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Sample records for ceramide pathway metagene

  1. Assessment of an RNA interference screen-derived mitotic and ceramide pathway metagene as a predictor of response to neoadjuvant paclitaxel for primary triple-negative breast cancer: a retrospective analysis of five clinical trials

    DEFF Research Database (Denmark)

    Juul, Nicolai Stefan; Szallasi, Zoltan Imre; Eklund, Aron Charles;

    2010-01-01

    involved in mitosis or ceramide metabolism that influenced sensitivity to paclitaxel, with an RNA interference (RNAi) screen in three cancer cell lines, including a triple-negative breast-cancer cell line. Here, we assess these genes as a predictor of pCR to paclitaxel combination chemotherapy in triple...

  2. A novel pathway of ceramide metabolism in Saccharomyces cerevisiae

    DEFF Research Database (Denmark)

    Voynova, Natalia S; Vionnet, Christine; Ejsing, Christer S.;

    2012-01-01

    be monitored using fluorescent NBD (7-nitrobenz-2-oxa-1,3-diazole) ceramides as an acceptor substrate for microsomal assays. The Lro1p-dependent transfer of oleic acid on to NBD ceramide was confirmed by high-resolution Fourier transform and tandem MS. Immunopurified Lro1p was equally able to acylate...... NBD ceramide. Lro1p acylates NBD ceramide by attaching a fatty acid to the hydroxy group on the first carbon atom of the long-chain base. Acylceramides are mobilized when cells are diluted into fresh medium in the presence of cerulenin, an inhibitor of fatty acid biosynthesis....

  3. Alterations of the Ceramide Metabolism in the Peri-Infarct Cortex Are Independent of the Sphingomyelinase Pathway and Not Influenced by the Acid Sphingomyelinase Inhibitor Fluoxetine

    OpenAIRE

    Brunkhorst, R.; Friedlaender, F.; Ferreirós, N.; Schwalm, S.; Koch, A.; Grammatikos, G.; Toennes, S.; Foerch, C; Pfeilschifter, J.; Pfeilschifter, W.

    2015-01-01

    Ceramides induce important intracellular signaling pathways, modulating proliferation, migration, apoptosis, and inflammation. However, the relevance of the ceramide metabolism in the reconvalescence phase after stroke is unclear. Besides its well-known property as a selective serotonin reuptake inhibitor, fluoxetine has been reported to inhibit the acid sphingomyelinase (ASM), a key regulator of ceramide levels which derives ceramide from sphingomyelin. Furthermore, fluoxetine has shown ther...

  4. Clathrin-dependent pathways and the cytoskeleton network are involved in ceramide endocytosis by a parasitic protozoan, Giardia lamblia.

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    Hernandez, Yunuen; Castillo, Cynthia; Roychowdhury, Sukla; Hehl, Adrian; Aley, Stephen B; Das, Siddhartha

    2007-01-01

    Although identified as an early-diverged protozoan, Giardia lamblia shares many similarities with higher eukaryotic cells, including an internal membrane system and cytoskeleton, as well as secretory pathways. However, unlike many other eukaryotes, Giardia does not synthesize lipids de novo, but rather depends on exogenous sources for both energy production and organelle or membrane biogenesis. It is not known how lipid molecules are taken up by this parasite and if endocytic pathways are involved in this process. In this investigation, we tested the hypothesis that highly regulated and selective lipid transport machinery is present in Giardia and necessary for the efficient internalization and intracellular targeting of ceramide molecules, the major sphingolipid precursor. Using metabolic and pathway inhibitors, we demonstrate that ceramide is internalized through endocytic pathways and is primarily targeted into perinuclear/endoplasmic reticulum membranes. Further investigations suggested that Giardia uses both clathrin-dependent pathways and the actin cytoskeleton for ceramide uptake, as well as microtubule filaments for intracellular localization and targeting. We speculate that this parasitic protozoan has evolved cytoskeletal and clathrin-dependent endocytic mechanisms for importing ceramide molecules from the cell exterior for the synthesis of membranes and vesicles during growth and differentiation. PMID:17087963

  5. Targeting ceramide metabolic pathway induces apoptosis in human breast cancer cell lines

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    Vethakanraj, Helen Shiphrah; Babu, Thabraz Ahmed; Sudarsanan, Ganesh Babu; Duraisamy, Prabhu Kumar; Ashok Kumar, Sekar, E-mail: sekarashok@gmail.com

    2015-08-28

    The sphingolipid ceramide is a pro apoptotic molecule of ceramide metabolic pathway and is hydrolyzed to proliferative metabolite, sphingosine 1 phosphate by the action of acid ceramidase. Being upregulated in the tumors of breast, acid ceramidase acts as a potential target for breast cancer therapy. We aimed at targeting this enzyme with a small molecule acid ceramidase inhibitor, Ceranib 2 in human breast cancer cell lines MCF 7 and MDA MB 231. Ceranib 2 effectively inhibited the growth of both the cell lines in dose and time dependant manner. Morphological apoptotic hallmarks such as chromatin condensation, fragmented chromatin were observed in AO/EtBr staining. Moreover, ladder pattern of fragmented DNA observed in DNA gel electrophoresis proved the apoptotic activity of Ceranib 2 in breast cancer cell lines. The apoptotic events were associated with significant increase in the expression of pro-apoptotic genes (Bad, Bax and Bid) and down regulation of anti-apoptotic gene (Bcl 2). Interestingly, increase in sub G1 population of cell cycle phase analysis and elevated Annexin V positive cells after Ceranib 2 treatment substantiated its apoptotic activity in MCF 7 and MDA MB 231 cell lines. Thus, we report Ceranib 2 as a potent therapeutic agent against both ER{sup +} and ER{sup −} breast cancer cell lines. - Highlights: • Acid Ceramidase inhibitor, Ceranib 2 induced apoptosis in Breast cancer cell lines (MCF 7 and MDA MB 231 cell lines). • Apoptosis is mediated by DNA fragmentation and cell cycle arrest. • Ceranib 2 upregulated the expression of pro-apoptotic genes and down regulated anti-apoptotic gene expression. • More potent compared to the standard drug Tamoxifen.

  6. Ceramide Induces Human Hepcidin Gene Transcription through JAK/STAT3 Pathway.

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    Sizhao Lu

    Full Text Available Changes in lipid metabolism and iron content are observed in the livers of patients with fatty liver disease. The expression of hepcidin, an iron-regulatory and acute phase protein synthesized by the liver, is also modulated. The potential interaction of lipid and iron metabolism is largely unknown. We investigated the role of lipid intermediate, ceramide in the regulation of human hepcidin gene, HAMP. Human hepatoma HepG2 cells were treated with cell-permeable ceramide analogs. Ceramide induced significant up-regulation of HAMP mRNA expression in HepG2 cells. The effect of ceramide on HAMP expression was mediated through transcriptional mechanisms because it was completely blocked with actinomycin D treatment. Reporter assays also confirmed the activation of 0.6 kb HAMP promoter by ceramide. HepG2 cells treated with ceramide displayed increased phosphorylation of STAT3, JNK, and NF-κB proteins. However, ceramide induced the binding of STAT3, but not NF-κB or c-Jun, to HAMP promoter, as shown by the chromatin immunoprecipitation assays. The mutation of STAT3 response element within 0.6 kb HAMP promoter region significantly inhibited the stimulatory effect of ceramide on HAMP promoter activity. Similarly, the inhibition of STAT3 with a pan-JAK kinase inhibitor and STAT3 siRNA pool also diminished the induction of both HAMP promoter activity and mRNA expression by ceramide. In conclusion, we have shown a direct role for ceramide in the activation of hepatic HAMP transcription via STAT3. Our findings suggest a crosstalk between lipid and iron metabolism in the liver, which may contribute to the pathogenesis of obesity-related fatty liver disease.

  7. Ceramide Induces Human Hepcidin Gene Transcription through JAK/STAT3 Pathway.

    Science.gov (United States)

    Lu, Sizhao; Natarajan, Sathish Kumar; Mott, Justin L; Kharbanda, Kusum K; Harrison-Findik, Duygu Dee

    2016-01-01

    Changes in lipid metabolism and iron content are observed in the livers of patients with fatty liver disease. The expression of hepcidin, an iron-regulatory and acute phase protein synthesized by the liver, is also modulated. The potential interaction of lipid and iron metabolism is largely unknown. We investigated the role of lipid intermediate, ceramide in the regulation of human hepcidin gene, HAMP. Human hepatoma HepG2 cells were treated with cell-permeable ceramide analogs. Ceramide induced significant up-regulation of HAMP mRNA expression in HepG2 cells. The effect of ceramide on HAMP expression was mediated through transcriptional mechanisms because it was completely blocked with actinomycin D treatment. Reporter assays also confirmed the activation of 0.6 kb HAMP promoter by ceramide. HepG2 cells treated with ceramide displayed increased phosphorylation of STAT3, JNK, and NF-κB proteins. However, ceramide induced the binding of STAT3, but not NF-κB or c-Jun, to HAMP promoter, as shown by the chromatin immunoprecipitation assays. The mutation of STAT3 response element within 0.6 kb HAMP promoter region significantly inhibited the stimulatory effect of ceramide on HAMP promoter activity. Similarly, the inhibition of STAT3 with a pan-JAK kinase inhibitor and STAT3 siRNA pool also diminished the induction of both HAMP promoter activity and mRNA expression by ceramide. In conclusion, we have shown a direct role for ceramide in the activation of hepatic HAMP transcription via STAT3. Our findings suggest a crosstalk between lipid and iron metabolism in the liver, which may contribute to the pathogenesis of obesity-related fatty liver disease. PMID:26807955

  8. Sustained Action of Ceramide on the Insulin Signaling Pathway in Muscle Cells: IMPLICATION OF THE DOUBLE-STRANDED RNA-ACTIVATED PROTEIN KINASE.

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    Hage Hassan, Rima; Pacheco de Sousa, Ana Catarina; Mahfouz, Rana; Hainault, Isabelle; Blachnio-Zabielska, Agnieszka; Bourron, Olivier; Koskas, Fabien; Górski, Jan; Ferré, Pascal; Foufelle, Fabienne; Hajduch, Eric

    2016-02-01

    In vivo, ectopic accumulation of fatty acids in muscles leads to alterations in insulin signaling at both the IRS1 and Akt steps. However, in vitro treatments with saturated fatty acids or their derivative ceramide demonstrate an effect only at the Akt step. In this study, we adapted our experimental procedures to mimic the in vivo situation and show that the double-stranded RNA-dependent protein kinase (PKR) is involved in the long-term effects of saturated fatty acids on IRS1. C2C12 or human muscle cells were incubated with palmitate or directly with ceramide for short or long periods, and insulin signaling pathway activity was evaluated. PKR involvement was assessed through pharmacological and genetic studies. Short-term treatments of myotubes with palmitate, a ceramide precursor, or directly with ceramide induce an inhibition of Akt, whereas prolonged periods of treatment show an additive inhibition of insulin signaling through increased IRS1 serine 307 phosphorylation. PKR mRNA, protein, and phosphorylation are increased in insulin-resistant muscles. When PKR activity is reduced (siRNA or a pharmacological inhibitor), serine phosphorylation of IRS1 is reduced, and insulin-induced phosphorylation of Akt is improved. Finally, we show that JNK mediates ceramide-activated PKR inhibitory action on IRS1. Together, in the long term, our results show that ceramide acts at two distinct levels of the insulin signaling pathway (IRS1 and Akt). PKR, which is induced by both inflammation signals and ceramide, could play a major role in the development of insulin resistance in muscle cells. PMID:26698173

  9. Sustained Action of Ceramide on the Insulin Signaling Pathway in Muscle Cells: IMPLICATION OF THE DOUBLE-STRANDED RNA-ACTIVATED PROTEIN KINASE.

    Science.gov (United States)

    Hage Hassan, Rima; Pacheco de Sousa, Ana Catarina; Mahfouz, Rana; Hainault, Isabelle; Blachnio-Zabielska, Agnieszka; Bourron, Olivier; Koskas, Fabien; Górski, Jan; Ferré, Pascal; Foufelle, Fabienne; Hajduch, Eric

    2016-02-01

    In vivo, ectopic accumulation of fatty acids in muscles leads to alterations in insulin signaling at both the IRS1 and Akt steps. However, in vitro treatments with saturated fatty acids or their derivative ceramide demonstrate an effect only at the Akt step. In this study, we adapted our experimental procedures to mimic the in vivo situation and show that the double-stranded RNA-dependent protein kinase (PKR) is involved in the long-term effects of saturated fatty acids on IRS1. C2C12 or human muscle cells were incubated with palmitate or directly with ceramide for short or long periods, and insulin signaling pathway activity was evaluated. PKR involvement was assessed through pharmacological and genetic studies. Short-term treatments of myotubes with palmitate, a ceramide precursor, or directly with ceramide induce an inhibition of Akt, whereas prolonged periods of treatment show an additive inhibition of insulin signaling through increased IRS1 serine 307 phosphorylation. PKR mRNA, protein, and phosphorylation are increased in insulin-resistant muscles. When PKR activity is reduced (siRNA or a pharmacological inhibitor), serine phosphorylation of IRS1 is reduced, and insulin-induced phosphorylation of Akt is improved. Finally, we show that JNK mediates ceramide-activated PKR inhibitory action on IRS1. Together, in the long term, our results show that ceramide acts at two distinct levels of the insulin signaling pathway (IRS1 and Akt). PKR, which is induced by both inflammation signals and ceramide, could play a major role in the development of insulin resistance in muscle cells.

  10. Glioma cell death induced by irradiation or alkylating agent chemotherapy is independent of the intrinsic ceramide pathway.

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    Dorothee Gramatzki

    Full Text Available BACKGROUND/AIMS: Resistance to genotoxic therapy is a characteristic feature of glioma cells. Acid sphingomyelinase (ASM hydrolyzes sphingomyelin to ceramide and glucosylceramide synthase (GCS catalyzes ceramide metabolism. Increased ceramide levels have been suggested to enhance chemotherapy-induced death of cancer cells. METHODS: Microarray and clinical data for ASM and GCS in astrocytomas WHO grade II-IV were acquired from the Rembrandt database. Moreover, the glioblastoma database of the Cancer Genome Atlas network (TCGA was used for survival data of glioblastoma patients. For in vitro studies, increases in ceramide levels were achieved either by ASM overexpression or by the GCS inhibitor DL-threo-1-phenyl-2-palmitoylamino-3-morpholino-1-propanol (PPMP in human glioma cell lines. Combinations of alkylating chemotherapy or irradiation and ASM overexpression, PPMP or exogenous ceramide were applied in parental cells. The anti-glioma effects were investigated by assessing proliferation, metabolic activity, viability and clonogenicity. Finally, viability and clonogenicity were assessed in temozolomide (TMZ-resistant cells upon treatment with PPMP, exogenous ceramide, alkylating chemotherapy, irradiation or their combinations. RESULTS: Interrogations from the Rembrandt and TCGA database showed a better survival of glioblastoma patients with low expression of ASM or GCS. ASM overexpression or PPMP treatment alone led to ceramide accumulation but did not enhance the anti-glioma activity of alkylating chemotherapy or irradiation. PPMP or exogenous ceramide induced acute cytotoxicity in glioblastoma cells. Combined treatments with chemotherapy or irradiation led to additive, but not synergistic effects. Finally, no synergy was found when TMZ-resistant cells were treated with exogenous ceramide or PPMP alone or in combination with TMZ or irradiation. CONCLUSION: Modulation of intrinsic glioma cell ceramide levels by ASM overexpression or GCS

  11. Consistent metagenes from cancer expression profiles yield agent specific predictors of chemotherapy response

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    Pusztai Lajos

    2011-07-01

    Full Text Available Abstract Background Genome scale expression profiling of human tumor samples is likely to yield improved cancer treatment decisions. However, identification of clinically predictive or prognostic classifiers can be challenging when a large number of genes are measured in a small number of tumors. Results We describe an unsupervised method to extract robust, consistent metagenes from multiple analogous data sets. We applied this method to expression profiles from five "double negative breast cancer" (DNBC (not expressing ESR1 or HER2 cohorts and derived four metagenes. We assessed these metagenes in four similar but independent cohorts and found strong associations between three of the metagenes and agent-specific response to neoadjuvant therapy. Furthermore, we applied the method to ovarian and early stage lung cancer, two tumor types that lack reliable predictors of outcome, and found that the metagenes yield predictors of survival for both. Conclusions These results suggest that the use of multiple data sets to derive potential biomarkers can filter out data set-specific noise and can increase the efficiency in identifying clinically accurate biomarkers.

  12. ORMDL proteins regulate ceramide levels during sterile inflammation.

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    Cai, Lin; Oyeniran, Clement; Biswas, Debolina D; Allegood, Jeremy; Milstien, Sheldon; Kordula, Tomasz; Maceyka, Michael; Spiegel, Sarah

    2016-08-01

    The bioactive sphingolipid metabolite, ceramide, regulates physiological processes important for inflammation and elevated levels of ceramide have been implicated in IL-1-mediated events. Although much has been learned about ceramide generation by activation of sphingomyelinases in response to IL-1, the contribution of the de novo pathway is not completely understood. Because yeast ORM1 and ORM2 proteins negatively regulate ceramide levels through inhibition of serine palmitoyltransferase, the first committed step in ceramide biosynthesis, we examined the functions of individual mammalian ORM orthologs, ORM (yeast)-like (ORMDL)1-3, in regulation of ceramide levels. In HepG2 liver cells, downregulation of ORMDL3 markedly increased the ceramide precursors, dihydrosphingosine and dihydroceramide, primarily from de novo biosynthesis based on [U-(13)C]palmitate incorporation into base-labeled and dual-labeled dihydroceramides, whereas downregulation of each isoform increased dihydroceramides [(13)C]labeled in only the amide-linked fatty acid. IL-1 and the IL-6 family cytokine, oncostatin M, increased dihydroceramide and ceramide levels in HepG2 cells and concomitantly decreased ORMDL proteins. Moreover, during irritant-induced sterile inflammation in mice leading to induction of the acute-phase response, which is dependent on IL-1, expression of ORMDL proteins in the liver was strongly downregulated and accompanied by increased ceramide levels in the liver and accumulation in the blood. Together, our results suggest that ORMDLs may be involved in regulation of ceramides during IL-1-mediated sterile inflammation. PMID:27313060

  13. Ceramide limits phosphatidylinositol-3-kinase C2β-controlled cell motility in ovarian cancer: potential of ceramide as a metastasis-suppressor lipid.

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    Kitatani, K; Usui, T; Sriraman, S K; Toyoshima, M; Ishibashi, M; Shigeta, S; Nagase, S; Sakamoto, M; Ogiso, H; Okazaki, T; Hannun, Y A; Torchilin, V P; Yaegashi, N

    2016-05-01

    Targeting cell motility, which is required for dissemination and metastasis, has therapeutic potential for ovarian cancer metastasis, and regulatory mechanisms of cell motility need to be uncovered for developing novel therapeutics. Invasive ovarian cancer cells spontaneously formed protrusions, such as lamellipodia, which are required for generating locomotive force in cell motility. Short interfering RNA screening identified class II phosphatidylinositol 3-kinase C2β (PI3KC2β) as the predominant isoform of PI3K involved in lamellipodia formation of ovarian cancer cells. The bioactive sphingolipid ceramide has emerged as an antitumorigenic lipid, and treatment with short-chain C6-ceramide decreased the number of ovarian cancer cells with PI3KC2β-driven lamellipodia. Pharmacological analysis demonstrated that long-chain ceramide regenerated from C6-ceramide through the salvage/recycling pathway, at least in part, mediated the action of C6-ceramide. Mechanistically, ceramide was revealed to interact with the PIK-catalytic domain of PI3KC2β and affect its compartmentalization, thereby suppressing PI3KC2β activation and its driven cell motility. Ceramide treatment also suppressed cell motility promoted by epithelial growth factor, which is a prometastatic factor. To examine the role of ceramide in ovarian cancer metastasis, ceramide liposomes were employed and confirmed to suppress cell motility in vitro. Ceramide liposomes had an inhibitory effect on peritoneal metastasis in a murine xenograft model of human ovarian cancer. Metastasis of PI3KC2β knocked-down cells was insensitive to treatment with ceramide liposomes, suggesting specific involvement of ceramide interaction with PI3KC2β in metastasis suppression. Our study identified ceramide as a bioactive lipid that limits PI3KC2β-governed cell motility, and ceramide is proposed to serve as a metastasis-suppressor lipid in ovarian cancer. These findings could be translated into developing ceramide

  14. Oxidized phospholipids induce ceramide accumulation in RAW 264.7 macrophages: role of ceramide synthases.

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    Lingaraju M Halasiddappa

    Full Text Available Oxidized phospholipids (OxPLs, including 1-palmitoyl-2-glutaroyl-sn-glycero-3-phosphocholine (PGPC and 1-palmitoyl-2-oxovaleroyl-sn-glycero-3-phosphocholine (POVPC are among several biologically active derivatives that are generated during oxidation of low-density lipoproteins (LDLs. These OxPLs are factors contributing to pro-atherogenic effects of oxidized LDLs (OxLDLs, including inflammation, proliferation and death of vascular cells. OxLDL also elicits formation of the lipid messenger ceramide (Cer which plays a pivotal role in apoptotic signaling pathways. Here we report that both PGPC and POVPC are cytotoxic to cultured macrophages and induce apoptosis in these cells which is associated with increased cellular ceramide levels after several hours. In addition, exposure of RAW 264.7 cells to POVPC and PGPC under the same conditions resulted in a significant increase in ceramide synthase activity, whereas, acid or neutral sphingomyelinase activities were not affected. PGPC is not only more toxic than POVPC, but also a more potent inducer of ceramide formation by activating a limited subset of CerS isoforms. The stimulated CerS activities are in line with the C16-, C22-, and C24:0-Cer species that are generated under the influence of the OxPL. Fumonisin B1, a specific inhibitor of CerS, suppressed OxPL-induced ceramide generation, demonstrating that OxPL-induced CerS activity in macrophages is responsible for the accumulation of ceramide. OxLDL elicits the same cellular ceramide and CerS effects. Thus, it is concluded that PGPC and POVPC are active components that contribute to the capacity of this lipoprotein to elevate ceramide levels in macrophages.

  15. Ceramide is involved in alcohol-induced neural proliferation****

    Institute of Scientific and Technical Information of China (English)

    Zhixin Wang; Tongxing Deng; Jiexin Deng; Jinbo Deng; Xiaoqun Gao; Yuanyuan Shi; Bin Liu; Zhanyou Ma; Haixiao Jin

    2013-01-01

    Prenatal alcohol exposure, especial y during early pregnancy, can lead to fetal alcohol syndrome. The pharmacological and toxicological mechanisms of ethanol are related to the effects of ceramide. In this study, we established an alcohol exposure model in wild-type mice and in knockout mice for the key enzyme involved in ceramide metabolism, sphingomyelin synthase 2. This model received daily intragastric administration of 25%ethanol, and pups were used at postnatal days 0, 7, 14, 30 for experiments. Serology and immunofluorescence staining found that ethanol exposure dose-dependently reduced blood sphingomyelin levels in two genotypes of pups, and increased neural cel proliferation and the number of new neurons in the hippocampal dentate gyrus. Western blot analysis showed that the relative expression level of protein kinase C α increased in two notypes of pups after ethanol exposure. Compared with wild-type pups, the expression level of the important activator protein of the ceramide/ceramide-1-phosphate pathway, protein kinase Cα, was reduced in the hippocampus of sphingomyelin synthase 2 knockouts. Our findings il ustrate that ceramide is involved in alcohol-induced neural proliferation in the hippocampal dentate gyrus of pups after prenatal ethanol exposure, and the mechanism may be associated with increased pression of protein kinase Cαactivating the ceramide/ceramide-1-phosphate pathway.

  16. The role of ceramide in receptor- and stress-induced apoptosis studied in acidic ceramidase-deficient Farber disease cells

    OpenAIRE

    Burek, C. J.; Roth, J.; Koch, H. G.; Harzer, K.; Los, Marek Jan; Schulze-Osthoff, Klaus

    2001-01-01

    The activation of sphingomyelinases leading to the generation of ceramide has been implicated in various apoptotic pathways. However, the role of ceramide as an essential death mediator remains highly controversial. In the present study, we investigated the functional relevance of ceramide in a genetic model by using primary cells from a Farber disease patient. These cells accumulate ceramide as the result of an inherited deficiency of acidic ceramidase. We demonstrate that Farber disease lym...

  17. Ceramides and cell signaling molecules in psoriatic epidermis: reduced levels of ceramides, PKC-alpha, and JNK.

    Science.gov (United States)

    Lew, Bark-Lynn; Cho, Yunhi; Kim, Jungmin; Sim, Woo-Young; Kim, Nack-In

    2006-02-01

    Ceramides are the main lipids in the stratum corneum and are generated during cellular stress and apoptosis by de novo synthesis or by the action of sphingomyelinase. In addition, they are lipid second messengers produced by sphingolipid metabolism and trigger important cell responses, including protein kinase C-alpha (PKC-alpha) activation and the stimulation of signal transduction pathways with apoptosis and stress-activated protein kinases (SAPK), such as c-jun N-terminal kinase (JNK). Thus, ceramides have anti-proliferative and apoptotic effects. This study measured the changes in the levels of epidermal ceramides and ceramide-related apoptotic signaling molecules in psoriasis patients. Samples from lesional and non-lesional epidermis were obtained from psoriasis patients. Total ceramides were fractionated using thin-layer chromatography, and the levels of PKC-alpha and JNK expression were measured using Western blot analysis with specific antibodies. The ceramide level was reduced significantly, and this was associated with the downregulation of apoptotic signaling molecules, such as PKC-alpha and JNK, in the lesional epidermis of psoriasis patients. These results suggest that the decreased level of ceramides downregulates the apoptotic pathway, leading to epidermal proliferation in psoriasis. PMID:16479073

  18. Targeting acid sphingomyelinase reduces cardiac ceramide accumulation in the post-ischemic heart.

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    Klevstig, Martina; Ståhlman, Marcus; Lundqvist, Annika; Scharin Täng, Margareta; Fogelstrand, Per; Adiels, Martin; Andersson, Linda; Kolesnick, Richard; Jeppsson, Anders; Borén, Jan; Levin, Malin C

    2016-04-01

    Ceramide accumulation is known to accompany acute myocardial ischemia, but its role in the pathogenesis of ischemic heart disease is unclear. In this study, we aimed to determine how ceramides accumulate in the ischemic heart and to determine if cardiac function following ischemia can be improved by reducing ceramide accumulation. To investigate the association between ceramide accumulation and heart function, we analyzed myocardial left ventricle biopsies from subjects with chronic ischemia and found that ceramide levels were higher in biopsies from subjects with reduced heart function. Ceramides are produced by either de novo synthesis or hydrolysis of sphingomyelin catalyzed by acid and/or neutral sphingomyelinase. We used cultured HL-1 cardiomyocytes to investigate these pathways and showed that acid sphingomyelinase activity rather than neutral sphingomyelinase activity or de novo sphingolipid synthesis was important for hypoxia-induced ceramide accumulation. We also used mice with a partial deficiency in acid sphingomyelinase (Smpd1(+/-) mice) to investigate if limiting ceramide accumulation under ischemic conditions would have a beneficial effect on heart function and survival. Although we showed that cardiac ceramide accumulation was reduced in Smpd1(+/-) mice 24h after an induced myocardial infarction, this reduction was not accompanied by an improvement in heart function or survival. Our findings show that accumulation of cardiac ceramides in the post-ischemic heart is mediated by acid sphingomyelinase. However, targeting ceramide accumulation in the ischemic heart may not be a beneficial treatment strategy. PMID:26930027

  19. Metagenes Associated with Survival in Non-Small Cell Lung Cancer

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    Urgard, Egon; Vooder, Tõnu; Võsa, Urmo; Välk, Kristjan; Liu, Mingming; Luo, Cheng; Hoti, Fabian; Roosipuu, Retlav; Annilo, Tarmo; Laine, Jukka; Frenz, Christopher M.; Zhang, Liqing; Metspalu, Andres

    2011-01-01

    NSCLC (non-small cell lung cancer) comprises about 80% of all lung cancer cases worldwide. Surgery is most effective treatment for patients with early-stage disease. However, 30%–55% of these patients develop recurrence within 5 years. Therefore, markers that can be used to accurately classify early-stage NSCLC patients into different prognostic groups may be helpful in selecting patients who should receive specific therapies. A previously published dataset was used to evaluate gene expression profiles of different NSCLC subtypes. A moderated two-sample t-test was used to identify differentially expressed genes between all tumor samples and cancer-free control tissue, between SCC samples and AC/BC samples and between stage I tumor samples and all other tumor samples. Gene expression microarray measurements were validated using qRT-PCR. Bayesian regression analysis and Kaplan-Meier survival analysis were performed to determine metagenes associated with survival. We identified 599 genes which were down-regulated and 402 genes which were up-regulated in NSCLC compared to the normal lung tissue and 112 genes which were up-regulated and 101 genes which were down-regulated in AC/BC compared to the SCC. Further, for stage Ib patients the metagenes potentially associated with survival were identified. Genes that expressed differently between normal lung tissue and cancer showed enrichment in gene ontology terms which were associated with mitosis and proliferation. Bayesian regression and Kaplan-Meier analysis showed that gene-expression patterns and metagene profiles can be applied to predict the probability of different survival outcomes in NSCLC patients. PMID:21695068

  20. Prognostic evaluation of the B cell/IL-8 metagene in different intrinsic breast cancer subtypes.

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    Hanker, Lars C; Rody, Achim; Holtrich, Uwe; Pusztai, Lajos; Ruckhaeberle, Eugen; Liedtke, Cornelia; Ahr, Andre; Heinrich, Tomas M; Sänger, Nicole; Becker, Sven; Karn, Thomas

    2013-01-01

    We recently reported that a ratio of high B cell and low IL-8 metagene expression identified 32 % of triple negative breast cancers (TNBC) with good prognosis and was the only significant predictor in multivariate analysis including routine clinicopathological variables. However, the clinical relevance of this signature in other breast cancer subtypes remains unclear. We compiled Affymetrix gene expression datasets from 4,467 primary breast cancer samples and excluded 329 triple negative samples which were used as discovery cohort in our previous study. Molecular classification of the remaining 4,138 samples was performed by two methods, including single genes (ER, PgR, HER2, and Ki67) and a centroid-based method using the intrinsic gene list. The prognostic value within the respective subtypes was assessed by analyzing the event-free survival of patients as a function of the B cell/IL-8 metagene ratio using previously published cutoff. ER-negative subtypes had the highest expression of the B cell and the IL-8 metagenes. The IL-8/B cell signature assigned a considerable fraction of samples (range 20.7-42.0 %) into the "good prognosis" group. However, a significant prognostic value was only observed in the subgroup of triple negative breast cancer (P = 0.035). The prognostic value of the B cell/IL-8 ratio is mainly confined to the basal-like and TNBC subtypes of breast cancer. This result underlines the importance of subtype-specific analyses and suggests a sequential multistep approach to developing and applying outcome predictors in the clinic.

  1. Synthesis and photochemical properties of PEGylated coumarin-caged ceramides for cell studies.

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    Kim, Young Ah; Day, Jenna; Lirette, Carol Ann; Costain, Willard J; Johnston, Linda J; Bittman, Robert

    2016-01-01

    Caged ceramide analogues (C6-, C16-, C18-, C22- and C24-Cer) have been prepared by introducing a hydrophilic coumarin-based cage bearing a short polyethylene glycol (PEG) chain. (6-Bromo-7-mTEGylated-coumarin-4-yl)methyl (Btc) caged ceramide showed efficient photo-uncaging to release the parent ceramide upon direct exposure to 350 nm UV light; in contrast (7-mTEGylated-coumarin-4-yl)methyl (Tc) caged ceramide was photolysed more slowly. In preliminary experiments, Btc-caged ceramides were taken up by cells and their photolysis led to decreases in cell viability, but not to activation of caspase enzymes, suggesting that either reactive oxygen species or an alternate caspase-independent pathway may be responsible for the decreases in cell viability caused by photolysis of caged ceramides.

  2. Hyperthyroidism Evokes Myocardial Ceramide Accumulation

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    Agnieszka Mikłosz

    2015-01-01

    Full Text Available Background: Thyroid hormones (THs are key regulators of cardiac physiology as well as modulators of different cellular signals including the sphingomyelin/ceramide pathway. The objective of this study was to examine the effect of hyperthyroidism on the metabolism of sphingolipids in the muscle heart. Methods: Male Wistar rats were treated for 10 days with triiodothyronine (T3 at a dose of 50µg/100g of body weight. Animals were then anaesthetized and samples of the left ventricle were excised. Results: We have demonstrated that prolonged, in vivo, T3 treatment increased the content of sphinganine (SFA, sphingosine (SFO, ceramide (CER and sphingomyelin (SM, but decreased the level of sphingosine-1-phosphate (S1P in cardiac muscle. Accordingly, the changes in sphingolipids content were accompanied by a lesser activity of neutral sphingomyelinase and without significant changes in ceramidases activity. Hyperthyroidism also induced activation of AMP-activated protein kinase (AMPK with subsequently increased expression of mitochondrial proteins: cytochrome c oxidase IV (COX IV, β-hydroxyacyl-CoA dehydrogenase (β-HAD, carnityne palmitoyltransferase I (CPT I and nuclear peroxisome proliferator-activated receptor-γ coactivator-1α (PGC1α. Conclusions: We conclude that prolonged T3 treatment increases sphingolipids metabolism which is reflected by higher concentration of SFA and CER in heart muscle. Furthermore, hyperthyroidism-induced increase in heart sphingomyelin (SM concentration might be one of the mechanisms underlying maintenance of CER at relatively low level by its conversion to SM together with decreased S1P content.

  3. Eczema and ceramides: an update

    DEFF Research Database (Denmark)

    Jungersted, Jakob Mutanu; Agner, Tove

    2013-01-01

    mutations in almost 50% of patients with moderate/severe atopic dermatitis, and lipid disturbances, mainly expressed as insufficient ceramides. In this review, with an emphasis on human studies, we consider the latest research on ceramides, on ceramides in different types of eczema and following various...... types of treatment. We also consider the genetic influence on stratum corneum lipids. The review is an update on research indexed in PubMed following the discovery of the filaggrin mutations in atopic dermatitis in 2006, but when newer publications cannot stand alone, we include publications from before...

  4. Ethnicity and stratum corneum ceramides

    DEFF Research Database (Denmark)

    Jungersted, J.M.; Høgh, Julie Kaae; Hellgren, Lars;

    2010-01-01

    diseases were enrolled in the study. Twenty-five participants of Asian origin (Asians), 18 of African origin (Africans) and 28 of Danish origin (white-skinned), all students at universities in the Copenhagen area of Denmark, had the ceramide profile of their stratum corneum examined using the cyanoacrylate...... method and analysed using high-performance thin layer chromatography. RESULTS: For the ceramide/cholesterol ratio we found statistically significant differences between groups, with Asians having the highest ratio (P Africans), white......-skinned individuals having intermediate values, and Africans having the lowest values. No statistically significant differences were found between any of the ceramide subgroups. CONCLUSIONS: We found different ceramide/cholesterol ratios in comparable groups of different ethnicity, pointing to unknown genetic...

  5. Ceramide inhibits PKCθ by regulating its phosphorylation and translocation to lipid rafts in Jurkat cells.

    Science.gov (United States)

    Hage-Sleiman, Rouba; Hamze, Asmaa B; El-Hed, Aimée F; Attieh, Randa; Kozhaya, Lina; Kabbani, Sarah; Dbaibo, Ghassan

    2016-08-01

    Protein kinase C theta (PKCθ) is a novel, calcium-independent member of the PKC family of kinases that was identified as a central player in T cell signaling and proliferation. Upon T cell activation by antigen-presenting cells, PKCθ gets phosphorylated and activated prior to its translocation to the immunological synapse where it couples with downstream effectors. PKCθ may be regulated by ceramide, a crucial sphingolipid that is known to promote differentiation, growth arrest, and apoptosis. To further investigate the mechanism, we stimulated human Jurkat T cells with either PMA or anti-CD3/anti-CD28 antibodies following induction of ceramide accumulation by adding exogenous ceramide, bacterial sphingomyelinase, or Fas ligation. Our results suggest that ceramide regulates the PKCθ pathway through preventing its critical threonine 538 (Thr538) phosphorylation and subsequent activation, thereby inhibiting the kinase's translocation to lipid rafts. Moreover, this inhibition is not likely to be a generic effect of ceramide on membrane reorganization. Other lipids, namely dihydroceramide, palmitate, and sphingosine, did not produce similar effects on PKCθ. Addition of the phosphatase inhibitors okadaic acid and calyculin A reversed the inhibition exerted by ceramide, and this suggests involvement of a ceramide-activated protein phosphatase. Such previously undescribed mechanism of regulation of PKCθ raises the possibility that ceramide, or one of its derivatives, and may prove valuable in novel therapeutic approaches for disorders involving autoimmunity or excessive inflammation-where PKCθ plays a critical role.

  6. Ceramide inhibits PKCθ by regulating its phosphorylation and translocation to lipid rafts in Jurkat cells.

    Science.gov (United States)

    Hage-Sleiman, Rouba; Hamze, Asmaa B; El-Hed, Aimée F; Attieh, Randa; Kozhaya, Lina; Kabbani, Sarah; Dbaibo, Ghassan

    2016-08-01

    Protein kinase C theta (PKCθ) is a novel, calcium-independent member of the PKC family of kinases that was identified as a central player in T cell signaling and proliferation. Upon T cell activation by antigen-presenting cells, PKCθ gets phosphorylated and activated prior to its translocation to the immunological synapse where it couples with downstream effectors. PKCθ may be regulated by ceramide, a crucial sphingolipid that is known to promote differentiation, growth arrest, and apoptosis. To further investigate the mechanism, we stimulated human Jurkat T cells with either PMA or anti-CD3/anti-CD28 antibodies following induction of ceramide accumulation by adding exogenous ceramide, bacterial sphingomyelinase, or Fas ligation. Our results suggest that ceramide regulates the PKCθ pathway through preventing its critical threonine 538 (Thr538) phosphorylation and subsequent activation, thereby inhibiting the kinase's translocation to lipid rafts. Moreover, this inhibition is not likely to be a generic effect of ceramide on membrane reorganization. Other lipids, namely dihydroceramide, palmitate, and sphingosine, did not produce similar effects on PKCθ. Addition of the phosphatase inhibitors okadaic acid and calyculin A reversed the inhibition exerted by ceramide, and this suggests involvement of a ceramide-activated protein phosphatase. Such previously undescribed mechanism of regulation of PKCθ raises the possibility that ceramide, or one of its derivatives, and may prove valuable in novel therapeutic approaches for disorders involving autoimmunity or excessive inflammation-where PKCθ plays a critical role. PMID:26798039

  7. Mechanisms of ceramide-induced COX-2-dependent apoptosis in human ovarian cancer OVCAR-3 cells partially overlapped with resveratrol

    DEFF Research Database (Denmark)

    Lin, Hung-Yun; Delmas, Dominique; Vang, Ole;

    2013-01-01

    Ceramide is a member of the sphingolipid family of bioactive molecules demonstrated to have profound, diverse biological activities. Ceramide is a potential chemotherapeutic agent via the induction of apoptosis. Exposure to ceramide activates extracellular-signal-regulated kinases (ERK)1/2- and p38......, resveratrol and ceramide converge on an endocytosis-requiring, ERK1/2-dependent signal transduction pathway and induction of COX-expression as an essential molecular antecedent for subsequent p53-dependent apoptosis. In addition, expressions of caspase-3 and -7 are observed. However, a p38 kinase...

  8. Macrophages transfer antigens to dendritic cells by releasing exosomes containing dead-cell-associated antigens partially through a ceramide-dependent pathway to enhance CD4(+) T-cell responses.

    Science.gov (United States)

    Xu, Yingping; Liu, Yi; Yang, Chunqing; Kang, Li; Wang, Meixiang; Hu, Jingxia; He, Hao; Song, Wengang; Tang, Hua

    2016-10-01

    Defects in rapid clearance of apoptotic cells lead to an accumulation of dead cells (late apoptotic or secondary necrotic cells), which results in an aberrant immune response. However, little is known about whether and how macrophages (Mφs) cooperate with dendritic cells (DCs) in the presentation of dead-cell-associated antigens in this process. By transferring high numbers of dead cells to mimic a failure of apoptotic cell clearance in vivo, we found that Mφs and neutrophils were the predominant phagocytes in the uptake of dead cells in the spleen. Moreover, both Mφs and DCs were required for an optimal CD4(+) T-cell response triggered by dead-cell-associated antigens. Importantly, although Mφs alone had a poor capacity for antigen presentation, they could transfer phagocytosed antigens to DCs for potent antigen presentation to enhance T-cell responses. Finally, we found that exosomes released from Mφs acted as a transmitter to convey antigens to DCs partially in a ceramide-dependent manner, since treatment with the neutral sphingomyelinase inhibitor GW4869 and spiroepoxide resulted in a significant reduction of T-cell proliferation in vitro and in vivo. These findings point to a novel pathway of cross-talk between Mφs and DCs, which will be helpful to explain possible mechanisms for autoimmune diseases characterized by increased rates of apoptosis.

  9. Ceramide in Stem Cell Differentiation and Embryo Development: Novel Functions of a Topological Cell-Signaling Lipid and the Concept of Ceramide Compartments

    Directory of Open Access Journals (Sweden)

    Erhard Bieberich

    2011-01-01

    Full Text Available In the last two decades, the view on the function of ceramide as a sole metabolic precursor for other sphingolipids has completely changed. A plethora of studies has shown that ceramide is an important lipid cell-signaling factor regulating apoptosis in a variety of cell types. With the advent of new stem cell technologies and knockout mice for specific steps in ceramide biosynthesis, this view is about to change again. Recent studies suggest that ceramide is a critical cell-signaling factor for stem cell differentiation and cell polarity, two processes at the core of embryo development. This paper discusses studies on ceramide using in vitro differentiated stem cells, embryo cultures, and knockout mice with the goal of linking specific developmental stages to exciting and novel functions of this lipid. Particular attention is devoted to the concept of ceramide as a topological cell-signaling lipid: a lipid that forms distinct structures (membrane domains and vesicles termed “sphingosome”, which confines ceramide-induced cell signaling pathways to localized and even polarized compartments.

  10. Ceramide and ceramide 1-phosphate in health and disease

    Directory of Open Access Journals (Sweden)

    Gómez-Muñoz Antonio

    2010-02-01

    Full Text Available Abstract Sphingolipids are essential components of cell membranes, and many of them regulate vital cell functions. In particular, ceramide plays crucial roles in cell signaling processes. Two major actions of ceramides are the promotion of cell cycle arrest and the induction of apoptosis. Phosphorylation of ceramide produces ceramide 1-phosphate (C1P, which has opposite effects to ceramide. C1P is mitogenic and has prosurvival properties. In addition, C1P is an important mediator of inflammatory responses, an action that takes place through stimulation of cytosolic phospholipase A2, and the subsequent release of arachidonic acid and prostaglandin formation. All of the former actions are thought to be mediated by intracellularly generated C1P. However, the recent observation that C1P stimulates macrophage chemotaxis implicates specific plasma membrane receptors that are coupled to Gi proteins. Hence, it can be concluded that C1P has dual actions in cells, as it can act as an intracellular second messenger to promote cell survival, or as an extracellular receptor agonist to stimulate cell migration.

  11. Ceramide signaling in cancer and stem cells

    OpenAIRE

    Bieberich, Erhard

    2008-01-01

    Most of the previous work on the sphingolipid ceramide has been devoted to its function as an apoptosis inducer. Recent studies, however, have shown that in stem cells, ceramide has additional nonapoptotic functions. In this article, ceramide signaling will be reviewed in light of ‘systems interface biology’: as an interconnection of sphingolipid metabolism, membrane biophysics and cell signaling. The focus will be on the metabolic interconversion of ceramide and sphingomyelin or sphingosine-...

  12. Ceramide stimulates ABCA12 expression via peroxisome proliferator-activated receptor {delta} in human keratinocytes.

    Science.gov (United States)

    Jiang, Yan J; Uchida, Yoshikazu; Lu, Biao; Kim, Peggy; Mao, Cungui; Akiyama, Masashi; Elias, Peter M; Holleran, Walter M; Grunfeld, Carl; Feingold, Kenneth R

    2009-07-10

    ABCA12 (ATP binding cassette transporter, family 12) is a cellular membrane transporter that facilitates the delivery of glucosylceramides to epidermal lamellar bodies in keratinocytes, a process that is critical for permeability barrier formation. Following secretion of lamellar bodies into the stratum corneum, glucosylceramides are metabolized to ceramides, which comprise approximately 50% of the lipid in stratum corneum. Gene mutations of ABCA12 underlie harlequin ichthyosis, a devastating skin disorder characterized by abnormal lamellar bodies and a severe barrier abnormality. Recently we reported that peroxisome proliferator-activated receptor (PPAR) and liver X receptor activators increase ABCA12 expression in human keratinocytes. Here we demonstrate that ceramide (C(2)-Cer and C(6)-Cer), but not C(8)-glucosylceramides, sphingosine, or ceramide 1-phosphate, increases ABCA12 mRNA expression in a dose- and time-dependent manner. Inhibitors of glucosylceramide synthase, sphingomyelin synthase, and ceramidase and small interfering RNA knockdown of human alkaline ceramidase, which all increase endogenous ceramide levels, also increased ABCA12 mRNA levels. Moreover, simultaneous treatment with C(6)-Cer and each of these same inhibitors additively increased ABCA12 expression, indicating that ceramide is an important inducer of ABCA12 expression and that the conversion of ceramide to other sphingolipids or metabolites is not required. Finally, both exogenous and endogenous ceramides preferentially stimulate PPARdelta expression (but not other PPARs or liver X receptors), whereas PPARdelta knockdown by siRNA transfection specifically diminished the ceramide-induced increase in ABCA12 mRNA levels, indicating that PPARdelta is a mediator of the ceramide effect. Together, these results show that ceramide, an important lipid component of epidermis, up-regulates ABCA12 expression via the PPARdelta-mediated signaling pathway, providing a substrate-driven, feed

  13. Network Analysis of a Comprehensive Knowledge Repository Reveals a Dual Role for Ceramide in Alzheimer's Disease.

    Science.gov (United States)

    Mizuno, Satoshi; Ogishima, Soichi; Kitatani, Kazuyuki; Kikuchi, Masataka; Tanaka, Hiroshi; Yaegashi, Nobuo; Nakaya, Jun

    2016-01-01

    Alzheimer's disease (AD) is the most common cause of senile dementia. Many inflammatory factors such as amyloid-β and pro-inflammatory cytokines are known to contribute to the inflammatory response in the AD brain. Sphingolipids are widely known to have roles in the pathogenesis of inflammatory diseases, where the precise roles for sphingolipids in inflammation-associated pathogenesis of AD are not well understood. Here we performed a network analysis to clarify the importance of sphingolipids and to model relationships among inflammatory factors and sphingolipids in AD. In this study, we have updated sphingolipid signaling and metabolic cascades in a map of AD signaling networks that we named "AlzPathway," a comprehensive knowledge repository of signaling pathways in AD. Our network analysis of the updated AlzPathway indicates that the pathways related to ceramide are one of the primary pathways and that ceramide is one of the important players in the pathogenesis of AD. The results of our analysis suggest the following two prospects about inflammation in AD: (1) ceramide could play important roles in both inflammatory and anti-inflammatory pathways of AD, and (2) several factors such as Sphingomyelinase and Siglec-11 may be associated with ceramide related inflammation and anti-inflammation pathways in AD. In this study, network analysis of comprehensive knowledge repository reveals a dual role for ceramide in AD. This result provides a clue to clarify sphingolipids related inflammatory and anti-inflammatory pathways in AD. PMID:26849355

  14. Network Analysis of a Comprehensive Knowledge Repository Reveals a Dual Role for Ceramide in Alzheimer's Disease.

    Directory of Open Access Journals (Sweden)

    Satoshi Mizuno

    Full Text Available Alzheimer's disease (AD is the most common cause of senile dementia. Many inflammatory factors such as amyloid-β and pro-inflammatory cytokines are known to contribute to the inflammatory response in the AD brain. Sphingolipids are widely known to have roles in the pathogenesis of inflammatory diseases, where the precise roles for sphingolipids in inflammation-associated pathogenesis of AD are not well understood. Here we performed a network analysis to clarify the importance of sphingolipids and to model relationships among inflammatory factors and sphingolipids in AD. In this study, we have updated sphingolipid signaling and metabolic cascades in a map of AD signaling networks that we named "AlzPathway," a comprehensive knowledge repository of signaling pathways in AD. Our network analysis of the updated AlzPathway indicates that the pathways related to ceramide are one of the primary pathways and that ceramide is one of the important players in the pathogenesis of AD. The results of our analysis suggest the following two prospects about inflammation in AD: (1 ceramide could play important roles in both inflammatory and anti-inflammatory pathways of AD, and (2 several factors such as Sphingomyelinase and Siglec-11 may be associated with ceramide related inflammation and anti-inflammation pathways in AD. In this study, network analysis of comprehensive knowledge repository reveals a dual role for ceramide in AD. This result provides a clue to clarify sphingolipids related inflammatory and anti-inflammatory pathways in AD.

  15. Topological Domains, Metagenes, and the Emergence of Pleiotropic Regulations at Hox Loci.

    Science.gov (United States)

    Darbellay, Fabrice; Duboule, Denis

    2016-01-01

    Hox gene clusters of jaw vertebrates display a tight genomic organization, which has no equivalent in any other bilateria genomes sequenced thus far. It was previously argued that such a topological consolidation toward a condensed, metagenic structure was due to the accumulation of long-range regulations flanking Hox loci, a phenomenon made possible by the successive genome duplications that occurred at the root of the vertebrate lineage, similar to gene neofunctionalization but applied to a coordinated multigenic system. Here, we propose that the emergence of such large vertebrate regulatory landscapes containing a range of global enhancers was greatly facilitated by the presence of topologically associating domains (TADs). These chromatin domains, mostly constitutive, may have been used as genomic niches where novel regulations could evolve due to both the preexistence of a structural backbone poised to integrate novel regulatory inputs, and a highly adaptive transcriptional readout. We propose a scenario for the coevolution of such TADs and the emergence of pleiotropy at ancestral vertebrate Hox loci. PMID:26970625

  16. Ceramide-induced TCR up-regulation

    DEFF Research Database (Denmark)

    Menné, C; Lauritsen, Jens Peter Holst; Dietrich, J;

    2000-01-01

    The TCR is a constitutively recycling receptor meaning that a constant fraction of TCR from the plasma membrane is transported inside the cell at the same time as a constant fraction of TCR from the intracellular pool is transported to the plasma membrane. TCR recycling is affected by protein...... kinase C activity. Thus, an increase in protein kinase C activity affects TCR recycling kinetics leading to a new TCR equilibrium with a reduced level of TCR expressed at the T cell surface. Down-regulation of TCR expression compromises T cell activation. Conversely, TCR up-regulation is expected...... to increase T cell responsiveness. The purpose of this study was to identify and characterize potential pathways for TCR up-regulation. We found that ceramide affected TCR recycling dynamics and induced TCR up-regulation in a concentration- and time-dependent manner. Experiments applying phosphatase...

  17. Ceramides and Cell Signaling Molecules in Psoriatic Epidermis: Reduced Levels of Ceramides, PKC-α, and JNK

    OpenAIRE

    Lew, Bark-Lynn; Cho, Yunhi; Kim, Jungmin; Sim, Woo-Young; Kim, Nack-In

    2006-01-01

    Ceramides are the main lipids in the stratum corneum and are generated during cellular stress and apoptosis by de novo synthesis or by the action of sphingomyelinase. In addition, they are lipid second messengers produced by sphingolipid metabolism and trigger important cell responses, including protein kinase C-alpha (PKC-α) activation and the stimulation of signal transduction pathways with apoptosis and stress-activated protein kinases (SAPK), such as c-jun N-terminal kinase (JNK). Thus, c...

  18. Ceramides and barrier function in healthy skin

    DEFF Research Database (Denmark)

    Jungerstedt, J; Hellgren, Lars; Drachmann, Tue;

    2010-01-01

    Lipids in the stratum corneum are key components in the barrier function of the skin. Changes in lipid composition related to eczematous diseases are well known, but limited data are available on variations within healthy skin. The objective of the present study was to compare ceramide subgroups...... and ceramide/cholesterol ratios in young, old, male and female healthy skin. A total of 55 participants with healthy skin was included in the study. Lipid profiles were correlated with transepidermal water loss and with information on dry skin from a questionnaire including 16 people. No statistically...... significant differences were found between young and old skin for ceramide subgroups or ceramide/cholesterol ratios, and there was no statistically significant correlation between answers about dry skin and ceramide levels. Interestingly, a statistically significant higher ceramide/cholesterol ratio was found...

  19. New ceramides from Acnistus arborescens

    Energy Technology Data Exchange (ETDEWEB)

    Maia, Ana Isabel V.; Veras, Maria Leopoldina; Braz-Filho, Raimundo; Silveira, Edilberto R.; Pessoa, Otilia Deusdenia L., E-mail: opessoa@ufc.b [Universidade Federal do Ceara (UFC), Fortaleza, CE (Brazil). Dept. de Quimica Organica e Inorganica; Lopes, Norberto P. [Universidade de Sao Paulo (USP), Ribeirao Preto, SP (Brazil). Faculdade de Ciencias Farmaceuticas. Dept. de Fisica e Quimica

    2010-07-01

    Two new ceramides, N-(4-hydroxyphenethyl)octacosamide (1) and rel-(2S,3S,4R,16E)-2- [(2'R)-2'-hydroxynonadecanoylamino]-heneicosadec-16-ene-1,3,4-triol (2) were isolated from the EtOH extract of Acnistus arborescens. The structures were elucidated by spectroscopic (1D and 2D NMR experiments, HR-ESI-MS, LR-MS and IR) methods. (author)

  20. Potential Mechanisms Involved in Ceramide-induced Apoptosis in Human Colon Cancer HT29 Cells

    Institute of Scientific and Technical Information of China (English)

    JING WANG; XIAO-WEN LV; YU-GUO DU

    2009-01-01

    Objective To investigate the potential mechanisms of cell death after the treatment with ceramide. Methods MTT assay,DNA ladder, reporter assay, FACS and Western blot assay were employed to investigate the potential mechanisms of cell death after the treatment with C2-ceramide. Results A short-time treatment with C2-ceramide induced cell death, which was associated with p38 MAP kinase activation, but had no links with typical caspase activation or PARP degradation. Rather than caspase inhibitor, Inhibitor of p38 MAP kinase blocked cell death induced by a short-time treatment with ceramide (12 h). Moreover, incubation of cells with ceramide for a long time (>12 h) increased subGl, but reduced S phase accompanied by caspase-dependent and caspase-independent changes including NFκB activation. Conclusion Ceramide-induced cell apoptosis involves both caspase-dependent and -independent signaling pathway. Caspase-independent cell death occurring in a relatively early stage, which is mediated via p38 MAP kinase, can progress into a stage involving both caspase-dependent and -independent mechanisms accompanied by cell signaling of MAPKs and NFκB.

  1. Enzymatic production of ceramide from sphingomyelin

    DEFF Research Database (Denmark)

    Zhang, Long; Hellgren, Lars; Xu, Xuebing

    2006-01-01

    Due to its major role in maintaining the water-retaining properties of the epidermis, ceramide is of great commercial potentials in cosmetic and pharmaceutical industries such as in hair and skin care products. Chemical synthesis of ceramide is a costly process, and developments of alternative cost...

  2. Ceramide Accumulation in Yeast Yarrowia lipolitica

    Institute of Scientific and Technical Information of China (English)

    周全; 陈国强

    2005-01-01

    Ceramides are a class of lipid molecules widely distributed in eukaryotic cells in small amount. To investigate the possibility of ceramide production by yeast, a yeast strain Yarrowia lipolitica was grown under different conditions including changing carbon/nitrogen ratio, and serine concentration, dissolved oxygen and presence of ethanol. It was found that increased dissolved oxygen supply increased the ceramide content in the yeast 2.5 fold of its normal control level. Ethanol treatment could also enhance ceramide accumulation by 3.3 fold compared with the control although the cell growth was negatively affected. Cellular redox potential was shown to affect ceramide accumulation by the yeast. This was possibly related to the cellular reactive oxygen species presented in the yeast.

  3. Short Term Palmitate Supply Impairs Intestinal Insulin Signaling via Ceramide Production.

    Science.gov (United States)

    Tran, Thi Thu Trang; Postal, Bárbara Graziela; Demignot, Sylvie; Ribeiro, Agnès; Osinski, Céline; Pais de Barros, Jean-Paul; Blachnio-Zabielska, Agnieszka; Leturque, Armelle; Rousset, Monique; Ferré, Pascal; Hajduch, Eric; Carrière, Véronique

    2016-07-29

    The worldwide prevalence of metabolic diseases is increasing, and there are global recommendations to limit consumption of certain nutrients, especially saturated lipids. Insulin resistance, a common trait occurring in obesity and type 2 diabetes, is associated with intestinal lipoprotein overproduction. However, the mechanisms by which the intestine develops insulin resistance in response to lipid overload remain unknown. Here, we show that insulin inhibits triglyceride secretion and intestinal microsomal triglyceride transfer protein expression in vivo in healthy mice force-fed monounsaturated fatty acid-rich olive oil but not in mice force-fed saturated fatty acid-rich palm oil. Moreover, when mouse intestine and human Caco-2/TC7 enterocytes were treated with the saturated fatty acid, palmitic acid, the insulin-signaling pathway was impaired. We show that palmitic acid or palm oil increases ceramide production in intestinal cells and that treatment with a ceramide analogue partially reproduces the effects of palmitic acid on insulin signaling. In Caco-2/TC7 enterocytes, ceramide effects on insulin-dependent AKT phosphorylation are mediated by protein kinase C but not by protein phosphatase 2A. Finally, inhibiting de novo ceramide synthesis improves the response of palmitic acid-treated Caco-2/TC7 enterocytes to insulin. These results demonstrate that a palmitic acid-ceramide pathway accounts for impaired intestinal insulin sensitivity, which occurs within several hours following initial lipid exposure. PMID:27255710

  4. Ceramides in Alzheimer’s Disease: Key Mediators of Neuronal Apoptosis Induced by Oxidative Stress and Aβ Accumulation

    Directory of Open Access Journals (Sweden)

    Maja Jazvinšćak Jembrek

    2015-01-01

    Full Text Available Alzheimer’s disease (AD, the most common chronic and progressive neurodegenerative disorder, is characterized by extracellular deposits of amyloid β-peptides (Aβ and intracellular deposits of hyperphosphorylated tau (phospho-tau protein. Ceramides, the major molecules of sphingolipid metabolism and lipid second messengers, have been associated with AD progression and pathology via Aβ generation. Enhanced levels of ceramides directly increase Aβ through stabilization of β-secretase, the key enzyme in the amyloidogenic processing of Aβ precursor protein (APP. As a positive feedback loop, the generated oligomeric and fibrillar Aβ induces a further increase in ceramide levels by activating sphingomyelinases that catalyze the catabolic breakdown of sphingomyelin to ceramide. Evidence also supports important role of ceramides in neuronal apoptosis. Ceramides may initiate a cascade of biochemical alterations, which ultimately leads to neuronal death by diverse mechanisms, including depolarization and permeabilization of mitochondria, increased production of reactive oxygen species (ROS, cytochrome c release, Bcl-2 depletion, and caspase-3 activation, mainly by modulating intracellular signalling, particularly along the pathways related to Akt/PKB kinase and mitogen-activated protein kinases (MAPKs. This review summarizes recent findings related to the role of ceramides in oxidative stress-driven neuronal apoptosis and interplay with Aβ in the cascade of events ending in neuronal degeneration.

  5. Structure of cholesterol/ceramide monolayer mixtures

    DEFF Research Database (Denmark)

    Scheffer, L.; Solomonov, I.; Weygand, M.J.;

    2005-01-01

    The structure of monolayers of cholesterol/ ceramide mixtures was investigated using grazing incidence x-ray diffraction, immunofluorescence, and atomic force microscopy techniques. Grazing incidence x-ray diffraction measurements showed the existence of a crystalline mixed phase of the two....... As ceramide incorporates the lipid backbone common to all sphingolipids, this arrangement may be relevant to the understanding of the molecular organization of lipid rafts....

  6. Ceramide mediates lung fibrosis in cystic fibrosis

    OpenAIRE

    Ziobro, Regan; Henry, Brian; Edwards, Michael J.; Lentsch, Alex B.; Gulbins, Erich

    2013-01-01

    Fibrosis of the lung is one of the major clinical problems of cystic fibrosis and chronic obstructive pulmonary disease. However, the molecular mechanisms leading to pulmonary fibrosis are poorly characterized and require definition. Here, we demonstrate that chronic accumulation of ceramide in the lung contributes to the development of fibrosis in aged cystic fibrosis mice. Genetic or pharmacological normalization of ceramide in cystic fibrosis mice, which was achieved by heterozygosity of a...

  7. Ceramide signalling: regulatory role in cell proliferation, differentiation and apoptosis in human epidermis.

    Science.gov (United States)

    Geilen, C C; Wieder, T; Orfanos, C E

    1997-09-01

    The stratum corneum of vertebrates is a major structural compartment that provides mechanical protection and prevents skin desiccation. The water barrier function of the stratum corneum was first reported in 1944, and this was shown later to be associated with multilayered lipid lamellae localized in the extracellular spaces. The major lipid components isolated from the cornified epidermal layers are ceramides, which belong to the class of sphingolipids, cholesterol and free fatty acids; their biosynthesis is in tight relationship with the cutaneous barrier function. In studies in which the barrier is artificially disturbed, lipid biosynthesis is found to be directly regulated by barrier permeability. As mentioned above, the ceramides involved in this process are located in the extracellular spaces of the upper epidermal layers, whereas sphingomyelin, the most common sphingolipid, is an integral part of the bilayer plasma membrane of the keratinocytes. During the last few years, however, increasing evidence has shown that sphingolipids may also take part in cell signalling, and the term 'sphingomyelin cycle' has been coined to describe this novel path-way of signal transduction. Intracellular messengers of the sphingomyelin cycle are ceramides as the products of an agonist-stimulated sphingomyelin hydrolysis. Increased levels of intracellular ceramides induce cell differentiation and/or apoptosis and reduce cell proliferation. In contrast to the extracellular barrier-forming ceramides which are complex partly O-acylated species containing long-chain fatty acids, intracellular signal-transducing ceramides are not O-acylated and have acyl chain lengths of 16 and 18 carbon atoms. We present here a review of our present knowledge on the sphingomyelin cycle as a possible signal transduction pathway in the human epidermis. We discuss the common origin of extracellular ceramides constituting the lipid barrier and of intracellular ceramides generated by agonist

  8. Role of Intracellular Lipid Logistics in the Preferential Usage of Very Long Chain-Ceramides in Glucosylceramide

    Science.gov (United States)

    Yamaji, Toshiyuki; Horie, Aya; Tachida, Yuriko; Sakuma, Chisato; Suzuki, Yusuke; Kushi, Yasunori; Hanada, Kentaro

    2016-01-01

    Ceramide is a common precursor of sphingomyelin (SM) and glycosphingolipids (GSLs) in mammalian cells. Ceramide synthase 2 (CERS2), one of the six ceramide synthase isoforms, is responsible for the synthesis of very long chain fatty acid (C20–26 fatty acids) (VLC)-containing ceramides (VLC-Cer). It is known that the proportion of VLC species in GSLs is higher than that in SM. To address the mechanism of the VLC-preference of GSLs, we used genome editing to establish three HeLa cell mutants that expressed different amounts of CERS2 and compared the acyl chain lengths of SM and GSLs by metabolic labeling experiments. VLC-sphingolipid expression was increased along with that of CERS2, and the proportion of VLC species in glucosylceramide (GlcCer) was higher than that in SM for all expression levels of CERS2. This higher proportion was still maintained even when the proportion of C16-Cer to the total ceramides was increased by disrupting the ceramide transport protein (CERT)-dependent C16-Cer delivery pathway for SM synthesis. On the other hand, merging the Golgi apparatus and the endoplasmic reticulum (ER) by Brefeldin A decreased the proportion of VLC species in GlcCer probably due to higher accessibility of UDP-glucose ceramide glucosyltransferase (UGCG) to C16-rich ceramides. These results suggest the existence of a yet-to-be-identified mechanism rendering VLC-Cer more accessible than C16-Cer to UGCG, which is independent of CERT. PMID:27775668

  9. Anti-immunoglobulin-induced apoptosis in WEHI 231 cells involves the slow formation of ceramide from sphingomyelin and is blocked by bcl-XL.

    Science.gov (United States)

    Wiesner, D A; Kilkus, J P; Gottschalk, A R; Quintáns, J; Dawson, G

    1997-04-11

    Prolonged (>24 h) exposure to anti-IgM (an antigen surrogate that induces membrane cross-linking and apoptosis) induced a 3-fold increase in the mass of endogenous ceramide measured by 32P labeling by diacylglycerol kinase and a 4-fold increase in ceramide as measured by metabolic labeling with [3H]palmitate in a B-lymphocyte cell line, WEHI 231. This correlated with the induction of apoptosis. Shorter exposure times to anti-IgM (up to 8 h) failed to elicit apoptosis and did not elicit increased ceramide formation. After 8 h, apoptosis occurs concomitantly with ceramide formation over the next 40 h. Further, we showed that exogenous ceramide mimicked anti-IgM-induced apoptosis and that apoptosis was potentiated in serum-free media. Treatment of cells with an inhibitor of ceramide catabolism, N-oleoylethanolamine, increased both ceramide formation and apoptosis and accelerated apoptosis induced by anti-IgM. To examine further how ceramide metabolism is involved in apoptosis, we derived cell lines from a small population of cells resistant to N-oleoylethanolamine. These cell lines were selected based on an altered ceramide metabolic pathway, were resistant to apoptosis induced by anti-IgM, and showed no significant increase in ceramide when challenged with anti-IgM. The basis of this resistance was shown to be the failure to activate neutral sphingomyelinase activity following 24-h treatment with anti-IgM, in contrast to the 2-fold increase in neutral sphingomyelinase activity observed in wild type cells. We have shown previously that transfection of WEHI cells with bcl-xL conferred resistance to anti-IgM-induced apoptosis, whereas transfection with bcl-2 did not (Gottschalk, A., Boise, L., Thompson, C., and Quintans, J. (1994) Proc. Natl. Acad. Sci. U. S. A. 91, 7350-7354). In this study, these bcl-xL transfectants also displayed increased resistance to exogenous N-acetylsphingosine (C2-ceramide) or N-hexanoylsphingosine (C6-ceramide). However, when challenged with

  10. T-cell receptor downregulation by ceramide-induced caspase activation and cleavage of the zeta chain

    DEFF Research Database (Denmark)

    Menné, C; Lauritsen, Jens Peter Holst; Dietrich, J;

    2001-01-01

    gamma L-based motif-dependent and the tyrosine kinase-dependent pathways. This pathway is dependent on ceramide-induced activation of caspases and correlate with caspase-mediated cleavage of the zeta chain. Thus, a 10--15% downregulation of the TCR was induced following the treatment of the T cells with...... ceramide for 4 h. A close correlation between TCR downregulation, caspase activation, and cleavage of the zeta chain was found. Furthermore, the caspase inhibitors abolished the cleavage of the zeta chain and TCR downregulation in parallel with the inhibition of the caspase activity....

  11. Enhanced de novo ceramide generation through activation of serine palmitoyltransferase by the P-glycoprotein antagonist SDZ PSC 833 in breast cancer cells.

    Science.gov (United States)

    Wang, Hongtao; Giuliano, Armando E; Cabot, Myles C

    2002-07-01

    SDZ PSC 833 (PSC 833), a P-glycoprotein-targeted multidrug resistance modulator, sensitizes cancer cells to chemotherapy. Here we show that PSC 833 also potentiates the formation of ceramide. Because ceramide is a second messenger in chemotherapy-induced apoptosis, knowledge of the lipid pathways influenced by PSC 833 is of relevance. In intact MDA-MB 468 breast cancer cells, ceramide generation increased 3-fold 1 h after PSC 833 addition (5.0 microM). Cyclosporine A, a structural analogue, failed to impact ceramide metabolism. Sphinganine, the upstream precursor of ceramide, also increased in response to PSC 833, and this could be blocked by adding L-cycloserine, a serine palmitoyltransferase (SPT) inhibitor. Exposure of cultured cells to PSC 833 (30 min to 4 h; 1-10 microM), followed by isolation of microsomes for in vitro assay, increased SPT activity 60%, whereas palmitoyl CoA synthetase and ceramide synthase activities were not altered. SPT activity was also heightened by pretreating cells with either paclitaxel, N-(4-hydroxyphenyl)retinamide, etoposide, or daunorubicin; however, activation was half that attained by PSC 833. PSC 833 stimulated ceramide generation in other breast cancer cell lines as well, including BT-20, MDA-MB 231, Hs 578T, T-47D, and MCF-7. In summary, several types of anticancer agents and the P-glycoprotein modulator PSC 833 share the ability to increase cellular ceramide levels by activation of SPT, the rate-limiting enzyme in the de novo pathway of ceramide synthesis. These data provide novel insight in the area of lipid-mediated cell death.

  12. Mechanisms involved in ceramide-induced cell cycle arrest in human hepatocarcinoma cells

    Institute of Scientific and Technical Information of China (English)

    Jing Wang; Xiao-Wen Lv; Jie-Ping Shi; Xiao-Song Hu

    2007-01-01

    AIM:To investigate the effect of ceramide on the cell cycle in human hepatocarcinoma Bel7402 cells.Possible molecular mechanisms were explored.METHODS:[3-(4,5)-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide(MTT)assay,plasmid transfection,reporter assay,FACS and Western blotting analyses were employed to investigate the effect and the related molecular mechanisms of C2-ceramide on the cell cycle of Bel7402 cells.RESULTS:C2-ceramide was found to inhibit the growth of Bel7402 cells by inducing cell cycle arrest.During the process,the expression of p21 protein increased,while that of cyclinD1,phospho-ERK1/2 and c-myc decreased.Furthermore,the level of CDK7 was downregulated,while the transcriptional activity of PPARγ was upregulated.Addition of GW9662,which is a PPARγ specific antagonist,could reserve the modulation action on CDK7.CONCLUSION:Our results support the hypothesis that cell cycle arrest induced by C2-ceramide may be mediated via accumulation of p21 and reduction of cyclinD1 and CDK7,at least partly,through PPARγ activation.The ERK signaling pathway was involved in this process.

  13. Stress-induced ceramide generation and apoptosis via the phosphorylation and activation of nSMase1 by JNK signaling.

    Science.gov (United States)

    Yabu, T; Shiba, H; Shibasaki, Y; Nakanishi, T; Imamura, S; Touhata, K; Yamashita, M

    2015-02-01

    Neutral sphingomyelinase (nSMase) activation in response to environmental stress or inflammatory cytokine stimuli generates the second messenger ceramide, which mediates the stress-induced apoptosis. However, the signaling pathways and activation mechanism underlying this process have yet to be elucidated. Here we show that the phosphorylation of nSMase1 (sphingomyelin phosphodiesterase 2, SMPD2) by c-Jun N-terminal kinase (JNK) signaling stimulates ceramide generation and apoptosis and provide evidence for a signaling mechanism that integrates stress- and cytokine-activated apoptosis in vertebrate cells. An nSMase1 was identified as a JNK substrate, and the phosphorylation site responsible for its effects on stress and cytokine induction was Ser-270. In zebrafish cells, the substitution of Ser-270 for alanine blocked the phosphorylation and activation of nSMase1, whereas the substitution of Ser-270 for negatively charged glutamic acid mimicked the effect of phosphorylation. The JNK inhibitor SP600125 blocked the phosphorylation and activation of nSMase1, which in turn blocked ceramide signaling and apoptosis. A variety of stress conditions, including heat shock, UV exposure, hydrogen peroxide treatment, and anti-Fas antibody stimulation, led to the phosphorylation of nSMase1, activated nSMase1, and induced ceramide generation and apoptosis in zebrafish embryonic ZE and human Jurkat T cells. In addition, the depletion of MAPK8/9 or SMPD2 by RNAi knockdown decreased ceramide generation and stress- and cytokine-induced apoptosis in Jurkat cells. Therefore the phosphorylation of nSMase1 is a pivotal step in JNK signaling, which leads to ceramide generation and apoptosis under stress conditions and in response to cytokine stimulation. nSMase1 has a common central role in ceramide signaling during the stress and cytokine responses and apoptosis.

  14. PKCzeta protects against UV-C-induced apoptosis by inhibiting acid sphingomyelinase-dependent ceramide production

    OpenAIRE

    Charruyer, Alexandra; Jean, Christine; Colomba, Audrey; Jaffrézou, Jean-Pierre; Quillet-Mary, Anne; Laurent, Guy; Bezombes, Christine

    2007-01-01

    Abstract In a recent study, we described that UV-C irradiation resulted in redox-dependent activation and relocalization of acid sphingomyelinase (A-SMase) to the external surface of raft membrane microdomains, hydrolysis of sphingomyelin (SM) associated to the plasma membrane outer leaflet, ceramide (CER) generation and apoptosis. In the present study, we have investigated the influence of PKC? , an atypical form of PKC on this pathway. This study shows that PKC? overexpression r...

  15. Lipid alterations in experimental murine colitis: role of ceramide and imipramine for matrix metalloproteinase-1 expression.

    Directory of Open Access Journals (Sweden)

    Jessica Bauer

    Full Text Available BACKGROUND: Dietary lipids or pharmacologic modulation of lipid metabolism are potential therapeutic strategies in inflammatory bowel disease (IBD. Therefore, we analysed alterations of bioactive lipids in experimental models of colitis and examined the functional consequence of the second messenger ceramide in inflammatory pathways leading to tissue destruction. METHODOLOGY/PRINCIPAL FINDINGS: Chronic colitis was induced by dextran-sulphate-sodium (DSS or transfer of CD4(+CD62L(+ cells into RAG1(-/--mice. Lipid content of isolated murine intestinal epithelial cells (IEC was analysed by tandem mass spectrometry. Concentrations of MMP-1 in supernatants of Caco-2-IEC and human intestinal fibroblasts from patients with ulcerative colitis were determined by ELISA. Imipramine was used for pharmacologic inhibition of acid sphingomyelinase (ASM. Ceramide increased by 71% in chronic DSS-induced colitis and by 159% in the transfer model of colitis. Lysophosphatidylcholine (LPC decreased by 22% in both models. No changes were detected for phosphatidylcholine. Generation of ceramide by exogenous SMase increased MMP-1-protein production of Caco-2-IEC up to 7-fold. Inhibition of ASM completely abolished the induction of MMP-1 by TNF or IL-1beta in Caco-2-IEC and human intestinal fibroblasts. CONCLUSIONS/SIGNIFICANCE: Mucosal inflammation leads to accumulation of ceramide and decrease of LPC in the intestinal epithelium. One aspect of ceramide generation is an increase of MMP-1. Induction of MMP-1 by TNF or IL-1beta is completely blocked by inhibition of ASM with imipramine. Therefore, inhibition of ASM may offer a treatment strategy to reduce MMP-1 expression and tissue destruction in inflammatory conditions.

  16. Ceramide synthases expression and role of ceramide synthase-2 in the lung: insight from human lung cells and mouse models.

    Directory of Open Access Journals (Sweden)

    Irina Petrache

    Full Text Available Increases in ceramide levels have been implicated in the pathogenesis of both acute or chronic lung injury models. However, the role of individual ceramide species, or of the enzymes that are responsible for their synthesis, in lung health and disease has not been clarified. We now show that C24- and C16-ceramides are the most abundant lung ceramide species, paralleled by high expression of their synthetic enzymes, ceramide synthase 2 (CerS2 and CerS5, respectively. Furthermore, the ceramide species synthesis in the lung is homeostatically regulated, since mice lacking very long acyl chain C24-ceramides due to genetic deficiency of CerS2 displayed a ten-fold increase in C16-ceramides and C16-dihydroceramides along with elevation of acid sphingomyelinase and CerS5 activities. Despite relatively preserved total lung ceramide levels, inhibition of de novo sphingolipid synthesis at the level of CerS2 was associated with significant airflow obstruction, airway inflammation, and increased lung volumes. Our results suggest that ceramide species homeostasis is crucial for lung health and that CerS2 dysfunction may predispose to inflammatory airway and airspace diseases.

  17. Anti-Plasmodium activity of ceramide analogs

    Directory of Open Access Journals (Sweden)

    Gatt Shimon

    2004-12-01

    Full Text Available Abstract Background Sphingolipids are key molecules regulating many essential functions in eukaryotic cells and ceramide plays a central role in sphingolipid metabolism. A sphingolipid metabolism occurs in the intraerythrocytic stages of Plasmodium falciparum and is associated with essential biological processes. It constitutes an attractive and potential target for the development of new antimalarial drugs. Methods The anti-Plasmodium activity of a series of ceramide analogs containing different linkages (amide, methylene or thiourea linkages between the fatty acid part of ceramide and the sphingoid core was investigated in culture and compared to the sphingolipid analog PPMP (d,1-threo-1-phenyl-2-palmitoylamino-3-morpholino-1-propanol. This analog is known to inhibit the parasite sphingomyelin synthase activity and block parasite development by preventing the formation of the tubovesicular network that extends from the parasitophorous vacuole to the red cell membrane and delivers essential extracellular nutrients to the parasite. Results Analogs containing methylene linkage showed a considerably higher anti-Plasmodium activity (IC50 in the low nanomolar range than PPMP and their counterparts with a natural amide linkage (IC50 in the micromolar range. The methylene analogs blocked irreversibly P. falciparum development leading to parasite eradication in contrast to PPMP whose effect is cytostatic. A high sensitivity of action towards the parasite was observed when compared to their effect on the human MRC-5 cell growth. The toxicity towards parasites did not correlate with the inhibition by methylene analogs of the parasite sphingomyelin synthase activity and the tubovesicular network formation, indicating that this enzyme is not their primary target. Conclusions It has been shown that ceramide analogs were potent inhibitors of P. falciparum growth in culture. Interestingly, the nature of the linkage between the fatty acid part and the

  18. Systemic ceramide accumulation leads to severe and varied pathological consequences

    OpenAIRE

    Alayoubi, Abdulfatah M; Wang, James C M; Au, Bryan C.Y.; Carpentier, Stéphane; Garcia, Virginie; Dworski, Shaalee; El-Ghamrasni, Samah; Kirouac, Kevin N.; Exertier, Mathilde J; Xiong, Zi Jian; Privé, Gilbert G.; Calogera M Simonaro; Casas, Josefina; Fabrias, Gemma; Schuchman, Edward H.

    2013-01-01

    Farber disease (FD) is a severe inherited disorder of lipid metabolism characterized by deficient lysosomal acid ceramidase (ACDase) activity, resulting in ceramide accumulation. Ceramide and metabolites have roles in cell apoptosis and proliferation. We introduced a single-nucleotide mutation identified in human FD patients into the murine Asah1 gene to generate the first model of systemic ACDase deficiency. Homozygous Asah1 P361R/P361R animals showed ACDase defects, accumulated ceramide, de...

  19. Enzymatic Production of Ceramide from Sphingomyelin

    DEFF Research Database (Denmark)

    Zhang, Long; Hellgren, Lars; Xu, Xuebing

    Ceramide is the key intermediate in the biosynthesis of all complex sphingolipids. Due to its major role in maintaining the water-retaining properties of the epidermis, ceramide is of great commercial potential in cosmetic and pharmaceuticals such as hair and skin care products. Currently, chemical...... through system evaluation and the optimization of several important factors. Sphingomyelin hydrolysis proved to be more efficient in two-phase (water: organic solvent) system than in one-phase (water-saturated organic solvent) system. Phospholipase C from Clostridium perfringens is the tested enzyme which...... has the most advantageous properties. For reusing the enzyme, the immobilization of phospholipase C and the properties of immobilized enzyme have been addressed. By screening nine different carriers, we found that the enzyme immobilized on Lewatit VP OC 1600 (Bayer AG) have the highest catalytic...

  20. Mechanisms and impact of ceramide phosphoethanolamine biosynthesis

    OpenAIRE

    Hentes Vacaru, A.M.

    2009-01-01

    Sphingolipids represent an essential class of membrane molecules in eukaryotic cells. They are primarily found in the outer leaflet of the plasma membrane where they help create a rigid and impermeable barrier to the extracellular environment. While sphingomyelin (SM) is the most abundant sphingolipid in mammals and nematodes, insects produce the SM analogue ceramide phosphoethanolamine (CPE) as a major plasma membrane constituent. Little is known about the biological role of CPE or about the...

  1. Topically applied ceramide accumulates in skin glyphs

    OpenAIRE

    Zhang Q; Flach CR; Mendelsohn R; Mao G; Pappas A; Mack MC; Walters RM; Southall MD

    2015-01-01

    Qihong Zhang,1 Carol R Flach,1 Richard Mendelsohn,1 Guangru Mao,2 Apostolos Pappas,2 M Catherine Mack,2 Russel M Walters,2 Michael D Southall2 1Department of Chemistry, Rutgers University, Newark, 2Johnson & Johnson Consumer Companies, Inc., Skillman, NJ, USAAbstract: Ceramides (CERs), structural components of the stratum corneum (SC), impart essential barrier properties to this thin outer layer of the epidermis. Variations in CER species within this layer have been linked to several ...

  2. Ceramide targets autophagosomes to mitochondria and induces lethal mitophagy

    OpenAIRE

    Sentelle, R. David; Senkal, Can E.; Jiang, Wenhui; Ponnusamy, Suriyan; Gencer, Salih; Selvam, Shanmugam Panneer; Ramshesh, Venkat K.; Peterson, Yuri K.; Lemasters, John J.; Szulc, Zdzislaw M.; Bielawski, Jacek; Ogretmen, Besim

    2012-01-01

    Mechanisms by which autophagy promotes cell survival or death are unclear. We provide evidence that C18-pyridinium ceramide (C18-Pyr-Cer) treatment, or endogenous C18-ceramide generation by ceramide synthase 1 (CerS1) expression mediates autophagic cell death, independent of apoptosis in human cancer cells. C18-ceramide-induced lethal autophagy was regulated via microtubule-associated protein 1 light chain 3 beta lipidation (LC3B-II) and selective targeting of mitochondria by LC3B-II-containi...

  3. Lipid domain morphologies in phosphatidylcholine-ceramide monolayers

    DEFF Research Database (Denmark)

    Karttunen, Mikko; Haataja, Mikko P; Säily, Matti;

    2009-01-01

    In cells, one of the main roles of ceramide-enriched membrane domains is to recruit or exclude intracellular signaling molecules and receptors, thereby facilitating signal transduction cascades. Accordingly, in model membranes, even low contents of ceramide segregate into lateral domains. The...... of fluorescent NBD-phosphatidylcholine into DMPC/Cer mixtures was found to be very sensitive to the N-acyl chain length. Shorter ceramides (Cer10-Cer14) formed flower-like (seaweed) domains, whereas longer ceramides (N-acyl chain length>14 carbon atoms) formed round and regular domains. We attribute...

  4. Ceramide induces release of mitochondrial proapoptotic proteins in caspase-dependent and -independent manner in HT-29 cells

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    In this study, the release of mitochondrial proapoptotic intermembrane space proteins induced by exogenous C2-ceramide in human colon carcinoma (HT-29) cell line was investigated. HT-29 cells were treated with 12.5, 25 and 50 μmol/L C2-ceramide in vitro. Flow cytometer was used to detect the mitochondrial membrane potential (△Ψm). Subcellular fractions were extracted by Mitochondrial/Cytosol Fractionation Kit after C2-ceramide treatment for 24 h. SDS-PAGE was used to determine the level of cytochrome c (Cyt c), high temperature requirement A2 (HtrA2) and second mitochondrial-derived activator of caspases (Smac) released from mitochondria, the expression of X-linked inhibitor of apoptosis protein (XIAP) and caspase-3 for 24 h. The results showed that △Ψm began to decrease from 6 h after 25 and 50 μmol/L C2-ceramide treatment (P<0.05) and cyclosporin A (CsA) could inhibit the collapse of △Ψm through regulating mitochondrial membrane permeability transition pore. There was no effect of C2-ceramide on the expression of Cyt c, HtrA2 and Smac in the total levels. 12.5, 25 and 50 μmol/L C2-ceramide could induce Cyt c, HtrA2 and Smac to release from mitochondria to cytosol and down-regulate the expression of XIAP (P<0.05). Also there was expression of cleaved caspase-3 with C2-ceramide treatment. After the treatment with caspase inhibitor, C2-ceramide still induced the release of Cyt c and HtrA2, but Smac did not. Therefore, C2-ceramide could induce apoptosis of HT-29 cells through the mitochondria pathway. The release of Cyt c, HtrA2 and Smac from mitochondria did not occur via the same mechanism, the release of Cyt c and HtrA2 was caspase-independent and the release of Smac was caspase-dependent.

  5. Ceramide induces release of mitochondrial proapop-totic proteins in caspase-dependent and -independent manner in HT-29 cells

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    In this study, the release of mitochondrial proapoptotic intermembrane space proteins induced by ex-ogenous C2-ceramide in human colon carcinoma (HT-29) cell line was investigated. HT-29 cells were treated with 12.5, 25 and 50 μmol/L C2-ceramide in vitro. Flow cytometer was used to detect the mito-chondrial membrane potential (ΔΨm). Subcellular fractions were extracted by Mitochondrial/Cytosol Fractionation Kit after C2-ceramide treatment for 24 h. SDS-PAGE was used to determine the level of cytochrome c (Cyt c), high temperature requirement A2 (HtrA2) and second mitochondrial-derived ac-tivator of caspases (Smac) released from mitochondria, the expression of X-linked inhibitor of apop-tosis protein (XIAP) and caspase-3 for 24 h. The results showed that ΔΨm began to decrease from 6 h after 25 and 50 μmol/L C2-ceramide treatment (P<0.05) and cyclosporin A (CsA) could inhibit the col-lapse of ΔΨm through regulating mitochondrial membrane permeability transition pore. There was no effect of C2-ceramide on the expression of Cyt c, HtrA2 and Smac in the total levels. 12.5, 25 and 50 μmol/L C2-ceramide could induce Cyt c, HtrA2 and Smac to release from mitochondria to cytosol and down-regulate the expression of XIAP (P<0.05). Also there was expression of cleaved caspase-3 with C2-ceramide treatment. After the treatment with caspase inhibitor, C2-ceramide still induced the release of Cyt c and HtrA2, but Smac did not. Therefore, C2-ceramide could induce apoptosis of HT-29 cells through the mitochondria pathway. The release of Cyt c, HtrA2 and Smac from mitochondria did not occur via the same mechanism, the release of Cyt c and HtrA2 was caspase-independent and the re-lease of Smac was caspase-dependent.

  6. A global in vivo Drosophila RNAi screen identifies a key role of ceramide phosphoethanolamine for glial ensheathment of axons.

    Directory of Open Access Journals (Sweden)

    Aniket Ghosh

    Full Text Available Glia are of vital importance for all complex nervous system. One of the many functions of glia is to insulate and provide trophic and metabolic support to axons. Here, using glial-specific RNAi knockdown in Drosophila, we silenced 6930 conserved genes in adult flies to identify essential genes and pathways. Among our screening hits, metabolic processes were highly represented, and genes involved in carbohydrate and lipid metabolic pathways appeared to be essential in glia. One critical pathway identified was de novo ceramide synthesis. Glial knockdown of lace, a subunit of the serine palmitoyltransferase associated with hereditary sensory and autonomic neuropathies in humans, resulted in ensheathment defects of peripheral nerves in Drosophila. A genetic dissection study combined with shotgun high-resolution mass spectrometry of lipids showed that levels of ceramide phosphoethanolamine are crucial for axonal ensheathment by glia. A detailed morphological and functional analysis demonstrated that the depletion of ceramide phosphoethanolamine resulted in axonal defasciculation, slowed spike propagation, and failure of wrapping glia to enwrap peripheral axons. Supplementing sphingosine into the diet rescued the neuropathy in flies. Thus, our RNAi study in Drosophila identifies a key role of ceramide phosphoethanolamine in wrapping of axons by glia.

  7. Ceramides: A potential therapeutic target in pulmonary emphysema

    NARCIS (Netherlands)

    J. Tibboel (Jeroen); I.K.M. Reiss (Irwin); J.C. de Jongste (Johan); M.R. Post (Martin)

    2013-01-01

    textabstractBackground: The aim of this manuscript was to characterize airway ceramide profiles in a rodent model of elastase-induced emphysema and to examine the effect of pharmacological intervention directed towards ceramide metabolism.Methods: Adult mice were anesthetized and treated with an int

  8. Ceramide mediates Ox-LDL-induced human vascular smooth muscle cell calcification via p38 mitogen-activated protein kinase signaling.

    Directory of Open Access Journals (Sweden)

    Lizhen Liao

    Full Text Available Vascular calcification is associated with significant cardiovascular morbidity and mortality, and has been demonstrated as an actively regulated process resembling bone formation. Oxidized low density lipoprotein (Ox-LDL has been identified as a regulatory factor involved in calcification of vascular smooth muscle cells (VSMCs. Additionally, over-expression of recombinant human neutral sphingomyelinase (N-SMase has been shown to stimulate VSMC apoptosis, which plays an important role in the progression of vascular calcification. The aim of this study is to investigate whether ceramide regulates Ox-LDL-induced calcification of VSMCs via activation of p38 mitogen-activated protein kinase (MAPK pathway. Ox-LDL increased the activity of N-SMase and the level of ceramide in cultured VSMCs. Calcification and the osteogenic transcription factor, Msx2 mRNA expression were reduced by N-SMase inhibitor, GW4869 in the presence of Ox-LDL. Usage of GW4869 inhibited Ox-LDL-induced apoptosis in VSMCs, an effect which was reversed by C2-ceramide. Additionally, C2-ceramide treatment accelerated VSMC calcification, with a concomitant increase in ALP activity. Furthermore, C2-ceramide treatment enhanced Ox-LDL-induced VSMC calcification. Addition of caspase inhibitor, ZVAD-fmk attenuated Ox-LDL-induced calcification. Both Ox-LDL and C2-ceramide treatment increased the phosphorylation of p38 MAPK. Inhibition of p38 MAPK by SB203580 attenuated Ox-LDL-induced calcification of VSMCs. These data suggest that Ox-LDL activates N-SMase-ceramide signaling pathway, and stimulates phosphorylation of p38 MAPK, leading to apoptosis in VSMCs, which initiates VSMC calcification.

  9. Quantitative Determination of Ceramide Molecular Species in Dendritic Cells

    Directory of Open Access Journals (Sweden)

    Samar Al Makdessi

    2016-09-01

    Full Text Available Background/Aims: The activation of acid sphingomyelinase by cellular stress or receptors or the de novo synthesis lead to the formation of ceramide (N-acylsphingosine, which in turn modifies the biophysical properties of cellular membrane and greatly amplifies the intensity of the initial signal. Ceramide, which acts by re-organizing a given signalosome rather than being a second messenger, has many functions in infection biology, cancer, cardiovascular syndromes, and immune regulation. Experimental studies on the infection of human cells with different bacterial agents demonstrated the activation of the acid sphingomyelinase/ceramide system. Moreover, the release of ceramide was found to be a requisite for the uptake of the pathogen. Considering the particular importance of the cellular role of ceramide, it was necessary to develop sensitive and accurate methods for its quantification. Methods: Here, we describe a method quantifying ceramide in dendritic cells and defining the different fatty acids (FA bound to sphingosine. The main steps of the method include extraction of total lipids, separation of the ceramide by thin-layer chromatography, derivatization of ceramide-fatty acids (Cer-FA, and quantitation of these acids in their methyl form by gas chromatography on polar capillary columns. The identification of FA was achieved by means of known standards and confirmed by mass spectrometry. Results: FA ranging between C10 and C24 could be detected and quantified. The concentration of the sum of Cer-FA amounted to 14.88 ± 8.98 nmol/106 cells (n=10. Oleic acid, which accounted for approximately half of Cer-FA (7.73 ± 6.52 nmol/106 cells was the predominant fatty acid followed by palmitic acid (3.47 ± 1.54 nmol/106 cells. Conclusion: This highly sensitive method allows the quantification of different molecular species of ceramides.

  10. Inhibition of sphingomyelin synthase 1 affects ceramide accumulation and hydrogen peroxide-induced apoptosis in Neuro-2a cells.

    Science.gov (United States)

    Tu, Ranran; Yang, Wei; Hu, Zhiping

    2016-09-01

    Oxidative stress plays a key role in brain injury after cerebral ischemia-reperfusion, which contributes toward excessive apoptosis of nerve cells. Therefore, it would be beneficial to identify a therapy that could interfere with the progression of apoptosis and protect the brain from ischemia-reperfusion injury. As ceramide, a well-known second messenger of apoptosis, can be metabolized by sphingomyelin synthase 1 (SMS1), recent research has focused on the link between SMS1 and apoptosis in different cells. To investigate whether SMS1 is involved in the process of oxidative stress-induced apoptosis in neurons and to explore the possible underlying mechanism, we treated mouse neuroblastoma Neuro-2A (N2a) cells with hydrogen peroxide (H2O2). Incubation with H2O2 significantly upregulated the expression of SMS1, increased the intracellular levels of ceramide and sphingomyelin synthase activity, and induced apoptosis. Moreover, pretreatment of N2a cells with D609, an sphingomyelin synthase inhibitor, or SMS1-silencing RNA (siRNA) further increased ceramide and potentiated H2O2-induced apoptosis which could be reversed by SB203580 (a p38 inhibitor). Thus, our study has shown that SMS1 regulates ceramide levels in N2a cells and plays a potent protective role in this oxidative stress-induced apoptosis partly through the p38 pathway.

  11. Endurance and Resistance Training Affect High Fat Diet-Induced Increase of Ceramides, Inflammasome Expression, and Systemic Inflammation in Mice

    Directory of Open Access Journals (Sweden)

    Cornelia Mardare

    2016-01-01

    Full Text Available The study aimed to investigate the effects of differentiated exercise regimes on high fat-induced metabolic and inflammatory pathways. Mice were fed a standard diet (ST or a high fat diet (HFD and subjected to regular endurance training (ET or resistance training (RT. After 10 weeks body weight, glucose tolerance, fatty acids (FAs, circulating ceramides, cytokines, and immunological mediators were determined. The HFD induced a significant increase in body weight and a disturbed glucose tolerance (p<0.05. An increase of plasma FA, ceramides, and inflammatory mediators in adipose tissue and serum was found (p<0.05. Both endurance and resistance training decreased body weight (p<0.05 and reduced serum ceramides (p<0.005. While RT attenuated the increase of NLRP-3 (RT expression in adipose tissue, ET was effective in reducing TNF-α and IL-18 expression. Furthermore, ET reduced levels of MIP-1γ, while RT decreased levels of IL-18, MIP-1γ, Timp-1, and CD40 in serum (p<0.001, respectively. Although both exercise regimes improved glucose tolerance (p<0.001, ET was more effective than RT. These results suggest that exercise improves HFD-induced complications possibly through a reduction of ceramides, the reduction of inflammasome activation in adipose tissues, and a systemic downregulation of inflammatory cytokines.

  12. Cholesterol interactions with ceramide and sphingomyelin.

    Science.gov (United States)

    García-Arribas, Aritz B; Alonso, Alicia; Goñi, Felix M

    2016-09-01

    Sphingolipids contain in their polar heads chemical groups allowing them to establish a complex network of H-bonds (through different OH and NHgroups) with other lipids in the bilayer. In the recent years the specific interaction of sphingomyelin (SM) with cholesterol (Chol) has been examined, largely in the context of the "lipid raft" hypothesis. Formation of SM-Ceramide (Cer) complexes, proposed to exist in cell membranes in response to stress, has also been described. More recently, a delicate balance of phase formation and transformation in ternary mixtures of SM, Chol and Cer, with mutual displacement of Chol and Cer from their interaction with SM is considered to exist. In addition, data demonstrating direct Chol-Cer interaction are becoming available. PMID:27132117

  13. Reduced ceramide synthase 2 activity causes progressive myoclonic epilepsy

    DEFF Research Database (Denmark)

    Mosbech, Mai-Britt; Olsen, Anne S B; Neess, Ditte;

    2014-01-01

    OBJECTIVE: Ceramides are precursors of complex sphingolipids (SLs), which are important for normal functioning of both the developing and mature brain. Altered SL levels have been associated with many neurodegenerative disorders, including epilepsy, although few direct links have been identified...

  14. LCL124, a Cationic Analog of Ceramide, Selectively Induces Pancreatic Cancer Cell Death by Accumulating in Mitochondria

    OpenAIRE

    Beckham, Thomas H; Lu, Ping; Jones, Elizabeth E.; Marrison, Tucker; Lewis, Clayton S.; Cheng, Joseph C.; Ramshesh, Venkat K.; Beeson, Gyda; Beeson, Craig C.; Richard R. Drake; Bielawska, Alicja; Bielawski, Jacek; Szulc, Zdzislaw M; Ogretmen, Besim; Norris, James S.

    2013-01-01

    Treatment of pancreatic cancer that cannot be surgically resected currently relies on minimally beneficial cytotoxic chemotherapy with gemcitabine. As the fourth leading cause of cancer-related death in the United States with dismal survival statistics, pancreatic cancer demands new and more effective treatment approaches. Resistance to gemcitabine is nearly universal and appears to involve defects in the intrinsic/mitochondrial apoptotic pathway. The bioactive sphingolipid ceramide is a crit...

  15. Ceramide Production Mediates Aldosterone-Induced Human Umbilical Vein Endothelial Cell (HUVEC Damages.

    Directory of Open Access Journals (Sweden)

    Yumei Zhang

    Full Text Available Here, we studied the underlying mechanism of aldosterone (Aldo-induced vascular endothelial cell damages by focusing on ceramide. We confirmed that Aldo (at nmol/L inhibited human umbilical vein endothelial cells (HUVEC survival, and induced considerable cell apoptosis. We propose that ceramide (mainly C18 production might be responsible for Aldo-mediated damages in HUVECs. Sphingosine-1-phosphate (S1P, an anti-ceramide lipid, attenuated Aldo-induced ceramide production and following HUVEC damages. On the other hand, the glucosylceramide synthase (GCS inhibitor PDMP or the ceramide (C6 potentiated Aldo-induced HUVEC apoptosis. Eplerenone, a mineralocorticoid receptor (MR antagonist, almost completely blocked Aldo-induced C18 ceramide production and HUVEC damages. Molecularly, ceramide synthase 1 (CerS-1 is required for C18 ceramide production by Aldo. Knockdown of CerS-1 by targeted-shRNA inhibited Aldo-induced C18 ceramide production, and protected HUVECs from Aldo. Reversely, CerS-1 overexpression facilitated Aldo-induced C18 ceramide production, and potentiated HUVEC damages. Together, these results suggest that C18 ceramide production mediates Aldo-mediated HUVEC damages. MR and CerS-1 could be the two signaling molecule regulating C18 ceramide production by Aldo.

  16. Molecular dynamics modelling of EGCG clusters on ceramide bilayers

    Energy Technology Data Exchange (ETDEWEB)

    Yeo, Jingjie; Cheng, Yuan; Li, Weifeng; Zhang, Yong-Wei [Institute of High Performance Computing, A*STAR, 138632 (Singapore)

    2015-12-31

    A novel method of atomistic modelling and characterization of both pure ceramide and mixed lipid bilayers is being developed, using only the General Amber ForceField. Lipid bilayers modelled as pure ceramides adopt hexagonal packing after equilibration, and the area per lipid and bilayer thickness are consistent with previously reported theoretical results. Mixed lipid bilayers are modelled as a combination of ceramides, cholesterol, and free fatty acids. This model is shown to be stable after equilibration. Green tea extract, also known as epigallocatechin-3-gallate, is introduced as a spherical cluster on the surface of the mixed lipid bilayer. It is demonstrated that the cluster is able to bind to the bilayers as a cluster without diffusing into the surrounding water.

  17. Topically applied ceramide accumulates in skin glyphs

    Directory of Open Access Journals (Sweden)

    Zhang Q

    2015-07-01

    Full Text Available Qihong Zhang,1 Carol R Flach,1 Richard Mendelsohn,1 Guangru Mao,2 Apostolos Pappas,2 M Catherine Mack,2 Russel M Walters,2 Michael D Southall2 1Department of Chemistry, Rutgers University, Newark, 2Johnson & Johnson Consumer Companies, Inc., Skillman, NJ, USAAbstract: Ceramides (CERs, structural components of the stratum corneum (SC, impart essential barrier properties to this thin outer layer of the epidermis. Variations in CER species within this layer have been linked to several skin diseases. A recent proliferation of CER-containing topical skin-care products warrants the elucidation of CER penetration profiles in both healthy and diseased skin. In the current study, the spatial distributions of CER concentration profiles, following topical application of two species of CER, were tracked using infrared imaging. Suspensions of single-chain perdeuterated sphingosine and phytosphingosine CER in oleic acid were applied, in separate experiments, to the surface of healthy intact ex vivo human skin using Franz diffusion cells. Following either a 24- or 48-hour incubation period at 34°C, infrared images were acquired from microtomed skin sections. Both CER species accumulated in glyph regions of the skin and penetrated into the SC, to a limited extent, only in these regions. The concentration profiles observed herein were independent of the CER species and incubation time utilized in the study. As a result, a very heterogeneous, sparse, spatial distribution of CERs in the SC was revealed. In contrast, oleic acid was found to be fairly homogeneously distributed throughout the SC and viable epidermis, albeit at lower concentrations in the latter. A more uniform, lateral distribution of CERs in the SC would likely be important for barrier efficacy or enhancement.Keywords: stratum corneum, infrared imaging, topical delivery, oleic acid

  18. Intrinsic, pro-apoptotic effects of IGFBP-3 on breast cancer cells are reversible: Involvement of PKA, Rho and ceramide.

    Directory of Open Access Journals (Sweden)

    Claire M Perks

    2011-05-01

    Full Text Available We established previously that IGFBP-3 could exert positive or negative effects on cell function depending upon the extracellular matrix composition and by interacting with integrin signalling. To elicit its pro-apoptotic effects IGFBP-3 bound to caveolin-1 and the beta 1 integrin receptor and increased their association culminating in MAPK activation. Disruption of these complexes or blocking the beta 1 integrin receptor reversed these intrinsic actions of IGFBP-3. In this study we have examined the signalling pathway between integrin receptor binding and MAPK activation that mediates the intrinsic, pro-apoptotic actions of IGFBP-3. We found on inhibiting protein kinase A(PKA, Rho associated kinase (ROCK and ceramide, the accentuating effects of IGFBP-3 on apoptotic triggers were reversed, such that IGFBP-3 then conferred cell survival. We established that IGFBP-3 activated Rho, the upstream regulator of ROCK and that beta1 integrin and PKA were upstream of Rho activation, whereas the involvement of ceramide was downstream. The beta 1 integrin, PKA, Rho and ceramide were all upstream of MAPK activation. These data highlight key components involved in the pro-apoptotic effects of IGFBP-3 and that inhibiting them leads to a reversal in the action of IGFBP-3.

  19. Ceramide Synthase 5 Is Essential to Maintain C16:0-Ceramide Pools and Contributes to the Development of Diet-induced Obesity.

    Science.gov (United States)

    Gosejacob, Dominic; Jäger, Philipp S; Vom Dorp, Katharina; Frejno, Martin; Carstensen, Anne C; Köhnke, Monika; Degen, Joachim; Dörmann, Peter; Hoch, Michael

    2016-03-25

    Ceramides are bioactive sphingolipids, which are composed of sphingoid bases carrying acyl chains of various lengths. Ceramides are synthesized by a family of six ceramide synthases (CerS) in mammals, which produce ceramides with differentN-linked acyl chains. Increased ceramide levels are known to contribute to the development of obesity and insulin resistance. Recently, it has been demonstrated that the ceramide acylation pattern is of particular importance for an organism to maintain energy homeostasis. However, which of theCerSfamily members are involved in this process is not yet completely known. Using newly developedCerS5knock-out mice, we show here thatCerS5is essential to maintain cellular C16:0sphingolipid pools in lung, spleen, muscle, liver, and white adipose tissue. Glycerophospholipid levels inCerS5-deficient mice were not altered. We found a strong impact of CerS5-dependent ceramide synthesis in white adipose tissue after high fat diet feeding. In skeletal muscle, liver, and spleen, C16:0-ceramide levels were altered independent of feeding conditions. The loss ofCerS5is associated with reduced weight gain and improved systemic health, including maintenance of glucose homeostasis and reduced white adipose tissue inflammation after high fat diet challenge. Our findings indicate that reduction of endogenous C16:0-ceramide by genetic inhibition ofCerS5is sufficient to ameliorate obesity and its comorbidities.

  20. Kinetic study of sphingomyelin hydrolysis for ceramide production

    DEFF Research Database (Denmark)

    Zhang, Long; Hellgren, Lars; Xu, Xuebing

    2008-01-01

    in cosmetic and pharmaceutical industries such as in hair and skin care products. The enzymatic hydrolysis of sphingomyelin has been proved to be a feasible method to produce ceramide. The kinetic performance of sphingomyelin hydrolysis in the optimal two-phase (water:organic solvent) reaction system...

  1. Regulation of Ceramide Synthase-Mediated Crypt Epithelium Apoptosis by DNA Damage Repair Enzymes

    Science.gov (United States)

    Rotolo, Jimmy A.; Mesicek, Judith; Maj, Jerzy; Truman, Jean-Philip; Haimovitz-Friedman, Adriana; Kolesnick, Richard; Fuks, Zvi

    2015-01-01

    Acute endothelial cell apoptosis and microvascular compromise couple GI tract irradiation to reproductive death of intestinal crypt stem cell clonogens (SCCs) following high-dose radiation. Genetic or pharmacologic inhibition of endothelial apoptosis prevents intestinal damage, but as the radiation dose is escalated, SCCs become directly susceptible to an alternate cell death mechanism, mediated via ceramide synthase (CS)-stimulated de novo synthesis of the pro-apoptotic sphingolipid ceramide, and p53-independent apoptosis of crypt SCCs. We previously reported that ATM deficiency resets the primary radiation lethal pathway, allowing CS-mediated apoptosis at the low-dose range of radiation. The mechanism for this event, termed target reordering, remains unknown. Here we show that inactivation of DNA damage repair pathways signal CS-mediated apoptosis in crypt SCCs, presumably via persistent unrepaired DNA double strand breaks (DSBs). Genetic loss-of-function of sensors and transducers of DNA DSB repair confers the CS-mediated lethal pathway in intestines of sv129/B6Mre11ATLD1/ATLD1 and C57BL/6Prkdc/SCID (SCID) mice exposed to low-dose radiation. In contrast, CS-mediated SCC lethality was mitigated in irradiated gain-of-function Rad50S/S mice, and epistasis studies order Rad50 upstream of Mre11. These studies suggest unrepaired DNA DSBs as causative in target re-ordering in intestinal SCCs. As such, we provide an in vivo model of DNA damage repair that is standardized, can be exploited to understand allele-specific regulation in intact tissue, and is pharmacologically tractable. PMID:20086180

  2. Differential protection by wildtype vs. organelle-specific Bcl-2 suggests a combined requirement of both the ER and mitochondria in ceramide-mediated caspase-independent programmed cell death

    Directory of Open Access Journals (Sweden)

    Belka Claus

    2009-10-01

    Full Text Available Abstract Background Programmed cell death (PCD is essential for development and homeostasis of multicellular organisms and can occur by caspase-dependent apoptosis or alternatively, by caspase-independent PCD (ciPCD. Bcl-2, a central regulator of apoptosis, localizes to both mitochondria and the endoplasmic reticulum (ER. Whereas a function of mitochondrial and ER-specific Bcl-2 in apoptosis has been established in multiple studies, corresponding data for ciPCD do not exist. Methods We utilized Bcl-2 constructs specifically localizing to mitochondria (Bcl-2 ActA, the ER (Bcl-2 cb5, both (Bcl-2 WT or the cytosol/nucleus (Bcl-2 ΔTM and determined their protective effect on ceramide-mediated ciPCD in transiently and stably transfected Jurkat cells. Expression of the constructs was verified by immunoblots. Ceramide-mediated ciPCD was induced by treatment with human recombinant tumor necrosis factor and determined by flow cytometric measurement of propidium iodide uptake as well as by optical analysis of cell morphology. Results Only wildtype Bcl-2 had the ability to efficiently protect from ceramide-mediated ciPCD, whereas expression of Bcl-2 solely at mitochondria, the ER, or the cytosol/nucleus did not prevent ceramide-mediated ciPCD. Conclusion Our data suggest a combined requirement for both mitochondria and the ER in the induction and the signaling pathways of ciPCD mediated by ceramide.

  3. Differential protection by wildtype vs. organelle-specific Bcl-2 suggests a combined requirement of both the ER and mitochondria in ceramide-mediated caspase-independent programmed cell death

    International Nuclear Information System (INIS)

    Programmed cell death (PCD) is essential for development and homeostasis of multicellular organisms and can occur by caspase-dependent apoptosis or alternatively, by caspase-independent PCD (ciPCD). Bcl-2, a central regulator of apoptosis, localizes to both mitochondria and the endoplasmic reticulum (ER). Whereas a function of mitochondrial and ER-specific Bcl-2 in apoptosis has been established in multiple studies, corresponding data for ciPCD do not exist. We utilized Bcl-2 constructs specifically localizing to mitochondria (Bcl-2 ActA), the ER (Bcl-2 cb5), both (Bcl-2 WT) or the cytosol/nucleus (Bcl-2 ΔTM) and determined their protective effect on ceramide-mediated ciPCD in transiently and stably transfected Jurkat cells. Expression of the constructs was verified by immunoblots. Ceramide-mediated ciPCD was induced by treatment with human recombinant tumor necrosis factor and determined by flow cytometric measurement of propidium iodide uptake as well as by optical analysis of cell morphology. Only wildtype Bcl-2 had the ability to efficiently protect from ceramide-mediated ciPCD, whereas expression of Bcl-2 solely at mitochondria, the ER, or the cytosol/nucleus did not prevent ceramide-mediated ciPCD. Our data suggest a combined requirement for both mitochondria and the ER in the induction and the signaling pathways of ciPCD mediated by ceramide

  4. The role of MAPK signalling pathways in acetic acid-induced cell death of Saccharomyces cerevisiae

    OpenAIRE

    Azevedo, Flávio Humberto Torres Dias Feio de

    2011-01-01

    Dissertação de mestrado em Genética Molecular Mitogenic Activated Protein Kinase (MAPK) cascades are important signalling pathways that allow yeast cells to swiftly adapt to changing environmental conditions. Previous studies suggested that the High Osmolarity Glycerol (HOG) MAPK pathway and ceramide production are involved in acetic-acid induced apoptosis in yeast. Evidence that changes in the levels of endogenous ceramides can affect yeast cell fate has also been put forth...

  5. Moisturizers and Ceramide-containing Moisturizers May Offer Concomitant Therapy with Benefits

    OpenAIRE

    Lynde, Chuck W.; Andriessen, Anneke; Barankin, Benjamin; de Gannes, Gillian; Gulliver, Wayne; Haber, Richard; Mccuaig, Catherine; Rajan, Poonam; Skotnicki, Sandra P.; Thomas, Richard; Toole, Jack; Vender, Ron

    2014-01-01

    Introduction: Ceramide-containing moisturizers may offer benefits as an adjunct to acne treatment. Methods: An expert panel of 11 Canadian dermatologists, including an international clinical scientist, used the following modified Delphi process: 1) A systematic literature review for acne treatment, dry skin, irritation, depletion of ceramides in acne, and benefits of moisturizers and ceramide-containing moisturizers was conducted; 2) panel members gave their opinion on the resulting statement...

  6. All members in the sphingomyelin synthase gene family have ceramide phosphoethanolamine synthase activity[S

    OpenAIRE

    Ding, Tingbo; Kabir, Inamul; Li, Yue; Lou, Caixia; Yazdanyar, Amirfarbod; Xu, Jiachen; Dong, Jibin; Zhou, Hongwen; Park, Taesik; Boutjdir, Mohamed; Li, Zhiqiang; Jiang, Xian-Cheng

    2015-01-01

    Sphingomyelin synthase-related protein (SMSr) synthesizes the sphingomyelin analog ceramide phosphoethanolamine (CPE) in cells. Previous cell studies indicated that SMSr is involved in ceramide homeostasis and is crucial for cell function. To further examine SMSr function in vivo, we generated Smsr KO mice that were fertile and had no obvious phenotypic alterations. Quantitative MS analyses of plasma, liver, and macrophages from the KO mice revealed only marginal changes in CPE and ceramide a...

  7. An Inverse Relationship Between Ceramide Synthesis and Clinical Severity in Patients with Psoriasis

    OpenAIRE

    Cho, Yunhi; Lew, Bark-Lynn; Seong, Kyunghwa; Kim, Nack-In

    2004-01-01

    Ceramides play major roles in maintaining the epidermal barrier. It has been sus-pected that the depletion of ceramides, associated with disrupted barrier function in the epidermis, leads to the clinical manifestation of dryness and inflammation seen in patients with psoriasis. The aim of the present study was to determine the relation-ship between the level of ceramide synthesis in the epidermis and the clinical severity in patients with psoriasis. Samples from lesional and unlesional epider...

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

    Science.gov (United States)

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

    2016-07-01

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

  9. Effect of monoglycerides and fatty acids on a ceramide bilayer

    OpenAIRE

    Akinshina, Anna; Das, Chinmay; Noro, Massimo G.

    2016-01-01

    Monoglycerides and unsaturated fatty acids, naturally present in trace amounts in the stratum corneum (top layer of skin) lipid matrix, are commonly used in pharmaceutical, cosmetic and health care formulations. However, a detailed molecular understanding of how the oil additives get incorporated into the skin lipids from topical application and, once incorporated, how they affect the properties and integrity of the lipid matrix remains unexplored. Using ceramide 2 bilayers as skin lipid surr...

  10. Solenopsin A and analogs exhibit ceramide-like biological activity

    OpenAIRE

    Karlsson, Isabella; Zhou, Xin; Thomas, Raquela; Smith, Allorie T; Bonner, Michael Y.; Bakshi, Pooja; Banga, Ajay K.; Bowen, J. Phillip; Qabaja, Ghassan; Ford, Shavon L; Ballard, Matthew D; Petersen, Kimberly S.; Li, Xuechen; Chen, Guangping; Ogretmen, Besim

    2015-01-01

    Background (−)-Solenopsin A is a piperidine alkaloid that is a component of the venom of the fire ant Solenopsis invicta. Previously, we have demonstrated that solenopsin exhibit anti-angiogenic activity and downregulate phosphoinositol-3 kinase (PI3K) in the p53 deficient renal cell carcinoma cell line 786-O. Solenopsin has structural similarities to ceramide, a major endogenous regulator of cell signaling and cancer therapy induced apoptosis. Methods Different analogs of solenopsin were syn...

  11. Treating atopic dermatitis: safety, efficacy, and patient acceptability of a ceramide hyaluronic acid emollient foam

    Directory of Open Access Journals (Sweden)

    Pacha O

    2012-05-01

    Full Text Available Omar Pacha, Adelaide A HebertDepartment of Dermatology, University of Texas Health Science Center, Houston, TX, USAAbstract: Advances in current understanding of the pathophysiology of atopic dermatitis have led to improved targeting of the structural deficiencies in atopic skin. Ceramide deficiency appears to be one of the major alterations in atopic dermatitis and the replenishment of this epidermal component through topically applied ceramide based emollients appears to be safe, well tolerated, and effective. Recently a ceramide hyaluronic acid foam has become commercially available and increasing evidence supports its safety and efficacy in patients who suffer from atopic dermatitis.Keywords: atopic dermatitis, ceramide, Hylatopic, eczema, non-steroidal, dermatology

  12. Sphingomyelinase D/Ceramide 1-Phosphate in Cell Survival and Inflammation

    Directory of Open Access Journals (Sweden)

    Io-Guané Rivera

    2015-04-01

    Full Text Available Sphingolipids are major constituents of biological membranes of eukaryotic cells. Many studies have shown that sphingomyelin (SM is a major phospholipid in cell bilayers and is mainly localized to the plasma membrane of cells, where it serves both as a building block for cell architecture and as a precursor of bioactive sphingolipids. In particular, upregulation of (C-type sphingomyelinases will produce ceramide, which regulates many physiological functions including apoptosis, senescence, or cell differentiation. Interestingly, the venom of some arthropodes including spiders of the genus Loxosceles, or the toxins of some bacteria such as Corynebacterium tuberculosis, or Vibrio damsela possess high levels of D-type sphingomyelinase (SMase D. This enzyme catalyzes the hydrolysis of SM to yield ceramide 1-phosphate (C1P, which promotes cell growth and survival and is a potent pro-inflammatory agent in different cell types. In particular, C1P stimulates cytosolic phospholipase A2 leading to arachidonic acid release and the subsequent formation of eicosanoids, actions that are all associated to the promotion of inflammation. In addition, C1P potently stimulates macrophage migration, which has also been associated to inflammatory responses. Interestingly, this action required the interaction of C1P with a specific plasma membrane receptor, whereas accumulation of intracellular C1P failed to stimulate chemotaxis. The C1P receptor is coupled to Gi proteins and activates of the PI3K/Akt and MEK/ERK1-2 pathways upon ligation with C1P. The proposed review will address novel aspects on the control of inflammatory responses by C1P and will highlight the molecular mechanisms whereby C1P exerts these actions.

  13. Sphingolipid and Ceramide Homeostasis: Potential Therapeutic Targets

    Directory of Open Access Journals (Sweden)

    Simon A. Young

    2012-01-01

    Full Text Available Sphingolipids are ubiquitous in eukaryotic cells where they have been attributed a plethora of functions from the formation of structural domains to polarized cellular trafficking and signal transduction. Recent research has identified and characterised many of the key enzymes involved in sphingolipid metabolism and this has led to a heightened interest in the possibility of targeting these processes for therapies against cancers, Alzheimer's disease, and numerous important human pathogens. In this paper we outline the major pathways in eukaryotic sphingolipid metabolism and discuss these in relation to disease and therapy for both chronic and infectious conditions.

  14. The impact of ultraviolet therapy on stratum corneum ceramides and barrier function

    DEFF Research Database (Denmark)

    Jungersted, Jakob Mutanu; Høgh, Julie Kaae; Hellgren, Lars;

    2011-01-01

    The ceramide profile as well as the barrier function is known to be deteriorated in atopic eczema and psoriasis, and ultraviolet (UV) light is known to improve the barrier function. The impact of UV light on ceramides, however, is not clarified.The aim of this study was to examine the effect of UV...

  15. Human skeletal muscle ceramide content is not a major factor in muscle insulin sensitivity

    DEFF Research Database (Denmark)

    Skovbro, M; Baranowski, M; Skov-Jensen, C;

    2008-01-01

    AIMS/HYPOTHESIS: In skeletal muscle, ceramides may be involved in the pathogenesis of insulin resistance through an attenuation of insulin signalling. This study investigated total skeletal muscle ceramide fatty acid content in participants exhibiting a wide range of insulin sensitivities. METHODS...

  16. Producing human ceramide-NS by metabolic engineering using yeast Saccharomyces cerevisiae.

    Science.gov (United States)

    Murakami, Suguru; Shimamoto, Toshi; Nagano, Hideaki; Tsuruno, Masahiro; Okuhara, Hiroaki; Hatanaka, Haruyo; Tojo, Hiromasa; Kodama, Yukiko; Funato, Kouichi

    2015-01-01

    Ceramide is one of the most important intercellular components responsible for the barrier and moisture retention functions of the skin. Because of the risks involved with using products of animal origin and the low productivity of plants, the availability of ceramides is currently limited. In this study, we successfully developed a system that produces sphingosine-containing human ceramide-NS in the yeast Saccharomyces cerevisiae by eliminating the genes for yeast sphingolipid hydroxylases (encoded by SUR2 and SCS7) and introducing the gene for a human sphingolipid desaturase (encoded by DES1). The inactivation of the ceramidase gene YDC1, overexpression of the inositol phosphosphingolipid phospholipase C gene ISC1, and endoplasmic reticulum localization of the DES1 gene product resulted in enhanced production of ceramide-NS. The engineered yeast strains can serve as hosts not only for providing a sustainable source of ceramide-NS but also for developing further systems to produce sphingosine-containing sphingolipids.

  17. Influence of cholesterol and ceramide VI on the structure of multilamellar lipid membranes at water exchange

    International Nuclear Information System (INIS)

    The structural changes in the multilamellar lipid membranes of dipalmitoylphosphatidylcholine (DPPC)/cholesterol and DPPC/ceramide VI binary systems during hydration and dehydration have been studied by neutron diffraction. The effect of cholesterol and ceramide on the kinetics of water exchange in DPPC membranes is characterized. Compared to pure DPPC, membranes of binary systems swell faster during hydration (with a characteristic time of ∼30 min). Both compounds, ceramide VI and cholesterol, similarly affect the hydration of DPPC membranes, increasing the repeat distance due to the bilayer growth. However, in contrast to cholesterol, ceramide significantly reduces the thickness of the membrane water layer. The introduction of cholesterol into a DPPC membrane slows down the change in the parameters of the bilayer internal structure during dehydration. In the DPPC/ceramide VI/cholesterol ternary system (with a molar cholesterol concentration of 40%), cholesterol is partially released from the lamellar membrane structure into the crystalline phase.

  18. Disruption of sphingolipid metabolism augments ceramide-induced autophagy in preeclampsia.

    Science.gov (United States)

    Melland-Smith, Megan; Ermini, Leonardo; Chauvin, Sarah; Craig-Barnes, Hayley; Tagliaferro, Andrea; Todros, Tullia; Post, Martin; Caniggia, Isabella

    2015-04-01

    Bioactive sphingolipids including ceramides are involved in a variety of pathophysiological processes by regulating cell death and survival. The objective of the current study was to examine ceramide metabolism in preeclampsia, a serious disorder of pregnancy characterized by oxidative stress, and increased trophoblast cell death and autophagy. Maternal circulating and placental ceramide levels quantified by tandem mass spectrometry were elevated in pregnancies complicated by preeclampsia. Placental ceramides were elevated due to greater de novo synthesis via high serine palmitoyltransferase activity and reduced lysosomal breakdown via diminished ASAH1 expression caused by TGFB3-induced E2F4 transcriptional repression. SMPD1 activity was reduced; hence, sphingomyelin degradation by SMPD1 did not contribute to elevated ceramide levels in preeclampsia. Oxidative stress triggered similar changes in ceramide levels and acid hydrolase expression in villous explants and trophoblast cells. MALDI-imaging mass spectrometry localized the ceramide increases to the trophophoblast layers and syncytial knots of placentae from pregnancies complicated by preeclampsia. ASAH1 inhibition or ceramide treatment induced autophagy in human trophoblast cells via a shift of the BOK-MCL1 rheostat toward prodeath BOK. Pharmacological inhibition of ASAH1 activity in pregnant mice resulted in increased placental ceramide content, abnormal placentation, reduced fetal growth, and increased autophagy via a similar shift in the BOK-MCL1 system. Our results reveal that oxidative stress-induced reduction of lysosomal hydrolase activities in combination with elevated de novo synthesis leads to ceramide overload, resulting in increased trophoblast cell autophagy, and typifies preeclampsia as a sphingolipid storage disorder.

  19. Myristic acid potentiates palmitic acid-induced lipotoxicity and steatohepatitis associated with lipodystrophy by sustaning de novo ceramide synthesis.

    Science.gov (United States)

    Martínez, Laura; Torres, Sandra; Baulies, Anna; Alarcón-Vila, Cristina; Elena, Montserrat; Fabriàs, Gemma; Casas, Josefina; Caballeria, Joan; Fernandez-Checa, Jose C; García-Ruiz, Carmen

    2015-12-01

    Palmitic acid (PA) induces hepatocyte apoptosis and fuels de novo ceramide synthesis in the endoplasmic reticulum (ER). Myristic acid (MA), a free fatty acid highly abundant in copra/palmist oils, is a predictor of nonalcoholic steatohepatitis (NASH) and stimulates ceramide synthesis. Here we investigated the synergism between MA and PA in ceramide synthesis, ER stress, lipotoxicity and NASH. Unlike PA, MA is not lipotoxic but potentiated PA-mediated lipoapoptosis, ER stress, caspase-3 activation and cytochrome c release in primary mouse hepatocytes (PMH). Moreover, MA kinetically sustained PA-induced total ceramide content by stimulating dehydroceramide desaturase and switched the ceramide profile from decreased to increased ceramide 14:0/ceramide16:0, without changing medium and long-chain ceramide species. PMH were more sensitive to equimolar ceramide14:0/ceramide16:0 exposure, which mimics the outcome of PA plus MA treatment on ceramide homeostasis, than to either ceramide alone. Treatment with myriocin to inhibit ceramide synthesis and tauroursodeoxycholic acid to prevent ER stress ameliorated PA plus MA induced apoptosis, similar to the protection afforded by the antioxidant BHA, the pan-caspase inhibitor z-VAD-Fmk and JNK inhibition. Moreover, ruthenium red protected PMH against PA and MA-induced cell death. Recapitulating in vitro findings, mice fed a diet enriched in PA plus MA exhibited lipodystrophy, hepatosplenomegaly, increased liver ceramide content and cholesterol levels, ER stress, liver damage, inflammation and fibrosis compared to mice fed diets enriched in PA or MA alone. The deleterious effects of PA plus MA-enriched diet were largely prevented by in vivo myriocin treatment. These findings indicate a causal link between ceramide synthesis and ER stress in lipotoxicity, and imply that the consumption of diets enriched in MA and PA can cause NASH associated with lipodystrophy.

  20. Ultraviolet (UV and Hydrogen Peroxide Activate Ceramide-ER Stress-AMPK Signaling Axis to Promote Retinal Pigment Epithelium (RPE Cell Apoptosis

    Directory of Open Access Journals (Sweden)

    Jin Yao

    2013-05-01

    Full Text Available Ultraviolet (UV radiation and reactive oxygen species (ROS impair the physiological functions of retinal pigment epithelium (RPE cells by inducing cell apoptosis, which is the main cause of age-related macular degeneration (AMD. The mechanism by which UV/ROS induces RPE cell death is not fully addressed. Here, we observed the activation of a ceramide-endoplasmic reticulum (ER stress-AMP activated protein kinase (AMPK signaling axis in UV and hydrogen peroxide (H2O2-treated RPE cells. UV and H2O2 induced an early ceramide production, profound ER stress and AMPK activation. Pharmacological inhibitors against ER stress (salubrinal, ceramide production (fumonisin B1 and AMPK activation (compound C suppressed UV- and H2O2-induced RPE cell apoptosis. Conversely, cell permeable short-chain C6 ceramide and AMPK activator AICAR (5-amino-1-β-D-ribofuranosyl-imidazole-4-carboxamide mimicked UV and H2O2’s effects and promoted RPE cell apoptosis. Together, these results suggest that UV/H2O2 activates the ceramide-ER stress-AMPK signaling axis to promote RPE cell apoptosis.

  1. Separation and Detection of Ceramides by HPLC Followed by Evaporative Light-Scattering Detection and Thin Layer Chromatography

    Institute of Scientific and Technical Information of China (English)

    张琳; 周全; 傅学奇; 陈国强

    2002-01-01

    Ceramides are important signaling molecules involved in a variety of cellular processes, including cell growth, differentiation, and apoptosis. Currently, different methods are used for ceramide analysis, some of which are insensitive or cumbersome. This paper described methods utilizing thin layer chromatography (TLC) and high-performance liquid chromatography (HPLC) followed by evaporative light scattering detection (ELSD) to detect ceramide directly in cell extracts without derivatization, which was proved to be efficient and reproducible. Five kinds of ceramides were used as standards. Both TLC and normal-phase HPLC/ELSD results indicate that yeast contains several kinds of ceramides.

  2. Regulation of Neuronal Stem Cell Proliferation in the Hippocampus by Endothelial Ceramide

    Directory of Open Access Journals (Sweden)

    Anne Gulbins

    2016-08-01

    Full Text Available Background/Aims: Major depressive disorder is one of the most common diseases in western countries. The disease is mainly defined by its psychiatric symptoms. However, the disease has also many symptoms outside the central nervous system, in particular cardiovascular symptoms. Recent studies demonstrated that the acid sphingomyelinase/ceramide system plays an important role in the development of major depressive disorder and functions as a target of antidepressants. Methods: Here, we investigated (i whether ceramide accumulates in endothelial cells in the neurogenetic zone of the hippocampus after glucocorticosterone-mediated stress, (ii whether ceramide is released into the extracellular space of the hippocampus and (iii whether extracellular ceramide inhibits neuronal proliferation. Ceramide was determined in endothelial cell culture supernatants or extracellular hippocampus extracts by a kinase assay. Endothelial ceramide in the hippocampus was analyzed by confocal microscopy of brain sections stained with Cy3-labelled anti-ceramide antibodies and FITC-Isolectin B4. Neuronal proliferation was measured by incubation of pheochromocytoma neuronal cells with culture supernatants and extracellular hippocampus extracts. Results: Treatment of cultured endothelial cells with glucocorticosterone induces a release of ceramide into the supernatant. Likewise, treatment of mice with glucocorticosterone triggers a release of ceramide into the extracellular space of the hippocampus. The release of ceramide is inhibited by concomitant treatment with the antidepressant amitriptyline, which also inhibits the activity of the acid sphingomyelinase. Studies employing confocal microscopy revealed that ceramide is formed and accumulates exclusively in endothelial cells in the hippocampus of stressed mice, a process that was again prevented by co-application of amitriptyline. Ceramide released in the culture supernatant or into the extracellular space of the

  3. Ceramide Signaling and Metabolism in Pathophysiological States of the Lung.

    Science.gov (United States)

    Petrache, Irina; Berdyshev, Evgeny V

    2016-01-01

    Following the discovery of ceramide as the central signaling and metabolic relay among sphingolipids, studies of its involvement in lung health and pathophysiology have exponentially increased. In this review, we highlight key studies in the context of recent progress in metabolomics and translational research methodologies. Evidence points toward an important role for the ceramide/sphingosine-1-phosphate rheostat in maintaining lung cell survival, vascular barrier function, and proper host response to airway microbial infections. Sphingosine kinase 1 has emerged as an important determinant of sphingosine-1-phosphate lung levels, which, when aberrantly high, contribute to lung fibrosis, maladaptive vascular remodeling, and allergic asthma. New sphingolipid metabolites have been discovered as potential biomarkers of several lung diseases. Although multiple acute and chronic lung pathological conditions involve perturbations in sphingolipid signaling and metabolism, there are specific patterns, unique sphingolipid species, enzymes, metabolites, and receptors, which have emerged that deepen our understanding of lung pathophysiology and inform the development of new therapies for lung diseases. PMID:26667073

  4. Proteome-wide Identification of Novel Ceramide-binding Proteins by Yeast Surface cDNA Display and Deep Sequencing.

    Science.gov (United States)

    Bidlingmaier, Scott; Ha, Kevin; Lee, Nam-Kyung; Su, Yang; Liu, Bin

    2016-04-01

    Although the bioactive sphingolipid ceramide is an important cell signaling molecule, relatively few direct ceramide-interacting proteins are known. We used an approach combining yeast surface cDNA display and deep sequencing technology to identify novel proteins binding directly to ceramide. We identified 234 candidate ceramide-binding protein fragments and validated binding for 20. Most (17) bound selectively to ceramide, although a few (3) bound to other lipids as well. Several novel ceramide-binding domains were discovered, including the EF-hand calcium-binding motif, the heat shock chaperonin-binding motif STI1, the SCP2 sterol-binding domain, and the tetratricopeptide repeat region motif. Interestingly, four of the verified ceramide-binding proteins (HPCA, HPCAL1, NCS1, and VSNL1) and an additional three candidate ceramide-binding proteins (NCALD, HPCAL4, and KCNIP3) belong to the neuronal calcium sensor family of EF hand-containing proteins. We used mutagenesis to map the ceramide-binding site in HPCA and to create a mutant HPCA that does not bind to ceramide. We demonstrated selective binding to ceramide by mammalian cell-produced wild type but not mutant HPCA. Intriguingly, we also identified a fragment from prostaglandin D2synthase that binds preferentially to ceramide 1-phosphate. The wide variety of proteins and domains capable of binding to ceramide suggests that many of the signaling functions of ceramide may be regulated by direct binding to these proteins. Based on the deep sequencing data, we estimate that our yeast surface cDNA display library covers ∼60% of the human proteome and our selection/deep sequencing protocol can identify target-interacting protein fragments that are present at extremely low frequency in the starting library. Thus, the yeast surface cDNA display/deep sequencing approach is a rapid, comprehensive, and flexible method for the analysis of protein-ligand interactions, particularly for the study of non-protein ligands. PMID

  5. Ceramide synthesis from free fatty acids in rat brain: function of NADPH and substrate specificity

    Energy Technology Data Exchange (ETDEWEB)

    Singh, I.

    1983-06-01

    At the subcellular level, the synthesis of ceramide from free lignoceric acid and sphingosine in brain required reconstituted enzyme system (particulate fraction, heat-stable and heat-labile factors) and pyridine nucleotide (NADPH). The mitochondrial electron transfer inhibitors (KCN and antimycin A), energy uncouplers (oligomycin and 2,4-dinitrophenol), and carboxyatractyloside, which prevents the transport of ATP and ADP through the mitochondrial wall, inhibit the synthesis of ceramide in the presence of NADPH but have very little effect in the presence of ATP. Similar to the synthesis of ceramide, the synthesis of ATP from NADPH and NADH by the particulate fraction also required cytoplasmic factors (heat-stable and heat-labile factors). Moreover, ATP, but not its analog (AMP-CH2-P-O-P), can replace NADPH, thus suggesting that the function of the pyridine nucleotide is to provide ATP for the synthesis of ceramide. The cytoplasmic factors were not required for the synthesis of ceramide in the presence of ATP. The maximum velocity for synthesis of ceramide from free fatty acids of different chain lengths (C16-C26) was bimodal, with maxima around stearic acid (C18) and behenic acid (C22). The relative rate of synthesis of ceramide parallels the relative distribution of these fatty acids in brain cerebrosides and sulfatides.

  6. The impact of ultraviolet therapy on stratum corneum ceramides and barrier function

    DEFF Research Database (Denmark)

    Jungersted, Jakob Mutanu; Høgh, Julie Kaae; Hellgren, Lars;

    2011-01-01

    therapy in dermatological patients on ceramides and skin barrier function. We found that UV light treatment does not change the ratio of important stratum corneum lipids, but we confirm earlier findings of decreased susceptibility to irritants after UV- therapy.......The ceramide profile as well as the barrier function is known to be deteriorated in atopic eczema and psoriasis, and ultraviolet (UV) light is known to improve the barrier function. The impact of UV light on ceramides, however, is not clarified. The aim of this study was to examine the effect of UV...

  7. Ceramide metabolism analysis in a model of binge drinking reveals both neuroprotective and toxic effects of ethanol

    Science.gov (United States)

    Bae, Mihyun; Bandaru, Veera Venkata Ratnam; Patel, Neha; Haughey, Norman J.

    2014-01-01

    Binge drinking is a common form of alcohol abuse that involves repeated rounds of intoxication followed by withdrawal. The episodic effects of binge drinking and withdrawal on brain resident cells are thought to contribute to neural remodeling and neurological damage. However, the molecular mechanisms for these neurodegenerative effects are not understood. Ethanol (EtOH) regulates the metabolism of ceramide, a highly bioactive lipid that is enriched in brain. We used a mouse model of binge drinking to determine the effects of EtOH intoxication and withdrawal on brain ceramide metabolism. Intoxication and acute alcohol withdrawal were each associated with distinct changes in ceramide regulatory genes and metabolic products. EtOH intoxication was accompanied by decreased concentrations of multiple ceramides, coincident with reductions in the expression of enzymes involved in the production of ceramides, and increased expression of ceramide degrading enzymes. EtOH withdrawal was associated with specific increases in ceramide C16:0, C18:0 and C20:0 and increased expression of enzymes involved with ceramide production. These data suggest that EtOH intoxication may evoke a ceramide phenotype that is neuroprotective, while EtOH withdrawal results in a metabolic shift that increases the production of potentially toxic ceramide species. PMID:25060779

  8. Effect of Laser and LED on Enzymatic Production of Ceramide

    DEFF Research Database (Denmark)

    Hongyu, Zhang; Zhang, Long; Tidemand-Lichtenberg, Peter;

    2011-01-01

    An enzyme (Phospholipase C Type I from Clostridium perfringens) was exposed to 0-810J/cm2 of energy using laser light at wavelengths 808 nm, 532nm, 1064 nm, and 1342 nm and two LED light sources at wavelengths 810 nm and 640 nm. Enzyme responses were evaluated by measuring ceramide concentration...... using HPTLC (high performance thin-layer chromatography) at 0.5, 1, 2, 3, 4, 6, 17, 24 h after irradiation. The duration of effect was evaluated from the experimental data. The results show that enzyme activity can be increased by using both laser and LED sources whose wavelength is located within...... a certain range. The effect depends on the energy and wavelength of the light. The increase in enzyme activity continued for about 4 h after irradiation. This study shows that the duration of irradiation should be included as one of the main laser parameters when reporting on the effects of laser...

  9. Dynamics of the Heat Stress Response of Ceramides with Different Fatty-Acyl Chain Lengths in Baker's Yeast.

    Directory of Open Access Journals (Sweden)

    Po-Wei Chen

    2015-08-01

    Full Text Available The article demonstrates that computational modeling has the capacity to convert metabolic snapshots, taken sequentially over time, into a description of cellular, dynamic strategies. The specific application is a detailed analysis of a set of actions with which Saccharomyces cerevisiae responds to heat stress. Using time dependent metabolic concentration data, we use a combination of mathematical modeling, reverse engineering, and optimization to infer dynamic changes in enzyme activities within the sphingolipid pathway. The details of the sphingolipid responses to heat stress are important, because they guide some of the longer-term alterations in gene expression, with which the cells adapt to the increased temperature. The analysis indicates that all enzyme activities in the system are affected and that the shapes of the time trends in activities depend on the fatty-acyl CoA chain lengths of the different ceramide species in the system.

  10. Ceramide formation mediated by acid sphingomyelinase facilitates endosomal escape of caliciviruses.

    Science.gov (United States)

    Shivanna, Vinay; Kim, Yunjeong; Chang, Kyeong-Ok

    2015-09-01

    Our recent results demonstrated that bile acids facilitate virus escape from the endosomes into the cytoplasm for successful replication of porcine enteric calicivirus (PEC). We report a novel finding that bile acids can be substituted by cold treatment for endosomal escape and virus replication. This endosomal escape by cold treatment or bile acids is associated with ceramide formation by acid sphingomyelinase (ASM). ASM catalyzes hydrolysis of sphingomyelin into ceramide, which is known to destabilize lipid bilayer. Treatment of LLC-PK cells with bile acids or cold led to ceramide formation, and small molecule antagonists or siRNA of ASM blocked ceramide formation in the endosomes and significantly reduced PEC replication. Inhibition of ASM resulted in the retention of PEC, feline calicivirus or murine norovirus in the endosomes in correlation with reduced viral replication. These results suggest the importance of viral escape from the endosomes for the replication of various caliciviruses. PMID:25985440

  11. Host defense against Pseudomonas aeruginosa requires ceramide-rich membrane rafts.

    Science.gov (United States)

    Grassmé, H; Jendrossek, V; Riehle, A; von Kürthy, G; Berger, J; Schwarz, H; Weller, M; Kolesnick, R; Gulbins, E

    2003-03-01

    Pseudomonas aeruginosa infection is a serious complication in patients with cystic fibrosis and in immunocompromised individuals. Here we show that P. aeruginosa infection triggers activation of the acid sphingomyelinase and the release of ceramide in sphingolipid-rich rafts. Ceramide reorganizes these rafts into larger signaling platforms that are required to internalize P. aeruginosa, induce apoptosis and regulate the cytokine response in infected cells. Failure to generate ceramide-enriched membrane platforms in infected cells results in an unabated inflammatory response, massive release of interleukin (IL)-1 and septic death of mice. Our findings show that ceramide-enriched membrane platforms are central to the host defense against this potentially lethal pathogen. PMID:12563314

  12. Effect of monoglycerides and fatty acids on a ceramide bilayer.

    Science.gov (United States)

    Akinshina, Anna; Das, Chinmay; Noro, Massimo G

    2016-07-14

    Monoglycerides and unsaturated fatty acids, naturally present in trace amounts in the stratum corneum (top layer of skin) lipid matrix, are commonly used in pharmaceutical, cosmetic and health care formulations. However, a detailed molecular understanding of how the oil additives get incorporated into the skin lipids from topical application and, once incorporated, how they affect the properties and integrity of the lipid matrix remains unexplored. Using ceramide 2 bilayers as skin lipid surrogates, we use a series of molecular dynamics simulations with six different natural oil ingredients at multiple concentrations to investigate the effect of the oils on the properties and stability of the bilayers. The six oils: monoolein, monostearin, monoelaidin, oleic acid, stearic acid and linoleic acid - all having the same length of the alkyl chain, C18, but a varying degree of saturation, allow us to systematically address the effect of unsaturation in the additives. Our results show that at low oil concentration (∼5%) the mixed bilayers containing any of the oils and ceramide 2 (CER2) become more rigid than pure CER2 bilayers due to more efficient lipid packing. Better packing also results in the formation of larger numbers of hydrogen bonds between the lipids, which occurs at the expense of the hydrogen bonds between lipids and water. The mixed bilayers with saturated or trans-unsaturated oils remain stable over the whole range of oil concentration. In contrast, the presence of the oils with at least one cis-double bond leads to bilayer instability and complete loss of bilayer structure at the oil content of about 50-65%. Two cis-double bonds in the lipid tail induce bilayer disruption at even lower concentration (∼30%). The mixed bilayers remain in the gel phase (without melting to a fluid phase) until the phase transition to a non-bilayer phase occurs. We also demonstrate that the stability of the bilayer strongly correlates with the order parameter of the lipid

  13. Ceramide and S1P signaling in embryonic stem cell differentiation

    OpenAIRE

    Bieberich, Erhard

    2012-01-01

    Recent studies show that bioactive lipids are important regulators for stem cell survival and differentiation. The sphingolipid ceramide and its derivative, sphingosine-1-phosphate (S1P), can act synergistically on embryonic stem (ES) cell differentiation. We show here simple methods to analyze sphingolipids in differentiating ES cells and to use ceramide and S1P analogs for the guided differentiation of mouse ES cells toward neuronal and glial lineage.

  14. Synthesis and Characterization of Long-Chain Tartaric Acid Diamides as Novel Ceramide-Like Compounds

    Directory of Open Access Journals (Sweden)

    Krisztina Takács-Novák

    2010-02-01

    Full Text Available Ceramides play a crucial role in the barrier function of the skin as well as in transmembrane signaling. In this study long aliphatic chain tartaric acid diamides able to replace ceramides in an in vitro model of the stratum corneum lipid matrix due to their similar physico-chemical properties were synthesized from diacetoxysuccinic anhydride in four steps. Their pro-apoptotic effect on fibroblast cells was also investigated.

  15. The Role of Sphingolipids and Ceramide in Pulmonary Inflammation in Cystic Fibrosis

    OpenAIRE

    Becker, Katrin Anne; Riethmüller, Joachim; Zhang, Yang; Gulbins, Erich

    2010-01-01

    Sphingolipids and in particular ceramide have been shown to be critically involved in the response to many receptor-mediated, but also receptor-independent, mainly stress stimuli. Recent studies demonstrate that ceramide plays an important role in the pathogenesis of cystic fibrosis, a hereditary metabolic disorder caused by mutations of the Cystic Fibrosis Transmembrane Conductance Regulator. Patients with cystic fibrosis suffer from chronic pulmonary inflammation and microbial lung infectio...

  16. Clinical use of a ceramide-based moisturizer for treating dogs with atopic dermatitis

    OpenAIRE

    Jung, Ji-Young; Nam, Eui-Hwa; Park, Seol-hee; Han, Seung-Hee; HWANG, Cheol-Yong

    2013-01-01

    In humans, skin barrier dysfunction is thought to be responsible for enhanced penetration of allergens. Similar to conditions seen in humans, canine atopic dermatitis (CAD) is characterized by derangement of corneocytes and disorganization of intercellular lipids in the stratum corenum (SC) with decreased ceramide levels. This study was designed to evaluate the effects of a moisturizer containing ceramide on dogs with CAD. Dogs (n = 20, 3~8 years old) with mild to moderate clinical signs were...

  17. Role of Ceramide from Glycosphingolipids and Its Metabolites in Immunological and Inflammatory Responses in Humans

    Directory of Open Access Journals (Sweden)

    Kazuhisa Iwabuchi

    2015-01-01

    Full Text Available Glycosphingolipids (GSLs are composed of hydrophobic ceramide and hydrophilic sugar chains. GSLs cluster to form membrane microdomains (lipid rafts on plasma membranes, along with several kinds of transducer molecules, including Src family kinases and small G proteins. However, GSL-mediated biological functions remain unclear. Lactosylceramide (LacCer, CDw17 is highly expressed on the plasma membranes of human phagocytes and mediates several immunological and inflammatory reactions, including phagocytosis, chemotaxis, and superoxide generation. LacCer forms membrane microdomains with the Src family tyrosine kinase Lyn and the Gαi subunit of heterotrimeric G proteins. The very long fatty acids C24:0 and C24:1 are the main ceramide components of LacCer in neutrophil plasma membranes and are directly connected with the fatty acids of Lyn and Gαi. These observations suggest that the very long fatty acid chains of ceramide are critical for GSL-mediated outside-in signaling. Sphingosine is another component of ceramide, with the hydrolysis of ceramide by ceramidase producing sphingosine and fatty acids. Sphingosine is phosphorylated by sphingosine kinase to sphingosine-1-phosphate, which is involved in a wide range of cellular functions, including growth, differentiation, survival, chemotaxis, angiogenesis, and embryogenesis, in various types of cells. This review describes the role of ceramide moiety of GSLs and its metabolites in immunological and inflammatory reactions in human.

  18. Nanoemulsification of pseudo-ceramide by molecular association with mannosylerythritol lipid.

    Science.gov (United States)

    Kim, Min Kyung; Jeong, Eun Seon; Kim, Kwang Nyeon; Park, Seung Han; Kim, Jin Woong

    2014-04-01

    Ceramide molecules in water-based solutions readily attract each other to form molecular crystals, which seriously hampers to diversify their formulations. This paper describes a facile method that allows fabrication of stable ceramide emulsions through an effective molecular association with a lipid having an asymmetric molecular geometry. The lipid considered in this study is mannosylerythritol lipid (MEL). MEL is specialized in having a unique molecular structure containing sugar alcohol erythritol as a hydrophilic part and two alkyl chains with different number of carbons as hydrophobic moieties. Our particular interest has been focused on experimentally demonstrating how MEL interacts with pseudo-ceramide molecules by observing phase properties, emulsion morphology, and suspension stability. The pseudo-ceramide emulsions prepared with MEL show remarkably improved dispersion stability without either formation of molecular crystals or changes in particle sizes even after storing them for a long time. This suggests that MEL readily associates with the pseudo-ceramide due to the hydrophobic interaction, while it makes a break in the continuity of the molecular assembly of the pseudo-ceramide molecules themselves due to the geometric hindrance coming from MEL's asymmetric molecular structure. PMID:24290102

  19. Hydrogen peroxide/ceramide/Akt signaling axis play a critical role in the antileukemic potential of sanguinarine.

    Science.gov (United States)

    Rahman, Anees; Thayyullathil, Faisal; Pallichankandy, Siraj; Galadari, Sehamuddin

    2016-07-01

    Dysregulation of apoptosis is a prime hallmark of leukemia. Therefore, drugs which restore the sensitivity of leukemic cells to apoptotic stimuli are promising candidates in the treatment of leukemia. Recently, we have demonstrated that sanguinarine (SNG), a benzophenanthridine alkaloid, isolated from Sanguinaria canadensis induces ROS-dependent ERK1/2 activation and autophagic cell death in human malignant glioma cells (Pallichankandy et al., 2015; [43]). In this study, we investigated the antileukemic potential of SNG in vitro, and further examined the molecular mechanisms of SNG-induced cell death. In human leukemic cells, SNG activated apoptotic cell death pathway characterized by activation of caspase cascade, DNA fragmentation and down-regulation of anti-apoptotic proteins. Importantly, we have identified a crucial role for hydrogen peroxide (H2O2)-dependent ceramide (Cer) generation in the facilitation of SNG-induced apoptosis. Additionally, we have found that SNG inhibits Akt, a key anti-apoptotic protein kinase by dephosphorylating it at Ser(473), leading to the dephosphorylation of its downstream targets, GSK3β and mTOR. Interestingly, inhibition of Cer generation, using acid sphingomyelinase inhibitor, significantly reduced the SNG-induced Akt dephosphorylation and apoptosis, whereas, activation of Cer generation using inhibitors of acid ceramidase and glucosylceramide synthase enhanced it. Furthermore, using a group of ceramide activated protein phosphatases (CAPPs) inhibitor (calyculin A, Okadaic acid, and phosphatidic acid), the involvement of protein phosphatase 1 form of CAPP in SNG-induced Akt dephosphorylation and apoptosis was demonstrated. Altogether, these results underscore a critical role for H2O2-Cer-Akt signaling axis in the antileukemic action of SNG. PMID:27154977

  20. Comprehensive quantification of ceramide species in human stratum corneum.

    Science.gov (United States)

    Masukawa, Yoshinori; Narita, Hirofumi; Sato, Hirayuki; Naoe, Ayano; Kondo, Naoki; Sugai, Yoshiya; Oba, Tsuyoshi; Homma, Rika; Ishikawa, Junko; Takagi, Yutaka; Kitahara, Takashi

    2009-08-01

    One of the key challenges in lipidomics is to quantify lipidomes of interest, as it is practically impossible to collect all authentic materials covering the targeted lipidomes. For diverse ceramides (CER) in human stratum corneum (SC) that play important physicochemical roles in the skin, we developed a novel method for quantification of the overall CER species by improving our previously reported profiling technique using normal-phase liquid chromatography-electrospray ionization-mass spectrometry (NPLC-ESI-MS). The use of simultaneous selected ion monitoring measurement of as many as 182 kinds of molecular-related ions enables the highly sensitive detection of the overall CER species, as they can be analyzed in only one SC-stripped tape as small as 5 mm x 10 mm. To comprehensively quantify CERs, including those not available as authentic species, we designed a procedure to estimate their levels using relative responses of representative authentic species covering the species targeted, considering the systematic error based on intra-/inter-day analyses. The CER levels obtained by this method were comparable to those determined by conventional thin-layer chromatography (TLC), which guarantees the validity of this method. This method opens lipidomics approaches for CERs in the SC. PMID:19349641

  1. Ceramides and cytotoxic constituents from Ficus glumosa Del. (Moraceae)

    Energy Technology Data Exchange (ETDEWEB)

    Nana, Frederic; Sandjo, Louis Pergaud; Keumedjio, Felix; Ambassa, Pantaleon [Department of Organic Chemistry, University of Yaounde I, Yaounde (Cameroon); Malik, Rizwana [H.E.J. Research Institute of Chemistry, International Center for Chemical and Biological Sciences, University of Karachi, Karachi (Pakistan); Kuete, Victor; Choudhary, Muhammad Iqbal [Department of Biochemistry, University of Dschang, Dschang (Cameroon); Rincheval, Vincent [Laboratoire de Genetique et Biologie Cellulaire Batiment Fermat, University of Versailles, St Quentin-en-Yvelines (France); Ngadjui, Bonaventure Tchaleu [Department of Pharmaceutical Sciences and Traditional Pharmacopeia, Faculty of Medicine and Biomedical Sciences, University of Yaounde I, Yaounde (Cameroon)

    2012-03-15

    Chemical investigation of the stem bark of Ficus glumosa (Moraceae) yielded two new ceramides (2R,7E)-2-hydroxy-N-[(2S,3S,4R)-1,3,4-trihydroxyhexadecan-2-yl] hexacos-7-enamide and (2R)-N-{l_brace}(2S,3S,4R,9Z)-1-O-[({beta}-D-glucopyranosyl]-3,4-dihydroxyheptadec -9-en-2-yl{r_brace}-2-hydroxypentacosanamide together with twenty one known compounds. The structures were established using NMR data, mass spectrometry, chemical transformation and by comparison with the reported data. Twenty one compounds were further tested against the prostate cancer PC-3 cell line and six of them revealed cytotoxic effect. Dongnoside E was the most active compound with an IC{sub 50} 0.75 {mu}mol L{sup -1}against the cancer cells line PC-3 while the reference drug doxorubicin displayed 0.91 {mu}mol L{sup -1}. This compound also proved to inhibit the cell growth of the fibrosarcoma cancer HT1080 (IC{sub 50} 0.7 {mu}mol L{sup -1}). (author)

  2. Ceramides and cytotoxic constituents from Ficus glumosa Del. (Moraceae)

    International Nuclear Information System (INIS)

    Chemical investigation of the stem bark of Ficus glumosa (Moraceae) yielded two new ceramides (2R,7E)-2-hydroxy-N-[(2S,3S,4R)-1,3,4-trihydroxyhexadecan-2-yl] hexacos-7-enamide and (2R)-N-{(2S,3S,4R,9Z)-1-O-[(β-D-glucopyranosyl]-3,4-dihydroxyheptadec -9-en-2-yl}-2-hydroxypentacosanamide together with twenty one known compounds. The structures were established using NMR data, mass spectrometry, chemical transformation and by comparison with the reported data. Twenty one compounds were further tested against the prostate cancer PC-3 cell line and six of them revealed cytotoxic effect. Dongnoside E was the most active compound with an IC50 0.75 μmol L-1against the cancer cells line PC-3 while the reference drug doxorubicin displayed 0.91 μmol L-1. This compound also proved to inhibit the cell growth of the fibrosarcoma cancer HT1080 (IC50 0.7 μmol L-1). (author)

  3. Sphingomyelinase D activity in model membranes: structural effects of in situ generation of ceramide-1-phosphate.

    Directory of Open Access Journals (Sweden)

    Roberto P Stock

    Full Text Available The toxicity of Loxosceles spider venom has been attributed to a rare enzyme, sphingomyelinase D, which transforms sphingomyelin to ceramide-1-phosphate. The bases of its inflammatory and dermonecrotic activity, however, remain unclear. In this work the effects of ceramide-1-phosphate on model membranes were studied both by in situ generation of this lipid using a recombinant sphingomyelinase D from the spider Loxosceles laeta and by pre-mixing it with sphingomyelin and cholesterol. The systems of choice were large unilamellar vesicles for bulk studies (enzyme kinetics, fluorescence spectroscopy and dynamic light scattering and giant unilamellar vesicles for fluorescence microscopy examination using a variety of fluorescent probes. The influence of membrane lateral structure on the kinetics of enzyme activity and the consequences of enzyme activity on the structure of target membranes containing sphingomyelin were examined. The findings indicate that: 1 ceramide-1-phosphate (particularly lauroyl ceramide-1-phosphate can be incorporated into sphingomyelin bilayers in a concentration-dependent manner and generates coexistence of liquid disordered/solid ordered domains, 2 the activity of sphingomyelinase D is clearly influenced by the supramolecular organization of its substrate in membranes and, 3 in situ ceramide-1-phosphate generation by enzymatic activity profoundly alters the lateral structure and morphology of the target membranes.

  4. Apoptosis of human colon carcinoma HT-29 cells induced by ceramide

    Institute of Scientific and Technical Information of China (English)

    Xiao-Feng Zhang; Bai-Xiang Li; Chun-Yan Dong; Rui Ren

    2006-01-01

    AIM: To investigate the effect of exogenous ceramideinduced apoptosis on human colon carcinoma HT-29cells.METHODS: Light microscope, transmission electron microscope and fluorescence microscope were used to observe the morphology change of apoptosis in HT-29cells. Agarose gel electrophoresis was performed to detect the DNA fragment. Mitochondrial function was detected by MTT assay. mRNA expression of Bcl-2 family gene members was determined by reverse transcription polymerase chain reaction (RT-PCR) assay.RESULTS: After C2-ceramide treatment, typical characteristics of apoptosis, such as nuclear chromatin breakage, apoptotic body and DNA ladder, could be observed. After exposure to 50 μmol/L C2-ceramide for 12 and 24 h, cell apoptosis was 64.1% and 81.3% respectively, which had a time-and dose-effect relationship. Mitochondrial function started to decrease from 6 h after exposure to ceramide. Meanwhile,ceramide up-regulated or down-regulated the mRNA expression of Bcl-2 family gene members.CONCLUSION: Ceramide induces apoptosis of human colon carcinoma HT-29 cells by affecting the expression of Bcl-2 family gene members and impacting the mitochondrial function.

  5. Inhibition of ceramide synthesis ameliorates glucocorticoid-, saturated-fat-, and obesity-induced insulin resistance.

    Science.gov (United States)

    Holland, William L; Brozinick, Joseph T; Wang, Li-Ping; Hawkins, Eric D; Sargent, Katherine M; Liu, Yanqi; Narra, Krishna; Hoehn, Kyle L; Knotts, Trina A; Siesky, Angela; Nelson, Don H; Karathanasis, Sotirios K; Fontenot, Greg K; Birnbaum, Morris J; Summers, Scott A

    2007-03-01

    Insulin resistance occurs in 20%-25% of the human population, and the condition is a chief component of type 2 diabetes mellitus and a risk factor for cardiovascular disease and certain forms of cancer. Herein, we demonstrate that the sphingolipid ceramide is a common molecular intermediate linking several different pathological metabolic stresses (i.e., glucocorticoids and saturated fats, but not unsaturated fats) to the induction of insulin resistance. Moreover, inhibition of ceramide synthesis markedly improves glucose tolerance and prevents the onset of frank diabetes in obese rodents. Collectively, these data have two important implications. First, they indicate that different fatty acids induce insulin resistance by distinct mechanisms discerned by their reliance on sphingolipid synthesis. Second, they identify enzymes required for ceramide synthesis as therapeutic targets for combating insulin resistance caused by nutrient excess or glucocorticoid therapy.

  6. Acid ceramidase and the treatment of ceramide diseases: The expanding role of enzyme replacement therapy.

    Science.gov (United States)

    Schuchman, Edward H

    2016-09-01

    Ceramides are a diverse group of sphingolipids that play important roles in many biological processes. Acid ceramidase (AC) is one key enzyme that regulates ceramide metabolism. Early research on AC focused on the fact that it is the enzyme deficient in the rare genetic disorder, Farber Lipogranulomatosis. Recent research has revealed that deficiency of the same enzyme is responsible for a rare form of spinal muscular atrophy associated with myoclonic epilepsy (SMA-PME). Due to their diverse role in biology, accumulation of ceramides also has been implicated in the pathobiology of many other common diseases, including infectious lung diseases, diabetes, cancers and others. This has revealed the potential of AC as a therapy for many of these diseases. This review will focus on the biology of AC and the potential role of this enzyme in the treatment of human disease. PMID:27155573

  7. Sphingomyelinase D activity in model membranes: structural effects of in situ generation of ceramide-1-phosphate

    DEFF Research Database (Denmark)

    Stock, Roberto; Brewer, Jonathan R.; Wagner, Kerstin;

    2012-01-01

    The toxicity of Loxosceles spider venom has been attributed to a rare enzyme, sphingomyelinase D, which transforms sphingomyelin to ceramide-1-phosphate. The bases of its inflammatory and dermonecrotic activity, however, remain unclear. In this work the effects of ceramide-1-phosphate on model...... membranes were studied both by in situ generation of this lipid using a recombinant sphingomyelinase D from the spider Loxosceles laeta and by pre-mixing it with sphingomyelin and cholesterol. The systems of choice were large unilamellar vesicles for bulk studies (enzyme kinetics, fluorescence spectroscopy...

  8. Hypertension is associated with marked alterations in sphingolipid biology: a potential role for ceramide.

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    Léon J A Spijkers

    Full Text Available BACKGROUND: Hypertension is, amongst others, characterized by endothelial dysfunction and vascular remodeling. As sphingolipids have been implicated in both the regulation of vascular contractility and growth, we investigated whether sphingolipid biology is altered in hypertension and whether this is reflected in altered vascular function. METHODS AND FINDINGS: In isolated carotid arteries from spontaneously hypertensive rats (SHR and normotensive Wistar-Kyoto (WKY rats, shifting the ceramide/S1P ratio towards ceramide dominance by administration of a sphingosine kinase inhibitor (dimethylsphingosine or exogenous application of sphingomyelinase, induced marked endothelium-dependent contractions in SHR vessels (DMS: 1.4±0.4 and SMase: 2.1±0.1 mN/mm; n = 10, that were virtually absent in WKY vessels (DMS: 0.0±0.0 and SMase: 0.6±0.1 mN/mm; n = 9, p<0.05. Imaging mass spectrometry and immunohistochemistry indicated that these contractions were most likely mediated by ceramide and dependent on iPLA(2, cyclooxygenase-1 and thromboxane synthase. Expression levels of these enzymes were higher in SHR vessels. In concurrence, infusion of dimethylsphingosine caused a marked rise in blood pressure in anesthetized SHR (42±4%; n = 7, but not in WKY (-12±10%; n = 6. Lipidomics analysis by mass spectrometry, revealed elevated levels of ceramide in arterial tissue of SHR compared to WKY (691±42 vs. 419±27 pmol, n = 3-5 respectively, p<0.05. These pronounced alterations in SHR sphingolipid biology are also reflected in increased plasma ceramide levels (513±19 pmol WKY vs. 645±25 pmol SHR, n = 6-12, p<0.05. Interestingly, we observed similar increases in ceramide levels (correlating with hypertension grade in plasma from humans with essential hypertension (185±8 pmol vs. 252±23 pmol; n = 18 normotensive vs. n = 19 hypertensive patients, p<0.05. CONCLUSIONS: Hypertension is associated with marked alterations in vascular

  9. Bioassay-guided fractionation of extracts from Codiaeum variegatum against Entamoeba histolytica discovers compounds that modify expression of ceramide biosynthesis related genes.

    Science.gov (United States)

    Mfotie Njoya, Emmanuel; Weber, Christian; Hernandez-Cuevas, Nora Adriana; Hon, Chung-Chau; Janin, Yves; Kamini, Melanie F G; Moundipa, Paul F; Guillén, Nancy

    2014-01-01

    Leaves of Codiaeum variegatum ("garden croton") are used against bloody diarrhoea by local populations in Cameroon. This study aims to search for the active components from C. variegatum against Entamoeba histolytica, and thereby initiate the study of their mechanism of action. A bioassay-guided screening of the aqueous extracts from C. variegatum leaves and various fractions was carried out against trophozoites of E. histolytica axenic culture. We found that the anti-amoebic activity of extracts changed with respect to the collection criteria of leaves. Thereby, optimal conditions were defined for leaves' collection to maximise the anti-amoebic activity of the extracts. A fractionation process was performed, and we identified several sub-fractions (or isolated compounds) with significantly higher anti-amoebic activity compared to the unfractionated aqueous extract. Anti-amoebic activity of the most potent fraction was confirmed with the morphological characteristics of induced death in trophozoites, including cell rounding and lysis. Differential gene expression analysis using high-throughput RNA sequencing implies the potential mechanism of its anti-amoebic activity by targeting ceramide, a bioactive lipid involved in disturbance of biochemical processes within the cell membrane including differentiation, proliferation, cell growth arrest and apoptosis. Regulation of ceramide biosynthesis pathway as a target for anti-amoebic compounds is a novel finding which could be an alternative for drug development against E. histolytica. PMID:24416462

  10. Bioassay-guided fractionation of extracts from Codiaeum variegatum against Entamoeba histolytica discovers compounds that modify expression of ceramide biosynthesis related genes.

    Directory of Open Access Journals (Sweden)

    Emmanuel Mfotie Njoya

    Full Text Available Leaves of Codiaeum variegatum ("garden croton" are used against bloody diarrhoea by local populations in Cameroon. This study aims to search for the active components from C. variegatum against Entamoeba histolytica, and thereby initiate the study of their mechanism of action. A bioassay-guided screening of the aqueous extracts from C. variegatum leaves and various fractions was carried out against trophozoites of E. histolytica axenic culture. We found that the anti-amoebic activity of extracts changed with respect to the collection criteria of leaves. Thereby, optimal conditions were defined for leaves' collection to maximise the anti-amoebic activity of the extracts. A fractionation process was performed, and we identified several sub-fractions (or isolated compounds with significantly higher anti-amoebic activity compared to the unfractionated aqueous extract. Anti-amoebic activity of the most potent fraction was confirmed with the morphological characteristics of induced death in trophozoites, including cell rounding and lysis. Differential gene expression analysis using high-throughput RNA sequencing implies the potential mechanism of its anti-amoebic activity by targeting ceramide, a bioactive lipid involved in disturbance of biochemical processes within the cell membrane including differentiation, proliferation, cell growth arrest and apoptosis. Regulation of ceramide biosynthesis pathway as a target for anti-amoebic compounds is a novel finding which could be an alternative for drug development against E. histolytica.

  11. CD95/Fas-induced ceramide formation proceeds with slow kinetics and is not blocked by caspase-3/CPP32 inhibition.

    Science.gov (United States)

    Tepper, A D; Cock, J G; de Vries, E; Borst, J; van Blitterswijk, W J

    1997-09-26

    The current confusion regarding the relevance of endogenous ceramide in mediating CD95/Fas-induced apoptosis is based mainly on (i) discrepancies in kinetics of the ceramide response between different studies using the same apoptotic stimulus and (ii) the observation that late ceramide formation (hours) often parallels apoptosis onset. We investigated CD95-induced ceramide formation in Jurkat cells, using two methods (radiolabeling/thin layer chromatography and benzoylation/high performance liquid chromatography), which, unlike the commonly used diglyceride kinase assay, discriminate between ceramide species and de novo formed dihydroceramide. We demonstrate that ceramide accumulates after several hours, reaching a 7-fold increase after 8 h, kinetics closely paralleling apoptosis induction. No fast response was observed, not even in the presence of inhibitors of ceramide metabolism. The majority ( approximately 70%) of the ceramide response remained unaffected when apoptosis was completely inhibited at the level of caspase-3/CPP32 processing by the inhibitor peptide DEVD-CHO. Exogenous cell-permeable C2-ceramide induced the proteolytic processing of caspase-3, albeit with somewhat slower kinetics than with CD95. DEVD-CHO dose-dependently inhibited C2-ceramide- or exogenous sphingomyelinase-induced apoptosis. The results support the idea that ceramide acts in conjunction with the caspase cascade in CD95-induced apoptosis. PMID:9305886

  12. The novel HDAC inhibitor AR-42-induced anti-colon cancer cell activity is associated with ceramide production

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Weihong; Xu, Bin; Yao, Yiting; Yu, Xiaoling [Department of Clinical Laboratory, Tongren Hospital, Shanghai (China); Shen, Jie, E-mail: tongrensj163@163.com [Department of Administrative, Tongren Hospital, No. 786 Yuyuan Road, Changning District, Shanghai (China)

    2015-08-07

    In the current study, we investigated the potential activity of AR-42, a novel histone deacetylase (HDAC) inhibitor, against colon cancer cells. Our in vitro results showed that AR-42 induced ceramide production, exerted potent anti-proliferative and pro-apoptotic activities in established (SW-620 and HCT-116 lines) and primary human colon cancer cells. Exogenously-added sphingosine 1-phosphate (S1P) suppressed AR-42-induced activity, yet a cell-permeable ceramide (C4) facilitated AR-42-induced cytotoxicity against colon cancer cells. In addition, AR-42-induced ceramide production and anti-colon cancer cell activity were inhibited by the ceramide synthase inhibitor fumonisin B1, but were exacerbated by PDMP, which is a ceramide glucosylation inhibitor. In vivo, oral administration of a single dose of AR-42 dramatically inhibited SW-620 xenograft growth in severe combined immunodeficient (SCID) mice, without inducing overt toxicities. Together, these results show that AR-42 dramatically inhibits colon cancer cell proliferation in vitro and in vivo, and ceramide production might be the key mechanism responsible for its actions. - Highlights: • AR-42 is anti-proliferative against primary/established colon cancer cells. • AR-42 induces significant apoptotic death in primary/established colon cancer cells. • Ceramide production mediates AR-42-induced cytotoxicity in colon cancer cells. • AR-42 oral administration potently inhibits SW-620 xenograft growth in SCID mice.

  13. Ceramide formation is involved in Lactobacillus acidophilus-induced IFN-beta response in dendritic cells

    DEFF Research Database (Denmark)

    Fuglsang, Eva; Henningsen, Louise; Frøkiær, Hanne

    The sphingolipid ceramide is known to play a role in lipid raft fusion and receptor clustering in the plasma membrane (PM). Upon bacterial encounter, dendritic cells (DCs) endocytose the bacteria and initiate a bacteria-specific downstream signaling event. We hypothesized that conversion...

  14. Phytoceramide in vertebrate tissues: one step chromatography separation for molecular characterization of ceramide species.

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    Somsankar Dasgupta

    Full Text Available Ceramide is a precursor for complex sphingolipids in vertebrates, while plants contain phytoceramide. By using a novel chromatography purification method we show that phytoceramide comprises a significant proportion of animal sphingolipids. Total ceramide including phytoceramide from mouse tissue (brain, heart, liver lipid extracts and cell culture (mouse primary astrocytes, human oligodendroglioma cells was eluted as a single homogenous fraction, and then analyzed by thin layer chromatography, and further characterized by gas chromatography-mass spectrometry (GC-MS. We detected a unique band that migrated between non-hydroxy fatty acyl ceramide and hydroxy fatty acyl ceramide, and identified it as phytoceramide. Using RT-PCR, we confirmed that mouse tissues expressed desaturase 2, an enzyme that has been reported to generate phytoceramide from dihydroceramide. Previously, only trace amounts of phytoceramide were reported in vertebrate intestine, kidney, and skin. While its function is still elusive, this is the first report of phytoceramide characterization in glial cells and vertebrate brain, heart, and liver.

  15. Immobilization of phospholipase C for the production of ceramide from sphingomyelin hydrolysis

    DEFF Research Database (Denmark)

    Zhang, Long; Hellgren, Lars; Xu, Xuebing

    2007-01-01

    industries such as in hair and skin care products, due to its major role in maintaining the water-retaining properties of the epidermis. The feasibility of enzymatic production of ceramide through hydrolysis of sphingomyelin has previously been proven. In order to improve the reusability of the enzyme...

  16. Ceramide formation is involved in Lactobacillus acidophilus-induced IFN-beta response in dendritic cells

    DEFF Research Database (Denmark)

    Fuglsang, Eva; Henningsen, Louise; Frøkiær, Hanne

    of sphingomyelin to ceramide by acid sphingomyelinase (ASMase) at the outer leaflet of the PM is a key event in endocytosis of gram-positive Lactobacillus acidophilus (L. acidophilus) and the subsequent induction of IFN-beta in DCs and, as the gram-negative Escherichia coli (E. coli) does not induce appreciable...

  17. Ceramide in lipid emulsions used in parenteral nutrition: an innocent bystander?

    NARCIS (Netherlands)

    J.E. Groener; M.J. Serlie; A. Poppema; M. Mirzaian; J.M.F.G. Aerts

    2011-01-01

    Parenteral nutrition-associated liver disease is a prevalent and severe complication of long term parenteral nutrition. We present here for the first time data on the presence of ceramide, a bioactive compound involved in a variety of metabolic processes, in different lipid emulsions used in parente

  18. The challenge to verify ceramide's role of apoptosis induction in human cardiomyocytes - a pilot study

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    Voth Vladimir

    2011-03-01

    Full Text Available Abstract Background Cardioplegia and reperfusion of the myocardium may be associated with cardiomyocyte apoptosis and subsequent myocardial injury. In order to establish a pharmacological strategy for the prevention of these events, this study aimed to verify the reliability of our human cardiac model and to evaluate the pro-apoptotic properties of the sphingolipid second messenger ceramide and the anti-apoptotic properties of the acid sphingomyelinase inhibitor amitryptiline during simulated cardioplegia and reperfusion ex vivo. Methods Cardiac biopsies were retrieved from the right auricle of patients undergoing elective CABG before induction of cardiopulmonary bypass. Biopsies were exposed to ex vivo conditions of varying periods of cp/rep (30/10, 60/20, 120/40 min. Groups: I (untreated control, n = 10, II (treated control cp/rep, n = 10, III (cp/rep + ceramide, n = 10, IV (cp/rep + amitryptiline, n = 10 and V (cp/rep + ceramide + amitryptiline, n = 10. For detection of apoptosis anti-activated-caspase-3 and PARP-1 cleavage immunostaining were employed. Results In group I the percentage of apoptotic cardiomyocytes was significantly (p Conclusion Ceramid induces and amitryptiline suppresses apoptosis significantly in our ex vivo setting. This finding warrants further studies aiming to evaluate potential beneficial effects of selective inhibition of apoptosis inducing mediators on the suppression of ischemia/reperfusion injury in clinical settings.

  19. Human Trabecular Meshwork Sphingolipid and Ceramide Profiles and Potential Latent Fungal Commensalism

    OpenAIRE

    Aljohani, Ayman J.; Edwards, Genea; Guerra, Yenifer; Dubovy, Sander; Miller, Darlene; Lee, Richard K; Bhattacharya, Sanjoy K.

    2014-01-01

    The mass spectrometry-identified sphingolipids and ceramides in the trabecular meshwork (TM) showed presence of nonmammalian sphingoid base Fumonisins. Taken together with Gomori methenamine silver staining and DNA amplification, this suggests widespread latent commensalism by Fusarium species in the human TM.

  20. 4,8-Sphingadienine and 4-hydroxy-8-sphingenine activate ceramide production in the skin

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    Shirakura Yoshiyuki

    2012-08-01

    Full Text Available Abstract Background Ingestion of glucosylceramide improves transepidermal water loss (TEWL from the skin, but the underlying mechanism by which a small amount of dietary glucosylceramide can vastly improve skin conditions remains unclear. In a previous report, glucosylceramides were shown to be digested to sphingoids, which were shown to be absorbed through the intestinal epithelium. Based on these observations, we hypothesized that sphingoids are the key molecules facilitating endogenous ceramide production. In this study, we assessed the effect of 4,8-sphingadienine (d18:2 and 4-hydroxy-8-sphingenine (t18:1, derived from konjac glucosylceramide, on stimulating ceramide production. Methods Konjac glucosylceramide acidolysis was performed using hydrochloric acid; the resulting d18:2 and t18:1 were fractionated by column chromatography. Real-time quantitative RT-PCR was performed to assess the effect of d18:2 and t18:1 on gene expression in normal human epidermal keratinocytes, while their effect on the nuclear receptor, peroxisome proliferator-activated receptor (PPARγ, was measured using a receptor-cofactor assay system. The effect of d18:2 and t18:1 on stimulating ceramide production was evaluated using HPTLC analysis in a 3-dimensional human skin model. Results We noted the upregulation of genes related to de novo ceramide synthesis as well as of those encoding the elongases of very long-chain fatty acids by d18:2 and t18:1, but not by glucosylceramide and 4-sphingenine. Both these sphingoids also facilitated the expression of PPARβ/δ and PPARγ; moreover, they also demonstrated ligand activity for PPARγ. These results indicated that d18:2 and t18:1 promote the differentiation of keratinocytes. Analysis of the lipids within the 3-dimensional human skin model indicated that treatment with d18:2 and t18:1 not only upregulated gene expression but also increased ceramide production. Conclusions The sphingoids d18:2 and t18:1 activated genes

  1. Neutral sphingomyelinase-2, acid sphingomyelinase, and ceramide levels in COPD patients compared to controls

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    Lea SR

    2016-09-01

    Full Text Available Simon R Lea,1,* Hannah J Metcalfe,1,* Jonathan Plumb,1 Christian Beerli,2 Chris Poll,3 Dave Singh,1 Katharine H Abbott-Banner3 1Centre for Respiratory Medicine and Allergy, Institute of Inflammation and Repair, Manchester Academic Health Science Centre, The University of Manchester and University Hospital of South Manchester, NHS Foundation Trust, Manchester, UK; 2Novartis Pharma AG, Postfach, Basel, Switzerland; 3Respiratory Diseases, Novartis Institute for Biomedical Research, Horsham, West Sussex, UK *These authors contributed equally to this work Background: Increased pulmonary ceramide levels are suggested to play a causative role in lung diseases including COPD. Neutral sphingomyelinase-2 (nSMase-2 and acid SMase (aSMase, which hydrolyze sphingomyelin to produce ceramide, are activated by a range of cellular stresses, including inflammatory cytokines and pathogens, but notably cigarette smoke appears to only activate nSMase-2. Our primary objective was to investigate nSMase-2 and aSMase protein localization and quantification in lung tissue from nonsmokers (NS, smokers (S, and COPD patients. In addition, various ceramide species (C16, C18, and C20 were measured in alveolar macrophages from COPD patients versus controls. Materials and methods: Patients undergoing surgical resection for suspected or confirmed lung cancer were recruited, and nSMase-2 and aSMase protein was investigated in different areas of lung tissue (small airways, alveolar walls, subepithelium, and alveolar macrophages by immunohistochemistry. Ceramide species were measured in alveolar macrophages from COPD patients and controls by mass spectrometry. Results: nSMase-2 and aSMase were detected in the majority of small airways. There was a significant increase in nSMase-2 immunoreactivity in alveolar macrophages from COPD patients (54% compared with NS (31.7% (P<0.05, and in aSMase immunoreactivity in COPD (68.2% and S (69.5% alveolar macrophages compared with NS (52.4% (P

  2. Functional loss of two ceramide synthases elicits autophagy-dependent lifespan extension in C. elegans.

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    Mai-Britt Mosbech

    Full Text Available Ceramide and its metabolites constitute a diverse group of lipids, which play important roles as structural entities of biological membranes as well as regulators of cellular growth, differentiation, and development. The C. elegans genome comprises three ceramide synthase genes; hyl-1, hyl-2, and lagr-1. HYL-1 function is required for synthesis of ceramides and sphingolipids containing very long acyl-chains (≥C24, while HYL-2 is required for synthesis of ceramides and sphingolipids containing shorter acyl-chains (≤C22. Here we show that functional loss of HYL-2 decreases lifespan, while loss of HYL-1 or LAGR-1 does not affect lifespan. We show that loss of HYL-1 and LAGR-1 functions extend lifespan in an autophagy-dependent manner, as knock down of the autophagy-associated gene ATG-12 abolishes hyl-1;lagr-1 longevity. The transcription factors PHA-4/FOXA, DAF-16/FOXO, and SKN-1 are also required for the observed lifespan extension, as well as the increased number of autophagosomes in hyl-1;lagr-1 animals. Both autophagic events and the transcription factors PHA-4/FOXA, DAF-16, and SKN-1 have previously been associated with dietary restriction-induced longevity. Accordingly, we find that hyl-1;lagr-1 animals display reduced feeding, increased resistance to heat, and reduced reproduction. Collectively, our data suggest that specific sphingolipids produced by different ceramide synthases have opposing roles in determination of C. elegans lifespan. We propose that loss of HYL-1 and LAGR-1 result in dietary restriction-induced autophagy and consequently prolonged longevity.

  3. Chronic Voluntary Ethanol Consumption Induces Favorable Ceramide Profiles in Selectively Bred Alcohol-Preferring (P Rats.

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    Jessica Godfrey

    Full Text Available Heavy alcohol consumption has detrimental neurologic effects, inducing widespread neuronal loss in both fetuses and adults. One proposed mechanism of ethanol-induced cell loss with sufficient exposure is an elevation in concentrations of bioactive lipids that mediate apoptosis, including the membrane sphingolipid metabolites ceramide and sphingosine. While these naturally-occurring lipids serve as important modulators of normal neuronal development, elevated levels resulting from various extracellular insults have been implicated in pathological apoptosis of neurons and oligodendrocytes in several neuroinflammatory and neurodegenerative disorders. Prior work has shown that acute administration of ethanol to developing mice increases levels of ceramide in multiple brain regions, hypothesized to be a mediator of fetal alcohol-induced neuronal loss. Elevated ceramide levels have also been implicated in ethanol-mediated neurodegeneration in adult animals and humans. Here, we determined the effect of chronic voluntary ethanol consumption on lipid profiles in brain and peripheral tissues from adult alcohol-preferring (P rats to further examine alterations in lipid composition as a potential contributor to ethanol-induced cellular damage. P rats were exposed for 13 weeks to a 20% ethanol intermittent-access drinking paradigm (45 ethanol sessions total or were given access only to water (control. Following the final session, tissues were collected for subsequent chromatographic analysis of lipid content and enzymatic gene expression. Contrary to expectations, ethanol-exposed rats displayed substantial reductions in concentrations of ceramides in forebrain and heart relative to non-exposed controls, and modest but significant decreases in liver cholesterol. qRT-PCR analysis showed a reduction in the expression of sphingolipid delta(4-desaturase (Degs2, an enzyme involved in de novo ceramide synthesis. These findings indicate that ethanol intake levels

  4. Ceramide content is higher in type I compared to type II fibers in obesity and type 2 diabetes mellitus

    DEFF Research Database (Denmark)

    Kristensen, Ditte Bech; Prats Gavalda, Clara; Ara, Ignacio;

    2012-01-01

    This study investigated fiber-type-specific muscle ceramide content in obese subjects and type 2 diabetes patients. Two substudies, one which compared type 2 diabetes patients to both lean- and obese BMI-matched subjects and the other study which compared lean body-matched post-obese, obese...... index was higher in lean compared to type 2 diabetes patients and obese controls. Also in control and post-obese subjects, a higher insulin sensitivity was observed compared to obese subjects. Ceramide content was consistently higher in type I than in type II muscle fibers and higher in deltoideus than...... vastus lateralis across all groups. No significant differences between groups were observed in ceramide content in either of the two substudies. In human skeletal muscle, ceramide content was higher in type I than in type II fibers in patients with type 2 diabetes and in obese subjects, but overall...

  5. Magnesium deficiency upregulates sphingomyelinases in cardiovascular tissues and cells: cross-talk among proto-oncogenes, Mg(2+), NF-κB and ceramide and their potential relationships to resistant hypertension, atherogenesis and cardiac failure.

    Science.gov (United States)

    Altura, Burton M; Shah, Nilank C; Shah, Gatha J; Li, Wenyan; Zhang, Aimin; Zheng, Tao; Li, Zhiqiang; Jiang, Xian-Cheng; Perez-Albela, Jose Luis; Altura, Bella T

    2013-01-01

    The present study tested the hypotheses that 1) short-term (ST) dietary deficiency of magnesium (MgD; 21 days) in rats would result in the upregulation of neutral-, acid-, and alkaline- sphingomyelinases SMases) in cardiac and vascular smooth muscles (VSMCs), 2) ST MgD would result in an upregulation of proto-oncogenes, i.e., c-Fos and c-Jun, as well as the p65 and c-Rel components of NF-κB in cardiac and VSMCs, 3) low levels of Mg(2+) added to drinking water would either prevent or greatly reduce the upregulation of the SMases and proto-oncogene expression, 4) exposure of primary cultured VSMCs to low extracellular Mg(2+) concentration would lead to release of ceramide in both cerebral and aortic VSMCs, 5) specific inhibitors of neutral- and acid-SMAs would reduce the release of ceramide in cultured VSMCs exposed to low extracellular Mg(2+), and 6) specific inhibitors of neutral- and acid-SMases would lead to reductions in the expression of c-fos, c-Jun, and NF-κB components. The data indicate that neutral-, acid-and alkaline-SMases exist in rat cardiac and VSMCs. ST MgD resulted in over 150% increases in SMase activity and proto-oncogene expression in left and right ventricular muscle, atrial muscle, and abdominal aortic smooth muscle; even very low levels of Mg(2+) added to drinking water either prevented or ameliorated the activation of all 3-SMases as well as expression of c-Fos and c-Jun; scyphostatin and desipramine reduced the low Mg(2+) - induced expression of the proto-oncogenes as well as p65 and c-Rel in VSMCs. Exposure of the VSMCs to low Mg(2+) resulted in more than a 100% increase in release of ceramide; scyphostatin and desipramine reduced greatly the release of ceramide from the VSMCs. We believe when the present data are viewed in light of our previous, recent findings on the effects of Mg deficiency on most of the major enzymes in the sphingomyelin-ceramide pathway, that they could provide a rational basis for the treatment and prevention of

  6. Role of Sphingolipid Mediator Ceramide in Obesity and Renal Injury in Mice Fed a High-Fat DietS⃞

    OpenAIRE

    Boini, Krishna M.; Zhang, Chun; Xia, Min; Poklis, Justin L.; Li, Pin-Lan

    2010-01-01

    The present study tested a hypothesis that excess accumulation of sphingolipid, ceramide, its metabolites, or a combination contributes to the development of obesity and associated kidney damage. Liquid chromatography/mass spectrometry analysis demonstrated that C57BL/6J mice on the high-fat diet (HFD) had significantly increased plasma total ceramide levels compared with animals fed a low-fat diet (LFD)...

  7. Suppression of sphingomyelin synthase 1 by small interference RNA is associated with enhanced ceramide production and apoptosis after photodamage

    OpenAIRE

    Separovic, Duska; Semaan, Louie; Tarca, Adi L.; Maitah, Ma’In Yehya Awad; Hanada, Kentaro; Bielawski, Jacek; Villani, Maristella; Luberto, Chiara

    2008-01-01

    We have shown that overexpression of SMS1, an enzyme that converts de novo ceramide into sphingomyelin, is accompanied by attenuated ceramide response and apoptotic resistance after photodamage with the photosensitizer Pc 4 (photodynamic therapy; PDT). To test whether SMS1 overexpression-related effects after PDT can be reversed, in this study SMS1 was downregulated in Jurkat T lymphoma/leukemia cells using small inhibitory RNA (siRNA) for SMS1. Compared to scrambled (control) siRNA-transfect...

  8. Topical effects of N-acetyl-L-hydroxyproline on ceramide synthesis and alleviation of pruritus

    Directory of Open Access Journals (Sweden)

    Hashizume E

    2013-02-01

    Full Text Available Erika Hashizume,1 Tetsuo Nakano,2 Ayako Kamimura,1 Koji Morishita31Healthcare Products Development Center, Kyowa Hakko Bio, Tsukuba, Ibaraki, 2Technical Research Laboratories, Kyowa Hakko Bio, Hofu, Yamaguchi, 3Technology Development and Research Department, Kyowa Hakko Bio, Tokyo, JapanPurpose: N-acetyl-l-hydroxyproline (AHYP is an acetylated form of l-hydroxyproline that is used to treat skin ulcers and porphyria cutanea tarda. Its other biological and physiological effects on the skin have not been elucidated. We investigated the effects of AHYP on the skin-barrier function, focusing on ceramide synthesis and the effects of topical AHYP on atopic dermatitis.Materials and methods: AHYP was applied to a three-dimensional cultured skin model. Ceramides were quantified by high-performance thin-layer chromatography. Serine palmitoyltransferase (SPT is the rate-limiting enzyme in de novo ceramide synthesis, and the mRNA of its long-chain base subunit 1 (SPTLC1 was evaluated by quantitative reverse-transcription polymerase chain reaction. A clinical trial in the form of an intraindividual, comparative, double-blind, randomized, vehicle-controlled test involving 15 female subjects suffering from slight atopic dermatitis was performed. Subjects applied 1% (w/w AHYP cream to one forearm and a control cream to the other forearm twice daily for 4 weeks. Skin condition was evaluated by measuring transepidermal water loss (TEWL. Dermatological observations were made by a dermatologist, and subjects evaluated their own pruritus intensity before beginning treatment and 4 weeks after the start of treatment.Results: SPTLC1 expression and ceramide synthesis were significantly increased in an AHYP-treated skin model (P < 0.05. In the clinical trial, no adverse effects were observed in any subjects. TEWL was increased in the control-treated region of the forearm (P < 0.05 after 4 weeks' application, whereas there was no change in the AHYP-treated region of the

  9. Isolation and characterization of new ceramides from aerial parts of Lepidaploa cotoneaster.

    Science.gov (United States)

    dos Santos, Edlene O; Meira, Marilena; do Vale, Ademir E; David, Jorge M; de Queiróz, Luciano P; David, Juceni P

    2012-06-01

    Two new ceramides were isolated from the bulbs of Lepidaploa cotoneaster (Willd. ex Spreng.) H. Rob. [Vernonia cotoneaster (Willd. ex Spreng.) Less.)], in addition to germanicol, beta-sitosterol, stigmasterol, 3-beta-O-beta-D-glucopyranosyl-sitosterol, lupeol, lupeoyl acetate and tiliroside. The structures of the new compounds were elucidated by spectral techniques (MS, 1H NMR, 13C NMR, HSQC, HMBC, DEPT, and TOCSY) and were compared with data reported in literature, and were established as 2S*,2'R*,3S*,4R*,11E)-N-[2'-hydroxyhenicosanoyl]-2-amino-nonadec-11-ene-1,3,4-triol (1) and (2S*,2'R*,3S*,4R*,8E)-N-[2'-hydroxytricosanoyl]-2-amino-nonadec-8-ene-1,3,4-triol (2). To establish the structure and to locate the double bond, the methyl ester of the fatty acid and dimethyl disulfide (DMDS) derivatives were prepared for both ceramides.

  10. The Permeability Enhancing Mechanism of DMSO in Ceramide Bilayers Simulated by Molecular Dynamics

    OpenAIRE

    Notman, Rebecca; den Otter, Wouter K.; Noro, Massimo G.; Briels, W. J.; Anwar, Jamshed

    2007-01-01

    The lipids of the topmost layer of the skin, the stratum corneum, represent the primary barrier to molecules penetrating the skin. One approach to overcoming this barrier for the purpose of delivery of active molecules into or via the skin is to employ chemical permeability enhancers, such as dimethylsulfoxide (DMSO). How these molecules exert their effect at the molecular level is not understood. We have investigated the interaction of DMSO with gel-phase bilayers of ceramide 2, the predomin...

  11. Ceramide Stimulates ABCA12 Expression via Peroxisome Proliferator-activated Receptor δ in Human Keratinocytes*

    OpenAIRE

    Jiang, Yan J.; Uchida, Yoshikazu; Lu, Biao; Kim, Peggy; Mao, Cungui; Akiyama, Masashi; Elias, Peter M.; Holleran, Walter M.; Grunfeld, Carl; Feingold, Kenneth R.

    2009-01-01

    ABCA12 (ATP binding cassette transporter, family 12) is a cellular membrane transporter that facilitates the delivery of glucosylceramides to epidermal lamellar bodies in keratinocytes, a process that is critical for permeability barrier formation. Following secretion of lamellar bodies into the stratum corneum, glucosylceramides are metabolized to ceramides, which comprise ∼50% of the lipid in stratum corneum. Gene mutations of ABCA12 underlie harlequin ichthyosis, a devastating skin disorde...

  12. Induction of a Hardening Phenomenon and Quantitative Changes of Ceramides in Stratum Corneum

    OpenAIRE

    Park, Sook Young; Kim, Jin Hye; Cho, Soo Ick; Kim, Kyeong Il; Cho, Hee Jin; Park, Chun Wook; Lee, Cheol Heon; Kim, Hye One

    2014-01-01

    Background Hardening phenomenon of human skin after repeated exposure to the irritants is well-known, but the precise mechanism remains elusive. Objective To modify the previous experimental model of hardening phenomenon by repeated applications of two different concentrations of sodium lauryl sulfate (SLS) solutions to Korean healthy volunteers and to investigate the quantitative changes of ceramides in stratum corneum before and after chronic repeated irritation. Methods Eight hundred micro...

  13. Comprehensive quantification of ceramide species in human stratum corneum[S

    OpenAIRE

    Masukawa, Yoshinori; Narita, Hirofumi; Sato, Hirayuki; Naoe, Ayano; Kondo, Naoki; Sugai, Yoshiya; Oba, Tsuyoshi; Homma, Rika; Ishikawa, Junko; Takagi, Yutaka; Kitahara, Takashi

    2009-01-01

    One of the key challenges in lipidomics is to quantify lipidomes of interest, as it is practically impossible to collect all authentic materials covering the targeted lipidomes. For diverse ceramides (CER) in human stratum corneum (SC) that play important physicochemical roles in the skin, we developed a novel method for quantification of the overall CER species by improving our previously reported profiling technique using normal-phase liquid chromatog­raphy-electrospray ionization-mass spec...

  14. Accumulation of Ordered Ceramide-Cholesterol Domains in Farber Disease Fibroblasts

    OpenAIRE

    Ferreira, Natalia Santos; Goldschmidt-Arzi, Michal; Sabanay, Helena; Storch, Judith; Levade, Thierry; Ribeiro, Maria Gil; Addadi, Lia; Futerman, Anthony H.

    2013-01-01

    Farber disease is an inherited metabolic disorder caused by mutations in the acid ceramidase gene, which leads to ceramide accumulation in lysosomes. Farber disease patients display a wide variety of symptoms with most patients eventually displaying signs of nervous system dysfunction. We now present a novel tool that could potentially be used to distinguish between the milder and more severe forms of the disease, namely, an antibody that recognizes a mixed monolayer or bilayer of cholesterol...

  15. Hyperosmolarity-induced lipid droplet formation depends on ceramide production by neutral sphingomyelinase 2[S

    OpenAIRE

    Robciuc, Alexandra; Hyötyläinen, Tuulia; Jauhiainen, Matti; Holopainen, Juha M.

    2012-01-01

    Hyperosmolarity (HO) imposes a remarkable stress on membranes, especially in tissues in direct contact with the external environment. Our efforts were focused on revealing stress-induced lipid changes that precede the inflammatory cytokine response in human corneal epithelial cells exposed to increasing osmolarity. We used a lipidomic analysis that detected significant and systematic changes in the lipid profile, highly correlated with sodium concentrations in the medium. Ceramides and trigly...

  16. Functions of Ceramide Synthase Paralogs YPR114w and YJR116w of Saccharomyces cerevisiae.

    Directory of Open Access Journals (Sweden)

    Shamroop K Mallela

    Full Text Available Ceramide is synthesized in yeast by two redundant acyl-CoA dependent synthases, Lag1 and Lac1. In lag1∆ lac1∆ cells, free fatty acids and sphingoid bases are elevated, and ceramides are produced through the redundant alkaline ceramidases Ypc1 and Ydc1, working backwards. Even with all four of these genes deleted, cells are surviving and continue to contain small amounts of complex sphingolipids. Here we show that these residual sphingolipids are not synthesized by YPR114w or YJR116w, proteins of unknown function showing a high degree of homology to Lag1 and Lac1. Indeed, the hextuple lag1∆ lac1∆ ypc1∆ ydc1∆ ypr114w∆ yjr116w∆ mutant still contains ceramides and complex sphingolipids. Yjr116w∆ exhibit an oxygen-dependent hypersensitivity to Cu2+ due to an increased mitochondrial production of reactive oxygen species (ROS and a mitochondrially orchestrated programmed cell death in presence of copper, but also a general copper hypersensitivity that cannot be counteracted by the antioxidant N-acetyl-cysteine (NAC. Myriocin efficiently represses the synthesis of sphingoid bases of ypr114w∆, but not its growth. Both yjr116w∆ and ypr114w∆ have fragmented vacuoles and produce less ROS than wild type, before and after diauxic shift. Ypr114w∆/ypr114w∆ have an increased chronological life span. Thus, Yjr116w and Ypr114w are related, but not functionally redundant.

  17. Functions of Ceramide Synthase Paralogs YPR114w and YJR116w of Saccharomyces cerevisiae

    DEFF Research Database (Denmark)

    Mallela, Shamroop K; Almeida, Reinaldo; Ejsing, Christer S;

    2016-01-01

    Ceramide is synthesized in yeast by two redundant acyl-CoA dependent synthases, Lag1 and Lac1. In lag1∆ lac1∆ cells, free fatty acids and sphingoid bases are elevated, and ceramides are produced through the redundant alkaline ceramidases Ypc1 and Ydc1, working backwards. Even with all four...... of these genes deleted, cells are surviving and continue to contain small amounts of complex sphingolipids. Here we show that these residual sphingolipids are not synthesized by YPR114w or YJR116w, proteins of unknown function showing a high degree of homology to Lag1 and Lac1. Indeed, the hextuple lag1∆ lac1......∆ ypc1∆ ydc1∆ ypr114w∆ yjr116w∆ mutant still contains ceramides and complex sphingolipids. Yjr116w∆ exhibit an oxygen-dependent hypersensitivity to Cu2+ due to an increased mitochondrial production of reactive oxygen species (ROS) and a mitochondrially orchestrated programmed cell death in presence...

  18. Exercise and training effects on ceramide metabolism in human skeletal muscle

    DEFF Research Database (Denmark)

    Helge, Jørn Wulff; Dobrzyn, Agnieszka; Saltin, Bengt;

    2004-01-01

    In rat skeletal muscle prolonged exercise affects the content and composition of ceramides, but in human skeletal muscle no data are available on this compound. Our aim was to examine the content of ceramide- and sphingomyelin fatty acids and neutral, Mg(2+)-dependent sphingomyelinase activity in...... and in trained subjects and this may influence muscle cell adaptation and metabolism....... in skeletal muscle in untrained and trained subjects before and after prolonged exercise. Healthy male subjects were recruited into an untrained (n = 8, VO2,max 3.8 +/- 0.2 1 min1) and a trained (n = 8, Vo2,max 5.1 +/- 0.1 1 min2) group. Before and after a 3-h exercise bout (58 +/- 1% VO2,max) a muscle biopsy...... was measured using N-[14CH3]-sphingomyelin as a substrate. Prior to exercise, the muscle total ceramide fatty acid content in both groups was similar (201 +/- 18 and 197 +/- 9 nmol g(-1) in the untrained and trained group, respectively) and after exercise a 25% increase in the content was observed in each...

  19. Analysis of Skeletal Muscle Torque Capacity and Circulating Ceramides in Patients with Advanced Heart Failure

    Science.gov (United States)

    Brunjes, Danielle L.; Dunlop, Mark; Wu, Christina; Jones, Meaghan; Kato, Tomoko S.; Kennel, Peter J.; Armstrong, Hilary F.; Choo, Tse-Hwei; Bartels, Matthew N.; Forman, Daniel E.; Mancini, Donna M.; Schulze, P. Christian

    2016-01-01

    Background Heart failure (HF)-related exercise intolerance is thought to be perpetuated by peripheral skeletal muscle functional, structural, and metabolic abnormalities. We analyzed specific dynamics of muscle contraction in patients with HF compared with healthy, sedentary controls. Methods Isometric and isokinetic muscle parameters were measured in the dominant upper and lower limbs of 45 HF patients and 15 healthy age-matched controls. Measurements included peak torque normalized to body weight, work normalized to body weight, power, time to peak torque, and acceleration and deceleration to maximum strength times. Body morphometry (dual energy X-ray absorptiometry scan) and circulating fatty acids and ceramides (lipodomics) were analyzed in a subset of subjects (18 HF and 9 controls). Results Extension and flexion time-to-peak torque was longer in the lower limbs of HF patients. Furthermore, acceleration and deceleration times in the lower limbs were also prolonged in HF subjects. HF subjects had increased adiposity and decreased lean muscle mass compared with controls. Decreased circulating unsaturated fatty acids and increased ceramides were found in subjects with HF. Conclusions Delayed torque development suggests skeletal muscle impairments that may reflect abnormal neuromuscular functional coupling. These impairments may be further compounded by increased adiposity and inflammation associated with increased ceramides. PMID:26879888

  20. Plasma ceramide and glucosylceramide metabolism is altered in sporadic Parkinson's disease and associated with cognitive impairment: a pilot study.

    Directory of Open Access Journals (Sweden)

    Michelle M Mielke

    Full Text Available BACKGROUND: Mutations in the gene coding for glucocerebrosidase (GBA, which metabolizes glucosylceramide (a monohexosylceramide into glucose and ceramide, is the most common genetic risk factor for sporadic Parkinson's disease (PD. GBA mutation carriers are more likely to have an earlier age of onset and to develop cognitive impairment and dementia. We hypothesized that plasma levels of lipids involved in ceramide metabolism would also be altered in PD non-GBA mutation carriers and associated with worse cognition. METHODS: Plasma ceramide, monohexosylceramide, and lactosylceramide levels in 26 cognitively normal PD patients, 26 PD patients with cognitive impairment or dementia, and 5 cognitively normal non-PD controls were determined by LC/ESI/MS/MS. RESULTS: Levels of all lipid species were higher in PD patients versus controls. Among PD patients, levels of ceramide C16:0, C18:0, C20:0, C22:0, and C24:1 and monohexosylceramide C16:0, C20:0 and C24:0 species were higher (all P<0.05 in those with versus without cognitive impairment. CONCLUSION: These results suggest that plasma ceramide and monohexosylceramide metabolism is altered in PD non-GBA mutation carriers and that higher levels are associated with worse cognition. Additional studies with larger sample sizes, including cognitively normal controls, are needed to confirm these findings.

  1. Serum sphingolipidomic analyses reveal an upregulation of C16-ceramide and sphingosine-1-phosphate in hepatocellular carcinoma.

    Science.gov (United States)

    Grammatikos, Georgios; Schoell, Niklas; Ferreirós, Nerea; Bon, Dimitra; Herrmann, Eva; Farnik, Harald; Köberle, Verena; Piiper, Albrecht; Zeuzem, Stefan; Kronenberger, Bernd; Waidmann, Oliver; Pfeilschifter, Josef

    2016-04-01

    We have recently shown that major alterations of serum sphingolipid metabolites in chronic liver disease associate significantly with the stage of liver fibrosis in corresponding patients. In the current study we assessed via mass spectrometry serum concentrations of sphingolipid metabolites in a series of 122 patients with hepatocellular carcinoma (HCC) compared to an age- and sex-matched series of 127 patients with cirrhosis. We observed a highly significant upregulation of long and very long chain ceramides (C16-C24) in the serum of patients with HCC as compared to patients with cirrhosis (P < 0.001). Accordingly, dihydro-ceramides, synthetic precursors of ceramides and notably sphingosine, sphingosine-1-phosphate (S1P) and sphinganine-1-phosphate (SA1P) were upregulated in patients with HCC (P < 0.001). Especially the diagnostic accuracy of C16-ceramide and S1P, assessed by receiver operating curve (ROC) analysis, showed a higher area under the curve (AUC) value as compared to alpha fetoprotein (AFP) (0.999 and 0.985 versus 0.823, P < 0.001 respectively). In conclusion, serum levels of sphingolipid metabolites show a significant upregulation in patients with HCC as compared to patients with cirrhosis. Particularly C16-ceramide and S1P may serve as novel diagnostic markers for the identification of HCC in patients with liver diseases. Our data justify further investigations on the role of sphingolipids in HCC. PMID:26933996

  2. Fenofibrate Reverses Palmitate Induced Impairment in Glucose Uptake in Skeletal Muscle Cells by Preventing Cytosolic Ceramide Accumulation

    Directory of Open Access Journals (Sweden)

    Sudarshan Bhattacharjee

    2015-10-01

    Full Text Available Backgrounds/Aims: The lipid induced insulin resistance is a major pathophysiologic mechanism underlying glucose intolerance of varying severity. PPARα-agonists are proven as effective hypolipidemic agents. The aim of this study was to see if impaired glucose uptake in palmitate treated myotubes is reversed by fenofibrate. Methods: Palmitate-treated myotubes were used as a model for insulin resistance, impaired glucose uptake, fatty acid oxidation and ceramide synthesis. mRNA levels of CPT1 and CPT2 were determined by PCR array and Q-PCR. Results: The incubation of myotubes with 750 uM palmitate not only reduced glucose uptake but also impaired fatty acid oxidation and cytosolic ceramide accumulation. Palmitate upregulated CPT1b expression in L6 myotubes, while CPT2 expression level remained unchanged. The altered stoichiometric ratio between the two CPT isoforms led to reduced fatty acid oxidation (FAO, ceramide accumulation and impaired glucose uptake, whereas administration of 200 µM fenofibrate signifcantly reversed the above abnormalities by increasing CPT2 mRNA levels and restoring CPT1b to CPT2 ratio. Conclusion: Palmitate-induced alteration in the stoichiometric ratio of mitochondrial CPT isoforms leads to incomplete FAO and enhanced cytosolic ceramide accumulation that lead to insulin resistance. Fenofibrate ameliorated insulin resistance by restoring the altered stoichiometry by upregulating CPT2 and preventing, cytoplasmic ceramide accumulation.

  3. Induction of membrane ceramides: a novel strategy to interfere with T lymphocyte cytoskeletal reorganisation in viral immunosuppression.

    Directory of Open Access Journals (Sweden)

    Evelyn Gassert

    2009-10-01

    Full Text Available Silencing of T cell activation and function is a highly efficient strategy of immunosuppression induced by pathogens. By promoting formation of membrane microdomains essential for clustering of receptors and signalling platforms in the plasma membrane, ceramides accumulating as a result of membrane sphingomyelin breakdown are not only essential for assembly of signalling complexes and pathogen entry, but also act as signalling modulators, e. g. by regulating relay of phosphatidyl-inositol-3-kinase (PI3K signalling. Their role in T lymphocyte functions has not been addressed as yet. We now show that measles virus (MV, which interacts with the surface of T cells and thereby efficiently interferes with stimulated dynamic reorganisation of their actin cytoskeleton, causes ceramide accumulation in human T cells in a neutral (NSM and acid (ASM sphingomyelinase-dependent manner. Ceramides induced by MV, but also bacterial sphingomyelinase, efficiently interfered with formation of membrane protrusions and T cell spreading and front/rear polarisation in response to beta1 integrin ligation or alphaCD3/CD28 activation, and this was rescued upon pharmacological or genetic ablation of ASM/NSM activity. Moreover, membrane ceramide accumulation downmodulated chemokine-induced T cell motility on fibronectin. Altogether, these findings highlight an as yet unrecognised concept of pathogens able to cause membrane ceramide accumulation to target essential processes in T cell activation and function by preventing stimulated actin cytoskeletal dynamics.

  4. Dimyristoylphosphatidylcholine/C16 : 0-ceramide binary liposomes studied by differential scanning calorimetry and wide- and small-angle X-ray scattering

    DEFF Research Database (Denmark)

    Holopainen, J.M.; Lemmich, J.; Richter, F.;

    2000-01-01

    hydrated binary membranes composed of dimyristoylphosphatidylcholine (DMPC) and N-palmitoyl-ceramide (C16:0-ceramide, up to a mole fraction X-cer = 0.35) were resolved in further detail by high-sensitivity differential scanning calorimetry (DSC) and x-ray diffraction. Both methods reveal very strong...

  5. Ceramide Accumulation in Yeast Yarrowia lipolitica%解脂假丝酵母中神经酰胺的积累研究

    Institute of Scientific and Technical Information of China (English)

    周全; 陈国强

    2005-01-01

    Ceramides are a class of lipid molecules widely distributed in eukaryotic cells in small amount. To investigate the possibility of ceramide production by yeast, a yeast strain Yarrowia lipolitica was grown under different conditions including changing carbon/nitrogen ratio, and serine concentration, dissolved oxygen and presence of ethanol It was found that increased dissolved oxygen supply increased the ceramide content in the yeast 2.5 fold of its normal control level. Ethanol treatment could also enhance ceramide accumulation by 3.3 fold compared with the control although the cell growth was negatively affected. Cellular redox potential was shown to affect ceramide accumulation by the yeast. This was possibly related to the cellular reactive oxygen species presented in the yeast.

  6. Extending the Glucosyl Ceramide Cassette Approach: Application in the Total Synthesis of Ganglioside GalNAc-GM1b

    Directory of Open Access Journals (Sweden)

    Miku Konishi

    2013-12-01

    Full Text Available The development of a novel cyclic glucosyl ceramide cassette acceptor for efficient glycolipid syntheses was investigated. p-Methoxybenzyl (PMB groups were selected as protecting groups at C2 and C3 of the glucose residue with the aim of improving the functionality of the cassette acceptor. The choice of the PMB group resulted in a loss of β-selectivity, which was corrected by using an appropriate tether to control the spatial arrangement and the nitrile solvent effect. To investigate the effect of linker structure on the β-selectivity of intramolecular glycosylation, several linkers for tethering the glucose and ceramide moiety were designed and prepared, namely, succinyl, glutaryl, dimethylmalonyl, and phthaloyl esters. The succinyl ester linker was the best for accessing the cassette form. The newly designed glucosyl ceramide cassette acceptor was then applied in the total synthesis of ganglioside GalNAc-GM1b.

  7. Ceramide-Enriched Membrane Domains in Red Blood Cells and the Mechanism ofSphingomyelinase-Induced Hot-Cold Hemolysis

    DEFF Research Database (Denmark)

    Montes, Ruth; Lopez, David; Sot, Jesus;

    2008-01-01

    Hot-cold hemolysis is the phenomenon whereby red blood cells, preincubated at 37 °C in the presence of certain agents, undergo rapid hemolysis when transferred to 4 °C. The mechanism of this phenomenon is not understood. PlcHR2, a phospholipase C/sphingomyelinase from Pseudomonas aeruginosa......) but also in goat erythrocytes, which lack PC. However, in horse erythrocytes, with a large proportion of PC and almost no SM, hot-cold hemolysis induced by PlcHR2 is not observed. Fluorescence microscopy observations confirm the formation of ceramide-enriched domains as a result of PlcHR2 activity. After......-cold hemolysis. Differential scanning calorimetry of erytrocyte membranes treated with PlcHR2 demonstrates the presence of ceramide-rich domains that are rigid at 4 °C but fluid at 37 °C. Ceramidase treatment causes the disapperance of the calorimetric signal assigned to ceramide-rich domains. Finally...

  8. A single prior bout of exercise protects against palmitate-induced insulin resistance despite an increase in total ceramide content.

    Science.gov (United States)

    Thrush, A Brianne; Harasim, Ewa; Chabowski, Adrian; Gulli, Roberto; Stefanyk, Leslie; Dyck, David J

    2011-05-01

    Ceramide accumulation has been implicated in the impairment of insulin-stimulated glucose transport in skeletal muscle following saturated fatty acid (FA) exposure. Importantly, a single bout of exercise can protect against acute lipid-induced insulin resistance. The mechanism by which exercise protects against lipid-induced insulin resistance is not completely known but may occur through a redirection of FA toward triacylglycerol (TAG) and away from ceramide and diacylglycerol (DAG). Therefore, in the current study, an in vitro preparation was used to examine whether a prior bout of exercise could confer protection against palmitate-induced insulin resistance and whether the pharmacological [50 μM fumonisin B(1) (FB1)] inhibition of ceramide synthesis in the presence of palmitate could mimic the protective effect of exercise. Soleus muscle of sedentary (SED), exercised (EX), and SED in the presence of FB1 (SED+FB1) were incubated with or without 2 mM palmitate for 4 h. This 2-mM palmitate exposure impaired insulin-stimulated glucose transport (-28%, P TAG accumulation in the SED group (P TAG (P net increase in ceramide content in response to palmitate exposure in the EX group was not different compared with SED, despite the maintenance of insulin sensitivity. The incubation of soleus from SED rats with FB1 (SED+FB1) prevented the detrimental effects of palmitate and caused a redirection of FA toward TAG accumulation (P < 0.05). Therefore, this research suggests that although inhibiting ceramide accumulation can prevent the detrimental effects of palmitate, a single prior bout of exercise appears to protect against palmitate-induced insulin resistance, which may be independent of changes in ceramide content. PMID:21325642

  9. Mechanisms of lung endothelial barrier disruption induced by cigarette smoke: role of oxidative stress and ceramides.

    Science.gov (United States)

    Schweitzer, Kelly S; Hatoum, Hadi; Brown, Mary Beth; Gupta, Mehak; Justice, Matthew J; Beteck, Besem; Van Demark, Mary; Gu, Yuan; Presson, Robert G; Hubbard, Walter C; Petrache, Irina

    2011-12-01

    The epithelial and endothelial cells lining the alveolus form a barrier essential for the preservation of the lung respiratory function, which is, however, vulnerable to excessive oxidative, inflammatory, and apoptotic insults. Whereas profound breaches in this barrier function cause pulmonary edema, more subtle changes may contribute to inflammation. The mechanisms by which cigarette smoke (CS) exposure induce lung inflammation are not fully understood, but an early alteration in the epithelial barrier function has been documented. We sought to investigate the occurrence and mechanisms by which soluble components of mainstream CS disrupt the lung endothelial cell barrier function. Using cultured primary rat microvascular cell monolayers, we report that CS induces endothelial cell barrier disruption in a dose- and time-dependent manner of similar magnitude to that of the epithelial cell barrier. CS exposure triggered a mechanism of neutral sphingomyelinase-mediated ceramide upregulation and p38 MAPK and JNK activation that were oxidative stress dependent and that, along with Rho kinase activation, mediated the endothelial barrier dysfunction. The morphological changes in endothelial cell monolayers induced by CS included actin cytoskeletal rearrangement, junctional protein zonula occludens-1 loss, and intercellular gap formation, which were abolished by the glutathione modulator N-acetylcysteine and ameliorated by neutral sphingomyelinase inhibition. The direct application of ceramide recapitulated the effects of CS, by disrupting both endothelial and epithelial cells barrier, by a mechanism that was redox and apoptosis independent and required Rho kinase activation. Furthermore, ceramide induced dose-dependent alterations of alveolar microcirculatory barrier in vivo, measured by two-photon excitation microscopy in the intact rat. In conclusion, soluble components of CS have direct endothelial barrier-disruptive effects that could be ameliorated by glutathione

  10. Phospholipase C-catalyzed sphingomyelin hydrolysis in a membrane reactor for ceramide production

    DEFF Research Database (Denmark)

    Zhang, Long; Liang, Shanshan; Hellgren, Lars;

    2008-01-01

    of sphingomyelin has been proven to be a feasible method to produce ceramide. In the membrane reactor constructed, the aqueous phase and the organic phase were separated by a membrane containing the immobilized enzyme, while the organic phasewas continuously circulated. Among the 10 selected membranes, the enzyme...... immobilized in membrane RC 70PP had low immobilization efficiency, but retained the highest catalytic activity. Three immobilization methods, i.e. filtration (adsorption/entrapment), covalent binding, and cross-linking, were compared. The enzyme immobilized by filtration had the highest activity even under...

  11. Preclinical development of a C6-ceramide NanoLiposome, a novel sphingolipid therapeutic.

    Science.gov (United States)

    Kester, Mark; Bassler, Jocelyn; Fox, Todd E; Carter, Carly J; Davidson, Jeff A; Parette, Mylisa R

    2015-06-01

    Despite the therapeutic potential of sphingolipids, the ability to develop this class of compounds as active pharmaceutical ingredients has been hampered by issues of solubility and delivery. Beyond these technical hurdles, significant challenges in completing the necessary preclinical studies to support regulatory review are necessary for commercialization. This review seeks to identify the obstacles and potential solutions in the translation of a novel liposomal technology from the academic bench to investigational new drug (IND) stage by discussing the preclinical development of the Ceramide NanoLiposome (CNL), which is currently being developed as an anticancer drug for the initial indication of hepatocellular carcinoma (HCC).

  12. Comparative atomic-scale hydration of the ceramide and phosphocholine headgroup in solution and bilayer environments.

    Science.gov (United States)

    Gillams, Richard J; Lorenz, Christian D; McLain, Sylvia E

    2016-06-14

    Previous studies have used neutron diffraction to elucidate the hydration of the ceramide and the phosphatidylcholine headgroup in solution. These solution studies provide bond-length resolution information on the system, but are limited to liquid samples. The work presented here investigates how the hydration of ceramide and phosphatidylcholine headgroups in a solution compares with that found in a lipid bilayer. This work shows that the hydration patterns seen in the solution samples provide valuable insight into the preferential location of hydrating water molecules in the bilayer. There are certain subtle differences in the distribution, which result from a combination of the lipid conformation and the lipid-lipid interactions within the bilayer environment. The lipid-lipid interactions in the bilayer will be dependent on the composition of the bilayer, whereas the restricted exploration of conformational space is likely to be applicable in all membrane environments. The generalized description of hydration gathered from the neutron diffraction studies thus provides good initial estimation for the hydration pattern, but this can be further refined for specific systems. PMID:27306021

  13. HOS3, an ELO-Like Gene, Inhibits Effects of ABA and Implicates a S-1-P/Ceramide Control System for Abiotic Stress Responses in Arabidopsis thaliana

    Institute of Scientific and Technical Information of China (English)

    Tanya M. Quist; Irina Sokolchik; Huazhong Shi; Robert J. Joly; Ray A. Bressan; Albino Maggio; Meena Narsimhan; Xia Li

    2009-01-01

    A hyper-osmotically sensitive mutant of Arabidopsis thaliana, designated hos3-1 (high expression of osmotically responsive genes), was identified based on its hyper-luminescence of RD29A:LUC promoter fusion plants upon treatment with NaCI and ABA. These responses implicate the disrupted gene as a direct or indirect negative regulator of the RD29A stress-responsive pathway. By sequencing the flanking regions of the T-DNA borders, it was determined that the disrupted gene is at locus At4g36830, annotated as encoding a putative protein with high homology to CIG30 (ELO2/FEN1).CIG30 has been implicated in synthesis of very long chain fatty acids (VLCFA), which are essential precursors for sphingolipids and ceramides. Altered stress responses characteristic of ABA-hypersensitivity, including reduced root growth inhibition and reduced germination with ABA treatment and reduced water loss from leaves, were exhibited by allelic hos3-1 and hos3-2 mutants. The hos3-2 mutant is partially suppressed in its transcript abundance and is inherited as a recessive trait. Further, the HOS30RF under the control of the 35SCaMV promoter restored wild-type NaCI- and ABA-root growth sensitivity as well as RD29A:LUC luminescence in mutant plants. We also show here that the HOS3 wild-type gene functionally complements the sensitivity of elo2 and elo3 yeast mutants to monensin. Furthermore, both hos3-1 and hos3-2 alleles shared increased sensitivity to the herbicide Metolachlor, which inhibits acyl chain elongation in synthesis of VLCFA, and HOS3 functionally complemented both elo2 and elo3 and restored levels of VLCFA. Together, these data establish that HOS3 inhibits ABA-mediated stress responses and implicate the VLCFA pathway and products as control points for several aspects of abiotic stress signaling and responses. The results also provide support for a role of ceramide in the control of stomatal behavior.

  14. Differential activation of acid sphingomyelinase and ceramide release determines invasiveness of Neisseria meningitidis into brain endothelial cells.

    Directory of Open Access Journals (Sweden)

    Alexander Simonis

    2014-06-01

    Full Text Available The interaction with brain endothelial cells is central to the pathogenicity of Neisseria meningitidis infections. Here, we show that N. meningitidis causes transient activation of acid sphingomyelinase (ASM followed by ceramide release in brain endothelial cells. In response to N. meningitidis infection, ASM and ceramide are displayed at the outer leaflet of the cell membrane and condense into large membrane platforms which also concentrate the ErbB2 receptor. The outer membrane protein Opc and phosphatidylcholine-specific phospholipase C that is activated upon binding of the pathogen to heparan sulfate proteoglycans, are required for N. meningitidis-mediated ASM activation. Pharmacologic or genetic ablation of ASM abrogated meningococcal internalization without affecting bacterial adherence. In accordance, the restricted invasiveness of a defined set of pathogenic isolates of the ST-11/ST-8 clonal complex into brain endothelial cells directly correlated with their restricted ability to induce ASM and ceramide release. In conclusion, ASM activation and ceramide release are essential for internalization of Opc-expressing meningococci into brain endothelial cells, and this segregates with invasiveness of N. meningitidis strains.

  15. The ceramide inhibitor fumonisin B1 mitigates the pulmonary effects of low-dose diesel exhaust inhalation in mice.

    Science.gov (United States)

    Shaheen, Hazem M; Onoda, Atsuto; Shinkai, Yusuke; Nakamura, Masayuki; El-Ghoneimy, Ashraf A; El-Sayed, Yasser S; Takeda, Ken; Umezawa, Masakazu

    2016-10-01

    Recent studies have suggested that inhalation of diesel exhaust (DE), a major source of air pollution, results in pulmonary alterations; however, the effects of DE at low concentrations are poorly understood. Therefore, this study was conducted to elucidate the pulmonary effects of low-level exposure to DE and the potential role of a ceramide de novo biosynthesis inhibitor, fumonisin B1 (FB1) to ameliorate the DE-toxicity. Male C57BL/6J mice underwent 1- or 7-day experiments (4 equal groups/experiment) and were assigned to the control, DE (0.1mg/m(3)), FB1 (6.75mg/kg body weight SC at days 0, 3 and 6) or DE+FB1 groups. DE and/or FB1 treatment had no effect on the expression of Nos2, a biomarker of oxidative stress. Ceramide production in the bronchial epithelial cells and Sphk1 mRNA expression were induced in the lung after the 7-day DE exposure and were partially suppressed by the FB1 treatment. Additionally, the effects of DE on SP-A and SP-D mRNA expression were also suppressed by the FB1 treatment. These results suggest that ceramide and Sphk1 may be sensitive biomarkers for low-level DE-induced pulmonary effects. Collectively, ceramide likely contributes to the DE-induced early stage of airway inflammation, which is considered a potential pulmonary target during low-level DE exposure. PMID:27376354

  16. Ceramide targets xIAP and cIAP1 to sensitize metastatic colon and breast cancer cells to apoptosis induction to suppress tumor progression

    International Nuclear Information System (INIS)

    Ceramide is a bioeffector that mediates various cellular processes, including apoptosis. However, the mechanism underlying ceramide function in apoptosis is apparently cell type-dependent and is not well-understood. We aimed at identifying molecular targets of ceramide in metastatic human colon and breast cancer cells, and determining the efficacy of ceramide analog in suppression of colon and breast cancer metastasis. The activity of and mechanism underlying ceramide as a cytotoxic agent, and as a sensitizer for Fas-mediated apoptosis was analyzed in human cell lines established from primary or metastatic colon and breast cancers. The efficacy of ceramide analog LCL85 in suppression of metastasis was examined in preclinical mouse tumor models. Exposure of human colon carcinoma cells to ceramide analog LCL85 results in apoptosis in a dose-dependent manner. Interestingly, a sublethal dose of LCL85 increased C16 ceramide content and overcame tumor cell resistance to Fas-mediated apoptosis. Subsequently, treatment of tumor cells with exogenous C16 ceramide resulted in increased tumor cell sensitivity to Fas-mediated apoptosis. LCL85 resembles Smac mimetic BV6 in sensitization of colon carcinoma cells to Fas-mediated apoptosis by inducing proteasomal degradation of cIAP1 and xIAP proteins. LCL85 also decreased xIAP1 and cIAP1 protein levels and sensitized metastatic human breast cancer cells to Fas-mediated apoptosis. Silencing xIAP and cIAP1 with specific siRNAs significantly increased the metastatic human colon carcinoma cell sensitivity to Fas-mediated apoptosis, suggesting that IAP proteins mediate apoptosis resistance in metastatic human colon carcinoma cells and ceramide induces IAP protein degradation to sensitize the tumor cells to apoptosis induction. Consistent with its apoptosis sensitization activity, subtoxic doses of LCL85 suppressed colon carcinoma cell metastatic potential in an experimental lung metastasis mouse model, as well as breast cancer growth

  17. Role of sphingolipid mediator ceramide in obesity and renal injury in mice fed a high-fat diet.

    Science.gov (United States)

    Boini, Krishna M; Zhang, Chun; Xia, Min; Poklis, Justin L; Li, Pin-Lan

    2010-09-01

    The present study tested a hypothesis that excess accumulation of sphingolipid, ceramide, its metabolites, or a combination contributes to the development of obesity and associated kidney damage. Liquid chromatography/mass spectrometry analysis demonstrated that C57BL/6J mice on the high-fat diet (HFD) had significantly increased plasma total ceramide levels compared with animals fed a low-fat diet (LFD). Treatment of mice with the acid sphingomyelinase (ASMase) inhibitor amitriptyline significantly attenuated the HFD-induced plasma ceramide levels. Corresponding to increase in plasma ceramide, the HFD significantly increased the body weight gain, plasma leptin concentration, urinary total protein and albumin excretion, glomerular damage index, and adipose tissue ASMase activity compared with the LFD-fed mice. These HFD-induced changes were also significantly attenuated by treatment of mice with amitriptyline. In addition, the decline of plasma glucose concentration after an intraperitoneal injection of insulin (0.15 U/kg b.wt.) was more sustained in mice on the HFD with amitriptyline than on the HFD alone. Intraperitoneal injection of glucose (3 g/kg b.wt.) resulted in a slow increase followed by a rapid decrease in the plasma glucose concentration in LFD and HFD plus amitriptyline-treated mice, but such blood glucose response was not observed in HFD-fed mice. Immunofluorescence analysis demonstrated a decrease in the podocin and an increase in the desmin in the glomeruli of HFD-fed mice compared with the LFD and HFD plus amitriptyline-treated mice. In conclusion, our results reveal a pivotal role for ceramide biosynthesis in obesity, metabolic syndrome, and associated kidney damage. PMID:20543095

  18. Use of ceramides and related products for childhood-onset eczema.

    Science.gov (United States)

    Hon, Kam L; Leung, Alexander K C

    2013-01-01

    Atopic eczema or dermatitis (AD) is a chronically relapsing dermatosis associated with pruritus, sleep disturbance and impaired quality of life. AD affects 10 to 20% of school-aged children. The prevalence has increased two to three folds over the past three decades in industrialized countries and there is evidence to suggest that this prevalence is increasing. AD is frustrating to both patients and caregivers and can impose considerable financial impact on the families. The pruritus and sleep disturbance can be intractable and the disease has important physical and psychological implications. Filaggrin (filament-aggregating protein) has an important function in epidermal differentiation and barrier function. Null mutations within the filaggrin gene cause ichthyosis vulgaris and are major risk factors for developing AD. The affected skin of atopic individuals is deficient in natural moisturizing factors (derived from deiminated filaggrin peptides filaggrin) or ceramides (a family of lipid molecules, composed of sphingosine and a fatty acid, found in high concentrations within the cell membrane of cells in the stratum corneum). Avoidance of triggering factors, optimal skin care and topical corticosteroids are the mainstay of therapy for AD. There are two important dermatologic facets to its management, namely, preventive and therapeutic measures. Preventive measures refer to the frequent and proper application of skin moisturizers. When these preventive measures fail to control the disease exacerbation, therapeutic measures such as topical/systemic corticosteroids, antibiotics and immunomodulating agents may be required to control the skin inflammation. Proper moisturizer therapy can reduce the frequency of flares and the demand of topical corticosteroids or topical calcineurin inhibitors. Regular topical application of a moisturizer is the key in the management of patients with AD. Moisturizer therapy of childhood-onset AD is significantly complicated by the

  19. Influence of palmitoyl pentapeptide and Ceramide III B on the droplet size of nanoemulsion

    Science.gov (United States)

    Sondari, Dewi; Haryono, Agus; Harmami, Sri Budi; Randy, Ahmad

    2010-05-01

    The influence of the Palmitoyl Pentapeptide (PPp) and Ceramide IIIB (Cm III B) as active ingredients on the droplet size of nano-emulsion was studied using different kinds of oil (avocado oil, sweet almond oil, jojoba oil, mineral oil and squalene). The formation of nano-emulsions were prepared in water mixed non ionic surfactant/oils system using the spontaneous emulsification mechanism. The aqueous solution, which consist of water and Tween® 20 as a hydrophilic surfactant was mixed homogenously. The organic solution, which consist of oil and Span® 80 as a lipophilic surfactant was mixed homogenously in ethanol. Ethanol was used as a water miscible solvent, which can help the formation of nano-emulsion. The oil phase (containing the blend of surfactant Span® 80, ethanol, oil and active ingredient) and the aqueous phase (containing water and Tween® 20) were separately prepared at room temperatures. The oil phase was slowly added into aqueous phase under continuous mechanical agitation (18000 rpm). All samples were subsequently homogenized with Ultra-Turrax for 30 minutes. The characterizations of nano-emulsion were carried out using photo-microscope and particle size analyzer. Addition of active ingredients on the formation of nano-emulsion gave smallest droplet size compared without active ingredients addition on the formation of nano-emulsion. Squalene oil with Palmitoyl Pentapeptide (PPm) and Ceramide IIIB (Cm IIIB) gave smallest droplet size (184.0 nm) compared without Palmitoyl Pentapeptide and Ceramide IIIB (214.9 nm), however the droplets size of the emulsion prepared by the other oils still in the range of nano-emulsion (below 500 nm). The stability of nano-emulsion was observed using two methods. In one method, the stability of nano-emulsion was observed for three months at temperature of 5°C and 50°C, while in the other method, the stability nano-emulsion was observed by centrifuged at 12000 rpm for 30 minutes. Nanoemulsion with active ingredient

  20. Super-resolution imaging of the Golgi in live cells with a bioorthogonal ceramide probe.

    Science.gov (United States)

    Erdmann, Roman S; Takakura, Hideo; Thompson, Alexander D; Rivera-Molina, Felix; Allgeyer, Edward S; Bewersdorf, Joerg; Toomre, Derek; Schepartz, Alanna

    2014-09-15

    We report a lipid-based strategy to visualize Golgi structure and dynamics at super-resolution in live cells. The method is based on two novel reagents: a trans-cyclooctene-containing ceramide lipid (Cer-TCO) and a highly reactive, tetrazine-tagged near-IR dye (SiR-Tz). These reagents assemble via an extremely rapid "tetrazine-click" reaction into Cer-SiR, a highly photostable "vital dye" that enables prolonged live-cell imaging of the Golgi apparatus by 3D confocal and STED microscopy. Cer-SiR is nontoxic at concentrations as high as 2 μM and does not perturb the mobility of Golgi-resident enzymes or the traffic of cargo from the endoplasmic reticulum through the Golgi and to the plasma membrane. PMID:25081303

  1. Novel structural features of the immunocompetent ceramide phospho-inositol glycan core from Trichomonas vaginalis.

    Science.gov (United States)

    Heiss, Christian; Wang, Zhirui; Black, Ian; Azadi, Parastoo; Fichorova, Raina N; Singh, Bibhuti N

    2016-01-01

    The ceramide phosphoinositol glycan core (CPI-GC) of the lipophosphoglycan of Trichomonas vaginalis is a major virulent factor of this common genitourinary parasite. While its carbohydrate composition has been reported before, its structure has remained largely unknown. We isolated the glycan portions of CPI-GC by nitrous acid deamination and hydrofluoric acid treatment and investigated their structures by methylation analysis and 1- and 2-D NMR. We found that the α-anomer of galactose is a major constituent of CPI-GC. The β-anomer was found exclusively at the non-reducing end of CPI-GC side chains. Furthermore the data showed that the rhamnan backbone is more complex than previously thought and that the inositol residue at the reducing end is linked to a 4-linked α-glucuronic acid (GlcA) residue. This appears to be the most striking and novel feature of this GPI-anchor type molecule.

  2. Cholesterol Depletion from a Ceramide/Cholesterol Mixed Monolayer: A Brewster Angle Microscope Study

    KAUST Repository

    Mandal, Pritam

    2016-06-01

    Cholesterol is crucial to the mechanical properties of cell membranes that are important to cells’ behavior. Its depletion from the cell membranes could be dramatic. Among cyclodextrins (CDs), methyl beta cyclodextrin (MβCD) is the most efficient to deplete cholesterol (Chol) from biomembranes. Here, we focus on the depletion of cholesterol from a C16 ceramide/cholesterol (C16-Cer/Chol) mixed monolayer using MβCD. While the removal of cholesterol by MβCD depends on the cholesterol concentration in most mixed lipid monolayers, it does not depend very much on the concentration of cholesterol in C16-Cer/Chol monolayers. The surface pressure decay during depletion were described by a stretched exponential that suggested that the cholesterol molecules are unable to diffuse laterally and behave like static traps for the MβCD molecules. Cholesterol depletion causes morphology changes of domains but these disrupted monolayers domains seem to reform even when cholesterol level was low.

  3. New ceramide from the aerial part of Tinospora oblongifolia with cytotoxic activities.

    Science.gov (United States)

    Samita, Fidelis; Ochieng, Charles O; Owuor, Philip O; Manguro, Lawrence A O

    2014-01-01

    A new ceramide, 2,3-dihydroxy-N-[(2S,3S,4R)-1,3,4-trihydroxyicosan-2-yl[tetracosanamide (1) along with four known compounds: 2-(4'-hydroxyphenyl)-ethyl lignocerate (2), docosyl-3,4-dihydroxy-trans-cinnamate (3), β-sitosterol (4) and β-sitosterol glycoside (5) were isolated from Tinospora oblongifolia (Menispermaceae). Their structures were determined on the basis of spectroscopic methods, mass spectrometry analysis as well as chemical transformation and by comparing their physical and spectral data with those reported in the literature. Compound 1 exhibited strong cytotoxic activity against KB cells with IC50 = 3.4 μM although less than that of camptothecin IC50 = 0.3 μM (positive control). PMID:24635055

  4. Membrane Organization and Ionization Behavior of the Minor but Crucial Lipid Ceramide-1-Phosphate

    Energy Technology Data Exchange (ETDEWEB)

    Kooijman, Edgar E.; Sot, Jesus; Montes, L.-Ruth; Alonso, Alicia; Gericke, Arne; de Kruijff, Ben; Kumar, Satyendra; Goni, Felix M. (Utrecht); (Kent); (Basque)

    2008-08-06

    Ceramide-1-phosphate (Cer-1-P), one of the simplest of all sphingophospholipids, occurs in minor amounts in biological membranes. Yet recent evidence suggests important roles of this lipid as a novel second messenger with crucial tasks in cell survival and inflammatory responses. We present a detailed description of the physical chemistry of this hitherto little explored membrane lipid. At full hydration Cer-1-P forms a highly organized subgel (crystalline) bilayer phase (L{sub c}) at low temperature, which transforms into a regular gel phase (L{sub {beta}}) at {approx}45 C, with the gel to fluid phase transition (L{sub {beta}}-L{sub {alpha}}) occurring at {approx}65 C. When incorporated at 5mol % in a phosphatidylcholine bilayer, the pK{sub a2} of Cer-1-P, 7.39{+-}0.03, lies within the physiological pH range. Inclusion of phosphatidylethanolamine in the phosphatidylcholine bilayer, at equimolar ratio, dramatically reduces the pK{sub a2} to 6.64{+-}0.03. We explain these results in light of the novel electrostatic/hydrogen bond switch model described recently for phosphatidic acid. In mixtures with dielaidoylphosphatidylethanolamine, small concentrations of Cer-1-P cause a large reduction of the lamellar-to-inverted hexagonal phase transition temperature, suggesting that Cer-1-P induces, like phosphatidic acid, negative membrane curvature in these types of lipid mixtures. These properties place Cer-1-P in a class more akin to certain glycerophospholipids (phosphatidylethanolamine, phosphatidic acid) than to any other sphingolipid. In particular, the similarities and differences between ceramide and Cer-1-P may be relevant in explaining some of their physiological roles.

  5. Membrane organization and ionization behavior of the minor but crucial lipid ceramide-1-phosphate.

    Science.gov (United States)

    Kooijman, Edgar E; Sot, Jesús; Montes, L-Ruth; Alonso, Alicia; Gericke, Arne; de Kruijff, Ben; Kumar, Satyendra; Goñi, Felix M

    2008-06-01

    Ceramide-1-phosphate (Cer-1-P), one of the simplest of all sphingophospholipids, occurs in minor amounts in biological membranes. Yet recent evidence suggests important roles of this lipid as a novel second messenger with crucial tasks in cell survival and inflammatory responses. We present a detailed description of the physical chemistry of this hitherto little explored membrane lipid. At full hydration Cer-1-P forms a highly organized subgel (crystalline) bilayer phase (L(c)) at low temperature, which transforms into a regular gel phase (L(beta)) at approximately 45 degrees C, with the gel to fluid phase transition (L(beta)-L(alpha)) occurring at approximately 65 degrees C. When incorporated at 5 mol % in a phosphatidylcholine bilayer, the pK(a2) of Cer-1-P, 7.39 +/- 0.03, lies within the physiological pH range. Inclusion of phosphatidylethanolamine in the phosphatidylcholine bilayer, at equimolar ratio, dramatically reduces the pK(a2) to 6.64 +/- 0.03. We explain these results in light of the novel electrostatic/hydrogen bond switch model described recently for phosphatidic acid. In mixtures with dielaidoylphosphatidylethanolamine, small concentrations of Cer-1-P cause a large reduction of the lamellar-to-inverted hexagonal phase transition temperature, suggesting that Cer-1-P induces, like phosphatidic acid, negative membrane curvature in these types of lipid mixtures. These properties place Cer-1-P in a class more akin to certain glycerophospholipids (phosphatidylethanolamine, phosphatidic acid) than to any other sphingolipid. In particular, the similarities and differences between ceramide and Cer-1-P may be relevant in explaining some of their physiological roles. PMID:18296489

  6. Plasma ceramides are elevated in overweight Holstein dairy cows experiencing greater lipolysis and insulin resistance during the transition from late pregnancy to early lactation.

    Science.gov (United States)

    Rico, J E; Bandaru, V V R; Dorskind, J M; Haughey, N J; McFadden, J W

    2015-11-01

    Insulin resistance is a homeorhetic adaptation to parturition in dairy cows transitioning from late pregnancy to early lactation. An increase in prepartum adiposity can predispose periparturient cows to greater lipolysis and insulin resistance, thus increasing the risk for metabolic disease. Mechanisms mediating the development of insulin resistance in overweight peripartal dairy cows may depend on ceramide metabolism. The sphingolipid ceramide accumulates in plasma and tissues of overweight monogastric animals, and facilitates saturated fatty acid-induced insulin resistance. Considering this evidence, we hypothesized that plasma ceramides would be elevated in periparturient dairy cattle and that these sphingolipids would correlate with the magnitude of lipolysis and insulin resistance. To test our central hypothesis, multiparous Holstein cows were allocated into 2 groups according to their body condition score (BCS) at d -30 prepartum: lean (BCS BCS >4.0; n=11). Blood samples were collected at d -45, -30, -15, and -7, relative to expected parturition, and at d 4 postpartum. Plasma glucose, insulin, nonesterified fatty acids (NEFA), and β-hydroxybutyrate (BHBA) concentrations were measured, and insulin sensitivity was estimated. The concentrations of individual plasma ceramide and glycosylated ceramide were determined using liquid chromatography-based mass spectrometry. Results demonstrated that greater adiposity was associated with a greater loss in body condition during late pregnancy. Overweight cows had greater circulating concentrations of glucose, insulin, and NEFA, and lower insulin sensitivity relative to lean cows. We detected 30 different sphingolipids across 6 lipid classes with acyl chains ranging from 16 to 26 carbons. The most abundant plasma sphingolipids detected were C24:0-ceramide, C24:0-monohexosylceramide, and C16:0-lactosylceramide. Plasma concentrations of total ceramide and monohexosylceramide increased as lactation approached, and saturated

  7. Saturated- and n-6 polyunsaturated-fat diets each induce ceramide accumulation in mouse skeletal muscle: reversal and improvement of glucose tolerance by lipid metabolism inhibitors.

    Science.gov (United States)

    Frangioudakis, G; Garrard, J; Raddatz, K; Nadler, J L; Mitchell, T W; Schmitz-Peiffer, C

    2010-09-01

    Lipid-induced insulin resistance is associated with intracellular accumulation of inhibitory intermediates depending on the prevalent fatty acid (FA) species. In cultured myotubes, ceramide and phosphatidic acid (PA) mediate the effects of the saturated FA palmitate and the unsaturated FA linoleate, respectively. We hypothesized that myriocin (MYR), an inhibitor of de novo ceramide synthesis, would protect against glucose intolerance in saturated fat-fed mice, while lisofylline (LSF), a functional inhibitor of PA synthesis, would protect unsaturated fat-fed mice. Mice were fed diets enriched in saturated fat, n-6 polyunsaturated fat, or chow for 6 wk. Saline, LSF (25 mg/kg x d), or MYR (0.3 mg/kg x d) were administered by mini-pumps in the final 4 wk. Glucose homeostasis was examined by glucose tolerance test. Muscle ceramide and PA were analyzed by mass spectrometry. Expression of LASS isoforms (ceramide synthases) was evaluated by immunoblotting. Both saturated and polyunsaturated fat diets increased muscle ceramide and induced glucose intolerance. MYR and LSF reduced ceramide levels in saturated and unsaturated fat-fed mice. Both inhibitors also improved glucose tolerance in unsaturated fat-fed mice, but only LSF was effective in saturated fat-fed mice. The discrepancy between ceramide and glucose tolerance suggests these improvements may not be related directly to changes in muscle ceramide and may involve other insulin-responsive tissues. Changes in the expression of LASS1 were, however, inversely correlated with alterations in glucose tolerance. The demonstration that LSF can ameliorate glucose intolerance in vivo independent of the dietary FA type indicates it may be a novel intervention for the treatment of insulin resistance. PMID:20660065

  8. Saturated- and n-6 polyunsaturated-fat diets each induce ceramide accumulation in mouse skeletal muscle: reversal and improvement of glucose tolerance by lipid metabolism inhibitors.

    Science.gov (United States)

    Frangioudakis, G; Garrard, J; Raddatz, K; Nadler, J L; Mitchell, T W; Schmitz-Peiffer, C

    2010-09-01

    Lipid-induced insulin resistance is associated with intracellular accumulation of inhibitory intermediates depending on the prevalent fatty acid (FA) species. In cultured myotubes, ceramide and phosphatidic acid (PA) mediate the effects of the saturated FA palmitate and the unsaturated FA linoleate, respectively. We hypothesized that myriocin (MYR), an inhibitor of de novo ceramide synthesis, would protect against glucose intolerance in saturated fat-fed mice, while lisofylline (LSF), a functional inhibitor of PA synthesis, would protect unsaturated fat-fed mice. Mice were fed diets enriched in saturated fat, n-6 polyunsaturated fat, or chow for 6 wk. Saline, LSF (25 mg/kg x d), or MYR (0.3 mg/kg x d) were administered by mini-pumps in the final 4 wk. Glucose homeostasis was examined by glucose tolerance test. Muscle ceramide and PA were analyzed by mass spectrometry. Expression of LASS isoforms (ceramide synthases) was evaluated by immunoblotting. Both saturated and polyunsaturated fat diets increased muscle ceramide and induced glucose intolerance. MYR and LSF reduced ceramide levels in saturated and unsaturated fat-fed mice. Both inhibitors also improved glucose tolerance in unsaturated fat-fed mice, but only LSF was effective in saturated fat-fed mice. The discrepancy between ceramide and glucose tolerance suggests these improvements may not be related directly to changes in muscle ceramide and may involve other insulin-responsive tissues. Changes in the expression of LASS1 were, however, inversely correlated with alterations in glucose tolerance. The demonstration that LSF can ameliorate glucose intolerance in vivo independent of the dietary FA type indicates it may be a novel intervention for the treatment of insulin resistance.

  9. Ceramide lipids in alive and thermally stressed mussels: an investigation by hydrophilic interaction liquid chromatography-electrospray ionization Fourier transform mass spectrometry.

    Science.gov (United States)

    Facchini, Laura; Losito, Ilario; Cataldi, Tommaso R I; Palmisano, Francesco

    2016-09-01

    Hydrophilic interaction liquid chromatography coupled to electrospray ionization-Fourier transform mass spectrometry was employed to study ceramide lipids occurring in mussels of sp. Mytilus galloprovincialis. Lipid extracts from alive mussels and mussels deliberately subjected to specific thermal treatments were analyzed. In particular, single and tandem MS measurements were performed on a hybrid quadrupole-Orbitrap mass spectrometer and then complemented by MS(n) analyses (n = 2, 3) achieved by a linear ion trap mass spectrometer. This approach enabled the characterization of 66 ceramide lipids, encompassing ceramide phosphoethanolamines (CPE), ceramide aminoethylphosphonates (CAEP) and N-monomethylated CAEP. The sphingoid and acyl chains of each ceramide lipid could be distinctly recognized in terms of numbers of carbon atoms and C=C bonds, and indications on the possible location of the latter on the sphingoid chain could be often inferred from fragmentation patterns. The occurrence of several species hydroxylated on the α carbon of the acyl chain was also discovered. On the other hand, the sphingoid chain of ceramide lipids was never found to be involved in oxidation processes, unless forced exposure of the mussel lipid extracts to atmospheric oxygen was performed. CPE(d19:3/16:0) and its hydroxylated form, CPE(d19:3/2-OH-16:0), were found to be the prevailing species among CPE, whereas CAEP(d18:2/16:0), CAEP(d19:3/16:0) and CAEP(d19:3/2-OH-16:0) were the most abundant CAEP. Finally, ceramide lipids showed a remarkably higher stability, compared with glycerophospholipids, in mussels subjected to different thermal treatments. This finding opens interesting perspectives on the role of ceramide-based lipids in the adaptation of aquatic organisms to thermal stresses. Copyright © 2016 John Wiley & Sons, Ltd.

  10. Saturated- and n-6 Polyunsaturated-Fat Diets Each Induce Ceramide Accumulation in Mouse Skeletal Muscle: Reversal and Improvement of Glucose Tolerance by Lipid Metabolism Inhibitors

    OpenAIRE

    Frangioudakis, G.; J. Garrard; Raddatz, K.; Nadler, J L; Mitchell, T. W.; Schmitz-Peiffer, C.

    2010-01-01

    Lipid-induced insulin resistance is associated with intracellular accumulation of inhibitory intermediates depending on the prevalent fatty acid (FA) species. In cultured myotubes, ceramide and phosphatidic acid (PA) mediate the effects of the saturated FA palmitate and the unsaturated FA linoleate, respectively. We hypothesized that myriocin (MYR), an inhibitor of de novo ceramide synthesis, would protect against glucose intolerance in saturated fat-fed mice, while lisofylline (LSF), a funct...

  11. Thermodynamic Insights and Conceptual Design of Skin-Sensitive Chitosan Coated Ceramide/PLGA Nanodrug for Regeneration of Stratum Corneum on Atopic Dermatitis

    Science.gov (United States)

    Jung, Sang-Myung; Yoon, Gwang Heum; Lee, Hoo Chul; Jung, Moon Hee; Yu, Sun Il; Yeon, Seung Ju; Min, Seul Ki; Kwon, Yeo Seon; Hwang, Jin Ha; Shin, Hwa Sung

    2015-01-01

    Atopic dermatitis (AD) is a complex skin disease primarily characterized by psoriasis of the stratum corneum. AD drugs have usually been used in acidic and hydrophilic solvents to supply moisture and prevent lipid defects. Ceramide is a typical treatment agent to regenerate the stratum corneum and relieve symptoms of AD. However, ceramide has limitation on direct use for skin because of its low dispersion properties in hydrophilic phase and side effects at excessive treatment. In this study, ceramide imbedded PLGA nanoparticles were developed with chitosan coating (Chi-PLGA/Cer) to overcome this problem. The chitosan coating enhanced initial adherence to the skin and prevented the initial burst of ceramide, but was degraded by the weakly acidic nature of skin, resulting in controlled release of ceramide with additional driving force of the squeezed PLGA nanoparticles. Additionally, the coating kinetics of chitosan were controlled by manipulating the reaction conditions and then mathematically modeled. The Chi-PLGA/Cer was not found to be cytotoxic and ceramide release was controlled by pH, temperature, and chitosan coating. Finally, Chi-PLGA/Cer was demonstrated to be effective at stratum corneum regeneration in a rat AD model. Overall, the results presented herein indicated that Chi-PLGA/Cer is a novel nanodrug for treatment of AD. PMID:26666701

  12. Efficient trafficking of ceramide from the endoplasmic reticulum to the Golgi apparatus requires a VAMP-associated protein-interacting FFAT motif of CERT.

    Science.gov (United States)

    Kawano, Miyuki; Kumagai, Keigo; Nishijima, Masahiro; Hanada, Kentaro

    2006-10-01

    Ceramide is synthesized at the endoplasmic reticulum (ER) and transported to the Golgi apparatus by CERT for its conversion to sphingomyelin in mammalian cells. CERT has a pleck-strin homology (PH) domain for Golgi targeting and a START domain catalyzing the intermembrane transfer of ceramide. The region between the two domains contains a short peptide motif designated FFAT, which is supposed to interact with the ER-resident proteins VAP-A and VAP-B. Both VAPs were actually co-immunoprecipitated with CERT, and the CERT/VAP interaction was abolished by mutations in the FFAT motif. These mutations did not affect the Golgi targeting activity of CERT. Whereas mutations of neither the FFAT motif nor the PH domain inhibited the ceramide transfer activity of CERT in a cell-free system, they impaired the ER-to-Golgi transport of ceramide in intact and in semi-intact cells at near endogenous expression levels. By contrast, when overexpressed, both the FFAT motif and the PH domain mutants of CERT substantially supported the transport of ceramide from the ER to the site where sphingomyelin is produced. These results suggest that the Golgi-targeting PH domain and ER-interacting FFAT motif of CERT spatially restrict the random ceramide transfer activity of the START domain in cells.

  13. Phosphoregulation of the ceramide transport protein CERT at serine 315 in the interaction with VAMP-associated protein (VAP) for inter-organelle trafficking of ceramide in mammalian cells.

    Science.gov (United States)

    Kumagai, Keigo; Kawano-Kawada, Miyuki; Hanada, Kentaro

    2014-04-11

    The ceramide transport protein CERT mediates the inter-organelle transport of ceramide for the synthesis of sphingomyelin, presumably through endoplasmic reticulum (ER)-Golgi membrane contact sites. CERT has a short peptide motif named FFAT, which associates with the ER-resident membrane protein VAP. We show that the phosphorylation of CERT at serine 315, which is adjacent to the FFAT motif, markedly enhanced the interaction of CERT with VAP. The phosphomimetic CERT S315E mutant exhibited higher activity to support the ER-to-Golgi transport of ceramide than the wild-type control in a semi-intact cell system, and this enhanced activity was abrogated when its FFAT motif was deleted. The level of phosphorylation of CERT at Ser-315 increased in HeLa cells treated with a sphingolipid biosynthesis inhibitor or exogenous sphingomyelinase. Expression of CERT S315E induced intracellular punctate structures, to which CERT and VAP were co-localized, and the occurrence of the structure was dependent on both phosphatidylinositol 4-monophosphate binding and VAP binding activities of CERT. Phosphorylation of another region (named a serine-rich motif) in CERT is known to down-regulate the activity of CERT. Analysis of various CERT mutant constructs showed that the de-phosphorylation of the serine-rich motif and the phosphorylation of Ser-315 likely have the additive contribution to enhance the activity of CERT. These results demonstrate that the phosphorylation of CERT at the FFAT motif-adjacent serine affected its affinity for VAP, which may regulate the inter-organelle trafficking of ceramide in response to the perturbation of cellular sphingomyelin and/or other sphingolipids.

  14. Phosphoregulation of the Ceramide Transport Protein CERT at Serine 315 in the Interaction with VAMP-associated Protein (VAP) for Inter-organelle Trafficking of Ceramide in Mammalian Cells*

    Science.gov (United States)

    Kumagai, Keigo; Kawano-Kawada, Miyuki; Hanada, Kentaro

    2014-01-01

    The ceramide transport protein CERT mediates the inter-organelle transport of ceramide for the synthesis of sphingomyelin, presumably through endoplasmic reticulum (ER)-Golgi membrane contact sites. CERT has a short peptide motif named FFAT, which associates with the ER-resident membrane protein VAP. We show that the phosphorylation of CERT at serine 315, which is adjacent to the FFAT motif, markedly enhanced the interaction of CERT with VAP. The phosphomimetic CERT S315E mutant exhibited higher activity to support the ER-to-Golgi transport of ceramide than the wild-type control in a semi-intact cell system, and this enhanced activity was abrogated when its FFAT motif was deleted. The level of phosphorylation of CERT at Ser-315 increased in HeLa cells treated with a sphingolipid biosynthesis inhibitor or exogenous sphingomyelinase. Expression of CERT S315E induced intracellular punctate structures, to which CERT and VAP were co-localized, and the occurrence of the structure was dependent on both phosphatidylinositol 4-monophosphate binding and VAP binding activities of CERT. Phosphorylation of another region (named a serine-rich motif) in CERT is known to down-regulate the activity of CERT. Analysis of various CERT mutant constructs showed that the de-phosphorylation of the serine-rich motif and the phosphorylation of Ser-315 likely have the additive contribution to enhance the activity of CERT. These results demonstrate that the phosphorylation of CERT at the FFAT motif-adjacent serine affected its affinity for VAP, which may regulate the inter-organelle trafficking of ceramide in response to the perturbation of cellular sphingomyelin and/or other sphingolipids. PMID:24569996

  15. C16-Ceramide Analog Combined with Pc 4 Photodynamic Therapy Evokes Enhanced Total Ceramide Accumulation, Promotion of DEVDase Activation in the Absence of Apoptosis, and Augmented Overall Cell Killing

    Directory of Open Access Journals (Sweden)

    Duska Separovic

    2011-01-01

    Full Text Available Because of the failure of single modality approaches, combination therapy for cancer treatment is a promising alternative. Sphingolipid analogs, with or without anticancer drugs, can improve tumor response. C16-pyridinium ceramide analog LCL30, was used in combination with photodynamic therapy (PDT, an anticancer treatment modality, to test the hypothesis that the combined treatment will trigger changes in the sphingolipid profile and promote cell death. Using SCCVII mouse squamous carcinoma cells, and the silicone phthalocyanine Pc 4 for PDT, we showed that combining PDT with LCL30 (PDT/LCL30 was more effective than individual treatments in raising global ceramide levels, as well as in reducing dihydrosphingosine levels. Unlike LCL30, PDT, alone or combined, increased total dihydroceramide levels. Sphingosine levels were unaffected by LCL30, but were abolished after PDT or the combination. LCL30-triggered rise in sphingosine-1-phosphate was reversed post-PDT or the combination. DEVDase activation was evoked after PDT or LCL30, and was promoted post- PDT/LCL30. Neither mitochondrial depolarization nor apoptosis were observed after any of the treatments. Notably, treatment with the combination resulted in augmented overall cell killing. Our data demonstrate that treatment with PDT/LCL30 leads to enhanced global ceramide levels and DEVDase activation in the absence of apoptosis, and promotion of total cell killing.

  16. Analysis of the Involvement of Different Ceramide Variants in the Response to Hydroxyurea Stress in Baker's Yeast.

    Directory of Open Access Journals (Sweden)

    Po-Wei Chen

    Full Text Available Sphingolipids have been identified as important signaling compounds in stress responses. However, it is not always clear how different sphingolipid profiles are achieved in a particular stress situation. Here we propose a detailed mass action model, containing 42 dependent variables and 137 reactions, that offers explanations of the roles of variant ceramides species, which differ in the lengths of their fatty acyl chains and their saturation state, in the response to hydroxyurea stress. The simulations demonstrate that the cells manage to achieve hydroxyurea tolerance through a well-coordinated, differential usage of the variant ceramide species. Moreover, the results suggest that key enzymes have different affinities toward saturated and unsaturated fatty acyl chains, which implies that the saturation state affords the cells with an additional mode of regulation that had not been recognized so far. These conclusions from our computational analysis are yet to be validated experimentally.

  17. Bioactives of Artemisia dracunculus L. Mitigate the Role of Ceramides in Attenuating Insulin Signaling in Rat Skeletal Muscle Cells

    OpenAIRE

    Diana N Obanda; Hernandez, Amy; RIBNICKY, DAVID; Yu, Yongmei; Zhang, Xian H.; Wang, Zhong Q.; Cefalu, William T.

    2012-01-01

    Ectopic lipids in peripheral tissues have been implicated in attenuating insulin action in vivo. The botanical extract of Artemisia dracunculus L. (PMI 5011) improves insulin action, yet the precise mechanism is not known. We sought to determine whether the mechanism by which PMI 5011 improves insulin signaling is through regulation of lipid metabolism. After differentiation, cells were separately preincubated with free fatty acids (FFAs) and ceramide C2, and the effects on glycogen content, ...

  18. Saturated and unsaturated fat induce hepatic insulin resistance independently of TLR-4 signaling and ceramide synthesis in vivo.

    Science.gov (United States)

    Galbo, Thomas; Perry, Rachel J; Jurczak, Michael J; Camporez, João-Paulo G; Alves, Tiago C; Kahn, Mario; Guigni, Blas A; Serr, Julie; Zhang, Dongyan; Bhanot, Sanjay; Samuel, Varman T; Shulman, Gerald I

    2013-07-30

    Hepatic insulin resistance is a principal component of type 2 diabetes, but the cellular and molecular mechanisms responsible for its pathogenesis remain unknown. Recent studies have suggested that saturated fatty acids induce hepatic insulin resistance through activation of the toll-like receptor 4 (TLR-4) receptor in the liver, which in turn transcriptionally activates hepatic ceramide synthesis leading to inhibition of insulin signaling. In this study, we demonstrate that TLR-4 receptor signaling is not directly required for saturated or unsaturated fat-induced hepatic insulin resistance in both TLR-4 antisense oligonucleotide treated and TLR-4 knockout mice, and that ceramide accumulation is not dependent on TLR-4 signaling or a primary event in hepatic steatosis and impairment of insulin signaling. Further, we show that both saturated and unsaturated fats lead to hepatic accumulation of diacylglycerols, activation of PKCε, and impairment of insulin-stimulated IRS-2 signaling. These data demonstrate that saturated fat-induced insulin resistance is independent of TLR-4 activation and ceramides.

  19. C6 ceramide sensitizes the anti-hepatocellular carcinoma (HCC) activity by AZD-8055, a novel mTORC1/2 dual inhibitor.

    Science.gov (United States)

    Liu, Mo; Gu, Peng; Guo, Wenjia; Fan, Xiwen

    2016-08-01

    Aberrant activation of mammalian target of rapamycin (mTOR) plays pivotal roles in promoting hepatocellular carcinoma (HCC) tumorigenesis and chemoresistance. Here, we tested the potential anti-HCC activity by a novel mTOR complex 1/2 (mTORC1/2) dual inhibitor AZD-8055 and, more importantly, the potential AZD-8055 sensitization effect by a cell-permeable short-chain ceramide (C6). We showed that AZD-8055 mainly exerted moderate cytotoxic effect against a panel of HCC cell lines (HepG2, Hep3B, and SMMC-7721). Co-treatment of C6 ceramide remarkably augmented AZD-8055-induced HCC cytotoxicity. Meanwhile, C6 ceramide dramatically potentiated AZD-8055-induced HCC cell apoptotic death. Further studies demonstrated that AZD-8055 and C6 ceramide synergistically induced anti-survival and pro-apoptotic activity in primary cultured human HCC cells, but not in the non-cancerous human hepatocytes. Signaling studies showed that AZD-8055 and C6 ceramide synergistically suppressed Akt-mTOR complex 1/2 cascade activation. In vivo, AZD-8055 oral administration suppressed HepG2 hepatoma xenograft growth in nude mice, while moderately improving mice survival. Its anti-tumor activity was dramatically potentiated with co-administration of a liposome-packed C6 ceramide. Together, these results demonstrate that concurrent targeting mTORC1/2 by AZD-8055 exerts anti-tumor ability in preclinical HCC models, and its activity is further sensitized with co-administration of C6 ceramide.

  20. A deficiency of ceramide biosynthesis causes cerebellar purkinje cell neurodegeneration and lipofuscin accumulation.

    Directory of Open Access Journals (Sweden)

    Lihong Zhao

    2011-05-01

    Full Text Available Sphingolipids, lipids with a common sphingoid base (also termed long chain base backbone, play essential cellular structural and signaling functions. Alterations of sphingolipid levels have been implicated in many diseases, including neurodegenerative disorders. However, it remains largely unclear whether sphingolipid changes in these diseases are pathological events or homeostatic responses. Furthermore, how changes in sphingolipid homeostasis shape the progression of aging and neurodegeneration remains to be clarified. We identified two mouse strains, flincher (fln and toppler (to, with spontaneous recessive mutations that cause cerebellar ataxia and Purkinje cell degeneration. Positional cloning demonstrated that these mutations reside in the Lass1 gene. Lass1 encodes (dihydroceramide synthase 1 (CerS1, which is highly expressed in neurons. Both fln and to mutations caused complete loss of CerS1 catalytic activity, which resulted in a reduction in sphingolipid biosynthesis in the brain and dramatic changes in steady-state levels of sphingolipids and sphingoid bases. In addition to Purkinje cell death, deficiency of CerS1 function also induced accumulation of lipofuscin with ubiquitylated proteins in many brain regions. Our results demonstrate clearly that ceramide biosynthesis deficiency can cause neurodegeneration and suggest a novel mechanism of lipofuscin formation, a common phenomenon that occurs during normal aging and in some neurodegenerative diseases.

  1. The combined effect of encapsulating curcumin and C6 ceramide in liposomal nanoparticles against osteosarcoma.

    Science.gov (United States)

    Dhule, Santosh S; Penfornis, Patrice; He, Jibao; Harris, Michael R; Terry, Treniece; John, Vijay; Pochampally, Radhika

    2014-02-01

    This study examines the antitumor potential of curcumin and C6 ceramide (C6) against osteosarcoma (OS) cell lines when both are encapsulated in the bilayer of liposomal nanoparticles. Three liposomal formulations were prepared: curcumin liposomes, C6 liposomes and C6-curcumin liposomes. Curcumin in combination with C6 showed 1.5 times enhanced cytotoxic effect in the case of MG-63 and KHOS OS cell lines, in comparison with curcumin liposomes alone. Importantly, C6-curcumin liposomes were found to be less toxic on untransformed primary human cells (human mesenchymal stem cells) in comparison to OS cell lines. In addition, cell cycle assays on a KHOS cell line after treatment revealed that curcumin only liposomes induced G2/M arrest by upregulation of cyclin B1, while C6 only liposomes induced G1 arrest by downregulation of cyclin D1. C6-curcumin liposomes induced G2/M arrest and showed a combined effect in the expression levels of cyclin D1 and cyclin B1. The efficiency of the preparations was tested in vivo using a human osteosarcoma xenograft assay. Using pegylated liposomes to increase the plasma half-life and tagging with folate (FA) for targeted delivery in vivo, a significant reduction in tumor size was observed with C6-curcumin-FA liposomes. The encapsulation of two water insoluble drugs, curcumin and C6, in the lipid bilayer of liposomes enhances the cytotoxic effect and validates the potential of combined drug therapy.

  2. Molecular cloning, chromosomal mapping, and characterization of the mouse UDP-galactose: Ceramide galactosyltransferase gene

    Energy Technology Data Exchange (ETDEWEB)

    Coetzee, T.; Fujita, N.; Marcus, J. [Univ. of North Carolina, Chapel Hill, NC (United States)] [and others

    1996-07-01

    UDP-galactose:ceramide galactosyltransferase (CGT) (EC 2.11.62) catalyzes the final step in the synthesis of galactocerebroside, a glycosphingolipid characteristically abundant in myelin. In this report, we describe the isolation of genomic clones spanning the mouse CGT gene. The mouse CGT gene consists of six exons that span a minimum of 70 kb of DNA and that encode a 541 amino acid translation product with extensive sequence similarity to the rat CGT enzyme and to UDP-glucuronosyltransferases (UGT). The 5{prime}-untranslated region of the mouse CGT gene is encoded by a separate exon located approximately 25 kb upstream of the first protein-encoding exon. Furthermore, the genomic organization of the five encoding region exons of the mouse CGT gene resembles that of the human UGT1 and rat UGT2B1 genes. Finally, analysis of somatic cell hybrids by PCR and fluorescence in situ hybridization to metaphase chromosomes has localized the mouse CGT gene to chromosome 3, bands E3-F1. 26 refs., 5 figs., 1 tab.

  3. Control of glucosylceramide production and morphogenesis by the Bar1 ceramide synthase in Fusarium graminearum.

    Directory of Open Access Journals (Sweden)

    William R Rittenour

    Full Text Available The contribution of plasma membrane proteins to the virulence of plant pathogenic fungi is poorly understood. Accordingly, the objective of this study was to characterize the acyl-CoA dependent ceramide synthase Bar1 (previously implicated in plasma membrane organization in the wheat pathogen Fusarium graminearum. The role of Bar1 in mediating cell membrane organization was confirmed as ΔBAR1 mutants failed to display a distinct sterol-rich domain at the hyphal tip. The ΔBAR1 mutants were non-pathogenic when inoculated onto wheat heads, and their in vitro growth also was severely perturbed. ΔBAR1 mutants were incapable of producing perithecia (sexual fruiting structures and only produced macroconidia (asexual spores in the presence of NaCl. Sphingolipid analyses indicated that Bar1 is specifically necessary for the production of glucosylceramides in both F. graminearum and Aspergillus nidulans. Interestingly, glucosylceramides appear to mediate sensitivity to heat stable antifungal factor (HSAF, as, in addition to ΔBAR1 mutants, a glucosylceramide synthase deficient mutant of Yarrowia lipolytica is also resistant to HSAF.

  4. [Topical application of vitamins, phytosterols and ceramides. Protection against increased expression of interstital collagenase and reduced collagen-I expression after single exposure to UVA irradiation].

    Science.gov (United States)

    Grether-Beck, S; Mühlberg, K; Brenden, H; Krutmann, J

    2008-07-01

    Photoaged skin is characterized by a decrease of dermal collagen fibers, resulting from an increased breakdown and a diminished de novo synthesis. The increased breakdown results from an increased expression of matrix metalloproteinases (MMPs). The main building blocks involved in de novo synthesis of collagen fibers are collagen 1A1 and 1A2, the expression of which is reduced in photoaged skin. We studied the effect of topical application of vitamins, phytosterols and ceramides on UV-induced up-regulation of the expression of MMP-1 and on UV-induced down-regulation of COL1A1 and COL1A2. The study was conducted with 10 subjects with healthy skin who were comparatively treated for 10 days with (i) a basic preparation containing jojoba oil, (ii) the basic preparation supplemented with vitamins, (iii) the basic preparation supplemented with phytosterols and ceramides, and (iv) the basic preparation supplemented with vitamins, phytosterols and ceramides. All four preparations inhibited the UV induced up-regulation of MMP-1. Neither the basic product nor that supplemented with vitamins inhibited down-regulation of COL1A1 and COL1A2, but addition of phytosterols and ceramides caused a decreased down-regulation of the expression of these genes. Our results indicate that phytosterols and ceramides are effective in blocking the reduced collagen synthesis after UV irradiation and even stimulating synthesis. They may be useful additions to anti-aging products.

  5. Sphingosine Kinase 2 and Ceramide Transport as Key Targets of the Natural Flavonoid Luteolin to Induce Apoptosis in Colon Cancer Cells.

    Directory of Open Access Journals (Sweden)

    Loubna Abdel Hadi

    Full Text Available The plant flavonoid luteolin exhibits different biological effects, including anticancer properties. Little is known on the molecular mechanisms underlying its actions in colorectal cancer (CRC. Here we investigated the effects of luteolin on colon cancer cells, focusing on the balance between ceramide and sphingosine-1-phosphate (S1P, two sphingoid mediators with opposite roles on cell fate. Using cultured cells, we found that physiological concentrations of luteolin induce the elevation of ceramide, followed by apoptotic death of colon cancer cells, but not of differentiated enterocytes. Pulse studies revealed that luteolin inhibits ceramide anabolism to complex sphingolipids. Further experiments led us to demonstrate that luteolin induces an alteration of the endoplasmic reticulum (ER-Golgi flow of ceramide, pivotal to its metabolic processing to complex sphingolipids. We report that luteolin exerts its action by inhibiting both Akt activation, and sphingosine kinase (SphK 2, with the consequent reduction of S1P, an Akt stimulator. S1P administration protected colon cancer cells from luteolin-induced apoptosis, most likely by an intracellular, receptor-independent mechanism. Overall this study reveals for the first time that the dietary flavonoid luteolin exerts toxic effects on colon cancer cells by inhibiting both S1P biosynthesis and ceramide traffic, suggesting its dietary introduction/supplementation as a potential strategy to improve existing treatments in CRC.

  6. Muscle ceramide content is similar after 3 weeks’ consumption of fat or carbohydrate diet in a crossover design in patients with type 2 diabetes

    DEFF Research Database (Denmark)

    Helge, J. W.; Tobin, L.; Drachmann, Tue;

    2012-01-01

    This study aimed at investigating the effect of prolonged adaptation to fat- or carbohydrate-rich diet on muscle ceramide in type 2 diabetes patients, using a longitudinal crossover study. Eleven type 2 diabetes patients consumed isocaloric fat- or carbohydrate-rich diet for 3 weeks in random order...... sensitivity, muscle glycogen, triacylglycerol and ceramide content were similar. Plasma adiponectin concentration was significantly higher after fat compared with carbohydrate-rich diet. Results indicated that following fat-rich diet intake muscle ceramide and triacylglycerol concentrations were not different...... compared with that after carbohydrate-rich diet. Furthermore, plasma adiponectin concentration was higher after fat-rich compared with carbohydrate-rich diet, but insulin sensitivity remained similar despite the major difference in dietary macronutrient composition....

  7. Ceramide-induced intracellular oxidant formation, iron signaling, and apoptosis in endothelial cells: protective role of endogenous nitric oxide.

    Science.gov (United States)

    Matsunaga, Toshiyuki; Kotamraju, Srigiridhar; Kalivendi, Shasi V; Dhanasekaran, Anuradha; Joseph, Joy; Kalyanaraman, B

    2004-07-01

    Sphingolipid ceramide (N-acetylsphingosine), a bioactive second messenger lipid, was shown to activate reactive oxygen species (ROS), mitochondrial oxidative damage, and apoptosis in neuronal and vascular cells. The proapoptotic effects of tumor necrosis factor-alpha, hypoxia, and chemotherapeutic drugs were attributed to increased ceramide formation. Here we investigated the protective role of nitric oxide (.NO) during hydrogen peroxide (H(2)O(2))-mediated transferrin receptor (TfR)-dependent iron signaling and apoptosis in C(2)-ceramide (C(2)-cer)-treated bovine aortic endothelial cells (BAECs). Addition of C(2)-cer (5-20 microm) to BAECs enhanced .NO generation. However, at higher concentrations of C(2)-cer (> or =20 microm), .NO generation did not increase proportionately. C(2)-cer (20-50 microm) also resulted in H(2)O(2)-mediated dichlorodihydrofluorescein oxidation, reduced glutathione depletion, aconitase inactivation, TfR overexpression, TfR-dependent uptake of (55)Fe, release of cytochrome c from mitochondria into cytosol, caspase-3 activation, and DNA fragmentation. N(w)-Nitro-l-arginine methyl ester (l-NAME), a nonspecific inhibitor of nitricoxide synthases, augmented these effects in BAECs at much lower (i.e. nonapoptotic) concentrations of C(2)-cer. The 26 S proteasomal activity in BAECs was slightly elevated at lower concentrations of C(2)-cer (10 microm). Intracellular scavengers of H(2)O(2), cell-permeable iron chelators, anti-TfR receptor antibody, or mitochondria-targeted antioxidant greatly abrogated C(2)-cer- and/or l-NAME-induced oxidative damage, iron signaling, and apoptosis. We conclude that C(2)-cer-induced H(2)O(2) and TfR-dependent iron signaling are responsible for its prooxidant and proapoptotic effects and that .NO exerts an antioxidative and cytoprotective role.

  8. Tetanus Toxin Hc Fragment Induces the Formation of Ceramide Platforms and Protects Neuronal Cells against Oxidative Stress.

    Directory of Open Access Journals (Sweden)

    Roger Cubí

    Full Text Available Tetanus toxin (TeTx is the protein, synthesized by the anaerobic bacteria Clostridium tetani, which causes tetanus disease. TeTx gains entry into target cells by means of its interaction with lipid rafts, which are membrane domains enriched in sphingomyelin and cholesterol. However, the exact mechanism of host membrane binding remains to be fully established. In the present study we used the recombinant carboxyl terminal fragment from TeTx (Hc-TeTx, the domain responsible for target neuron binding, showing that Hc-TeTx induces a moderate but rapid and sustained increase in the ceramide/sphingomyelin ratio in primary cultures of cerebellar granule neurons and in NGF-differentiated PC12 cells, as well as induces the formation of ceramide platforms in the plasma membrane. The mentioned increase is due to the promotion of neutral sphingomyelinase activity and not to the de novo synthesis, since GW4869, a specific neutral sphingomyelinase inhibitor, prevents neutral sphingomyelinase activity increase and formation of ceramide platforms. Moreover, neutral sphingomyelinase inhibition with GW4869 prevents Hc-TeTx-triggered signaling (Akt phosphorylation, as well as the protective effect of Hc-TeTx on PC12 cells subjected to oxidative stress, while siRNA directed against nSM2 prevents protection by Hc-TeTx of NSC-34 cells against oxidative insult. Finally, neutral sphingomyelinase activity seems not to be related with the internalization of Hc-TeTx into PC12 cells. Thus, the presented data shed light on the mechanisms triggered by TeTx after membrane binding, which could be related with the events leading to the neuroprotective action exerted by the Hc-TeTx fragment.

  9. Implication of matrix metalloproteinases 2 and 9 in ceramide 1-phosphate-stimulated macrophage migration.

    Science.gov (United States)

    Ordoñez, Marta; Rivera, Io-Guané; Presa, Natalia; Gomez-Muñoz, Antonio

    2016-08-01

    Cell migration is a complex biological function involved in both physiologic and pathologic processes. Although this is a subject of intense investigation, the mechanisms by which cell migration is regulated are not completely understood. In this study we show that the bioactive sphingolipid ceramide 1-phosphate (C1P), which is involved in inflammatory responses, causes upregulation of metalloproteinases (MMP) -2 and -9 in J774A.1 macrophages. This effect was shown to be dependent on stimulation of phosphatidylinositol 3-kinase (PI3K) and extracellularly regulated kinases 1-2 (ERK1-2) as demonstrated by treating the cells with specific siRNA to knockdown the p85 regulatory subunit of PI3K, or ERK1-2. Inhibition of MMP-2 or MMP-9 pharmacologically or with specific siRNA to silence the genes encoding these MMPs abrogated C1P-stimulated macrophage migration. Also, C1P induced actin polymerization and potently increased phosphorylation of the focal adhesion protein paxillin, which are essential factors in the regulation of cell migration. As expected, blockade of paxillin activation with specific siRNA significantly reduced actin polymerization. In addition, inhibition of actin polymerization with cytochalasin D completely blocked C1P-induced MMP-2 and -9 expression as well as C1P-stimulated macrophage migration. It was also observed that pertussis toxin (Ptx) inhibited Akt, ERK1-2, and paxillin phosphorylation, and completely blocked cell migration. The latter findings support the notion that C1P-stimulated macrophage migration is a receptor mediated effect, and point to MMP-2 and -9 as possible therapeutic targets to control inflammation. PMID:27164414

  10. Implication of matrix metalloproteinases 2 and 9 in ceramide 1-phosphate-stimulated macrophage migration.

    Science.gov (United States)

    Ordoñez, Marta; Rivera, Io-Guané; Presa, Natalia; Gomez-Muñoz, Antonio

    2016-08-01

    Cell migration is a complex biological function involved in both physiologic and pathologic processes. Although this is a subject of intense investigation, the mechanisms by which cell migration is regulated are not completely understood. In this study we show that the bioactive sphingolipid ceramide 1-phosphate (C1P), which is involved in inflammatory responses, causes upregulation of metalloproteinases (MMP) -2 and -9 in J774A.1 macrophages. This effect was shown to be dependent on stimulation of phosphatidylinositol 3-kinase (PI3K) and extracellularly regulated kinases 1-2 (ERK1-2) as demonstrated by treating the cells with specific siRNA to knockdown the p85 regulatory subunit of PI3K, or ERK1-2. Inhibition of MMP-2 or MMP-9 pharmacologically or with specific siRNA to silence the genes encoding these MMPs abrogated C1P-stimulated macrophage migration. Also, C1P induced actin polymerization and potently increased phosphorylation of the focal adhesion protein paxillin, which are essential factors in the regulation of cell migration. As expected, blockade of paxillin activation with specific siRNA significantly reduced actin polymerization. In addition, inhibition of actin polymerization with cytochalasin D completely blocked C1P-induced MMP-2 and -9 expression as well as C1P-stimulated macrophage migration. It was also observed that pertussis toxin (Ptx) inhibited Akt, ERK1-2, and paxillin phosphorylation, and completely blocked cell migration. The latter findings support the notion that C1P-stimulated macrophage migration is a receptor mediated effect, and point to MMP-2 and -9 as possible therapeutic targets to control inflammation.

  11. Probiotic sonicates selectively induce mucosal immune cells apoptosis through ceramide generation via neutral sphingomyelinase.

    Directory of Open Access Journals (Sweden)

    Sandra Angulo

    Full Text Available BACKGROUND: Probiotics appear to be beneficial in inflammatory bowel disease, but their mechanism of action is incompletely understood. We investigated whether probiotic-derived sphingomyelinase mediates this beneficial effect. METHODOLOGY/PRINCIPAL FINDINGS: Neutral sphingomyelinase (NSMase activity was measured in sonicates of the probiotic L. brevis (LB and S. thermophilus (ST and the non-probiotic E. coli (EC and E. faecalis (EF. Lamina propria mononuclear cells (LPMC were obtained from patients with Crohn's disease (CD and Ulcerative Colitis (UC, and peripheral blood mononuclear cells (PBMC from healthy volunteers, analysing LPMC and PBMC apoptosis susceptibility, reactive oxygen species (ROS generation and JNK activation. In some experiments, sonicates were preincubated with GSH or GW4869, a specific NSMase inhibitor. NSMase activity of LB and ST was 10-fold that of EC and EF sonicates. LB and ST sonicates induced significantly more apoptosis of CD and UC than control LPMC, whereas EC and EF sonicates failed to induce apoptosis. Pre-stimulation with anti-CD3/CD28 induced a significant and time-dependent increase in LB-induced apoptosis of LPMC and PBMC. Exposure to LB sonicates resulted in JNK activation and ROS production by LPMC. NSMase activity of LB sonicates was completely abrogated by GW4869, causing a dose-dependent reduction of LB-induced apoptosis. LB and ST selectively induced immune cell apoptosis, an effect dependent on the degree of cell activation and mediated by bacterial NSMase. CONCLUSIONS: These results suggest that induction of immune cell apoptosis is a mechanism of action of some probiotics, and that NSMase-mediated ceramide generation contributes to the therapeutic effects of probiotics.

  12. Super-Resolution Imaging of the Golgi in Live Cells with a Bio-orthogonal Ceramide Probe**

    OpenAIRE

    Erdmann, Roman S.; Takakura, Hideo; Thompson, Alexander D.; Rivera-Molina, Felix; Allgeyer, Edward S.; Bewersdorf, Joerg; Toomre, Derek K.; Schepartz, Alanna

    2014-01-01

    We report a lipid-based strategy to visualize Golgi structure and dynamics at super-resolution in live cells. The method is based on two novel reagents: a trans-cyclooctene-containing ceramide lipid (Cer-TCO) and a highly reactive, tetrazine-tagged near-IR dye (SiR-Tz). These reagents assemble via an extremely rapid ‘tetrazine-click’ reaction into Cer-SiR, a highly photostable ‘vital dye’ that enables prolonged live cell imaging of the Golgi apparatus by 3D confocal and STED microscopy. Cer-S...

  13. Isolation,structural determination and cytotoxic activity of two new ceramides from the root of Isatis indigotica

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Two new ceramides were isolated from the 95% EtOH extract of traditional Chinese medicinal plant Isatis indigotica. Their structures were elucidated as 1-O-β-D-glucopyranosyl-(2S, 3R)-N-(2’-hydroxypentacosanoyl)-octadeca-11E-sphingenine (1) and 1-O-β-D-glucopyranosyl-(2S,3R)-N-(2’-hydroxyhe xacosanoyl)-octadeca-11E-sphingenine (2) on the basis of spectroscopic data. Their cytotoxic effects were evaluated by using MTT method.

  14. C6-ceramide nanoliposome suppresses tumor metastasis by eliciting PI3K and PKCζ tumor-suppressive activities and regulating integrin affinity modulation

    OpenAIRE

    Zhang, Pu; Fu, Changliang; Hu, Yijuan; Dong, Cheng; Song, Yang; Song, Erqun

    2015-01-01

    Nanoliposomal formulation of C6-ceramide, a proapoptotic sphingolipid metabolite, presents an effective way to treat malignant tumor. Here, we provide evidence that acute treatment (30 min) of melanoma and breast cancer cells with nanoliposomal C6-ceramide (NaL-C6) may suppress cell migration without inducing cell death. By employing a novel flow migration assay, we demonstrated that NaL-C6 decreased tumor extravasation under shear conditions. Compared with ghost nanoliposome, NaL-C6 triggere...

  15. Expression of ceramide glucosyltransferases, which are essential for glycosphingolipid synthesis, is only required in a small subset of C. elegans cells

    DEFF Research Database (Denmark)

    Marza, Esther; Simonsen, Karina T; Færgeman, Nils J;

    2009-01-01

    Glycosphingolipids (GSLs) are glycosylated derivatives of ceramide in the lipid bilayer. Their ubiquitous distribution and complexity suggest that they have important functions, but what these are in vivo is still poorly understood. Here, we characterize the phenotype of Caenorhabditis elegans...... mutants with essentially no GSLs. The C. elegans genome encodes three ceramide glucosyltransferase (CGT) genes, which encode enzymes required for GSL biosynthesis. Animals lacking CGT do not synthesize GSLs, arrest growth at the first larval stage, and display defects in a subset of cells...... suggest that GSLs are dispensable in most C. elegans cells, including those of the nervous system....

  16. Acyl-CoA-binding protein, Acb1p, is required for normal vacuole function and ceramide synthesis in Saccharomyces cerevisiae

    DEFF Research Database (Denmark)

    Færgeman, Nils J.; Feddersen, Søren; Christiansen, Janne K;

    2004-01-01

    In the present study, we show that depletion of acyl-CoA-binding protein, Acb1p, in yeast affects ceramide levels, protein trafficking, vacuole fusion and structure. Vacuoles in Acb1p-depleted cells are multi-lobed, contain significantly less of the SNAREs (soluble N -ethylmaleimide......-sensitive fusion protein attachment protein receptors) Nyv1p, Vam3p and Vti1p, and are unable to fuse in vitro. Mass spectrometric analysis revealed a dramatic reduction in the content of ceramides in whole-cell lipids and in vacuoles isolated from Acb1p-depleted cells. Maturation of yeast aminopeptidase I and...

  17. Ceramide Kinase Contributes to Proliferation but not to Prostaglandin E2 Formation in Renal Mesangial Cells and Fibroblasts

    Directory of Open Access Journals (Sweden)

    Oleksandr Pastukhov

    2014-06-01

    Full Text Available Background/Aims: Ceramide kinase (CerK catalyzes the generation of the sphingolipid ceramide-1-phosphate (C1P which regulates various cellular functions including cell growth and death, and inflammation. Here, we used a novel catalytic inhibitor of CerK, NVP-231, and CerK knockout cells to investigate the contribution of CerK to proliferation and inflammation in renal mesangial cells and fibroblasts. Methods: Cells were treated with NVP-231 and [3H]-thymidine incorporation into DNA, [3H]-arachidonic acid release, prostaglandin E2 (PGE2 synthesis, cell cycle distribution, and apoptosis were determined. Results: Treatment of rat mesangial cells and mouse renal fibroblasts with NVP-231 decreased DNA synthesis, but not of agonist-stimulated arachidonic acid release or PGE2 synthesis. Similarly, proliferation but not arachidonic acid release or PGE2 synthesis was reduced in CERK knockout renal fibroblasts. The anti-proliferative effect of NVP-231 on mesangial cells was due to M phase arrest as determined using the mitosis markers phospho-histone H3, cdc2 and polo-like kinase-1, and induction of apoptosis. Moreover, loss of CerK sensitized cells towards stress-induced apoptosis. Conclusions: Our data demonstrate that CerK induces proliferation but not PGE2 formation of renal mesangial cells and fibroblasts, and suggest that targeted CerK inhibition has potential for treating mesangioproliferative kidney diseases.

  18. Hydration effects on the barrier function of stratum corneum lipids: Raman analysis of ceramides 2, III and 5.

    Science.gov (United States)

    Tfayli, Ali; Jamal, Dima; Vyumvuhore, Raoul; Manfait, Michel; Baillet-Guffroy, Arlette

    2013-11-01

    The stratum corneum is the outermost layer of the skin; its barrier function is highly dependent on the composition and the structure as well as the organization of lipids in its extracellular matrix. Ceramides, free fatty acids and cholesterol represent the major lipid classes present in this matrix. They play an important role in maintaining the normal hydration levels required for the normal physiological function. Despite the advancement in the understanding of the structure, composition and the function of the stratum corneum (SC), the concern of "dry skin" remains important in dermatology and care research. Most studies focus on the quantification of water in the skin using different techniques including Raman spectroscopy, while the studies that investigate the effect of hydration on the quality of the barrier function of the skin are limited. Raman spectroscopy provides structural, conformational and organizational information that could help elucidate the effect of hydration on the barrier function of the skin. In order to assess the effect of relative humidity on the lipid barrier function; we used Raman spectroscopy to follow-up the evolution of the conformation and the organization of three synthetic ceramides (CER) differing from each other by the nature of their polar heads (sphingosine, phytosphingosine and α hydroxyl sphingosine), CER 2, III and 5 respectively. CER III and 5 showed a more compact and ordered organization with stronger polar interactions at intermediate relative humidity values, while CER 2 showed opposite tendencies to those observed with CER III and 5.

  19. Inhibition of ceramide glucosylation sensitizes lung cancer cells to ABC294640, a first-in-class small molecule SphK2 inhibitor.

    Science.gov (United States)

    Guan, Shuhong; Liu, Yuan Y; Yan, Tingzan; Zhou, Jun

    2016-08-01

    Sphingosine kinase 2 (SphK2) is proposed as a novel oncotarget for lung cancer. Here, we studied the anti-lung cancer cell activity by ABC294640, a first-in-class SphK2 inhibitor. We showed that ABC294640 suppressed growth of primary and A549 human lung cancer cells, but sparing SphK2-low lung epithelial cells. Inhibition of SphK2 by ABC294640 increased ceramide accumulation, but decreased pro-survival sphingosine-1-phosphate (S1P) content, leading to lung cancer cell apoptosis activation. Significantly, we show that glucosylceramide synthase (GCS) might be a major resistance factor of ABC294640. The GCS inhibitor 1-phenyl-2-decanoylamino-3-morpholino-1-propanol (PDMP) or GCS shRNA/siRNA knockdown facilitated ABC294640-induced ceramide production and lung cancer cell apoptosis. Reversely, forced overexpression of GCS reduced ABC294640's sensitivity, resulting in decreased ceramide accumulation and apoptosis induction in A549 cells. These findings provide further evidences to support that targeting SphK2 by ABC294640 may be a rational treatment option for lung cancer. Ceramide glucosylation inhibition may further sensitize lung cancer cells to ABC294640. PMID:27221045

  20. Stinging Nettle (Urtica dioica L. Attenuates FFA Induced Ceramide Accumulation in 3T3-L1 Adipocytes in an Adiponectin Dependent Manner.

    Directory of Open Access Journals (Sweden)

    Diana N Obanda

    Full Text Available Excess dietary lipids result in the accumulation of lipid metabolites including ceramides that can attenuate insulin signaling. There is evidence that a botanical extract of Urtica dioica L. (stinging nettle improves insulin action, yet the precise mechanism(s are not known. Hence, we examined the effects of Urtica dioica L. (UT on adipocytes.We investigated the effects of an ethanolic extract of UT on free fatty acid (palmitic acid induced inhibition of insulin-stimulated Akt serine phosphorylation and modulation of ceramidase expression in 3T3-L1 adipocytes. Adipocytes were exposed to excess FFAs in the presence or absence of UT. Effects on adiponectin expression, ceramidase expression, ceramidase activity, ceramide accumulation and insulin signaling were determined.As expected, FFAs reduced adiponectin expression and increased the expression of ceramidase enzymes but not their activity. FFA also induced the accumulation of ceramides and reduced insulin-stimulated phosphorylation of Akt in adipocytes. The effects of FFA were partially reversed by UT. UT enhanced adiponectin expression and ceramidase activity in the presence of excess FFAs. UT abated ceramide accumulation and increased insulin sensitivity via enhanced Akt phosphorylation. A siRNA knockdown of adiponectin expression prevented UT from exerting positive effects on ceramidase activity but not Akt phosphorylation.In adipocytes, the ability of UT to antagonize the negative effects of FFA by modulating ceramidase activity and ceramide accumulation is dependent on the presence of adiponectin. However, the ability of UT to enhance Akt phosphorylation is independent of adiponectin expression. These studies demonstrate direct effects of UT on adipocytes and suggest this botanical extract is metabolically beneficial.

  1. Stinging Nettle (Urtica dioica L.) Attenuates FFA Induced Ceramide Accumulation in 3T3-L1 Adipocytes in an Adiponectin Dependent Manner

    Science.gov (United States)

    Obanda, Diana N.; Zhao, Peng; Richard, Allison J.; Ribnicky, David; Cefalu, William T.; Stephens, Jacqueline M.

    2016-01-01

    Objective Excess dietary lipids result in the accumulation of lipid metabolites including ceramides that can attenuate insulin signaling. There is evidence that a botanical extract of Urtica dioica L. (stinging nettle) improves insulin action, yet the precise mechanism(s) are not known. Hence, we examined the effects of Urtica dioica L. (UT) on adipocytes. Research Design We investigated the effects of an ethanolic extract of UT on free fatty acid (palmitic acid) induced inhibition of insulin-stimulated Akt serine phosphorylation and modulation of ceramidase expression in 3T3-L1 adipocytes. Adipocytes were exposed to excess FFAs in the presence or absence of UT. Effects on adiponectin expression, ceramidase expression, ceramidase activity, ceramide accumulation and insulin signaling were determined. Results As expected, FFAs reduced adiponectin expression and increased the expression of ceramidase enzymes but not their activity. FFA also induced the accumulation of ceramides and reduced insulin-stimulated phosphorylation of Akt in adipocytes. The effects of FFA were partially reversed by UT. UT enhanced adiponectin expression and ceramidase activity in the presence of excess FFAs. UT abated ceramide accumulation and increased insulin sensitivity via enhanced Akt phosphorylation. A siRNA knockdown of adiponectin expression prevented UT from exerting positive effects on ceramidase activity but not Akt phosphorylation. Conclusions In adipocytes, the ability of UT to antagonize the negative effects of FFA by modulating ceramidase activity and ceramide accumulation is dependent on the presence of adiponectin. However, the ability of UT to enhance Akt phosphorylation is independent of adiponectin expression. These studies demonstrate direct effects of UT on adipocytes and suggest this botanical extract is metabolically beneficial. PMID:26939068

  2. Apoptosis and the activity of ceramide, Bax and Bcl-2 in the lungs of neonatal rats exposed to limited and prolonged hyperoxia

    Directory of Open Access Journals (Sweden)

    Bitar Fadi F

    2006-07-01

    Full Text Available Abstract Background The aim of the study is to examine the effect of limited and prolonged hyperoxia on neonatal rat lung. This is done by examining the morphologic changes of apoptosis, the expression of ceramide, an important mediator of apoptosis, the expression of inflammatory mediators represented by IL-1β and the expression of 2 proto-oncogenes that appear to modulate apoptosis (Bax and Bcl-2. Methods Newborn rats were placed in chambers containing room air or oxygen above 90% for 7 days. The rats were sacrificed at 3, 7 or 14 days and their lungs removed. Sections were fixed, subjected to TUNEL, Hoechst, and E-Cadherin Staining. Sections were also incubated with anti-Bcl-2 and anti-Bax antisera. Bcl-2 and Bax were quantitated by immunohistochemistry. Lipids were extracted, and ceramide measured through a modified diacylglycerol kinase assay. RT-PCR was utilized to assess IL-1β expression. Results TUNEL staining showed significant apoptosis in the hyperoxia-exposed lungs at 3 days only. Co-staining of the apoptotic cells with Hoechst, and E-Cadherin indicated that apoptotic cells were mainly epithelial cells. The expression of Bax and ceramide was significantly higher in the hyperoxia-exposed lungs at 3 and 14 days of age, but not at 7 days. Bcl-2 was significantly elevated in the hyperoxia-exposed lungs at 3 and 14 days. IL-1β expression was significantly increased at 14 days. Conclusion Exposure of neonatal rat lung to hyperoxia results in early apoptosis documented by TUNEL assay. The early rise in Bax and ceramide appears to overcome the anti-apoptotic activity of Bcl-2. Further exposure did not result in late apoptotic changes. This suggests that apoptotic response to hyperoxia is time sensitive. Prolonged hyperoxia results in acute lung injury and the shifting balance of ceramide, Bax and Bcl-2 may be related to the evolution of the inflammatory process.

  3. Effects of Topical Corticosteroid and Tacrolimus on Ceramides and Irritancy to Sodium Lauryl Sulphate in Healthy Skin

    DEFF Research Database (Denmark)

    Jungersted, Jakob Mutanu; Høgh, Julie Kaae; Hellgren, Lars;

    2011-01-01

    treatments. The aim of this study was to examine the effects of topically applied corticosteroid, tacrolimus and emollient on stratum corneum lipids and barrier parameters. Nineteen healthy volunteers participated in the study. Both forearms of the subjects were divided into four areas, which were treated......The skin barrier, located in the stratum corneum, is influenced mainly by the lipid and protein composition of this layer. In eczematous diseases impairment of the skin barrier is thought to be of prime importance. Topical anti-inflammatory drugs and emollients are the most widely used eczema...... found between treatment regimes. Pretreatment with betamethasone (p = 0.01) or with tacrolimus (p = 0.001) causes a decreased inflammatory response to sodium lauryl sulphate compared with emollient. In conclusion, treatment with betamethasone and tacrolimus has a positive effect on the ceramide...

  4. Effects of topical corticosteroid and tacrolimus on ceramides and irritancy to sodium lauryl sulphate in healthy skin

    DEFF Research Database (Denmark)

    Jungersted, Jakob Mutanu; Høgh, Julie Kaae; Hellegren, Lars I;

    2011-01-01

    treatments. The aim of this study was to examine the effects of topically applied corticosteroid, tacrolimus and emollient on stratum corneum lipids and barrier parameters. Nineteen healthy volunteers participated in the study. Both forearms of the subjects were divided into four areas, which were treated......The skin barrier, located in the stratum corneum, is influenced mainly by the lipid and protein composition of this layer. In eczematous diseases impairment of the skin barrier is thought to be of prime importance. Topical anti-inflammatory drugs and emollients are the most widely used eczema...... found between treatment regimes. Pretreatment with betamethasone (p¿=¿0.01) or with tacrolimus (p¿=¿0.001) causes a decreased inflammatory response to sodium lauryl sulphate compared with emollient. In conclusion, treatment with betamethasone and tacrolimus has a positive effect on the ceramide...

  5. In Vitro Palmitate Treatment of Myotubes from Postmenopausal Women Leads to Ceramide Accumulation, Inflammation and Affected Insulin Signaling

    DEFF Research Database (Denmark)

    Abildgaard, Julie; Henstridge, Darren C; Pedersen, Anette Tønnes;

    2014-01-01

    Menopause is associated with an increased incidence of insulin resistance and metabolic diseases. In a chronic palmitate treatment model, we investigated the role of skeletal muscle fatty acid exposure in relation to the metabolic deterioration observed with menopause. Human skeletal muscle...... satellite cells were isolated from premenopausal (n = 6) and postmenopausal (n = 5) women. In an in vitro model, the myotubes were treated with palmitate (300 µM) for one-, two- or three days during differentiation. Effects on lipid accumulation, inflammation and insulin signaling were studied. Palmitate...... treatment led to a 108% (CI 95%: 50%; 267%) increase in intramyocellular ceramide in the myotubes from the postmenopausal women (post-myotubes) compared with a 26% (CI 95%: -57%; 96%) increase in myotubes from the premenopausal women (pre-myotubes), (p

  6. A neurotoxic glycerophosphocholine impacts PtdIns-4, 5-bisphosphate and TORC2 signaling by altering ceramide biosynthesis in yeast.

    Science.gov (United States)

    Kennedy, Michael A; Gable, Kenneth; Niewola-Staszkowska, Karolina; Abreu, Susana; Johnston, Anne; Harris, Linda J; Reggiori, Fulvio; Loewith, Robbie; Dunn, Teresa; Bennett, Steffany A L; Baetz, Kristin

    2014-01-01

    Unbiased lipidomic approaches have identified impairments in glycerophosphocholine second messenger metabolism in patients with Alzheimer's disease. Specifically, we have shown that amyloid-β42 signals the intraneuronal accumulation of PC(O-16:0/2:0) which is associated with neurotoxicity. Similar to neuronal cells, intracellular accumulation of PC(O-16:0/2:0) is also toxic to Saccharomyces cerevisiae, making yeast an excellent model to decipher the pathological effects of this lipid. We previously reported that phospholipase D, a phosphatidylinositol-4,5-bisphosphate (PtdIns(4,5)P2)-binding protein, was relocalized in response to PC(O-16:0/2:0), suggesting that this neurotoxic lipid may remodel lipid signaling networks. Here we show that PC(O-16:0/2:0) regulates the distribution of the PtdIns(4)P 5-kinase Mss4 and its product PtdIns(4,5)P2 leading to the formation of invaginations at the plasma membrane (PM). We further demonstrate that the effects of PC(O-16:0/2:0) on the distribution of PM PtdIns(4,5)P2 pools are in part mediated by changes in the biosynthesis of long chain bases (LCBs) and ceramides. A combination of genetic, biochemical and cell imaging approaches revealed that PC(O-16:0/2:0) is also a potent inhibitor of signaling through the Target of rampamycin complex 2 (TORC2). Together, these data provide mechanistic insight into how specific disruptions in phosphocholine second messenger metabolism associated with Alzheimer's disease may trigger larger network-wide disruptions in ceramide and phosphoinositide second messenger biosynthesis and signaling which have been previously implicated in disease progression.

  7. A neurotoxic glycerophosphocholine impacts PtdIns-4, 5-bisphosphate and TORC2 signaling by altering ceramide biosynthesis in yeast.

    Directory of Open Access Journals (Sweden)

    Michael A Kennedy

    2014-01-01

    Full Text Available Unbiased lipidomic approaches have identified impairments in glycerophosphocholine second messenger metabolism in patients with Alzheimer's disease. Specifically, we have shown that amyloid-β42 signals the intraneuronal accumulation of PC(O-16:0/2:0 which is associated with neurotoxicity. Similar to neuronal cells, intracellular accumulation of PC(O-16:0/2:0 is also toxic to Saccharomyces cerevisiae, making yeast an excellent model to decipher the pathological effects of this lipid. We previously reported that phospholipase D, a phosphatidylinositol-4,5-bisphosphate (PtdIns(4,5P2-binding protein, was relocalized in response to PC(O-16:0/2:0, suggesting that this neurotoxic lipid may remodel lipid signaling networks. Here we show that PC(O-16:0/2:0 regulates the distribution of the PtdIns(4P 5-kinase Mss4 and its product PtdIns(4,5P2 leading to the formation of invaginations at the plasma membrane (PM. We further demonstrate that the effects of PC(O-16:0/2:0 on the distribution of PM PtdIns(4,5P2 pools are in part mediated by changes in the biosynthesis of long chain bases (LCBs and ceramides. A combination of genetic, biochemical and cell imaging approaches revealed that PC(O-16:0/2:0 is also a potent inhibitor of signaling through the Target of rampamycin complex 2 (TORC2. Together, these data provide mechanistic insight into how specific disruptions in phosphocholine second messenger metabolism associated with Alzheimer's disease may trigger larger network-wide disruptions in ceramide and phosphoinositide second messenger biosynthesis and signaling which have been previously implicated in disease progression.

  8. Platelet activating factor-induced ceramide micro-domains drive endothelial NOS activation and contribute to barrier dysfunction.

    Directory of Open Access Journals (Sweden)

    Sanda Predescu

    Full Text Available The spatial and functional relationship between platelet activating factor-receptor (PAF-R and nitric oxide synthase (eNOS in the lateral plane of the endothelial plasma membrane is poorly characterized. In this study, we used intact mouse pulmonary endothelial cells (ECs as well as endothelial plasma membrane patches and subcellular fractions to define a new microdomain of plasmalemma proper where the two proteins colocalize and to demonstrate how PAF-mediated nitric oxide (NO production fine-tunes ECs function as gatekeepers of vascular permeability. Using fluorescence microscopy and immunogold labeling electron microscopy (EM on membrane patches we demonstrate that PAF-R is organized as clusters and colocalizes with a subcellular pool of eNOS, outside recognizable vesicular profiles. Moreover, PAF-induced acid sphingomyelinase activation generates a ceramide-based microdomain on the external leaflet of plasma membrane, inside of which a signalosome containing eNOS shapes PAF-stimulated NO production. Real-time measurements of NO after PAF-R ligation indicated a rapid (5 to 15 min increase in NO production followed by a > 45 min period of reduction to basal levels. Moreover, at the level of this new microdomain, PAF induces a dynamic phosphorylation/dephosphorylation of Ser, Thr and Tyr residues of eNOS that correlates with NO production. Altogether, our findings establish the existence of a functional partnership PAF-R/eNOS on EC plasma membrane, at the level of PAF-induced ceramide plasma membrane microdomains, outside recognized vesicular profiles.

  9. IL-1beta-Induced iNOS Expression, NO Release and Loss in Metabolic Cell Viability Are Resistant to Inhibitors of Ceramide Synthase and Sphingomyelinase in INS 832/13 Cells

    Directory of Open Access Journals (Sweden)

    Rajakrishnan Veluthakal

    2006-11-01

    Full Text Available Context Emerging evidence indicates regulatory roles for ceramide in the metabolic dysfunction of the islet beta cell. Recently, potential similarities between IL-1beta and ceramide on their effects on islet beta cell have been reported, including reduction in mitochondrial membrane potential and loss in metabolic cell viability.Objective Herein, we investigated whether IL-1beta-induced nitric oxide synthetase (iNOS expression, nitric oxide (NO release and loss in metabolic cell viability require ceramide biosynthesis either via the activation of sphingomyelinase or ceramide synthase.Setting Insulin-secreting INS 832/13 cells.Results We found that two structurally-distinct inhibitors of sphingomyelinase activation (e.g., 3-O-methylsphingomyelin or desipramine or ceramide biosynthesis inhib-itor (e.g., fumonisin failed to exert clear effects on IL-1beta-induced iNOS expression, NO release and loss in cell viability.Conclusions Taken together, our findings indicate that neither the sphingomyelinase nor the ceramide synthase activation is required for IL-1beta-induced metabolic abnormalities in insulin-secreting INS 832/13 cells.

  10. EXOGENOUS CERAMIDE-INDUCED APOPTOSIS IN COLON CARCINOMA LoVo CELLS%神经酰胺诱导大肠癌LoVo细胞的凋亡

    Institute of Scientific and Technical Information of China (English)

    谭晓华; 张亚历; 周殿元

    2001-01-01

    Objective To investigate exogenous ceramide-induced apoptosis in colon carcinoma LoVo cells.Methods LoVo cells were pretreated for 3 h with or without the presence of phorbol 12-myristate 13-acetate (PMA), a potent protein kinase C (PKC) stimulator, later treated with C2-, C6-ceramide or C2-dihydroceramide, and then passed through gel electrophoresis, Heochest 33342 fluorescence staining and flow cytometry with Annexin V/PI staining. The treated LoVo cells were observed for biochemical and morphologic changes. Results Treatment with C2- or C6-ceramide in the range of indicated concentrations (10~25 μmol/L) for 12 to 24 hours resulted in apoptosis in LoVo cells, whereas C2-dihydroceramide, which is similar to C2-ceramide in configuration but lacks the trans double bond at C4-C5 of the sphingoid base backbone, did not induce the apoptosis at the same or even higher concentrations, indicating that the ceramide-induced apoptosis was stereospecific. Moreover, the exogenous ceramide-induced apoptosis in LoVo cells was inhibited in part by PMA. Conclusion Ceramide takes part in the process of apoptotic signal transduction in LoVo cells. PKC may be one of downstream target molecules acted by ceramide.%目的 探讨外源性神经酰胺诱导大肠癌LoVo细胞凋亡的作用。方法 在有或无蛋白激酶C激活剂PMA预处理LoVo细胞3 h的条件下,分别用C2-和C6-神经酰胺以及C2-二羟基神经酰胺处理指数生长期的LoVo细胞,用琼脂糖凝胶电泳,Heochest 33342荧光染色和Annexin V/PI双染色流式细胞仪观测LoVo细胞的形态学和生化特征方面的改变。结果 C2-和C6-神经酰胺在一定的浓度范围内(10-25 μmol/L)处理LoVo细胞12~24 h可诱导其凋亡,但浓度超过50 μmol/L则引起LoVo细胞的坏死增多,而与神经酰胺结构相似但缺乏鞘脂碱基骨架C4-C5反式双键的C2-二羟基神经酰胺在相同甚至更大的剂量时都不引起LoVo细胞的凋亡;PMA对C2-和C6

  11. Resuscitation of wild-type p53 expression by disrupting ceramide glycosylation: a novel approach to target mutant p53 tumors

    OpenAIRE

    Liu, Yong-Yu

    2011-01-01

    Mutant p53 is frequently detected in cancers lose of its ability in tumor suppression and gain of function in promoting tumor progression. Restoration of p53 functions by replacement of wild-type p53 and inhibition of its degradation or increment of its transcriptional activity has been applied in prevention and treatment of cancers. Recent evidence indicates that disrupting ceramide glycosylation can resuscitate wild-type p53 expression and p53-dependent apoptosis in mutant p53 tumors. Actin...

  12. High-energy collision-induced dissociation of [M+Na]+ ions desorbed by fast atom bombardment of ceramides isolated from the starfish Distolasterias nipon.

    Science.gov (United States)

    Yoo, Ji Sun; Park, Taeseong; Bang, Geul; Lee, Chulhyun; Rho, Jung-Rae; Kim, Young Hwan

    2013-02-01

    Ten ceramides and four cerebrosides were extracted from the starfish Distolasterias nipon by solvent extraction, silica gel column chromatography and reversed-phase high-performance liquid chromatography. Structural identification was conducted using tandem mass spectrometry of monosodiated ions desorbed by fast atom bombardment. The complete structures of four cerebrosides were determined by a previously reported method. The high-energy collision-induced dissociation (CID) spectral characteristics of ceramides with various structures depend on the number and positions of double bonds on both the N-acyl and sphingoid chains, the presence of a hydroxyl group or a double bond at the C-4 position of the sphingoid chain and the presence of an α-hydroxy group on the N-acyl chain. The high-energy CID of the monosodiated ion, [M+Na](+), of each ceramide molecular species generated abundant ions, providing information on the composition of the fatty acyl chains and sphingoid long-chain bases. Each homologous ion series along the fatty acyl group and aliphatic chain of the sphingoid base was used for locating the double-bond positions of both chains and hydroxyl groups on the sphingoid base chain. The double-bond positions were also confirmed by the m/z values of abundant allylic even- and odd-electron ions, and the intensity ratio of the T ion peak relative to the O ion peak. This technique could determine the complete structures of ceramides and cerebrosides in an extract mixture and has great potential for determining other sphingolipids isolated from various biological sources. PMID:23378088

  13. Persistence of HCV in Acutely-Infected Patients Depletes C24-Ceramide and Upregulates Sphingosine and Sphinganine Serum Levels

    Science.gov (United States)

    Grammatikos, Georgios; Dietz, Julia; Ferreiros, Nerea; Koch, Alexander; Dultz, Georg; Bon, Dimitra; Karakasiliotis, Ioannis; Lutz, Thomas; Knecht, Gaby; Gute, Peter; Herrmann, Eva; Zeuzem, Stefan; Mavromara, Penelope; Sarrazin, Christoph; Pfeilschifter, Josef

    2016-01-01

    Hepatitis C virus (HCV) substantially affects lipid metabolism, and remodeling of sphingolipids appears to be essential for HCV persistence in vitro. The aim of the current study is the evaluation of serum sphingolipid variations during acute HCV infection. We enrolled prospectively 60 consecutive patients with acute HCV infection, most of them already infected with human immunodeficiency virus (HIV), and serum was collected at the time of diagnosis and longitudinally over a six-month period until initiation of antiviral therapy or confirmed spontaneous clearance. Quantification of serum sphingolipids was performed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Spontaneous clearance was observed in 11 out of 60 patients (18.3%), a sustained viral response (SVR) in 43 out of 45 patients (95.5%) receiving an antiviral treatment after follow-up, whereas persistence of HCV occurred in six out of 60 patients (10%). C24-ceramide (C24-Cer)-levels increased at follow-up in patients with spontaneous HCV eradication (p < 0.01), as compared to baseline. Sphingosine and sphinganine values were significantly upregulated in patients unable to clear HCV over time compared to patients with spontaneous clearance of HCV infection on follow-up (p = 0.013 and 0.006, respectively). In summary, the persistence of HCV after acute infection induces a downregulation of C24Cer and a simultaneous elevation of serum sphingosine and sphinganine concentrations. PMID:27304952

  14. By activating Fas/ceramide synthase 6/p38 kinase in lipid rafts, stichoposide D inhibits growth of leukemia xenografts.

    Science.gov (United States)

    Yun, Seong-Hoon; Park, Eun-Seon; Shin, Sung-Won; Ju, Mi-Ha; Han, Jin-Yeong; Jeong, Jin-Sook; Kim, Sung-Hyun; Stonik, Valentin A; Kwak, Jong-Young; Park, Joo-In

    2015-09-29

    Stichoposide D (STD) is a marine triterpene glycoside isolated from sea cucumbers. We examined the molecular mechanisms underlying the antitumor activity of STD in human leukemia cells. The role of Fas (CD95), ceramide synthase 6 (CerS6) and p38 kinase during STD-induced apoptosis was examined in human leukemia cells. In addition, the antitumor effects of STD in K562 and HL-60 leukemia xenograft models were investigated. We found that STD induces Fas translocation to lipid rafts, and thus mediates cell apoptosis. We also observed the activation of CerS6 and p38 kinase during STD-induced apoptosis. The use of methyl-β-cyclodextrin and nystatin to disrupt lipid rafts prevents the clustering of Fas and the activation of CerS6 and p38 kinase, and also inhibits STD-induced apoptosis. Specific inhibition by Fas, CerS6, and p38 kinase siRNA transfection partially blocked STD-induced apoptosis. In addition, STD has antitumor activity through the activation of CerS6 and p38 kinase without displaying any toxicity in HL-60 and K562 xenograft models. We observed that the anti-tumor effect of STD is partially prevented in CerS6 shRNA-silenced xenograft models. We first report that Fas/CerS6/p38 kinase activation in lipid rafts by STD is involved in its anti-leukemic activity. We also established that STD is able to enhance the chemosensitivity of K562 cells to etoposide or Ara-C. These data suggest that STD may be used alone or in combination with other chemotherapeutic agents to treat leukemia.

  15. Molecular pathways

    DEFF Research Database (Denmark)

    Cox, Thomas R; Erler, Janine Terra

    2014-01-01

    45% of deaths in the developed world are linked to fibrotic disease. Fibrosis and cancer are known to be inextricably linked; however, we are only just beginning to understand the common and overlapping molecular pathways between the two. Here, we discuss what is known about the intersection of...... fibrosis and cancer, with a focus on cancer metastasis, and highlight some of the exciting new potential clinical targets that are emerging from analysis of the molecular pathways associated with these two devastating diseases. Clin Cancer Res; 20(14); 3637-43. ©2014 AACR....

  16. Controlled Penetration of a Novel Dimeric Ceramide into and across the Stratum Corneum Using Microemulsions and Various Types of Semisolid Formulations.

    Science.gov (United States)

    Neubert, Reinhard H H; Sonnenberger, Stefan; Dobner, Bodo; Gray, Charles W; Barger, K Natalie; Sevi-Maxwell, Kara; Sommer, Elfi; Wohlrab, Johannes

    2016-01-01

    Ceramides (CERs) are integral parts of the intercellular lipid lamellae of the stratum corneum (SC), which is responsible for the barrier function of the skin. Many skin diseases such as atopic dermatitis and psoriasis are associated with the depletion or disturbance of the level of CERs in the SC. Administration of an exogenous novel dimeric ceramide (dCER) deep into the SC may help to stabilize the SC barrier substantially and to treat some skin disease conditions. Consequently, with the help of the existing technology, it might be possible to formulate various pharmaceutical dosage forms that can facilitate penetration of dCER into the SC. Therefore, the penetration of dCER was studied using a high-performance liquid chromatography/atmospheric-pressure ionization/mass spectrometry method for the detection and quantification of exogenous dCER in the SC as well as other skin layers. Penetration studies were carried out in the Franz diffusion cell using excised human skin ex vivo. Penetration of dCER was studied with 3 model formulations: a colloidal formulation (microemulsion), a cream formulation with ethoxydiglycol as penetration enhancer and a nanoformulation. The highest concentrations of dCER in the different skin layers were found after application of the cream with penetration enhancer. Surprisingly, the lowest concentrations of dCER in the different skin layers were found after application of the microemulsion. PMID:27193887

  17. Liposomal short-chain C6 ceramide induces potent anti-osteosarcoma activity in vitro and in vivo.

    Science.gov (United States)

    Zhai, Lei; Sun, Nan; Han, Zhe; Jin, Hai-chao; Zhang, Bo

    Osteosarcoma (OS) remains one deadly disease for many affected patients. The search for novel and more efficient anti-OS agents is urgent. In the current study, we demonstrated that liposome-packed C6 ceramide exerted potent cytotoxic effect against established (U2OS and MG-63 lines) and primary human OS cells. Meanwhile, the liposomal C6 (ceramide) induced caspase-mediated apoptotic death in OS cells. Liposomal C6 was significantly more potent than conventional free C6 in inhibiting OS cells, yet it was safe to non-cancerous bone cells (primary murine osteoblasts or human MLO-Y4 osteocytic cells). At the signaling level, we showed that liposomal C6 potently inhibited Akt activation in OS cells. Further studies revealed that a low dose of liposomal C6 dramatically sensitized the in vitro anti-OS activity of two conventional chemodrugs: methotrexate (MTX) and doxorubicin. In vivo, intravenous injection of liposomal C6 inhibited Akt activation and suppressed U2OS xenograft growth in nude mice without causing apparent toxicities. Meanwhile, when given at a low-dose (5 mg/kg body weight), liposomal C6 dramatically sensitized MTX's anti-U2OS activity in vivo. Collectively, our data demonstrate that liposomal C6 exerts potent anti-tumor activity in preclinical OS models. PMID:26505795

  18. Carbon nanoparticles induce ceramide- and lipid raft-dependent signalling in lung epithelial cells: a target for a preventive strategy against environmentally-induced lung inflammation

    Directory of Open Access Journals (Sweden)

    Peuschel Henrike

    2012-12-01

    Full Text Available Abstract Background Particulate air pollution in lung epithelial cells induces pathogenic endpoints like proliferation, apoptosis, and pro-inflammatory reactions. The activation of the epidermal growth factor receptor (EGFR is a key event responsible for signalling events involving mitogen activated protein kinases specific for these endpoints. The molecular events leading to receptor activation however are not well understood. These events are relevant for the toxicological evaluation of inhalable particles as well as for potential preventive strategies in situations when particulate air pollution cannot be avoided. The current study therefore had the objective to elucidate membrane-coupled events leading to EGFR activation and the subsequent signalling cascade in lung epithelial cells. Furthermore, we aimed to identify the molecular target of ectoine, a biophysical active substance which we described to prevent carbon nanoparticle-induced lung inflammation. Methods Membrane signalling events were investigated in isolated lipid rafts from lung epithelial cells with regard to lipid and protein content of the signalling platforms. Using positive and negative intervention approaches, lipid raft changes, subsequent signalling events, and lung inflammation were investigated in vitro in lung epithelial cells (RLE-6TN and in vivo in exposed animals. Results Carbon nanoparticle treatment specifically led to an accumulation of ceramides in lipid rafts. Detailed analyses demonstrated a causal link of ceramides and subsequent EGFR activation coupled with a loss of the receptor in the lipid raft fractions. In vitro and in vivo investigations demonstrate the relevance of these events for carbon nanoparticle-induced lung inflammation. Moreover, the compatible solute ectoine was able to prevent ceramide-mediated EGFR phosphorylation and subsequent signalling as well as lung inflammation in vivo. Conclusion The data identify a so far unknown event in pro

  19. Activation of 3-phosphoinositide-dependent kinase 1 (PDK1) and serum- and glucocorticoid-induced protein kinase 1 (SGK1) by short-chain sphingolipid C4-ceramide rescues the trafficking defect of ΔF508-cystic fibrosis transmembrane conductance regulator (ΔF508-CFTR).

    Science.gov (United States)

    Caohuy, Hung; Yang, Qingfeng; Eudy, Yvonne; Ha, Thien-An; Xu, Andrew E; Glover, Matthew; Frizzell, Raymond A; Jozwik, Catherine; Pollard, Harvey B

    2014-12-26

    Cystic fibrosis (CF) is due to a folding defect in the CF transmembrane conductance regulator (CFTR) protein. The most common mutation, ΔF508, prevents CFTR from trafficking to the apical plasma membrane. Here we show that activation of the PDK1/SGK1 signaling pathway with C4-ceramide (C4-CER), a non-toxic small molecule, functionally corrects the trafficking defect in both cultured CF cells and primary epithelial cell explants from CF patients. The mechanism of C4-CER action involves a series of mutual autophosphorylation and phosphorylation events between PDK1 and SGK1. Detailed mechanistic studies indicate that C4-CER initially induces autophosphorylation of SGK1 at Ser(422). SGK1[Ser(P)(422)] and C4-CER coincidently bind PDK1 and permit PDK1 to autophosphorylate at Ser(241). Then PDK1[Ser(P)(241)] phosphorylates SGK1[Ser(P)(422)] at Thr(256) to generate fully activated SGK1[Ser(422), Thr(P)(256)]. SGK1[Ser(P)(422),Thr(P)(256)] phosphorylates and inactivates the E3 ubiquitin ligase Nedd4-2. ΔF508-CFTR is thus free to traffic to the plasma membrane. Importantly, C4-CER-mediated activation of both PDK1 and SGK1 is independent of the PI3K/Akt/mammalian target of rapamycin signaling pathway. Physiologically, C4-CER significantly increases maturation and stability of ΔF508-CFTR (t½ ∼10 h), enhances cAMP-activated chloride secretion, and suppresses hypersecretion of interleukin-8 (IL-8). We suggest that candidate drugs for CF directed against the PDK1/SGK1 signaling pathway, such as C4-CER, provide a novel therapeutic strategy for a life-limiting disorder that affects one child, on average, each day.

  20. Enzymatic Production of Ceramide

    DEFF Research Database (Denmark)

    Zhang, Long

    indgår også et afsnit om syntese af særskilte ceramidstrukturer. Når reaktionen skedte som en single-batch reaction, var SM hydrolys effektivere i et to-fas system (vand:organisk) end i et en-fase system (vand-mætted organisk solvent).. Ud af de undersøgte enzymer, viste sig phospholipase C (PLC) fra C...... hydrolyse reaktionen. For at forbedre mulighederne at genbruge enzymet, undersøgtes immobilisering af PLC samt det immobiliserede enzyms egenskaber. I en undersøgelse af forskellige carriers, havde det immobiliserede enzyme højst aktivitet på Lewatit VP OC 1600 (Lew). Det var muligt at forøge mængden bundet......, som puder eller når det var immobiliseret til partikulære carriers. Både opløst og immobiliseret PLC fulgte Michaelis-Menten kinetik. Immobiliseringen sænkede Vmax markant, uden at fore til en nævneværdig forandring af Km. som om immobiliseringen førte til en non-kompetetiv inhibering. Produktet...

  1. Influence of ceramide 2 on in vitro skin permeation and retention of 5-ALA and its ester derivatives, for Photodynamic Therapy

    Directory of Open Access Journals (Sweden)

    Maria Bernadete Riemma Pierre

    2009-03-01

    Full Text Available Photodynamic therapy (PDT based on topical 5-aminolevulinic acid (5-ALA, an endogenous precursor of protoporphyrin, is an interesting approach for the treatment of skin cancer. However, 5-ALA is a hydrophilic molecule and such a characteristic limits its appropriate cutaneous penetration and retention. In this way, more lipophilic molecules, such as esterified 5-ALA derivatives, have been under investigation in order to improve the skin penetration of this molecule. Drug formulation can also alter 5-ALA skin penetration. Therefore, the aim of this work was to study the influence of ceramide 2 - the main lipid of the SC- on the cutaneous delivery of 5-ALA and its ester derivatives in vitro, using Franz diffusion cell. The skin permeation of all studied drugs was decreased in the presence of ceramide, representing a desirable characteristic in order to avoid the risk of systemic side effects. Nevertheless, the SC and [epidermis + dermis] retention after 16 h has also been decreased in the presence of ceramide, as compared to control. In conclusion, ceramide was not a good adjuvant, meaning that research of other vehicles could be useful to improve cutaneous delivery of 5-ALA.A Terapia Fotodinâmica (TFD tópica com um precursor das porfirinas endógenas, o ácido 5-aminolevulínico (5-ALA, constitui uma nova modalidade para o tratamento do câncer de pele. Entretanto, o 5-ALA é uma molécula hidrofílica, o que limita sua penetração e retenção cutânea apropriadas. Moléculas mais lipofílicas, tais como derivados esterificados do 5-ALA, estão sob intensa investigação para melhorar a penetração cutânea desta molécula. A formulação que contém o fármaco também pode alterar a penetração cutânea do 5-ALA. Desta forma, o objetivo deste trabalho foi estudar a influência da ceramida 2 - o principal lipídeo do EC- sobre a penetração cutânea de 5-ALA e seus derivados esterificados usando células de difusão de Franz. A permea

  2. Distinct roles of two ceramide synthases, CaLag1p and CaLac1p, in the morphogenesis of Candida albicans

    DEFF Research Database (Denmark)

    Cheon, Seon Ah; Bal, Jyotiranjan; Song, Yunkyoung;

    2012-01-01

    Lag1p and Lac1p catalyse ceramide synthesis in Saccharomyces cerevisiae. This study shows that Lag1 family proteins are generally required for polarized growth in hemiascomycetous yeast. However, in contrast to S. cerevisiae where these proteins are functionally redundant, C. albicans Lag1p (CaLag1......p) and Lac1p (CaLac1p) are functionally distinct. Lack of CaLag1p, but not CaLac1p, caused severe defects in the growth and hyphal morphogenesis of C. albicans. Deletion of CaLAG1 decreased expression of the hypha-specific HWP1 and ECE1 genes. Moreover, overexpression of CaLAG1 induced pseudohyphal....... albicans....

  3. Mechanisms of Mycotoxin-Induced Neurotoxicity through Oxidative Stress-Associated Pathways

    Directory of Open Access Journals (Sweden)

    Koji Uetsuka

    2011-08-01

    Full Text Available Among many mycotoxins, T-2 toxin, macrocyclic trichothecenes, fumonisin B1 (FB1 and ochratochin A (OTA are known to have the potential to induce neurotoxicity in rodent models. T-2 toxin induces neuronal cell apoptosis in the fetal and adult brain. Macrocyclic trichothecenes bring about neuronal cell apoptosis and inflammation in the olfactory epithelium and olfactory bulb. FB1 induces neuronal degeneration in the cerebral cortex, concurrent with disruption of de novo ceramide synthesis. OTA causes acute depletion of striatal dopamine and its metabolites, accompanying evidence of neuronal cell apoptosis in the substantia nigra, striatum and hippocampus. This paper reviews the mechanisms of neurotoxicity induced by these mycotoxins especially from the viewpoint of oxidative stress-associated pathways.

  4. Neural differentiation from embryonic stem cells in vitro :An overview of the signaling pathways

    Institute of Scientific and Technical Information of China (English)

    Jen-Hua Chuang; Li-Chu Tung; Yenshou Lin

    2015-01-01

    Neurons derived from embryonic stem cells (ESCs)have gained great merit in both basic research andregenerative medicine. Here we review and summarizethe signaling pathways that have been reported tobe involved in the neuronal differentiation of ESCs,particularly those associated with in vitro differentiation.The inducers and pathways explored include retinoicacid, Wnt/b-catenin, transforming growth factor/bonemorphogenetic protein, Notch, fibroblast growthfactor, cytokine, Hedgehog, c-Jun N-terminal kinase/mitogen-activated protein kinase and others. Someother miscellaneous molecular factors that have beenreported in the literature are also summarized anddiscussed. These include calcium, calcium receptor,calcineurin, estrogen receptor, Hox protein, ceramide,glycosaminioglycan, ginsenoside Rg1, opioids, two porechannel 2, nitric oxide, chemically defined medium, cellcellinteractions, and physical stimuli. The interaction orcrosstalk between these signaling pathways and factorswill be explored. Elucidating these signals in detail shouldmake a significant contribution to future progress in stemcell biology and allow, for example, better comparisonsto be made between differentiation in vivo and in vitro .Of equal importance, a comprehensive understandingof the pathways that are involved in the developmentof neurons from ESCs in vitro will also accelerate theirapplication as part of translational medicine.

  5. A new analytical bench assay for the determination of arylsulfatase a activity toward galactosyl-3-sulfate ceramide: implication for metachromatic leukodystrophy diagnosis.

    Science.gov (United States)

    Morena, Francesco; di Girolamo, Ilaria; Emiliani, Carla; Gritti, Angela; Biffi, Alessandra; Martino, Sabata

    2014-01-01

    Here, we present the design and validation of a new assay for the diagnosis of metachromatic leukodystrophy. The method is highly specific, simple, reproducible, and straightforward. In our spectrophotometric method, the determination of arylsulfatase A (ARSA) activity toward the natural substrate, galactosyl-3-sulfate ceramide (or sulfatide), is performed using neat sulfatide without chemical modification. This confers to the assay high analytical specificity. The hydrolyzed sulfatide is monitored upon inclusion of the colorimetric reagent Azure A. The nonhydrolyzed sulfatide-Azure A is recovered and measured at a wavelength of λ = 650 nm. Thus, ARSA activity toward the sulfatide is obtained by subtracting the nonhydrolyzed sulfatide from the total sulfatide used in the enzyme reaction (sulfatide-Azure A present in a parallel assay performed in the absence of ARSA). Within a clinical context, our method definitely discriminated between healthy subject samples and metachromatic leukodystrophy patient samples, and, therefore, it is suitable for diagnostic applications and for monitoring the efficacy of therapeutic treatments in patients or animal models.

  6. Formation of lysosulfatide, 3',6'-anhydropsychosine, ceramide, and sphingosine by saponification of cerebroside sulfate. Effect of the sulfate group on the hydrolysis.

    Science.gov (United States)

    Nonaka, G; Kishimoto, Y; Seyama, Y; Yamakawa, T

    1979-02-01

    Saponification of cerebroside sulfate (sulfatide) by refluxing with 1 N KOH in 90% n-butanol for 1 h yielded ceramide, sphingosine, lysosulfatide (psychosine-3'-sulfate ester) and a hitherto unknown compound. The latter compound was identified as 3,6-anhydrogalactosyl sphingosine (3',6'-anhydropsychosine) from its mass spectrum. The structure of lysosulfatide was confirmed by reacylating it to sulfatide by condensing it with lignoceroyl chloride. The resulting sulfatide, which was chromatographically identical to control sulfatides, was not oxidized by periodate. The sulfatide was also permethylated and methanolyzed. The sugar moiety obtained was identified as methyl 2,4,6-tri-O-methylgalactoside by gas-liquid chromatography and thin-layer chromatography. The presence of the sulfate group in lysosulfatide was further confirmed by IR spectroscopy and the presence of radioactivity when it was prepared from [35S]sulfatide. The effect of the sulfate group on cleavage of the galactoside linkage and on the formation of the 3,6-anhydro derivative is discussed.

  7. Andrographolide, a Novel NF-κB Inhibitor, Induces Vascular Smooth Muscle Cell Apoptosis via a Ceramide-p47phox-ROS Signaling Cascade

    Directory of Open Access Journals (Sweden)

    Yu-Ying Chen

    2013-01-01

    Full Text Available Atherosclerosis is linked with the development of many cardiovascular complications. Abnormal proliferation of vascular smooth muscle cells (VSMCs plays a crucial role in the development of atherosclerosis. Accordingly, the apoptosis of VSMCs, which occurs in the progression of vascular proliferation, may provide a beneficial strategy for managing cardiovascular diseases. Andrographolide, a novel nuclear factor-κB inhibitor, is the most active and critical constituent isolated from the leaves of Andrographis paniculata. Recent studies have indicated that andrographolide is a potential therapeutic agent for treating cancer through the induction of apoptosis. In this study, the apoptosis-inducing activity and mechanisms in andrographolide-treated rat VSMCs were characterized. Andrographolide significantly induced reactive oxygen species (ROS formation, p53 activation, Bax, and active caspase-3 expression, and these phenomena were suppressed by pretreating the cells with N-acetyl-L-cysteine, a ROS scavenger, or diphenylene iodonium, a nicotinamide adenine dinucleotide phosphate (NADPH oxidase (Nox inhibitor. Furthermore, p47phox, a Nox subunit protein, was phosphorylated in andrographolide-treated rat VSMCs. However, pretreatment with 3-O-methyl-sphingomyelin, a neutral sphingomyelinase inhibitor, significantly inhibited andrographolide-induced p47phox phosphorylation as well as Bax and active caspase-3 expression. Our results collectively demonstrate that andrographolide-reduced cell viability can be attributed to apoptosis in VSMCs, and this apoptosis-inducing activity was associated with the ceramide-p47phox-ROS signaling cascade.

  8. CD40L induces multidrug resistance to apoptosis in breast carcinoma and lymphoma cells through caspase independent and dependent pathways

    Directory of Open Access Journals (Sweden)

    Blay Jean-Yves

    2006-03-01

    Full Text Available Abstract Background CD40L was found to reduce doxorubicin-induced apoptosis in non Hodgkin's lymphoma cell lines through caspase-3 dependent mechanism. Whether this represents a general mechanism for other tumor types is unknown. Methods The resistance induced by CD40L against apoptosis induced by a panel of cytotoxic chemotherapeutic drugs in non Hodgkin's lymphoma and breast carcinoma cell lines was investigated. Results Doxorubicin, cisplatyl, etoposide, vinblastin and paclitaxel increased apoptosis in a dose-dependent manner in breast carcinoma as well as in non Hodgkin's lymphoma cell lines. Co-culture with irradiated L cells expressing CD40L significantly reduced the percentage of apoptotic cells in breast carcinoma and non Hodgkin's lymphoma cell lines treated with these drugs. In breast carcinoma cell lines, these 5 drugs induced an inconsistent increase of caspase-3/7 activity, while in non Hodgkin's lymphoma cell lines all 5 drugs increased caspase-3/7 activity up to 28-fold above baseline. Co-culture with CD40L L cells reduced (-39% to -89% the activation of caspase-3/7 induced by these agents in all 5 non Hodgkin's lymphoma cell lines, but in none of the 2 breast carcinoma cell lines. Co culture with CD40L L cells also blocked the apoptosis induced by exogenous ceramides in breast carcinoma and non Hodgkin's lymphoma cell lines through a caspase-3-like, 8-like and 9-like dependent pathways. Conclusion These results indicate that CD40L expressed on adjacent non tumoral cells induces multidrug resistance to cytotoxic agents and ceramides in both breast carcinoma and non Hodgkin's lymphoma cell lines, albeit through a caspase independent and dependent pathway respectively.

  9. Modulation of Apoptosis Pathways by Oxidative Stress and Autophagy in β Cells

    Directory of Open Access Journals (Sweden)

    Maorong Wang

    2012-01-01

    Full Text Available Human islets isolated for transplantation are exposed to multiple stresses including oxidative stress and hypoxia resulting in significant loss of functional β cell mass. In this study we examined the modulation of apoptosis pathway genes in islets exposed to hydrogen peroxide, peroxynitrite, hypoxia, and cytokines. We observed parallel induction of pro- and antiapoptotic pathways and identified several novel genes including BFAR, CARD8, BNIP3, and CIDE-A. As BNIP3 is an inducer of autophagy, we examined this pathway in MIN6 cells, a mouse beta cell line and in human islets. Culture of MIN6 cells under low serum conditions increased the levels of several proteins in autophagy pathway, including ATG4, Beclin 1, LAMP-2, and UVRAG. Amino acid deprivation led to induction of autophagy in human islets. Preconditioning of islets with inducers of autophagy protected them from hypoxia-induced apoptosis. However, induction of autophagy during hypoxia exacerbated apoptotic cell death. ER stress led to induction of autophagy and apoptosis in β cells. Overexpression of MnSOD, an enzyme that scavenges free radicals, resulted in protection of MIN6 cells from cytokine-induced apoptosis. Ceramide, a mediator of cytokine-induced injury, reduced the active phosphorylated form of Akt and downregulated the promoter activity of the antiapoptotic gene bcl-2. Furthermore, cytokine-stimulated JNK pathway downregulated the bcl-2 promoter activity which was reversed by preincubation with SP600125, a JNK inhibitor. Our findings suggest that β cell apoptosis by multiple stresses in islets isolated for transplantation is the result of orchestrated gene expression in apoptosis pathway.

  10. Structure elucidation of the blood group B like and blood group I active octaantennary ceramide tetracontasaccharide from rabbit erythrocyte membranes by two-dimensional 1H NMR spectroscopy at 600 MHz

    International Nuclear Information System (INIS)

    The primary structure of the ceramide tetracontasaccharide (1) from rabbit erythrocyte membranes has been determined with the aid of 600-MHz two-dimensional phase-sensitive correlated, totally correlated (TOCSY, homonuclear Hartmann-Hahn), relayed coherence transfer, triple quantum filtered, and nuclear Overhauser enhancement 1H NMR spectra. It was shown that obtaining subspectra of the constituent sugar residues from a totally correlated spectrum and assigning the resonances occurring in these subspectra by analyzing the relevant cross-peaks in phase-sensitive correlated spectra is the most efficient way for establishing complex oligosaccharide structures. This analysis has shown 1 to be the highest homologue of the multiantennary neolactoglycosphingolipids

  11. Determination of Functional Ceramide Lipids in Beet and By-products%甜菜及副产品中功能性神经酰胺脂质的测定

    Institute of Scientific and Technical Information of China (English)

    热娜古丽·木沙; 魏佼

    2013-01-01

    Using beet, beet pulp and beet molasses as raw material,extraction and determination of it's functional ceramide, to provide a theoretical basis for the extraction and utilization of ceramide. The result show total lipid contents in beet, beet pulp and beet molasses in raw material is 0.4 %, 0.7 % and 0.1 %, respectively. The proportion of polar lipid in total lipid is 44.7 %, 55.6 % and 54.8 %, respectively. In molasses, glycolipids accounted for the highest proportion of total lipids, up to 19.4%. TLC analysis proved that in beet and beet pulp contain the functional ceramide lipids. The ceramide content of beet pup was slightly higher than the beet, the result of 0.46 mg/g and 0.35 mg/g,but extremely low in molasses (<0.1 mg/g).%  以甜菜、甜菜渣和甜菜糖蜜为原料,提取测定其功能性成分神经酰胺的含量,为提取利用神经酰胺提供理论依据。结果表明,甜菜、甜菜渣及甜菜糖蜜原物中的总脂质含量分别为0.4%、0.7%及0.1%。总脂质中极性脂质的比例分别为44.7%、55.6%和54.8%。甜菜糖蜜中糖脂占总脂质中的比例最高,达19.4%。TLC分析初步检测出甜菜和甜菜渣中含有功能性脂质神经酰胺;甜菜渣中神经酰胺含量略高于甜菜,分别为0.46 mg/g和0.35 mg/g,但在甜菜糖蜜中含量极少(<0.1 mg/g)。

  12. Molecular trapping of a fluorescent ceramide analogue at the Golgi apparatus of fixed cells: interaction with endogenous lipids provides a trans-Golgi marker for both light and electron microscopy

    OpenAIRE

    1989-01-01

    We have previously shown that a fluorescent derivative of ceramide, N- (epsilon-7-nitrobenz-2-oxa-1,3-diazol-4-yl-aminocaproyl)-D-eryth ro- sphingosin e (C6-NBD-Cer), vitally stains the Golgi apparatus of cells (Lipsky, N. G., and R. E. Pagano. 1985. Science (Wash. DC). 228:745- 747). In the present paper we demonstrate that C6-NBD-Cer also accumulates at the Golgi apparatus of fixed cells and we explore the mechanism by which this occurs. When human skin fibroblasts were fixed with glutarald...

  13. 甜菜及副产品中功能性神经酰胺脂质的测定%Determination of Functional Ceramide Lipids in Beet and By-products

    Institute of Scientific and Technical Information of China (English)

    热娜古丽·木沙; 魏佼

    2013-01-01

      以甜菜、甜菜渣和甜菜糖蜜为原料,提取测定其功能性成分神经酰胺的含量,为提取利用神经酰胺提供理论依据。结果表明,甜菜、甜菜渣及甜菜糖蜜原物中的总脂质含量分别为0.4%、0.7%及0.1%。总脂质中极性脂质的比例分别为44.7%、55.6%和54.8%。甜菜糖蜜中糖脂占总脂质中的比例最高,达19.4%。TLC分析初步检测出甜菜和甜菜渣中含有功能性脂质神经酰胺;甜菜渣中神经酰胺含量略高于甜菜,分别为0.46 mg/g和0.35 mg/g,但在甜菜糖蜜中含量极少(<0.1 mg/g)。%Using beet, beet pulp and beet molasses as raw material,extraction and determination of it's functional ceramide, to provide a theoretical basis for the extraction and utilization of ceramide. The result show total lipid contents in beet, beet pulp and beet molasses in raw material is 0.4 %, 0.7 % and 0.1 %, respectively. The proportion of polar lipid in total lipid is 44.7 %, 55.6 % and 54.8 %, respectively. In molasses, glycolipids accounted for the highest proportion of total lipids, up to 19.4%. TLC analysis proved that in beet and beet pulp contain the functional ceramide lipids. The ceramide content of beet pup was slightly higher than the beet, the result of 0.46 mg/g and 0.35 mg/g,but extremely low in molasses (<0.1 mg/g).

  14. The caveolae-mediated sv40 entry pathway bypasses the golgi complex en route to the endoplasmic reticulum

    Directory of Open Access Journals (Sweden)

    Kuksin Dmitry

    2005-04-01

    Full Text Available Abstract Background Simian virus 40 (SV40 enters cells via an atypical caveolae-mediated endocytic pathway, which delivers the virus to a new intermediary compartment, the caveosome. The virus then is believed to go directly from the caveosome to the endoplasmic reticulum. Cholera toxin likewise enters via caveolae and traffics to caveosomes. But, in contrast to SV40, cholera toxin is transported from caveosomes to the endoplasmic reticulum via the Golgi. For that reason, and because the caveosome and Golgi may have some common markers, we revisited the issue of whether SV40 might access the endoplasmic reticulum via the Golgi. Results We confirmed our earlier finding that SV40 co localizes with the Golgi marker β-COP. However, we show that the virus does not co localize with the more discriminating Golgi markers, golgin 97 and BODIPY-ceramide. Conclusion The caveolae-mediated SV40 entry pathway does not intersect the Golgi. SV40 is seen to co localize with β-COP because that protein is a marker for caveosomes as well as the Golgi. Moreover, these results are consistent with the likelihood that the caveosome is a sorting organelle. In addition, there are at least two distinct but related routes by which a ligand might traffic from the caveosome to the ER; one route involving transport through the Golgi, and another pathway that does not involve the Golgi.

  15. Metagenes Associated with Survival in Non-Small Cell Lung Cancer

    OpenAIRE

    Egon Urgard; Tõnu Vooder; Urmo Võsa; Kristjan Välk; Mingming Liu; Cheng Luo; Fabian Hoti; Retlav Roosipuu; Tarmo Annilo; Jukka Laine; Frenz, Christopher M.; Liqing Zhang; Andres Metspalu

    2011-01-01

    NSCLC (non-small cell lung cancer) comprises about 80% of all lung cancer cases worldwide. Surgery is most effective treatment for patients with early-stage disease. However, 30%–55% of these patients develop recurrence within 5 years. Therefore, markers that can be used to accurately classify early-stage NSCLC patients into different prognostic groups may be helpful in selecting patients who should receive specific therapies. A previously published dataset was used to evaluate gene expressio...

  16. Consistent metagenes from cancer expression profiles yield agent specific predictors of chemotherapy response

    DEFF Research Database (Denmark)

    Li, Qiyuan; Eklund, Aron Charles; Birkbak, Nicolai Juul;

    2011-01-01

    BACKGROUND: Genome scale expression profiling of human tumor samples is likely to yield improved cancer treatment decisions. However, identification of clinically predictive or prognostic classifiers can be challenging when a large number of genes are measured in a small number of tumors. RESULTS...

  17. DMPD: Regulatory pathways in inflammation. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 17967718 Regulatory pathways in inflammation. Mantovani A, Garlanda C, Locati M, Ro....html) (.csml) Show Regulatory pathways in inflammation. PubmedID 17967718 Title Regulatory pathways in infl

  18. Ethnicity and stratum corneum ceramides

    DEFF Research Database (Denmark)

    Jungersted, J M; Høgh, J K; Hellgren, Lars;

    2010-01-01

    The barrier function of the skin is dependent on an optimal composition of the stratum corneum lipids, exemplified by the altered lipid profile in patients with atopic eczema (AE). Differences in the global prevalence of AE point to the environment as an important factor in AE. Studies on filaggrin...

  19. Clinical Pathway for Thyroidectomy.

    Science.gov (United States)

    Villar del Moral, Jesús María; Soria Aledo, Víctor; Colina Alonso, Alberto; Flores Pastor, Benito; Gutiérrez Rodríguez, María Teresa; Ortega Serrano, Joaquín; Parra Hidalgo, Pedro; Ros López, Susana

    2015-05-01

    Clinical pathways are care plans applicable to patient care procedures that present variations in practice and a predictable clinical course. They are designed not as a substitute for clinical judgment, but rather as a means to improve the effectiveness and efficiency of the procedures. This clinical pathway is the result of a collaborative work of the Sections of Endocrine Surgery and Quality Management of the Spanish Association of Surgeons. It attempts to provide a framework for standardizing the performance of thyroidectomy, the most frequently performed operation in endocrine surgery. Along with the usual documents of clinical pathways (temporary matrix, variance tracking and information sheets, assessment indicators and a satisfaction questionnaire) it includes a review of the scientific evidence around different aspects of pre, intra and postoperative management. Among others, antibiotic and antithrombotic prophylaxis, preoperative preparation in hyperthyroidism, intraoperative neuromonitoring and systems for obtaining hemostasis are included, along with management of postoperative hypocalcemia.

  20. Expression of ceramide galactosy transferase in sciatic nerve of rats with diabetic peripheral neuropathy after electroacupuncture at Zusanli and Shenshu points

    Institute of Scientific and Technical Information of China (English)

    Hongsheng Dong; Yunyun Zhang; Yin Shi; Min Zheng; Qiujuan Zhang

    2006-01-01

    BACKGROUND: Ceramide galactosyltransferase (GGT) protein and mRNA expression defect can cause the abnormal morphology and slowing conduction velocity of peripheral nerve. Morphologic change and functional disorder of myelin sheath and axon appear when diabetic peripheral neuropathy (DPN) occurs. Whether electroacupuncture at Zusanli(ST 36) and Shenshu(BL 32) points can enhance the expression of CGT protein and mRNA in the DPN tissue?OBJECTIVE: To observe the effect of electroacupuncture at Zusanli and Shenshu points on motor, sensory conduction velocity and CGT mRNA and its protein expression of sciatic nerve in rats with DPN.DESIGN: A randomized and controlled animal experiment.SETTING: Department of Neurology and Central Laboratory, Yueyang Hospital of Traditional Chinese & Western Medicine, Shanghai University of Traditional Chinese Medicine.MATERIALS : Totally 60 healthy male Wistar rats of clean grade, aged 4 month, with body mass of 200 to 220 g, were enrolled in this study. Streptozotocin (STZ, Sigma Company of USA, Batch No. S-0130).METHODS: This study was carried out in the Animal Experimental Center and Central Laboratory, YueyangHospital of Traditional Chinese & Western Medicine during February 2005 to March 2006. ① Fifteen rats were randomly chosen,serving as normal group.All the other rets were intraperitoneally injected once with STZ to develop experimental diabetic rat models. If fasting blood glucose was ≥ 15 mmol/L,sensory nerve and motor nerve conduction velocity of sciatic nerve was obviously slowed, tail-swaying temperature threshold was increased and myelinated nerve fiber of sciatic nerve changed, DPN models were successful. The successful model rats were randomly assigned into 3 groups: model group, control group(electroacupuncture at non-meridian-non-acupoint)and electroacupuncture group [electroacupuncture at Zusanli and Shenshu points], with 15 rats each. The rats in the normal group and model group were untouched. In the

  1. Policies built upon pathways

    NARCIS (Netherlands)

    S. Musterd; Z. Kovács

    2013-01-01

    After the general introductions, the first substantive part of this volume (Part II) provides concise research-based discussions of policies developed in recognition of the important role played by the pathways along which city-regions have travelled. Our research has shown that it is highly importa

  2. Dexter energy transfer pathways.

    Science.gov (United States)

    Skourtis, Spiros S; Liu, Chaoren; Antoniou, Panayiotis; Virshup, Aaron M; Beratan, David N

    2016-07-19

    Energy transfer with an associated spin change of the donor and acceptor, Dexter energy transfer, is critically important in solar energy harvesting assemblies, damage protection schemes of photobiology, and organometallic opto-electronic materials. Dexter transfer between chemically linked donors and acceptors is bridge mediated, presenting an enticing analogy with bridge-mediated electron and hole transfer. However, Dexter coupling pathways must convey both an electron and a hole from donor to acceptor, and this adds considerable richness to the mediation process. We dissect the bridge-mediated Dexter coupling mechanisms and formulate a theory for triplet energy transfer coupling pathways. Virtual donor-acceptor charge-transfer exciton intermediates dominate at shorter distances or higher tunneling energy gaps, whereas virtual intermediates with an electron and a hole both on the bridge (virtual bridge excitons) dominate for longer distances or lower energy gaps. The effects of virtual bridge excitons were neglected in earlier treatments. The two-particle pathway framework developed here shows how Dexter energy-transfer rates depend on donor, bridge, and acceptor energetics, as well as on orbital symmetry and quantum interference among pathways.

  3. Dexter energy transfer pathways.

    Science.gov (United States)

    Skourtis, Spiros S; Liu, Chaoren; Antoniou, Panayiotis; Virshup, Aaron M; Beratan, David N

    2016-07-19

    Energy transfer with an associated spin change of the donor and acceptor, Dexter energy transfer, is critically important in solar energy harvesting assemblies, damage protection schemes of photobiology, and organometallic opto-electronic materials. Dexter transfer between chemically linked donors and acceptors is bridge mediated, presenting an enticing analogy with bridge-mediated electron and hole transfer. However, Dexter coupling pathways must convey both an electron and a hole from donor to acceptor, and this adds considerable richness to the mediation process. We dissect the bridge-mediated Dexter coupling mechanisms and formulate a theory for triplet energy transfer coupling pathways. Virtual donor-acceptor charge-transfer exciton intermediates dominate at shorter distances or higher tunneling energy gaps, whereas virtual intermediates with an electron and a hole both on the bridge (virtual bridge excitons) dominate for longer distances or lower energy gaps. The effects of virtual bridge excitons were neglected in earlier treatments. The two-particle pathway framework developed here shows how Dexter energy-transfer rates depend on donor, bridge, and acceptor energetics, as well as on orbital symmetry and quantum interference among pathways. PMID:27382185

  4. Molecular Pathways: Estrogen Pathway in Colorectal Cancer

    Science.gov (United States)

    Barzi, Afsaneh; Lenz, Annika Medea; Labonte, Melissa J.; Lenz, Heinz-Josef

    2013-01-01

    Worldwide colorectal cancer (CRC) has a higher incidence rate in men than in women, suggesting a protective role for sex hormones in the development of the disease. Preclinical data supports a role for estrogen and its receptors in the initiation and progression of CRC and establishes that protective effects of estrogen are exerted through ERβ. Hormone replacement therapy (HRT) in postmenopausal women as well as consumption of soy reduces the incidence of CRC. In the Women’s Health Initiative (WHI) trial use of HRT in postmenopausal women reduced the risk of colon cancer by 56% (95% CI, 0.38 to 0.81; P=0.003). A recent meta-analysis showed that in females, consumption of soy reduced the risk of colon cancer by 21% (95% CI, 0.03 to 0.35; P=0.026). In this review, utilizing the preclinical data, we translate the findings in the clinical trials and observational studies to define the role of estrogen in the prevention of CRC. We hypothesize that sometime during the tumorigenesis process ERβ expression in colonocytes is lost and the estrogen ligand, HRT or soy products, exerts its effects through preventing this loss. Thus in the adenoma to carcinoma continuum, timing of HRT is a significant determinant of the observed benefit from this intervention. We further argue that the protective effects of estrogen are limited to certain molecular subtypes. Successful development of estrogen modulators for prevention of CRC depends on identification of susceptible CRC population(s). Thus research to better understand the estrogen pathway is fundamental for clinical delivery of these agents. PMID:23965904

  5. Pathway analysis of IMC

    DEFF Research Database (Denmark)

    Skrypnyuk, Nataliya; Nielson, Flemming; Pilegaard, Henrik

    2009-01-01

    We present the ongoing work on the pathway analysis of a stochastic calculus. Firstly we present a particular stochastic calculus that we have chosen for our modeling - the Interactive Markov Chains calculus, IMC for short. After that we specify a few restrictions that we have introduced into the......We present the ongoing work on the pathway analysis of a stochastic calculus. Firstly we present a particular stochastic calculus that we have chosen for our modeling - the Interactive Markov Chains calculus, IMC for short. After that we specify a few restrictions that we have introduced...... into the syntax of IMC in order to make our analysis feasible. Finally we describe the analysis itself together with several theoretical results that we have proved for it....

  6. Enhanced Cytotoxicity of Folic Acid-Targeted Liposomes Co-Loaded with C6 Ceramide and Doxorubicin: In Vitro Evaluation on HeLa, A2780-ADR, and H69-AR Cells.

    Science.gov (United States)

    Sriraman, Shravan Kumar; Pan, Jiayi; Sarisozen, Can; Luther, Ed; Torchilin, Vladimir

    2016-02-01

    Current research in cancer therapy is beginning to shift toward the use of combinational drug treatment regimens. However, the efficient delivery of drug combinations is governed by a number of complex factors in the clinical setting. Therefore, the ability to synchronize the pharmacokinetics of the individual therapeutic agents present in combination not only to allow for simultaneous tumor accumulation but also to allow for a synergistic relationship at the intracellular level could prove to be advantageous. In this work, we report the development of a novel folic acid-targeted liposomal formulation simultaneously co-loaded with C6 ceramide and doxorubicin [FA-(C6+Dox)-LP]. In vitro cytotoxicity assays showed that the FA-(C6+Dox)-LP was able to significantly reduce the IC50 of Dox when compared to that after the treatment with the doxorubicin-loaded liposomes (Dox-LP) as well as the untargeted drug co-loaded (C6+Dox)-LP on HeLa, A2780-ADR, and H69-AR cells. The analysis of the cell cycle distribution showed that while the C6 liposomes (C6-LP) did not cause cell cycle arrest, all the Dox-containing liposomes mediated cell cycle arrest in HeLa cells in the G2 phase at Dox concentrations of 0.3 and 1 μM and in the S phase at the higher concentrations. It was also found that this arrest in the S phase precedes the progression of the cells to apoptosis. The targeted FA-(C6+Dox)-LP were able to significantly enhance the induction of apoptotic events in HeLa cell monolayers as compared to the other treatment groups. Next, using time-lapse phase holographic imaging microscopy, it was found that upon treatment with the FA-(C6+Dox)-LP, the HeLa cells underwent rapid progression to apoptosis after 21 h as evidenced by a drastic drop in the average area of the cells after loss of cell membrane integrity. Finally, upon evaluation in a HeLa spheroid cell model, treatment with the FA-(C6+Dox)-LP showed significantly higher levels of cell death compared to those with C6-LP and

  7. Polyurethane film dressings and ceramide 2-containing hydrocolloid dressing reduce the risk of pressure ulcer development in high-risk patients undergoing surgery: a matched case-control study

    Directory of Open Access Journals (Sweden)

    Kohta M

    2015-02-01

    Full Text Available Masushi Kohta,1 Kazumi Sakamoto,2 Tsunao Oh-i31Medical Engineering Laboratory, ALCARE Co, Ltd, Sumida-ku, Tokyo, 2Department of Nursing, 3Department of Dermatology, Tokyo Medical University Ibaraki Medical Center, Ami, Ibaraki, JapanBackground: Numerous clinical challenges regarding adhesive dressings have shown that using an adhesive dressing could minimize or prevent superficial skin loss in patients at risk of developing pressure ulcers. However, evidence that polyurethane film dressings and ceramide 2-containing hydrocolloid dressing can reduce the risk of pressure ulcer development in high-risk patients undergoing surgery is limited. Therefore, we assessed the effects of application of these dressings for reducing the risk of pressure ulcer development in these patients and identified other risk factors.Methods: A matched case-control study was conducted involving 254 patients at high risk for pressure ulcer development at one acute care hospital in Japan. No patients in this study had a pressure ulcer at the start of the study. Thirty-one patients developed a pressure ulcer during surgery, and these patients were defined as cases. Controls were randomly matched for sex and age (±4 years, from which 62 patients were selected. Medical records were obtained for preoperative factors, including age, sex, body mass index, diabetes mellitus, albumin, total protein, C-reactive protein, white cell count, red cell count, and hemoglobin, and for intraoperative factors, including dressing application, operation time, body position, and surgery type. The odds ratio (OR and 95% confidence interval (CI were determined to identify risk factors for pressure ulcer development in patients undergoing surgery.Results: By multiple logistic regression analysis, there was a significantly reduced risk of pressure ulcer development for patients who had dressing applications as compared with those without dressing applications (OR 0.063; 95% CI 0.012–0.343; P=0

  8. Pathways of tau fibrillization.

    Science.gov (United States)

    Kuret, Jeff; Chirita, Carmen N; Congdon, Erin E; Kannanayakal, Theresa; Li, Guibin; Necula, Mihaela; Yin, Haishan; Zhong, Qi

    2005-01-01

    New methods for analyzing tau fibrillization have yielded insights into the biochemical transitions involved in the process. Here we review the parallels between the sequential progression of tau fibrillization observed macroscopically in Alzheimer's disease (AD) lesions and the pathway of tau aggregation observed in vitro with purified tau preparations. In addition, pharmacological agents for further dissection of fibrillization mechanism and lesion formation are discussed. PMID:15615636

  9. DMPD: Antiviral innate immunity pathways. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 16474426 Antiviral innate immunity pathways. Seth RB, Sun L, Chen ZJ. Cell Res. 200...6 Feb;16(2):141-7. (.png) (.svg) (.html) (.csml) Show Antiviral innate immunity pathways. PubmedID 16474426 ...Title Antiviral innate immunity pathways. Authors Seth RB, Sun L, Chen ZJ. Publication Cell Res. 2006 Feb;16

  10. Bioactive lipids sphingosine-1-phosphate and ceramide-1-phosphate are pro-metastatic factors in human rhabdomyosarcomas cell lines, and their tissue level increases in response to radio/chemotherapy

    Science.gov (United States)

    Schneider, Gabriela; Bryndza, Ewa; Abdel-Latif, Ahmed; Ratajczak, Janina; Maj, Magdalena; Tarnowski, Maciej; Klyachkin, Yurij; Houghton, Peter; Morris, Andrew J.; Vater, Axel; Klussmann, Sven; Kucia, Magdalena; Ratajczak, Mariusz Z.

    2013-01-01

    We observed that sphingosine-1-phosphate (S1P) and ceramide-1-phosphate (C1P) strongly enhance in vitro motility and adhesion of human rhabdomyosarcoma (RMS) cells. This effect was observed at physiological concentrations of both bioactive lipids, which are present in biological fluids, and is much stronger than the effects observed in response to known RMS pro-metastatic factors such as stromal derived factors-1 (SDF-1) or hepatocyte growth factor/scatter factor (HGF/SF). We also present novel evidence that the levels of S1P and C1P increase in several organs after γ-irradiation or chemotherapy, which indicates induction of an unwanted pro-metastatic environment related to treatment. Most importantly, we found that the metastasis of RMS cells in response to S1P can be effectively inhibited in vivo with the S1P-specific binder NOX-S93 that is based on a high affinity Spiegelmer. We propose that bioactive lipids play a previously underappreciated role in dissemination of RMS and the unwanted side effects of radio/chemotherapy by creating a pro-metastatic microenvironment. Therefore, an anti-metastatic treatment with specific S1P-binding scavenger such as NOX-S93 could become a part of standard radio/chemotherapy. PMID:23615526

  11. Aquatic pathway 1

    International Nuclear Information System (INIS)

    This first part of the study discusses problems of exposure due to the emission of radioactive substances into the environment via the water pathway. Discussion is started with a paper on the fundamentals of calculation and another paper on the results of preliminary radiological model calculations. The colloquium will assess the present state of knowledge, helps to find an agreement between divergent opinions and determine open questions and possible solutions. Ten main problems have been raised, most of which pertain to site conditions. They are trated as sub-investigations by individual participants or working groups. The findings will be discussed in further colloquia. (orig.)

  12. WikiPathways: capturing the full diversity of pathway knowledge.

    Science.gov (United States)

    Kutmon, Martina; Riutta, Anders; Nunes, Nuno; Hanspers, Kristina; Willighagen, Egon L; Bohler, Anwesha; Mélius, Jonathan; Waagmeester, Andra; Sinha, Sravanthi R; Miller, Ryan; Coort, Susan L; Cirillo, Elisa; Smeets, Bart; Evelo, Chris T; Pico, Alexander R

    2016-01-01

    WikiPathways (http://www.wikipathways.org) is an open, collaborative platform for capturing and disseminating models of biological pathways for data visualization and analysis. Since our last NAR update, 4 years ago, WikiPathways has experienced massive growth in content, which continues to be contributed by hundreds of individuals each year. New aspects of the diversity and depth of the collected pathways are described from the perspective of researchers interested in using pathway information in their studies. We provide updates on extensions and services to support pathway analysis and visualization via popular standalone tools, i.e. PathVisio and Cytoscape, web applications and common programming environments. We introduce the Quick Edit feature for pathway authors and curators, in addition to new means of publishing pathways and maintaining custom pathway collections to serve specific research topics and communities. In addition to the latest milestones in our pathway collection and curation effort, we also highlight the latest means to access the content as publishable figures, as standard data files, and as linked data, including bulk and programmatic access. PMID:26481357

  13. Signaling Pathways in Melanogenesis

    Directory of Open Access Journals (Sweden)

    Stacey A. N. D’Mello

    2016-07-01

    Full Text Available Melanocytes are melanin-producing cells found in skin, hair follicles, eyes, inner ear, bones, heart and brain of humans. They arise from pluripotent neural crest cells and differentiate in response to a complex network of interacting regulatory pathways. Melanins are pigment molecules that are endogenously synthesized by melanocytes. The light absorption of melanin in skin and hair leads to photoreceptor shielding, thermoregulation, photoprotection, camouflage and display coloring. Melanins are also powerful cation chelators and may act as free radical sinks. Melanin formation is a product of complex biochemical events that starts from amino acid tyrosine and its metabolite, dopa. The types and amounts of melanin produced by melanocytes are determined genetically and are influenced by a variety of extrinsic and intrinsic factors such as hormonal changes, inflammation, age and exposure to UV light. These stimuli affect the different pathways in melanogenesis. In this review we will discuss the regulatory mechanisms involved in melanogenesis and explain how intrinsic and extrinsic factors regulate melanin production. We will also explain the regulatory roles of different proteins involved in melanogenesis.

  14. Signaling Pathways in Melanogenesis.

    Science.gov (United States)

    D'Mello, Stacey A N; Finlay, Graeme J; Baguley, Bruce C; Askarian-Amiri, Marjan E

    2016-01-01

    Melanocytes are melanin-producing cells found in skin, hair follicles, eyes, inner ear, bones, heart and brain of humans. They arise from pluripotent neural crest cells and differentiate in response to a complex network of interacting regulatory pathways. Melanins are pigment molecules that are endogenously synthesized by melanocytes. The light absorption of melanin in skin and hair leads to photoreceptor shielding, thermoregulation, photoprotection, camouflage and display coloring. Melanins are also powerful cation chelators and may act as free radical sinks. Melanin formation is a product of complex biochemical events that starts from amino acid tyrosine and its metabolite, dopa. The types and amounts of melanin produced by melanocytes are determined genetically and are influenced by a variety of extrinsic and intrinsic factors such as hormonal changes, inflammation, age and exposure to UV light. These stimuli affect the different pathways in melanogenesis. In this review we will discuss the regulatory mechanisms involved in melanogenesis and explain how intrinsic and extrinsic factors regulate melanin production. We will also explain the regulatory roles of different proteins involved in melanogenesis. PMID:27428965

  15. The Kallikrein-Kinin-System in Experimental Chagas Disease: A Paradigm to Investigate the Impact of Inflammatory Edema on GPCR-mediated pathways of Host Cell Invasion by Trypanosoma cruzi

    Directory of Open Access Journals (Sweden)

    Julio eScharfstein

    2013-01-01

    Full Text Available Chronic chagasic myocarditis (CCM depends on Trypanosoma cruzi persistence in the myocardium. Studies of the proteolytic mechanisms governing host/parasite balance in peripheral sites of T. cruzi infection revealed that tissue culture trypomastigotes (TCTs elicit inflammatory edema and stimulate protective type-1 effector T cells through the activation of the Kallikrein-Kinin System (KKS. Molecular studies linked the proinflammatory phenotype of Dm28c TCTs to the synergistic activities of tGPI, a lipid anchor that functions as a TLR2 ligand, and cruzipain, a kinin-releasing cysteine protease. Analysis of the dynamics of inflammation revealed that TCTs activate innate sentinel cells via TLR2, releasing CXC chemokines, which in turn evoke neutrophil/CXCR2-dependent extravasation of plasma proteins, including high molecular weight kininogen (HK, in parasite-laden tissues. Further downstream, TCTs process surface bound HK, liberating lysyl-BK (LBK, which then propagates inflammatory edema via signaling of endothelial G-protein-coupled bradykinin B2 receptors (BK2R. Dm28 TCTs take advantage of the transient availability of infection-promoting peptides (e.g., bradykinin and endothelins in inflamed tissues to invade cardiovascular cells via interdependent signaling of BKRs and endothelin receptors (ETRs. Herein we present a space-filling model whereby ceramide-enriched endocytic vesicles generated by the shingomyelinase pathway might incorporate BK2R and ETRs, which then trigger Ca2+-driven responses that optimize the housekeeping mechanism of plasma membrane repair from cell wounding. The hypothesis predicts that the NFB-inducible BKR (BK1R may integrate the multimolecular signaling platforms forged by ceramide rafts, as the chronic myocarditis progresses. Exploited as gateways for parasite invasion, BK2R, BK1R, ETAR, ETBR and other GPCR partners may enable persistent myocardial parasitism in the edematous tissues at expense of adverse cardiac

  16. Summer 2014 Pathways Report

    Science.gov (United States)

    Hand, Zachary

    2014-01-01

    Over the summer I had the exciting opportunity to work for NASA at the Kennedy Space Center as a Mission Assurance Engineering intern. When I was offered a position in mission assurance for the Safety and Mission Assurance directorate's Launch Services Division, I didn't really know what I would be doing, but I knew it would be an excellent opportunity to learn and grow professionally. In this report I will provide some background information on the Launch Services Division, as well as detail my duties and accomplishments during my time as an intern. Additionally, I will relate the significance of my work experience to my current academic work and future career goals. This report contains background information on Mission Assurance Engineering, a description of my duties and accomplishments over the summer of 2014, and relates the significance of my work experience to my school work and future career goals. It is a required document for the Pathways program.

  17. Exposures from aquatic pathways

    International Nuclear Information System (INIS)

    Methods for estimation aquatic pathways contribution to the total population exposure are discussed. Aquatic pathways are the major factor for radionuclides spreading from the Chernobyl Exclusion zone. An annual outflow of 90Sr and 137Cs comprised 10-20 TBq and 2-4 TBq respectively and the population exposed by this effluence constitutes almost 30 million people. The dynamic of doses from 90Sr and 'Cs, which Dnieper water have to delivered, is calculated. The special software has been developed to simulate the process of dose formation in the of diverse Dnieper regions. Regional peculiarities of municipal tap, fishing and irrigation are considered. Seventy-year prediction of dose structure and function of dose forming is performed. The exposure is estimated for 12 regions of the Dnieper basin and the Crimea. The maximal individual annual committed effective doses due to the use of water by ordinary members of the population in Kiev region from 90Sr and 137Cs in 1986 are 1.7*10-5 Sv and 2.7*10-5 Sv respectively. A commercial fisherman on Kiev reservoir in 1986 received 4.7*10-4 Sv and 5*10-3 Sv from 90Sr and 137Cs, respectively. The contributions to the collective cumulative (over 70 years) committed effective dose (CCCED70) of irrigation, municipal tap water and fish consumption for members of the population respectively are 18%, 43%, 39% in Kiev region, 8%, 25%, 67% in Poltava region, and 50%, 50%, 0% (consumption of Dnieper fish is absent) in the Crimea. The predicted contribution of the Strontium-90 to CCCED70 resulting from the use of water is 80%. The CCCED70 to the population of the Dnieper regions (32.5 million people) is 3000 person-Sv due to the use the Dnieper water

  18. Combinatorial pathway assembly in yeast

    Directory of Open Access Journals (Sweden)

    Khalil Essani

    2015-10-01

    Full Text Available With the emergence of synthetic biology and the vast knowledge about individual biocatalytic reactions, the challenge nowadays is to implement whole natural or synthetic pathways into microorganisms. For this purpose balanced enzyme activities throughout the pathway need to be achieved in addition to simple functional gene expression to avoid bottlenecks and to obtain high titers of the desired product. As the optimization of pathways in a specific biological context is often hard to achieve by rational design, combinatorial approaches have been developed to address this issue. Here, current strategies and proof of concepts for combinatorial pathway assembly in yeasts are reviewed. By exploiting its ability to join multiple DNA fragments in a very efficient and easy manner, the yeast Saccharomyces cerevisiae does not only constitute an attractive host for heterologous pathway expression, but also for assembling pathways by recombination in vivo.

  19. Pathways to man

    International Nuclear Information System (INIS)

    The study of radionuclide pathways leading to man generally has the goal of allowing us to predict human exposure from measurements of the radionuclide concentration in some segment of the environment. This modelling process provides a valuable tool in both the regulatory and health protection fields. However, most of the models in the regulatory field and in the health physics profession were designed to maximize exposure estimates. It is preferable to have scientifically defensible estimates and to add suitable safety factors at the end. Thus we are still faced with the development and validation of suitable models for many of the radionuclides of interest. The most useful models will include means of assessing variability and uncertainty. In this case variability might be considered as the differences in behavior due to age, sex or other factors in animals or man and those differences among plant species or animal species that determine their uptake factors. The uncertainty, on the other hand, would be the estimate of possible error in the experimental measurements. Model parameters would always have some variability even for site-specific cases and broad averages for population groups would have to include a factor expressing the possible variabilty and uncertainity. Thus any exposure calculation would have to be expressed with some range and valid assessments of this range are required

  20. Evolution of the TOR Pathway.

    NARCIS (Netherlands)

    Dam, T.J.P. van; Zwartkruis, F.J.; Bos, J.L.; Snel, B.

    2011-01-01

    The TOR kinase is a major regulator of growth in eukaryotes. Many components of the TOR pathway are implicated in cancer and metabolic diseases in humans. Analysis of the evolution of TOR and its pathway may provide fundamental insight into the evolution of growth regulation in eukaryotes and provid

  1. KeyPathwayMinerWeb

    DEFF Research Database (Denmark)

    List, Markus; Alcaraz, Nicolas; Dissing-Hansen, Martin;

    2016-01-01

    We present KeyPathwayMinerWeb, the first online platform for de novo pathway enrichment analysis directly in the browser. Given a biological interaction network (e.g. protein-protein interactions) and a series of molecular profiles derived from one or multiple OMICS studies (gene expression......, for instance), KeyPathwayMiner extracts connected sub-networks containing a high number of active or differentially regulated genes (proteins, metabolites) in the molecular profiles. The web interface at (http://keypathwayminer.compbio.sdu.dk) implements all core functionalities of the KeyPathwayMiner tool set...... such as data integration, input of background knowledge, batch runs for parameter optimization and visualization of extracted pathways. In addition to an intuitive web interface, we also implemented a RESTful API that now enables other online developers to integrate network enrichment as a web service...

  2. Signaling pathways in diabetic nephropathy.

    Science.gov (United States)

    Kawanami, Daiji; Matoba, Keiichiro; Utsunomiya, Kazunori

    2016-10-01

    Diabetic nephropathy (DN) is a major cause of end-stage renal disease (ESRD), however, specific treatment for DN has not yet been elucidated. Therefore, it is critically important to understand the molecular mechanism underlying DN to develop cause-related therapeutic strategy. To date, various factors such as hemodynamic changes and metabolic pathways have been shown to be involved in the pathogenesis of DN. Excessive glucose influx activates cellular signaling pathways, including the diacylglycerol (DAG)-protein kinase C (PKC) pathway, advanced glycation end-products (AGE), polyol pathway, hexosamine pathway and oxidative stress. These factors interact with one another, thereby facilitating inflammatory processes, leading to the development of glomerulosclerosis under diabetic conditions. In addition to metabolic pathways, Rho-kinase, an effector of small-GTPase binding protein Rho, has been implicated as an important factor in the pathogenesis of DN. A number of studies have demonstrated that Rho-kinase plays key roles in the development of DN by inducing endothelial dysfunction, mesangial excessive extracellular matrix (ECM) production, podocyte abnormality, and tubulointerstitial fibrosis. In this review article, we describe our current understanding of the signaling pathways in DN. PMID:27094540

  3. A New Sphingolipid from the Fungus Paxillus panuoides

    Institute of Scientific and Technical Information of China (English)

    GAO Jin-Ming; ZHANG Zeng-Qiang; LIU Ji-Kai

    2003-01-01

    @@ The ceramides, cleavage products of various sphingolipids, including gangliosides and cerebrosides, are in volved in various signal transduction pathways. Many extracellular stresses, such as tumor necrosis factors-α (TNFα) and human immunodeficiency virus (HIV) have been shown to activate sphingomyelinases that release ceramides which inhibit cell growth and induce apoptosis. Because of the importance of ceramides, chemistry and biology of ceramides have been the vital subject of the latest research in recent years. [1~4

  4. Metabolic pathway engineering of the toluene degradation pathway

    OpenAIRE

    Regan, L.

    1995-01-01

    This thesis addresses the problem of how to examine a metabolic pathway and identify what are the key elements, specifically with respect to rate-limitation. The aim is to be able to analyze a pathway, identify the bottlenecks and implement genetic modifications to remove these bottlenecks. This is done by defining the system of interest and developing a predictive model using kinetic data. The model predictions can then be verified using fermentation data and genetic technique...

  5. Jasmonate Signal Pathway in Arabidopsis

    Institute of Scientific and Technical Information of China (English)

    Xiao-Yi Shan; Zhi-Long Wang; Daoxin Xie

    2007-01-01

    Jasmonates (JAs), which include jasmonic acid and its cyclopentane derivatives are synthesized from the octadecanoid pathway and widely distributed throughout the plant kingdom. JAs modulate the expression of numerous genes and mediate responses to stress, wounding, insect attack, pathogen infection, and UV damage. They also affect a variety of processes in many plant developmental processes. The JA signal pathway involves two important events: the biosynthesis of JA and the transduction of JA signal. Several important Arabidopsis mutants in jasmonate signal pathway were described in this review.

  6. Multiple pathways regulate shoot branching

    Directory of Open Access Journals (Sweden)

    Catherine eRameau

    2015-01-01

    Full Text Available Shoot branching patterns result from the spatio-temporal regulation of axillary bud outgrowth. Numerous endogenous, developmental and environmental factors are integrated at the bud and plant levels to determine numbers of growing shoots. Multiple pathways that converge to common integrators are most probably involved. We propose several pathways involving not only the classical hormones auxin, cytokinins and strigolactones, but also other signals with a strong influence on shoot branching such as gibberellins, sugars or molecular actors of plant phase transition. We also deal with recent findings about the molecular mechanisms and the pathway involved in the response to shade as an example of an environmental signal controlling branching. We propose the TCP transcription factor TB1/BRC1 and the polar auxin transport stream in the stem as possible integrators of these pathways. We finally discuss how modeling can help to represent this highly dynamic system by articulating knowledges and hypothesis and calculating the phenotype properties they imply.

  7. HealthPathways: creating a pathway for health systems reform.

    Science.gov (United States)

    Robinson, Suzanne; Varhol, Richard; Bell, Colin; Quirk, Frances; Durrington, Learne

    2015-02-01

    Inefficiencies in the co-ordination and integration of primary and secondary care services in Australia, have led to increases in waiting times, unnecessary presentations to emergency departments and issues around poor discharge of patients. HealthPathways is a program developed in Canterbury, New Zealand, that builds relationships between General Practitioners and Specialists and uses information technology so that efficiency is maximised and the right patient is given the right care at the right time. Healthpathways is being implemented by a number of Medicare Locals across Australia however, little is known about the impact HealthPathways may have in Australia. This article provides a short description of HealthPathways and considers what it may offer in the Australian context and some of the barriers and facilitators to implementation.

  8. HealthPathways: creating a pathway for health systems reform.

    Science.gov (United States)

    Robinson, Suzanne; Varhol, Richard; Bell, Colin; Quirk, Frances; Durrington, Learne

    2015-02-01

    Inefficiencies in the co-ordination and integration of primary and secondary care services in Australia, have led to increases in waiting times, unnecessary presentations to emergency departments and issues around poor discharge of patients. HealthPathways is a program developed in Canterbury, New Zealand, that builds relationships between General Practitioners and Specialists and uses information technology so that efficiency is maximised and the right patient is given the right care at the right time. Healthpathways is being implemented by a number of Medicare Locals across Australia however, little is known about the impact HealthPathways may have in Australia. This article provides a short description of HealthPathways and considers what it may offer in the Australian context and some of the barriers and facilitators to implementation. PMID:25433515

  9. Aberrant Signaling Pathways in Glioma

    International Nuclear Information System (INIS)

    Glioblastoma multiforme (GBM), a WHO grade IV malignant glioma, is the most common and lethal primary brain tumor in adults; few treatments are available. Median survival rates range from 12–15 months. The biological characteristics of this tumor are exemplified by prominent proliferation, active invasiveness, and rich angiogenesis. This is mainly due to highly deregulated signaling pathways in the tumor. Studies of these signaling pathways have greatly increased our understanding of the biology and clinical behavior of GBM. An integrated view of signal transduction will provide a more useful approach in designing novel therapies for this devastating disease. In this review, we summarize the current understanding of GBM signaling pathways with a focus on potential molecular targets for anti-signaling molecular therapies

  10. Rapid prototype extruded conductive pathways

    Energy Technology Data Exchange (ETDEWEB)

    Bobbitt, III, John T.

    2016-06-21

    A process of producing electrically conductive pathways within additively manufactured parts and similar parts made by plastic extrusion nozzles. The process allows for a three-dimensional part having both conductive and non-conductive portions and allows for such parts to be manufactured in a single production step.

  11. Diverse Pathways in Children's Learning.

    Science.gov (United States)

    Lambert, Beverley

    1996-01-01

    Used a Partially Ordered Scaling of Items method to analyze block construction play in a replication of Innes and King-Shaw's 1985 study. Found several developmental pathways for block play, illustrating the web-like nature of conceptual development. Results suggest a contextual developmental approach to better acknowledge individual diversity in…

  12. Auditory pathways: anatomy and physiology.

    Science.gov (United States)

    Pickles, James O

    2015-01-01

    This chapter outlines the anatomy and physiology of the auditory pathways. After a brief analysis of the external, middle ears, and cochlea, the responses of auditory nerve fibers are described. The central nervous system is analyzed in more detail. A scheme is provided to help understand the complex and multiple auditory pathways running through the brainstem. The multiple pathways are based on the need to preserve accurate timing while extracting complex spectral patterns in the auditory input. The auditory nerve fibers branch to give two pathways, a ventral sound-localizing stream, and a dorsal mainly pattern recognition stream, which innervate the different divisions of the cochlear nucleus. The outputs of the two streams, with their two types of analysis, are progressively combined in the inferior colliculus and onwards, to produce the representation of what can be called the "auditory objects" in the external world. The progressive extraction of critical features in the auditory stimulus in the different levels of the central auditory system, from cochlear nucleus to auditory cortex, is described. In addition, the auditory centrifugal system, running from cortex in multiple stages to the organ of Corti of the cochlea, is described.

  13. The lectin pathway of complement

    DEFF Research Database (Denmark)

    Ballegaard, Vibe Cecilie Diederich; Haugaard, Anna Karen; Garred, P;

    2014-01-01

    The pattern recognition molecules of the lectin complement pathway are important components of the innate immune system with known functions in host-virus interactions. This paper summarizes current knowledge of how these intriguing molecules, including mannose-binding lectin (MBL), Ficolin-1, -2...

  14. Reverse Engineering Adverse Outcome Pathways

    Energy Technology Data Exchange (ETDEWEB)

    Perkins, Edward; Chipman, J.K.; Edwards, Stephen; Habib, Tanwir; Falciani, Francesco; Taylor, Ronald C.; Van Aggelen, Graham; Vulpe, Chris; Antczak, Philipp; Loguinov, Alexandre

    2011-01-30

    The toxicological effects of many stressors are mediated through unknown, or poorly characterized, mechanisms of action. We describe the application of reverse engineering complex interaction networks from high dimensional omics data (gene, protein, metabolic, signaling) to characterize adverse outcome pathways (AOPs) for chemicals that disrupt the hypothalamus-pituitary-gonadal endocrine axis in fathead minnows. Gene expression changes in fathead minnow ovaries in response to 7 different chemicals, over different times, doses, and in vivo versus in vitro conditions were captured in a large data set of 868 arrays. We examined potential AOPs of the antiandrogen flutamide using two mutual information theory methods, ARACNE and CLR to infer gene regulatory networks and potential adverse outcome pathways. Representative networks from these studies were used to predict a network path from stressor to adverse outcome as a candidate AOP. The relationship of individual chemicals to an adverse outcome can be determined by following perturbations through the network in response to chemical treatment leading to the nodes associated with the adverse outcome. Identification of candidate pathways allows for formation of testable hypotheses about key biologic processes, biomarkers or alternative endpoints, which could be used to monitor an adverse outcome pathway. Finally, we identify the unique challenges facing the application of this approach in ecotoxicology, and attempt to provide a road map for the utilization of these tools. Key Words: mechanism of action, toxicology, microarray, network inference

  15. Critical nodes in signalling pathways

    DEFF Research Database (Denmark)

    Taniguchi, Cullen M; Emanuelli, Brice; Kahn, C Ronald

    2006-01-01

    Physiologically important cell-signalling networks are complex, and contain several points of regulation, signal divergence and crosstalk with other signalling cascades. Here, we use the concept of 'critical nodes' to define the important junctions in these pathways and illustrate their unique ro...

  16. Fumonisin B1, a mycotoxin contaminant of cereal grains, and inducer of apoptosis via the tumour necrosis factor pathway and caspase activation.

    Science.gov (United States)

    Ciacci-Zanella, J R; Jones, C

    1999-07-01

    Fumonisins are mycotoxins produced by Fusarium moniliforme, a prevalent fungus which infects corn or other cereal grains. Fumonisin B1 (FB1) is the most common mycotoxin produced by F. moniliforme, suggesting that it has toxicological significance. The structure of FB1 resembles sphingoid bases and it inhibits ceramide synthase. As sphingoid bases regulate cell growth, differentiation, transformation and apoptosis, it is reasonable to hypothesize that FB1 can also regulate these activities. Previous studies concluded that FB1 induced apoptosis or cell-cycle arrest in CV-1 cells (African green monkey kidney fibroblasts). In this study, we have identified genes that inhibit FB1-induced apoptosis in CV-1 cells and in two primary human cell types (lung fibroblasts and neonatal kidney cells). A baculovirus gene. inhibitor of apoptosis (IAP), protected CV-1 and the human cells from apoptosis. IAP blocks apoptosis which is induced by the tumour necrosis factor (TNF) pathway. Inhibition of interleukin converting enzymes (ICE proteases or caspases) by the baculovirus gene p35 also inhibited FB1-induced apoptosis. FB1 treatment led to cleavage of Rb (retinoblastoma protein) at its C-terminus in CV-1 or human lung cells. As the C-terminus of Rb is cleaved by ICE proteases during apoptosis, this supports an active role for ICE proteases in FB1-induced apoptosis. The tumour suppressor gene p53 was not required for FB1-induced apoptosis because p53-/- primary mouse embryo fibroblasts underwent apoptosis following FB1 treatment. Furthermore, Bcl-2 was not an effective inhibitor of FB1-induced apoptosis in CV-1 or IMR-90 cells. In summary, these results demonstrate that the TNF pathway and caspases plays an important role in FB1-induced apoptosis.

  17. Ceramide profile in hypohidrotic ectodermal dysplasia

    DEFF Research Database (Denmark)

    Jungersted, J. M.; Høgh, Julie Kaae; Hellgren, Lars;

    2012-01-01

    with HED (n = 7) and patients with AD (n = 21), using cyanoacrylate to take biopsy samples from the stratum corneum. Lipids were extracted from the biopsies and analysed using high‐performance thin‐layer chromatography. Results. The lipid profiles of HED and AD were similar in distribution, apart from...

  18. Mechanisms and impact of ceramide phosphoethanolamine biosynthesis

    NARCIS (Netherlands)

    Hentes Vacaru, A.M.

    2009-01-01

    Sphingolipids represent an essential class of membrane molecules in eukaryotic cells. They are primarily found in the outer leaflet of the plasma membrane where they help create a rigid and impermeable barrier to the extracellular environment. While sphingomyelin (SM) is the most abundant sphingolip

  19. Hand eczema and stratum corneum ceramides

    DEFF Research Database (Denmark)

    Jungersted, J. M.; Høgh, Julie Kaae; Hellgren, Lars;

    2015-01-01

    Index (HECSI), and skin barrier susceptibility was assessed by measuring transepidermal water loss (TEWL) after a 24-hour patch test with sodium lauryl sulfate (SLS). Results: No statistically significant difference was found between groups for the lipid analysis or for skin susceptibility to SLS. We...

  20. 线纹香茶菜地下部分甾体与神经酰胺类成分%Steroidal and Ceramide Constituents from Underground Part of Isodon lophanthoides

    Institute of Scientific and Technical Information of China (English)

    徐伟; 孙俊哲; 赵明早; 王靖雯; 董相; 姜北

    2016-01-01

    目的:对线纹香茶菜(Isodon lophanthoides)地下部分化学成分进行研究。方法:采用硅胶、Sephadex LH-20等多种柱层析方法对线纹香茶菜地下部分进行分离纯化,并运用现代波谱学技术与理化性质等手段对分离的化合物进行结构鉴定。结果:从线纹香茶菜地下部分70%丙酮-水提取物的乙酸乙酯部位分离得到5个甾体类化合物和2个神经酰胺类化合物,分别鉴定为:豆甾-4-烯-3-酮(1)、豆甾醇(2)、7α-羟基谷甾醇(3)、胡萝卜苷(4)、5α,6β-二羟基胡萝卜苷(5)、(2S,3S,4R,8E)-2-[(2′R)-2′-羟基-二十四酰氨基]-8-十八烯-1,3,4-三醇(6)、(2S,3R,4E,8Z)-1-O-β-D-葡萄糖-2-[(2′R)-2′-羟基-二十四酰氨基]-4,8-十八二烯-1,3-二醇(7)。结论:化合物1、3、5~7为首次从该植物中分离得到,其中化合物5~7为首次从该属植物地下部分分离得到。%Objective: To explore the chemical constituents from the underground part of Isodon lophanthoides. Methods: The compounds were isolated and purified by silica gel and Sephadex LH-20 column chromatography. Their structures were identified by various spectral analysis and physicochemical properties. Results: Five steroidal compounds and two ceramide compounds were obtained from ethyl acetate fraction of 70% acetone-water extract of the Isodon lophanthoides underground part and identified as stigmast-4-ene-3-one(1), stigmasterol(2), 7α-hydroxysitosterol(3), daucosterol(4), 5α, 6β-dihydroxy-daucosterol(5),(2S, 3S, 4R, 8E)-2-[(2′R)-2-hydroxytetracosanoylamino]-1, 3, 4-octadecanetriol-8-ene(6), and 1-O-β-D-glucopyranosyl-(2S, 3R, 4E, 8Z)-2-[(2′R)-2-hydroxytetracosanoylamino]-1,3-octadecanediol-4, 8-diene(7). Conclusion:All of these compounds except for 2 and 4 were isolated from this plant for the first time, while the compounds 5-7 were firstly obtained from the underground part of Isodon

  1. Molecular Pathways: Targeting DNA Repair Pathway Defects Enriched in Metastasis.

    Science.gov (United States)

    Corcoran, Niall M; Clarkson, Michael J; Stuchbery, Ryan; Hovens, Christopher M

    2016-07-01

    The maintenance of a pristine genome, free from errors, is necessary to prevent cellular transformation and degeneration. When errors in DNA are detected, DNA damage repair (DDR) genes and their regulators are activated to effect repair. When these DDR pathways are themselves mutated or aberrantly downregulated, cancer and neurodegenerative disorders can ensue. Multiple lines of evidence now indicate, however, that defects in key regulators of DNA repair pathways are highly enriched in human metastasis specimens and hence may be a key step in the acquisition of metastasis and the ability of localized disease to disseminate. Some of the key regulators of checkpoints in the DNA damage response are the TP53 protein and the PARP enzyme family. Targeting of these pathways, especially through PARP inhibition, is now being exploited therapeutically to effect significant clinical responses in subsets of individuals, particularly in patients with ovarian cancer or prostate cancer, including cancers with a marked metastatic burden. Targeting DNA repair-deficient tumors with drugs that take advantage of the fundamental differences between normal repair-proficient cells and repair-deficient tumors offers new avenues for treating advanced disease in the future. Clin Cancer Res; 22(13); 3132-7. ©2016 AACR. PMID:27169997

  2. Plasma Metabolic Profile Determination in Young ST-segment Elevation Myocardial Infarction Patients with Ischemia and Reperfusion: Ultra-performance Liquid Chromatography and Mass Spectrometry for Pathway Analysis

    Institute of Scientific and Technical Information of China (English)

    Lei Huang; Tong Li; Ying-Wu Liu; Lei Zhang; Zhi-Huan Dong; Shu-Ye Liu; Ying-Tang Gao

    2016-01-01

    Background:This study was to establish a disease differentiation model for ST-segment elevation myocardial infarction (STEMI) youth patients experiencing ischemia and reperfusion via ultra-performance liquid chromatography and mass spectrometry (UPLC/MS) platform,which searches for closely related characteristic metabolites and metabolic pathways to evaluate their predictive value in the prognosis after discharge.Methods:Forty-seven consecutive STEMI patients (23 patients under 45 years of age,referred to here as "youth," and 24 "elderly" patients) and 48 healthy control group members (24 youth,24 elderly) were registered prospectively.The youth patients were required to provide a second blood draw during a follow-up visit one year after morbidity (n =22,one lost).Characteristic metabolites and relative metabolic pathways were screened via UPLC/MS platform base on the Kyoto encyclopedia of genes and genomes (KEGG) and Human Metabolome Database.Receiver operating characteristic (ROC) curves were drawn to evaluate the predictive value of characteristic metabolites in the prognosis after discharge.Results:We successfully established an orthogonal partial least squares discriminated analysis model (R2X =71.2%,R2Y =79.6%,and Q2 =55.9%) and screened out 24 ions; the sphingolipid metabolism pathway showed the most drastic change.The ROC curve analysis showed that ceramide [Cer(d18:0/16:0),Cer(t18:0/12:0)] and sphinganine in the sphingolipid pathway have high sensitivity and specificity on the prognosis related to major adverse cardiovascular events after youth patients were discharged.The area under curve (AUC) was 0.671,0.750,and 0.711,respectively.A follow-up validation one year after morbidity showed corresponding AUC of 0.778,0.833,and 0.806.Conclusions:By analyzing the plasma metabolism of myocardial infarction patients,we successfully established a model that can distinguish two different factors simultaneously:pathological conditions and age

  3. DMPD: Signalling pathways mediating type I interferon gene expression. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 17904888 Signalling pathways mediating type I interferon gene expression. Edwards M...csml) Show Signalling pathways mediating type I interferon gene expression. PubmedID 17904888 Title Signalling pathways media

  4. Fragmentation pathways of polymer ions.

    Science.gov (United States)

    Wesdemiotis, Chrys; Solak, Nilüfer; Polce, Michael J; Dabney, David E; Chaicharoen, Kittisak; Katzenmeyer, Bryan C

    2011-01-01

    Tandem mass spectrometry (MS/MS) is increasingly applied to synthetic polymers to characterize chain-end or in-chain substituents, distinguish isobaric and isomeric species, and determine macromolecular connectivities and architectures. For confident structural assignments, the fragmentation mechanisms of polymer ions must be understood, as they provide guidelines on how to deduce the desired information from the fragments observed in MS/MS spectra. This article reviews the fragmentation pathways of synthetic polymer ions that have been energized to decompose via collisionally activated dissociation (CAD), the most widely used activation method in polymer analysis. The compounds discussed encompass polystyrenes, poly(2-vinyl pyridine), polyacrylates, poly(vinyl acetate), aliphatic polyester copolymers, polyethers, and poly(dimethylsiloxane). For a number of these polymers, several substitution patterns and architectures are considered, and questions regarding the ionization agent and internal energy of the dissociating precursor ions are also addressed. Competing and consecutive dissociations are evaluated in terms of the structural insight they provide about the macromolecular structure. The fragmentation pathways of the diverse array of polymer ions examined fall into three categories, viz. (1) charge-directed fragmentations, (2) charge-remote rearrangements, and (3) charge-remote fragmentations via radical intermediates. Charge-remote processes predominate. Depending on the ionizing agent and the functional groups in the polymer, the incipient fragments arising by pathways (1)-(3) may form ion-molecule complexes that survive long enough to permit inter-fragment hydrogen atom, proton, or hydride transfers. PMID:20623599

  5. Dual pathways to prospective remembering

    Science.gov (United States)

    McDaniel, Mark A.; Umanath, Sharda; Einstein, Gilles O.; Waldum, Emily R.

    2015-01-01

    According to the multiprocess framework (McDaniel and Einstein, 2000), the cognitive system can support prospective memory (PM) retrieval through two general pathways. One pathway depends on top–down attentional control processes that maintain activation of the intention and/or monitor the environment for the triggering or target cues that indicate that the intention should be executed. A second pathway depends on (bottom–up) spontaneous retrieval processes, processes that are often triggered by a PM target cue; critically, spontaneous retrieval is assumed not to require monitoring or active maintenance of the intention. Given demand characteristics associated with experimental settings, however, participants are often inclined to monitor, thereby potentially masking discovery of bottom–up spontaneous retrieval processes. In this article, we discuss parameters of laboratory PM paradigms to discourage monitoring and review recent behavioral evidence from such paradigms that implicate spontaneous retrieval in PM. We then re-examine the neuro-imaging evidence from the lens of the multiprocess framework and suggest some critical modifications to existing neuro-cognitive interpretations of the neuro-imaging results. These modifications illuminate possible directions and refinements for further neuro-imaging investigations of PM. PMID:26236213

  6. Dual Pathways to Prospective Remembering

    Directory of Open Access Journals (Sweden)

    Mark A Mcdaniel

    2015-07-01

    Full Text Available According to the multiprocess framework (McDaniel & Einstein, 2000, the cognitive system can support prospective memory (PM retrieval through two general pathways. One pathway depends on top-down attentional control processes that maintain activation of the intention and/or monitor the environment for the triggering or target cues that indicate that the intention should be executed. A second pathway depends on (bottom-up spontaneous retrieval processes, processes that are often triggered by a PM target cue; critically spontaneous retrieval is assumed to not require monitoring or active maintenance of the intention. Given demand characteristics associated with experimental settings, however, participants are often inclined to monitor, thereby potentially masking discovery of bottom-up spontaneous retrieval processes. In this article, we discuss parameters of laboratory PM paradigms to discourage monitoring and review recent behavioral evidence from such paradigms that implicate spontaneous retrieval in PM. We then re-examine the neuro-imaging evidence from the lens of the multiprocess framework and suggest some critical modifications to existing neuro-cognitive interpretations of the neuro-imaging results. These modifications illuminate possible directions and refinements for further neuro-imaging investigations of PM.

  7. Identification of Metabolic Pathway Systems

    Directory of Open Access Journals (Sweden)

    Sepideh eDolatshahi

    2016-02-01

    Full Text Available The estimation of parameters in even moderately large biological systems is a significant challenge. This challenge is greatly exacerbated if the mathematical formats of appropriate process descriptions are unknown. To address this challenge, the method of dynamic flux estimation (DFE was proposed for the analysis of metabolic time series data. Under ideal conditions, the first phase of DFE yields numerical representations of all fluxes within a metabolic pathway system, either as values at each time point or as plots against their substrates and modulators. However, this numerical result does not reveal the mathematical format of each flux. Thus, the second phase of DFE selects functional formats that are consistent with the numerical trends obtained from the first phase. While greatly facilitating metabolic data analysis, DFE is only directly applicable if the pathway system contains as many dependent variables as fluxes. Because most actual systems contain more fluxes than metabolite pools, this requirement is seldom satisfied. Auxiliary methods have been proposed to alleviate this issue, but they are not general. Here we propose strategies that extend DFE toward general, slightly underdetermined pathway systems.

  8. Imbalanced kynurenine pathway in schizophrenia.

    Science.gov (United States)

    Kegel, Magdalena E; Bhat, Maria; Skogh, Elisabeth; Samuelsson, Martin; Lundberg, Kristina; Dahl, Marja-Liisa; Sellgren, Carl; Schwieler, Lilly; Engberg, Göran; Schuppe-Koistinen, Ina; Erhardt, Sophie

    2014-01-01

    Several studies suggest a role for kynurenic acid (KYNA) in the pathophysiology of schizophrenia. It has been proposed that increased brain KYNA levels in schizophrenia result from a pathological shift in the kynurenine pathway toward enhanced KYNA formation, away from the other branch of the pathway leading to quinolinic acid (QUIN). Here we investigate the levels of QUIN in cerebrospinal fluid (CSF) of patients with schizophrenia and healthy controls, and relate those to CSF levels of KYNA and other kynurenine metabolites from the same individuals. CSF QUIN levels from stable outpatients treated with olanzapine (n = 22) and those of controls (n = 26) were analyzed using liquid chromatography-mass spectrometry. No difference in CSF QUIN levels between patients and controls was observed (20.6 ± 1.5 nM vs. 18.2 ± 1.1 nM, P = 0.36). CSF QUIN was positively correlated to CSF kynurenine and CSF KYNA in patients but not in controls. The CSF QUIN/KYNA ratio was lower in patients than in controls (P = 0.027). In summary, the present study offers support for an over-activated and imbalanced kynurenine pathway, favoring the production of KYNA over QUIN in patients with schizophrenia. PMID:25288889

  9. Identification of Metabolic Pathway Systems.

    Science.gov (United States)

    Dolatshahi, Sepideh; Voit, Eberhard O

    2016-01-01

    The estimation of parameters in even moderately large biological systems is a significant challenge. This challenge is greatly exacerbated if the mathematical formats of appropriate process descriptions are unknown. To address this challenge, the method of dynamic flux estimation (DFE) was proposed for the analysis of metabolic time series data. Under ideal conditions, the first phase of DFE yields numerical representations of all fluxes within a metabolic pathway system, either as values at each time point or as plots against their substrates and modulators. However, this numerical result does not reveal the mathematical format of each flux. Thus, the second phase of DFE selects functional formats that are consistent with the numerical trends obtained from the first phase. While greatly facilitating metabolic data analysis, DFE is only directly applicable if the pathway system contains as many dependent variables as fluxes. Because most actual systems contain more fluxes than metabolite pools, this requirement is seldom satisfied. Auxiliary methods have been proposed to alleviate this issue, but they are not general. Here we propose strategies that extend DFE toward general, slightly underdetermined pathway systems.

  10. Synergy between methylerythritol phosphate pathway and mevalonate pathway for isoprene production in Escherichia coli.

    Science.gov (United States)

    Yang, Chen; Gao, Xiang; Jiang, Yu; Sun, Bingbing; Gao, Fang; Yang, Sheng

    2016-09-01

    Isoprene, a key building block of synthetic rubber, is currently produced entirely from petrochemical sources. In this work, we engineered both the methylerythritol phosphate (MEP) pathway and the mevalonate (MVA) pathway for isoprene production in E. coli. The synergy between the MEP pathway and the MVA pathway was demonstrated by the production experiment, in which overexpression of both pathways improved the isoprene yield about 20-fold and 3-fold, respectively, compared to overexpression of the MEP pathway or the MVA pathway alone. The (13)C metabolic flux analysis revealed that simultaneous utilization of the two pathways resulted in a 4.8-fold increase in the MEP pathway flux and a 1.5-fold increase in the MVA pathway flux. The synergy of the dual pathway was further verified by quantifying intracellular flux responses of the MEP pathway and the MVA pathway to fosmidomycin treatment and mevalonate supplementation. Our results strongly suggest that coupling of the complementary reducing equivalent demand and ATP requirement plays an important role in the synergy of the dual pathway. Fed-batch cultivation of the engineered strain overexpressing the dual pathway resulted in production of 24.0g/L isoprene with a yield of 0.267g/g of glucose. The synergy of the MEP pathway and the MVA pathway also successfully increased the lycopene productivity in E. coli, which demonstrates that it can be used to improve the production of a broad range of terpenoids in microorganisms. PMID:27174717

  11. Regulation of SREBPs by Sphingomyelin in Adipocytes via a Caveolin and Ras-ERK-MAPK-CREB Signaling Pathway.

    Directory of Open Access Journals (Sweden)

    Nehman Makdissy

    Full Text Available Sterol response element binding protein (SREBP is a key transcription factor in insulin and glucose metabolism. We previously demonstrated that elevated levels of membrane sphingomyelin (SM were related to peroxisome proliferator-activated receptor-γ (PPARγ, which is a known target gene of SREBP-1 in adipocytes. However, the role of SM in SREBP expression in adipocytes remains unknown. In human abdominal adipose tissue from obese women with various concentrations of fasting plasma insulin, SREBP-1 proteins decreased in parallel with increases in membrane SM levels. An inverse correlation was found between the membrane SM content and the levels of SREBP-1c/ERK/Ras/PPARγ/CREB proteins. For the first time, we demonstrate the effects of SM and its signaling pathway in 3T3-F442A adipocytes. These cells were enriched or unenriched with SM in a range of concentrations similar to those observed in obese subjects by adding exogenous natural SMs (having different acyl chain lengths or by inhibiting neutral sphingomyelinase. SM accumulated in caveolae of the plasma membrane within 24 h and then in the intracellular space. SM enrichment decreased SREBP-1 through the inhibition of extracellular signal-regulated protein kinase (ERK but not JNK or p38 mitogen-activated protein kinase (MAPK. Ras/Raf-1/MEK1/2 and KSR proteins, which are upstream mediators of ERK, were down-regulated, whereas SREBP-2/caveolin and cholesterol were up-regulated. In SM-unmodulated adipocytes treated with DL-1-Phenyl-2-Palmitoylamino-3-morpholino-1-propanol (PPMP, where the ceramide level increased, the expression levels of SREBPs and ERK were modulated in an opposite direction relative to the SM-enriched cells. SM inhibited the insulin-induced expression of SREBP-1. Rosiglitazone, which is an anti-diabetic agent and potent activator of PPARγ, reversed the effects of SM on SREBP-1, PPARγ and CREB. Taken together, these findings provide novel insights indicating that excess

  12. Apoptotic engulfment pathway and schizophrenia.

    LENUS (Irish Health Repository)

    Chen, Xiangning

    2009-01-01

    BACKGROUND: Apoptosis has been speculated to be involved in schizophrenia. In a previously study, we reported the association of the MEGF10 gene with the disease. In this study, we followed the apoptotic engulfment pathway involving the MEGF10, GULP1, ABCA1 and ABCA7 genes and tested their association with the disease. METHODOLOGY\\/PRINCIPAL FINDINGS: Ten, eleven and five SNPs were genotyped in the GULP1, ABCA1 and ABCA7 genes respectively for the ISHDSF and ICCSS samples. In all 3 genes, we observed nominally significant associations. Rs2004888 at GULP1 was significant in both ISHDSF and ICCSS samples (p = 0.0083 and 0.0437 respectively). We sought replication in independent samples for this marker and found highly significant association (p = 0.0003) in 3 Caucasian replication samples. But it was not significant in the 2 Chinese replication samples. In addition, we found a significant 2-marker (rs2242436 * rs3858075) interaction between the ABCA1 and ABCA7 genes in the ISHDSF sample (p = 0.0022) and a 3-marker interaction (rs246896 * rs4522565 * rs3858075) amongst the MEGF10, GULP1 and ABCA1 genes in the ICCSS sample (p = 0.0120). Rs3858075 in the ABCA1 gene was involved in both 2- and 3-marker interactions in the two samples. CONCLUSIONS\\/SIGNIFICANCE: From these data, we concluded that the GULP1 gene and the apoptotic engulfment pathway are involved in schizophrenia in subjects of European ancestry and multiple genes in the pathway may interactively increase the risks to the disease.

  13. Primary Metabolic Pathways and Metabolic Flux Analysis

    DEFF Research Database (Denmark)

    Villadsen, John

    2015-01-01

    his chapter introduces the metabolic flux analysis (MFA) or stoichiometry-based MFA, and describes the quantitative basis for MFA. It discusses the catabolic pathways in which free energy is produced to drive the cell-building anabolic pathways. An overview of these primary pathways provides...... the reader who is primarily trained in the engineering sciences with atleast a preliminary introduction to biochemistry and also shows how carbon is drained off the catabolic pathways to provide precursors for cell mass building and sometimes for important industrial products. The primary pathways...

  14. AlzPathway, an Updated Map of Curated Signaling Pathways: Towards Deciphering Alzheimer's Disease Pathogenesis.

    Science.gov (United States)

    Ogishima, Soichi; Mizuno, Satoshi; Kikuchi, Masataka; Miyashita, Akinori; Kuwano, Ryozo; Tanaka, Hiroshi; Nakaya, Jun

    2016-01-01

    Alzheimer's disease (AD) is a complex neurodegenerative disorder in which loss of neurons and synaptic function causes dementia in the elderly. To clarify AD pathogenesis and develop drugs for AD, thousands of studies have elucidated signaling pathways involved. However, knowledge of AD signaling pathways has not been compiled as a pathway map. In this chapter, we introduce the manual construction of a pathway map in AD which we call "AlzPathway", that comprehensively catalogs signaling pathways in the field of AD. We have collected and manually curated over 100 review articles related to AD, and have built the AD pathway map. AlzPathway is currently composed of thousands of molecules and reactions in neurons, brain blood barrier, presynaptic, postsynaptic, astrocyte, and microglial cells, with their cellular localizations. AlzPathway provides a systems-biology platform of comprehensive AD signaling and related pathways which is expected to contribute to clarification of AD pathogenesis and AD drug development.

  15. Oxylipin Pathway in Rice and Arabidopsis

    Institute of Scientific and Technical Information of China (English)

    E. Wassim Chehab; John V. Perea; Banu Gopalan; Steve Theg; Katayoon Dehesh

    2007-01-01

    Plants have evolved complex signaling pathways to coordinate responses to developmental and environmental information. The oxylipin pathway is one pivotal lipid-based signaling network, composed of several competing branch pathways, that determines the plant's ability to adapt to various stimuli. Activation of the oxylipin pathway induces the de novo synthesis of biologically active metabolltes called "oxylipins". The relative levels of these metabolltes are a distinct indicator of each plant species and determine the ability of plants to adapt to different stimuli. The two major branches of the oxylipln pathway, allene oxide synthase (AOS) and hydroperoxide lyase (HPL) are responsible for production of the signaling compounds,jasmonates and aldehydes respectively. Here, we compare and contrast the regulation of AOS and HPL branch pathways in rice and Arabidopsis as model monocotyledonous and dicotyledonous systems. These analyses provide new Insights into the evolution of JAs and aldehydes signaling pathways, and the complex network of processes responsible for stress adaptations in monocots and dicots.

  16. Pulmonary gas conducting interstitial pathway

    International Nuclear Information System (INIS)

    In spite of the growing efforts oriented towards revealing different aspects of emphysema, the persistence of the emphysematous or emphysema-like changes (ELCs) is not explored yet in the open literature. In this study we demonstrate the persistence of an ELC for 22 years in a spontaneous pneumothorax (SP) patient which indicates a hitherto unknown gas supply to the ELC. For this purpose we used high resolution computed tomography (HRCT) images processed into three-dimensional (3D) geometry. By the same token, not only a long persistence but also the volume increase of this ELC between 2002 and 2010 was demonstrated. The 3D geometry visualized an aerated interstitial structure between the sites of supposed gas leakage at the wall of the third generation airways and the ELC. This potential gas conducting interstitial pathway is not a continuation and has neither the form nor the structure of a bronchus. The finding suggests that in this patient the intrabronchial gas passes through the bronchial wall and via a gas conducting interstitial pathway reaches the ELC. Despite the availability of the presently employed techniques for at least 15 years, such case and phenomenon have not been described previously. The retrieval of the patient suggests that the findings could be relevant for a considerable proportion of the population

  17. Combustion kinetics and reaction pathways

    Energy Technology Data Exchange (ETDEWEB)

    Klemm, R.B.; Sutherland, J.W. [Brookhaven National Laboratory, Upton, NY (United States)

    1993-12-01

    This project is focused on the fundamental chemistry of combustion. The overall objectives are to determine rate constants for elementary reactions and to elucidate the pathways of multichannel reactions. A multitechnique approach that features three independent experiments provides unique capabilities in performing reliable kinetic measurements over an exceptionally wide range in temperature, 300 to 2500 K. Recent kinetic work has focused on experimental studies and theoretical calculations of the methane dissociation system (CH{sub 4} + Ar {yields} CH{sub 3} + H + Ar and H + CH{sub 4} {yields} CH{sub 3} + H{sub 2}). Additionally, a discharge flow-photoionization mass spectrometer (DF-PIMS) experiment is used to determine branching fractions for multichannel reactions and to measure ionization thresholds of free radicals. Thus, these photoionization experiments generate data that are relevant to both reaction pathways studies (reaction dynamics) and fundamental thermochemical research. Two distinct advantages of performing PIMS with high intensity, tunable vacuum ultraviolet light at the National Synchrotron Light Source are high detection sensitivity and exceptional selectivity in monitoring radical species.

  18. Transneuronal pathways to the vestibulocerebellum

    Science.gov (United States)

    Kaufman, G. D.; Mustari, M. J.; Miselis, R. R.; Perachio, A. A.

    1996-01-01

    The alpha-herpes virus (pseudorabies, PRV) was used to observe central nervous system (CNS) pathways associated with the vestibulocerebellar system. Retrograde transneuronal migration of alpha-herpes virions from specific lobules of the gerbil and rat vestibulo-cerebellar cortex was detected immunohistochemically. Using a time series analysis, progression of infection along polyneuronal cerebellar afferent pathways was examined. Pressure injections of > 20 nanoliters of a 10(8) plaque forming units (pfu) per ml solution of virus were sufficient to initiate an infectious locus which resulted in labeled neurons in the inferior olivary subnuclei, vestibular nuclei, and their afferent cell groups in a progressive temporal fashion and in growing complexity with increasing incubation time. We show that climbing fibers and some other cerebellar afferent fibers transported the virus retrogradely from the cerebellum within 24 hours. One to three days after cerebellar infection discrete cell groups were labeled and appropriate laterality within crossed projections was preserved. Subsequent nuclei labeled with PRV after infection of the flocculus/paraflocculus, or nodulus/uvula, included the following: vestibular (e.g., z) and inferior olivary nuclei (e.g., dorsal cap), accessory oculomotor (e.g., Darkschewitsch n.) and accessory optic related nuclei, (e.g., the nucleus of the optic tract, and the medial terminal nucleus); noradrenergic, raphe, and reticular cell groups (e.g., locus coeruleus, dorsal raphe, raphe pontis, and the lateral reticular tract); other vestibulocerebellum sites, the periaqueductal gray, substantia nigra, hippocampus, thalamus and hypothalamus, amygdala, septal nuclei, and the frontal, cingulate, entorhinal, perirhinal, and insular cortices. However, there were differences in the resulting labeling between infection in either region. Double-labeling experiments revealed that vestibular efferent neurons are located adjacent to, but are not included

  19. Asparagine Metabolic Pathways in Arabidopsis.

    Science.gov (United States)

    Gaufichon, Laure; Rothstein, Steven J; Suzuki, Akira

    2016-04-01

    Inorganic nitrogen in the form of ammonium is assimilated into asparagine via multiple steps involving glutamine synthetase (GS), glutamate synthase (GOGAT), aspartate aminotransferase (AspAT) and asparagine synthetase (AS) in Arabidopsis. The asparagine amide group is liberated by the reaction catalyzed by asparaginase (ASPG) and also the amino group of asparagine is released by asparagine aminotransferase (AsnAT) for use in the biosynthesis of amino acids. Asparagine plays a primary role in nitrogen recycling, storage and transport in developing and germinating seeds, as well as in vegetative and senescence organs. A small multigene family encodes isoenzymes of each step of asparagine metabolism in Arabidopsis, except for asparagine aminotransferase encoded by a single gene. The aim of this study is to highlight the structure of the genes and encoded enzyme proteins involved in asparagine metabolic pathways; the regulation and role of different isogenes; and kinetic and physiological properties of encoded enzymes in different tissues and developmental stages. PMID:26628609

  20. Post-Communist Welfare Pathways

    DEFF Research Database (Denmark)

    Cerami, Alfio; Vanhuysse, Pieter

    This collection adopts novel theoretical approaches to study the diverse welfare state pathways that have evolved across Central and Eastern Europe since the fall of communism in 1989. Going beyond existing path dependency and neo-institutionalist explanations, it highlights the role of explanatory...... to be protected from the high social costs of market transitions. In the Visegrad countries, sending laid-off workers into pensions, which were relatively well protected (p. 87) was the mechanism to buy political peace from older people who were more likely to vote anyway. In the Baltic States the same aim...... received inadequate attention ... The book integrates several strands of the existing literature – ranging from national social policy models to specific policy areas – which have rarely been examined together. This is very valuable, as it is only by confronting theories with detailed country case studies...

  1. Shadows Along the Spiritual Pathway.

    Science.gov (United States)

    Humphrey, Caroline

    2015-12-01

    Contemporary spirituality discourses tend to assume that a canopy of light and love overarches all spiritual pathways. Unfortunately, the dark side of humanity cannot be spirited away so easily, and aberrations of personal spiritual development, interpersonal spiritual relationships and new spiritual movements can often be traced to the denial, repression and return of our dark side. Transpersonal psychology offers a way of approaching, reframing and redeeming the unconscious depths of our psyche, with its metaphors of shadows and daimons on the one hand, and its therapeutic practices for symbolically containing and transcending polarities on the other. In its absence, any spirituality which eulogises holistic growth is likely to engender the reverse effect. PMID:25794547

  2. Fuel Dependence of Benzene Pathways

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, H; Eddings, E; Sarofim, A; Westbrook, C

    2008-07-14

    The relative importance of formation pathways for benzene, an important precursor to soot formation, was determined from the simulation of 22 premixed flames for a wide range of equivalence ratios (1.0 to 3.06), fuels (C{sub 1}-C{sub 12}), and pressures (20 to 760 torr). The maximum benzene concentrations in 15 out of these flames were well reproduced within 30% of the experimental data. Fuel structural properties were found to be critical for benzene production. Cyclohexanes and C{sub 3} and C{sub 4} fuels were found to be among the most productive in benzene formation; and long-chain normal paraffins produce the least amount of benzene. Other properties, such as equivalence ratio and combustion temperatures, were also found to be important in determining the amount of benzene produced in flames. Reaction pathways for benzene formation were examined critically in four premixed flames of structurally different fuels of acetylene, n-decane, butadiene, and cyclohexane. Reactions involving precursors, such as C{sub 3} and C{sub 4} species, were examined. Combination reactions of C{sub 3} species were identified to be the major benzene formation routes with the exception of the cyclohexane flame, in which benzene is formed exclusively from cascading fuel dehydrogenation via cyclohexene and cyclohexadiene intermediates. Acetylene addition makes a minor contribution to benzene formation, except in the butadiene flame where C{sub 4}H{sub 5} radicals are produced directly from the fuel, and in the n-decane flame where C{sub 4}H{sub 5} radicals are produced from large alkyl radical decomposition and H atom abstraction from the resulting large olefins.

  3. Reaction pathways of propene pyrolysis.

    Science.gov (United States)

    Qu, Yena; Su, Kehe; Wang, Xin; Liu, Yan; Zeng, Qingfeng; Cheng, Laifei; Zhang, Litong

    2010-05-01

    The gas-phase reaction pathways in preparing pyrolytic carbon with propene pyrolysis have been investigated in detail with a total number of 110 transition states and 50 intermediates. The structure of the species was determined with density functional theory at B3PW91/6-311G(d,p) level. The transition states and their linked intermediates were confirmed with frequency and the intrinsic reaction coordinates analyses. The elementary reactions were explored in the pathways of both direct and the radical attacking decompositions. The energy barriers and the reaction energies were determined with accurate model chemistry method at G3(MP2) level after an examination of the nondynamic electronic correlations. The heat capacities and entropies were obtained with statistical thermodynamics. The Gibbs free energies at 298.15 K for all the reaction steps were reported. Those at any temperature can be developed with classical thermodynamics by using the fitted (as a function of temperature) heat capacities. It was found that the most favorable paths are mainly in the radical attacking chain reactions. The chain was proposed with 26 reaction steps including two steps of the initialization of the chain to produce H and CH(3) radicals. For a typical temperature (1200 K) adopted in the experiments, the highest energy barriers were found in the production of C(3) to be 203.4 and 193.7 kJ/mol. The highest energy barriers for the production of C(2) and C were found 174.1 and 181.4 kJ/mol, respectively. These results are comparable with the most recent experimental observation of the apparent activation energy 201.9 +/- 0.6 or 137 +/- 25 kJ/mol. PMID:20082392

  4. Premetazoan Origin of the Hippo Signaling Pathway

    Directory of Open Access Journals (Sweden)

    Arnau Sebé-Pedrós

    2012-01-01

    Full Text Available Nonaggregative multicellularity requires strict control of cell number. The Hippo signaling pathway coordinates cell proliferation and apoptosis and is a central regulator of organ size in animals. Recent studies have shown the presence of key members of the Hippo pathway in nonbilaterian animals, but failed to identify this pathway outside Metazoa. Through comparative analyses of recently sequenced holozoan genomes, we show that Hippo pathway components, such as the kinases Hippo and Warts, the coactivator Yorkie, and the transcription factor Scalloped, were already present in the unicellular ancestors of animals. Remarkably, functional analysis of Hippo components of the amoeboid holozoan Capsaspora owczarzaki, performed in Drosophila melanogaster, demonstrate that the growth-regulatory activity of the Hippo pathway is conserved in this unicellular lineage. Our findings show that the Hippo pathway evolved well before the origin of Metazoa and highlight the importance of Hippo signaling as a key developmental mechanism predating the origin of Metazoa.

  5. Pathway-Based Functional Analysis of Metagenomes

    Science.gov (United States)

    Bercovici, Sivan; Sharon, Itai; Pinter, Ron Y.; Shlomi, Tomer

    Metagenomic data enables the study of microbes and viruses through their DNA as retrieved directly from the environment in which they live. Functional analysis of metagenomes explores the abundance of gene families, pathways, and systems, rather than their taxonomy. Through such analysis researchers are able to identify those functional capabilities most important to organisms in the examined environment. Recently, a statistical framework for the functional analysis of metagenomes was described that focuses on gene families. Here we describe two pathway level computational models for functional analysis that take into account important, yet unaddressed issues such as pathway size, gene length and overlap in gene content among pathways. We test our models over carefully designed simulated data and propose novel approaches for performance evaluation. Our models significantly improve over current approach with respect to pathway ranking and the computations of relative abundance of pathways in environments.

  6. Driving and dementia: a clinical decision pathway

    OpenAIRE

    Carter, Kirsty; Monaghan, Sophie; O'Brien, John; Teodorczuk, Andrew; Mosimann, Urs; Taylor, John-Paul

    2014-01-01

    Objective This study aimed to develop a pathway to bring together current UK legislation, good clinical practice and appropriate management strategies that could be applied across a range of healthcare settings. Methods The pathway was constructed by a multidisciplinary clinical team based in a busy Memory Assessment Service. A process of successive iteration was used to develop the pathway, with input and refinement provided via survey and small group meetings with individuals from a wide ra...

  7. Driving and dementia: a clinical decision pathway

    OpenAIRE

    Carter, Kirsty; Monaghan, Sophie; O'Brien, John; Teodorczuk, Andrew; Mosimann, Urs Peter; Taylor, John-Paul

    2014-01-01

    OBJECTIVE This study aimed to develop a pathway to bring together current UK legislation, good clinical practice and appropriate management strategies that could be applied across a range of healthcare settings. METHODS The pathway was constructed by a multidisciplinary clinical team based in a busy Memory Assessment Service. A process of successive iteration was used to develop the pathway, with input and refinement provided via survey and small group meetings with individuals fr...

  8. Female offenders’ pathways to prison in Belgium

    Directory of Open Access Journals (Sweden)

    Nuytiens An

    2012-01-01

    Full Text Available This paper examines some results of a research on female offenders’ life histories and pathways to prison in Belgium. Women’s pathways into crime will be presented and the connection of these pathways to their life histories will be explored. The study reveals that the greater part of the research population are adult-onset offenders. The authors argue that the importance of adult-onset pathways for female offenders might be explained by the emergence of (gendered vulnerabilities within the women’s lives, often accumulated not before adulthood.

  9. Machine learning methods for metabolic pathway prediction

    Directory of Open Access Journals (Sweden)

    Karp Peter D

    2010-01-01

    Full Text Available Abstract Background A key challenge in systems biology is the reconstruction of an organism's metabolic network from its genome sequence. One strategy for addressing this problem is to predict which metabolic pathways, from a reference database of known pathways, are present in the organism, based on the annotated genome of the organism. Results To quantitatively validate methods for pathway prediction, we developed a large "gold standard" dataset of 5,610 pathway instances known to be present or absent in curated metabolic pathway databases for six organisms. We defined a collection of 123 pathway features, whose information content we evaluated with respect to the gold standard. Feature data were used as input to an extensive collection of machine learning (ML methods, including naïve Bayes, decision trees, and logistic regression, together with feature selection and ensemble methods. We compared the ML methods to the previous PathoLogic algorithm for pathway prediction using the gold standard dataset. We found that ML-based prediction methods can match the performance of the PathoLogic algorithm. PathoLogic achieved an accuracy of 91% and an F-measure of 0.786. The ML-based prediction methods achieved accuracy as high as 91.2% and F-measure as high as 0.787. The ML-based methods output a probability for each predicted pathway, whereas PathoLogic does not, which provides more information to the user and facilitates filtering of predicted pathways. Conclusions ML methods for pathway prediction perform as well as existing methods, and have qualitative advantages in terms of extensibility, tunability, and explainability. More advanced prediction methods and/or more sophisticated input features may improve the performance of ML methods. However, pathway prediction performance appears to be limited largely by the ability to correctly match enzymes to the reactions they catalyze based on genome annotations.

  10. Inconsistent pathways of household waste

    International Nuclear Information System (INIS)

    The aim of this study was to provide policy-makers and waste management planners with information about how recycling programs affect the quantities of specific materials recycled and disposed of. Two questions were addressed: which factors influence household waste generation and pathways? and how reliable are official waste data? Household waste flows were studied in 35 Swedish municipalities, and a wide variation in the amount of waste per capita was observed. When evaluating the effect of different waste collection policies, it was found to be important to identify site-specific factors influencing waste generation. Eleven municipal variables were investigated in an attempt to explain the variation. The amount of household waste per resident was higher in populous municipalities and when net commuting was positive. Property-close collection of dry recyclables led to increased delivery of sorted metal, plastic and paper packaging. No difference was seen in the amount of separated recyclables per capita when weight-based billing for the collection of residual waste was applied, but the amount of residual waste was lower. Sixteen sources of error in official waste statistics were identified and the results of the study emphasize the importance of reliable waste generation and composition data to underpin waste management policies.

  11. Glycosyltransferase efficiently controls phenylpropanoid pathway

    Directory of Open Access Journals (Sweden)

    Kulma Anna

    2008-03-01

    Full Text Available Abstract Background In a previous study, anthocyanin levels in potato plants were increased by manipulating genes connected with the flavonoid biosynthesis pathway. However, starch content and tuber yield were dramatically reduced in the transgenic plants, which over-expressed dihydroflavonol reductase (DFR. Results Transgenic plants over-expressing dihydroflavonol reductase (DFR were subsequently transformed with the cDNA coding for the glycosyltransferase (UGT of Solanum sogarandinum in order to obtain plants with a high anthocyanin content without reducing tuber yield and quality. Based on enzyme studies, the recombinant UGT is a 7-O-glycosyltransferase whose natural substrates include both anthocyanidins and flavonols such as kaempferol and quercetin. In the super-transformed plants, tuber production was much higher than in the original transgenic plants bearing only the transgene coding for DFR, and was almost the same as in the control plants. The anthocyanin level was lower than in the initial plants, but still higher than in the control plants. Unexpectedly, the super-transformed plants also produced large amounts of kaempferol, chlorogenic acid, isochlorogenic acid, sinapic acid and proanthocyanins. Conclusion In plants over-expressing both the transgene for DFR and the transgene for UGT, the synthesis of phenolic acids was diverted away from the anthocyanin branch. This represents a novel approach to manipulating phenolic acids synthesis in plants.

  12. Nicotinic receptors in addiction pathways.

    Science.gov (United States)

    Leslie, Frances M; Mojica, Celina Y; Reynaga, Daisy D

    2013-04-01

    Neuronal nicotinic acetylcholine receptors (nAChRs) are ligand-gated ion channels that consist of pentameric combinations of α and β subunits. These receptors are widely distributed throughout the brain and are highly expressed in addiction circuitry. The role of nAChRs in regulating neuronal activity and motivated behavior is complex and varies both in and among brain regions. The rich diversity of central nAChRs has hampered the characterization of their structure and function with use of classic pharmacological techniques. However, recent molecular approaches using null mutant mice with specific regional lentiviral re-expression, in combination with neuroanatomical and electrophysiological techniques, have allowed the elucidation of the influence of different nAChR types on neuronal circuit activity and behavior. This review will address the influence of nAChRs on limbic dopamine circuitry and the medial habenula-interpeduncular nucleus complex, which are critical mediators of reinforced behavior. Characterization of the mechanisms underlying regulation of addiction pathways by endogenous cholinergic transmission and by nicotine may lead to the identification of new therapeutic targets for treating tobacco dependence and other addictions. PMID:23247824

  13. A brain cancer pathway in clinical practice

    DEFF Research Database (Denmark)

    Laursen, Emilie Lund; Rasmussen, Birthe Krogh

    2012-01-01

    Danish healthcare seeks to improve cancer survival through improved diagnostics, rapid treatment and increased focus on cancer prevention and early help-seeking. In neuro-oncology, this has resulted in the Integrated Brain Cancer Pathway (IBCP). The paper explores how the pathway works...

  14. Optic pathway degeneration in Japanese black cattle.

    Science.gov (United States)

    Chiba, Shiori; Funato, Shingo; Horiuchi, Noriyuki; Matsumoto, Kotaro; Inokuma, Hisashi; Furuoka, Hidefumi; Kobayashi, Yoshiyasu

    2015-02-01

    Degeneration of the optic pathway has been reported in various animal species including cattle. We experienced a case of bilateral optic tract degeneration characterized by severe gliosis in a Japanese black cattle without any obvious visual defects. To evaluate the significance, pathological nature and pathogenesis of the lesions, we examined the optic pathway in 60 cattle (41 Japanese black, 13 Holstein and 6 crossbreed) with or without ocular abnormalities. None of these animals had optic canal stenosis. Degenerative changes with severe gliosis in the optic pathway, which includes the optic nerve, optic chiasm and optic tract, were only observed in 8 Japanese black cattle with or without ocular abnormalities. Furthermore, strong immunoreactivity of glial fibrillary acidic protein was observed in the retinal stratum opticum and ganglion cell layer in all 5 cattle in which the optic pathway lesions could be examined. As etiological research, we also examined whether the concentrations of vitamin A and vitamin B12 or bovine viral diarrhea virus (BVDV) infection was associated with optic pathway degeneration. However, our results suggested that the observed optic pathway degeneration was probably not caused by these factors. These facts indicate the presence of optic pathway degeneration characterized by severe gliosis that has never been reported in cattle without bilateral compressive lesions in the optic pathway or bilateral severe retinal atrophy.

  15. Opportunities for pharmaceutical care with critical pathways.

    Science.gov (United States)

    Koch, K E

    1995-01-01

    Critical pathways are multidisciplinary tools designed to improve patient care and efficiency. Almost every path requires some type of pharmacotherapeutic intervention, from selection of surgical prophylaxis to management of anticoagulation. Pharmacists should become involved with the critical pathway process because it offers an excellent opportunity to incorporate pharmaceutical care and to meet Joint Commission on Accreditation of Healthcare Organization compliance criteria.

  16. A brain cancer pathway in clinical practice

    DEFF Research Database (Denmark)

    Laursen, Emilie Lund; Rasmussen, Birthe Krogh

    2012-01-01

    Danish healthcare seeks to improve cancer survival through improved diagnostics, rapid treatment and increased focus on cancer prevention and early help-seeking. In neuro-oncology, this has resulted in the Integrated Brain Cancer Pathway (IBCP). The paper explores how the pathway works in the...

  17. Calcium influx pathways in rat pancreatic ducts

    DEFF Research Database (Denmark)

    Hug, M J; Pahl, C; Novak, I

    1996-01-01

    A number of agonists increase intracellular Ca2+ activity, [Ca2+]i, in pancreatic ducts, but the influx/efflux pathways and intracellular Ca2+ stores in this epithelium are unknown. The aim of the present study was to characterise the Ca2+ influx pathways, especially their pH sensitivity, in nati...

  18. Women's Work Pathways Across the Life Course.

    Science.gov (United States)

    Damaske, Sarah; Frech, Adrianne

    2016-04-01

    Despite numerous changes in women's employment in the latter half of the twentieth century, women's employment continues to be uneven and stalled. Drawing from data on women's weekly work hours in the National Longitudinal Survey of Youth (NLSY79), we identify significant inequality in women's labor force experiences across adulthood. We find two pathways of stable full-time work for women, three pathways of part-time employment, and a pathway of unpaid labor. A majority of women follow one of the two full-time work pathways, while fewer than 10% follow a pathway of unpaid labor. Our findings provide evidence of the lasting influence of work-family conflict and early socioeconomic advantages and disadvantages on women's work pathways. Indeed, race, poverty, educational attainment, and early family characteristics significantly shaped women's work careers. Work-family opportunities and constraints also were related to women's work hours, as were a woman's gendered beliefs and expectations. We conclude that women's employment pathways are a product of both their resources and changing social environment as well as individual agency. Significantly, we point to social stratification, gender ideologies, and work-family constraints, all working in concert, as key explanations for how women are "tracked" onto work pathways from an early age. PMID:27001314

  19. Insight Projects: PATHway and Replay overview

    OpenAIRE

    Monaghan, David; Walsh, Deirdre; Ahmadi, Amin

    2015-01-01

    An overview of current projects within Insight presented during the Insight Summer Research Event, including PATHway: Technology enabled behavioural change as a pathway towards better self-management of CVD and RePLAY: Digitally Capturing Unique skills in European Traditional Sports and Games.

  20. Modeling biochemical pathways in the gene ontology.

    Science.gov (United States)

    Hill, David P; D'Eustachio, Peter; Berardini, Tanya Z; Mungall, Christopher J; Renedo, Nikolai; Blake, Judith A

    2016-01-01

    The concept of a biological pathway, an ordered sequence of molecular transformations, is used to collect and represent molecular knowledge for a broad span of organismal biology. Representations of biomedical pathways typically are rich but idiosyncratic presentations of organized knowledge about individual pathways. Meanwhile, biomedical ontologies and associated annotation files are powerful tools that organize molecular information in a logically rigorous form to support computational analysis. The Gene Ontology (GO), representing Molecular Functions, Biological Processes and Cellular Components, incorporates many aspects of biological pathways within its ontological representations. Here we present a methodology for extending and refining the classes in the GO for more comprehensive, consistent and integrated representation of pathways, leveraging knowledge embedded in current pathway representations such as those in the Reactome Knowledgebase and MetaCyc. With carbohydrate metabolic pathways as a use case, we discuss how our representation supports the integration of variant pathway classes into a unified ontological structure that can be used for data comparison and analysis. PMID:27589964

  1. DMPD: Signaling pathways activated by microorganisms. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 17303405 Signaling pathways activated by microorganisms. Takeuchi O, Akira S. Curr ...Opin Cell Biol. 2007 Apr;19(2):185-91. Epub 2007 Feb 15. (.png) (.svg) (.html) (.csml) Show Signaling pathwa...ys activated by microorganisms. PubmedID 17303405 Title Signaling pathways activated by microorganisms. Auth

  2. DMPD: LPS/TLR4 signal transduction pathway. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 18304834 LPS/TLR4 signal transduction pathway. Lu YC, Yeh WC, Ohashi PS. Cytokine. ...2008 May;42(2):145-51. Epub 2008 Mar 4. (.png) (.svg) (.html) (.csml) Show LPS/TLR4 signal transduction path...way. PubmedID 18304834 Title LPS/TLR4 signal transduction pathway. Authors Lu YC, Yeh WC, Ohashi PS. Publica

  3. DMPD: All is not Toll: new pathways in DNA recognition. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 16446382 All is not Toll: new pathways in DNA recognition. Wagner H, Bauer S. J Exp... Med. 2006 Feb 20;203(2):265-8. Epub 2006 Jan 30. (.png) (.svg) (.html) (.csml) Show All is not Toll: new path...ways in DNA recognition. PubmedID 16446382 Title All is not Toll: new pathways in DNA recognition. Authors

  4. DMPD: Parallel pathways of virus recognition. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 16713969 Parallel pathways of virus recognition. Tenoever BR, Maniatis T. Immunity.... 2006 May;24(5):510-2. (.png) (.svg) (.html) (.csml) Show Parallel pathways of virus recognition. PubmedID 1...6713969 Title Parallel pathways of virus recognition. Authors Tenoever BR, Maniatis T. Publication Immunity.

  5. DMPD: Afferent pathways of pyrogen signaling. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 9917870 Afferent pathways of pyrogen signaling. Blatteis CM, Sehic E, Li S. Ann N Y... Acad Sci. 1998 Sep 29;856:95-107. (.png) (.svg) (.html) (.csml) Show Afferent pathways of pyrogen signaling.... PubmedID 9917870 Title Afferent pathways of pyrogen signaling. Authors Blatteis CM, Sehic E, Li S. Publica

  6. DMPD: Regulation of mitochondrial antiviral signaling pathways. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 18549796 Regulation of mitochondrial antiviral signaling pathways. Moore CB, Ting J...P. Immunity. 2008 Jun;28(6):735-9. (.png) (.svg) (.html) (.csml) Show Regulation of mitochondrial antiviral signaling path...ways. PubmedID 18549796 Title Regulation of mitochondrial antiviral signaling pathways. Author

  7. DMPD: Signal integration between IFNgamma and TLR signalling pathways in macrophages. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 16920490 Signal integration between IFNgamma and TLR signalling pathways in macroph...tml) (.csml) Show Signal integration between IFNgamma and TLR signalling pathways in macrophages. PubmedID 1...6920490 Title Signal integration between IFNgamma and TLR signalling pathways in

  8. DMPD: Pathways connecting inflammation and cancer. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 18325755 Pathways connecting inflammation and cancer. Allavena P, Garlanda C, Borre...llo MG, Sica A, Mantovani A. Curr Opin Genet Dev. 2008 Feb;18(1):3-10. Epub 2008 Mar 5. (.png) (.svg) (.html) (.csml) Show Pathways... connecting inflammation and cancer. PubmedID 18325755 Title Pathways connecting infl

  9. A thermosensory pathway that controls body temperature.

    Science.gov (United States)

    Nakamura, Kazuhiro; Morrison, Shaun F

    2008-01-01

    Defending body temperature against environmental thermal challenges is one of the most fundamental homeostatic functions that are governed by the nervous system. Here we describe a somatosensory pathway that essentially constitutes the afferent arm of the thermoregulatory reflex that is triggered by cutaneous sensation of environmental temperature changes. Using in vivo electrophysiological and anatomical approaches in the rat, we found that lateral parabrachial neurons are pivotal in this pathway by glutamatergically transmitting cutaneous thermosensory signals received from spinal somatosensory neurons directly to the thermoregulatory command center, the preoptic area. This feedforward pathway mediates not only sympathetic and shivering thermogenic responses but also metabolic and cardiac responses to skin cooling challenges. Notably, this 'thermoregulatory afferent' pathway exists in parallel with the spinothalamocortical somatosensory pathway that mediates temperature perception. These findings make an important contribution to our understanding of both the somatosensory system and thermal homeostasis -- two mechanisms that are fundamental to the nervous system and to our survival.

  10. Wood ethanol and synthetic natural gas pathways

    International Nuclear Information System (INIS)

    This report provided details of updates to the wood ethanol pathway recently added to the GHGenius model, an analytical tool used to analyze emissions from conventional and alternative fuel combustion processes. The pathway contains data developed by the United States Department of Energy. A number of co-products were added to the wood and agricultural residue pathways, including furfural, xylitol, lignin, and glycerol. New chemical inputs included nitrogen gas, ammonia, enzymes and yeast. Biological ethanol pathways were reviewed, and separate inputs for wood, agricultural residues, corn ethanol, and wheat ethanol were added. The model was updated to reflect current research conducted on the gasification of wood and the upgrading of the gas to produce pipeline quality natural gas. New process developments in producing pipeline quality gas from coal were also added. The ability to model enzyme consumption was added to all ethanol pathways. 25 refs., 41 tabs., 8 figs

  11. Wood ethanol and synthetic natural gas pathways

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2006-11-30

    This report provided details of updates to the wood ethanol pathway recently added to the GHGenius model, an analytical tool used to analyze emissions from conventional and alternative fuel combustion processes. The pathway contains data developed by the United States Department of Energy. A number of co-products were added to the wood and agricultural residue pathways, including furfural, xylitol, lignin, and glycerol. New chemical inputs included nitrogen gas, ammonia, enzymes and yeast. Biological ethanol pathways were reviewed, and separate inputs for wood, agricultural residues, corn ethanol, and wheat ethanol were added. The model was updated to reflect current research conducted on the gasification of wood and the upgrading of the gas to produce pipeline quality natural gas. New process developments in producing pipeline quality gas from coal were also added. The ability to model enzyme consumption was added to all ethanol pathways. 25 refs., 41 tabs., 8 figs.

  12. Pathway projector: web-based zoomable pathway browser using KEGG atlas and Google Maps API.

    Directory of Open Access Journals (Sweden)

    Nobuaki Kono

    Full Text Available BACKGROUND: Biochemical pathways provide an essential context for understanding comprehensive experimental data and the systematic workings of a cell. Therefore, the availability of online pathway browsers will facilitate post-genomic research, just as genome browsers have contributed to genomics. Many pathway maps have been provided online as part of public pathway databases. Most of these maps, however, function as the gateway interface to a specific database, and the comprehensiveness of their represented entities, data mapping capabilities, and user interfaces are not always sufficient for generic usage. METHODOLOGY/PRINCIPAL FINDINGS: We have identified five central requirements for a pathway browser: (1 availability of large integrated maps showing genes, enzymes, and metabolites; (2 comprehensive search features and data access; (3 data mapping for transcriptomic, proteomic, and metabolomic experiments, as well as the ability to edit and annotate pathway maps; (4 easy exchange of pathway data; and (5 intuitive user experience without the requirement for installation and regular maintenance. According to these requirements, we have evaluated existing pathway databases and tools and implemented a web-based pathway browser named Pathway Projector as a solution. CONCLUSIONS/SIGNIFICANCE: Pathway Projector provides integrated pathway maps that are based upon the KEGG Atlas, with the addition of nodes for genes and enzymes, and is implemented as a scalable, zoomable map utilizing the Google Maps API. Users can search pathway-related data using keywords, molecular weights, nucleotide sequences, and amino acid sequences, or as possible routes between compounds. In addition, experimental data from transcriptomic, proteomic, and metabolomic analyses can be readily mapped. Pathway Projector is freely available for academic users at (http://www.g-language.org/PathwayProjector/.

  13. Pathway Analysis Incorporating Protein-Protein Interaction Networks Identified Candidate Pathways for the Seven Common Diseases.

    Science.gov (United States)

    Lin, Peng-Lin; Yu, Ya-Wen; Chung, Ren-Hua

    2016-01-01

    Pathway analysis has become popular as a secondary analysis strategy for genome-wide association studies (GWAS). Most of the current pathway analysis methods aggregate signals from the main effects of single nucleotide polymorphisms (SNPs) in genes within a pathway without considering the effects of gene-gene interactions. However, gene-gene interactions can also have critical effects on complex diseases. Protein-protein interaction (PPI) networks have been used to define gene pairs for the gene-gene interaction tests. Incorporating the PPI information to define gene pairs for interaction tests within pathways can increase the power for pathway-based association tests. We propose a pathway association test, which aggregates the interaction signals in PPI networks within a pathway, for GWAS with case-control samples. Gene size is properly considered in the test so that genes do not contribute more to the test statistic simply due to their size. Simulation studies were performed to verify that the method is a valid test and can have more power than other pathway association tests in the presence of gene-gene interactions within a pathway under different scenarios. We applied the test to the Wellcome Trust Case Control Consortium GWAS datasets for seven common diseases. The most significant pathway is the chaperones modulate interferon signaling pathway for Crohn's disease (p-value = 0.0003). The pathway modulates interferon gamma, which induces the JAK/STAT pathway that is involved in Crohn's disease. Several other pathways that have functional implications for the seven diseases were also identified. The proposed test based on gene-gene interaction signals in PPI networks can be used as a complementary tool to the current existing pathway analysis methods focusing on main effects of genes. An efficient software implementing the method is freely available at http://puppi.sourceforge.net. PMID:27622767

  14. Remodeling the isoprenoid pathway in tobacco by expressing the cytoplasmic mevalonate pathway in chloroplasts.

    Science.gov (United States)

    Kumar, Shashi; Hahn, Frederick M; Baidoo, Edward; Kahlon, Talwinder S; Wood, Delilah F; McMahan, Colleen M; Cornish, Katrina; Keasling, Jay D; Daniell, Henry; Whalen, Maureen C

    2012-01-01

    Metabolic engineering to enhance production of isoprenoid metabolites for industrial and medical purposes is an important goal. The substrate for isoprenoid synthesis in plants is produced by the mevalonate pathway (MEV) in the cytosol and by the 2-C-methyl-d-erythritol 4-phosphate (MEP) pathway in plastids. A multi-gene approach was employed to insert the entire cytosolic MEV pathway into the tobacco chloroplast genome. Molecular analysis confirmed the site-specific insertion of seven transgenes and homoplasmy. Functionality was demonstrated by unimpeded growth on fosmidomycin, which specifically inhibits the MEP pathway. Transplastomic plants containing the MEV pathway genes accumulated higher levels of mevalonate, carotenoids, squalene, sterols, and triacyglycerols than control plants. This is the first time an entire eukaryotic pathway with six enzymes has been transplastomically expressed in plants. Thus, we have developed an important tool to redirect metabolic fluxes in the isoprenoid biosynthesis pathway and a viable multigene strategy for engineering metabolism in plants.

  15. Logical modelling of Drosophila signalling pathways.

    Science.gov (United States)

    Mbodj, Abibatou; Junion, Guillaume; Brun, Christine; Furlong, Eileen E M; Thieffry, Denis

    2013-09-01

    A limited number of signalling pathways are involved in the specification of cell fate during the development of all animals. Several of these pathways were originally identified in Drosophila. To clarify their roles, and possible cross-talk, we have built a logical model for the nine key signalling pathways recurrently used in metazoan development. In each case, we considered the associated ligands, receptors, signal transducers, modulators, and transcription factors reported in the literature. Implemented using the logical modelling software GINsim, the resulting models qualitatively recapitulate the main characteristics of each pathway, in wild type as well as in various mutant situations (e.g. loss-of-function or gain-of-function). These models constitute pluggable modules that can be used to assemble comprehensive models of complex developmental processes. Moreover, these models of Drosophila pathways could serve as scaffolds for more complicated models of orthologous mammalian pathways. Comprehensive model annotations and GINsim files are provided for each of the nine considered pathways.

  16. A markov classification model for metabolic pathways

    Directory of Open Access Journals (Sweden)

    Mamitsuka Hiroshi

    2010-01-01

    Full Text Available Abstract Background This paper considers the problem of identifying pathways through metabolic networks that relate to a specific biological response. Our proposed model, HME3M, first identifies frequently traversed network paths using a Markov mixture model. Then by employing a hierarchical mixture of experts, separate classifiers are built using information specific to each path and combined into an ensemble prediction for the response. Results We compared the performance of HME3M with logistic regression and support vector machines (SVM for both simulated pathways and on two metabolic networks, glycolysis and the pentose phosphate pathway for Arabidopsis thaliana. We use AltGenExpress microarray data and focus on the pathway differences in the developmental stages and stress responses of Arabidopsis. The results clearly show that HME3M outperformed the comparison methods in the presence of increasing network complexity and pathway noise. Furthermore an analysis of the paths identified by HME3M for each metabolic network confirmed known biological responses of Arabidopsis. Conclusions This paper clearly shows HME3M to be an accurate and robust method for classifying metabolic pathways. HME3M is shown to outperform all comparison methods and further is capable of identifying known biologically active pathways within microarray data.

  17. Dissecting the PCP pathway: one or more pathways?: Does a separate Wnt-Fz-Rho pathway drive morphogenesis?

    Science.gov (United States)

    Lapébie, Pascal; Borchiellini, Carole; Houliston, Evelyn

    2011-10-01

    Planar cell polarity (PCP), the alignment of cells within 2D tissue planes, involves a set of core molecular regulators highly conserved between animals and cell types. These include the transmembrane proteins Frizzled (Fz) and VanGogh and the cytoplasmic regulators Dishevelled (Dsh) and Prickle. It is widely accepted that this core forms part of a 'PCP pathway' for signal transduction, which can affect cell morphology through activation of an evolutionary ancient regulatory module involving Rho family GTPases and Myosin II, and/or the JNK kinase cascade. We have re-examined the evidence for interactions between the proposed PCP pathway components, and question the placing of the cell morphology regulators in the same pathway as the PCP core. While Fz and Dsh are clearly involved in both PCP and Rho-based cell morphology regulation, available evidence cannot currently discriminate whether these processes are linked mechanistically by a shared Fz/Dsh population, or pass by two distinct pathways.

  18. Role of care pathways in interprofessional teamwork.

    Science.gov (United States)

    Scaria, Minimol Kulakkottu

    2016-08-24

    Cohesive interprofessional teamwork is essential to successful healthcare services. Interprofessional teamwork is the means by which different healthcare professionals - with diverse knowledge, skills and talents - collaborate to achieve a common goal. Several interventions are available to improve teamwork in the healthcare setting. This article explores the role of care pathways in improving interprofessional teamwork. Care pathways enhance teamwork by promoting coordination, collaboration, communication and decision making to achieve optimal healthcare outcomes. They result in improved staff knowledge, communication, documentation and interprofessional relations. Care pathways also contribute to patient-centred care and increase patient satisfaction. PMID:27641591

  19. Electron Transfer Pathways in Cholesterol Synthesis.

    Science.gov (United States)

    Porter, Todd D

    2015-10-01

    Cholesterol synthesis in the endoplasmic reticulum requires electron input at multiple steps and utilizes both NADH and NADPH as the electron source. Four enzymes catalyzing five steps in the pathway require electron input: squalene monooxygenase, lanosterol demethylase, sterol 4α-methyl oxidase, and sterol C5-desaturase. The electron-donor proteins for these enzymes include cytochrome P450 reductase and the cytochrome b5 pathway. Here I review the evidence for electron donor protein requirements with these enzymes, the evidence for additional electron donor pathways, and the effect of deletion of these redox enzymes on cholesterol and lipid metabolism. PMID:26344922

  20. Syngas Upgrading to Hydrocarbon Fuels Technology Pathway

    Energy Technology Data Exchange (ETDEWEB)

    Talmadge, M.; Biddy, M.; Dutta, A.; Jones, S.; Meyer, A.

    2013-03-01

    This technology pathway case investigates the upgrading of woody biomass derived synthesis gas (syngas) to hydrocarbon biofuels. While this specific discussion focuses on the conversion of syngas via a methanol intermediate to hydrocarbon blendstocks, there are a number of alternative conversion routes for production of hydrocarbons through a wide array of intermediates from syngas. Future work will also consider the variations to this pathway to determine the most economically viable and lowest risk conversion route. Technical barriers and key research needs have been identified that should be pursued for the syngas-to-hydrocarbon pathway to be competitive with petroleum-derived gasoline-, diesel- and jet-range hydrocarbon blendstocks.

  1. Cellular Signaling Pathways and Their Clinical Reflections

    Directory of Open Access Journals (Sweden)

    N. Ceren Sumer-Turanligil

    2010-06-01

    Full Text Available Cellular signaling pathways have important roles in cellular growth, differentiation, inflammatory response and apoptosis and in regulation of cellular responses under various chemical stimulators. Different proteins which belong to these pathways may be exposed to loss-of-function or gain-of-function mutations; this may lead to many clinical phenotypes including primarily cancer. In this review information about basic working principles of these pathways and diseases related to them are included. [Archives Medical Review Journal 2010; 19(3.000: 180-191

  2. Role of care pathways in interprofessional teamwork.

    Science.gov (United States)

    Scaria, Minimol Kulakkottu

    2016-08-24

    Cohesive interprofessional teamwork is essential to successful healthcare services. Interprofessional teamwork is the means by which different healthcare professionals - with diverse knowledge, skills and talents - collaborate to achieve a common goal. Several interventions are available to improve teamwork in the healthcare setting. This article explores the role of care pathways in improving interprofessional teamwork. Care pathways enhance teamwork by promoting coordination, collaboration, communication and decision making to achieve optimal healthcare outcomes. They result in improved staff knowledge, communication, documentation and interprofessional relations. Care pathways also contribute to patient-centred care and increase patient satisfaction.

  3. The intervention study of Danggui Yinzi decoction on the expression of gene and protein of AQP-3 and the content of ceramide in the posriasis vulgaris model of guinea pig%当归饮子对银屑病模型豚鼠神经酰胺含量、AQP-3基因及蛋白表达的干预研究

    Institute of Scientific and Technical Information of China (English)

    文谦; 李芳梅; 杨志波

    2016-01-01

    Objective To investigate the effect of Danggui Yinzi on the expression of AQP-3 gene and Cer protein of psoriasis model. Methods To establish an animal model of psoriasis vulgaris. The animals were divided into Danggui Yinzi group,methotrexate group,saline group,model control group and blank control group. Aquaporin 3 (AQP-3) of skin lesions part was detected with RT-PCR and Western blot methods and ELISA methods was used to detect the ceramide content of skin lesions part. Compared the results of the five groups, and the relationship of the expression changes of gene and protein in skin lesions and skin barrier function was analysed. Results The animal models of psoriasis vulgaris was successful In model control group,the content of ceramide and the expression of gene and protein of AQP-3 were all decreased significantly (P<0. 01). The expression index was increased in Danggui Yinzi group and methotrexate group and Danggui Yinzi group was increased obviously(P<0. 01). Conclusion Danggui Yinzi can enhance the expression of gene and protein of AQP-3 and the protein content of ceramide in skin lesions of psoriasis vulgaris model. It has a definite effect for skin barrier function of psoriasis vulgaris in animal model. The results indicate that the therapeutic effect is more effective than methotrexate medicine.%目的:探讨当归饮子对寻常型银屑病模型豚鼠皮肤神经酰胺( ceramide,Cer)含量、水通道蛋白3(aquaporin 3,AQP-3)基因及蛋白表达的干预影响。方法建立寻常型银屑病动物模型,分为当归饮子组、甲氨蝶呤组、生理盐水组、模型对照组、空白对照组,每组8只,酶联免疫吸附实验( ELISA)法检测造模皮损部位Cer含量,逆转录PCR( RT-PCR)和免疫印迹试验( Western blot)法检测造模皮损部位AQP-3基因及蛋白表达,分析寻常型银屑病动物模型皮损与皮肤屏障功能密切相关的基因及蛋白表达的变化。结果豚鼠耳部皮肤银屑病模型造模成功

  4. Clinical implications of hedgehog signaling pathway inhibitors

    Institute of Scientific and Technical Information of China (English)

    Hailan Liu; Dongsheng Gu; Jingwu Xie

    2011-01-01

    Hedgehog was first described in Drosophila melanogaster by the Nobel laureates Eric Wieschaus and Christiane Nusslein-Volhard. The hedgehog (Hh) pathway is a major regulator of cell differentiation,proliferation, tissue polarity, stem cell maintenance, and carcinogenesis. The first link of Hh signaling to cancer was established through studies of a rare familial disease, Gorlin syndrome, in 1996. Follow-up studies revealed activation of this pathway in basal cell carcinoma, medulloblastoma and, leukemia as well as in gastrointestinal, lung, ovarian, breast, and prostate cancer. Targeted inhibition of Hh signaling is now believed to be effective in the treatment and prevention of human cancer. The discovery and synthesis of specific inhibitors for this pathway are even more exciting. In this review, we summarize major advances in the understanding of Hh signaling pathway activation in human cancer, mouse models for studying Hhmediated carcinogenesis, the roles of Hh signaling in tumor development and metastasis, antagonists for Hh signaling and their clinical implications.

  5. Imaging the Visual Pathway in Neuromyelitis Optica

    Directory of Open Access Journals (Sweden)

    Caspar F. Pfueller

    2011-01-01

    Full Text Available The focus of this paper is to summarize the current knowledge on visual pathway damage in neuromyelitis optica (NMO assessed by magnetic resonance imaging (MRI and optical coherence tomography (OCT.

  6. The Pentose Phosphate Pathway in Parasitic Trypanosomatids.

    Science.gov (United States)

    Kovářová, Julie; Barrett, Michael P

    2016-08-01

    Parasitic trypanosomatids cause important diseases. Dissecting the biochemistry of these organisms offers a means of discovering targets against which inhibitors may be designed and developed as drugs. The pentose phosphate pathway is a key route of glucose metabolism in most organisms, providing NADPH for use as a cellular reductant and various carbohydrate intermediates used in cellular metabolism. The pathway and its enzymes have been studied in Trypanosoma brucei, Trypanosoma cruzi, and various Leishmania species. Its functions in these parasites are becoming clear. Some enzymes of the pathway are essential to the parasites and have structural features distinguishing them from their mammalian counterparts, and this has stimulated several programs of inhibitor discovery with a view to targeting the pathway with new drugs.

  7. Lysosome: regulator of lipid degradation pathways

    OpenAIRE

    Settembre, Carmine; Ballabio, Andrea

    2014-01-01

    Autophagy is a catabolic pathway that has a fundamental role in the adaptation to fasting and primarily relies on the activity of the endolysosomal system, to which the autophagosome targets substrates for degradation. Recent studies have revealed that the lysosomal–autophagic pathway plays an important part in the early steps of lipid degradation. In this review, we discuss the transcriptional mechanisms underlying co-regulation between lysosome, autophagy, and other steps of lipid catabolis...

  8. The mevalonate pathway in C. Elegans

    Directory of Open Access Journals (Sweden)

    Rauthan Manish

    2011-12-01

    Full Text Available Abstract The mevalonate pathway in human is responsible for the synthesis of cholesterol and other important biomolecules such as coenzyme Q, dolichols and isoprenoids. These molecules are required in the cell for functions ranging from signaling to membrane integrity, protein prenylation and glycosylation, and energy homeostasis. The pathway consists of a main trunk followed by sub-branches that synthesize the different biomolecules. The majority of our knowledge about the mevalonate pathway is currently focused on the cholesterol synthesis branch, which is the target of the cholesterol-lowering statins; less is known about the function and regulation of the non-cholesterol-related branches. To study them, we need a biological system where it is possible to specifically modulate these metabolic branches individually or in groups. The nematode Caenorhabditis elegans (C. elegans is a promising model to study these non-cholesterol branches since its mevalonate pathway seems very well conserved with that in human except that it has no cholesterol synthesis branch. The simple genetic makeup and tractability of C. elegans makes it relatively easy to identify and manipulate key genetic components of the mevalonate pathway, and to evaluate the consequences of tampering with their activity. This general experimental approach should lead to new insights into the physiological roles of the non-cholesterol part of the mevalonate pathway. This review will focus on the current knowledge related to the mevalonate pathway in C. elegans and its possible applications as a model organism to study the non-cholesterol functions of this pathway.

  9. A shared pathway among supraventricular tachycardias

    Directory of Open Access Journals (Sweden)

    Moghaddam M

    1995-07-01

    Full Text Available AVNRT, (Atrioventricular nodal reentry tachycardia, atrial tachycardia and atrial flutter are 3 kinds of supraventricular tachycardia, which their mechanism are explained based on reentry. A 60-years-old man is presented with all of the above-mentioned arrhythmias, responsive to intravenous injection of adenosine. Radiofrequency ablation of the slow pathway territories cured all of them. Therefore, we suggest that there was a common pathway among all kinds of these arrhythmias, which were ablated with single RF lesion.

  10. Pathway Model and Nonextensive Statistical Mechanics

    Science.gov (United States)

    Mathai, A. M.; Haubold, H. J.; Tsallis, C.

    2015-12-01

    The established technique of eliminating upper or lower parameters in a general hypergeometric series is profitably exploited to create pathways among confluent hypergeometric functions, binomial functions, Bessel functions, and exponential series. One such pathway, from the mathematical statistics point of view, results in distributions which naturally emerge within nonextensive statistical mechanics and Beck-Cohen superstatistics, as pursued in generalizations of Boltzmann-Gibbs statistics.

  11. The Kynurenine Pathway in Stem Cell Biology

    OpenAIRE

    Jones, Simon P; Guillemin, Gilles J; Bruce J Brew

    2013-01-01

    The kynurenine pathway (KP) is the main catabolic pathway of the essential amino acid tryptophan. The KP has been identified to play a critical role in regulating immune responses in a variety of experimental settings. It is also known to be involved in several neuroinflammatory diseases including Huntington’s disease, amyotrophic lateral sclerosis, and Alzheimer’s disease. This review considers the current understanding of the role of the KP in stem cell biology. Both of these fundamental ar...

  12. A More Flexible Lipoprotein Sorting Pathway

    OpenAIRE

    Chahales, Peter; Thanassi, David G.

    2015-01-01

    Lipoprotein biogenesis in Gram-negative bacteria occurs by a conserved pathway, each step of which is considered essential. In contrast to this model, LoVullo and colleagues demonstrate that the N-acyl transferase Lnt is not required in Francisella tularensis or Neisseria gonorrhoeae. This suggests the existence of a more flexible lipoprotein pathway, likely due to a modified Lol transporter complex, and raises the possibility that pathogens may regulate lipoprotein processing to modulate int...

  13. Precursors of Young Women's Family Formation Pathways

    OpenAIRE

    Amato, Paul R.; Landale, Nancy S.; Havasevich, Tara C.; Booth, Alan; Eggebeen, David J.; Schoen, Robert; McHale, Susan M.

    2008-01-01

    We used latent class analysis to create family formation pathways for women between the ages of 18 and 23. Input variables included cohabitation, marriage, parenthood, full-time employment, and attending school. Data (n = 2,290) came from Waves I and III of the National Longitudinal Study of Adolescent Health (Add Health). The analysis revealed seven latent pathways: college-no family formation (29%), high school-no family formation (19%), cohabitation without children (15%), married mothers ...

  14. A more flexible lipoprotein sorting pathway.

    Science.gov (United States)

    Chahales, Peter; Thanassi, David G

    2015-05-01

    Lipoprotein biogenesis in Gram-negative bacteria occurs by a conserved pathway, each step of which is considered essential. In contrast to this model, LoVullo and colleagues demonstrate that the N-acyl transferase Lnt is not required in Francisella tularensis or Neisseria gonorrhoeae. This suggests the existence of a more flexible lipoprotein pathway, likely due to a modified Lol transporter complex, and raises the possibility that pathogens may regulate lipoprotein processing to modulate interactions with the host. PMID:25755190

  15. The ectodysplasin pathway: from diseases to adaptations.

    Science.gov (United States)

    Sadier, Alexa; Viriot, Laurent; Pantalacci, Sophie; Laudet, Vincent

    2014-01-01

    The ectodysplasin (EDA) pathway, which is active during the development of ectodermal organs, including teeth, hairs, feathers, and mammary glands, and which is crucial for fine-tuning the developmental network controlling the number, size, and density of these structures, was discovered by studying human patients affected by anhidrotic/hypohidrotic ectodermal dysplasia. It comprises three main gene products: EDA, a ligand that belongs to the tumor necrosis factor (TNF)-α family, EDAR, a receptor related to the TNFα receptors, and EDARADD, a specific adaptor. This core pathway relies on downstream NF-κB pathway activation to regulate target genes. The pathway has recently been found to be associated with specific adaptations in natural populations: the magnitude of armor plates in sticklebacks and the hair structure in Asian human populations. Thus, despite its role in human disease, the EDA pathway is a 'hopeful pathway' that could allow adaptive changes in ectodermal appendages which, as specialized interfaces with the environment, are considered hot-spots of morphological evolution. PMID:24070496

  16. Novel personalized pathway-based metabolomics models reveal key metabolic pathways for breast cancer diagnosis

    DEFF Research Database (Denmark)

    Huang, Sijia; Chong, Nicole; Lewis, Nathan;

    2016-01-01

    .993. Moreover, important metabolic pathways, such as taurine and hypotaurine metabolism and the alanine, aspartate, and glutamate pathway, are revealed as critical biological pathways for early diagnosis of breast cancer. Conclusions: We have successfully developed a new type of pathway-based model to study....... Methods: We propose that higher-order functional representation of metabolomics data, such as pathway-based metabolomic features, can be used as robust biomarkers for breast cancer. Towards this, we have developed a new computational method that uses personalized pathway dysregulation scores for disease...... diagnosis. We applied this method to predict breast cancer occurrence, in combination with correlation feature selection (CFS) and classification methods. Results: The resulting all-stage and early-stage diagnosis models are highly accurate in two sets of testing blood samples, with average AUCs (Area Under...

  17. Subpathway Analysis based on Signaling-Pathway Impact Analysis of Signaling Pathway.

    Directory of Open Access Journals (Sweden)

    Xianbin Li

    Full Text Available Pathway analysis is a common approach to gain insight from biological experiments. Signaling-pathway impact analysis (SPIA is one such method and combines both the classical enrichment analysis and the actual perturbation on a given pathway. Because this method focuses on a single pathway, its resolution generally is not very high because the differentially expressed genes may be enriched in a local region of the pathway. In the present work, to identify cancer-related pathways, we incorporated a recent subpathway analysis method into the SPIA method to form the "sub-SPIA method." The original subpathway analysis uses the k-clique structure to define a subpathway. However, it is not sufficiently flexible to capture subpathways with complex structure and usually results in many overlapping subpathways. We therefore propose using the minimal-spanning-tree structure to find a subpathway. We apply this approach to colorectal cancer and lung cancer datasets, and our results show that sub-SPIA can identify many significant pathways associated with each specific cancer that other methods miss. Based on the entire pathway network in the Kyoto Encyclopedia of Genes and Genomes, we find that the pathways identified by sub-SPIA not only have the largest average degree, but also are more closely connected than those identified by other methods. This result suggests that the abnormality signal propagating through them might be responsible for the specific cancer or disease.

  18. Neural pathways for visual speech perception

    Directory of Open Access Journals (Sweden)

    Lynne E Bernstein

    2014-12-01

    Full Text Available This paper examines the questions, what levels of speech can be perceived visually, and how is visual speech represented by the brain? Review of the literature leads to the conclusions that every level of psycholinguistic speech structure (i.e., phonetic features, phonemes, syllables, words, and prosody can be perceived visually, although individuals differ in their abilities to do so; and that there are visual modality-specific representations of speech qua speech in higher-level vision brain areas. That is, the visual system represents the modal patterns of visual speech. The suggestion that the auditory speech pathway receives and represents visual speech is examined in light of neuroimaging evidence on the auditory speech pathways. We outline the generally agreed-upon organization of the visual ventral and dorsal pathways and examine several types of visual processing that might be related to speech through those pathways, specifically, face and body, orthography, and sign language processing. In this context, we examine the visual speech processing literature, which reveals widespread diverse patterns activity in posterior temporal cortices in response to visual speech stimuli. We outline a model of the visual and auditory speech pathways and make several suggestions: (1 The visual perception of speech relies on visual pathway representations of speech qua speech. (2 A proposed site of these representations, the temporal visual speech area (TVSA has been demonstrated in posterior temporal cortex, ventral and posterior to multisensory posterior superior temporal sulcus (pSTS. (3 Given that visual speech has dynamic and configural features, its representations in feedforward visual pathways are expected to integrate these features, possibly in TVSA.

  19. Bacterial variations on the methionine salvage pathway

    Directory of Open Access Journals (Sweden)

    Haas Dieter

    2004-03-01

    Full Text Available Abstract Background The thiomethyl group of S-adenosylmethionine is often recycled as methionine from methylthioadenosine. The corresponding pathway has been unravelled in Bacillus subtilis. However methylthioadenosine is subjected to alternative degradative pathways depending on the organism. Results This work uses genome in silico analysis to propose methionine salvage pathways for Klebsiella pneumoniae, Leptospira interrogans, Thermoanaerobacter tengcongensis and Xylella fastidiosa. Experiments performed with mutants of B. subtilis and Pseudomonas aeruginosa substantiate the hypotheses proposed. The enzymes that catalyze the reactions are recruited from a variety of origins. The first, ubiquitous, enzyme of the pathway, MtnA (methylthioribose-1-phosphate isomerase, belongs to a family of proteins related to eukaryotic intiation factor 2B alpha. mtnB codes for a methylthioribulose-1-phosphate dehydratase. Two reactions follow, that of an enolase and that of a phosphatase. While in B. subtilis this is performed by two distinct polypeptides, in the other organisms analyzed here an enolase-phosphatase yields 1,2-dihydroxy-3-keto-5-methylthiopentene. In the presence of dioxygen an aci-reductone dioxygenase yields the immediate precursor of methionine, ketomethylthiobutyrate. Under some conditions this enzyme produces carbon monoxide in B. subtilis, suggesting a route for a new gaseous mediator in bacteria. Ketomethylthiobutyrate is finally transaminated by an aminotransferase that exists usually as a broad specificity enzyme (often able to transaminate aromatic aminoacid keto-acid precursors or histidinol-phosphate. Conclusion A functional methionine salvage pathway was experimentally demonstrated, for the first time, in P. aeruginosa. Apparently, methionine salvage pathways are frequent in Bacteria (and in Eukarya, with recruitment of different polypeptides to perform the needed reactions (an ancestor of a translation initiation factor and Ru

  20. Molecular Pathways: Targeting the PI3K Pathway in Cancer-BET Inhibitors to the Rescue.

    Science.gov (United States)

    Stratikopoulos, Elias E; Parsons, Ramon E

    2016-06-01

    The PI3K signaling pathway is a complex and tightly regulated network that is critical for many physiologic processes, such as cell growth, proliferation, metabolism, and survival. Aberrant activation of this pathway can occur through mutation of almost any of its major nodes and has been implicated in a number of human diseases, including cancer. The high frequency of mutations in this pathway in multiple types of cancer has led to the development of small-molecule inhibitors of PI3K, several of which are currently in clinical trials. However, several feedback mechanisms either within the PI3K pathway or in compensatory pathways can render tumor cells resistant to therapy. Recently, targeting proteins of the bromodomain and extraterminal (BET) family of epigenetic readers of histone acetylation has been shown to effectively block adaptive signaling response of cancer cells to inhibitors of the PI3K pathway, which at least in some cases can restore sensitivity. BET inhibitors also enforce blockade of the MAPK, JAK/STAT, and ER pathways, suggesting they may be a rational combinatorial partner for divergent oncogenic signals that are subject to homeostatic regulation. Here, we review the PI3K pathway as a target for cancer therapy and discuss the potential use of BET inhibition to enhance the clinical efficacy of PI3K inhibitors. Clin Cancer Res; 22(11); 2605-10. ©2016 AACR. PMID:27250929

  1. Genome-Wide Pathway Analysis Identifies Genetic Pathways Associated with Psoriasis.

    Science.gov (United States)

    Aterido, Adrià; Julià, Antonio; Ferrándiz, Carlos; Puig, Lluís; Fonseca, Eduardo; Fernández-López, Emilia; Dauden, Esteban; Sánchez-Carazo, José Luís; López-Estebaranz, José Luís; Moreno-Ramírez, David; Vanaclocha, Francisco; Herrera, Enrique; de la Cueva, Pablo; Dand, Nick; Palau, Núria; Alonso, Arnald; López-Lasanta, María; Tortosa, Raül; García-Montero, Andrés; Codó, Laia; Gelpí, Josep Lluís; Bertranpetit, Jaume; Absher, Devin; Capon, Francesca; Myers, Richard M; Barker, Jonathan N; Marsal, Sara

    2016-03-01

    Psoriasis is a chronic inflammatory disease with a complex genetic architecture. To date, the psoriasis heritability is only partially explained. However, there is increasing evidence that the missing heritability in psoriasis could be explained by multiple genetic variants of low effect size from common genetic pathways. The objective of this study was to identify new genetic variation associated with psoriasis risk at the pathway level. We genotyped 598,258 single nucleotide polymorphisms in a discovery cohort of 2,281 case-control individuals from Spain. We performed a genome-wide pathway analysis using 1,053 reference biological pathways. A total of 14 genetic pathways (PFDR ≤ 2.55 × 10(-2)) were found to be significantly associated with psoriasis risk. Using an independent validation cohort of 7,353 individuals from the UK, a total of 6 genetic pathways were significantly replicated (PFDR ≤ 3.46 × 10(-2)). We found genetic pathways that had not been previously associated with psoriasis risk such as retinol metabolism (Pcombined = 1.84 × 10(-4)), the transport of inorganic ions and amino acids (Pcombined = 1.57 × 10(-7)), and post-translational protein modification (Pcombined = 1.57 × 10(-7)). In the latter pathway, MGAT5 showed a strong network centrality, and its association with psoriasis risk was further validated in an additional case-control cohort of 3,429 individuals (P psoriasis susceptibility. PMID:26743605

  2. Genome-Wide Pathway Analysis Identifies Genetic Pathways Associated with Psoriasis.

    Science.gov (United States)

    Aterido, Adrià; Julià, Antonio; Ferrándiz, Carlos; Puig, Lluís; Fonseca, Eduardo; Fernández-López, Emilia; Dauden, Esteban; Sánchez-Carazo, José Luís; López-Estebaranz, José Luís; Moreno-Ramírez, David; Vanaclocha, Francisco; Herrera, Enrique; de la Cueva, Pablo; Dand, Nick; Palau, Núria; Alonso, Arnald; López-Lasanta, María; Tortosa, Raül; García-Montero, Andrés; Codó, Laia; Gelpí, Josep Lluís; Bertranpetit, Jaume; Absher, Devin; Capon, Francesca; Myers, Richard M; Barker, Jonathan N; Marsal, Sara

    2016-03-01

    Psoriasis is a chronic inflammatory disease with a complex genetic architecture. To date, the psoriasis heritability is only partially explained. However, there is increasing evidence that the missing heritability in psoriasis could be explained by multiple genetic variants of low effect size from common genetic pathways. The objective of this study was to identify new genetic variation associated with psoriasis risk at the pathway level. We genotyped 598,258 single nucleotide polymorphisms in a discovery cohort of 2,281 case-control individuals from Spain. We performed a genome-wide pathway analysis using 1,053 reference biological pathways. A total of 14 genetic pathways (PFDR ≤ 2.55 × 10(-2)) were found to be significantly associated with psoriasis risk. Using an independent validation cohort of 7,353 individuals from the UK, a total of 6 genetic pathways were significantly replicated (PFDR ≤ 3.46 × 10(-2)). We found genetic pathways that had not been previously associated with psoriasis risk such as retinol metabolism (Pcombined = 1.84 × 10(-4)), the transport of inorganic ions and amino acids (Pcombined = 1.57 × 10(-7)), and post-translational protein modification (Pcombined = 1.57 × 10(-7)). In the latter pathway, MGAT5 showed a strong network centrality, and its association with psoriasis risk was further validated in an additional case-control cohort of 3,429 individuals (P psoriasis susceptibility.

  3. Pathways to deep decarbonization - 2015 report

    International Nuclear Information System (INIS)

    In September 2015, the Deep Decarbonization Pathways Project published the Executive Summary of the Pathways to Deep Decarbonization: 2015 Synthesis Report. The full 2015 Synthesis Report was launched in Paris on December 3, 2015, at a technical workshop with the Mitigation Action Plans and Scenarios (MAPS) program. The Deep Decarbonization Pathways Project (DDPP) is a collaborative initiative to understand and show how individual countries can transition to a low-carbon economy and how the world can meet the internationally agreed target of limiting the increase in global mean surface temperature to less than 2 degrees Celsius (deg. C). Achieving the 2 deg. C limit will require that global net emissions of greenhouse gases (GHG) approach zero by the second half of the century. In turn, this will require a profound transformation of energy systems by mid-century through steep declines in carbon intensity in all sectors of the economy, a transition we call 'deep decarbonization'

  4. Exergetical Evaluation of Biobased Synthesis Pathways

    Directory of Open Access Journals (Sweden)

    Philipp Frenzel

    2014-01-01

    Full Text Available The vast majority of today’s chemical products are based on crude oil. An attractive and sustainable alternative feedstock is biomass. Since crude oil and biomass differ in various properties, new synthesis pathways and processes have to be developed. In order to prioritize limited resources for research and development (R & D, their economic potential must be estimated in the early stages of development. A suitable measure for an estimation of the economic potential is based on exergy balances. Different structures of synthesis pathways characterised by the chemical exergy of the main components are evaluated. Based on a detailed evaluation of the underlying processes, general recommendations for future bio-based synthesis pathways are derived.

  5. Complement pathways and meningococcal disease : diagnostic aspects

    DEFF Research Database (Denmark)

    Sjöholm, A G; Truedsson, L; Jensenius, Jens Christian

    2001-01-01

    Complement is an immunological effector system that bridges innate and acquired immunity in several ways. There is a striking association between susceptibility to meningococcal disease and various forms of complement deficiency (1,2). In defense against bacterial infection, the most important...... function of complement is probably to serve as a mediator of antibody-dependent immunity. Specific antibodies can trigger activation of the classical and the alternative pathways of complement activation (3-5). It is well known that antibody-independent mechanisms interfere with alternative pathway...... activation on the bacterial surface (6,7). The newly discovered mannan-binding lectin (MBL) pathway of complement activation appears to be protective against many types of infection (8) and adds previously unsuspected aspects of innate immunity to complement-mediated defense. Interestingly, immune responses...

  6. Policy Pathways: Energy Management Programmes for Industry

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-09-06

    The IEA Policy Pathway publications provide details on how to implement specific recommendations drawn from the IEA 25 Energy Efficiency Policy Recommendations. This Policy Pathway, jointly produced by the International Energy Agency and the Institute for Industrial Productivity, develops the critical steps for policy makers implementing energy management programmes for industry. Optimising energy use in industry is essential to improve industrial competitiveness and achieve wider societal goals such as energy security, economic recovery and development, climate change mitigation and environmental protection.While there is significant potential to decrease energy consumption in this sector, opportunities to improve energy efficiency are still under-exploited. Energy management programmes have shown to be instrumental in addressing many of the barriers that inhibit wide-scale uptake of energy management in industry. The Policy Pathway builds on lessons learned from country experiences and provides actionable guidance on how to plan and design, implement, evaluate and monitor energy management programmes for industry.

  7. Pathways to deep decarbonization - Interim 2014 Report

    International Nuclear Information System (INIS)

    The interim 2014 report by the Deep Decarbonization Pathways Project (DDPP), coordinated and published by IDDRI and the Sustainable Development Solutions Network (SDSN), presents preliminary findings of the pathways developed by the DDPP Country Research Teams with the objective of achieving emission reductions consistent with limiting global warming to less than 2 deg. C. The DDPP is a knowledge network comprising 15 Country Research Teams and several Partner Organizations who develop and share methods, assumptions, and findings related to deep decarbonization. Each DDPP Country Research Team has developed an illustrative road-map for the transition to a low-carbon economy, with the intent of taking into account national socio-economic conditions, development aspirations, infrastructure stocks, resource endowments, and other relevant factors. The interim 2014 report focuses on technically feasible pathways to deep decarbonization

  8. Pathways of microbial metabolism of parathion.

    Science.gov (United States)

    Munnecke, D M; Hsieh, D P

    1976-01-01

    A mixed bacterial culture, consisting of a minimum of nine isolates, was adapted to growth on technical parathion (PAR) as a sole carbon and energy source. The primary oxidative pathway for PAR metabolism involved an initial hydrolysis to yield diethylthiophosphoric acid and p-nitrophenol. A secondary oxidative pathway involved the oxidation of PAR to paraoxon and then hydrolysis to yield p-nitrophenol and diethylphosphoric acid. Under low oxgen conditions PAR was reduced via a third pathway to p-aminoparathion and subsequently hydrolyzed to p-aminophenol and diethylthiophosphoric acid. PAR hydrolase, an enzyme produced by an isolate from the mixed culture, rapidly hydrolyzed PAR and paraoxon (6.0 mumol/mg per min). This enzyme was inducible and stable at room temperature and retained 100% of its activity when heated for 55 C for 10 min.

  9. MetaGen: a Promising Tool for Modeling Metabolic Networks From KEGG%MetaGen:从KEGG建模代谢网络的新工具

    Institute of Scientific and Technical Information of China (English)

    周婷婷; 容健锋; 陈振冲; 王正华; 朱云平; 贺福初

    2010-01-01

    为便于大规模代谢网络的计算,发展了一款方便实用的工具:MetaGen,对Kyoto Encyclopedia of Genes and Genomes(KEGG)中物种特异的各层次代谢系统进行建模,生成的代谢网络以酶图和通路图的方式表示.利用该工具,对人类代谢系统的bow-tie结构进行了初步研究,并以此为例展示了该工具广阔的应用前景.MetaGen利用KEGGweb服务保证建模数据的可靠性,依靠本地关系数据库加速网络建模过程并提供更多的数据管理和利用方式,并结合高级JAVA技术提高代码的可扩展性.MetaGen完全开源,可直接从http://bnct.sourceforge.net/下载.

  10. Understanding trade pathways to target biosecurity surveillance

    Directory of Open Access Journals (Sweden)

    Manuel Colunga-Garcia

    2013-09-01

    Full Text Available Increasing trends in global trade make it extremely difficult to prevent the entry of all potential invasive species (IS. Establishing early detection strategies thus becomes an important part of the continuum used to reduce the introduction of invasive species. One part necessary to ensure the success of these strategies is the determination of priority survey areas based on invasion pressure. We used a pathway-centred conceptual model of pest invasion to address these questions: what role does global trade play in invasion pressure of plant ecosystems and how could an understanding of this role be used to enhance early detection strategies? We concluded that the relative level of invasion pressure for destination ecosystems can be influenced by the intensity of pathway usage (import volume and frequency, the number and type of pathways with a similar destination, and the number of different ecological regions that serve as the source for imports to the same destination. As these factors increase, pressure typically intensifies because of increasing a propagule pressure, b likelihood of transporting pests with higher intrinsic invasion potential, and c likelihood of transporting pests into ecosystems with higher invasibility. We used maritime containerized imports of live plants into the contiguous U.S. as a case study to illustrate the practical implications of the model to determine hotspot areas of relative invasion pressure for agricultural and forest ecosystems (two ecosystems with high potential invasibility. Our results illustrated the importance of how a pathway-centred model could be used to highlight potential target areas for early detection strategies for IS. Many of the hotspots in agricultural and forest ecosystems were within major U.S. metropolitan areas. Invasion ecologists can utilize pathway-centred conceptual models to a better understand the role of human-mediated pathways in pest establishment, b enhance current

  11. Reciprocal regulation of metabolic and signaling pathways

    Directory of Open Access Journals (Sweden)

    Barth Andreas S

    2010-03-01

    Full Text Available Abstract Background By studying genome-wide expression patterns in healthy and diseased tissues across a wide range of pathophysiological conditions, DNA microarrays have revealed unique insights into complex diseases. However, the high-dimensionality of microarray data makes interpretation of heterogeneous gene expression studies inherently difficult. Results Using a large-scale analysis of more than 40 microarray studies encompassing ~2400 mammalian tissue samples, we identified a common theme across heterogeneous microarray studies evident by a robust genome-wide inverse regulation of metabolic and cell signaling pathways: We found that upregulation of cell signaling pathways was invariably accompanied by downregulation of cell metabolic transcriptional activity (and vice versa. Several findings suggest that this characteristic gene expression pattern represents a new principle of mammalian transcriptional regulation. First, this coordinated transcriptional pattern occurred in a wide variety of physiological and pathophysiological conditions and was identified across all 20 human and animal tissue types examined. Second, the differences in metabolic gene expression predicted the magnitude of differences for signaling and all other pathways, i.e. tissue samples with similar expression levels of metabolic transcripts did not show any differences in gene expression for all other pathways. Third, this transcriptional pattern predicted a profound effect on the proteome, evident by differences in structure, stability and post-translational modifications of proteins belonging to signaling and metabolic pathways, respectively. Conclusions Our data suggest that in a wide range of physiological and pathophysiological conditions, gene expression changes exhibit a recurring pattern along a transcriptional axis, characterized by an inverse regulation of major metabolic and cell signaling pathways. Given its widespread occurrence and its predicted effects

  12. Developmental pathways to antisocial behavior: the delayed-onset pathway in girls.

    Science.gov (United States)

    Silverthorn, P; Frick, P J

    1999-01-01

    Recent research has suggested that there are two distinct trajectories for the development of antisocial behavior in boys: a childhood-onset pathway and an adolescent-onset pathway. After reviewing the limited available research on antisocial girls, we propose that this influential method of conceptualizing the development of severe antisocial behavior may not apply to girls without some important modifications. Antisocial girls appear to show many of the correlates that have been associated with the childhood-onset pathway in boys, and they tend to show impaired adult adjustment, which is also similar to boys in the childhood-onset pathway. However, antisocial girls typically show an adolescent-onset to their antisocial behavior. We have proposed that these girls show a third developmental pathway which we have labeled the "delayed-onset" pathway. This model rests on the assumption that many of the putative pathogenic mechanisms that contribute to the development of antisocial behavior in girls, such as cognitive and neuropsychological deficits, a dysfunctional family environment, and/or the presence of a callous and unemotional interpersonal style, may be present in childhood, but they do not lead to severe and overt antisocial behavior until adolescence. Therefore, we propose that the delayed-onset pathway for girls is analogous to the childhood-onset pathway in boys and that there is no analogous pathway in girls to the adolescent-onset pathway in boys. Although this model clearly needs to be tested in future research, it highlights the need to test the applicability of current theoretical models for explaining the development of antisocial behavior in girls.

  13. Geoscience Academic Provenance: A Comparison of Undergraduate Students' Pathways to Faculty Pathways

    Science.gov (United States)

    Houlton, H. R.; Keane, C. M.; Wilson, C. E.

    2012-12-01

    Most Science, Technology, Engineering and Mathematics (STEM) disciplines have a direct recruiting method of high school science courses to supply their undergraduate majors. However, recruitment and retention of students into geoscience academic programs, who will be the future workforce, remains an important issue. The geoscience community is reaching a critical point in its ability to supply enough geoscientists to meet the current and near-future demand. Previous work done by Houlton (2010) determined that undergraduate geoscience majors follow distinct pathways when pursuing their degree and career. These pathways are comprised of students' interests, experiences, goals and career aspirations, which are depicted in six pathway steps. Three population groups were determined from the original 17 participants, which exhibited differences in pathway trajectories. Continued data collection efforts developed and refined the pathway framework. As part of an informal workshop activity, data were collected from 27 participants who are underrepresented minority early-career and future faculty in the geosciences. In addition, 20 geoscience departments' Heads and Chairs participated in an online survey about their pathway trajectories. Pathways were determined from each of these new sample populations and compared against the original geoscience undergraduate student participants. Several pathway components consistently spanned across sample populations. Identification of these themes have illuminated broad geoscience-related interests, experiences and aspirations that can be used to broadly impact recruitment and retention initiatives for our discipline. Furthermore, fundamental differences between participants' ages, stages in career and racial/ethnic backgrounds have exhibited subtle nuances in their geoscience pathway trajectories. In particular, those who've had research experiences, who think "creativity" is an important aspect of a geoscience career and those who

  14. PI3K pathway in NSCLC

    Directory of Open Access Journals (Sweden)

    Alex eMartínez Martí

    2012-01-01

    Full Text Available The phosphatidylinositol 3-kinases (PI3Ks are members of a family of intracellular lipid kinases that phosphorylate the 3’-hydroxyl group of phosphatidylinositol and phosphoinositides. PI3K regulate signaling pathways for neoplasia, including cell proliferation, adhesion, survival and motility. Different classes of PI3K have distinct roles in cellular signal transduction. PI3K pathway is activated by several different mechanisms in cancers, including, somatic mutation and gene amplification. In this review, we examine the literature addressing PI3K mutation status and gene amplification, with an emphasis on non-small cell lung cancer (NSCLC.

  15. Intracranial pathology of the visual pathway

    Energy Technology Data Exchange (ETDEWEB)

    Mueller-Forell, W. E-mail: mueller-forell@neuroradio.klinik.uni-mainz.de

    2004-02-01

    Intracranial pathologies involving the visual pathway are manifold. Aligning to anatomy, the most frequent and/or most important extrinsic and intrinsic intracranial lesions are presented. Clinical symptoms and imaging characteristics of lesions of the sellar region are demonstrated in different imaging modalities. The extrinsic lesions mainly consist of pituitary adenomas, meningeomas, craniopharyngeomas and chordomas. In (asymptomatic and symptomatic) aneurysms, different neurological symptoms depend on the location of aneurysms of the circle of Willis. Intrinsic tumors as astrocytoma of any grade, ependymoma and primary CNS-lymphoma require the main pathology in the course of the visual pathway. Vascular and demyelinating diseases complete this overview of intracranial lesions.

  16. Simplified analysis for liquid pathway studies

    International Nuclear Information System (INIS)

    The analysis of the potential contamination of surface water via groundwater contamination from severe nuclear accidents is routinely calculated during licensing reviews. This analysis is facilitated by the methods described in this report, which is codified into a BASIC language computer program, SCREENLP. This program performs simplified calculations for groundwater and surface water transport and calculates population doses to potential users for the contaminated water irrespective of possible mitigation methods. The results are then compared to similar analyses performed using data for the generic sites in NUREG-0440, Liquid Pathway Generic Study, to determine if the site being investigated would pose any unusual liquid pathway hazards

  17. Pathway-based classification of cancer subtypes

    Directory of Open Access Journals (Sweden)

    Kim Shinuk

    2012-07-01

    Full Text Available Abstract Background Molecular markers based on gene expression profiles have been used in experimental and clinical settings to distinguish cancerous tumors in stage, grade, survival time, metastasis, and drug sensitivity. However, most significant gene markers are unstable (not reproducible among data sets. We introduce a standardized method for representing cancer markers as 2-level hierarchical feature vectors, with a basic gene level as well as a second level of (more stable pathway markers, for the purpose of discriminating cancer subtypes. This extends standard gene expression arrays with new pathway-level activation features obtained directly from off-the-shelf gene set enrichment algorithms such as GSEA. Such so-called pathway-based expression arrays are significantly more reproducible across datasets. Such reproducibility will be important for clinical usefulness of genomic markers, and augment currently accepted cancer classification protocols. Results The present method produced more stable (reproducible pathway-based markers for discriminating breast cancer metastasis and ovarian cancer survival time. Between two datasets for breast cancer metastasis, the intersection of standard significant gene biomarkers totaled 7.47% of selected genes, compared to 17.65% using pathway-based markers; the corresponding percentages for ovarian cancer datasets were 20.65% and 33.33% respectively. Three pathways, consisting of Type_1_diabetes mellitus, Cytokine-cytokine_receptor_interaction and Hedgehog_signaling (all previously implicated in cancer, are enriched in both the ovarian long survival and breast non-metastasis groups. In addition, integrating pathway and gene information, we identified five (ID4, ANXA4, CXCL9, MYLK, FBXL7 and six (SQLE, E2F1, PTTG1, TSTA3, BUB1B, MAD2L1 known cancer genes significant for ovarian and breast cancer respectively. Conclusions Standardizing the analysis of genomic data in the process of cancer staging

  18. The Lectin Pathway of Complement and Biocompatibility

    DEFF Research Database (Denmark)

    Hein, Estrid; Garred, Peter

    2015-01-01

    activation, the coagulation system and the complement system. The complement system is an important part of the initial immune response and consists of fluid phase molecules in the blood stream. Three different activation pathways can initiate the complement system, the lectin, the classical...... and the alternative pathway, all converging in an amplification loop of the cascade system and downstream reactions. Thus, when exposed to foreign substances complement components will be activated and lead to a powerful inflammatory response. Biosurface induced complement activation is a recognised issue that has...

  19. Pathways to Sexual Risk Taking Among Female Adolescent Detainees

    OpenAIRE

    Lopez, Vera; Kopak, Albert; Robillard, Alyssa; Gillmore, Mary Rogers; Holliday, Rhonda C.; Braithwaite, Ronald L.

    2010-01-01

    Sexual risk taking among female delinquents represents a significant public health problem. Research is needed to understand the pathways leading to sexual risk taking among this population. This study sought to address this issue by identifying and testing two pathways from child maltreatment to non-condom use among 329 White and 484 African American female adolescent detainees: a relational pathway and a substance use coping pathway. The relational pathway indicated that child maltreatment ...

  20. Wnt/Ca2+ signaling pathway: a brief overview

    Institute of Scientific and Technical Information of China (English)

    Antara De

    2011-01-01

    The non-canonical Wnt/Ca2+ signaling cascade is less characterized than their canonical counterpart,the Wnt/β-catenin pathway.The non-canonical Wnt signaling pathways are diverse,defined as planer cell polarity pathway,Wnt-RAP1 signaling pathway,Wnt-Ror2 signaling pathway,Wnt-PKA pathway,Wnt-GSK3MT pathway,Wnt-aPKC pathway,Wnt-RYK pathway,Wnt-mTOR pathway,and Wnt/calcium signaling pathway.All these pathways exhibit a considerable degree of overlap between them.The Wnt/Ca2+ signaling pathway was deciphered as a crucial mediator in development.However,now there is substantial evidence that the signaling cascade is involved in many other molecular phenomena.Many aspects of Wnt/Ca2+ pathway are yet enigmatic.This review will give a brief overview of the fundamental and evolving concepts of the Wnt/Ca2+ signaling pathway.

  1. Pathway Tools version 19.0 update: software for pathway/genome informatics and systems biology.

    Science.gov (United States)

    Karp, Peter D; Latendresse, Mario; Paley, Suzanne M; Krummenacker, Markus; Ong, Quang D; Billington, Richard; Kothari, Anamika; Weaver, Daniel; Lee, Thomas; Subhraveti, Pallavi; Spaulding, Aaron; Fulcher, Carol; Keseler, Ingrid M; Caspi, Ron

    2016-09-01

    Pathway Tools is a bioinformatics software environment with a broad set of capabilities. The software provides genome-informatics tools such as a genome browser, sequence alignments, a genome-variant analyzer and comparative-genomics operations. It offers metabolic-informatics tools, such as metabolic reconstruction, quantitative metabolic modeling, prediction of reaction atom mappings and metabolic route search. Pathway Tools also provides regulatory-informatics tools, such as the ability to represent and visualize a wide range of regulatory interactions. This article outlines the advances in Pathway Tools in the past 5 years. Major additions include components for metabolic modeling, metabolic route search, computation of atom mappings and estimation of compound Gibbs free energies of formation; addition of editors for signaling pathways, for genome sequences and for cellular architecture; storage of gene essentiality data and phenotype data; display of multiple alignments, and of signaling and electron-transport pathways; and development of Python and web-services application programming interfaces. Scientists around the world have created more than 9800 Pathway/Genome Databases by using Pathway Tools, many of which are curated databases for important model organisms.

  2. Robust de novo pathway enrichment with KeyPathwayMiner 5

    DEFF Research Database (Denmark)

    Alcaraz, Nicolas; List, Markus; Dissing-Hansen, Martin;

    2016-01-01

    Identifying functional modules or novel active pathways, recently termed de novo pathway enrichment, is a computational systems biology challenge that has gained much attention during the last decade. Given a large biological interaction network, KeyPathwayMiner extracts connected subnetworks tha...... several network perturbation techniques and over a range of perturbation degrees. In addition, users may now provide a gold-standard set to determine how enriched extracted pathways are with relevant genes compared to randomized versions of the original network.......Identifying functional modules or novel active pathways, recently termed de novo pathway enrichment, is a computational systems biology challenge that has gained much attention during the last decade. Given a large biological interaction network, KeyPathwayMiner extracts connected subnetworks...... that are enriched for differentially active entities from a series of molecular profiles encoded as binary indicator matrices. Since interaction networks constantly evolve, an important question is how robust the extracted results are when the network is modified. We enable users to study this effect through...

  3. Multiple oxygen entry pathways in globin proteins revealed by intrinsic pathway identification method

    Science.gov (United States)

    Takayanagi, Masayoshi; Kurisaki, Ikuo; Nagaoka, Masataka

    2015-12-01

    Each subunit of human hemoglobin (HbA) stores an oxygen molecule (O2) in the binding site (BS) cavity near the heme group. The BS is buried in the interior of the subunit so that there is a debate over the O2 entry pathways from solvent to the BS; histidine gate or multiple pathways. To elucidate the O2 entry pathways, we executed ensemble molecular dynamics (MD) simulations of T-state tetramer HbA in high concentration O2 solvent to simulate spontaneous O2 entry from solvent into the BS. By analyzing 128 independent 8 ns MD trajectories by intrinsic pathway identification by clustering (IPIC) method, we found 141 and 425 O2 entry events into the BS of the α and β subunits, respectively. In both subunits, we found that multiple O2 entry pathways through inside cavities play a significant role for O2 entry process of HbA. The rate constants of O2 entry estimated from the MD trajectories correspond to the experimentally observed values. In addition, by analyzing monomer myoglobin, we verified that the high O2 concentration condition can reproduce the ratios of each multiple pathway in the one-tenth lower O2 concentration condition. These indicate the validity of the multiple pathways obtained in our MD simulations.

  4. Targeting stem cell signaling pathways for drug discovery: advances in the Notch and Wnt pathways.

    Science.gov (United States)

    An, Songzhu Michael; Ding, Qiang; Zhang, Jie; Xie, JingYi; Li, LingSong

    2014-06-01

    Signaling pathways transduce extracellular stimuli into cells through molecular cascades to regulate cellular functions. In stem cells, a small number of pathways, notably those of TGF-β/BMP, Hedgehog, Notch, and Wnt, are responsible for the regulation of pluripotency and differentiation. During embryonic development, these pathways govern cell fate specifications as well as the formation of tissues and organs. In adulthood, their normal functions are important for tissue homeostasis and regeneration, whereas aberrations result in diseases, such as cancer and degenerative disorders. In complex biological systems, stem cell signaling pathways work in concert as a network and exhibit crosstalk, such as the negative crosstalk between Wnt and Notch. Over the past decade, genetic and genomic studies have identified a number of potential drug targets that are involved in stem cell signaling pathways. Indeed, discovery of new targets and drugs for these pathways has become one of the most active areas in both the research community and pharmaceutical industry. Remarkable progress has been made and several promising drug candidates have entered into clinical trials. This review focuses on recent advances in the discovery of novel drugs which target the Notch and Wnt pathways.

  5. Pathways to Relationship Aggression between Adult Partners

    Science.gov (United States)

    Busby, Dean M.; Holman, Thomas B.; Walker, Eric

    2008-01-01

    In this study, the pathways to adult aggression beginning in the family of origin (FOO) and continuing through adult relationships were investigated. With a sample of 30,600 individuals, a comprehensive model was evaluated that included the unique influences of violent victimization in the family, witnessing parental violence, perpetrating…

  6. Using biological pathway data with paxtools.

    Directory of Open Access Journals (Sweden)

    Emek Demir

    Full Text Available A rapidly growing corpus of formal, computable pathway information can be used to answer important biological questions including finding non-trivial connections between cellular processes, identifying significantly altered portions of the cellular network in a disease state and building predictive models that can be used for precision medicine. Due to its complexity and fragmented nature, however, working with pathway data is still difficult. We present Paxtools, a Java library that contains algorithms, software components and converters for biological pathways represented in the standard BioPAX language. Paxtools allows scientists to focus on their scientific problem by removing technical barriers to access and analyse pathway information. Paxtools can run on any platform that has a Java Runtime Environment and was tested on most modern operating systems. Paxtools is open source and is available under the Lesser GNU public license (LGPL, which allows users to freely use the code in their software systems with a requirement for attribution. Source code for the current release (4.2.0 can be found in Software S1. A detailed manual for obtaining and using Paxtools can be found in Protocol S1. The latest sources and release bundles can be obtained from biopax.org/paxtools.

  7. Apoptosis signaling pathways and lymphocyte homeostasis

    Institute of Scientific and Technical Information of China (English)

    Guangwu Xu; Yufang Shi

    2007-01-01

    It has been almost three decades since the term "apoptosis" was first coined to describe a unique form of cell death that involves orderly, gene-dependent cell disintegration. It is now well accepted that apoptosis is an essential life process for metazoan animals and is critical for the formation and function of tissues and organs. In the adult mammalian body, apoptosis is especially important for proper functioning of the immune system. In recent years, along with the rapid advancement of molecular and cellular biology, great progress has been made in understanding the mechanisms leading to apoptosis. It is generally accepted that there are two major pathways of apoptotic cell death induction: extrinsic signaling through death receptors that leads to the formation of the death-inducing signaling complex (DISC), and intrinsic signaling mainly through mitochondria which leads to the formation of the apoptosome. Formation of the DISC or apoptosome, respectively, activates initiator and common effector caspases that execute the apoptosis process. In the immune system, both pathways operate; however, it is not known whether they are sufficient to maintain lymphocyte homeostasis. Recently, new apoptotic mechanisms including caspase-independent pathways and granzyme-initiated pathways have been shown to exist in lymphocytes. This review will summarize our understanding of the mechanisms that control the homeostasis of various lymphocyte populations.

  8. Engineering the spatial organization of metabolic pathways

    DEFF Research Database (Denmark)

    Albertsen, Line; Maury, Jerome; Bach, Lars Stougaard;

    or assembly into large complexes. The vision is that by positioning sequentially acting enzymes in close proximity, the cell can accelerate reaction rates and thereby prevent loss of intermediates through diffusion, degradation or competing pathways. The production of valuable metabolites in cell factories...

  9. MDRC Research on Career Pathways. Issue Brief

    Science.gov (United States)

    Kazis, Richard

    2016-01-01

    As postsecondary credentials have become increasingly important to accessing higher-quality employment, a growing number of education and workforce programs are implementing "career pathways" approaches to help both youth and adults prepare for further education and better jobs. In recent years, the Manpower Demonstration Research…

  10. Whole Algae Hydrothermal Liquefaction Technology Pathway

    Energy Technology Data Exchange (ETDEWEB)

    Biddy, M.; Davis, R.; Jones, S.

    2013-03-01

    This technology pathway case investigates the feasibility of using whole wet microalgae as a feedstock for conversion via hydrothermal liquefaction. Technical barriers and key research needs have been assessed in order for the hydrothermal liquefaction of microalgae to be competitive with petroleum-derived gasoline-, diesel-, and jet-range hydrocarbon blendstocks.

  11. Syngas Upgrading to Hydrocarbon Fuels Technology Pathway

    Energy Technology Data Exchange (ETDEWEB)

    Talmadge, M.; Biddy, Mary J.; Dutta, Abhijit; Jones, Susanne B.; Meyer, Pimphan A.

    2013-03-31

    In support of the Bioenergy Technologies Office, the National Renewable Energy Laboratory (NREL) and the Pacific Northwest National Laboratory (PNNL) are undertaking studies of biomass conversion technologies to hydrocarbon fuels to identify barriers and target research toward reducing conversion costs. Process designs and preliminary economic estimates for each of these pathway cases were developed using rigorous modeling tools (Aspen Plus and Chemcad). These analyses incorporated the best information available at the time of development, including data from recent pilot and bench-scale demonstrations, collaborative industrial and academic partners, and published literature and patents. This pathway case investigates the upgrading of biomass derived synthesis gas (‘syngas’) to hydrocarbon biofuels. While this specific discussion focuses on the conversion of syngas via a methanol intermediate to hydrocarbon blendstocks, there are a number of alternative conversion routes for production of hydrocarbons through a wide array of intermediates from syngas. Future work will also consider the variations to this pathway to determine the most economically viable and risk adverse conversion route. Technical barriers and key research needs have been identified that should be pursued for the syngas to hydrocarbon pathway to be competitive with petroleum-derived gasoline, diesel and jet range blendstocks.

  12. Crowding in the S-cone pathway.

    Science.gov (United States)

    Coates, Daniel R; Chung, Susana T L

    2016-05-01

    The spatial extent of interference from nearby object or contours (the critical spacing of "crowding") has been thoroughly characterized across the visual field, typically using high contrast achromatic stimuli. However, attempts to link this measure with known properties of physiological pathways have been inconclusive. The S-cone pathway, with its ease of psychophysical isolation and known anatomical characteristics, offers a unique tool to gain additional insights into crowding. In this study, we measured the spatial extent of crowding in the S-cone pathway at several retinal locations using a chromatic adaptation paradigm. S-cone crowding was evident and extensive, but its spatial extent changed less markedly as a function of retinal eccentricity than the extent found using traditional achromatic stimuli. However, the spatial extent agreed with that of low contrast achromatic stimuli matched for isolated resolvability. This suggests that common cortical mechanisms mediate the crowding effect in the S-cone and achromatic pathway, but contrast is an important factor. The low contrast of S-cone stimuli makes S-cone vision more acuity-limited than crowding-limited.

  13. Pathways from jobs to social cohesion

    OpenAIRE

    Wietzke, Frank-Borge

    2014-01-01

    There is growing recognition that access to good jobs is an important driver of social cohesion. While economic dimensions of labor market outcomes are relatively well documented, evidence on the link between social cohesion and jobs is still surprisingly scarce. This paper, based on an earlier background report for the WDR 2013, presents empirical evidence for pathways between labor marke...

  14. Regulatory pathways in the European Union

    OpenAIRE

    Kohler, Manuela

    2011-01-01

    In principle, there are three defined procedures to obtain approval for a medicinal product in the European Union. As discussed in this overview of the procedures, the decision on which regulatory pathway to use will depend on the nature of the active substance, the target indication(s), the history of product and/or the marketing strategy.

  15. Learning figurative idioms via cognitive semantic pathway

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    In FTL contexts, traditional view treats idiomatic language as essentially arbitrary, which has typically led to the belief that they can only be learned through blind memoriztion. However, the cognitive semantic idea considers that idioms are typically motivated, which can help learners to identify their senses. This paper demonstrates how to learn figurative idioms through cognitive semantic pathway by taking anger as one example.

  16. Precursors of Young Women's Family Formation Pathways

    Science.gov (United States)

    Amato, Paul R.; Landale, Nancy S.; Havasevich-Brooks, Tara C.; Booth, Alan; Eggebeen, David J.; Schoen, Robert; McHale, Susan M.

    2008-01-01

    We used latent class analysis to create family formation pathways for women between the ages of 18 and 23. Input variables included cohabitation, marriage, parenthood, full-time employment, and attending school. Data (n = 2,290) came from Waves I and III of the National Longitudinal Study of Adolescent Health (Add Health). The analysis revealed…

  17. Pathways to deep decarbonization in India

    DEFF Research Database (Denmark)

    Shukla, P.; Dhar, Subash; Pathak, Minal;

    This report is a part of the global Deep Decarbonisation Pathways (DDP) Project. The analysis consider two development scenarios for India and assess alternate roadmaps for transiting to a low carbon economy consistent with the globally agreed 2°C stabilization target. The report does not consider...

  18. Regulatory pathways in the European Union.

    Science.gov (United States)

    Kohler, Manuela

    2011-01-01

    In principle, there are three defined procedures to obtain approval for a medicinal product in the European Union. As discussed in this overview of the procedures, the decision on which regulatory pathway to use will depend on the nature of the active substance, the target indication(s), the history of product and/or the marketing strategy. PMID:21487236

  19. Policy Pathways: Energy Performance Certification of Buildings

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2010-07-01

    Improving energy efficiency is one of the most effective measures to address energy security, climate change and economic objectives. The Policy Pathways series can help countries capture this potential by assisting with the implementation of the 25 energy efficiency policy recommendations that were published by the International Energy Agency (IEA) in 2008. This policy pathway on energy performance certification of buildings is the second in the series. It aims to provide a 'how-to' guide to policy makers and relevant stakeholders on the essential elements in implementing energy performance certification of buildings programmes. Energy performance certification of buildings is a way to rate the energy efficiency of individual buildings -- whether they be residential, commercial or public. It is a key policy instrument that can assist governments in reducing energy consumption in buildings. This policy pathway showcases experiences from countries around the world to show examples of good practice and delivers a pathway of ten critical steps to implement energy performance certification of buildings programmes.

  20. Fetal and neonatal pathways to obesity.

    Science.gov (United States)

    Gluckman, Peter D; Hanson, Mark A; Beedle, Alan S; Raubenheimer, David

    2008-01-01

    Evolutionary and developmental perspectives add considerably to our understanding of the aetiology of obesity and its related disorders. One pathway to obesity represents the maladaptive consequences of an evolutionarily preserved mechanism by which the developing mammal monitors nutritional cues from its mother and adjusts its developmental trajectory accordingly. Prediction of a nutritionally sparse environment leads to a phenotype that promotes metabolic parsimony by favouring fat deposition, insulin resistance, sarcopenia and low energy expenditure. But this adaptive mechanism evolved to accommodate gradual changes in nutritional environment; rapid transition to a situation of high energy density results in a mismatch between predicted and actual environments and increased susceptibility to metabolic disease. This pathway may also explain why breast and bottle feeding confer different risks of obesity. We discuss how early environmental signals act through epigenetic mechanisms to alter metabolic partitioning, glucocorticoid action and neuroendocrine control of appetite. A second pathway involves alterations in fetal insulin levels, as seen in gestational diabetes, leading to increased prenatal fat mass which is subsequently amplified by postnatal factors. Both classes of pathway may coexist in an individual. This developmental approach to obesity suggests that potential interventions will vary according to the target population.

  1. Final report on the Pathway Analysis Task

    International Nuclear Information System (INIS)

    The Pathway Analysis Task constituted one of several multi-laboratory efforts to estimate radiation doses to people, considering all important pathways of exposure, from the testing of nuclear devices at the Nevada Test Site (NTS). The primary goal of the Pathway Analysis Task was to predict radionuclide ingestion by residents of Utah, Nevada, and portions of seven other adjoining western states following radioactive fallout deposition from individual events at the NTS. This report provides comprehensive documentation of the activities and accomplishments of Colorado State University's Pathway Analysis Task during the entire period of support (1979--91). The history of the project will be summarized, indicating the principal dates and milestones, personnel involved, subcontractors, and budget information. Accomplishments, both primary and auxiliary, will be summarized with general results rather than technical details being emphasized. This will also serve as a guide to the reports and open literature publications produced, where the methodological details and specific results are documented. Selected examples of results on internal dose estimates are provided in this report because the data have not been published elsewhere

  2. Macropinocytosis: a pathway to protozoan infection

    Directory of Open Access Journals (Sweden)

    Tecia Maria Ulisses Carvalho

    2015-04-01

    Full Text Available Among the various endocytic mechanisms in mammalian cells, macropinocytosis involves internalization of large amounts of plasma membrane together with extracellular medium, leading to macropinosome formation. These structures are formed when plasma membrane ruffles are assembled after actin filament rearrangement. In dendritic cells, macropinocytosis has been reported to play a role in antigen presentation. Several intracellular pathogens are internalized by host cells via multiple endocytic pathways and macropinocytosis has been described as an important entry site for various organisms. Some bacteria, such as Legionella pneumophila, as well as various viruses, use this pathway to penetrate and subvert host cells. Some protozoa, which are larger than bacteria and virus, can also use this pathway to invade host cells. As macropinocytosis is characterized by the formation of large uncoated vacuoles and is triggered by various signaling pathways, which is similar to what occurs during the formation of the majority of parasitophorous vacuoles, it is believed that this phenomenon may be more widely used by parasites than is currently appreciated. Here we review protozoa host cell invasion via macropinocytosis.

  3. Final report on the Pathway Analysis Task

    Energy Technology Data Exchange (ETDEWEB)

    Whicker, F.W.; Kirchner, T.B. [Colorado State Univ., Fort Collins, CO (United States)

    1993-04-01

    The Pathway Analysis Task constituted one of several multi-laboratory efforts to estimate radiation doses to people, considering all important pathways of exposure, from the testing of nuclear devices at the Nevada Test Site (NTS). The primary goal of the Pathway Analysis Task was to predict radionuclide ingestion by residents of Utah, Nevada, and portions of seven other adjoining western states following radioactive fallout deposition from individual events at the NTS. This report provides comprehensive documentation of the activities and accomplishments of Colorado State University`s Pathway Analysis Task during the entire period of support (1979--91). The history of the project will be summarized, indicating the principal dates and milestones, personnel involved, subcontractors, and budget information. Accomplishments, both primary and auxiliary, will be summarized with general results rather than technical details being emphasized. This will also serve as a guide to the reports and open literature publications produced, where the methodological details and specific results are documented. Selected examples of results on internal dose estimates are provided in this report because the data have not been published elsewhere.

  4. Salicylic acid-independent plant defence pathways

    NARCIS (Netherlands)

    Pieterse, C.M.J.; Loon, L.C. van

    1999-01-01

    Salicylic acid is an important signalling molecule involved in both locally and systemically induced disease resistance responses. Recent advances in our understanding of plant defence signalling have revealed that plants employ a network of signal transduction pathways, some of which are independen

  5. Origin and evolution of metabolic pathways

    Science.gov (United States)

    Fani, Renato; Fondi, Marco

    2009-03-01

    The emergence and evolution of metabolic pathways represented a crucial step in molecular and cellular evolution. In fact, the exhaustion of the prebiotic supply of amino acids and other compounds that were likely present in the ancestral environment, imposed an important selective pressure, favoring those primordial heterotrophic cells which became capable of synthesizing those molecules. Thus, the emergence of metabolic pathways allowed primitive organisms to become increasingly less-dependent on exogenous sources of organic compounds. Comparative analyses of genes and genomes from organisms belonging to Archaea, Bacteria and Eukarya revealed that, during evolution, different forces and molecular mechanisms might have driven the shaping of genomes and the arisal of new metabolic abilities. Among these gene elongations, gene and operon duplications undoubtedly played a major role since they can lead to the (immediate) appearance of new genetic material that, in turn, might undergo evolutionary divergence giving rise to new genes coding for new metabolic abilities. Gene duplication has been invoked in the different schemes proposed to explain why and how the extant metabolic pathways have arisen and shaped. Both the analysis of completely sequenced genomes and directed evolution experiments strongly support one of them, i.e. the patchwork hypothesis, according to which metabolic pathways have been assembled through the recruitment of primitive enzymes that could react with a wide range of chemically related substrates. However, the analysis of the structure and organization of genes belonging to ancient metabolic pathways, such as histidine biosynthesis and nitrogen fixation, suggested that other different hypothesis, i.e. the retrograde hypothesis or the semi-enzymatic theory, may account for the arisal of some metabolic routes.

  6. Expression of hippo pathway in colorectal cancer

    Directory of Open Access Journals (Sweden)

    Kun Liang

    2014-01-01

    Full Text Available Background/Aims: Hippo pathway plays a crucial role in cell proliferation, apoptosis, and tumorigenesis. This study aimed to investigate the expression of Hippo pathway components in the progression and metastasis of colorectal cancer (CRC. Materials and Methods: Quantitative real-time polymerase chain reaction (qRT-PCR was used to examine the mRNA expression levels of MST1, LATS2, YAP, TAZ, TEAD1, CDX2, and OCT4, and western blot (WB was used to examine the protein expression levels of MST1, YAP, TEAD1, and CDX2 in 30 specimens of human colorectal adenomas, 50 pairs of human CRC tissues, and adjacent nontumorous tissues from CRC patients. Glyceraldehyde 3-phosphate dehydrogenase (GAPDH was used as the housekeeping gene in qRT-PCR. Results: The mRNA expression levels of MST1 and LATS2 showed an increasing tendency from CRC to adjacent nontumorous tissues (P < 0.001. Conversely, the mRNA expression levels of YAP, TAZ, TEAD, and OCT4 showed a decreasing tendency from CRC to adjacent nontumorous tissues (P < 0.001. MST1 protein was downregulated and YAP and TEAD1 proteins were upregulated in CRC (all P < 0.001. The mRNA and protein expression levels of CDX2 in CRC were significantly lower than those in colorectal adenomas and adjacent nontumorous tissues (P < 0.001, but there was no significant difference between the latter two groups (qRT-PCR, P = 0.113; WB, P = 0.151. Furthermore, statistical analysis showed that the expression levels of Hippo signal pathway components were associated with tumor differentiation, lymph node metastasis, and TNM stage. Conclusion: Hippo pathway is suppressed in the progression from colorectal adenomas to CRC and is associated with CRC progression and metastasis. This study suggests the components of Hippo pathway might be prognostic indicators for CRC patients.

  7. e-Science and biological pathway semantics

    Directory of Open Access Journals (Sweden)

    Luciano Joanne S

    2007-05-01

    Full Text Available Abstract Background The development of e-Science presents a major set of opportunities and challenges for the future progress of biological and life scientific research. Major new tools are required and corresponding demands are placed on the high-throughput data generated and used in these processes. Nowhere is the demand greater than in the semantic integration of these data. Semantic Web tools and technologies afford the chance to achieve this semantic integration. Since pathway knowledge is central to much of the scientific research today it is a good test-bed for semantic integration. Within the context of biological pathways, the BioPAX initiative, part of a broader movement towards the standardization and integration of life science databases, forms a necessary prerequisite for its successful application of e-Science in health care and life science research. This paper examines whether BioPAX, an effort to overcome the barrier of disparate and heterogeneous pathway data sources, addresses the needs of e-Science. Results We demonstrate how BioPAX pathway data can be used to ask and answer some useful biological questions. We find that BioPAX comes close to meeting a broad range of e-Science needs, but certain semantic weaknesses mean that these goals are missed. We make a series of recommendations for re-modeling some aspects of BioPAX to better meet these needs. Conclusion Once these semantic weaknesses are addressed, it will be possible to integrate pathway information in a manner that would be useful in e-Science.

  8. Targeting the Fanconi Anemia Pathway to Identify Tailored Anticancer Therapeutics

    Directory of Open Access Journals (Sweden)

    Chelsea Jenkins

    2012-01-01

    Full Text Available The Fanconi Anemia (FA pathway consists of proteins involved in repairing DNA damage, including interstrand cross-links (ICLs. The pathway contains an upstream multiprotein core complex that mediates the monoubiquitylation of the FANCD2 and FANCI heterodimer, and a downstream pathway that converges with a larger network of proteins with roles in homologous recombination and other DNA repair pathways. Selective killing of cancer cells with an intact FA pathway but deficient in certain other DNA repair pathways is an emerging approach to tailored cancer therapy. Inhibiting the FA pathway becomes selectively lethal when certain repair genes are defective, such as the checkpoint kinase ATM. Inhibiting the FA pathway in ATM deficient cells can be achieved with small molecule inhibitors, suggesting that new cancer therapeutics could be developed by identifying FA pathway inhibitors to treat cancers that contain defects that are synthetic lethal with FA.

  9. Discovery of Unclustered Fungal Indole Diterpene Biosynthetic Pathways through Combinatorial Pathway Reassembly in Engineered Yeast.

    Science.gov (United States)

    Tang, Man-Cheng; Lin, Hsiao-Ching; Li, Dehai; Zou, Yi; Li, Jian; Xu, Wei; Cacho, Ralph A; Hillenmeyer, Maureen E; Garg, Neil K; Tang, Yi

    2015-11-01

    The structural diversity and biological activities of fungal indole diterpenes (IDTs) are generated in large part by the IDT cyclases (IDTCs). Identifying different IDTCs from IDT biosynthetic pathways is therefore important toward understanding how these enzymes introduce chemical diversity from a common linear precursor. However, IDTCs involved in the cyclization of the well-known aflavinine subgroup of IDTs have not been discovered. Here, using Saccharomyces cerevisiae as a heterologous host and a phylogenetically guided enzyme mining approach, we combinatorially assembled IDT biosynthetic pathways using IDTCs homologues identified from different fungal hosts. We identified the genetically standalone IDTCs involved in the cyclization of aflavinine and anominine and produced new IDTs not previously isolated. The cyclization mechanisms of the new IDTCs were proposed based on the yeast reconstitution results. Our studies demonstrate heterologous pathway assembly is a useful tool in the reconstitution of unclustered biosynthetic pathways.

  10. Signal transduction pathway(s) in guard cells after prolonged exposure to low vapour pressure deficit

    NARCIS (Netherlands)

    Ali Niaei Fard, S.

    2014-01-01

    Keywords: Abscisic acid, Arabidopsis thaliana, calcium, CYP707As, desiccation, environmental factors, guard cells’ signalling pathway, hydrogen peroxide, natural variation, nitric oxide, photosystem II efficiency, RD29A, relative water content, secondary messengers, stomata, vapour pressure def

  11. Estudo da variação do pH da pele humana exposta à formulação cosmética acrescida ou não das vitaminas A, E ou de ceramida, por metodologia não invasiva Study of pH variation on the skin using cosmetic formulation s with and without vitamins A, E or ceramide: by a non-invasive method

    Directory of Open Access Journals (Sweden)

    Gislaine Ricci Leonardi

    2002-10-01

    Full Text Available FUNDAMENTOS: Os cosméticos hidratantes melhoram a pele, aproximando-a de suas condições ideais, pois aumentam a quantidade de água no estrato córneo. As vitaminas A e E, bem como as ceramidas, são substâncias ativas que vêm sendo muito empregadas em hidratantes, os quais constituem uma das mais importantes classes de produtos cosméticos e de higiene corporal. OBJETIVO: - O objetivo deste trabalho foi avaliar o efeito no pH cutâneo da pele humana de uma emulsão O/A (constituída de base auto-emulsionante não iônica acrescida, ou não, de vitamina A palmitato ou vitamina E acetato ou ceramida III, por metodologia não invasiva MÉTODOS:O estudo foi realizado em 40 mulheres com idade entre 30 e 45 anos, empregando-se o equipamento Skin Phmeter PH 900 PC. As medidas foram efetuadas no antebraço das voluntárias nos tempos de sete e 30 dias após auto-aplicação diária (duas vezes ao dia, dos produtos envolvidos no estudo RESULTADOS E CONCLUSÃO: A presença das vitaminas A ou E, ou da ceramida não alterou de maneira significativa o pH da pele, o que mostra que as formulações estudadas são adequadas para o uso cosmético.BACKGROUND: Moisturizers are believed to improve the skin's condition by increasing the water content of the stratum corneum. Vitamins A and E and ceramides have been widely used in cosmetic moisturizing products, and these are one of the most important cosmetic and body care products. OBJECTIVE: The aim of this research was to evaluate the effects on the pH of human skin of an O/W emulsion (non ionic self-emulsifying base with and without vitamin A palmitate, or vitamin E acetate, or ceramide III, using a non-invasive method. METHOD: The investigations were carried out on a group of 40 healthy female test subjects aged between 30 and 45 years old, using the Skin pH meter PH 900 PC. The measurements were performed on the forearm of volunteers at 7 and 30 days after daily use (twice a day of the products used in

  12. Phosphoketolase Pathway Dominates in Lactobacillus reuteri ATCC 55730 Containing Dual Pathways for Glycolysis▿

    OpenAIRE

    Årsköld, Emma; Lohmeier-Vogel, Elke; Cao, Rong; Roos, Stefan; Rådström, Peter; van Niel, Ed W. J.

    2007-01-01

    Metabolic flux analysis indicated that the heterofermentative Lactobacillus reuteri strain ATCC 55730 uses both the Embden-Meyerhof pathway (EMP) and phosphoketolase pathway (PKP) when glucose or sucrose is converted into the three-carbon intermediate stage of glycolysis. In all cases studied, the main flux is through the PKP, while the EMP is used as a shunt. In the exponential growth phase, 70%, 73%, and 84% of the flux goes through the PKP in cells metabolizing (i) glucose plus fructose, (...

  13. Phosphoketolase pathway dominates in Lactobacillus reuteri ATCC 55730 containing dual pathways for glycolysis

    OpenAIRE

    Årsköld, Emma; Lohmeier-Vogel, Elke; Cao, Rong; Roos, Stefan; Rådström, Peter; van Niel, Ed

    2008-01-01

    Metabolic flux analysis indicated that the heterofermentative Lactobacillus reuteri strain ATCC 55730 uses both the Embden-Meyerhof pathway (EMP) and phosphoketolase pathway (PKP) when glucose or sucrose is converted into the three-carbon intermediate stage of glycolysis. In all cases studied, the main flux is through the PKP, while the EMP is used as a shunt. In the exponential growth phase, 70%, 73%, and 84% of the flux goes through the PKP in cells metabolizing (i) glucose plus fructose, (...

  14. The cardiopulmonary effects of ambient air pollution and mechanistic pathways: a comparative hierarchical pathway analysis.

    Directory of Open Access Journals (Sweden)

    Ananya Roy

    Full Text Available Previous studies have investigated the associations between exposure to ambient air pollution and biomarkers of physiological pathways, yet little has been done on the comparison across biomarkers of different pathways to establish the temporal pattern of biological response. In the current study, we aim to compare the relative temporal patterns in responses of candidate pathways to different pollutants. Four biomarkers of pulmonary inflammation and oxidative stress, five biomarkers of systemic inflammation and oxidative stress, ten parameters of autonomic function, and three biomarkers of hemostasis were repeatedly measured in 125 young adults, along with daily concentrations of ambient CO, PM2.5, NO2, SO2, EC, OC, and sulfate, before, during, and after the Beijing Olympics. We used a two-stage modeling approach, including Stage I models to estimate the association between each biomarker and pollutant over each of 7 lags, and Stage II mixed-effect models to describe temporal patterns in the associations when grouping the biomarkers into the four physiological pathways. Our results show that candidate pathway groupings of biomarkers explained a significant amount of variation in the associations for each pollutant, and the temporal patterns of the biomarker-pollutant-lag associations varied across candidate pathways (p<0.0001 and were not linear (from lag 0 to lag 3: p = 0.0629, from lag 3 to lag 6: p = 0.0005. These findings suggest that, among this healthy young adult population, the pulmonary inflammation and oxidative stress pathway is the first to respond to ambient air pollution exposure (within 24 hours and the hemostasis pathway responds gradually over a 2-3 day period. The initial pulmonary response may contribute to the more gradual systemic changes that likely ultimately involve the cardiovascular system.

  15. KeyPathwayMiner: Detecting Case-Specific Biological Pathways Using Expression Data

    OpenAIRE

    Alcaraz, Nicolas; Kücük, Hande; Weile, Jochen; Wipat, Anil; Baumbach, Jan

    2011-01-01

    Recent advances in systems biology have provided us with massive amounts of pathway data that describe the interplay of genes and their products. The resulting biological networks can be modeled as graphs. By means of "omics" technologies, such as microarrays, the activity of genes and proteins can be measured. Here, data from microarray experiments is integrated with the network data to gain deeper insights into gene expression. We introduce KeyPathwayMiner, a method that enab...

  16. Impact of MAPK Cascade Pathway and P53 Pathway upon Liver Transplant

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    The change and the role of MAPK cascade pathway and P53 pathway after liver transplantation were explored. Thirty-four punctured donor liver specimens and 10 normal liver specimens were classified as group A (no rejection, n= 10), group B (mild/moderate acute rejection, n = 10), group C (serious acute rejection, n = 8), group D (chronic rejection/fibrosis, n = 6) and group E (control, n= 10). By using tmmunohistochemistry, the expression levels of mitogen activated protein kinase (MAPK), Ras and P53 proteins, and by in situ hybridization, MAPK and ras mRNA expression levels were detected. The results showed that the expression levels of MAPK and Ras proteins were increased by turns in groups A, B and C, and decreased by turns in groups D and E. The protein expression of P53 was higher in the treated groups. The expression of Ras,HSP70 mRNA was identical as that of protein. It is suggested that the MAPK cascade pathway and P53 pathway can protect the hepatocytes by different mechanisms after liver transplantation.MAPKs cascade pathway repairs hepatocyte injury or accelerates hepatocytes into proliferation or differentiation. P53 pathway blocks cell cycle within G1 phase to make hepatocyte repair or apoptosis to reduce disorder differentiation.

  17. Degenerative Pathways of Lumbar Motion Segments

    DEFF Research Database (Denmark)

    Jensen, Rikke K.; Kjaer, Per; Jensen, Tue S.;

    2016-01-01

    the spinal MRI reports of 4,162 low back pain patients and (2) data from an MRI research protocol of 631 low back pain patients. Latent Class Analysis was used in both samples to cluster MRI findings from lumbar motion segments. Using content analysis, each cluster was then categorised into hypothetical...... into the association with clinical outcomes (such as pain) has predominantly focused on individual MRI findings. This study aimed to: (i) investigate how multiple MRI lumbar spine findings cluster together within two different samples of patients with low back pain, (ii) classify these clusters into hypothetical...... samples were not identical, the overall pattern of increasing degeneration within the pathways was the same. CONCLUSIONS: It was expected that different clusters could emerge from different samples, however, when organised into hypothetical pathways of degeneration, the overall pattern of increasing...

  18. Arbovirus-mosquito interactions: RNAi pathway.

    Science.gov (United States)

    Olson, Ken E; Blair, Carol D

    2015-12-01

    Arthropod-borne (arbo) viruses infect hematophagous arthropods (vectors) to maintain virus transmission between vertebrate hosts. The mosquito vector actively controls arbovirus infection to minimize its fitness costs. The RNA interference (RNAi) pathway is the major antiviral response vectors use to restrict arbovirus infections. We know this because depleting RNAi gene products profoundly impacts arbovirus replication, the antiviral RNAi pathway genes undergo positive, diversifying selection and arboviruses have evolved strategies to evade the vector's RNAi responses. The vector's RNAi defense and arbovirus countermeasures lead to an arms race that prevents potential virus-induced fitness costs yet maintains arbovirus infections needed for transmission. This review will discuss the latest findings in RNAi-arbovirus interactions in the model insect (Drosophila melanogaster) and in specific mosquito vectors.

  19. Stochastic Processes via the Pathway Model

    Directory of Open Access Journals (Sweden)

    Arak M. Mathai

    2015-04-01

    Full Text Available After collecting data from observations or experiments, the next step is to analyze the data to build an appropriate mathematical or stochastic model to describe the data so that further studies can be done with the help of the model. In this article, the input-output type mechanism is considered first, where reaction, diffusion, reaction-diffusion, and production-destruction type physical situations can fit in. Then techniques are described to produce thicker or thinner tails (power law behavior in stochastic models. Then the pathway idea is described where one can switch to different functional forms of the probability density function through a parameter called the pathway parameter. The paper is a continuation of related solar neutrino research published previously in this journal.

  20. A Pathway Idea in Model Building

    Science.gov (United States)

    Mathai, A. M.; Haubold, H. J.

    2014-01-01

    The pathway idea is a way of going from one family of functions to another family of functions and yet another family of functions through a parameter in the mode l so that a switching mechanism is introduced into the model through a parameter. The advantage of the idea is that the model can cover the ideal or stable situation in a physical situation as well as cover the unstable neighborhoods or move from unstable neighborhoods to the stable situation. The basic idea is illustrated for the real scalar case here and its connections to topics in astrophysics and non-extens ive statistical mechanics, namely superstatistics and Tsallis statistics, Mittag-Leffler models, hypergeometric functions and generalized special functions such as the H-function etc are pointed out. The pathway idea is available for the real and complex rectangular matrix variate cases but only the real scalar case is illustrated here.

  1. Whole Algae Hydrothermal Liquefaction Technology Pathway

    Energy Technology Data Exchange (ETDEWEB)

    Biddy, Mary J.; Davis, Ryan; Jones, Susanne B.; Zhu, Yunhua

    2013-03-31

    In support of the Bioenergy Technologies Office, the National Renewable Energy Laboratory (NREL) and the Pacific Northwest National Laboratory (PNNL) are undertaking studies of biomass conversion technologies to hydrocarbon fuels to identify barriers and target research toward reducing conversion costs. Process designs and preliminary economic estimates for each of these pathway cases were developed using rigorous modeling tools (Aspen Plus and Chemcad). These analyses incorporated the best information available at the time of development, including data from recent pilot and bench-scale demonstrations, collaborative industrial and academic partners, and published literature and patents. This pathway case investigates the feasibility of using whole wet microalgae as a feedstock for conversion via hydrothermal liquefaction. Technical barriers and key research needs have been assessed in order for the hydrothermal liquefaction of microalgae to be competitive with petroleum-derived gasoline, diesel and jet range blendstocks.

  2. Pathways: Strategies for Susceptibility Genes in SLE

    Science.gov (United States)

    Kelley, James M.; Edberg, Jeffrey C.; Kimberly, Robert P.

    2010-01-01

    Systemic lupus erythematosus (SLE) is a complex autoimmune disorder marked by an inappropriate immune response to nuclear antigens. Recent whole genome association and more focused studies have revealed numerous genes implicated in this disease process, including ITGAM, Fc gamma receptors, complement components, C-reactive protein, and others. One common feature of these molecules is their involvement in the immune opsonins pathway and phagocytic clearing of nuclear antigens and apoptotic debris which provide excessive exposure of lupus-related antigens to immune cells. Analysis of gene-gene interactions in the opsonin pathway and its relationship to SLE may provide a systems-based approach to identify additional candidate genes associated with disease able to account for a larger part of lupus susceptibility. PMID:20144911

  3. The Competitiveness of Alternative Hydrogen Pathways

    DEFF Research Database (Denmark)

    Hansen, Anders Chr.

    to transport services and in market competitiveness and societal competitiveness. The major societal competitive advantage of hydrogen is its convertibility to electricity and from any other source of energy. This enables a flexible use of natural gas and primary electricity as transport fuels. The major......The paper surveys the literature on the competitiveness of alternative hydrogen pathways in the transport sector. The competitiveness of the alternative systems can be differentiated in the “well-to-tank (WtT)” and “tank-to-wheel (TtW)” sections of the pathway transforming primary energy...... advantage in market competitiveness is the energy efficiency of the fuel cell. This advantage is, however, to some extent balanced by the costs associated with conversion, transport, and storage. The balance between these factors required for market competitiveness is identified....

  4. Obesity-Induced Hypertension: Brain Signaling Pathways.

    Science.gov (United States)

    do Carmo, Jussara M; da Silva, Alexandre A; Wang, Zhen; Fang, Taolin; Aberdein, Nicola; de Lara Rodriguez, Cecilia E P; Hall, John E

    2016-07-01

    Obesity greatly increases the risk for cardiovascular, metabolic, and renal diseases and is one of the most significant and preventable causes of increased blood pressure (BP) in patients with essential hypertension. This review highlights recent advances in our understanding of central nervous system (CNS) signaling pathways that contribute to the etiology and pathogenesis of obesity-induced hypertension. We discuss the role of excess adiposity and activation of the brain leptin-melanocortin system in causing increased sympathetic activity in obesity. In addition, we highlight other potential brain mechanisms by which increased weight gain modulates metabolic and cardiovascular functions. Unraveling the CNS mechanisms responsible for increased sympathetic activation and hypertension and how circulating hormones activate brain signaling pathways to control BP offer potentially important therapeutic targets for obesity and hypertension. PMID:27262997

  5. Lung carcinoma signaling pathways activated by smoking

    Institute of Scientific and Technical Information of China (English)

    Jing Wen; Jian-Hua Fu; Wei Zhang; Ming Guo

    2011-01-01

    Lung cancer is the leading cause of cancer death in men and women worldwide, with over a million deaths annually. Tobacco smoke is the major etiologic risk factor for lung cancer in current or previous smokers and has been strongly related to certain types of lung cancer, such as small cell lung carcinoma and squamous cell lung carcinoma. In recent years, there has been an increased incidence of lung adenocarcinoma. This change is strongly associated with changes in smoking behavior and cigarette design. Carcinogens present in tobacco products and their intermediate metabolites can activate multiple signaling pathways that contribute to lung cancer carcinogenesis. In this review, we summarize the smoking-activated signaling pathways involved in lung cancer.

  6. Finding pathways between distant local minima

    Science.gov (United States)

    Carr, Joanne M.; Trygubenko, Semen A.; Wales, David J.

    2005-06-01

    We report a new algorithm for constructing pathways between local minima that involve a large number of intervening transition states on the potential energy surface. A significant improvement in efficiency has been achieved by changing the strategy for choosing successive pairs of local minima that serve as endpoints for the next search. We employ Dijkstra's algorithm [E. W. Dijkstra, Numer. Math. 1, 269 (1959)] to identify the "shortest" path corresponding to missing connections within an evolving database of local minima and the transition states that connect them. The metric employed to determine the shortest missing connection is a function of the minimized Euclidean distance. We present applications to the formation of buckminsterfullerene and to the folding of various biomolecules: the B1 domain of protein G, tryptophan zippers, and the villin headpiece subdomain. The corresponding pathways contain up to 163 transition states and will be used in future discrete path sampling calculations.

  7. Multiple Pathways Linking Racism to Health Outcomes

    OpenAIRE

    Harrell, Camara Jules P.; Burford, Tanisha I.; Cage, Brandi N.; Nelson, Travette McNair; Shearon, Sheronda; Thompson, Adrian; Green, Steven

    2011-01-01

    This commentary discusses advances in the conceptual understanding of racism and selected research findings in the social neurosciences. The traditional stress and coping model holds that racism constitutes a source of aversive experiences that, when perceived by the individual, eventually lead to poor health outcomes. Current evidence points to additional psychophysiological pathways linking facets of racist environments with physiological reactions that contribute to disease. The alternativ...

  8. Remixing as a Pathway to Computational Thinking

    OpenAIRE

    Dasgupta, Sayamindu; Hale, William; Monroy-Hernández, Andrés; Hill, Benjamin Mako

    2016-01-01

    Theorists and advocates of "remixing" have suggested that appropriation can act as a pathway for learning. We test this theory quantitatively using data from more than 2.4 million multimedia programming projects shared by more than 1 million users in the Scratch online community. First, we show that users who remix more often have larger repertoires of programming commands even after controlling for the numbers of projects and amount of code shared. Second, we show that exposure to computatio...

  9. Pathway and network analysis of cancer genomes

    DEFF Research Database (Denmark)

    Creixell, Pau; Reimand, Jueri; Haider, Syed;

    2015-01-01

    Genomic information on tumors from 50 cancer types cataloged by the International Cancer Genome Consortium (ICGC) shows that only a few well-studied driver genes are frequently mutated, in contrast to many infrequently mutated genes that may also contribute to tumor biology. Hence there has been...... large interest in developing pathway and network analysis methods that group genes and illuminate the processes involved. We provide an overview of these analysis techniques and show where they guide mechanistic and translational investigations....

  10. Regulatory pathways for vaccines for developing countries.

    OpenAIRE

    Milstien, Julie; Belgharbi, Lahouari

    2004-01-01

    Vaccines that are designed for use only in developing countries face regulatory hurdles that may restrict their use. There are two primary reasons for this: most regulatory authorities are set up to address regulation of products for use only within their jurisdictions and regulatory authorities in developing countries traditionally have been considered weak. Some options for regulatory pathways for such products have been identified: licensing in the country of manufacture, file review by th...

  11. Online treatment compliance checking for clinical pathways.

    Science.gov (United States)

    Huang, Zhengxing; Bao, Yurong; Dong, Wei; Lu, Xudong; Duan, Huilong

    2014-10-01

    Compliance checking for clinical pathways (CPs) is getting increasing attention in health-care organizations due to stricter requirements for cost control and treatment excellence. Many compliance measures have been proposed for treatment behavior inspection in CPs. However, most of them look at aggregated data seen from an external perspective, e.g. length of stay, cost, infection rate, etc., which may provide only a posterior impression of the overall conformance with the established CPs such that in-depth and in near real time checking on the compliance of the essential/critical treatment behaviors of CPs is limited. To provide clinicians real time insights into violations of the established CP specification and support online compliance checking, this article presents a semantic rule-based CP compliance checking system. In detail, we construct a CP ontology (CPO) model to provide a formal grounding of CP compliance checking. Using the proposed CPO, domain treatment constraints are modeled into Semantic Web Rule Language (SWRL) rules to specify the underlying treatment behaviors and their quantified temporal structure in a CP. The established SWRL rules are integrated with the CP workflow such that a series of applicable compliance checking and evaluation can be reminded and recommended during the pathway execution. The proposed approach can, therefore, provides a comprehensive compliance checking service as a paralleling activity to the patient treatment journey of a CP rather than an afterthought. The proposed approach is illustrated with a case study on the unstable angina clinical pathway implemented in the Cardiology Department of a Chinese hospital. The results demonstrate that the approach, as a feasible solution to provide near real time conformance checking of CPs, not only enables clinicians to uncover non-compliant treatment behaviors, but also empowers clinicians with the capability to make informed decisions when dealing with treatment compliance

  12. Isoprenoid Pathway And Neurological And Psychiatric Disorders

    Directory of Open Access Journals (Sweden)

    Ravikumar A

    1999-01-01

    Full Text Available The coexistence of neuronal degeneration, psychiatric manifestation, immune activation and malignant transformation has been documented in literature, suggesting a central dysfunction in the pathophysiology of these disorders. The isoprenoid pathway may be candidate in this respect, in view of the changes in the concentration of some products of this pathway in many of these disorders, however, no detailed study has been carried out in this respect. In view of this, a study was undertaken on the isoprenoid pathway in some of these disorders - primary generalized epilepsy, Parkinson’s disease (PD, schizophrenia, manic depressive psychosis (MDP, CNS glioma, multiple sclerosis, subacute sclerosing panencephalitis (SSPEand a familial group with familial coexistence of schizophrenia, PD, primary generalized epilepsy, malignant neoplasia, rheumatoid arthritis and syndrome-X over three generations. The following parameters were studied in the patients of these disorders as compared to age and sex matched control subjects - ubiquinone dolichol, digoxin, activity of HMG CoA reductase in the plasma and erthyorcyte membrane Na -K--ATpase. Increase in the activity of HMG CoA reductase and in the concentration of plasma digoxin and dolichol was observed in most of these cases. On the other hand, there was decrease in the concentration of plasma ubiquinone. Decrease in the activity of erythrocyte membrane Na-K- ATpase activity for which digoxin is an inhibitor was also observed in all the cases studied. These results indicate an upregulation of the isoprenoid pathway in the neurological and psychiatric disorders studied. The implications of this change is discussed in details.

  13. Loss of vision: imaging the visual pathways

    International Nuclear Information System (INIS)

    This is an overview of diseases presenting with visual impairment, which aims to provide an understanding of the anatomy and pathology of the visual pathways. It discusses the relevant clinical background and neuroimaging findings on CT and standard and advanced MRI of diseases affecting the globe; optic nerve/sheath complex; optic chiasm, tract and radiation; and visual cortex. The overview covers common tumours, trauma, inflammatory and vascular pathology, and conditions such as benign intracranial hypertension and posterior reversible leukoencephalopathy syndrome. (orig.)

  14. Targeting the Hedgehog Pathway in Pediatric Medulloblastoma

    OpenAIRE

    Sherri Y. Huang; Jer-Yen Yang

    2015-01-01

    Medulloblastoma (MB), a primitive neuroectomal tumor of the cerebellum, is the most common malignant pediatric brain tumor. The cause of MB is largely unknown, but aberrant activation of Hedgehog (Hh) pathway is responsible for ~30% of MB. Despite aggressive treatment with surgical resection, radiation and chemotherapy, 70%–80% of pediatric medulloblastoma cases can be controlled, but most treated patients suffer devastating side effects. Therefore, developing a new effective treatment strate...

  15. Insulin signaling pathways in lepidopteran steroidogenesis

    Directory of Open Access Journals (Sweden)

    Wendy eSmith

    2014-02-01

    Full Text Available Molting and metamorphosis are stimulated by the secretion of ecdysteroid hormones from the prothoracic glands. Insulin-like hormones have been found to enhance prothoracic gland activity, providing a mechanism to link molting to nutritional state. In silk moths (Bombyx mori, the prothoracic glands are directly stimulated by insulin and the insulin-like hormone bombyxin. Further, in Bombyx , the neuropeptide prothoracicotropic hormone (PTTH appears to act at least in part through the insulin-signaling pathway. In the prothoracic glands of Manduca sexta, while insulin stimulates the phosphorylation of the insulin receptor and Akt, neither insulin nor bombyxin II stimulate ecdysone secretion. Involvement of the insulin-signaling pathway in Manduca prothoracic glands was explored using two inhibitors of phosphatidylinositol-3-kinase (PI3K, LY294002 and wortmannin. PI3K inhibitors block the phosphorylation of Akt and 4EBP but have no effect on ecdysone secretion, or on the phosphorylation of the MAPkinase, ERK. Inhibitors that block phosphorylation of ERK, including the MEK inhibitor U0126, and high doses of the RSK inhibitor SL0101, effectively inhibit ecdysone secretion. The results highlight differences between the two lepidopteran insects most commonly used to directly study ecdysteroid secretion. In Bombyx, the PTTH and insulin-signaling pathways intersect; both insulin and PTTH enhance the phosphorylation of Akt and stimulate ecdysteroid secretion, and inhibition of PI3K reduces ecdysteroid secretion. By contrast, in Manduca, the action of PTTH is distinct from insulin. The results highlight species differences in the roles of translational regulators such as 4EBP, and members of the MAPkinase pathway such as ERK and RSK, in the effects of nutritionally-sensitive hormones such as insulin on ecdysone secretion and molting.

  16. BMP pathway regulation of and by macrophages.

    Directory of Open Access Journals (Sweden)

    Megha Talati

    Full Text Available Pulmonary arterial hypertension (PAH is a disease of progressively increasing pulmonary vascular resistance, associated with mutations of the type 2 receptor for the BMP pathway, BMPR2. The canonical signaling pathway for BMPR2 is through the SMAD family of transcription factors. BMPR2 is expressed in every cell type, but the impact of BMPR2 mutations affecting SMAD signaling, such as Bmpr2delx4+, had only previously been investigated in smooth muscle and endothelium. In the present study, we created a mouse with universal doxycycline-inducible expression of Bmpr2delx4+ in order to determine if broader expression had an impact relevant to the development of PAH. We found that the most obvious phenotype was a dramatic, but patchy, increase in pulmonary inflammation. We crossed these double transgenic mice onto an NF-κB reporter strain, and by luciferase assays on live mice, individual organs and isolated macrophages, we narrowed down the origin of the inflammatory phenotype to constitutive activation of tissue macrophages. Study of bone marrow-derived macrophages from mutant and wild-type mice suggested a baseline difference in differentiation state in Bmpr2 mutants. When activated with LPS, both mutant and wild-type macrophages secrete BMP pathway inhibitors sufficient to suppress BMP pathway activity in smooth muscle cells (SMC treated with conditioned media. Functionally, co-culture with macrophages results in a BMP signaling-dependent increase in scratch closure in cultured SMC. We conclude that SMAD signaling through BMP is responsible, in part, for preventing macrophage activation in both live animals and in cells in culture, and that activated macrophages secrete BMP inhibitors in sufficient quantity to cause paracrine effect on vascular smooth muscle.

  17. Three competitive dissociation pathways of glyoxalate

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Three possible lower barrier dissociation pathways of the deportonated glyoxylic acid in aqueous solution axe predicated by means of B3LYP and CCSD(T) (single-point) methods. The calculated results suggest that the formation of formate ion is the energetically most favorable process, and that the decomposition reaction is occurring through nucleophilic attack of negatively charged carboxylic oxygen on the a-carbon. This is in good agreement with the proposed mechanisms of the mass spectrometry experiment.

  18. Signaling Pathways Involved in Cardiac Hypertrophy

    Institute of Scientific and Technical Information of China (English)

    Tao Zewei; Li Longgui

    2006-01-01

    Cardiac hypertrophy is the heart's response to a variety of extrinsic and intrinsic stimuli that impose increased biomechanical stress.Traditionally, it has been considered a beneficial mechanism; however, sustained hypertrophy has been associated with a significant increase in the risk of cardiovascular disease and mortality. Delineating intracellular signaling pathways involved in the different aspects of cardiac hypertrophy will permit future improvements in potential targets for therapeutic intervention. Generally, there are two types of cardiac hypertrophies, adaptive hypertrophy, including eutrophy (normal growth) and physiological hypertrophy (growth induced by physical conditioning), and maladaptive hypertrophy, including pathologic or reactive hypertrophy (growth induced by pathologic stimuli) and hypertrophic growth caused by genetic mutations affecting sarcomeric or cytoskeletal proteins. Accumulating observations from animal models and human patients have identified a number of intracellular signaling pathways that characterized as important transducers of the hypertrophic response,including calcineurin/nuclear factor of activated Tcells, phosphoinositide 3-kinases/Akt (PI3Ks/Akt),G protein-coupled receptors, small G proteins,MAPK, PKCs, Gp130/STAT'3, Na+/H+ exchanger,peroxisome proliferator-activated receptors, myocyte enhancer factor 2/histone deacetylases, and many others. Furthermore, recent evidence suggests that adaptive cardiac hypertrophy is regulated in large part by the growth hormone/insulin-like growth factors axis via signaling through the PI3K/Akt pathway. In contrast, pathological or reactive hypertrophy is triggered by autocrine and paracrine neurohormonal factors released during biomechanical stress that signal through the Gq/phosphorlipase C pathway, leading to an increase in cytosolic calcium and activation of PKC.

  19. Rabies Virus-Induced Membrane Fusion Pathway

    OpenAIRE

    Gaudin, Yves

    2000-01-01

    Fusion of rabies virus with membranes is triggered at low pH and is mediated by the viral glycoprotein (G). The rabies virus-induced fusion pathway was studied by investigating the effects of exogenous lipids having various dynamic molecular shapes on the fusion process. Inverted cone-shaped lysophosphatidylcholines (LPCs) blocked fusion at a stage subsequent to fusion peptide insertion into the target membrane. Consistent with the stalk-hypothesis, LPC with shorter alkyl chains inhibited fus...

  20. Brain evolution by brain pathway duplication

    OpenAIRE

    Chakraborty, Mukta; Jarvis, Erich D

    2015-01-01

    Understanding the mechanisms of evolution of brain pathways for complex behaviours is still in its infancy. Making further advances requires a deeper understanding of brain homologies, novelties and analogies. It also requires an understanding of how adaptive genetic modifications lead to restructuring of the brain. Recent advances in genomic and molecular biology techniques applied to brain research have provided exciting insights into how complex behaviours are shaped by selection of novel ...

  1. Online treatment compliance checking for clinical pathways.

    Science.gov (United States)

    Huang, Zhengxing; Bao, Yurong; Dong, Wei; Lu, Xudong; Duan, Huilong

    2014-10-01

    Compliance checking for clinical pathways (CPs) is getting increasing attention in health-care organizations due to stricter requirements for cost control and treatment excellence. Many compliance measures have been proposed for treatment behavior inspection in CPs. However, most of them look at aggregated data seen from an external perspective, e.g. length of stay, cost, infection rate, etc., which may provide only a posterior impression of the overall conformance with the established CPs such that in-depth and in near real time checking on the compliance of the essential/critical treatment behaviors of CPs is limited. To provide clinicians real time insights into violations of the established CP specification and support online compliance checking, this article presents a semantic rule-based CP compliance checking system. In detail, we construct a CP ontology (CPO) model to provide a formal grounding of CP compliance checking. Using the proposed CPO, domain treatment constraints are modeled into Semantic Web Rule Language (SWRL) rules to specify the underlying treatment behaviors and their quantified temporal structure in a CP. The established SWRL rules are integrated with the CP workflow such that a series of applicable compliance checking and evaluation can be reminded and recommended during the pathway execution. The proposed approach can, therefore, provides a comprehensive compliance checking service as a paralleling activity to the patient treatment journey of a CP rather than an afterthought. The proposed approach is illustrated with a case study on the unstable angina clinical pathway implemented in the Cardiology Department of a Chinese hospital. The results demonstrate that the approach, as a feasible solution to provide near real time conformance checking of CPs, not only enables clinicians to uncover non-compliant treatment behaviors, but also empowers clinicians with the capability to make informed decisions when dealing with treatment compliance

  2. A case study in pathway knowledgebase verification

    Directory of Open Access Journals (Sweden)

    Shah Nigam H

    2006-04-01

    Full Text Available Abstract Background Biological databases and pathway knowledgebases are proliferating rapidly. We are developing software tools for computer-aided hypothesis design and evaluation, and we would like our tools to take advantage of the information stored in these repositories. But before we can reliably use a pathway knowledgebase as a data source, we need to proofread it to ensure that it can fully support computer-aided information integration and inference. Results We design a series of logical tests to detect potential problems we might encounter using a particular knowledgebase, the Reactome database, with a particular computer-aided hypothesis evaluation tool, HyBrow. We develop an explicit formal language from the language implicit in the Reactome data format and specify a logic to evaluate models expressed using this language. We use the formalism of finite model theory in this work. We then use this logic to formulate tests for desirable properties (such as completeness, consistency, and well-formedness for pathways stored in Reactome. We apply these tests to the publicly available Reactome releases (releases 10 through 14 and compare the results, which highlight Reactome's steady improvement in terms of decreasing inconsistencies. We also investigate and discuss Reactome's potential for supporting computer-aided inference tools. Conclusion The case study described in this work demonstrates that it is possible to use our model theory based approach to identify problems one might encounter using a knowledgebase to support hypothesis evaluation tools. The methodology we use is general and is in no way restricted to the specific knowledgebase employed in this case study. Future application of this methodology will enable us to compare pathway resources with respect to the generic properties such resources will need to possess if they are to support automated reasoning.

  3. Mathematical modeling of the Phoenix Rising pathway.

    Directory of Open Access Journals (Sweden)

    Chad Liu

    2014-02-01

    Full Text Available Apoptosis is a tightly controlled process in mammalian cells. It is important for embryogenesis, tissue homoeostasis, and cancer treatment. Apoptosis not only induces cell death, but also leads to the release of signals that promote rapid proliferation of surrounding cells through the Phoenix Rising (PR pathway. To quantitatively understand the kinetics of interactions of different molecules in this pathway, we developed a mathematical model to simulate the effects of various changes in the PR pathway on the secretion of prostaglandin E2 (PGE2, a key factor for promoting cell proliferation. These changes include activation of caspase 3 (C3, caspase 7 (C7, and nuclear factor κB (NFκB. In addition, we simulated the effects of cyclooxygenase-2 (COX2 inhibition and C3 knockout on the level of secreted PGE2. The model predictions on PGE2 in MEF and 4T1 cells at 48 hours after 10-Gray radiation were quantitatively consistent with the experimental data in the literature. Compared to C7, the model predicted that C3 activation was more critical for PGE2 production. The model also predicted that PGE2 production could be significantly reduced when COX2 expression was blocked via either NFκB inactivation or treatment of cells with exogenous COX2 inhibitors, which led to a decrease in the rate of conversion from arachidonic acid to prostaglandin H2 in the PR pathway. In conclusion, the mathematical model developed in this study yielded new insights into the process of tissue regrowth stimulated by signals from apoptotic cells. In future studies, the model can be used for experimental data analysis and assisting development of novel strategies/drugs for improving cancer treatment or normal tissue regeneration.

  4. Building pathway clusters from Random Forests classification using class votes

    Directory of Open Access Journals (Sweden)

    Zhao Hongyu

    2008-02-01

    Full Text Available Abstract Background Recent years have seen the development of various pathway-based methods for the analysis of microarray gene expression data. These approaches have the potential to bring biological insights into microarray studies. A variety of methods have been proposed to construct networks using gene expression data. Because individual pathways do not act in isolation, it is important to understand how different pathways coordinate to perform cellular functions. However, there are no published methods describing how to build pathway clusters that are closely related to traits of interest. Results We propose to build pathway clusters from pathway-based classification methods. The proposed methods allow researchers to identify clusters of pathways sharing similar functions. These pathways may or may not share genes. As an illustration, our approach is applied to three human breast cancer microarray data sets. We found that our methods yielded consistent and interpretable results for these three data sets. We further investigated one of the pathway clusters found using PubMatrix. We found that informative genes in the pathway clusters do have more publications with keywords, like estrogen receptor, compared with informative genes in other top pathways. In addition, using the shortest path analysis in GeneGo's MetaCore and Human Protein Reference Database, we were able to identify the links which connect the pathways without shared genes within the pathway cluster. Conclusion Our proposed pathway clustering methods allow bioinformaticians and biologists to investigate how informative genes within pathways are related to each other and understand possible crosstalk between pathways in a cluster. Therefore, building pathway clusters may lead to a better understanding of molecular mechanisms affecting a trait of interest, and help generate further biological hypotheses from gene expression data.

  5. Proton transfer pathways in Photosystem II

    Science.gov (United States)

    Ishikita, Hiroshi

    2014-03-01

    Using quantum mechanics/molecular mechanics calculations and the 1.9-Å crystal structure of Photosystem II (Umena, Y., Kawakami, K., Shen, J.-R., and Kamiya, N. (2011) Nature 473, 55-60), we investigated the H-bonding environment of the redox active tyrosine, TyrD and obtained insights that help explain its slow redox kinetics and the stability of TyrD radical. The water molecule distal to TyrD, 4 Å away from the phenolic O of TyrD (OTyrD) , corresponds to the presence of the tyrosyl radical state. The water molecule proximal to TyrD, in H-bonding distance to OTyrD, corresponds to the presence of the unoxidised tyrosine. The H+ released upon oxidation of TyrD is transferred to the proximal water, which shifts to the distal position, triggering a concerted proton transfer pathway involving D2-Arg180 and a series of waters, through which the proton reaches the aqueous phase at D2-His61. The water movement linked to the ejection of the proton from the hydrophobic environment near TyrD makes oxidation slow and quasi-irreversible, explaining the great stability of the TyrD radical. A symmetry-related proton pathway associated with TyrZ is pointed out and this is associated with one of the Cl- sites. This may represent a proton pathway functional in the water oxidation cycle.

  6. Pathways, Networks and Systems Medicine Conferences

    Energy Technology Data Exchange (ETDEWEB)

    Nadeau, Joseph H. [Pacific Northwest Research Institute

    2013-11-25

    The 6th Pathways, Networks and Systems Medicine Conference was held at the Minoa Palace Conference Center, Chania, Crete, Greece (16-21 June 2008). The Organizing Committee was composed of Joe Nadeau (CWRU, Cleveland), Rudi Balling (German Research Centre, Brauschweig), David Galas (Institute for Systems Biology, Seattle), Lee Hood (Institute for Systems Biology, Seattle), Diane Isonaka (Seattle), Fotis Kafatos (Imperial College, London), John Lambris (Univ. Pennsylvania, Philadelphia),Harris Lewin (Univ. of Indiana, Urbana-Champaign), Edison Liu (Genome Institute of Singapore, Singapore), and Shankar Subramaniam (Univ. California, San Diego). A total of 101 individuals from 21 countries participated in the conference: USA (48), Canada (5), France (5), Austria (4), Germany (3), Italy (3), UK (3), Greece (2), New Zealand (2), Singapore (2), Argentina (1), Australia (1), Cuba (1), Denmark (1), Japan (1), Mexico (1), Netherlands (1), Spain (1), Sweden (1), Switzerland (1). With respect to speakers, 29 were established faculty members and 13 were graduate students or postdoctoral fellows. With respect to gender representation, among speakers, 13 were female and 28 were male, and among all participants 43 were female and 58 were male. Program these included the following topics: Cancer Pathways and Networks (Day 1), Metabolic Disease Networks (Day 2), Day 3 ? Organs, Pathways and Stem Cells (Day 3), and Day 4 ? Inflammation, Immunity, Microbes and the Environment (Day 4). Proceedings of the Conference were not published.

  7. Targeting autophagic pathways for cancer drug discovery

    Institute of Scientific and Technical Information of China (English)

    Bo Liu; Jin-Ku Bao; Jin-Ming Yang; Yan Cheng

    2013-01-01

    Autophagy,an evolutionarily conserved lysosomal degradation process,has drawn an increasing amount of attention in recent years for its role in a variety of human diseases,such as cancer.Notably,autophagy plays an important role in regulating several survival and death signaling pathways that determine cell fate in cancer.To date,substantial evidence has demonstrated that some key autophagic mediators,such as autophagy-related genes (ATGs),PI3K,mTOR,p53,and Beclin-1,may play crucial roles in modulating autophagic activity in cancer initiation and progression.Because autophagy-modulating agents such as rapamycin and chloroquine have already been used clinically to treat cancer,it is conceivable that targeting autophagic pathways may provide a new opportunity for discovery and development of more novel cancer therapeutics.With a deeper understanding of the regulatory mechanisms governing autophagy,we will have a better opportunity to facilitate the exploitation of autophagy as a target for therapeutic intervention in cancer.This review discusses the current status of targeting autophagic pathways as a potential cancer therapy.

  8. Molecular Pathways: Targeting ATR in Cancer Therapy.

    Science.gov (United States)

    Karnitz, Larry M; Zou, Lee

    2015-11-01

    The human ATR gene encodes a kinase that is activated by DNA damage and replication stress as a central transducer of a checkpoint signaling pathway. Once activated, ATR phosphorylates multiple substrates, including the kinase Chk1, to regulate cell-cycle progression, replication fork stability, and DNA repair. These events promote cell survival during replication stress and in cells with DNA damage. Accordingly, there has been the tantalizing possibility that ATR inhibitors would be therapeutically useful, especially if they were more effective in tumor versus normal cells. Indeed, multiple studies have demonstrated that alterations that promote tumorigenesis, such as defects in the ATM-p53 pathway, constitutive oncogene activation, and acquisition of the alternative lengthening of telomeres pathway, render tumor cells sensitive to ATR inhibitor monotherapy and/or increase the synergy between ATR inhibitors and genotoxic chemotherapies. Now, nearly two decades after the discovery of ATR, two highly selective and potent ATR inhibitors, AZD6738 and VX-970, are in early-phase clinical trials either as monotherapies or paired with a variety of genotoxic chemotherapies. These trials will generate important insights into the effects of ATR inhibition in humans and the potential role of inhibiting this kinase in the treatment of human malignancies. PMID:26362996

  9. Purinergic signaling pathways in endocrine system.

    Science.gov (United States)

    Bjelobaba, Ivana; Janjic, Marija M; Stojilkovic, Stanko S

    2015-09-01

    Adenosine-5'-triphosphate is released by neuroendocrine, endocrine, and other cell types and acts as an extracellular agonist for ligand-gated P2X cationic channels and G protein-coupled P2Y receptors in numerous organs and tissues, including the endocrine system. The breakdown of ATP by ectonucleotidases not only terminates its extracellular messenger functions, but also provides a pathway for the generation of two additional agonists: adenosine 5'-diphosphate, acting via some P2Y receptors, and adenosine, a native agonist for G protein-coupled adenosine receptors, also expressed in the endocrine system. This article provides a review of purinergic signaling pathways in the hypothalamic magnocellular neurosecretory cells and neurohypophysis, hypothalamic parvocellular neuroendocrine system, adenohypophysis, and effector glands organized in five axes: hypothalamic-pituitary-gonadal, hypothalamic-pituitary-thyroid, hypothalamic-pituitary-adrenal, hypothalamic-pituitary-growth hormone, and hypothalamic-pituitary-prolactin. We attempted to summarize current knowledge of purinergic receptor subtypes expressed in the endocrine system, including their roles in intracellular signaling, hormone secretion, and other cell functions. We also briefly review the release mechanism for adenosine-5'-triphosphate by neuroendocrine, endocrine and surrounding cells, the enzymes involved in adenosine-5'-triphosphate hydrolysis to adenosine-5'-diphosphate and adenosine, and the relevance of this pathway for sequential activation of receptors and termination of signaling.

  10. Environmental pathways of radioactivity to man

    International Nuclear Information System (INIS)

    The report reviews and discusses the environmental pathways by which radioactive materials can lead to the irradiation of man, in a way that should be understood by non-specialists who have neither the time nor the knowledge to study all of the relevant literature on this subject. The role of these environmental pathways in the general structure of radiological protection is considered, and the various mechanisms which lead to the dispersion or re-concentration of radioactive materials are discussed at some length. Particular groups of radionuclides from the nuclear power industry are considered in some detail. Similarly the question of the corresponding pathways from naturally-occurring radioactive materials is covered. The doses to animals and plants resulting from the nuclear industry are examined, and it is concluded that there is no reason to expect that these doses will lead to significant harm. Finally a summary is presented, and it is noted that it has been possible to obtain a very extensive knowledge of the behaviour of radionuclides in the environment only because of the extreme sensitivity of the techniques available for their detection, identification and assay. As a result a fund of knowledge has been built up about the behaviour of radioactive materials in the environment which is far more extensive than our knowledge of the behaviour of many highly toxic chemicals which are also discharged into the environment. (UK)

  11. Alternative pathway for atmospheric particles growth.

    Science.gov (United States)

    Monge, Maria Eugenia; Rosenørn, Thomas; Favez, Olivier; Müller, Markus; Adler, Gabriela; Abo Riziq, Ali; Rudich, Yinon; Herrmann, Hartmut; George, Christian; D'Anna, Barbara

    2012-05-01

    Credible climate change predictions require reliable fundamental scientific knowledge of the underlying processes. Despite extensive observational data accumulated to date, atmospheric aerosols still pose key uncertainties in the understanding of Earth's radiative balance due to direct interaction with radiation and because they modify clouds' properties. Specifically, major gaps exist in the understanding of the physicochemical pathways that lead to aerosol growth in the atmosphere and to changes in their properties while in the atmosphere. Traditionally, the driving forces for particle growth are attributed to condensation of low vapor pressure species following atmospheric oxidation of volatile compounds by gaseous oxidants. The current study presents experimental evidence of an unaccounted-for new photoinduced pathway for particle growth. We show that heterogeneous reactions activated by light can lead to fast uptake of noncondensable Volatile Organic Compounds (VOCs) at the surface of particles when only traces of a photosensitizer are present in the seed aerosol. Under such conditions, size and mass increase; changes in the chemical composition of the aerosol are also observed upon exposure to volatile organic compounds such as terpenes and near-UV irradiation. Experimentally determined growth rate values match field observations, suggesting that this photochemical process can provide a new, unaccounted-for pathway for atmospheric particle growth and should be considered by models.

  12. Putative adverse outcome pathways relevant to neurotoxicity

    Science.gov (United States)

    Bal-Price, Anna; Crofton, Kevin M.; Sachana, Magdalini; Shafer, Timothy J.; Behl, Mamta; Forsby, Anna; Hargreaves, Alan; Landesmann, Brigitte; Lein, Pamela J.; Louisse, Jochem; Monnet-Tschudi, Florianne; Paini, Alicia; Rolaki, Alexandra; Schrattenholz, André; Suñol, Cristina; van Thriel, Christoph; Whelan, Maurice; Fritsche, Ellen

    2016-01-01

    The Adverse Outcome Pathway (AOP) framework provides a template that facilitates understanding of complex biological systems and the pathways of toxicity that result in adverse outcomes (AOs). The AOP starts with an molecular initiating event (MIE) in which a chemical interacts with a biological target(s), followed by a sequential series of KEs, which are cellular, anatomical, and/or functional changes in biological processes, that ultimately result in an AO manifest in individual organisms and populations. It has been developed as a tool for a knowledge-based safety assessment that relies on understanding mechanisms of toxicity, rather than simply observing its adverse outcome. A large number of cellular and molecular processes are known to be crucial to proper development and function of the central (CNS) and peripheral nervous systems (PNS). However, there are relatively few examples of well-documented pathways that include causally linked MIEs and KEs that result in adverse outcomes in the CNS or PNS. As a first step in applying the AOP framework to adverse health outcomes associated with exposure to exogenous neurotoxic substances, the EU Reference Laboratory for Alternatives to Animal Testing (EURL ECVAM) organized a workshop (March 2013, Ispra, Italy) to identify potential AOPs relevant to neurotoxic and developmental neurotoxic outcomes. Although the AOPs outlined during the workshop are not fully described, they could serve as a basis for further, more detailed AOP development and evaluation that could be useful to support human health risk assessment in a variety of ways. PMID:25605028

  13. Nonlinear fitness landscape of a molecular pathway.

    Directory of Open Access Journals (Sweden)

    Lilia Perfeito

    2011-07-01

    Full Text Available Genes are regulated because their expression involves a fitness cost to the organism. The production of proteins by transcription and translation is a well-known cost factor, but the enzymatic activity of the proteins produced can also reduce fitness, depending on the internal state and the environment of the cell. Here, we map the fitness costs of a key metabolic network, the lactose utilization pathway in Escherichia coli. We measure the growth of several regulatory lac operon mutants in different environments inducing expression of the lac genes. We find a strikingly nonlinear fitness landscape, which depends on the production rate and on the activity rate of the lac proteins. A simple fitness model of the lac pathway, based on elementary biophysical processes, predicts the growth rate of all observed strains. The nonlinearity of fitness is explained by a feedback loop: production and activity of the lac proteins reduce growth, but growth also affects the density of these molecules. This nonlinearity has important consequences for molecular function and evolution. It generates a cliff in the fitness landscape, beyond which populations cannot maintain growth. In viable populations, there is an expression barrier of the lac genes, which cannot be exceeded in any stationary growth process. Furthermore, the nonlinearity determines how the fitness of operon mutants depends on the inducer environment. We argue that fitness nonlinearities, expression barriers, and gene-environment interactions are generic features of fitness landscapes for metabolic pathways, and we discuss their implications for the evolution of regulation.

  14. Biochemical research elucidating metabolic pathways in Pneumocystis*

    Directory of Open Access Journals (Sweden)

    Kaneshiro E.S.

    2010-12-01

    Full Text Available Advances in sequencing the Pneumocystis carinii genome have helped identify potential metabolic pathways operative in the organism. Also, data from characterizing the biochemical and physiological nature of these organisms now allow elucidation of metabolic pathways as well as pose new challenges and questions that require additional experiments. These experiments are being performed despite the difficulty in doing experiments directly on this pathogen that has yet to be subcultured indefinitely and produce mass numbers of cells in vitro. This article reviews biochemical approaches that have provided insights into several Pneumocystis metabolic pathways. It focuses on 1 S-adenosyl-L-methionine (AdoMet; SAM, which is a ubiquitous participant in numerous cellular reactions; 2 sterols: focusing on oxidosqualene cyclase that forms lanosterol in P. carinii; SAM:sterol C-24 methyltransferase that adds methyl groups at the C-24 position of the sterol side chain; and sterol 14α-demethylase that removes a methyl group at the C-14 position of the sterol nucleus; and 3 synthesis of ubiquinone homologs, which play a pivotal role in mitochondrial inner membrane and other cellular membrane electron transport.

  15. Integrated GWAS and Pathway profiling for feed efficiency traits in pigs leads to novel genes and their molecular pathways

    DEFF Research Database (Denmark)

    Do, Duy Ngoc; Ostersen, Tage; Strathe, Anders Bjerring;

    2013-01-01

    in Database for Annotation, Visualization and Integrated Discovery (DAVID). Neuroactive ligand-receptor interaction, SNARE interactions in vesicular transport, pyruvate metabolism and Wnt signaling pathway were detected by using KEGG tools, growth hormone and phospholipase C signaling pathway were detected...... by using BioCarta pathway analysis tools and asynaptic_vesicle_trafficking and thyrotropin-releasing hormone receptor signaling pathways were identified by using Panther-pathway profiling tools. Several of these pathways such as Wnt, growth hormone and thyrotropin-releasing hormone receptor signaling...

  16. Integrated GWAS and Pathway profiling for feed efficiency traits in pigs leads to novel genes and their molecular pathways

    DEFF Research Database (Denmark)

    Do, Duy Ngoc; Ostersen, Tage; Strathe, Anders Bjerring;

    in Database for Annotation, Visualization and Integrated Discovery (DAVID). Neuroactive ligand-receptor interaction, SNARE interactions in vesicular transport, pyruvate metabolism and Wnt signaling pathway were detected by using KEGG tools, growth hormone and phospholipase C signaling pathway were detected...... by using BioCarta pathway analysis tools and asynaptic_vesicle_trafficking and thyrotropin-releasing hormone receptor signaling pathways were identified by using Panther-pathway profiling tools. Several of these pathways such as Wnt, growth hormone and thyrotropin-releasing hormone receptor signaling...

  17. The Smad pathway in transforming growth factor-β signaling

    Institute of Scientific and Technical Information of China (English)

    林海燕; 王红梅; 祝诚

    2003-01-01

    The Smad pathway is involved in transforming growth factor-β (TGF-β) signal transduction. The Smad complex binds with the promoter of target gene to modulate gene transcription. Various transcriptional coactivators and corepressors associate directly with Smads for appropriate binding of Smads to target promoters and regulation of Smads transcriptional activities. The ultimate degradation of Smads mediated by the ubiquitin-proteasome pathway (UPP) has been established as a mechanism to shut off the Smad pathway. In addition to the Smad pathway, TGF-β can also activate other signaling pathway such as the MAPK pathway. The cross-talk of the Smad pathway with other signaling pathways constitutes an important mechanism for the regulatory network of TGF-β Signaling.

  18. Sonic hedgehog-Gli1 pathway in colorectal adenocarcinomas

    OpenAIRE

    Bian, Yue-Hong; Huang, Shu-Hong; Yang, Ling; Ma, Xiao-Li; Xie, Jing-Wu; Zhang, Hong-Wei

    2007-01-01

    AIM: To determine the role of Sonic hedgehog (Shh) pathway in colorectal adenocarcinomas through analysis of the expression of Shh pathway-related molecules, Shh, Ptch1, hedgehog-interacting protein (Hip), Gli1, Gli3 and PDGFRα.

  19. Finding dominant transition pathways via global optimization of action

    CERN Document Server

    Lee, Juyong; Joung, InSuk; Lee, Jooyoung; Brooks, Bernard R

    2016-01-01

    We present a new computational approach, Action-CSA, to sample multiple reaction pathways with fixed initial and final states through global optimization of the Onsager-Machlup action using the conformational space annealing method. This approach successfully samples not only the most dominant pathway but also many other possible paths without initial guesses on reaction pathways. Pathway space is efficiently sampled by crossover operations of a set of paths and preserving the diversity of sampled pathways. The sampling ability of the approach is assessed by finding pathways for the conformational changes of alanine dipeptide and hexane. The benchmarks demonstrate that the rank order and the transition time distribution of multiple pathways identified by the new approach are in good agreement with those of long molecular dynamics simulations. We also show that the lowest action folding pathway of the mini-protein FSD-1 identified by the new approach is consistent with previous molecular dynamics simulations a...

  20. Teaching Biochemical Pathways Using Concept Maps

    Directory of Open Access Journals (Sweden)

    Simon Brown

    2013-08-01

    Full Text Available The interesting paper by Dinarvand and Vaisi-Raygan (1 makes valuable points about a particularly challenging aspect of biochemistry learning and teaching. Their work prompts me to ask two questions and make a comment. First, what do the authors mean by a concept map (CM? A pathway map could be considered a CM, but a CM could cover modes of regulation and kinetics in relation to particular reactions or pathways and there are many other possibilities. Irrespective of this, a CM can get extremely complex if more than a few concepts are involved (2, as can be seen in examples given by Novak (3. This is the fundamental problem of teaching and learning biochemistry (4, which combines the network of pathways, compartmentation, macromol¬ecular structure, regulation, kinetics and some fairly sophisticated chemical concepts.Second, how did the students go about preparing CMs? My experience is that students prefer to use a computer for most tasks, but standard CM software (5 may not be suitable. For example, they often struggle unnec¬essarily to use software to prepare a graphical summary of the structural features of a protein, its precursors and the gene encoding it. This distracts them from the material. My suggestions that pencil and paper might be sufficient are usually met with amazement. Third, as Dinarvand and Vaisi-Raygan (1 make clear, a coherent summary of the metabolism considered in a course in metabolic biochemistry is crucial if students are to appreciate the pathways and their interconn-ection and regulation. For many years I have used an approach in which students collaborate in tutorials to achieve this. The sessions are usually initiated by me drawing the plasma membrane and the mitochondrial membranes on a large board and inviting the students to fill in the blanks (I provide large sheets of paper so that students can make copies. With coaxing, someone volunteers and I explain that the volunteer is not alone because everyone is

  1. Evaluating pathway enumeration algorithms in metabolic engineering case studies

    OpenAIRE

    Liu, Filipe; Vilaça, Paulo; Rocha, I; Rocha, Miguel

    2014-01-01

    The design of cell factories for the production of compounds involves the search for suitable heterologous pathways. Different strategies have been proposed to infer such pathways, but most are optimization approaches with specific objective functions, not suited to enumerate multiple pathways. In this work, we analyze two pathway enumeration algorithms based on graph representations: the Solution Structure Generation and the Find Path algorithms. Both are capable of enumerating exhaustively ...

  2. Lethal Mutations in the Isoprenoid Pathway of Salmonella enterica

    OpenAIRE

    Cornish, Rita M.; Roth, John R.; Poulter, C. Dale

    2006-01-01

    Essential isoprenoid compounds are synthesized using the 2-C-methyl-d-erythritol 4-phosphate (MEP) pathway in many gram-negative bacteria, some gram-positive bacteria, some apicomplexan parasites, and plant chloroplasts. The alternative mevalonate pathway is found in archaea and eukaryotes, including cytosolic biosynthesis in plants. The existence of orthogonal essential pathways in eukaryotes and bacteria makes the MEP pathway an attractive target for the development of antimicrobial agents....

  3. Inherited variation in immune genes and pathways and glioblastoma risk

    OpenAIRE

    Schwartzbaum, Judith A.; Xiao, Yuanyuan; Liu, Yanhong; Tsavachidis, Spyros; Berger, Mitchel S.; Bondy, Melissa L,; Chang, Jeffrey S.; Chang, Susan M.; Decker, Paul A.; Ding, Bo; Hepworth, Sarah J; Richard S. Houlston; Hosking, Fay J; Jenkins, Robert B.; Kosel, Matthew L.

    2010-01-01

    To determine whether inherited variations in immune function single-nucleotide polymorphisms (SNPs), genes or pathways affect glioblastoma risk, we analyzed data from recent genome-wide association studies in conjunction with predefined immune function genes and pathways. Gene and pathway analyses were conducted on two independent data sets using 6629 SNPs in 911 genes on 17 immune pathways from 525 glioblastoma cases and 602 controls from the University of California, San Francisco (UCSF) an...

  4. The carotenoid biosynthetic pathway: thinking in all dimensions.

    Science.gov (United States)

    Shumskaya, Maria; Wurtzel, Eleanore T

    2013-07-01

    The carotenoid biosynthetic pathway serves manifold roles in plants related to photosynthesis, photoprotection, development, stress hormones, and various volatiles and signaling apocarotenoids. The pathway also produces compounds that impact human nutrition and metabolic products that contribute to fragrance and flavor of food and non-food crops. It is no surprise that the pathway has been a target of metabolic engineering, most prominently in the case of Golden Rice. The future success and predictability of metabolic engineering of carotenoids rests in the ability to target carotenoids for specific physiological purposes as well as to simultaneously modify carotenoids along with other desired traits. Here, we ask whether predictive metabolic engineering of the carotenoid pathway is indeed possible. Despite a long history of research on the pathway, at this point in time we can only describe the pathway as a parts list and have almost no knowledge of the location of the complete pathway, how it is assembled, and whether there exists any trafficking of the enzymes or the carotenoids themselves. We discuss the current state of knowledge regarding the "complete" pathway and make the argument that predictive metabolic engineering of the carotenoid pathway (and other pathways) will require investigation of the three dimensional state of the pathway as it may exist in plastids of different ultrastructures. Along with this message we point out the need to develop new types of visualization tools and resources that better reflect the dynamic nature of biosynthetic pathways. PMID:23683930

  5. Men's and Women's Pathways to Adulthood and Their Adolescent Precursors

    Science.gov (United States)

    Oesterle, Sabrina; Hawkins, J. David; Hill, Karl G.; Bailey, Jennifer A.

    2010-01-01

    This study compared men's and women's pathways to adulthood by examining how role transitions in education, work, marriage, and parenthood intersect and form developmental pathways from ages 18-30. The study investigated how sociodemographic factors and adolescent experiences were associated with these pathways. We used latent class analysis to…

  6. "Distal common pathway in atrioventricular node reentrant tachycardia "

    Directory of Open Access Journals (Sweden)

    "Moghaddam M

    2001-06-01

    Full Text Available Anotomical boundary of atrioventricular node reentrant tachycardia (AVNRT is composed of fast and slow pathways right atrium in upper turnaround and common distal pathway in lower turnaround. We performed electophsiologic study (EPS in 152 patients and could show the existence of distal common pathway with decremental conduction properties in approximately 40 patients.

  7. A Study of the PDGF Signaling Pathway with PRISM

    OpenAIRE

    Qixia Yuan; Jun Pang; Sjouke Mauw; Panuwat Trairatphisan; Monique Wiesinger; Thomas Sauter

    2011-01-01

    In this paper, we apply the probabilistic model checker PRISM to the analysis of a biological system -- the Platelet-Derived Growth Factor (PDGF) signaling pathway, demonstrating in detail how this pathway can be analyzed in PRISM. We show that quantitative verification can yield a better understanding of the PDGF signaling pathway.

  8. Development of Network Analysis and Visualization System for KEGG Pathways

    Directory of Open Access Journals (Sweden)

    Dongmin Seo

    2015-07-01

    Full Text Available Big data refers to informationalization technology for extracting valuable information through the use and analysis of large-scale data and, based on that data, deriving plans for response or predicting changes. With the development of software and devices for next generation sequencing, a vast amount of bioinformatics data has been generated recently. Also, bioinformatics data based big-data technology is rising rapidly as a core technology by the bioinformatician, biologist and big-data scientist. KEGG pathway is bioinformatics data for understanding high-level functions and utilities of the biological system. However, KEGG pathway analysis requires a lot of time and effort because KEGG pathways are high volume and very diverse. In this paper, we proposed a network analysis and visualization system that crawl user interest KEGG pathways, construct a pathway network based on a hierarchy structure of pathways and visualize relations and interactions of pathways by clustering and selecting core pathways from the network. Finally, we construct a pathway network collected by starting with an Alzheimer’s disease pathway and show the results on clustering and selecting core pathways from the pathway network.

  9. Pathways to nuclear disarmament:delegitimising nuclear violence

    OpenAIRE

    Ritchie, Nicholas Edward

    2016-01-01

    This paper explores pathways for diplomatic responses to the continuing threat of nuclear violence. It differentiates between pathways focussed on the devaluing of nuclear weapons by the nuclear-armed states and pathways focussed on delegitimising nuclear weapons by a wider community of states.

  10. Phosphoketolase pathway dominates in Lactobacillus reuteri ATCC 55730 containing dual pathways for glycolysis.

    Science.gov (United States)

    Arsköld, Emma; Lohmeier-Vogel, Elke; Cao, Rong; Roos, Stefan; Rådström, Peter; van Niel, Ed W J

    2008-01-01

    Metabolic flux analysis indicated that the heterofermentative Lactobacillus reuteri strain ATCC 55730 uses both the Embden-Meyerhof pathway (EMP) and phosphoketolase pathway (PKP) when glucose or sucrose is converted into the three-carbon intermediate stage of glycolysis. In all cases studied, the main flux is through the PKP, while the EMP is used as a shunt. In the exponential growth phase, 70%, 73%, and 84% of the flux goes through the PKP in cells metabolizing (i) glucose plus fructose, (ii) glucose alone, and (iii) sucrose alone, respectively. Analysis of the genome of L. reuteri ATCC 55730 confirmed the presence of the genes for both pathways. Further evidence for the simultaneous operation of two central carbon metabolic pathways was found through the detection of fructose-1,6-bisphosphate aldolase, phosphofructokinase, and phosphoglucoisomerase activities and the presence of phosphorylated EMP and PKP intermediates using in vitro 31P NMR. The maximum specific growth rate and biomass yield obtained on glucose were twice as low as on sucrose. This was the result of low ATP levels being present in glucose-metabolizing cells, although the ATP production flux was as high as in sucrose-metabolizing cells due to a twofold increase of enzyme activities in both glycolytic pathways. Growth performance on glucose could be improved by adding fructose as an external electron acceptor, suggesting that the observed behavior is due to a redox imbalance causing energy starvation. PMID:17965151

  11. Development and Implementation of Oncology Care Pathways in an Integrated Care Network: The Via Oncology Pathways Experience

    OpenAIRE

    Ellis, Peter G.

    2013-01-01

    The Via Pathways model used at the UPMC CancerCenter, in which the oncologists developing the clinical content are ultimately those who use the pathways portal, has proven to be successful in ensuring physician participation.

  12. pathways to deep decarbonization - 2014 report

    International Nuclear Information System (INIS)

    The Deep Decarbonization Pathways Project (DDPP) is a collaborative initiative to understand and show how individual countries can transition to a low-carbon economy and how the world can meet the internationally agreed target of limiting the increase in global mean surface temperature to less than 2 degrees Celsius (deg. C). Achieving the 2 deg. C limit will require that global net emissions of greenhouse gases (GHG) approach zero by the second half of the century. This will require a profound transformation of energy systems by mid-century through steep declines in carbon intensity in all sectors of the economy, a transition we call 'deep decarbonization.' Successfully transition to a low-carbon economy will require unprecedented global cooperation, including a global cooperative effort to accelerate the development and diffusion of some key low carbon technologies. As underscored throughout this report, the results of the DDPP analyses remain preliminary and incomplete. The DDPP proceeds in two phases. This 2014 report describes the DDPP's approach to deep decarbonization at the country level and presents preliminary findings on technically feasible pathways to deep decarbonization, utilizing technology assumptions and timelines provided by the DDPP Secretariat. At this stage we have not yet considered the economic and social costs and benefits of deep decarbonization, which will be the topic for the next report. The DDPP is issuing this 2014 report to the UN Secretary-General Ban Ki-moon in support of the Climate Leaders' Summit at the United Nations on September 23, 2014. This 2014 report by the Deep Decarbonization Pathway Project (DDPP) summarizes preliminary findings of the technical pathways developed by the DDPP Country Research Partners with the objective of achieving emission reductions consistent with limiting global warming to less than 2 deg. C., without, at this stage, consideration of economic and social costs and benefits. The DDPP is a knowledge

  13. Nutrient shortage triggers the hexosamine biosynthetic pathway via the GCN2-ATF4 signalling pathway.

    Science.gov (United States)

    Chaveroux, Cédric; Sarcinelli, Carmen; Barbet, Virginie; Belfeki, Sofiane; Barthelaix, Audrey; Ferraro-Peyret, Carole; Lebecque, Serge; Renno, Toufic; Bruhat, Alain; Fafournoux, Pierre; Manié, Serge N

    2016-06-03

    The hexosamine biosynthetic pathway (HBP) is a nutrient-sensing metabolic pathway that produces the activated amino sugar UDP-N-acetylglucosamine, a critical substrate for protein glycosylation. Despite its biological significance, little is known about the regulation of HBP flux during nutrient limitation. Here, we report that amino acid or glucose shortage increase GFAT1 production, the first and rate-limiting enzyme of the HBP. GFAT1 is a transcriptional target of the activating transcription factor 4 (ATF4) induced by the GCN2-eIF2α signalling pathway. The increased production of GFAT1 stimulates HBP flux and results in an increase in O-linked β-N-acetylglucosamine protein modifications. Taken together, these findings demonstrate that ATF4 provides a link between nutritional stress and the HBP for the regulation of the O-GlcNAcylation-dependent cellular signalling.

  14. Notch, Wnt, and Hedgehog Pathways in Rhabdomyosarcoma: From Single Pathways to an Integrated Network

    Directory of Open Access Journals (Sweden)

    Josep Roma

    2012-01-01

    Full Text Available Rhabdomyosarcoma (RMS is the most common type of soft tissue sarcoma in children. Regarding histopathological criteria, RMS can be divided into 2 main subtypes: embryonal and alveolar. These subtypes differ considerably in their clinical phenotype and molecular features. Abnormal regulation or mutation of signalling pathways that regulate normal embryonic development such as Notch, Hedgehog, and Wnt is a recurrent feature in tumorigenesis. Herein, the general features of each of the three pathways, their implication in cancer and particularly in RMS are reviewed. Finally, the cross-talking among these three pathways and the possibility of better understanding of the horizontal communication among them, leading to the development of more potent therapeutic approaches, are discussed.

  15. Policy Pathways: Modernising Building Energy Codes

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2013-08-01

    Buildings are the largest consumers of energy worldwide and will continue to be a source of increasing energy demand in the future. Globally, the sector’s final energy consumption doubled between 1971 and 2010 to reach 2 794 million tonnes of oil equivalent (Mtoe), driven primarily by population increase and economic growth. Under current policies, the global energy demand of buildings is projected by the IEA experts to grow by an additional 838 Mtoe by 2035 compared to 2010. The challenges of the projected increase of energy consumption due to the built environment vary by country. In IEA member countries, much of the future buildings stock is already in place, and so the main challenge is to renovate existing buildings stock. In non-IEA countries, more than half of the buildings stock needed by 2050 has yet to be built. The IEA and the UNDP partnered to analyse current practices in the design and implementation of building energy codes. The aim is to consolidate existing efforts and to encourage more attention to the role of the built environment in a low-carbon and climate-resilient world. This joint IEA-UNDP Policy Pathway aims to share lessons learned between IEA member countries and non-IEA countries. The objective is to spread best practices, limit pressures on global energy supply, improve energy security, and contribute to environmental sustainability. Part of the IEA Policy Pathway series, Modernising building energy codes to secure our global energy future sets out key steps in planning, implementation, monitoring and evaluation. The Policy Pathway series aims to help policy makers implement the IEA 25 Energy Efficiency Policy Recommendations endorsed by IEA Ministers (2011).

  16. Integrated care pathways and task shifting

    Directory of Open Access Journals (Sweden)

    Linda Panton

    2014-11-01

    Full Text Available Delivery of HIV care has evolved over the last 10 years, and nurse specialists are a driving force in developing new pathways to enhance patient care. Despite the continued rise in numbers of people living with HIV, the financial constraints on the NHS have unfortunately resulted in a reduction in service provision. Experienced nurses are integral to patient care management. They not only provide standardized care for stable patients, therefore increasing consultant capacity for the more complex medical patient, but have a degree of flexibility that allows newly diagnosed patients quick access to care and support. With a strong emphasis being placed on an integrated and collaborative multidisciplinary team approach, to ensure patients receive the same standard of care, Scotland's HIV centres follow an integrated care pathway. The nurse oversees the completion of this document and co-ordinates the pathway of care depending on the clinical need. Nurses develop and maintain necessary partnerships between primary care, specialist care, psychological services, social care and third sector support services. The nurse case load continues to expand and diversify. Stable patients may be maintained on therapy but are living with a stigmatized long-term chronic condition and rely on the nurse as a point of contact to access advice and support readily. The more chaotic and vulnerable clients with complex care needs require the nurse to co-ordinate their care, ensuring the appropriate agencies remain involved. Overseeing the transition of care to other units and tracing patients who are lost to follow up is also a necessity, as retention in care is paramount for the continued improvement in clinical outcomes. The contribution that specialist nurses make to the provision of HIV care is valuable and will continue to play a large role in the delivery of such care.

  17. DMPD: Multiple signaling pathways leading to the activation of interferon regulatoryfactor 3. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 12213596 Multiple signaling pathways leading to the activation of interferon regula...(.html) (.csml) Show Multiple signaling pathways leading to the activation of interferon regulatoryfactor 3.... PubmedID 12213596 Title Multiple signaling pathways leading to the activation of

  18. DMPD: Toll-like receptors. II. Distribution and pathways involved in TLR signalling. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 16419614 Toll-like receptors. II. Distribution and pathways involved in TLR signall...ceptors. II. Distribution and pathways involved in TLR signalling. PubmedID 16419614 Title Toll-like recepto...rs. II. Distribution and pathways involved in TLR signalling. Authors Sandor F, B

  19. DMPD: Dual role of oxidized LDL on the NF-kappaB signaling pathway. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 15346645 Dual role of oxidized LDL on the NF-kappaB signaling pathway. Robbesyn F, ... role of oxidized LDL on the NF-kappaB signaling pathway. PubmedID 15346645 Title Dual role of oxidized LDL ...on the NF-kappaB signaling pathway. Authors Robbesyn F, Salvayre R, Negre-Salvayr

  20. DMPD: The negative regulation of Toll-like receptor and associated pathways. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 17621314 The negative regulation of Toll-like receptor and associated pathways. Lan...) Show The negative regulation of Toll-like receptor and associated pathways. PubmedID 17621314 Title The ne...gative regulation of Toll-like receptor and associated pathways. Authors Lang T,