of DAF-2 (insulin-like growth factor 1 [IGF-1] receptor) or RSKS-1 (S6K), key molecules in the insulin/IGF-1 signaling (IIS) and target of rapamycin (TOR) pathways, respectively, extend lifespan in Caenorhabditis elegans. However, it has not been clear how and in which tissues they interact with each other to modulate longevity. Here, we demonstrate that a combination of mutations in daf-2 and rsks-1 produces a nearly 5-fold increase in longevity that is much greater than the sum of single mutations. This synergistic lifespan extension requires positive feedback regulation of DAF-16 (FOXO) via the AMP-activated protein kinase (AMPK) complex. Furthermore, we identify germline as the key tissue for this synergistic longevity. Moreover, germline-specific inhibition of rsks-1 activates DAF-16 in the intestine. Together, our findings highlight the importance of the germline in the significantly increased longevity produced by daf-2 rsks-1, which has important implications for interactions between the two major conserved longevity pathways in more complex organisms. Copyright © 2013 The Authors. Published by Elsevier Inc. All rights reserved.

Localization of a guanylyl cyclase to chemosensory cilia requires the novel ciliary MYND domain protein DAF-25.

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Victor L Jensen

2010-11-01

Full Text Available In harsh conditions, Caenorhabditis elegans arrests development to enter a non-aging, resistant diapause state called the dauer larva. Olfactory sensation modulates the TGF-β and insulin signaling pathways to control this developmental decision. Four mutant alleles of daf-25 (abnormal DAuer Formation were isolated from screens for mutants exhibiting constitutive dauer formation and found to be defective in olfaction. The daf-25 dauer phenotype is suppressed by daf-10/IFT122 mutations (which disrupt ciliogenesis, but not by daf-6/PTCHD3 mutations (which prevent environmental exposure of sensory cilia, implying that DAF-25 functions in the cilia themselves. daf-25 encodes the C. elegans ortholog of mammalian Ankmy2, a MYND domain protein of unknown function. Disruption of DAF-25, which localizes to sensory cilia, produces no apparent cilia structure anomalies, as determined by light and electron microscopy. Hinting at its potential function, the dauer phenotype, epistatic order, and expression profile of daf-25 are similar to daf-11, which encodes a cilium-localized guanylyl cyclase. Indeed, we demonstrate that DAF-25 is required for proper DAF-11 ciliary localization. Furthermore, the functional interaction is evolutionarily conserved, as mouse Ankmy2 interacts with guanylyl cyclase GC1 from ciliary photoreceptors. The interaction may be specific because daf-25 mutants have normally-localized OSM-9/TRPV4, TAX-4/CNGA1, CHE-2/IFT80, CHE-11/IFT140, CHE-13/IFT57, BBS-8, OSM-5/IFT88, and XBX-1/D2LIC in the cilia. Intraflagellar transport (IFT (required to build cilia is not defective in daf-25 mutants, although the ciliary localization of DAF-25 itself is influenced in che-11 mutants, which are defective in retrograde IFT. In summary, we have discovered a novel ciliary protein that plays an important role in cGMP signaling by localizing a guanylyl cyclase to the sensory organelle.

Role of DAF-21protein in Caenorhabditis elegans immunity against Proteus mirabilis infection.

Science.gov (United States)

JebaMercy, Gnanasekaran; Durai, Sellegounder; Prithika, Udayakumar; Marudhupandiyan, Shanmugam; Dasauni, Pushpanjali; Kundu, Suman; Balamurugan, Krishnaswamy

2016-08-11

Caenorhabditis elegans is emerging as one of the handy model for proteome related studies due to its simplest system biology. The present study, deals with changes in protein expression in C. elegans infected with Proteus mirabilis. Proteins were separated using two-dimensional differential gel electrophoresis (2D-DIGE) and identified using MALDI-TOF. Twelve distinctly regulated proteins identified in the infected worms, included heat shock proteins involved stress pathway (HSP-1 and HSP-6), proteins involved in immune response pathway (DAF-21), enzymes involved in normal cellular process (Eukaryotic translation Elongation Factor, actin family member, S-adenosyl homocysteine hydrolase ortholog, glutamate dehydrogenase and Vacuolar H ATPase family member) and few least characterized proteins (H28O16.1 and H08J11.2). The regulation of selected players at the transcriptional level during Proteus mirabilis infection was analyzed using qPCR. Physiological experiments revealed the ability of P. mirabilis to kill daf-21 mutant C. elegans significantly compared with the wild type. This is the first report studying proteome changes in C. elegans and exploring the involvement of MAP Kinase pathway during P. mirabilis infection. This is the first report studying proteome changes in C. elegans during P. mirabilis infection. The present study explores the role and contribution of MAP Kinase pathway and its regulator protein DAF-21 involvement in the immunity against opportunistic pathogen P. mirabilis infection. Manipulation of this DAF-21 protein in host, may pave the way for new drug development or disease control strategy during opportunistic pathogen infections. Copyright © 2016 Elsevier B.V. All rights reserved.

Cholesterol regulates DAF-16 nuclear localization and fasting-induced longevity in C. elegans.

Science.gov (United States)

Ihara, Akiko; Uno, Masaharu; Miyatake, Koichi; Honjoh, Sakiko; Nishida, Eisuke

2017-01-01

Cholesterol has attracted significant attention as a possible lifespan regulator. It has been reported that serum cholesterol levels have an impact on mortality due to age-related disorders such as cardiovascular disease. Diet is also known to be an important lifespan regulator. Dietary restriction retards the onset of age-related diseases and extends lifespan in various organisms. Although cholesterol and dietary restriction are known to be lifespan regulators, it remains to be established whether cholesterol is involved in dietary restriction-induced longevity. Here, we show that cholesterol deprivation suppresses longevity induced by intermittent fasting, which is one of the dietary restriction regimens that effectively extend lifespan. We also found that cholesterol is required for the fasting-induced upregulation of transcriptional target genes such as the insulin/IGF-1 pathway effector DAF-16 and that cholesterol deprivation suppresses the long lifespan of the insulin/IGF-1 receptor daf-2 mutant. Remarkably, we found that cholesterol plays an important role in the fasting-induced nuclear accumulation of DAF-16. Moreover, knockdown of the cholesterol-binding protein NSBP-1, which has been shown to bind to DAF-16 in a cholesterol-dependent manner and to regulate DAF-16 activity, suppresses both fasting-induced longevity and DAF-16 nuclear accumulation. Furthermore, this suppression was not additive to the cholesterol deprivation-induced suppression, which suggests that NSBP-1 mediates, at least in part, the action of cholesterol to promote fasting-induced longevity and DAF-16 nuclear accumulation. These findings identify a novel role for cholesterol in the regulation of lifespan. Copyright © 2016 Elsevier Inc. All rights reserved.

DhHP-6 extends lifespan of Caenorhabditis elegans by enhancing nuclear translocation and transcriptional activity of DAF-16.

Science.gov (United States)

Huang, Lei; Li, Pengfei; Wang, Guan; Guan, Shuwen; Sun, Xiaoli; Wang, Liping

2013-04-01

Earlier studies have demonstrated that Deuterohaemin-AlaHisThrValGluLys (DhHP-6), a novel porphyrin-peptide, increases lifespan and enhances stress resistance of Caenorhabditis elegans. To explore the possible mechanisms, in this study we investigated the roles of SIR-2.1 and DAF-16 in DhHP-6's function using wild-type and various other mutant strains of C. elegans. DhHP-6's effect was dependent upon DAF-16, and it did not extend the lifespan of the loss-of-function daf-16 mutant strain (daf-16(mu86) I). DhHP-6 enhanced DAF-16 translocation from cytoplasm to nuclei; and it increased DAF-16's transcriptional activity, likely by activating the SIR-2.1/DAF-16 complex. DhHP-6's effect was also dependent upon SIR-2.1, and it did not increase the lifespan of the worms with SIR-2.1 deacetylase activity inhibited by niacin amide (SIR-2.1 inhibitor) and SIR-2.1 RNA interference (RNAi). Niacin amide and RNAi increased DAF-16's nuclear localization; but they decreased DAF-16's transcriptional activity, likely by preventing the formation of the SIR-2.1/DAF-16 complex. These results suggest that DhHP-6 extends the lifespan of C. elegans via SIR 2.1 and DAF-16, and they provide new insights into the molecular mechanisms of aging.

The Deubiquitylase MATH-33 Controls DAF-16 Stability and Function in Metabolism and Longevity

NARCIS (Netherlands)

Heimbucher, Thomas; Liu, Zheng; Bossard, Carine; McCloskey, Richard; Carrano, Andrea C.; Riedel, Christian G.; Tanasa, Bogdan; Klammt, Christian; Fonslow, Bryan R.; Riera, Celine E.; Lillemeier, Bjorn F.; Kemphues, Kenneth; Yates, John R.; O'Shea, Clodagh; Hunter, Tony; Dillin, Andrew

2015-01-01

FOXO family transcription factors are downstream effectors of Insulin/IGF-1 signaling (IIS) and major determinants of aging in organisms ranging from worms to man. The molecular mechanisms that actively promote DAF16/FOXO stability and function are unknown. Here we identify the deubiquitylating

Dansk Almenmedicinsk Forskningsdag - DAF 2013

DEFF Research Database (Denmark)

Jensen, Jacob Reinholdt; Ryborg, Christina Trankjær; Smidth, Margrethe

2013-01-01

Ideen om DAF udsprang på en indisk restaurant for to år siden, da repræsentanter fra det daværende Forskningsudvalg var til Society for Academic Primary Care (SAPC) i Bristol. En konference, hvor den nyeste forskning og de hotteste forskere inden for almen medicin i Storbritannien var repræsenteret...

IFN-γ-producing NKT cells exacerbate sepsis by enhancing C5a generation via IL-10-mediated inhibition of CD55 expression on neutrophils.

Science.gov (United States)

Kim, Ji Hyung; Oh, Sae Jin; Ahn, Sehee; Chung, Doo Hyun

2014-07-01

A role for NKT cells has been implicated in sepsis, but the mechanism by which NKT cells contribute to sepsis remains unclear. Here, we examined WT and NKT-cell-deficient mice of C57BL/6 background during cecal ligation and puncture-induced sepsis. The levels of C5a, IFN-γ, and IL-10 were higher in the serum and peritoneal fluid of WT mice than in those of CD1d(-/-) mice, while the mortality rate was lower in CD1d(-/-) mice than in WT mice. C5a blockade decreased mortality of WT mice during sepsis, whereas it did not alter that of CD1d(-/-) mice. As assessed by intracellular staining, NKT cells expressed IFN-γ, while neutrophils expressed IL-10. Upon coculture, IL-10-deficient NKT cells enhanced IL-10 production by WT, but not IFN-γR-deficient, neutrophils. Meanwhile, CD1d(-/-) mice exhibited high CD55 expression on neutrophils during sepsis, whereas those cells from WT mice expressed minimal levels of CD55. Recombinant IL-10 administration into CD1d(-/-) mice reduced CD55 expression on neutrophils. Furthermore, adoptive transfer of sorted WT, but not IFN-γ-deficient, NKT cells into CD1d(-/-) mice suppressed CD55 expression on neutrophils, but increased IL-10 and C5a levels. Taken together, IFN-γ-producing NKT cells enhance C5a generation via IL-10-mediated inhibition of CD55 expression on neutrophils, thereby exacerbating sepsis. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

DAF-16-dependent suppression of immunity during reproduction in Caenorhabditis elegans.

Science.gov (United States)

Miyata, Sachiko; Begun, Jakob; Troemel, Emily R; Ausubel, Frederick M

2008-02-01

To further understand how the nematode Caenorhabditis elegans defends itself against pathogen attack, we analyzed enhanced pathogen resistance (epr) mutants obtained from a forward genetic screen. We also examined several well-characterized sterile mutants that exhibit an Epr phenotype. We found that sterility and pathogen resistance are highly correlated and that resistance in both epr and sterile mutants is dependent on DAF-16 activity. Our data indicate that a DAF-16-dependent signaling pathway distinct from previously described pathways is involved in the activation of genes that confer resistance to bacterial pathogens. The timing of DAF-16-dependent gene activation in sterile mutants coincides with the onset of embryonic development in wild-type animals, suggesting that signals from developing embryos normally downregulate the immune response.

Linking the environment, DAF-7/TGFβ signaling and LAG-2/DSL ligand expression in the germline stem cell niche.

Science.gov (United States)

Pekar, Olga; Ow, Maria C; Hui, Kailyn Y; Noyes, Marcus B; Hall, Sarah E; Hubbard, E Jane Albert

2017-08-15

The developmental accumulation of proliferative germ cells in the C. elegans hermaphrodite is sensitive to the organismal environment. Previously, we found that the TGFβ signaling pathway links the environment and proliferative germ cell accumulation. Neuronal DAF-7/TGFβ causes a DAF-1/TGFβR signaling cascade in the gonadal distal tip cell (DTC), the germline stem cell niche, where it negatively regulates a DAF-3 SMAD and DAF-5 Sno-Ski. LAG-2, a founding DSL ligand family member, is produced in the DTC and activates the GLP-1/Notch receptor on adjacent germ cells to maintain germline stem cell fate. Here, we show that DAF-7/TGFβ signaling promotes expression of lag-2 in the DTC in a daf-3- dependent manner. Using ChIP and one-hybrid assays, we find evidence for direct interaction between DAF-3 and the lag-2 promoter. We further identify a 25 bp DAF-3 binding element required for the DTC lag-2 reporter response to the environment and to DAF-7/TGFβ signaling. Our results implicate DAF-3 repressor complex activity as a key molecular mechanism whereby the environment influences DSL ligand expression in the niche to modulate developmental expansion of the germline stem cell pool. © 2017. Published by The Company of Biologists Ltd.

The influence of floc size and hydraulic detention time on the performance of a dissolved air flotation (DAF) pilot unit in the light of a mathematical model.

Science.gov (United States)

Moruzzi, R B; Reali, M A P

2014-12-01

The influence of floc size and hydraulic detention time on the performance of a dissolved air flotation (DAF) pilot unit was investigated in the light of a known mathematical model. The following design and operational parameters were considered: the hydraulic detention time (tdcz) and hydraulic loading rate in the contact zone, the down-flow loading rate in the clarification zone, the particle size distribution (d F), and the recirculation rate (p). As a reference for DAF performance analysis, the proposed β.td parameter from the above mentioned mathematical model was employed. The results indicated that tdcz is an important factor in DAF performance and that d F and floc size are also determinants of DAF efficiency. Further, β.td was sensitive to both design and operational parameters, which were varied in the DAF pilot plant. The performance of the DAF unit decreases with increasing β.td values because a higher td (considering a fixed β) or a higher β (e.g., higher hydrophobicity of the flocs for a fixed td) would be necessary in the reaction zone to reach desired flotation efficiency.

Site-Directed Mutagenesis Study Revealed Three Important Residues in Hc-DAF-22, a Key Enzyme Regulating Diapause of Haemonchus contortus

Directory of Open Access Journals (Sweden)

Yan Huang

2017-11-01

Full Text Available Haemonchus contortus (H. contortus is one of the most important parasites of small ruminants, especially goats and sheep. The complex life cycle of this nematode is a main obstacle for the control and prevention of haemonchosis. So far, a special form of arrested development called diapause different from the dauer stage in Caenorhabditis elegans (C. elegans has been found in many parasitic nematodes. In our previous study, we have characterized a novel gene Hc-daf-22 from H. contortus sharing high homology with Ce-daf-22 and functional analysis showed this gene has similar biological function with Ce-daf-22. In this study, Hc-daf-22 mutants were constructed using site-directed mutagenesis, and carried out rescue experiments, RNA interference (RNAi experiments and in vitro enzyme activity analysis with the mutants to further explore the precise function site of Hc-DAF-22. The results showed that Hc-daf-22 mutants could be expressed in the rescued ok693 worms and the expression positions were mainly in the intestine which was identical with that of Hc-daf-22 rescued worms. Through lipid staining we found that Hc-daf-22 could rescue daf-22 mutant (ok693 from the fatty acid metabolism deficiency while Hc-daf-22 mutants failed. Brood size and body length analyses in rescue experiment along with body length and life span analyses in RNAi experiment elucidated that Hc-daf-22 resembled Ce-daf-22 in effecting the development and capacity of C. elegans and mutants impaired the function of Hc-daf-22. Together with the protease activity assay, this research revealed three important active resides 84C/299H/349H in Hc-DAF-22 by site-directed mutagenesis.

Site-Directed Mutagenesis Study Revealed Three Important Residues in Hc-DAF-22, a Key Enzyme Regulating Diapause of Haemonchus contortus.

Science.gov (United States)

Huang, Yan; Zheng, Xiuping; Zhang, Hongli; Ding, Haojie; Guo, Xiaolu; Yang, Yi; Chen, Xueqiu; Zhou, Qianjin; Du, Aifang

2017-01-01

Haemonchus contortus ( H. contortus ) is one of the most important parasites of small ruminants, especially goats and sheep. The complex life cycle of this nematode is a main obstacle for the control and prevention of haemonchosis. So far, a special form of arrested development called diapause different from the dauer stage in Caenorhabditis elegans ( C. elegans ) has been found in many parasitic nematodes. In our previous study, we have characterized a novel gene Hc-daf-22 from H. contortus sharing high homology with Ce-daf-22 and functional analysis showed this gene has similar biological function with Ce-daf-22 . In this study, Hc-daf-22 mutants were constructed using site-directed mutagenesis, and carried out rescue experiments, RNA interference (RNAi) experiments and in vitro enzyme activity analysis with the mutants to further explore the precise function site of Hc-DAF-22. The results showed that Hc-daf-22 mutants could be expressed in the rescued ok693 worms and the expression positions were mainly in the intestine which was identical with that of Hc-daf-22 rescued worms. Through lipid staining we found that Hc-daf-22 could rescue daf-22 mutant ( ok693 ) from the fatty acid metabolism deficiency while Hc-daf-22 mutants failed. Brood size and body length analyses in rescue experiment along with body length and life span analyses in RNAi experiment elucidated that Hc-daf-22 resembled Ce-daf-22 in effecting the development and capacity of C. elegans and mutants impaired the function of Hc-daf-22 . Together with the protease activity assay, this research revealed three important active resides 84C/299H/349H in Hc-DAF-22 by site-directed mutagenesis.

DAF-16 and Δ9 desaturase genes promote cold tolerance in long-lived Caenorhabditis elegans age-1 mutants.

Directory of Open Access Journals (Sweden)

Fiona R Savory

Full Text Available In Caenorhabditis elegans, mutants of the conserved insulin/IGF-1 signalling (IIS pathway are long-lived and stress resistant due to the altered expression of DAF-16 target genes such as those involved in cellular defence and metabolism. The three Δ(9 desaturase genes, fat-5, fat-6 and fat-7, are included amongst these DAF-16 targets, and it is well established that Δ(9 desaturase enzymes play an important role in survival at low temperatures. However, no assessment of cold tolerance has previously been reported for IIS mutants. We demonstrate that long-lived age-1(hx546 mutants are remarkably resilient to low temperature stress relative to wild type worms, and that this is dependent upon daf-16. We also show that cold tolerance following direct transfer to low temperatures is increased in wild type worms during the facultative, daf-16 dependent, dauer stage. Although the cold tolerant phenotype of age-1(hx546 mutants is predominantly due to the Δ(9 desaturase genes, additional transcriptional targets of DAF-16 are also involved. Surprisingly, survival of wild type adults following a rapid temperature decline is not dependent upon functional daf-16, and cellular distributions of a DAF-16::GFP fusion protein indicate that DAF-16 is not activated during low temperature stress. This suggests that cold-induced physiological defences are not specifically regulated by the IIS pathway and DAF-16, but expression of DAF-16 target genes in IIS mutants and dauers is sufficient to promote cross tolerance to low temperatures in addition to other forms of stress.

DAF-16/FoxO directly regulates an atypical AMP-activated protein kinase gamma isoform to mediate the effects of insulin/IGF-1 signaling on aging in Caenorhabditis elegans.

Directory of Open Access Journals (Sweden)

Jennifer M A Tullet

2014-02-01

Full Text Available The DAF-16/FoxO transcription factor controls growth, metabolism and aging in Caenorhabditis elegans. The large number of genes that it regulates has been an obstacle to understanding its function. However, recent analysis of transcript and chromatin profiling implies that DAF-16 regulates relatively few genes directly, and that many of these encode other regulatory proteins. We have investigated the regulation by DAF-16 of genes encoding the AMP-activated protein kinase (AMPK, which has α, β and γ subunits. C. elegans has 5 genes encoding putative AMP-binding regulatory γ subunits, aakg-1-5. aakg-4 and aakg-5 are closely related, atypical isoforms, with orthologs throughout the Chromadorea class of nematodes. We report that ∼75% of total γ subunit mRNA encodes these 2 divergent isoforms, which lack consensus AMP-binding residues, suggesting AMP-independent kinase activity. DAF-16 directly activates expression of aakg-4, reduction of which suppresses longevity in daf-2 insulin/IGF-1 receptor mutants. This implies that an increase in the activity of AMPK containing the AAKG-4 γ subunit caused by direct activation by DAF-16 slows aging in daf-2 mutants. Knock down of aakg-4 expression caused a transient decrease in activation of expression in multiple DAF-16 target genes. This, taken together with previous evidence that AMPK promotes DAF-16 activity, implies the action of these two metabolic regulators in a positive feedback loop that accelerates the induction of DAF-16 target gene expression. The AMPK β subunit, aakb-1, also proved to be up-regulated by DAF-16, but had no effect on lifespan. These findings reveal key features of the architecture of the gene-regulatory network centered on DAF-16, and raise the possibility that activation of AMP-independent AMPK in nutritionally replete daf-2 mutant adults slows aging in C. elegans. Evidence of activation of AMPK subunits in mammals suggests that such FoxO-AMPK interactions may be

DAF-16/FoxO directly regulates an atypical AMP-activated protein kinase gamma isoform to mediate the effects of insulin/IGF-1 signaling on aging in Caenorhabditis elegans.

Science.gov (United States)

Tullet, Jennifer M A; Araiz, Caroline; Sanders, Matthew J; Au, Catherine; Benedetto, Alexandre; Papatheodorou, Irene; Clark, Emily; Schmeisser, Kathrin; Jones, Daniel; Schuster, Eugene F; Thornton, Janet M; Gems, David

2014-02-01

The DAF-16/FoxO transcription factor controls growth, metabolism and aging in Caenorhabditis elegans. The large number of genes that it regulates has been an obstacle to understanding its function. However, recent analysis of transcript and chromatin profiling implies that DAF-16 regulates relatively few genes directly, and that many of these encode other regulatory proteins. We have investigated the regulation by DAF-16 of genes encoding the AMP-activated protein kinase (AMPK), which has α, β and γ subunits. C. elegans has 5 genes encoding putative AMP-binding regulatory γ subunits, aakg-1-5. aakg-4 and aakg-5 are closely related, atypical isoforms, with orthologs throughout the Chromadorea class of nematodes. We report that ∼75% of total γ subunit mRNA encodes these 2 divergent isoforms, which lack consensus AMP-binding residues, suggesting AMP-independent kinase activity. DAF-16 directly activates expression of aakg-4, reduction of which suppresses longevity in daf-2 insulin/IGF-1 receptor mutants. This implies that an increase in the activity of AMPK containing the AAKG-4 γ subunit caused by direct activation by DAF-16 slows aging in daf-2 mutants. Knock down of aakg-4 expression caused a transient decrease in activation of expression in multiple DAF-16 target genes. This, taken together with previous evidence that AMPK promotes DAF-16 activity, implies the action of these two metabolic regulators in a positive feedback loop that accelerates the induction of DAF-16 target gene expression. The AMPK β subunit, aakb-1, also proved to be up-regulated by DAF-16, but had no effect on lifespan. These findings reveal key features of the architecture of the gene-regulatory network centered on DAF-16, and raise the possibility that activation of AMP-independent AMPK in nutritionally replete daf-2 mutant adults slows aging in C. elegans. Evidence of activation of AMPK subunits in mammals suggests that such FoxO-AMPK interactions may be evolutionarily conserved.

Oleanolic acid activates daf-16 to increase lifespan in Caenorhabditis elegans

International Nuclear Information System (INIS)

Zhang, Jiaolong; Lu, Lulu; Zhou, Lijun

2015-01-01

Oleanolic acid (OA) is an active ingredient in natural plants. It has been reported to possess a variety of pharmacological activities, but very little is known about its effects of anti-aging. We investigate here whether OA has an impact on longevity in vivo, and more specifically, we have examined effects of OA on the lifespan and stress tolerance in Caenorhabditis elegans (C. elegans). Our results showed that OA could extend the lifespan, increase its stress resistance and reduce the intracellular reactive oxygen species (ROS) in wild-type worms. Moreover, we have found that OA-induced longevity may not be associated with the calorie restriction (CR) mechanism. Our mechanistic studies using daf-16 loss-of-function mutant strains (GR1307) indicated that the extension of lifespan by OA requires daf-16. In addition, OA treatment could also modulate the nuclear localization, and the quantitative real-time PCR results revealed that up-regulation of daf-16 target genes such as sod-3, hsp-16.2 and ctl-1 could prolong lifespan and increase stress response in C. elegans. This study overall uncovers the longevity effect of OA and its underpinning mechanisms. - Graphical abstract: Oleanolic acid modulates the activity of DAF-16 to promote longevity and increase stress resistance in Caenorhabditis elegans. - Highlights: • OA extends the lifespan of wild-type Caenorhabditis elegans. • OA improves the stress resistance and reduces the intracellular ROS level in C. elegans. • OA induces lifespan extension may not proceed through the CR mechanism. • OA extends the lifespan in C. elegans is modulated by daf-16.

Oleanolic acid activates daf-16 to increase lifespan in Caenorhabditis elegans

Energy Technology Data Exchange (ETDEWEB)

Zhang, Jiaolong; Lu, Lulu; Zhou, Lijun, E-mail: lijunzhou@tju.edu.cn

2015-12-25

Oleanolic acid (OA) is an active ingredient in natural plants. It has been reported to possess a variety of pharmacological activities, but very little is known about its effects of anti-aging. We investigate here whether OA has an impact on longevity in vivo, and more specifically, we have examined effects of OA on the lifespan and stress tolerance in Caenorhabditis elegans (C. elegans). Our results showed that OA could extend the lifespan, increase its stress resistance and reduce the intracellular reactive oxygen species (ROS) in wild-type worms. Moreover, we have found that OA-induced longevity may not be associated with the calorie restriction (CR) mechanism. Our mechanistic studies using daf-16 loss-of-function mutant strains (GR1307) indicated that the extension of lifespan by OA requires daf-16. In addition, OA treatment could also modulate the nuclear localization, and the quantitative real-time PCR results revealed that up-regulation of daf-16 target genes such as sod-3, hsp-16.2 and ctl-1 could prolong lifespan and increase stress response in C. elegans. This study overall uncovers the longevity effect of OA and its underpinning mechanisms. - Graphical abstract: Oleanolic acid modulates the activity of DAF-16 to promote longevity and increase stress resistance in Caenorhabditis elegans. - Highlights: • OA extends the lifespan of wild-type Caenorhabditis elegans. • OA improves the stress resistance and reduces the intracellular ROS level in C. elegans. • OA induces lifespan extension may not proceed through the CR mechanism. • OA extends the lifespan in C. elegans is modulated by daf-16.

DAFS Storage for High Performance Computing Using MPI-I/O: Design and Experience

National Research Council Canada - National Science Library

Velusamy, Vijay

2004-01-01

.... DAFS is a well-defined highperformance protocol for file access across a network as well as set of APIs, uDAFS, for user level OS-bypassing application programming, designed to take advantage of RDMA-based transports, such as Virtual Interface Architecture (VIA), InfiniBand Architecture1, and iWARP.

The thioredoxin TRX-1 modulates the function of the insulin-like neuropeptide DAF-28 during dauer formation in Caenorhabditis elegans.

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Fierro-González, Juan Carlos; Cornils, Astrid; Alcedo, Joy; Miranda-Vizuete, Antonio; Swoboda, Peter

2011-01-27

Thioredoxins comprise a conserved family of redox regulators involved in many biological processes, including stress resistance and aging. We report that the C. elegans thioredoxin TRX-1 acts in ASJ head sensory neurons as a novel modulator of the insulin-like neuropeptide DAF-28 during dauer formation. We show that increased formation of stress-resistant, long-lived dauer larvae in mutants for the gene encoding the insulin-like neuropeptide DAF-28 requires TRX-1 acting in ASJ neurons, upstream of the insulin-like receptor DAF-2. Genetic rescue experiments demonstrate that redox-independent functions of TRX-1 specifically in ASJ neurons are needed for the dauer formation constitutive (Daf-c) phenotype of daf-28 mutants. GFP reporters of trx-1 and daf-28 show opposing expression patterns in dauers (i.e. trx-1 is up-regulated and daf-28 is down-regulated), an effect that is not observed in growing L2/L3 larvae. In addition, functional TRX-1 is required for the down-regulation of a GFP reporter of daf-28 during dauer formation, a process that is likely subject to DAF-28-mediated feedback regulation. Our findings demonstrate that TRX-1 modulates DAF-28 signaling by contributing to the down-regulation of daf-28 expression during dauer formation. We propose that TRX-1 acts as a fluctuating neuronal signaling modulator within ASJ neurons to monitor the adjustment of neuropeptide expression, including insulin-like proteins, during dauer formation in response to adverse environmental conditions.

Kinetic analysis of DAF-FM activation by NO: toward calibration of a NO-sensitive fluorescent dye.

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Namin, Shabnam M; Nofallah, Sara; Joshi, Mahesh S; Kavallieratos, Konstantinos; Tsoukias, Nikolaos M

2013-01-15

Nitric oxide (NO) research in biomedicine has been hampered by the absence of a method that will allow quantitative measurement of NO in biological tissues with high sensitivity and selectivity, and with adequate spatial and temporal resolution. 4-amino-5-methylamino-2',7'-difluorofluorescein (DAF-FM) is a NO sensitive fluorescence probe that has been used widely for qualitative assessment of cellular NO production. However, calibration of the fluorescent signal and quantification of NO concentration in cells and tissues using fluorescent probes, have provided significant challenge. In this study we utilize a combination of mathematical modeling and experimentation to elucidate the kinetics of NO/DAF-FM reaction in solution. Modeling and experiments suggest that the slope of fluorescent intensity (FI) can be related to NO concentration according to the equation: ddtFI=2αk(1)NO(2)O(2)DAF-FMkNO+DAF-FM where α is a proportionality coefficient that relates FI to unit concentration of activated DAF-FM, k(1) is the NO oxidation rate constant, and k was estimated to be 4.3±0.6. The FI slope exhibits saturation kinetics with DAF-FM concentration. Interestingly, the effective half-maximum constant (EC(50)) increases proportionally to NO concentration. This result is not in agreement with the proposition that N(2)O(3) is the NO oxidation byproduct that activates DAF-FM. Kinetic analysis suggests that the reactive intermediate should exhibit NO-dependent consumption and thus NO(2)() is a more likely candidate. The derived rate law can be used for the calibration of DAF-FM fluorescence and the quantification of NO concentration in biological tissues. Copyright © 2012 Elsevier Inc. All rights reserved.

Increased Protein Stability and Decreased Protein Turnover in the Caenorhabditis elegans Ins/IGF-1 daf-2 Mutant.

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Depuydt, Geert; Shanmugam, Nilesh; Rasulova, Madina; Dhondt, Ineke; Braeckman, Bart P

2016-12-01

In Caenorhabditis elegans, cellular proteostasis is likely essential for longevity. Autophagy has been shown to be essential for lifespan extension of daf-2 insulin/IGF mutants. Therefore, it can be hypothesized that daf-2 mutants achieve this phenotype by increasing protein turnover. However, such a mechanism would exert a substantial energy cost. By using classical 35 S pulse-chase labeling, we observed that protein synthesis and degradation rates are decreased in young adults of the daf-2 insulin/IGF mutants. Although reduction of protein turnover may be energetically favorable, it may lead to accumulation and aggregation of damaged proteins. As this has been shown not to be the case in daf-2 mutants, another mechanism must exist to maintain proteostasis in this strain. We observed that proteins isolated from daf-2 mutants are more soluble in acidic conditions due to increased levels of trehalose. This suggests that trehalose may decrease the potential for protein aggregation and increases proteostasis in the daf-2 mutants. We postulate that daf-2 mutants save energy by decreasing protein turnover rates and instead stabilize their proteome by trehalose. © The Author 2016. Published by Oxford University Press on behalf of The Gerontological Society of America.

The thioredoxin TRX-1 modulates the function of the insulin-like neuropeptide DAF-28 during dauer formation in Caenorhabditis elegans.

Directory of Open Access Journals (Sweden)

Juan Carlos Fierro-González

2011-01-01

Full Text Available Thioredoxins comprise a conserved family of redox regulators involved in many biological processes, including stress resistance and aging. We report that the C. elegans thioredoxin TRX-1 acts in ASJ head sensory neurons as a novel modulator of the insulin-like neuropeptide DAF-28 during dauer formation. We show that increased formation of stress-resistant, long-lived dauer larvae in mutants for the gene encoding the insulin-like neuropeptide DAF-28 requires TRX-1 acting in ASJ neurons, upstream of the insulin-like receptor DAF-2. Genetic rescue experiments demonstrate that redox-independent functions of TRX-1 specifically in ASJ neurons are needed for the dauer formation constitutive (Daf-c phenotype of daf-28 mutants. GFP reporters of trx-1 and daf-28 show opposing expression patterns in dauers (i.e. trx-1 is up-regulated and daf-28 is down-regulated, an effect that is not observed in growing L2/L3 larvae. In addition, functional TRX-1 is required for the down-regulation of a GFP reporter of daf-28 during dauer formation, a process that is likely subject to DAF-28-mediated feedback regulation. Our findings demonstrate that TRX-1 modulates DAF-28 signaling by contributing to the down-regulation of daf-28 expression during dauer formation. We propose that TRX-1 acts as a fluctuating neuronal signaling modulator within ASJ neurons to monitor the adjustment of neuropeptide expression, including insulin-like proteins, during dauer formation in response to adverse environmental conditions.

Up-regulation of intestinal vascular endothelial growth factor by Afa/Dr diffusely adhering Escherichia coli.

Directory of Open Access Journals (Sweden)

Gaëlle Cane

Full Text Available BACKGROUND: Angiogenesis has been recently described as a novel component of inflammatory bowel disease pathogenesis. The level of vascular endothelial growth factor (VEGF has been found increased in Crohn's disease and ulcerative colitis mucosa. To question whether a pro-inflammatory Escherichia coli could regulate the expression of VEGF in human intestinal epithelial cells, we examine the response of cultured human colonic T84 cells to infection by E. coli strain C1845 that belongs to the typical Afa/Dr diffusely adhering E. coli family (Afa/Dr DAEC. METHODOLOGY: VEGF mRNA expression was examined by Northern blotting and q-PCR. VEGF protein levels were assayed by ELISA and its bioactivity was analysed in endothelial cells. The bacterial factor involved in VEGF induction was identified using recombinant E. coli expressing Dr adhesin, purified Dr adhesin and lipopolysaccharide. The signaling pathway activated for the up-regulation of VEGF was identified using a blocking monoclonal anti-DAF antibody, Western blot analysis and specific pharmacological inhibitors. PRINCIPAL FINDINGS: C1845 bacteria induce the production of VEGF protein which is bioactive. VEGF is induced by adhering C1845 in both a time- and bacteria concentration-dependent manner. This phenomenon is not cell line dependent since we reproduced this observation in intestinal LS174, Caco2/TC7 and INT407 cells. Up-regulation of VEGF production requires: (1 the interaction of the bacterial F1845 adhesin with the brush border-associated decay accelerating factor (DAF, CD55 acting as a bacterial receptor, and (2 the activation of a Src protein kinase upstream of the activation of the Erk and Akt signaling pathways. CONCLUSIONS: Results demonstrate that a Afa/Dr DAEC strain induces an adhesin-dependent activation of DAF signaling that leads to the up-regulation of bioactive VEGF in cultured human intestinal cells. Thus, these results suggest a link between an entero-adherent, pro

ins-7 Gene expression is partially regulated by the DAF-16/IIS signaling pathway in Caenorhabditis elegans under celecoxib intervention.

Directory of Open Access Journals (Sweden)

Shanqing Zheng

Full Text Available DAF-16 target genes are employed as reporters of the insulin/IGF-1 like signal pathway (IIS, and this is notably true when Caenorhabditis elegans (C. elegans is used to study the action of anti-aging compounds on IIS activity. However, some of these genes may not be specific to DAF-16, even if their expression levels are altered when DAF-16 is activated. Celecoxib was reported to extend the lifespan of C. elegans through activation of DAF-16. Our results confirmed the function of celecoxib on aging; however, we found that the expression of ins-7, a DAF-16 target gene, was abnormally regulated by celecoxib. ins-7 plays an important role in regulating aging, and its expression is suppressed in C. elegans when DAF-16 is activated. However, we found that celecoxib upregulated the expression of ins-7 in contrast to its role in DAF-16 activation. Our subsequent analysis indicated that the expression level of ins-7 in C. elegans was negatively regulated by DAF-16 activity. Additionally, its expression was also positively regulated by DAF-16-independent mechanisms, at least following external pharmacological intervention. Our study suggests that ins-7 is not a specific target gene of DAF-16, and should not be chosen as a reporter for IIS activity. This conclusion is important in the study of INSs on aging in C. elegans, especially under the circumstance of drug intervention.

ins-7 Gene expression is partially regulated by the DAF-16/IIS signaling pathway in Caenorhabditis elegans under celecoxib intervention.

Science.gov (United States)

Zheng, Shanqing; Liao, Sentai; Zou, Yuxiao; Qu, Zhi; Liu, Fan

2014-01-01

DAF-16 target genes are employed as reporters of the insulin/IGF-1 like signal pathway (IIS), and this is notably true when Caenorhabditis elegans (C. elegans) is used to study the action of anti-aging compounds on IIS activity. However, some of these genes may not be specific to DAF-16, even if their expression levels are altered when DAF-16 is activated. Celecoxib was reported to extend the lifespan of C. elegans through activation of DAF-16. Our results confirmed the function of celecoxib on aging; however, we found that the expression of ins-7, a DAF-16 target gene, was abnormally regulated by celecoxib. ins-7 plays an important role in regulating aging, and its expression is suppressed in C. elegans when DAF-16 is activated. However, we found that celecoxib upregulated the expression of ins-7 in contrast to its role in DAF-16 activation. Our subsequent analysis indicated that the expression level of ins-7 in C. elegans was negatively regulated by DAF-16 activity. Additionally, its expression was also positively regulated by DAF-16-independent mechanisms, at least following external pharmacological intervention. Our study suggests that ins-7 is not a specific target gene of DAF-16, and should not be chosen as a reporter for IIS activity. This conclusion is important in the study of INSs on aging in C. elegans, especially under the circumstance of drug intervention.

daf-16/FoxO promotes gluconeogenesis and trehalose synthesis during starvation to support survival.

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Hibshman, Jonathan D; Doan, Alexander E; Moore, Brad T; Kaplan, Rebecca Ew; Hung, Anthony; Webster, Amy K; Bhatt, Dhaval P; Chitrakar, Rojin; Hirschey, Matthew D; Baugh, L Ryan

2017-10-24

daf-16 /FoxO is required to survive starvation in Caenorhabditis elegans , but how daf-16I FoxO promotes starvation resistance is unclear. We show that daf-16 /FoxO restructures carbohydrate metabolism by driving carbon flux through the glyoxylate shunt and gluconeogenesis and into synthesis of trehalose, a disaccharide of glucose. Trehalose is a well-known stress protectant, capable of preserving membrane organization and protein structure during abiotic stress. Metabolomic, genetic, and pharmacological analyses confirm increased trehalose synthesis and further show that trehalose not only supports survival as a stress protectant but also serves as a glycolytic input. Furthermore, we provide evidence that metabolic cycling between trehalose and glucose is necessary for this dual function of trehalose. This work demonstrates that daf-16 /FoxO promotes starvation resistance by shifting carbon metabolism to drive trehalose synthesis, which in turn supports survival by providing an energy source and acting as a stress protectant.

daf-16/FoxO promotes gluconeogenesis and trehalose synthesis during starvation to support survival

Science.gov (United States)

Hibshman, Jonathan D; Doan, Alexander E; Moore, Brad T; Kaplan, Rebecca EW; Hung, Anthony; Webster, Amy K; Bhatt, Dhaval P; Chitrakar, Rojin; Hirschey, Matthew D

2017-01-01

daf-16/FoxO is required to survive starvation in Caenorhabditis elegans, but how daf-16IFoxO promotes starvation resistance is unclear. We show that daf-16/FoxO restructures carbohydrate metabolism by driving carbon flux through the glyoxylate shunt and gluconeogenesis and into synthesis of trehalose, a disaccharide of glucose. Trehalose is a well-known stress protectant, capable of preserving membrane organization and protein structure during abiotic stress. Metabolomic, genetic, and pharmacological analyses confirm increased trehalose synthesis and further show that trehalose not only supports survival as a stress protectant but also serves as a glycolytic input. Furthermore, we provide evidence that metabolic cycling between trehalose and glucose is necessary for this dual function of trehalose. This work demonstrates that daf-16/FoxO promotes starvation resistance by shifting carbon metabolism to drive trehalose synthesis, which in turn supports survival by providing an energy source and acting as a stress protectant. PMID:29063832

The solution structure of the forkhead box-O DNA binding domain of Brugia malayi DAF-16a.

Science.gov (United States)

Casper, Sarah K; Schoeller, Scott J; Zgoba, Danielle M; Phillips, Andrew J; Morien, Thomas J; Chaffee, Gary R; Sackett, Peter C; Peterson, Francis C; Crossgrove, Kirsten; Veldkamp, Christopher T

2014-12-01

Brugia malayi is a parasitic nematode that causes lymphatic filariasis in humans. Here the solution structure of the forkhead DNA binding domain of Brugia malayi DAF-16a, a putative ortholog of Caenorhabditis elegans DAF-16, is reported. It is believed to be the first structure of a forkhead or winged helix domain from an invertebrate. C. elegans DAF-16 is involved in the insulin/IGF-I signaling pathway and helps control metabolism, longevity, and development. Conservation of sequence and structure with human FOXO proteins suggests that B. malayi DAF-16a is a member of the FOXO family of forkhead proteins. © 2014 Wiley Periodicals, Inc.

Device Assembly Facility (DAF) Glovebox Radioactive Waste Characterization

International Nuclear Information System (INIS)

Dominick, J L

2001-01-01

The Device Assembly Facility (DAF) at the Nevada Test Site (NTS) provides programmatic support to the Joint Actinide Shock Physics Experimental Research (JASPER) Facility in the form of target assembly. The target assembly activities are performed in a glovebox at DAF and include Special Nuclear Material (SNM). Currently, only activities with transuranic SNM are anticipated. Preliminary discussions with facility personnel indicate that primarily two distributions of SNM will be used: Weapons Grade Plutonium (WG-Pu), and Pu-238 enhanced WG-Pu. Nominal radionuclide distributions for the two material types are included in attachment 1. Wastes generated inside glove boxes is expected to be Transuranic (TRU) Waste which will eventually be disposed of at the Waste Isolation Pilot Plant (WIPP). Wastes generated in the Radioactive Material Area (RMA), outside of the glove box is presumed to be low level waste (LLW) which is destined for disposal at the NTS. The process knowledge quantification methods identified herein may be applied to waste generated anywhere within or around the DAF and possibly JASPER as long as the fundamental waste stream boundaries are adhered to as outlined below. The method is suitable for quantification of waste which can be directly surveyed with the Blue Alpha meter or swiped. An additional quantification methodology which requires the use of a high resolution gamma spectroscopy unit is also included and relies on the predetermined radionuclide distribution and utilizes scaling to measured nuclides for quantification

The longevity effect of echinacoside in Caenorhabditis elegans mediated through daf-16.

Science.gov (United States)

Wang, Xue; Zhang, Jiaolong; Lu, Lulu; Zhou, Lijun

2015-01-01

Echinacoside (ECH), a natural polyphenolic compound, has been reported to possess important pharmacological activities. However, very little is known about whether or how ECH affects longevity in vivo. We have examined the effects of ECH on the life span and stress tolerance in Caenorhabditis elegans. Our studies demonstrate that the life span of wild-type worms could be extended in the presence of ECH. Furthermore, ECH was found to increase tolerance of worms to heat shock and oxidative stress, while not exerting any influence on pharyngeal pumping rate and progeny production. Our mechanistic studies indicate that supplementation of ECH increases the transcript level of daf-16. ECH treatment also modulates the nuclear localization and transcriptional activities of daf-16, thus fine tunes the expression of daf-16 target genes to promote longevity and increases stress response in C. elegans. Overall, this work reveals the longevity effect of ECH and elucidates the underpinning mechanisms.

Regulation of lead toxicity by heat shock protein 90 (daf-21) is affected by temperature in Caenorhabditis elegans.

Science.gov (United States)

Wang, Yunbiao; Xu, Songbai; Liu, Jing; Zhang, Yanhui; Guo, Tai L

2014-06-01

In the nematode Caenorhabditis elegans, stress resistance can be regulated by dauer formation (daf) genes. In the present study, regulation of heavy metal lead (Pb) toxicity by the 90-kDa heat shock proteins (Hsp90; daf-21) was investigated in both wild-type C. elegans and daf-21/Hsp90 mutants by focusing on the effects of varied temperatures below (15°C) or above (25 and 30°C) the presumptive optimum growth temperature (20°C). More acute toxicity of Pb, indicated by the 24-h median lethal concentrations (LC50), was observed in wild-type adults than in the daf-21 mutant adults at 15, 20 and 25°C; however, the daf-21 mutant adults showed more sensitivity at 30°C. Enhanced Pb sensitivity (e.g., decrease LC50) in both types of C. elegans was observed with both increased and decreased temperatures when compared to that at 20°C. Additional examined endpoints included time course of toxicity at LC50s, pharyngeal pumping, reproduction, life span, and Hsp90 expression. Collective results showed that temperatures both above and below 20°C exacerbated Pb toxicity, and that the protein level of daf-21/Hsp90 was one of the most sensitive indicators of Pb toxicity in wild-type C. elegans, while pharyngeal pumping was more Pb sensitive in daf-21 mutants. Therefore, the expression of daf-21/Hsp90 has apparent utility for the prediction and assessment of Pb-induced toxicity in nematodes. Further, the stress responses related to Hsp90 expression in C. elegans may have considerable potential as sensitive biomarkers for the monitoring of environmental Pb contamination. Copyright © 2014 Elsevier Inc. All rights reserved.

Structural study of (CdS/ZnSe)/BeTe superlattices for λ=1.55 μm intersubband transition

International Nuclear Information System (INIS)

Li, B.S.; Akimoto, R.; Akita, K.; Hasama, H.

2004-01-01

A (CdS/ZnSe)/BeTe superlattice (SL), based on wide band gap II-VI compounds, with a large band offset of 3.1 eV was grown on a GaAs (001) substrate using molecular-beam epitaxy and an intersubband transition (ISB-T) of 0.78 eV (λ=1.58 μm) with a full width at half maximum (FWHM) of 96 meV observed. We studied structural properties using high-resolution x-ray diffraction combined with dynamic simulation and found through the strain state in samples that a ZnSe/BeTe interface having a quaternary interface layer (ZnTe) 0.45 (BeSe) 0.55 is preferentially formed despite the promotion of one molecular layer (ML) ZnTe interface formation. Be-Se bonds thus replace the Zn-Te bond in the transition region. For the CdS/ZnSe interface, an approximately 1 ML Zn 0.75 Cd 0.25 S ternary layer accompanied by ∼1 ML Zn 0.85 Cd 0.15 Se forms at the transition region due to Cd diffusion. X-ray (002) ω/2θ scan curves for (CdS/ZnSe)/BeTe SLs show sharp, intense satellite peaks exceeding ten orders, indicating high structure quality. We obtained excellent agreement between experimental diffraction patterns and the calculated curve via dynamic simulation for (CdS/ZnSe)/BeTe SLs. The good fits allows us to identify structure parameters in (CdS/ZnSe)/BeTe SLs, which are consistent with results of high-resolution transmission electron microscopy measurement. Based on dynamic simulated results, we obtained a structure of (CdS/ZnSe)/Be 1-x Mg x Te (x=1.2%) with an average lattice constant a SL matching the GaAs substrate. An ISB-T located at wavelength λ=1.55 μm with a narrow FWHM of 90 meV was thus realized at room temperature

Increased deposition of C3b on red cells with low CR1 and CD55 in a malaria-endemic region of western Kenya: Implications for the development of severe anemia

Directory of Open Access Journals (Sweden)

Odera Michael M

2008-08-01

Full Text Available Abstract Background Severe anemia due to Plasmodium falciparum malaria is a major cause of mortality among young children in western Kenya. The factors that lead to the age-specific incidence of this anemia are unknown. Previous studies have shown an age-related expression of red cell complement regulatory proteins, which protect erythrocytes from autologous complement attack and destruction. Our primary objective was to determine whether in a malaria-endemic area red cells with low levels of complement regulatory proteins are at increased risk for complement (C3b deposition in vivo. Secondarily, we studied the relationship between red cell complement regulatory protein levels and hemoglobin levels. Methods Three hundred and forty-two life-long residents of a malaria-holoendemic region of western Kenya were enrolled in a cross-sectional study and stratified by age. We measured red cell C3b, CR1, CD55, and immune complex binding capacity by flow cytometry. Individuals who were positive for malaria were treated and blood was collected when they were free of parasitemia. Analysis of variance was used to identify independent variables associated with the %C3b-positive red cells and the hemoglobin level. Results Individuals between the ages of 6 and 36 months had the lowest red cell CR1, highest %C3b-positive red cells, and highest parasite density. Malaria prevalence also reached its peak within this age group. Among children ≤ 24 months of age the %C3b-positive red cells was usually higher in individuals who were treated for malaria than in uninfected individuals with similarly low red cell CR1 and CD55. The variables that most strongly influenced the %C3b-positive red cells were age, malaria status, and red cell CD55 level. Although it did not reach statistical significance, red cell CR1 was more important than red cell CD55 among individuals treated for malaria. The variables that most strongly influenced the hemoglobin level were age, the %C3b

Catalpol Modulates Lifespan via DAF-16/FOXO and SKN-1/Nrf2 Activation in Caenorhabditis elegans

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Hyun Won Seo

2015-01-01

Full Text Available Catalpol is an effective component of rehmannia root and known to possess various pharmacological properties. The present study was aimed at investigating the potential effects of catalpol on the lifespan and stress tolerance using C. elegans model system. Herein, catalpol showed potent lifespan extension of wild-type nematode under normal culture condition. In addition, survival rate of catalpol-fed nematodes was significantly elevated compared to untreated control under heat and oxidative stress but not under hyperosmolality conditions. We also found that elevated antioxidant enzyme activities and expressions of stress resistance proteins were attributed to catalpol-mediated increased stress tolerance of nematode. We further investigated whether catalpol’s longevity effect is related to aging-related factors including reproduction, food intake, and growth. Interestingly, catalpol exposure could attenuate pharyngeal pumping rate, indicating that catalpol may induce dietary restriction of nematode. Moreover, locomotory ability of aged nematode was significantly improved by catalpol treatment, while lipofuscin levels were attenuated, suggesting that catalpol may affect age-associated changes of nematode. Our mechanistic studies revealed that mek-1, daf-2, age-1, daf-16, and skn-1 are involved in catalpol-mediated longevity. These results indicate that catalpol extends lifespan and increases stress tolerance of C. elegans via DAF-16/FOXO and SKN-1/Nrf activation dependent on insulin/IGF signaling and JNK signaling.

Rifampicin reduces advanced glycation end products and activates DAF-16 to increase lifespan in Caenorhabditis elegans.

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Golegaonkar, Sandeep; Tabrez, Syed S; Pandit, Awadhesh; Sethurathinam, Shalini; Jagadeeshaprasad, Mashanipalya G; Bansode, Sneha; Sampathkumar, Srinivasa-Gopalan; Kulkarni, Mahesh J; Mukhopadhyay, Arnab

2015-06-01

Advanced glycation end products (AGEs) are formed when glucose reacts nonenzymatically with proteins; these modifications are implicated in aging and pathogenesis of many age-related diseases including type II diabetes, atherosclerosis, and neurodegenerative disorders. Thus, pharmaceutical interventions that can reduce AGEs may delay age-onset diseases and extend lifespan. Using LC-MS(E), we show that rifampicin (RIF) reduces glycation of important cellular proteins in vivo and consequently increases lifespan in Caenorhabditis elegans by up to 60%. RIF analog rifamycin SV (RSV) possesses similar properties, while rifaximin (RMN) lacks antiglycation activity and therefore fails to affect lifespan positively. The efficacy of RIF and RSV as potent antiglycating agents may be attributed to the presence of a p-dihydroxyl moiety that can potentially undergo spontaneous oxidation to yield highly reactive p-quinone structures, a feature absent in RMN. We also show that supplementing rifampicin late in adulthood is sufficient to increase lifespan. For its effect on longevity, rifampicin requires DAF-18 (nematode PTEN) as well as JNK-1 and activates DAF-16, the FOXO homolog. Interestingly, the drug treatment modulates transcription of a different subset of DAF-16 target genes, those not controlled by the conserved Insulin-IGF-1-like signaling pathway. RIF failed to increase the lifespan of daf-16 null mutant despite reducing glycation, showing thereby that DAF-16 may not directly affect AGE formation. Together, our data suggest that the dual ability to reduce glycation in vivo and activate prolongevity processes through DAF-16 makes RIF and RSV effective lifespan-extending interventions. © 2015 The Authors. Aging Cell published by the Anatomical Society and John Wiley & Sons Ltd.

Gαo and Gαq regulate the expression of daf-7, a TGFβ-like gene, in Caenorhabditis elegans.

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Edith M Myers

Full Text Available Caenorhabditis elegans enter an alternate developmental stage called dauer in unfavorable conditions such as starvation, overcrowding, or high temperature. Several evolutionarily conserved signaling pathways control dauer formation. DAF-7/TGFβ and serotonin, important ligands in these signaling pathways, affect not only dauer formation, but also the expression of one another. The heterotrimeric G proteins GOA-1 (Gα(o and EGL-30 (Gα(q mediate serotonin signaling as well as serotonin biosynthesis in C. elegans. It is not known whether GOA-1 or EGL-30 also affect dauer formation and/or daf-7 expression, which are both modulated in part by serotonin. The purpose of this study is to better understand the relationship between proteins important for neuronal signaling and developmental plasticity in both C. elegans and humans. Using promoter-GFP transgenic worms, it was determined that both goa-1 and egl-30 regulate daf-7 expression during larval development. In addition, the normal daf-7 response to high temperature or starvation was altered in goa-1 and egl-30 mutants. Despite the effect of goa-1 and egl-30 mutations on daf-7 expression in various environmental conditions, there was no effect of the mutations on dauer formation. This paper provides evidence that while goa-1 and egl-30 are important for normal daf-7 expression, mutations in these genes are not sufficient to disrupt dauer formation.

Activated AKT/PKB signaling in C. elegans uncouples temporally distinct outputs of DAF-2/insulin-like signaling

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Hanselman Keaton B

2006-10-01

Full Text Available Abstract Background In the nematode, Caenorhabditis elegans, a conserved insulin-like signaling pathway controls larval development, stress resistance and adult lifespan. AGE-1, a homolog of the p110 catalytic subunit of phosphoinositide 3-kinases (PI3K comprises the major known effector pathway downstream of the insulin receptor, DAF-2. Phospholipid products of AGE-1/PI3K activate AKT/PKB kinase signaling via PDK-1. AKT/PKB signaling antagonizes nuclear translocation of the DAF-16/FOXO transcription factor. Reduced AGE-1/PI3K signaling permits DAF-16 to direct dauer larval arrest and promote long lifespan in adult animals. In order to study the downstream effectors of AGE-1/PI3K signaling in C. elegans, we conducted a genetic screen for mutations that suppress the constitutive dauer arrest phenotype of age-1(mg109 animals. Results This report describes mutations recovered in a screen for suppressors of the constitutive dauer arrest (daf-C phenotype of age-1(mg109. Two mutations corresponded to alleles of daf-16. Two mutations were gain-of-function alleles in the genes, akt-1 and pdk-1, encoding phosphoinositide-dependent serine/threonine kinases. A fifth mutation, mg227, located on chromosome X, did not correspond to any known dauer genes, suggesting that mg227 may represent a new component of the insulin pathway. Genetic epistasis analysis by RNAi showed that reproductive development in age-1(mg109;akt-1(mg247 animals was dependent on the presence of pdk-1. Similarly, reproductive development in age-1(mg109;pdk-1(mg261 animals was dependent on akt-1. However, reproductive development in age-1(mg109; mg227 animals required only akt-1, and pdk-1 activity was dispensable in this background. Interestingly, while mg227 suppressed dauer arrest in age-1(mg109 animals, it enhanced the long lifespan phenotype. In contrast, akt-1(mg247 and pdk-1(mg261 did not affect lifespan or stress resistance, while both daf-16 alleles fully suppressed these

Activated AKT/PKB signaling in C. elegans uncouples temporally distinct outputs of DAF-2/insulin-like signaling.

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Gami, Minaxi S; Iser, Wendy B; Hanselman, Keaton B; Wolkow, Catherine A

2006-10-04

In the nematode, Caenorhabditis elegans, a conserved insulin-like signaling pathway controls larval development, stress resistance and adult lifespan. AGE-1, a homolog of the p110 catalytic subunit of phosphoinositide 3-kinases (PI3K) comprises the major known effector pathway downstream of the insulin receptor, DAF-2. Phospholipid products of AGE-1/PI3K activate AKT/PKB kinase signaling via PDK-1. AKT/PKB signaling antagonizes nuclear translocation of the DAF-16/FOXO transcription factor. Reduced AGE-1/PI3K signaling permits DAF-16 to direct dauer larval arrest and promote long lifespan in adult animals. In order to study the downstream effectors of AGE-1/PI3K signaling in C. elegans, we conducted a genetic screen for mutations that suppress the constitutive dauer arrest phenotype of age-1(mg109) animals. This report describes mutations recovered in a screen for suppressors of the constitutive dauer arrest (daf-C) phenotype of age-1(mg109). Two mutations corresponded to alleles of daf-16. Two mutations were gain-of-function alleles in the genes, akt-1 and pdk-1, encoding phosphoinositide-dependent serine/threonine kinases. A fifth mutation, mg227, located on chromosome X, did not correspond to any known dauer genes, suggesting that mg227 may represent a new component of the insulin pathway. Genetic epistasis analysis by RNAi showed that reproductive development in age-1(mg109);akt-1(mg247) animals was dependent on the presence of pdk-1. Similarly, reproductive development in age-1(mg109);pdk-1(mg261) animals was dependent on akt-1. However, reproductive development in age-1(mg109); mg227 animals required only akt-1, and pdk-1 activity was dispensable in this background. Interestingly, while mg227 suppressed dauer arrest in age-1(mg109) animals, it enhanced the long lifespan phenotype. In contrast, akt-1(mg247) and pdk-1(mg261) did not affect lifespan or stress resistance, while both daf-16 alleles fully suppressed these phenotypes. A screen for suppressors of PI3K

Context-dependent regulation of feeding behaviour by the insulin receptor, DAF-2, in Caenorhabditis elegans.

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Dillon, James; Holden-Dye, Lindy; O'Connor, Vincent; Hopper, Neil A

2016-06-01

Insulin signalling plays a significant role in both developmental programmes and pathways modulating the neuronal signalling that controls adult behaviour. Here, we have investigated insulin signalling in food-associated behaviour in adult C. elegans by scoring locomotion and feeding on and off bacteria, the worm's food. This analysis used mutants (daf-2, daf-18) of the insulin signalling pathway, and we provide evidence for an acute role for insulin signalling in the adult nervous system distinct from its impact on developmental programmes. Insulin receptor daf-2 mutants move slower than wild type both on and off food and showed impaired locomotory responses to food deprivation. This latter behaviour is manifest as a failure to instigate dispersal following prolonged food deprivation and suggests a role for insulin signalling in this adaptive response. Insulin receptor daf-2 mutants are also deficient in pharyngeal pumping on food and off food. Pharmacological analysis showed the pharynx of daf-2 is selectively compromised in its response to 5-HT compared to the excitatory neuropeptide FLP-17. By comparing the adaptive pharyngeal behaviour in intact worms and isolated pharyngeal preparations, we determined that an insulin-dependent signal extrinsic to the pharyngeal system is involved in feeding adaptation. Hence, we suggest that reactive insulin signalling modulates both locomotory foraging and pharyngeal pumping as the animal adapts to the absence of food. We discuss this in the context of insulin signalling directing a shift in the sensitivity of neurotransmitter systems to regulate the worm's response to changes in food availability in the environment.

Oleanolic acid activates daf-16 to increase lifespan in Caenorhabditis elegans.

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Zhang, Jiaolong; Lu, Lulu; Zhou, Lijun

2015-12-25

Oleanolic acid (OA) is an active ingredient in natural plants. It has been reported to possess a variety of pharmacological activities, but very little is known about its effects of anti-aging. We investigate here whether OA has an impact on longevity in vivo, and more specifically, we have examined effects of OA on the lifespan and stress tolerance in Caenorhabditis elegans (C. elegans). Our results showed that OA could extend the lifespan, increase its stress resistance and reduce the intracellular reactive oxygen species (ROS) in wild-type worms. Moreover, we have found that OA-induced longevity may not be associated with the calorie restriction (CR) mechanism. Our mechanistic studies using daf-16 loss-of-function mutant strains (GR1307) indicated that the extension of lifespan by OA requires daf-16. In addition, OA treatment could also modulate the nuclear localization, and the quantitative real-time PCR results revealed that up-regulation of daf-16 target genes such as sod-3, hsp-16.2 and ctl-1 could prolong lifespan and increase stress response in C. elegans. This study overall uncovers the longevity effect of OA and its underpinning mechanisms. Copyright © 2015 Elsevier Inc. All rights reserved.

Evaluation of Dissolved Air Flotation (DAF for Pretreatment of the Karoon River Water

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Naeim Banisaeid

2007-09-01

Full Text Available The efficiency of a pilot dissolved air flotation (DAF unit is evaluated. It is the objective of the present study to determine the removal efficiency of DAF in removing turbidity and organic matter from theKaroonRiverfeeding a water treatment plant. Water quality investigations over the study period revealed that, thanks to the self-purification process in the river, the Karoon water quality is acceptable with respect to total organic carbon (TOC (never exceeding 2.89 mg/l but its turbidity has great fluctuations (from as low as 42 to 1,000 NTU due to the nature of the river. Its true color is in desirable conditions. Suspended solids removal efficiency of the pilot DAF unit varied from 38% to 95%, with an average level of 72%. The results from this study indicate that DAF removal efficiency is inversely related to the volume of inflow of solids into the system so that increasing TSS decreases removal efficiency. The high turbidity level in the absence of a primary sedimentation unit causes the flotation system to lose its desired efficiency. FAD cannot be, therefore, recommended for water treatment plants fed by the Karoon water unless a pretreatment unit is used. Furthermore, as FAD's TOC removal efficiency varies by up to 82%, and since part of the organic content includes volatile organic matter causing odors and undesirable taste, FAD is recommended as a complementary process in the treatment of high quality water.

Characterization of PUD-1 and PUD-2, two proteins up-regulated in a long-lived daf-2 mutant.

Science.gov (United States)

Ding, Yue-He; Du, Yun-Guang; Luo, Shukun; Li, Yu-Xin; Li, Tie-Mei; Yoshina, Sawako; Wang, Xing; Klage, Karsten; Mitani, Shohei; Ye, Keqiong; Dong, Meng-Qiu

2013-01-01

C. elegans PUD-1 and PUD-2, two proteins up-regulated in daf-2(loss-of-function) (PUD), are homologous 17-kD proteins with a large abundance increase in long-lived daf-2 mutant animals of reduced insulin signaling. In this study, we show that both PUD-1 and PUD-2 are abundantly expressed in the intestine and hypodermis, and form a heterodimer. We have solved their crystal structure to 1.9-Å resolution and found that both proteins adopt similar β-sandwich folds in the V-shaped dimer. In contrast, their homologs PUD-3, PUD-4, PUDL-1 and PUDL-2 are all monomeric proteins with distinct expression patterns in C. elegans. Thus, the PUD-1/PUD-2 heterodimer probably has a function distinct from their family members. Neither overexpression nor deletion of pud-1 and pud-2 affected the lifespan of WT or daf-2 mutant animals, suggesting that their induction in daf-2 worms does not contribute to longevity. Curiously, deletion of pud-1 and pud-2 was associated with a protective effect against paralysis induced by the amyloid β-peptide (1-42), which further enhanced the protection conferred by daf-2(RNAi) against Aβ.

DAFS study of site-specific local structure of Mn in manganese ferrite films

International Nuclear Information System (INIS)

Kravtsov, E.; Haskel, D.; Cady, A.; Yang, A.; Vittoria, C.; Zuo, X.; Harris, V.G.

2006-01-01

Manganese ferrite (MnFe 2 O 4 ) is a well-known magnetic material widely used in electronics for many years. It is well established that its magnetic behavior is strongly influenced by local structural properties of Mn ions, which are distributed between crystallographically inequivalent tetrahedral and octahedral sites in the unit cell. In order to understand and be able to tune properties of these structures, it is necessary to have detailed site-specific structural information on the system. Here we report on the application of diffraction-anomalous fine structure (DAFS) spectroscopy to resolve site-specific Mn local structures in manganese ferrite films. The DAFS measurements were done at undulator beamline 4-ID-D of the Advanced Photon Source at Argonne National Laboratory. The DAFS spectra (Fig. 1) were measured at several Bragg reflections in the vicinity of the Mn absorption K-edge, having probed separately contributions from tetrahedrally and octahedrally coordinated Mn sites. The DAFS data analysis done with an iterative Kramers-Kroenig algorithm made it possible to solve separately the local structure around different inequivalent Mn sites in the unit cell. The reliability of the data treatment was checked carefully, and it was showed that the site-specific structural parameters obtained with DAFS allow us to describe fluorescence EXAFS spectrum measured independently. Fig. 2 shows individual site contributions to the imaginary part of the resonant scattering amplitude obtained from the treatment of the data of Fig. 1. The analysis of the refined site-specific absorption spectra was done using EXAFS methods based on theoretical standards. We provided direct evidence for the tetrahedral Mn-O bond distance being increased relative to the corresponding Fe-O distance in bulk manganese ferrites. The first coordination shell number was found to be reduced significantly for Mn atoms at these sites. This finding is consistent with the well-known tendency of Mn

LC-MS Proteomics Analysis of the Insulin/IGF-1 Deficient Caenorhabditis elegans daf-2(e1370) Mutant Reveals Extensive Restructuring of Intermediary Metabolism

Energy Technology Data Exchange (ETDEWEB)

Depuydt, Geert G.; Xie, Fang; Petyuk, Vladislav A.; Smolders, Arne; Brewer, Heather M.; Camp, David G.; Smith, Richard D.; Braeckman, Bart P.

2014-02-20

The insulin/IGF-1 receptor is a major known determinant of dauer formation, stress resistance, longevity and metabolism in C. elegans. In the past, whole-genome transcript profiling was used extensively to study differential gene expression in response to reduced insulin/IGF-1 signaling, including expression levels of metabolism-associated genes. Taking advantage of the recent developments in quantitative liquid chromatography mass-spectrometry (LC-MS) based proteomics, we profiled the proteomic changes that occur in response to activation of the DAF-16 transcription factor in the germline-less glp-4(bn2); daf-2(e1370) receptor mutant. Strikingly, the daf-2 profile suggests extensive reorganization of intermediary metabolism, characterized by the up-regulation of many core intermediary metabolic pathways. These include, glycolysis/gluconeogenesis, glycogenesis, pentose phosphate cycle, citric acid cycle, glyoxylate shunt, fatty acid β-oxidation, one-carbon metabolism, propionate and tyrosine catabolism, and complex I, II, III and V of the electron transport chain. Interestingly, we found simultaneous activation of reciprocally regulated metabolic pathways, which is indicative for spatio-temporal coordination of energy metabolism and/or extensive post-translational regulation of these enzymes. This restructuring of daf-2 metabolism is reminiscent to that of hypometabolic dauers, allowing the efficient and economical utilization of internal nutrient reserves, possibly also shunting metabolites through alternative energy-generating pathways, in order to sustain longevity.

LC–MS Proteomics Analysis of the Insulin/IGF-1-Deficient Caenorhabditis elegans daf-2(e1370) Mutant Reveals Extensive Restructuring of Intermediary Metabolism

Science.gov (United States)

2015-01-01

The insulin/IGF-1 receptor is a major known determinant of dauer formation, stress resistance, longevity, and metabolism in Caenorhabditis elegans. In the past, whole-genome transcript profiling was used extensively to study differential gene expression in response to reduced insulin/IGF-1 signaling, including the expression levels of metabolism-associated genes. Taking advantage of the recent developments in quantitative liquid chromatography mass spectrometry (LC–MS)-based proteomics, we profiled the proteomic changes that occur in response to activation of the DAF-16 transcription factor in the germline-less glp-4(bn2);daf-2(e1370) receptor mutant. Strikingly, the daf-2 profile suggests extensive reorganization of intermediary metabolism, characterized by the upregulation of many core intermediary metabolic pathways. These include glycolysis/gluconeogenesis, glycogenesis, pentose phosphate cycle, citric acid cycle, glyoxylate shunt, fatty acid β-oxidation, one-carbon metabolism, propionate and tyrosine catabolism, and complexes I, II, III, and V of the electron transport chain. Interestingly, we found simultaneous activation of reciprocally regulated metabolic pathways, which is indicative of spatiotemporal coordination of energy metabolism and/or extensive post-translational regulation of these enzymes. This restructuring of daf-2 metabolism is reminiscent to that of hypometabolic dauers, allowing the efficient and economical utilization of internal nutrient reserves and possibly also shunting metabolites through alternative energy-generating pathways to sustain longevity. PMID:24555535

DAF-2/insulin-like signaling in C. elegans modifies effects of dietary restriction and nutrient stress on aging, stress and growth.

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Wendy B Iser

2007-11-01

Full Text Available Dietary restriction (DR and reduced insulin/IGF-I-like signaling (IIS are two regimens that promote longevity in a variety of organisms. Genetic analysis in C. elegans nematodes has shown that DR and IIS couple to distinct cellular signaling pathways. However, it is not known whether these pathways ultimately converge on overlapping or distinct targets to extend lifespan.We investigated this question by examining additional effects of DR in wildtype animals and in daf-2 mutants with either moderate or severe IIS deficits. Surprisingly, DR and IIS had opposing effects on these physiological processes. First, DR induced a stress-related change in intestinal vesicle trafficking, termed the FIRE response, which was suppressed in daf-2 mutants. Second, DR did not strongly affect expression of a daf-2- and stress-responsive transcriptional reporter. Finally, DR-related growth impairment was suppressed in daf-2 mutants.These findings reveal that an important biological function of DAF-2/IIS is to enhance growth and survival under nutrient-limited conditions. However, we also discovered that levels of DAF-2 pathway activity modified the effects of DR on longevity. Thus, while DR and IIS clearly affect lifespan through independent targets, there may also be some prolongevity targets that are convergently regulated by these pathways.

DAF-2/insulin-like signaling in C. elegans modifies effects of dietary restriction and nutrient stress on aging, stress and growth.

Science.gov (United States)

Iser, Wendy B; Wolkow, Catherine A

2007-11-28

Dietary restriction (DR) and reduced insulin/IGF-I-like signaling (IIS) are two regimens that promote longevity in a variety of organisms. Genetic analysis in C. elegans nematodes has shown that DR and IIS couple to distinct cellular signaling pathways. However, it is not known whether these pathways ultimately converge on overlapping or distinct targets to extend lifespan. We investigated this question by examining additional effects of DR in wildtype animals and in daf-2 mutants with either moderate or severe IIS deficits. Surprisingly, DR and IIS had opposing effects on these physiological processes. First, DR induced a stress-related change in intestinal vesicle trafficking, termed the FIRE response, which was suppressed in daf-2 mutants. Second, DR did not strongly affect expression of a daf-2- and stress-responsive transcriptional reporter. Finally, DR-related growth impairment was suppressed in daf-2 mutants. These findings reveal that an important biological function of DAF-2/IIS is to enhance growth and survival under nutrient-limited conditions. However, we also discovered that levels of DAF-2 pathway activity modified the effects of DR on longevity. Thus, while DR and IIS clearly affect lifespan through independent targets, there may also be some prolongevity targets that are convergently regulated by these pathways.

Doxycyclin ameliorates a starvation-induced germline tumor in C. elegans daf-18/PTEN mutant background.

Science.gov (United States)

Wolf, Tim; Qi, Wenjing; Schindler, Verena; Runkel, Eva Diana; Baumeister, Ralf

2014-08-01

Managing available resources is a key necessity of each organism to cope with the environment. The nematode C. elegans responds to nutritional deprivation or harsh environmental conditions with a multitude of developmental adaptations, among them a starvation-induced quiescence at early larval development (L1). daf-18, the C. elegans homolog of the human tumor suppressor gene PTEN, is essential for the maintenance of survival and germline stem cell arrest during the L1 diapause. We show here that daf-18 mutants, independently to their failure to maintain G2 arrest of the primordial germ cells, develop a gonad phenotype after refeeding. This highly penetrant gonadal phenotype is further enhanced by a mutation in shc-1, encoding a protein homologous to the human adaptor ShcA. Features of this phenotype are a tumor-like phenotype encompassing hyper-proliferation of germ cell nuclei and disruption/invasion of the basement membrane surrounding the gonad. The penetrance of this phenotype is reduced by decreasing starvation temperature. In addition, it is also ameliorated in a dose-dependent way by exposure to the antibiotic doxycyclin either during starvation or during subsequent refeeding. Since, in eukaryotic cells, doxycyclin specifically blocks mitochondrial translation, our results suggest that daf-18 and shc-1;daf-18 mutants fail to adapt mitochondrial activity to reduced nutritional availability during early larval developing. Copyright © 2014 Elsevier Inc. All rights reserved.

Monascin from Monascus-Fermented Products Reduces Oxidative Stress and Amyloid-β Toxicity via DAF-16/FOXO in Caenorhabditis elegans.

Science.gov (United States)

Shi, Yeu-Ching; Pan, Tzu-Ming; Liao, Vivian Hsiu-Chuan

2016-09-28

Amyloid-β (Aβ)-induced oxidative stress and toxicity are leading risk factors for Alzheimer's disease (AD). Monascin (MS) is a novel compound proposed for antioxidative stress applications and is derived from an edible fungus secondary metabolite. This study assessed the effects of MS on oxidative stress, paralysis, Aβ accumulation, and lifespan in the nematode Caenorhabditis elegans and investigated its underlying mechanisms of action. The results showed that MS increased the survival of C. elegans under juglone-induced oxidative stress and attenuated endogenous levels of reactive oxygen species. Furthermore, MS induced a decline in Aβ-induced paralysis phenotype and Aβ deposits in the transgenic strains CL4176 and CL2006 of C. elegans, which expresses human muscle-specific Aβ1-42 in the cytoplasm of body wall muscle cells. In addition, mRNA levels of strain CL4176 of several antioxidant genes (sod-1, sod-2, sod-3, hsp16.2) and daf-16 were up-regulated by MS treatment when compared to the nontreated controls. Further evidence showed that MS treatment in C. elegans strains lacking DAF-16/FOXO did not affect paralysis or lifespan phenotypes. The findings indicate that MS reduces oxidative stress and Aβ toxicity via DAF-16 in C. elegans, suggesting that MS can be used for the prevention of AD-associated oxidative stress complications.

Waste management in the meat processing industry: Conversion of paunch and DAF sludge into solid fuel.

Science.gov (United States)

Hamawand, Ihsan; Pittaway, Pam; Lewis, Larry; Chakrabarty, Sayan; Caldwell, Justin; Eberhard, Jochen; Chakraborty, Arpita

2017-02-01

This article addresses the novel dewatering process of immersion-frying of paunch and dissolved air flotation (DAF) sludge to produce high energy pellets. Literature have been analysed to address the feasibility of replacing conventional boiler fuel at meat processing facilities with high energy paunch-DAF sludge pellets (capsules). The value proposition of pelleting and frying this mixture into energy pellets is based on a Cost-Benefit Analysis (CBA). The CBA is based on information derived from the literature and consultation with the Australian Meat Processing Industry. The calorific properties of a mixture of paunch cake solids and DAF sludge were predicted from literature and industry consultation to validate the product. This study shows that the concept of pelletizing and frying paunch is economically feasible. The complete frying and dewatering of the paunch and DAF sludge mixture produces pellets with energy content per kilogram equivalent to coal. The estimated cost of this new product is half the price of coal and the payback period is estimated to be between 1.8 and 3.2years. Further research is required for proof of concept, and to identify the technical challenges associated with integrating this technology into existing meat processing plants. Crown Copyright © 2016. Published by Elsevier Ltd. All rights reserved.

LC–MS Proteomics Analysis of the Insulin/IGF-1-Deficient Caenorhabditis elegans daf-2(e1370) Mutant Reveals Extensive Restructuring of Intermediary Metabolism

Energy Technology Data Exchange (ETDEWEB)

Depuydt, Geert; Xie, Fang; Petyuk, Vladislav A.; Smolders, Arne; Brewer, Heather M.; Camp, David G.; Smith, Richard D.; Braeckman, Bart P.

2014-04-04

The insulin/IGF-1 receptor is a major known determinant of dauer formation, stress resistance, longevity, and metabolism in Caenorhabditis elegans. In the past, whole-genome transcript profiling was used extensively to study differential gene expression in response to reduced insulin/IGF-1 signaling, including the expression levels of metabolism-associated genes. Taking advantage of the recent developments in quantitative liquid chromatography mass spectrometry (LC–MS)-based proteomics, we profiled the proteomic changes that occur in response to activation of the DAF-16 transcription factor in the germline-less glp-4(bn2);daf-2(e1370) receptor mutant. Strikingly, the daf-2 profile suggests extensive reorganization of intermediary metabolism, characterized by the upregulation of many core intermediary metabolic pathways. These include glycolysis/gluconeogenesis, glycogenesis, pentose phosphate cycle, citric acid cycle, glyoxylate shunt, fatty acid β-oxidation, one-carbon metabolism, propionate and tyrosine catabolism, and complexes I, II, III, and V of the electron transport chain. Interestingly, we found simultaneous activation of reciprocally regulated metabolic pathways, which is indicative of spatiotemporal coordination of energy metabolism and/or extensive post-translational regulation of these enzymes. Finally, this restructuring of daf-2 metabolism is reminiscent to that of hypometabolic dauers, allowing the efficient and economical utilization of internal nutrient reserves and possibly also shunting metabolites through alternative energy-generating pathways to sustain longevity.

DAFS study of local structure of ordered nanodomains in PbMg1/3Nb2/3O3

International Nuclear Information System (INIS)

Frenkel, A.I.; Robinson, I.K.; Robinson, I.K.; Adler, D.L.; Cross, J.O.

1998-01-01

We have performed a Diffraction Anomalous Fine Structure (DAFS) study of a single crystal of the relaxor ferroelectric PbMg 1/3 Nb 2/3 O 3 . DAFS measurements were performed at the Nb K edge on a half-order Bragg reflection originating from the 1:1 ordered nanodomains. DAFS data analysis provided us with the local structure around Nb atoms in the ordered nanodomains. The Nb-O distance in the ordered region was determined to be 0.052(10) Angstrom shorter than half the lattice parameter of the bulk crystal, in good agreement with one model of the ferroelectric phase transition broadening [JETP 84, 994 (1997)]. copyright 1998 American Institute of Physics

DESIGN OF A DISSOLVED AIR FLOAT (DAF) IN THE TREATMENT OF WASTE WATER A TEXTILE

OpenAIRE

Salas Colotta, G.

2014-01-01

We presented the design of a dissolved air flotation system (DAF) to separate coagulated solids (dye) in the wastewater of a textile plant. The obtained yields of removal of suspended solids (SS) they are 82%. The size of the float to treat 35 m3/h of residual water of a textile is 5,7 m. Se presenta el diseño de un flotador por aire disuelto (DAF) para separar sólidos coagulados y floculados (tinte) provenientes de los efluentes de una planta textil. Los rendimientos obtenidos de remoción...

Muscle-Specific Histone H3K36 Dimethyltransferase SET-18 Shortens Lifespan of Caenorhabditis elegans by Repressing daf-16a Expression

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Liangping Su

2018-03-01

Full Text Available Mounting evidence shows that histone methylation, a typical epigenetic mark, is crucial for gene expression regulation during aging. Decreased trimethylation of Lys 36 on histone H3 (H3K36me3 in worms and yeast is reported to shorten lifespan. The function of H3K36me2 in aging remains unclear. In this study, we identified Caenorhabditis elegans SET-18 as a histone H3K36 dimethyltransferase. SET-18 deletion extended lifespan and increased oxidative stress resistance, dependent on daf-16 activity in the insulin/IGF pathway. In set-18 mutants, transcription of daf-16 isoform a (daf-16a was specifically upregulated. Accordingly, a decrease in H3K36me2 on daf-16a promoter was observed. Muscle-specific expression of SET-18 increased in aged worms (day 7 and day 11, attributable to elevation of global H3K36me2 and inhibition of daf-16a expression. Consequently, longevity was shortened. These findings suggested that chromatic repression mediated by tissue-specific H3K36 dimethyltransferase might be detrimental to lifespan and may have implications in human age-related diseases.

Caenorhabditis elegans DAF-2 as a Model for Human Insulin Receptoropathies

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David A. Bulger

2017-01-01

Full Text Available Human exome sequencing has dramatically increased the rate of identification of disease-associated polymorphisms. However, examining the functional consequences of those variants has created an analytic bottleneck. Insulin-like signaling in Caenorhabditis elegans has long provided a model to assess consequences of human insulin signaling mutations, but this has not been evaluated in the context of current genetic tools. We have exploited strains derived from the Million Mutation Project (MMP and gene editing to explore further the evolutionary relationships and conservation between the human and C. elegans insulin receptors. Of 40 MMP alleles analyzed in the C. elegans insulin-like receptor gene DAF-2, 35 exhibited insulin-like signaling indistinguishable from wild-type animals, indicating tolerated mutations. Five MMP alleles proved to be novel dauer-enhancing mutations, including one new allele in the previously uncharacterized C-terminus of DAF-2. CRISPR-Cas9 genome editing was used to confirm the phenotypic consequence of six of these DAF-2 mutations and to replicate an allelic series of known human disease mutations in a highly conserved tyrosine kinase active site residue, demonstrating the utility of C. elegans for directly modeling human disease. Our results illustrate the challenges associated with prediction of the phenotypic consequences of amino acid substitutions, the value of assaying mutant isoform function in vivo, and how recently developed tools and resources afford the opportunity to expand our understanding even of highly conserved regulatory modules such as insulin signaling. This approach may prove generally useful for modeling phenotypic consequences of candidate human pathogenic mutations in conserved signaling and developmental pathways.

Isoamyl alcohol odor promotes longevity and stress tolerance via DAF-16 in Caenorhabditis elegans.

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Kurino, Chiho; Furuhashi, Tsubasa; Sudoh, Kaori; Sakamoto, Kazuichi

2017-04-01

The possibility that odor plays a role in lifespan regulation through effects on the nervous system is indicated by research on Caenorhabditis elegans. In fact, ablation of AWA and AWC, which are suggested as olfactory neurons, has been shown to extend lifespan via DAF-16, a homolog of FoxO. However, the effects of odor stimuli on the lifespan still remain unclear. Thus, we here aimed to clarify the effect of attractive and repulsive odors on longevity and stress tolerance in C. elegans and to analyze the pathways thereof. We used isoamyl alcohol as an attractive odor, and acetic acid as a repellent component, as identified by chemotaxis assay. We found that isoamyl alcohol stimulus promoted longevity in a DAF-16-dependent manner. On the other hand, acetic acid stimulus promoted thermotolerance through mechanisms independent of DAF-16. Above all, our results indicate that odor stimuli affect the lifespan and stress tolerance of C. elegans, with attractive and repulsive odors exerting their effects through different mechanisms, and that longevity is induced by both activation and inactivation of olfactory neurons. Copyright © 2017 Elsevier Inc. All rights reserved.

Two potential hookworm DAF-16 target genes, SNR-3 and LPP-1: gene structure, expression profile, and implications of a cis-regulatory element in the regulation of gene expression.

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Gao, Xin; Goggin, Kevin; Dowling, Camille; Qian, Jason; Hawdon, John M

2015-01-08

Hookworms infect nearly 700 million people, causing anemia and developmental stunting in heavy infections. Little is known about the genomic structure or gene regulation in hookworms, although recent publication of draft genome assemblies has allowed the first investigations of these topics to be undertaken. The transcription factor DAF-16 mediates multiple developmental pathways in the free living nematode Caenorhabditis elegans, and is involved in the recovery from the developmentally arrested L3 in hookworms. Identification of downstream targets of DAF-16 will provide a better understanding of the molecular mechanism of hookworm infection. Genomic Fragment 2.23 containing a DAF-16 binding element (DBE) was used to identify overlapping complementary expressed sequence tags (ESTs). These sequences were used to search a draft assembly of the Ancylostoma caninum genome, and identified two neighboring genes, snr-3 and lpp-1, in a tail-to-tail orientation. Expression patterns of both genes during parasitic development were determined by qRT-PCR. DAF-16 dependent cis-regulatory activity of fragment 2.23 was investigated using an in vitro reporter system. The snr-3 gene spans approximately 5.6 kb in the genome and contains 3 exons and 2 introns, and contains the DBE in its 3' untranslated region. Downstream from snr-3 in a tail-to-tail arrangement is the gene lpp-1. The lpp-1 gene spans more than 6 kb and contains 10 exons and 9 introns. The A. caninum genome contains 2 apparent splice variants, but there are 7 splice variants in the A. ceylanicum genome. While the gene order is similar, the gene structures of the hookworm genes differ from their C. elegans orthologs. Both genes show peak expression in the late L4 stage. Using a cell culture based expression system, fragment 2.23 was found to have both DAF-16-dependent promoter and enhancer activity that required an intact DBE. Two putative DAF-16 targets were identified by genome wide screening for DAF-16 binding

DAF-16 and TCER-1 Facilitate Adaptation to Germline Loss by Restoring Lipid Homeostasis and Repressing Reproductive Physiology in C. elegans

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Amrit, Francis Raj Gandhi; Steenkiste, Elizabeth Marie; Ratnappan, Ramesh; Chen, Shaw-Wen; McClendon, T. Brooke; Kostka, Dennis; Yanowitz, Judith; Olsen, Carissa Perez; Ghazi, Arjumand

2016-01-01

Elimination of the proliferating germline extends lifespan in C. elegans. This phenomenon provides a unique platform to understand how complex metazoans retain metabolic homeostasis when challenged with major physiological perturbations. Here, we demonstrate that two conserved transcription regulators essential for the longevity of germline-less adults, DAF-16/FOXO3A and TCER-1/TCERG1, concurrently enhance the expression of multiple genes involved in lipid synthesis and breakdown, and that both gene classes promote longevity. Lipidomic analyses revealed that key lipogenic processes, including de novo fatty acid synthesis, triglyceride production, desaturation and elongation, are augmented upon germline removal. Our data suggest that lipid anabolic and catabolic pathways are coordinately augmented in response to germline loss, and this metabolic shift helps preserve lipid homeostasis. DAF-16 and TCER-1 also perform essential inhibitory functions in germline-ablated animals. TCER-1 inhibits the somatic gene-expression program that facilitates reproduction and represses anti-longevity genes, whereas DAF-16 impedes ribosome biogenesis. Additionally, we discovered that TCER-1 is critical for optimal fertility in normal adults, suggesting that the protein acts as a switch supporting reproductive fitness or longevity depending on the presence or absence of the germline. Collectively, our data offer insights into how organisms adapt to changes in reproductive status, by utilizing the activating and repressive functions of transcription factors and coordinating fat production and degradation. PMID:26862916

Muscle-Specific Histone H3K36 Dimethyltransferase SET-18 Shortens Lifespan of Caenorhabditis elegans by Repressing daf-16a Expression.

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Su, Liangping; Li, Hongyuan; Huang, Cheng; Zhao, Tingting; Zhang, Yongjun; Ba, Xueqing; Li, Zhongwei; Zhang, Yu; Huang, Baiqu; Lu, Jun; Zhao, Yanmei; Li, Xiaoxue

2018-03-06

Mounting evidence shows that histone methylation, a typical epigenetic mark, is crucial for gene expression regulation during aging. Decreased trimethylation of Lys 36 on histone H3 (H3K36me3) in worms and yeast is reported to shorten lifespan. The function of H3K36me2 in aging remains unclear. In this study, we identified Caenorhabditis elegans SET-18 as a histone H3K36 dimethyltransferase. SET-18 deletion extended lifespan and increased oxidative stress resistance, dependent on daf-16 activity in the insulin/IGF pathway. In set-18 mutants, transcription of daf-16 isoform a (daf-16a) was specifically upregulated. Accordingly, a decrease in H3K36me2 on daf-16a promoter was observed. Muscle-specific expression of SET-18 increased in aged worms (day 7 and day 11), attributable to elevation of global H3K36me2 and inhibition of daf-16a expression. Consequently, longevity was shortened. These findings suggested that chromatic repression mediated by tissue-specific H3K36 dimethyltransferase might be detrimental to lifespan and may have implications in human age-related diseases. Copyright © 2018 The Author(s). Published by Elsevier Inc. All rights reserved.

Emodin extends lifespan of Caenorhabditis elegans through insulin/IGF-1 signaling pathway depending on DAF-16 and SIR-2.1.

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Zhao, Xuan; Lu, Lulu; Qi, Yonghao; Li, Miao; Zhou, Lijun

2017-10-01

The naturally occurring anthraquinone emodin has been serving primarily as an anti-bacterial and anti-inflammatory agent. However, little is known about its potential on anti-aging. This investigation examined the effect of emodin on lifespan and focused on its physiological molecular mechanisms in vivo. Using Caenorhabditis elegans (C. elegans) as an animal model, we found emodin could extend lifespan of worms and improve their antioxidant capacity. Our mechanistic studies revealed that emodin might function via insulin/IGF-1 signaling (IIS) pathway involving, specifically the core transcription factor DAF-16. Quantitative RT-PCR results illustrated that emodin up-regulated transcription of DAF-16 target genes which express antioxidants to promote antioxidant capacity and lifespan of worms. In addition, attenuated effect in sir-2.1 mutants suggests that emodin likely functioned in a SIR-2.1-dependent manner. Our study uncovers a novel role of emodin in prolonging lifespan and supports the understanding of emodin being a beneficial dietary supplement.

Caenorhabditis elegans DAF-2 as a Model for Human Insulin Receptoropathies.

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Bulger, David A; Fukushige, Tetsunari; Yun, Sijung; Semple, Robert K; Hanover, John A; Krause, Michael W

2017-01-05

Human exome sequencing has dramatically increased the rate of identification of disease-associated polymorphisms. However, examining the functional consequences of those variants has created an analytic bottleneck. Insulin-like signaling in Caenorhabditis elegans has long provided a model to assess consequences of human insulin signaling mutations, but this has not been evaluated in the context of current genetic tools. We have exploited strains derived from the Million Mutation Project (MMP) and gene editing to explore further the evolutionary relationships and conservation between the human and C. elegans insulin receptors. Of 40 MMP alleles analyzed in the C. elegans insulin-like receptor gene DAF-2, 35 exhibited insulin-like signaling indistinguishable from wild-type animals, indicating tolerated mutations. Five MMP alleles proved to be novel dauer-enhancing mutations, including one new allele in the previously uncharacterized C-terminus of DAF-2 CRISPR-Cas9 genome editing was used to confirm the phenotypic consequence of six of these DAF-2 mutations and to replicate an allelic series of known human disease mutations in a highly conserved tyrosine kinase active site residue, demonstrating the utility of C. elegans for directly modeling human disease. Our results illustrate the challenges associated with prediction of the phenotypic consequences of amino acid substitutions, the value of assaying mutant isoform function in vivo, and how recently developed tools and resources afford the opportunity to expand our understanding even of highly conserved regulatory modules such as insulin signaling. This approach may prove generally useful for modeling phenotypic consequences of candidate human pathogenic mutations in conserved signaling and developmental pathways. Copyright © 2017 Bulger et al.

Characterization of phosphates and phosphogypsum by x-ray fluorescence with radioisotopic excitation sources of 55 Fe, 238 Pu and 109 Cd

International Nuclear Information System (INIS)

Parreira, Paulo S.; Nascimento Filho, Virgilio F.

1999-01-01

Using the energy dispersive X-ray fluorescence technique (ED-XRF), with radioisotopic sources of 55 Fe, 238 Pu e 109 Cd samples excitation, a qualitative study was carried out in a phosphogypsum and phosphate samples from different origin. The objective was to verify the excitation responses from different sources and to establish the analytical conditions of the technique for these kind of matrices. Besides the P and Ca, characteristic macro elements of this of matrix, it was also observed the elements Si, S, K, matrix, it was also observed the elements Si, S, K, Ti, Cr, Mn, Cu, Zn, Pb, Sr, Y, Zr and Nb. With different sources could be observed different groups of elements, since the emission response of the characteristic X-rays are associated to the excitation energy, in other words to the radioactive source. From the nutrients of major interest in this kind of matrix (P, S and Ca), the P and S elements showed small analytical sensibilities to the 109 Cd source. Greater intensities of characteristics X-ray emissions for the mainly elements of interest, was observed with the 55 Fe source and with the 238 Pu and 109 Cd sources analysis could be done showing trace elements which are present in those sort of samples. (author)

A Tandem Repeat in Decay Accelerating Factor 1 Is Associated with Severity of Murine Mercury-Induced Autoimmunity

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David M. Cauvi

2014-01-01

Full Text Available Decay accelerating factor (DAF, a complement-regulatory protein, protects cells from bystander complement-mediated lysis and negatively regulates T cells. Reduced expression of DAF occurs in several systemic autoimmune diseases including systemic lupus erythematosus, and DAF deficiency exacerbates disease in several autoimmune models, including murine mercury-induced autoimmunity (mHgIA. Daf1, located within Hmr1, a chromosome 1 locus associated in DBA/2 mice with resistance to mHgIA, could be a candidate. Here we show that reduced Daf1 transcription in lupus-prone mice was not associated with a reduction in the Daf1 transcription factor SP1. Studies of NZB mice congenic for the mHgIA-resistant DBA/2 Hmr1 locus suggested that Daf1 expression was controlled by the host genome and not the Hmr1 locus. A unique pentanucleotide repeat variant in the second intron of Daf1 in DBA/2 mice was identified and shown in F2 intercrosses to be associated with less severe disease; however, analysis of Hmr1 congenics indicated that this most likely reflected the presence of autoimmunity-predisposing genetic variants within the Hmr1 locus or that Daf1 expression is mediated by the tandem repeat in epistasis with other genetic variants present in autoimmune-prone mice. These studies argue that the effect of DAF on autoimmunity is complex and may require multiple genetic elements.

Involvement of nuclear factor κB in platelet CD40 signaling

International Nuclear Information System (INIS)

Hachem, Ahmed; Yacoub, Daniel; Zaid, Younes; Mourad, Walid; Merhi, Yahye

2012-01-01

Highlights: ► sCD40L induces TRAF2 association to CD40 and NF-κB activation in platelets. ► IκBα phosphorylation downstream of CD40L/CD40 signaling is independent of p38 MAPK phosphorylation. ► IκBα is required for sCD40L-induced platelet activation and potentiation of aggregation. -- Abstract: CD40 ligand (CD40L) is a thrombo-inflammatory molecule that predicts cardiovascular events. Platelets constitute the major source of soluble CD40L (sCD40L), which has been shown to potentiate platelet activation and aggregation, in a CD40-dependent manner, via p38 mitogen activated protein kinase (MAPK) and Rac1 signaling. In many cells, the CD40L/CD40 dyad also induces activation of nuclear factor kappa B (NF-κB). Given that platelets contain NF-κB, we hypothesized that it may be involved in platelet CD40 signaling and function. In human platelets, sCD40L induces association of CD40 with its adaptor protein the tumor necrosis factor receptor associated factor 2 and triggers phosphorylation of IκBα, which are abolished by CD40L blockade. Inhibition of IκBα phosphorylation reverses sCD40L-induced IκBα phosphorylation without affecting p38 MAPK phosphorylation. On the other hand, inhibition of p38 MAPK phosphorylation has no effect on IκBα phosphorylation, indicating a divergence in the signaling pathway originating from CD40 upon its ligation. In functional studies, inhibition of IκBα phosphorylation reverses sCD40L-induced platelet activation and potentiation of platelet aggregation in response to a sub-threshold concentration of collagen. This study demonstrates that the sCD40L/CD40 axis triggers NF-κB activation in platelets. This signaling pathway plays a critical role in platelet activation and aggregation upon sCD40L stimulation and may represent an important target against thrombo-inflammatory disorders.

Cloning and characterization of cDNAs encoding the complete sequence of decay-accelerating factor of human complement

International Nuclear Information System (INIS)

Medof, M.E.; Lublin, D.M.; Holers, V.M.; Ayers, D.J.; Getty, R.R.; Leykam, J.F.; Atkinson, J.P.; Tykocinski, M.L.

1987-01-01

cDNAs encoding the complement decay-accelerating factor (DAF) were isolated from HeLa and differentiated HL-60 λgt cDNA libraries by screening with a codon preference oligonucleotide corresponding to DAF NH 2 -terminal amino acids 3-14. The composite cDNA sequence showed a 347-amino acid protein preceded by an NH 2 -terminal leader peptide sequence. The translated sequence beginning at the DAF NH 2 terminus encodes four contiguous ≅ 61-amino acid long repetitive units of internal homology. The repetitive regions contain four conserved cysteines, one proline, one glycine, one glycine/alanine, four leucines/isoleucines/valines, one serine, three tyrosines/phenylalanines, and on tryptophan and show striking homology to similar regions previously identified in factor B, C2, C4 binding protein, factor H, C1r, factor XIII, interleukin 2 receptor, and serum β 2 -glycoprotein I. The consensus repeats are attached to a 70-amino acid long segment rich in serine and threonine (potential O-glycosylation sites), which is in turn followed by a stretch of hydrophobic amino acids. RNA blot analysis of HeLa and HL-60 RNA revealed three DAF mRNA species of 3.1, 2.7, and 2.0 kilobases. The results indicate that portions of the DAF gene may have evolved from a DNA element common to the above proteins, that DAF cDNA predicts a COOH-terminal anchoring polypeptide, and that distinct species of DAF message are elaborated in cells

Comparative metabolomics reveals endogenous ligands of DAF-12, a nuclear hormone receptor regulating C. elegans development and lifespan

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Mahanti, Parag; Bose, Neelanjan; Bethke, Axel; Judkins, Joshua C.; Wollam, Joshua; Dumas, Kathleen J.; Zimmerman, Anna M.; Campbell, Sydney L.; Hu, Patrick J.; Antebi, Adam; Schroeder, Frank C.

2014-01-01

SUMMARY Small-molecule ligands of nuclear hormone receptors (NHRs) govern the transcriptional regulation of metazoan development, cell differentiation, and metabolism. However, the physiological ligands of many NHRs remain poorly characterized primarily due to lack of robust analytical techniques. Using comparative metabolomics, we identified endogenous steroids that act as ligands of the C. elegans NHR, DAF-12, a vitamin-D and liver-X receptor homolog regulating larval development, fat metabolism, and lifespan. The identified molecules feature unexpected chemical modifications and include only one of two DAF-12 ligands reported earlier, necessitating a revision of previously proposed ligand biosynthetic pathways. We further show that ligand profiles are regulated by a complex enzymatic network including the Rieske oxygenase DAF-36, the short-chain dehydrogenase DHS-16, and the hydroxysteroid dehydrogenase, HSD-1. Our results demonstrate the advantages of comparative metabolomics over traditional candidate-based approaches and provide a blueprint for the identification of ligands for other C. elegans and mammalian NHRs. PMID:24411940

Involvement of nuclear factor {kappa}B in platelet CD40 signaling

Energy Technology Data Exchange (ETDEWEB)

Hachem, Ahmed [Laboratory of Thrombosis and Hemostasis, Montreal Heart Institute, 5000 Belanger, Montreal, Quebec, Canada H1T 1C8 (Canada); Yacoub, Daniel [Laboratory of Thrombosis and Hemostasis, Montreal Heart Institute, 5000 Belanger, Montreal, Quebec, Canada H1T 1C8 (Canada); Centre Hospitalier Universite de Montreal, 264 boul. Rene-Levesque est, Montreal, Quebec, Canada H2X 1P1 (Canada); Zaid, Younes [Laboratory of Thrombosis and Hemostasis, Montreal Heart Institute, 5000 Belanger, Montreal, Quebec, Canada H1T 1C8 (Canada); Mourad, Walid [Universite de Montreal, Department of Medicine, 2900 boul. Edouard-Montpetit, Montreal, Quebec, Canada H3T 1J4 (Canada); Centre Hospitalier Universite de Montreal, 264 boul. Rene-Levesque est, Montreal, Quebec, Canada H2X 1P1 (Canada); Merhi, Yahye, E-mail: yahye.merhi@icm-mhi.org [Laboratory of Thrombosis and Hemostasis, Montreal Heart Institute, 5000 Belanger, Montreal, Quebec, Canada H1T 1C8 (Canada); Universite de Montreal, Department of Medicine, 2900 boul. Edouard-Montpetit, Montreal, Quebec, Canada H3T 1J4 (Canada)

2012-08-17

Highlights: Black-Right-Pointing-Pointer sCD40L induces TRAF2 association to CD40 and NF-{kappa}B activation in platelets. Black-Right-Pointing-Pointer I{kappa}B{alpha} phosphorylation downstream of CD40L/CD40 signaling is independent of p38 MAPK phosphorylation. Black-Right-Pointing-Pointer I{kappa}B{alpha} is required for sCD40L-induced platelet activation and potentiation of aggregation. -- Abstract: CD40 ligand (CD40L) is a thrombo-inflammatory molecule that predicts cardiovascular events. Platelets constitute the major source of soluble CD40L (sCD40L), which has been shown to potentiate platelet activation and aggregation, in a CD40-dependent manner, via p38 mitogen activated protein kinase (MAPK) and Rac1 signaling. In many cells, the CD40L/CD40 dyad also induces activation of nuclear factor kappa B (NF-{kappa}B). Given that platelets contain NF-{kappa}B, we hypothesized that it may be involved in platelet CD40 signaling and function. In human platelets, sCD40L induces association of CD40 with its adaptor protein the tumor necrosis factor receptor associated factor 2 and triggers phosphorylation of I{kappa}B{alpha}, which are abolished by CD40L blockade. Inhibition of I{kappa}B{alpha} phosphorylation reverses sCD40L-induced I{kappa}B{alpha} phosphorylation without affecting p38 MAPK phosphorylation. On the other hand, inhibition of p38 MAPK phosphorylation has no effect on I{kappa}B{alpha} phosphorylation, indicating a divergence in the signaling pathway originating from CD40 upon its ligation. In functional studies, inhibition of I{kappa}B{alpha} phosphorylation reverses sCD40L-induced platelet activation and potentiation of platelet aggregation in response to a sub-threshold concentration of collagen. This study demonstrates that the sCD40L/CD40 axis triggers NF-{kappa}B activation in platelets. This signaling pathway plays a critical role in platelet activation and aggregation upon sCD40L stimulation and may represent an important target against thrombo

Excitation wavelength dependent photoluminescence emission behavior, UV induced photoluminescence enhancement and optical gap tuning of Zn0.45Cd0.55S nanoparticles for optoelectronic applications

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Osman, M. A.; Abd-Elrahim, A. G.

2018-03-01

In the present study, we investigate the excitation wavelength (λex) dependent photoluminescence (PL) behavior in Zn0.45Cd0.55S nanoparticles. The deconvoluted PL emission bands for nanopowders and nanocolloids reveal noticeable spectral blue shift with decreasing λex accompanied by intensity enhancement. This unusual behavior is explained in terms of selective particle size distribution in nanostructures, advancing of fast ionization process at short λex; and solvation process in polar solvent. In addition, we attributed the UV-induced PL intensity enhancement and blue shift of the optical gap to the reduction in particle size by photo-corrosion process associated with the improvement in the quantum size effect; surface modification due to cross-linkage improvement of capping molecules at NPs surface; the creation of new radiative centers and the formation of photo-passivation layers from ZnSO4 and CdSO4, and photo-enhanced oxygen adsorption on Zn0.45Cd0.55S nanoparticles surface.

Antioxidative Activities of Both Oleic Acid and Camellia tenuifolia Seed Oil Are Regulated by the Transcription Factor DAF-16/FOXO in Caenorhabditis elegans.

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Chia-Cheng Wei

Full Text Available Tea seed oil is a high quality edible oil, yet lacking sufficient scientific evidences to support the nutritional and medical purposes. We identified major and minor components in Camellia tenuifolia seed oil and investigated the antioxidative activity and its underlying mechanisms in Caenorhabditis elegans.The results showed that the major constitutes in C. tenuifolia seed oil were unsaturated fatty acids (~78.4%. Moreover, two minor compounds, β-amyrin and β-sitosterol, were identified and their antioxidative activity was examined. We found that oleic acid was the major constitute in C. tenuifolia seed oil and plays a key role in the antioxidative activity of C. tenuifolia seed oil in C. elegans.This study found evidences that the transcription factor DAF-16/FOXO was involved in both oleic acid- and C. tenuifolia seed oil-mediated oxidative stress resistance in C. elegans. This study suggests the potential of C. tenuifolia seed oil as nutrient or functional foods.

Central nervous system promotes thermotolerance via FoxO/DAF-16 activation through octopamine and acetylcholine signaling in Caenorhabditis elegans.

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Furuhashi, Tsubasa; Sakamoto, Kazuichi

2016-03-25

The autonomic nervous system (ANS) responds to many kinds of stressors to maintain homeostasis. Although the ANS is believed to regulate stress tolerance, the exact mechanism underlying this is not well understood. To understand this, we focused on longevity genes, which have functions such as lifespan extension and promotion of stress tolerance. To understand the relationship between ANS and longevity genes, we analyzed stress tolerance of Caenorhabditis elegans treated with octopamine, which has an affinity to noradrenaline in insects, and acetylcholine. Octopamine and acetylcholine did not show resistance against H2O2, but the neurotransmitters promoted thermotolerance via DAF-16. However, chronic treatment with octopamine and acetylcholine did not extend the lifespan, although DAF-16 plays an important role in longevity. In conclusion, our results show that octopamine and acetylcholine activate DAF-16 in response to stress, but chronic induction of octopamine and acetylcholine is not beneficial for increasing longevity. Copyright © 2016 Elsevier Inc. All rights reserved.

Optimized processing of growth factor mobilized peripheral blood CD34+ products by counterflow centrifugal elutriation.

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Tran, Chy-Anh; Torres-Coronado, Monica; Gardner, Agnes; Gu, Angel; Vu, Hieu; Rao, Anitha; Cao, Lan-Feng; Ahmed, Amira; Digiusto, David

2012-05-01

Cell separation by counterflow centrifugal elutriation has been described for the preparation of monocytes for vaccine applications, but its use in other current good manufacturing practice (cGMP) operations has been limited. In this study, growth factor-mobilized peripheral blood progenitor cell products were collected from healthy donors and processed by elutriation using a commercial cell washing device. Fractions were collected for each product as per the manufacturer's instructions or using a modified protocol developed in our laboratory. Each fraction was analyzed for cell count, viability, and blood cell differential. Our data demonstrate that, using standard elutriation procedures, >99% of red blood cells and platelets were removed from apheresis products with high recoveries of total white blood cells and enrichment of CD34+ cells in two of five fractions. With modification of the basic protocol, we were able to collect all of the CD34+ cells in a single fraction. The CD34-enriched fractions were formulated, labeled with a ferromagnetic antibody to CD34, washed using the Elutra device, and transferred directly to a magnetic bead selection device for further purification. CD34+ cell purities from the column were extremely high (98.7 ± 0.9%), and yields were typical for the device (55.7 ± 12.3%). The processes were highly automated and closed from receipt of the apheresis product through formulation of target-enriched cell fractions. Thus, elutriation is a feasible method for the initial manipulations associated with primary blood cell therapy products and supports cGMP and current good tissue practice-compliant cell processing.

Caffeic acid phenethylester increases stress resistance and enhances lifespan in Caenorhabditis elegans by modulation of the insulin-like DAF-16 signalling pathway.

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Havermann, Susannah; Chovolou, Yvonni; Humpf, Hans-Ulrich; Wätjen, Wim

2014-01-01

CAPE is an active constituent of propolis which is widely used in traditional medicine. This hydroxycinnamic acid derivate is a known activator of the redox-active Nrf2 signalling pathway in mammalian cells. We used C. elegans to investigate the effects of this compound on accumulation of reactive oxygen species and the modulation of the pivotal redox-active pathways SKN-1 and DAF-16 (homologues of Nrf2 and FoxO, respectively) in this model organism; these results were compared to the effects in Hct116 human colon carcinoma cells. CAPE exerts a strong antioxidative effect in C. elegans: The increase of reactive oxygen species induced by thermal stress was diminished by about 50%. CAPE caused a nuclear translocation of DAF-16, but not SKN-1. CAPE increased stress resistance of the nematode against thermal stress and finally a prolongation of the median and maximum lifespan by 9 and 17%, respectively. This increase in stress resistance and lifespan was dependent on DAF-16 as shown in experiments using a DAF-16 loss of function mutant strain. Life prolongation was retained under SKN-1 RNAi conditions showing that the effect is SKN-1 independent. The results of CAPE obtained in C. elegans differed from the results obtained in Hct116 colon carcinoma cells: CAPE also caused strong antioxidative effects in the mammalian cells, but no activation of the FoxO4 signalling pathway was detectable. Instead, an activation of the Nrf2 signalling pathway was shown by luciferase assay and western blots. CAPE activates the insulin-like DAF-16, but not the SKN-1 signalling pathway in C. elegans and therefore enhances the stress resistance and lifespan of this organism. Since modulation of the DAF-16 pathway was found to be a pivotal effect of CAPE in C. elegans, this has to be taken into account for the investigation of the molecular mechanisms of the traditional use of propolis.

Pattern of Coronary Artery Disease Risk Factors in Population Younger than 55 Years and Above 55 Years: A Population Study of 31999 Healthy Individuals

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Zinat Nadia Hatmi

2011-06-01

Full Text Available More than eighty percent of patients with coronary heart diseases (CHD have conventional risk factors. Prevalence of well known risk factors seems to show a different pattern in younger patients and individual above 55 years. To evaluate the pattern of conventional CHD risk factors in healthy individuals in two different age groups. A large scale population based survey of 31999 individuals from ten medical centers was designed. Screening of risk factors was performed upon these protocols: taking medical history, physical examination and blood tests of complete blood cell counts, fasting blood sugar, lipid profile, urinalysis and creatinine. Prevalence of the risk factors in healthy people aged above 55 years were: 8.1% for systolic blood pressure (SBP>140 mmHg, 3.8% for diastolic blood pressure (DBP>90mmHg, 13.9% for fasting blood glucose (FBS≥126 Mg/dl, 36.9% for total cholesterol>200 Mg/dl, 19.2% for triglyceride (TG>200 Mg/dl, 67.8% for HDL-c130 Mg/dl, 4.72 for TC/HDL-c ratio, 2.88 for LDL-c/HDL/c ratio and 4.24 for TG/HDL-c ratio. Prevalence of risk factors in individuals younger than 55 years were: 1.7% for SBP>140 mmHg, 1.2% for DBP>90 mmHg, 5.2% for FBS≥126 Mg/dl, 31.3% for TC>200 Mg/dl, 21.5% for TG>200 Mg/dl, 69.4% for HDL-c130 Mg/dl, 4.7 for TC/HDL-c ratio, 2.83 for LDL-c/HDL-c ratio and 4.43 for TG/HDL-c ratio. In univariate model of analysis: prevalence of the risk factors were significantly higher in age above 55 years than in people younger than 55 years except for hypertriglyceridemia and HDL-c200 Mg/dl P= 0.002, HDL-c140 mmHg P=0.001. Pattern of such a CHD risk factors of FBS≥126 Mg/dl, TG>200 Mg/dl, HDL-c140 mmHg demonstrated a statistically significant difference in the age above 55 years to the healthy people younger than 55 years. These results cab be implicated to set up prediction models for stratifying individuals at higher risk of CHD.

The Future of Architecture Collaborative Information Sharing: DoDAF Version 2.03 Updates

Science.gov (United States)

2012-04-30

Salamander x Select Solution Factory Select Business Solutions BPMN , UML x SimonTool Simon Labs x SimProcess CACI BPMN x System Architecture Management...for DoDAF Mega UML x Metastorm ProVision Metastorm BPMN x Naval Simulation System - 4 Aces METRON x NetViz CA x OPNET OPNET x Tool Name Vendor Primary

DAFS measurements using the image-plate Weissenberg method

International Nuclear Information System (INIS)

Sugioka, N.; Matsumoto, K.; Sasaki, S.; Tanaka, M.; Mori, T.

1998-01-01

An instrumental technique for DAFS measurements which can provide site-specific information is proposed. The approach uses (i) focusing optics with parabolic mirrors and a double-crystal monochromator, (ii) the Laue and Bragg settings and (iii) data collection by the image-plate Weissenberg method. Six image exposures are recorded per plate at five intrinsic energies and one reference energy. The single-crystal measurements were performed at the Co K-absorption edge, and the 200, 220 and 311 reflections of CoO and 511 and 911 reflections of Co 3 O 4 were used for analysis. The regression analysis of χ(k), Fourier transforms of k 3 χ(k) and back-Fourier filtering have been performed

High Energy X-Ray System Specification for the Device Assembly Facility (DAF) at the NNSS

International Nuclear Information System (INIS)

Fry, David A.

2012-01-01

This specification establishes requirements for an X-Ray System to be used at the Device Assembly Facility (DAF) at the Nevada National Security Site (NNSS) to support radiography of experimental assemblies for Laboratory (LANL, LLNL, SNL) programs conducting work at the NNSS.

The ThPOK transcription factor differentially affects the development and function of self-specific CD8(+) T cells and regulatory CD4(+) T cells.

Science.gov (United States)

Twu, Yuh-Ching; Teh, Hung-Sia

2014-03-01

The zinc finger transcription factor ThPOK plays a crucial role in CD4 T-cell development and CD4/CD8 lineage decision. In ThPOK-deficient mice, developing T cells expressing MHC class II-restricted T-cell receptors are redirected into the CD8 T-cell lineage. In this study, we investigated whether the ThPOK transgene affected the development and function of two additional types of T cells, namely self-specific CD8 T cells and CD4(+) FoxP3(+) T regulatory cells. Self-specific CD8 T cells are characterized by high expression of CD44, CD122, Ly6C, 1B11 and proliferation in response to either IL-2 or IL-15. The ThPOK transgene converted these self-specific CD8 T cells into CD4 T cells. The converted CD4(+) T cells are no longer self-reactive, lose the characteristics of self-specific CD8 T cells, acquire the properties of conventional CD4 T cells and survive poorly in peripheral lymphoid organs. By contrast, the ThPOK transgene promoted the development of CD4(+) FoxP3(+) regulatory T cells resulting in an increased recovery of CD4(+) FoxP3(+) regulatory T cells that expressed higher transforming growth factor-β-dependent suppressor activity. These studies indicate that the ThPOK transcription factor differentially affects the development and function of self-specific CD8 T cells and CD4(+) FoxP3(+) regulatory T cells. © 2013 John Wiley & Sons Ltd.

Stable thermophilic anaerobic digestion of dissolved air flotation (DAF) sludge by co-digestion with swine manure.

Science.gov (United States)

Creamer, K S; Chen, Y; Williams, C M; Cheng, J J

2010-05-01

Environmentally sound treatment of by-products in a value-adding process is an ongoing challenge in animal agriculture. The sludge produced as a result of the dissolved air flotation (DAF) wastewater treatment process in swine processing facilities is one such low-value residue. The objective of this study was to determine the fundamental performance parameters for thermophilic anaerobic digestion of DAF sludge. Testing in a semi-continuous stirred tank reactor and in batch reactors was conducted to determine the kinetics of degradation and biogas yield. Stable operation could not be achieved using pure DAF sludge as a substrate, possibly due to inhibition by long-chain fatty acids or to nutrient deficiencies. However, in a 1:1 ratio (w/w, dry basis) with swine manure, operation was both stable and productive. In the semi-continuous stirred reactor at 54.5 degrees Celsius, a hydraulic residence time of 10 days, and an organic loading rate of 4.68 gVS/day/L, the methane production rate was 2.19 L/L/day and the specific methane production rate was 0.47 L/gVS (fed). Maximum specific methanogenic activity (SMA) in batch testing was 0.15 mmoles CH(4) h(-1) gVS(-1) at a substrate concentration of 6.9 gVS L(-1). Higher substrate concentrations cause an initial lag in methane production, possibly due to long-chain fatty acid or nitrogen inhibition. Copyright 2009 Elsevier Ltd. All rights reserved.

Protective role of hypoxia-inducible factor-1α-dependent CD39 and CD73 in fulminant acute liver failure

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Tak, Eunyoung [Asan Institute for Life Sciences and Asan-Minnesota Institute for Innovating Transplantation, Asan Medical Center, University of Ulsan College of Medicine, Seoul (Korea, Republic of); Jung, Dong-Hwan; Kim, Seok-Hwan; Park, Gil-Chun [Division of Liver Transplantation and Hepatobiliary Surgery, Asan-Minnesota Institute for Innovating Transplantation, Department of Surgery, Asan Medical Center, University of Ulsan College of Medicine, Seoul (Korea, Republic of); Jun, Dae Young; Lee, Jooyoung [Asan Institute for Life Sciences and Asan-Minnesota Institute for Innovating Transplantation, Asan Medical Center, University of Ulsan College of Medicine, Seoul (Korea, Republic of); Jung, Bo-hyun [Department of Surgery, Inje University Haeundae Paik Hospital, Inje University College of Medicine, Busan (Korea, Republic of); Kirchner, Varvara A. [Division of Transplantation, Department of Surgery and Asan-Minnesota Institute for Innovating Transplantation, University of Minnesota, Minneapolis, MN (United States); Hwang, Shin [Division of Liver Transplantation and Hepatobiliary Surgery, Asan-Minnesota Institute for Innovating Transplantation, Department of Surgery, Asan Medical Center, University of Ulsan College of Medicine, Seoul (Korea, Republic of); Song, Gi-Won, E-mail: drsong71@amc.seoul.kr [Division of Liver Transplantation and Hepatobiliary Surgery, Asan-Minnesota Institute for Innovating Transplantation, Department of Surgery, Asan Medical Center, University of Ulsan College of Medicine, Seoul (Korea, Republic of); Lee, Sung-Gyu [Division of Liver Transplantation and Hepatobiliary Surgery, Asan-Minnesota Institute for Innovating Transplantation, Department of Surgery, Asan Medical Center, University of Ulsan College of Medicine, Seoul (Korea, Republic of)

2017-01-01

Acute liver failure (ALF) is a severe life-threatening disease which usually arises in patients with-irreversible liver illnesses. Although human ectonucleotide triphosphate diphosphohydrolase-1, E-NTPDase1 (CD39) and ecto-5′-nucleotidase, Ecto5′NTase (CD73) are known to protect tissues from ALF, the expression and function of CD39 and CD73 during ALF are currently not fully investigated. We tested whether CD39 and CD73 are upregulated by hypoxia inducible factor (HIF)-1α, and improve ischemic tolerance to ALF. To test our hypothesis, liver biopsies were obtained and we found that CD39 and CD73 mRNA and proteins from human specimens were dramatically elevated in ALF. We investigated that induction of CD39 and CD73 in ALF-related with wild type mice. In contrast, deletion of cd39 and cd73 mice has severe ALF. In this study, we concluded that CD39 and CD73 are molecular targets for the development of drugs for ALF patients care. - Highlights: • HIF-1a is stabilized during acute liver failure • Upregulation of CD39 and CD73 following acute liver failure • CD39 and CD73 are transcriptionally induced by HIF-1a • Deletion of Cd39 and CD73 aggravates murine acute liver failure • DMOG treatment induces HIF-1a stabilization, CD39 and CD73 during acute liver failure in WT mice.

Cooperation of decay-accelerating factor and membrane cofactor protein in regulating survival of human cervical cancer cells

International Nuclear Information System (INIS)

Gao, Ling-Juan; Guo, Shu-Yu; Cai, You-Qun; Gu, Ping-Qing; Su, Ya-Juan; Gong, Hui; Liu, Yun; Chen, Chen

2009-01-01

Decay-accelerating factor (DAF) and membrane cofactor protein (MCP) are the key molecules involved in cell protection against autologus complement, which restricts the action of complement at critical stages of the cascade reaction. The cooperative effect of DAF and MCP on the survival of human cervical cancer cell (ME180) has not been demonstrated. In this study we applied, for the first time, short hairpin RNA (shRNA) to knock down the expression of the DAF and MCP with the aim of exploiting complement more effectively for tumor cell damage. Meanwhile, we investigated the cooperative effects of DAF and MCP on the viability and migration, moreover the proliferation of ME180 cell. The results showed that shRNA inhibition of DAF and MCP expression enhanced complement-dependent cytolysis (CDC) up to 39% for MCP and up to 36% for DAF, and the combined inhibition of both regulators yielded further additive effects in ME180 cells. Thus, the activities of DAF and MCP, when present together, are greater than the sum of the two protein individually. These data indicated that combined DAF and MCP shRNA described in this study may offer an additional alternative to improve the efficacy of antibody-and complement-based cancer immunotherapy

Intrinsic JNK-MAPK pathway involvement requires daf-16-mediated immune response during Shigella flexneri infection in C. elegans.

Science.gov (United States)

Marudhupandiyan, Shanmugam; Balamurugan, Krishnaswamy

2017-06-01

The c-Jun N-terminal kinase-mitogen-activated protein kinase (JNK-MAPK) pathway assists in modulating signals for growth, survival, and metabolism, thereby coordinating many cellular events during normal and stress conditions. To understand the role of the JNK-MAPK pathway during bacterial infection, an in vivo model organism Caenorhabditis elegans was used. In order to check the involvement of the JNK-MAPK pathway, the survival rate of C. elegans wild type (WT), and JNK-MAPK pathway mutant worms' upon exposure to selective Gram-positive and Gram-negative pathogenic bacteria, was studied. Among the pathogens, Shigella flexneri M9OT was found to efficiently colonize inside the WT and JNK-MAPK pathway mutant worms. qPCR studies had suggested that the above pathway-specific genes kgb-2 and jnk-1 were prominently responsible for the immune response elicited by the host during the M9OT infection. In addition, daf-16, which is a major transcription factor of the insulin/insulin growth factor-1 signaling (IIS) pathway, was also found to be involved during the host response. Crosstalk between IIS and JNK-MAPK pathways has probably been involved in the activation of the host immune system, which consequently leads to lifespan extension. Furthermore, it is also observed that daf-16 activation by JNK-MAPK pathway leads to antimicrobial response, by activating lys-7 expression. These findings suggest that JNK-MAPK is not the sole pathway that enhances the immunity of the host. Nonetheless, the IIS pathway bridges the JNK-MAPK pathway that influences in protecting the host in counter to the M9OT infection.

Dafachronic acid inhibits C. elegans germ cell proliferation in a DAF-12-dependent manner.

Science.gov (United States)

Mukherjee, Madhumati; Chaudhari, Snehal N; Balachandran, Riju S; Vagasi, Alexandra S; Kipreos, Edward T

2017-12-15

Dafachronic acid (DA) is a bile acid-like steroid hormone that regulates dauer formation, heterochrony, and lifespan in C. elegans. Here, we describe that DA is an inhibitor of C. elegans germ stem cell proliferation in adult hermaphrodites. Using a C. elegans germ cell primary culture system, we show that DA inhibits the proliferation of germ cells in vitro. Exogenous DA reduces the frequency of large tumors in adult tumorous germline mutants and decreases the proliferation of wild-type germ stem cells in adult hermaphrodites. In contrast, DA has no appreciable effect on the proliferation of larval-stage germ cells in wild type. The inhibition of adult germ cell proliferation by DA requires its canonical receptor DAF-12. Blocking DA production by inactivating the cytochrome P450 DAF-9 increases germ cell proliferation in wild-type adult hermaphrodites and the frequency of large tumors in germline tumorous mutants, suggesting that DA inhibits the rate of germ cell proliferation under normal growth conditions. Copyright © 2017 Elsevier Inc. All rights reserved.

Plasma CXCL10, sCD163 and sCD14 Levels Have Distinct Associations with Antiretroviral Treatment and Cardiovascular Disease Risk Factors.

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Alison Castley

Full Text Available We investigate the associations of three established plasma biomarkers in the context of HIV and treatment-related variables including a comprehensive cardiovascular disease risk assessment, within a large ambulatory HIV cohort. Patients were recruited in 2010 to form the Royal Perth Hospital HIV/CVD risk cohort. Plasma sCD14, sCD163 and CXCL10 levels were measured in 475 consecutive patients with documented CVD risk (age, ethnicity, gender, smoking, blood pressure, BMI, fasting metabolic profile and HIV treatment history including immunological/virological outcomes. The biomarkers assessed showed distinct associations with virological response: CXCL10 strongly correlated with HIV-1 RNA (p0.2. Associations between higher sCD163 and protease inhibitor therapy (p = 0.05 and lower sCD14 with integrase inhibitor therapy (p = 0.02 were observed. Levels of sCD163 were also associated with CVD risk factors (age, ethnicity, HDL, BMI, with a favourable influence of Framingham score <10% (p = 0.04. Soluble CD14 levels were higher among smokers (p = 0.002, with no effect of other CVD risk factors, except age (p = 0.045. Our findings confirm CXCL10, sCD163 and sCD14 have distinct associations with different aspects of HIV infection and treatment. Levels of CXCL10 correlated with routinely monitored variables, sCD163 levels reflect a deeper level of virological suppression and influence of CVD risk factors, while sCD14 levels were not associated with routinely monitored variables, with evidence of specific effects of smoking and integrase inhibitor therapy warranting further investigation.

Plasma CXCL10, sCD163 and sCD14 Levels Have Distinct Associations with Antiretroviral Treatment and Cardiovascular Disease Risk Factors

Science.gov (United States)

Castley, Alison; Williams, Leah; James, Ian; Guelfi, George; Berry, Cassandra; Nolan, David

2016-01-01

We investigate the associations of three established plasma biomarkers in the context of HIV and treatment-related variables including a comprehensive cardiovascular disease risk assessment, within a large ambulatory HIV cohort. Patients were recruited in 2010 to form the Royal Perth Hospital HIV/CVD risk cohort. Plasma sCD14, sCD163 and CXCL10 levels were measured in 475 consecutive patients with documented CVD risk (age, ethnicity, gender, smoking, blood pressure, BMI, fasting metabolic profile) and HIV treatment history including immunological/virological outcomes. The biomarkers assessed showed distinct associations with virological response: CXCL10 strongly correlated with HIV-1 RNA (p0.2). Associations between higher sCD163 and protease inhibitor therapy (p = 0.05) and lower sCD14 with integrase inhibitor therapy (p = 0.02) were observed. Levels of sCD163 were also associated with CVD risk factors (age, ethnicity, HDL, BMI), with a favourable influence of Framingham score <10% (p = 0.04). Soluble CD14 levels were higher among smokers (p = 0.002), with no effect of other CVD risk factors, except age (p = 0.045). Our findings confirm CXCL10, sCD163 and sCD14 have distinct associations with different aspects of HIV infection and treatment. Levels of CXCL10 correlated with routinely monitored variables, sCD163 levels reflect a deeper level of virological suppression and influence of CVD risk factors, while sCD14 levels were not associated with routinely monitored variables, with evidence of specific effects of smoking and integrase inhibitor therapy warranting further investigation. PMID:27355513

The enhancement by arbuscular mycorrhizal fungi of the Cd remediation ability and bioenergy quality-related factors of five switchgrass cultivars in Cd-contaminated soil

Directory of Open Access Journals (Sweden)

Hong Sun

2018-03-01

Full Text Available A greenhouse experiment was carried out to investigate the effects of arbuscular mycorrhizal fungi (AMF on the growth, P and Cd concentrations and bioenergy quality-related factors of five cultivars of switchgrass, including three lowland cultivars (Alamo (Ala, Kanlow (Kan, Performer (Per and two highland cultivars (Blackwell (Bw, Summer (Sum, with 0, 1 and 10 mg/kg Cd addition levels. The results showed that AMF inoculation notably increased the biomass and P concentrations of all the cultivars. The Cd concentrations in the roots were higher than those in the shoots of all cultivars irrespective of inoculation, but the AMF had different effects on Cd accumulation in highland and lowland cultivars. AMF inoculation decreased the shoot and root concentrations in Ala and Kan, increased the shoot and root concentrations of Cd in Bw and Sum, and increased shoot Cd concentrations and decreased root Cd concentrations in Per. The highest Cd concentrations were detected in the roots of Bw and in the shoots of Sum with AMF symbiosis. Bw contained the highest total extracted Cd which was primarily in the roots. Ala had the second highest extracted Cd in the shoots, reaching 32% with 1 mg/kg of added Cd, whereas Sum had the lowest extracted Cd. AMF symbiosis had varied effects on bioenergy quality-related factors: for example, AMF decreased the ash lignin content in Ala and the C/N in Sum, increased the nitrogen, gross calorie values, and maintained the hemicellulose and cellulose contents in all cultivars with all tested concentrations of Cd. A principal component analysis (PCA showed that AMF inoculation could enhance, weaken or transform (positive-negative, PC1-PC2 the correlations of these factors with the principle components under Cd stress. Therefore, AMF symbiosis enhanced the growth of different cultivars of switchgrass, increased/decreased Cd accumulation, promoted Cd extraction, and regulated the bioenergy quality-related factors in Cd

Baseline tests of the C. H. Waterman DAF electric passenger vehicle

Science.gov (United States)

Sargent, N. B.; Maslowski, E. A.; Soltis, R. F.; Schuh, R. M.

1977-01-01

An electric vehicle was tested as part of an Energy Research Development Administration (ERDA) project to characterize the state-of-the-art of electric vehicles. The Waterman vehicle performance test results are presented in this report. The vehicle is a converted four-passenger DAF 46 sedan. It is powered by sixteen 6-volt traction batteries through a three-step contactor controller actuated by a foot throttle to change the voltage applied to the 6.7 kW motor. The braking system is a conventional hydraulic braking system.

Macrophage Migration Inhibitory Factor Mediates Proliferative GN via CD74

Science.gov (United States)

Djudjaj, Sonja; Lue, Hongqi; Rong, Song; Papasotiriou, Marios; Klinkhammer, Barbara M.; Zok, Stephanie; Klaener, Ole; Braun, Gerald S.; Lindenmeyer, Maja T.; Cohen, Clemens D.; Bucala, Richard; Tittel, Andre P.; Kurts, Christian; Moeller, Marcus J.; Floege, Juergen; Ostendorf, Tammo

2016-01-01

Pathologic proliferation of mesangial and parietal epithelial cells (PECs) is a hallmark of various glomerulonephritides. Macrophage migration inhibitory factor (MIF) is a pleiotropic cytokine that mediates inflammation by engagement of a receptor complex involving the components CD74, CD44, CXCR2, and CXCR4. The proliferative effects of MIF may involve CD74 together with the coreceptor and PEC activation marker CD44. Herein, we analyzed the effects of local glomerular MIF/CD74/CD44 signaling in proliferative glomerulonephritides. MIF, CD74, and CD44 were upregulated in the glomeruli of patients and mice with proliferative glomerulonephritides. During disease, CD74 and CD44 were expressed de novo in PECs and colocalized in both PECs and mesangial cells. Stress stimuli induced MIF secretion from glomerular cells in vitro and in vivo, in particular from podocytes, and MIF stimulation induced proliferation of PECs and mesangial cells via CD74. In murine crescentic GN, Mif-deficient mice were almost completely protected from glomerular injury, the development of cellular crescents, and the activation and proliferation of PECs and mesangial cells, whereas wild-type mice were not. Bone marrow reconstitution studies showed that deficiency of both nonmyeloid and bone marrow–derived Mif reduced glomerular cell proliferation and injury. In contrast to wild-type mice, Cd74-deficient mice also were protected from glomerular injury and ensuing activation and proliferation of PECs and mesangial cells. Our data suggest a novel molecular mechanism and glomerular cell crosstalk by which local upregulation of MIF and its receptor complex CD74/CD44 mediate glomerular injury and pathologic proliferation in GN. PMID:26453615

Royal jelly promotes DAF-16-mediated proteostasis to tolerate β-amyloid toxicity in C. elegans model of Alzheimer's disease.

Science.gov (United States)

Wang, Xiaoxia; Cao, Min; Dong, Yuqing

2016-08-23

Numerous studies have demonstrated that dietary intervention may promote health and help prevent Alzheimer's disease (AD). We recently reported that bee products of royal jelly (RJ) and enzyme-treated royal jelly (eRJ) were potent to promote healthy aging in C. elegans. Here, we examined whether RJ/eRJ consumption may benefit to mitigate the AD symptom in the disease model of C. elegans. Our results showed that RJ/eRJ supplementation significantly delayed the body paralysis in AD worms, suggesting the β-amyloid (Aβ) toxicity attenuation effects of RJ/eRJ. Genetic analyses suggested that RJ/eRJ-mediated alleviation of Aβ toxicity in AD worms required DAF-16, rather than HSF-1 and SKN-1, in an insulin/IGF signaling dependent manner. Moreover, RJ/eRJ modulated the transactivity of DAF-16 and dramatically improved the protein solubility in aged worms. Given protein solubility is a hallmark of healthy proteostasis, our findings demonstrated that RJ/eRJ supplementation improved proteostasis, and this promotion depended on the transactivity of DAF-16. Collectively, the present study not only elucidated the possible anti-AD mechanism of RJ/eRJ, but also provided evidence from a practical point of view to shed light on the extensive correlation of proteostasis and the prevention of neurodegenerative disorders.

rBTI reduced β-amyloid-induced toxicity by promoting autophagy-lysosomal degradation via DAF-16 in Caenorhabditis elegans.

Science.gov (United States)

Li, Jiao; Cui, Xiaodong; Ma, Xiaoli; Wang, Zhuanhua

2017-03-01

Alzheimer's disease (AD) is an age-related neurodegenerative disease, of which β-amyloid (Aβ) induced toxicity was suggested as a main cause. Some substances with prolongevity effects have been shown to be protective against AD. In a previous study we demonstrated that a recombinant buckwheat trypsin inhibitor (rBTI) could prolonge the lifespan in Caenorhabditis elegans (C. elegans). Here, we investigated whether rBTI may benefit to mitigate the AD symptom by feeding the AD model C. elegans CL4176. CL4176 is a transgenic C. elegans expressing human Aβ 3-42 in muscle tissue. The results showed that rBTI not only could extend lifespan but also could reduce Aβ toxicity-triggered body paralysis in AD worms. Further study found the accumulation of Aβ was decreased and autophagy-lysosomal degradation pathway was activated in AD worms treated with rBTI. Moreover, the inhibition of autophagy reduced rBTI-mediated paralysis delay. Genetic analyses showed rBTI increased the transcriptional activity of dauer formation abnormal-16 (DAF-16) and the disruption of daf-16 abolished rBTI-mediated protective effect in AD worms. Taken together, these data indicated that rBTI promoted the autophagy-lysosomal degradation pathway to reduce the Aβ-induced toxicity via DAF-16 in an AD model C. elegans, implying that BTI has the potential to protect against AD. Copyright © 2017 Elsevier Inc. All rights reserved.

Comparison between XAS, AWAXS and DAFS applied to nanometer scale supported metallic clusters. Pt.1; monometallic clusters

International Nuclear Information System (INIS)

Bazin, D.C.; Sayers, D.A.

1993-01-01

The structural information found using three techniques related to synchrotron radiation are compared. XAS (X-ray Absorption Spectroscopy), AWAXS (Anomalous Wide Angle X-ray Scattering) and DAFS (Diffraction Anomalous Fine Structure) are applied to nanometer scale metallic clusters. (author)

FOXO/DAF-16 Activation Slows Down Turnover of the Majority of Proteins in C. elegans

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Ineke Dhondt

2016-09-01

Full Text Available Most aging hypotheses assume the accumulation of damage, resulting in gradual physiological decline and, ultimately, death. Avoiding protein damage accumulation by enhanced turnover should slow down the aging process and extend the lifespan. However, lowering translational efficiency extends rather than shortens the lifespan in C. elegans. We studied turnover of individual proteins in the long-lived daf-2 mutant by combining SILeNCe (stable isotope labeling by nitrogen in Caenorhabditis elegans and mass spectrometry. Intriguingly, the majority of proteins displayed prolonged half-lives in daf-2, whereas others remained unchanged, signifying that longevity is not supported by high protein turnover. This slowdown was most prominent for translation-related and mitochondrial proteins. In contrast, the high turnover of lysosomal hydrolases and very low turnover of cytoskeletal proteins remained largely unchanged. The slowdown of protein dynamics and decreased abundance of the translational machinery may point to the importance of anabolic attenuation in lifespan extension, as suggested by the hyperfunction theory.

CD147, CD44, and the epidermal growth factor receptor (EGFR) signaling pathway cooperate to regulate breast epithelial cell invasiveness.

Science.gov (United States)

Grass, G Daniel; Tolliver, Lauren B; Bratoeva, Momka; Toole, Bryan P

2013-09-06

The immunoglobulin superfamily glycoprotein CD147 (emmprin; basigin) is associated with an invasive phenotype in various types of cancers, including malignant breast cancer. We showed recently that up-regulation of CD147 in non-transformed, non-invasive breast epithelial cells is sufficient to induce an invasive phenotype characterized by membrane type-1 matrix metalloproteinase (MT1-MMP)-dependent invadopodia activity (Grass, G. D., Bratoeva, M., and Toole, B. P. (2012) Regulation of invadopodia formation and activity by CD147. J. Cell Sci. 125, 777-788). Here we found that CD147 induces breast epithelial cell invasiveness by promoting epidermal growth factor receptor (EGFR)-Ras-ERK signaling in a manner dependent on hyaluronan-CD44 interaction. Furthermore, CD147 promotes assembly of signaling complexes containing CD147, CD44, and EGFR in lipid raftlike domains. We also found that oncogenic Ras regulates CD147 expression, hyaluronan synthesis, and formation of CD147-CD44-EGFR complexes, thus forming a positive feedback loop that may amplify invasiveness. Last, we showed that malignant breast cancer cells are heterogeneous in their expression of surface-associated CD147 and that high levels of membrane CD147 correlate with cell surface EGFR and CD44 levels, activated EGFR and ERK1, and activated invadopodia. Future studies should evaluate CD147 as a potential therapeutic target and disease stratification marker in breast cancer.

CD147, CD44, and the Epidermal Growth Factor Receptor (EGFR) Signaling Pathway Cooperate to Regulate Breast Epithelial Cell Invasiveness*

Science.gov (United States)

Grass, G. Daniel; Tolliver, Lauren B.; Bratoeva, Momka; Toole, Bryan P.

2013-01-01

The immunoglobulin superfamily glycoprotein CD147 (emmprin; basigin) is associated with an invasive phenotype in various types of cancers, including malignant breast cancer. We showed recently that up-regulation of CD147 in non-transformed, non-invasive breast epithelial cells is sufficient to induce an invasive phenotype characterized by membrane type-1 matrix metalloproteinase (MT1-MMP)-dependent invadopodia activity (Grass, G. D., Bratoeva, M., and Toole, B. P. (2012) Regulation of invadopodia formation and activity by CD147. J. Cell Sci. 125, 777–788). Here we found that CD147 induces breast epithelial cell invasiveness by promoting epidermal growth factor receptor (EGFR)-Ras-ERK signaling in a manner dependent on hyaluronan-CD44 interaction. Furthermore, CD147 promotes assembly of signaling complexes containing CD147, CD44, and EGFR in lipid raftlike domains. We also found that oncogenic Ras regulates CD147 expression, hyaluronan synthesis, and formation of CD147-CD44-EGFR complexes, thus forming a positive feedback loop that may amplify invasiveness. Last, we showed that malignant breast cancer cells are heterogeneous in their expression of surface-associated CD147 and that high levels of membrane CD147 correlate with cell surface EGFR and CD44 levels, activated EGFR and ERK1, and activated invadopodia. Future studies should evaluate CD147 as a potential therapeutic target and disease stratification marker in breast cancer. PMID:23888049

Comparison between XAS, AWAXS and DAFS applied to nanometer scale supported metallic clusters. Pt.2; bimetallic clusters

International Nuclear Information System (INIS)

Bazin, D.; Sayers, D.

1993-01-01

The structural information obtained using three techniques related to synchrotron radiation are compared. XAS (X-ray Absorption Spectroscopy), AWAXS (Anomalous Wide Angle X-ray Scattering) and DAFS (Diffraction Anomalous Fine Structure) are applied to the study of nanometer scale bimetallic clusters. (author)

hypoxia-inducible factors activate CD133 promoter through ETS family transcription factors.

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Shunsuke Ohnishi

Full Text Available CD133 is a cellular surface protein that has been reported to be a cancer stem cell marker, and thus it is considered to be a potential target for cancer treatment. However, the mechanism regulating CD133 expression is not yet understood. In this study, we analyzed the activity of five putative promoters (P1-P5 of CD133 in human embryonic kidney (HEK 293 cells and colon cancer cell line WiDr, and found that the activity of promoters, particularly of P5, is elevated by overexpression of hypoxia-inducible factors (HIF-1α and HIF-2α. Deletion and mutation analysis identified one of the two E-twenty six (ETS binding sites (EBSs in the P5 region as being essential for its promoter activity induced by HIF-1α and HIF-2α. In addition, a chromatin imunoprecipitation assay demonstrated that HIF-1α and HIF-2α bind to the proximal P5 promoter at the EBSs. The immunoprecipitation assay showed that HIF-1α physically interacts with Elk1; however, HIF-2α did not bind to Elk1 or ETS1. Furthermore, knockdown of both HIF-1α and HIF-2α resulted in a reduction of CD133 expression in WiDr. Taken together, our results revealed that HIF-1α and HIF-2α activate CD133 promoter through ETS proteins.

Effects of environmental biomass-producing factors on Cd uptake in two Swedish ecotypes of Pinus sylvestris

Energy Technology Data Exchange (ETDEWEB)

Ekvall, Lars; Greger, Maria

2003-03-01

Cadmium uptake in Scots pine seedlings was mainly regulated by biomass production. - A factorial design was used to study direct effects of external biomass-producing factors such as light, temperature and photoperiod on cadmium (Cd) uptake and indirect effects, via change in biomass production in two ecotypes of Scots pine (Pinus silvestris). The aim was to find out if the external factors affect the Cd uptake directly or via change in biomass production, and if the effect differs between ecotypes. Seedlings were grown under 10 combinations of external factors, i.e. temperature (15 and 20 deg. C), light intensity (50 and 200 {mu}mol photons m{sup -2} s{sup -1}), photoperiod (18 h light/8 h darkness and continuous light) and external Cd concentration (totally 1.88 and 7.50 {mu}mol). The treatment lasted for 18 days and Cd concentrations in roots and shoots were determined by AAS. The results showed that an increased biomass production increased the total Cd uptake but had a dilution effect on the Cd concentration, especially in the root tissues. The external factors tested did not have any direct effects on the Cd uptake, only in the case of Cd translocation to the shoot did the higher temperature show a direct increase, but only in the southern ecotype. The two ecotypes reacted differently in Cd uptake and translocation to the external factors studied. The relative Cd uptake increased with increasing photoperiod in the northern but not in the southern ecotype. The southern ecotype decreased the Cd concentration in the shoot with increased light intensity caused by a dilution effect due to extensive shoot growth of this ecotype. The conclusion is that the uptake in pine seedlings is mainly regulated via biomass production, and not directly by light and temperature and that resulting plant Cd contents to a certain extent depend on plant origin.

Effects of environmental biomass-producing factors on Cd uptake in two Swedish ecotypes of Pinus sylvestris

International Nuclear Information System (INIS)

Ekvall, Lars; Greger, Maria

2003-01-01

Cadmium uptake in Scots pine seedlings was mainly regulated by biomass production. - A factorial design was used to study direct effects of external biomass-producing factors such as light, temperature and photoperiod on cadmium (Cd) uptake and indirect effects, via change in biomass production in two ecotypes of Scots pine (Pinus silvestris). The aim was to find out if the external factors affect the Cd uptake directly or via change in biomass production, and if the effect differs between ecotypes. Seedlings were grown under 10 combinations of external factors, i.e. temperature (15 and 20 deg. C), light intensity (50 and 200 μmol photons m -2 s -1 ), photoperiod (18 h light/8 h darkness and continuous light) and external Cd concentration (totally 1.88 and 7.50 μmol). The treatment lasted for 18 days and Cd concentrations in roots and shoots were determined by AAS. The results showed that an increased biomass production increased the total Cd uptake but had a dilution effect on the Cd concentration, especially in the root tissues. The external factors tested did not have any direct effects on the Cd uptake, only in the case of Cd translocation to the shoot did the higher temperature show a direct increase, but only in the southern ecotype. The two ecotypes reacted differently in Cd uptake and translocation to the external factors studied. The relative Cd uptake increased with increasing photoperiod in the northern but not in the southern ecotype. The southern ecotype decreased the Cd concentration in the shoot with increased light intensity caused by a dilution effect due to extensive shoot growth of this ecotype. The conclusion is that the uptake in pine seedlings is mainly regulated via biomass production, and not directly by light and temperature and that resulting plant Cd contents to a certain extent depend on plant origin

Detection and Significance of CD4+CD25+CD127dim Regulatory T Cells in Individuals with Severe Aplastic Anemia

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Weiwei Qi

2015-09-01

Full Text Available Objective: To investigate the relationship between CD4+CD25+CD127dim regulatory T cells (Tregs and immune imbalance in acquired severe aplastic anemia (SAA. Materials and Methods: The quantity of CD4+CD25+CD127dim Tregs in 44 SAA patients and 23 normal controls was measured by flow cytometry. Correlations between Tregs and T cell subsets, dendritic cell (DC subsets, granulocyte counts, and percentage of reticulocytes (RET% were analyzed. Results: The percentage of CD4+CD25+CD127dim Tregs in peripheral blood lymphocytes (PBLs of untreated patients was lower than in recovery patients and normal controls (0.83±0.44% vs. 2.91±1.24% and 2.18±0.55%, respectively, p<0.05. The percentage of CD4+CD25+CD127dim Tregs in CD4+ T lymphocytes of recovery patients was higher than that of untreated patients and normal controls (9.39±3.51% vs. 7.61±5.3% and 6.83±1.4%, respectively, p<0.05. The percentage of CD4+ T lymphocytes in PBLs of untreated patients was lower than in recovery patients and normal controls (13.55±7.37% vs. 31.82±8.43% and 32.12±5.88%, respectively, p<0.05. T cell subset (CD4+/CD8+ ratio was 0.41±0.24 in untreated patients, which was lower than in recovery patients (1.2±0.4 and normal controls (1.11±0.23 (p<0.05. DC subset (myeloid DC/plasmacytoid DC ratio, DC1/DC2 ratio was 3.08±0.72 in untreated patients, which was higher than in recovery patients (1.61±0.49 and normal controls (1.39±0.36 (p<0.05. The percentage of CD4+CD25+CD127dim Tregs in PBLs was positively associated with T cell subset (r=0.955, p<0.01 and negatively associated with DC subset (r=-0.765, p<0.01. There were significant positive correlations between CD4+CD25+CD127dim Tregs/PBL and granulocyte counts and RET% (r=0.739 and r=0.749, respectively, p<0.01. Conclusion: The decrease of CD4+CD25+CD127dim Tregs in SAA patients may cause excessive functioning of T lymphocytes and thus lead to hematopoiesis failure in SAA.

A study on some welfare-related parameters of hDAF transgenic pigs when compared with their conventional close relatives.

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Martelli, G; Sardi, L; Stancampiano, L; Govoni, N; Zannoni, A; Nannoni, E; Forni, M; Bacci, M L

2014-05-01

Pigs are increasingly used in medical research as transgenic laboratory animals; however, little knowledge is presently available concerning their welfare assessment. The aim of the present study was to investigate some welfare-related parameters of transgenic pigs intended for xenotrasplantation (human decay-accelerating factor (hDAF)) when compared with their conventional (i.e. not transgenic) close relatives (full sibs and half sibs). A total of 14 Large White female transgenic pigs and 10 female non-transgenic (conventional) pigs from four litters were used. All pigs were from the same conventional boar, donor of the semen treated for sperm-mediated gene transfer. During the experiment, BW ranged from 50 to about 80 kg and pigs were weighed at the beginning and at the end of the experiment. Animals were subjected to a set of behavioural tests: a human approach test (HAT), a novel object test (NOT) and an open-door test (ODT). Food preferences were tested through the offer of different foods (banana, apple, carrot, cracker and lemon). During a 4-day period, pigs were diurnally videotaped to study the prevalence of the different behaviours and social interactions (aggressive and non-aggressive interactions). At the end of the trial, cortisol level had been assessed on bristles. No significant differences (P>0.05) were observed between hDAF transgenic and conventional pigs with respect to growth traits, reactivity towards unexpected situations (HAT, NOT, ODT), food preferences, main behavioural traits, social interactions and hair cortisol.

Assessing the factor structures of the 55- and 22-item versions of the conformity to masculine norms inventory.

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Owen, Jesse

2011-03-01

The current study examined the psychometric properties of the abbreviated versions, 55- and 22-items, of the Conformity to Masculine Norms Inventory (CMNI). The authors tested the factor structure for the 11 subscales of the CMNI-55 and the global masculinity factor for the CMNI-55 and the CMNI-22. In a clinical sample of men and women (n=522), the results supported the 11-factor model. Furthermore, the factor structure was invariant for men and women. The higher order model, which tested the utility of the global masculine score, demonstrated marginal fit. The factor structures for the global masculinity score for the CMNI-22 demonstrated poor fit. Collectively, the results suggest that the CMNI-55 is better represented in a multidimensional construct. The subscales' alpha levels and factor loadings were, generally, within acceptable limits. Gender and ethnic mean level differences are also reported. © The Author(s) 2011

Morphogenesis of Strongyloides stercoralis infective larvae requires the DAF-16 ortholog FKTF-1.

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Michelle L Castelletto

2009-04-01

Full Text Available Based on metabolic and morphological similarities between infective third-stage larvae of parasitic nematodes and dauer larvae of Caenorhabditis elegans, it is hypothesized that similar genetic mechanisms control the development of these forms. In the parasite Strongyloides stercoralis, FKTF-1 is an ortholog of DAF-16, a forkhead transcription factor that regulates dauer larval development in C. elegans. Using transgenesis, we investigated the role of FKTF-1 in S. stercoralis' infective larval development. In first-stage larvae, GFP-tagged recombinant FKTF-1b localizes to the pharynx and hypodermis, tissues remodeled in infective larvae. Activating and inactivating mutations at predicted AKT phosphorylation sites on FKTF-1b give constitutive cytoplasmic and nuclear localization of the protein, respectively, indicating that its post-translational regulation is similar to other FOXO-class transcription factors. Mutant constructs designed to interfere with endogenous FKTF-1b function altered the intestinal and pharyngeal development of the larvae and resulted in some transgenic larvae failing to arrest in the infective stage. Our findings indicate that FKTF-1b is required for proper morphogenesis of S. stercoralis infective larvae and support the overall hypothesis of similar regulation of dauer development in C. elegans and the formation of infective larvae in parasitic nematodes.

FOXO/DAF-16 Activation Slows Down Turnover of the Majority of Proteins in C. elegans.

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Dhondt, Ineke; Petyuk, Vladislav A; Cai, Huaihan; Vandemeulebroucke, Lieselot; Vierstraete, Andy; Smith, Richard D; Depuydt, Geert; Braeckman, Bart P

2016-09-13

Most aging hypotheses assume the accumulation of damage, resulting in gradual physiological decline and, ultimately, death. Avoiding protein damage accumulation by enhanced turnover should slow down the aging process and extend the lifespan. However, lowering translational efficiency extends rather than shortens the lifespan in C. elegans. We studied turnover of individual proteins in the long-lived daf-2 mutant by combining SILeNCe (stable isotope labeling by nitrogen in Caenorhabditiselegans) and mass spectrometry. Intriguingly, the majority of proteins displayed prolonged half-lives in daf-2, whereas others remained unchanged, signifying that longevity is not supported by high protein turnover. This slowdown was most prominent for translation-related and mitochondrial proteins. In contrast, the high turnover of lysosomal hydrolases and very low turnover of cytoskeletal proteins remained largely unchanged. The slowdown of protein dynamics and decreased abundance of the translational machinery may point to the importance of anabolic attenuation in lifespan extension, as suggested by the hyperfunction theory. Copyright © 2016 The Author(s). Published by Elsevier Inc. All rights reserved.

CD47 is an adverse prognostic factor and a therapeutic target in gastric cancer

International Nuclear Information System (INIS)

Yoshida, Kazumichi; Tsujimoto, Hironori; Matsumura, Kouji; Kinoshita, Manabu; Takahata, Risa; Matsumoto, Yusuke; Hiraki, Shuichi; Ono, Satoshi; Seki, Shuhji; Yamamoto, Junji; Hase, Kazuo

2015-01-01

CD47 is an antiphagocytic molecule that acts via ligation to signal regulatory protein alpha on phagocytes; its enhanced expression and therapeutic targeting have recently been reported for several malignancies. However, CD47 expression in gastric cancer is not well documented. Immunohistochemical expression of CD47 in surgical specimens was investigated. Expression of CD47 and CD44, a known gastric cancer stem cell marker, were investigated in gastric cancer cell lines by flow cytometry. MKN45 and MKN74 gastric cancer cells were sorted by fluorescence-activated cell sorting according to CD44 and CD47 expression levels, and their in vitro proliferation, spheroid-forming capacity, and in vivo tumorigenicity were studied. In vitro phagocytosis of cancer cells by human macrophages in the presence of a CD47 blocking monoclonal antibody (B6H12) and the survival of immunodeficient mice intraperitoneally engrafted with MKN45 cells and B6H12 were compared to experiments using control antibodies. Immunohistochemistry of the clinical specimens indicated that CD47 was positive in 57 out of 115 cases, and its positivity was an independent adverse prognostic factor. Approximately 90% of the MKN45 and MKN74 cells expressed CD47 and CD44. CD47 hi gastric cancer cells showed significantly higher proliferation and spheroid colony formation than CD47 lo , and CD44 hi CD47 hi cells showed the highest proliferation in vitro and tumorigenicity in vivo. B6H12 significantly enhanced in vitro phagocytosis of cancer cells by human macrophages and prolonged the survival of intraperitoneal cancer dissemination in mice compared to control antibodies. In conclusion, CD47 is an adverse prognostic factor and promising therapeutic target in gastric cancer

Soluble CD30 as a prognostic factor for outcome following renal transplantation.

Science.gov (United States)

Platt, R E; Wu, K S T; Poole, K; Newstead, C G; Clark, B

2009-07-01

To determine whether measurement of soluble CD30 (sCD30) levels predicts for early rejection in a cohort of first deceased kidney transplant recipients. Pre-transplant serum samples were analysed for sCD30 levels using a commercial ELISA kit (Biotest). A 100 U/ml cut-off for "high sCD30" was applied. Clinical outcome parameters were biopsy-proven rejection episodes, creatinine levels and glomerular filtration rate. In the cohort of patients who experienced at least one episode of rejection in the first 6 months post-transplant, levels of pre-transplant sCD30 were significantly higher than in those who did not experience rejection. Despite this association, the occurrence of a high sCD30 level did not predict for rejection on an individual basis. The prognostic value of pre-transplant sCD30 testing is diminished by the large number of patients with high sCD30 levels who do not develop rejection. Although this limits the utility of the test in informing clinical management of individual patients, a high pre-transplant sCD30 level should still be considered a risk factor for poorer outcome.

CD34+ cells cultured in stem cell factor and interleukin-2 generate CD56+ cells with antiproliferative effects on tumor cell lines

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Hensel Nancy

2005-04-01

Full Text Available Abstract In vitro stimulation of CD34+ cells with IL-2 induces NK cell differentiation. In order to define the stages of NK cell development, which influence their generation from CD34 cells, we cultured G-CSF mobilized peripheral blood CD34+ cells in the presence of stem cell factor and IL-2. After three weeks culture we found a diversity of CD56+ subsets which possessed granzyme A, but lacked the cytotoxic apparatus required for classical NK-like cytotoxicity. However, these CD56+ cells had the unusual property of inhibiting proliferation of K562 and P815 cell lines in a cell-contact dependent fashion.

Comparison of DNA aneuploidy, chromosome 1 abnormalities, MYCN amplification and CD44 expression as prognostic factors in neuroblastoma.

Science.gov (United States)

Christiansen, H; Sahin, K; Berthold, F; Hero, B; Terpe, H J; Lampert, F

1995-01-01

A comparison of the prognostic impact of five molecular variables in a large series was made, including tests of their nonrandom association and multivariate analysis. Molecular data were available for 377 patients and MYCN amplification, cytogenetic chromosome 1p deletion, loss of chromosome 1p heterozygosity, DNA ploidy and CD44 expression were investigated. Their interdependence and influence on event-free survival was tested uni- and multivariately using Pearson's chi 2-test, Kaplan-Meier estimates, log rank tests and the Cox's regression model. MYCN amplification was present in 18% (58/322) of cases and predicted poorer prognosis in localised (P < 0.001), metastatic (P = 0.002) and even 4S (P = 0.040) disease. CD44 expression was found in 86% (127/148) of cases, and was a marker for favourable outcome in patients with neuroblastoma stages 1-3 (P = 0.003) and 4 (P = 0.017). Chromosome 1p deletion was cytogenetically detected in 51% (28/55), and indicated reduced event-free survival in localised neuroblastoma (P = 0.020). DNA ploidy and loss of heterozygosity on chromosome 1p were of less prognostic value. Most factors of prognostic significance were associated with each other. By multivariate analysis, MYCN was selected as the only relevant factor. Risk estimation of high discriminating power is, therefore, possible for patients with localised and metastatic neuroblastoma using stage and MYCN.

The regulation of protein synthesis and translation factors by CD3 and CD28 in human primary T lymphocytes

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Proud Christopher G

2002-05-01

Full Text Available Abstract Background Activation of human resting T lymphocytes results in an immediate increase in protein synthesis. The increase in protein synthesis after 16–24 h has been linked to the increased protein levels of translation initiation factors. However, the regulation of protein synthesis during the early onset of T cell activation has not been studied in great detail. We studied the regulation of protein synthesis after 1 h of activation using αCD3 antibody to stimulate the T cell receptor and αCD28 antibody to provide the co-stimulus. Results Activation of the T cells with both antibodies led to a sustained increase in the rate of protein synthesis. The activities and/or phosphorylation states of several translation factors were studied during the first hour of stimulation with αCD3 and αCD28 to explore the mechanism underlying the activation of protein synthesis. The initial increase in protein synthesis was accompanied by activation of the guanine nucleotide exchange factor, eukaryotic initiation factor (eIF 2B, and of p70 S6 kinase and by dephosphorylation of eukaryotic elongation factor (eEF 2. Similar signal transduction pathways, as assessed using signal transduction inhibitors, are involved in the regulation of protein synthesis, eIF2B activity and p70 S6 kinase activity. A new finding was that the p38 MAPK α/β pathway was involved in the regulation of overall protein synthesis in primary T cells. Unexpectedly, no changes were detected in the phosphorylation state of the cap-binding protein eIF4E and the eIF4E-binding protein 4E-BP1, or the formation of the cap-binding complex eIF4F. Conclusions Both eIF2B and p70 S6 kinase play important roles in the regulation of protein synthesis during the early onset of T cell activation.

Assessment of the frequency of regulatory T cells (CD4+CD25+CD127-) in children with hemophilia A: relation to factor VIII inhibitors and disease severity.

Science.gov (United States)

El-Asrar, Mohamed Abo; Hamed, Ahmed El-Saeed; Darwish, Yasser Wagih; Ismail, Eman Abdel Rahman; Ismail, Noha Ali

2016-01-01

A rapidly growing evidence showed that regulatory T cells (Tregs) play a crucial role in tolerance to coagulation factors and may be involved in the pathogenesis of inhibitor formation in patients with hemophilia. We determined the percentage of Tregs (CD4CD25CD127) in 45 children with hemophilia A compared with 45 healthy controls, and assessed their relation to the clinical characteristics of patients and factor VIII (FVIII) inhibitors. Patients were studied stressing on frequency of bleeding attacks, joint pain, history of viral hepatitis, and the received therapy (FVIII precipitate/cryotherapy). FVIII activity and FVIII inhibitors were assessed with flow cytometric analysis of CD4CD25CD127 Tregs. According to residual FVIII activity levels, 30 patients (66.7%) had mild/moderate hemophilia A, whereas 15 (33.3%) patients had severe hemophilia A. The frequency of Tregs was significantly lower among all patients with hemophilia A compared with controls (2.59 ± 1.1 versus 3.73 ± 1.12%; P = 0.002). Tregs were significantly decreased among patients with FVIII inhibitors compared with the inhibitor-negative group (P hemophilia A had lower Tregs levels than those without (P = 0.34 and P = 0.011, respectively). A significant positive correlation was found between the percentage of Tregs and FVIII among hemophilia A patients. ROC curve analysis revealed that the cut-off value of Tregs at 1.91% could differentiate patients with and without FVIII inhibitors, with a sensitivity of 100% and a specificity of 91.3%. We suggest that alteration in the frequency of Tregs in young patients with hemophilia A may contribute to inhibitor formation and disease severity.

Epigenetic landscapes reveal transcription factors regulating CD8+ T cell differentiation

Science.gov (United States)

Yu, Bingfei; Zhang, Kai; Milner, J. Justin; Toma, Clara; Chen, Runqiang; Scott-Browne, James P.; Pereira, Renata M.; Crotty, Shane; Chang, John T.; Pipkin, Matthew E.; Wang, Wei; Goldrath, Ananda W.

2017-01-01

Dynamic changes in the expression of transcription factors (TFs) can influence specification of distinct CD8+ T cell fates, but the observation of equivalent expression of TF among differentially-fated precursor cells suggests additional underlying mechanisms. Here, we profiled genome-wide histone modifications, open chromatin and gene expression of naive, terminal-effector, memory-precursor and memory CD8+ T cell populations induced during the in vivo response to bacterial infection. Integration of these data suggested that TF expression and binding contributed to establishment of subset-specific enhancers during differentiation. We developed a new bioinformatics method using the PageRank algorithm to reveal novel TFs influencing the generation of effector and memory populations. The TFs YY1 and Nr3c1, both constitutively expressed during CD8+ T cell differentiation, regulated the formation of terminal-effector and memory-precursor cell-fates, respectively. Our data define the epigenetic landscape of differentiation intermediates, facilitating identification of TFs with previously unappreciated roles in CD8+ T cell differentiation. PMID:28288100

Optimization of deposition conditions of CdS thin films using response surface methodology

Energy Technology Data Exchange (ETDEWEB)

Yücel, Ersin, E-mail: dr.ersinyucel@gmail.com [Department of Physics, Faculty of Arts and Sciences, Mustafa Kemal University, 31034 Hatay (Turkey); Güler, Nuray [Department of Physics, Faculty of Arts and Sciences, Mustafa Kemal University, 31034 Hatay (Turkey); Yücel, Yasin [Department of Chemistry, Faculty of Arts and Sciences, Mustafa Kemal University, 31034 Hatay (Turkey)

2014-03-15

Highlights: • Statistical methods used for optimization of CdS deposition parameters. • The morphology of the films was smooth, homogeneous and continuous. • Optimal conditions found as pH 11, stirring speed:361 rpm and deposition time: 55 min. • CdS thin film band gap value was 2.72 eV under the optimum conditions. -- Abstract: Cadmium sulfide (CdS) thin films were prepared on glass substrates by chemical bath deposition (CBD) technique under different pH, stirring speed and deposition time. Response Surface Methodology (RSM) and Central Composite Design (CCD) were used to optimization of deposition parameters of the CdS thin films. RSM and CCD were also used to understand the significance and interaction of the factors affecting the film quality. Variables were determined as pH, stirring speed and deposition time. The band gap was chosen as response in the study. Influences of the variables on the band gap and the film quality were investigated. 5-level-3-factor central composite design was employed to evaluate the effects of the deposition conditions parameters such as pH (10.2–11.8), stirring speed (132–468 rpm) and deposition time (33–67 min) on the band gap of the films. The samples were characterized using X-ray diffraction (XRD), scanning electron microscope (SEM) and ultraviolet–visible spectroscopy (UV–vis) measurements. The optimal conditions for the deposition parameters of the CdS thin films have been found to be: pH 11, 361 of stirring speed and 55 min of deposition time. Under the optimal conditions theoretical (predicted) band gap of CdS (2.66 eV) was calculated using optimal coded values from the model and the theoretical value is good agreement with the value (2.72 eV) obtained by verification experiment.

Analysis of CD45- [CD34+/KDR+] endothelial progenitor cells as juvenile protective factors in a rat model of ischemic-hemorrhagic stroke.

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Julius L Decano

Full Text Available Identification of juvenile protective factors (JPFs which are altered with age and contribute to adult-onset diseases could identify novel pathways for reversing the effects of age, an accepted non-modifiable risk factor to adult-onset diseases. Since endothelial progenitor cells (EPCs have been observed to be altered in stroke, hypertension and hypercholesterolemia, said EPCs are candidate JPFs for adult-onset stroke. A priori, if EPC aging plays a 'master-switch JPF-role' in stroke pathogenesis, juvenile EPC therapy alone should delay stroke-onset. Using a hypertensive, transgenic-hyperlipidemic rat model of spontaneous ischemic-hemorrhagic stroke, spTg25, we tested the hypothesis that freshly isolated juvenile EPCs are JPFs that can attenuate stroke progression and delay stroke onset.FACS analysis revealed that CD45- [CD34+/KDR+] EPCs decrease with progression to stroke in spTg25 rats, exhibit differential expression of the dual endodthelin-1/VEGFsp receptor (DEspR and undergo differential DEspR-subtype specific changes in number and in vitro angiogenic tube-incorporation. In vivo EPC infusion of male, juvenile non-expanded cd45-[CD34+/KDR+] EPCs into female stroke-prone rats prior to stroke attenuated progression and delayed stroke onset (P<0.003. Detection of Y-chromosome DNA in brain microvessels of EPC-treated female spTg25 rats indicates integration of male EPCs into female rat brain microvessels. Gradient-echo MRI showed delay of ischemic-hemorrhagic lesions in EPC-treated rats. Real-time RT-PCR pathway-specific array-analysis revealed age-associated gene expression changes in CD45-[CD34+/KDR]EPC subtypes, which were accelerated in stroke-prone rats. Pro-angiogenic genes implicated in intimal hyperplasia were increased in stroke-prone rat EPCs (P<0.0001, suggesting a maladaptive endothelial repair system which acts like a double-edged sword repairing while predisposing to age-associated intimal hyperplasia.Altogether, the data

Regulation of the CD56 promoter and its association with proliferation, anti-apoptosis and clinical factors in multiple myeloma

DEFF Research Database (Denmark)

Damgaard, Tina; Knudsen, Lene M; Dahl, Inger Marie S

2009-01-01

the regulation of the CD56 promoter in relation to typical clinical factors. We used qPCR and FACS to measure the expression levels of CD56, and potential regulatory factors in patients with MM and related these with MM progression/prognosis. The transcription factors BTBD3, Pax5, RUNX1 and MMSET were positively...... associated with CD56 expression, as was CYCLIN D1, which is involved in disease progression, anti-apoptosis and proliferation. RUNX1 was negatively associated with the survival of stem-cell transplanted patients. Our findings propose four potential activators of the CD56 promoter and for CD56 to be involved...

Criticality Safety Evaluation for the TACS at DAF

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Percher, C. M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Heinrichs, D. P. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

2011-06-10

Hands-on experimental training in the physical behavior of multiplying systems is one of ten key areas of training required for practitioners to become qualified in the discipline of criticality safety as identified in DOE-STD-1135-99, Guidance for Nuclear Criticality Safety Engineer Training and Qualification. This document is a criticality safety evaluation of the training activities and operations associated with HS-3201-P, Nuclear Criticality 4-Day Training Course (Practical). This course was designed to also address the training needs of nuclear criticality safety professionals under the auspices of the NNSA Nuclear Criticality Safety Program1. The hands-on, or laboratory, portion of the course will utilize the Training Assembly for Criticality Safety (TACS) and will be conducted in the Device Assembly Facility (DAF) at the Nevada Nuclear Security Site (NNSS). The training activities will be conducted by Lawrence Livermore National Laboratory following the requirements of an Integrated Work Sheet (IWS) and associated Safety Plan. Students will be allowed to handle the fissile material under the supervision of an LLNL Certified Fissile Material Handler.

Nuclear decay scheme studies of 30-h 131Te/sup m/, 25-min 131Te/sup g/, and 55.5-min 105Cd

International Nuclear Information System (INIS)

Jackson, S.V.

1975-01-01

High-resolution Ge(Li) detectors have been used to observe γ-ray singles and coincidence spectra of 30-h 11 / 2 - , /sup 131m/Te, 25-min 3 / 2 + , and 55.5-min 5 / 2 + 105 Cd. Sources of /sup 131m/Te and /sup 131g/Te were produced by neutron irradiation of enriched 130 Te metal, and, in the case of /sup 131m/Te, were chemically purified to remove the 131 I daughter. A total of 190 and 80 γ-rays are attributed to the decays of /sup 131m/Te and /sup 131g/Te, respectively; and 174 and 77 of these transitions have been placed in a 131 I level scheme involving 52 excited states. Absolute β group intensities were determined for the transitions to 131 I levels. Spin and parity assignments were made for all observed levels. The β feeding from the 11 / 2 - /sup 131m/Te to the 7 / 2 + 131 I ground state was determined to be (5.2 +- 3.0) percent (log ft = 10.5). The isomeric transition of 11 / 2 - /sup 131m/Te to 3 / 2 + /sup 131g/Te was determined to be (22.2 +- 1.6) percent. The 6-nsec isomer in 131 I at 1797 keV has been assigned as 15 / 2 - and interpreted as a πν 1 ν 2 three quasi-particle state. Sources of 105 Cd were produced via the 106 Cd(n,2n) reaction on enriched 106 CdO using 14 MeV neutrons. A total of 274 γ-rays are attributed to the decay of 105 Cd, and 248 of these have been placed in a 105 Ag level scheme involving 50 excited states. Absolute values for the β + /EC transition intensities to 105 Ag levels were determined. The β + /EC feeding from the 5 / 2 + 105 Cd to the 7 / 2 + 25.5-keV isomeric state in 105 Ag was determined to be (51.4 +- 4.0) percent (log ft = 5.4). The experimentally determined level structures of 131 I and 105 Cd are interpreted in terms of the shell model and core excitation considerations with emphasis placed on the core coupling model and the three-particle models. (U.S.)

The transcription factor KLF2 restrains CD4⁺ T follicular helper cell differentiation.

Science.gov (United States)

Lee, June-Yong; Skon, Cara N; Lee, You Jeong; Oh, Soohwan; Taylor, Justin J; Malhotra, Deepali; Jenkins, Marc K; Rosenfeld, M Geoffrey; Hogquist, Kristin A; Jameson, Stephen C

2015-02-17

T follicular helper (Tfh) cells are essential for efficient B cell responses, yet the factors that regulate differentiation of this CD4(+) T cell subset are incompletely understood. Here we found that the KLF2 transcription factor serves to restrain Tfh cell generation. Induced KLF2 deficiency in activated CD4(+) T cells led to increased Tfh cell generation and B cell priming, whereas KLF2 overexpression prevented Tfh cell production. KLF2 promotes expression of the trafficking receptor S1PR1, and S1PR1 downregulation is essential for efficient Tfh cell production. However, KLF2 also induced expression of the transcription factor Blimp-1, which repressed transcription factor Bcl-6 and thereby impaired Tfh cell differentiation. Furthermore, KLF2 induced expression of the transcription factors T-bet and GATA3 and enhanced Th1 differentiation. Hence, our data indicate KLF2 is pivotal for coordinating CD4(+) T cell differentiation through two distinct and complementary mechanisms: via control of T cell localization and by regulation of lineage-defining transcription factors. Copyright © 2015 Elsevier Inc. All rights reserved.

Association Between Promoter Polymorphisms in CD46 and CD59 in Kidney Donors and Transplant Outcome

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Laura A. Michielsen

2018-05-01

Full Text Available Complement regulating proteins, including CD46, CD55, and CD59, protect cells against self-damage. Because of their expression on the donor endothelium, they are hypothesized to be involved in accommodation. Polymorphisms in their promoter regions may affect their expression. The aim of this study was to investigate if donor polymorphisms in complement regulating proteins influence kidney transplant outcomes. We included 306 kidney transplantations between 2005 and 2010. Five polymorphisms in the promoters of CD46, CD55, and CD59 were genotyped. A CD59 promoter polymorphism (rs147788946 in donors was associated with a lower 1-year rejection-free survival [adjusted hazard ratio (aHR 2.18, 95% CI 1.12–4.24] and a trend toward impaired 5-year graft survival (p = 0.08. Patients receiving a kidney with at least one G allele for the CD46 promoter polymorphism rs2796267 (A/G showed a lower rejection-free survival, though this became borderline significant after adjustment for potential confounders (aHR 1.87, 95% CI 0.96–3.65. A second CD46 promoter polymorphism (rs2796268, A/G, was also associated with a lower freedom from acute rejection in the presence of at least one G allele (aHR 1.95, 95% CI 1.03–3.68. Finally, the combined presence of both favorable genotypes of rs2796267 and rs147788946 had an additional protective effect both on acute rejection (p = 0.006 and graft survival (p = 0.03. These findings could help to identify patients who could benefit from intensified immunosuppressive therapy or novel complement inhibitory therapeutics.

Using weigh-in-motion data to determine bridge dynamic amplification factor

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Kalin Jan

2015-01-01

Full Text Available The dynamic component of bridge traffic loading is commonly taken into account with a Dynamic Amplification Factor (DAF – the ratio between the maximum dynamic and static load effects on a bridge. In the design codes, this factor is generally higher than in reality. While this is fine for new bridges that must account for various risks during their life-time, it imposes unnecessary conservativism into assessment of the existing well defined bridges. Therefore, analysis of existing bridges should apply more realistic DAF values. One way of obtaining them experimentally is by bridge weigh-in-motion (B-WIM measurements, which use an existing instrumented bridge or culvert to weigh all crossing vehicles at highway speeds. The B-WIM system had been equipped with two methods of obtaining an approximation to the static response of the. The first method uses the sum of influence lines. This method relies on accurate axle identification, the failure of which can have a large influence on the DAF value. The other method uses a pre-determined low-pass filter to remove the dynamic component of the measured signal; however an expert is needed to set the filter parameters. A new approach that tries to eliminate these two drawbacks has been developed. In this approach the parameters for the filter are determined automatically by fitting the filtered response to the sum of the influence lines. The measurement of DAF on a typical bridge site agrees with experiments performed in the ARCHES [1] project: dynamic amplification decreases as static loading increases.

A novel strategy inducing autophagic cell death in Burkitt's lymphoma cells with anti-CD19-targeted liposomal rapamycin

International Nuclear Information System (INIS)

Ono, K; Sato, T; Iyama, S; Tatekoshi, A; Hashimoto, A; Kamihara, Y; Horiguchi, H; Kikuchi, S; Kawano, Y; Takada, K; Hayashi, T; Miyanishi, K; Sato, Y; Takimoto, R; Kobune, M; Kato, J

2014-01-01

Relapsed or refractory Burkitt's lymphoma often has a poor prognosis in spite of intensive chemotherapy that induces apoptotic and/or necrotic death of lymphoma cells. Rapamycin (Rap) brings about autophagy, and could be another treatment. Further, anti-CD19-targeted liposomal delivery may enable Rap to kill lymphoma cells specifically. Rap was encapsulated by anionic liposome and conjugated with anti-CD19 antibody (CD19-GL-Rap) or anti-CD2 antibody (CD2-GL-Rap) as a control. A fluorescent probe Cy5.5 was also liposomized in the same way (CD19 or CD2-GL-Cy5.5) to examine the efficacy of anti-CD19-targeted liposomal delivery into CD19-positive Burkitt's lymphoma cell line, SKW6.4. CD19-GL-Cy5.5 was more effectively uptaken into SKW6.4 cells than CD2-GL-Cy5.5 in vitro. When the cells were inoculated subcutaneously into nonobese diabetic/severe combined immunodeficiency mice, intravenously administered CD19-GL-Cy5.5 made the subcutaneous tumor fluorescent, while CD2-GL-Cy5.5 did not. Further, CD19-GL-Rap had a greater cytocidal effect on not only SKW6.4 cells but also Burkitt's lymphoma cells derived from patients than CD2-GL-Rap in vitro. The specific toxicity of CD19-GL-Rap was cancelled by neutralizing anti-CD19 antibody. The survival period of mice treated with intravenous CD19-GL-Rap was significantly longer than that of mice treated with CD2-GL-Rap after intraperitoneal inoculation of SKW6.4 cells. Anti-CD19-targeted liposomal Rap could be a promising lymphoma cell-specific treatment inducing autophagic cell death

Neuronal migration is regulated by endogenous RNAi and chromatin-binding factor ZFP-1/AF10 in Caenorhabditis elegans.

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Kennedy, Lisa M; Grishok, Alla

2014-05-01

Endogenous short RNAs and the conserved plant homeodomain (PHD) zinc-finger protein ZFP-1/AF10 regulate overlapping sets of genes in Caenorhabditis elegans, which suggests that they control common biological pathways. We have shown recently that the RNAi factor RDE-4 and ZFP-1 negatively modulate transcription of the insulin/PI3 signaling-dependent kinase PDK-1 to promote C. elegans fitness. Moreover, we have demonstrated that the insulin/IGF-1-PI3K-signaling pathway regulates the activity of the DAF-16/FOXO transcription factor in the hypodermis to nonautonomously promote the anterior migrations of the hermaphrodite-specific neurons (HSNs) during embryogenesis of C. elegans. In this study, we implicate the PHD-containing isoform of ZFP-1 and endogenous RNAi in the regulation of HSN migration. ZFP-1 affects HSN migration in part through its negative effect on pdk-1 transcription and modulation of downstream DAF-16 activity. We also identify a novel role for ZFP-1 and RNAi pathway components, including RDE-4, in the regulation of HSN migration in parallel with DAF-16. Therefore, the coordinated activities of DAF-16, ZFP-1, and endogenous RNAi contribute to gene regulation during development to ensure proper neuronal positioning.

Tchaikovsky, P.: Orchestral Suite no. 3 op. 55 / Terry Williams

Index Scriptorium Estoniae

Williams, Terry

1996-01-01

Uuest heliplaadist "Tchaikovsky, P.: Orchestral Suite no. 3 op. 55. Francesca di Rimini op. 32. Detroit Symphony Orchestra, Neeme Järvi". Chandos CHAN 9 419, distribution Media 7 (CD: 160F). TT: 1h 09'20"

The effect of stem cell factor on proliferation of human endometrial CD146+ cells

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Mehri Fayazi

2016-07-01

Full Text Available Background: Stem cell factor (SCF is a transcriptional factor which plays crucial roles in normal proliferation, differentiation and survival in a range of stem cells. Objective: The aim of the present study was to examine the proliferation effect of different concentrations of SCF on expansion of human endometrial CD146+ cells. Materials and Methods: In this experimental study, total populations of isolated human endometrial suspensions after fourth passage were isolated by magnetic activated cell sorting (MACS into CD146+ cells. Human endometrial CD146+ cells were karyotyped and tested for the effect of SCF on proliferation of CD146+ cells, then different concentrations of 0, 12.5, 25, 50 and 100 ng/ml was carried out and mitogens-stimulated endometrial CD146+ cells proliferation was assessed by MTT assay. Results: Chromosomal analysis showed a normal metaphase spread and 46XX karyotype. The proliferation rate of endometrial CD146P + P cells in the presence of 0, 12.5, 25, 50 and 100 ng/ml SCF were 0.945±0.094, 0.962±0.151, 0.988±0.028, 1.679±0.012 and 1.129±0.145 respectively. There was a significant increase in stem/ stromal cell proliferation following in vitro treatment by 50 ng/ml than other concentrations of SCF (p=0.01. Conclusion: The present study suggests that SCF could have effect on the proliferation and cell survival of human endometrial CD146P+P cells and it has important implications for medical sciences and cell therapies

Tumor Necrosis Factor-Mediated Survival of CD169+ Cells Promotes Immune Activation during Vesicular Stomatitis Virus Infection

DEFF Research Database (Denmark)

Shinde, Prashant V; Xu, Haifeng C; Maney, Sathish Kumar

2018-01-01

Innate immune activation is essential to mount an effective antiviral response and to prime adaptive immunity. Although a crucial role of CD169(+) cells during vesicular stomatitis virus (VSV) infections is increasingly recognized, factors regulating CD169(+) cells during viral infections remain...... stomatitis virus infection, phagocytes produce tumor necrosis factor (TNF) which signals via TNFR1 and promote "enforced virus replication" in CD169(+) macrophages. Consequently, lack of TNF or TNFR1 resulted in defective immune activation and VSV clearance....

Cis and trans acting factors involved in human cytomegalovirus experimental and natural latent infection of CD14 (+ monocytes and CD34 (+ cells.

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Cyprian C Rossetto

Full Text Available The parameters involved in human cytomegalovirus (HCMV latent infection in CD14 (+ and CD34 (+ cells remain poorly identified. Using next generation sequencing we deduced the transcriptome of HCMV latently infected CD14 (+ and CD34 (+ cells in experimental as well as natural latency settings. The gene expression profile from natural infection in HCMV seropositive donors closely matched experimental latency models, and included two long non-coding RNAs (lncRNAs, RNA4.9 and RNA2.7 as well as the mRNAs encoding replication factors UL84 and UL44. Chromatin immunoprecipitation assays on experimentally infected CD14 (+ monocytes followed by next generation sequencing (ChIP-Seq were employed to demonstrate both UL84 and UL44 proteins interacted with the latent viral genome and overlapped at 5 of the 8 loci identified. RNA4.9 interacts with components of the polycomb repression complex (PRC as well as with the MIE promoter region where the enrichment of the repressive H3K27me3 mark suggests that this lncRNA represses transcription. Formaldehyde Assisted Isolation of Regulatory Elements (FAIRE, which identifies nucleosome-depleted viral DNA, was used to confirm that latent mRNAs were associated with actively transcribed, FAIRE analysis also showed that the terminal repeat (TR region of the latent viral genome is depleted of nucleosomes suggesting that this region may contain an element mediating viral genome maintenance. ChIP assays show that the viral TR region interacts with factors associated with the pre replication complex and a plasmid subclone containing the HCMV TR element persisted in latently infected CD14 (+ monocytes, strongly suggesting that the TR region mediates viral chromosome maintenance.

Human tumor cells induce angiogenesis through positive feedback between CD147 and insulin-like growth factor-I.

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Yanke Chen

Full Text Available Tumor angiogenesis is a complex process based upon a sequence of interactions between tumor cells and endothelial cells. Previous studies have shown that CD147 was correlated with tumor angiogenesis through increasing tumor cell secretion of vascular endothelial growth factor (VEGF and matrix metalloproteinases (MMPs. In this study, we made a three-dimensional (3D tumor angiogenesis model using a co-culture system of human hepatocellular carcinoma cells SMMC-7721 and humanumbilical vein endothelial cells (HUVECs in vitro. We found that CD147-expressing cancer cells could promote HUVECs to form net-like structures resembling the neo-vasculature, whereas the ability of proliferation, migration and tube formation of HUVECs was significantly decreased in tumor conditioned medium (TCM of SMMC-7721 cells transfected with specific CD147-siRNA. Furthermore, by assaying the change of pro-angiogenic factors in TCM, we found that the inhibition of CD147 expression led to significant decrease of VEGF and insulin-like growth factor-I (IGF-I secretion. Interestingly, we also found that IGF-I up-regulated the expression of CD147 in both tumor cells and HUVECs. These findings suggest that there is a positive feedback between CD147 and IGF-I at the tumor-endothelial interface and CD147 initiates the formation of an angiogenesis niche.

Uptake of Mn and Cd by Wild Water Spinach and Their Bioaccumulation and Translocation Factors

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Billy Teck Huat Guan

2017-01-01

Full Text Available Polluted ponds and lakes close to agricultural activities become the exposure route of manganese (Mn and cadmium (Cd to aquatic plants in near vicinity. Therefore, a study of the uptake, bioaccumulation, and translocation of Mn and Cd by the water spinach (Ipomoea aquatica is presented in this paper. Different concentrations of Mn and Cd were added to the hydroponic nutrient solution that was used to grow the plants for the heavy metal uptake experiment under greenhouse conditions. The plant samples exposed to heavy metals were collected to determine the metal concentrations using atomic absorption spectroscopy (AAS and the metal concentrations were found for Mn was between 1.589 to 9.696 µg/g and Cd from 5.309 to 10.947 µg/g. The correlation and regression results showed that the water-to-shoot bioaccumulation factor (BAF decreased for Mn, while root-to-shoot translocation factor (TF values increased in the order Cd > Mn to the increasing levels of metals in the water. Furthermore, it was revealed from the two-way analysis of variance (ANOVA that the different metal types influenced the BAF and TF values at different metal concentration treatments.

Enhancing organic matter removal in desalination pretreatment systems by application of dissolved air flotation

DEFF Research Database (Denmark)

Shutova, Yulia; Karna, Barun Lal; Hambly, Adam C.

2016-01-01

on the sample, respectively. The optimal normalised coagulant dose (Fe3+ to DOC ratio) was observed to be 0.5-4 at pH5.5 increasing to 4-12 at pH7.5. At pH5.5, the optimum coagulant dose increased with increasing humic character of the feed water. Overall, the OM removal efficiency by DAF observed in this study......Membrane fouling in reverse osmosis (RO) systems caused by organic matter (OM) remains a significant operational issue during desalination. Dissolved air flotation (DAF) has recently received attention as a pre-treatment option for seawater OM removal; however, only a limited number of studies have...... been undertaken. This may be because it is difficult to characterise OM in seawater due to the high salt content and low carbon concentration. In this study, DAF pre-treatment experiments were conducted using a model seawater solution, and real seawater and brackish water samples. DAF performance...

Slow-release nitrogen fertilizers can improve yield and reduce Cd concentration in pakchoi (Brassica chinensis L.) grown in Cd-contaminated soil.

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Zhang, Ran-Ran; Liu, Yue; Xue, Wan-Lei; Chen, Rong-Xin; Du, Shao-Ting; Jin, Chong-Wei

2016-12-01

Cadmium (Cd) pollution in vegetable crops has become a serious problem in recent years. Owing to the limited availability of arable land resources, large areas of Cd-contaminated lands are inevitably being used for the production of vegetables, posing great risks to human health via the food chain. However, strategies to improve yield and reduce Cd concentration in crops grown in contaminated soils are being developed. In the present study, using pot experiments, we investigated the effects of two slow-release nitrogen fertilizers (SRNFs), resin-coated ammonium nitrate (Osmocote 313s ), and resin-coated urea (urea 620 ), on the growth and Cd concentration of the Cd-contaminated pakchoi. The results showed that pakchoi grown in soil containing 5 mg kg -1 of Cd-induced oxidative stress (indicated by malondialdehyde (MDA), H 2 O 2 , and O 2 ·- ) and photosynthesis inhibition, which in turn was restored with the application of SRNFs. However, pakchoi grown in Cd-contaminated soil supplied with Osmocote 313s and urea 620 showed 103 and 203 % increase in fresh weight and 51-55 % and 44-56 % decrease in Cd concentration, respectively, as compared with their controls (pakchoi treated with instant soluble nitrogen fertilizers). On the basis of an increase in their tolerance index (47-238 %) and a decrease in their translocation factor (7.5-21.6 %), we inferred that the plants treated with SRNFs have a stronger tolerance to Cd and a lower efficiency of Cd translocation to edible parts than those treated with instant soluble nitrogen fertilizers. Therefore, in terms of both crop production and food safety, application of SRNFs could be an effective strategy for improving both biomass production and quality in pakchoi grown under Cd stress.

Spanish validation of the 10-item Connor-Davidson Resilience Scale (CD-RISC 10) with non-professional caregivers.

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Blanco, Vanessa; Guisande, María Adelina; Sánchez, María Teresa; Otero, Patricia; Vázquez, Fernando L

2017-11-08

Despite the importance of resilience in populations under stress, and the fact that the 10-item version Connor-Davidson Resilience Scale (CD-RISC 10) is the shortest instrument for reliable and valid evaluation of resilience, there are no data on their psychometric properties in non-professional caregivers. The aim of this study was to analyze the psychometric properties and factorial structure of the spanish version of the CD-RISC 10 in non-professional caregivers. Independently trained assessors evaluated resilience, self-esteem, social support, emotional distress and depression in a sample of 294 caregivers (89.8% women, mean age 55.3 years). The internal consistency of CD-RISC 10 was α = .86. A single factor was found that accounted for 44.7% of the total variance. Confirmatory factor analysis corroborated this unifactorial model. The CD-RISC 10 was significantly correlated with the self-esteem (r = .416, p caregivers with depression (sensitivity = 70.0%, specificity = 68.2%). The CD-RISC 10 is a reliable and valid instrument to evaluate resilience in the caregiver population.

Structural modeling and DNA binding autoinhibition analysis of Ergp55, a critical transcription factor in prostate cancer.

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Shanti P Gangwar

Full Text Available BACKGROUND: The Ergp55 protein belongs to Ets family of transcription factor. The Ets proteins are highly conserved in their DNA binding domain and involved in various development processes and regulation of cancer metabolism. To study the structure and DNA binding autoinhibition mechanism of Ergp55 protein, we have produced full length and smaller polypeptides of Ergp55 protein in E. coli and characterized using various biophysical techniques. RESULTS: The Ergp55 polypeptides contain large amount of α-helix and random coil structures as measured by circular dichorism spectroscopy. The full length Ergp55 forms a flexible and elongated molecule as revealed by molecular modeling, dynamics simulation and structural prediction algorithms. The binding analyses of Ergp55 polypeptides with target DNA sequences of E74 and cfos promoters indicate that longer fragments of Ergp55 (beyond the Ets domain showed the evidence of auto-inhibition. This study also revealed the parts of Ergp55 protein that mediate auto-inhibition. SIGNIFICANCE: The current study will aid in designing the compounds that stabilize the inhibited form of Ergp55 and inhibit its binding to promoter DNA. It will contribute in the development of drugs targeting Ergp55 for the prostate cancer treatment.

Epigenetic landscapes reveal transcription factors that regulate CD8+ T cell differentiation.

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Yu, Bingfei; Zhang, Kai; Milner, J Justin; Toma, Clara; Chen, Runqiang; Scott-Browne, James P; Pereira, Renata M; Crotty, Shane; Chang, John T; Pipkin, Matthew E; Wang, Wei; Goldrath, Ananda W

2017-05-01

Dynamic changes in the expression of transcription factors (TFs) can influence the specification of distinct CD8 + T cell fates, but the observation of equivalent expression of TFs among differentially fated precursor cells suggests additional underlying mechanisms. Here we profiled the genome-wide histone modifications, open chromatin and gene expression of naive, terminal-effector, memory-precursor and memory CD8 + T cell populations induced during the in vivo response to bacterial infection. Integration of these data suggested that the expression and binding of TFs contributed to the establishment of subset-specific enhancers during differentiation. We developed a new bioinformatics method using the PageRank algorithm to reveal key TFs that influence the generation of effector and memory populations. The TFs YY1 and Nr3c1, both constitutively expressed during CD8 + T cell differentiation, regulated the formation of terminal-effector cell fates and memory-precursor cell fates, respectively. Our data define the epigenetic landscape of differentiation intermediates and facilitate the identification of TFs with previously unappreciated roles in CD8 + T cell differentiation.

CD4+CD25highCD127low Regulatory T Cells in Peripheral Blood Are Not an Independent Factor for Chronic Graft-versus-Host Disease after Allogeneic Stem Cell Transplantation

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Jolanta B. Perz

2012-01-01

Full Text Available Background. The therapeutic efficacy of allogeneic hemopoietic stem cell transplantation (HSCT largely relies on the graft-versus-leukemia (GVL effect. Uncontrolled graft-versus-host disease (GVHD is a feared complication of HSCT. Regulatory T cells (Treg are a subset of CD4+ T-helper cells believed to maintain tolerance after HSCT. It remains unclear whether low peripheral blood Treg have an impact on the risk for acute (aGVHD and chronic GVHD (cGVHD. Methods. In this paper we enumerated the CD4+CD25highCD127low Treg in the peripheral blood of 84 patients after at least 150 days from HSCT and in 20 healthy age-matched controls. Results. Although similar mean lymphocyte counts were found in patients and controls, CD3+CD4+ T-cell counts were significantly lower in patients. Patients also had significantly lower Treg percentages among lymphocytes as compared to controls. Patients with cGVHD had even higher percentages of Treg if compared to patients without cGVHD. In multivariate analysis, Treg percentages were not an independent factor for cGVHD. Conclusions. This paper did not show a relation between deficient peripheral blood Treg and cGVHD, therefore cGVHD does not seem to occur as a result of peripheral Treg paucity.

Soluble CD30 and HLA antibodies as potential risk factors for kidney transplant rejection.

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Slavcev, Antonij; Lácha, Jiri; Honsová, Eva; Sajdlová, Helena; Lodererová, Alena; Vitko, Stefan; Skibová, Jelena; Striz, Ilja

2005-06-01

Recent literary data suggest that high pre- and post-transplant serum levels of the soluble CD30 (sCD30) molecule may be a risk factor for acute rejection and worse prognosis of the transplanted kidney. The aim of our study was to correlate the concentrations of sCD30 and the presence of HLA antibodies as defined by flow cytometry and ELISA with the clinical course and graft prognosis after transplantation. One hundred and seventeen kidney transplant patients were included into the study. The incidence of rejection episodes, graft function and graft survival for up to 1 year post-transplant were evaluated. Soluble CD30 levels before transplantation were virtually the same in patients who experienced rejection and in non-rejecting patients. In both patient groups, a significant decrease of sCD30 was detected 2 weeks after transplantation (104.4 U/ml before vs. 37.0 U/ml post-transplant, P sCD30 between rejecting and non-rejecting patients. Patients without rejection had lower sCD30 values (31.2 U/ml post-transplant) compared to patients who experienced rejection episodes (62.9 U/ml), P antigens and elevated concentrations of sCD30 shortly after transplantation were associated with increased risk for acute rejection in the first post-transplant year. Measurement of soluble CD30 after transplantation, taken into consideration with the presence of HLA class II antibodies, might be helpful for evaluating the potential risk for acute rejection.

Expression of tumor necrosis factor-alpha and receptor I(P55in pterygium

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Bing Wu

2014-06-01

Full Text Available AIM:To observe the expression of tumor necrosis factor- alpha(TNF-αand its receptor I(P55in different pterygium and discuss the role of TNF-α and receptor I(P55in pterygium.METHODS: Immunohistochemistical staining method(PVwas adopted to detect the expression of TNF-α and receptor I in pterygium(72 eyesand para-pterygium conjunctival tissue(30 eyes. The relationship between the expression and clinical-pathological parameters was also analyzed. RESULTS: The positive rates of TNF-α were 65.3%(47/72, 26.7%(8/30in pterygium and para-pterygium conjunctival tissue. The positive expression of TNF-α had statistic difference between the two groups(χ2=12.706, Pχ2=13.875, Pχ2=6.547, P=0.011. There had no statistically significance of the expression intensity between the two groups(F=1.288, P=0.393; the positive rate in advanced pterygium group was higher than quiescent pterygium group(χ2=4.082, P=0.043. The expression intensity had no statistically significance between the two groups(F=0.489, P=0.708. The positive rate of P55 in recurrent pterygium group was higher than primary pterygium group(χ2=9.907, P=0.002. There had no statistically significance of the two group's expression intensity(F=1.175, P=0.424; the positive rate in advanced pterygium group was higher than in quiescent pterygium group(χ2=11.140, P=0.001. The expression intensity had no statistically significance between the two groups(F=0.665, P=0.621. CONCLUSION:The expression of TNF-α and P55 are changing according to the development of clinical staging and onset. The expression of TNF-α and P55 may be related to clinical classification, staging and patient's working conditions of pterygium. There has no significant difference expression intensity of TNF-α and P55 in clinical staging and onset of pterygium.

A transcription elongation factor that links signals from the reproductive system to lifespan extension in Caenorhabditis elegans.

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Arjumand Ghazi

2009-09-01

Full Text Available In Caenorhabditis elegans and Drosophila melanogaster, the aging of the soma is influenced by the germline. When germline-stem cells are removed, aging slows and lifespan is increased. The mechanism by which somatic tissues respond to loss of the germline is not well-understood. Surprisingly, we have found that a predicted transcription elongation factor, TCER-1, plays a key role in this process. TCER-1 is required for loss of the germ cells to increase C. elegans' lifespan, and it acts as a regulatory switch in the pathway. When the germ cells are removed, the levels of TCER-1 rise in somatic tissues. This increase is sufficient to trigger key downstream events, as overexpression of tcer-1 extends the lifespan of normal animals that have an intact reproductive system. Our findings suggest that TCER-1 extends lifespan by promoting the expression of a set of genes regulated by the conserved, life-extending transcription factor DAF-16/FOXO. Interestingly, TCER-1 is not required for DAF-16/FOXO to extend lifespan in animals with reduced insulin/IGF-1 signaling. Thus, TCER-1 specifically links the activity of a broadly deployed transcription factor, DAF-16/FOXO, to longevity signals from reproductive tissues.

Per a 10 protease activity modulates CD40 expression on dendritic cell surface by nuclear factor-kappaB pathway.

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Goel, C; Kalra, N; Dwarakanath, B S; Gaur, S N; Arora, N

2015-05-01

Serine protease activity of Per a 10 from Periplaneta americana modulates dendritic cell (DC) functions by a mechanism(s) that remains unclear. In the present study, Per a 10 protease activity on CD40 expression and downstream signalling was evaluated in DCs. Monocyte-derived DCs from cockroach-allergic patients were treated with proteolytically active/heat-inactivated Per a 10. Stimulation with active Per a 10 demonstrated low CD40 expression on DCs surface (P Per a 10, suggesting cleavage of CD40. Per a 10 activity reduced the interleukin (IL)-12 and interferon (IFN)-γ secretion by DCs (P Per a 10, indicating that low CD40 expression is associated with low levels of IL-12 secretion. Active Per a 10 stimulation caused low nuclear factor-kappa B (NF-κB) activation in DCs compared to heat-inactivated Per a 10. Inhibition of the NF-κB pathway suppressed the CD40 expression and IL-12 secretion by DCs, further indicating that NF-κB is required for CD40 up-regulation. CD40 expression activated the tumour necrosis factor (TNF) receptor-associated factor 6 (TRAF6), thereby suggesting its involvement in NF-κB activation. Protease activity of Per a 10 induced p38 mitogen-activated protein kinase (MAPK) activation that showed no significant effect on CD40 expression by DCs. However, inhibiting p38 MAPK or NF-κB suppressed the secretion of IL-12, IFN-γ, IL-6 and TNF-α by DCs. Such DCs further reduced the secretion of IL-4, IL-6, IL-12 and TNF-α by CD4(+) T cells. In conclusion, protease activity of Per a 10 reduces CD40 expression on DCs. CD40 down-regulation leads to low NF-κB levels, thereby modulating DC-mediated immune responses. © 2014 British Society for Immunology.

Soluble CD30 and Hepatocyte growth factor as predictive markers of antibody-mediated rejection of the kidney allograft.

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Pavlova, Yelena; Viklicky, Ondrej; Slatinska, Janka; Bürgelova, Marcela; Süsal, Caner; Skibova, Jelena; Honsová, Eva; Striz, Ilja; Kolesar, Libor; Slavcev, Antonij

2011-07-01

Our retrospective study was aimed to assess the relevance of pre- and post-transplant measurements of serum concentrations of the soluble CD30 molecule (soluble CD30, sCD30) and the cytokine Hepatocyte growth factor (HGF) for prediction of the risk for development of antibody-mediated rejection (AMR) in kidney transplant patients. Evaluation of sCD30, HGF levels and the presence of HLA-specific antibodies in a cohort of 205 patients was performed before, 2weeks and 6months after transplantation. Patients were followed up for kidney graft function and survival for two years. We found a tendency of higher incidence of AMR in retransplanted patients with elevated pre-transplant sCD30 (≥100U/ml) (p=0.051), however no such correlation was observed in first-transplant patients. Kidney recipients with simultaneously high sCD30 and HLA-specific antibodies (sCD30+/Ab+) before transplantation had significantly lower AMR-free survival compared to the other patient groups (psCD30 showed increased incidence of AMR in recipients with elevated pretransplant sCD30 and low HGF levels. the predictive value of pretransplant sCD30 for the development of antibody-mediated rejection after transplantation is significantly potentiated by the co-presence of HLA specific antibodies. The role of HGF as a rejection-protective factor in patients with high pretransplant HGF levels would need further investigation. Copyright © 2011 Elsevier B.V. All rights reserved.

Involvement of macrophage migration inhibitory factor and its receptor (CD74) in human breast cancer.

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Richard, Vincent; Kindt, Nadège; Decaestecker, Christine; Gabius, Hans-Joachim; Laurent, Guy; Noël, Jean-Christophe; Saussez, Sven

2014-08-01

Macrophage migration inhibitory factor (MIF) and its receptor CD74 appear to be involved in tumorigenesis. We evaluated, by immunohistochemical staining, the tissue expression and distribution of MIF and CD74 in serial sections of human invasive breast cancer tumor specimens. The serum MIF level was also determined in breast cancer patients. We showed a significant increase in serum MIF average levels in breast cancer patients compared to healthy individuals. MIF tissue expression, quantified by a modified Allred score, was strongly increased in carcinoma compared to tumor-free specimens, in the cancer cells and in the peritumoral stroma, with fibroblasts the most intensely stained. We did not find any significant correlation with histoprognostic factors, except for a significant inverse correlation between tumor size and MIF stromal positivity. CD74 staining was heterogeneous and significantly decreased in cancer cells but increased in the surrounding stroma, namely in lymphocytes, macrophages and vessel endothelium. There was no significant variation according to classical histoprognostic factors, except that CD74 stromal expression was significantly correlated with triple-negative receptor (TRN) status and the absence of estrogen receptors. In conclusion, our data support the concept of a functional role of MIF in human breast cancer. In addition to auto- and paracrine effects on cancer cells, MIF could contribute to shape the tumor microenvironment leading to immunomodulation and angiogenesis. Interfering with MIF effects in breast tumors in a therapeutic perspective remains an attractive but complex challenge. Level of co-expression of MIF and CD74 could be a surrogate marker for efficacy of anti-angiogenic drugs, particularly in TRN breast cancer tumor.

Ex-vivo expansion of nonhuman primate CD34+ cells by stem cell factor Sall4B

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Bin Shen

2016-10-01

Full Text Available Abstract Background Hematopoietic CD34+ stem cells are widely used in the clinical therapy of complicated blood diseases. Stem cell factor Sall4B is a zinc finger transcription factor that plays a vital role in hematopoietic stem cell expansion. The purpose of our current study is to further evaluate how Sall4B might affect the expansion of CD34+ cells derived from nonhuman primates. Methods Sall4B was overexpressed in nonhuman primate bone marrow-derived CD34+ cells via a lentiviral transduction system. The granulocyte–erythrocyte–macrophage–megakaryocyte colony-forming unit (CFU assay evaluated the differentiation potential of primate CD34+ cells that were expanded with Sall4B. Furthermore, an in-vivo murine system was employed to evaluate the hematopoietic potential of primate Sall4B-expanded CD34+ cells. Results Overexpression of Sall4B promoted ex-vivo nonhuman primate CD34+ cell expansion by 9.21 ± 1.94-fold on day 9, whereas lentiviral transduction without Sall4B expanded cells by only 2.95 ± 0.77-fold. Sall4B maintained a significant percentage of CD34+ cells as well. The CFU assay showed that the Sall4B-expanded CD34+ cells still possessed multilineage differentiation potential. A study using nonobese diabetic/severe combined immunodeficiency (NOD/SCID mice in vivo revealed that Sall4B led to an increase in the number of repopulating cells and the 9-day-old Sall4B-transduced CD34+ cells still possess self-renewal and multilineage differentiation capacity in vivo, which are similar stemness characteristics to those in freshly isolated primate bone marrow-derived CD34+ cells. Conclusions We investigated the expansion of nonhuman primate bone marrow-derived CD34+ cells using the Sall4B lentiviral overexpression approach; our findings provide a new perspective on mechanisms of rapid stem cell proliferation. The utilization of Sall4B to expand CD34+ cells on a large scale through use of suitable model systems would prove

Transcriptome Profile of Near-Isogenic Soybean Lines for β-Conglycinin α-Subunit Deficiency during Seed Maturation.

Science.gov (United States)

Song, Bo; An, Lixin; Han, Yanjing; Gao, Hongxiu; Ren, Hongbo; Zhao, Xue; Wei, Xiaoshuang; Krishnan, Hari B; Liu, Shanshan

2016-01-01

Crossing, backcrossing, and molecular marker-assisted background selection produced a soybean (Glycine max) near-isogenic line (cgy-2-NIL) containing the cgy-2 allele, which is responsible for the absence of the allergenic α-subunit of β-conglycinin. To identify α-null-related transcriptional changes, the gene expressions of cgy-2-NIL and its recurrent parent DN47 were compared using Illumina high-throughput RNA-sequencing of samples at 25, 35, 50, and 55 days after flowering (DAF). Seeds at 18 DAF served as the control. Comparison of the transcript profiles identified 3,543 differentially expressed genes (DEGs) between the two genotypes, with 2,193 genes downregulated and 1,350 genes upregulated. The largest numbers of DEGs were identified at 55 DAF. The DEGs identified at 25 DAF represented a unique pattern of GO category distributions. KEGG pathway analyses identified 541 altered metabolic pathways in cgy-2-NIL. At 18DAF, 12 DEGs were involved in arginine and proline metabolism. The cgy-2 allele in the homozygous form modified the expression of several Cupin allergen genes. The cgy-2 allele is an alteration of a functional allele that is closely related to soybean protein amino acid quality, and is useful for hypoallergenic soybean breeding programs that aim to improve seed protein quality.

Diosgenin a phytosterol substitute for cholesterol, prolongs the lifespan and mitigates glucose toxicity via DAF-16/FOXO and GST-4 in Caenorhabditis elegans.

Science.gov (United States)

Shanmugam, Govindan; Mohankumar, Amirthalingam; Kalaiselvi, Duraisamy; Nivitha, Sundararaj; Murugesh, Easwaran; Shanmughavel, Piramanayagam; Sundararaj, Palanisamy

2017-11-01

Caenorhabditis elegans is a sterol auxotroph requires minute amount of exogenous sterol for their growth and development. To culture the C. elegans, cholesterol was given as sterol molecule to maintain the optimum survival of worms. Diosgenin (DG), a plant derived steroidal saponin, structurally similar to cholesterol has been used as a precursor for the synthesis of steroidal hormones. In this study, worms were cultured with cholesterol (Cho + ) and cholesterol-free (Cho - ) medium with DG (5, 10 and 50μg/mL) at 20°C. It was observed that worms cultured in (Cho - ) exhibits late egg production, reduced lipid level and short lifespan, while addition of DG overcomes all defective facts. Combinations of both cholesterol and DG further extend the lifespan (20.8%), hinder lipid level and resistance to oxidative, thermal and high glucose stress. The intracellular ROS quantification was done by flouroscenic probe H2DCF-DA and confirmed that DG had significantly reduced ROS level (35.85%). Increased lifespan of worms were observed in the medium treated with DG which activates the nuclear translocation of DAF-16/FOXO transcription factor, followed by downstream antioxidant gene sod-3 as evidenced by GFP tagged strain. The expression of Phase II detoxification enzyme GST-4 significantly (pdaf-16, skn-1, and eat-2. These studies have proved that DG is a sterol source to worms and modulate the DAF-16, SOD-3 and GST-4 expression levels to extend the lifespan of worms. The present study has also highlighted the use of phytosterols as an alternative to cholesterol. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

The UCP2 -866G/A, Ala55Val and UCP3 -55C/T polymorphisms are associated with premature coronary artery disease and cardiovascular risk factors in Mexican population.

Science.gov (United States)

Gamboa, Ricardo; Huesca-Gómez, Claudia; López-Pérez, Vanessa; Posadas-Sánchez, Rosalinda; Cardoso-Saldaña, Guillermo; Medina-Urrutia, Aida; Juárez-Rojas, Juan Gabriel; Soto, María Elena; Posadas-Romero, Carlos; Vargas-Alarcón, Gilberto

2018-05-21

We examined the role of UCP gene polymorphisms as susceptibility markers for premature coronary artery disease (pCAD). The UCP2 Ala55Val (C/T rs660339), UCP2 -866G/A (rs659366), and UCP3 -55C/T (rs1800849) polymorphisms were genotyped in 948 patients with pCAD, and 763 controls. The distribution of the UCP2 A55V (C/T rs660339) and UCP3 -55 (rs1800849) was similar in patients and controls. However, under a recessive model, the UCP2 -866 (rs659366) A allele was associated with increased risk of developing pCAD (OR = 1.43, Pc = 0.003). On the other hand, patients with pCAD and UCP2 A55V (rs660339) TT showed high levels of visceral abdominal fat (VAF) (Pc = 0.002), low levels of subcutaneous abdominal fat (SAF) (Pc = 0.001) and high VAT/SAT ratio (Pc cardiovascular risk factors.

Epidermal growth factor receptor inhibition by anti-CD147 therapy in cutaneous squamous cell carcinoma.

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Frederick, John W; Sweeny, Larissa; Hartman, Yolanda; Zhou, Tong; Rosenthal, Eben L

2016-02-01

Advanced cutaneous squamous cell carcinoma (SCC) is an uncommon and aggressive malignancy. As a result, there is limited understanding of its biology and pathogenesis. CD147 and epidermal growth factor receptor (EGFR) have been identified as oncologically important targets, but their relationship remains undefined in cutaneous SCC. Multiple cutaneous SCC cell lines (Colo-16, SRB-1, and SRB-12), were treated in vitro with a range of chimeric anti-CD147 monoclonal antibody (mAb) (0, 50, 100, and 200 µg/mL) or transfected with a small interfering RNA against CD147 (SiCD147). Cell proliferation, migration (scratch wound healing assay), and protein expression was then assessed. In vivo, Colo-16 flank xenografts were treated anti-CD147 mAb (150 µg i.p. triweekly). After treatment with anti-CD147 (200 µg/mL), there was a significant decrease in proliferation for all cell lines relative to controls (p CD147 (200 µg/mL) resulted in decreased cell migration for all cell lines, with an average of 43% reduction in closure compared to controls (p CD147 antibody therapy and siRNA mediated reduction in CD147 expression were both found to decrease protein expression of EGFR, which correlated with a reduction in downstream total and phosphorylated protein kinase B (pAKT). Tumor growth in vivo was reduced for both the anti-CD147 treatment group and the SiCD147 group relative to controls. Inhibition and downregulation of CD147 in cutaneous SCC resulted in suppression of the malignant phenotype in vitro and in vivo, which may be mediated in part by an alteration in EGFR expression. As a result, CD147 may serve as a potential therapeutic target for advanced cutaneous SCC. © 2014 Wiley Periodicals, Inc.

Platelet released growth factors boost expansion of bone marrow derived CD34(+) and CD133(+) endothelial progenitor cells for autologous grafting.

Science.gov (United States)

Lippross, Sebastian; Loibl, Markus; Hoppe, Sven; Meury, Thomas; Benneker, Lorin; Alini, Mauro; Verrier, Sophie

2011-01-01

Stem cell based autologous grafting has recently gained mayor interest in various surgical fields for the treatment of extensive tissue defects. CD34(+) and CD133(+) cells that can be isolated from the pool of bone marrow mononuclear cells (BMC) are capable of differentiating into mature endothelial cells in vivo. These endothelial progenitor cells (EPC) are believed to represent a major portion of the angiogenic regenerative cells that are released from bone marrow when tissue injury has occurred. In recent years tissue engineers increasingly looked at the process of vessel neoformation because of its major importance for successful cell grafting to replace damaged tissue. Up to now one of the greatest problems preventing a clinical application is the large scale of expansion that is required for such purpose. We established a method to effectively enhance the expansion of CD34(+) and CD133(+) cells by the use of platelet-released growth factors (PRGF) as a media supplement. PRGF were prepared from thrombocyte concentrates and used as a media supplement to iscove's modified dulbecco's media (IMDM). EPC were immunomagnetically separated from human bone morrow monocyte cells and cultured in IMDM + 10% fetal calf serum (FCS), IMDM + 5%, FCS + 5% PRGF and IMDM + 10% PRGF. We clearly demonstrate a statistically significant higher and faster cell proliferation rate at 7, 14, 21, and 28 days of culture when both PRGF and FCS were added to the medium as opposed to 10% FCS or 10% PRGF alone. The addition of 10% PRGF to IMDM in the absence of FCS leads to a growth arrest from day 14 on. In histochemical, immunocytochemical, and gene-expression analysis we showed that angiogenic and precursor markers of CD34(+) and CD133(+) cells are maintained during long-term culture. In summary, we established a protocol to boost the expansion of CD34(+) and CD133(+) cells. Thereby we provide a technical step towards the clinical application of autologous stem cell

A conserved neuronal DAF-16/FoxO plays an important role in conveying pheromone signals to elicit repulsion behavior in Caenorhabditis elegans.

Science.gov (United States)

Park, Donha; Hahm, Jeong-Hoon; Park, Saeram; Ha, Go; Chang, Gyeong-Eon; Jeong, Haelim; Kim, Heekyeong; Kim, Sunhee; Cheong, Eunji; Paik, Young-Ki

2017-08-03

Animals use pheromones as a conspecific chemical language to respond appropriately to environmental changes. The soil nematode Caenorhabditis elegans secretes ascaroside pheromones throughout the lifecycle, which influences entry into dauer phase in early larvae, in addition to sexual attraction and aggregation. In adult hermaphrodites, pheromone sensory signals perceived by worms usually elicit repulsion as an initial behavioral signature. However, the molecular mechanisms underlying neuronal pheromone sensory process from perception to repulsion in adult hermaphrodites remain poorly understood. Here, we show that pheromone signals perceived by GPA-3 is conveyed through glutamatergic neurotransmission in which neuronal DAF-16/FoxO plays an important modulatory role by controlling glutaminase gene expression. We further provide evidence that this modulatory role for DAF-16/FoxO seems to be conserved evolutionarily by electro-physiological study in mouse primary hippocampal neurons that are responsible for glutamatergic neurotransmission. These findings provide the basis for understanding the nematode pheromone signaling, which seems crucial for adaptation of adult hermaphrodites to changes in environmental condition for survival.

DAF-18/PTEN signals through AAK-1/AMPK to inhibit MPK-1/MAPK in feedback control of germline stem cell proliferation.

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Patrick Narbonne

2017-04-01

Full Text Available Under replete growth conditions, abundant nutrient uptake leads to the systemic activation of insulin/IGF-1 signalling (IIS and the promotion of stem cell growth/proliferation. Activated IIS can stimulate the ERK/MAPK pathway, the activation of which also supports optimal stem cell proliferation in various systems. Stem cell proliferation rates can further be locally refined to meet the resident tissue's need for differentiated progeny. We have recently shown that the accumulation of mature oocytes in the C. elegans germ line, through DAF-18/PTEN, inhibits adult germline stem cell (GSC proliferation, despite high systemic IIS activation. We show here that this feedback occurs through a novel cryptic signalling pathway that requires PAR-4/LKB1, AAK-1/AMPK and PAR-5/14-3-3 to inhibit the activity of MPK-1/MAPK, antagonize IIS, and inhibit both GSC proliferation and the production of additional oocytes. Interestingly, our results imply that DAF-18/PTEN, through PAR-4/LKB1, can activate AAK-1/AMPK in the absence of apparent energy stress. As all components are conserved, similar signalling cascades may regulate stem cell activities in other organisms and be widely implicated in cancer.

In-situ CdS/CdTe Heterojuntions Deposited by Pulsed Laser Deposition

KAUST Repository

Avila-Avendano, Jesus

2016-04-09

In this paper pulsed laser deposition (PLD) methods are used to study p-n CdTe/CdS heterojunctions fabricated in-situ. In-situ film deposition allows higher quality p-n interfaces by minimizing spurious contamination from the atmosphere. Morphologic and structural analyses were carried for CdTe films deposited on various substrates and different deposition conditions. The electrical characteristics and performance of the resulting p-n heterojunctions were studied as function of substrate and post-deposition anneal temperature. In-situ growth results on diodes with a rectification factor of ~ 105, an ideality factor < 2, and a reverse saturation current ~ 10-8 A. The carrier concentration in the CdTe film was in the range of ~ 1015 cm-3, as measured by C-V methods. The possible impact of sulfur diffusion from the CdS into the CdTe film is also investigated using High Resolution Rutherford Back-Scattering.

In-situ CdS/CdTe Heterojuntions Deposited by Pulsed Laser Deposition

KAUST Repository

Avila-Avendano, Jesus; Mejia, Israel; Alshareef, Husam N.; Guo, Zaibing; Young, Chadwin; Quevedo-Lopez, Manuel

2016-01-01

In this paper pulsed laser deposition (PLD) methods are used to study p-n CdTe/CdS heterojunctions fabricated in-situ. In-situ film deposition allows higher quality p-n interfaces by minimizing spurious contamination from the atmosphere. Morphologic and structural analyses were carried for CdTe films deposited on various substrates and different deposition conditions. The electrical characteristics and performance of the resulting p-n heterojunctions were studied as function of substrate and post-deposition anneal temperature. In-situ growth results on diodes with a rectification factor of ~ 105, an ideality factor < 2, and a reverse saturation current ~ 10-8 A. The carrier concentration in the CdTe film was in the range of ~ 1015 cm-3, as measured by C-V methods. The possible impact of sulfur diffusion from the CdS into the CdTe film is also investigated using High Resolution Rutherford Back-Scattering.

DAF: differential ACE filtering image quality assessment by automatic color equalization

Science.gov (United States)

Ouni, S.; Chambah, M.; Saint-Jean, C.; Rizzi, A.

2008-01-01

Ideally, a quality assessment system would perceive and measure image or video impairments just like a human being. But in reality, objective quality metrics do not necessarily correlate well with perceived quality [1]. Plus, some measures assume that there exists a reference in the form of an "original" to compare to, which prevents their usage in digital restoration field, where often there is no reference to compare to. That is why subjective evaluation is the most used and most efficient approach up to now. But subjective assessment is expensive, time consuming and does not respond, hence, to the economic requirements [2,3]. Thus, reliable automatic methods for visual quality assessment are needed in the field of digital film restoration. The ACE method, for Automatic Color Equalization [4,6], is an algorithm for digital images unsupervised enhancement. It is based on a new computational approach that tries to model the perceptual response of our vision system merging the Gray World and White Patch equalization mechanisms in a global and local way. Like our vision system ACE is able to adapt to widely varying lighting conditions, and to extract visual information from the environment efficaciously. Moreover ACE can be run in an unsupervised manner. Hence it is very useful as a digital film restoration tool since no a priori information is available. In this paper we deepen the investigation of using the ACE algorithm as a basis for a reference free image quality evaluation. This new metric called DAF for Differential ACE Filtering [7] is an objective quality measure that can be used in several image restoration and image quality assessment systems. In this paper, we compare on different image databases, the results obtained with DAF and with some subjective image quality assessments (Mean Opinion Score MOS as measure of perceived image quality). We study also the correlation between objective measure and MOS. In our experiments, we have used for the first image

The GATA transcription factor egl-27 delays aging by promoting stress resistance in Caenorhabditis elegans.

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Xiao Xu

Full Text Available Stress is a fundamental aspect of aging, as accumulated damage from a lifetime of stress can limit lifespan and protective responses to stress can extend lifespan. In this study, we identify a conserved Caenorhabditis elegans GATA transcription factor, egl-27, that is involved in several stress responses and aging. We found that overexpression of egl-27 extends the lifespan of wild-type animals. Furthermore, egl-27 is required for the pro-longevity effects from impaired insulin/IGF-1 like signaling (IIS, as reduced egl-27 activity fully suppresses the longevity of worms that are mutant for the IIS receptor, daf-2. egl-27 expression is inhibited by daf-2 and activated by pro-longevity factors daf-16/FOXO and elt-3/GATA, suggesting that egl-27 acts at the intersection of IIS and GATA pathways to extend lifespan. Consistent with its role in IIS signaling, we found that egl-27 is involved in stress response pathways. egl-27 expression is induced in the presence of multiple stresses, its targets are significantly enriched for many types of stress genes, and altering levels of egl-27 itself affects survival to heat and oxidative stress. Finally, we found that egl-27 expression increases between young and old animals, suggesting that increased levels of egl-27 in aged animals may act to promote stress resistance. These results identify egl-27 as a novel factor that links stress and aging pathways.

Characterization of transcription factor networks involved in umbilical cord blood CD34+ stem cells-derived erythropoiesis.

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Biaoru Li

Full Text Available Fetal stem cells isolated from umbilical cord blood (UCB possess a great capacity for proliferation and differentiation and serve as a valuable model system to study gene regulation. Expanded knowledge of the molecular control of hemoglobin synthesis will provide a basis for rational design of therapies for β-hemoglobinopathies. Transcriptome data are available for erythroid progenitors derived from adult stem cells, however studies to define molecular mechanisms controlling globin gene regulation during fetal erythropoiesis are limited. Here, we utilize UCB-CD34+ stem cells induced to undergo erythroid differentiation to characterize the transcriptome and transcription factor networks (TFNs associated with the γ/β-globin switch during fetal erythropoiesis. UCB-CD34+ stem cells grown in the one-phase liquid culture system displayed a higher proliferative capacity than adult CD34+ stem cells. The γ/β-globin switch was observed after day 42 during fetal erythropoiesis in contrast to adult progenitors where the switch occurred around day 21. To gain insights into transcription factors involved in globin gene regulation, microarray analysis was performed on RNA isolated from UCB-CD34+ cell-derived erythroid progenitors harvested on day 21, 42, 49 and 56 using the HumanHT-12 Expression BeadChip. After data normalization, Gene Set Enrichment Analysis identified transcription factors (TFs with significant changes in expression during the γ/β-globin switch. Forty-five TFs were silenced by day 56 (Profile-1 and 30 TFs were activated by day 56 (Profile-2. Both GSEA datasets were analyzed using the MIMI Cytoscape platform, which discovered TFNs centered on KLF4 and GATA2 (Profile-1 and KLF1 and GATA1 for Profile-2 genes. Subsequent shRNA studies in KU812 leukemia cells and human erythroid progenitors generated from UCB-CD34+ cells supported a negative role of MAFB in γ-globin regulation. The characteristics of erythroblasts derived from UCB-CD34

A new addition to the Phillipsite family of molecular sieves: A divalent metal-ion-framework substituted microporous aluminophosphate (DAF-8)

Science.gov (United States)

Barrett, Philip A.; Sankar, Gopinathan; Stephenson, Richard; Catlow, C. Richard A.; Thomas, John Meurig; Jones, Richard H.; Teat, Simon J.

2006-03-01

By adding substantial amounts of either Co(II) or Zn(II) salts to a gel composed of Al 2O 3, P 2O 5 and the organic template 1,4-diaminocyclohexane, the tendency to yield layered aluminophosphates (AlPOs) is tilted in favour of the production of three-dimensional microporous MAlPOs: in particular, phase-pure samples of a novel Phillipsite structure (designated Davy-Faraday number 8, DAF-8) are formed.

Investigations of Spectroscopic Factors and Sum Rules from the Single Neutron Transfer Reaction 111Cd(overrightarrow {{d}} ,p)112Cd

Science.gov (United States)

Jamieson, D. S.; Garrett, P. E.; Ball, G. C.; Demand, G. A.; Faestermann, T.; Finlay, P.; Green, K. L.; Hertenberger, R.; Krücken, R.; Leach, K. G.; Phillips, A. A.; Sumithrarachchi, C. S.; Triambak, S.; Wirth, H.-F.

2014-03-01

Cadmium isotopes have been presented for decades as excellent examples of vibrational nuclei, with low-lying levels interpreted as multi-phonon quadrupole, octupole, and mixed-symmetry states. A large amount of spectroscopic data has been obtained through various experimental studies of cadmiumisotopes. In the present work, the 111Cd(overrightarrow {{d}} ,p)112Cd reaction was used to investigate the single-particle structure of the 112Cd nucleus. A 22 MeV beam of polarized deuterons was obtained at the Maier-Leibnitz laboratory in Garching, Germany. The reaction ejectiles were momentum analyzed using a Q3D spectrograph, and 130 levels have been identified up to 4.2 MeV of excitation energy. Using DWBA analysis with optical model calculations, spin-parity assignments have been made for observed levels, and spectroscopic factors have been extracted from the experimental angular distributions of differential cross section and analyzing power. In this high energy resolution investigation, many additional levels have been observed compared with the previous (d,p) study using 8 MeV deuterons [1]. There were a total of 44 new levels observed, and the parity assignments of 34 levels were improved.

High soluble CD30 levels and associated anti-HLA antibodies in patients with failed renal allografts.

Science.gov (United States)

Karahan, Gonca E; Caliskan, Yasar; Ozdilli, Kursat; Kekik, Cigdem; Bakkaloglu, Huseyin; Caliskan, Bahar; Turkmen, Aydin; Sever, Mehmet S; Oguz, Fatma S

2017-01-13

Serum soluble CD30 (sCD30), a 120-kD glycoprotein that belongs to the tumor necrosis factor receptor family, has been suggested as a marker of rejection in kidney transplant patients. The aim of this study was to evaluate the relationship between sCD30 levels and anti-HLA antibodies, and to compare sCD30 levels in patients undergoing hemodialysis (HD) with and without failed renal allografts and transplant recipients with functioning grafts. 100 patients undergoing HD with failed grafts (group 1), 100 patients undergoing HD who had never undergone transplantation (group 2), and 100 kidney transplant recipients (group 3) were included in this study. Associations of serum sCD30 levels and anti-HLA antibody status were analyzed in these groups. The sCD30 levels of group 1 and group 2 (154 ± 71 U/mL and 103 ± 55 U/mL, respectively) were significantly higher than those of the transplant recipients (group 3) (39 ± 21 U/mL) (p<0.001 and p<0.001). The serum sCD30 levels in group 1 (154 ± 71 U/mL) were also significantly higher than group 2 (103 ± 55 U/mL) (p<0.001). Anti-HLA antibodies were detected in 81 (81%) and 5 (5%) of patients in groups 1 and 2, respectively (p<0.001). When multiple regression analysis was performed to predict sCD30 levels, the independent variables in group 1 were the presence of class I anti-HLA antibodies (β = 0.295; p = 0.003) and age (β = -0.272; p = 0.005), and serum creatinine (β = 0.218; p = 0.027) and presence of class II anti-HLA antibodies (standardized β = 0.194; p = 0.046) in group 3. Higher sCD30 levels and anti-HLA antibodies in patients undergoing HD with failed renal allografts may be related to higher inflammatory status in these patients.

Transforming growth factor-β-mediated CD44/STAT3 signaling contributes to the development of atrial fibrosis and fibrillation.

Science.gov (United States)

Chang, Shang-Hung; Yeh, Yung-Hsin; Lee, Jia-Lin; Hsu, Yu-Juei; Kuo, Chi-Tai; Chen, Wei-Jan

2017-09-04

Atrial fibrillation (AF) is associated with atrial fibrosis. Inhibition of atrial fibrosis might be a plausible approach for AF prevention and therapy. This study is designed to evaluate the potential role of CD44, a membrane receptor known to regulate fibrosis, and its related signaling in the pathogenesis of atrial fibrosis and AF. Treatment of cultured rat atrial fibroblasts with transforming growth factor-β (TGF-β, a key mediator of atrial fibrosis) led to a higher expression of hyaluronan (HA), CD44, STAT3, and collagen (a principal marker of fibrosis) than that of ventricular fibroblasts. In vivo, TGF-β transgenic mice and AF patients exhibited a greater expression of HA, CD44, STAT3, and collagen in their atria than wild-type mice and sinus rhythm subjects, respectively. Treating TGF-β transgenic mice with an anti-CD44 blocking antibody resulted in a lower expression of STAT3 and collagen in their atria than those with control IgG antibody. Programmed stimulation triggered less AF episodes in TGF-β transgenic mice treated with anti-CD44 blocking antibody than in those with control IgG. Blocking CD44 signaling with anti-CD44 antibody and mutated CD44 plasmids attenuated TGF-β-induced STAT3 activation and collagen expression in cultured atrial fibroblasts. Deletion and mutational analysis of the collagen promoter along with chromatin immunoprecipitation demonstrated that STAT3 served as a vital transcription factor in collagen expression. TGF-β-mediated HA/CD44/STAT3 pathway plays a crucial role in the development of atrial fibrosis and AF. Blocking CD44-dependent signaling may be a feasible way for AF management.

Spectroscopic Factors from the Single Neutron Transfer Reaction 111Cd(d,p)112Cd

Science.gov (United States)

Jamieson, D. S.; Garrett, P. E.; Demand, G. A.; Finlay, P.; Green, K. L.; Leach, K. G.; Phillips, A. A.; Svensson, C. E.; Sumithrarachchi, C. S.; Triambak, S.; Wong, J.; Ball, G.; Faestermann, T.; Krücken, R.; Hertenberger, R.; Wirth, H.-F.

2013-03-01

The cadmium isotopes have been cited as excellent examples of vibrational nuclei for decades, with multi-phonon quadrupole, quadrupole-octupole, and mixed-symmetry states proposed. From a variety of experimental studies, a large amount of spectroscopic data has been obtained, recently focused on γ-ray studies. In the present work, the single-particle structure of 112Cd has been investigated using the 111Cd(ěcd, p)112Cd reaction. The investigation was carried out using a 22 MeV beam of polarized deuterons obtained from the Maier-Leibnitz Laboratory at Garching, Germany. The reaction ejectiles were momentum analyzed using a Q3D spectrograph, and 115 levels have been identified up to 4.2 MeV of excitation energy. Spin-parity has been assigned to each analyzed level, and angular distributions for the reaction cross sections and analyzing powers were obtained. Many additional levels have been observed compared with the previous (d,p) study performed with 8 MeV deuterons,1 including strongly populated 5- and 6- states. The former was previously assigned as a member of the quadrupole-octupole quintuplet, based on a strongly enhanced B(E2) value to the 3- state, but is now re-assigned as being predominately s1/2 ⊗ h11/2 configuration.

Tumor necrosis factor-alpha induces activation of coagulation and fibrinolysis in baboons through an exclusive effect on the p55 receptor

NARCIS (Netherlands)

van der Poll, T.; Jansen, P. M.; van Zee, K. J.; Welborn, M. B.; de Jong, I.; Hack, C. E.; Loetscher, H.; Lesslauer, W.; Lowry, S. F.; Moldawer, L. L.

1996-01-01

Tumor necrosis factor-alpha (TNF-alpha) can bind to two distinct transmembrane receptors, the p55 and p75 TNF receptors. We compared the capability of two mutant TNF proteins with exclusive affinity for the p55 or p75 TNF receptor with that of wild type TNF, to activate the hemostatic mechanism in

CD3+/CD16+CD56+ cell numbers in peripheral blood are correlated with higher tumor burden in patients with diffuse large B-cell lymphoma

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Anna Twardosz

2011-04-01

Full Text Available Diffuse large B-cell lymphoma is the commonest histological type of malignant lymphoma, andremains incurable in many cases. Developing more efficient immunotherapy strategies will require betterunderstanding of the disorders of immune responses in cancer patients. NKT (natural killer-like T cells wereoriginally described as a unique population of T cells with the co-expression of NK cell markers. Apart fromtheir role in protecting against microbial pathogens and controlling autoimmune diseases, NKT cells havebeen recently revealed as one of the key players in the immune responses against tumors. The objective of thisstudy was to evaluate the frequency of CD3+/CD16+CD56+ cells in the peripheral blood of 28 diffuse largeB-cell lymphoma (DLBCL patients in correlation with clinical and laboratory parameters. Median percentagesof CD3+/CD16+CD56+ were significantly lower in patients with DLBCL compared to healthy donors(7.37% vs. 9.01%, p = 0.01; 4.60% vs. 5.81%, p = 0.03, although there were no differences in absolute counts.The frequency and the absolute numbers of CD3+/CD16+CD56+ cells were lower in advanced clinical stagesthan in earlier ones. The median percentage of CD3+/CD16+CD56+ cells in patients in Ann Arbor stages 1–2 was5.55% vs. 3.15% in stages 3–4 (p = 0.02, with median absolute counts respectively 0.26 G/L vs. 0.41 G/L (p == 0.02. The percentage and absolute numbers of CD3+/CD16+CD56+ cells were significantly higher in DL-BCL patients without B-symptoms compared to the patients with B-symptoms, (5.51% vs. 2.46%, p = 0.04;0.21 G/L vs. 0.44 G/L, p = 0.04. The percentage of CD3+/CD16+CD56+ cells correlated adversely with serumlactate dehydrogenase (R= –445; p < 0.05 which might influence NKT count. These figures suggest a relationshipbetween higher tumor burden and more aggressive disease and decreased NKT numbers. But it remains tobe explained whether low NKT cell counts in the peripheral blood of patients with DLBCL are the result

Soluble CD40 ligand directly alters glomerular permeability and may act as a circulating permeability factor in FSGS.

Science.gov (United States)

Doublier, Sophie; Zennaro, Cristina; Musante, Luca; Spatola, Tiziana; Candiano, Giovanni; Bruschi, Maurizio; Besso, Luca; Cedrino, Massimo; Carraro, Michele; Ghiggeri, Gian Marco; Camussi, Giovanni; Lupia, Enrico

2017-01-01

CD40/CD40 ligand (CD40L) dyad, a co-stimulatory bi-molecular complex involved in the adaptive immune response, has also potent pro-inflammatory actions in haematopoietic and non-haematopoietic cells. We describe here a novel role for soluble CD40L (sCD40L) as modifier of glomerular permselectivity directly acting on glomerular epithelial cells (GECs). We found that stimulation of CD40, constitutively expressed on GEC cell membrane, by the sCD40L rapidly induced redistribution and loss of nephrin in GECs, and increased albumin permeability in isolated rat glomeruli. Pre-treatment with inhibitors of CD40-CD40L interaction completely prevented these effects. Furthermore, in vivo injection of sCD40L induced a significant reduction of nephrin and podocin expression in mouse glomeruli, although no significant increase of urine protein/creatinine ratio was observed after in vivo injection. The same effects were induced by plasma factors partially purified from post-transplant plasma exchange eluates of patients with focal segmental glomerulosclerosis (FSGS), and were blocked by CD40-CD40L inhibitors. Moreover, 17 and 34 kDa sCD40L isoforms were detected in the same plasmapheresis eluates by Western blotting. Finally, the levels of sCD40Lwere significantly increased in serum of children both with steroid-sensitive and steroid-resistant nephrotic syndrome (NS), and in adult patients with biopsy-proven FSGS, compared to healthy subjects, but neither in children with congenital NS nor in patients with membranous nephropathy. Our results demonstrate that sCD40L directly modifies nephrin and podocin distribution in GECs. Moreover, they suggest that sCD40L contained in plasmapheresis eluates from FSGS patients with post-transplant recurrence may contribute, presumably cooperating with other mediators, to FSGS pathogenesis by modulating glomerular permeability.

Soluble CD40 ligand directly alters glomerular permeability and may act as a circulating permeability factor in FSGS.

Directory of Open Access Journals (Sweden)

Sophie Doublier

Full Text Available CD40/CD40 ligand (CD40L dyad, a co-stimulatory bi-molecular complex involved in the adaptive immune response, has also potent pro-inflammatory actions in haematopoietic and non-haematopoietic cells. We describe here a novel role for soluble CD40L (sCD40L as modifier of glomerular permselectivity directly acting on glomerular epithelial cells (GECs. We found that stimulation of CD40, constitutively expressed on GEC cell membrane, by the sCD40L rapidly induced redistribution and loss of nephrin in GECs, and increased albumin permeability in isolated rat glomeruli. Pre-treatment with inhibitors of CD40-CD40L interaction completely prevented these effects. Furthermore, in vivo injection of sCD40L induced a significant reduction of nephrin and podocin expression in mouse glomeruli, although no significant increase of urine protein/creatinine ratio was observed after in vivo injection. The same effects were induced by plasma factors partially purified from post-transplant plasma exchange eluates of patients with focal segmental glomerulosclerosis (FSGS, and were blocked by CD40-CD40L inhibitors. Moreover, 17 and 34 kDa sCD40L isoforms were detected in the same plasmapheresis eluates by Western blotting. Finally, the levels of sCD40Lwere significantly increased in serum of children both with steroid-sensitive and steroid-resistant nephrotic syndrome (NS, and in adult patients with biopsy-proven FSGS, compared to healthy subjects, but neither in children with congenital NS nor in patients with membranous nephropathy. Our results demonstrate that sCD40L directly modifies nephrin and podocin distribution in GECs. Moreover, they suggest that sCD40L contained in plasmapheresis eluates from FSGS patients with post-transplant recurrence may contribute, presumably cooperating with other mediators, to FSGS pathogenesis by modulating glomerular permeability.

[Combined assay of soluble CD30 and hepatocyte growth factor for diagnosis of acute renal allograft rejection].

Science.gov (United States)

Li, Chuan-jiang; Yu, Li-xin; Xu, Jian; Fu, Shao-jie; Deng, Wen-feng; Du, Chuan-fu; Wang, Yi-bin

2008-02-01

To study the value of detection of both preoperative soluble CD30 (sCD30) and hepatocyte growth factor (HGF) level 5 days after transplantation in the diagnosis of acute rejection of renal allograft. Preoperative serum sCD30 levels and HGF level 5 days after transplantation were determined in 65 renal-transplant recipients using enzyme-linked immunosorbent assay. The recipients were divided according to the sCD30 levels positivity. Receiver operating characteristic (ROC) curves were used to assess the value of HGF level on day 5 posttransplantation for diagnosis of acute renal allograft rejection, and the value of combined assay of the sCD30 and HGF levels was also estimated. After transplantation, 26 recipients developed graft rejection and 39 had uneventful recovery without rejection. With the cut-off value of sCD30 of 120 U/ml, the positivity rate of sCD30 was significantly higher in recipients with graft rejection than in those without (61.5% vs 17.9%, Pacute rejection showed also significantly higher HGF levels on day 5 posttransplantation than those without rejection (Pacute renal allograft rejection, and at the cut-off value of 90 ug/L, the diagnostic sensitivity was 84.6% and specificity 76.9%. Evaluation of both the sCD30 and HGF levels significantly enhanced the diagnostic accuracy of acute graft rejection. Combined assay of serum sCD30 and HGF levels offers a useful means for diagnosis of acute renal allograft rejection.

Neuroplastin-55 binds to and signals through the fibroblast growth factor receptor

DEFF Research Database (Denmark)

Owczarek, Sylwia; Kiryushko, Darya; Hald Larsen, Marianne

2010-01-01

Neuroplastin (Np) is a glycoprotein belonging to the immunoglobulin superfamily of cell adhesion molecules (CAMs) and existing in two isoforms, Np55 and Np65, named according to their molecular weights. The extracellular part of Np65 contains three immunoglobulin (Ig)-like modules (Ig1, Ig2, and Ig......3), whereas Np55 lacks the Ig1 module. Of these two isoforms, only Np65 is involved in homophilic interactions resulting in cell adhesion, whereas the role of Np55 is poorly understood. The present study reports for the first time the crystal structure of the ectodomain of Np55 at 1.95-A resolution...

CD151, a novel host factor of nuclear export signaling in influenza virus infection.

Science.gov (United States)

Qiao, Yongkang; Yan, Yan; Tan, Kai Sen; Tan, Sheryl S L; Seet, Ju Ee; Arumugam, Thiruma Valavan; Chow, Vincent T K; Wang, De Yun; Tran, Thai

2018-05-01

Despite advances in our understanding of the mechanisms of influenza A virus (IAV) infection, the crucial virus-host interactions during the viral replication cycle still remain incomplete. Tetraspanin CD151 is highly expressed in the human respiratory tract, but its pathological role in IAV infection is unknown. We sought to characterize the functional role and mechanisms of action of CD151 in IAV infection of the upper and lower respiratory tracts with H1N1 and H3N2 strains. We used CD151-null mice in an in vivo model of IAV infection and clinical donor samples of in vitro-differentiated human nasal epithelial cells cultured at air-liquid interface. As compared with wild-type infected mice, CD151-null infected mice exhibited a significant reduction in virus titer and improvement in survival that is associated with pronounced host antiviral response and inflammasome activation together with accelerated lung repair. Interestingly, we show that CD151 complexes newly synthesized viral proteins with host nuclear export proteins and stabilizes microtubule complexes, which are key processes necessary for the polarized trafficking of viral progeny to the host plasma membrane for assembly. Our results provide new mechanistic insights into our understanding of IAV infection. We show that CD151 is a critical novel host factor of nuclear export signaling whereby the IAV nuclear export uses it to complement its own nuclear export proteins (a site not targeted by current therapy), making this regulation unique, and holds promise for the development of novel alternative/complementary strategies to reduce IAV severity. Copyright © 2017 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.

Co-expression of CD147 and GLUT-1 indicates radiation resistance and poor prognosis in cervical squamous cell carcinoma.

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Huang, Xin-Qiong; Chen, Xiang; Xie, Xiao-Xue; Zhou, Qin; Li, Kai; Li, Shan; Shen, Liang-Fang; Su, Juan

2014-01-01

The aim of this study was to investigate the association of CD147 and GLUT-1, which play important roles in glycolysis in response to radiotherapy and clinical outcomes in patients with locally advanced cervical squamous cell carcinoma (LACSCC). The records of 132 female patients who received primary radiation therapy to treat LACSCC at FIGO stages IB-IVA were retrospectively reviewed. Forty-seven patients with PFS (progression-free survival) of less than 36 months were regarded as radiation-resistant. Eighty-five patients with PFS longer than 36 months were regarded as radiation-sensitive. Using pretreatment paraffin-embedded tissues, we evaluated CD147 and GLUT-1 expression by immunohistochemistry. Overexpression of CD147, GLUT-1, and CD147 and GLUT-1 combined were 44.7%, 52.9% and 36.5%, respectively, in the radiation-sensitive group, and 91.5%, 89.4% and 83.0%, respectively, in the radiation-resistant group. The 5-year progress free survival (PFS) rates in the CD147-low, CD147-high, GLUT-1-low, GLUT-1-high, CD147- and/or GLUT-1-low and CD147- and GLUT-1- dual high expression groups were 66.79%, 87.10%, 52.78%, 85.82%, 55.94%, 82.90% and 50.82%, respectively. CD147 and GLUT-1 co-expression, FIGO stage and tumor diameter were independent poor prognostic factors for patients with LACSCC in multivariate Cox regression analysis. Patients with high expression of CD147 alone, GLUT-1 alone or co-expression of CD147 and GLUT-1 showed greater resistance to radiotherapy and a shorter PFS than those with low expression. In particular, co-expression of CD147 and GLUT-1 can be considered as a negative independent prognostic factor.

Inflammation in disseminated lesions: an analysis of CD4+, CD20+, CD68+, CD31+ and vW+ cells in non-ulcerated lesions of disseminated leishmaniasis

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Dayana Santos Mendes

2013-02-01

Full Text Available Disseminated leishmaniasis (DL differs from other clinical forms of the disease due to the presence of many non-ulcerated lesions (papules and nodules in non-contiguous areas of the body. We describe the histopathology of DL non-ulcerated lesions and the presence of CD4-, CD20-, CD68-, CD31- and von Willebrand factor (vW-positive cells in the inflamed area. We analysed eighteen biopsies from non-ulcerated lesions and quantified the inflamed areas and the expression of CD4, CD20, CD68, CD31 and vW using Image-Pro software (Media Cybernetics. Diffuse lymphoplasmacytic perivascular infiltrates were found in dermal skin. Inflammation was observed in 3-73% of the total biopsy area and showed a significant linear correlation with the number of vW+ vessels. The most common cells were CD68+ macrophages, CD20+ B-cells and CD4+ T-cells. A significant linear correlation between CD4+ and CD20+ cells and the size of the inflamed area was also found. Our findings show chronic inflammation in all DL non-ulcerated lesions predominantly formed by macrophages, plasmacytes and T and B-cells. As the inflamed area expanded, the number of granulomas and extent of the vascular framework increased. Thus, we demonstrate that vessels may have an important role in the clinical evolution of DL lesions.

Determination of the valence-band offset of CdS/CIS solar cell devices by target factor analysis

Energy Technology Data Exchange (ETDEWEB)

Niles, D.W.; Contreras, M.; Ramanathan, K.; Noufi, R. [National Renewable Energy Lab., Golden, CO (United States)

1996-05-01

X-ray photoemission spectroscopy (XPS) is used to determine and compare the valence-band offsets ({Delta}E{sub v}) for CdS grown by chemical bath deposition on single-crystal and thin-film CuInSe{sub 2} (CIS). The thin-film CIS device was suitable for photovoltaic energy production. By sputtering through the CdS/CIS interface and reducing the depth profile with target factor analysis, the magnitude of {Delta}E{sub v} was determined to be {Delta}E{sub v} = 1.06 {+-} 0.15 eV for both the single-crystal and thin-film interfaces. This determination of {Delta}E{sub v} is about 0.25 eV larger than many previously reported estimations CdS grown by physical vapor deposition on CIS and helps explain the record performance of CdS/CIS photovoltaic devices.

CD5-Positive Primary Intraocular B-Cell Lymphoma Arising during Methotrexate and Tumor Necrosis Factor Inhibitor Treatment

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Kenji Nagata

2015-09-01

Full Text Available Purpose: To report a case of CD5+ primary intraocular B-cell lymphoma arising during methotrexate (MTX and tumor necrosis factor (TNF inhibitor treatment in a young patient with rheumatoid arthritis and uveitis. Case Presentation: A 39-year-old woman treated with MTX and a TNF inhibitor for rheumatoid arthritis and uveitis had steroid-resistant vitreous opacity. A vitreous sample was obtained by using diagnostic vitrectomy and was categorized as class V based on cytologic examination. Flow cytometric analysis of the vitreous sample revealed that abnormal cells were CD5+, CD10-, CD19+, CD20+ and immunoglobulin light-chain kappa+, suggesting the diagnosis of CD5+ primary intraocular B-cell lymphoma. Polymerase chain reaction (PCR detected immunoglobulin heavy-chain gene rearrangement. Epstein-Barr virus (EBV DNA was detected in the vitreous sample by using PCR, and immunohistochemistry revealed EBV latent membrane protein-1 expression in the abnormal cells infiltrating the vitreous. Optic nerve invasion was observed on magnetic resonance imaging. Conclusion: Primary intraocular lymphoma (PIOL may develop in patients receiving MTX and TNF inhibitor treatment. EBV infection may play an important role in the pathogenesis of PIOL arising during immunosuppressive therapy.

Optically Active CdSe-Dot/CdS-Rod Nanocrystals with Induced Chirality and Circularly Polarized Luminescence.

Science.gov (United States)

Cheng, Jiaji; Hao, Junjie; Liu, Haochen; Li, Jiagen; Li, Junzi; Zhu, Xi; Lin, Xiaodong; Wang, Kai; He, Tingchao

2018-05-30

Ligand-induced chirality in semiconductor nanocrystals (NCs) has attracted attention because of the tunable optical properties of the NCs. Induced circular dichroism (CD) has been observed in CdX (X = S, Se, Te) NCs and their hybrids, but circularly polarized luminescence (CPL) in these fluorescent nanomaterials has been seldom reported. Herein, we describe the successful preparation of l- and d-cysteine-capped CdSe-dot/CdS-rods (DRs) with tunable CD and CPL behaviors and a maximum anisotropic factor ( g lum ) of 4.66 × 10 -4 . The observed CD and CPL activities are sensitive to the relative absorption ratio of the CdS shell to the CdSe core, suggesting that the anisotropic g-factors in both CD and CPL increase to some extent for a smaller shell-to-core absorption ratio. In addition, the molar ratio of chiral cysteine to the DRs is investigated. Instead of enhancing the chiral interactions between the chiral molecules and DRs, an excess of cysteine molecules in aqueous solution inhibits both the CD and CPL activities. Such chiral and emissive NCs provide an ideal platform for the rational design of semiconductor nanomaterials with chiroptical properties.

Risk factors associated with low CD4+ lymphocyte count among HIV-positive pregnant women in Nigeria.

Science.gov (United States)

Abimiku, Alash'le; Villalba-Diebold, Pacha; Dadik, Jelpe; Okolo, Felicia; Mang, Edwina; Charurat, Man

2009-09-01

To determine the risk factors for CD4+ lymphocyte counts of 200 cells/mm(3) or lower in HIV-positive pregnant women in Nigeria. A cross-sectional data analysis from a prospective cohort of 515 HIV-positive women attending a prenatal clinic. Risk of a low CD4+ count was estimated using logistic regression analysis. CD4+ lymphocyte counts of 200 cells/mm(3) or lower (280+/-182 cells/mm(3)) were recorded in 187 (36.3%) out of 515 HIV-positive pregnant women included in the study. Low CD4+ count was associated with older age (adjusted odds ratio [aOR] 10.71; 95% confidence interval [CI], 1.20-95.53), lack of condom use (aOR, 5.16; 95% CI, 1.12-23.8), history of genital ulcers (aOR, 1.78; 95% CI, 1.12-2.82), and history of vaginal discharge (aOR; 1.62; 1.06-2.48). Over 35% of the HIV-positive pregnant women had low CD4+ counts, indicating the need for treatment. The findings underscore the need to integrate prevention of mother-to-child transmission with HIV treatment and care, particularly services for sexually transmitted infections.

Task-shifting of CD4 T cell count monitoring by the touchscreen-based Muse™ Auto CD4/CD4% single-platform system for CD4 T cell numeration: Implication for decentralization in resource-constrained settings.

Science.gov (United States)

Kouabosso, André; Mossoro-Kpinde, Christian Diamant; Bouassa, Ralph-Sydney Mboumba; Longo, Jean De Dieu; Mbeko Simaleko, Marcel; Grésenguet, Gérard; Bélec, Laurent

2018-04-01

The accuracy of CD4 T cell monitoring by the recently developed flow cytometry-based CD4 T cell counting Muse™ Auto CD4/CD4% Assay analyzer (EMD Millipore Corporation, Merck Life Sciences, KGaA, Darmstadt, Germany) was evaluated in trained lay providers against laboratory technicians. After 2 days of training on the Muse™ Auto CD4/CD4% analyzer, EDTA-blood samples from 6 HIV-positive and 4 HIV-negative individuals were used for CD4 T cell counting in triplicate in parallel by 12 trained lay providers as compared to 10 lab technicians. Mean number of CD4 T cells in absolute number was 829 ± 380 cells/μl by lay providers and 794 ± 409 cells/μl by technicians (P > 0.05); and in percentage 36.2 ± 14.8%CD4 by lay providers and 36.1 ± 15.0%CD4 by laboratory technician (P > 0.05). The unweighted linear regression and Passing-Bablok regression analyses on CD4 T cell results expressed in absolute count revealed moderate correlation between CD4 T cell counts obtained by lay providers and lab technicians. The mean absolute bias measured by Bland-Altman analysis between CD4 T cell/μl obtained by lay providers and lab technicians was -3.41 cells/μl. Intra-assay coefficient of variance (CV) of Muse™ Auto CD4/CD4% in absolute number was 10.1% by lay providers and 8.5% by lab technicians (P > 0.05), and in percentage 5.5% by lay providers and 4.4% by lab technicians (P > 0.05). The inter-assay CV of Muse™ Auto CD4/CD4% in absolute number was 13.4% by lay providers and 10.3% by lab technicians (P > 0.05), and in percentage 7.8% by lay providers and 6.9% by lab technicians (P > 0.05). The study demonstrates the feasibility of CD4 T cell counting using the alternative flow cytometer Muse™ Auto CD4/CD4% analyzer by trained lay providers and therefore the practical possibility of decentralization CD4 T cell counting to health community centers. Copyright © 2018. Published by Elsevier B.V.

[Effects of Rice Cultivar and Typical Soil Improvement Measures on the Uptake of Cd in Rice Grains].

Science.gov (United States)

Wang, Mei-e; Peng, Chi; Chen, Wei-ping

2015-11-01

Cadmium pollution of rice is a big problem in agricultural food safety. The accident "Cd rice" occurred last year in Youxian County, Hunan Province caused serious social panic. In this study, trials on "Cd rice" controlling techniques specific to the Cd pollution in paddy soil in Youxian were investigated. It was suggested that the average Cd contents in rice grains of the rice variety "Zhu Liang You 06" in Datongqiao and Wangling were 0.167 and 0.127 mg x kg(-1), respectively, which were only equal to 20% of the contents of other varieties. The trials for stabilizing agents revealed that treatments of lime and mineral fertilizer decreased Cd contents in rice grains to 20-30% of the control. Plastic film-mulched treatment decreased the rice grain Cd to 50%. And combined treatment of plastic film-mulched and biochar and silicon foliar-fertilizer decreased 80% of rice Cd content. Single treatments of silicon foliar-fertilizer and combined treatment of silicon foliar-fertilizer and topdressing fertilizer decreased more than 90% of Cd content. Results of BCR revealed that the percentage of cationic exchangeable and/or carbonate associated Cd fraction was more than 55% for most of the soil samples. Lime treatment significantly decreased the percentage of cationic exchangeable and/or carbonate and oxides of Fe and Mn associated Cd and increased the crystalline structure of clay minerals associated Cd. The change rate reached about 20%. Our results suggested concentration of soil Cd and pH were the two significant factors impacting the uptake of Cd by rice grains.

Assessment of an X-Ray Spectrometer for fluorescence cross sections measurements of elements with 22≤Ζ≤55 in a secondary target configuration

International Nuclear Information System (INIS)

Delabat Diaz, Y.

2015-01-01

A performance evaluation of an X-Ray Fluorescence Spectrometer for X-Ray Fluorescence (XRF) cross section measurements in a Secondary Target (ST) set-up has been carried out. Using Cd and Dy as STs, an annular 241 Am (∼1 Ci) radioactive source and an X-Ray Spectrometer with a Si(Li) semiconductor detector, the photon effective flux factors (Ι 0 Gε) were measured for some elements with 22≤Ζ≤55 as a function of the characteristics X-Rays energy for two different distances Source-St (0.5 cm and 1.0 cm). Thin high purity foils and a few pellets made out of composed materials were used as samples for the Ι 0 Gε calibrations. the contribution of 59.54 KeV scattered photons to the XRF was analysed and the Scattering Correction Factor (SCF) due to excitation by 59.54 keV scattered photons was estimated in the Cd configuration for further cross section measurements improvements. (Author)

Investigations of Spectroscopic Factors and Sum Rules from the Single Neutron Transfer Reaction 111Cd(d→$\\overrightarrow {\\rm{d}} $,p112Cd

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Jamieson D.S.

2014-03-01

Full Text Available Cadmium isotopes have been presented for decades as excellent examples of vibrational nuclei, with low-lying levels interpreted as multi-phonon quadrupole, octupole, and mixed-symmetry states. A large amount of spectroscopic data has been obtained through various experimental studies of cadmiumisotopes. In the present work, the 111Cd(d→$\\overrightarrow {\\rm{d}} $,p112Cd reaction was used to investigate the single-particle structure of the 112Cd nucleus. A 22 MeV beam of polarized deuterons was obtained at the Maier-Leibnitz laboratory in Garching, Germany. The reaction ejectiles were momentum analyzed using a Q3D spectrograph, and 130 levels have been identified up to 4.2 MeV of excitation energy. Using DWBA analysis with optical model calculations, spin-parity assignments have been made for observed levels, and spectroscopic factors have been extracted from the experimental angular distributions of differential cross section and analyzing power. In this high energy resolution investigation, many additional levels have been observed compared with the previous (d,p study using 8 MeV deuterons [1]. There were a total of 44 new levels observed, and the parity assignments of 34 levels were improved.

Surface preparation effects on efficient indium-tin-oxide-CdTe and CdS-CdTe heterojunction solar cells

Science.gov (United States)

Werthen, J. G.; Fahrenbruch, A. L.; Bube, R. H.; Zesch, J. C.

1983-05-01

The effects of CdTe surface preparation and subsequent junction formation have been investigated through characterization of ITO/CdTe and CdS/CdTe heterojunction solar cells formed by electron beam evaporation of indium-tin-oxide (ITO) and CdS onto single crystal p-type CdTe. Surfaces investigated include air-cleaved (110) surfaces, bromine-in-methanol etched (110) and (111) surfaces, and teh latter surfaces subjected to a hydrogen heat treatment. Both air-cleaved and hydrogen heat treated surfaces have a stoichiometric Cd to Te ratio. The ITO/CdTe junction formation process involves an air heat treatment, which ahs serious effects on the behavior of junctions formed on these surfaces. Etched surfaces which have a large excesss of Te, are less affected by the junction formation process and result in ITO/CdTe heterojunctions with solar efficiencies of 9% (Vsc =20 mA/cm2). Use of low-doped CdTe results in junctions characterized by considerably larger open-circuit votages (Voc =0.81 V) which are attributable to increasing diode factors caused by a shift from interfacial recombination to recombination in the depletion region. Resulting solar efficiencies reach 10.5% which is the highest value reported to date for a genuine CdTe heterojunction, CdS/CdTe heterojunctions show a strong dependence on CdTe surface condition, but less influence on the junction formation process. Solar efficiencies of 7.5% on an etched and heat treated surface are observed. All of these ITO/CdTe and CdS/CdTe heterojunctions have been stable for at least 10 months.

Inhibition of Allograft Inflammatory Factor-1 in Dendritic Cells Restrains CD4+ T Cell Effector Responses and Induces CD25+Foxp3+ T Regulatory Subsets

Directory of Open Access Journals (Sweden)

Diana M. Elizondo

2017-11-01

Full Text Available Allograft inflammatory factor-1 (AIF1 is a cytoplasmic scaffold protein shown to influence immune responses in macrophages and microglial cells. The protein contains Ca2+ binding EF-hand and PDZ interaction domains important for mediating intracellular signaling complexes. This study now reports that AIF1 is expressed in CD11c+ dendritic cells (DC and silencing of expression restrains induction of antigen-specific CD4+ T cell effector responses. AIF1 knockdown in murine DC resulted in impaired T cell proliferation and skewed polarization away from T helper type 1 and 17 fates. In turn, there was a parallel expansion of IL-10-producing and CD25+Foxp3+ T regulatory subsets. These studies are the first to demonstrate that AIF1 expression in DC serves as a potent governor of cognate T cell responses and presents a novel target for engineering tolerogenic DC-based immunotherapies.

Decreased Expression of T-Cell Costimulatory Molecule CD28 on CD4 and CD8 T Cells of Mexican Patients with Pulmonary Tuberculosis

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German Bernal-Fernandez

2010-01-01

Full Text Available Patients with tuberculosis frequently develop anergy, a state of T-cell hyporesponsiveness in which defective T-cell costimulation could be a factor. To know if the expression of T-cell costimulatory molecules was altered in tuberculosis, we analyzed the peripheral blood T-cell phenotype of 23 Mexican patients with pulmonary tuberculosis. There was severe CD4 (P<.001 and CD8 (P<.01 lymphopenia and upregulation of costimulatory molecule CD30 on CD4 and CD8 T cells (P<.05; this increase was higher in relapsing tuberculosis. The main finding was severe downregulation of the major costimulatory molecule CD28 on both CD8 and CD4 T cells (P<.001. Depletion of the CD4/CD28 subset, a hitherto undescribed finding, is relevant because CD4 T cells constitute the main arm of the cell-mediated antimycobacterial immune response.

P55 tumour necrosis factor receptor in bone marrow-derived cells promotes atherosclerosis development in low-density lipoprotein receptor knock-out mice

NARCIS (Netherlands)

Xanthoulea, Sofia; Gijbels, Marion J. J.; van der Made, Ingeborg; Mujcic, Hilda; Thelen, Melanie; Vergouwe, Monique N.; Ambagts, Matheus H. C.; Hofker, Marten H.; de Winther, Menno P. J.

2008-01-01

Tumour necrosis factor (TNF) is a pivotal pro-inflammatory cytokine with a clear pathogenic role in many chronic inflammatory diseases, and p55 TNF receptor (TNFR) mediates the majority of TNF responses. The aim of the current study was to investigate the role of p55 TNFR expression in bone

TGFβR signalling controls CD103+CD11b+ dendritic cell development in the intestine

NARCIS (Netherlands)

L.J. Bain (Lisa); Montgomery, J. (J.); C.L. Scott (C.); J.M. Kel (Junda); M.J.H. Girard-Madoux (Mathilde); L. Martens (Liesbet); Zangerle-Murray, T.F.P. (T. F.P.); J.L. Ober-Blöbaum (Julia); D.J. Lindenbergh-Kortleve (Dicky); J.N. Samsom (Janneke); S. Henri (Sandrine); T. Lawrence (Toby); Y. Saeys (Yvan); B. Malissen (Bernard); M. Dalod (Marc); B.E. Clausen (Bjorn); Mowat, A.M. (A. McI.)

2017-01-01

textabstractCD103+CD11b+ dendritic cells (DCs) are unique to the intestine, but the factors governing their differentiation are unclear. Here we show that transforming growth factor receptor 1 (TGFβR1) has an indispensable, cell intrinsic role in the development of these cells. Deletion of Tgfbr1

A Low Peripheral Blood CD4/CD8 Ratio Is Associated with Pulmonary Emphysema in HIV.

Science.gov (United States)

Triplette, Matthew; Attia, Engi F; Akgün, Kathleen M; Soo Hoo, Guy W; Freiberg, Matthew S; Butt, Adeel A; Wongtrakool, Cherry; Goetz, Matthew Bidwell; Brown, Sheldon T; Graber, Christopher J; Huang, Laurence; Crothers, Kristina

2017-01-01

The prevalence of emphysema is higher among HIV-infected (HIV+) individuals compared to HIV-uninfected persons. While greater tobacco use contributes, HIV-related effects on immunity likely confer additional risk. Low peripheral blood CD4+ to CD8+ T-lymphocyte (CD4/CD8) ratio may reflect chronic inflammation in HIV and may be a marker of chronic lung disease in this population. Therefore, we sought to determine whether the CD4/CD8 ratio was associated with chronic obstructive pulmonary disease (COPD), particularly the emphysema subtype, in a cohort of HIV+ subjects. We performed a cross-sectional analysis of 190 HIV+ subjects enrolled in the Examinations of HIV Associated Lung Emphysema (EXHALE) study. Subjects underwent baseline laboratory assessments, pulmonary function testing and chest computed tomography (CT) analyzed for emphysema severity and distribution. We determined the association between CD4/CD8 ratio and emphysema, and the association between CD4/CD8 ratio and pulmonary function markers of COPD. Mild or greater emphysema (>10% lung involvement) was present in 31% of subjects. Low CD4/CD8 ratio was associated with >10% emphysema in multivariable models, adjusting for risk factors including smoking, current and nadir CD4 count and HIV RNA level. Those with CD4/CD8 ratio 10% emphysema compared to those with a ratio >1.0 in fully adjusted models. A low CD4/CD8 ratio was also associated with reduced diffusion capacity (DLCO). A low CD4/CD8 ratio was associated with emphysema and low DLCO in HIV+ subjects, independent of other risk factors and clinical markers of HIV. The CD4/CD8 ratio may be a useful, clinically available, marker for risk of emphysema in HIV+ subjects in the antiretroviral therapy (ART) era.

HIV infection and aging: enhanced Interferon- and Tumor Necrosis Factor-alpha production by the CD8+ CD28- T subset

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Colón-Martinez Sol

2001-10-01

Full Text Available Abstract Background T cells from HIV+ and aged individuals show parallels in terms of suppressed proliferative activity and interleukin-2 (I1-2 production and an increased number of CD8+ CD28- T cells. In order to compare cytokine production from T cells from these two states, CD4+ and CD8+ T cells from HIV+ aged, and normal young donors (controls were monitored for cytokine production by flow cytometry, quantitative PCR and ELISA upon activation by PMA and anti-CD3. In addition, the CD8+ T cell subsets CD28+ and CD28- from the HIV+ and the aged groups were evaluated for cytokine production by flow cytometry, and compared with those from young controls. Results Flow cytometric analysis indicated that CD8+ T cells from both HIV+ and aged donors showed an increase of approximately 2–3 fold over controls in percentage of cells producing inflammatory cytokines IFN-γ and TNF-α. Similar analysis also revealed that the production of interleukins-4,6 and 10, production was very low (1–2% of cells and unchanged in these cells. Quantitative PCR also showed a substantial increase (4–5 fold in IFN-γ and TNF-α mRNA from HIV+ and aged CD8+ T cells, as did ELISA for secreted IFN-γ and TNF-α (2.3–4 fold. Flow cytometric analysis showed that the CD8+ CD28- T cell subset accounts for approximately 80–86% of the IFN-γ and TNF-α production from the CD8+ subset in the aged and HIV+ states. The CD4+ T cell, while not significantly changed in the HIV+ or aged states in terms of IFN-γ production, showed a small but significant increase in TNF-α production in both states. Conclusions Our data appear compatible with physiologic conditions existing in HIV+ and aged individuals, i.e. elevated serum levels and elevated CD8+ T cell production of IFN-γ and TNF-α. Thus, the capacity for increased production of cytokines IFN-γ and TNF-α in the aged individual by the dominant CD8+ CD28- subset may have a profound influence on the clinical state by

Human HMG box transcription factor HBP1: a role in hCD2 LCR function.

Science.gov (United States)

Zhuma, T; Tyrrell, R; Sekkali, B; Skavdis, G; Saveliev, A; Tolaini, M; Roderick, K; Norton, T; Smerdon, S; Sedgwick, S; Festenstein, R; Kioussis, D

1999-01-01

The locus control region (LCR) of the human CD2 gene (hCD2) confers T cell-specific, copy-dependent and position-independent gene expression in transgenic mice. This LCR consists of a strong T cell-specific enhancer and an element without enhancer activity (designated HSS3), which is required for prevention of position effect variegation (PEV) in transgenic mice. Here, we identified the HMG box containing protein-1 (HBP1) as a factor binding to HSS3 of the hCD2 LCR. Within the LCR, HBP1 binds to a novel TTCATTCATTCA sequence that is higher in affinity than other recently reported HBP1-binding sites. Mice transgenic for a hCD2 LCR construct carrying a deletion of the HBP1-binding sequences show a propensity for PEV if the transgene integrates in a heterochromatic region of the chromosome such as the centromere or telomere. We propose that HBP1 plays an important role in chromatin opening and remodelling activities by binding to and bending the DNA, thus allowing DNA-protein and/or protein-protein interactions, which increase the probability of establishing an active locus. PMID:10562551

CD52 expression on CD4+ T cells in HIV-positive individuals on cART

DEFF Research Database (Denmark)

Vojdeman, Fie Juhl; Gaardbo, Julie Christine; Hartling, Hans Jakob

2018-01-01

BACKGROUND: Human immune defect virus (HIV) persists in a latent state in quiescent CD4+ T cells preventing eradication of HIV. CD52 is a surface molecule modulated by HIV. We aimed at examining factors related to CD52 expression on CD4+ T cells in HIV-positive individuals and the impact...... of initiation of combination antiretroviral therapy (cART). METHODS: Peripheral blood mononuclear cells (PBMC) from 18 HIV-positive individuals and 10 uninfected age and gender matched controls were examined by flow cytometry for CD38 and CD52 expression on CD4+ T cells. Stimulation assays were performed on 8...... healthy blood donors to determine a cut-off for CD52 expression. RESULTS: All examined CD4+ T cells expressed CD52. However, both CD4+ T cells with higher (CD52++) and with lower CD52 expression (CD52dim) were found in HIV-positive individuals compared to uninfected controls. Two % CD52dim cells defined...

Dynamic balance between master transcription factors determines the fates and functions of CD4 T cell and innate lymphoid cell subsets

Science.gov (United States)

2017-01-01

CD4 T cells, including T regulatory cells (Treg cells) and effector T helper cells (Th cells), and recently identified innate lymphoid cells (ILCs) play important roles in host defense and inflammation. Both CD4 T cells and ILCs can be classified into distinct lineages based on their functions and the expression of lineage-specific genes, including those encoding effector cytokines, cell surface markers, and key transcription factors. It was first recognized that each lineage expresses a specific master transcription factor and the expression of these factors is mutually exclusive because of cross-regulation among these factors. However, recent studies indicate that the master regulators are often coexpressed. Furthermore, the expression of master regulators can be dynamic and quantitative. In this review, we will first discuss similarities and differences between the development and functions of CD4 T cell and ILC subsets and then summarize recent literature on quantitative, dynamic, and cell type–specific balance between the master transcription factors in determining heterogeneity and plasticity of these subsets. PMID:28630089

Single-particle states in ^112Cd probed with the ^111Cd(d,p) reaction

Science.gov (United States)

Garrett, P. E.; Jamieson, D.; Demand, G. A.; Finlay, P.; Green, K. L.; Leach, K. G.; Phillips, A. A.; Sumithrarachchi, C. S.; Svensson, C. E.; Triambak, S.; Wong, J.; Ball, G. C.; Hertenberger, R.; Wirth, H.-F.; Kr"Ucken, R.; Faestermann, T.

2009-10-01

As part of a program of detailed spectroscopy of the Cd isotopes, the single-particle neutron states in ^112Cd have been probed with the ^111Cd(d,p) reaction. Beams of polarized 22 MeV deuterons, obtained from the LMU/TUM Tandem Accelerator, bombarded a target of ^111Cd. The protons from the reaction, corresponding to excitation energies up to 3 MeV in ^112Cd, were momentum analyzed with the Q3D spectrograph. Cross sections and analyzing powers were fit to results of DWBA calculations, and spectroscopic factors were determined. The results from the experiment, and implications for the structure of ^112Cd, will be presented.

Physical properties of Bi doped CdTe thin films grown by CSVT and their influence on the CdS/CdTe solar cells PV-properties

International Nuclear Information System (INIS)

Vigil-Galan, O.; Sanchez-Meza, E.; Ruiz, C.M.; Sastre-Hernandez, J.; Morales-Acevedo, A.; Cruz-Gandarilla, F.; Aguilar-Hernandez, J.; Saucedo, E.; Contreras-Puente, G.; Bermudez, V.

2007-01-01

The physical properties of Bi doped CdTe films, grown on glass substrates by the Closed Space Transport Vapour (CSVT) method, from different Bi doped CdTe powders are presented. The CdTe:Bi films were characterized using Photoluminescence, Hall effect, X-Ray diffraction, SEM and Photoconductivity measurements. Moreover, CdS/CdTe:Bi solar cells were made and their characteristics like short circuit current density (J sc ), open circuit voltage (V OC ), fill factor (FF) and efficiency (η) were determined. These devices were fabricated from Bi doped CdTe layers deposited on CdS with the same growth conditions than those used for the single CdTe:Bi layers. A correlation between the CdS/CdTe:Bi solar cell characteristics and the physical properties of the Bi doped CdTe thin films are presented and discussed

Genetics of Cd36 and the clustering of multiple cardiovascular risk factors in spontaneous hypertension

Czech Academy of Sciences Publication Activity Database

Pravenec, Michal; Zídek, Václav; Šimáková, Miroslava; Křen, Vladimír; Křenová, D.; Horký, K.; Jáchymová, M.; Míková, B.; Kazdová, L.; Aitman, T. J.; Churchill, P. C.; Webb, R. C.; Hingarh, N. H.; Yang, Y.; Wang, J. M.; St.Lezin, E. M.; Kurtz, W. T.

1999-01-01

Roč. 103, č. 12 (1999), s. 1651-1657 ISSN 0021-9738 R&D Projects: GA ČR GA306/97/0521; GA ČR GV204/98/K015 Grant - others:NIH(US) ROI HL-56028; NIH(US) PO1 HL-35018; NIH(US) HL-18575 Institutional research plan: CEZ:AV0Z5011922 Keywords : Cd36 * cardiovascular risk factors * spontaneous hypertension Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 10.921, year: 1999

CD21+ (B2 antigen+) cell decrement and CD4+CD29+ (helper-inducer) cell increment suggest an activation of cell immune reactivity in multiple sclerosis.

Science.gov (United States)

Gambi, D; Porrini, A M; Giampietro, A; Macor, S

1991-08-01

Two-color flow cytometric analysis on peripheral blood lymphocytes of 35 untreated multiple sclerosis (MS) patients, 17 other medical disease (OMD) patients and 14 healthy control (HC) subjects was performed to evaluate the levels of different T and B cell subpopulations. In MS patients we observed an increase in CD4+CD29+ helper-inducer cells but this increase was not related to the different phases of the disease. We hypothesize that this change is related to the reduction of CD21+ cells expressing B2 antigen, a 140 kDa molecule disappearing after B cell activation. An increased level of CD4+CD45RA- (helper-inducer-like cells) and a reduction of CD4+CD29- (suppressor-inducer-like cells) were also present in our patients. These findings demonstrate an immune 'disequilibrium' in MS, which is linked with an increased level of CD25+ cells expressing the interleukin-2 (IL-2) receptor. IL-2, besides being a T cell growth factor, is also a B cell growth factor. These data let us hypothesize that an activation of the immune response is present in MS.

Lineage determination of CD7+ CD5- CD2- and CD7+ CD5+ CD2- lymphoblasts: studies on phenotype, genotype, and gene expression of myeloperoxidase, CD3 epsilon, and CD3 delta.

Science.gov (United States)

Yoneda, N; Tatsumi, E; Teshigawara, K; Nagata, S; Nagano, T; Kishimoto, Y; Kimura, T; Yasunaga, K; Yamaguchi, N

1994-04-01

The gene expression of myeloperoxidase (MPO), CD3 epsilon, and CD3 delta molecules, the gene rearrangement of T-cell receptor (TCR) delta, gamma, and beta and immunoglobulin heavy (IgH) chain, and the expression of cell-surface antigens were investigated in seven cases of CD7+ CD5- CD2- and four cases of CD7+ CD5+ CD2- acute lymphoblastic leukemia or lymphoblastic lymphoma (ALL/LBL) blasts, which were negative for cytochemical myeloperoxidase (cyMPO). More mature T-lineage blasts were also investigated in a comparative manner. In conclusion, the CD7+ CD5- CD2- blasts included four categories: undifferentiated blasts without lineage commitment, T-lineage blasts, T-/myeloid lineage blasts, and cyMPO-negative myeloblasts. The CD7+ CD5+ CD2- blasts included two categories; T-lineage and T-/myeloid lineage blasts. The 11 cases were of the germ-line gene (G) for TCR beta and IgH. Four cases were G for TCR delta and TCR gamma. The others were of the monoclonally rearranged gene (R) for TCR delta and G for TCR gamma or R for both TCR delta and TCR gamma. The expression or in vitro induction of CD13 and/or CD33 antigens correlated with the immaturity of these neoplastic T cells, since it was observed in all 11 CD7+ CD5- CD2- and CD7+ CD5+ CD2-, and some CD7+ CD5+ CD2+ (CD3- CD4- CD8-) cases, but not in CD3 +/- CD4+ CD8+ or CD3+ CD4+ CD8- cases. CD3 epsilon mRNA, but not CD3 delta mRNA, was detected in two CD7+ CD5- CD2- cases, while mRNA of neither of the two CD3 molecules was detected in the other tested CD7+ CD5- CD2- cases. In contrast, mRNA of both CD3 epsilon and CD3 delta were detected in all CD7+ CD5+ CD2- cases, indicating that CD7+ CD5- CD2- blasts at least belong to T-lineage. The blasts of two CD7+ CD5- CD2- cases with entire germ-line genes and without mRNA of the three molecules (MPO, CD3 epsilon, and CD3 delta) were regarded as being at an undifferentiated stage prior to their commitment to either T- or myeloid-lineage. The co-expression of the genes of MPO

Soil geochemical factors regulate Cd accumulation by metal hyperaccumulating Noccaea caerulescens (J. Presl & C. Presl) F.K. Mey in field-contaminated soils.

Science.gov (United States)

Rosenfeld, Carla E; Chaney, Rufus L; Martínez, Carmen E

2018-03-01

Cadmium contamination in soil is a substantial global problem, and of significant concern due to high food-chain transfer. Cadmium hyperaccumulators are of particular interest because of their ability to tolerate and take up significant amounts of heavy metal pollution from soils. One particular plant, Noccaea caerulescens (formerly, Thlaspi caerulescens), has been extensively studied in terms of its capacity to accumulate heavy metals (specifically Zn and Cd), though these studies have primarily utilized hydroponic and metal-spiked model soil systems. We studied Cd and nutrient uptake by two N. caerulescens ecotypes, Prayon (Zn-only hyperaccumulator) and Ganges (Zn- and Cd-hyperaccumulator) in four long-term field-contaminated soils. Our data suggest that individual soil properties such as total soil Cd, Zn:Cd molar ratio, or soil pH do not accurately predict Cd uptake by hyperaccumulating plants. Additionally, total Cd uptake by the hyperaccumulating Ganges ecotype was substantially less than its physiological capacity, which is likely due to Cd-containing solid phases (primarily iron oxides) and pH that play an important role in regulating and limiting Cd solubility. Increased P accumulation in the Ganges leaves, and greater plant Fe accumulation from Cd-containing soils suggests that rhizosphere alterations via proton, and potentially organic acid, secretion may also play a role in nutrient and Cd acquisition by the plant roots. The current study highlights the role that soil geochemical factors play in influencing Cd uptake by hyperaccumulating plants. While these plants may have high physiological potential to accumulate metals from contaminated soils, individual soil geochemical factors and the plant-soil interactions in that soil will dictate the actual amount of phytoextractable metal. This underlines the need for site-specific understanding of metal-containing solid phases and geochemical properties of soils before undertaking phytoextraction efforts

A theoretical investigation of the structural and electronic properties of 55-atom nanoclusters: The examples of Y-Tc and Pt.

Science.gov (United States)

Batista, Krys E A; Piotrowski, Maurício J; Chaves, Anderson S; Da Silva, Juarez L F

2016-02-07

Several studies have found that the Pt55 nanocluster adopts a distorted reduced core structure, DRC55, in which there are 8-11 atoms in the core and 47-44 atoms in the surface, instead of the compact and high-symmetry icosahedron structure, ICO55, with 13 and 42 atoms in the core and surface, respectively. The DRC structure has also been obtained as the putative global minimum configuration (GMC) for the Zn55 (3d), Cd55 (4d), and Au55 (5d) systems. Thus, the DRC55 structure has been reported only for systems with a large occupation of the d-states, where the effects of the occupation of the valence anti-bonding d-states might play an important role. Can we observe the DRC structure for 55-atom transition-metal systems with non-occupation of the anti-bonding d-states? To address this question, we performed a theoretical investigation of the Y 55, Zr55, Nb55, Mo55, Tc55, and Pt55 nanoclusters, employing density functional theory calculations. For the putative GMCs, we found that the Y 55 adopts the ICO55 structure, while Nb55 and Mo55 adopt a bulk-like fragment based on the hexagonal close-packed structure and Tc55 adopts a face-centered cubic fragment; however, Zr55 adopts a DRC55 structure, like Zn55, Cd55, Pt55, and Au55. Thus we can conclude that the preference for DRC55 structure is not related to the occupation of the anti-bonding d-states, but to a different effect, in fact, a combination of structural and electronic effects. Furthermore, we obtained that the binding energy per atom follows the occupation of the bonding and anti-bonding model, i.e., the stability of the studied systems increases from Y to Tc with a small oscillation for Mo, which also explains the equilibrium bond lengths. We obtained a larger magnetic moment for Y 55 (31 μB) which can be explained by the localization of the d-states in Y at nanoscale, which is not observed for the remaining systems (0-1 μB).

Mucosal immunization in macaques upregulates the innate APOBEC 3G anti-viral factor in CD4(+) memory T cells.

Science.gov (United States)

Wang, Yufei; Bergmeier, Lesley A; Stebbings, Richard; Seidl, Thomas; Whittall, Trevor; Singh, Mahavir; Berry, Neil; Almond, Neil; Lehner, Thomas

2009-02-05

APOBEC3G is an innate intracellular anti-viral factor which deaminates retroviral cytidine to uridine. In vivo studies of APOBEC3G (A3G) were carried out in rhesus macaques, following mucosal immunization with SIV antigens and CCR5 peptides, linked to the 70kDa heat shock protein. A progressive increase in A3G mRNA was elicited in PBMC after each immunization (p<0.0002 to p< or =0.02), which was maintained for at least 17 weeks. Analysis of memory T cells showed a significant increase in A3G mRNA and protein in CD4(+)CCR5(+) memory T cells in circulating (p=0.0001), splenic (p=0.0001), iliac lymph nodes (p=0.002) and rectal (p=0.01) cells of the immunized compared with unimmunized macaques. Mucosal challenge with SIVmac 251 showed a significant increase in A3G mRNA in the CD4(+)CCR5(+) circulating cells (p<0.01) and the draining iliac lymph node cells (p<0.05) in the immunized uninfected macaques, consistent with a protective effect exerted by A3G. The results suggest that mucosal immunization in a non-human primate can induce features of a memory response to an innate anti-viral factor in CCR5(+)CD4(+) memory and CD4(+)CD95(+)CCR7(-) effector memory T cells.

Factors associated with esophageal candidiasis and its endoscopic severity in the era of antiretroviral therapy.

Directory of Open Access Journals (Sweden)

So Nishimura

Full Text Available Candidia esophagitis (CE is an AIDS-defining condition, usually occurring in individuals with low CD4 counts of <200 cells/µL. Endoscopy is a valuable definitive diagnostic method for CE but may not be indicated for asymptomatic patients or for those with high CD4 counts or without oral candidiasis. This study assessed such patients to clarify the factors associated with CE and its severity on endoscopy in the highly active antiretroviral therapy (HAART era.A total of 733 HIV-infected patients who underwent upper gastrointestinal (GI endoscopy were analyzed. Sexual behavior, CD4(+ count, HIV-RNA viral load (VL, history of HAART, GI symptoms, GI diseases, and oral candidiasis were assessed. Endoscopic severity of CE was classified as mild (Kodsi's grade I/II or severe (grade III/IV. Of the 733 subjects, 62 (8.46% were diagnosed with CE (mild, n = 33; severe, n = 29. Of them, 56.5% (35/62 had no GI symptoms, 30.6% (19/62 had CD4 + ≥200 cells/μL, and 55.3% (21/38 had no oral candidiasis. Univariate analysis found lower CD4+ counts, higher HIV VL, and no history of HAART to be significantly associated with CE. With lower CD4(+ counts and higher HIV VL, CE occurrence increased significantly (P<0.01 for trend in odds. Multivariate analysis showed low CD4+ counts and high HIV VL to be independently associated with CE. Of the severe CE patients, 55.2% (16/29 had no GI symptoms and 44.4% (8/18 had no oral candidiasis. Median CD4(+ counts in severe cases were significantly lower than in mild cases (27 vs. 80; P = 0.04.Low CD4+ counts and high HIV VL were found to be factors associated with CE, and advanced immunosuppression was associated with the development of severity. Endoscopy is useful as it can detect CE, even severe CE, in patients without GI symptoms, those with high CD4 counts, and those without oral candidiasis.

Heat shock factor-1 intertwines insulin/IGF-1, TGF-β and cGMP signaling to control development and aging

Directory of Open Access Journals (Sweden)

Barna János

2012-11-01

Full Text Available Abstract Background Temperature affects virtually all cellular processes. A quick increase in temperature challenges the cells to undergo a heat shock response to maintain cellular homeostasis. Heat shock factor-1 (HSF-1 functions as a major player in this response as it activates the transcription of genes coding for molecular chaperones (also called heat shock proteins that maintain structural integrity of proteins. However, the mechanisms by which HSF-1 adjusts fundamental cellular processes such as growth, proliferation, differentiation and aging to the ambient temperature remain largely unknown. Results We demonstrate here that in Caenorhabditis elegans HSF-1 represses the expression of daf-7 encoding a TGF-β (transforming growth factor-beta ligand, to induce young larvae to enter the dauer stage, a developmentally arrested, non-feeding, highly stress-resistant, long-lived larval form triggered by crowding and starvation. Under favorable conditions, HSF-1 is inhibited by crowding pheromone-sensitive guanylate cyclase/cGMP (cyclic guanosine monophosphate and systemic nutrient-sensing insulin/IGF-1 (insulin-like growth factor-1 signaling; loss of HSF-1 activity allows DAF-7 to promote reproductive growth. Thus, HSF-1 interconnects the insulin/IGF-1, TGF-β and cGMP neuroendocrine systems to control development and longevity in response to diverse environmental stimuli. Furthermore, HSF-1 upregulates another TGF-β pathway-interacting gene, daf-9/cytochrome P450, thereby fine-tuning the decision between normal growth and dauer formation. Conclusion Together, these results provide mechanistic insight into how temperature, nutrient availability and population density coordinately influence development, lifespan, behavior and stress response through HSF-1.

40 CFR 1033.535 - Adjusting emission levels to account for infrequently regenerating aftertreatment devices.

Science.gov (United States)

2010-07-01

... the downward adjustment factor (DAF) using the following equation: DAF = EFH−EFA (d) Sample... = 0.14 g/ bhp-hr−0.10 g/ bhp-hr = 0.04 g/ bhp-hr. DAF = 0.50 g/ bhp-hr−0.14 g/ bhp-hr = 0.36 g/ bhp-hr...

Effect of granulocyte colony-stimulating factor (G-CSF) in human immunodeficiency virus-infected patients: increase in numbers of naive CD4 cells and CD34 cells makes G-CSF a candidate for use in gene therapy or to support antiretroviral therapy

DEFF Research Database (Denmark)

Nielsen, S D; Afzelius, P; Dam-Larsen, S

1998-01-01

The potential of granulocyte colony-stimulating factor (G-CSF) to mobilize CD4 cells and/or CD34 cells for use in gene therapy or to support antiretroviral therapy was examined. Ten human immunodeficiency virus-infected patients were treated with G-CSF (300 microg/day) for 5 days. Numbers of CD4.......01/microL (P CSF induced increases in numbers of CD34 cells and CD4 cells in HIV-infected patients...

CD25 shedding by human natural occurring CD4+CD25+ regulatory T cells does not inhibit the action of IL-2

DEFF Research Database (Denmark)

Pedersen, Anders Elm; Lauritsen, Jens Peter Holst

2009-01-01

Tregs are known to inhibit CD4+ T cell in a contact-dependent manner, but at the same time, various suppressive factors are secreted. We, here, demonstrate that human naturally occurring CD4+CD25+ Tregs are able to shed large amounts of soluble CD25 upon activation. Secretion of sCD25 could add......Regulatory T (Treg) cells are important for the maintenance of peripheral tolerance and inhibition of pathogenic T-cell responses. Therefore, they are important for the limitation of chronic inflammation but can also be deleterious by e.g. limiting antitumour immune responses. Natural occurring...... to the inhibitory effect of Tregs as such secretion in other settings has been proposed to act as a sink for local IL-2. However, we here demonstrate that supernatant from human Tregs containing high concentration of sCD25 does not inhibit proliferation of CD4+CD25(-) T cells or inhibit the action of IL-2...

The Transcription Factor Hobit Identifies Human Cytotoxic CD4(+) T Cells

NARCIS (Netherlands)

Oja, Anna E.; Vieira Braga, Felipe A.; Remmerswaal, Ester B. M.; Kragten, Natasja A. M.; Hertoghs, Kirsten M. L.; Zuo, Jianmin; Moss, Paul A.; van Lier, René A. W.; van Gisbergen, Klaas P. J. M.; Hombrink, Pleun

2017-01-01

The T cell lineage is commonly divided into CD4-expressing helper T cells that polarize immune responses through cytokine secretion and CD8-expressing cytotoxic T cells that eliminate infected target cells by virtue of the release of cytotoxic molecules. Recently, a population of CD4(+) T cells that

Immobilization remediation of Cd-polluted soil with different water condition.

Science.gov (United States)

Li, Jianrui; Xu, Yingming

2017-05-15

To demonstrate effects of water management on soil Cd immobilization using palygorskite, the investigation evaluated impacts of palygorskite on uptake of Cd present in soils with different water condition by rice plant. Pot experiment results showed that, pH, available Fe and P in untreated soils were higher in continuous flooding than in traditional irrigation and wetting irrigation, which were reasons for lower soil exchangeable Cd and plant Cd in continuous flooding. In control group (untreated soils), compared to traditional irrigation, continuous flooding reduced brown rice Cd by 37.9%, that in wetting irrigation increased by 31.0%. At palygorskite concentrations of 5 g kg -1 , 10 g kg -1 and 15 g kg -1 , brown rice Cd reduced by 16.7%, 44.4% and 55.6% under continuous flooding, 13.8%, 34.5% and 44.8% under traditional irrigation, 13.1%, 36.8% and 47.3% under wetting irrigation (p soils. Copyright © 2017 Elsevier Ltd. All rights reserved.

CD19 CAR-T cells of defined CD4+:CD8+ composition in adult B cell ALL patients.

Science.gov (United States)

Turtle, Cameron J; Hanafi, Laïla-Aïcha; Berger, Carolina; Gooley, Theodore A; Cherian, Sindhu; Hudecek, Michael; Sommermeyer, Daniel; Melville, Katherine; Pender, Barbara; Budiarto, Tanya M; Robinson, Emily; Steevens, Natalia N; Chaney, Colette; Soma, Lorinda; Chen, Xueyan; Yeung, Cecilia; Wood, Brent; Li, Daniel; Cao, Jianhong; Heimfeld, Shelly; Jensen, Michael C; Riddell, Stanley R; Maloney, David G

2016-06-01

T cells that have been modified to express a CD19-specific chimeric antigen receptor (CAR) have antitumor activity in B cell malignancies; however, identification of the factors that determine toxicity and efficacy of these T cells has been challenging in prior studies in which phenotypically heterogeneous CAR-T cell products were prepared from unselected T cells. We conducted a clinical trial to evaluate CD19 CAR-T cells that were manufactured from defined CD4+ and CD8+ T cell subsets and administered in a defined CD4+:CD8+ composition to adults with B cell acute lymphoblastic leukemia after lymphodepletion chemotherapy. The defined composition product was remarkably potent, as 27 of 29 patients (93%) achieved BM remission, as determined by flow cytometry. We established that high CAR-T cell doses and tumor burden increase the risks of severe cytokine release syndrome and neurotoxicity. Moreover, we identified serum biomarkers that allow testing of early intervention strategies in patients at the highest risk of toxicity. Risk-stratified CAR-T cell dosing based on BM disease burden decreased toxicity. CD8+ T cell-mediated anti-CAR transgene product immune responses developed after CAR-T cell infusion in some patients, limited CAR-T cell persistence, and increased relapse risk. Addition of fludarabine to the lymphodepletion regimen improved CAR-T cell persistence and disease-free survival. Immunotherapy with a CAR-T cell product of defined composition enabled identification of factors that correlated with CAR-T cell expansion, persistence, and toxicity and facilitated design of lymphodepletion and CAR-T cell dosing strategies that mitigated toxicity and improved disease-free survival. ClinicalTrials.gov NCT01865617. R01-CA136551; Life Science Development Fund; Juno Therapeutics; Bezos Family Foundation.

CD19 CAR–T cells of defined CD4+:CD8+ composition in adult B cell ALL patients

Science.gov (United States)

Turtle, Cameron J.; Hanafi, Laïla-Aïcha; Berger, Carolina; Gooley, Theodore A.; Cherian, Sindhu; Hudecek, Michael; Sommermeyer, Daniel; Melville, Katherine; Pender, Barbara; Budiarto, Tanya M.; Robinson, Emily; Steevens, Natalia N.; Chaney, Colette; Soma, Lorinda; Chen, Xueyan; Li, Daniel; Cao, Jianhong; Heimfeld, Shelly; Jensen, Michael C.; Riddell, Stanley R.; Maloney, David G.

2016-01-01

BACKGROUND. T cells that have been modified to express a CD19-specific chimeric antigen receptor (CAR) have antitumor activity in B cell malignancies; however, identification of the factors that determine toxicity and efficacy of these T cells has been challenging in prior studies in which phenotypically heterogeneous CAR–T cell products were prepared from unselected T cells. METHODS. We conducted a clinical trial to evaluate CD19 CAR–T cells that were manufactured from defined CD4+ and CD8+ T cell subsets and administered in a defined CD4+:CD8+ composition to adults with B cell acute lymphoblastic leukemia after lymphodepletion chemotherapy. RESULTS. The defined composition product was remarkably potent, as 27 of 29 patients (93%) achieved BM remission, as determined by flow cytometry. We established that high CAR–T cell doses and tumor burden increase the risks of severe cytokine release syndrome and neurotoxicity. Moreover, we identified serum biomarkers that allow testing of early intervention strategies in patients at the highest risk of toxicity. Risk-stratified CAR–T cell dosing based on BM disease burden decreased toxicity. CD8+ T cell–mediated anti-CAR transgene product immune responses developed after CAR–T cell infusion in some patients, limited CAR–T cell persistence, and increased relapse risk. Addition of fludarabine to the lymphodepletion regimen improved CAR–T cell persistence and disease-free survival. CONCLUSION. Immunotherapy with a CAR–T cell product of defined composition enabled identification of factors that correlated with CAR–T cell expansion, persistence, and toxicity and facilitated design of lymphodepletion and CAR–T cell dosing strategies that mitigated toxicity and improved disease-free survival. TRIAL REGISTRATION. ClinicalTrials.gov NCT01865617. FUNDING. R01-CA136551; Life Science Development Fund; Juno Therapeutics; Bezos Family Foundation. PMID:27111235

Royal Jelly-Mediated Prolongevity and Stress Resistance in Caenorhabditis elegans Is Possibly Modulated by the Interplays of DAF-16, SIR-2.1, HCF-1, and 14-3-3 Proteins.

Science.gov (United States)

Wang, Xiaoxia; Cook, Lauren F; Grasso, Lindsay M; Cao, Min; Dong, Yuqing

2015-07-01

Recent studies suggest that royal jelly (RJ) and its related substances may have antiaging properties. However, the molecular mechanisms underlying the beneficial effects remain elusive. We report that the effects of RJ and enzyme-treated RJ (eRJ) on life span and health span in Caenorhabditis elegans (C elegans) are modulated by the sophisticated interplays of DAF-16, SIR-2.1, HCF-1, and 14-3-3 proteins. Dietary supplementation with RJ or eRJ increased C. elegans life span in a dose-dependent manner. The RJ and eRJ consumption increased the tolerance of C elegans to oxidative stress, ultraviolet irradiation, and heat shock stress. Our genetic analyses showed that RJ/eRJ-mediated life-span extension requires insulin/IGF-1 signaling and the activities of DAF-16, SIR-2.1, HCF-1, and FTT-2, a 14-3-3 protein. Earlier studies reported that DAF-16/FOXO, SIR-2.1/SIRT1, FTT-2, and HCF-1 have extensive interplays in worms and mammals. Our present findings suggest that RJ/eRJ-mediated promotion of longevity and stress resistance in C elegans is dependent on these conserved interplays. From an evolutionary point of view, this study not only provides new insights into the molecular mechanisms of RJ's action on health span promotion in C elegans, but also has imperative implications in using RJ/eRJ as nutraceuticals to delay aging and age-related disorders. © The Author 2014. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

DAF-2 and ERK Couple Nutrient Availability to Meiotic Progression during Caenorhabditis elegans Oogenesis

Science.gov (United States)

Lopez, Andrew L.; Chen, Jessica; Joo, Hyoe-Jin; Drake, Melanie; Shidate, Miri; Kseib, Cedric; Arur, Swathi

2013-01-01

Coupling the production of mature gametes and fertilized zygotes to favorable nutritional conditions improves reproductive success. In invertebrates, the proliferation of female germ line stem cells is regulated by nutritional status. But, in mammals the number of female germ line stem cells is set early in development, with oocytes progressing through meiosis later in life. Mechanisms that couple later steps of oogenesis to environmental conditions remain largely undefined. We show that in the presence of food, the DAF-2 insulin-like receptor signals through the RAS-ERK pathway to drive meiotic prophase I progression and oogenesis; in the absence of food, the resultant inactivation of insulin-like signaling leads to downregulation of RAS-ERK pathway, and oogenesis is stalled. Thus, the insulin-like signaling pathway couples nutrient sensing to meiotic I progression and oocyte production in C. elegans, ensuring that oocytes are only produced under conditions favorable for the survival of the resulting zygotes. PMID:24120884

CXC chemokine receptor 3 expression on CD34(+) hematopoietic progenitors from human cord blood induced by granulocyte-macrophage colony-stimulating factor

DEFF Research Database (Denmark)

Jinquan, T; Quan, S; Jacobi, H H

2000-01-01

-induced CD34(+) progenitor chemotaxis. These chemotactic attracted CD34(+) progenitors are colony-forming units-granulocyte-macrophage. gamma IP-10 and Mig also induced GM-CSF-stimulated CD34(+) progenitor adhesion and aggregation by means of CXCR3, a finding confirmed by the observation that anti-CXCR3 m......Ab blocked these functions of gammaIP-10 and Mig but not of chemokine stromal cell-derived factor 1 alpha. gamma IP-10-induced and Mig-induced up-regulation of integrins (CD49a and CD49b) was found to play a crucial role in adhesion of GM-CSF-stimulated CD34(+) progenitors. Moreover, gamma IP-10 and Mig...... stimulated CXCR3 redistribution and cellular polarization in GM-CSF-stimulated CD34(+) progenitors. These results indicate that CXCR3-gamma IP-10 and CXCR3-Mig receptor-ligand pairs, as well as the effects of GM-CSF on them, may be especially important in the cytokine/chemokine environment...

Factors influencing utilization of postpartum CD4 count testing by HIV-positive women not yet eligible for antiretroviral treatment.

Science.gov (United States)

Gilles, Kate P; Zimba, Chifundo; Mofolo, Innocent; Bobrow, Emily; Hamela, Gloria; Martinson, Francis; Hoffman, Irving; Hosseinipour, Mina

2011-03-01

Delayed antiretroviral initiation is associated with increased mortality, but individuals frequently delay seeking treatment. To increase early antiretroviral therapy (ART) enrollment of HIV-positive women, antenatal clinics are implementing regular, postpartum CD4 count testing. We examined factors influencing women's utilization of extended CD4 count testing. About 53 in-depth interviews were conducted with nurses, patients, social support persons, and government health officials at three antenatal clinics in Lilongwe, Malawi. Counseling and positive interactions with staff emerged as facilitating factors. Women wanted to know their CD4 count, but didn't understand the importance of early ART initiation. Support from husbands facilitated women's return to the clinic. Reminders were perceived as helpful but ineffectively employed. Staff identified lack of communication, difficulty in tracking, and referring women as barriers. Counseling messages should emphasize the importance of starting ART early. Clinics should focus on male partner involvement, case management, staff communication, and appointment reminders. Follow-up should be offered at multiple service points.

Evaluation of CD40 and CD80 receptors in the colonic mucosal membrane of children with inflammatory bowel disease

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Barbara Kamińska

2015-12-01

Full Text Available [b][/b][b]Introduction. [/b]The most prevalent inflammatory bowel diseases (IBD include ulcerative colitis (UC and Crohn’s disease (CD. Immune processes play a vital role in the etiopathogenesis of these conditions, involving both cellular and humoral response mechanisms. The aim of this study was to quantify CD40- and CD80-positive cells in the biopsy specimens of large intestinal mucosa from children with IBD. [b]Materials and method. [/b]The study comprised 38 children aged between 3–17 years (mean 11.5±3.7 years – 20 boys (52.6 % and 18 girls (47.4%. Eighteen patients were diagnosed with UC on the basis of clinical manifestation, endoscopic and histopathological findings. Mean age of this subgroup was 11.55±4.07 years. A group of 10 children (mean age 12.30±2.83 diagnosed with CD was also included. The control group comprised 10 IBD-free children (mean age 10.28±4.07 years. The surface expressions of CD40 and CD80 were analyzed in large intestine mucosa biopsy specimens, fixed in formaldehyde, embedded in paraffin, and cut with a microtome into 4 µm slices. [b]Results. [/b]The number of CD40- and CD80-positive cells in the large intestinal mucosa of children with Crohn’s disease and ulcerative colitis was significantly higher than in the controls. The highest number of CD40+ and CD80+ cells was observed in the caecal mucosal membrane of Crohn’s disease patients and in the rectal mucosa of individuals with ulcerative colitis. [b]Conclusion.[/b] IBD is characterized by elevated, segment-specific, expression of CD40 and CD80.

Human CD34+ cells engineered to express membrane-bound tumor necrosis factor-related apoptosis-inducing ligand target both tumor cells and tumor vasculature.

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Lavazza, Cristiana; Carlo-Stella, Carmelo; Giacomini, Arianna; Cleris, Loredana; Righi, Marco; Sia, Daniela; Di Nicola, Massimo; Magni, Michele; Longoni, Paolo; Milanesi, Marco; Francolini, Maura; Gloghini, Annunziata; Carbone, Antonino; Formelli, Franca; Gianni, Alessandro M

2010-03-18

Adenovirus-transduced CD34+ cells expressing membrane-bound tumor necrosis factor-related apoptosis-inducing ligand (CD34-TRAIL+ cells) exert potent antitumor activity. To further investigate the mechanism(s) of action of CD34-TRAIL+ cells, we analyzed their homing properties as well as antitumor and antivascular effects using a subcutaneous myeloma model in immunodeficient mice. After intravenous injection, transduced cells homed in the tumor peaking at 48 hours when 188 plus or minus 25 CD45+ cells per 10(5) tumor cells were detected. Inhibition experiments showed that tumor homing of CD34-TRAIL+ cells was largely mediated by vascular cell adhesion molecule-1 and stromal cell-derived factor-1. Both CD34-TRAIL+ cells and soluble (s)TRAIL significantly reduced tumor volume by 40% and 29%, respectively. Computer-aided analysis of TdT-mediated dUTP nick end-labeling-stained tumor sections demonstrated significantly greater effectiveness for CD34-TRAIL+ cells in increasing tumor cell apoptosis and necrosis over sTRAIL. Proteome array analysis indicated that CD34-TRAIL+ cells and sTRAIL activate similar apoptotic machinery. In vivo staining of tumor vasculature with sulfosuccinimidyl-6-(biotinamido) hexanoate-biotin revealed that CD34-TRAIL+ cells but not sTRAIL significantly damaged tumor vasculature, as shown by TdT-mediated dUTP nick end-labeling+ endothelial cells, appearance of hemorrhagic areas, and marked reduction of endothelial area. These results demonstrate that tumor homing of CD34-TRAIL+ cells induces early vascular disruption, resulting in hemorrhagic necrosis and tumor destruction.

Enhanced Cadmium (Cd Phytoextraction from Contaminated Soil using Cd-Resistant Bacterium

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Kunchaya Setkit

2014-01-01

Full Text Available A cadmium (Cd-resistant bacterium, Micrococcus sp. MU1, is able to produce indole-3-acetic acid and promotes root elongation and plant growth. The potential of this bacterium on enhancement of Cd uptake and bioaccumulation of Cd in Helianthus annuus L. planted in Cd-contaminated soil was evaluated in greenhouse condition. The results showed that Micrococcus sp. MU1promoted the growth of H. annuus L. by increasing the root length, stem height, dry biomass, root to shoot ratio and also significantly increased Cd accumulation in the root and above-ground tissues of H. annuus L. compared to uninoculated control. Re-inoculation with Micrococcus sp. MU1in contaminated soil helped in promoting plant growth and Cd phytoextraction throughout the cultivation period. In addition, phytoextraction coefficient and translocation factor (TF of H. annuus L. inoculated with Micrococcus sp. MU1were higher than that of uninoculated control and TF continuously increased with time. Our results suggested that Micrococcus sp. MU1 has an ability to enhance plant growth and Cd uptake in H. annuus L. Synergistic interaction between Micrococcus sp. MU1 and H. annuus L. could be further applied for Cd phytoextraction in polluted areas.

Evaluation of structure models of Ho2PdSi3 using DAFS, inter alia at a satellite reflection

International Nuclear Information System (INIS)

Nentwich, M; Zschornak, M; Richter, C; Meyer, D C

2014-01-01

The compounds R 2 PdSi 3 , with R = rare earth, exhibit a very interesting magnetic behavior with two phase transitions. Substituting one in four Si atoms by Pd in HoSi 2 results in a modulation of the aristotype. There are several different variants discussed in literature about the nature of the modulation of this rare-earth compound. Two of the latest models were compared: a 2 × 2 × 1 layer and a 2 × 2 × 8 stack. The chosen method is Diffraction Anomalous Fine Structure (DAFS) and was applied both experimentally and by simulation at different absorption edges and reflections, i. a. a satellite reflection, aiming on finding the correct crystal structure

Neuropilin-1highCD4+CD25+ Regulatory T Cells Exhibit Primary Negative Immunoregulation in Sepsis

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Yu-Lei Gao

2016-01-01

Full Text Available Regulatory T cells (Tregs appear to be involved in sepsis-induced immune dysfunction; neuropilin-1 (Nrp-1 was identified as a surface marker for CD4+CD25+Tregs. In the current study, we investigated the negative immunoregulation of Nrp-1highCD4+CD25+Tregs and the potential therapeutic value of Nrp-1 in sepsis. Splenic CD4+CD25+Tregs from cecal ligation and puncture (CLP mouse models were further segregated into Nrp-1highTregs and Nrp-1lowTregs; they were cocultured with CD4+CD25−  T cells. The expression of forkhead/winged helix transcription factor-3 (Foxp-3, cytotoxic T-lymphocyte associated antigen-4 (CTLA-4, membrane associated transforming growth factor-β (TGF-βm+, apoptotic rate, and secretive ability [including TGF-β and interleukin-10 (IL-10] for various types of Tregs, as well as the immunosuppressive ability of Tregs on CD4+CD25−  T cells, were determined. Meanwhile, the impact of recombinant Nrp-1 polyclonal antibody on the demethylation of Foxp-3-TSDR (Treg-specific demethylated region was measured in in vitro study. Sepsis per se markedly promoted the expression of Nrp-1 of CD4+CD25+Tregs. Foxp-3/CTLA-4/TGF-βm+ of Nrp-1highTregs were upregulated by septic challenge. Nrp-1highTregs showed strong resilience to apoptosis and secretive ability and the strongest immunosuppressive ability on CD4+CD25−  T cells. In the presence of lipopolysaccharide (LPS, the recombinant Nrp-1 polyclonal antibody reduced the demethylation of Foxp-3-TSDR. Nrp-1highTregs might reveal primary negative immunoregulation in sepsis; Nrp-1 could represent a new potential therapeutic target for the study of immune regulation in sepsis.

Overexpression of CD44 accompanies acquired tamoxifen resistance in MCF7 cells and augments their sensitivity to the stromal factors, heregulin and hyaluronan

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Hiscox Stephen

2012-10-01

Full Text Available Abstract Background Acquired resistance to endocrine therapy in breast cancer is a significant problem with relapse being associated with local and/or regional recurrence and frequent distant metastases. Breast cancer cell models reveal that endocrine resistance is accompanied by a gain in aggressive behaviour driven in part through altered growth factor receptor signalling, particularly involving erbB family receptors. Recently we identified that CD44, a transmembrane cell adhesion receptor known to interact with growth factor receptors, is upregulated in tamoxifen-resistant (TamR MCF7 breast cancer cells. The purpose of this study was to explore the consequences of CD44 upregulation in an MCF7 cell model of acquired tamoxifen resistance, specifically with respect to the hypothesis that CD44 may influence erbB activity to promote an adverse phenotype. Methods CD44 expression in MCF7 and TamR cells was assessed by RT-PCR, Western blotting and immunocytochemistry. Immunofluorescence and immunoprecipitation studies revealed CD44-erbB associations. TamR cells (± siRNA-mediated CD44 suppression or MCF7 cells (± transfection with the CD44 gene were treated with the CD44 ligand, hyaluronon (HA, or heregulin and their in vitro growth (MTT, migration (Boyden chamber and wound healing and invasion (Matrigel transwell migration determined. erbB signalling was assessed using Western blotting. The effect of HA on erbB family dimerisation in TamR cells was determined by immunoprecipitation in the presence or absence of CD44 siRNA. Results TamR cells overexpressed CD44 where it was seen to associate with erbB2 at the cell surface. siRNA-mediated suppression of CD44 in TamR cells significantly attenuated their response to heregulin, inhibiting heregulin-induced cell migration and invasion. Furthermore, TamR cells exhibited enhanced sensitivity to HA, with HA treatment resulting in modulation of erbB dimerisation, ligand-independent activation of erbB2

Overexpression of CD44 accompanies acquired tamoxifen resistance in MCF7 cells and augments their sensitivity to the stromal factors, heregulin and hyaluronan

International Nuclear Information System (INIS)

Hiscox, Stephen; Gee, Julia; Baruha, Bedanta; Smith, Chris; Bellerby, Rebecca; Goddard, Lindy; Jordan, Nicola; Poghosyan, Zaruhi; Nicholson, Robert I; Barrett-Lee, Peter

2012-01-01

Acquired resistance to endocrine therapy in breast cancer is a significant problem with relapse being associated with local and/or regional recurrence and frequent distant metastases. Breast cancer cell models reveal that endocrine resistance is accompanied by a gain in aggressive behaviour driven in part through altered growth factor receptor signalling, particularly involving erbB family receptors. Recently we identified that CD44, a transmembrane cell adhesion receptor known to interact with growth factor receptors, is upregulated in tamoxifen-resistant (TamR) MCF7 breast cancer cells. The purpose of this study was to explore the consequences of CD44 upregulation in an MCF7 cell model of acquired tamoxifen resistance, specifically with respect to the hypothesis that CD44 may influence erbB activity to promote an adverse phenotype. CD44 expression in MCF7 and TamR cells was assessed by RT-PCR, Western blotting and immunocytochemistry. Immunofluorescence and immunoprecipitation studies revealed CD44-erbB associations. TamR cells (± siRNA-mediated CD44 suppression) or MCF7 cells (± transfection with the CD44 gene) were treated with the CD44 ligand, hyaluronon (HA), or heregulin and their in vitro growth (MTT), migration (Boyden chamber and wound healing) and invasion (Matrigel transwell migration) determined. erbB signalling was assessed using Western blotting. The effect of HA on erbB family dimerisation in TamR cells was determined by immunoprecipitation in the presence or absence of CD44 siRNA. TamR cells overexpressed CD44 where it was seen to associate with erbB2 at the cell surface. siRNA-mediated suppression of CD44 in TamR cells significantly attenuated their response to heregulin, inhibiting heregulin-induced cell migration and invasion. Furthermore, TamR cells exhibited enhanced sensitivity to HA, with HA treatment resulting in modulation of erbB dimerisation, ligand-independent activation of erbB2 and EGFR and induction of cell migration

40 CFR 1042.525 - How do I adjust emission levels to account for infrequently regenerating aftertreatment devices?

Science.gov (United States)

2010-07-01

... the downward adjustment factor (DAF) using the following equation: DAF = EFH−EFA (d) Sample...−0.10 g/kW-hr = 0.04 g/kW-hr. DAF = 0.50 g/kW-hr−0.14 g/kW-hr = 0.36 g/kW-hr. (e) Ramped-modal...

CD147 induces up-regulation of vascular endothelial growth factor in U937-derived foam cells through PI3K/AKT pathway.

Science.gov (United States)

Zong, JiaXin; Li, YunTian; Du, DaYong; Liu, Yang; Yin, YongJun

2016-11-01

Intraplaque angiogenesis has been recognized as an important risk factor for the rupture of advanced atherosclerotic plaques in recent years. CD147, also called Extracellular Matrix Metalloproteinase Inducer, has been found the ability to promote angiogenesis in many pathological conditions such as cancer diseases and rheumatoid arthritis via the up-regulation of vascular endothelial growth factor (VEGF), a critical mediator of angiogenesis. We investigated whether CD147 would also induce the up-regulation of VEGF in the foam cells formation process and explored the probable signaling pathway. The results showed the expression of CD147 and VEGF was significantly higher in U937-derived foam cells. After CD147 stealth siRNA transfection treatment, the production of VEGF was reduced depended on the inhibition efficiency of CD147 siRNAs.The special signaling pathway inhibitors LY294002, SP600125, SB203580 and U0126 were added to cultures respectively and the results showed LY294002 dose-dependently inhibited the expression of VEGF. The reduction of phospho-Akt was observed in both LY294002 and siRNA groups, suggested that the phosphatidylinositol 3-kinase/Akt pathway may be the probable signaling pathway underlying CD147 induced up-regulation of VEGF in U937-derived foam cells. Copyright © 2016 Elsevier Inc. All rights reserved.

Cycling G1 CD34+/CD38+ cells potentiate the motility and engraftment of quiescent G0 CD34+/CD38-/low severe combined immunodeficiency repopulating cells.

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Byk, Tamara; Kahn, Joy; Kollet, Orit; Petit, Isabelle; Samira, Sarit; Shivtiel, Shoham; Ben-Hur, Herzl; Peled, Amnon; Piacibello, Wanda; Lapidot, Tsvee

2005-04-01

The mechanism of human stem cell expansion ex vivo is not fully understood. Furthermore, little is known about the mechanisms of human stem cell homing/repopulation and the role that differentiating progenitor cells may play in these processes. We report that 2- to 3-day in vitro cytokine stimulation of human cord blood CD34(+)-enriched cells induces the production of short-term repopulating, cycling G1 CD34(+)/CD38(+) cells with increased matrix metalloproteinase (MMP)-9 secretion as well as increased migration capacity to the chemokine stromal cell-derived factor-1 (SDF-1) and homing to the bone marrow of irradiated nonobese diabetic severe/combined immunodeficiency (NOD/SCID) mice. These cycling G1 cells enhance SDF-1-mediated in vitro migration and in vivo homing of quiescent G0 CD34(+) cells, which is partially abrogated after inhibition of MMP-2/-9 activity. Moreover, the engraftment potential of quiescent G0 SCID repopulating cells (SRCs) is also increased by the cycling G1 CD34(+)/CD38(+) cells. This effect is significantly abrogated after incubation of cycling G1 cells with a neutralizing anti-CXCR4 antibody. Our data suggest synergistic interactions between accessory cycling G1 CD34(+)/CD38(+) committed progenitor cells and quiescent, primitive G0 CD34(+)/CD38(-/low) SRC/stem cells, the former increasing the motility and engraftment potential of the latter, partly via secretion of MMP-9.

Elevated Temperature Photophysical Properties and Morphological Stability of CdSe and CdSe/CdS Nanoplatelets

Energy Technology Data Exchange (ETDEWEB)

Rowland, Clare E. [Department; Center; Fedin, Igor [Department; Diroll, Benjamin T. [Center; Liu, Yuzi [Center; Talapin, Dmitri V. [Center; Department; Schaller, Richard D. [Department; Center

2018-01-03

Elevated temperature optoelectronic performance of semiconductor nanomaterials remains an important issue for applications. Here we examine two-dimensional CdSe nanoplatelets (NPs) and CdS/CdSe/CdS shell/core/shell sandwich NPs at temperatures ranging from 300-700 K using static and transient spectroscopies as well as in-situ transmission electron microscopy. NPs exhibit reversible changes in PL intensity, spectral position, and emission linewidth with temperature elevation up to ~500 K, losing a factor of ~8 to 10 in PL intensity at 400 K relative to ambient. Temperature elevation above ~500 K yields thickness dependent, irreversible degradation in optical properties. Electron microscopy relates stability of the NP morphology up to near 600 K followed by sintering and evaporation at still higher temperatures. The mechanism of reversible PL loss, based on differences in decay dynamics between time-resolved photoluminescence and transient absorption, arise primarily from hole trapping in both NPs and sandwich NPs.

A theoretical investigation of the structural and electronic properties of 55-atom nanoclusters: The examples of Y–Tc and Pt

Energy Technology Data Exchange (ETDEWEB)

Batista, Krys E. A.; Piotrowski, Maurício J., E-mail: mauriciomjp@gmail.com [Department of Physics, Federal University of Pelotas, P.O. Box 354, 96010 − 900, Pelotas, RS (Brazil); Chaves, Anderson S.; Da Silva, Juarez L. F., E-mail: juarez-dasilva@iqsc.usp.br [São Carlos Institute of Chemistry, University of São Paulo, P.O. Box 780, 13560 − 970, São Carlos, SP (Brazil)

2016-02-07

Several studies have found that the Pt{sub 55} nanocluster adopts a distorted reduced core structure, DRC{sub 55}, in which there are 8–11 atoms in the core and 47–44 atoms in the surface, instead of the compact and high-symmetry icosahedron structure, ICO{sub 55}, with 13 and 42 atoms in the core and surface, respectively. The DRC structure has also been obtained as the putative global minimum configuration (GMC) for the Zn{sub 55} (3d), Cd{sub 55} (4d), and Au{sub 55} (5d) systems. Thus, the DRC{sub 55} structure has been reported only for systems with a large occupation of the d-states, where the effects of the occupation of the valence anti-bonding d-states might play an important role. Can we observe the DRC structure for 55-atom transition-metal systems with non-occupation of the anti-bonding d-states? To address this question, we performed a theoretical investigation of the Y {sub 55}, Zr{sub 55}, Nb{sub 55}, Mo{sub 55}, Tc{sub 55}, and Pt{sub 55} nanoclusters, employing density functional theory calculations. For the putative GMCs, we found that the Y {sub 55} adopts the ICO{sub 55} structure, while Nb{sub 55} and Mo{sub 55} adopt a bulk-like fragment based on the hexagonal close-packed structure and Tc{sub 55} adopts a face-centered cubic fragment; however, Zr{sub 55} adopts a DRC{sub 55} structure, like Zn{sub 55}, Cd{sub 55}, Pt{sub 55}, and Au{sub 55}. Thus we can conclude that the preference for DRC{sub 55} structure is not related to the occupation of the anti-bonding d-states, but to a different effect, in fact, a combination of structural and electronic effects. Furthermore, we obtained that the binding energy per atom follows the occupation of the bonding and anti-bonding model, i.e., the stability of the studied systems increases from Y to Tc with a small oscillation for Mo, which also explains the equilibrium bond lengths. We obtained a larger magnetic moment for Y {sub 55} (31 μ{sub B}) which can be explained by the localization of the d

CD8+ T Cells Specific to Apoptosis-Associated Antigens Predict the Response to Tumor Necrosis Factor Inhibitor Therapy in Rheumatoid Arthritis.

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Alessandra Citro

Full Text Available CD8+ T cells specific to caspase-cleaved antigens derived from apoptotic T cells (apoptotic epitopes represent a principal player in chronic immune activation, which is known to amplify immunopathology in various inflammatory diseases. The purpose of the present study was to investigate the relationship involving these autoreactive T cells, the rheumatoid arthritis immunopathology, and the response to tumor necrosis factor-α inhibitor therapy. The frequency of autoreactive CD8+ T cells specific to various apoptotic epitopes, as detected by both enzyme-linked immunospot assay and dextramers of major histocompatibility complex class I molecules complexed with relevant apoptotic epitopes, was longitudinally analyzed in the peripheral blood of rheumatoid arthritis patients who were submitted to etanercept treatment (or other tumor necrosis factor inhibitors as a control. The percentage of apoptotic epitope-specific CD8+ T cells was significantly higher in rheumatoid arthritis patients than in healthy donors, and correlated with the disease activity. More important, it was significantly more elevated in responders to tumor necrosis factor-α inhibitor therapy than in non-responders before the start of therapy; it significantly dropped only in the former following therapy. These data indicate that apoptotic epitope-specific CD8+ T cells may be involved in rheumatoid arthritis immunopathology through the production of inflammatory cytokines and that they may potentially represent a predictive biomarker of response to tumor necrosis factor-α inhibitor therapy to validate in a larger cohort of patients.

Responses of different water spinach cultivars and their hybrid to Cd, Pb and Cd-Pb exposures.

Science.gov (United States)

Xin, Junliang; Huang, Baifei; Yang, Zhongyi; Yuan, Jiangang; Dai, Hongwen; Qiu, Qiu

2010-03-15

A pot experiment was conducted to investigate the stability of Cd and/or Pb accumulation in shoot of Cd and Pb pollution-safe cultivars (PSCs), the hereditary pattern of shoot Cd accumulation, and the transfer potentials of Cd and Pb in water spinach (Ipomoea aquatica Forsk.). A typical Cd-PSC, a typical non-Cd-PSC (Cd accumulative cultivar), a hybrid from the former two cultivars, and two typical Cd+Pb-PSCs were grown in seven soils with different concentrations of Cd and Pb. The results showed that concentrations of Cd and Pb in shoot of the PSCs were always lower than the non-PSC and the highest Cd and Pb transfer factors were also always observed in the non-PSC, indicating the stability of the PSCs in Cd and Pb accumulation. Shoot Cd concentration seemed to be controlled by high Cd dominant gene(s) and thus crossbreeding might not minimize Cd accumulation in water spinach. Interaction between Cd and Pb in soils affected the accumulations of the metals in shoot of water spinach. Under middle Cd and Pb treatments, the presence of higher Pb promoted the accumulation of Cd. However, under high Pb treatment, accumulations of Cd and Pb were both restricted. (c) 2009 Elsevier B.V. All rights reserved.

Expression of macrophage migration inhibitory factor and CD74 in the inner ear and middle ear in lipopolysaccharide-induced otitis media.

Science.gov (United States)

Ishihara, Hisashi; Kariya, Shin; Okano, Mitsuhiro; Zhao, Pengfei; Maeda, Yukihide; Nishizaki, Kazunori

2016-10-01

Significant expression of macrophage migration inhibitory factor and its receptor (CD74) was observed in both the middle ear and inner ear in experimental otitis media in mice. Modulation of macrophage migration inhibitory factor and its signaling pathway might be useful in the management of inner ear inflammation due to otitis media. Inner ear dysfunction secondary to otitis media has been reported. However, the specific mechanisms involved are not clearly understood. The aim of this study is to investigate the expression of macrophage migration inhibitory factor and CD74 in the middle ear and inner ear in lipopolysaccharide-induced otitis media. BALB/c mice received a transtympanic injection of either lipopolysaccharide or phosphate-buffered saline (PBS). The mice were sacrificed 24 h after injection, and temporal bones were processed for polymerase chain reaction (PCR) analysis, histologic examination, and immunohistochemistry. PCR examination revealed that the lipopolysaccharide-injected mice showed a significant up-regulation of macrophage migration inhibitory factor in both the middle ear and inner ear as compared with the PBS-injected control mice. The immunohistochemical study showed positive reactions for macrophage migration inhibitory factor and CD74 in infiltrating inflammatory cells, middle ear mucosa, and inner ear in the lipopolysaccharide-injected mice.

Pulsed dye laser in the treatment of localized scleroderma and its effects on CD34+ and factor XIIIa+ cells: an immunohistochemical study.

Science.gov (United States)

Tawfik, Abeer Attia; Shokir, Hisham; Soliman, Mona; Salah, Lila; Fathy, Sahar

2013-06-01

Localized scleroderma (morphea) is characterized by hardening and thickening of the dermis due to excessive collagen deposition. A decreased number of CD34+ cells and an increased number of Factor XIIIa+ cells are seen in the affected skin. The flashlamp pulsed dye laser (FLPDL) has been used in the treatment of localized morphea with promising results. The purpose of this study was to evaluate the therapeutic effectiveness of the pulsed dye laser in localized scleroderma and to assess its effect on CD34+ cells, Factor XIIIa+ cells, and blood vessels. Thirty patients with plaque morphea were treated with a FLPDL (585 nm wavelength, 450 μs pulse duration). Fluence ranged from 7.5 to 8.5 J/cm(2). Sessions were performed biweekly for a maximum of 6 months. Clinical, histopathologic, and immunohistochemical assessments were performed. Patients showed varying degrees of improvement of indurated skin. There was no worsening or further improvement at the treated sites during the follow-up assessments at 3, 6, and 12 months. An increased number of CD34+ cells were found in both the upper and the lower dermis, and a decreased number of Factor XIIIa+ cells were found in the lower dermis. The FLPDL is effective in the treatment of morphea, as confirmed by the changes in the pathologic tissue and levels of CD34+ and Factor XIIIa+ cells.

Expression of KAI1/CD82 and MRP-1/CD9 in transitional cell carcinoma of bladder.

Science.gov (United States)

Ai, Xing; Zhang, Xu; Wu, Zhun; Ma, Xin; Ju, Zhenghua; Wang, Baojun; Shi, Taoping

2007-02-01

The expression of KAI1/CD82 and MRP-1/CD9 in transitional cell carcinoma of bladder (TCCB) and its clinical significance were investigated. Immunohistochemistry was used to detect KAI1/CD82 and MRP-1/CD9 protein expression in 52 TCCB specimens. Correlation between the expression of KAI1/CD82 and MRP-1/CD9 to clinicopathologic factors was statistically analyzed. The results showed that the positive rate of KAI1/CD82 and MRP-1/CD9 in TCCB was 50% and 61.5%, respectively. The MRP-1/CD9 and KAI1/CD82 expression was significantly associated with grade of TCCB (PMRP-1/CD9 or KAI1/CD82 expression and clinical stage of TCCB (P>0.05). The expression level of MRP-1/CD9 and KAI1/CD82 in recurrent TCCB samples was lower than that in non-recurrent samples (PMRP-1/CD9 expression was statistically significant (r=0.316, PMRP-1/CD9 expression may be important prognostic indicators and potentially useful for assessing the biological behavior of TCCB.

Time to and Predictors of CD4+ T-Lymphocytes Recovery in HIV-Infected Children Initiating Highly Active Antiretroviral Therapy in Ghana

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Lorna Renner

2011-01-01

Full Text Available Background. CD4+ T-lymphocyte monitoring is not routinely available in most resource-limited settings. We investigated predictors of time to CD4+ T-lymphocyte recovery in HIV-infected children on highly active antiretroviral (HAART at Korle-Bu Teaching Hospital, Ghana. Methods. Time to CD4+ T-lymphocyte recovery was defined as achieving percent CD4+ T-lymphocytes of 25%. We used Cox proportional hazard models for identifying significant predictor variables. Results. Of the 233 children with complete CD4+ T-lymphocyte data, the mean age at HAART initiation was 5.5 (SD=3.1 years. The median recovery time was 60 weeks (95% CL: 55–65. Evidence at baseline of severe suppression in CD4+ T-lymphocyte count adjusted for age, age at HAART initiation, gender, and having parents alive were statistically significant in predicting time to CD4+ T-lymphocyte recovery. Conclusions. A targeted approach based on predictors of CD4+ T-lymphocyte recovery can be a viable and cost-effective way of monitoring HAART in HIV-infected children in resource-limited settings.

CD137 is induced by the CD40 signal on chronic lymphocytic leukemia B cells and transduces the survival signal via NF-κB activation.

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Yukana Nakaima

Full Text Available CD137 is a member of the tumor necrosis factor receptor family that is expressed on activated T cells. This molecule provides a co-stimulatory signal that enhances the survival, and differentiation of cells, and has a crucial role in the development of CD8 cytotoxic T cells and anti-tumor immunity. Here we report that CD137 expression is also induced on normal or malignant human B cells by CD40 ligation by its ligand CD154. This CD137 induction was more prominent in chronic lymphocytic leukemia (CLL cells than in other types of B cells. CD137 stimulation on B cells by its ligand induced the nuclear translocation of p52 (a non-canonical NF-κB factor. In agreement with this finding, expression of the survival factor BCL-XL was upregulated. Consequently, the CD137 signal augmented the survival of CD154-stimulated CLL B cells in vitro. This unexpected induction of CD137 on B cells by CD40 signal may influence the clinical course of CLL.

Reduced CD300LG mRNA tissue expression, increased intramyocellular lipid content and impaired glucose metabolism in healthy male carriers of Arg82Cys in CD300LG

DEFF Research Database (Denmark)

Støy, Julie; Kampmann, Ulla; Mengel, Annette

2015-01-01

BACKGROUND: CD300LG rs72836561 (c.313C>T, p.Arg82Cys) has in genetic-epidemiological studies been associated with the lipoprotein abnormalities of the metabolic syndrome. CD300LG belongs to the CD300-family of membrane-bound molecules which have the ability to recognize and interact with extracel......BACKGROUND: CD300LG rs72836561 (c.313C>T, p.Arg82Cys) has in genetic-epidemiological studies been associated with the lipoprotein abnormalities of the metabolic syndrome. CD300LG belongs to the CD300-family of membrane-bound molecules which have the ability to recognize and interact...... with extracellular lipids. We tested whether this specific polymorphism results in abnormal lipid accumulation in skeletal muscle and liver and other indices of metabolic dysfunction. METHODS: 40 healthy men with a mean age of 55 years were characterized metabolically including assessment of insulin sensitivity...

Distribution characteristics of Cd, Pb and their influencing factors after earthquake-with example of a disater area named xinhuang village

International Nuclear Information System (INIS)

Cai Yan; Zhang Yi; Zhang Shirong; Song Xu; Wang Jibing; Huang Aiping

2010-01-01

Using hydrochloric acid, nitric acid, hydrofluoric acid and perchloric acid digestion, ICP determination method, combined with geostatistics and GIS, this paper studied the distribution characteristics and influencing factors of Cd, Pb of the soil samples in a typical 5.12 earthquake-stricken area named Xinhuang village as an example. The results showed that the average Cd content of the soil samples was 0.36 ± 0.20 mg /kg, 23.08% of which exceeded the national soil environmental quality standard II, but didn't exceed the standard III. The average Pb content of the soil samples was 28.97 ± 6.82 mg /kg and did not exceed the national standard II. The spatial distribution of Cd, Pb content appeared as belt-shaped and group shape respectively. Cd content took the mid-eastern part as a center, whose concentration was low, and gradually increased to north, to mid-west and to south, respectively; Pb content decreased first and increased afterward from north to south and from east to west. However, Cd, Pb contents in the soil under tent settlements after the earthquake, living garbage dumps and the housing collapse were significantly higher than the soil where were not affected by the earthquake. Cd content in the paddy field soil of 40 ∼ 60 cm depth under tent settlements was the highest, which was 0.46 mg /kg, the highest was 0.57 mg /kg; in the natural paddy field soil of 0 ∼ 20 cm, which. Pb content in the paddy field soil of 0 ∼ 20 cm depth under tent settlements and the natural paddy field soil, were 25.22 mg /kg and 26.16 mg /kg respectively. The influencing factors indicated that: Cd content of paddy fields, dry land and wasteland had not significant difference; Pb content of paddy fields were significantly higher than that of wasteland; The correlation coefficient of organic matter content and the Pb content was 0.616, which took a highly significant positive correlation; Cd content and pH or Cd content and organic matter content did not take significant

CD16xCD33 bispecific killer cell engager (BiKE) activates NK cells against primary MDS and MDSC CD33+ targets.

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Gleason, Michelle K; Ross, Julie A; Warlick, Erica D; Lund, Troy C; Verneris, Michael R; Wiernik, Andres; Spellman, Stephen; Haagenson, Michael D; Lenvik, Alexander J; Litzow, Mark R; Epling-Burnette, Pearlie K; Blazar, Bruce R; Weiner, Louis M; Weisdorf, Daniel J; Vallera, Daniel A; Miller, Jeffrey S

2014-05-08

Myelodysplastic syndromes (MDS) are stem cell disorders that can progress to acute myeloid leukemia. Although hematopoietic cell transplantation can be curative, additional therapies are needed for a disease that disproportionally afflicts the elderly. We tested the ability of a CD16xCD33 BiKE to induce natural killer (NK) cell function in 67 MDS patients. Compared with age-matched normal controls, CD7(+) lymphocytes, NK cells, and CD16 expression were markedly decreased in MDS patients. Despite this, reverse antibody-dependent cell-mediated cytotoxicity assays showed potent degranulation and cytokine production when resting MDS-NK cells were triggered with an agonistic CD16 monoclonal antibody. Blood and marrow MDS-NK cells treated with bispecific killer cell engager (BiKE) significantly enhanced degranulation and tumor necrosis factor-α and interferon-γ production against HL-60 and endogenous CD33(+) MDS targets. MDS patients had a significantly increased proportion of immunosuppressive CD33(+) myeloid-derived suppressor cells (MDSCs) that negatively correlated with MDS lymphocyte populations and CD16 loss on NK cells. Treatment with the CD16xCD33 BiKE successfully reversed MDSC immunosuppression of NK cells and induced MDSC target cell lysis. Lastly, the BiKE induced optimal MDS-NK cell function irrespective of disease stage. Our data suggest that the CD16xCD33 BiKE functions against both CD33(+) MDS and MDSC targets and may be therapeutically beneficial for MDS patients.

Co-regulation of the DAF-16 target gene, cyp-35B1/dod-13, by HSF-1 in C. elegans dauer larvae and daf-2 insulin pathway mutants.

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Wendy B Iser

2011-03-01

Full Text Available Insulin/IGF-I-like signaling (IIS has both cell autonomous and non-autonomous functions. In some cases, targets through which IIS regulates cell-autonomous functions, such as cell growth and metabolism, have been identified. In contrast, targets for many non-autonomous IIS functions, such as C. elegans dauer morphogenesis, remain elusive. Here, we report the use of genomic and genetic approaches to identify potential non-autonomous targets of C. elegans IIS. First, we used transcriptional microarrays to identify target genes regulated non-autonomously by IIS in the intestine or in neurons. C. elegans IIS controls expression of a number of stress response genes, which were differentially regulated by tissue-restricted IIS. In particular, expression of sod-3, a MnSOD enzyme, was not regulated by tissue-restricted IIS on the microarrays, while expression of hsp-16 genes was rescued back to wildtype by tissue restricted IIS. One IIS target regulated non-autonomously by age-1 was cyp-35B1/dod-13, encoding a cytochrome P450. Genetic analysis of the cyp-35B1 promoter showed both DAF-16 and HSF-1 are direct regulators. Based on these findings, we propose that hsf-1 may participate in the pathways mediating non-autonomous activities of age-1 in C. elegans.

Co-regulation of the DAF-16 target gene, cyp-35B1/dod-13, by HSF-1 in C. elegans dauer larvae and daf-2 insulin pathway mutants.

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Iser, Wendy B; Wilson, Mark A; Wood, William H; Becker, Kevin; Wolkow, Catherine A

2011-03-09

Insulin/IGF-I-like signaling (IIS) has both cell autonomous and non-autonomous functions. In some cases, targets through which IIS regulates cell-autonomous functions, such as cell growth and metabolism, have been identified. In contrast, targets for many non-autonomous IIS functions, such as C. elegans dauer morphogenesis, remain elusive. Here, we report the use of genomic and genetic approaches to identify potential non-autonomous targets of C. elegans IIS. First, we used transcriptional microarrays to identify target genes regulated non-autonomously by IIS in the intestine or in neurons. C. elegans IIS controls expression of a number of stress response genes, which were differentially regulated by tissue-restricted IIS. In particular, expression of sod-3, a MnSOD enzyme, was not regulated by tissue-restricted IIS on the microarrays, while expression of hsp-16 genes was rescued back to wildtype by tissue restricted IIS. One IIS target regulated non-autonomously by age-1 was cyp-35B1/dod-13, encoding a cytochrome P450. Genetic analysis of the cyp-35B1 promoter showed both DAF-16 and HSF-1 are direct regulators. Based on these findings, we propose that hsf-1 may participate in the pathways mediating non-autonomous activities of age-1 in C. elegans.

Partial characterization of the cross-reacting determinant, a carbohydrate epitope shared by decay accelerating factor and the variant surface glycoprotein of the African Trypanosoma brucei.

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Shak, S; Davitz, M A; Wolinsky, M L; Nussenzweig, V; Turner, M J; Gurnett, A

1988-03-15

The variant surface glycoprotein (VSG) of the African trypanosome is anchored in the cell membrane by a complex glycan attached to phosphatidylinositol. The carboxyl terminal portion of VSG contains a cryptic carbohydrate epitope, the cross-reacting determinant (CRD), that is revealed only after removal of the diacylglycerol by phosphatidylinositol-specific phospholipase C (PIPLC) or VSG lipase. Recently, we have shown that after hydrolysis by PIPLC, decay-accelerating factor (DAF)--a mammalian phosphatidylinositol-anchored protein--also contains the CRD epitope. Using a two site immunoradiometric assay in which the capturing antibody is a monoclonal antibody to DAF and the revealing antibody is anti-CRD, we now show that sugar phosphates significantly inhibited the binding of anti-CRD antibody to DAF released by PIPLC. DL-myo-inositol 1,2-cyclic phosphate was the most potent inhibitor of binding (IC50 less than 10(-8) M). Other sugar phosphates, such as alpha-D-glucose-1-phosphate, which also possess adjacent hydroxyl and phosphate moieties in cis also inhibited binding at low concentrations (IC50 = 10(-5) to 10(-4) M). In contrast, sugar phosphates which do not possess adjacent hydroxyl and phosphate moieties in cis and simple sugars weakly inhibited binding (IC50 greater than 10(-3) M). These results suggest that myo-inositol 1,2-cyclic phosphate contributes significantly to the epitope recognized by the anti-CRD antibody and is consistent with analysis of the carboxyl terminus of VSG, which also suggested the presence of the cyclic inositol phosphate. In light of the recent findings that human serum contains a glycan-phosphatidyl-inositol-specific phospholipase D, which converts DAF from a hydrophobic to a hydrophilic form lacking the CRD, the observation that the phosphate is crucial for expression of the epitope may be relevant in understanding the origin of CRD-negative DAF in urine and plasma.

CD-ROMs in Astronomy

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Robertson, K.

The CD-ROM has become a major data storage medium in astronomy. The release of the Digitized Sky Survey is the most recent example of this phenomena. I will summarize the large scale jukebox technologies available for making the DSS available over LANs (Local Area Networks). I will also give an overview of the developments in disciplines such as medicine, chemistry and business, where CD-ROMs have been used to distribute the full text of journals. These factors may give us insights into the future role of CD-ROMs.

Carnitine protects the nematode Caenorhabditis elegans from glucose-induced reduction of survival depending on the nuclear hormone receptor DAF-12

International Nuclear Information System (INIS)

Deusing, Dorothé Jenni; Beyrer, Melanie; Fitzenberger, Elena; Wenzel, Uwe

2015-01-01

Besides its function in transport of fatty acids into mitochondria in order to provide substrates for β-oxidation, carnitine has been shown to affect also glucose metabolism and to inhibit several mechanisms associated with diabetic complications. In the present study we used the mev-1 mutant of the nematode Caenorhabditis elegans fed on a high glucose concentration in liquid media as a diabetes model and tested the effects of carnitine supplementation on their survival under heat-stress. Carnitine at 100 μM completely prevented the survival reduction that was caused by the application of 10 mM glucose. RNA-interference for sir-2.1, a candidate genes mediating the effects of carnitine revealed no contribution of the sirtuin for the rescue of survival. Under daf-12 RNAi rescue of survival by carnitine was abolished. RNA-interference for γ-butyrobetaine hydroxylase 2, encoding the key enzyme for carnitine biosynthesis did neither increase glucose toxicity nor prevent the rescue of survival by carnitine, suggesting that the effects of carnitine supplementation on carnitine levels were significant. Finally, it was demonstrated that neither the amount of lysosomes nor the proteasomal activity were increased by carnitine, excluding that protein degradation pathways, such as autophagy or proteasomal degradation, are involved in the protective carnitine effects. In conclusion, carnitine supplementation prevents the reduction of survival caused by glucose in C. elegans in dependence on a nuclear hormone receptor which displays high homologies to the vertebrate peroxisomal proliferator activated receptors. - Highlights: • Carnitine protects from glucose-induced reduction of stress-resistance. • Carnitine acts via the PPAR homolog DAF-12 on glucose toxicity. • Carnitine protects from glucose toxicity independent of protein degradation

Carnitine protects the nematode Caenorhabditis elegans from glucose-induced reduction of survival depending on the nuclear hormone receptor DAF-12

Energy Technology Data Exchange (ETDEWEB)

Deusing, Dorothé Jenni, E-mail: Dorothe.J.Deusing@ernaehrung.uni-giessen.de; Beyrer, Melanie, E-mail: m.beyrer@web.de; Fitzenberger, Elena, E-mail: Elena.Fitzenberger@ernaehrung.uni-giessen.de; Wenzel, Uwe, E-mail: uwe.wenzel@ernaehrung.uni-giessen.de

2015-05-08

Besides its function in transport of fatty acids into mitochondria in order to provide substrates for β-oxidation, carnitine has been shown to affect also glucose metabolism and to inhibit several mechanisms associated with diabetic complications. In the present study we used the mev-1 mutant of the nematode Caenorhabditis elegans fed on a high glucose concentration in liquid media as a diabetes model and tested the effects of carnitine supplementation on their survival under heat-stress. Carnitine at 100 μM completely prevented the survival reduction that was caused by the application of 10 mM glucose. RNA-interference for sir-2.1, a candidate genes mediating the effects of carnitine revealed no contribution of the sirtuin for the rescue of survival. Under daf-12 RNAi rescue of survival by carnitine was abolished. RNA-interference for γ-butyrobetaine hydroxylase 2, encoding the key enzyme for carnitine biosynthesis did neither increase glucose toxicity nor prevent the rescue of survival by carnitine, suggesting that the effects of carnitine supplementation on carnitine levels were significant. Finally, it was demonstrated that neither the amount of lysosomes nor the proteasomal activity were increased by carnitine, excluding that protein degradation pathways, such as autophagy or proteasomal degradation, are involved in the protective carnitine effects. In conclusion, carnitine supplementation prevents the reduction of survival caused by glucose in C. elegans in dependence on a nuclear hormone receptor which displays high homologies to the vertebrate peroxisomal proliferator activated receptors. - Highlights: • Carnitine protects from glucose-induced reduction of stress-resistance. • Carnitine acts via the PPAR homolog DAF-12 on glucose toxicity. • Carnitine protects from glucose toxicity independent of protein degradation.

The Ikaros transcription factor regulates responsiveness to IL-12 and expression of IL-2 receptor alpha in mature, activated CD8 T cells.

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Eric T Clambey

Full Text Available The Ikaros family of transcription factors is critical for normal T cell development while limiting malignant transformation. Mature CD8 T cells express multiple Ikaros family members, yet little is known about their function in this context. To test the functions of this gene family, we used retroviral transduction to express a naturally occurring, dominant negative (DN isoform of Ikaros in activated CD8 T cells. Notably, expression of DN Ikaros profoundly enhanced the competitive advantage of activated CD8 T cells cultured in IL-12, such that by 6 days of culture, DN Ikaros-transduced cells were 100-fold more abundant than control cells. Expression of a DN isoform of Helios, a related Ikaros-family transcription factor, conferred a similar advantage to transduced cells in IL-12. While DN Ikaros-transduced cells had higher expression of the IL-2 receptor alpha chain, DN Ikaros-transduced cells achieved their competitive advantage through an IL-2 independent mechanism. Finally, the competitive advantage of DN Ikaros-transduced cells was manifested in vivo, following adoptive transfer of transduced cells. These data identify the Ikaros family of transcription factors as regulators of cytokine responsiveness in activated CD8 T cells, and suggest a role for this family in influencing effector and memory CD8 T cell differentiation.

Impact of CD68/(CD3+CD20 ratio at the invasive front of primary tumors on distant metastasis development in breast cancer.

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Noemí Eiró

Full Text Available Tumors are infiltrated by macrophages, T and B-lymphocytes, which may favor tumor development by promoting angiogenesis, growth and invasion. The aim of this study was to investigate the clinical relevance of the relative amount of macrophages (CD68⁺, T-cells (CD3⁺ and B-cells (CD20⁺ at the invasive front of breast carcinomas, and the expression of matrix metalloproteases (MMPs and their inhibitors (TIMPs either at the invasive front or at the tumor center. We performed an immunohistochemical study counting CD3, CD20 and CD68 positive cells at the invasive front, in 102 breast carcinomas. Also, tissue sections were stained with MMP-2, -9, -11, -14 and TIMP-2 antibodies, and immunoreactivity location, percentage of reactive area and intensity were determined at the invasive front and at the tumor center. The results showed that an increased CD68 count and CD68/(CD3+CD20 ratio were directly associated with both MMP-11 and TIMP-2 expression by mononuclear inflammatory cells at the tumor center (p = 0.041 and p = 0.025 for CD68 count and p = 0.001 and p = 0.045 for ratio, respectively for MMP-11 and TIMP-2. In addition, a high CD68/(CD3+CD20 ratio (>0.05 was directly associated with a higher probability of shortened relapse-free survival. Multivariate analysis revealed that CD68/(CD3+CD20 ratio was an independent factor associated with distant relapse-free survival (RR: 2.54, CI: (1.23-5.24, p<0.01. Therefore, CD68/(CD3+CD20 ratio at the invasive front could be used as an important prognostic marker.

40 CFR 1039.525 - How do I adjust emission levels to account for infrequently regenerating aftertreatment devices?

Science.gov (United States)

2010-07-01

... measured emission rate. Determine the downward adjustment factor (DAF) using the following equation: DAF... g/kW-hr. UAF = 0.14 g/kW-hr − 0.10 g/kW-hr = 0.04 g/kW-hr. DAF = 0.50 g/kW-hr − 0.14 g/kW-hr = 0.36...

Dissection of a circulating CD3+ CD20+ T cell subpopulation in patients with psoriasis.

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Niu, J; Zhai, Z; Hao, F; Zhang, Y; Song, Z; Zhong, H

2018-05-01

CD3 + CD20 + T cells are a population of CD3 + T cells that express CD20 and identified in healthy donors and autoimmune diseases. However, the nature and role of these cells in patients with psoriasis remain unclear. In this study, we aimed to investigate the level, phenotype, functional and clinical relevance of CD3 + CD20 + T cells in the peripheral blood of patients with psoriasis. We found that a small subset of CD3 + T cells expressed CD20 molecule in the peripheral blood of patients with psoriasis, and their levels were similar to those in healthy donors. Circulating CD3 + CD20 + T cells in patients with psoriasis were enriched in CD4 + cells and displayed an activated effector phenotype, as these cells contained fewer CD45RA + -naive and CCR7 + cells with increased activity than those of CD3 + T cells lacking CD20. In addition, compared with healthy donors, circulating CD3 + CD20 + T cells in patients with psoriasis produced more cytokines, interleukin (IL)-17A, tumour necrosis factor (TNF)-α and IL-21, but not IL-4 and IFN-γ. Furthermore, a significantly positive correlation was found between the levels of IL-17A, TNF-α and IL-21-production CD3 + CD20 + T cells with Psoriasis Area and Severity Index scores. Our findings suggest that CD3 + CD20 + T cells may play a role in the pathogenesis of psoriasis. © 2018 British Society for Immunology.

The silkworm Bombyx mori cuticular protein CPR55 gene is regulated by the transcription factor βFTZ-F1

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Md. Saheb Ali

2016-01-01

Full Text Available The insect cuticle is composed of various proteins and formed during the moult under a complex biological process that depends on the cross talk between hormone levels and gene expression. In the present study, we aimed to clarify the ecdysone-dependent temporal regulation mechanisms of cuticular proteins expression and the underlying control of Bombyx mori metamorphosis. The expression of CPR55 was observed from the W3 early stage and peaked at pupation when the ecdysteroid titre declined. CPR55 was induced by the ecdysone pulse, and their expression peaked at 24 h after transfer to a hormone free medium. Transcripts of CPR55 were neither observed after the 20E pulse treatment in the presence of cycloheximide nor after the addition of 20E in V4 wing discs. We analysed the upstream region of the CPR55 gene using a transient reporter assay with a gene gun system which identified only one βFTZ-F1 binding site important for cis-acting elements for the transcription activation of the luciferase reporter gene by an ecdysone pulse. Site-directed mutagenesis of this element in the context of the 589-bp promoter fragment drastically decreased the reporter activity. The nuclear protein bound to βFTZ-F1 sites was identified by an electrophoretic mobility shift assay suggesting that CPR55 expression was regulated by βFTZ-F1 through the ecdysone pulse. The results confirmed that transcription factor, BmβFTZ-F1, binds to the cis-regulatory elements in the promoter of the gene coding for cuticle protein, CPR55, and regulates its expression during B. mori metamorphosis.

Downregulation of IL-12 and a novel negative feedback system mediated by CD25+CD4+ T cells

International Nuclear Information System (INIS)

Sato, Kojiro; Tateishi, Shoko; Kubo, Kanae; Mimura, Toshihide; Yamamoto, Kazuhiko; Kanda, Hiroko

2005-01-01

CD25 + CD4 + regulatory T cells suppress immune responses and are believed to play roles in preventing autoimmune diseases. However, the mechanism(s) underlying the suppression and the regulation of their homeostasis remain to be elucidated. Here we show that these regulatory T cells downregulated CD25 - CD4 + T-cell-mediated production of IL-12 from antigen-presenting cells, which can act as a growth factor for CD25 - CD4 + T cells. We further found that CD25 + CD4 + T cells, despite their well-documented 'anergic' nature, proliferate significantly in vitro only when CD25 - CD4 + T cells are present. Notably, this proliferation was strongly dependent on IL-2 and relatively independent of IL-12. Thus, CD25 + CD4 + T cells suppress CD25 - CD4 + T-cell responses, at least in part, by inhibiting IL-12 production while they themselves can undergo proliferation with the mediation of CD25 - CD4 + T cells in vitro. These results offer a novel negative feedback system involving a tripartite interaction among CD25 + CD4 + and CD25 - CD4 + T cells, and APCs that may contribute to the termination of immune responses

Electrical characterization of the temperature dependence in CdTe/CdS heterojunctions deposited in-situ by pulsed laser deposition

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Avila-Avendano, Jesus; Quevedo-Lopez, Manuel; Young, Chadwin

2018-02-01

The I-V and C-V characteristics of CdTe/CdS heterojunctions deposited in-situ by Pulsed Laser Deposition (PLD) were evaluated. In-situ deposition enables the study of the CdTe/CdS interface by avoiding potential impurities at the surface and interface as a consequence of exposure to air. The I-V and C-V characteristics of the resulting junctions were obtained at different temperatures, ranging from room temperature to 150 °C, where the saturation current (from 10-8 to 10-4 A/cm2), ideality factor (between 1 and 2), series resistance (from 102 to 105 Ω), built-in potential (0.66-0.7 V), rectification factor (˜106), and carrier concentration (˜1016 cm-3) were obtained. The current-voltage temperature dependence study indicates that thermionic emission is the main transport mechanism at the CdTe/CdS interface. This study also demonstrated that the built-in potential (Vbi) calculated using a thermionic emission model is more accurate than that calculated using C-V extrapolation since C-V plots showed a Vbi shift as a function of frequency. Although CdTe/CdS is widely used for photovoltaic applications, the parameters evaluated in this work indicate that CdTe/CdS heterojunctions could be used as rectifying diodes and junction field effect transistors (JFETs). JFETs require a low PN diode saturation current, as demonstrated for the CdTe/CdS junction studied here.

Co-chaperone p23 regulates C. elegans Lifespan in Response to Temperature.

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Makoto Horikawa

2015-04-01

Full Text Available Temperature potently modulates various physiologic processes including organismal motility, growth rate, reproduction, and ageing. In ectotherms, longevity varies inversely with temperature, with animals living shorter at higher temperatures. Thermal effects on lifespan and other processes are ascribed to passive changes in metabolic rate, but recent evidence also suggests a regulated process. Here, we demonstrate that in response to temperature, daf-41/ZC395.10, the C. elegans homolog of p23 co-chaperone/prostaglandin E synthase-3, governs entry into the long-lived dauer diapause and regulates adult lifespan. daf-41 deletion triggers constitutive entry into the dauer diapause at elevated temperature dependent on neurosensory machinery (daf-10/IFT122, insulin/IGF-1 signaling (daf-16/FOXO, and steroidal signaling (daf-12/FXR. Surprisingly, daf-41 mutation alters the longevity response to temperature, living longer than wild-type at 25°C but shorter than wild-type at 15°C. Longevity phenotypes at 25°C work through daf-16/FOXO and heat shock factor hsf-1, while short lived phenotypes converge on daf-16/FOXO and depend on the daf-12/FXR steroid receptor. Correlatively daf-41 affected expression of DAF-16 and HSF-1 target genes at high temperature, and nuclear extracts from daf-41 animals showed increased occupancy of the heat shock response element. Our studies suggest that daf-41/p23 modulates key transcriptional changes in longevity pathways in response to temperature.