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Sample records for corticocollicular pathway mediates

  1. AAV-Mediated Anterograde Transsynaptic Tagging: Mapping Corticocollicular Input-Defined Neural Pathways for Defense Behaviors.

    Science.gov (United States)

    Zingg, Brian; Chou, Xiao-Lin; Zhang, Zheng-Gang; Mesik, Lukas; Liang, Feixue; Tao, Huizhong Whit; Zhang, Li I

    2017-01-04

    To decipher neural circuits underlying brain functions, viral tracers are widely applied to map input and output connectivity of neuronal populations. Despite the successful application of retrograde transsynaptic viruses for identifying presynaptic neurons of transduced neurons, analogous anterograde transsynaptic tools for tagging postsynaptically targeted neurons remain under development. Here, we discovered that adeno-associated viruses (AAV1 and AAV9) exhibit anterograde transsynaptic spread properties. AAV1-Cre from transduced presynaptic neurons effectively and specifically drives Cre-dependent transgene expression in selected postsynaptic neuronal targets, thus allowing axonal tracing and functional manipulations of the latter input-defined neuronal population. Its application in superior colliculus (SC) reveals that SC neuron subpopulations receiving corticocollicular projections from auditory and visual cortex specifically drive flight and freezing, two different types of defense behavior, respectively. Together with an intersectional approach, AAV-mediated anterograde transsynaptic tagging can categorize neurons by their inputs and molecular identity, and allow forward screening of distinct functional neural pathways embedded in complex brain circuits. Copyright © 2017 Elsevier Inc. All rights reserved.

  2. Cancer cachexia: mediators, signaling, and metabolic pathways.

    Science.gov (United States)

    Fearon, Kenneth C H; Glass, David J; Guttridge, Denis C

    2012-08-08

    Cancer cachexia is characterized by a significant reduction in body weight resulting predominantly from loss of adipose tissue and skeletal muscle. Cachexia causes reduced cancer treatment tolerance and reduced quality and length of life, and remains an unmet medical need. Therapeutic progress has been impeded, in part, by the marked heterogeneity of mediators, signaling, and metabolic pathways both within and between model systems and the clinical syndrome. Recent progress in understanding conserved, molecular mechanisms of skeletal muscle atrophy/hypertrophy has provided a downstream platform for circumventing the variations and redundancy in upstream mediators and may ultimately translate into new targeted therapies. Copyright © 2012 Elsevier Inc. All rights reserved.

  3. Endocytic pathways mediating oligomeric Aβ42 neurotoxicity

    Directory of Open Access Journals (Sweden)

    Laxton Kevin

    2010-05-01

    Full Text Available Abstract Background One pathological hallmark of Alzheimer's disease (AD is amyloid plaques, composed primarily of amyloid-β peptide (Aβ. Over-production or diminished clearance of the 42 amino acid form of Aβ (Aβ42 in the brain leads to accumulation of soluble Aβ and plaque formation. Soluble oligomeric Aβ (oAβ has recently emerged to be as a likely proximal cause of AD. Results Here we demonstrate that endocytosis is critical in mediating oAβ42-induced neurotoxicity and intraneuronal accumulation of Aβ. Inhibition of clathrin function either with a pharmacological inhibitor, knock-down of clathrin heavy chain expression, or expression of the dominant-negative mutant of clathrin-assembly protein AP180 did not block oAβ42-induced neurotoxicity or intraneuronal accumulation of Aβ. However, inhibition of dynamin and RhoA by expression of dominant negative mutants reduced neurotoxicity and intraneuronal Aβ accumulation. Pharmacologic inhibition of the dynamin-mediated endocytic pathway by genistein also reduced neurotoxicity. Conclusions These data suggest that dynamin-mediated and RhoA-regulated endocytosis are integral steps for oligomeric Aβ42-induced neurotoxicity and intraneuronal Aβ accumulation.

  4. Triglyceride-mediated pathways and coronary disease

    DEFF Research Database (Denmark)

    Sarwar, Nadeem; Sandhu, Manjinder S; Ricketts, Sally L

    2010-01-01

    disease who had information about lipoprotein concentration and diameter obtained by nuclear magnetic resonance spectroscopy. FINDINGS: The minor allele frequency of -1131T>C was 8% (95% CI 7-9). -1131T>C was not significantly associated with several non-lipid risk factors or LDL cholesterol......BACKGROUND: Whether triglyceride-mediated pathways are causally relevant to coronary heart disease is uncertain. We studied a genetic variant that regulates triglyceride concentration to help judge likelihood of causality. METHODS: We assessed the -1131T>C (rs662799) promoter polymorphism...... of the apolipoprotein A5 (APOA5) gene in relation to triglyceride concentration, several other risk factors, and risk of coronary heart disease. We compared disease risk for genetically-raised triglyceride concentration (20,842 patients with coronary heart disease, 35,206 controls) with that recorded for equivalent...

  5. 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...hways mediating type I interferon gene expression. PubmedID 17904888 Title Signalling pathways...R, Slater L, Johnston SL. Microbes Infect. 2007 Sep;9(11):1245-51. Epub 2007 Jul 1. (.png) (.svg) (.html) (.csml) Show Signalling pat

  6. Dispositional optimism and sleep quality: a test of mediating pathways.

    Science.gov (United States)

    Uchino, Bert N; Cribbet, Matthew; de Grey, Robert G Kent; Cronan, Sierra; Trettevik, Ryan; Smith, Timothy W

    2017-04-01

    Dispositional optimism has been related to beneficial influences on physical health outcomes. However, its links to global sleep quality and the psychological mediators responsible for such associations are less studied. This study thus examined if trait optimism predicted global sleep quality, and if measures of subjective well-being were statistical mediators of such links. A community sample of 175 participants (93 men, 82 women) completed measures of trait optimism, depression, and life satisfaction. Global sleep quality was assessed using the Pittsburgh Sleep Quality Index. Results indicated that trait optimism was a strong predictor of better PSQI global sleep quality. Moreover, this association was mediated by depression and life satisfaction in both single and multiple mediator models. These results highlight the importance of optimism for the restorative process of sleep, as well as the utility of multiple mediator models in testing distinct psychological pathways.

  7. White matter pathways mediate parental effects on children's reading precursors.

    Science.gov (United States)

    Vandermosten, Maaike; Cuynen, Lieselore; Vanderauwera, Jolijn; Wouters, Jan; Ghesquière, Pol

    2017-10-01

    Previous studies have shown that the link between parental and offspring's reading is mediated by the cognitive system of the offspring, yet information about the mediating role of the neurobiological system is missing. This family study includes cognitive and diffusion MRI (dMRI) data collected in 71 pre-readers as well as parental reading and environmental data. Using sequential path analyses, which take into account the interrelationships between the different components, we observed mediating effects of the neurobiological system. More specifically, fathers' reading skills predicted reading of the child by operating through a child's left ventral white matter pathway. For mothers no clear mediating role of the neural system was observed. Given that our study involves children who have not yet learned to read and that environmental measures were taken into account, the paternal effect on a child's white matter pathway is unlikely to be only driven by environmental factors. Future intergenerational studies focusing on the genetic, neurobiological and cognitive level of parents and offspring will provide more insight in the relative contribution of parental environment and genes. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. Intergenerational continuity in parenting behavior: mediating pathways and child effects.

    Science.gov (United States)

    Neppl, Tricia K; Conger, Rand D; Scaramella, Laura V; Ontai, Lenna L

    2009-09-01

    This prospective, longitudinal investigation examined mechanisms proposed to explain continuities in parenting behavior across 2 generations (G1, G2). Data came from 187 G2 adults, their mothers (G1), and their children (G3). Prospective information regarding G2 was collected both during adolescence and early adulthood. G1 data were collected during G2's adolescence, and G3 data were generated during the preschool years. Assessments included both observational and self-report measures. The results indicated a direct relationship between G1 and G2 harsh parenting, and between G1 and G2 positive parenting. As predicted, specific mediators accounted for intergenerational continuity in particular types of parenting behavior. G2 externalizing behavior mediated the relationship between G1 and G2 harsh parenting, whereas G2 academic attainment mediated the relationship between G1 and G2 positive parenting. In addition, the hypothesized mediating pathways remained statistically significant after taking into account possible G2 effects on G1 parenting and G3 effects on G2 parenting.

  9. Frontal-Brainstem Pathways Mediating Placebo Effects on Social Rejection.

    Science.gov (United States)

    Koban, Leonie; Kross, Ethan; Woo, Choong-Wan; Ruzic, Luka; Wager, Tor D

    2017-03-29

    Placebo treatments can strongly affect clinical outcomes, but research on how they shape other life experiences and emotional well-being is in its infancy. We used fMRI in humans to examine placebo effects on a particularly impactful life experience, social pain elicited by a recent romantic rejection. We compared these effects with placebo effects on physical (heat) pain, which are thought to depend on pathways connecting prefrontal cortex and periaqueductal gray (PAG). Placebo treatment, compared with control, reduced both social and physical pain, and increased activity in the dorsolateral prefrontal cortex (dlPFC) in both modalities. Placebo further altered the relationship between affect and both dlPFC and PAG activity during social pain, and effects on behavior were mediated by a pathway connecting dlPFC to the PAG, building on recent work implicating opioidergic PAG activity in the regulation of social pain. These findings suggest that placebo treatments reduce emotional distress by altering affective representations in frontal-brainstem systems. SIGNIFICANCE STATEMENT Placebo effects are improvements due to expectations and the socio-medical context in which treatment takes place. Whereas they have been extensively studied in the context of somatic conditions such as pain, much less is known of how treatment expectations shape the emotional experience of other important stressors and life events. Here, we use brain imaging to show that placebo treatment reduces the painful feelings associated with a recent romantic rejection by recruiting a prefrontal-brainstem network and by shifting the relationship between brain activity and affect. Our findings suggest that this brain network may be important for nonspecific treatment effects across a wide range of therapeutic approaches and mental health conditions. Copyright © 2017 the authors 0270-6474/17/373621-11$15.00/0.

  10. The effect of chronic seaweed subsidies on herbivory: plant-mediated fertilization pathway overshadows lizard-mediated predator pathways.

    Science.gov (United States)

    Piovia-Scott, Jonah; Spiller, David A; Takimoto, Gaku; Yang, Louie H; Wright, Amber N; Schoener, Thomas W

    2013-08-01

    Flows of energy and materials link ecosystems worldwide and have important consequences for the structure of ecological communities. While these resource subsidies typically enter recipient food webs through multiple channels, most previous studies focussed on a single pathway of resource input. We used path analysis to evaluate multiple pathways connecting chronic marine resource inputs (in the form of seaweed deposits) and herbivory in a shoreline terrestrial ecosystem. We found statistical support for a fertilization effect (seaweed increased foliar nitrogen content, leading to greater herbivory) and a lizard numerical response effect (seaweed increased lizard densities, leading to reduced herbivory), but not for a lizard diet-shift effect (seaweed increased the proportion of marine-derived prey in lizard diets, but lizard diet was not strongly associated with herbivory). Greater seaweed abundance was associated with greater herbivory, and the fertilization effect was larger than the combined lizard effects. Thus, the bottom-up, plant-mediated effect of fertilization on herbivory overshadowed the top-down effects of lizard predators. These results, from unmanipulated shoreline plots with persistent differences in chronic seaweed deposition, differ from those of a previous experimental study of the short-term effects of a pulse of seaweed deposition: while the increase in herbivory in response to chronic seaweed deposition was due to the fertilization effect, the short-term increase in herbivory in response to a pulse of seaweed deposition was due to the lizard diet-shift effect. This contrast highlights the importance of the temporal pattern of resource inputs in determining the mechanism of community response to resource subsidies.

  11. DMPD: Signal transduction pathways mediated by the interaction of CpG DNA withToll-like receptor 9. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 14751759 Signal transduction pathways mediated by the interaction of CpG DNA withTo...;16(1):17-22. (.png) (.svg) (.html) (.csml) Show Signal transduction pathways mediated by the interaction of... CpG DNA withToll-like receptor 9. PubmedID 14751759 Title Signal transduction pathways

  12. Toll-Like Receptor Pathway as Mediator of Bisphosphonate Effects in Breast Cancer

    Science.gov (United States)

    2005-07-01

    receptors TLR4, TLR5 and TLR9 on the gastric epithelium in Helicobacter pylori infection. Clin Exp Immunol 136, 521-526. 10. Leifer, C.A., Kennedy...AD Award Number: W81XWH-04-1-0600 TITLE: Toll -Like Receptor Pathway’as Mediator of Bisphosphonate Effects in Breast Cancer PRINCIPAL INVESTIGATOR...2004 - 14 Jun 2005 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER Toll -Like Receptor Pathway as Mediator of Bisphosphonate Effects in Breast Cancer 5b

  13. Curcumin mediates anticancer effects by modulating multiple cell signaling pathways.

    Science.gov (United States)

    Kunnumakkara, Ajaikumar B; Bordoloi, Devivasha; Harsha, Choudhary; Banik, Kishore; Gupta, Subash C; Aggarwal, Bharat B

    2017-08-01

    Curcumin, a component of a spice native to India, was first isolated in 1815 by Vogel and Pelletier from the rhizomes of Curcuma longa (turmeric) and, subsequently, the chemical structure of curcumin as diferuloylmethane was reported by Milobedzka et al. [(1910) 43., 2163-2170]. Since then, this polyphenol has been shown to exhibit antioxidant, anti-inflammatory, anticancer, antiviral, antibacterial, and antifungal activities. The current review primarily focuses on the anticancer potential of curcumin through the modulation of multiple cell signaling pathways. Curcumin modulates diverse transcription factors, inflammatory cytokines, enzymes, kinases, growth factors, receptors, and various other proteins with an affinity ranging from the pM to the mM range. Furthermore, curcumin effectively regulates tumor cell growth via modulation of numerous cell signaling pathways and potentiates the effect of chemotherapeutic agents and radiation against cancer. Curcumin can interact with most of the targets that are modulated by FDA-approved drugs for cancer therapy. The focus of this review is to discuss the molecular basis for the anticancer activities of curcumin based on preclinical and clinical findings. © 2017 The Author(s). Published by Portland Press Limited on behalf of the Biochemical Society.

  14. The SCAP/SREBP Pathway: A Mediator of Hepatic Steatosis

    Directory of Open Access Journals (Sweden)

    Young-Ah Moon

    2017-01-01

    Full Text Available Nonalcoholic fatty liver disease (NAFLD is strongly associated with insulin resistance, obesity, and dyslipidemia. NAFLD encompasses a wide range of states from the simple accumulation of triglycerides in the hepatocytes to serious states accompanied by inflammation and fibrosis in the liver. De novo lipogenesis has been shown to be a significant factor in the development of hepatic steatosis in insulin-resistant states. Sterol regulatory element binding protein-1c (SREBP-1c is the main transcription factor that mediates the activation of lipogenesis, and SREBP cleavage activating protein (SCAP is required for the activation of SREBPs. Here, recent animal studies that suggest SCAP as a therapeutic target for hepatic steatosis and hypertriglyceridemia are discussed.

  15. Specificity in mediated pathways by anxiety symptoms linking adolescent stress profiles to depressive symptoms: Results of a moderated mediation approach.

    Science.gov (United States)

    Anyan, Frederick; Bizumic, Boris; Hjemdal, Odin

    2018-03-01

    We investigated the specificity in mediated pathways that separately link specific stress dimensions through anxiety to depressive symptoms and the protective utility of resilience. Thus, this study goes beyond lumping together potential mediating and moderating processes that can explain the relations between stress and (symptoms of) psychopathology and the buffering effect of resilience. Ghanaian adolescents between 13 and 17 years (female = 285; male = 244) completed the Adolescent Stress Questionnaire (ASQ), Spielberger State Anxiety Inventory (STAI), Short Mood Feeling Questionnaire (SMFQ) and the Resilience Scale for Adolescents (READ). Independent samples t-test, multivariate analysis of covariance with follow-up tests and moderated mediation analyses were performed. Evidences were found for specificity in the associations between dimensions of adolescent stressors and depressive symptoms independent of transient anxiety. Transient anxiety partly accounted for the indirect effects of eight stress dimensions on depressive symptoms. Except stress of school attendance and school/leisure conflict, resilience moderated the indirect effects of specific stress dimensions on depressive symptoms. Results suggested differences in how Ghanaian adolescents view the various stress dimensions, and mediated pathways associated with anxiety and depressive symptoms. Use of cross-sectional data does not show causal process and temporal changes over time. Findings support and clarify the specificity in the interrelations and mediated pathways among dimensions of adolescent stress, transient anxiety, and depressive symptoms. Conditional process analyses shows that resilience does not only buffer direct, but also indirect psychological adversities. Interventions for good mental health may focus on low resilience subgroups in specific stress dimensions while minimizing transient anxiety. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Identification of a Novel Gnao-Mediated Alternate Olfactory Signaling Pathway in Murine OSNs.

    Science.gov (United States)

    Scholz, Paul; Mohrhardt, Julia; Jansen, Fabian; Kalbe, Benjamin; Haering, Claudia; Klasen, Katharina; Hatt, Hanns; Osterloh, Sabrina

    2016-01-01

    It is generally agreed that in olfactory sensory neurons (OSNs), the binding of odorant molecules to their specific olfactory receptor (OR) triggers a cAMP-dependent signaling cascade, activating cyclic-nucleotide gated (CNG) channels. However, considerable controversy dating back more than 20 years has surrounded the question of whether alternate signaling plays a role in mammalian olfactory transduction. In this study, we demonstrate a specific alternate signaling pathway in Olfr73-expressing OSNs. Methylisoeugenol (MIEG) and at least one other known weak Olfr73 agonist (Raspberry Ketone) trigger a signaling cascade independent from the canonical pathway, leading to the depolarization of the cell. Interestingly, this pathway is mediated by Gnao activation, leading to Cl(-) efflux; however, the activation of adenylyl cyclase III (ACIII), the recruitment of Ca(2+) from extra-or intracellular stores, and phosphatidylinositol 3-kinase-dependent signaling (PI signaling) are not involved. Furthermore, we demonstrated that our newly identified pathway coexists with the canonical olfactory cAMP pathway in the same OSN and can be triggered by the same OR in a ligand-selective manner. We suggest that this pathway might reflect a mechanism for odor recognition predominantly used in early developmental stages before olfactory cAMP signaling is fully developed. Taken together, our findings support the existence of at least one odor-induced alternate signal transduction pathway in native OSNs mediated by Olfr73 in a ligand-selective manner.

  17. Identification of a novel Gnao-mediated alternate olfactory signaling pathway in murine OSNs

    Directory of Open Access Journals (Sweden)

    Paul eScholz

    2016-03-01

    Full Text Available It is generally agreed that in olfactory sensory neurons (OSNs, the binding of odorant molecules to their specific olfactory receptor (OR triggers a cAMP-dependent signaling cascade, activating cyclic-nucleotide gated (CNG channels. However, considerable controversy dating back more than 20 years has surrounded the question of whether alternate signaling plays a role in mammalian olfactory transduction. In this study, we demonstrate a specific alternate signaling pathway in Olfr73-expressing OSNs. Methylisoeugenol (MIEG and at least one other known weak Olfr73 agonist (Raspberry Ketone trigger a signaling cascade independent from the canonical pathway, leading to the depolarization of the cell. Interestingly, this pathway is mediated by Gnao activation, leading to Cl- efflux; however, the activation of adenylyl cyclase III (ACIII, the recruitment of Ca2+ from extra-or intracellular stores, and phosphatidylinositol 3-kinase-dependent signaling (PI signaling are not involved. Furthermore, we demonstrated that our newly identified pathway coexists with the canonical olfactory cAMP pathway in the same OSN and can be triggered by the same OR in a ligand-selective manner. We suggest that this pathway might reflect a mechanism for odor recognition predominantly used in early developmental stages before olfactory cAMP signaling is fully developed. Taken together, our findings support the existence of at least one odor-induced alternate signal transduction pathway in native OSNs mediated by Olfr73 in a ligand-selective manner.

  18. Epistatic role of base excision repair and mismatch repair pathways in mediating cisplatin cytotoxicity

    Science.gov (United States)

    Kothandapani, Anbarasi; Sawant, Akshada; Dangeti, Venkata Srinivas Mohan Nimai; Sobol, Robert W.; Patrick, Steve M.

    2013-01-01

    Base excision repair (BER) and mismatch repair (MMR) pathways play an important role in modulating cis-Diamminedichloroplatinum (II) (cisplatin) cytotoxicity. In this article, we identified a novel mechanistic role of both BER and MMR pathways in mediating cellular responses to cisplatin treatment. Cells defective in BER or MMR display a cisplatin-resistant phenotype. Targeting both BER and MMR pathways resulted in no additional resistance to cisplatin, suggesting that BER and MMR play epistatic roles in mediating cisplatin cytotoxicity. Using a DNA Polymerase β (Polβ) variant deficient in polymerase activity (D256A), we demonstrate that MMR acts downstream of BER and is dependent on the polymerase activity of Polβ in mediating cisplatin cytotoxicity. MSH2 preferentially binds a cisplatin interstrand cross-link (ICL) DNA substrate containing a mismatch compared with a cisplatin ICL substrate without a mismatch, suggesting a novel mutagenic role of Polβ in activating MMR in response to cisplatin. Collectively, these results provide the first mechanistic model for BER and MMR functioning within the same pathway to mediate cisplatin sensitivity via non-productive ICL processing. In this model, MMR participation in non-productive cisplatin ICL processing is downstream of BER processing and dependent on Polβ misincorporation at cisplatin ICL sites, which results in persistent cisplatin ICLs and sensitivity to cisplatin. PMID:23761438

  19. Triglyceride-mediated pathways and coronary disease: collaborative analysis of 101 studies

    NARCIS (Netherlands)

    Sarwar, Nadeem; Sandhu, Manjinder S.; Ricketts, Sally L.; Butterworth, Adam S.; Di Angelantonio, Emanuele; Boekholdt, S. Matthijs; Ouwehand, Willem; Watkins, Hugh; Samani, Nilesh J.; Saleheen, Danish; Lawlor, Debbie; Reilly, Muredach P.; Hingorani, Aroon D.; Talmud, Philippa J.; Danesh, John; Braund, P. S.; Hall, A. S.; Samani, N. J.; Thompson, J.; März, W.; Ouwehand, W.; Sivapalaratnam, S.; Soranzo, N.; Trip, M.; Lawlor, D. A.; Casas, J. P.; Ebrahim, S.; Arsenault, B. J.; Khaw, K. T.; Ricketts, S. L.; Sandhu, M. S.; Wareham, N. J.; Grallert, H.; Illig, T.; Humphries, S. E.; Talmud, Talmud; Rader, D. J.; He, J.; Reilly, M. P.; Clarke, R.; Hamsten, A.; Hopewell, J. C.; Watkins, H.; Saleheen, D.; Frossard, P.; Deloukas, P.; Danesh, J.; Ye, S.; Simpson, I. A.; Onat, A.; Kömürcü-Bayrak, E.; Martinelli, N.; Olivieri, O.; Girelli, D.; Hingorani, A. D.; Kivimäki, M.; Kumari, M.; Aouizerat, B. E.; Baum, L.; Campos, H.; Chaaba, R.; Chen, B. S.; Cho, E. Y.; Evans, D.; Hill, J.; Hsu, L. A.; Hubacek, J. A.; Lai, C. Q.; Lee, J. H.; Klos, K.; Liu, H.; Masana, L.; Melegh, B.; Nabika, T.; Ribalta, J.; Ruiz-Narvaez, E.; Thomas, G. N.; Tomlinson, B.; Szalai, C.; Vaverkova, H.; Yamada, Y.; Yang, Y.; Kastelein, J. J.; Tipping, R. W.; Ford, C. E.; Pressel, S. L.; Ballantyne, C.; Brautbar, A.; Knuiman, M.; Whincup, P. H.; Wannamethee, S. G.; Morris, R. W.; Kiechl, S.; Willeit, J.; Santer, P.; Mayr, A.; Wald, N.; Yarnell, J. W. G.; Gallacher, J.; Casiglia, E.; Tikhonoff, V.; Cushman, M.; Psaty, B. M.; Tracy, R. P.; Tybjaerg-Hansen, A.; Nordestgaard, B. G.; Benn, M.; Frikke-Schmidt, R.; Giampaoli, S.; Palmieri, L.; Panico, S.; Vanuzzo, D.; Pilotto, L.; de la Cámara, A. Gómez; Gómez-Gerique, J. A.; Simons, L.; McCallum, J.; Friedlander, Y.; Fowkes, F. G. R.; Lee, A. J.; Taylor, J.; Guralnik, J. M.; Phillips, C. L.; Wallace, R.; Blazer, D. G.; Khaw, K.-T.; Brenner, H.; Raum, E.; Müller, H.; Rothenbacher, D.; Jansson, J. H.; Wennberg, P.; Nissinen, A.; Donfrancesco, C.; Salomaa, V.; Harald, K.; Jousilahti, P.; Vartiainen, E.; D'Agostino, R. B.; Vasan, R. S.; Pencina, M. J.; Bladbjerg, E. M.; Jørgensen, T.; Møller, L.; Jespersen, J.; Dankner, R.; Chetrit, A.; Lubin, F.; Björkelund, C.; Lissner, L.; Bengtsson, C.; Cremer, P.; Nagel, D.; Rodriguez, B.; Dekker, J. M.; Nijpels, G.; Stehouwer, C. D. A.; Sato, S.; Iso, H.; Kitamura, A.; Noda, H.; Salonen, J. T.; Nyyssönen, K.; Tuomainen, T.-P.; Voutilainen, S.; Meade, T. W.; Cooper, J. A.; Kuller, L. H.; Grandits, G.; Gillum, R.; Mussolino, M.; Rimm, E.; Hankinson, S.; Manson, J. A. E.; Pai, J. K.; Bauer, K. A.; Naito, Y.; Amouyel, P.; Arveiler, D.; Evans, A.; Ferrières, J.; Schulte, H.; Assmann, G.; Packard, C. J.; Sattar, N.; Westendorp, R. G.; Buckley, B. M.; Cantin, B.; Lamarche, B.; Després, J.-P.; Dagenais, G. R.; Barrett-Connor, E.; Wingard, D. L.; Bettencourt, R.; Gudnason, V.; Aspelund, T.; Sigurdsson, G.; Thorsson, B.; Trevisan, M.; Tunstall-Pedoe, H.; Tavendale, R.; Lowe, G. D. O.; Woodward, M.; Howard, B. V.; Zhang, Y.; Best, L.; Umans, J.; Ben-Shlomo, Y.; Davey-Smith, G.; Njølstad, I.; Mathiesen, E. B.; Løchen, M. L.; Wilsgaard, T.; Ingelsson, E.; Lind, L.; Giedraitis, V.; Michaëlsson, K.; Brunner, E.; Shipley, M.; Ridker, P.; Buring, J.; Shepherd, J.; Cobbe, S. M.; Ford, I.; Robertson, M.; Ibañez, A. Marin; Feskens, E. J. M.; Kromhout, D.; Walker, M.; Watson, S.; Collins, R.; Di Angelantonio, E.; Kaptoge, S.; Perry, P. L.; Sarwar, N.; Thompson, A.; Thompson, S. G.; White, I. R.; Wood, A. M.

    2010-01-01

    BACKGROUND: Whether triglyceride-mediated pathways are causally relevant to coronary heart disease is uncertain. We studied a genetic variant that regulates triglyceride concentration to help judge likelihood of causality. METHODS: We assessed the -1131T>C (rs662799) promoter polymorphism of the

  20. Ficolin-3-mediated lectin complement pathway activation in patients with subarachnoid hemorrhage

    DEFF Research Database (Denmark)

    Zanier, Elisa R; Zangari, Rosalia; Munthe-Fog, Lea

    2014-01-01

    OBJECTIVES: To assess the involvement of ficolin-3, the main initiator of the lectin complement pathway (LCP), in subarachnoid hemorrhage (SAH) pathology and outcome. METHODS: In this preliminary exploratory study, plasma concentration of ficolin-3 and of ficolin-3-mediated functional LCP activity...

  1. EVIDENCE FOR EGFR PATHWAY MEDIATION OF CLEFT PALATE INDUCTION BY TCDD

    Science.gov (United States)

    EVIDENCE FOR EGFR PATHWAY MEDIATION OF CLEFT PALATE INDUCTION BY TCDD. B D Abbott, A R Buckalew, and K E Leffler. RTD, NHEERL, ORD,US EPA, RTP, NC, USA.2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) is teratogenic in C57BL/6J mice, producing cleft palate (CP) after exposure...

  2. Roles of TRAFs in NF-κB signaling pathways mediated by BAFF.

    Science.gov (United States)

    Tang, Xiaoyu; Zhang, Lingling; Wei, Wei

    2018-04-01

    B cell activating factor (BAFF) is an important cytokine for the maintenance of B cell development, survival and homeostasis. BAFF/BAFF-R could directly activate nuclear factor kappa B (NF-κB) pathway. Tumour necrosis factor receptor-associated factors (TRAFs) are key regulatory proteins in NF-κB signaling pathways. TRAF1 enhances the activation of tumor necrosis factor receptor 2 (TNF-R2) induced by NF-κB. TRAF2 and TRAF3 signal adapters act cooperatively to control the maturation and survival signals mediated by BAFF receptor. TRAF5 is most homologous to TRAF3, as well as most functionally similar to TRAF2. TRAF6 is also required for the BAFF-mediated activation of NF-κB signal pathway. TRAF7 is involved in signal transduction pathways that lead either to activation or repression of NF-κB transcription factor. In this article, we reviewed the roles of TRAFs in NF-κB signaling pathway mediated by BAFF. Copyright © 2018 European Federation of Immunological Societies. Published by Elsevier B.V. All rights reserved.

  3. Syndecans promote integrin-mediated adhesion of mesenchymal cells in two distinct pathways

    DEFF Research Database (Denmark)

    Whiteford, James; Behrends, Volker; Kirby, Hishani

    2007-01-01

    and signaling through the cytoplasmic domain of syndecan-4. Here an alternate pathway mediated by the extracellular domains of syndecans-2 and -4 is characterized that is independent of both heparan sulphate and syndecan signaling. This pathway is restricted to mesenchymal cells and was not seen in any...... epithelial cell line tested, apart from vascular endothelia. The syndecan ectodomains coated as substrates promoted integrin-dependent attachment, spreading and focal adhesion formation. Syndecan-4 null cells were competent, as were fibroblasts compromised in heparan sulphate synthesis that were unable...... to form focal adhesions in response to fibronectin. Consistent with actin cytoskeleton organization, the process required Rho-GTP and Rho kinase. While syndecan-2 and -4 ectodomains could both promote integrin-mediated adhesion, their pathways were distinct, as shown by competition assays. Evidence...

  4. Acetylcholine produces contraction mediated by cyclooxigenase pathway in arterial vessels in the marine fish (Isacia conceptionis

    Directory of Open Access Journals (Sweden)

    FA. Moraga

    Full Text Available Preliminary studies showed that dorsal artery contraction mediated by acetylcholine (ACh is blocked with indomethacin in intertidal fish (G. laevifrons. Our objective was to characterize the cholinergic pathway in several artery vessels of the I. conceptionis. Afferent and efferent branchial, dorsal and mesenteric arteries were dissected of 6 juvenile specimens, isometric tension studies were done using doses response curves (DRC for Ach (10–13 to 10–3 M, and cholinergic pathways were obtained by blocking with atropine or indomethacin. CRC to ACh showed a pattern of high sensitivity only in efferente branchial artery and low sensibility in all vessels. Furthermore, these contractions were blocked in the presence of atropine and indomethacin in all vessels. Our results corroborate previous results observed in intertidal species that contraction induced by acetylcholine is mediated by receptors that activate a cyclooxygenase contraction pathway.

  5. Therapeutic Potential of IL-17-Mediated Signaling Pathway in Autoimmune Liver Diseases

    Science.gov (United States)

    Zhang, Haiyan; Bernuzzi, Francesca; Lleo, Ana; Ma, Xiong; Invernizzi, Pietro

    2015-01-01

    Emerging evidence reveals that various cytokines and tissue microenvironments contribute to liver inflammation and autoimmunity, and IL-17 family is one of highlights acknowledged. Although the implication of IL-17 family in most common autoimmune diseases (such as psoriasis, inflammatory bowel disease, and rheumatoid arthritis) has been extensively characterized, the role of this critical family in pathophysiology of autoimmune liver diseases (AILD) still needs to be clarified. In the review, we look into the intriguing biology of IL-17 family and further dissect on the intricate role of IL-17-mediated pathway in AILD. Considering encouraging data from preclinical and clinical trials, IL-17 targeted therapy has shown promises in several certain autoimmune conditions. However, blocking IL-17-mediated pathway is just beginning, and more fully investigation and reflection are required. Taking together, targeting IL-17-mediated responses may open up new areas of potential clinical treatment for AILD. PMID:26146463

  6. Transmissible gastroenteritis virus infection induces apoptosis through FasL- and mitochondria-mediated pathways.

    Science.gov (United States)

    Ding, Li; Xu, Xingang; Huang, Yong; Li, Zhaocai; Zhang, Kuan; Chen, Guangda; Yu, Gaoshui; Wang, Zhisheng; Li, Wei; Tong, Dewen

    2012-07-06

    Transmissible gastroenteritis virus (TGEV) has been reported to induce apoptosis in swine testis (ST) cells. However, the mechanisms underlying TGEV-induced apoptosis are still unclear. In this study we observed that TGEV infection induced apoptosis in porcine kidney (PK-15) cells in a time- and dose-dependent manner. TGEV infection up-regulated FasL, activated FasL-mediated apoptotic pathway, leading to activation of caspase-8 and cleavage of Bid. In addition, TGEV infection down-regulated Bcl-2, up-regulated Bax expression, promoted translocation of Bax to mitochondria, activated mitochondria-mediated apoptotic pathway, which in turn caused the release of cytochrome c and the activation of caspase-9. Both extrinsic and intrinsic pathways activated downstream effector caspase-3, followed by the cleavage of PARP, resulting in cell apoptosis. Moreover, TGEV infection did not induce significant DNA fragmentation in ammonium chloride (NH(4)Cl) pretreated PK-15 cells or cells infected with UV-inactivated TGEV. In turn, block of caspases activation also did not affect TGEV replication. Taken together, this study demonstrates that TGEV-induced apoptosis is dependent on viral replication in PK-15 cells and occurs through activation of FasL- and mitochondria-mediated apoptotic pathways. Copyright © 2012 Elsevier B.V. All rights reserved.

  7. Assessing mediation of behavioral and stress pathways in the association between neighborhood environments and obesity outcomes

    Directory of Open Access Journals (Sweden)

    Samaah M. Sullivan

    2016-12-01

    Full Text Available Although many studies have reported associations between characteristics of the neighborhood environment and obesity, little is understood about the pathways or mechanisms through which these associations operate. The purpose of this study was to examine possible behavioral and stress pathways hypothesized to mediate the association between neighborhood environments and obesity and whether pathways contribute to different obesity outcomes. Cross-sectional data were used from the 2012–2014 Women and Their Children's Health Study (WaTCH in Louisiana (N = 909. Participants' neighborhoods, body mass index (BMI and waist circumference (WC were objectively measured. The causal inference approach to mediation analysis was used to obtain indirect estimates for self-reported measures of physical activity, low access to food, and depression. The mean BMI was 32.0 kg/m2 and the mean WC was 98.6 cm. The (adverse neighborhood environment was significantly associated BMI (β = 0.17 kg/m2; 95% Confidence Interval (CI: 0.03, 0.31 and WC (β = 0.64; 95% CI: 0.34, 0.95, after adjusting for covariates. Neither depression, physical activity, nor low food access mediated those associations. Further research that investigates and uses better measures of the behavioral and stress pathways through which the neighborhood environment influences obesity is warranted.

  8. Transcription Profiles Reveal Sugar and Hormone Signaling Pathways Mediating Flower Induction in Apple (Malus domestica Borkh.).

    Science.gov (United States)

    Xing, Li-Bo; Zhang, Dong; Li, You-Mei; Shen, Ya-Wen; Zhao, Cai-Ping; Ma, Juan-Juan; An, Na; Han, Ming-Yu

    2015-10-01

    Flower induction in apple (Malus domestica Borkh.) is regulated by complex gene networks that involve multiple signal pathways to ensure flower bud formation in the next year, but the molecular determinants of apple flower induction are still unknown. In this research, transcriptomic profiles from differentiating buds allowed us to identify genes potentially involved in signaling pathways that mediate the regulatory mechanisms of flower induction. A hypothetical model for this regulatory mechanism was obtained by analysis of the available transcriptomic data, suggesting that sugar-, hormone- and flowering-related genes, as well as those involved in cell-cycle induction, participated in the apple flower induction process. Sugar levels and metabolism-related gene expression profiles revealed that sucrose is the initiation signal in flower induction. Complex hormone regulatory networks involved in cytokinin (CK), abscisic acid (ABA) and gibberellic acid pathways also induce apple flower formation. CK plays a key role in the regulation of cell formation and differentiation, and in affecting flowering-related gene expression levels during these processes. Meanwhile, ABA levels and ABA-related gene expression levels gradually increased, as did those of sugar metabolism-related genes, in developing buds, indicating that ABA signals regulate apple flower induction by participating in the sugar-mediated flowering pathway. Furthermore, changes in sugar and starch deposition levels in buds can be affected by ABA content and the expression of the genes involved in the ABA signaling pathway. Thus, multiple pathways, which are mainly mediated by crosstalk between sugar and hormone signals, regulate the molecular network involved in bud growth and flower induction in apple trees. © The Author 2015. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists.

  9. Bisphenol-A Mediated Inhibition of Hippocampal Neurogenesis Attenuated by Curcumin via Canonical Wnt Pathway.

    Science.gov (United States)

    Tiwari, Shashi Kant; Agarwal, Swati; Tripathi, Anurag; Chaturvedi, Rajnish Kumar

    2016-07-01

    Bisphenol A (BPA) is an environmental xenoestrogenic endocrine disruptor, utilized for production of consumer products, and exerts adverse effects on the developing nervous system. Recently, we found that BPA impairs the finely tuned dynamic processes of neurogenesis (generation of new neurons) in the hippocampus of the developing rat brain. Curcumin is a natural polyphenolic compound, which provides neuroprotection against various environmental neurotoxicants and in the cellular and animal models of neurodegenerative disorders. Here, we have assessed the neuroprotective efficacy of curcumin against BPA-mediated reduced neurogenesis and the underlying cellular and molecular mechanism(s). Both in vitro and in vivo studies showed that curcumin protects against BPA-induced hippocampal neurotoxicity. Curcumin protects against BPA-mediated reduced neural stem cells (NSC) proliferation and neuronal differentiation and enhanced neurodegeneration. Curcumin also enhances the expression/levels of neurogenic and the Wnt pathway genes/proteins, which were reduced due to BPA exposure in the hippocampus. Curcumin-mediated neuroprotection against BPA-induced neurotoxicity involved activation of the Wnt/β-catenin signaling pathway, which was confirmed by the use of Wnt specific activators (LiCl and GSK-3β siRNA) and inhibitor (Dkk-1). BPA-mediated increased β-catenin phosphorylation, decreased GSK-3β levels, and β-catenin nuclear translocation were significantly reversed by curcumin, leading to enhanced neurogenesis. Curcumin-induced protective effects on neurogenesis were blocked by Dkk-1 in NSC culture treated with BPA. Curcumin-mediated enhanced neurogenesis was correlated well with improved learning and memory in BPA-treated rats. Overall, our results conclude that curcumin provides neuroprotection against BPA-mediated impaired neurogenesis via activation of the Wnt/β-catenin signaling pathway.

  10. Therapeutic implications of chemokine-mediated pathways in atherosclerosis: realistic perspectives and utopias.

    Science.gov (United States)

    Apostolakis, Stavros; Amanatidou, Virginia; Spandidos, Demetrios A

    2010-09-01

    Current perspectives on the pathogenesis of atherosclerosis strongly support the involvement of inflammatory mediators in the establishment and progression of atherosclerostic lesions. Chemokine-mediated mechanisms are potent regulators of such processes by orchestrating the interactions of inflammatory cellular components of the peripheral blood with cellular components of the arterial wall. The increasing evidence supporting the role of chemokine pathways in atherosclerosis renders chemokine ligands and their receptors potential therapeutic targets. In the following review, we aim to highlight the special structural and functional features of chemokines and their receptors in respect to their roles in atherosclerosis, and examine to what extent available data can be applied in disease management practices.

  11. Early induction of NRF2 antioxidant pathway by RHBDF2 mediates rapid cutaneous wound healing.

    Science.gov (United States)

    Hosur, Vishnu; Burzenski, Lisa M; Stearns, Timothy M; Farley, Michelle L; Sundberg, John P; Wiles, Michael V; Shultz, Leonard D

    2017-04-01

    Rhomboid family protein RHBDF2, an upstream regulator of the epidermal growth factor (EGF) receptor signaling, has been implicated in cutaneous wound healing. However, the underlying molecular mechanisms are still emerging. In humans, a gain-of-function mutation in the RHBDF2 gene accelerates cutaneous wound healing in an EGFR-dependent manner. Likewise, a gain-of-function mutation in the mouse Rhbdf2 gene (Rhbdf2 cub/cub ) shows a regenerative phenotype (rapid ear-hole closure) resulting from constitutive activation of the EGFR pathway. Because the RHBDF2-regulated EGFR pathway is relevant to cutaneous wound healing in humans, we used Rhbdf2 cub/cub mice to investigate the biological networks and pathways leading to accelerated ear-hole closure, with the goal of identifying therapeutic targets potentially effective in promoting wound healing in humans. Comparative transcriptome analysis of ear pinna tissue from Rhbdf2 cub/cub and Rhbdf2 +/+ mice at 0h, 15min, 2h, and 24h post-wounding revealed an early induction of the nuclear factor E2-related factor 2 (NRF2)-mediated anti-oxidative pathway (0h and 15min), followed by the integrin-receptor aggregation pathway (2h) as early-stage events immediately and shortly after wounding in Rhbdf2 cub/cub mice. Additionally, we observed genes enriched for the Fc fragment of the IgG receptor IIIa (FCGR3A)-mediated phagocytosis pathway 24h post-wounding. Although cutaneous wound repair in healthy individuals is generally non-problematic, it can be severely impaired due to aging, diabetes, and chronic inflammation. This study suggests that activation of the NRF2-antioxidant pathway by rhomboid protein RHBDF2 might be beneficial in treating chronic non-healing wounds. Copyright © 2017 Elsevier Inc. All rights reserved.

  12. Integrated genomics identifies convergence of ankylosing spondylitis with global immune mediated disease pathways.

    Science.gov (United States)

    Uddin, Mohammed; Codner, Dianne; Hasan, S M Mahmud; Scherer, Stephen W; O'Rielly, Darren D; Rahman, Proton

    2015-05-18

    Ankylosing spondylitis(AS), a highly heritable complex inflammatory arthritis. Although, a handful of non-HLA risk loci have been identified, capturing the unexplained genetic contribution to AS pathogenesis remains a challenge attributed to additive, pleiotropic and epistatic-interactions at the molecular level. Here, we developed multiple integrated genomic approaches to quantify molecular convergence of non-HLA loci with global immune mediated diseases. We show that non-HLA genes are significantly sensitive to deleterious mutation accumulation in the general population compared with tolerant genes. Human developmental proteomics (prenatal to adult) analysis revealed that proteins encoded by non-HLA AS risk loci are 2-fold more expressed in adult hematopoietic cells.Enrichment analysis revealed AS risk genes overlap with a significant number of immune related pathways (p pathways with other immune mediated diseases. This information will be pivotal to fully explain AS pathogenesis and identify new therapeutic targets.

  13. Neddylation inhibits CtIP-mediated resection and regulates DNA double strand break repair pathway choice.

    Science.gov (United States)

    Jimeno, Sonia; Fernández-Ávila, María Jesús; Cruz-García, Andrés; Cepeda-García, Cristina; Gómez-Cabello, Daniel; Huertas, Pablo

    2015-01-01

    DNA double strand breaks are the most cytotoxic lesions that can occur on the DNA. They can be repaired by different mechanisms and optimal survival requires a tight control between them. Here we uncover protein deneddylation as a major controller of repair pathway choice. Neddylation inhibition changes the normal repair profile toward an increase on homologous recombination. Indeed, RNF111/UBE2M-mediated neddylation acts as an inhibitor of BRCA1 and CtIP-mediated DNA end resection, a key process in repair pathway choice. By controlling the length of ssDNA produced during DNA resection, protein neddylation not only affects the choice between NHEJ and homologous recombination but also controls the balance between different recombination subpathways. Thus, protein neddylation status has a great impact in the way cells respond to DNA breaks. © The Author(s) 2015. Published by Oxford University Press on behalf of Nucleic Acids Research.

  14. Simultaneous modulation of the intrinsic and extrinsic pathways by simvastatin in mediating prostate cancer cell apoptosis

    International Nuclear Information System (INIS)

    Goc, Anna; Kochuparambil, Samith T; Al-Husein, Belal; Al-Azayzih, Ahmad; Mohammad, Shuaib; Somanath, Payaningal R

    2012-01-01

    Recent studies suggest the potential benefits of statins as anti-cancer agents. Mechanisms by which statins induce apoptosis in cancer cells are not clear. We previously showed that simvastatin inhibit prostate cancer cell functions and tumor growth. Molecular mechanisms by which simvastatin induce apoptosis in prostate cancer cells is not completely understood. Effect of simvastatin on PC3 cell apoptosis was compared with docetaxel using apoptosis, TUNEL and trypan blue viability assays. Protein expression of major candidates of the intrinsic pathway downstream of simvastatin-mediated Akt inactivation was analyzed. Gene arrays and western analysis of PC3 cells and tumor lysates were performed to identify the candidate genes mediating extrinsic apoptosis pathway by simvastatin. Data indicated that simvastatin inhibited intrinsic cell survival pathway in PC3 cells by enhancing phosphorylation of Bad, reducing the protein expression of Bcl-2, Bcl-xL and cleaved caspases 9/3. Over-expression of PC3 cells with Bcl-2 or DN-caspase 9 did not rescue the simvastatin-induced apoptosis. Simvastatin treatment resulted in increased mRNA and protein expression of molecules such as TNF, Fas-L, Traf1 and cleaved caspase 8, major mediators of intrinsic apoptosis pathway and reduced protein levels of pro-survival genes Lhx4 and Nme5. Our study provides the first report that simvastatin simultaneously modulates intrinsic and extrinsic pathways in the regulation of prostate cancer cell apoptosis in vitro and in vivo, and render reasonable optimism that statins could become an attractive anti-cancer agent

  15. The role of the TOR pathway in mediating the link between nutrition and longevity.

    Science.gov (United States)

    Lushchak, Oleh; Strilbytska, Olha; Piskovatska, Veronika; Storey, Kenneth B; Koliada, Alexander; Vaiserman, Alexander

    2017-06-01

    The target of rapamycin (TOR) pathway integrates signals from extracellular and intracellular agents, such as growth factors, nutrients, mediators of energy balance, oxygen availability and other environmental cues. It allows the regulation of multiple cellular processes including protein and lipid synthesis, ribosome biogenesis, autophagy and metabolic processes. Being conserved across different phyla, TOR regulates longevity of various organisms in response to dietary conditions. In this review we described the main components of the TOR pathway and its upstream effectors and downstream processes in relation to aging. The potential contribution of the TOR pathway in lifespan-extending effects of varied dietary interventions, and the anti-aging drugs rapamycin and metformin direct or indirect regulation of TOR activity in yeasts, worms, flies and mammals are also discussed. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. The JNK pathway is a key mediator of Anopheles gambiae antiplasmodial immunity.

    Directory of Open Access Journals (Sweden)

    Lindsey S Garver

    Full Text Available The innate immune system of Anopheles gambiae mosquitoes limits Plasmodium infection through multiple molecular mechanisms. For example, midgut invasion by the parasite triggers an epithelial nitration response that promotes activation of the complement-like system. We found that suppression of the JNK pathway, by silencing either Hep, JNK, Jun or Fos expression, greatly enhanced Plasmodium infection; while overactivating this cascade, by silencing the suppressor Puckered, had the opposite effect. The JNK pathway limits infection via two coordinated responses. It induces the expression of two enzymes (HPx2 and NOX5 that potentiate midgut epithelial nitration in response to Plasmodium infection and regulates expression of two key hemocyte-derived immune effectors (TEP1 and FBN9. Furthermore, the An. gambiae L3-5 strain that has been genetically selected to be refractory (R to Plasmodium infection exhibits constitutive overexpression of genes from the JNK pathway, as well as midgut and hemocyte effector genes. Silencing experiments confirmed that this cascade mediates, to a large extent, the drastic parasite elimination phenotype characteristic of this mosquito strain. In sum, these studies revealed the JNK pathway as a key regulator of the ability of An. gambiae mosquitoes to limit Plasmodium infection and identified several effector genes mediating these responses.

  17. How Social Participation Benefits the Chronically Ill: Self-Management as a Mediating Pathway.

    Science.gov (United States)

    Ang, Shannon

    2018-03-01

    Few studies have tested the purported causal mechanisms between social participation and health, especially among those in poor health. This study aimed to determine whether self-management of chronic disease operates as a pathway through which social participation affects health-related quality of life. I utilized causal mediation analysis among 600 low-income older Singaporeans living with chronic conditions, to test whether self-management mediates the association between social participation and health-related quality of life. Results show that self-management fully mediated the positive effect of informal social participation on health-related quality of life. Formal social participation was found to have a negative direct effect on health-related quality of life. These findings reiterate the primacy of family and friends for older adults, but highlight that a better understanding of formal engagement with the low-income population is still needed.

  18. Reverse endocytosis of transmembrane ephrin-B ligands via a clathrin-mediated pathway

    International Nuclear Information System (INIS)

    Parker, Monica; Roberts, Richard; Enriquez, Miriam; Zhao Xia; Takahashi, Takamune; Pat Cerretti, Douglas; Daniel, Tom; Chen Jin

    2004-01-01

    Eph/ephrin receptors and ligands mediate cell-cell interaction through reciprocal signaling upon juxtacrine contact, and play a critical role in embryonic patterning, neuronal targeting, and vascular assembly. To study transmembrane ephrin-B ligand trafficking, we determined the cellular localization of ephrin-B1-GFP upon engagement by EphB1. Under normal culture conditions ephrin-B1-GFP is localized to the plasma membrane, mostly at the lateral cell borders. Addition of soluble EphB1-Fc receptor induces ephrin-B1-GFP clustering on the cell surface and subsequent internalization, as judged by biochemical studies, electron microscopy, and co-localization with endosomal markers. A dominant-negative mutant of dynamin or potassium depletion blocks ephrin-B1 endocytosis. These results suggest that ephrin-B1 internalization is an active receptor-mediated process that utilizes the clathrin-mediated endocytic pathway

  19. Pathway Linking Internet Health Information Seeking to Better Health: A Moderated Mediation Study.

    Science.gov (United States)

    Jiang, Shaohai; Street, Richard L

    2017-08-01

    The Internet increasingly has been recognized as an important medium with respect to population health. However, little is known about the mechanisms that underlie the potential impact of health-related Internet use on health outcomes. Based on the three-stage model of health promotion using interactive media, this study empirically tested a moderated mediation pathway model. Results showed that the effect of Internet health information seeking on three health outcomes (general, emotional, and physical) was completely mediated by respondents' access to social support resources. In addition, users' online health information seeking experience positively moderated this mediation path. The findings have significant theoretical and practical implications for the design of Internet-based health promotion resources to improve health outcomes.

  20. Dihydroartemisinin induces apoptosis preferentially via a Bim-mediated intrinsic pathway in hepatocarcinoma cells.

    Science.gov (United States)

    Qin, Guiqi; Zhao, ChuBiao; Zhang, Lili; Liu, Hongyu; Quan, Yingyao; Chai, Liuying; Wu, Shengnan; Wang, Xiaoping; Chen, Tongsheng

    2015-08-01

    This report is designed to dissect the detail molecular mechanism by which dihydroartemisinin (DHA), a derivative of artemisinin, induces apoptosis in human hepatocellular carcinoma (HCC) cells. DHA induced a loss of the mitochondrial transmemberane potential (ΔΨm), release of cytochrome c, activation of caspases, and externalization of phosphatidylserine indicative of apoptosis induction. Compared with the modest inhibitory effects of silencing Bax, silencing Bak largely prevented DHA-induced ΔΨm collapse and apoptosis though DHA induced a commensurable activation of Bax and Bak, demonstrating a key role of the Bak-mediated intrinsic apoptosis pathway. DHA did not induce Bid cleavage and translocation from cytoplasm to mitochondria and had little effects on the expressions of Puma and Noxa, but did increase Bim and Bak expressions and decrease Mcl-1 expression. Furthermore, the cytotoxicity of DHA was remarkably reduced by silencing Bim, and modestly but significantly reduced by silencing Puma or Noxa. Silencing Bim or Noxa preferentially reduced DHA-induced Bak activation, while silencing Puma preferentially reduced DHA-induced Bax activation, demonstrating that Bim and to a lesser extent Noxa act as upstream mediators to trigger the Bak-mediated intrinsic apoptosis pathway. In addition, silencing Mcl-1 enhanced DHA-induced Bak activation and apoptosis. Taken together, our data demonstrate a crucial role of Bim in preferentially regulating the Bak/Mcl-1 rheostat to mediate DHA-induced apoptosis in HCC cells.

  1. Infectious Entry Pathway Mediated by the Human Endogenous Retrovirus K Envelope Protein.

    Science.gov (United States)

    Robinson, Lindsey R; Whelan, Sean P J

    2016-01-20

    Endogenous retroviruses (ERVs), the majority of which exist as degraded remnants of ancient viruses, comprise approximately 8% of the human genome. The youngest human ERVs (HERVs) belong to the HERV-K(HML-2) subgroup and were endogenized within the past 1 million years. The viral envelope protein (ENV) facilitates the earliest events of endogenization (cellular attachment and entry), and here, we characterize the requirements for HERV-K ENV to mediate infectious cell entry. Cell-cell fusion assays indicate that a minimum of two events are required for fusion, proteolytic processing by furin-like proteases and exposure to acidic pH. We generated an infectious autonomously replicating recombinant vesicular stomatitis virus (VSV) in which the glycoprotein was replaced by HERV-K ENV. HERV-K ENV imparts an endocytic entry pathway that requires dynamin-mediated membrane scission and endosomal acidification but is distinct from clathrin-dependent or macropinocytic uptake pathways. The lack of impediments to the replication of the VSV core in eukaryotic cells allowed us to broadly survey the HERV-K ENV-dictated tropism. Unlike extant betaretroviral envelopes, which impart a narrow species tropism, we found that HERV-K ENV mediates broad tropism encompassing cells from multiple mammalian and nonmammalian species. We conclude that HERV-K ENV dictates an evolutionarily conserved entry pathway and that the restriction of HERV-K to primate genomes reflects downstream stages of the viral replication cycle. Approximately 8% of the human genome is of retroviral origin. While many of those viral genomes have become inactivated, some copies of the most recently endogenized human retrovirus, HERV-K, can encode individual functional proteins. Here, we characterize the envelope protein (ENV) of the virus to define how it mediates infection of cells. We demonstrate that HERV-K ENV undergoes a proteolytic processing step and triggers membrane fusion in response to acidic pH--a strategy

  2. miR2Pathway: A Novel Analytical Method to Discover MicroRNA-mediated Dysregulated Pathways Involved in Hepatocellular Carcinoma.

    Science.gov (United States)

    Li, Chaoxing; Dinu, Valentin

    2018-03-22

    MicroRNAs (miRNAs) are small, non-coding RNAs involved in the regulation of gene expression at a post-transcriptional level. Recent studies have shown miRNAs as key regulators of a variety of biological processes, such as proliferation, differentiation, apoptosis, metabolism, etc. Aberrantly expressed miRNAs influence individual gene expression level, but rewired miRNA-mRNA connections can influence the activity of biological pathways. Here, we define rewired miRNA-mRNA connections as the differential (rewiring) effects on the activity of biological pathways between hepatocellular carcinoma (HCC) and normal phenotypes. Our work presented here uses a PageRank-based approach to measure the degree of miRNA-mediated dysregulation of biological pathways between HCC and normal samples based on rewired miRNA-mRNA connections. In our study, we regard the degree of miRNA-mediated dysregulation of biological pathways as disease risk of biological pathways. Therefore, we propose a new method, miR2Pathway, to measure and rank the degree of miRNA-mediated dysregulation of biological pathways by measuring the total differential influence of miRNAs on the activity of pathways between HCC and normal states. miR2Pathway proposed here systematically shows the first evidence for a mechanism of biological pathways being dysregulated by rewired miRNA-mRNA connections, and provides new insight into exploring mechanisms behind HCC. Thus, miR2Pathway is a novel method to identify and rank miRNA-dysregulated pathways in HCC. Copyright © 2018. Published by Elsevier Inc.

  3. Agrobacterium mediated transient gene silencing (AMTS in Stevia rebaudiana: insights into steviol glycoside biosynthesis pathway.

    Directory of Open Access Journals (Sweden)

    Praveen Guleria

    Full Text Available Steviol glycoside biosynthesis pathway has emerged as bifurcation from ent-kaurenoic acid, substrate of methyl erythritol phosphate pathway that also leads to gibberellin biosynthesis. However, the genetic regulation of steviol glycoside biosynthesis has not been studied. So, in present study RNA interference (RNAi based Agrobacterium mediated transient gene silencing (AMTS approach was followed. SrKA13H and three SrUGTs (SrUGT85C2, SrUGT74G1 and SrUGT76G1 genes encoding ent-kaurenoic acid-13 hydroxylase and three UDP glycosyltransferases of steviol glycoside biosynthesis pathway were silenced in Stevia rebaudiana to understand its molecular mechanism and association with gibberellins.RNAi mediated AMTS of SrKA13H and three SrUGTs has significantly reduced the expression of targeted endogenous genes as well as total steviol glycoside accumulation. While gibberellins (GA3 content was significantly enhanced on AMTS of SrUGT85C2 and SrKA13H. Silencing of SrKA13H and SrUGT85C2 was found to block the metabolite flux of steviol glycoside pathway and shifted it towards GA3 biosynthesis. Further, molecular docking of three SrUGT proteins has documented highest affinity of SrUGT76G1 for the substrates of alternate pathways synthesizing steviol glycosides. This could be a plausible reason for maximum reduction in steviol glycoside content on silencing of SrUGT76G1 than other genes.SrKA13H and SrUGT85C2 were identified as regulatory genes influencing carbon flux between steviol glycoside and gibberellin biosynthesis. This study has also documented the existence of alternate steviol glycoside biosynthesis route.

  4. Agrobacterium Mediated Transient Gene Silencing (AMTS) in Stevia rebaudiana: Insights into Steviol Glycoside Biosynthesis Pathway

    Science.gov (United States)

    Guleria, Praveen; Yadav, Sudesh Kumar

    2013-01-01

    Background Steviol glycoside biosynthesis pathway has emerged as bifurcation from ent-kaurenoic acid, substrate of methyl erythritol phosphate pathway that also leads to gibberellin biosynthesis. However, the genetic regulation of steviol glycoside biosynthesis has not been studied. So, in present study RNA interference (RNAi) based Agrobacterium mediated transient gene silencing (AMTS) approach was followed. SrKA13H and three SrUGTs (SrUGT85C2, SrUGT74G1 and SrUGT76G1) genes encoding ent-kaurenoic acid-13 hydroxylase and three UDP glycosyltransferases of steviol glycoside biosynthesis pathway were silenced in Stevia rebaudiana to understand its molecular mechanism and association with gibberellins. Methodology/Principal Findings RNAi mediated AMTS of SrKA13H and three SrUGTs has significantly reduced the expression of targeted endogenous genes as well as total steviol glycoside accumulation. While gibberellins (GA3) content was significantly enhanced on AMTS of SrUGT85C2 and SrKA13H. Silencing of SrKA13H and SrUGT85C2 was found to block the metabolite flux of steviol glycoside pathway and shifted it towards GA3 biosynthesis. Further, molecular docking of three SrUGT proteins has documented highest affinity of SrUGT76G1 for the substrates of alternate pathways synthesizing steviol glycosides. This could be a plausible reason for maximum reduction in steviol glycoside content on silencing of SrUGT76G1 than other genes. Conclusions SrKA13H and SrUGT85C2 were identified as regulatory genes influencing carbon flux between steviol glycoside and gibberellin biosynthesis. This study has also documented the existence of alternate steviol glycoside biosynthesis route. PMID:24023961

  5. Silver Nanoparticles Induce HePG-2 Cells Apoptosis Through ROS-Mediated Signaling Pathways

    Science.gov (United States)

    Zhu, Bing; Li, Yinghua; Lin, Zhengfang; Zhao, Mingqi; Xu, Tiantian; Wang, Changbing; Deng, Ning

    2016-04-01

    Recently, silver nanoparticles (AgNPs) have been shown to provide a novel approach to overcome tumors, especially those of hepatocarcinoma. However, the anticancer mechanism of silver nanoparticles is unclear. Thus, the purpose of this study was to estimate the effect of AgNPs on proliferation and activation of ROS-mediated signaling pathway on human hepatocellular carcinoma HePG-2 cells. A simple chemical method for preparing AgNPs with superior anticancer activity has been showed in this study. AgNPs were detected by transmission electronic microscopy (TEM) and energy dispersive X-ray (EDX). The size distribution and zeta potential of silver nanoparticles were detected by Zetasizer Nano. The average size of AgNPs (2 nm) observably increased the cellular uptake by endocytosis. AgNPs markedly inhibited the proliferation of HePG-2 cells through induction of apoptosis with caspase-3 activation and PARP cleavage. AgNPs with dose-dependent manner significantly increased the apoptotic cell population (sub-G1). Furthermore, AgNP-induced apoptosis was found dependent on the overproduction of reactive oxygen species (ROS) and affecting of MAPKs and AKT signaling and DNA damage-mediated p53 phosphorylation to advance HePG-2 cells apoptosis. Therefore, our results show that the mechanism of ROS-mediated signaling pathways may provide useful information in AgNP-induced HePG-2 cell apoptosis.

  6. Macrophages mediate a switch between canonical and non-canonical Wnt pathways in canine mammary tumors.

    Science.gov (United States)

    Król, Magdalena; Mucha, Joanna; Majchrzak, Kinga; Homa, Agata; Bulkowska, Małgorzata; Majewska, Alicja; Gajewska, Małgorzata; Pietrzak, Marta; Perszko, Mikołaj; Romanowska, Karolina; Pawłowski, Karol; Manuali, Elisabetta; Hellmen, Eva; Motyl, Tomasz

    2014-01-01

    According to the current hypothesis, tumor-associated macrophages (TAMs) are "corrupted" by cancer cells and subsequently facilitate, rather than inhibit, tumor metastasis. Because the molecular mechanisms of cancer cell-TAM interactions are complicated and controversial we aimed to better define this phenomenon. Using microRNA microarrays, Real-time qPCR and Western blot we showed that co-culture of canine mammary tumor cells with TAMs or treatment with macrophage-conditioned medium inhibited the canonical Wnt pathway and activated the non-canonical Wnt pathway in tumor cells. We also showed that co-culture of TAMs with tumor cells increased expression of canonical Wnt inhibitors in TAMs. Subsequently, we demonstrated macrophage-induced invasive growth patterns and epithelial-mesenchymal transition of tumor cells. Validation of these results in canine mammary carcinoma tissues (n = 50) and xenograft tumors indicated the activation of non-canonical and canonical Wnt pathways in metastatic tumors and non-metastatic malignancies, respectively. Activation of non-canonical Wnt pathway correlated with number of TAMs. We demonstrated that TAMs mediate a "switch" between canonical and non-canonical Wnt signaling pathways in canine mammary tumors, leading to increased tumor invasion and metastasis. Interestingly, similar changes in neoplastic cells were observed in the presence of macrophage-conditioned medium or live macrophages. These observations indicate that rather than being "corrupted" by cancer cells, TAMs constitutively secrete canonical Wnt inhibitors that decrease tumor proliferation and development, but as a side effect, they induce the non-canonical Wnt pathway, which leads to tumor metastasis. These data challenge the conventional understanding of TAM-cancer cell interactions.

  7. Macrophages mediate a switch between canonical and non-canonical Wnt pathways in canine mammary tumors.

    Directory of Open Access Journals (Sweden)

    Magdalena Król

    Full Text Available OBJECTIVE: According to the current hypothesis, tumor-associated macrophages (TAMs are "corrupted" by cancer cells and subsequently facilitate, rather than inhibit, tumor metastasis. Because the molecular mechanisms of cancer cell-TAM interactions are complicated and controversial we aimed to better define this phenomenon. METHODS AND RESULTS: Using microRNA microarrays, Real-time qPCR and Western blot we showed that co-culture of canine mammary tumor cells with TAMs or treatment with macrophage-conditioned medium inhibited the canonical Wnt pathway and activated the non-canonical Wnt pathway in tumor cells. We also showed that co-culture of TAMs with tumor cells increased expression of canonical Wnt inhibitors in TAMs. Subsequently, we demonstrated macrophage-induced invasive growth patterns and epithelial-mesenchymal transition of tumor cells. Validation of these results in canine mammary carcinoma tissues (n = 50 and xenograft tumors indicated the activation of non-canonical and canonical Wnt pathways in metastatic tumors and non-metastatic malignancies, respectively. Activation of non-canonical Wnt pathway correlated with number of TAMs. CONCLUSIONS: We demonstrated that TAMs mediate a "switch" between canonical and non-canonical Wnt signaling pathways in canine mammary tumors, leading to increased tumor invasion and metastasis. Interestingly, similar changes in neoplastic cells were observed in the presence of macrophage-conditioned medium or live macrophages. These observations indicate that rather than being "corrupted" by cancer cells, TAMs constitutively secrete canonical Wnt inhibitors that decrease tumor proliferation and development, but as a side effect, they induce the non-canonical Wnt pathway, which leads to tumor metastasis. These data challenge the conventional understanding of TAM-cancer cell interactions.

  8. The Ebola virus glycoprotein mediates entry via a non-classical dynamin-dependent macropinocytic pathway

    International Nuclear Information System (INIS)

    Mulherkar, Nirupama; Raaben, Matthijs; Torre, Juan Carlos de la; Whelan, Sean P.; Chandran, Kartik

    2011-01-01

    Ebola virus (EBOV) has been reported to enter cultured cell lines via a dynamin-2-independent macropinocytic pathway or clathrin-mediated endocytosis. The route(s) of productive EBOV internalization into physiologically relevant cell types remain unexplored, and viral-host requirements for this process are incompletely understood. Here, we use electron microscopy and complementary chemical and genetic approaches to demonstrate that the viral glycoprotein, GP, induces macropinocytic uptake of viral particles into cells. GP's highly-glycosylated mucin domain is dispensable for virus-induced macropinocytosis, arguing that interactions between other sequences in GP and the host cell surface are responsible. Unexpectedly, we also found a requirement for the large GTPase dynamin-2, which is proposed to be dispensable for several types of macropinocytosis. Our results provide evidence that EBOV uses an atypical dynamin-dependent macropinocytosis-like entry pathway to enter Vero cells, adherent human peripheral blood-derived monocytes, and a mouse dendritic cell line.

  9. Taraxerol Induces Cell Apoptosis through A Mitochondria-Mediated Pathway in HeLa Cells.

    Science.gov (United States)

    Yaoi, Xiangyang; Lu, Binyu; Lü, Chaotian; Bai, Qin; Yan, Dazhong; Xu, Hui

    2017-10-01

    Taraxerol acetate has potent anti-cancer effects via the induction of apoptosis, autophagy, cell cycle arrest, and inhibition of cell migration. However, whether taraxerol induced apoptosis and its underlying mechanisms of action is not clear. In the present study, we assess the effects of taraxerol on the mitochondrial apoptotic pathway and determine the release of cytochrome c to the cytosol and activation of caspases. In this experimental study, we mainly investigated the effect of taraxerol on HeLa cells. We tested cell viability by the MTT assay and morphologic changes, analyzed apoptosis by DAPI staining and flow cytometry. We also determined reactive oxygen species (ROS) and mitochondrial membrane potential (MMP) using a Microplate Reader. In addition, the apoptotic proteins were tested by Western blot. Taraxerol enhanced ROS levels and attenuated the MMP (Δψm) in HeLa cells. Taraxerol induced apoptosis mainly via the mitochondrial pathway including the release of cytochrome c to the cytosol and activation of caspases 9 and 3, and anti-poly (ADPribose) polymerase (PARP). Taraxerol could induce the down-regulation of the anti-apoptotic protein Bcl-2 and up-regulation of pro-apoptotic protein Bax. It suppressed the PI3K/ Akt signaling pathway. These results demonstrated that taraxerol induced cell apoptosis through a mitochondria-mediated pathway in HeLa cells. Thus, taraxerol might be a potential anticervical cancer candidate.

  10. Mediation pathways and effects of green structures on respiratory mortality via reducing air pollution

    Science.gov (United States)

    Shen, Yu-Sheng; Lung, Shih-Chun Candice

    2017-02-01

    Previous studies have shown both health and environmental benefits of green spaces, especially in moderating temperature and reducing air pollution. However, the characteristics of green structures have been overlooked in previous investigations. In addition, the mediation effects of green structures on respiratory mortality have not been assessed. This study explores the potential mediation pathways and effects of green structure characteristics on respiratory mortality through temperature, primary and secondary air pollutants separately using partial least squares model with data from Taiwan. The measurable characteristics of green structure include the largest patch percentage, landscape proportion, aggregation, patch distance, and fragmentation. The results showed that mortality of pneumonia and chronic lower respiratory diseases could be reduced by minimizing fragmentation and increasing the largest patch percentage of green structure, and the mediation effects are mostly through reducing air pollutants rather than temperature. Moreover, a high proportion of but fragmented green spaces would increase secondary air pollutants and enhance health risks; demonstrating the deficiency of traditional greening policy with primary focus on coverage ratio. This is the first research focusing on mediation effects of green structure characteristics on respiratory mortality, revealing that appropriate green structure planning can be a useful complementary strategy in environmental health management.

  11. Mediating pathways and gender differences between shift work and subjective cognitive function.

    Science.gov (United States)

    Wong, Imelda S; Smith, Peter M; Ibrahim, Selahadin; Mustard, Cameron A; Gignac, Monique A M

    2016-11-01

    Increased injury risk among shift workers is often attributed to cognitive function deficits that come about as a result of sleep disruptions. However, little is known about the intermediate influences of other factors (eg, work stress, health) which may affect this relationship. In addition, gender differences in these the complex relationships have not been fully explored. The purpose of this study is to (1) identify the extent to which work and non-work factors mediate the relationship between shift work, sleep and subsequent subjective cognitive function; and (2) determine if the mediating pathways differ for men and women. Data from the 2010 National Population Health Survey was used to create a cross-sectional sample of 4255 employed Canadians. Using path modelling, we examined the direct and indirect relationships between shift work, sleep duration, sleep quality and subjective cognitive function. Multigroup analyses tested for significantly different pathways between men and women. Potential confounding effects of age and self-reported health and potential mediating effects of work stress were simultaneously examined. Work stress and sleep quality significantly mediated the effects of shift work on cognition. Age and health confounded the relationship between sleep quality and subjective cognition. No differences were found between men and women. Occupational health and safety programmes are needed to address stress and health factors, in addition to sleep hygiene, to effectively address cognitive function among shift workers. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  12. Wnt/β-catenin signalling pathway mediated aberrant hippocampal neurogenesis in kainic acid-induced epilepsy.

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    Qu, Zhengyi; Su, Fang; Qi, Xueting; Sun, Jianbo; Wang, Hongcai; Qiao, Zhenkui; Zhao, Hong; Zhu, Yulan

    2017-10-01

    Temporal lobe epilepsy is a chronic disorder of nerve system, mainly characterized by hippocampal sclerosis with massive neuronal loss and severe gliosis. Aberrant neurogenesis has been shown in the epileptogenesis process of temporal lobe epilepsy. However, the molecular mechanisms underlying aberrant neurogenesis remain unclear. The roles of Wnt signalling cascade have been well established in neurogenesis during multiple aspects. Here, we used kainic acid-induced rat epilepsy model to investigate whether Wnt/β-catenin signalling pathway is involved in the aberrant neurogenesis in temporal lobe epilepsy. Immunostaining and western blotting results showed that the expression levels of β-catenin, Wnt3a, and cyclin D1, the key regulators in Wnt signalling pathway, were up-regulated during acute epilepsy induced by the injection of kainic acids, indicating that Wnt signalling pathway was activated in kainic acid-induced temporal lobe epilepsy. Moreover, BrdU labelling results showed that blockade of the Wnt signalling by knocking down β-catenin attenuated aberrant neurogenesis induced by kainic acids injection. Altogether, Wnt/β-catenin signalling pathway mediated hippocampal neurogenesis during epilepsy, which might provide new strategies for clinical treatment of temporal lobe epilepsy. Temporal lobe epilepsy is a chronic disorder of nerve system, mainly characterized by hippocampal sclerosis. Aberrant neurogenesis has been shown to involve in the epileptogenesis process of temporal lobe epilepsy. In the present study, we discovered that Wnt3a/β-catenin signalling pathway serves as a link between aberrant neurogenesis and underlying remodelling in the hippocampus, leading to temporal lobe epilepsy, which might provide new strategies for clinical treatment of temporal lobe epilepsy. Copyright © 2017 John Wiley & Sons, Ltd.

  13. Endoplasmic reticulum (ER) stress and cAMP/PKA pathway mediated Zn-induced hepatic lipolysis.

    Science.gov (United States)

    Song, Yu-Feng; Hogstrand, Christer; Wei, Chuan-Chuan; Wu, Kun; Pan, Ya-Xiong; Luo, Zhi

    2017-09-01

    The present study was performed to determine the effect of Zn exposure influencing endoplasmic reticulum (ER) stress, explore the underlying molecular mechanism of Zn-induced hepatic lipolysis in a fish species of significance for aquaculture, yellow catfish Pelteobagrus fulvidraco. We found that waterborne Zn exposure evoked ER stress and unfolded protein response (UPR), and activated cAMP/PKA pathway, and up-regulated hepatic lipolysis. The increase in ER stress and lipolysis were associated with activation of cAMP/PKA signaling pathway. Zn also induced an increase in intracellular Ca 2+ level, which could be partially prevented by dantrolene (RyR receptor inhibitor) and 2-APB (IP3 receptor inhibitor), demonstrating that the disturbed Ca 2+ homeostasis in ER contributed to ER stress and dysregulation of lipolysis. Inhibition of ER stress by PBA attenuated UPR, inhibited the activation of cAMP/PKA pathway and resulted in down-regulation of lipolysis. Inhibition of protein kinase RNA-activated-like ER kinase (PERK) by GSK2656157 and inositol-requiring enzyme (IRE) by STF-083010 differentially influenced Zn-induced changes of lipid metabolism, indicating that PERK and IRE pathways played different regulatory roles in Zn-induced lipolysis. Inhibition of PKA by H89 blocked the Zn-induced activation of cAMP/PKA pathway with a concomitant inhibition of ER stress-mediated lipolysis. Taken together, our findings highlight the importance of the ER stress-cAMP/PKA axis in Zn-induced lipolysis, which provides new insights into Zn toxicology in fish and probably in other vertebrates. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Emergency room nurses' pathway to turnover intention: a moderated serial mediation analysis.

    Science.gov (United States)

    Bruyneel, Luk; Thoelen, Tom; Adriaenssens, Jef; Sermeus, Walter

    2017-04-01

    The aim of this study was to explore the association between the quality of the work environment, job characteristics, demographic characteristics and a pathway of job satisfaction, emotional exhaustion and turnover intention among nurses in emergency departments and perform subgroup analyses. Turnover intention among nurses is high. Multiple causes have been described, mostly in large studies of nurses working on general wards, often without considering complementarity of conceptual models and showing scant interest in the consistency of associations across subgroups of nurses. Cross-sectional multicentre survey. Convenience sample of 294 nurses in 11 Belgian emergency departments during 2014-2015. Indirect effects in the form of mediation and serial mediation were estimated to assess the association between work environment (Magnet model), job characteristics (Job Demand Control Support model) and turnover intention via job satisfaction and emotional exhaustion. Consistency of these indirect effects across subgroups of nurses was examined using moderated mediation analysis (conditional indirect effects). Several Magnet and Job Demand Control Support dimensions were related to turnover intention, either via job dissatisfaction (mediation) or via job satisfaction and emotional exhaustion (serial mediation). In the case of social support from supervisor, these indirect effects were only significant for female nurses, among whom turnover intention was higher. Last, nurses with more years of experience were less likely to indicate turnover intention. To maximize prevention of turnover intention at emergency departments, interventions could target early career nurses, work environment and job characteristics. Female nurses in particular may also benefit from improved social support from their supervisor. © 2016 John Wiley & Sons Ltd.

  15. ANGUSTIFOLIA mediates one of the multiple SCRAMBLED signaling pathways regulating cell growth pattern in Arabidopsis thaliana.

    Science.gov (United States)

    Kwak, Su-Hwan; Song, Sang-Kee; Lee, Myeong Min; Schiefelbein, John

    2015-09-25

    In Arabidopsis thaliana, an atypical leucine-rich repeat receptor-like kinase, SCRAMBLED (SCM), is required for multiple developmental processes including root epidermal cell fate determination, silique dehiscence, inflorescence growth, ovule morphogenesis, and tissue morphology. Previous work suggested that SCM regulates these multiple pathways using distinct mechanisms via interactions with specific downstream factors. ANGUSTIFOLIA (AN) is known to regulate cell and tissue morphogenesis by influencing cortical microtubule arrangement, and recently, the AN protein was reported to interact with the SCM protein. Therefore, we examined whether AN might be responsible for mediating some of the SCM-dependent phenotypes. We discovered that both scm and an mutant lines cause an abnormal spiral or twisting growth of roots, but only the scm mutant affected root epidermal patterning. The siliques of the an and scm mutants also exhibited spiral growth, as previously reported, but only the scm mutant altered silique dehiscence. Interestingly, we discovered that the spiral growth of roots and siliques of the scm mutant is rescued by a truncated SCM protein that lacks its kinase domain, and that a juxtamembrane domain of SCM was sufficient for AN binding in the yeast two-hybrid analysis. These results suggest that the AN protein is one of the critical downstream factors of SCM pathways specifically responsible for mediating its effects on cell/tissue morphogenesis through cortical microtubule arrangement. Copyright © 2015 Elsevier Inc. All rights reserved.

  16. HCV upregulates Bim through the ROS/JNK signalling pathway, leading to Bax-mediated apoptosis.

    Science.gov (United States)

    Deng, Lin; Chen, Ming; Tanaka, Motofumi; Ku, Yonson; Itoh, Tomoo; Shoji, Ikuo; Hotta, Hak

    2015-09-01

    We previously reported that hepatitis C virus (HCV) infection induces Bax-triggered, mitochondrion-mediated apoptosis by using the HCV J6/JFH1 strain and Huh-7.5 cells. However, it was still unclear how HCV-induced Bax activation. In this study, we showed that the HCV-induced activation and mitochondrial accumulation of Bax were significantly attenuated by treatment with a general antioxidant, N-acetyl cysteine (NAC), or a specific c-Jun N-terminal kinase (JNK) inhibitor, SP600125, with the result suggesting that the reactive oxygen species (ROS)/JNK signalling pathway is upstream of Bax activation in HCV-induced apoptosis. We also demonstrated that HCV infection transcriptionally activated the gene for the pro-apoptotic protein Bim and the protein expression of three major splice variants of Bim (BimEL, BimL and BimS). The HCV-induced increase in the Bim mRNA and protein levels was significantly counteracted by treatment with NAC or SP600125, suggesting that the ROS/JNK signalling pathway is involved in Bim upregulation. Moreover, HCV infection led to a marked accumulation of Bim on the mitochondria to facilitate its interaction with Bax. On the other hand, downregulation of Bim by siRNA (small interfering RNA) significantly prevented HCV-mediated activation of Bax and caspase 3. Taken together, these observations suggest that HCV-induced ROS/JNK signalling transcriptionally activates Bim expression, which leads to Bax activation and apoptosis induction.

  17. Cherry Valley Ducks Mitochondrial Antiviral-Signaling Protein-Mediated Signaling Pathway and Antiviral Activity Research.

    Science.gov (United States)

    Li, Ning; Hong, Tianqi; Li, Rong; Wang, Yao; Guo, Mengjiao; Cao, Zongxi; Cai, Yumei; Liu, Sidang; Chai, Tongjie; Wei, Liangmeng

    2016-01-01

    Mitochondrial antiviral-signaling protein (MAVS), an adaptor protein of retinoic acid-inducible gene I (RIG-I)-like receptors (RLRs)-mediated signal pathway, is involved in innate immunity. In this study, Cherry Valley duck MAVS (duMAVS) was cloned from the spleen and analyzed. duMAVS was determined to have a caspase activation and recruitment domain at N-terminal, followed by a proline-rich domain and a transmembrane domain at C-terminal. Quantitative real-time PCR indicated that duMAVS was expressed in all tissues tested across a broad expression spectrum. The expression of duMAVS was significantly upregulated after infection with duck Tembusu virus (DTMUV). Overexpression of duMAVS could drive the activation of interferon (IFN)-β, nuclear factor-κB, interferon regulatory factor 7, and many downstream factors (such as Mx, PKR, OAS, and IL-8) in duck embryo fibroblast cells. What is more, RNA interference further confirmed that duMAVS was an important adaptor for IFN-β activation. The antiviral assay showed that duMAVS could suppress the various viral replications (DTMUV, novel reovirus, and duck plague virus) at early stages of infection. Overall, these results showed that the main signal pathway mediated by duMAVS and it had a broad-spectrum antiviral ability. This research will be helpful to better understanding the innate immune system of ducks.

  18. Genistein Stimulates Jejunum Chloride Secretion via an Akt-Mediated Pathway in Intact Female Mice

    Directory of Open Access Journals (Sweden)

    Lana Leung

    2015-02-01

    Full Text Available Background/Aims: We have previously shown that daily subcutaneous injections with the naturally occurring phytoestrogen genistein (600 mg genistein/kg body weight/day, 600G results in a significantly increased basal intestinal chloride, Cl-, secretion (Isc, a measure of transepithelial secretion in intact C57BL/6J female mice after 1-week of treatment, compared to controls (DMSO vehicle injected. Removal of endogenous estrogen via ovariectomy (OVX had no effect on the 600G-mediated increase in basal Isc. Methods: Given the estrogen-like characteristics of genistein, we compared the effects of daily estradiol (E2 injections (10 mg E2/kg body weight/day, 10E2 on basal Isc in intact and OVX mice. In intact mice, 10E2 was without effect on basal Isc, however, in OVX mice, 10E2 significantly increased basal Isc (mimicked 600G. The goal of the current study was to characterize the intracellular signaling pathways responsible for mediating 600G- or 10E2-stimulated increases in basal Isc in intact female or OVX mice. Results: We measured total protein expression in isolated segments of jejunum using western blot from the following six groups of mice; intact or OVX with; 600G, 10E2 or control. The proteins of interest were: Akt, p-Akt, p-PDK1, p-PTEN, p-c-Raf, p-GSK-3β, rap-1 and ERK1/2. All blots were normalized to GAPDH levels (n = 6-18/group. Conclusion: These data suggest that the presence of the endogenous sex steroid, estrogen, modifies the intracellular signaling pathway required to mediate Cl- secretion when the intestine is exposed to exogenous 600G or E2. These studies may have relevance for designing pharmacological tools for women with intestinal chloride secretory dysfunctions.

  19. Mediating pathways explaining psychosocial functioning and revictimization as sequelae of parental violence among adolescent mothers.

    Science.gov (United States)

    Lindhorst, Taryn; Beadnell, Blair; Jackson, Lovie J; Fieland, Karen; Lee, Angela

    2009-04-01

    Adolescent mothers are at high risk for negative life events, such as previous childhood physical abuse, impaired psychosocial functioning, and young adulthood revictimization. However, little is known about the potential pathways in these events; hence, little is known about opportunities for intervention. This study used structural equation modeling to investigate mediators of the effects of parental child abuse on later psychosocial functioning and revictimization (in the form of intimate partner violence and sexual violence) among adolescent mothers, with longitudinal data spanning 2.4 years. On psychological distress in the final time period, parental physical child abuse had an early and then maintained effect but also effects mediated by earlier psychological distress and revictimization. Psychological distress rather than substance use appeared as the primary psychosocial factor mediating the effects of parental violence on both future distress and revictimization. For prevention of further psychosocial impairment and revictimization, these findings indicate the need for early intervention with adolescent mothers who come from abusive families and who display higher levels of psychological distress. (c) 2009 APA, all rights reserved.

  20. Sulforaphane-induced autophagy flux prevents prion protein-mediated neurotoxicity through AMPK pathway.

    Science.gov (United States)

    Lee, J-H; Jeong, J-K; Park, S-Y

    2014-10-10

    Prion diseases are neurodegenerative and infectious disorders that involve accumulation of misfolded scrapie prion protein, and which are characterized by spongiform degeneration. Autophagy, a major homeostatic process responsible for the degradation of cytoplasmic components, has garnered attention as the potential target for neurodegenerative diseases such as prion disease. We focused on protective effects of sulforaphane found in cruciferous vegetables on prion-mediated neurotoxicity and the mechanism of sulforaphane related to autophagy. In human neuroblastoma cells, sulforaphane protected prion protein (PrP) (106-126)-mediated neurotoxicity and increased autophagy flux marker microtubule-associated protein 1 light chain 3-II protein levels, following a decrease of p62 protein level. Pharmacological and genetical inhibition of autophagy by 3MA, wortmannin and knockdown of autophagy-related 5 (ATG5) led to block the effect of sulforaphane against PrP (106-126)-induced neurotoxicity. Furthermore we demonstrated that both sulforaphane-induced autophagy and protective effect of sulforaphane against PrP (106-126)-induced neurotoxicity are dependent on the AMP-activated protein kinase (AMPK) signaling. The present results indicated that sulforaphane of cruciferous vegetables enhanced autophagy flux led to the protection effects against prion-mediated neurotoxicity, which was regulated by AMPK signaling pathways in human neuron cells. Our data also suggest that sulforaphane has a potential value as a therapeutic tool in neurodegenerative disease including prion diseases. Copyright © 2014 IBRO. Published by Elsevier Ltd. All rights reserved.

  1. Measles Virus Enters Breast and Colon Cancer Cell Lines through a PVRL4-Mediated Macropinocytosis Pathway.

    Science.gov (United States)

    Delpeut, Sebastien; Sisson, Gary; Black, Karen M; Richardson, Christopher D

    2017-05-15

    Measles virus (MeV) is a member of the family Paramixoviridae that causes a highly contagious respiratory disease but has emerged as a promising oncolytic platform. Previous studies of MeV entry focused on the identification of cellular receptors. However, the endocytic and trafficking pathways utilized during MeV entry remain poorly described. The contribution of each endocytic pathway has been examined in cells that express the MeV receptors SLAM (signaling lymphocyte-activating molecule) and PVRL4 (poliovirus receptor-like 4) (nectin-4). Recombinant MeVs expressing either firefly luciferase or green fluorescent protein together with a variety of inhibitors were used. The results showed that MeV uptake was dynamin independent in the Vero.hPVRL4, Vero.hSLAM, and PVRL4-positive MCF7 breast cancer cell lines. However, MeV infection was blocked by 5-( N -ethyl- N -propyl)amiloride (EIPA), the hallmark inhibitor of macropinocytosis, as well as inhibitors of actin polymerization. By using phalloidin staining, MeV entry was shown to induce actin rearrangements and the formation of membrane ruffles accompanied by transient elevated fluid uptake. Small interfering RNA (siRNA) knockdown of p21-activated kinase 1 (PAK1) demonstrated that MeV enters both Vero.hPVRL4 and Vero.hSLAM cells in a PAK1-independent manner using a macropinocytosis-like pathway. In contrast, MeV entry into MCF7 human breast cancer cells relied upon Rac1 and its effector PAK1 through a PVRL4-mediated macropinocytosis pathway. MeV entry into DLD-1 colon and HTB-20 breast cancer cells also appeared to use the same pathway. Overall, these findings provide new insight into the life cycle of MeV, which could lead to therapies that block virus entry or methods that improve the uptake of MeV by cancer cells during oncolytic therapy. IMPORTANCE In the past decades, measles virus (MeV) has emerged as a promising oncolytic platform. Previous studies concerning MeV entry focused mainly on the identification of

  2. A glutamatergic network mediates lithium response in bipolar disorder as defined by epigenome pathway analysis.

    Science.gov (United States)

    Higgins, Gerald A; Allyn-Feuer, Ari; Barbour, Edward; Athey, Brian D

    2015-01-01

    A regulatory network in the human brain mediating lithium response in bipolar patients was revealed by analysis of functional SNPs from genome-wide association studies (GWAS) and published gene association studies, followed by epigenome mapping. An initial set of 23,312 SNPs in linkage disequilibrium with lead SNPs, and sub-threshold GWAS SNPs rescued by pathway analysis, were studied in the same populations. These were assessed using our workflow and annotation by the epigenome roadmap consortium. Twenty-seven percent of 802 SNPs that were associated with lithium response (13 published studies gene association studies and two GWAS) were shared in common with 1281 SNPs from 18 GWAS examining psychiatric disorders and adverse events associated with lithium treatment. Nineteen SNPs were annotated as active regulatory elements such as enhancers and promoters in a tissue-specific manner. They were located within noncoding regions of ten genes: ANK3, ARNTL, CACNA1C, CACNG2, CDKN1A, CREB1, GRIA2, GSK3B, NR1D1 and SLC1A2. Following gene set enrichment and pathway analysis, these genes were found to be significantly associated (p = 10(-27); Fisher exact test) with an AMPA2 glutamate receptor network in human brain. Our workflow results showed concordance with annotation of regulatory elements from the epigenome roadmap. Analysis of cognate mRNA and enhancer RNA exhibited patterns consistent with an integrated pathway in human brain. This pharmacoepigenomic regulatory pathway is located in the same brain regions that exhibit tissue volume loss in bipolar disorder. Although in silico analysis requires biological validation, the approach provides value for identification of candidate variants that may be used in pharmacogenomic testing to identify bipolar patients likely to respond to lithium.

  3. H19 mediates methotrexate resistance in colorectal cancer through activating Wnt/β-catenin pathway

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Ke-feng [Guangdong Key Laboratory for Research and Development of Natural Drugs, Guangdong Medical University, Zhanjiang, Guangdong (China); Liang, Wei-Cheng [School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong (China); Feng, Lu [Department of Orthopaedics & Traumatology, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, Hong Kong (China); Pang, Jian-xin [School of Pharmaceutical Sciences, Southern Medical University, Guangzhou 510515 (China); Waye, Mary Miu-Yee [School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong (China); Zhang, Jin-Fang [Department of Orthopaedics & Traumatology, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, Hong Kong (China); Fu, Wei-Ming, E-mail: fuweiming76@smu.edu.cn [School of Pharmaceutical Sciences, Southern Medical University, Guangzhou 510515 (China)

    2017-01-15

    Colorectal cancer (CRC) is a common malignancy, most of which remain unresponsive to chemotherapy. As one of the earliest cytotoxic drugs, methotrexate (MTX) serves as an anti-metabolite and anti-folate chemotherapy for various cancers. Unfortunately, MTX resistance prevents its clinical application in cancer therapy. Thereby, overcoming the drug resistance is an alternative strategy to maximize the therapeutic efficacy of MTX in clinics. Long noncoding RNAs (lncRNAs) have gained widespread attention in recent years. More and more emerging evidences have demonstrated that they play important regulatory roles in various biological activities and disease progression including drug resistance. In the present study, a MTX-resistant colorectal cell line HT-29 (HT-29-R) was developed, which displayed the active proliferation and shortened cell cycle. LncRNA H19 was found to be significantly upregulated in this resistant cell line. Further investigation showed that H19 knockdown sensitized the MTX resistance in HT-29-R cells while its overexpression improved the MTX resistance in the parental cells, suggesting that H19 mediate MTX resistance. The Wnt/β-catenin signaling was activated in HT-29-R cells, and H19 knockdown suppressed this signaling in the parental cells. In conclusion, H19 mediated MTX resistance via activating Wnt/β-catenin signaling, which help to develop H19 as a promising therapeutic target for MTX resistant CRC. - Highlights: • A methotrexate (MTX) -resistant colorectal cancer cell line HT-29 (HT-29-R) has been developed. • H19 was upregulated in HT-29-R cells. • H19 mediated MTX resistance in colorectal cancer (CRC). • Wnt/β-catenin pathway was involved in the H19-mediated MTX resistance in CRC cells.

  4. H19 mediates methotrexate resistance in colorectal cancer through activating Wnt/β-catenin pathway

    International Nuclear Information System (INIS)

    Wu, Ke-feng; Liang, Wei-Cheng; Feng, Lu; Pang, Jian-xin; Waye, Mary Miu-Yee; Zhang, Jin-Fang; Fu, Wei-Ming

    2017-01-01

    Colorectal cancer (CRC) is a common malignancy, most of which remain unresponsive to chemotherapy. As one of the earliest cytotoxic drugs, methotrexate (MTX) serves as an anti-metabolite and anti-folate chemotherapy for various cancers. Unfortunately, MTX resistance prevents its clinical application in cancer therapy. Thereby, overcoming the drug resistance is an alternative strategy to maximize the therapeutic efficacy of MTX in clinics. Long noncoding RNAs (lncRNAs) have gained widespread attention in recent years. More and more emerging evidences have demonstrated that they play important regulatory roles in various biological activities and disease progression including drug resistance. In the present study, a MTX-resistant colorectal cell line HT-29 (HT-29-R) was developed, which displayed the active proliferation and shortened cell cycle. LncRNA H19 was found to be significantly upregulated in this resistant cell line. Further investigation showed that H19 knockdown sensitized the MTX resistance in HT-29-R cells while its overexpression improved the MTX resistance in the parental cells, suggesting that H19 mediate MTX resistance. The Wnt/β-catenin signaling was activated in HT-29-R cells, and H19 knockdown suppressed this signaling in the parental cells. In conclusion, H19 mediated MTX resistance via activating Wnt/β-catenin signaling, which help to develop H19 as a promising therapeutic target for MTX resistant CRC. - Highlights: • A methotrexate (MTX) -resistant colorectal cancer cell line HT-29 (HT-29-R) has been developed. • H19 was upregulated in HT-29-R cells. • H19 mediated MTX resistance in colorectal cancer (CRC). • Wnt/β-catenin pathway was involved in the H19-mediated MTX resistance in CRC cells.

  5. Toll-Like Receptor 4 Signaling Pathway Mediates Inhalant Organic Dust-Induced Bone Loss.

    Directory of Open Access Journals (Sweden)

    Elizabeth Staab

    Full Text Available Agriculture workers have increased rates of airway and skeletal disease. Inhalant exposure to agricultural organic dust extract (ODE induces bone deterioration in mice; yet, mechanisms underlying lung-bone crosstalk remain unclear. Because Toll-like receptor 2 (TLR2 and TLR4 are important in mediating the airway consequences of ODE, this study investigated their role in regulating bone responses. First, swine facility ODE stimulated wild-type (WT bone marrow macrophages to form osteoclasts, and this finding was inhibited in TLR4 knock-out (KO, but not TLR2 KO cells. Next, using an established intranasal inhalation exposure model, WT, TLR2 KO and TLR4 KO mice were treated daily with ODE or saline for 3 weeks. ODE-induced airway neutrophil influx and cytokine/chemokine release were similarly reduced in TLR2 and TLR4 KO animals as compared to WT mice. Utilizing micro-computed tomography (CT, analysis of tibia showed loss of bone mineral density, volume and deterioration of bone micro-architecture and mechanical strength induced by ODE in WT mice were significantly reduced in TLR4 but not TLR2 KO animals. Bone marrow osteoclast precursor cell populations were analyzed by flow cytometry from exposed animals. In WT animals, exposure to inhalant ODE increased osteoclast precursor cell populations as compared to saline, an effect that was reduced in TLR4 but not TLR2 KO mice. These results show that TLR2 and TLR4 pathways mediate ODE-induced airway inflammation, but bone deterioration consequences following inhalant ODE treatment is strongly dependent upon TLR4. Thus, the TLR4 signaling pathway appears critical in regulating the lung-bone inflammatory axis to microbial component-enriched organic dust exposures.

  6. Nasopharyngeal carcinoma progression is mediated by EBER-triggered inflammation via the RIG-I pathway.

    Science.gov (United States)

    Duan, Yumei; Li, Zhi; Cheng, Shiyue; Chen, Yan; Zhang, Lu; He, Jiang; Liao, Qiong; Yang, Lifang; Gong, Zhicheng; Sun, Lun-Quan

    2015-05-28

    EBERs (EBER1 and EBER2) are suggested to be involved in cellular transformation and tumor growth. Cytoplasmic pattern recognition receptor-RIG-I, which is characterized by the recognition of viral dsRNAs, could efficiently trigger the downstream pathways of innate immunity. Although some previous reports have shown that EBERs and RIG-I associate with hematological malignancies, the role of EBERs-RIG-I signaling in solid tumors remains to be clarified. Here we demonstrate that EBER mediation of the inflammatory response via RIG-I contributes to NPC development in vitro and in vivo. We first verified that the expression level of RIG-I was associated with EBER transcription in a dose-dependent manner in NPC cells and specimens from NPC patients. Furthermore, pro-inflammatory cytokine transcription and release were sharply reduced after RIG-I knockdown compared with the control shRNA group in the presence of EBERs, accompanied by an attenuation of the NF-κB and MAPK signaling pathways. Consequently, the tumor burden was greatly alleviated in the RIG-I knockdown group in a xenograft model. In addition, macrophage colony-stimulating factor (M-CSF) and monocyte chemoattractant protein (MCP-1), which promote the maturation and attraction of tumor-associated macrophages, were stimulated upon the introduction of EBERs, and this upregulation conceivably led to the tumor-promoting subset transition of the macrophages. Taken together, our results reveal that EBERs could promote NPC progression through RIG-I-mediated cancer-related inflammation. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  7. Signaling pathways required for macrophage scavenger receptor-mediated phagocytosis: analysis by scanning cytometry

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    Winkler Aaron R

    2008-08-01

    Full Text Available Abstract Background Scavenger receptors are important components of the innate immune system in the lung, allowing alveolar macrophages to bind and phagocytose numerous unopsonized targets. Mice with genetic deletions of scavenger receptors, such as SR-A and MARCO, are susceptible to infection or inflammation from inhaled pathogens or dusts. However, the signaling pathways required for scavenger receptor-mediated phagocytosis of unopsonized particles have not been characterized. Methods We developed a scanning cytometry-based high-throughput assay of macrophage phagocytosis that quantitates bound and internalized unopsonized latex beads. This assay allowed the testing of a panel of signaling inhibitors which have previously been shown to target opsonin-dependent phagocytosis for their effect on unopsonized bead uptake by human in vitro-derived alveolar macrophage-like cells. The non-selective scavenger receptor inhibitor poly(I and the actin destabilizer cytochalasin D were used to validate the assay and caused near complete abrogation of bead binding and internalization, respectively. Results Microtubule destabilization using nocodazole dramatically inhibited bead internalization. Internalization was also significantly reduced by inhibitors of tyrosine kinases (genistein and herbimycin A, protein kinase C (staurosporine, chelerythrine chloride and Gö 6976, phosphoinositide-3 kinase (LY294002 and wortmannin, and the JNK and ERK pathways. In contrast, inhibition of phospholipase C by U-73122 had no effect. Conclusion These data indicate the utility of scanning cytometry for the analysis of phagocytosis and that phagocytosis of unopsonized particles has both shared and distinct features when compared to opsonin-mediated phagocytosis.

  8. Histamine H4 Receptor mediates interleukin-8 and TNF-α release in human mast cells via multiple signaling pathways.

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    Chen, X-F; Zhang, Z; Dou, X; Li, J-J; Zhang, W; Yu, Y-Y; Yu, B; Yu, B

    2016-01-27

    Histamine, mainly produced by mast cells, is an important inflammatory mediator in immune response. Recently Histamine H4 Receptor (H4R) was also identified in mast cells, from which pro-inflammatory cytokines and chemokines are released. However, the mechanism of how H4R mediates these cytokines and chemokines release in mast cells was still unclear. To further explore the role of H4R in the immune inflammatory response in mast cells, we tested the release of inflammatory cytokine tumor necrosis factor-α (TNF-α), chemokine interleukin-8 (IL-8) and the relevant signaling pathways activated by H4R on LAD2 cells (a human mast cell line). We found that the release of IL-8 and TNF-α were blocked by inhibitors of PI3K, ERK and Ca2+-Calcineurin-NFAT signaling pathways, while the release of these cytokines and chemokines were enhanced by the inhibitor of P38 signaling pathway. However, inhibitors of the JNK and NF-κB signaling pathways had little effect on the expression of the pro-inflammatory mediators. Moreover, activation of the H4R could induce phosphorylation of ERK, p38 and AKT in mast cells. In conclusion, we found that H4R mediates the release of inflammatory cytokine TNF-α and chemokine IL-8 in human mast cells via PI3K, Ca2+-Calcineurin-NFAT and MAPKs signaling pathways.

  9. Sonic hedgehog mediates a novel pathway of PDGF-BB-dependent vessel maturation.

    Science.gov (United States)

    Yao, Qinyu; Renault, Marie-Ange; Chapouly, Candice; Vandierdonck, Soizic; Belloc, Isabelle; Jaspard-Vinassa, Béatrice; Daniel-Lamazière, Jean-Marie; Laffargue, Muriel; Merched, Aksam; Desgranges, Claude; Gadeau, Alain-Pierre

    2014-04-10

    Recruitment of mural cells (MCs), namely pericytes and smooth muscle cells (SMCs), is essential to improve the maturation of newly formed vessels. Sonic hedgehog (Shh) has been suggested to promote the formation of larger and more muscularized vessels, but the underlying mechanisms of this process have not yet been elucidated. We first identified Shh as a target of platelet-derived growth factor BB (PDGF-BB) and found that SMCs respond to Shh by upregulating extracellular signal-regulated kinase 1/2 and Akt phosphorylation. We next showed that PDGF-BB-induced SMC migration was reduced after inhibition of Shh or its signaling pathway. Moreover, we found that PDGF-BB-induced SMC migration involves Shh-mediated motility. In vivo, in the mouse model of corneal angiogenesis, Shh is expressed by MCs of newly formed blood vessels. PDGF-BB inhibition reduced Shh expression, demonstrating that Shh is a target of PDGF-BB, confirming in vitro experiments. Finally, we found that in vivo inhibition of either PDGF-BB or Shh signaling reduces NG2(+) MC recruitment into neovessels and subsequently reduces neovessel life span. Our findings demonstrate, for the first time, that Shh is involved in PDGF-BB-induced SMC migration and recruitment of MCs into neovessels and elucidate the molecular signaling pathway involved in this process.

  10. Dysregulation of AKT Pathway by SMYD2-Mediated Lysine Methylation on PTEN

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    Makoto Nakakido

    2015-04-01

    Full Text Available Phosphatase and tensin homologue (PTEN, one of the well-characterized tumor suppressor proteins, counteracts the phosphatidylinositol 3-kinase-AKT pathway through its unique lipid phosphatase activity. The functions of PTEN are regulated by a variety of posttranslational modifications such as acetylation, oxidation, ubiquitylation, phosphorylation, and SUMOylation. However, methylation of PTEN has not been reported so far. In this study, we demonstrated that the oncogenic protein lysine methyltransferase SET and MYND domain containing 2 (SMYD2 methylates PTEN at lysine 313 in vitro and in vivo. Knockdown of SMYD2 suppressed the cell growth of breast cancer cells and attenuated phosphorylation levels of AKT, indicating that SMYD2-mediated methylation negatively regulates PTEN tumor suppressor activity and results in activation of the phosphatidylinositol 3-kinase-AKT pathway. Furthermore, PTEN protein with lysine 313 substitution diminished phosphorylation of PTEN at serine 380, which is known to inactivate tumor suppressor functions of PTEN. Taken together, our findings unveil a novel mechanism of PTEN dysregulation regulated by lysine methylation in human cancer.

  11. Surfactant protein D delays Fas- and TRAIL-mediated extrinsic pathway of apoptosis in T cells.

    Science.gov (United States)

    Djiadeu, Pascal; Kotra, Lakshmi P; Sweezey, Neil; Palaniyar, Nades

    2017-05-01

    Only a few extracellular soluble proteins are known to modulate apoptosis. We considered that surfactant-associated protein D (SP-D), an innate immune collectin present on many mucosal surfaces, could regulate apoptosis. Although SP-D is known to be important for immune cell homeostasis, whether SP-D affects apoptosis is unknown. In this study we aimed to determine the effects of SP-D on Jurkat T cells and human T cells dying by apoptosis. Here we show that SP-D binds to Jurkat T cells and delays the progression of Fas (CD95)-Fas ligand and TRAIL-TRAIL receptor induced, but not TNF-TNF receptor-mediated apoptosis. SP-D exerts its effects by reducing the activation of initiator caspase-8 and executioner caspase-3. SP-D also delays the surface exposure of phosphatidylserine. The effect of SP-D was ablated by the presence of caspase-8 inhibitor, but not by intrinsic pathway inhibitors. The binding ability of SP-D to dying cells decreases during the early stages of apoptosis, suggesting the release of apoptotic cell surface targets during apoptosis. SP-D also delays FasL-induced death of primary human T cells. SP-D delaying the progression of the extrinsic pathway of apoptosis could have important implications in regulating immune cell homeostasis at mucosal surfaces.

  12. Risk factors and mediating pathways of loneliness and social support in community-dwelling older adults.

    Science.gov (United States)

    Schnittger, Rebecca I B; Wherton, Joseph; Prendergast, David; Lawlor, Brian A

    2012-01-01

    To develop biopsychosocial models of loneliness and social support thereby identifying their key risk factors in an Irish sample of community-dwelling older adults. Additionally, to investigate indirect effects of social support on loneliness through mediating risk factors. A total of 579 participants (400 females; 179 males) were given a battery of biopsychosocial assessments with the primary measures being the De Jong Gierveld Loneliness Scale and the Lubben Social Network Scale along with a broad range of secondary measures. Bivariate correlation analyses identified items to be included in separate psychosocial, cognitive, biological and demographic multiple regression analyses. The resulting model items were then entered into further multiple regression analyses to obtain overall models. Following this, bootstrapping mediation analyses was conducted to examine indirect effects of social support on the subtypes (emotional and social) of loneliness. The overall model for (1) emotional loneliness included depression, neuroticism, perceived stress, living alone and accommodation type, (2) social loneliness included neuroticism, perceived stress, animal naming and number of grandchildren and (3) social support included extraversion, executive functioning (Trail Making Test B-time), history of falls, age and whether the participant drives or not. Social support influenced emotional loneliness predominantly through indirect means, while its effect on social loneliness was more direct. These results characterise the biopsychosocial risk factors of emotional loneliness, social loneliness and social support and identify key pathways by which social support influences emotional and social loneliness. These findings highlight issues with the potential for consideration in the development of targeted interventions.

  13. Involvement of SGT1 in COR-mediated signal transduction pathway leading to disease symptom development.

    Science.gov (United States)

    Ishiga, Yasuhiro; Uppalapati, Srinivasa Rao; Ishiga, Takako; Mysore, Kirankumar S

    2011-07-01

    Pseudomonas syringae pv. tomato DC3000 (Pst DC3000), that causes bacterial speck disease on tomato, produces a non-host-specific virulence effector, coronatine (COR). COR functions as a jasmonic acid (JA)-isoleucine mimic in planta and has multiple roles in the pathogenicity of Pst DC3000. One of the hallmarks of bacterial speck disease on tomato is the formation of necrotic lesions surrounded by chlorosis and COR is required for disease development. However, the molecular basis of COR-mediated disease symptom development including chlorosis and necrosis is still largely unknown. In our recent publication in New Phytologist, using virus-induced gene silencing (VIGS) based reverse genetics screen, we demonstrated that SGT1 (suppressor of G2 allele of skp1) is required for COR-induced chlorosis in Nicotiana benthamiana. SGT1-silenced tomato leaves showed a complete loss of COR-induced chlorosis and reduced disease symptom development after the inoculation with Pst DC3000. Furthermore, Arabidopsis sgt1b mutant was less sensitive to COR-induced root growth inhibition and showed delayed Pst DC3000 disease symptoms. In this addendum, we discuss the possible contribution of SGT1 to COR-mediated signal transduction pathway leading to disease symptom development during Pst DC3000 pathogenesis in tomato and Arabidopsis.

  14. Functional analysis of the Asian soybean rust resistance pathway mediated by Rpp2.

    Science.gov (United States)

    Pandey, Ajay K; Yang, Chunling; Zhang, Chunquan; Graham, Michelle A; Horstman, Heidi D; Lee, Yeunsook; Zabotina, Olga A; Hill, John H; Pedley, Kerry F; Whitham, Steven A

    2011-02-01

    Asian soybean rust is an aggressive foliar disease caused by the obligate biotrophic fungus Phakopsora pachyrhizi. On susceptible plants, the pathogen penetrates and colonizes leaf tissue, resulting in the formation of necrotic lesions and the development of numerous uredinia. The soybean Rpp2 gene confers resistance to specific isolates of P. pachyrhizi. Rpp2-mediated resistance limits the growth of the pathogen and is characterized by the formation of reddish-brown lesions and few uredinia. Using virus-induced gene silencing, we screened 140 candidate genes to identify those that play a role in Rpp2 resistance toward P. pachyrhizi. Candidate genes included putative orthologs to known defense-signaling genes, transcription factors, and genes previously found to be upregulated during the Rpp2 resistance response. We identified 11 genes that compromised Rpp2-mediated resistance when silenced, including GmEDS1, GmNPR1, GmPAD4, GmPAL1, five predicted transcription factors, an O-methyl transferase, and a cytochrome P450 monooxygenase. Together, our results provide new insight into the signaling and biochemical pathways required for resistance against P. pachyrhizi.

  15. Functions of the nonsense-mediated mRNA decay pathway in Drosophila development.

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    Mark M Metzstein

    2006-12-01

    Full Text Available Nonsense-mediated mRNA decay (NMD is a cellular surveillance mechanism that degrades transcripts containing premature translation termination codons, and it also influences expression of certain wild-type transcripts. Although the biochemical mechanisms of NMD have been studied intensively, its developmental functions and importance are less clear. Here, we describe the isolation and characterization of Drosophila "photoshop" mutations, which increase expression of green fluorescent protein and other transgenes. Mapping and molecular analyses show that photoshop mutations are loss-of-function mutations in the Drosophila homologs of NMD genes Upf1, Upf2, and Smg1. We find that Upf1 and Upf2 are broadly active during development, and they are required for NMD as well as for proper expression of dozens of wild-type genes during development and for larval viability. Genetic mosaic analysis shows that Upf1 and Upf2 are required for growth and/or survival of imaginal cell clones, but this defect can be overcome if surrounding wild-type cells are eliminated. By contrast, we find that the PI3K-related kinase Smg1 potentiates but is not required for NMD or for viability, implying that the Upf1 phosphorylation cycle that is required for mammalian and Caenorhabditis elegans NMD has a more limited role during Drosophila development. Finally, we show that the SV40 3' UTR, present in many Drosophila transgenes, targets the transgenes for regulation by the NMD pathway. The results establish that the Drosophila NMD pathway is broadly active and essential for development, and one critical function of the pathway is to endow proliferating imaginal cells with a competitive growth advantage that prevents them from being overtaken by other proliferating cells.

  16. Glioma cell fate decisions mediated by Dll1-Jag1-Fringe in Notch1 signaling pathway.

    Science.gov (United States)

    Shi, Xiaofei; Wang, Ruiqi

    2017-09-21

    The Notch family of proteins plays a vital role in determining cell fates, such as proliferation, differentiation, and apoptosis. It has been shown that Notch1 and its ligands, Dll1 and Jag1, are overexpressed in many glioma cell lines and primary human gliomas. The roles of Notch1 in some cancers have been firmly established, and recent data implicate that it plays important roles in glioma cell fate decisions. This paper focuses on devising a specific theoretical framework that incorporates Dll1, Jag1, and Fringe in Notch1 signaling pathway to explore their functional roles of these proteins in glioma cells in the tumorigenesis and progression of human gliomas, and to study how glioma cell fate decisions are modulated by both trans-activation and cis-inhibition. This paper presents a computational model for Notch1 signaling pathway in glioma cells. Based on the bifurcation analysis of the model, we show that how the glioma cell fate decisions are modulated by both trans-activation and cis-inhibition mediated by the Fringe protein, providing insight into the design and control principles of the Notch signaling system and the gliomas. This paper presents a computational model for Notch1 signaling pathway in glioma cells based on intertwined dynamics with cis-inhibition and trans-activation involving the proteins Notch1, Dll1, Jag1, and Fringe. The results show that how the glioma cell fate transitions are performed by the Notch1 signaling. Transition from grade III ∼ IV with significantly high Notch1 to grade I ∼ II with high Notch1, and then to normal cells by repressing the Fringe levels or decreasing the strength of enhancement induced by Fringe.

  17. Butyrate attenuates lipolysis in adipocytes co-cultured with macrophages through non-prostaglandin E2-mediated and prostaglandin E2-mediated pathways.

    Science.gov (United States)

    Ohira, Hideo; Tsutsui, Wao; Mamoto, Rie; Yamaguchi, Sayaka; Nishida, Masako; Ito, Miki; Fujioka, Yoshio

    2016-12-09

    Interactions between adipocytes and macrophages are associated with metabolic disorders. Production of pro-inflammatory mediators and the release of free fatty acids (FFAs) increase when these cells are co-cultured; butyrate significantly diminishes these effects by suppressing both the macrophage inflammatory and adipocyte lipolysis pathways. Butyrate is known to up-regulate the expression of prostaglandin E2 (PGE2). Therefore, we hypothesized that PGE2 is associated with the suppression of lipolysis by butyrate in co-culture. Using contact or transwell co-culture methods with differentiated 3T3-L1 adipocytes and RAW264.7 macrophages, we investigated the effects of butyrate on the release of PGE2 into the medium and on lipolysis in adipocytes. To elucidate the underlying mechanism, we examined the effects of butyrate on cyclooxygenase-2 (COX2) and phospholipase A2 (PLA2) in co-cultured cells, and cyclic adenine monophosphate (cAMP) and protein kinase A type 1-α regulatory subunit (PRKAR1A) in co-cultured adipocytes. Silent interfering (si)RNA targeting of G-protein-coupled receptor (GPR)41 and 109A was employed to examine the effect on lipolysis in TNF-α-stimulated adipocytes. Co-culture increased PGE2 release into the medium, compared with cells cultured separately. Butyrate significantly increased PGE2 production. Co-culture elevated COX2 expression in macrophages and adipocytes, and butyrate further enhanced this effect. Co-culture enhanced cytosolic PLA2 activity in macrophages, which was further enhanced by butyrate. As for lipolysis, co-culture increased the release of FFAs and free glycerol into the medium, whereas butyrate (and to a lesser extent, PGE2) suppressed FFAs and free glycerol release. An inhibition study using a prostaglandin E receptor 3-selective antagonist suggested that approximately 40% of the suppressive effect of butyrate depends on the PGE2-mediated pathway, whereas 60% depends on a non-PGE2-mediated pathway. Co-culture increased c

  18. The Cholinergic and Adrenergic Autocrine Signaling Pathway Mediates Immunomodulation in Oyster Crassostrea gigas

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    Zhaoqun Liu

    2018-02-01

    Full Text Available It is becoming increasingly clear that neurotransmitters impose direct influence on regulation of the immune process. Recently, a simple but sophisticated neuroendocrine–immune (NEI system was identified in oyster, which modulated neural immune response via a “nervous-hemocyte”-mediated neuroendocrine immunomodulatory axis (NIA-like pathway. In the present study, the de novo synthesis of neurotransmitters and their immunomodulation in the hemocytes of oyster Crassostrea gigas were investigated to understand the autocrine/paracrine pathway independent of the nervous system. After hemocytes were exposed to lipopolysaccharide (LPS stimulation, acetylcholine (ACh, and norepinephrine (NE in the cell supernatants, both increased to a significantly higher level (2.71- and 2.40-fold, p < 0.05 comparing with that in the control group. The mRNA expression levels and protein activities of choline O-acetyltransferase and dopamine β-hydroxylase in hemocytes which were involved in the synthesis of ACh and NE were significantly elevated at 1 h after LPS stimulation, while the activities of acetylcholinesterase and monoamine oxidase, two enzymes essential in the metabolic inactivation of ACh and NE, were inhibited. These results demonstrated the existence of the sophisticated intracellular machinery for the generation, release and inactivation of ACh and NE in oyster hemocytes. Moreover, the hemocyte-derived neurotransmitters could in turn regulate the mRNA expressions of tumor necrosis factor (TNF genes, the activities of superoxide dismutase, catalase and lysosome, and hemocyte phagocytosis. The phagocytic activities of hemocytes, the mRNA expressions of TNF and the activities of key immune-related enzymes were significantly changed after the block of ACh and NE receptors with different kinds of antagonists, suggesting that autocrine/paracrine self-regulation was mediated by transmembrane receptors on hemocyte. The present study proved that

  19. Chlorpromazine-induced hepatotoxicity during inflammation is mediated by TIRAP-dependent signaling pathway in mice

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    Gandhi, Adarsh, E-mail: adarsh.gandhi@nih.gov [University of Houston, Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, 1441 Moursund Street, Room 517, Houston, TX 77030 (United States); Guo, Tao, E-mail: tguo4@jhu.edu [University of Houston, Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, 1441 Moursund Street, Room 517, Houston, TX 77030 (United States); Shah, Pranav [University of Houston, Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, 1441 Moursund Street, Room 517, Houston, TX 77030 (United States); Moorthy, Bhagavatula [Baylor College of Medicine, Department of Pediatrics, 1102 Bates Avenue, Suite 530, Houston, TX 77030 (United States); Ghose, Romi, E-mail: rghose@uh.edu [University of Houston, Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, 1441 Moursund Street, Room 517, Houston, TX 77030 (United States)

    2013-02-01

    Inflammation is a major component of idiosyncratic adverse drug reactions (IADRs). To understand the molecular mechanism of inflammation-mediated IADRs, we determined the role of the Toll-like receptor (TLR) signaling pathway in idiosyncratic hepatotoxicity of the anti-psychotic drug, chlorpromazine (CPZ). Activation of TLRs recruits the first adaptor protein, Toll-interleukin 1 receptor domain containing adaptor protein (TIRAP) to the TIR domain of TLRs leading to the activation of the downstream kinase, c-Jun-N-terminal kinase (JNK). Prolonged activation of JNK leads to cell-death. We hypothesized that activation of TLR2 by lipoteichoic acid (LTA) or TLR4 by lipopolysaccharide (LPS) will augment the hepatotoxicity of CPZ by TIRAP-dependent mechanism involving prolonged activation of JNK. Adult male C57BL/6, TIRAP{sup +/+} and TIRAP{sup −/−} mice were pretreated with saline, LPS (2 mg/kg) or LTA (6 mg/kg) for 30 min or 16 h followed by CPZ (5 mg/kg) or saline (vehicle) up to 24 h. We found that treatment of mice with CPZ in presence of LPS or LTA leads to ∼ 3–4 fold increase in serum ALT levels, a marked reduction in hepatic glycogen content, significant induction of serum tumor necrosis factor (TNF) α and prolonged JNK activation, compared to LPS or LTA alone. Similar results were observed in TIRAP{sup +/+} mice, whereas the effects of LPS or LTA on CPZ-induced hepatotoxicity were attenuated in TIRAP{sup −/−} mice. For the first time, we show that inflammation-mediated hepatotoxicity of CPZ is dependent on TIRAP, and involves prolonged JNK activation in vivo. Thus, TIRAP-dependent pathways may be targeted to predict and prevent inflammation-mediated IADRs. -- Highlights: ► Inflammation augments the toxicity of an idiosyncratic hepatotoxin chlorpromazine. ► Activation of Toll-like receptors by LPS or LTA induces chlorpromazine toxicity. ► Sustained stress kinase (JNK) activation is associated with chlorpromazine toxicity. ► These studies

  20. Chlorpromazine-induced hepatotoxicity during inflammation is mediated by TIRAP-dependent signaling pathway in mice

    International Nuclear Information System (INIS)

    Gandhi, Adarsh; Guo, Tao; Shah, Pranav; Moorthy, Bhagavatula; Ghose, Romi

    2013-01-01

    Inflammation is a major component of idiosyncratic adverse drug reactions (IADRs). To understand the molecular mechanism of inflammation-mediated IADRs, we determined the role of the Toll-like receptor (TLR) signaling pathway in idiosyncratic hepatotoxicity of the anti-psychotic drug, chlorpromazine (CPZ). Activation of TLRs recruits the first adaptor protein, Toll-interleukin 1 receptor domain containing adaptor protein (TIRAP) to the TIR domain of TLRs leading to the activation of the downstream kinase, c-Jun-N-terminal kinase (JNK). Prolonged activation of JNK leads to cell-death. We hypothesized that activation of TLR2 by lipoteichoic acid (LTA) or TLR4 by lipopolysaccharide (LPS) will augment the hepatotoxicity of CPZ by TIRAP-dependent mechanism involving prolonged activation of JNK. Adult male C57BL/6, TIRAP +/+ and TIRAP −/− mice were pretreated with saline, LPS (2 mg/kg) or LTA (6 mg/kg) for 30 min or 16 h followed by CPZ (5 mg/kg) or saline (vehicle) up to 24 h. We found that treatment of mice with CPZ in presence of LPS or LTA leads to ∼ 3–4 fold increase in serum ALT levels, a marked reduction in hepatic glycogen content, significant induction of serum tumor necrosis factor (TNF) α and prolonged JNK activation, compared to LPS or LTA alone. Similar results were observed in TIRAP +/+ mice, whereas the effects of LPS or LTA on CPZ-induced hepatotoxicity were attenuated in TIRAP −/− mice. For the first time, we show that inflammation-mediated hepatotoxicity of CPZ is dependent on TIRAP, and involves prolonged JNK activation in vivo. Thus, TIRAP-dependent pathways may be targeted to predict and prevent inflammation-mediated IADRs. -- Highlights: ► Inflammation augments the toxicity of an idiosyncratic hepatotoxin chlorpromazine. ► Activation of Toll-like receptors by LPS or LTA induces chlorpromazine toxicity. ► Sustained stress kinase (JNK) activation is associated with chlorpromazine toxicity. ► These studies provide novel mechanistic

  1. RhoA/ROCK Signaling Pathway Mediates Shuanghuanglian Injection-Induced Pseudo-allergic Reactions.

    Science.gov (United States)

    Han, Jiayin; Zhao, Yong; Zhang, Yushi; Li, Chunying; Yi, Yan; Pan, Chen; Tian, Jingzhuo; Yang, Yifei; Cui, Hongyu; Wang, Lianmei; Liu, Suyan; Liu, Jing; Deng, Nuo; Liang, Aihua

    2018-01-01

    SHLI-induced hypersensitivity reactions in both endothelial cells and mice indicating its protective effect. SHLI-induced pseudo-allergic reactions were mediated by the activation of the RhoA/ROCK signaling pathway. Conclusion : This study presents a novel mechanism of SHLI-induced immediate hypersensitivity reactions and suggests a potential therapeutic strategy to prevent the associated adverse reactions.

  2. RhoA/ROCK Signaling Pathway Mediates Shuanghuanglian Injection-Induced Pseudo-allergic Reactions

    Directory of Open Access Journals (Sweden)

    Jiayin Han

    2018-02-01

    , ameliorated the SHLI-induced hypersensitivity reactions in both endothelial cells and mice indicating its protective effect. SHLI-induced pseudo-allergic reactions were mediated by the activation of the RhoA/ROCK signaling pathway.Conclusion: This study presents a novel mechanism of SHLI-induced immediate hypersensitivity reactions and suggests a potential therapeutic strategy to prevent the associated adverse reactions.

  3. Antibody-mediated activation of the classical pathway of complement may compensate for mannose-binding lectin deficiency

    NARCIS (Netherlands)

    Roos, Anja; Garred, Peter; Wildenberg, Manon E.; Lynch, Nicholas J.; Munoz, Jeric R.; Zuiverloon, Tahlita C. M.; Bouwman, Lee H.; Schlagwein, Nicole; Fallaux van den Houten, Francien C.; Faber-Krol, Maria C.; Madsen, Hans O.; Schwaeble, Wilhelm J.; Matsushita, Misao; Fujita, Teizo; Daha, Mohamed R.

    2004-01-01

    Deficiency of mannose-binding lectin (MBL), a recognition molecule of the lectin pathway of complement, is associated with increased susceptibility to infections. The high frequency of MBL deficiency suggests that defective MBL-mediated innate immunity can be compensated by alternative defense

  4. Estimating the direct and indirect pathways between education and diabetes incidence among Canadian men and women: a mediation analysis.

    Science.gov (United States)

    Smith, Peter M; Smith, Brendan T; Mustard, Cameron A; Lu, Hong; Glazier, Richard H

    2013-03-01

    To estimate the direct and indirect pathways between education and diabetes. We examined the relative contribution of eight different pathways between education and diabetes incidence over a 9-year period in Ontario, Canada. Our data source was respondents (35-60 years of age) to the 2000-2001 Canadian Community Health Survey individually linked with physician and hospital administrative data. Our sample contained 11,899 participants with no previous diagnosis of diabetes. The direct and indirect effects of education level on incident diabetes were estimated using Aalen additive hazard models. Not having completed secondary education was associated with 120 extra diabetes cases per 10,000 men per year and 43 additional diabetes cases per 10,000 women per year, compared with having Bachelors education or higher. Body mass index accounted for 13 of the 120 extra diabetes cases among men, and 24 of the 43 additional diabetes cases for women. Of the mediating pathways examined in this paper, body mass index was the pathway through which the largest number of diabetes cases was mediated among men and women. A substantial number of excess diabetes cases among respondents with lower education levels, in particular among men, were not mediated through any of the eight pathways examined. Copyright © 2013 Elsevier Inc. All rights reserved.

  5. Inhibition of a novel specific neuroglial integrin signaling pathway increases STAT3-mediated CNTF expression

    Science.gov (United States)

    2013-01-01

    Background Ciliary neurotrophic factor (CNTF) expression is repressed in astrocytes by neuronal contact in the CNS and is rapidly induced by injury. Here, we defined an inhibitory integrin signaling pathway. Results The integrin substrates laminin, fibronectin and vitronectin, but not collagen, thrombospondin or fibrinogen, reduced CNTF expression in C6 astroglioma cells. Antibodies against αv and β5, but not α6 or β1, integrin induced CNTF. Together, the ligand and antibody specificity suggests that CNTF is repressed by αvβ5 integrin. Antibodies against Thy1, an abundant neuronal surface protein whose function is unclear, induced CNTF in neuron-astrocyte co-cultures indicating that it is a neuroglial CNTF repressor. Inhibition of the integrin signaling molecule Focal Adhesion Kinase (FAK) or the downstream c-Jun N-terminal kinase (JNK), but not extracellular regulated kinase (ERK) or p38 MAPK, greatly induced CNTF mRNA and protein expression within 4 hours. This selective inhibitory pathway phosphorylated STAT3 on its inhibitory ser-727 residue interfering with activity of the pro-transcription Tyr-705 residue. STAT3 can activate CNTF transcription because it bound to its promoter and FAK antagonist-induced CNTF was reduced by blocking STAT3. Microinjection of FAK inhibitor directly into the brain or spinal cord in adult mice rapidly induced CNTF mRNA and protein expression. Importantly, systemic treatment with FAK inhibitors over 3 days induced CNTF in the subventricular zone and increased neurogenesis. Conclusions Neuron-astroglia contact mediated by integrins serves as a sensor to enable rapid neurotrophic responses and provides a new pharmacological avenue to exploit the neuroprotective properties of endogenous CNTF. PMID:23693126

  6. Micromanaging the gut: unravelling the regulatory pathways that mediate the intestinal adaptive response.

    Science.gov (United States)

    Balakrishnan, A

    2018-03-01

    Short bowel syndrome occurs following the loss of a large portion of functional intestine and is associated with high morbidity and mortality. The intestine exhibits pronounced diurnal rhythms in glucose absorption and mounts a profound proliferative response following massive small bowel resection. Understanding the molecular pathways that underpin this could yield novel treatment options. Two in vivo models were employed using the nocturnally active Sprague Dawley® rat, namely daytime feeding and massive small bowel resection. Glucose absorption exhibited a 24-hour periodicity in the gut and peaked during maximal nutrient delivery, mediated by rhythms in the glucose transporter sodium glucose co-transporter 1 (SGLT1). Feeding during the day shifted the peak in the circadian clock gene PER1 and SGLT1. RNA interference and luciferase assays demonstrated that PER1 transcriptionally regulates SGLT1, linking for the first time clock genes and intestinal glucose absorption. Intestinal proliferation also exhibited diurnal rhythmicity, with peak absorptive surface area occurring during maximal nutrient availability. mir-16 is diurnally expressed in intestinal crypts, exhibiting minimal expression during maximal nutritional availability. mir-16 overexpression increased apoptosis and arrested proliferation in vitro. mir-125a was upregulated in intestinal crypts following 80% small bowel resection, and induced apoptosis and growth arrest upon overexpression in vitro. This work provides novel insights into the role of circadian clock genes, intestinal transporters and microRNAs in regulating intestinal absorption and proliferation and is the first demonstration of a role for microRNAs in these adaptive phenomena. Modulation of these pathways may represent a new therapeutic option for the management of short bowel syndrome.

  7. Dual pathways of carbon monoxide-mediated vasoregulation: modulation by redox mechanisms.

    Science.gov (United States)

    Lamon, Brian D; Zhang, Frank F; Puri, Nitin; Brodsky, Sergey V; Goligorsky, Michael S; Nasjletti, Alberto

    2009-10-09

    Vascular tissues produce carbon monoxide (CO) via HO-dependent and HO-independent mechanisms; the former in tandem with biliverdin and iron and the latter as a lone product. CO has been shown to function as both a vasoconstrictor and vasodilator; however, factors that dictate the vasoregulatory phenotype of this gas are unknown. We investigated whether CO-mediated vasoconstriction is mechanistically linked to enhanced reactive oxygen species production that masks vasodilatory pathways. Sprague-Dawley rat interlobar and interlobular arteries were examined in terms of superoxide (O2*-) generation and vascular reactivity in the absence and presence of antioxidants. Both authentic CO and the CO-releasing molecule (CORM)-3 constricted renal arteries and increased O2*- production in a dose-dependent manner. The antioxidants tempol, ebselen, and deferoxamine inhibited CO-induced O2*- production and converted CO from constrictor to dilator. CO-induced O2*- generation was found to involve the activity of multiple oxidases including nitric oxide synthase, NADPH oxidase, xanthine oxidase, and complex IV of the mitochondrial electron chain. Furthermore, inhibition of these enzymes converted CO from constrictor to dilator. Similarly, biliverdin and bilirubin inhibited CO-induced O2*- production and vasoconstriction, allowing for a vasodilatory response to CO to be expressed. CO-induced vasoconstriction was dependent on a non-thromboxane agonist of the thromboxane receptor, whereas vasodilatory mechanisms of CO relied on the activation of soluble guanylate cyclase and calcium-gated potassium channels. CO-induced vasoconstriction involves the generation of reactive oxygen species, which, when negated, allows for the expression of vasodilatory pathways which are masked by the primary oxidative stress response to this gas.

  8. Analysis of Human TAAR8 and Murine Taar8b Mediated Signaling Pathways and Expression Profile

    Directory of Open Access Journals (Sweden)

    Jessica Mühlhaus

    2014-11-01

    Full Text Available The thyroid hormone derivative 3-iodothyronamine (3-T1AM exerts metabolic effects in vivo that contradict known effects of thyroid hormones. 3-T1AM acts as a trace amine-associated receptor 1 (TAAR1 agonist and activates Gs signaling in vitro. Interestingly, 3-T1AM-meditated in vivo effects persist in Taar1 knockout-mice indicating that further targets of 3-T1AM might exist. Here, we investigated another member of the TAAR family, the only scarcely studied mouse and human trace-amine-associated receptor 8 (Taar8b, TAAR8. By RT-qPCR and locked-nucleic-acid (LNA in situ hybridization, Taar8b expression in different mouse tissues was analyzed. Functionally, we characterized TAAR8 and Taar8b with regard to cell surface expression and signaling via different G-protein-mediated pathways. Cell surface expression was verified by ELISA, and cAMP accumulation was quantified by AlphaScreen for detection of Gs and/or Gi/o signaling. Activation of G-proteins Gq/11 and G12/13 was analyzed by reporter gene assays. Expression analyses revealed at most marginal Taar8b expression and no gender differences for almost all analyzed tissues. In heart, LNA-in situ hybridization demonstrated the absence of Taar8b expression. We could not identify 3-T1AM as a ligand for TAAR8 and Taar8b, but both receptors were characterized by a basal Gi/o signaling activity, a so far unknown signaling pathway for TAARs.

  9. A convergent and essential interneuron pathway for Mauthner-cell-mediated escapes.

    Science.gov (United States)

    Lacoste, Alix M B; Schoppik, David; Robson, Drew N; Haesemeyer, Martin; Portugues, Ruben; Li, Jennifer M; Randlett, Owen; Wee, Caroline L; Engert, Florian; Schier, Alexander F

    2015-06-01

    The Mauthner cell (M-cell) is a command-like neuron in teleost fish whose firing in response to aversive stimuli is correlated with short-latency escapes [1-3]. M-cells have been proposed as evolutionary ancestors of startle response neurons of the mammalian reticular formation [4], and studies of this circuit have uncovered important principles in neurobiology that generalize to more complex vertebrate models [3]. The main excitatory input was thought to originate from multisensory afferents synapsing directly onto the M-cell dendrites [3]. Here, we describe an additional, convergent pathway that is essential for the M-cell-mediated startle behavior in larval zebrafish. It is composed of excitatory interneurons called spiral fiber neurons, which project to the M-cell axon hillock. By in vivo calcium imaging, we found that spiral fiber neurons are active in response to aversive stimuli capable of eliciting escapes. Like M-cell ablations, bilateral ablations of spiral fiber neurons largely eliminate short-latency escapes. Unilateral spiral fiber neuron ablations shift the directionality of escapes and indicate that spiral fiber neurons excite the M-cell in a lateralized manner. Their optogenetic activation increases the probability of short-latency escapes, supporting the notion that spiral fiber neurons help activate M-cell-mediated startle behavior. These results reveal that spiral fiber neurons are essential for the function of the M-cell in response to sensory cues and suggest that convergent excitatory inputs that differ in their input location and timing ensure reliable activation of the M-cell, a feedforward excitatory motif that may extend to other neural circuits. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. HMGB1 mediates depressive behavior induced by chronic stress through activating the kynurenine pathway.

    Science.gov (United States)

    Wang, Bo; Lian, Yong-Jie; Su, Wen-Jun; Peng, Wei; Dong, Xin; Liu, Lin-Lin; Gong, Hong; Zhang, Ting; Jiang, Chun-Lei; Wang, Yun-Xia

    2017-11-28

    Our previous study has reported that the proactive secretion and role of central high mobility group box 1 (HMGB1) in lipopolysaccharide-induced depressive behavior. Here, the potential mechanism of HMGB1 mediating chronic-stress-induced depression through the kynurenine pathway (KP) was further explored both in vivo and in vitro. Depression model was established with the 4-week chronic unpredictable mild stress (CUMS). Sucrose preference and Barnes maze test were performed to reflect depressive behaviors. The ratio of kynurenine (KYN)/tryptophan (Trp) represented the enzyme activity of indoleamine-2,3-dioxygenase (IDO). Gene transcription and protein expression were assayed by real-time RT-PCR and western-blot or ELISA kit respectively. Along with depressive behaviors, HMGB1 concentrations in the hippocampus and serum substantially increased post 4-week CUMS exposure. Concurrent with the upregulated HMGB1 protein, the regulator of translocation of HMGB1, sirtuin 1 (SIRT1) concentration in the hippocampus remarkably increased. In addition to HMGB1 and SIRT1, IDO, the rate limiting enzyme of KP, was upregulated at the level of mRNA expression and enzyme activity in stressed hippocampi and LPS/HMGB1-treated hippocampal slices. The gene transcription of kynurenine monooxygenase (KMO) and kynureninase (KYNU) in the downstream of KP also increased both in vivo and in vitro. Mice treated with ethyl pyruvate (EP), the inhibitor of HMGB1 releasing, were observed with lower tendency of developing depressive behaviors and reduced activation of enzymes in KP. All of these experiments demonstrate that the role of HMGB1 on the induction of depressive behavior is mediated by KP activation. Copyright © 2017 Elsevier Inc. All rights reserved.

  11. 25-Hydroxycholesterol promotes fibroblast-mediated tissue remodeling through NF-κB dependent pathway

    Energy Technology Data Exchange (ETDEWEB)

    Ichikawa, Tomohiro [Third Department of Internal Medicine, Wakayama Medical University, School of Medicine, 811-1 Kimiidera, Wakayama 641-8509 (Japan); Sugiura, Hisatoshi, E-mail: sugiura@rm.med.tohoku.ac.jp [Department of Respiratory Medicine, Tohoku University Graduate School of Medicine, 1-1 Seiryo-machi, Aoba-ku, Sendai 980-8574 (Japan); Koarai, Akira; Kikuchi, Takashi; Hiramatsu, Masataka; Kawabata, Hiroki; Akamatsu, Keiichiro; Hirano, Tsunahiko; Nakanishi, Masanori; Matsunaga, Kazuto; Minakata, Yoshiaki [Third Department of Internal Medicine, Wakayama Medical University, School of Medicine, 811-1 Kimiidera, Wakayama 641-8509 (Japan); Ichinose, Masakazu [Department of Respiratory Medicine, Tohoku University Graduate School of Medicine, 1-1 Seiryo-machi, Aoba-ku, Sendai 980-8574 (Japan)

    2013-05-01

    Abnormal structural alterations termed remodeling, including fibrosis and alveolar wall destruction, are important features of the pathophysiology of chronic airway diseases such as chronic obstructive pulmonary disease (COPD) and asthma. 25-hydroxycholesterol (25-HC) is enzymatically produced by cholesterol 25-hydorxylase (CH25H) in macrophages and is reported to be involved in the formation of arteriosclerosis. We previously demonstrated that the expression of CH25H and production of 25HC were increased in the lungs of COPD. However, the role of 25-HC in lung tissue remodeling is unknown. In this study, we investigated the effect of 25-HC on fibroblast-mediated tissue remodeling using human fetal lung fibroblasts (HFL-1) in vitro. 25-HC significantly augmented α-smooth muscle actin (SMA) (P<0.001) and collagen I (P<0.001) expression in HFL-1. 25-HC also significantly enhanced the release and activation of matrix metallaoproteinase (MMP)-2 (P<0.001) and MMP-9 (P<0.001) without any significant effect on the production of tissue inhibitor of metalloproteinase (TIMP)-1 and TIMP-2. 25-HC stimulated transforming growth factor (TGF)-β{sub 1} production (P<0.01) and a neutralizing anti-TGF-β antibody restored these 25-HC-augmented pro-fibrotic responses. 25-HC significantly promoted the translocation of nuclear factor (NF)-κB p65 into the nuclei (P<0.01), but not phospholylated-c-jun, a complex of activator protein-1. Pharmacological inhibition of NF-κB restored the 25-HC-augmented pro-fibrotic responses and TGF-β{sub 1} release. These results suggest that 25-HC could contribute to fibroblast-mediated lung tissue remodeling by promoting myofibroblast differentiation and the excessive release of extracellular matrix protein and MMPs via an NF-κB-TGF-β dependent pathway.

  12. Alpha-Linolenic Acid Confers Neuroprotection and Improves Behavioral Deficits After Soman Exposure: Involvement of Neurogenesis Through an mTOR-Mediated Pathway

    Science.gov (United States)

    2015-01-15

    ALPHA-LINOLENIC ACID CONFERS NEUROPROTECTION AND IMPROVES BEHAVIORAL DEFICITS AFTER SOMAN EXPOSURE: INVOLVEMENT OF NEUROGENESIS THROUGH...soman exposure: involvement of neurogenesis through an mTOR-mediated pathway" Name of Candidate: Tetsade CB Piermartiri Doctor of Philosophy Degree...IMPROVES BEHAVIORAL DEFICITS AFTER SOMAN EXPOSURE: INVOLVEM OF NEUROGENESIS THROUGH AN mTOR-MEDIATED PATHWAY" is appropriately acknowledged and, beyond

  13. PME-1 protects ERK pathway activity from protein phosphatase 2A-mediated inactivation in human malignant glioma

    Science.gov (United States)

    Puustinen, Pietri; Junttila, Melissa R.; Vanhatupa, Sari; Sablina, Anna A.; Hector, Melissa E.; Teittinen, Kaisa; Raheem, Olayinka; Ketola, Kirsi; Lin, Shujun; Kast, Juergen; Haapasalo, Hannu; Hahn, William C.; Westermarck, Jukka

    2010-01-01

    ERK/MAPK pathway activity is regulated by the antagonist function of activating kinases and inactivating protein phosphatases. Sustained ERK pathway activity is commonly observed in human malignancies, however the mechanisms by which the pathway is protected from phosphatase-mediated inactivation in the tumor tissue remain obscure. Here we show that methylesterase PME-1-mediated inhibition of the protein phosphatase 2A (PP2A) promotes basal ERK pathway activity, and is required for efficient growth factor response. Mechanistically PME-1 is shown to support ERK pathway signaling upstream of Raf, but downstream of growth factor receptors and PKC. In malignant glioblastoma, PME-1 expression levels correlate with both ERK activity and cell proliferation in vivo. Moreover, PME-1 expression significantly correlates with disease progression in human astrocytic gliomas (N=222). Together, these observations identify PME-1 expression as one mechanism by which ERK pathway activity is maintained in cancer cells, and suggest important functional role for PME-1 in the disease progression of human astrocytic gliomas. PMID:19293187

  14. Role of the Nrf2-heme oxygenase-1 pathway in silver nanoparticle-mediated cytotoxicity

    International Nuclear Information System (INIS)

    Kang, Su Jin; Ryoo, In-geun; Lee, Young Joon; Kwak, Mi-Kyoung

    2012-01-01

    Silver nanoparticles (nano-Ag) have been widely used in various commercial products including textiles, electronic appliances and biomedical products. However, there remains insufficient information on the potential risk of nano-Ag to human health and environment. In the current study, we have investigated the role of NF-E2-related factor 2 (Nrf2) transcription factor in nano-Ag-induced cytotoxicity. When Nrf2 expression was blocked using interring RNA expression in ovarian carcinoma cell line, nano-Ag treatment showed a substantial decrease in cell viability with concomitant increases in apoptosis and DNA damage compared to the control cells. Target gene analysis revealed that the expression of heme oxygenase-1 (HO-1) was highly elevated by nano-Ag in nonspecific shRNA expressing cells, while Nrf2 knockdown cells (NRF2i) did not increase HO-1 expression. The role of HO-1 in cytoprotection against nano-Ag was reinforced by results using pharmacological inducer of HO-1: cobalt protoporphyrin-mediated HO-1 activation in the NRF2i cells prevented nano-Ag-mediated cell death. Similarly, pharmacological or genetic inhibition of HO-1 in nonspecific control cells exacerbated nano-Ag toxicity. As the upstream signaling mechanism, nano-Ag required the phosphoinositide 3-kinase (PI3K) and p38MAPK signaling cascades for HO-1 induction. The treatment with either PI3K inhibitor or p38MAPK inhibitor suppressed HO-1 induction and intensified nano-Ag-induced cell death. Taken together, these results suggest that Nrf2-dependent HO-1 up-regulation plays a protective role in nano-Ag-induced DNA damage and consequent cell death. In addition, nano-Ag-mediated HO-1 induction is associated with the PI3K and p38MAPK signaling pathways. -- Highlights: ► Role of Nrf2 signaling in silver nanoparticle toxicity. ► Silver nanoparticle toxicity is increased by Nrf2 blockade. ► Nrf2-dependent HO-1 induction protects cells from silver nanoparticle toxicity. ► PI3K and p38MAPK cascades are

  15. Suppression of the auxin response pathway enhances susceptibility to Phytophthora cinnamomi while phosphite-mediated resistance stimulates the auxin signalling pathway

    Science.gov (United States)

    2014-01-01

    Background Phytophthora cinnamomi is a devastating pathogen worldwide and phosphite (Phi), an analogue of phosphate (Pi) is highly effective in the control of this pathogen. Phi also interferes with Pi starvation responses (PSR), of which auxin signalling is an integral component. In the current study, the involvement of Pi and the auxin signalling pathways in host and Phi-mediated resistance to P. cinnamomi was investigated by screening the Arabidopsis thaliana ecotype Col-0 and several mutants defective in PSR and the auxin response pathway for their susceptibility to this pathogen. The response to Phi treatment was also studied by monitoring its effect on Pi- and the auxin response pathways. Results Here we demonstrate that phr1-1 (phosphate starvation response 1), a mutant defective in response to Pi starvation was highly susceptible to P. cinnamomi compared to the parental background Col-0. Furthermore, the analysis of the Arabidopsis tir1-1 (transport inhibitor response 1) mutant, deficient in the auxin-stimulated SCF (Skp1 − Cullin − F-Box) ubiquitination pathway was also highly susceptible to P. cinnamomi and the susceptibility of the mutants rpn10 and pbe1 further supported a role for the 26S proteasome in resistance to P. cinnamomi. The role of auxin was also supported by a significant (P < 0.001) increase in susceptibility of blue lupin (Lupinus angustifolius) to P. cinnamomi following treatment with the inhibitor of auxin transport, TIBA (2,3,5-triiodobenzoic acid). Given the apparent involvement of auxin and PSR signalling in the resistance to P. cinnamomi, the possible involvement of these pathways in Phi mediated resistance was also investigated. Phi (especially at high concentrations) attenuates the response of some Pi starvation inducible genes such as AT4, AtACP5 and AtPT2 in Pi starved plants. However, Phi enhanced the transcript levels of PHR1 and the auxin responsive genes (AUX1, AXR1and AXR2), suppressed the primary root

  16. O-GlcNAc regulates NEDD4-1 stability via caspase-mediated pathway

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Kuan; Bai, Bingyang; Ta, Yajie; Zhang, Tingling; Xiao, Zikang; Wang, Peng George, E-mail: pwang@nankai.edu.cn; Zhang, Lianwen, E-mail: lianwen@nankai.edu.cn

    2016-03-18

    O-GlcNAc modification of cytosolic and nuclear proteins regulates essential cellular processes such as stress responses, transcription, translation, and protein degradation. Emerging evidence indicates O-GlcNAcylation has a dynamic interplay with ubiquitination in cellular regulation. Here, we report that O-GlcNAc indirectly targets a vital E3 ubiquitin ligase enzyme of NEDD4-1. The protein level of NEDD4-1 is accordingly decreased following an increase of overall O-GlcNAc level upon PUGNAc or glucosamine stimulation. O-GlcNAc transferase (OGT) knockdown, overexpression and mutation results confirm that the stability of NEDD4-1 is negatively regulated by cellular O-GlcNAc. Moreover, the NEDD4-1 degradation induced by PUGNAc or GlcN is significantly inhibited by the caspase inhibitor. Our study reveals a regulation mechanism of NEDD4-1 stability by O-GlcNAcylation. - Highlights: • Reduced NEDD4-1 correlates with increased overall O-GlcNAc level. • OGT negatively regulates NEDD4-1 stability. • O-GlcNAc regulates NEDD4-1 through caspase-mediated pathway.

  17. Hexachlorophene inhibits Wnt/beta-catenin pathway by promoting Siah-mediated beta-catenin degradation.

    Science.gov (United States)

    Park, Seoyoung; Gwak, Jungsug; Cho, Munju; Song, Taeyun; Won, Jaejoon; Kim, Dong-Eun; Shin, Jae-Gook; Oh, Sangtaek

    2006-09-01

    Aberrant activation of Wnt/beta-catenin signaling and subsequent up-regulation of beta-catenin response transcription (CRT) is a critical event in the development of human colon cancer. Thus, Wnt/beta-catenin signaling is an attractive target for the development of anticancer therapeutics. In this study, we identified hexachlorophene as an inhibitor of Wnt/beta-catenin signaling from cell-based small-molecule screening. Hexachlorophene antagonized CRT that was stimulated by Wnt3a-conditioned medium by promoting the degradation of beta-catenin. This degradation pathway is Siah-1 and adenomatous polyposis colidependent, but glycogen synthase kinase-3beta and F-box beta-transducin repeat-containing protein-independent. In addition, hexachlorophene represses the expression of cyclin D1, which is a known beta-catenin target gene, and inhibits the growth of colon cancer cells. Our findings suggest that hexachlorophene attenuates Wnt/beta-catenin signaling through the Siah-1-mediated beta-catenin degradation.

  18. Pathways of influence in school-based mentoring: the mediating role of parent and teacher relationships.

    Science.gov (United States)

    Chan, Christian S; Rhodes, Jean E; Howard, Waylon J; Lowe, Sarah R; Schwartz, Sarah E O; Herrera, Carla

    2013-02-01

    This study explores the pathways through which school-based mentoring relationships are associated with improvements in elementary and high school students' socio-emotional, academic, and behavioral outcomes. Participants in the study (N=526) were part of a national evaluation of the Big Brothers Big Sisters school-based mentoring programs, all of whom had been randomly assigned to receive mentoring at their schools over the course of one academic year. Students were assessed at the beginning and end of the school year. The results of structural equation modeling showed that mentoring relationship quality, as measured by the Youth-Centered Relationship scale and the Youth's Emotional Engagement scale, was significantly associated with positive changes in youths' relationships with parents and teachers, as measured by subscales of the Inventory of Parent and Peer Attachment, the Teacher Relationship Quality scale, and the Hemingway Measure of Adolescent Connectedness. Higher quality relationships with parents and teachers, in turn, were significantly associated with better youth outcomes, including self-esteem, academic attitudes, prosocial behaviors, and misconduct. The effect sizes of the associations ranged from 0.12 to 0.52. Mediation analysis found that mentoring relationship quality was indirectly associated with some of the outcomes through its association with improved parent and teacher relationships. Implications of the findings for theory and research are discussed. Copyright © 2012 Society for the Study of School Psychology. Published by Elsevier Ltd. All rights reserved.

  19. Novel Hematopoietic Target Genes in the NRF2-Mediated Transcriptional Pathway

    Directory of Open Access Journals (Sweden)

    Michelle R. Campbell

    2013-01-01

    Full Text Available Nuclear factor- (erythroid-derived 2 like 2 (NFE2L2, NRF2 is a key transcriptional activator of the antioxidant response pathway and is closely related to erythroid transcription factor NFE2. Under oxidative stress, NRF2 heterodimerizes with small Maf proteins and binds cis-acting enhancer sequences found near oxidative stress response genes. Using the dietary isothiocyanate sulforaphane (SFN to activate NRF2, chromatin immunoprecipitation sequencing (ChIP-seq identified several hundred novel NRF2-mediated targets beyond its role in oxidative stress. Activated NRF2 bound the antioxidant response element (ARE in promoters of several known and novel target genes involved in iron homeostasis and heme metabolism, including known targets FTL and FTH1, as well as novel binding in the globin locus control region. Five novel NRF2 target genes were chosen for followup: AMBP, ABCB6, FECH, HRG-1 (SLC48A1, and TBXAS1. SFN-induced gene expression in erythroid K562 and lymphoid cells were compared for each target gene. NRF2 silencing showed reduced expression in lymphoid, lung, and hepatic cells. Furthermore, stable knockdown of NRF2 negative regulator KEAP1 in K562 cells resulted in increased NQO1, AMBP, and TBXAS1 expression. NFE2 binding sites in K562 cells revealed similar binding profiles as lymphoid NRF2 sites in all potential NRF2 candidates supporting a role for NRF2 in heme metabolism and erythropoiesis.

  20. Inositol Hexakisphosphate Mediates Apoptosis in Human Breast Adenocarcinoma MCF-7 Cell Line via Intrinsic Pathway

    Science.gov (United States)

    Agarwal, Rakhee; Ali, Nawab

    2010-04-01

    Inositol polyphosphates (InsPs) are naturally occurring compounds ubiquitously present in plants and animals. Inositol hexakisphosphate (InsP6) is the most abundant among all InsPs and constitutes the major portion of dietary fiber in most cereals, legumes and nuts. Certain derivatives of InsPs also regulate cellular signaling mechanisms. InsPs have also been shown to reduce tumor formation and induce apoptosis in cancerous cells. Therefore, in this study, the effects of InsPs on apoptosis were studied in an attempt to investigate their potential anti-cancer therapeutic application and understand their mechanism of action. Acridine orange and ethidium bromide staining suggested that InsP6 dose dependently induced apoptosis in human breast adenocarcinoma MCF-7 cells. Among InsPs tested (InsP3, InsP4, InsP5, and InsP6), InsP6 was found to be the most effective in inducing apoptosis. Furthermore, effects of InsP6 were found most potent inducing apoptosis. Etoposide, the drug known to induce apoptosis in both in vivo and in vitro, was used as a positive control. Western blotting experiments using specific antibodies against known apoptotic markers suggested that InsP6 induced apoptotic changes were mediated via an intrinsic apoptotic pathway.

  1. Nano Copper Induces Apoptosis in PK-15 Cells via a Mitochondria-Mediated Pathway.

    Science.gov (United States)

    Zhang, Hui; Chang, Zhenyu; Mehmood, Khalid; Abbas, Rao Zahid; Nabi, Fazul; Rehman, Mujeeb Ur; Wu, Xiaoxing; Tian, Xinxin; Yuan, Xiaodan; Li, Zhaoyang; Zhou, Donghai

    2018-01-01

    Nano-sized copper particles are widely used in various chemical, physical, and biological fields. However, earlier studies have shown that nano copper particles (40-100 μg/mL) can induce cell toxicity and apoptosis. Therefore, this study was conducted to investigate the role of nano copper in mitochondrion-mediated apoptosis in PK-15 cells. The cells were treated with different doses of nano copper (20, 40, 60, and 80 μg/mL) to determine the effects of apoptosis using acridine orange/ethidium bromide (AO/EB) fluorescence staining and a flow cytometry assay. The levels of malondialdehyde (MDA) and superoxide dismutase (SOD) in the PK-15 cells were examined using commercially available kits. Moreover, the mRNA levels of the Bax, Bid, Caspase-3, and CYCS genes were assessed by real-time PCR. The results revealed that nano copper exposure induced apoptosis and changed the mitochondrial membrane potential. In addition, nano copper significantly altered the levels of the Bax, Bid, Caspase-3, and CYCS genes at a concentration of 40 μg/mL. To summarize, nano copper significantly (P nano copper can play an important role in inducing the apoptotic pathway in PK-15 cells, which may be the mechanism by which nano copper induces nephrotoxicity.

  2. Class 3 Semaphorin Mediates Dendrite Growth in Adult Newborn Neurons through Cdk5/FAK Pathway

    Science.gov (United States)

    Sohn, Jae Ho; Tan, Terence; Song, Hongjun; Ming, Guo-li; Goh, Eyleen L. K.

    2013-01-01

    Class 3 semaphorins are well-known axonal guidance cues during the embryonic development of mammalian nervous system. However, their activity on postnatally differentiated neurons in neurogenic regions of adult brains has not been characterized. We found that silencing of semaphorin receptors neuropilins (NRP) 1 or 2 in neural progenitors at the adult mouse dentate gyrus resulted in newly differentiated neurons with shorter dendrites and simpler branching in vivo. Tyrosine phosphorylation (Tyr 397) and serine phosphorylation (Ser 732) of FAK were essential for these effects. Semaphorin 3A and 3F mediate serine phosphorylation of FAK through the activation of Cdk5. Silencing of either Cdk5 or FAK in newborn neurons phenocopied the defects in dendritic development seen upon silencing of NRP1 or NRP2. Furthermore, in vivo overexpression of Cdk5 or FAK rescued the dendritic phenotypes seen in NRP1 and NRP2 deficient neurons. These results point to a novel role for class 3 semaphorins in promoting dendritic growth and branching during adult hippocampal neurogenesis through the activation of Cdk5-FAK signaling pathway. PMID:23762397

  3. Class 3 semaphorin mediates dendrite growth in adult newborn neurons through Cdk5/FAK pathway.

    Directory of Open Access Journals (Sweden)

    Teclise Ng

    Full Text Available Class 3 semaphorins are well-known axonal guidance cues during the embryonic development of mammalian nervous system. However, their activity on postnatally differentiated neurons in neurogenic regions of adult brains has not been characterized. We found that silencing of semaphorin receptors neuropilins (NRP 1 or 2 in neural progenitors at the adult mouse dentate gyrus resulted in newly differentiated neurons with shorter dendrites and simpler branching in vivo. Tyrosine phosphorylation (Tyr 397 and serine phosphorylation (Ser 732 of FAK were essential for these effects. Semaphorin 3A and 3F mediate serine phosphorylation of FAK through the activation of Cdk5. Silencing of either Cdk5 or FAK in newborn neurons phenocopied the defects in dendritic development seen upon silencing of NRP1 or NRP2. Furthermore, in vivo overexpression of Cdk5 or FAK rescued the dendritic phenotypes seen in NRP1 and NRP2 deficient neurons. These results point to a novel role for class 3 semaphorins in promoting dendritic growth and branching during adult hippocampal neurogenesis through the activation of Cdk5-FAK signaling pathway.

  4. PGE2 Modulates GABAA Receptors via an EP1 Receptor-Mediated Signaling Pathway

    Directory of Open Access Journals (Sweden)

    Guang Yang

    2015-07-01

    Full Text Available Aims: PGE2 is one of the most abundant prostanoids in mammalian tissues, but its effect on neuronal receptors has not been well investigated. This study examines the effect of PGE2 on GABAA receptor currents in rat cerebellar granule neurons. Methods: GABAA currents were recorded using a patch-clamp technique. Cell surface and total protein of GABAA β1/2/3 subunits was carried out by Western blot analysis. Results: Upon incubation of neurons with PGE2 (1 µM for 60 minutes, GABAA currents were significantly potentiated. This PGE2-driven effect could be blocked by PKC or CaMKII inhibitors as well as EP1 receptor antagonist, and mimicked by PMA or EP1 receptor agonist. Furthermore, Western blot data showed that PGE2 did not increase the total expression level of GABAA receptors, but significantly increased surface levels of GABAA β1/2/3 subunits after 1 h of treatment. Consistently, both PKC and CaMKII inhibitors were able to reduce PGE2-induced increases in cell surface expression of GABAA receptors. Conclusion: Activation of either the PKC or CaMKII pathways by EP1 receptors mediates the PGE2-induced increase in GABAA currents. This suggests that upregulation of postsynaptic GABAA receptors by PGE2 may have profound effects on cerebellar functioning under physiological and pathological conditions.

  5. Diffused and sustained inhibitory effects of intestinal electrical stimulation on intestinal motility mediated via sympathetic pathway.

    Science.gov (United States)

    Zhao, Xiaotuan; Yin, Jieyun; Wang, Lijie; Chen, Jiande D Z

    2014-06-01

    The aims were to investigate the energy-dose response effect of intestinal electrical stimulation (IES) on small bowel motility, to compare the effect of forward and backward IES, and to explore the possibility of using intermittent IES and mechanism of IES on intestinal motility. Five dogs implanted with a duodenal cannula and one pair of intestinal serosal electrodes were studied in five sessions: 1) energy-dose response study; 2) forward IES; 3) backward IES; 4) intermittent IES vs. continuous IES; 5) administration of guanethidine. The contractile activity and tonic pressure of the small intestine were recorded. The duration of sustained effect after turning off IES was manually calculated. 1) IES with long pulse energy dose dependently inhibited contractile activity and tonic pressure of the small intestine (p intestine depended on the energy of IES delivered (p intestine. 5) Guanethidine blocked the inhibitory effect of IES on intestinal motility. IES with long pulses inhibits small intestinal motility; the effect is energy-dose dependent, diffused, and sustained. Intermittent IES has the same efficacy as the continuous IES in inhibiting small intestinal motility. Forward and backward IES have similar inhibitory effects on small bowel motility. This IES-induced inhibitory effect is mediated via the sympathetic pathway. © 2013 International Neuromodulation Society.

  6. INOSITOL HEXAKISPHOSPHATE MEDIATES APOPTOSIS IN HUMAN BREAST ADENOCARCINOMA MCF-7 CELL LINE VIA INTRINSIC PATHWAY

    International Nuclear Information System (INIS)

    Agarwal, Rakhee; Ali, Nawab

    2010-01-01

    Inositol polyphosphates (InsP s ) are naturally occurring compounds ubiquitously present in plants and animals. Inositol hexakisphosphate (InsP 6 ) is the most abundant among all InsP s and constitutes the major portion of dietary fiber in most cereals, legumes and nuts. Certain derivatives of InsP s also regulate cellular signaling mechanisms. InsP s have also been shown to reduce tumor formation and induce apoptosis in cancerous cells. Therefore, in this study, the effects of InsPs on apoptosis were studied in an attempt to investigate their potential anti-cancer therapeutic application and understand their mechanism of action. Acridine orange and ethidium bromide staining suggested that InsP 6 dose dependently induced apoptosis in human breast adenocarcinoma MCF-7 cells. Among InsP s tested (InsP 3 , InsP 4 , InsP 5 , and InsP 6 ), InsP 6 was found to be the most effective in inducing apoptosis. Furthermore, effects of InsP 6 were found most potent inducing apoptosis. Etoposide, the drug known to induce apoptosis in both in vivo and in vitro, was used as a positive control. Western blotting experiments using specific antibodies against known apoptotic markers suggested that InsP 6 induced apoptotic changes were mediated via an intrinsic apoptotic pathway.

  7. Do Trust and Sexual Intimacy Mediate Attachment's Pathway Toward Sexual Violence Occurring in Same Sex Romantic Relationships?

    Science.gov (United States)

    Gabbay, Nicolas; Lafontaine, Marie-France

    2017-07-01

    This study tested a serial mediation model examining how dyadic trust and sexual intimacy mediate the relationship between insecure romantic attachment and perpetrated sexual violence occurring between same sex intimate partners (sexual SSIPV). A community sample of adults ( N = 310; 203 women, 107 men) involved in a committed (6 months or longer) same sex romantic relationship completed an encrypted online questionnaire package which included psychometric measures designed to assess the aforementioned variables. Controlling for gender effects, analyses conducted using bootstrapping procedures supported full mediation pathways for both attachment anxiety and attachment avoidance. That is, attachment anxiety and avoidance were both directly associated to the perpetration of sexual SSIPV, and these relationships were both fully mediated by dyadic trust and sexual intimacy, in that respective order.

  8. TLR4-mediated NF-κB signaling pathway mediates HMGB1-induced pancreatic injury in mice with severe acute pancreatitis.

    Science.gov (United States)

    Li, Gang; Wu, Xuejun; Yang, Le; He, Yuxiang; Liu, Yang; Jin, Xing; Yuan, Hai

    2016-01-01

    Severe acute pancreatitis (SAP) is an extremely dangerous acute abdominal disorder which causes multiple complications and has a high mortality rate. Previous research has suggested that high-mobility group box 1 (HMGB1) plays an important role in the pathogenesis of SAP; however, the mechanisms underlying this strong correlation remain unclear. In this study, to further investigate whether HMGB1 acts as a stimulating factor, and whether Toll-like receptor 4 (TLR4) acts as its major mediator in the development of pancreatic injury during SAP, recombinant human HMGB1 (rhHMGB1) and TLR4-deficient mice were used. We found that HMGB1 and TLR4 were highly expressed, and nuclear factor-κB (NF-κB) was activated in our mouse model of SAP. We noted that the rhHMGB1 pancreas-targeted injection activated the TLR4-mediated NF-κB signaling pathway and induced pancreatic injury in wild-type mice. In TLR4-deficient mice, the rhHMGB1-induced activation of NF-κB and pathological changes in the pancreas were less evident than in wild-type mice. Therefore, this study provides evidence that HMGB1 promotes the pathogenesis of pancreatitis, and its downstream TLR4-mediated NF-κB signaling pathway is a potential important mediator in the development of this form of pancreatic injury.

  9. Obesity Suppresses Estrogen Receptor Beta Expression in Breast Cancer Cells via a HER2-Mediated Pathway.

    Science.gov (United States)

    Bowers, Laura W; Wiese, Megan; Brenner, Andrew J; Rossi, Emily L; Tekmal, Rajeshwar R; Hursting, Stephen D; deGraffenried, Linda A

    2015-01-01

    Obesity is associated with a worse breast cancer prognosis, while greater breast tumor estrogen receptor beta (ERβ) expression is correlated with improved therapy response and survival. The objective of this study was to determine the impact of obesity on breast cancer cell ERβ expression, which is currently unknown. We utilized an in vitro model of obesity in which breast cancer cells were exposed to patient serum pooled by body mass index category (obese (OB): ≥30 kg/m2; normal weight (N): 18.5-24.9 kg/m2). Four human mammary tumor cell lines representing the major breast cancer subtypes (SKBR3, MCF-7, ZR75, MDA-MB-231) and mammary tumor cells from MMTV-neu mice were used. ERβ expression, assessed by qPCR and western blotting, was suppressed in the two HER2-overexpressing cell lines (SKBR3, MMTV-neu) following OB versus N sera exposure, but did not vary in the other cell lines. Expression of Bcl-2 and cyclin D1, two genes negatively regulated by ERβ, was elevated in SKBR3 cells following exposure to OB versus N sera, but this difference was eliminated when the ERβ gene was silenced with siRNA. Herceptin, a HER2 antagonist, and siRNA to HER2 were used to evaluate the role of HER2 in sera-induced ERβ modulation. SKBR3 cell treatment with OB sera plus Herceptin increased ERβ expression three-fold. Similar results were obtained when HER2 expression was silenced with siRNA. OB sera also promoted greater SKBR3 cell viability and growth, but this variance was not present when ERβ was silenced or the cells were modified to overexpress ERβ. Based on this data, we conclude that obesity-associated systemic factors suppress ERβ expression in breast cancer cells via a HER2-mediated pathway, leading to greater cell viability and growth. Elucidation of the mechanism(s) mediating this effect could provide important insights into how ERβ expression is regulated as well as how obesity promotes a more aggressive disease.

  10. Obesity Suppresses Estrogen Receptor Beta Expression in Breast Cancer Cells via a HER2-Mediated Pathway.

    Directory of Open Access Journals (Sweden)

    Laura W Bowers

    Full Text Available Obesity is associated with a worse breast cancer prognosis, while greater breast tumor estrogen receptor beta (ERβ expression is correlated with improved therapy response and survival. The objective of this study was to determine the impact of obesity on breast cancer cell ERβ expression, which is currently unknown. We utilized an in vitro model of obesity in which breast cancer cells were exposed to patient serum pooled by body mass index category (obese (OB: ≥30 kg/m2; normal weight (N: 18.5-24.9 kg/m2. Four human mammary tumor cell lines representing the major breast cancer subtypes (SKBR3, MCF-7, ZR75, MDA-MB-231 and mammary tumor cells from MMTV-neu mice were used. ERβ expression, assessed by qPCR and western blotting, was suppressed in the two HER2-overexpressing cell lines (SKBR3, MMTV-neu following OB versus N sera exposure, but did not vary in the other cell lines. Expression of Bcl-2 and cyclin D1, two genes negatively regulated by ERβ, was elevated in SKBR3 cells following exposure to OB versus N sera, but this difference was eliminated when the ERβ gene was silenced with siRNA. Herceptin, a HER2 antagonist, and siRNA to HER2 were used to evaluate the role of HER2 in sera-induced ERβ modulation. SKBR3 cell treatment with OB sera plus Herceptin increased ERβ expression three-fold. Similar results were obtained when HER2 expression was silenced with siRNA. OB sera also promoted greater SKBR3 cell viability and growth, but this variance was not present when ERβ was silenced or the cells were modified to overexpress ERβ. Based on this data, we conclude that obesity-associated systemic factors suppress ERβ expression in breast cancer cells via a HER2-mediated pathway, leading to greater cell viability and growth. Elucidation of the mechanism(s mediating this effect could provide important insights into how ERβ expression is regulated as well as how obesity promotes a more aggressive disease.

  11. DMPD: Fragments of extracellular matrix as mediators of inflammation. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 18243041 Fragments of extracellular matrix as mediators of inflammation. Adair-Kirk...l) Show Fragments of extracellular matrix as mediators of inflammation. PubmedID 18243041 Title Fragments of extracellular matrix

  12. RANTES/CCL5 mediated-biological effects depend on the syndecan-4/PKCα signaling pathway

    Directory of Open Access Journals (Sweden)

    Loïc Maillard

    2014-09-01

    Full Text Available The perpetuation of angiogenesis is involved in certain chronic inflammatory diseases. The accelerated neovascularisation may result from an inflammatory status with a response of both endothelial cells and monocytes to inflammatory mediators such as chemokines. We have previously described in vitro and in vivo the pro-angiogenic effects of the chemokine Regulated on Activation, Normal T Cell Expressed and Secreted (RANTES/CCL5. The effects of RANTES/CCL5 may be related to its binding to G protein-coupled receptors and to proteoglycans such as syndecan-1 and -4. The aim of this study was to evaluate the functionality of syndecan-4 as a co-receptor of RANTES/CCL5 by the use of mutated syndecan-4 constructs. Our data demonstrate that site-directed mutations in syndecan-4 modify RANTES/CCL5 biological activities in endothelial cells. The SDC4S179A mutant, associated with an induced protein kinase C (PKCα activation, leads to higher RANTES/CCL5 pro-angiogenic effects, whereas the SDC4L188QQ and the SDC4A198del mutants, leading to lower phosphatidylinositol 4,5-bisphosphate (PIP2 binding or to lower PDZ protein binding respectively, are associated with reduced RANTES/CCL5 cellular effects. Moreover, our data highlight that the intracellular domain of SDC-4 is involved in RANTES/CCL5-induced activation of the PKCα signaling pathway and biological effect. As RANTES/CCL5 is involved in various physiopathological processes, the development of a new therapeutic strategy may be reliant on the mechanism by which RANTES/CCL5 exerts its biological activities, for example by targeting the binding of the chemokine to its proteoglycan receptor.

  13. The Hippo pathway mediates inhibition of vascular smooth muscle cell proliferation by cAMP.

    Science.gov (United States)

    Kimura, Tomomi E; Duggirala, Aparna; Smith, Madeleine C; White, Stephen; Sala-Newby, Graciela B; Newby, Andrew C; Bond, Mark

    2016-01-01

    Inhibition of vascular smooth muscle cell (VSMC) proliferation by intracellular cAMP prevents excessive neointima formation and hence angioplasty restenosis and vein-graft failure. These protective effects are mediated via actin-cytoskeleton remodelling and subsequent regulation of gene expression by mechanisms that are incompletely understood. Here we investigated the role of components of the growth-regulatory Hippo pathway, specifically the transcription factor TEAD and its co-factors YAP and TAZ in VSMC. Elevation of cAMP using forskolin, dibutyryl-cAMP or the physiological agonists, Cicaprost or adenosine, significantly increased phosphorylation and nuclear export YAP and TAZ and inhibited TEAD-luciferase report gene activity. Similar effects were obtained by inhibiting RhoA activity with C3-transferase, its downstream kinase, ROCK, with Y27632, or actin-polymerisation with Latrunculin-B. Conversely, expression of constitutively-active RhoA reversed the inhibitory effects of forskolin on TEAD-luciferase. Forskolin significantly inhibited the mRNA expression of the pro-mitogenic genes, CCN1, CTGF, c-MYC and TGFB2 and this was reversed by expression of constitutively-active YAP or TAZ phospho-mutants. Inhibition of YAP and TAZ function with RNAi or Verteporfin significantly reduced VSMC proliferation. Furthermore, the anti-mitogenic effects of forskolin were reversed by overexpression of constitutively-active YAP or TAZ. Taken together, these data demonstrate that cAMP-induced actin-cytoskeleton remodelling inhibits YAP/TAZ-TEAD dependent expression of pro-mitogenic genes in VSMC. This mechanism contributes novel insight into the anti-mitogenic effects of cAMP in VSMC and suggests a new target for intervention. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

  14. DMPD: Negative regulation of cytoplasmic RNA-mediated antiviral signaling. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 18703349 Negative regulation of cytoplasmic RNA-mediated antiviral signaling. Komur...Show Negative regulation of cytoplasmic RNA-mediated antiviral signaling. PubmedID 18703349 Title Negative r...egulation of cytoplasmic RNA-mediated antiviral signaling. Authors Komuro A, Bamm

  15. DMPD: Complement-mediated phagocytosis--the role of Syk. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 16754322 Complement-mediated phagocytosis--the role of Syk. Tohyama Y, Yamamura H. ...IUBMB Life. 2006 May-Jun;58(5-6):304-8. (.png) (.svg) (.html) (.csml) Show Complement-mediated phagocytosis-...-the role of Syk. PubmedID 16754322 Title Complement-mediated phagocytosis--the role of Syk. Authors Tohyama

  16. Fas- and Mitochondria-Mediated Signaling Pathway Involved in Osteoblast Apoptosis Induced by AlCl3.

    Science.gov (United States)

    Xu, Feibo; Ren, Limin; Song, Miao; Shao, Bing; Han, Yanfei; Cao, Zheng; Li, Yanfei

    2017-10-12

    Aluminum (Al) is known to induce apoptosis of osteoblasts (OBs). However, the mechanism is not yet established. To investigate the apoptotic mechanism of OBs induced by aluminum trichloride (AlCl 3 ), the primary OBs from the craniums of fetal Wistar rats were exposed to 0 mg/mL (control group, CG), 0.06 mg/mL (low-dose group, LG), 0.12 mg/mL (mid-dose group, MG), and 0.24 mg/mL (high-dose group, HG) AlCl 3 for 24 h, respectively. We observed that AlCl 3 induced OB apoptosis with the appearance of apoptotic morphology and increase of apoptosis rate. Additionally, AlCl 3 treatment activated mitochondrial-mediated signaling pathway, accompanied by mitochondrial membrane potential (ΔΨm) depolarization, release of cytochrome c from the mitochondria to the cytoplasm, as well as survival signal-related factor caspase-9 and caspase-3 activation. AlCl 3 exposure also activated Fas/Fas ligand signaling pathway, presented as Fas, Fas ligand, and Fas-associated death domain expression enhancement and caspase-8 activation, as well as the hydrolysis of Bid to truncated Bid, suggesting that the Fas-mediated signaling pathway might aggravate mitochondria-mediated OB apoptosis through hydrolyzing Bid. Furthermore, AlCl 3 exposure inhibited Bcl-2 protein expression and increased the expressions of Bax, Bak, and Bim in varying degrees. These results indicated that AlCl 3 exposure induced OB apoptosis through activating Fas- and mitochondria-mediated signaling pathway and disrupted B-cell lymphoma-2 family proteins.

  17. Dietary Blueberry and Bifidobacteria Attenuate Nonalcoholic Fatty Liver Disease in Rats by Affecting SIRT1-Mediated Signaling Pathway

    Science.gov (United States)

    Ren, Tingting; Huang, Chao; Cheng, Mingliang

    2014-01-01

    NAFLD model rats were established and divided into NAFLD model (MG group), SIRT1 RNAi (SI group), blueberry juice (BJ group), blueberry juice + bifidobacteria (BJB group), blueberry juice + SIRT1 RNAi (BJSI group), and blueberry juice + bifidobacteria + SIRT1 RNAi groups (BJBSI group). A group with normal rats was a control group (CG). BJB group ameliorated NAFLD, which was better than BJ group (P Blueberry juice and bifidobacteria improve NAFLD by activating SIRTI-mediating signaling pathway. PMID:25544867

  18. Silencing of Pokemon enhances caspase-dependent apoptosis via fas- and mitochondria-mediated pathways in hepatocellular carcinoma cells.

    Directory of Open Access Journals (Sweden)

    Yu-Qin Zhang

    Full Text Available The role of Pokemon (POK erythroid myeloid ontogenic actor, a recently identified POK transcription factor with proto-oncogenic activity, in hepatocellular carcinogenesis has only been assessed by a few studies. Our previous study revealed that Pokemon is overexpressed in hepatocellular carcinomas (HCC and promotes HCC cell proliferation and migration via an AKT- and ERK- dependent manner. In the present study, we used the TUNEL assay and FACS analysis to demonstrate that oxaliplatin induced apoptosis was significantly increased in cells with silenced Pokemon. Western blots showed that p53 expression and phosphorylation were significantly increased in Pokemon defective cells, thereby initiating the mitochondria-mediated and death receptor-mediated apoptotic pathways. In the mitochondria-mediated pathway, expression of pro-apoptotic Bcl-2 family members (including Bad, Bid, Bim and Puma as well as AIF was increased and decreasing the mitochondrial membrane potential resulted in cytochrome C released from mitochondrial in HepG2 si-Pokemon cells. In addition, upon oxaliplatin treatment of Pokemon-silenced cells, the FAS receptor, FADD and their downstream targets caspase-10 and caspase-8 were activated, causing increased release of caspase-8 active fragments p18 and p10. Increased activated caspase-8-mediated cleavage and activation of downstream effector caspases such as caspase-9 and caspase-3 was observed in HepG2 si-Pokemon cells as compared to control. Therefore, Pokemon might serve as an important mediator of crosstalk between intrinsic and extrinsic apoptotic pathways in HCC cells. Moreover, our findings suggest that Pokemon could be an attractive therapeutic target gene for human cancer therapy.

  19. Silencing of Pokemon enhances caspase-dependent apoptosis via fas- and mitochondria-mediated pathways in hepatocellular carcinoma cells.

    Science.gov (United States)

    Zhang, Yu-Qin; Xiao, Chuan-Xing; Lin, Bi-Yun; Shi, Ying; Liu, Yun-Peng; Liu, Jing-Jing; Guleng, Bayasi; Ren, Jian-Lin

    2013-01-01

    The role of Pokemon (POK erythroid myeloid ontogenic actor), a recently identified POK transcription factor with proto-oncogenic activity, in hepatocellular carcinogenesis has only been assessed by a few studies. Our previous study revealed that Pokemon is overexpressed in hepatocellular carcinomas (HCC) and promotes HCC cell proliferation and migration via an AKT- and ERK- dependent manner. In the present study, we used the TUNEL assay and FACS analysis to demonstrate that oxaliplatin induced apoptosis was significantly increased in cells with silenced Pokemon. Western blots showed that p53 expression and phosphorylation were significantly increased in Pokemon defective cells, thereby initiating the mitochondria-mediated and death receptor-mediated apoptotic pathways. In the mitochondria-mediated pathway, expression of pro-apoptotic Bcl-2 family members (including Bad, Bid, Bim and Puma) as well as AIF was increased and decreasing the mitochondrial membrane potential resulted in cytochrome C released from mitochondrial in HepG2 si-Pokemon cells. In addition, upon oxaliplatin treatment of Pokemon-silenced cells, the FAS receptor, FADD and their downstream targets caspase-10 and caspase-8 were activated, causing increased release of caspase-8 active fragments p18 and p10. Increased activated caspase-8-mediated cleavage and activation of downstream effector caspases such as caspase-9 and caspase-3 was observed in HepG2 si-Pokemon cells as compared to control. Therefore, Pokemon might serve as an important mediator of crosstalk between intrinsic and extrinsic apoptotic pathways in HCC cells. Moreover, our findings suggest that Pokemon could be an attractive therapeutic target gene for human cancer therapy.

  20. Viral Small T Oncoproteins Transform Cells by Alleviating Hippo-Pathway-Mediated Inhibition of the YAP Proto-oncogene

    Directory of Open Access Journals (Sweden)

    Hung Thanh Nguyen

    2014-08-01

    Full Text Available Primary human cells can be transformed into tumor cells by a defined set of genetic alterations including telomerase, oncogenic RasV12, and the tumor suppressors p53 and pRb. SV40 small T (ST is required for anchorage-independent growth in vitro and in vivo. Here, we identify the Hippo tumor suppressor pathway as a critical target of ST in cellular transformation. We report that ST uncouples YAP from the inhibitory activity of the Hippo pathway through PAK1-mediated inactivation of NF2. Membrane-tethered activated PAK is sufficient to bypass the requirement for ST in anchorage-independent growth. PAK acts via YAP to mediate the transforming effects of ST. Activation of endogenous YAP is required for ST-mediated transformation and is sufficient to bypass ST in anchorage-independent growth and xenograft tumor formation. Our findings uncover the Hippo tumor suppressor pathway as a final gatekeeper to transformation and tumorigenesis of primary cells.

  1. Excessive Time on Social Networking Sites and Disordered Eating Behaviors Among Undergraduate Students: Appearance and Weight Esteem as Mediating Pathways.

    Science.gov (United States)

    Murray, Marisa; Maras, Danijela; Goldfield, Gary S

    2016-12-01

    Social networking sites (SNS) are a popular form of communication among undergraduate students. Body image concerns and disordered eating behaviors are also quite prevalent among this population. Maladaptive use of SNS has been associated with disordered eating behaviors; however, the mechanisms remain unclear. The present study examined if body image concerns (e.g., appearance and weight esteem) mediate the relationship between excessive time spent on SNS and disordered eating behaviors (restrained and emotional eating). The sample included 383 (70.2 percent female) undergraduate students (mean age = 23.08 years, standard deviation = 3.09) who completed self-report questionnaires related to SNS engagement, body image, disordered eating behaviors, and demographics. Parallel multiple mediation and moderated mediation analyses revealed that lower weight and appearance esteem mediated the relationship between excessive time on SNS and restrained eating for males and females, whereas appearance esteem mediated the relationship between excessive time on SNS and emotional eating for females only. The study adds to the literature by highlighting mediational pathways and gender differences. Intervention research is needed to determine if teaching undergraduate students more adaptive ways of using SNS or reducing exposure to SNS reduces body dissatisfaction and disordered eating in this high-risk population.

  2. CHARACTERISTICS OF SIGNALING PATHWAYS MEDIATING A CYTOTOXIC EFFECT OF DENDRITIC CELLS UPON ACTIVATED Т LYMPHOCYTES AND NK CELLS

    Directory of Open Access Journals (Sweden)

    T. V. Tyrinova

    2012-01-01

    Full Text Available Abstract. Cytotoxic/pro-apoptogenic effects of IFNα-induced dendritic cells (IFN-DCs directed against Т-lymphocytes and NK cells were investigated in healthy donors. Using an allogenic MLC system, it was revealed that IFN-DCs induce apoptosis of both activated CD4+ and CD8+ T-lymphocytes, and NK cells. Apoptosis of CD4+ and CD8+ T-lymphocytes induced by their interaction with IFN-DCs was mediated by various signaling pathways. In particular, activated CD4+Т-lymphocytes were most sensitive to TRAIL- и Fas/ FasL-transduction pathways, whereas activated CD8+ T-lymphocytes were induced to apoptosis via TNFα-mediated pathway. PD-1/B7-H1-signaling pathway also played a distinct role in cytotoxic activity of IFNDCs towards both types of T lymphocytes and activated NK cells. The pro-apoptogenic/cytotoxic activity of IFN-DC against activated lymphocytes may be regarded as a mechanism of a feedback regulation aimed at restriction of immune response and maintenance of immune homeostasis. Moreover, upregulation of proapoptogenic molecules on DCs under pathological conditions may lead to suppression of antigen-specific response, thus contributing to the disease progression.

  3. Ethylene responses in rice roots and coleoptiles are differentially regulated by a carotenoid isomerase-mediated abscisic acid pathway.

    Science.gov (United States)

    Yin, Cui-Cui; Ma, Biao; Collinge, Derek Phillip; Pogson, Barry James; He, Si-Jie; Xiong, Qing; Duan, Kai-Xuan; Chen, Hui; Yang, Chao; Lu, Xiang; Wang, Yi-Qin; Zhang, Wan-Ke; Chu, Cheng-Cai; Sun, Xiao-Hong; Fang, Shuang; Chu, Jin-Fang; Lu, Tie-Gang; Chen, Shou-Yi; Zhang, Jin-Song

    2015-04-01

    Ethylene and abscisic acid (ABA) act synergistically or antagonistically to regulate plant growth and development. ABA is derived from the carotenoid biosynthesis pathway. Here, we analyzed the interplay among ethylene, carotenoid biogenesis, and ABA in rice (Oryza sativa) using the rice ethylene response mutant mhz5, which displays a reduced ethylene response in roots but an enhanced ethylene response in coleoptiles. We found that MHZ5 encodes a carotenoid isomerase and that the mutation in mhz5 blocks carotenoid biosynthesis, reduces ABA accumulation, and promotes ethylene production in etiolated seedlings. ABA can largely rescue the ethylene response of the mhz5 mutant. Ethylene induces MHZ5 expression, the production of neoxanthin, an ABA biosynthesis precursor, and ABA accumulation in roots. MHZ5 overexpression results in enhanced ethylene sensitivity in roots and reduced ethylene sensitivity in coleoptiles. Mutation or overexpression of MHZ5 also alters the expression of ethylene-responsive genes. Genetic studies revealed that the MHZ5-mediated ABA pathway acts downstream of ethylene signaling to inhibit root growth. The MHZ5-mediated ABA pathway likely acts upstream but negatively regulates ethylene signaling to control coleoptile growth. Our study reveals novel interactions among ethylene, carotenogenesis, and ABA and provides insight into improvements in agronomic traits and adaptive growth through the manipulation of these pathways in rice. © 2015 American Society of Plant Biologists. All rights reserved.

  4. Endosomal "sort" of signaling control: The role of ESCRT machinery in regulation of receptor-mediated signaling pathways.

    Science.gov (United States)

    Szymanska, Ewelina; Budick-Harmelin, Noga; Miaczynska, Marta

    2018-02-01

    The endosomal sorting complexes required for transport (ESCRTs) machinery consists of four protein assemblies (ESCRT-0 to -III subcomplexes) which mediate various processes of membrane remodeling in the cell. In the endocytic pathway, ESCRTs sort cargo destined for degradation into intraluminal vesicles (ILVs) of endosomes. Cargos targeted by ESCRTs include various signaling molecules, mainly internalized cell-surface receptors but also some cytosolic proteins. It is therefore expected that aberrant trafficking caused by ESCRT dysfunction affects different signaling pathways. Here we review how perturbation of ESCRT activity alters intracellular transport of membrane receptors, causing their accumulation on endocytic compartments, decreased degradation and/or altered recycling to the plasma membrane. We further describe how perturbed trafficking of receptors impacts the activity of their downstream signaling pathways, with or without changes in transcriptional responses. Finally, we present evidence that ESCRT components can also control activity and intracellular distribution of cytosolic signaling proteins (kinases, other effectors and soluble receptors). The underlying mechanisms involve sequestration of such proteins in ILVs, their sorting for degradation or towards non-lysosomal destinations, and regulating their availability in various cellular compartments. All these ESCRT-mediated processes can modulate final outputs of multiple signaling pathways. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. TOR Pathway-Mediated Juvenile Hormone Synthesis Regulates Nutrient-Dependent Female Reproduction in Nilaparvata lugens (Stål).

    Science.gov (United States)

    Lu, Kai; Chen, Xia; Liu, Wen-Ting; Zhou, Qiang

    2016-03-28

    The "target of rapamycin" (TOR) nutritional signaling pathway and juvenile hormone (JH) regulation of vitellogenesis has been known for a long time. However, the interplay between these two pathways regulating vitellogenin (Vg) expression remains obscure. Here, we first demonstrated the key role of amino acids (AAs) in activation of Vg synthesis and egg development in Nilaparvata lugens using chemically defined artificial diets. AAs induced the expression of TOR and S6K (S6 kinase), whereas RNAi-mediated silencing of these two TOR pathway genes and rapamycin application strongly inhibited the AAs-induced Vg synthesis. Furthermore, knockdown of Rheb (Ras homologue enriched in brain), TOR, S6K and application of rapamycin resulted in a dramatic reduction in the mRNA levels of jmtN (juvenile hormone acid methyltransferase, JHAMT). Application of JH III on the RNAi (Rheb and TOR) and rapamycin-treated females partially rescued the Vg expression. Conversely, knockdown of either jmtN or met (methoprene-tolerant, JH receptor) and application of JH III had no effects on mRNA levels of Rheb, TOR and S6K and phosphorylation of S6K. In summary, our results demonstrate that the TOR pathway induces JH biosynthesis that in turn regulates AAs-mediated Vg synthesis in N. lugens.

  6. Longitudinal pathways from early maternal depression to children's dysregulated representations: a moderated mediation analysis of harsh parenting and gender.

    Science.gov (United States)

    Martoccio, Tiffany L; Brophy-Herb, Holly E; Maupin, Angela N; Robinson, Joann L

    2016-01-01

    There is some evidence linking maternal depression, harsh parenting, and children's internal representations of attachment, yet, longitudinal examinations of these relationships and differences in the developmental pathways between boys and girls are lacking. Moderated mediation growth curves were employed to examine harsh parenting as a mechanism underlying the link between maternal depression and children's dysregulated representations using a nationally-representative, economically-vulnerable sample of mothers and their children (n = 575; 49% boys, 51% girls). Dysregulation representations were measured using the MacArthur Story Stem Battery at five years of age (M = 5.14, SD = 0.29). Harsh parenting mediated the association between early maternal depression and dysregulated representations for girls. Though initial harsh parenting was a significant mediator for boys, a stronger direct effect of maternal depression to dysregulated representations emerged over time. Results are discussed in terms of their implications for intervention efforts aimed at promoting early supportive parenting.

  7. Agonist-induced internalisation of the glucagon-like peptide-1 receptor is mediated by the Gαq pathway.

    Science.gov (United States)

    Thompson, Aiysha; Kanamarlapudi, Venkateswarlu

    2015-01-01

    The glucagon-like peptide-1 receptor (GLP-1R) is a G-protein-coupled receptor (GPCR) and an important target in the treatment of type 2 diabetes mellitus (T2DM). Upon stimulation with agonist, the GLP-1R signals through both Gαs and Gαq coupled pathways to stimulate insulin secretion. The agonist-induced GLP-1R internalisation has recently been shown to be important for insulin secretion. However, the molecular mechanisms underlying GLP-1R internalisation remain unknown. The aim of this study was to determine the role of GLP-1R downstream signalling pathways in its internalisation. Agonist-induced human GLP-1R (hGLP-1R) internalisation and activity were examined using a number of techniques including immunoblotting, ELISA, immunofluorescence and luciferase assays to determine cAMP production, intracellular Ca(2+) accumulation and ERK phosphorylation. Agonist-induced hGLP-1R internalisation is dependent on caveolin-1 and dynamin. Inhibition of the Gαq pathway but not the Gαs pathway affected hGLP-1R internalisation. Consistent with this, hGLP-1R mutant T149M and small-molecule agonists (compound 2 and compound B), which activate only the Gαs pathway, failed to induce internalisation of the receptor. Chemical inhibitors of the Gαq pathway, PKC and ERK phosphorylation significantly reduced agonist-induced hGLP-1R internalisation. These inhibitors also suppressed agonist-induced ERK1/2 phosphorylation demonstrating that the phosphorylated ERK acts downstream of the Gαq pathway in the hGLP-1R internalisation. In summary, agonist-induced hGLP-1R internalisation is mediated by the Gαq pathway. The internalised hGLP-1R stimulates insulin secretion from pancreatic β-cells, indicating the importance of GLP-1 internalisation for insulin secretion. Copyright © 2014 Elsevier Inc. All rights reserved.

  8. Sodium fluoride induces apoptosis in mouse embryonic stem cells through ROS-dependent and caspase- and JNK-mediated pathways

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen Ngoc, Tam Dan [Institute of Oral Biosciences and School of Dentistry (BK21 Program), Chonbuk National University, Jeonju 561-756 (Korea, Republic of); Son, Young-Ok [Graduate Center for Toxicology, School of Medicine, University of Kentucky, Lexington, KY 40536-0305 (United States); Lim, Shin-Saeng [Institute of Oral Biosciences and School of Dentistry (BK21 Program), Chonbuk National University, Jeonju 561-756 (Korea, Republic of); Department of Bioactive Material Sciences and Research Center of Bioactive Materials, Chonbuk National University, Jeonju 561-756 (Korea, Republic of); Shi, Xianglin [Graduate Center for Toxicology, School of Medicine, University of Kentucky, Lexington, KY 40536-0305 (United States); Kim, Jong-Ghee [Institute of Oral Biosciences and School of Dentistry (BK21 Program), Chonbuk National University, Jeonju 561-756 (Korea, Republic of); Heo, Jung Sun [Department of Maxillofacial Biomedical Engineering and Institute of Oral Biology, School of Dentistry, Kyung Hee University, Seoul 130-701 (Korea, Republic of); Choe, Youngji [Institute of Oral Biosciences and School of Dentistry (BK21 Program), Chonbuk National University, Jeonju 561-756 (Korea, Republic of); Jeon, Young-Mi, E-mail: young@jbnu.ac.kr [Institute of Oral Biosciences and School of Dentistry (BK21 Program), Chonbuk National University, Jeonju 561-756 (Korea, Republic of); Lee, Jeong-Chae, E-mail: leejc88@jbnu.ac.kr [Institute of Oral Biosciences and School of Dentistry (BK21 Program), Chonbuk National University, Jeonju 561-756 (Korea, Republic of); Graduate Center for Toxicology, School of Medicine, University of Kentucky, Lexington, KY 40536-0305 (United States); Department of Bioactive Material Sciences and Research Center of Bioactive Materials, Chonbuk National University, Jeonju 561-756 (Korea, Republic of)

    2012-03-15

    Sodium fluoride (NaF) is used as a source of fluoride ions in diverse applications. Fluoride salt is an effective prophylactic for dental caries and is an essential element required for bone health. However, fluoride is known to cause cytotoxicity in a concentration-dependent manner. Further, no information is available on the effects of NaF on mouse embryonic stem cells (mESCs). We investigated the mode of cell death induced by NaF and the mechanisms involved. NaF treatment greater than 1 mM reduced viability and DNA synthesis in mESCs and induced cell cycle arrest in the G{sub 2}/M phase. The addition of NaF induced cell death mainly by apoptosis rather than necrosis. Catalase (CAT) treatment significantly inhibited the NaF-mediated cell death and also suppressed the NaF-mediated increase in phospho-c-Jun N-terminal kinase (p-JNK) levels. Pre-treatment with SP600125 or z-VAD-fmk significantly attenuated the NaF-mediated reduction in cell viability. In contrast, intracellular free calcium chelator, but not of sodium or calcium ion channel blockers, facilitated NaF-induced toxicity in the cells. A JNK specific inhibitor (SP600125) prevented the NaF-induced increase in growth arrest and the DNA damage-inducible protein 45α. Further, NaF-mediated loss of mitochondrial membrane potential was apparently inhibited by pifithrin-α or CAT inhibitor. These findings suggest that NaF affects viability of mESCs in a concentration-dependent manner, where more than 1 mM NaF causes apoptosis through hydroxyl radical-dependent and caspase- and JNK-mediated pathways. -- Highlights: ► The mode of NaF-induced cell death and the mechanisms involved were examined. ► NaF induced mainly apoptotic death of mouse embryonic stem cells (mESCs). ► NaF induced mitochondrial-mediated and caspase-dependent apoptosis. ► JNK- and p53-mediated pathways are involved in NaF-mediated apoptosis in the cells. ► ROS are the up-stream effector in NaF-mediated activation of JNK and p53 in mESCs.

  9. Sodium fluoride induces apoptosis in mouse embryonic stem cells through ROS-dependent and caspase- and JNK-mediated pathways

    International Nuclear Information System (INIS)

    Nguyen Ngoc, Tam Dan; Son, Young-Ok; Lim, Shin-Saeng; Shi, Xianglin; Kim, Jong-Ghee; Heo, Jung Sun; Choe, Youngji; Jeon, Young-Mi; Lee, Jeong-Chae

    2012-01-01

    Sodium fluoride (NaF) is used as a source of fluoride ions in diverse applications. Fluoride salt is an effective prophylactic for dental caries and is an essential element required for bone health. However, fluoride is known to cause cytotoxicity in a concentration-dependent manner. Further, no information is available on the effects of NaF on mouse embryonic stem cells (mESCs). We investigated the mode of cell death induced by NaF and the mechanisms involved. NaF treatment greater than 1 mM reduced viability and DNA synthesis in mESCs and induced cell cycle arrest in the G 2 /M phase. The addition of NaF induced cell death mainly by apoptosis rather than necrosis. Catalase (CAT) treatment significantly inhibited the NaF-mediated cell death and also suppressed the NaF-mediated increase in phospho-c-Jun N-terminal kinase (p-JNK) levels. Pre-treatment with SP600125 or z-VAD-fmk significantly attenuated the NaF-mediated reduction in cell viability. In contrast, intracellular free calcium chelator, but not of sodium or calcium ion channel blockers, facilitated NaF-induced toxicity in the cells. A JNK specific inhibitor (SP600125) prevented the NaF-induced increase in growth arrest and the DNA damage-inducible protein 45α. Further, NaF-mediated loss of mitochondrial membrane potential was apparently inhibited by pifithrin-α or CAT inhibitor. These findings suggest that NaF affects viability of mESCs in a concentration-dependent manner, where more than 1 mM NaF causes apoptosis through hydroxyl radical-dependent and caspase- and JNK-mediated pathways. -- Highlights: ► The mode of NaF-induced cell death and the mechanisms involved were examined. ► NaF induced mainly apoptotic death of mouse embryonic stem cells (mESCs). ► NaF induced mitochondrial-mediated and caspase-dependent apoptosis. ► JNK- and p53-mediated pathways are involved in NaF-mediated apoptosis in the cells. ► ROS are the up-stream effector in NaF-mediated activation of JNK and p53 in mESCs.

  10. The Alternative Epac/cAMP Pathway and the MAPK Pathway Mediate hCG Induction of Leptin in Placental Cells

    Science.gov (United States)

    Maymó, Julieta Lorena; Pérez Pérez, Antonio; Maskin, Bernardo; Dueñas, José Luis; Calvo, Juan Carlos; Sánchez Margalet, Víctor; Varone, Cecilia Laura

    2012-01-01

    Pleiotropic effects of leptin have been identified in reproduction and pregnancy, particularly in the placenta, where it works as an autocrine hormone. In this work, we demonstrated that human chorionic gonadotropin (hCG) added to JEG-3 cell line or to placental explants induces endogenous leptin expression. We also found that hCG increased cAMP intracellular levels in BeWo cells in a dose-dependent manner, stimulated cAMP response element (CRE) activity and the cotransfection with an expression plasmid of a dominant negative mutant of CREB caused a significant inhibition of hCG stimulation of leptin promoter activity. These results demonstrate that hCG indeed activates cAMP/PKA pathway, and that this pathway is involved in leptin expression. Nevertheless, we found leptin induction by hCG is dependent on cAMP levels. Treatment with (Bu)2cAMP in combination with low and non stimulatory hCG concentrations led to an increase in leptin expression, whereas stimulatory concentrations showed the opposite effect. We found that specific PKA inhibition by H89 caused a significant increase of hCG leptin induction, suggesting that probably high cAMP levels might inhibit hCG effect. It was found that hCG enhancement of leptin mRNA expression involved the MAPK pathway. In this work, we demonstrated that hCG leptin induction through the MAPK signaling pathway is inhibited by PKA. We observed that ERK1/2 phosphorylation increased when hCG treatment was combined with H89. In view of these results, the involvement of the alternative cAMP/Epac signaling pathway was studied. We observed that a cAMP analogue that specifically activates Epac (CPT-OMe) stimulated leptin expression by hCG. In addition, the overexpression of Epac and Rap1 proteins increased leptin promoter activity and enhanced hCG. In conclusion, we provide evidence suggesting that hCG induction of leptin gene expression in placenta is mediated not only by activation of the MAPK signaling pathway but also by the

  11. Aldosterone modulates thiazide-sensitive sodium chloride cotransporter abundance via DUSP6-mediated ERK1/2 signaling pathway.

    Science.gov (United States)

    Feng, Xiuyan; Zhang, Yiqian; Shao, Ningjun; Wang, Yanhui; Zhuang, Zhizhi; Wu, Ping; Lee, Matthew J; Liu, Yingli; Wang, Xiaonan; Zhuang, Jieqiu; Delpire, Eric; Gu, Dingying; Cai, Hui

    2015-05-15

    Thiazide-sensitive sodium chloride cotransporter (NCC) plays an important role in maintaining blood pressure. Aldosterone is known to modulate NCC abundance. Previous studies reported that dietary salts modulated NCC abundance through either WNK4 [with no lysine (k) kinase 4]-SPAK (Ste20-related proline alanine-rich kinase) or WNK4-extracellular signal-regulated kinase-1 and -2 (ERK1/2) signaling pathways. To exclude the influence of SPAK signaling pathway on the role of the aldosterone-mediated ERK1/2 pathway in NCC regulation, we investigated the effects of dietary salt changes and aldosterone on NCC abundance in SPAK knockout (KO) mice. We found that in SPAK KO mice low-salt diet significantly increased total NCC abundance while reducing ERK1/2 phosphorylation, whereas high-salt diet decreased total NCC while increasing ERK1/2 phosphorylation. Importantly, exogenous aldosterone administration increased total NCC abundance in SPAK KO mice while increasing DUSP6 expression, an ERK1/2-specific phosphatase, and led to decreasing ERK1/2 phosphorylation without changing the ratio of phospho-T53-NCC/total NCC. In mouse distal convoluted tubule (mDCT) cells, aldosterone increased DUSP6 expression while reducing ERK1/2 phosphorylation. DUSP6 Knockdown increased ERK1/2 phosphorylation while reducing total NCC expression. Inhibition of DUSP6 by (E)-2-benzylidene-3-(cyclohexylamino)-2,3-dihydro-1H-inden-1-one increased ERK1/2 phosphorylation and reversed the aldosterone-mediated increments of NCC partly by increasing NCC ubiquitination. Therefore, these data suggest that aldosterone modulates NCC abundance via altering NCC ubiquitination through a DUSP6-dependent ERK1/2 signal pathway in SPAK KO mice and part of the effects of dietary salt changes may be mediated by aldosterone in the DCTs.

  12. Examining a pathway for hormone mediated maternal effects - Yolk testosterone affects androgen receptor expression and endogenous testosterone production in young chicks (Gallus gallus domesticus)

    NARCIS (Netherlands)

    Pfannkuche, K. A.; Gahr, M.; Weites, I. M.; Riedstra, B.; Wolf, C.; Groothuis, T. G. G.

    2011-01-01

    In vertebrates maternal androgens can substantially influence developing offspring, inducing both short and long term changes in physiology and behavior, including androgen sensitive traits. However, how the effects of maternal hormones are mediated remains unknown. Two possible pathways are that

  13. DMPD: Modulation of Toll-interleukin 1 receptor mediated signaling. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 15662540 Modulation of Toll-interleukin 1 receptor mediated signaling. Li X, Qin J.... J Mol Med. 2005 Apr;83(4):258-66. Epub 2005 Jan 21. (.png) (.svg) (.html) (.csml) Show Modulation of Toll-i...nterleukin 1 receptor mediated signaling. PubmedID 15662540 Title Modulation of Toll-interleukin 1 receptor

  14. DMPD: IRAK1: a critical signaling mediator of innate immunity. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 17890055 IRAK1: a critical signaling mediator of innate immunity. Gottipati S, Rao ...NL, Fung-Leung WP. Cell Signal. 2008 Feb;20(2):269-76. Epub 2007 Aug 23. (.png) (.svg) (.html) (.csml) Show IRAK1: a critical sign...aling mediator of innate immunity. PubmedID 17890055 Title IRAK1: a critical signaling

  15. TSLP signaling pathway map: a platform for analysis of TSLP-mediated signaling.

    Science.gov (United States)

    Zhong, Jun; Sharma, Jyoti; Raju, Rajesh; Palapetta, Shyam Mohan; Prasad, T S Keshava; Huang, Tai-Chung; Yoda, Akinori; Tyner, Jeffrey W; van Bodegom, Diederik; Weinstock, David M; Ziegler, Steven F; Pandey, Akhilesh

    2014-01-01

    Thymic stromal lymphopoietin (TSLP) is a four-helix bundle cytokine that plays a critical role in the regulation of immune responses and in the differentiation of hematopoietic cells. TSLP signals through a heterodimeric receptor complex consisting of an interleukin-7 receptor α chain and a unique TSLP receptor (TSLPR) [also known as cytokine receptor-like factor 2 (CRLF2)]. Cellular targets of TSLP include dendritic cells, B cells, mast cells, regulatory T (Treg) cells and CD4+ and CD8+ T cells. The TSLP/TSLPR axis can activate multiple signaling transduction pathways including the JAK/STAT pathway and the PI-3 kinase pathway. Aberrant TSLP/TSLPR signaling has been associated with a variety of human diseases including asthma, atopic dermatitis, nasal polyposis, inflammatory bowel disease, eosinophilic eosophagitis and, most recently, acute lymphoblastic leukemia. A centralized resource of the TSLP signaling pathway cataloging signaling events is not yet available. In this study, we present a literature-annotated resource of reactions in the TSLP signaling pathway. This pathway map is publicly available through NetPath (http://www.netpath.org/), an open access signal transduction pathway resource developed previously by our group. This map includes 236 molecules and 252 reactions that are involved in TSLP/TSLPR signaling pathway. We expect that the TSLP signaling pathway map will provide a rich resource to study the biology of this important cytokine as well as to identify novel therapeutic targets for diseases associated with dysregulated TSLP/TSLPR signaling. Database URL: http://www.netpath.org/pathways?path_id=NetPath_24.

  16. Leukemia-Associated Nup214 Fusion Proteins Disturb the XPO1-Mediated Nuclear-Cytoplasmic Transport Pathway and Thereby the NF-κB Signaling Pathway.

    Science.gov (United States)

    Saito, Shoko; Cigdem, Sadik; Okuwaki, Mitsuru; Nagata, Kyosuke

    2016-07-01

    Nuclear-cytoplasmic transport through nuclear pore complexes is mediated by nuclear transport receptors. Previous reports have suggested that aberrant nuclear-cytoplasmic transport due to mutations or overexpression of nuclear pore complexes and nuclear transport receptors is closely linked to diseases. Nup214, a component of nuclear pore complexes, has been found as chimeric fusion proteins in leukemia. Among various Nup214 fusion proteins, SET-Nup214 and DEK-Nup214 have been shown to be engaged in tumorigenesis, but their oncogenic mechanisms remain unclear. In this study, we examined the functions of the Nup214 fusion proteins by focusing on their effects on nuclear-cytoplasmic transport. We found that SET-Nup214 and DEK-Nup214 interact with exportin-1 (XPO1)/CRM1 and nuclear RNA export factor 1 (NXF1)/TAP, which mediate leucine-rich nuclear export signal (NES)-dependent protein export and mRNA export, respectively. SET-Nup214 and DEK-Nup214 decreased the XPO1-mediated nuclear export of NES proteins such as cyclin B and proteins involved in the NF-κB signaling pathway by tethering XPO1 onto nuclear dots where Nup214 fusion proteins are localized. We also demonstrated that SET-Nup214 and DEK-Nup214 expression inhibited NF-κB-mediated transcription by abnormal tethering of the complex containing p65 and its inhibitor, IκB, in the nucleus. These results suggest that SET-Nup214 and DEK-Nup214 perturb the regulation of gene expression through alteration of the nuclear-cytoplasmic transport system. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

  17. Aqueous Extract of Terminalia chebula Induces Apoptosis in Lung Cancer Cells Via a Mechanism Involving Mitochondria-mediated Pathways

    Directory of Open Access Journals (Sweden)

    Meiling Wang

    2015-04-01

    Full Text Available The current study was designed to evaluate the aqueous extract of Terminalia chebula activity, and the main pathway was detected on lung cancer by extracts of T. chebula. Aqueous extract of T. chebula was separated using a zeolite, and five fractions of T. chebula extract were obtained and analyzed by ultraviolet (UV and infrared (IR spectroscopy. Antiproliferative activity was evaluated by 3-(4,5-dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide (MTT methods against human lung cancer (A549 and mouse lung cancer cell line LLC. T. chebula acts by regulating the Bcl-2 family protein-mediated mitochondrial pathway detected by western blot. Fraction 4 of the T. chebula extract showed much function and was thus studied further. Fraction 4 increased the activation of caspase-3, induced PARP cleavage, and promoted cytochrome c release into the cytoplasm. These data suggest that T. chebula acts by regulating the Bcl-2 family protein-mediated mitochondrial pathway and provide evidence that T. chebula deserves further investigation as a natural agent for treating and preventing cancer.

  18. The role of Ca(2+) mediated signaling pathways on the effect of taurine against Streptococcus uberis infection.

    Science.gov (United States)

    Dai, Bin; Zhang, Jinqiu; Liu, Ming; Lu, Jinye; Zhang, Yuanshu; Xu, Yuanyuan; Miao, Jinfeng; Yin, Yulong

    2016-08-30

    To provide insight into the mechanisms of taurine attenuation of pro-inflammatory response in mouse mammary epithelial cell line (EpH4-Ev, purchased by ATCC, USA) after Streptococcus uberis (S. uberis, 0140J) challenge, we infected MECs with S. uberis (2.5×10(7)cfumL(-1), MOI=10) for 3h and quantified changes in TLR-2 and calcium (Ca(2+)) mediated signaling pathways. The results indicate that S. uberis infection significantly increases the expression of TLR-2, intracellular Ca(2+) levels, PLC-γ1 and PKC-α, the activities of transcription factors NF-κB and NFAT, and related cytokines (TNF-α, IL-1β, IL-6, G-CSF, IL-2, KC, IL-15, FasL, MCP-1, and LIX) in culture supernatants. Taurine administration downregulated all these indices, the activities of NF-κB and NFAT. Cytokine secretions were similar using special PKC inhibitor Go 6983 and NFAT inhibitor VIVIT. Our data indicate that S. uberis infection induces pro-inflammatory response of MECs through a TLR-2 mediated signaling pathway. In addition, taurine can prevent MEC damage by affecting both PLC-γ1-Ca(2+)-PKC-α-NF-κB and PLC-γ1-Ca(2+)-NFATs signaling pathways. This is the first report to demonstrate the mechanisms of taurine attenuated pro-inflammatory response in MECs after S. uberis challenge. Copyright © 2016 Elsevier B.V. All rights reserved.

  19. Distinct polymer architecture mediates switching of complement activation pathways at the nanosphere-serum interface: implications for stealth nanoparticle engineering.

    Science.gov (United States)

    Hamad, Islam; Al-Hanbali, Othman; Hunter, A Christy; Rutt, Kenneth J; Andresen, Thomas L; Moghimi, S Moein

    2010-11-23

    Nanoparticles with surface projected polyethyleneoxide (PEO) chains in "mushroom-brush" and "brush" configurations display stealth properties in systemic circulation and have numerous applications in site-specific targeting for controlled drug delivery and release as well as diagnostic imaging. We report on the "structure-activity" relationship pertaining to surface-immobilized PEO of various configurations on model nanoparticles, and the initiation of complement cascade, which is the most ancient component of innate human immunity, and its activation may induce clinically significant adverse reactions in some individuals. Conformational states of surface-projected PEO chains, arising from the block copolymer poloxamine 908 adsorption, on polystyrene nanoparticles trigger complement activation differently. Alteration of copolymer architecture on nanospheres from mushroom to brush configuration not only switches complement activation from C1q-dependent classical to lectin pathway but also reduces the level of generated complement activation products C4d, Bb, C5a, and SC5b-9. Also, changes in adsorbed polymer configuration trigger alternative pathway activation differently and through different initiators. Notably, the role for properdin-mediated activation of alternative pathway was only restricted to particles displaying PEO chains in a transition mushroom-brush configuration. Since nanoparticle-mediated complement activation is of clinical concern, our findings provide a rational basis for improved surface engineering and design of immunologically safer stealth and targetable nanosystems with polymers for use in clinical medicine.

  20. The TEAD/TEF family protein Scalloped mediates transcriptional output of the Hippo growth-regulatory pathway.

    Science.gov (United States)

    Wu, Shian; Liu, Yi; Zheng, Yonggang; Dong, Jixin; Pan, Duojia

    2008-03-01

    The Hippo (Hpo) kinase cascade restricts tissue growth by inactivating the transcriptional coactivator Yorkie (Yki), which regulates the expression of target genes such as the cell death inhibitor diap1 by unknown mechanisms. Here we identify the TEAD/TEF family protein Scalloped (Sd) as a DNA-binding transcription factor that partners with Yki to mediate the transcriptional output of the Hpo growth-regulatory pathway. The diap1 (th) locus harbors a minimal Sd-binding Hpo Responsive Element (HRE) that mediates transcriptional regulation by the Hpo pathway. Sd binds directly to Yki, and a Yki missense mutation that abrogates Sd-Yki binding also inactivates Yki function in vivo. We further demonstrate that sd is required for yki-induced tissue overgrowth and target gene expression, and that sd activity is conserved in its mammalian homolog. Our results uncover a heretofore missing link in the Hpo signaling pathway and provide a glimpse of the molecular events on a Hpo-responsive enhancer element.

  1. Reversal of il-1β-mediated human embryonic pulmonary fibroblast transdifferentiation by targeting the ERK signaling pathway

    Directory of Open Access Journals (Sweden)

    Jin Long-Teng

    2014-01-01

    Full Text Available The aim of the present study was to determine whether Interleukin (IL-1β-mediated human embryonic pulmonary fibroblast transdifferentiation could be reversed by targeting of the ERK signaling pathway. The human embryonic pulmonary fibroblast MRC-5 cell line was used as a model to observe IL-1β-mediated transdifferentiation as well and the inhibitory effects of lentinan (LNT. Cell proliferation was examined by a CCK-8 assay. ERK signaling activity was detected using immunoblotting with phospho-ERK antibody. The expression levels of fibronectin (FN, Col I and α-smooth muscle actin (α-SMA were assessed by either reverse transcription PCR or the SABC assay. IL-1β-induced-ERK signaling activation in MRC-5 cells was inhibited by pretreatment with the LNT or ERK inhibitor U0126. IL-1β-enhanced cell proliferation and expression of FN, Col I and α-SMA were also attenuated by the treatment with LNT. Our study revealed that activation of ERK signaling is involved in IL-1β-mediated human embryonic pulmonary fibroblast proliferation, phenotypic switching and collagen secretion. These transdifferentiation events in MRC-5 cells could be reversed with LNT treatment by targeting the ERK signaling pathway.

  2. STAT1 pathway mediates amplification of metastatic potential and resistance to therapy.

    Directory of Open Access Journals (Sweden)

    Nikolai N Khodarev

    Full Text Available BACKGROUND: Traditionally IFN/STAT1 signaling is connected with an anti-viral response and pro-apoptotic tumor-suppressor functions. Emerging functions of a constitutively activated IFN/STAT1 pathway suggest an association with an aggressive tumor phenotype. We hypothesized that tumor clones that constitutively overexpress this pathway are preferentially selected by the host microenvironment due to a resistance to STAT1-dependent cytotoxicity and demonstrate increased metastatic ability combined with increased resistance to genotoxic stress. METHODOLOGY/PRINCIPAL FINDINGS: Here we report that clones of B16F1 tumors grown in the lungs of syngeneic C57BL/6 mice demonstrate variable transcriptional levels of IFN/STAT1 pathway expression. Tumor cells that constitutively overexpress the IFN/STAT1 pathway (STAT1(H genotype are selected by the lung microenvironment. STAT1(H tumor cells also demonstrate resistance to IFN-gamma (IFNgamma, ionizing radiation (IR, and doxorubicin relative to parental B16F1 and low expressors of the IFN/STAT1 pathway (STAT1(L genotype. Stable knockdown of STAT1 reversed the aggressive phenotype and decreased both lung colonization and resistance to genotoxic stress. CONCLUSIONS: Our results identify a pathway activated by tumor-stromal interactions thereby selecting for pro-metastatic and therapy-resistant tumor clones. New therapies targeted against the IFN/STAT1 signaling pathway may provide an effective strategy to treat or sensitize aggressive tumor clones to conventional cancer therapies and potentially prevent distant organ colonization.

  3. Molecular pathway profiling of T lymphocyte signal transduction pathways; Th1 and Th2 genomic fingerprints are defined by TCR and CD28-mediated signaling

    Directory of Open Access Journals (Sweden)

    Smeets Ruben L

    2012-03-01

    Full Text Available Abstract Background T lymphocytes are orchestrators of adaptive immunity. Naïve T cells may differentiate into Th1, Th2, Th17 or iTreg phenotypes, depending on environmental co-stimulatory signals. To identify genes and pathways involved in differentiation of Jurkat T cells towards Th1 and Th2 subtypes we performed comprehensive transcriptome analyses of Jurkat T cells stimulated with various stimuli and pathway inhibitors. Results from these experiments were validated in a human experimental setting using whole blood and purified CD4+ Tcells. Results Calcium-dependent activation of T cells using CD3/CD28 and PMA/CD3 stimulation induced a Th1 expression profile reflected by increased expression of T-bet, RUNX3, IL-2, and IFNγ, whereas calcium-independent activation via PMA/CD28 induced a Th2 expression profile which included GATA3, RXRA, CCL1 and Itk. Knock down with siRNA and gene expression profiling in the presence of selective kinase inhibitors showed that proximal kinases Lck and PKCθ are crucial signaling hubs during T helper cell activation, revealing a clear role for Lck in Th1 development and for PKCθ in both Th1 and Th2 development. Medial signaling via MAPkinases appeared to be less important in these pathways, since specific inhibitors of these kinases displayed a minor effect on gene expression. Translation towards a primary, whole blood setting and purified human CD4+ T cells revealed that PMA/CD3 stimulation induced a more pronounced Th1 specific, Lck and PKCθ dependent IFNγ production, whereas PMA/CD28 induced Th2 specific IL-5 and IL-13 production, independent of Lck activation. PMA/CD3-mediated skewing towards a Th1 phenotype was also reflected in mRNA expression of the master transcription factor Tbet, whereas PMA/CD28-mediated stimulation enhanced GATA3 mRNA expression in primary human CD4+ Tcells. Conclusions This study identifies stimulatory pathways and gene expression profiles for in vitro skewing of T helper cell

  4. The mitochondrial fatty acid synthesis (mtFASII) pathway is capable of mediating nuclear-mitochondrial cross talk through the PPAR system of transcriptional activation

    International Nuclear Information System (INIS)

    Parl, Angelika; Mitchell, Sabrina L.; Clay, Hayley B.; Reiss, Sara; Li, Zhen; Murdock, Deborah G.

    2013-01-01

    Highlights: •The function of the mitochondria fatty acid synthesis pathway is partially unknown. •Overexpression of the pathway causes transcriptional activation through PPARs. •Knock down of the pathway attenuates that activation. •The last enzyme in the pathway regulates its own transcription. •Products of the mtFASII pathway are able to drive nuclear transcription. -- Abstract: Mammalian cells contain two fatty acid synthesis pathways, the cytosolic FASI pathway, and the mitochondrial FASII pathway. The selection behind the conservation of the mitochondrial pathway is not completely understood, given the presence of the cytosolic FAS pathway. In this study, we show through heterologous gene reporter systems and PCR-based arrays that overexpression of MECR, the last step in the mtFASII pathway, causes modulation of gene expression through the PPAR pathway. Electromobility shift assays (EMSAs) demonstrate that overexpression of MECR causes increased binding of PPARs to DNA, while cell fractionation and imaging studies show that MECR remains localized to the mitochondria. Interestingly, knock down of the mtFASII pathway lessens the effect of MECR on this transcriptional modulation. Our data are most consistent with MECR-mediated transcriptional activation through products of the mtFASII pathway, although we cannot rule out MECR acting as a coactivator. Further investigation into the physiological relevance of this communication will be necessary to better understand some of the phenotypic consequences of deficits in this pathway observed in animal models and human disease

  5. Pathway of detergent-mediated and peptide ligand-mediated refolding of heterodimeric class II major histocompatibility complex (MHC) molecules.

    Science.gov (United States)

    Stöckel, J; Döring, K; Malotka, J; Jähnig, F; Dornmair, K

    1997-09-15

    We investigated the mechanism of refolding and reassembly of recombinant alpha and beta chains of the class II major histocompatibility molecules (MHC-II) HLA-DRB5*0101. Both chains were expressed in the cytosol of Escherichia coli, purified in urea and SDS, and reassembled to functional heterodimers by replacement of SDS by mild detergents, incubation in a redox-shuffling buffer and finally by oxidation and removal of detergent. Refolding was mediated by mild detergents and by peptide ligands. Early stages of structure formation were characterized by circular dichroism, fluorescence, and time-resolved fluorescence anisotropy decay (FAD) spectroscopies. We found that formation of secondary structure was detectable after replacement of SDS by mild detergents. At that stage the alpha and beta chains were still monomeric, the buffer was strongly reducing, and the folding intermediates did not yet interact with peptide ligands. Formation of folding intermediates capable of interacting with peptide ligands was detected after adjusting the redox potential with oxidized glutathione and incubation in mild detergents. We conclude that at that stage a tertiary structure close to the native structure is formed at least locally. The nature and concentration of detergent critically determined the refolding efficiency. We compared detergents with different carbohydrate headgroups, and with aliphatic chains ranging from C6 to C14 in length. For each of the detergents we observed a narrow concentration range for mediating refolding. Surprisingly, detergents with long aliphatic chains had to be used at higher concentrations than short-chain detergents, indicating that increasing the solubility of folding intermediates is not the only function of detergents during a refolding reaction. We discuss structure formation and interactions of detergents with stable folding intermediates. Understanding such interactions will help to develop rational strategies for refolding hydrophobic or

  6. Mechanical ventilation-induced apoptosis in newborn rat lung is mediated via FasL/Fas pathway.

    Science.gov (United States)

    Kroon, Andreas A; Delriccio, Veronica; Tseu, Irene; Kavanagh, Brian P; Post, Martin

    2013-12-01

    Mechanical ventilation induces pulmonary apoptosis and inhibits alveolar development in preterm infants, but the molecular basis for the apoptotic injury is unknown. The objective was to determine the signaling mechanism(s) of ventilation (stretch)-induced apoptosis in newborn rat lung. Seven-day-old rats were ventilated with room air for 24 h using moderate tidal volumes (8.5 ml/kg). Isolated fetal rat lung epithelial and fibroblast cells were subjected to continuous cyclic stretch (5, 10, or 17% elongation) for up to 12 h. Prolonged ventilation significantly increased the number of apoptotic alveolar type II cells (i.e., terminal deoxynucleotidyl transferase dUTP-mediated nick-end labeling and anti-cleaved caspase-3 immunochemistry) and was associated with increased expression of the apoptotic mediator Fas ligand (FasL). Fetal lung epithelial cells, but not fibroblasts, subjected to maximal (i.e., 17%, but not lesser elongation) cyclic stretch exhibited increased apoptosis (i.e., nuclear fragmentation and DNA laddering), which appeared to be mediated via the extrinsic pathway (increased expression of FasL and cleaved caspase-3, -7, and -8). The intrinsic pathway appeared not to be involved [minimal mitochondrial membrane depolarization (JC-1 flow analysis) and no activation of caspase-9]. Universal caspases inhibition and neutralization of FasL abrogated the stretch-induced apoptosis. Prolonged mechanical ventilation induces apoptosis of alveolar type II cells in newborn rats and the mechanism appears to involve activation of the extrinsic death pathway via the FasL/Fas system.

  7. Connexin 32 affects doxorubicin resistance in hepatocellular carcinoma cells mediated by Src/FAK signaling pathway.

    Science.gov (United States)

    Yu, Meiling; Zou, Qi; Wu, Xiaoxiang; Han, Guangshu; Tong, Xuhui

    2017-11-01

    Doxorubicin (DOX) is first-line chemotherapy for hepatocellular carcinoma (HCC), but the effect is not satisfactory. The resistance of HCC cells to DOX is the main reason leading to treatment failure. Therefore, it is necessary to study the mechanism of DOX resistance in HCC. In this study, expression of connexin (Cx)32 was significantly decreased in HCC tissues compared with corresponding paracancerous tissues, and activity of the Src/focal adhesion kinase (FAK) signaling pathway was significantly enhanced. Expression of Cx32 was closely associated with activity of the Src/FAK signaling pathway, Cx32, and the Src/FAK signaling pathway was also correlated with degree of HCC differentiation. In DOX-resistant HepG2 cells, compared with DOX-sensitive HepG2 cells, expression of Cx32 was significantly reduced and activity of the Src/FAK pathway increased. After silencing Cx32 in HepG2 cells, activity of the Src/FAK pathway increased and sensitivity to DOX decreased. In contrast, overexpression of Cx32 in HepG2/DOX cells decreased activity of the Src/FAK pathway and increased sensitivity to DOX. Dasatinib and KX2-391, inhibitors of the Src/FAK pathway, significantly increased the sensitivity of HepG2/DOX cells to DOX. The results suggest that Src/FAK is a downstream regulator of Cx32 and Cx32 regulates the sensitivity of HCC cells to DOX via the Src/FAK signaling pathway. Our study demonstrates a potential mechanism of DOX resistance in HCC cells and supports that Cx32-Src/FAK is an important target for reversing drug resistance of HCC. Copyright © 2017. Published by Elsevier Masson SAS.

  8. Ebola Virus Uses Clathrin-Mediated Endocytosis as an Entry Pathway

    Science.gov (United States)

    2010-01-01

    clathrin-mediated endocytosis is not restricted to small spherical coated pits. Listeria has been shown to utilize clathrin- mediated endocytosis to...enter cells (Veiga and Cossart, 2005). The large size of the Listeria , which extends to 2 μm (Giardini and Theriot, 2001), suggests that clathrin coated...membrane ATPases from microorganisms, animal cells, and plant cells. Proc. Natl. Acad. Sci. U. S. A. 85 (21), 7972–7976. Chan, S.Y., Empig, C.J

  9. The putrescine biosynthesis pathway in Lactococcus lactis is transcriptionally regulated by carbon catabolic repression, mediated by CcpA.

    Science.gov (United States)

    Linares, Daniel M; del Río, Beatriz; Ladero, Victor; Redruello, Begoña; Martín, María Cruz; Fernández, María; Alvarez, Miguel A

    2013-07-01

    Lactococcus lactis is the lactic acid bacterium most widely used by the dairy industry as a starter for the manufacture of fermented products such as cheese and buttermilk. However, some strains produce putrescine from agmatine via the agmatine deiminase (AGDI) pathway. The proteins involved in this pathway, including those necessary for agmatine uptake and conversion into putrescine, are encoded by the aguB, aguD, aguA and aguC genes, which together form an operon. This paper reports the mechanism of regulation of putrescine biosynthesis in L. lactis. It is shown that the aguBDAC operon, which contains a cre site at the promoter of aguB (the first gene of the operon), is transcriptionally regulated by carbon catabolic repression (CCR) mediated by the catabolite control protein CcpA. Copyright © 2013 Elsevier B.V. All rights reserved.

  10. Extracellular vesicle-driven information mediates the long-term effects of particulate matter exposure on coagulation and inflammation pathways.

    Science.gov (United States)

    Pavanello, Sofia; Bonzini, Matteo; Angelici, Laura; Motta, Valeria; Pergoli, Laura; Hoxha, Mirjam; Cantone, Laura; Pesatori, Angela Cecilia; Apostoli, Pietro; Tripodi, Armando; Baccarelli, Andrea; Bollati, Valentina

    2016-09-30

    Continuous exposure to particulate air pollution (PM) is a serious worldwide threat to public health as it coherently links with increased morbidity and mortality of cardiorespiratory diseases (CRD), and of type 2 diabetes (T2D). Extracellular vesicles (EVs) are circular plasma membrane fragments released from human cells that transfer microRNAs between tissues. In the present work it was explored the hypothesis that EVs with their encapsulated microRNAs (EVmiRNAs) contents might mediate PM effects by triggering key pathways in CRD and T2D. Expression of EVmiRNAs analyzed by real-time PCR was correlated with oxidative stress, coagulation and inflammation markers, from healthy steel plant workers (n=55) with a well-characterized exposure to PM and PM-associated metals. All p-values were adjusted for multiple comparisons. In-silico Ingenuity Pathway Analysis (IPA) was performed to identify biological pathways regulated by PM-associated EVmiRNAs. Increased expression in 17 EVmiRNAs is associated with PM and metal exposure (pinflammation, coagulation and glucose homeostasis pathways. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  11. The differentiation of skeletal muscle cells involves a protein-tyrosine phosphatase-alpha-mediated C-Src signaling pathway

    DEFF Research Database (Denmark)

    Lu, Huogen; Shah, Poonam; Ennis, David

    2002-01-01

    with previous reports, PTPalpha positively regulated the activity of the protein-tyrosine kinase Src. Treatment of L6 cells with PP2 or SU6656, specific inhibitors of Src family kinases, and transient transfection of dominant-inhibitory Src inhibited the formation of myotubes and expression of myogenin....... Moreover, enhanced expression of PTPalpha and activation of Src was detected during myogenesis. Together, these data indicate that PTPalpha is involved in the regulation of L6 myoblast growth and skeletal muscle cell differentiation via an Src-mediated signaling pathway....

  12. Feedback regulation on PTEN/AKT pathway by the ER stress kinase PERK mediated by interaction with the Vault complex

    DEFF Research Database (Denmark)

    Zhang, Wei; Neo, Suat Peng; Gunaratne, Jayantha

    2015-01-01

    inhibition of PERK has been reported to limit tumor growth in xenograft models. Here we provide evidence that inactive PERK interacts with the nuclear pore-associated Vault complex protein and that this compromises Vault-mediated nuclear transport of PTEN. Pharmacological inhibition of PERK under ER stress...... results is abnormal sequestration of the Vault complex, leading to increased cytoplasmic PTEN activity and lower AKT activation. As the PI3K/PTEN/AKT pathway is crucial for many aspects of cell growth and survival, this unexpected effect of PERK inhibitors on AKT activity may have implications...

  13. p53 and ATF4 mediate distinct and additive pathways to skeletal muscle atrophy during limb immobilization

    Science.gov (United States)

    Fox, Daniel K.; Ebert, Scott M.; Bongers, Kale S.; Dyle, Michael C.; Bullard, Steven A.; Dierdorff, Jason M.; Kunkel, Steven D.

    2014-01-01

    Immobilization causes skeletal muscle atrophy via complex signaling pathways that are not well understood. To better understand these pathways, we investigated the roles of p53 and ATF4, two transcription factors that mediate adaptations to a variety of cellular stresses. Using mouse models, we demonstrate that 3 days of muscle immobilization induces muscle atrophy and increases expression of p53 and ATF4. Furthermore, muscle fibers lacking p53 or ATF4 are partially resistant to immobilization-induced muscle atrophy, and forced expression of p53 or ATF4 induces muscle fiber atrophy in the absence of immobilization. Importantly, however, p53 and ATF4 do not require each other to promote atrophy, and coexpression of p53 and ATF4 induces more atrophy than either transcription factor alone. Moreover, muscle fibers lacking both p53 and ATF4 are more resistant to immobilization-induced atrophy than fibers lacking only p53 or ATF4. Interestingly, the independent and additive nature of the p53 and ATF4 pathways allows for combinatorial control of at least one downstream effector, p21. Using genome-wide mRNA expression arrays, we identified p21 mRNA as a skeletal muscle transcript that is highly induced in immobilized muscle via the combined actions of p53 and ATF4. Additionally, in mouse muscle, p21 induces atrophy in a manner that does not require immobilization, p53 or ATF4, and p21 is required for atrophy induced by immobilization, p53, and ATF4. Collectively, these results identify p53 and ATF4 as essential and complementary mediators of immobilization-induced muscle atrophy and discover p21 as a critical downstream effector of the p53 and ATF4 pathways. PMID:24895282

  14. Astrocytes protect neurons against methylmercury via ATP/P2Y(1) receptor-mediated pathways in astrocytes.

    Science.gov (United States)

    Noguchi, Yusuke; Shinozaki, Youichi; Fujishita, Kayoko; Shibata, Keisuke; Imura, Yoshio; Morizawa, Yosuke; Gachet, Christian; Koizumi, Schuichi

    2013-01-01

    Methylmercury (MeHg) is a well known environmental pollutant that induces serious neuronal damage. Although MeHg readily crosses the blood-brain barrier, and should affect both neurons and glial cells, how it affects glia or neuron-to-glia interactions has received only limited attention. Here, we report that MeHg triggers ATP/P2Y1 receptor signals in astrocytes, thereby protecting neurons against MeHg via interleukin-6 (IL-6)-mediated pathways. MeHg increased several mRNAs in astrocytes, among which IL-6 was the highest. For this, ATP/P2Y1 receptor-mediated mechanisms were required because the IL-6 production was (i) inhibited by a P2Y1 receptor antagonist, MRS2179, (ii) abolished in astrocytes obtained from P2Y1 receptor-knockout mice, and (iii) mimicked by exogenously applied ATP. In addition, (iv) MeHg released ATP by exocytosis from astrocytes. As for the intracellular mechanisms responsible for IL-6 production, p38 MAP kinase was involved. MeHg-treated astrocyte-conditioned medium (ACM) showed neuro-protective effects against MeHg, which was blocked by anti-IL-6 antibody and was mimicked by the application of recombinant IL-6. As for the mechanism of neuro-protection by IL-6, an adenosine A1 receptor-mediated pathway in neurons seems to be involved. Taken together, when astrocytes sense MeHg, they release ATP that autostimulates P2Y1 receptors to upregulate IL-6, thereby leading to A1 receptor-mediated neuro-protection against MeHg.

  15. TNF-α Mediates the Intrinsic and Extrinsic Pathway in Propofol-Induced Neuronal Apoptosis Via PI3K/Akt Signaling Pathway in Rat Prefrontal Cortical Neurons.

    Science.gov (United States)

    Deng, Xiaoyuan; Chen, Bo; Wang, Bin; Zhang, Junfang; Liu, Hongliang

    2017-10-01

    Propofol can cause developing neuronal apoptosis in both in vivo and in vitro studies, and the mechanism is unclear till now. Our previous study has demonstrated that propofol can increase the TNF-α expression in the prefrontal cortex in rat developing brain, the TNF-α antagonist, etanercept, can inhibit propofol-induced neuronal apoptosis, but little is known about how TNF-α mediates that process. This study reveals that propofol at clinically relevant concentrations increases the TNF-α synthesis and release in neurons, and induces neuronal apoptosis; etanercept significantly reduces neuronal apoptosis, the elevation of cleaved caspase-8 and cleaved caspase-9, or the Akt phosphorylation induced by propofol, while the selective PI3K antagonist blocks the neuroprotection of etanercept. Propofol does not change the expression of P2X7 receptor in neurons, and the P2X7 receptor antagonist cannot affect the TNF-α synthesis or release after propofol treatment. These results suggest that propofol can increase the synthesis and release of TNF-α in the primary cultured prefrontal cortical neurons, TNF-α contributes to the intrinsic and extrinsic pathway in propofol-induced neuronal apoptosis via PI3K/Akt signaling pathway, and P2X7R is not involved in the synthesis and release of TNF-α induced by propofol.

  16. Combined MEK and ERK inhibition overcomes therapy-mediated pathway reactivation in RAS mutant tumors.

    Science.gov (United States)

    Merchant, Mark; Moffat, John; Schaefer, Gabriele; Chan, Jocelyn; Wang, Xi; Orr, Christine; Cheng, Jason; Hunsaker, Thomas; Shao, Lily; Wang, Stephanie J; Wagle, Marie-Claire; Lin, Eva; Haverty, Peter M; Shahidi-Latham, Sheerin; Ngu, Hai; Solon, Margaret; Eastham-Anderson, Jeffrey; Koeppen, Hartmut; Huang, Shih-Min A; Schwarz, Jacob; Belvin, Marcia; Kirouac, Daniel; Junttila, Melissa R

    2017-01-01

    Mitogen-activated protein kinase (MAPK) pathway dysregulation is implicated in >30% of all cancers, rationalizing the development of RAF, MEK and ERK inhibitors. While BRAF and MEK inhibitors improve BRAF mutant melanoma patient outcomes, these inhibitors had limited success in other MAPK dysregulated tumors, with insufficient pathway suppression and likely pathway reactivation. In this study we show that inhibition of either MEK or ERK alone only transiently inhibits the MAPK pathway due to feedback reactivation. Simultaneous targeting of both MEK and ERK nodes results in deeper and more durable suppression of MAPK signaling that is not achievable with any dose of single agent, in tumors where feedback reactivation occurs. Strikingly, combined MEK and ERK inhibition is synergistic in RAS mutant models but only additive in BRAF mutant models where the RAF complex is dissociated from RAS and thus feedback productivity is disabled. We discovered that pathway reactivation in RAS mutant models occurs at the level of CRAF with combination treatment resulting in a markedly more active pool of CRAF. However, distinct from single node targeting, combining MEK and ERK inhibitor treatment effectively blocks the downstream signaling as assessed by transcriptional signatures and phospho-p90RSK. Importantly, these data reveal that MAPK pathway inhibitors whose activity is attenuated due to feedback reactivation can be rescued with sufficient inhibition by using a combination of MEK and ERK inhibitors. The MEK and ERK combination significantly suppresses MAPK pathway output and tumor growth in vivo to a greater extent than the maximum tolerated doses of single agents, and results in improved anti-tumor activity in multiple xenografts as well as in two Kras mutant genetically engineered mouse (GEM) models. Collectively, these data demonstrate that combined MEK and ERK inhibition is functionally unique, yielding greater than additive anti-tumor effects and elucidates a highly

  17. Electroretinographic assessment of rod- and cone-mediated bipolar cell pathways using flicker stimuli in mice

    Science.gov (United States)

    Tanimoto, Naoyuki; Sothilingam, Vithiyanjali; Kondo, Mineo; Biel, Martin; Humphries, Peter; Seeliger, Mathias W.

    2015-01-01

    Mouse full-field electroretinograms (ERGs) are dominated by responses of photoreceptors and depolarizing (ON-) bipolar cells, but not much of hyperpolarizing (OFF-) bipolar cells under conventional recording conditions. Here we investigate a novel ERG protocol in mice for functional assessment of the major ON- and OFF-bipolar cell pathways using flicker stimuli for a high luminance with varying frequency up to 30 Hz. Wild-type (WT) and functionally specific transgenic mice (Cnga3-/-, no cone photoreceptor function; rho-/-, no rod photoreceptor function; mGluR6-/-, no ON-bipolar cell function) were examined. The Cnga3-/- flicker ERG was similar to the WT flicker ERG at very low stimulus frequencies, whereas ERGs were comparable between WT and rho-/- mice at 5 Hz and above. Between 5 and 15 Hz, ERGs in mGluR6-/- mice differed in configuration and amplitude from those in WT and rho-/- mice; in contrast, response amplitudes above 15 Hz were comparable among WT, rho-/- and mGluR6-/- mice. In summary, we found three frequency ranges with these conditions that are dominated by activity in the rod pathways (below 5 Hz), cone ON-pathway (between 5 and 15 Hz), and cone OFF-pathway (above 15 Hz) that enables a quick overview of the functionality of the major bipolar cell pathways. PMID:26029863

  18. Cre-mediated stress affects sirtuin expression levels, peroxisome biogenesis and metabolism, antioxidant and proinflammatory signaling pathways.

    Directory of Open Access Journals (Sweden)

    Yu Xiao

    Full Text Available Cre-mediated excision of loxP sites is widely used in mice to manipulate gene function in a tissue-specific manner. To analyze phenotypic alterations related to Cre-expression, we have used AMH-Cre-transgenic mice as a model system. Different Cre expression levels were obtained by investigation of C57BL/6J wild type as well as heterozygous and homozygous AMH-Cre-mice. Our results indicate that Cre-expression itself in Sertoli cells already has led to oxidative stress and lipid peroxidation (4-HNE lysine adducts, inducing PPARα/γ, peroxisome proliferation and alterations of peroxisome biogenesis (PEX5, PEX13 and PEX14 as well as metabolic proteins (ABCD1, ABCD3, MFP1, thiolase B, catalase. In addition to the strong catalase increase, a NRF2- and FOXO3-mediated antioxidative response (HMOX1 of the endoplasmic reticulum and mitochondrial SOD2 and a NF-κB activation were noted. TGFβ1 and proinflammatory cytokines like IL1, IL6 and TNFα were upregulated and stress-related signaling pathways were induced. Sertoli cell mRNA-microarray analysis revealed an increase of TNFR2-signaling components. 53BP1 recruitment and expression levels for DNA repair genes as well as for p53 were elevated and the ones for related sirtuin deacetylases affected (SIRT 1, 3-7 in Sertoli cells. Under chronic Cre-mediated DNA damage conditions a strong downregulation of Sirt1 was observed, suggesting that the decrease of this important coordinator between DNA repair and metabolic signaling might induce the repression release of major transcription factors regulating metabolic and cytokine-mediated stress pathways. Indeed, caspase-3 was activated and increased germ cell apoptosis was observed, suggesting paracrine effects. In conclusion, the observed wide stress-induced effects and metabolic alterations suggest that it is essential to use the correct control animals (Cre/Wt with matched Cre expression levels to differentiate between Cre-mediated and specific gene-knock out-mediated

  19. Cre-Mediated Stress Affects Sirtuin Expression Levels, Peroxisome Biogenesis and Metabolism, Antioxidant and Proinflammatory Signaling Pathways

    Science.gov (United States)

    Xiao, Yu; Karnati, Srikanth; Qian, Guofeng; Nenicu, Anca; Fan, Wei; Tchatalbachev, Svetlin; Höland, Anita; Hossain, Hamid; Guillou, Florian; Lüers, Georg H.; Baumgart-Vogt, Eveline

    2012-01-01

    Cre-mediated excision of loxP sites is widely used in mice to manipulate gene function in a tissue-specific manner. To analyze phenotypic alterations related to Cre-expression, we have used AMH-Cre-transgenic mice as a model system. Different Cre expression levels were obtained by investigation of C57BL/6J wild type as well as heterozygous and homozygous AMH-Cre-mice. Our results indicate that Cre-expression itself in Sertoli cells already has led to oxidative stress and lipid peroxidation (4-HNE lysine adducts), inducing PPARα/γ, peroxisome proliferation and alterations of peroxisome biogenesis (PEX5, PEX13 and PEX14) as well as metabolic proteins (ABCD1, ABCD3, MFP1, thiolase B, catalase). In addition to the strong catalase increase, a NRF2- and FOXO3-mediated antioxidative response (HMOX1 of the endoplasmic reticulum and mitochondrial SOD2) and a NF-κB activation were noted. TGFβ1 and proinflammatory cytokines like IL1, IL6 and TNFα were upregulated and stress-related signaling pathways were induced. Sertoli cell mRNA-microarray analysis revealed an increase of TNFR2-signaling components. 53BP1 recruitment and expression levels for DNA repair genes as well as for p53 were elevated and the ones for related sirtuin deacetylases affected (SIRT 1, 3-7) in Sertoli cells. Under chronic Cre-mediated DNA damage conditions a strong downregulation of Sirt1 was observed, suggesting that the decrease of this important coordinator between DNA repair and metabolic signaling might induce the repression release of major transcription factors regulating metabolic and cytokine-mediated stress pathways. Indeed, caspase-3 was activated and increased germ cell apoptosis was observed, suggesting paracrine effects. In conclusion, the observed wide stress-induced effects and metabolic alterations suggest that it is essential to use the correct control animals (Cre/Wt) with matched Cre expression levels to differentiate between Cre-mediated and specific gene-knock out-mediated

  20. DFT-based Green's function pathways model for prediction of bridge-mediated electronic coupling.

    Science.gov (United States)

    Berstis, Laura; Baldridge, Kim K

    2015-12-14

    A density functional theory-based Green's function pathway model is developed enabling further advancements towards the long-standing challenge of accurate yet inexpensive prediction of electron transfer rate. Electronic coupling predictions are demonstrated to within 0.1 eV of experiment for organic and biological systems of moderately large size, with modest computational expense. Benchmarking and comparisons are made across density functional type, basis set extent, and orbital localization scheme. The resulting framework is shown to be flexible and to offer quantitative prediction of both electronic coupling and tunneling pathways in covalently bound non-adiabatic donor-bridge-acceptor (D-B-A) systems. A new localized molecular orbital Green's function pathway method (LMO-GFM) adaptation enables intuitive understanding of electron tunneling in terms of through-bond and through-space interactions.

  1. Network Mendelian randomization: using genetic variants as instrumental variables to investigate mediation in causal pathways.

    Science.gov (United States)

    Burgess, Stephen; Daniel, Rhian M; Butterworth, Adam S; Thompson, Simon G

    2015-04-01

    Mendelian randomization uses genetic variants, assumed to be instrumental variables for a particular exposure, to estimate the causal effect of that exposure on an outcome. If the instrumental variable criteria are satisfied, the resulting estimator is consistent even in the presence of unmeasured confounding and reverse causation. We extend the Mendelian randomization paradigm to investigate more complex networks of relationships between variables, in particular where some of the effect of an exposure on the outcome may operate through an intermediate variable (a mediator). If instrumental variables for the exposure and mediator are available, direct and indirect effects of the exposure on the outcome can be estimated, for example using either a regression-based method or structural equation models. The direction of effect between the exposure and a possible mediator can also be assessed. Methods are illustrated in an applied example considering causal relationships between body mass index, C-reactive protein and uric acid. These estimators are consistent in the presence of unmeasured confounding if, in addition to the instrumental variable assumptions, the effects of both the exposure on the mediator and the mediator on the outcome are homogeneous across individuals and linear without interactions. Nevertheless, a simulation study demonstrates that even considerable heterogeneity in these effects does not lead to bias in the estimates. These methods can be used to estimate direct and indirect causal effects in a mediation setting, and have potential for the investigation of more complex networks between multiple interrelated exposures and disease outcomes. © The Author 2014. Published by Oxford University Press on behalf of the International Epidemiological Association.

  2. A G-protein-coupled receptor regulation pathway in cytochrome P450-mediated permethrin-resistance in mosquitoes, Culex quinquefasciatus.

    Science.gov (United States)

    Li, Ting; Cao, Chuanwang; Yang, Ting; Zhang, Lee; He, Lin; Xi, Zhiyong; Bian, Guowu; Liu, Nannan

    2015-12-10

    Rhodopsin-like G protein-coupled receptors (GPCRs) are known to be involved in the GPCR signal transduction system and regulate many essential physiological processes in organisms. This study, for the first time, revealed that knockdown of the rhodopsin-like GPCR gene in resistant mosquitoes resulted in a reduction of mosquitoes' resistance to permethrin, simultaneously reducing the expression of two cAMP-dependent protein kinase A genes (PKAs) and four resistance related cytochrome P450 genes. The function of rhodopsin-like GPCR was further confirmed using transgenic lines of Drosophila melanogaster, in which the tolerance to permethrin and the expression of Drosophila resistance P450 genes were both increased. The roles of GPCR signaling pathway second messenger cyclic adenosine monophosphate (cAMP) and downstream effectors PKAs in resistance were investigated using cAMP production inhibitor Bupivacaine HCl and the RNAi technique. Inhibition of cAMP production led to significant decreases in both the expression of four resistance P450 genes and two PKA genes and mosquito resistance to permethrin. Knockdown of the PKA genes had shown the similar effects on permethrin resistance and P450 gene expression. Taken together, our studies revealed, for the first time, the role of the GPCR/cAMP/PKA-mediated regulatory pathway governing P450 gene expression and P450-mediated resistance in Culex mosquitoes.

  3. Can the TLR-4-Mediated Signaling Pathway Be “A Key Inflammatory Promoter for Sporadic TAA”?

    Directory of Open Access Journals (Sweden)

    Giovanni Ruvolo

    2014-01-01

    Full Text Available Thoracic aorta shows with advancing age various changes and a progressive deterioration in structure and function. As a result, vascular remodeling (VR and medial degeneration (MD occur as pathological entities responsible principally for the sporadic TAA onset. Little is known about their genetic, molecular, and cellular mechanisms. Recent evidence is proposing the strong role of a chronic immune/inflammatory process in their evocation and progression. Thus, we evaluated the potential role of Toll like receptor- (TLR- 4-mediated signaling pathway and its polymorphisms in sporadic TAA. Genetic, immunohistochemical, and biochemical analyses were assessed. Interestingly, the rs4986790 TLR4 polymorphism confers a higher susceptibility for sporadic TAA (OR=14.4, P=0.0008 and it represents, together with rs1799752 ACE, rs3918242 MMP-9, and rs2285053 MMP-2 SNPs, an independent sporadic TAA risk factor. In consistency with these data, a significant association was observed between their combined risk genotype and sporadic TAA. Cases bearing this risk genotype showed higher systemic inflammatory mediator levels, significant inflammatory/immune infiltrate, a typical MD phenotype, lower telomere length, and positive correlations with histopatological abnormalities, hypertension, smoking, and ageing. Thus, TLR4 pathway should seem to have a key role in sporadic TAA. It might represent a potential useful tool for preventing and monitoring sporadic TAA and developing personalized treatments.

  4. A G-protein-coupled receptor regulation pathway in cytochrome P450-mediated permethrin-resistance in mosquitoes, Culex quinquefasciatus

    Science.gov (United States)

    Li, Ting; Cao, Chuanwang; Yang, Ting; Zhang, Lee; He, Lin; Xi, Zhiyong; Bian, Guowu; Liu, Nannan

    2015-01-01

    Rhodopsin-like G protein-coupled receptors (GPCRs) are known to be involved in the GPCR signal transduction system and regulate many essential physiological processes in organisms. This study, for the first time, revealed that knockdown of the rhodopsin-like GPCR gene in resistant mosquitoes resulted in a reduction of mosquitoes’ resistance to permethrin, simultaneously reducing the expression of two cAMP-dependent protein kinase A genes (PKAs) and four resistance related cytochrome P450 genes. The function of rhodopsin-like GPCR was further confirmed using transgenic lines of Drosophila melanogaster, in which the tolerance to permethrin and the expression of Drosophila resistance P450 genes were both increased. The roles of GPCR signaling pathway second messenger cyclic adenosine monophosphate (cAMP) and downstream effectors PKAs in resistance were investigated using cAMP production inhibitor Bupivacaine HCl and the RNAi technique. Inhibition of cAMP production led to significant decreases in both the expression of four resistance P450 genes and two PKA genes and mosquito resistance to permethrin. Knockdown of the PKA genes had shown the similar effects on permethrin resistance and P450 gene expression. Taken together, our studies revealed, for the first time, the role of the GPCR/cAMP/PKA-mediated regulatory pathway governing P450 gene expression and P450-mediated resistance in Culex mosquitoes. PMID:26656663

  5. Research on the mechanism of HP mediated PI3K/AKT/GSK3β pathways in gastric cancer.

    Science.gov (United States)

    Geng, W; Zhang, H-Y

    2017-07-01

    This study aimed to investigate the mechanism of Helicobacter pylori (HP) mediated PI3K/AKT/GSK3β signal pathways in the occurrence of gastric cancer. For this purpose, a total of 90 patients were selected; 30 were suffering from gastric cancer and gastric ulcer (observation group I), 30 were suffering from pure gastric ulcer (observation group II) and 30 were with chronic gastritis (control group), and the lesion tissues were extracted by using endoscopy. Then, rapid urease test, RT-PCR and Western blot tests were conducted to detect the positivity rate of HP infection, the expression levels of PI3K/AKT/GSK3β mRNA and protein respectively. The results showed that the positivity rate of HP infection, expression level of the PI3K/AKT/GSK3β mRNA and protein from the samples of the observation group I were significantly higher than other two groups (p-value HP may mediate the PI3K/AKT/GSK3β signal pathways in the occurrence of gastric cancer.

  6. Endothelin and calciotropic hormones share regulatory pathways in multidrug resistance protein 2-mediated transport

    NARCIS (Netherlands)

    Wever, K.E.; Masereeuw, R.; Miller, D.S.; Hang, X.M.; Flik, G.

    2007-01-01

    The kidney of vertebrates plays a key role in excretion of endogenous waste products and xenobiotics. Active secretion in the proximal nephron is at the basis of this excretion, mediated by carrier proteins including multidrug resistance protein 2 (Mrp2). We previously showed that Mrp2 function is

  7. Endothelin and calciotropic hormones share regulatory pathways in multidrug resistance protein 2-mediated transport.

    NARCIS (Netherlands)

    Wever, K.E.; Masereeuw, R.; Miller, D.S.; Hang, X.M.; Flik, G.

    2007-01-01

    The kidney of vertebrates plays a key role in excretion of endogenous waste products and xenobiotics. Active secretion in the proximal nephron is at the basis of this excretion, mediated by carrier proteins including multidrug resistance protein 2 (Mrp2). We previously showed that Mrp2 function is

  8. Endothelin and calciotropic hormones share regulatory pathways in multidrug resistance protein 2 (Mrp2-) mediated transport

    NARCIS (Netherlands)

    Wever, K.E.; Masereeuw, R.; Miller, D.S.; Hang, X.M.; Flik, G.

    2006-01-01

    The kidney of vertebrates plays a key role in excretion of endogenous waste products and xenobiotics. Active secretion in the proximal nephron is at the basis of this excretion, mediated by carrier proteins including multidrug resistance protein 2 (Mrp2). We previously showed that Mrp2 function is

  9. Two conserved modules of Schizosaccharomyces pombe Mediator regulate distinct cellular pathways

    DEFF Research Database (Denmark)

    Linder, Tomas; Rasmussen, Nina; Samuelsen, Camilla O

    2008-01-01

    and Deltamed27 alleles revealed a stepwise head domain molecular architecture. Phenotypical analysis of Cdk8 and head module alleles including expression profiling classified the Mediator mutant alleles into one of two groups. Cdk8 module mutants flocculate due to overexpression of adhesive cell...

  10. Gendered Pathways? Gender, Mediating Factors, and the Gap in Boys' and Girls' Substance Use

    Science.gov (United States)

    Whaley, Rachel Bridges; Hayes-Smith, Justin; Hayes-Smith, Rebecca

    2013-01-01

    A gender gap in alcohol and drug use exists but is somewhat smaller than the gender gap in other forms of delinquency. This article extends studies that examine the gender-delinquency relationship to substance use in particular and estimate the extent to which major risk and protective factors mediate the association between gender and alcohol and…

  11. Characterization of murine melanocortin receptors mediating adipocyte lipolysis and examination of signalling pathways involved

    DEFF Research Database (Denmark)

    Møller, Cathrine Laustrup; Raun, Kirsten; Jacobsen, Marianne Lambert

    2011-01-01

    hormone (a-MSH) generated from proopiomelanocortin (POMC), as well as synthetic MSH analogues to stimulate lipolysis in murine 3T3-L1 adipocytes it is shown that MC2R and MC5R are lipolytic mediators in differentiated 3T3-L1 adipocytes. Involvement of cAMP, phosphorylated extracellular signal...

  12. Endothelin and calciotropic hormones share regulatory pathways in multidrug resistance protein 2-mediated transport

    NARCIS (Netherlands)

    Wever, K.E.; Masereeuw, R.; Miller, D.S.; Hang, X.M.; Flik, G.

    2006-01-01

    The kidney of vertebrates plays a key role in excretion of endogenous waste products and xenobiotics. Active secretion in the proximal nephron is at the basis of this excretion, mediated by carrier proteins including multidrug resistance protein 2 (Mrp2). We previously showed that Mrp2 function is

  13. Tyrosine kinase Btk regulates E-selectin–mediated integrin activation and neutrophil recruitment by controlling phospholipase C (PLC) γ2 and PI3Kγ pathways

    Science.gov (United States)

    Mueller, Helena; Stadtmann, Anika; Van Aken, Hugo; Hirsch, Emilio; Wang, Demin; Ley, Klaus

    2010-01-01

    Selectins mediate leukocyte rolling, trigger β2-integrin activation, and promote leukocyte recruitment into inflamed tissue. E-selectin binding to P-selectin glycoprotein ligand 1 (PSGL-1) leads to activation of an immunoreceptor tyrosine-based activation motif (ITAM)–dependent pathway, which in turn activates the spleen tyrosine kinase (Syk). However, the signaling pathway linking Syk to integrin activation after E-selectin engagement is unknown. To identify the pathway, we used different gene-deficient mice in autoperfused flow chamber, intravital microscopy, peritonitis, and biochemical studies. We report here that the signaling pathway downstream of Syk divides into a phospholipase C (PLC) γ2– and phosphoinositide 3-kinase (PI3K) γ–dependent pathway. The Tec family kinase Bruton tyrosine kinase (Btk) is required for activating both pathways, generating inositol-3,4,5-trisphosphate (IP3), and inducing E-selectin–mediated slow rolling. Inhibition of this signal-transduction pathway diminished Gαi-independent leukocyte adhesion to and transmigration through endothelial cells in inflamed postcapillary venules of the cremaster. Gαi-independent neutrophil recruitment into the inflamed peritoneal cavity was reduced in Btk−/− and Plcg2−/− mice. Our data demonstrate the functional importance of this newly identified signaling pathway mediated by E-selectin engagement. PMID:20167705

  14. Viral vector-mediated selective and reversible blockade of the pathway for visual orienting in mice

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    Tadashi eIsa

    2013-10-01

    Full Text Available Recently, by using a combination of two viral vectors, we developed a technique for pathway-selective and reversible synaptic transmission blockade, and successfully induced a behavioral deficit of dexterous hand movements in macaque monkeys by affecting a population of spinal interneurons. To explore the capacity of this technique to work in other pathways and species, and to obtain fundamental methodological information, we tried to block the crossed tecto-reticular pathway, which is known to control orienting responses to visual targets, in mice. A neuron-specific retrograde gene transfer vector with the gene encoding enhanced tetanus neurotoxin (eTeNT tagged with enhanced green fluorescent protein (EGFP under the control of a tetracycline responsive element was injected into the left medial pontine reticular formation. 7–17 days later, an adeno-associated viral vector with a highly efficient Tet-ON sequence, rtTAV16, was injected into the right superior colliculus. 5–9 weeks later, the daily administration of doxycycline (Dox was initiated. Visual orienting responses toward the left side were impaired 1 - 4 days after Dox administration. Anti-GFP immunohistochemistry revealed that a number of neurons in the intermediate and deep layers of the right superior colliculus were positively stained, indicating eTeNT expression. After the termination of Dox administration, the anti-GFP staining returned to the baseline level within 28 days. A second round of Dox administration, starting from 28 days after the termination of the first Dox administration, resulted in the reappearance of the behavioral impairment. These findings showed that pathway-selective and reversible blockade of synaptic transmission causes behavioral effects also in rodents, and that the crossed tecto-reticular pathway surely controls visual orienting behaviors.

  15. Pathway from Delirium to Death: Potential In-Hospital Mediators of Excess Mortality.

    Science.gov (United States)

    Dharmarajan, Kumar; Swami, Sunil; Gou, Ray Y; Jones, Richard N; Inouye, Sharon K

    2017-05-01

    (1) To determine the relationship of incident delirium during hospitalization with 90-day mortality; (2) to identify potential in-hospital mediators through which delirium increases 90-day mortality. Analysis of data from Project Recovery, a controlled clinical trial of a delirium prevention intervention from 1995 to 1998 with follow-up through 2000. Large academic hospital. Patients ≥70 years old without delirium at hospital admission who were at intermediate-to-high risk of developing delirium and received usual care only. (1) Incident delirium; (2) potential mediators of delirium on death including use of restraining devices (physical restraints, urinary catheters), development of hospital acquired conditions (HACs) (falls, pressure ulcers), and exposure to other noxious insults (sleep deprivation, acute malnutrition, dehydration, aspiration pneumonia); (3) death within 90 days of admission. Among 469 patients, 70 (15%) developed incident delirium. These patients were more likely to experience restraining devices (37% vs 16%, P delirium was 4.2 (95% CI = 2.8-6.3) in bivariable analyses, increased in a graded manner with additional exposures to restraining devices, HACs, and other noxious insults, and declined by 10.9% after addition of these potential mediator categories, providing evidence of mediation. Restraining devices, HACs, and additional noxious insults were more frequent among patients with delirium, increased mortality in a graded manner, and were responsible for a significant percentage of the association of delirium with death. Additional efforts to prevent potential downstream mediators through which delirium increases mortality may help to improve outcomes among hospitalized older adults. © 2016, Copyright the Authors Journal compilation © 2016, The American Geriatrics Society.

  16. Distinctive effects of eicosapentaenoic and docosahexaenoic acids in regulating neural stem cell fate are mediated via endocannabinoid signalling pathways.

    Science.gov (United States)

    Dyall, S C; Mandhair, H K; Fincham, R E A; Kerr, D M; Roche, M; Molina-Holgado, F

    2016-08-01

    Emerging evidence suggests a complex interplay between the endocannabinoid system, omega-3 fatty acids and the immune system in the promotion of brain self-repair. However, it is unknown if all omega-3 fatty acids elicit similar effects on adult neurogenesis and if such effects are mediated or regulated by interactions with the endocannabinoid system. This study investigated the effects of DHA and EPA on neural stem cell (NSC) fate and the role of the endocannabinoid signalling pathways in these effects. EPA, but not DHA, significantly increased proliferation of NSCs compared to controls, an effect associated with enhanced levels of the endocannabinoid 2-arachidonylglycerol (2-AG) and p-p38 MAPK, effects attenuated by pre-treatment with CB1 (AM251) or CB2 (AM630) receptor antagonists. Furthermore, in NSCs derived from IL-1β deficient mice, EPA significantly decreased proliferation and p-p38 MAPK levels compared to controls, suggesting a key role for IL-1β signalling in the effects observed. Although DHA similarly increased 2-AG levels in wild-type NSCs, there was no concomitant increase in proliferation or p-p38 MAPK activity. In addition, in NSCs from IL-1β deficient mice, DHA significantly increased proliferation without effects on p-P38 MAPK, suggesting effects of DHA are mediated via alternative signalling pathways. These results provide crucial new insights into the divergent effects of EPA and DHA in regulating NSC proliferation and the pathways involved, and highlight the therapeutic potential of their interplay with endocannabinoid signalling in brain repair. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. Heat Killed Attenuated Leishmania Induces Apoptosis of HepG2 Cells Through ROS Mediated p53 Dependent Mitochondrial Pathway

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    Dipayan Bose

    2016-03-01

    Full Text Available Background/Aims: Cytotoxic effect of attenuated Leishmania on liver cancer cells by inducing ROS generation. Methods: Spectrophotometric study to analyze cell death and levels of different active caspases. Flow cytometric study was done to analyze apoptosis induction and ROS generation and levels of different protein. Western blot analysis was performed to study the levels of protein. Confocal microscopy was done to ascertain the expression of different apoptotic markers. Results: We have now observed that attenuated Leishmania donovani UR6 also has potentiality towards growth inhibition of HepG2 cells and investigated the mechanism of action. The effect is associated with increased DNA fragmentation, rise in number of annexinV positive cells, and cell cycle arrest at G1 phase. The detection of unregulated levels of active PARP, cleaved caspases 3 and 9, cytosolic cytochrome C, Bax, and Bad, along with the observed downregulation of Bcl-2 and loss of mitochondrial membrane potential suggested the involvement of mitochondrial pathway. Enhanced ROS and p53 levels regulate the apoptosis of HepG2 cells. NAC was found to inhibit p53 production but PFT-α has no effect on ROS generation. In conclusion, Leishmania donovani UR6 efficiently induces apoptosis in HepG2 cells through ROS mediated p53 dependent mitochondrial pathway. Conclusion: It has been reported earlier that some parasites show prominent cytotoxic effect and prevent tumor growth. From our study we found that Leishmania donovani UR6 efficiently induced apoptosis in HepG2 cells through ROS mediated p53 dependent mitochondrial pathway. This study has rejuvenated the age old idea of bio-therapy.

  18. Hepatitis C virus infection induces apoptosis through a Bax-triggered, mitochondrion-mediated, caspase 3-dependent pathway.

    Science.gov (United States)

    Deng, Lin; Adachi, Tetsuya; Kitayama, Kikumi; Bungyoku, Yasuaki; Kitazawa, Sohei; Ishido, Satoshi; Shoji, Ikuo; Hotta, Hak

    2008-11-01

    We previously reported that cells harboring the hepatitis C virus (HCV) RNA replicon as well as those expressing HCV NS3/4A exhibited increased sensitivity to suboptimal doses of apoptotic stimuli to undergo mitochondrion-mediated apoptosis (Y. Nomura-Takigawa, et al., J. Gen. Virol. 87:1935-1945, 2006). Little is known, however, about whether or not HCV infection induces apoptosis of the virus-infected cells. In this study, by using the chimeric J6/JFH1 strain of HCV genotype 2a, we demonstrated that HCV infection induced cell death in Huh7.5 cells. The cell death was associated with activation of caspase 3, nuclear translocation of activated caspase 3, and cleavage of DNA repair enzyme poly(ADP-ribose) polymerase, which is known to be an important substrate for activated caspase 3. These results suggest that HCV-induced cell death is, in fact, apoptosis. Moreover, HCV infection activated Bax, a proapoptotic member of the Bcl-2 family, as revealed by its conformational change and its increased accumulation on mitochondrial membranes. Concomitantly, HCV infection induced disruption of mitochondrial transmembrane potential, followed by mitochondrial swelling and release of cytochrome c from mitochondria. HCV infection also caused oxidative stress via increased production of mitochondrial superoxide. On the other hand, HCV infection did not mediate increased expression of glucose-regulated protein 78 (GRP78) or GRP94, which are known as endoplasmic reticulum (ER) stress-induced proteins; this result suggests that ER stress is not primarily involved in HCV-induced apoptosis in our experimental system. Taken together, our present results suggest that HCV infection induces apoptosis of the host cell through a Bax-triggered, mitochondrion-mediated, caspase 3-dependent pathway(s).

  19. TRAF1 Coordinates Polyubiquitin Signaling to Enhance Epstein-Barr Virus LMP1-Mediated Growth and Survival Pathway Activation.

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    Hannah Greenfeld

    2015-05-01

    Full Text Available The Epstein-Barr virus (EBV encoded oncoprotein Latent Membrane Protein 1 (LMP1 signals through two C-terminal tail domains to drive cell growth, survival and transformation. The LMP1 membrane-proximal TES1/CTAR1 domain recruits TRAFs to activate MAP kinase, non-canonical and canonical NF-kB pathways, and is critical for EBV-mediated B-cell transformation. TRAF1 is amongst the most highly TES1-induced target genes and is abundantly expressed in EBV-associated lymphoproliferative disorders. We found that TRAF1 expression enhanced LMP1 TES1 domain-mediated activation of the p38, JNK, ERK and canonical NF-kB pathways, but not non-canonical NF-kB pathway activity. To gain insights into how TRAF1 amplifies LMP1 TES1 MAP kinase and canonical NF-kB pathways, we performed proteomic analysis of TRAF1 complexes immuno-purified from cells uninduced or induced for LMP1 TES1 signaling. Unexpectedly, we found that LMP1 TES1 domain signaling induced an association between TRAF1 and the linear ubiquitin chain assembly complex (LUBAC, and stimulated linear (M1-linked polyubiquitin chain attachment to TRAF1 complexes. LMP1 or TRAF1 complexes isolated from EBV-transformed lymphoblastoid B cell lines (LCLs were highly modified by M1-linked polyubiqutin chains. The M1-ubiquitin binding proteins IKK-gamma/NEMO, A20 and ABIN1 each associate with TRAF1 in cells that express LMP1. TRAF2, but not the cIAP1 or cIAP2 ubiquitin ligases, plays a key role in LUBAC recruitment and M1-chain attachment to TRAF1 complexes, implicating the TRAF1:TRAF2 heterotrimer in LMP1 TES1-dependent LUBAC activation. Depletion of either TRAF1, or the LUBAC ubiquitin E3 ligase subunit HOIP, markedly impaired LCL growth. Likewise, LMP1 or TRAF1 complexes purified from LCLs were decorated by lysine 63 (K63-linked polyubiqutin chains. LMP1 TES1 signaling induced K63-polyubiquitin chain attachment to TRAF1 complexes, and TRAF2 was identified as K63-Ub chain target. Co-localization of M1- and K63

  20. Role of SIRT1-mediated mitochondrial and Akt pathways in glioblastoma cell death induced by Cotinus coggygria flavonoid nanoliposomes

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    Wang G

    2015-08-01

    phosphorylated p53. Together, these results indicated SIRT1/p53-mediated cell death was induced by CCF-NLs, but not by extracellular signal-regulated kinase, in DBTRG-05MG cells. Overall, this study suggested caspase-dependent activation of both the intrinsic and extrinsic signaling pathways, probably through blockade of the SIRT1/p53-mediated mitochondrial and Akt pathways to exert the proapoptotic effect of CCF-NLs in DBTRG-05MG GBM cells. Keywords: Cotinus coggygria flavonoid nanoliposomes, cell death, SIRT1, mitochondrial, PI3K/Akt pathway

  1. The phosphatidylinositol-3 kinase pathway is not essential for insulin-like growth factor I receptor-mediated clonogenic radioresistance

    International Nuclear Information System (INIS)

    Yu, Dong; Watanabe, Hiroshi; Shibuya, Hitoshi; Miura, Masahiko

    2002-01-01

    The insulin-like growth factor I receptor (IGF-IR) is known to induce clonogenic radioresistance in cells following ionizing irradiation. To explore the downstream signaling pathways, we focused on the phosphatidylinositol-3 kinase (PI3-K) pathway, which is thought to be the primary cell survival signal originating from the receptor. For this purpose, R- cells deficient in the endogenous IGF-IR were used as a recipient of the human IGF-IR with or without mutations at potential PI3-K activation sites: NPXY 950 and Y 1316 XXM. Mutats with double mutation at Y950/Y1316 exhibited not abrogated, but reduced activation of insulin receptor substance-1 (IRS-1), PI3-K, and Akt upon IGF-I stimulation. However, the mutants had the same clonogenic radioresistance as cells with wild type (WT) receptors. Neither wortmannin nor LY294002, specific inhibitors of PI3-K, affected the radioresistance of cells with WT receptors at concentrations specific for PI3-K. Collectively, these results indicate that the PI3-K pathway is not essential for IGF-IR-mediated clonogenic radioresistance. (author)

  2. Angiotensin-II-induced Muscle Wasting is Mediated by 25-Hydroxycholesterol via GSK3β Signaling Pathway

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    Congcong Shen

    2017-02-01

    Full Text Available While angiotensin II (ang II has been implicated in the pathogenesis of cardiac cachexia (CC, the molecules that mediate ang II's wasting effect have not been identified. It is known TNF-α level is increased in patients with CC, and TNF-α release is triggered by ang II. We therefore hypothesized that ang II induced muscle wasting is mediated by TNF-α. Ang II infusion led to skeletal muscle wasting in wild type (WT but not in TNF alpha type 1 receptor knockout (TNFR1KO mice, suggesting that ang II induced muscle loss is mediated by TNF-α through its type 1 receptor. Microarray analysis identified cholesterol 25-hydroxylase (Ch25h as the down stream target of TNF-α. Intraperitoneal injection of 25-hydroxycholesterol (25-OHC, the product of Ch25h, resulted in muscle loss in C57BL/6 mice, accompanied by increased expression of atrogin-1, MuRF1 and suppression of IGF-1/Akt signaling pathway. The identification of 25-OHC as an inducer of muscle wasting has implications for the development of specific treatment strategies in preventing muscle loss.

  3. GFRA2 Identifies Cardiac Progenitors and Mediates Cardiomyocyte Differentiation in a RET-Independent Signaling Pathway

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    Hidekazu Ishida

    2016-07-01

    Full Text Available A surface marker that distinctly identifies cardiac progenitors (CPs is essential for the robust isolation of these cells, circumventing the necessity of genetic modification. Here, we demonstrate that a Glycosylphosphatidylinositol-anchor containing neurotrophic factor receptor, Glial cell line-derived neurotrophic factor receptor alpha 2 (Gfra2, specifically marks CPs. GFRA2 expression facilitates the isolation of CPs by fluorescence activated cell sorting from differentiating mouse and human pluripotent stem cells. Gfra2 mutants reveal an important role for GFRA2 in cardiomyocyte differentiation and development both in vitro and in vivo. Mechanistically, the cardiac GFRA2 signaling pathway is distinct from the canonical pathway dependent on the RET tyrosine kinase and its established ligands. Collectively, our findings establish a platform for investigating the biology of CPs as a foundation for future development of CP transplantation for treating heart failure.

  4. Ligand functionalization as a deactivation pathway in a fac-Ir(ppy)3-mediated radical addition.

    Science.gov (United States)

    Devery Iii, James J; Douglas, James J; Nguyen, John D; Cole, Kevin P; Flowers Ii, Robert A; Stephenson, Corey R J

    2015-01-01

    Knowledge of the kinetic behavior of catalysts under synthetically relevant conditions is vital for the efficient use of compounds that mediate important transformations regardless of their composition or driving force. In particular, these data are of great importance to add perspective to the growing number of applications of photoactive transition metal complexes. Here we present kinetic, synthetic, and spectroscopic evidence of the mechanistic behavior of fac -Ir(ppy) 3 in a visible light-mediated radical addition to 3-methylindole, demonstrating the instability of fac -Ir(ppy) 3 under these conditions. During the reaction, rapid in situ functionalization of the photocatalyst occurs, eventually leading to deactivation. These findings demonstrate a conceivable deactivation process for catalytic single electron reactions in the presence of radicophilic ligands. Attempts to inhibit photocatalyst deactivation through structural modification provide further insight into catalyst selection for a given system of interest.

  5. The neuronal pathways mediating the behavioral and addictive properties of nicotine.

    Science.gov (United States)

    Balfour, David J K

    2009-01-01

    This chapter considers the neurobiological mechanisms that are thought to mediate the reinforcing or rewarding properties of nicotine. It focuses on the data (derived principally from studies with experimental animals) showing that nicotine, like other drugs of dependence, stimulates the mesolimbic dopamine (DA) neurones that project to the nucleus accumbens and that these effects play a pivotal role in the biology underlying nicotine dependence. The reinforcing or rewarding properties of nicotine are thought to be associated particularly with the increase in DA overflow evoked in the shell subdivision of the accumbens. However, behavioural studies suggest that these properties of nicotine in experimental animals do not seem to be sufficiently potent to explain the powerful addiction to tobacco experienced by most habitual smokers. This chapter also considers the biological mechanisms that mediate the effects of cues and stimuli associated with the presentation of nicotine, which are thought to contribute significantly to the powerful addictive properties of tobacco smoke.

  6. Embryotoxicity Caused by DON-Induced Oxidative Stress Mediated by Nrf2/HO-1 Pathway

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    Miao Yu

    2017-06-01

    Full Text Available Deoxynivalenol (DON belongs to the type B group of trichothecenes family, which is composed of sesquiterpenoid metabolites produced by Fusarium and other fungi in grain. DON may cause various toxicities, such as cytotoxicity, immunotoxicity, genotoxicity as well as teratogenicity and carcinogenicity. In the present study, we focus on a hypothesis that DON alters the expressions of Nrf2/HO-1 pathway by inducing embryotoxicity in C57BL/6 mouse (5.0, 2.5, 1.0, and 0 mg/kg/day and BeWo cell lines (0 and 50 nM; 3 h, 12 h and 24 h. Our results indicate that DON treatment in mice during pregnancy leads to ROS accumulation in the placenta, which results in embryotoxicity. At the same time Nrf2/HO-1 pathway is up-regulated by ROS to protect placenta cells from oxidative damage. In DON-treated BeWo cells, the level of ROS has time–effect and dose–effect relationships with HO-1 expression. Moderate increase in HO-1 protects the cell from oxidative damage, while excessive increase in HO-1 aggravates the oxidative damage, which is called in some studies the “threshold effect”. Therefore, oxidative stress may be the critical molecular mechanism for DON-induced embryotoxicity. Besides, Nrf2/HO-1 pathway accompanied by the “threshold effect” also plays an important role against DON-induced oxidative damage in this process.

  7. Reactive astrocytes function as phagocytes after brain ischemia via ABCA1-mediated pathway.

    Science.gov (United States)

    Morizawa, Yosuke M; Hirayama, Yuri; Ohno, Nobuhiko; Shibata, Shinsuke; Shigetomi, Eiji; Sui, Yang; Nabekura, Junichi; Sato, Koichi; Okajima, Fumikazu; Takebayashi, Hirohide; Okano, Hideyuki; Koizumi, Schuichi

    2017-06-22

    Astrocytes become reactive following various brain insults; however, the functions of reactive astrocytes are poorly understood. Here, we show that reactive astrocytes function as phagocytes after transient ischemic injury and appear in a limited spatiotemporal pattern. Following transient brain ischemia, phagocytic astrocytes are observed within the ischemic penumbra region during the later stage of ischemia. However, phagocytic microglia are mainly observed within the ischemic core region during the earlier stage of ischemia. Phagocytic astrocytes upregulate ABCA1 and its pathway molecules, MEGF10 and GULP1, which are required for phagocytosis, and upregulation of ABCA1 alone is sufficient for enhancement of phagocytosis in vitro. Disrupting ABCA1 in reactive astrocytes result in fewer phagocytic inclusions after ischemia. Together, these findings suggest that astrocytes are transformed into a phagocytic phenotype as a result of increase in ABCA1 and its pathway molecules and contribute to remodeling of damaged tissues and penumbra networks.Astrocytic phagocytosis has been shown to play a role in synaptic pruning during development, but whether adult astrocytes possess phagocytic ability is unclear. Here the authors show that following brain ischemia, reactive astrocytes become phagocytic and engulf debris via the ABCA1 pathway.

  8. Pathways to positivity from perceived stress in adolescents: multiple mediation of emotion regulation and coping strategies

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    Mehmet Ali Yildiz

    2017-05-01

    Full Text Available Background The current study aimed to examine the multiple mediation of emotion regulation and coping strategies in the relationship between perceived stress and positivity in adolescents. Participants and procedure Participants included 312 adolescents attending high schools. 162 of the participants were female and 150 were male, with an average age of 16.26, SD = 1.21. Data collection was conducted with the Perceived Stress Scale, the Emotion Regulation Scale for Adolescents, the Coping Scale for Children and Youth, and the Positivity Scale. Descriptive statistics, Pearson’s correlation coefficient, regression based on ordinary least squares, and the bootstrap method were used to analyze the research data. Results The research findings indicated that internal dysfunctional emotion regulation, assistance seeking, problem solving, and behavioral avoidance mediated the relationship between perceived stress and positivity. Conclusion In conclusion, internal dysfunctional emotion regulation, seeking assistance, problem solving, and behavioral avoidance were found to mediate the relationship between adolescents’ perceived stress and positivity. Thus, preparing individual and group psychological counseling as well as emotion regulation and coping-oriented psycho-educational programs for adolescents to regulate negative emotions and to cope with stress may be important. The research findings were discussed and interpreted based on the relevant literature, and suggestions for relevant experts were included.

  9. The Association of CXC Receptor 4 Mediated Signaling Pathway with Oxaliplatin-Resistant Human Colorectal Cancer Cells.

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    Wen-Shih Huang

    Full Text Available The stromal cell-derived factor-1 (SDF-1/CXC receptor 4 (CXCR4 axis plays an important role in tumor angiogenesis and invasiveness in colorectal cancer (CRC progression. In addition, metastatic CRC remains one of the most difficult human malignancies to treat because of its chemoresistant behavior. However, the mechanism by which correlation occurs between CXCR4 and the clinical response of CRC to chemotherapy remains unknown. We generated chemoresistant cells with increasing doses of oxaliplatin (OXA and 5-Fluorouracil (5FU to develop resistance at a clinical dose. We found that the putative markers did not change in the parental cells, but HCT-116/OxR and HCT-116/5-FUR were more aggressive and had higher tumor growth (demonstrated by wound healing, chemotaxis assay, and a nude mice xenograft model with the use of oxaliplatin. Apoptosis induced by oxaliplatin treatment was significantly decreased in HCT-116/OxR compared to the parental cells. Moreover, HCT-116/OxR cells displayed increased levels of p-gp, p-Akt p-ERK, p-IKBβ, CXCR4, and Bcl-2, but they also significantly inhibited the apoptotic pathways when compared to the parental strain. We evaluated the molecular mechanism governing the signaling pathway associated with anti-apoptosis activity and the aggressive status of chemoresistant cells. Experiments involving specific inhibitors demonstrated that the activation of the pathways associated with CXCR4, ERK1/2 mitogen-activated protein kinase (MAPK, and phosphatidylinositol 3-kinase (PI3K/Akt is critical to the functioning of the HCT-116/OxR and HCT-116/5-FUR characteristics of chemosensitivity. These findings elucidate the mechanism of CXCR4/PI3K/Akt downstream signaling and provide strategies to inhibit CXCR4 mediated signaling pathway in order to overcome CRC's resistance to chemotherapy.

  10. An IMD-like pathway mediates both endosymbiont control and host immunity in the cereal weevil Sitophilus spp.

    Science.gov (United States)

    Maire, Justin; Vincent-Monégat, Carole; Masson, Florent; Zaidman-Rémy, Anna; Heddi, Abdelaziz

    2018-01-08

    Many insects developing on nutritionally unbalanced diets have evolved symbiotic associations with vertically transmitted intracellular bacteria (endosymbionts) that provide them with metabolic components, thereby improving the host's abilities to thrive on such poor ecological niches. While host-endosymbiont coevolutionary constraints are known to entail massive genomic changes in the microbial partner, host's genomic evolution remains elusive, particularly with regard to the immune system. In the cereal weevil Sitophilus spp., which houses Sodalis pierantonius, endosymbionts are secluded in specialized host cells, the bacteriocytes that group together as an organ, the bacteriome. We previously reported that at standard conditions, the bacteriome highly expresses the coleoptericin A (colA) antimicrobial peptide (AMP), which was shown to prevent endosymbiont escape from the bacteriocytes. However, following the insect systemic infection by pathogens, the bacteriome upregulates a cocktail of AMP encoding genes, including colA. The regulations that allow these contrasted immune responses remain unknown. In this short report, we provide evidence that an IMD-like pathway is conserved in two sibling species of cereal weevils, Sitophilus oryzae and Sitophilus zeamais. RNA interference (RNAi) experiments showed that imd and relish genes are essential for (i) colA expression in the bacteriome under standard conditions, (ii) AMP up-regulation in the bacteriome following a systemic immune challenge, and (iii) AMP systemic induction following an immune challenge. Histological analyses also showed that relish inhibition by RNAi resulted in endosymbiont escape from the bacteriome, strengthening the involvement of an IMD-like pathway in endosymbiont control. We conclude that Sitophilus' IMD-like pathway mediates both the bacteriome immune program involved in endosymbiont seclusion within the bacteriocytes and the systemic and local immune responses to exogenous challenges. This

  11. Trophoblast cell fusion and differentiation are mediated by both the protein kinase C and a pathways.

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    Waka Omata

    Full Text Available The syncytiotrophoblast of the human placenta is an epithelial barrier that interacts with maternal blood and is a key for the transfer of nutrients and other solutes to the developing fetus. The syncytiotrophoblast is a true syncytium and fusion of progenitor cytotrophoblasts is the cardinal event leading to the formation of this layer. BeWo cells are often used as a surrogate for cytotrophoblasts, since they can be induced to fuse, and then express certain differentiation markers associated with trophoblast syncytialization. Dysferlin, a syncytiotrophoblast membrane repair protein, is up-regulated in BeWo cells induced to fuse by treatment with forskolin; this fusion is thought to occur through cAMP/protein kinase A-dependent mechanisms. We hypothesized that dysferlin may also be up-regulated in response to fusion through other pathways. Here, we show that BeWo cells can also be induced to fuse by treatment with an activator of protein kinase C, and that this fusion is accompanied by increased expression of dysferlin. Moreover, a dramatic synergistic increase in dysferlin expression is observed when both the protein kinase A and protein kinase C pathways are activated in BeWo cells. This synergy in fusion is also accompanied by dramatic increases in mRNA for the placental fusion proteins syncytin 1, syncytin 2, as well as dysferlin. Dysferlin, however, was shown to be dispensable for stimulus-induced BeWo cell syncytialization, since dysferlin knockdown lines fused to the same extent as control cells. The classical trophoblast differentiation marker human chorionic gonadotropin was also monitored and changes in the expression closely parallel that of dysferlin in all of the experimental conditions employed. Thus different biochemical markers of trophoblast fusion behave in concert supporting the hypothesis that activation of both protein kinase C and A pathways lead to trophoblastic differentiation.

  12. Distinct pathways mediate the sorting of tail-anchored proteins to the plastid outer envelope.

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    Preetinder K Dhanoa

    Full Text Available BACKGROUND: Tail-anchored (TA proteins are a distinct class of membrane proteins that are sorted post-translationally to various organelles and function in a number of important cellular processes, including redox reactions, vesicular trafficking and protein translocation. While the molecular targeting signals and pathways responsible for sorting TA proteins to their correct intracellular destinations in yeasts and mammals have begun to be characterized, relatively little is known about TA protein biogenesis in plant cells, especially for those sorted to the plastid outer envelope. METHODOLOGY/PRINCIPAL FINDINGS: Here we investigated the biogenesis of three plastid TA proteins, including the 33-kDa and 34-kDa GTPases of the translocon at the outer envelope of chloroplasts (Toc33 and Toc34 and a novel 9-kDa protein of unknown function that we define here as an outer envelope TA protein (OEP9. Using a combination of in vivo and in vitro assays we show that OEP9 utilizes a different sorting pathway than that used by Toc33 and Toc34. For instance, while all three TA proteins interact with the cytosolic OEP chaperone/receptor, AKR2A, the plastid targeting information within OEP9 is distinct from that within Toc33 and Toc34. Toc33 and Toc34 also appear to differ from OEP9 in that their insertion is dependent on themselves and the unique lipid composition of the plastid outer envelope. By contrast, the insertion of OEP9 into the plastid outer envelope occurs in a proteinaceous-dependent, but Toc33/34-independent manner and membrane lipids appear to serve primarily to facilitate normal thermodynamic integration of this TA protein. CONCLUSIONS/SIGNIFICANCE: Collectively, the results provide evidence in support of at least two sorting pathways for plastid TA outer envelope proteins and shed light on not only the complex diversity of pathways involved in the targeting and insertion of proteins into plastids, but also the molecular mechanisms that underlie

  13. Elongation factor P mediates a novel post-transcriptional regulatory pathway critical for bacterial virulence

    DEFF Research Database (Denmark)

    Zou, S Betty; Roy, Hervé; Ibba, Michael

    2012-01-01

    of the pathogen to respond to external cues are typically attenuating. Here we discuss our recent discovery of a novel post-transcriptional regulatory pathway critical for Salmonella virulence and stress resistance. The enzymes PoxA and YjeK coordinately attach a unique beta-amino acid onto a highly conserved......Bacterial pathogens detect and integrate multiple environmental signals to coordinate appropriate changes in gene expression including the selective expression of virulence factors, changes to metabolism and the activation of stress response systems. Mutations that abolish the ability...... changes in the translation machinery during stress adaptation, indicating that the role of these factors in physiology may be broadly conserved....

  14. A CCR2 macrophage endocytic pathway mediates extravascular fibrin clearance in vivo

    DEFF Research Database (Denmark)

    Motley, Michael P; Madsen, Daniel H; Jürgensen, Henrik J

    2016-01-01

    cellular endocytosis and lysosomal targeting, revealing a novel intracellular pathway for extravascular fibrin degradation. A C-C chemokine receptor type 2 (CCR2)-positive macrophage subpopulation constituted the majority of fibrin-uptaking cells. Consequently, cellular fibrin uptake was diminished...... by elimination of CCR2-expressing cells. The CCR2-positive macrophage subtype was different from collagen-internalizing M2-like macrophages. Cellular fibrin uptake was strictly dependent on plasminogen and plasminogen activator. Surprisingly, however, fibrin endocytosis was unimpeded by the absence of the fibrin...

  15. Elongation factor P mediates a novel post-transcriptional regulatory pathway critical for bacterial virulence

    DEFF Research Database (Denmark)

    Zou, S Betty; Roy, Hervé; Ibba, Michael

    2012-01-01

    Bacterial pathogens detect and integrate multiple environmental signals to coordinate appropriate changes in gene expression including the selective expression of virulence factors, changes to metabolism and the activation of stress response systems. Mutations that abolish the ability...... of the pathogen to respond to external cues are typically attenuating. Here we discuss our recent discovery of a novel post-transcriptional regulatory pathway critical for Salmonella virulence and stress resistance. The enzymes PoxA and YjeK coordinately attach a unique beta-amino acid onto a highly conserved...

  16. Identification of miRNAs and miRNA-mediated regulatory pathways in Carica papaya.

    Science.gov (United States)

    Liang, Gang; Li, Yang; He, Hua; Wang, Fang; Yu, Diqiu

    2013-10-01

    Plant microRNAs (miRNAs) post-transcriptionally regulate target gene expression to modulate growth and development and biotic and abiotic stress responses. By analyzing small RNA deep sequencing data in combination with the genome sequence, we identified 75 conserved miRNAs and 11 novel miRNAs. Their target genes were also predicted. For most conserved miRNAs, the miRNA-target pairs were conserved across plant species. In addition to these conserved miRNA-target pairs, we also identified some papaya-specific miRNA-target regulatory pathways. Both miR168 and miR530 target the Argonaute 1 gene, indicating a second autoregulatory mechanism for miRNA regulation. A non-conserved miRNA was mapped within an intron of Dicer-like 1 (DCL1), suggesting a conserved homeostatic autoregulatory mechanism for DCL1 expression. A 21-nt miRNA triggers secondary siRNA production from its target genes, nucleotide-binding site leucine-rich repeat protein genes. Certain phased-miRNAs were processed from their conserved miRNA precursors, indicating a putative miRNA evolution mechanism. In addition, we identified a Carica papaya-specific miRNA that targets an ethylene receptor gene, implying its function in the ethylene signaling pathway. This work will also advance our understanding of miRNA functions and evolution in plants.

  17. Atractylenolide I-mediated Notch pathway inhibition attenuates gastric cancer stem cell traits

    International Nuclear Information System (INIS)

    Ma, Li; Mao, Rurong; Shen, Ke; Zheng, Yuanhong; Li, Yueqi; Liu, Jianwen; Ni, Lei

    2014-01-01

    Highlights: • This paper supports the anti-tumor effects of AT-I on gastric cancer in vitro. • AT-I attenuates gastric cancer stem cell traits. • It is the systematic study regarding AT-I suppression of Notch pathway in GC and GCSLCs. - Abstract: Atractylenolide I (AT-I), one of the main naturally occurring compounds of Rhizoma Atractylodis Macrocephalae, has remarkable anti-cancer effects on various cancers. However, its effects on the treatment of gastric cancer remain unclear. Via multiple cellular and molecular approaches, we demonstrated that AT-I could potently inhibit cancer cell proliferation and induce apoptosis through inactivating Notch pathway. AT-I treatment led to the reduction of expressions of Notch1, Jagged1, and its downstream Hes1/ Hey1. Our results showed that AT-I inhibited the self-renewal capacity of gastric stem-like cells (GCSLCs) by suppression of their sphere formation capacity and cell viability. AT-I attenuated gastric cancer stem cell (GCSC) traits partly through inactivating Notch1, leading to reducing the expressions of its downstream target Hes1, Hey1 and CD44 in vitro. Collectively, our results suggest that AT-I might develop as a potential therapeutic drug for the treatment of gastric cancer

  18. Distinct Effects of p19 RNA Silencing Suppressor on Small RNA Mediated Pathways in Plants.

    Directory of Open Access Journals (Sweden)

    Levente Kontra

    2016-10-01

    Full Text Available RNA silencing is one of the main defense mechanisms employed by plants to fight viruses. In change, viruses have evolved silencing suppressor proteins to neutralize antiviral silencing. Since the endogenous and antiviral functions of RNA silencing pathway rely on common components, it was suggested that viral suppressors interfere with endogenous silencing pathway contributing to viral symptom development. In this work, we aimed to understand the effects of the tombusviral p19 suppressor on endogenous and antiviral silencing during genuine virus infection. We showed that ectopically expressed p19 sequesters endogenous small RNAs (sRNAs in the absence, but not in the presence of virus infection. Our presented data question the generalized model in which the sequestration of endogenous sRNAs by the viral suppressor contributes to the viral symptom development. We further showed that p19 preferentially binds the perfectly paired ds-viral small interfering RNAs (vsiRNAs but does not select based on their sequence or the type of the 5' nucleotide. Finally, co-immunoprecipitation of sRNAs with AGO1 or AGO2 from virus-infected plants revealed that p19 specifically impairs vsiRNA loading into AGO1 but not AGO2. Our findings, coupled with the fact that p19-expressing wild type Cymbidium ringspot virus (CymRSV overcomes the Nicotiana benthamiana silencing based defense killing the host, suggest that AGO1 is the main effector of antiviral silencing in this host-virus combination.

  19. Camptothecin resistance is determined by the regulation of topoisomerase I degradation mediated by ubiquitin proteasome pathway.

    Science.gov (United States)

    Ando, Koji; Shah, Ankur K; Sachdev, Vibhu; Kleinstiver, Benjamin P; Taylor-Parker, Julian; Welch, Moira M; Hu, Yiheng; Salgia, Ravi; White, Forest M; Parvin, Jeffrey D; Ozonoff, Al; Rameh, Lucia E; Joung, J Keith; Bharti, Ajit K

    2017-07-04

    Proteasomal degradation of topoisomerase I (topoI) is one of the most remarkable cellular phenomena observed in response to camptothecin (CPT). Importantly, the rate of topoI degradation is linked to CPT resistance. Formation of the topoI-DNA-CPT cleavable complex inhibits DNA re-ligation resulting in DNA-double strand break (DSB). The degradation of topoI marks the first step in the ubiquitin proteasome pathway (UPP) dependent DNA damage response (DDR). Here, we show that the Ku70/Ku80 heterodimer binds with topoI, and that the DNA-dependent protein kinase (DNA-PKcs) phosphorylates topoI on serine 10 (topoI-pS10), which is subsequently ubiquitinated by BRCA1. A higher basal level of topoI-pS10 ensures rapid topoI degradation leading to CPT resistance. Importantly, PTEN regulates DNA-PKcs kinase activity in this pathway and PTEN deletion ensures DNA-PKcs dependent higher topoI-pS10, rapid topoI degradation and CPT resistance.

  20. Weight control and cancer preventive mechanisms: role of insulin growth factor-1-mediated signaling pathways.

    Science.gov (United States)

    Xie, Linglin; Wang, Weiqun

    2013-02-01

    Overweight and obese not only increase the risk of cardiovascular disease and type-2 diabetes mellitus, but are also now known risk factors for a variety of cancers. Weight control, via dietary calorie restriction and/or exercise, has been demonstrated to be beneficial for cancer prevention in various experimental models, but the underlying mechanisms are still not well defined. Recent studies conducted in a mouse skin carcinogenesis model show that weight loss induced a significant reduction of the circulating levels of insulin growth factor (IGF)-1 and other hormones, including insulin and leptin, resulting in reduced IGF-1-dependent signaling pathways, i.e. Ras-MAPK proliferation and protein kinase B-phosphoinositide 3-kinase (Akt-PI3K) antiapoptosis. Selective targeting IGF-1 to Akt/mammalian target of rapamycin and AMP-activated protein kinase pathways, via negative energy balance, might inactivate cell cycle progression and ultimately suppress tumor development. This review highlights the current studies focused on the major role of reducing IGF-1-activated signaling via weight control as a potential cancer preventive mechanism.

  1. The neural pathways mediating color shifts induced by temporally varying light.

    Science.gov (United States)

    Christiansen, Jens H; D'Antona, Anthony D; Shevell, Steven K

    2009-05-28

    In natural viewing, an object's background often changes over time. Temporally varying backgrounds were investigated here with a steady test field within a time-varying surrounding chromaticity. With slow surround variation (below approximately 3 Hz), the color appearance of a steady test is also perceived to fluctuate. At somewhat higher temporal frequencies, however, temporal variation of the surround is visible but the test appears steady (R. L. De Valois, M. A. Webster, K. K. De Valois, & B. Lingelbach, 1986); also above approximately 3 Hz, temporal chromatic variation along the l- or s-axis of the MacLeod-Boynton space (symmetric about equal-energy-spectrum "white") shifts the steady appearance of the test field toward redness or yellowness, respectively (A. D. D'Antona & S. K. Shevell, 2006). In the study here, color shifts were measured with temporal surround modulation at 6 Hz or greater along axes intermediate to the l and s directions. Varying the relative phase of simultaneous surround variation in l and s should not change responses within independent l and s pathways but should differentially excite neural representations that combine l and s signals (so-called higher order chromatic mechanisms). Varying the phase of l and s showed that the induced color shifts were accounted for by neural responses both from nearly independent l and s pathways and from higher order chromatic mechanisms.

  2. Development pathways from abusive parenting to delinquency: the mediating role of depression and aggression.

    Science.gov (United States)

    You, Sukkyung; Lim, Sun Ah

    2015-08-01

    This study investigated the long-term relationship between abusive parenting and adolescent mental health, and the path to delinquent behavior. Longitudinal data from 5th through 7th graders from the Korean Children and Youth Panel Survey (KCYPS) were analyzed to examine if abusive parenting was a predictor of early adolescent delinquency behavior, via aggression and depression as mediating factors. The results were as follows. First, parental abuse (both emotional and physical) was found to have significant effects on children's psychosocial factors (aggression and depression), while parental neglect (both emotional and physical) had significant effects on depression alone and not on aggression. Second, aggression exerted significant effects on both violent and non-violent delinquent behaviors, while depression had a significant effect on only non-violent delinquent behaviors. Third, children's psychosocial factors (aggression and depression) played significant mediating roles between earlier abusive parenting and delinquent behaviors. Fourth, for children living in a family with their grandparents, paths from abusive parenting, psychosocial adaptation, and later delinquent behaviors were not significant, implying that living with grandparents played a protective factor in these relationships. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. Bridge mediated two-electron transfer reactions: Analysis of stepwise and concerted pathways

    International Nuclear Information System (INIS)

    Petrov, E.G.; May, V.

    2004-01-01

    A theory of nonadiabatic donor (D)-acceptor (A) two-electron transfer (TET) mediated by a single regular bridge (B) is developed. The presence of different intermediate two-electron states connecting the reactant state D -- BA with the product state DBA -- results in complex multiexponential kinetics. The conditions are discussed at which a reduction to two-exponential as well as single-exponential kinetics becomes possible. For the latter case the rate K TET is calculated, which describes the bridge-mediated reaction as an effective two-electron D-A transfer. In the limit of small populations of the intermediate TET states D - B - A, DB -- A, D - BA - , and DB - A - , K TET is obtained as a sum of the rates K TET (step) and K TET (sup) . The first rate describes stepwise TET originated by transitions of a single electron. It starts at D -- BA and reaches DBA -- via the intermediate state D - BA - . These transitions cover contributions from sequential as well as superexchange reactions all including reduced bridge states. In contrast, a specific two-electron superexchange mechanism from D -- BA to DBA -- defines K TET (sup) . An analytic dependence of K TET (step) and K TET (sup) on the number of bridging units is presented and different regimes of D-A TET are studied

  4. The cystathionine β-synthase/hydrogen sulfide pathway contributes to microglia-mediated neuroinflammation following cerebral ischemia.

    Science.gov (United States)

    Zhang, Minjie; Wu, Xiaowei; Xu, Yingxiu; He, Meijun; Yang, Jiaying; Li, Jie; Li, Yuyao; Ao, Guizhen; Cheng, Jian; Jia, Jia

    2017-11-01

    The mechanisms underlying neuroinflammation following cerebral ischemia remain unclear. Hydrogen sulfide (H 2 S), a newly identified gasotransmitter, has been reported to regulate inflammation. In the current study, we investigated whether the endogenous H 2 S production pathway contributed to microglia-mediated neuroinflammation following stroke. We used a mouse middle cerebral artery occlusion (MCAO) model and an in vitro cellular model to mimic ischemia-induced microglial neuroinflammation. Expression of the H 2 S synthase cystathionine β-synthase (CBS) and H 2 S synthetic activity were rapidly decreased in the ischemic brain tissue following MCAO. Consistently, when cultured microglia were polarized toward a pro-inflammatory phenotype with conditioned medium collected from neurons that had been subjected to oxygen-glucose deprivation (OGD neuron CM), they displayed reduced CBS expression and H 2 S production. Enhancing H 2 S bioavailability either by overexpressing CBS or by supplementing with exogenous H 2 S donors promoted a shift in microglial polarization from ischemia-induced pro-inflammatory phenotypes toward anti-inflammatory phenotypes. Mechanistically, microglia that were exposed to OGD neuron CM displayed reduced activation of AMP-activated protein kinase (AMPK), which was rescued by overexpressing CBS or by supplementing with H 2 S donors. Moreover, the promoting effects of H 2 S donors on microglial anti-inflammatory polarization were abolished by an AMPK inhibitor or CaMKKβ inhibitor. Our results suggested that reduced CBS-H 2 S-AMPK cascade activity contributed to microglia-mediated neuroinflammation following stroke. Targeting the CBS-H 2 S pathway is a promising therapeutic approach for ischemic stroke. Copyright © 2017. Published by Elsevier Inc.

  5. Dysregulation of protein degradation pathways may mediate the liver injury and phospholipidosis associated with a cationic amphiphilic antibiotic drug

    Energy Technology Data Exchange (ETDEWEB)

    Mosedale, Merrie [Hamner-University of North Carolina Institute for Drug Safety Sciences, The Hamner Institutes for Health Sciences, Research Triangle Park, NC 27709 (United States); Wu, Hong [Drug Safety Research and Development, Pfizer Global Research and Development, Groton, CT06340 (United States); Kurtz, C. Lisa [Hamner-University of North Carolina Institute for Drug Safety Sciences, The Hamner Institutes for Health Sciences, Research Triangle Park, NC 27709 (United States); Schmidt, Stephen P. [Drug Safety Research and Development, Pfizer Global Research and Development, Groton, CT06340 (United States); Adkins, Karissa, E-mail: Karissa.Adkins@pfizer.com [Drug Safety Research and Development, Pfizer Global Research and Development, Groton, CT06340 (United States); Harrill, Alison H. [Hamner-University of North Carolina Institute for Drug Safety Sciences, The Hamner Institutes for Health Sciences, Research Triangle Park, NC 27709 (United States); University of Arkansas for Medical Sciences, Little Rock, AR72205 (United States)

    2014-10-01

    A large number of antibiotics are known to cause drug-induced liver injury in the clinic; however, interpreting clinical risk is not straightforward owing to a lack of predictivity of the toxicity by standard preclinical species and a poor understanding of the mechanisms of toxicity. An example is PF-04287881, a novel ketolide antibiotic that caused elevations in liver function tests in Phase I clinical studies. In this study, a mouse diversity panel (MDP), comprised of 34 genetically diverse, inbred mouse strains, was utilized to model the toxicity observed with PF-04287881 treatment and investigate potential mechanisms that may mediate the liver response. Significant elevations in serum alanine aminotransferase (ALT) levels in PF-04287881-treated animals relative to vehicle-treated controls were observed in the majority (88%) of strains tested following a seven day exposure. The average fold elevation in ALT varied by genetic background and correlated with microscopic findings of hepatocellular hypertrophy, hepatocellular single cell necrosis, and Kupffer cell vacuolation (confirmed as phospholipidosis) in the liver. Global liver mRNA expression was evaluated in a subset of four strains to identify transcript and pathway differences that distinguish susceptible mice from resistant mice in the context of PF-04287881 treatment. The protein ubiquitination pathway was highly enriched among genes associated with PF-04287881-induced hepatocellular necrosis. Expression changes associated with PF-04287881-induced phospholipidosis included genes involved in drug transport, phospholipid metabolism, and lysosomal function. The findings suggest that perturbations in genes involved in protein degradation leading to accumulation of oxidized proteins may mediate the liver injury induced by this drug. - Highlights: • Identified susceptible and resistant mouse strains to liver injury induced by a CAD • Liver injury characterized by single cell necrosis, and phospholipidosis

  6. Regulated Release of BDNF by Cortical Oligodendrocytes is Mediated Through Metabotropic Glutamate Receptors and the PLC Pathway

    Directory of Open Access Journals (Sweden)

    Issa P Bagayogo

    2009-02-01

    Full Text Available A number of studies suggest that OLGs (oligodendrocytes, the myelinating cells of the central nervous system, are also a source of trophic molecules, such as neurotrophins that may influence survival of proximate neurons. What is less clear is how the release of these molecules may be regulated. The present study investigated the effects of BDNF (brain-derived neurotrophic factor derived from cortical OLGs on proximate neurons, as well as regulatory mechanisms mediating BDNF release. Initial work determined that BDNF derived from cortical OLGs increased the numbers of VGLUT1 (vesicular glutamate transporter 1-positive glutamatergic cortical neurons. Furthermore, glutamate acting through metabotropic, and not AMPA/kainate or NMDA (N-methyl-D-aspartate, receptors increased BDNF release. The PLC (phospholipase C pathway is a key mediator of metabotropic actions to release BDNF in astrocytes and neurons. Treatment of OLGs with the PLC activator m-3M3FBS [N-(3-trifluoromethylphenyl-2,4,6-trimethylbenzenesulfonamide] induced robust release of BDNF. Moreover, release elicited by the metabotropic receptor agonist ACPD [trans-(1S,3R-1-aminocyclopentane-1,3-dicarboxylic acid] was inhibited by the PLC antagonist U73122, the IP3 (inositol triphosphate 3 receptor inhibitor 2-APB (2-aminoethoxydiphenylborane and the intracellular calcium chelator BAPTA/AM [1,2-bis-(o-aminophenoxyethane-N,N,N′,N′-tetra-acetic acid tetrakis(acetoxymethyl ester]. Taken together, these results suggest that OLG lineage cells release BDNF, a molecule trophic for proximate neurons. BDNF release is regulated by glutamate acting through mGluRs (metabotropic glutamate receptors and the PLC pathway. Thus glutamate and BDNF may be molecules that support neuron–OLG interactions in the cortex.

  7. Porcine parvovirus infection induces apoptosis in PK-15 cells through activation of p53 and mitochondria-mediated pathway

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Hongling; Huang, Yong; Du, Qian; Luo, Xiaomao; Zhang, Liang; Zhao, Xiaomin; Tong, Dewen, E-mail: dwtong@nwsuaf.edu.cn

    2015-01-09

    Highlights: • PPV reduces PK-15 cells viability by inducing apoptosis. • PPV infection induces apoptosis through mitochondria-mediated pathway. • PPV infection activates p53 to regulate the mitochondria apoptotic signaling. - Abstract: Porcine parvovirus (PPV) infection has been reported to induce the cytopathic effects (CPE) in some special host cells and contribute the occurrence of porcine parvovirus disease, but the molecular mechanisms underlying PPV-induced CPE are not clear. In this study, we investigated the morphological and molecular changes of porcine kidney cell line (PK-15 cells) infected with PPV. The results showed that PPV infection inhibited the viability of PK-15 cells in a time and concentration dependent manner. PPV infection induced typical apoptotic features including chromatin condensation, apoptotic body formation, nuclear fragmentation, and Annexin V-binding activity. Further studies showed that Bax was increased and translocated to mitochondria, whereas Bcl-2 was decreased in PPV-infected cells, which caused mitochondrial outer-membrane permeabilization, resulting in the release of mitochondrial cytochrome c, followed by caspase-9 and caspase-3 activation. However, the expression of Fas and Fas ligand (FasL) did not appear significant changes in the process of PPV-induced apoptosis. Moreover, PPV infection activated p53 signaling, which was involved in the activation of apoptotic signaling induced by PPV infection via regulation of Bax and Bcl-2. Taken together, our results demonstrated that PPV infection induced apoptosis in PK-15 cells through activation of p53 and mitochondria-mediated apoptosis pathway. This study may contribute to shed light on the molecular pathogenesis of PPV infection.

  8. Dysregulation of protein degradation pathways may mediate the liver injury and phospholipidosis associated with a cationic amphiphilic antibiotic drug

    International Nuclear Information System (INIS)

    Mosedale, Merrie; Wu, Hong; Kurtz, C. Lisa; Schmidt, Stephen P.; Adkins, Karissa; Harrill, Alison H.

    2014-01-01

    A large number of antibiotics are known to cause drug-induced liver injury in the clinic; however, interpreting clinical risk is not straightforward owing to a lack of predictivity of the toxicity by standard preclinical species and a poor understanding of the mechanisms of toxicity. An example is PF-04287881, a novel ketolide antibiotic that caused elevations in liver function tests in Phase I clinical studies. In this study, a mouse diversity panel (MDP), comprised of 34 genetically diverse, inbred mouse strains, was utilized to model the toxicity observed with PF-04287881 treatment and investigate potential mechanisms that may mediate the liver response. Significant elevations in serum alanine aminotransferase (ALT) levels in PF-04287881-treated animals relative to vehicle-treated controls were observed in the majority (88%) of strains tested following a seven day exposure. The average fold elevation in ALT varied by genetic background and correlated with microscopic findings of hepatocellular hypertrophy, hepatocellular single cell necrosis, and Kupffer cell vacuolation (confirmed as phospholipidosis) in the liver. Global liver mRNA expression was evaluated in a subset of four strains to identify transcript and pathway differences that distinguish susceptible mice from resistant mice in the context of PF-04287881 treatment. The protein ubiquitination pathway was highly enriched among genes associated with PF-04287881-induced hepatocellular necrosis. Expression changes associated with PF-04287881-induced phospholipidosis included genes involved in drug transport, phospholipid metabolism, and lysosomal function. The findings suggest that perturbations in genes involved in protein degradation leading to accumulation of oxidized proteins may mediate the liver injury induced by this drug. - Highlights: • Identified susceptible and resistant mouse strains to liver injury induced by a CAD • Liver injury characterized by single cell necrosis, and phospholipidosis

  9. Nitrate-Dependent Activation of the Dif Signaling Pathway of Myxococcus xanthus Mediated by a NarX-DifA Interspecies Chimera

    OpenAIRE

    Xu, Qian; Black, Wesley P.; Ward, Scott M.; Yang, Zhaomin

    2005-01-01

    Myxococcus xanthus fibril exopolysaccharide (EPS), essential for the social gliding motility and development of this bacterium, is regulated by the Dif chemotaxis-like pathway. DifA, an MCP homolog, is proposed to mediate signal input to the Dif pathway. However, DifA lacks a prominent periplasmic domain, which in classical chemoreceptors is responsible for signal perception and for initiating transmembrane signaling. To investigate the signaling properties of DifA, we constructed a NarX-DifA...

  10. The effect of body dissatisfaction on eating disorder symptomatology : mediating effects of depression and low self-esteem : a partial test of the Dual-Pathway Model

    OpenAIRE

    Jonstang, Ida Cecilie

    2009-01-01

    Aim. The present study is based on the dual-pathway model (Stice, 2001), specifically testing the negative affect pathway of this model. This study examined whether depression and low self-esteem separately mediate the relationship between body dissatisfaction and general eating disorder symptomatology, focusing primarily on restraint eating and bulimic symptoms. Method. A sample of 113 junior high-school boys and girls completed measures of body dissatisfaction, self-esteem, depression,...

  11. Rhein Elicits In Vitro Cytotoxicity in Primary Human Liver HL-7702 Cells by Inducing Apoptosis through Mitochondria-Mediated Pathway

    Directory of Open Access Journals (Sweden)

    Guy-Armel Bounda

    2015-01-01

    Full Text Available Objective. To study rhein-induced apoptosis signaling pathway and to investigate its molecular mechanisms in primary human hepatic cells. Results. Cell viability of HL-7702 cells treated with rhein showed significant decrease in dose-dependent manner. Following rhein treatment (25 μM, 50 μM, and 100 μM for 12 h, the detection of apoptotic cells was significantly analyzed by flow cytometry and nuclear morphological changes by Hoechst 33258, respectively. Fatty degeneration studies showed upregulation level of the relevant hepatic markers (P < 0.01. Caspase activities expressed significant upregulation of caspase-3, caspase-9, and caspase-8. Moreover, apoptotic cells by rhein were significantly inhibited by Z-LEHD-FMK and Z-DEVD-FMK, caspase-9 inhibitor, and caspase-3 inhibitor, respectively. Overproduction of reactive oxygen species, lipid peroxidation, and loss of mitochondrial membrane potential were detected by fluorometry. Additionally, NAC, a ROS scavenger, significantly attenuated rhein-induced oxidative damage in HL-7702 cells. Furthermore, real-time qPCR results showed significant upregulation of p53, PUMA, Apaf-1, and Casp-9 and Casp-3 mRNA, with no significant changes of Fas and Cytochrome-c. Immunoblotting revealed significant Cytochrome-c release from mitochondria into cytosol and no change in Fas expression. Conclusion. Taken together, these observations suggested that rhein could induce apoptosis in HL-7702 cells via mitochondria-mediated signal pathway with involvement of oxidative stress mechanism.

  12. The clinical relationship between the slug-mediated Puma/p53 signaling pathway and radiotherapy resistance in nasopharyngeal carcinoma.

    Science.gov (United States)

    Xu, T; Yuan, Y; Xiao, D-J

    2017-03-01

    To explore the clinical relationship between the Slug-mediated Puma/p53 signaling pathway and radiotherapy resistance in nasopharyngeal carcinoma. Forty surgical specimens were collected from nasopharyngeal carcinoma patients treated at our hospital between February 2010 and February 2015. Twenty patients with poorly differentiated nasopharyngeal carcinoma with and without radiotherapy resistance were included in the experimental and control groups, respectively. Slug, Puma, and p53 expression were quantified in all tissues using fluorescence quantitative polymerase chain reaction, enzyme-linked immunosorbent assay (ELISA), Western blotting, and immunohistochemistry. Slug and p53 mRNA levels were significantly higher in the experimental group than in the control group (p control group (p Slug protein expression was significantly higher in the experimental group (6.07 ± 0.203 μg/L) than in the control group (1.24 ± 0.171 μg/L) (p control group (0.63 ± 0.101 μg/L) (p control group (3.37 ± 0.112 μg/L) (v Slug, Puma, and p53-positive cells in the experimental group and the control group were quantified; these values confirmed the ELISA and Western blot findings. Slug downregulated the Puma protein expression signaling pathway and promoted radiotherapy resistance in poorly differentiated squamous cell carcinoma tissue, in a p53-independent manner.

  13. Meta-analysis of global transcriptomics reveals conserved genetic pathways of Quercetin and Tannic acid mediated longevity in C. elegans

    Directory of Open Access Journals (Sweden)

    Kerstin ePietsch

    2012-04-01

    Full Text Available Recent research has highlighted that the polyphenols Quercetin and Tannic acid are capable of extending the lifespan of C. elegans. To gain a deep understanding of the underlying molecular genetics, we analyzed the global transcriptional patterns of nematodes exposed to Quercetin or Tannic acid concentrations that are non-effective (in lifespan extension, lifespan extending or toxic. By means of an intricate meta-analysis it was possible to compare the transcriptomes of polyphenol exposure to recently published data sets derived from i longevity mutants or ii infection. This detailed comparative in silico analysis facilitated the identification of compound specific and overlapping transcriptional profiles and allowed the formulation of mechanistic models of Quercetin and Tannic acid mediated longevity. Lifespan extension due to Quercetin was predominantly driven by the metabolome, TGF-beta signaling, Insulin-like signaling and the p38 MAPK pathway and Tannic acid’s impact involved, in part, the amino acid metabolism and was modulated by the TGF-beta and the p38 MAPK pathways. DAF-12, which integrates TGF-beta and Insulin-like downstream signaling, therefore seems to be a crucial regulator for both polyphenols.

  14. The RpoE Stress Response Pathway Mediates Reduction of the Virulence of Enteropathogenic Escherichia coli by Zinc.

    Science.gov (United States)

    Xue, Yuan; Osborn, Jossef; Panchal, Anand; Mellies, Jay L

    2015-06-01

    Zinc supplements are an effective clinical treatment for infantile diarrheal disease caused by enteric pathogens. Previous studies demonstrated that zinc acts on enteropathogenic Escherichia coli (EPEC) bacteria directly to suppress several virulence-related genes at a concentration that can be achieved by oral delivery of dietary zinc supplements. Our in vitro studies showed that a micromolar concentration of zinc induced the envelope stress response and suppressed virulence in EPEC, providing a possible mechanistic explanation for zinc's therapeutic action. In this report, we investigated the molecular and physiological changes in EPEC induced by zinc. We found that micromolar concentrations of zinc reduced the bacterial growth rate without affecting viability. We observed increased membrane permeability caused by zinc. Zinc upregulated the RpoE-dependent envelope stress response pathway and suppressed EPEC virulence gene expression. RpoE alone was sufficient to inhibit virulence factor expression and to attenuate attaching and effacing lesion formation on human host cells. By mutational analysis we demonstrate that the DNA-binding motif of RpoE is necessary for suppression of the LEE1, but not the LEE4, operon. Predictably, inhibition of the RpoE-mediated envelope stress response in combination with micromolar concentrations of zinc reduced EPEC viability. In conclusion, zinc induces the RpoE and stress response pathways in EPEC, and the alternate sigma factor RpoE downregulates EPEC LEE and non-LEE virulence genes by multiple mechanisms. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  15. Acute ethanol exposure-induced autophagy-mediated cardiac injury via activation of the ROS-JNK-Bcl-2 pathway.

    Science.gov (United States)

    Zhu, Zhongxin; Huang, Yewei; Lv, Lingchun; Tao, Youli; Shao, Minglong; Zhao, Congcong; Xue, Mei; Sun, Jia; Niu, Chao; Wang, Yang; Kim, Sunam; Cong, Weitao; Mao, Wei; Jin, Litai

    2018-02-01

    Binge drinking is associated with increased cardiac autophagy, and often triggers heart injury. Given the essential role of autophagy in various cardiac diseases, this study was designed to investigate the role of autophagy in ethanol-induced cardiac injury and the underlying mechanism. Our study showed that ethanol exposure enhanced the levels of LC3-II and LC3-II positive puncta and promoted cardiomyocyte apoptosis in vivo and in vitro. In addition, we found that ethanol induced autophagy and cardiac injury largely via the sequential triggering of reactive oxygen species (ROS) accumulation, activation of c-Jun NH2-terminal kinase (JNK), phosphorylation of Bcl-2, and dissociation of the Beclin 1/Bcl-2 complex. By contrast, inhibition of ethanol-induced autophagic flux with pharmacologic agents in the hearts of mice and cultured cells significantly alleviated ethanol-induced cardiomyocyte apoptosis and heart injury. Elimination of ROS with the antioxidant N-acetyl cysteine (NAC) or inhibition of JNK with the JNK inhibitor SP600125 reduced ethanol-induced autophagy and subsequent autophagy-mediated apoptosis. Moreover, metallothionein (MT), which can scavenge reactive oxygen and nitrogen species, also attenuated ethanol-induced autophagy and cell apoptosis in MT-TG mice. In conclusion, our findings suggest that acute ethanol exposure induced autophagy-mediated heart toxicity and injury mainly through the ROS-JNK-Bcl-2 signaling pathway. © 2017 Wiley Periodicals, Inc.

  16. Intense picosecond pulsed electric fields induce apoptosis through a mitochondrial-mediated pathway in HeLa cells

    Science.gov (United States)

    HUA, YUAN-YUAN; WANG, XIAO-SHU; ZHANG, YU; YAO, CHEN-GUO; ZHANG, XI-MING; XIONG, ZHENG-AI

    2012-01-01

    The application of pulsed electric fields (PEF) is emerging as a new technique for tumor therapy. Picosecond pulsed electric fields (psPEF) can be transferred to target deep tissue non-invasively and precisely, but the research of the biological effects of psPEF on cells is limited. Electric theory predicts that intense psPEF will target mitochondria and lead to changes in transmembrane potential, therefore, it is hypothesized that it can induce mitochondrial-mediated apoptosis. HeLa cells were exposed to psPEF in this study to investigate this hypothesis. MTT assay demonstrated that intense psPEF significantly inhibited the proliferation of HeLa cells in a dose-dependent manner. Typical characteristics of apoptosis in HeLa cells were observed, using transmission electron microscopy. Loss of mitochondrial transmembrane potential was explored using laser scanning confocal microscopy with Rhodamine-123 (Rh123) staining. Furthermore, the mitochondrial apoptotic events were also confirmed by western blot analysis for the release of cytochrome C and apoptosis-inducing factor from mitochondria into the cytosol. In addition, activation of caspase-3, caspase-9, upregulation of Bax, p53 and downregulation of Bcl-2 were observed in HeLa cells also indicating apoptosis. Taken together, these results demonstrate that intense psPEF induce cell apoptosis through a mitochondrial-mediated pathway. PMID:22307872

  17. Nuclear import of chromatin remodeler Isw1 is mediated by atypical bipartite cNLS and classical import pathway.

    Science.gov (United States)

    Vasicova, Pavla; Stradalova, Vendula; Halada, Petr; Hasek, Jiri; Malcova, Ivana

    2013-02-01

    The protein Isw1 of Saccharomyces cerevisiae is an imitation-switch chromatin-remodeling factor. We studied the mechanisms of its nuclear import and found that the nuclear localization signal (NLS) mediating the transport of Isw1 into the nucleus is located at the end of the C-terminus of the protein (aa1079-1105). We show that it is an atypical bipartite signal with an unconventional linker of 19 aa (KRIR X(19) KKAK) and the only nuclear targeting signal within the Isw1 molecule. The efficiency of Isw1 nuclear import was found to be modulated by changes to the amino acid composition in the vicinity of the KRIR motif, but not by the linker length. Live-cell imaging of various karyopherin mutants and in vitro binding assays of Isw1NLS to importin-α revealed that the nuclear translocation of Isw1 is mediated by the classical import pathway. Analogous motifs to Isw1NLS are highly conserved in Isw1 homologues of other yeast species, and putative bipartite cNLS were identified in silico at the end of the C-termini of imitation switch (ISWI) proteins from higher eukaryotes. We suggest that the C-termini of the ISWI family proteins play an important role in their nuclear import. © 2012 John Wiley & Sons A/S.

  18. Non-thermal plasma induces mitochondria-mediated apoptotic signaling pathway via ROS generation in HeLa cells.

    Science.gov (United States)

    Li, Wei; Yu, K N; Ma, Jie; Shen, Jie; Cheng, Cheng; Zhou, Fangjian; Cai, Zhiming; Han, Wei

    2017-11-01

    Non-thermal plasma (NTP) has been proposed as a novel therapeutic method for anticancer treatment. Although increasing evidence suggests that NTP selectively induces apoptosis in some types of tumor cells, the molecular mechanisms underlying this phenomenon remain unclear. In this study, we further investigated possible molecular mechanisms for NTP-induced apoptosis of HeLa cells. The results showed that NTP exposure significantly inhibited the growth and viability of HeLa cells. Morphological observation and flow cytometry analysis demonstrated that NTP exposure induced HeLa cell apoptosis. NTP exposure also activated caspase-9 and caspase-3, which subsequently cleaved poly (ADP- ribose) polymerase. Furthermore, NTP exposure suppressed Bcl-2 expression, enhanced Bax expression and translocation to mitochondria, activated mitochondria-mediated apoptotic pathway, followed by the release of cytochrome c. Further studies showed that NTP treatment led to ROS generation, whereas blockade of ROS generation by N-acetyl-l-cysteine (NAC, ROS scavengers) significantly prevented NTP-induced mitochondrial alteration and subsequent apoptosis of HeLa cells via suppressing Bax translocation, cytochrome c and caspase-3 activation. Taken together, our results indicated that NTP exposure induced mitochondria-mediated intrinsic apoptosis of HeLa cells was activated by ROS generation. These findings provide insights to the therapeutic potential and clinical research of NTP as a novel tool in cervical cancer treatment. Copyright © 2017. Published by Elsevier Inc.

  19. Deprivation of L-Arginine Induces Oxidative Stress Mediated Apoptosis in Leishmania donovani Promastigotes: Contribution of the Polyamine Pathway

    Science.gov (United States)

    Mandal, Abhishek; Das, Sushmita; Roy, Saptarshi; Ghosh, Ayan Kumar; Sardar, Abul Hasan; Verma, Sudha; Saini, Savita; Singh, Ruby; Abhishek, Kumar; Kumar, Ajay; Mandal, Chitra; Das, Pradeep

    2016-01-01

    The growth and survival of intracellular parasites depends on the availability of extracellular nutrients. Deprivation of nutrients viz glucose or amino acid alters redox balance in mammalian cells as well as some lower organisms. To further understand the relationship, the mechanistic role of L-arginine in regulation of redox mediated survival of Leishmania donovani promastigotes was investigated. L-arginine deprivation from the culture medium was found to inhibit cell growth, reduce proliferation and increase L-arginine uptake. Relative expression of enzymes, involved in L-arginine metabolism, which leads to polyamine and trypanothione biosynthesis, were downregulated causing decreased production of polyamines in L-arginine deprived parasites and cell death. The resultant increase in reactive oxygen species (ROS), due to L-arginine deprivation, correlated with increased NADP+/NADPH ratio, decreased superoxide dismutase (SOD) level, increased lipid peroxidation and reduced thiol content. A deficiency of L-arginine triggered phosphatidyl serine externalization, a change in mitochondrial membrane potential, release of intracellular calcium and cytochrome-c. This finally led to DNA damage in Leishmania promastigotes. In summary, the growth and survival of Leishmania depends on the availability of extracellular L-arginine. In its absence the parasite undergoes ROS mediated, caspase-independent apoptosis-like cell death. Therefore, L-arginine metabolism pathway could be a probable target for controlling the growth of Leishmania parasites and disease pathogenesis. PMID:26808657

  20. Resveratrol inhibits Hexokinases II mediated glycolysis in non-small cell lung cancer via targeting Akt signaling pathway.

    Science.gov (United States)

    Li, Wei; Ma, Xiaoqian; Li, Na; Liu, Huasheng; Dong, Qiong; Zhang, Juan; Yang, Cejun; Liu, Yin; Liang, Qi; Zhang, Shengwang; Xu, Chang; Song, Wei; Tan, Shiming; Rong, Pengfei; Wang, Wei

    2016-12-10

    Deregulation of glycolysis was often observed in human cancer cells. In the present study, we reported resveratrol, a small polyphenol, which has been intensively studied in various tumor models, has a profound anti-tumor effect on human non-small cell lung cancer (NSCLC) via regulation of glycolysis. Resveratrol impaired hexokinase II (HK2)-mediated glycolysis, and markedly inhibited anchorage-dependent and -independent growth of NSCLC cells. Exposure to resveratrol decreased EGFR and downstream kinases Akt and ERK1/2 activation. Moreover, we revealed that resveratrol impaired glucose metabolism by mainly inhibiting expression of HK2 mediated by the Akt signaling pathway, and exogenous overexpression of constitutively activated Akt1 in NSCLC cells substantially rescued resveratrol-induced glycolysis suppression. The in vivo data indicated that resveratrol obviously suppressed tumor growth in a xenograft mouse model. Our results suggest targeting HK2 or metabolic enzymes appears to be a new approach for clinical NSCLC prevention or treatment. Copyright © 2016 Elsevier Inc. All rights reserved.

  1. LKB1 mediates the development of conventional and innate T cells via AMP-dependent kinase autonomous pathways.

    Directory of Open Access Journals (Sweden)

    Marouan Zarrouk

    Full Text Available The present study has examined the role of the serine/threonine kinase LKB1 in the survival and differentiation of CD4/8 double positive thymocytes. LKB1-null DPs can respond to signals from the mature α/β T-cell-antigen receptor and initiate positive selection. However, in the absence of LKB1, thymocytes fail to mature to conventional single positive cells causing severe lymphopenia in the peripheral lymphoid tissues. LKB1 thus appears to be dispensable for positive selection but important for the maturation of positively selected thymocytes. LKB1 also strikingly prevented the development of invariant Vα14 NKT cells and innate TCR αβ gut lymphocytes. Previous studies with gain of function mutants have suggested that the role of LKB1 in T cell development is mediated by its substrate the AMP-activated protein kinase (AMPK. The present study now analyses the impact of AMPK deletion in DP thymocytes and shows that the role of LKB1 during the development of both conventional and innate T cells is mediated by AMPK-independent pathways.

  2. The sedative activity of flavonoids from Passiflora quadrangularis is mediated through the GABAergic pathway.

    Science.gov (United States)

    Gazola, Andressa Corneo; Costa, Geison Modesti; Zucolotto, Silvana Maria; Castellanos, Leonardo; Ramos, Freddy Alejandro; de Lima, Thereza Christina Monteiro; Schenkel, Eloir Paulo

    2018-04-01

    The aim of this study was to investigate the sedative activity of the aqueous leaf extract of Passiflora quadrangularis, a species that is widely cultivated and consumed in South America, and to identify its main constituents and elucidate the involvement of the GABAergic pathway in its mechanism of action. The bioguided fractionation of the crude extract showed a positive relationship between the sedative activity of the extract and its flavonoids. The methods employed to identify and isolate its main flavonoids resulted in the identification of vitexin-2''-O-xyloside, vitexin-2''-O-glucoside, orientin-2''-O-xyloside and orientin-2''-O-glucoside. Vitexin-2"-O-xyloside, the major flavonoid of the extract, showed sedative activity after oral administration in mice. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

  3. Distinct neural pathways mediate alpha7 nicotinic acetylcholine receptor-dependent activation of the forebrain

    DEFF Research Database (Denmark)

    Thomsen, Morten S; Hay-Schmidt, Anders; Hansen, Henrik H

    2010-01-01

    alpha(7) nicotinic acetylcholine receptor (nAChR) agonists are candidates for the treatment of cognitive deficits in schizophrenia. Selective alpha(7) nAChR agonists, such as SSR180711, activate neurons in the medial prefrontal cortex (mPFC) and nucleus accumbens shell (ACCshell) in rats, regions......, as measured by c-Fos immunoreactivity, a marker of neuronal activation. Selective depletion of these cholinergic neurons abolishes the SSR180711-induced activation of the mPFC but not the ACCshell, demonstrating their critical importance for alpha(7) nAChR-dependent activation of the mPFC. Contrarily......, selective depletion of dopaminergic neurons in the ventral tegmental area abolishes the SSR180711-induced activation of the ACCshell but not the mPFC or HDB. These results demonstrate 2 distinct neural pathways activated by SSR180711. The BF and mPFC are important for attentional function and may subserve...

  4. Distinct phosphotyrosines on a growth factor receptor bind to specific molecules that mediate different signaling pathways.

    Science.gov (United States)

    Fantl, W J; Escobedo, J A; Martin, G A; Turck, C W; del Rosario, M; McCormick, F; Williams, L T

    1992-05-01

    The receptor for platelet-derived growth factor (PDGF) binds two proteins containing SH2 domains, GTPase activating protein (GAP) and phosphatidylinositol 3-kinase (PI3-kinase). The sites on the receptor that mediate this interaction were identified by using phosphotyrosine-containing peptides representing receptor sequences to block specifically binding of either PI3-kinase or GAP. These results suggested that PI3-kinase binds two phosphotyrosine residues, each located in a 5 aa motif with an essential methionine at the fourth position C-terminal to the tyrosine. Point mutations at these sites caused a selective elimination of PI3-kinase binding and loss of PDGF-stimulated DNA synthesis. Mutation of the binding site for GAP prevented the receptor from associating with or phosphorylating GAP, but had no effect on PI3-kinase binding and little effect on DNA synthesis. Therefore, GAP and PI3-kinase interact with the receptor by binding to different phosphotyrosine-containing sequence motifs.

  5. Transmitters and pathways mediating inhibition of spinal itch-signaling neurons by scratching and other counterstimuli.

    Directory of Open Access Journals (Sweden)

    Tasuku Akiyama

    Full Text Available Scratching relieves itch, but the underlying neural mechanisms are poorly understood. We presently investigated a role for the inhibitory neurotransmitters GABA and glycine in scratch-evoked inhibition of spinal itch-signaling neurons in a mouse model of chronic dry skin itch. Superficial dorsal horn neurons ipsilateral to hindpaw dry skin treatment exhibited a high level of spontaneous firing that was significantly attenuated by cutaneous scratching, pinch and noxious heat. Scratch-evoked inhibition was nearly abolished by spinal delivery of the glycine antagonist, strychnine, and was markedly attenuated by respective GABA(A and GABA(B antagonists bicuculline and saclofen. Scratch-evoked inhibition was also significantly attenuated (but not abolished by interruption of the upper cervical spinal cord, indicating the involvement of both segmental and suprasegmental circuits that engage glycine- and GABA-mediated inhibition of spinal itch-signaling neurons by noxious counterstimuli.

  6. RasGRP3 Mediates MAPK Pathway Activation in GNAQ Mutant Uveal Melanoma.

    Science.gov (United States)

    Chen, Xu; Wu, Qiuxia; Depeille, Philippe; Chen, Peirong; Thornton, Sophie; Kalirai, Helen; Coupland, Sarah E; Roose, Jeroen P; Bastian, Boris C

    2017-05-08

    Constitutive activation of Gαq signaling by mutations in GNAQ or GNA11 occurs in over 80% of uveal melanomas (UMs) and activates MAPK. Protein kinase C (PKC) has been implicated as a link, but the mechanistic details remained unclear. We identified PKC δ and ɛ as required and sufficient to activate MAPK in GNAQ mutant melanomas. MAPK activation depends on Ras and is caused by RasGRP3, which is significantly and selectively overexpressed in response to GNAQ/11 mutation in UM. RasGRP3 activation occurs via PKC δ- and ɛ-dependent phosphorylation and PKC-independent, DAG-mediated membrane recruitment, possibly explaining the limited effect of PKC inhibitors to durably suppress MAPK in UM. The findings nominate RasGRP3 as a therapeutic target for cancers driven by oncogenic GNAQ/11. Copyright © 2017 Elsevier Inc. All rights reserved.

  7. Mediatization

    DEFF Research Database (Denmark)

    Hjarvard, Stig

    2017-01-01

    Mediatization research shares media effects studies' ambition of answering the difficult questions with regard to whether and how media matter and influence contemporary culture and society. The two approaches nevertheless differ fundamentally in that mediatization research seeks answers...... research is concerned with long-term structural changes involving media, culture, and society, i.e. the influences of the media are understood in relation to how media are implicated in social and cultural changes and how these processes come to create new conditions for human communication and interaction....... From the perspective of mediatization research, the most important effect of the media stems from their embeddedness in culture and society....

  8. Shaofu Zhuyu decoction ameliorates obesity-mediated hepatic steatosis and systemic inflammation by regulating metabolic pathways.

    Directory of Open Access Journals (Sweden)

    Moonju Hong

    Full Text Available Shaofu Zhuyu decoction (SFZYD, also known as Sobokchugeo-tang, a classical prescription drug in traditional East Asian medicine, has been used to treat blood stasis syndrome (BSS. Hepatic steatosis is the result of excess caloric intake, and its pathogenesis involves internal retention of phlegm and dampness, blood stasis, and liver Qi stagnation. To evaluate the effects of treatment with SFZYD on obesity-induced inflammation and hepatic steatosis, we fed male C57BL/6N mice a high fat diet (HFD for 8 weeks and then treated them with SFZYD by oral gavage for an additional 4 weeks. The results of histological and biochemical examinations indicated that SFZYD treatment ameliorates systemic inflammation and hepatic steatosis. A partial least squares-discriminant analysis (PLS-DA scores plot of serum metabolites showed that HFD mice began to produce metabolites similar to those of normal chow (NC mice after SFZYD administration. We noted significant alterations in the levels of twenty-seven metabolites, alterations indicating that SFZYD regulates the TCA cycle, the pentose phosphate pathway and aromatic amino acid metabolism. Increases in the levels of TCA cycle intermediate metabolites, such as 2-oxoglutaric acid, isocitric acid, and malic acid, in the serum of obese mice were significantly reversed after SFZYD treatment. In addition to inducing changes in the above metabolites, treatment with SFZYD also recovered the expression of genes related to hepatic mitochondrial dysfunction, including Ucp2, Cpt1α, and Ppargc1α, as well as the expression of genes involved in lipid metabolism and inflammation, without affecting glucose uptake or insulin signaling. Taken together, these findings suggest that treatment with SFZYD ameliorated obesity-induced systemic inflammation and hepatic steatosis by regulating inflammatory cytokine and adipokine levels in the circulation and various tissues. Moreover, treatment with SFZYD also reversed alterations in the

  9. Iodinated contrast media induce neutrophil apoptosis through a mitochondrial and caspase mediated pathway.

    LENUS (Irish Health Repository)

    Fanning, N F

    2012-02-03

    Iodinated contrast media (ICM) can induce apoptosis (programmed cell death) in renal, myocardial and endothelial cells. Following intravascular injection, circulating immune cells are exposed to high concentrations of ICM. As neutrophils constitutively undergo apoptosis we hypothesized that ICM may adversely affect neutrophil survival. Our aim was to investigate the effect of ICM on neutrophil apoptosis. Neutrophils were isolated from healthy subjects and cultured in vitro with ionic (diatrizoate and ioxaglate) and non-ionic (iohexol and iotrolan) ICM. The effect of ICM on neutrophil apoptosis in both unstimulated and lipopolysaccharide-stimulated neutrophils was determined by annexin V flow cytometry. The influence of physicochemical properties of the different ICM on apoptosis of neutrophils was also studied. We further investigated the effects of ICM on key intracellular signal pathways, including p38 mitogen-activated protein kinase (MAPK) by Western blotting, and mitochondrial depolarization and caspase activity by flow cytometry. Isoiodine concentrations (20 mg ml(-1)) of ionic (diatrizoate 69.6+\\/-2.9%; ioxaglate 58.9+\\/-2.0%) and non-ionic (iohexol 57.3+\\/-2.9%; iotrolan 57.1+\\/-2.6%) ICM significantly induced neutrophil apoptosis over control levels (47.7+\\/-1.4%). The apoptotic effect of ICM was influenced by their chemical structure, with ionic ICM having a more significant (p<0.01) apoptotic effect than non-ionic ICM (p<0.05). Furthermore, ICM reversed the anti-apoptotic effect of lipopolysaccharide (1000 ng ml(-1)) treated neutrophils to control levels (23.0+\\/-3.5% to 61.2+\\/-5.3%; n=4; p<0.05). These agents induce apoptosis through a p38 MAPK independent pathway that results in mitochondrial depolarization, and is dependent on caspase activation. As neutrophils play a central role in host response to infection and injury, ICM, through induction of neutrophil apoptosis, could have a significant deleterious effect on host immune defence and

  10. Electroacupuncture Exerts Neuroprotection through Caveolin-1 Mediated Molecular Pathway in Intracerebral Hemorrhage of Rats

    Directory of Open Access Journals (Sweden)

    Hui-Qin Li

    2016-01-01

    Full Text Available Spontaneous intracerebral hemorrhage (ICH is one of the most devastating types of stroke. Here, we aim to demonstrate that electroacupuncture on Baihui (GV20 exerts neuroprotection for acute ICH possibly via the caveolin-1/matrix metalloproteinase/blood-brain barrier permeability pathway. The model of ICH was established by using collagenase VII. Rats were randomly divided into three groups: Sham-operation group, Sham electroacupuncture group, and electroacupuncture group. Each group was further divided into 4 subgroups according to the time points of 6 h, 1 d, 3 d, and 7 d after ICH. The methods were used including examination of neurological deficit scores according to Longa’s scale, measurement of blood-brain barrier permeability through Evans Blue content, in situ immunofluorescent detection of caveolin-1 in brains, western blot analysis of caveolin-1 in brains, and in situ zymography for measuring matrix metalloproteinase-2/9 activity in brains. Compared with Sham electroacupuncture group, electroacupuncture group has resulted in a significant improvement in neurological deficit scores and in a reduction in Evans Blue content, expression of caveolin-1, and activity of matrix metalloproteinase-2/9 at 6 h, 1 d, 3 d, and 7 d after ICH (P<0.05. In conclusion, the present results suggested that electroacupuncture on GV20 can improve neurological deficit scores and reduce blood-brain barrier permeability after ICH, and the mechanism possibly targets caveolin-1/matrix metalloproteinase/blood-brain barrier permeability pathway.

  11. Endosome-mediated autophagy: an unconventional MIIC-driven autophagic pathway operational in dendritic cells.

    Science.gov (United States)

    Kondylis, Vangelis; van Nispen Tot Pannerden, Hezder E; van Dijk, Suzanne; Ten Broeke, Toine; Wubbolts, Richard; Geerts, Willie J; Seinen, Cor; Mutis, Tuna; Heijnen, Harry F G

    2013-06-01

    Activation of TLR signaling has been shown to induce autophagy in antigen-presenting cells (APCs). Using high-resolution microscopy approaches, we show that in LPS-stimulated dendritic cells (DCs), autophagosomes emerge from MHC class II compartments (MIICs) and harbor both the molecular machinery for antigen processing and the autophagosome markers LC3 and ATG16L1. This ENdosome-Mediated Autophagy (ENMA) appears to be the major type of autophagy in DCs, as similar structures were observed upon established autophagy-inducing conditions (nutrient deprivation, rapamycin) and under basal conditions in the presence of bafilomycin A1. Autophagosome formation was not significantly affected in DCs expressing ATG4B (C74A) mutant and atg4b (-/-) bone marrow DCs, but the degradation of the autophagy substrate SQSTM1/p62 was largely impaired. Furthermore, we demonstrate that the previously described DC aggresome-like LPS-induced structures (DALIS) contain vesicular membranes, and in addition to SQSTM1 and ubiquitin, they are positive for LC3. LC3 localization on DALIS is independent of its lipidation. MIIC-driven autophagosomes preferentially engulf the LPS-induced SQSTM1-positive DALIS, which become later degraded in autolysosomes. DALIS-associated membranes also contain ATG16L1, ATG9 and the Q-SNARE VTI1B, suggesting that they may represent (at least in part) a membrane reservoir for autophagosome expansion. We propose that ENMA constitutes an unconventional, APC-specific type of autophagy, which mediates the processing and presentation of cytosolic antigens by MHC class II machinery, and/or the selective clearance of toxic by-products of elevated ROS/RNS production in activated DCs, thereby promoting their survival.

  12. Is there a classical nonsense-mediated decay pathway in trypanosomes?

    Directory of Open Access Journals (Sweden)

    Praveen Delhi

    Full Text Available In many eukaryotes, messenger RNAs with premature termination codons are destroyed by a process called "nonsense-mediated decay", which requires the RNA helicase Upf1 and also, usually, an interacting factor, Upf2. Recognition of premature termination codons may rely on their distance from either a splice site or the polyadenylation site, and long 3'-untranslated regions can trigger mRNA decay. The protist Trypanosoma brucei relies heavily on mRNA degradation to determine mRNA levels, and 3'-untranslated regions play a major role in control of mRNA decay. We show here that trypanosomes have a homologue of Upf1, TbUPF1, which interacts with TbUPF2 and (in an RNA-dependent fashion with poly(A binding protein 1, PABP1. Introduction of a premature termination codon in either an endogenous gene or a reporter gene decreased mRNA abundance, as expected for nonsense-mediated decay, but a dependence of this effect on TbUPF1 could not be demonstrated, and depletion of TbUPF1 by over 95% had no effect on parasite growth or the mRNA transcriptome. Further investigations of the reporter mRNA revealed that increases in open reading frame length tended to increase mRNA abundance. In contrast, inhibition of translation, either using 5'-secondary structures or by lengthening the 5'-untranslated region, usually decreased reporter mRNA abundance. Meanwhile, changing the length of the 3'-untranslated region had no consistent effect on mRNA abundance. We suggest that in trypanosomes, translation per se may inhibit mRNA decay, and interactions with multiple RNA-binding proteins preclude degradation based on 3'-untranslated region length alone.

  13. Nano-MnO2-mediated transformation of triclosan with humic molecules present: kinetics, products, and pathways.

    Science.gov (United States)

    Sun, Kai; Li, Shunyao; Waigi, Michael Gatheru; Huang, Qingguo

    2018-03-10

    It has been shown that manganese dioxide (MnO 2 ) can mediate transformation of phenolic contaminants to form phenoxyl radical intermediates, and subsequently, these intermediates intercouple to form oligomers via covalent binding. However, the reaction kinetics and transformation mechanisms of phenolic contaminants with humic molecules present in nano-MnO 2 -mediated systems were still unclear. In this study, it was proven that nano-MnO 2 were effective in transforming triclosan under acidic conditions (pH 3.5-5.0) during manganese reduction, and the apparent pseudo first-order kinetics rate constants (k = 0.0599-1.5314 h -1 ) increased as the pH decreased. In particular, the transformation of triclosan by nano-MnO 2 was enhanced in the presence of low-concentration humic acid (1-10 mg L -1 ). The variation in the absorption of humic molecules at 275 nm supported possible covalent binding between humic molecules and triclosan in the nano-MnO 2 -mediated systems. A total of four main intermediate products were identified by high-resolution mass spectrometry (HRMS), regardless of humic molecules present in the systems or not. These products correspond to a suite of radical intercoupling reactions (dimers and trimers), ether cleavage (2,4-dichlorophenol), and oxidation to quinone-like products, triggered by electron transfer from triclosan molecules to nano-MnO 2 . A possible reaction pathway in humic acid solutions, including homo-coupling, decomposition, oxidation, and cross-coupling, was proposed. Our findings provide valuable information regarding the environmental fate and transformation mechanism of triclosan by nano-MnO 2 in complex water matrices.

  14. Opportunistic Pathogen Porphyromonas gingivalis Modulates Danger Signal ATP-Mediated Antibacterial NOX2 Pathways in Primary Epithelial Cells

    Directory of Open Access Journals (Sweden)

    JoAnn S. Roberts

    2017-07-01

    Full Text Available Porphyromonas gingivalis, a major opportunistic pathogen in the etiology of chronic periodontitis, successfully survives in human gingival epithelial cells (GECs. P. gingivalis abrogates the effects of a host danger molecule, extracellular ATP (eATP/P2X7 signaling, such as the generation of reactive oxygen species (ROS via the mitochondria and NADPH oxidases (NOX from primary GECs. However, antimicrobial functions of ROS production are thoroughly investigated in myeloid-lineage immune cells and have not been well-understood in epithelial cells. Therefore, this study characterizes antibacterial NOX2 generated ROS and host downstream effects in P. gingivalis infected human primary GECs. We examined the expression of NOX isoforms in the GECs and demonstrate eATP stimulation increased the mRNA expression of NOX2 (p < 0.05. Specific peptide inhibition of NOX2 significantly reduced eATP-mediated ROS as detected by DCFDA probe. The results also showed P. gingivalis infection can temporally modulate NOX2 pathway by reorganizing the localization and activation of cytosolic molecules (p47phox, p67phox, and Rac1 during 24 h of infection. Investigation into downstream biocidal factors of NOX2 revealed an eATP-induced increase in hypochlorous acid (HOCl in GECs detected by R19-S fluorescent probe, which is significantly reduced by a myeloperoxidase (MPO inhibitor. MPO activity of the host cells was assayed and found to be positively affected by eATP treatment and/or infection. However, P. gingivalis significantly reduced the MPO product, bactericidal HOCl, in early times of infection upon eATP stimulation. Analysis of the intracellular levels of a major host-antioxidant, glutathione during early infection revealed a substantial decrease (p < 0.05 in reduced glutathione indicative of scavenging of HOCl by P. gingivalis infection and eATP treatment. Examination of the mRNA expression of key enzymes in the glutathione synthesis pathway displayed a marked

  15. Cdk1, PKCδ and calcineurin-mediated Drp1 pathway contributes to mitochondrial fission-induced cardiomyocyte death

    Energy Technology Data Exchange (ETDEWEB)

    Zaja, Ivan [Department of Anesthesiology, Medical College of Wisconsin, Milwaukee, WI 53226 (United States); Bai, Xiaowen, E-mail: xibai@mcw.edu [Department of Anesthesiology, Medical College of Wisconsin, Milwaukee, WI 53226 (United States); Liu, Yanan; Kikuchi, Chika; Dosenovic, Svjetlana; Yan, Yasheng; Canfield, Scott G. [Department of Anesthesiology, Medical College of Wisconsin, Milwaukee, WI 53226 (United States); Bosnjak, Zeljko J. [Department of Anesthesiology, Medical College of Wisconsin, Milwaukee, WI 53226 (United States); Department of Physiology, Medical College of Wisconsin, Milwaukee, WI 53226 (United States)

    2014-10-31

    Highlights: • Drp1-mediated increased mitochondrial fission but not fusion is involved the cardiomyocyte death during anoxia-reoxygenation injury. • Reactive oxygen species are upstream initiators of mitochondrial fission. • Increased mitochondrial fission is resulted from Cdk1-, PKCδ-, and calcineurin-mediated Drp1 pathways. - Abstract: Myocardial ischemia–reperfusion (I/R) injury is one of the leading causes of death and disability worldwide. Mitochondrial fission has been shown to be involved in cardiomyocyte death. However, molecular machinery involved in mitochondrial fission during I/R injury has not yet been completely understood. In this study we aimed to investigate molecular mechanisms of controlling activation of dynamin-related protein 1 (Drp1, a key protein in mitochondrial fission) during anoxia-reoxygenation (A/R) injury of HL1 cardiomyocytes. A/R injury induced cardiomyocyte death accompanied by the increases of mitochondrial fission, reactive oxygen species (ROS) production and activated Drp1 (pSer616 Drp1), and decrease of inactivated Drp1 (pSer637 Drp1) while mitochondrial fusion protein levels were not significantly changed. Blocking Drp1 activity with mitochondrial division inhibitor mdivi1 attenuated cell death, mitochondrial fission, and Drp1 activation after A/R. Trolox, a ROS scavenger, decreased pSer616 Drp1 level and mitochondrial fission after A/R. Immunoprecipitation assay further indicates that cyclin dependent kinase 1 (Cdk1) and protein kinase C isoform delta (PKCδ) bind Drp1, thus increasing mitochondrial fission. Inhibiting Cdk1 and PKCδ attenuated the increases in pSer616 Drp1, mitochondrial fission, and cardiomyocyte death. FK506, a calcineurin inhibitor, blocked the decrease in expression of inactivated pSer637 Drp1 and mitochondrial fission. Our findings reveal the following novel molecular mechanisms controlling mitochondrial fission during A/R injury of cardiomyocytes: (1) ROS are upstream initiators of

  16. Mechanism of Anti-glioblastoma Effect of Temzolomide Involved in ROS-Mediated SIRT 1 Pathway

    Directory of Open Access Journals (Sweden)

    Yuan Jiang

    2014-03-01

    Full Text Available Objective: To explore the new molecular mechanism of anti-tumor effect of temzolomide (TMZon glioblastoma cell strain. Methods: MTT methods and Hoechst 33342 staining method were applied to determine the effect of TMZ on the proliferation and apoptosis of glioblastoma cell strains U251 and SHG44, while flow cytometry was used to detect the impact of TMZ on cellular cycles. Additionally, DCFH-DA probe was adopted to test intracellular reactive oxygen species (ROS level while Real-time PCR and Western blot tests were applied to determine the influence of TMZ on SIRT1 expression. Results: TMZ in different concentrations added into glioblastoma cell strain for 72 h could concentration-dependently inhibit the proliferation of glioblastoma cells, 100 μmol/L of which could also block cells in phase G2/M and improve cellular apoptosis. In addition, TMZ could evidently increase intracellular ROS level so as to activate SIRT1. Conclusion: The mechanism of anti-tumor effect of TMZ on glioblastoma may be associated with ROS-induced SIRT1 pathway, providing theoretical basis for the clinical efficacy of TMZ.

  17. Betulinic Acid Induces Apoptosis in Differentiated PC12 Cells Via ROS-Mediated Mitochondrial Pathway.

    Science.gov (United States)

    Wang, Xi; Lu, Xiaocheng; Zhu, Ronglan; Zhang, Kaixin; Li, Shuai; Chen, Zhongjun; Li, Lixin

    2017-04-01

    Betulinic acid (BA), a pentacyclic triterpene of natural origin, has been demonstrated to have varied biologic activities including anti-viral, anti-inflammatory, and anti-malarial effects; it has also been found to induce apoptosis in many types of cancer. However, little is known about the effect of BA on normal cells. In this study, the effects of BA on normal neuronal cell apoptosis and the mechanisms involved were studied using differentiated PC12 cells as a model. Treatment with 50 μM BA for 24 h apparently induced PC12 cell apoptosis. In the early stage of apoptosis, the level of intracellular reactive oxygen species (ROS) increased. Afterwards, the loss of the mitochondrial membrane potential, the release of cytochrome c and the activation of caspase-3 occurred. Treatment with antioxidants could significantly reduce BA-induced PC12 cell apoptosis. In conclusion, we report for the first time that BA induced the mitochondrial apoptotic pathway in differentiated PC12 cells through ROS.

  18. Titanium dioxide-mediated heterogeneous photocatalytic degradation of terbufos: Parameter study and reaction pathways

    International Nuclear Information System (INIS)

    Wu, R.-J.; Chen, C.-C.; Chen, M.-H.; Lu, C.-S.

    2009-01-01

    The photocatalytic degradation of terbufos in aqueous suspensions was investigated by using titanium dioxide (TiO 2 ) as a photocatalyst. About 99% of terbufos was degraded after UV irradiation for 90 min. Factors such as pH of the system, TiO 2 dosage, and presence of anions were found to influence the degradation rate. Photodegradation of terbufos by TiO 2 /UV exhibited pseudo-first-order reaction kinetics, and a reaction quantum yield of 0.289. The electrical energy consumption per order of magnitude for photocatalytic degradation of terbufos was calculated and showed that a moderated efficiency (E EO = 71 kWh/(m 3 order)) was obtained in TiO 2 /UV process. To obtain a better understanding of the mechanistic details of this TiO 2 -assisted photodegradation of terbufos with UV irradiation, the intermediates of the processes were separated, identified, and characterized by the solid-phase microextraction (SPME) and gas chromatography/mass spectrometry (GC/MS) technique. The probable photodegradation pathways were proposed and discussed

  19. Active hexose-correlated compound enhances extrinsic-pathway-mediated apoptosis of Acute Myeloid Leukemic cells.

    Directory of Open Access Journals (Sweden)

    Kavin Fatehchand

    Full Text Available Active Hexose Correlated Compound (AHCC has been shown to have many immunostimulatory and anti-cancer activities in mice and in humans. As a natural product, AHCC has potential to create safer adjuvant therapies in cancer patients. Acute Myeloid Leukemia (AML is the least curable and second-most common leukemia in adults. AML is especially terminal to those over 60 years old, where median survival is only 5 to 10 months, due to inability to receive intensive chemotherapy. Hence, the purpose of this study was to investigate the effects of AHCC on AML cells both in vitro and in vivo. Results showed that AHCC induced Caspase-3-dependent apoptosis in AML cell lines as well as in primary AML leukopheresis samples. Additionally, AHCC induced Caspase-8 cleavage as well as Fas and TRAIL upregulation, suggesting involvement of the extrinsic apoptotic pathway. In contrast, monocytes from healthy donors showed suppressed Caspase-3 cleavage and lower cell death. When tested in a murine engraftment model of AML, AHCC led to significantly increased survival time and decreased blast counts. These results uncover a mechanism by which AHCC leads to AML-cell specific death, and also lend support for the further investigation of AHCC as a potential adjuvant for the treatment of AML.

  20. Autism as early neurodevelopmental disorder: evidence for an sAPPα-mediated anabolic pathway

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    Debomoy K Lahiri

    2013-06-01

    Full Text Available Autism is a neurodevelopmental disorder marked by social skills and communication deficits and interfering repetitive behavior. Intellectual disability often accompanies autism. In addition to behavioral deficits, autism is characterized by neuropathology and brain overgrowth. Increased intracranial volume often accompanies this brain growth. We have found that the Alzheimer’s disease (AD associated amyloid-β precursor protein (APP, especially its neuroprotective processing product, secreted APP α (sAPPα, is elevated in persons with autism. This has led to the anabolic hypothesis of autism etiology, in which neuronal overgrowth in the brain results in interneuronal misconnections that may underlie multiple autism symptoms. We review the contribution of research in brain volume and of APP to the anabolic hypothesis, and relate APP to other proteins and pathways that have already been directly associated with autism, such as fragile X mental retardation protein (FMRP, Ras small GTPase/Extracellular Signal-Regulated Kinase (Ras/ERK, and phosphoinositide 3 kinase/protein kinase B/mammalian target of rapamycin (PI3K/Akt/mTOR. We also present additional evidence of MRI intracranial measurements in favor of the anabolic hypothesis. Finally, since it appears that APP’s involvement in autism is part of a multi-partner network, we extend this concept into the inherently interactive realm of epigenetics. We speculate that the underlying molecular abnormalities that influence APP’s contribution to autism are epigenetic markers overlaid onto potentially vulnerable gene sequences due to environmental influence.

  1. Autism as early neurodevelopmental disorder: evidence for an sAPPα-mediated anabolic pathway.

    Science.gov (United States)

    Lahiri, Debomoy K; Sokol, Deborah K; Erickson, Craig; Ray, Balmiki; Ho, Chang Y; Maloney, Bryan

    2013-01-01

    Autism is a neurodevelopmental disorder marked by social skills and communication deficits and interfering repetitive behavior. Intellectual disability often accompanies autism. In addition to behavioral deficits, autism is characterized by neuropathology and brain overgrowth. Increased intracranial volume often accompanies this brain growth. We have found that the Alzheimer's disease (AD) associated amyloid-β precursor protein (APP), especially its neuroprotective processing product, secreted APP α, is elevated in persons with autism. This has led to the "anabolic hypothesis" of autism etiology, in which neuronal overgrowth in the brain results in interneuronal misconnections that may underlie multiple autism symptoms. We review the contribution of research in brain volume and of APP to the anabolic hypothesis, and relate APP to other proteins and pathways that have already been directly associated with autism, such as fragile X mental retardation protein, Ras small GTPase/extracellular signal-regulated kinase, and phosphoinositide 3 kinase/protein kinase B/mammalian target of rapamycin. We also present additional evidence of magnetic resonance imaging intracranial measurements in favor of the anabolic hypothesis. Finally, since it appears that APP's involvement in autism is part of a multi-partner network, we extend this concept into the inherently interactive realm of epigenetics. We speculate that the underlying molecular abnormalities that influence APP's contribution to autism are epigenetic markers overlaid onto potentially vulnerable gene sequences due to environmental influence.

  2. A "Bony" Proposition: Pathways Mediating Responses to Simulated Weightlessness and Radiation

    Science.gov (United States)

    Tahimic, Candice; Globus, Ruth

    2016-01-01

    There is evidence that weightlessness and radiation, two elements of the spaceflight environment, can lead to detrimental changes in human musculoskeletal tissue, including bone loss and muscle atrophy. This bone loss is thought to be brought about by the increased activity of bone-resorbing osteoclasts and functional changes in bone-forming osteoblasts, cells that give rise to mature osteocytes. My current area of research focuses on understanding the mechanistic basis for the responses of bone to the spaceflight environment using earth-based animal and cellular models. The overarching goal is to identify molecular targets to prevent bone loss in space exploration and earth-based scenarios of radiotherapy, accidental radiation exposure and reduced mobility. In this talk, I will highlight two signaling pathways that potentially play a role in the response of bone to spaceflight-like conditions. Firstly, I will discuss the role of insulin-like growth factor 1 (IGF1) signaling as it pertains to the recovery of bone from simulated weightlessness (rodent hindlimb unloading model). Secondly, I will share recent findings from our study that aims to understand the emerging role of autophagy in maintaining the balance between bone formation and resorption (bone homeostasis) as well as normal skeletal structure.

  3. Increased grassland arthropod production with mammalian herbivory and eutrophication: a test of mediation pathways.

    Science.gov (United States)

    Lind, Eric M; La Pierre, Kimberly J; Seabloom, Eric W; Alberti, Juan; Iribarne, Oscar; Firn, Jennifer; Gruner, Daniel S; Kay, Adam D; Pascal, Jesus; Wright, Justin P; Yang, Louie; Borer, Elizabeth T

    2017-12-01

    Increases in nutrient availability and alterations to mammalian herbivore communities are a hallmark of the Anthropocene, with consequences for the primary producer communities in many ecosystems. While progress has advanced understanding of plant community responses to these perturbations, the consequences for energy flow to higher trophic levels in the form of secondary production are less well understood. We quantified arthropod biomass after manipulating soil nutrient availability and wild mammalian herbivory, using identical methods across 13 temperate grasslands. Of experimental increases in nitrogen, phosphorus, and potassium, only treatments including nitrogen resulted in significantly increased arthropod biomass. Wild mammalian herbivore removal had a marginal, negative effect on arthropod biomass, with no interaction with nutrient availability. Path analysis including all sites implicated nutrient content of the primary producers as a driver of increased arthropod mean size, which we confirmed using 10 sites for which we had foliar nutrient data. Plant biomass and physical structure mediated the increase in arthropod abundance, while the nitrogen treatments accounted for additional variation not explained by our measured plant variables. The mean size of arthropod individuals was 2.5 times more influential on the plot-level total arthropod biomass than was the number of individuals. The eutrophication of grasslands through human activity, especially nitrogen deposition, thus may contribute to higher production of arthropod consumers through increases in nutrient availability across trophic levels. © 2017 by the Ecological Society of America.

  4. PKC α regulates netrin-1/UNC5B-mediated survival pathway in bladder cancer

    International Nuclear Information System (INIS)

    Liu, Jiao; Kong, Chui-ze; Gong, Da-xin; Zhang, Zhe; Zhu, Yu-yan

    2014-01-01

    Netrin-1 and its receptor UNC5B play important roles in angiogenesis, embryonic development, cancer and inflammation. However, their expression patttern and biological roles in bladder cancer have not been well characterized. The present study aims to investigating the clinical significance of PKC α, netrin-1 and UNC5B in bladder cancer as well as their association with malignant biological behavior of cancer cells. Netrin-1 and UNC5B expression was examined in 120 bladder cancer specimens using immunohistochemistry and in 40 fresh cancer tissues by western blot. Immunofluorescence was performed in cancer cell lines. PKC α agonist PMA and PKC siRNA was employed in bladder cancer cells. CCK-8, wound healing assays and flow cytometry analysis were used to examine cell proliferation, migration and cell cycle, respectively. Netrin-1 expression was positively correlated with histological grade, T stage, metastasis and poor prognosis in bladder cancer tissues. Immunofluorescence showed elevated netrin-1 and decreased UNC5B expression in bladder cancer cells compared with normal bladder cell line. Furthermore, cell proliferation, migration and cell cycle progression were promoted with PMA treatment while inhibited by calphostin C. In addition, PMA treatment could induce while calphostin C reduce netrin-1 expression in bladder cancer cells. The present study identified netrin-1/UNC5B, which could be regulated by PKC signaling, was important mediators of bladder cancer progression

  5. Neuromodulatory Effect of Thymoquinone in Attenuating Glutamate-Mediated Neurotoxicity Targeting the Amyloidogenic and Apoptotic Pathways

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    Ibram Amin Fouad

    2018-04-01

    Full Text Available Overexposure of the glutamatergic N-methyl-d-aspartate (NMDA receptor to the excitatory neurotransmitter l-glutamic acid leads to neuronal cell death by excitotoxicity as a result of increased intracellular Ca2+, mitochondrial dysfunction, and apoptosis. Moreover, it was previously reported that prolonged activation of the NMDA receptor increased beta-amyloid (Aβ levels in the brain. Thymoquinone (TQ, the active constituent of Nigella sativa seeds, has been shown to have potent antioxidant and antiapoptotic effects. The aim of the present study was to explore the neuromodulatory effects of different doses of TQ (2.5 and 10 mg/kg against apoptotic cell death and Aβ formation resulting from glutamate administration in rats using vitamin E as a positive control. Behavioral changes were assessed using Y-maze and Morris water maze tests for evaluating spatial memory and cognitive functions. Caspase-3, Lactate dehydrogenase, Aβ-42, and cytochrome c gene expression were determined. TQ-treated groups showed significant decreases in the levels of all tested biochemical and behavioral parameters compared with the glutamate-treated group. These findings demonstrated that TQ has a promising neuroprotective activity against glutamate-induced neurotoxicity and this effect is mediated through its anti-amyloidogenic, antioxidant, and antiapoptotic activities.

  6. Redundant Vasodilator Pathways Underlying Radial Artery Flow-Mediated Dilation Are Preserved in Healthy Aging

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    Kevin D. Ballard

    2014-01-01

    Full Text Available Background. Blocking nitric oxide (NO and vasodilator prostanoids (PN does not consistently reduce flow-mediated dilation (FMD in young adults. The impact of aging on the contribution of NO and PG to FMD is unknown. Methods. FMD was measured in older adults (n=10, 65±3 y after arterial infusion of saline, N(G-monomethyl-L-arginine (L-NMMA, and ketorolac + L-NMMA. Data were compared to published data in young adults. Results. L-NMMA reduced FMD in older adults (8.9±3.6 to 5.9±3.7% although this was not statistically significant (P=0.08 and did not differ (P=0.74 from the reduction observed in young adults (10.0±3.8 to 7.6±4.7%; P=0.03. Blocking PN did not affect FMD in young or older adults. In older adults, L-NMMA reduced (n=6; range = 36–123% decrease, augmented (n=3; 10–122% increase, or did not change FMD (n=1; 0.4% increase. After PN blockade, FMD responses were reduced (n=2, augmented (n=6, or unaffected (n=1. Conclusions. NO or PN blockade did not consistently reduce FMD in healthy older adults, suggesting the existence of redundant vasodilator phenotypes as observed previously in young adults.

  7. Involvement of cyclic AMP-mediated pathway in neural release of noradrenaline in canine isolated mesenteric artery and vein.

    Science.gov (United States)

    Mutafova-Yambolieva, Violeta N; Smyth, Lisa; Bobalova, Janette

    2003-01-01

    Our major hypothesis is that cyclic adenosine-3',5'-monophosphate (cAMP)-mediated modulation of neurotransmitter release plays different roles at low and high activity of the sympathetic nervous system. We further hypothesize that cAMP-mediated neuromodulation might underlie disparate neurovascular control in mesenteric arteries and veins. Electrical field stimulation (EFS)-evoked overflow of noradrenaline (NA) was evaluated in the absence or presence of activators and inhibitors of cAMP-dependent pathway at low (4 Hz) and high (16 Hz) frequencies of stimulation of endothelium-denuded secondary and tertiary branches of the canine isolated inferior mesenteric arteries and veins. The content of NA in samples of the superfusates collected before and during nerve stimulation was assayed by high-performance liquid chromatography (HPLC) technique in conjunction with electrochemical detection. Student's t-test and ANOVA analyses were applied for statistical analysis. Activation of cAMP-dependent pathway with either isoproterenol (ISO, 10 microM), forskolin (1 microM), dibutyryl cAMP (100 microM) or combined site-specific activators of cAMP-dependent protein kinase (PKA) [i.e. N(6)-phenyl-adenosine-3',5'-cyclic monophosphate, 8-(6-aminohexyl) aminoadenosine-3',5'-cyclic monophosphate, and the Sp-isomer of 5,6-dichloro-1-D-ribofuranosylbenzimidazole-3',5'-cyclic monophosphorothioate, each 100 microM] caused an enhancement of the EFS-evoked overflow of endogenous NA at 16 Hz of stimulation but was without an effect at 4 Hz of stimulation both in artery and vein. The EFS (16 Hz)-evoked overflow of NA in vein was also increased in the presence of inhibitors of phosphodiesterase (PDE) III and PDE IV (i.e. milrinone, 0.4 microM, and roilpram, 30 microM), whereas these inhibitors did not affect the overflow of NA in the artery. The facilitating effect of activators of cAMP-dependent pathway on the EFS-evoked release of NA at 16 Hz appears to be more pronounced in the vein than in

  8. Wnt5a mediated canonical Wnt signaling pathway activation in orthodontic tooth movement: possible role in the tension force-induced bone formation.

    Science.gov (United States)

    Fu, Hai-Di; Wang, Bei-Ke; Wan, Zi-Qiu; Lin, Heng; Chang, Mao-Lin; Han, Guang-Li

    2016-10-01

    Orthodontic tooth movement (OTM) is associated with bone remodeling mediated by orthodontic mechanical loading. Increasing studies reported that Wnt signaling played crucial roles in mechanical stimuli induced bone remodeling. However, little is known about the involvement of Wnt signaling in orthodontic force-induced bone formation during OTM. In virtue of the OTM mice model as we previously reported, where new bone formation was determined by micro-CT and immunoreactivity of osteocalcin and osterix, we explored the activation of Wnt signaling pathway during OTM. Our results proved the nuclei translocation of β-catenin, suggesting the activation of canonical Wnt signaling pathway in the periodontal ligament cells (PDLCs) near the alveolar bone at the tension site (TS). Moreover, the immunoreactivity of Wnt5a, but not Wnt3a in PDLCs indicated the activation of canonical Wnt pathway might be mediated by Wnt5a, but not Wnt3a as in most cases. The co-location of Wnt5a and β-catenin that was evidenced by double labeling immunofluorescence staining further supported the hypothesis. In addition, the high expression of FZD4 and LRP5 in PDLCs at TS of periodontium suggested that the activation of Wnt signaling pathway was mediated by these receptors. The negligible expression of ROR2 also indicated that canonical but not non-canonical Wnt signaling pathway was activated by Wnt5a, since previous studies demonstrated that the activation of canonical/non-canonical Wnt signaling pathway was largely dependent on the receptors. In summary, we here reported that Wnt5a mediated activation of canonical Wnt signaling pathway might contribute to the orthodontic force induced bone remodeling.

  9. β1 integrin mediates colorectal cancer cell proliferation and migration through regulation of the Hedgehog pathway.

    Science.gov (United States)

    Song, Jia; Zhang, Jixiang; Wang, Jing; Wang, Jun; Guo, Xufeng; Dong, Weiguo

    2015-03-01

    β1 integrin (ITGB1) is the major expressed integrin protein of normal cells and tumor-associated cells. It is often up-regulated in human malignancies and is involved in many developmental processes, such as tumor progression and metastasis. However, little is known about the function of ITGB1 in colorectal cancer. We constructed lentiviral vectors expressing ITGB1 or ITGB1-specific RNA interference (RNAi) and an unrelated control vector. After infecting HT29 cells in vitro, proliferation and migration were evaluated by Cell Counting Kit 8 (CCK-8) assays, transwell invasion assays, and Western blots. The influence of lentivirus infection on the tumor development capacity of HT29 cells in vivo was examined by xenografting the tumor cells. The expression of ITGB1 in the xenografted tumor cells was analyzed by immunohistochemistry. The up-regulation of ITGB1 significantly increased the proliferation in HT29 cells in vitro. Moreover, we found that the overexpression of ITGB1 up-regulated sonic hedgehog (Shh) while down-regulating Gli1 and SuFu in HT29-ITGB1 cells compared to controls. Moreover, the levels of c-myc and cyclin D1 proteins were up-regulated. Transwell assays showed that the number of migrating HT29-RNAi cells was lower than that in the other cell groups, indicating that ITGB1 significantly enhances the invasive ability of HT29 cells. In addition to these in vitro results, ITGB1 was found to be a significantly effective growth factor in a xenografted tumor mouse model. These results suggest that ITGB1 induces growth and invasion in a human colorectal cancer cell line through the hedgehog (Hh) signaling pathway in vitro and in vivo.

  10. TLR and NKG2D signaling pathways mediate CS-induced pulmonary pathologies.

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    Brian W Wortham

    Full Text Available Long-term exposure to cigarette smoke (CS can have deleterious effects on lung epithelial cells including cell death and the initiation of inflammatory responses. CS-induced cell injury can elaborate cell surface signals and cellular byproducts that stimulate immune system surveillance. Our previous work has shown that the expression of ligands for the cytotoxic lymphocyte activating receptor NKG2D is enhanced in patients with COPD and that the induction of these ligands in a mouse model can replicate COPD pathologies. Here, we extend these findings to demonstrate a role for the NKG2D receptor in CS-induced pathophysiology and provide evidence linking nucleic acid-sensing endosomal toll-like receptor (TLR signaling to COPD pathology through NKG2D activation. Specifically, we show that mice deficient in NKG2D exhibit attenuated pulmonary inflammation and airspace enlargement in a model of CS-induced emphysema. Additionally, we show that CS exposure induces the release of free nucleic acids in the bronchoalveolar lavage and that direct exposure of mouse lung epithelial cells to cigarette smoke extract similarly induces functional nucleic acids as assessed by TLR3, 7, and 9 reporter cell lines. We demonstrate that exposure of mouse lung epithelial cells to TLR ligands stimulates the surface expression of RAET1, a ligand for NKG2D, and that mice deficient in TLR3/7/9 receptor signaling do not exhibit CS-induced NK cell hyperresponsiveness and airspace enlargement. The findings indicate that CS-induced airway injury stimulates TLR signaling by endogenous nucleic acids leading to elevated NKG2D ligand expression. Activation of these pathways plays a major role in the altered NK cell function, pulmonary inflammation and remodeling related to long-term CS exposure.

  11. Induction of rat hepatic zinc thionein by phorbol ester-mediated protein kinase C pathway

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    Garrett, S.H.; Funk, A.E.; Brady, F.O.

    1986-05-01

    Metallothionein (MT) exists in rat liver mainly as a zinc protein. The levels of this protein fluctuate in response to a variety of internal and external stimuli. Among these inducers of MT are metals, glucocorticoids, catecholamines, and polypeptide hormones. Metals and glucocorticoids are primary inducers of MT, while the others operate either via adenylate cyclase/cAMP/cAMP-dependent protein kinase, or via phospholipase C/inositol 1,4,5-triphosphate, diacylglycerol/Ca/sup 2 +/-dependent protein kinase, protein kinase C. The authors have examined the role of the protein kinase C pathway in the induction of MT by using a phorbol ester, 12-O-tetradecanoyl-phorbol 13-acetate (TPA), to activate it. In vivo TPA is a good inducer of Zn/sub 7/-MT with an ED/sub 0.5/ of 26.5 nmoles/kg b.w. Maximal levels reached were about 7..mu..g Zn in MT/g liver, an induction increase of 8 to 10-fold. An inactive compound, 4..beta..-phorbol, and the vehicle (DMSO) did not stimulate the synthesis of Zn/sub 7/-MT. This induction by TPA requires de novo protein synthesis, as demonstrated by a cycloheximide/(/sup 35/S)-cysteine experiment. TPA stimulated Zn incorporation by 8.6-fold and (/sup 35/S)-cysteine incorporation by 4.8-fold during an 11h induction. These increases were blocked 100% by treatment with cycloheximide at -1 and +5h. These experiments have been repeated in cultured hepatocytes, using (/sup 35/S)-cysteine incorporation, slab SDS-PAGE, and autoradiography to quantitate MT levels.

  12. HuD-mediated distinct BDNF regulatory pathways promote regeneration after nerve injury.

    Science.gov (United States)

    Sanna, Maria Domenica; Ghelardini, Carla; Galeotti, Nicoletta

    2017-03-15

    Up-regulation of brain-derived neurotrophic factor (BDNF) synthesis is an important mechanism of peripheral nerve regeneration after injury. However, the cellular and molecular mechanisms underlying this process are not fully understood. This study examines the role of BDNF in the spared nerve injury (SNI) mice model. Protein expression and cellular localization were investigated in the dorsal root ganglia (DRG) and spinal cord by western blotting and immunofluorescence experiments respectively. BDNF protein was markedly increased 3 and 7days post-injury in the spinal cord and DRG. Following nerve injury sensory neurons produce molecules to promote regeneration, such as growth-associated protein 43 (GAP-43) and cytoskeletal proteins. Our results show that the expression of GAP-43 was increased in the DRG and spinal cord while, an increased of p-NFH content was detected in the spinal cord, with no modification in the DRG. Both events were counteracted by the administration of an anti-BDNF antibody. In DRG of SNI mice we also detected an increase of HuD expression, a RNA-binding protein known to stabilize BDNF and GAP-43 mRNA. Silencing of HuD prevented the nerve injury-induced BDNF and GAP-43 enhanced expression in the DRG. HuD-mediated BDNF synthesis in the primary sensory neurons, is followed by an anterograde transport of the neurotrophin to the central terminals of the primary afferents in the spinal dorsal horn, to modulate GAP-43 and NFH activation. Our data suggest that BDNF, GAP-43 and p-NFH proteins increase are linked events required for the enhanced regeneration after nerve injury. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Gastrointestinal stimulatory and uterotonic activities of dietary radish leaves extract are mediated through multiple pathways.

    Science.gov (United States)

    Ghayur, Muhammad Nabeel; Gilani, Anwarul Hassan

    2005-09-01

    Raphanus sativus, commonly known as radish, is a food plant known worldwide for its culinary and medicinal properties especially as a laxative and abortifacient. This study reports the gastrointestinal and uterine tone modulatory activities of the crude extract (Rl.Cr) of radish leaves. Rl.Cr, showing the presence of saponins and alkaloids, exhibited a spasmogenic effect (0.03-10 mg/mL) in isolated rabbit jejunum, rat stomach fundus and uterus which was partially blocked by atropine. In contrast, Rl.Cr was found to be devoid of any stimulatory effect in rat ileum, instead showed an inhibitory effect (0.1 mg/mL) on the ACh dose-response curves. A mild relaxant effect was also observed in rabbit jejunum at the lower doses (0.1-0.3 mg/mL) but not against K(+)-induced contractions, ruling out a calcium channel blocking effect. In guinea-pig ileum, Rl.Cr exhibited a stimulant effect resistant to atropine while sensitive to pyrilamine pretreatment. The aqueous fraction, showing a strong presence of saponins, was found to be more efficacious than the non-polar fractions in its spasmogenic effect. This study shows the presence of species-dependent gastrointestinal effects of radish mediated partially through cholinergic receptors in rabbit and rat tissues, but through histaminergic activation in the guinea-pig, providing a scientific basis for its use in gut and uterine affections while also giving a wider picture of the activity profile of radish by using different species of animals. Copyright 2005 John Wiley & Sons, Ltd.

  14. Multiple signal transduction pathways regulate TNF-induced actin reorganization in macrophages: inhibition of Cdc42-mediated filopodium formation by TNF

    NARCIS (Netherlands)

    Peppelenbosch, M.; Boone, E.; Jones, G. E.; van Deventer, S. J.; Haegeman, G.; Fiers, W.; Grooten, J.; Ridley, A. J.

    1999-01-01

    TNF is known to regulate macrophage (Mphi) migration, but the signaling pathways mediating this response have not been established. Here we report that stimulation of the 55-kDa TNF receptor (TNFR-1) induced an overall decrease in filamentous actin (F-actin), inhibited CSF-1- and Cdc42-dependent

  15. Copper metabolism domain-containing 1 represses the mediators involved in the terminal effector pathways of human labour and delivery.

    Science.gov (United States)

    Lappas, Martha

    2016-04-01

    Does Copper Metabolism MURR1 Domain 1 (COMMD1) play a role in regulating the mediators involved in the terminal processes of human labour and delivery? COMMD1 plays a critical role in the termination of nuclear factor-κB (NF-κB) activity and the control of pro-inflammatory and pro-labour mediators. Inflammation and infection are the biggest aetiological factors associated with preterm birth. NF-κB drives the transcription of pro-inflammatory mediators involved in the terminal effector pathways of human labour and delivery. In non-gestational tissues, COMMD1 is a negative regulator of NF-κB-induced inflammation. The mRNA and/or protein level of COMMD1 was assessed in myometrium (n = 8 per group) and fetal membranes (n = 8 per group) obtained from term non-labouring and labouring women at term, and fetal membranes (n = 8 per group) at preterm with and without histological chorioamnionitis. Primary human myometrial cells were used to determine the effect of pro-inflammatory mediators on COMMD1 level, and the effect of COMMD1 small interfering RNA (siRNA) on pro-labour mediators. Statistical significance was ascribed to a P labour in myometrium; in fetal membranes with histologically confirmed chorioamnionitis and in myometrial cells treated with pro-inflammatory cytokines interleukin (IL)-1β and tumour necrosis factor (TNF)-α, the bacterial product fibroblast-stimulating lipopeptide and the viral double stranded RNA analogue polyinosinic polycytidilic acid. Loss-of-function studies revealed an increase in inflammation- and infection-induced TNF-α, IL-1α, IL-1β, IL-6, IL-8 and/or monocyte chemoattractant protein-1 mRNA abundance and/or release; and cyclo-oxygenase-2 mRNA level, release of prostaglandin (PG) F2α and mRNA level of the PGF2α receptor FP. In addition, siRNA knockdown of COMMD1 was associated with significantly increased NF-κB activation as evidenced by increased IL-1β-induced IκB-α protein degradation and NF-κB DNA binding activity. The

  16. The development of repetitive motor behaviors in deer mice: Effects of environmental enrichment, repeated testing, and differential mediation by indirect basal ganglia pathway activation.

    Science.gov (United States)

    Bechard, Allison R; Bliznyuk, Nikolay; Lewis, Mark H

    2017-04-01

    Little is known about the mechanisms mediating the development of repetitive behaviors in human or animals. Deer mice reared with environmental enrichment (EE) exhibit fewer repetitive behaviors and greater indirect basal ganglia pathway activation as adults than those reared in standard cages. The developmental progression of these behavioral and neural circuitry changes has not been characterized. We assessed the development of repetitive behavior in deer mice using both a longitudinal and cohort design. Repeated testing negated the expected effect of EE, but cohort analyses showed that progression of repetitive behavior was arrested after 1 week of EE and differed significantly from controls after 3 weeks. Moreover, EE reductions in repetitive behavior were associated with increasing activation of indirect pathway nuclei in males across adolescence, but not females. These findings provide the first assessment of developmental trajectories within EE and support indirect pathway mediation of repetitive behavior in male deer mice. © 2017 Wiley Periodicals, Inc.

  17. The impact of human development on individual health: a causal mediation analysis examining pathways through education and body mass index

    Directory of Open Access Journals (Sweden)

    Aolin Wang

    2017-03-01

    Full Text Available Background The macro environment we live in projects what we can achieve and how we behave, and in turn, shapes our health in complex ways. Policymaking will benefit from insights into the mechanisms underlying how national socioeconomic context affects health. This study examined the impact of human development on individual health and the possible mediating roles of education and body mass index (BMI. Methods We analyzed World Health Survey data on 109,448 participants aged 25 or older from 42 low- and middle-income countries with augmented human development index (HDI in 1990. We used principal components method to create a health score based on measures from eight health state domains, used years of schooling as education indicator and calculated BMI from self-reported height and weight. We used causal mediation analysis technique with random intercepts to account for the multilevel structure. Results Below a reference HDI level of 0.48, HDI was negatively associated with good health (total effect at HDI of 0.23: b =  − 3.44, 95% CI [−6.39–−0.49] for males and b =  − 5.16, 95% CI [−9.24,–−1.08] for females but was positively associated with good health above this reference level (total effect at HDI of 0.75: b = 4.16, 95% CI [−0.33–8.66] for males and b = 6.62, 95% CI [0.85–12.38] for females. We found a small positive effect of HDI on health via education across reference HDI levels (b ranging from 0.24 to 0.29 for males and 0.40 to 0.49 for females but not via pathways involving BMI only. Conclusion Human development has a non-linear effect on individual health, but the impact appears to be mainly through pathways other than education and BMI.

  18. Enteric Glia Mediate Neuron Death in Colitis Through Purinergic Pathways That Require Connexin-43 and Nitric OxideSummary

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    Isola A.M. Brown

    2016-01-01

    Full Text Available Background & Aims: The concept of enteric glia as regulators of intestinal homeostasis is slowly gaining acceptance as a central concept in neurogastroenterology. Yet how glia contribute to intestinal disease is still poorly understood. Purines generated during inflammation drive enteric neuron death by activating neuronal P2X7 purine receptors (P2X7R; triggering adenosine triphosphate (ATP release via neuronal pannexin-1 channels that subsequently recruits intracellular calcium ([Ca2+]i in surrounding enteric glia. We tested the hypothesis that the activation of enteric glia contributes to neuron death during inflammation. Methods: We studied neuroinflammation in vivo using the 2,4-dinitrobenzene sulfonic acid model of colitis and in situ using whole-mount preparations of human and mouse intestine. Transgenic mice with a targeted deletion of glial connexin-43 (Cx43 [GFAP::CreERT2+/−/Cx43f/f] were used to specifically disrupt glial signaling pathways. Mice deficient in inducible nitric oxide (NO synthase (iNOS−/− were used to study NO production. Protein expression and oxidative stress were measured using immunohistochemistry and in situ Ca2+ and NO imaging were used to monitor glial [Ca2+]i and [NO]i. Results: Purinergic activation of enteric glia drove [Ca2+]i responses and enteric neuron death through a Cx43-dependent mechanism. Neurotoxic Cx43 activity, driven by NO production from glial iNOS, was required for neuron death. Glial Cx43 opening liberated ATP and Cx43-dependent ATP release was potentiated by NO. Conclusions: Our results show that the activation of glial cells in the context of neuroinflammation kills enteric neurons. Mediators of inflammation that include ATP and NO activate neurotoxic pathways that converge on glial Cx43 hemichannels. The glial response to inflammatory mediators might contribute to the development of motility disorders. Keywords: Enteric Nervous System, Hemichannels

  19. αν and β1 Integrins mediate Aβ-induced neurotoxicity in hippocampal neurons via the FAK signaling pathway.

    Directory of Open Access Journals (Sweden)

    Hai-Yan Han

    Full Text Available αν and β1 integrins mediate Aβ-induced neurotoxicity in primary hippocampal neurons. We treated hippocampal neurons with 2.5 µg/mL 17E6 and 5 µg/mL ab58524, which are specific αν and β1 integrin antagonists, respectively, for 42 h prior to 10 µM Aβ treatment. Next, we employed small interfering RNA (siRNA to silence focal adhesion kinase (FAK, a downstream target gene of integrins. The siRNAs were designed with a target sequence, an MOI of 10 and the addition of 5 µg/mL polybrene. Under these conditions, the neurons were transfected and the apoptosis of different cell types was detected. Moreover, we used real-time PCR and Western blotting analyses to detect the expression of FAK and ρFAK genes in different cell types and investigated the underlying mechanism and signal pathway by which αν and β1 integrins mediate Aβ-induced neurotoxicity in hippocampal neurons. An MTT assay showed that both 17E6 and ab58524 significantly increased cell viability compared with the Aβ-treated neurons (P<0.01 and P<0.05, respectively. However, this protective effect was markedly attenuated after transfection with silencing FAK (siFAK. Moreover, TUNEL immunostaining and flow cytometry indicated that both 17E6 and ab58524 significantly protected hippocampal neurons against apoptosis induced by Aβ (P<0.05 compared with the Aβ-treated cells. However, this protective effect was reversed with siFAK treatment. Both the gene and protein expression of FAK increased after Aβ treatment. Interestingly, as the gene and protein levels of FAK decreased, the ρFAK protein expression markedly increased. Furthermore, both the gene and protein expression of FAK and ρFAK were significantly diminished. Thus, we concluded that both αν and β1 integrins interfered with Aβ-induced neurotoxicity in hippocampal neurons and that this mechanism partially contributes to the activation of the Integrin-FAK signaling pathway.

  20. Selenite exacerbates hepatic insulin resistance in mouse model of type 2 diabetes through oxidative stress-mediated JNK pathway

    International Nuclear Information System (INIS)

    Zhou, Jun; Xu, Gang; Bai, Zhaoshuai; Li, Kaicheng; Yan, Junyan; Li, Fen; Ma, Shuai; Xu, Huibi; Huang, Kaixun

    2015-01-01

    Recent evidence suggests a potential pro-diabetic effect of selenite treatment in type 2 diabetics; however, the underlying mechanisms remain elusive. Here we investigated the effects and the underlying mechanisms of selenite treatment in a nongenetic mouse model of type 2 diabetes. High-fat diet (HFD)/streptozotocin (STZ)-induced diabetic mice were orally gavaged with selenite at 0.5 or 2.0 mg/kg body weight/day or vehicle for 4 weeks. High-dose selenite treatment significantly elevated fasting plasma insulin levels and insulin resistance index, in parallel with impaired glucose tolerance, insulin tolerance and pyruvate tolerance. High-dose selenite treatment also attenuated hepatic IRS1/Akt/FoxO1 signaling and pyruvate kinase gene expressions, but elevated the gene expressions of phosphoenolpyruvate carboxyl kinase (PEPCK), glucose 6-phosphatase (G6Pase), peroxisomal proliferator-activated receptor-γ coactivator 1α (PGC-1α) and selenoprotein P (SelP) in the liver. Furthermore, high-dose selenite treatment caused significant increases in MDA contents, protein carbonyl contents, and a decrease in GSH/GSSG ratio in the liver, concurrent with enhanced ASK1/MKK4/JNK signaling. Taken together, these findings suggest that high-dose selenite treatment exacerbates hepatic insulin resistance in mouse model of type 2 diabetes, at least in part through oxidative stress-mediated JNK pathway, providing new mechanistic insights into the pro-diabetic effect of selenite in type 2 diabetes. - Highlights: • Selenite exacerbates hepatic insulin resistance in HFD/STZ-induced diabetic mice. • Selenite elevates hepatic gluconeogenesis and reduces glycolysis in diabetic mice. • Selenite exacerbates hepatic oxidative stress and triggers JNK signaling pathway. • Selenite elevates hepatic selenoprotein P expression in diabetic mice.

  1. microRNA-200b modulates microglia-mediated neuroinflammation via the cJun/MAPK pathway.

    Science.gov (United States)

    Jadhav, Shweta P; Kamath, Sandhya P; Choolani, Mahesh; Lu, Jia; Dheen, S Thameem

    2014-08-01

    Chronic activation of microglia, the macrophages of the CNS, has been shown to enhance neuronal damage because of excessive release of proinflammatory cytokines and neurotoxic molecules in a number of neurodegenerative diseases. Recent reports showed altered microRNA (miRNA) expression in immune-mediated pathologies, thus suggesting that miRNAs modulate expression of genes involving immune responses. This study demonstrates that miRNA-200b is expressed in microglia and modulates inflammatory response of microglia by regulating mitogen-activated protein kinase pathway. miRNA-200b expression was found to be down-regulated in activated microglia in vivo (traumatic brain injury rat model) and in vitro. A luciferase assay and loss- and gain-of-function studies revealed c-Jun, the transcription factor of cJun-N terminal kinase (JNK) mitogen-activated protein kinase pathway to be the target of miR-200b. Knockdown of miR-200b in microglia increased JNK activity along with an increase in pro-inflammatory cytokines, inducible nitric oxide synthase expression and nitric oxide (NO) production. Conversely, over-expression of miRNA-200b in microglia resulted in a decrease in JNK activity, inducible nitric oxide synthase expression, NO production and migratory potential of activated microglia. Furthermore, miR-200b inhibition resulted in increased neuronal apoptosis after treatment of neuronal cells with conditioned medium obtained from microglial culture. Taken together, these results indicate that miRNA-200b modulates microglial inflammatory process including cytokine secretion, NO production, migration and neuronal survival. © 2014 International Society for Neurochemistry.

  2. Vasorelaxation Induced by a New Naphthoquinone-Oxime is Mediated by NO-sGC-cGMP Pathway

    Directory of Open Access Journals (Sweden)

    Bruna P. V. Dantas

    2014-07-01

    Full Text Available It has been established that oximes cause endothelium-independent relaxation in blood vessels. In the present study, the cardiovascular effects of the new oxime 3-hydroxy-4–(hydroxyimino-2-(3-methylbut-2-enylnaphtalen-1(4H-one (Oxime S1 derived from lapachol were evaluated. In normotensive rats, administration of Oxime S1 (10, 15, 20 and 30 mg/Kg, i.v. produced dose-dependent reduction in blood pressure. In isolated aorta and superior mesenteric artery rings, Oxime S1 induced endothelium-independent and concentration-dependent relaxations (10−8 M to 10−4 M. In addition, Oxime S1-induced vasorelaxations were attenuated by hydroxocobalamin or methylene blue in aorta and by PTIO or ODQ in mesenteric artery rings, suggesting a role for the nitric oxide (NO pathway. Additionally, Oxime S1 (30 and 100 µM significantly increased NO concentrations (13.9 ± 1.6 nM and 17.9 ± 4.1 nM, respectively measured by nitric oxide microsensors. Furthermore, pre-contraction with KCl (80 mM prevented Oxime S1-derived vasorelaxation in endothelium-denuded aortic rings. Of note, combined treatment with potassium channel inhibitors also reduced Oxime S1-mediated vasorelaxation suggesting a role for potassium channels, more precisely Kir, Kv and KATP channels. We observed the involvement of BKCa channels in Oxime S1-induced relaxation in mesenteric artery rings. In conclusion, these data suggest that the Oxime S1 induces hypotension and vasorelaxation via NO pathway by activating soluble guanylate cyclase (sGC and K+ channels.

  3. Does GRK-β arrestin machinery work as a "switch on" for GPR17-mediated activation of intracellular signaling pathways?

    Science.gov (United States)

    Daniele, Simona; Trincavelli, Maria Letizia; Fumagalli, Marta; Zappelli, Elisa; Lecca, Davide; Bonfanti, Elisabetta; Campiglia, Pietro; Abbracchio, Maria P; Martini, Claudia

    2014-06-01

    During oligodendrocyte-precursor cell (OPC) differentiation program, an impairment in the regulatory mechanisms controlling GPR17 spatio-temporal expression and functional activity has been suggested to contribute to defective OPC maturation, a crucial event in the pathogenesis of multiple sclerosis. GRK-β arrestin machinery is the primary actor in the control of G-protein coupled receptor (GPCR) functional responses and changes in these regulatory protein activities have been demonstrated in several immune/inflammatory diseases. Herein, in order to shed light on the molecular mechanisms controlling GPR17 regulatory events during cell differentiation, the role of GRK/β-arrestin machinery in receptor desensitization and signal transduction was investigated, in transfected cells and primary OPC. Following cell treatment with the two classes of purinergic and cysteinyl-leukotriene (cysLT) ligands, different GRK isoforms were recruited to regulate GPR17 functional responses. CysLT-mediated receptor desensitization mainly involved GRK2; this kinase, via a G protein-dependent mechanism, promoted a transient binding of the receptor to β-arrestins, rapid ERK phosphorylation and sustained nuclear CREB activation. Furthermore, GRK2, whose expression parallels that of the receptor during differentiation process, appeared to be crucial to induce cysLT-mediated maturation of OPCs. On the other hand, purinergic ligand exclusively recruited the GRK5 subtype, and induced, via a G protein-independent/β-arrestin-dependent mechanism, a receptor/β-arrestin stable association, slower and sustained ERK stimulation and marginal CREB activation. These results show that purinergic and cysLT ligands, through the recruitment of specific GRK isoforms, address distinct intracellular pathways, most likely reinforcing the same final response. The identification of these mechanisms and players controlling GPR17 responses during OPC differentiation could be useful to identify new targets in

  4. Src tyrosine kinases contribute to serotonin-mediated contraction by regulating calcium-dependent pathways in rat skeletal muscle arteries.

    Science.gov (United States)

    Zavaritskaya, Olga; Lubomirov, Lubomir T; Altay, Serdar; Schubert, Rudolf

    2017-06-01

    The Src tyrosine kinase family contributes to the signalling mechanism mediating serotonin (5-hydroxytryptamine (5-HT))-induced vasoconstriction. These kinases were reported to influence the calcium sensitivity of the contractile apparatus. Whether Src kinases affect also the intracellular calcium concentration during constriction of intact arteries is unknown. Thus, we tested the hypothesis that constriction of arteries is associated with a Src kinase-dependent alteration of the intracellular calcium concentration. Contractility of gracilis arteries of Wistar rats was studied using isometric and isobaric myography. The intracellular calcium concentration was measured simultaneously with tension by FURA-2 fluorimetry. Inhibition of Src kinases with 10 μM PP2, 30 μM dasatinib and 100 μM AZM 475271 resulted in a strong attenuation of 5-HT-induced contractions. Vessel incubation with 10 μM PP3, an inactive analogue of PP2, had no effect. Removal of the endothelium did not alter vessel contractile responses to 5-HT nor the action of the Src-kinase inhibitor PP2. The PP2-mediated inhibition of 5-HT-induced contraction was associated with a reduced response of [Ca 2+ ] i to 5-HT. In particular, inhibition of Src kinases attenuates 5-HT-induced calcium influx as well as calcium release from intracellular stores. In contrast, the calcium sensitivity of the contractile apparatus and the filling state of the sarcoplasmic reticulum were not influenced by Src kinases during 5-HT-induced contractions. We conclude that Src kinase activation is a powerful mechanism to produce vasoconstriction of small skeletal muscle arteries of rats. This effect is endothelium-independent. The data further suggest that the action of c-Src kinases is associated with a change in the intracellular calcium concentration that involves Ca 2+ entry and Ca 2+ release pathways.

  5. Regulation of stem-like cancer cells by glutamine through β-catenin pathway mediated by redox signaling.

    Science.gov (United States)

    Liao, Jianwei; Liu, Pan-Pan; Hou, Guoxin; Shao, Jiajia; Yang, Jing; Liu, Kaiyan; Lu, Wenhua; Wen, Shijun; Hu, Yumin; Huang, Peng

    2017-02-28

    Cancer stem cells (CSCs) are thought to play an important role in tumor recurrence and drug resistance, and present a major challenge in cancer therapy. The tumor microenvironment such as growth factors, nutrients and oxygen affect CSC generation and proliferation by providing the necessary energy sources and growth signals. The side population (SP) analysis has been used to detect the stem-like cancer cell populations based on their high expression of ABCG2 that exports Hoechst-33342 and certain cytotoxic drugs from the cells. The purpose of this research is to investigate the effect of a main nutrient molecule, glutamine, on SP cells and the possible underlying mechanism(s). Biochemical assays and flow cytometric analysis were used to evaluate the effect of glutamine on stem-like side population cells in vitro. Molecular analyses including RNAi interfering, qRT-PCR, and immunoblotting were employed to investigate the molecular signaling in response to glutamine deprivation and its influence on tumor formation capacity in vivo. We show that glutamine supports the maintenance of the stem cell phenotype by promoting glutathione synthesis and thus maintaining redox balance for SP cells. A deprivation of glutamine in the culture medium significantly reduced the proportion of SP cells. L-asparaginase, an enzyme that catalyzes the hydrolysis of asparagine and glutamine to aspartic acid and glutamate, respectively, mimics the effect of glutamine withdrawal and also diminished the proportion of SP cells. Mechanistically, glutamine deprivation increases intracellular ROS levels, leading to down-regulation of the β-catenin pathway. Glutamine plays a significant role in maintaining the stemness of cancer cells by a redox-mediated mechanism mediated by β-catenin. Inhibition of glutamine metabolism or deprivation of glutamine by L-asparaginase may be a new strategy to eliminate CSCs and overcome drug resistance.

  6. Propofol reduced myocardial contraction of vertebrates partly by mediating the cyclic AMP-dependent protein kinase phosphorylation pathway

    International Nuclear Information System (INIS)

    Sun, Xiaotong; Zhang, Xinyu; Bo, Qiyu; Meng, Tao; Lei, Zhen; Li, Jingxin; Hou, Yonghao; Yu, Xiaoqian; Yu, Jingui

    2016-01-01

    Propofol inhibits myocardial contraction in a dose dependent manner. The present study is designed to examine the effect of propofol on PKA mediated myocardial contraction in the absence of adrenoreceptor agonist. The contraction of isolated rat heart was measured in the presence or absence of PKA inhibitor H89 or propofol, using a pressure transducer. The levels of cAMP and PKA kinase activity were detected by ELISA. The mRNA and total protein or phosphorylation level of PKA and downstream proteins were tested in the presence or absence of PKA inhibitor H89 or propofol, using RT-PCR, QPCR and western blotting. The phosphorylation level of PKA was examined thoroughly using immunofluorescence and PKA activity non-radioactive detection kit. Propofol induced a dose-dependent negative contractile response on the rat heart. The inhibitory effect of high concentration propofol (50 μM) with 45% decease of control could be partly reversed by the PKA inhibitor H89 (10 μM) and the depressant effect of propofol decreased from 45% to 10%. PKA kinase activity was inhibited by propofol in a dose-dependent manner. Propofol also induced a decrease in phosphorylation of PKA, which was also inhibited by H89, but did not alter the production of cAMP and the mRNA levels of PKA. The downstream proteins of PKA, PLN and RyR2 were phosphorylated to a lesser extent with propofol or H89 than control. These results demonstrated that propofol induced a negative myocardial contractile response partly by mediating the PKA phosphorylation pathway.

  7. Neuroprotective effect of humanin on cerebral ischemia/reperfusion injury is mediated by a PI3K/Akt pathway

    Science.gov (United States)

    Xu, Xingshun; Chua, Chu Chang; Gao, Jinping; Chua, Kao-Wei; Wang, Hong; Hamdy, Ronald C.; Chua, Balvin H.L.

    2008-01-01

    Humanin (HN) is an anti-apoptotic peptide that suppresses neuronal cell death induced by Alzheimer's disease, prion protein fragments, and serum deprivation. Recently, we demonstrated that Gly14-HN (HNG), a variant of HN in which the 14th amino acid serine is replaced with glycine, can decrease apoptotic neuronal death and reduce infarct volume in a focal cerebral ischemia/reperfusion mouse model. In this study, we postulate that the mechanism of HNG's neuroprotective effect is mediated by the PI3K/Akt pathway. Oxygen-glucose deprivation (OGD) was performed in cultured mouse primary cortical neurons for 60 min. The effect of HNG and PI3K/Akt inhibitors on OGD-induced cell death was examined at 24 h after reperfusion. HNG increased cell viability after OGD in primary cortical neurons, whereas the PI3K/Akt inhibitors wortmannin and Akti-1/2 attenuated the protective effect of HNG. HNG rapidly increased Akt phosphorylation, an effect that was inhibited by wortmannin and Akti-1/2. Mouse brains were injected intraventricularly with HNG before being subjected to middle cerebral artery occlusion (MCAO) for 75 min followed by 24 h reperfusion. HNG treatment significantly elevated p-Akt levels after cerebral I/R injury and decreased infarct volume. The protective effect of HNG on infarct size was attenuated by wortmannin and Akti-1/2. Taken as a whole, these results suggest that PI3K/Akt activation mediates HNG's protective effect against hypoxia/ischemia reperfusion injury. PMID:18590709

  8. PME-1 protects extracellular signal-regulated kinase pathway activity from protein phosphatase 2A-mediated inactivation in human malignant glioma.

    Science.gov (United States)

    Puustinen, Pietri; Junttila, Melissa R; Vanhatupa, Sari; Sablina, Anna A; Hector, Melissa E; Teittinen, Kaisa; Raheem, Olayinka; Ketola, Kirsi; Lin, Shujun; Kast, Juergen; Haapasalo, Hannu; Hahn, William C; Westermarck, Jukka

    2009-04-01

    Extracellular signal-regulated kinase (ERK)/mitogen-activated protein kinase pathway activity is regulated by the antagonist function of activating kinases and inactivating protein phosphatases. Sustained ERK pathway activity is commonly observed in human malignancies; however, the mechanisms by which the pathway is protected from phosphatase-mediated inactivation in the tumor tissue remain obscure. Here, we show that methylesterase PME-1-mediated inhibition of the protein phosphatase 2A promotes basal ERK pathway activity and is required for efficient growth factor response. Mechanistically, PME-1 is shown to support ERK pathway signaling upstream of Raf, but downstream of growth factor receptors and protein kinase C. In malignant gliomas, PME-1 expression levels correlate with both ERK activity and cell proliferation in vivo. Moreover, PME-1 expression significantly correlates with disease progression in human astrocytic gliomas (n=222). Together, these observations identify PME-1 expression as one mechanism by which ERK pathway activity is maintained in cancer cells and suggest an important functional role for PME-1 in the disease progression of human astrocytic gliomas.

  9. Signal transduction pathway mediated by the novel regulator LoiA for low oxygen tension induced Salmonella Typhimurium invasion.

    Science.gov (United States)

    Jiang, Lingyan; Feng, Lu; Yang, Bin; Zhang, Wenwen; Wang, Peisheng; Jiang, Xiaohan; Wang, Lei

    2017-06-01

    Salmonella enterica serovar Typhimurium (S. Typhimurium) is a major intestinal pathogen of both humans and animals. Salmonella pathogenicity island 1 (SPI-1)-encoded virulence genes are required for S. Typhimurium invasion. While oxygen (O2) limitation is an important signal for SPI-1 induction under host conditions, how the signal is received and integrated to the central SPI-1 regulatory system in S. Typhimurium is not clear. Here, we report a signal transduction pathway that activates SPI-1 expression in response to low O2. A novel regulator encoded within SPI-14 (STM14_1008), named LoiA (low oxygen induced factor A), directly binds to the promoter and activates transcription of hilD, leading to the activation of hilA (the master activator of SPI-1). Deletion of loiA significantly decreased the transcription of hilA, hilD and other representative SPI-1 genes (sipB, spaO, invH, prgH and invF) under low O2 conditions. The response of LoiA to the low O2 signal is mediated by the ArcB/ArcA two-component system. Deletion of either arcA or arcB significantly decreased transcription of loiA under low O2 conditions. We also confirmed that SPI-14 contributes to S. Typhimurium virulence by affecting invasion, and that loiA is the virulence determinant of SPI-14. Mice infection assays showed that S. Typhimurium virulence was severely attenuated by deletion of either the entire SPI-14 region or the single loiA gene after oral infection, while the virulence was not affected by either deletion after intraperitoneal infection. The signal transduction pathway described represents an important mechanism for S. Typhimurium to sense and respond to low O2 conditions of the host intestinal tract for invasion. SPI-14-encoded loiA is an essential element of this pathway that integrates the low O2 signal into the SPI-1 regulatory system. Acquisition of SPI-14 is therefore crucial for the evolution of S. Typhimurium as an intestinal pathogen.

  10. Signal transduction pathway mediated by the novel regulator LoiA for low oxygen tension induced Salmonella Typhimurium invasion.

    Directory of Open Access Journals (Sweden)

    Lingyan Jiang

    2017-06-01

    Full Text Available Salmonella enterica serovar Typhimurium (S. Typhimurium is a major intestinal pathogen of both humans and animals. Salmonella pathogenicity island 1 (SPI-1-encoded virulence genes are required for S. Typhimurium invasion. While oxygen (O2 limitation is an important signal for SPI-1 induction under host conditions, how the signal is received and integrated to the central SPI-1 regulatory system in S. Typhimurium is not clear. Here, we report a signal transduction pathway that activates SPI-1 expression in response to low O2. A novel regulator encoded within SPI-14 (STM14_1008, named LoiA (low oxygen induced factor A, directly binds to the promoter and activates transcription of hilD, leading to the activation of hilA (the master activator of SPI-1. Deletion of loiA significantly decreased the transcription of hilA, hilD and other representative SPI-1 genes (sipB, spaO, invH, prgH and invF under low O2 conditions. The response of LoiA to the low O2 signal is mediated by the ArcB/ArcA two-component system. Deletion of either arcA or arcB significantly decreased transcription of loiA under low O2 conditions. We also confirmed that SPI-14 contributes to S. Typhimurium virulence by affecting invasion, and that loiA is the virulence determinant of SPI-14. Mice infection assays showed that S. Typhimurium virulence was severely attenuated by deletion of either the entire SPI-14 region or the single loiA gene after oral infection, while the virulence was not affected by either deletion after intraperitoneal infection. The signal transduction pathway described represents an important mechanism for S. Typhimurium to sense and respond to low O2 conditions of the host intestinal tract for invasion. SPI-14-encoded loiA is an essential element of this pathway that integrates the low O2 signal into the SPI-1 regulatory system. Acquisition of SPI-14 is therefore crucial for the evolution of S. Typhimurium as an intestinal pathogen.

  11. Dopamine Receptors Differentially Control Binge Alcohol Drinking-Mediated Synaptic Plasticity of the Core Nucleus Accumbens Direct and Indirect Pathways.

    Science.gov (United States)

    Ji, Xincai; Saha, Sucharita; Kolpakova, Jenya; Guildford, Melissa; Tapper, Andrew R; Martin, Gilles E

    2017-05-31

    Binge alcohol drinking, a behavior characterized by rapid repeated alcohol intake, is most prevalent in young adults and is a risk factor for excessive alcohol consumption and alcohol dependence. Although the alteration of synaptic plasticity is thought to contribute to this behavior, there is currently little evidence that this is the case. We used drinking in the dark (DID) as a model of binge alcohol drinking to assess its effects on spike timing-dependent plasticity (STDP) in medium spiny neurons (MSNs) of the core nucleus accumbens (NAc) by combining patch-clamp recordings with calcium imaging and optogenetics. After 2 weeks of daily alcohol binges, synaptic plasticity was profoundly altered. STDP in MSNs expressing dopamine D1 receptors shifted from spike-timing-dependent long-term depression (tLTD), the predominant form of plasticity in naive male mice, to spike-timing-dependent long-term potentiation (tLTP) in DID mice, an effect that was totally reversed in the presence of 4 μm SCH23390, a dopamine D1 receptor antagonist. In MSNs presumably expressing dopamine D2 receptors, tLTP, the main form of plasticity in naive mice, was inhibited in DID mice. Interestingly, 1 μm sulpiride, a D2 receptor antagonist, restored tLTP. Although we observed no alterations of AMPA and NMDA receptor properties, we found that the AMPA/NMDA ratio increased at cortical and amygdaloid inputs but not at hippocampal inputs. Also, DID effects on STDP were accompanied by lower dendritic calcium transients. These data suggest that the role of dopamine in mediating the effects of binge alcohol drinking on synaptic plasticity of NAc MSNs differs markedly whether these neurons belong to the direct or indirect pathways. SIGNIFICANCE STATEMENT We examined the relationship between binge alcohol drinking and spike timing-dependent plasticity in nucleus accumbens (NAc) neurons. We found that repeated drinking bouts modulate differently synaptic plasticity in medium spiny neurons of the

  12. Light-mediated Reversible Modulation of the Mitogen-activated Protein Kinase Pathway during Cell Differentiation and Xenopus Embryonic Development.

    Science.gov (United States)

    Krishnamurthy, Vishnu V; Turgeon, Aurora J; Khamo, John S; Mondal, Payel; Sharum, Savanna R; Mei, Wenyan; Yang, Jing; Zhang, Kai

    2017-06-15

    Kinase activity is crucial for a plethora of cellular functions, including cell proliferation, differentiation, migration, and apoptosis. During early embryonic development, kinase activity is highly dynamic and widespread across the embryo. Pharmacological and genetic approaches are commonly used to probe kinase activities. Unfortunately, it is challenging to achieve superior spatial and temporal resolution using these strategies. Furthermore, it is not feasible to control the kinase activity in a reversible fashion in live cells and multicellular organisms. Such a limitation remains a bottleneck for achieving a quantitative understanding of kinase activity during development and differentiation. This work presents an optogenetic strategy that takes advantage of a bicistronic system containing photoactivatable proteins Arabidopsis thaliana cryptochrome 2 (CRY2) and the N-terminal domain of cryptochrome-interacting basic-helix-loop-helix (CIBN). Reversible activation of the mitogen-activated protein kinase (MAPK) signaling pathway is achieved through light-mediated protein translocation in live cells. This approach can be applied to mammalian cell cultures and live vertebrate embryos. This bicistronic system can be generalized to control the activity of other kinases with similar activation mechanisms and can be applied to other model systems.

  13. TNF-α- mediated-p38-dependent signaling pathway contributes to myocyte apoptosis in rats subjected to surgical trauma.

    Science.gov (United States)

    Wu, Huaxing; Wang, Guonian; Li, Shuai; Zhang, Mingyue; Li, Hulun; Wang, Kun

    2015-01-01

    The accumulation of cytokines in the plasma after trauma can induce myocyte apoptosis. We aimed to identify which cytokine(s) present in the plasma responsible for myocyte apoptosis, and delineated the signal transduction mechanism in rats subjected to surgical trauma. Rats were randomized into two groups: control and trauma groups, which was divided into five subgroups: posttraumatic 0, 3, 6, 12, and 24 h subgroups. Cardiomyocytes isolated from traumatized rats were incubated with one of the factors for 12 h (normal plasma; Cytomix; TNF-α; IL-1β; IFN-γ; trauma plasma; anti-TNF-α antibody; SB203580). Myocyte apoptosis, cytokine levels, and MAPKs activation, as the primary experimental outcomes, were measured by TUNEL, flow cytometry, ELISA and Western blot, respectively. Myocyte apoptosis was induced by surgical trauma during the early stage after trauma. Accompanying this change, plasma TNF-α, IL-1β, and IFN-γ levels were elevated in traumatized rats. Incubation of traumatized cardiomyocytes with cytomix or TNF-α alone induced myocyte apoptosis, and increased the activation of p38 and ERK1/2. Myocyte apoptosis and p38 activation were elevated in traumatized cardiomyocytes with trauma plasma, and these increases were partly abolished by anti-TNF-α antibody or SB203580. Our study demonstrated that there exists the TNF-α-mediated-p38-dependent signaling pathway that contributed to posttraumatic myocyte apoptosis of rats undergoing surgical trauma. © 2015 S. Karger AG, Basel.

  14. TNF-α- Mediated-p38-Dependent Signaling Pathway Contributes to Myocyte Apoptosis in Rats Subjected to Surgical Trauma

    Directory of Open Access Journals (Sweden)

    Huaxing Wu

    2015-03-01

    Full Text Available Background: The accumulation of cytokines in the plasma after trauma can induce myocyte apoptosis. We aimed to identify which cytokine(s present in the plasma responsible for myocyte apoptosis, and delineated the signal transduction mechanism in rats subjected to surgical trauma. Methods: Rats were randomized into two groups: control and trauma groups, which was divided into five subgroups: posttraumatic 0, 3, 6, 12, and 24 h subgroups. Cardiomyocytes isolated from traumatized rats were incubated with one of the factors for 12 h (normal plasma; Cytomix; TNF-α; IL-1β; IFN-γ; trauma plasma; anti-TNF-α antibody; SB203580. Myocyte apoptosis, cytokine levels, and MAPKs activation, as the primary experimental outcomes, were measured by TUNEL, flow cytometry, ELISA and Western blot, respectively. Results: Myocyte apoptosis was induced by surgical trauma during the early stage after trauma. Accompanying this change, plasma TNF-α, IL-1β, and IFN-γ levels were elevated in traumatized rats. Incubation of traumatized cardiomyocytes with cytomix or TNF-α alone induced myocyte apoptosis, and increased the activation of p38 and ERK1/2. Myocyte apoptosis and p38 activation were elevated in traumatized cardiomyocytes with trauma plasma, and these increases were partly abolished by anti-TNF-α antibody or SB203580. Conclusion: Our study demonstrated that there exists the TNF-α-mediated-p38-dependent signaling pathway that contributed to posttraumatic myocyte apoptosis of rats undergoing surgical trauma.

  15. Nickel (II)-induced cytotoxicity and apoptosis in human proximal tubule cells through a ROS- and mitochondria-mediated pathway

    International Nuclear Information System (INIS)

    Wang, Yi-Fen; Shyu, Huey-Wen; Chang, Yi-Chuang; Tseng, Wei-Chang; Huang, Yeou-Lih; Lin, Kuan-Hua; Chou, Miao-Chen; Liu, Heng-Ling; Chen, Chang-Yu

    2012-01-01

    Nickel compounds are known to be toxic and carcinogenic in kidney and lung. In this present study, we investigated the roles of reactive oxygen species (ROS) and mitochondria in nickel (II) acetate-induced cytotoxicity and apoptosis in the HK-2 human renal cell line. The results showed that the cytotoxic effects of nickel (II) involved significant cell death and DNA damage. Nickel (II) increased the generation of ROS and induced a noticeable reduction of mitochondrial membrane potential (MMP). Analysis of the sub-G1 phase showed a significant increase in apoptosis in HK-2 cells after nickel (II) treatment. Pretreatment with N-acetylcysteine (NAC) not only inhibited nickel (II)-induced cell death and DNA damage, but also significantly prevented nickel (II)-induced loss of MMP and apoptosis. Cell apoptosis triggered by nickel (II) was characterized by the reduced protein expression of Bcl-2 and Bcl-xL and the induced the protein expression of Bad, Bcl-Xs, Bax, cytochrome c and caspases 9, 3 and 6. The regulation of the expression of Bcl-2-family proteins, the release of cytochrome c and the activation of caspases 9, 3 and 6 were inhibited in the presence of NAC. These results suggest that nickel (II) induces cytotoxicity and apoptosis in HK-2 cells via ROS generation and that the mitochondria-mediated apoptotic signaling pathway may be involved in the positive regulation of nickel (II)-induced renal cytotoxicity.

  16. Nickel (II)-induced cytotoxicity and apoptosis in human proximal tubule cells through a ROS- and mitochondria-mediated pathway

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yi-Fen; Shyu, Huey-Wen [Department of Medical Laboratory Sciences and Biotechnology, Fooyin University, Kaohsiung, Taiwan (China); Chang, Yi-Chuang [Department of Nursing, Fooyin University, Kaohsiung, Taiwan (China); Tseng, Wei-Chang [Department of Medical Laboratory Sciences and Biotechnology, Fooyin University, Kaohsiung, Taiwan (China); Huang, Yeou-Lih [Department of Medical Laboratory Science and Biotechnology, Kaohsiung Medical University, Kaohsiung, Taiwan (China); Lin, Kuan-Hua; Chou, Miao-Chen; Liu, Heng-Ling [Department of Medical Laboratory Sciences and Biotechnology, Fooyin University, Kaohsiung, Taiwan (China); Chen, Chang-Yu, E-mail: mt037@mail.fy.edu.tw [Department of Medical Laboratory Sciences and Biotechnology, Fooyin University, Kaohsiung, Taiwan (China)

    2012-03-01

    Nickel compounds are known to be toxic and carcinogenic in kidney and lung. In this present study, we investigated the roles of reactive oxygen species (ROS) and mitochondria in nickel (II) acetate-induced cytotoxicity and apoptosis in the HK-2 human renal cell line. The results showed that the cytotoxic effects of nickel (II) involved significant cell death and DNA damage. Nickel (II) increased the generation of ROS and induced a noticeable reduction of mitochondrial membrane potential (MMP). Analysis of the sub-G1 phase showed a significant increase in apoptosis in HK-2 cells after nickel (II) treatment. Pretreatment with N-acetylcysteine (NAC) not only inhibited nickel (II)-induced cell death and DNA damage, but also significantly prevented nickel (II)-induced loss of MMP and apoptosis. Cell apoptosis triggered by nickel (II) was characterized by the reduced protein expression of Bcl-2 and Bcl-xL and the induced the protein expression of Bad, Bcl-Xs, Bax, cytochrome c and caspases 9, 3 and 6. The regulation of the expression of Bcl-2-family proteins, the release of cytochrome c and the activation of caspases 9, 3 and 6 were inhibited in the presence of NAC. These results suggest that nickel (II) induces cytotoxicity and apoptosis in HK-2 cells via ROS generation and that the mitochondria-mediated apoptotic signaling pathway may be involved in the positive regulation of nickel (II)-induced renal cytotoxicity.

  17. Genetics of the DST-mediated mRNA decay pathway using a transgene-based selection.

    Science.gov (United States)

    Lidder, P; Johnson, M A; Sullivan, M L; Thompson, D M; Pérez-Amador, M A; Howard, C J; Green, P J

    2004-08-01

    mRNA sequences that control abundance, localization and translation initiation have been identified, yet the factors that recognize these sequences are largely unknown. In this report, a transgene-based strategy designed to isolate mutants of Arabidopsis thaliana that fail to recognize these sequences is described. In this strategy, a selectable gene and a screenable marker gene are put under the control of the sequence element being analysed and mutants are selected with altered abundance of the corresponding marker RNAs. The selection of mutants deficient in recognition of the DST (downstream) mRNA degradation signal is used as a test-case to illustrate some of the technical aspects that have facilitated success. Using this strategy, we report the isolation of a new mutant, dst3, deficient in the DST-mediated mRNA decay pathway. The targeted genetic strategy described circumvents certain technical limitations of biochemical approaches. Hence, it provides a means to investigate a variety of other mechanisms responsible for post-transcriptional regulation.

  18. Chlorogenic acid attenuates lipopolysaccharide-induced mice mastitis by suppressing TLR4-mediated NF-κB signaling pathway.

    Science.gov (United States)

    Ruifeng, Gao; Yunhe, Fu; Zhengkai, Wei; Ershun, Zhou; Yimeng, Li; Minjun, Yao; Xiaojing, Song; Zhengtao, Yang; Naisheng, Zhang

    2014-04-15

    Chlorogenic acid (CGA), one of the most abundant polyphenols in the diet, has been reported to have potent anti-inflammatory properties. However, the effect of CGA on lipopolysaccharide (LPS)-induced mice mastitis has not been investigated. The purpose of the present study was to elucidate whether CGA could ameliorate the inflammation response in LPS-induced mice mastitis and to clarify the possible mechanism. The mouse model of mastitis was induced by injection of LPS through the duct of mammary gland. CGA was administered intraperitoneally with the dose of 12.5, 25, and 50mg/kg respectively 1h before and 12h after induction of LPS. In this study, the effect of CGA on LPS-induced mice mastitis was assessed through histopathological examination, ELISA assay, and western blot analysis. The results showed that CGA significantly reduced TNF-α, IL-1β, and IL-6 production compared with LPS group. Besides, western blot analysis showed that CGA could inhibit the expression of TLR4 and the phosphorylation of NF-κB and IκB induced by LPS. These results suggested that anti-inflammatory effects of CGA against LPS-induced mastitis may be due to its ability to inhibit TLR4-mediated NF-κB signaling pathway. Therefore, CGA may be a potent therapeutic reagent for the prevention of the immunopathology encountered during Escherichia coli elicited mastitis. Copyright © 2014 Elsevier B.V. All rights reserved.

  19. I prostanoid receptor-mediated inflammatory pathway promotes hepatic gluconeogenesis through activation of PKA and inhibition of AKT.

    Science.gov (United States)

    Yan, Shuai; Zhang, Qianqian; Zhong, Xiaojing; Tang, Juan; Wang, Yuanyang; Yu, Junjie; Zhou, Yi; Zhang, Jian; Guo, Feifan; Liu, Yi; FitzGerald, Garret A; Yu, Ying

    2014-09-01

    Nonsteroidal anti-inflammatory drugs (NSAIDs), including acetylsalicylic acid (ASA), improve glucose metabolism in diabetic subjects, although the underlying mechanisms remain unclear. In this study, we observed dysregulated expression of cyclooxygenase-2, prostacyclin biosynthesis, and the I prostanoid receptor (IP) in the liver's response to diabetic stresses. High doses of ASA reduced hepatic prostaglandin generation and suppressed hepatic gluconeogenesis in mice during fasting, and the hypoglycemic effect of ASA could be restored by IP agonist treatment. IP deficiency inhibited starvation-induced hepatic gluconeogenesis, thus inhibiting the progression of diabetes, whereas hepatic overexpression of IP increased gluconeogenesis. IP deletion depressed cAMP-dependent CREB phosphorylation and elevated AKT phosphorylation by suppressing PI3K-γ/PKC-ζ-mediated TRB3 expression, which subsequently downregulated the gluconeogenic genes for glucose-6-phosphatase (G6Pase) and phosphoenol pyruvate carboxykinase 1 in hepatocytes. We therefore conclude that suppression of IP modulation of hepatic gluconeogenesis through the PKA/CREB and PI3K-γ/PKC-ζ/TRB3/AKT pathways contributes to the effects of NSAIDs in diabetes. © 2014 by the American Diabetes Association. Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered.

  20. Coptisine attenuates obesity-related inflammation through LPS/TLR-4-mediated signaling pathway in Syrian golden hamsters.

    Science.gov (United States)

    Zou, Zong-Yao; Hu, Yin-Ran; Ma, Hang; Wang, Yan-Zhi; He, Kai; Xia, Shuang; Wu, Hao; Xue, Dong-Fang; Li, Xue-Gang; Ye, Xiao-Li

    2015-09-01

    It is known that obesity resulted from consumption of diets high in fat and calories and associated with a chronic low-grade inflammation. Because the fat, sterol and bile acid metabolism of male Syrian golden hamster are more similar to that of human, in the present study, high fat and high cholesterol (HFHC) induced obese hamsters were used to evaluate the anti-inflammation and hypolipidemic role of coptisine. The results showed that body weight, plasma lipid levels of total cholesterol (TC), triglyceride (TG), low density lipoprotein-cholesterol (LDL-c), very low density lipoprotein-cholesterol (VLDL-c), ApoB and pro-inflammatory cytokines including TNF-α, IL-6 and lipopolysaccharide (LPS) were significantly altered in hamsters fed with HFHC diet. A strong correlation was observed between the LPS level in serum and the level of LBP and pro-inflammatory cytokines. Coptisine from the concentrations of 60 to 700 mg/L dose-dependently inhibited Enterobacter cloacae growth, which can easily induce obesity and insulin resistance. The results of endotoxin neutralization assay suggest that coptisine is capable of reducing the LPS content under inflammation status. Real time RT-PCR analyses revealed that coptisine suppressed TLR-4 in visceral fat of hamsters and decreased CD14 expression in livers of hamsters. These encouraging findings make the development of coptisine a good candidate for preventing obesity-related diseases through the LPS/TLR-4-mediated signaling pathway. Copyright © 2015 Elsevier B.V. All rights reserved.

  1. The gender specific mediational pathways between parenting styles, neuroticism, pathological reasons for drinking, and alcohol-related problems in emerging adulthood.

    Science.gov (United States)

    Patock-Peckham, Julie A; Morgan-Lopez, Antonio A

    2009-03-01

    Mediational links between parenting styles, neuroticism, pathological reasons for drinking, alcohol use and alcohol-related problems were tested. A two-group SEM path model with 441 (216 female, 225 male) college students was examined. In general, pathological reasons for drinking mediated the impact of neuroticism on alcohol use and alcohol-related problems. A different pattern of relationships was found for each of the two genders. Perceptions of having an authoritarian father were positively linked to higher levels of neuroticism among males but this pattern was not found among females. For males, neuroticism mediated the impact of having an authoritarian father on pathological reasons for drinking with pathological reasons for drinking mediating the impact of neuroticism on alcohol-related problems. Perceptions of having a permissive father were linked to lower levels of neuroticism in females (but have been found as a consistent risk factor for other pathways to alcohol use elsewhere). Compared with other work in this area, these findings indicate parental influences regarding vulnerabilities for alcohol use may be specific to parent-child gender matches for some pathways and specific to one parent (irrespective of child gender) for other pathways.

  2. Digital gene expression analysis of male and female bud transition in Metasequoia reveals high activity of MADS-box transcription factors and hormone-mediated sugar pathways

    Directory of Open Access Journals (Sweden)

    Ying eZhao

    2015-06-01

    Full Text Available Metasequoiaglyptostroboidies is a famous redwood tree of ecological and economic importance, and requires more than 20 years of juvenile-to-adult transition before producing female and male cones. Previously, we induced reproductive buds using a hormone solution in juvenile Metasequoia trees as young as5-to-7years old. In the current study, hormone-treated shoots found in female and male buds were used to identify candidate genes involved in reproductive bud transition in Metasequoia. Samples from hormone-treated cone reproductive shoots and naturally occurring non-cone setting shoots were analyzed using 24 digital gene expression (DGE tag profiles using Illumina, generating a total of 69,520 putative transcripts. Next, 32 differentially and specifically expressed transcripts were determined using quantitative real-time polymerase chain reaction, including the upregulation of MADS-box transcription factors involved in male bud transition and flowering time control proteins involved in female bud transition. These differentially expressed transcripts were associated with 243 KEGG pathways. Among the significantly changed pathways, sugar pathways were mediated by hormone signals during the vegetative-to-reproductive phase transition, including glycolysis/gluconeogenesis and sucrose and starch metabolism pathways. Key enzymes were identified in these pathways, including alcohol dehydrogenase (NAD and glutathione dehydrogenase for the glycolysis/gluconeogenesis pathway, and glucanphosphorylase for sucrose and starch metabolism pathways. Our results increase our understanding of the reproductive bud transition in gymnosperms. In addition, these studies on hormone-mediated sugar pathways increase our understanding of the relationship between sugar and hormone signaling during female and male bud initiation in Metasequoia.

  3. Adenosine A2A receptor-dependent proliferation of pulmonary endothelial cells is mediated through calcium mobilization, PI3-kinase and ERK1/2 pathways

    International Nuclear Information System (INIS)

    Ahmad, Aftab; Schaack, Jerome B.; White, Carl W.; Ahmad, Shama

    2013-01-01

    Highlights: •A 2A receptor-induced pulmonary endothelial growth is mediated by PI3K and ERK1/2. •Cytosolic calcium mobilization is also critical for pulmonary endothelial growth. •Effectors of A 2A receptor, like tyrosine kinases and cAMP increase PI3K/Akt signaling. •Activation of A 2A receptor can contribute to vascular remodeling. -- Abstract: Hypoxia and HIF-2α-dependent A 2A receptor expression and activation increase proliferation of human lung microvascular endothelial cells (HLMVECs). This study was undertaken to investigate the signaling mechanisms that mediate the proliferative effects of A 2A receptor. A 2A receptor-mediated proliferation of HLMVECs was inhibited by intracellular calcium chelation, and by specific inhibitors of ERK1/2 and PI3-kinase (PI3K). The adenosine A 2A receptor agonist CGS21680 caused intracellular calcium mobilization in controls and, to a greater extent, in A 2A receptor-overexpressing HLMVECs. Adenoviral-mediated A 2A receptor overexpression as well as receptor activation by CGS21680 caused increased PI3K activity and Akt phosphorylation. Cells overexpressing A 2A receptor also manifested enhanced ERK1/2 phosphorylation upon CGS21680 treatment. A 2A receptor activation also caused enhanced cAMP production. Likewise, treatment with 8Br-cAMP increased PI3K activity. Hence A 2A receptor-mediated cAMP production and PI3K and Akt phosphorylation are potential mediators of the A 2A -mediated proliferative response of HLMVECs. Cytosolic calcium mobilization and ERK1/2 phosphorylation are other critical effectors of HLMVEC proliferation and growth. These studies underscore the importance of adenosine A 2A receptor in activation of survival and proliferative pathways in pulmonary endothelial cells that are mediated through PI3K/Akt and ERK1/2 pathways

  4. Inhibition of the Jak-STAT pathway prevents CNTF-mediated survival of axotomized oxytocinergic magnocellular neurons in organotypic cultures of the rat supraoptic nucleus

    Science.gov (United States)

    Askvig, Jason M.; Lo, David Y.; Sudbeck, Adam W.; Behm, Kathryn E.; Leiphon, Laura J.; Watt, John A.

    2012-01-01

    Previous studies have demonstrated that ciliary neurotrophic factor (CNTF) enhances survival and process outgrowth from magnocellular neurons in the paraventricular (PVN) and the supraoptic (SON) nuclei. However, the mechanisms by which CNTF facilitates these processes remain to be determined. Therefore, the aim of this study was to identify the immediate signal transduction events that occur within the rat SON following administration of exogenous rat recombinant CNTF (rrCNTF) and to determine the contribution of those intracellular signaling pathway(s) to neuronal survival and process outgrowth, respectively. Immunohistochemical and Western blot analysis demonstrated that axonal injury and acute unilateral pressure injection of 100 ng/μl of rrCNTF directly over the rat SON resulted in a rapid and transient increase in phosphorylated-STAT3 (pSTAT3) in astrocytes but not neurons in the SON in vivo. Utilizing rat hypothalamic organotypic explant cultures, we then demonstrated that administration of 25 ng/ml rrCNTF for 14 days significantly increased the survival and process outgrowth of OT magnocellular neurons. In addition, pharmacological inhibition of the Jak-STAT pathway via AG490 and cucurbitacin I significantly reduced the survival of OT magnocellular neurons in the SON and PVN; however, the contribution of the Jak-STAT pathway to CNTF-mediated process outgrowth remains to be determined. Together, these data indicate that CNTF-induced survival of OT magnocellular neurons is mediated indirectly through astrocytes via the Jak-STAT signaling pathway. PMID:23123407

  5. Transcriptional mediators Kto and Skd are involved in the regulation of the IMD pathway and anti-Plasmodium defense in Anopheles gambiae.

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    Yang Chen

    Full Text Available The malarial parasite Plasmodium must complete a complex lifecycle in its Anopheles mosquito host, the main vector for Plasmodium. The mosquito resists infection with the human malarial parasite P. falciparum by engaging the NF-κB immune signaling pathway, IMD. Here we show that the conserved transcriptional mediators Kto and Skd are involved in the regulation of the mosquito IMD pathway. RNAi-mediated depletion of Kto and Skd in the Anopheles gambiae cell line L5-3 resulted in a decrease in the transcript abundance of Cec1, which is controlled by the IMD pathway. Silencing the two genes also resulted in an increased susceptibility of the mosquito to bacterial and Plasmodium falciparum infection, but not to infection with the rodent malaria parasite P. berghei. We also showed that Kto and Skd are not transcriptional co-activators of Rel2 or other key factors of the IMD pathway; however, they participate in the regulation of the IMD pathway, which is crucial for the mosquito's defense against P. falciparum.

  6. Size-dependent internalisation of folate-decorated nanoparticles via the pathways of clathrin and caveolae-mediated endocytosis in ARPE-19 cells.

    Science.gov (United States)

    Langston Suen, Wai-Leung; Chau, Ying

    2014-04-01

    We aim to quantify the effect of size and degree of folate loading of folate-decorated polymeric nanoparticles (NPs) on the kinetics of cellular uptake and the selection of endocytic pathways in retinal pigment epithelium (RPE) cells. In this study, methoxy-poly(ethylene glycol)-b-polycaprolactone (mPEG-b-PCL) and folate-functionalized PEG-b-PCL were synthesized for assembling into nanoparticles with sizes ranging from 50 nm to 250 nm. These nanoparticles were internalized into ARPE-19 (human RPE cell line) via receptor-mediated endocytosis. A two-step endocytosis process mathematical model was adopted to quantify binding affinity and uptake kinetics of nanoparticles in RPE cells in uptake and inhibition studies. Nanoparticles with 100% folate loading have highest binding affinity and uptake rate in RPE cells. Maximum uptake rate (Vmax) of nanoparticles increased as the size of particles decreased from 250 nm to 50 nm. Endocytic pathway study was studied by using chlorpromazine and methyl-β-cyclodextran (MβCD), which are clathrin- and caveolae-mediated endocytosis inhibitors, respectively. Both chlorpromazine and MβCD inhibited the uptake of folate-decorated nanoparticles. Inhibition constant (Ki) and maximum uptake rate (Vmax) revealed that 50 nm and 120 nm folate-decorated nanoparticles were found to be internalized via both clathrin- and caveolae-mediated endocytosis. The 250 nm folate-decorated nanoparticles, however, were only internalized via caveolae-mediated pathway. Increased uptake rate of folate-decorated NPs into RPE cells is observed with increasing degree of folate modification. These NPs utilize both clathrin- and caveolae-mediated receptor-mediated endocytosis pathways to enter RPE cells upon size variation. The 50 nm NPs are internalized the fastest, with clathrin-mediated endocytosis as the preferred route. Uptake of 250 nm particles is the slowest and is dominated by caveolae-mediated endocytosis. © 2013 Royal Pharmaceutical

  7. Metformin-mediated growth inhibition involves suppression of the IGF-I receptor signalling pathway in human pancreatic cancer cells

    International Nuclear Information System (INIS)

    Karnevi, Emelie; Said, Katarzyna; Andersson, Roland; Rosendahl, Ann H

    2013-01-01

    Epidemiological studies have shown direct associations between type 2 diabetes and obesity, both conditions associated with hyperglycaemia and hyperinsulinemia, and the risk of pancreatic cancer. Up to 80% of pancreatic cancer patients present with either new-onset type 2 diabetes or impaired glucose tolerance at the time of diagnosis. Recent population studies indicate that the incidence of pancreatic cancer is reduced among diabetics taking metformin. In this study, the effects of exposure of pancreatic cancer cells to high glucose levels on their growth and response to metformin were investigated. The human pancreatic cancer cell lines AsPC-1, BxPC-3, PANC-1 and MIAPaCa-2 were grown in normal (5 mM) or high (25 mM) glucose conditions, with or without metformin. The influence by metformin on proliferation, apoptosis and the AMPK and IGF-IR signalling pathways were evaluated in vitro. Metformin significantly reduced the proliferation of pancreatic cancer cells under normal glucose conditions. Hyperglycaemia however, protected against the metformin-induced growth inhibition. The anti-proliferative actions of metformin were associated with an activation of AMP-activated protein kinase AMPK Thr172 together with an inhibition of the insulin/insulin-like growth factor-I (IGF-I) receptor activation and downstream signalling mediators IRS-1 and phosphorylated Akt. Furthermore, exposure to metformin during normal glucose conditions led to increased apoptosis as measured by poly(ADP-ribose) polymerase (PARP) cleavage. In contrast, exposure to high glucose levels promoted a more robust IGF-I response and Akt activation which correlated to stimulated AMPK Ser485 phosphorylation and impaired AMPK Thr172 phosphorylation, resulting in reduced anti-proliferative and apoptotic effects by metformin. Our results indicate that metformin has direct anti-tumour activities in pancreatic cancer cells involving AMPK Thr172 activation and suppression of the insulin/IGF signalling pathways

  8. Low-level laser therapy regulates microglial function through Src-mediated signaling pathways: implications for neurodegenerative diseases

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    Song Sheng

    2012-09-01

    Full Text Available Abstract Background Activated microglial cells are an important pathological component in brains of patients with neurodegenerative diseases. The purpose of this study was to investigate the effect of He-Ne (632.8 nm, 64.6 mW/cm2 low-level laser therapy (LLLT, a non-damaging physical therapy, on activated microglia, and the subsequent signaling events of LLLT-induced neuroprotective effects and phagocytic responses. Methods To model microglial activation, we treated the microglial BV2 cells with lipopolysaccharide (LPS. For the LLLT-induced neuroprotective study, neuronal cells with activated microglial cells in a Transwell™ cell-culture system were used. For the phagocytosis study, fluorescence-labeled microspheres were added into the treated microglial cells to confirm the role of LLLT. Results Our results showed that LLLT (20 J/cm2 could attenuate toll-like receptor (TLR-mediated proinflammatory responses in microglia, characterized by down-regulation of proinflammatory cytokine expression and nitric oxide (NO production. LLLT-triggered TLR signaling inhibition was achieved by activating tyrosine kinases Src and Syk, which led to MyD88 tyrosine phosphorylation, thus impairing MyD88-dependent proinflammatory signaling cascade. In addition, we found that Src activation could enhance Rac1 activity and F-actin accumulation that typify microglial phagocytic activity. We also found that Src/PI3K/Akt inhibitors prevented LLLT-stimulated Akt (Ser473 and Thr308 phosphorylation and blocked Rac1 activity and actin-based microglial phagocytosis, indicating the activation of Src/PI3K/Akt/Rac1 signaling pathway. Conclusions The present study underlines the importance of Src in suppressing inflammation and enhancing microglial phagocytic function in activated microglia during LLLT stimulation. We have identified a new and important neuroprotective signaling pathway that consists of regulation of microglial phagocytosis and inflammation under LLLT

  9. XBP1-Independent UPR Pathways Suppress C/EBP-β Mediated Chondrocyte Differentiation in ER-Stress Related Skeletal Disease.

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    Trevor L Cameron

    2015-09-01

    Full Text Available Schmid metaphyseal chondrodysplasia (MCDS involves dwarfism and growth plate cartilage hypertrophic zone expansion resulting from dominant mutations in the hypertrophic zone collagen, Col10a1. Mouse models phenocopying MCDS through the expression of an exogenous misfolding protein in the endoplasmic reticulum (ER in hypertrophic chondrocytes have demonstrated the central importance of ER stress in the pathology of MCDS. The resultant unfolded protein response (UPR in affected chondrocytes involved activation of canonical ER stress sensors, IRE1, ATF6, and PERK with the downstream effect of disrupted chondrocyte differentiation. Here, we investigated the role of the highly conserved IRE1/XBP1 pathway in the pathology of MCDS. Mice with a MCDS collagen X p.N617K knock-in mutation (ColXN617K were crossed with mice in which Xbp1 was inactivated specifically in cartilage (Xbp1CartΔEx2, generating the compound mutant, C/X. The severity of dwarfism and hypertrophic zone expansion in C/X did not differ significantly from ColXN617K, revealing surprising redundancy for the IRE1/XBP1 UPR pathway in the pathology of MCDS. Transcriptomic analyses of hypertrophic zone cartilage identified differentially expressed gene cohorts in MCDS that are pathologically relevant (XBP1-independent or pathologically redundant (XBP1-dependent. XBP1-independent gene expression changes included large-scale transcriptional attenuation of genes encoding secreted proteins and disrupted differentiation from proliferative to hypertrophic chondrocytes. Moreover, these changes were consistent with disruption of C/EBP-β, a master regulator of chondrocyte differentiation, by CHOP, a transcription factor downstream of PERK that inhibits C/EBP proteins, and down-regulation of C/EBP-β transcriptional co-factors, GADD45-β and RUNX2. Thus we propose that the pathology of MCDS is underpinned by XBP1 independent UPR-induced dysregulation of C/EBP-β-mediated chondrocyte differentiation

  10. Acetylation mediated by the p300/CBP-associated factor determines cellular energy metabolic pathways in cancer.

    Science.gov (United States)

    Rajendran, Ramkumar; Garva, Richa; Ashour, Hassan; Leung, Travis; Stratford, Ian; Krstic-Demonacos, Marija; Demonacos, Constantinos

    2013-06-01

    Normal cells produce energy either through OXPHOS in the presence of oxygen or glycolysis in its absence. Cancer cells produce energy preferably through glycolysis even in the presence of oxygen, thereby, acquiring survival and proliferative advantages. Oncogenes and tumour suppressors control these metabolic pathways by regulating the expression of their target genes involved in these processes. During hypoxia, HIF-1 favours high glycolytic flux by upregulating glycolytic enzymes. Conversely, p53 inhibits glycolysis and increases OXPHOS expression through TIGAR and SCO2 gene expression, respectively. We hypothesise that the p300/CBP-associated factor (PCAF) as a common co-factor shared between p53 and HIF-1 plays an important role in the regulation of energy production by modulating SCO2 and TIGAR gene expression mediated by these two transcription factors. The possible involvement of HIF-1 in the regulation of SCO2 and TIGAR gene expression was investigated in cells with different p53 status in normoxia- and hypoxia-mimicking conditions. Putative hypoxia response elements (HREs) were identified in the regulatory region of SCO2 and TIGAR gene promoters. Chromatin immunoprecipitation experiments suggested that HIF-1 was recruited to the putative HREs present in the SCO2 and TIGAR promoters in a cell type-dependent manner. Transcriptional assays endorsed the notion that PCAF may be involved in the determination of the SCO2 and TIGAR cellular levels, thereby, regulating cellular energy metabolism, a view supported by assays measuring lactic acid production and oxygen consumption in cells ectopically expressing PCAF. The present study identified HIF-1 as a potential regulator of SCO2 and TIGAR gene expression. Furthermore, evidence to suggest that PCAF is involved in the regulation of cellular energy production pathways in hypoxia-mimicking conditions is presented. This effect of PCAF is exerted by orchestrating differential recruitment of HIF-1α and p53 to the

  11. L-carnitine reduces doxorubicin-induced apoptosis through a prostacyclin-mediated pathway in neonatal rat cardiomyocytes.

    Science.gov (United States)

    Chao, Hung-Hsin; Liu, Ju-Chi; Hong, Hong-Jye; Lin, Jia-wei; Chen, Cheng-Hsien; Cheng, Tzu-Hurng

    2011-01-21

    Clinical use of doxorubicin is greatly limited by its severe cardiotoxic side effects. L-carnitine is a vitamin-like substance which has been successfully used in many cardiomyopathies, however, the intracellular mechanism(s) remain unclear. The objective of this study was set to evaluate the protective effect of L-carnitine on doxorubicin-induced cardiomyocyte apoptosis, and to explore its intracellular mechanism(s). Primary cultured neonatal rat cardiomyocytes were treated with doxorubicin (1 µM) with or without pretreatment with L-carnitine (1-30 mM). Lactate dehydrogenase assay, terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end-labeling staining, and flow cytometry measurement were used to assess cytotoxicity and apoptosis. Fluorescent probes 2',7'-dichlorofluorescein diacetate and chemiluminescence assay of superoxide production were used to detect the production of reactive oxygen species. Western blotting was used to evaluate the quantity of cleaved caspase-3, cytosol cytochrome c, and Bcl-x(L) expression. L-carnitine inhibited doxorubicin-induced reactive oxygen species generation and NADPH oxidase activation, reduced the quantity of cleaved caspase-3 and cytosol cytochrome c, and increased Bcl-x(L) expression, resulting in protecting cardiomyocytes from doxorubicin-induced apoptosis. In addition, L-carnitine was found to increase the prostacyclin (PGI(2)) generation in cardiomyocytes. The siRNA transfection for PGI(2) synthase significantly reduced L-carnitine-induced PGI(2) and L-carnitine's protective effect. Furthermore, blockade the potential PGI(2) receptors, including PGI(2) receptors (IP receptors), and peroxisome proliferator-activated receptors alpha and delta (PPARα and PPARδ), revealed that the siRNA-mediated blockage of PPARα considerably reduced the anti-apoptotic effect of L-carnitine. These findings suggest that L-carnitine protects cardiomyocytes from doxorubicin-induced apoptosis in part through PGI(2

  12. Sildenafil (Viagra® Prevents Cox-1/ TXA2 Pathway-Mediated Vascular Hypercontractility in ApoE-/- Mice

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    Marcos A.S. Leal

    2017-12-01

    Full Text Available Background/Aims: The atherosclerotic apolipoprotein E-deficient (apoE-/- mouse exhibits impaired vasodilation and enhanced vasoconstriction responsiveness. The objectives of this study were: a to determine the relative contribution of cyclooxygenases (Cox-1 and Cox-2, thromboxane A2 (TXA2 and endothelin-1 (ET-1 to enhancing vascular hyperresponsiveness in this model of atherosclerosis and b to investigate the beneficial effects of the phosphodiesterase 5 inhibitor sildenafil on this endothelial dysfunction. Methods: Adult male apoE-/- mice were treated with sildenafil (40 mg/kg/day, for 3 weeks and compared with non-treated ApoE-/- and wild-type mice. The beneficial effects of sildenafil on vascular contractile response to phenylephrine (PE in aortic rings were evaluated before and after incubation with Cox-1 (SC-560 or Cox-2 (NS-398 inhibitors or the TP antagonist SQ-29548, and on contractile responsiveness to ET-1. Results: ApoE-/- mice exhibited enhanced vasoconstriction to PE (Rmax ∼35%, p<0.01, which was prevented by treatment with sildenafil. The enhanced PE-induced contractions were abolished by both Cox-1 inhibition and TP antagonist, but were not modified by Cox-2 inhibition. Aortic rings from ApoE-/- mice also exhibited enhanced contractions to ET-1 (Rmax ∼30%, p<0.01, which were attenuated in sildenafil-treated ApoE-/- mice. In addition, we observed augmented levels of vascular proinflammatory cytokines in ApoE-/- mice, which were partially corrected by treatment with sildenafil (IL-6, IL-10/IL-6 ratio and MCP-1. Conclusion: The present data show that the Cox-1/TXA2 pathway prevails over the Cox-2 isoform in the mediation of vascular hypercontractility observed in apoE-/-mice. The results also show a beneficial effect of sildenafil on this endothelial dysfunction and on the proinflammatory cytokines in atherosclerotic animals, opening new perspectives for the treatment of other endothelium-related cardiovascular abnormalities.

  13. CD44v6 regulates growth of brain tumor stem cells partially through the AKT-mediated pathway.

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    Mayumi Jijiwa

    Full Text Available Identification of stem cell-like brain tumor cells (brain tumor stem-like cells; BTSC has gained substantial attention by scientists and physicians. However, the mechanism of tumor initiation and proliferation is still poorly understood. CD44 is a cell surface protein linked to tumorigenesis in various cancers. In particular, one of its variant isoforms, CD44v6, is associated with several cancer types. To date its expression and function in BTSC is yet to be identified. Here, we demonstrate the presence and function of the variant form 6 of CD44 (CD44v6 in BTSC of a subset of glioblastoma multiforme (GBM. Patients with CD44(high GBM exhibited significantly poorer prognoses. Among various variant forms, CD44v6 was the only isoform that was detected in BTSC and its knockdown inhibited in vitro growth of BTSC from CD44(high GBM but not from CD44(low GBM. In contrast, this siRNA-mediated growth inhibition was not apparent in the matched GBM sample that does not possess stem-like properties. Stimulation with a CD44v6 ligand, osteopontin (OPN, increased expression of phosphorylated AKT in CD44(high GBM, but not in CD44(low GBM. Lastly, in a mouse spontaneous intracranial tumor model, CD44v6 was abundantly expressed by tumor precursors, in contrast to no detectable CD44v6 expression in normal neural precursors. Furthermore, overexpression of mouse CD44v6 or OPN, but not its dominant negative form, resulted in enhanced growth of the mouse tumor stem-like cells in vitro. Collectively, these data indicate that a subset of GBM expresses high CD44 in BTSC, and its growth may depend on CD44v6/AKT pathway.

  14. Cold Exposure Induces Proliferation of Mature Brown Adipocyte in a ß3-Adrenergic Receptor-Mediated Pathway.

    Science.gov (United States)

    Fukano, Keigo; Okamatsu-Ogura, Yuko; Tsubota, Ayumi; Nio-Kobayashi, Junko; Kimura, Kazuhiro

    2016-01-01

    Hyperplasia of brown adipose tissue (BAT) is a fundamental mechanism for adaptation to survive in the cold environment in rodents. To determine which cell types comprising BAT contribute to tissue hyperplasia, immunohistochemical analysis using a proliferative marker Ki67 was performed on the BAT from 6-week-old C57BL/6J mice housed at 23°C (control) or 10°C (cold) for 5 days. Interestingly, in the control group, the cell proliferative marker Ki67 was detected in the nuclei of uncoupling protein 1-positive mature brown adipocytes (7.2% ± 0.4% of brown adipocyte), as well as in the non-adipocyte stromal-vascular (SV) cells (19.6% ± 2.3% of SV cells), which include preadiopocytes. The percentage of Ki67-positive brown adipocytes increased to 25.6% ± 1.8% at Day 1 after cold exposure and was significantly higher than the non-cold acclimated control until Day 5 (21.8% ± 1.7%). On the other hand, the percentage of Ki67-positive SV cells gradually increased by a cold exposure and peaked to 42.1% ± 8.3% at Day 5. Injection of a ß3-adrenergic receptor (ß3-AR) agonist for continuous 5 days increased the number of Ki67-positive brown adipocytes even at Day 1 but not that of SV cells. In addition, the ß3-AR antagonist, but not ß1-AR antagonist, attenuated the cold exposure-induced increase in the number of Ki67-positive brown adipocytes. These results suggest that mature brown adipocytes proliferate immediately after cold exposure in a ß3-AR-mediated pathway. Thus, proliferation of mature brown adipocytes as well as preadipocytes in SV cells may contribute to cold exposure-induced BAT hyperplasia.

  15. The effect of noise exposure on insulin sensitivity in mice may be mediated by the JNK/IRS1 pathway.

    Science.gov (United States)

    Liu, Lijie; Fang, Cong; Yang, Jing; Zhang, Hongyu; Huang, Yi; Xuan, Chuanying; Wang, Yongfang; Li, Shengwei; Sha, Jun; Zha, Mingming; Guo, Min

    2018-02-12

    Epidemiological studies have suggested that noise exposure may increase the risk of type 2 diabetes mellitus (T2DM), and experimental studies have demonstrated that noise exposure can induce insulin resistance in rodents. The aim of the present study was to explore noise-induced processes underlying impaired insulin sensitivity in mice. Male ICR mice were randomly divided into four groups: a control group without noise exposure and three noise groups exposed to white noise at a 95-dB sound pressure level for 4 h/day for 1, 10, or 20 days (N1D, N10D, and N20D, respectively). Systemic insulin sensitivity was evaluated at 1 day, 1 week, and 1 month post-noise exposure (1DPN, 1WPN, and 1MPN) via insulin tolerance tests (ITTs). Several insulin-related processes, including the phosphorylation of Akt, IRS1, and JNK in the animals' skeletal muscles, were examined using standard immunoblots. Biomarkers of inflammation (circulating levels of TNF-α and IL-6) and oxidative stress (SOD and CAT activities and MDA levels in skeletal muscles) were measured via chemical analyses. The data obtained in this study showed the following: (1) The impairment of systemic insulin sensitivity was transient in the N1D group but prolonged in the N10D and N20D groups. (2) Noise exposure led to enhanced JNK phosphorylation and IRS1 serine phosphorylation as well as reduced Akt phosphorylation in skeletal muscles in response to exogenous insulin stimulation. (3) Plasma levels of TNF-α and IL-6, CAT activity, and MDA concentrations in skeletal muscles were elevated after 20 days of noise exposure. Impaired insulin sensitivity in noise-exposed mice might be mediated by an enhancement of the JNK/IRS1 pathway. Inflammation and oxidative stress might contribute to insulin resistance after chronic noise exposure.

  16. Activation of the NRF2-ARE signalling pathway by the Lentinula edodes polysaccharose LNT alleviates ROS-mediated cisplatin nephrotoxicity.

    Science.gov (United States)

    Chen, Qian; Peng, Huixia; Dong, Lei; Chen, Lijuan; Ma, Xiaobin; Peng, Yuping; Dai, Shejiao; Liu, Qiang

    2016-07-01

    The nephrotoxicity of cisplatin (cis-DDP) limits its general clinical applications. Lentinan (LNT), a dextran extracted from the mushroom Lentinula edodes, has been shown to have multiple pharmacological activities. The primary objective of the current study was to determine whether and how LNT alleviates cis-DDP- induced cytotoxicity in HK-2 cells and nephrotoxicity in mice. LNT did not interfere with cisplatin's anti-tumour efficacy in vitro and functioned cooperatively with cis-DDP to inhibit activity in HeLa and A549 tumour cells. LNT alleviated the cis-DDP-induced decrease in HK-2 cell viability, caspase-3 activation and cleavage of the DNA repair enzyme PARP, decreased HK-2 cell apoptosis and inhibited reactive oxygen species (ROS) accumulation in HK-2 cells. The inhibitor of ROS (N-acetyl-L-cysteine, NAC) could decreased the apoptosis of HK-2 cell. In addition, LNT significantly prevented cis-DDP-induced kidney injury in vivo. LNT itself could not eliminate ROS levels in vitro. Further studies demonstrated that LNT induced NF-E2 p45-related factor 2 (Nrf2) protein and mRNA expression in a time- and dose-dependent manner. LNT promoted Nrf2 translocation to the nucleus and binding to the antioxidant-response element (ARE) sequence and induced the transcription and translation of heme oxygenase 1 (HO-1), aldo-keto reductases 1C1 and 1C2 (AKR1C), and NADP(H):quinone oxidoreductase 1 (NQO1). Finally, we used hNrf2 siRNA and an Nrf2 agonist (tBHQ) to inhibit or enhance Nrf2 expression. The results demonstrated that the LNT-mediated alleviation of cis-DDP-induced nephrotoxicity was achieved by preventing the accumulation of ROS in a manner that depended on the activation of the Nrf2-ARE signalling pathway. Copyright © 2016 Elsevier B.V. All rights reserved.

  17. Stattic inhibits RANKL-mediated osteoclastogenesis by suppressing activation of STAT3 and NF-κB pathways.

    Science.gov (United States)

    Li, Chang-Hong; Xu, Lin-Lin; Jian, Lei-Lei; Yu, Ruo-Han; Zhao, Jin-Xia; Sun, Lin; Du, Guo-Hong; Liu, Xiang-Yuan

    2018-03-24

    Tofacitinib, a small molecule JAK inhibitor, has been widely used to reduce inflammation and inhibit progression of bone destruction in rheumatoid arthritis. STAT3, a downstream signaling molecule of JAK, plays a key role in the activation of signaling in response to inflammatory cytokines. Thus, targeting STAT3 may be an inspiring strategy for treating osteoclast-related diseases such as rheumatoid arthritis. In this study, we first investigated the effects of Stattic, a STAT3 inhibitor, on receptor activator of NF-κB ligand (RANKL)-mediated osteoclastogenesis. Stattic inhibited osteoclast differentiation and bone resorption in RANKL-induced RAW264.7 cells in a dose-dependent manner. Stattic also suppressed RANKL-induced upregulation of osteoclast-related genes tartrate-resistant acid phosphatase, matrix metalloproteinase 9, cathepsin K, RANK, tumor necrosis factor receptor-associated factor 6, and osteoclast-associated receptor in RAW264.7 cells. Moreover, Stattic exhibited an inhibitory effect on cell proliferation and cell cycle progression at higher dosages. At the molecular level, Stattic inhibited RANKL-induced activation of STAT3 and NF-κB pathways, without significantly affecting MAPK signaling. In addition, Stattic inhibited RANKL-induced expression of osteoclast-related transcription factors c-Fos and NFATc1. Importantly, Stattic also prevented bone loss caused by ovariectomy. Together, our data confirm that Stattic restricts osteoclastogenesis and bone loss by disturbing RANKL-induced STAT3 and NF-κB signaling. Thus, Stattic represents a novel type of osteoclast inhibitor that could be useful for conditions such as osteoporosis and rheumatoid arthritis. Copyright © 2018. Published by Elsevier B.V.

  18. Dissecting Bacterial Cell Wall Entry and Signaling in Eukaryotic Cells: an Actin-Dependent Pathway Parallels Platelet-Activating Factor Receptor-Mediated Endocytosis.

    Science.gov (United States)

    Loh, Lip Nam; Gao, Geli; Tuomanen, Elaine I

    2017-01-03

    The Gram-positive bacterial cell wall (CW) peptidoglycan-teichoic acid complex is released into the host environment during bacterial metabolism or death. It is a highly inflammatory Toll-like receptor 2 (TLR2) ligand, and previous in vivo studies have demonstrated its ability to recapitulate pathological features of pneumonia and meningitis. We report that an actin-dependent pathway is involved in the internalization of the CW by epithelial and endothelial cells, in addition to the previously described platelet-activating factor receptor (PAFr)-dependent uptake pathway. Unlike the PAFr-dependent pathway, which is mediated by clathrin and dynamin and does not lead to signaling, the alternative pathway is sensitive to 5-(N-ethyl-N-isopropyl) amiloride (EIPA) and engenders Rac1, Cdc42, and phosphatidylinositol 3-kinase (PI3K) signaling. Upon internalization by this macropinocytosis-like pathway, CW is trafficked to lysosomes. Intracellular CW trafficking is more complex than previously recognized and suggests multiple points of interaction with and without innate immune signaling. Streptococcus pneumoniae is a major human pathogen infecting the respiratory tract and brain. It is an established model organism for understanding how infection injures the host. During infection or bacterial growth, bacteria shed their cell wall (CW) into the host environment and trigger inflammation. A previous study has shown that CW enters and crosses cell barriers by interacting with a receptor on the surfaces of host cells, termed platelet-activating factor receptor (PAFr). In the present study, by using cells that are depleted of PAFr, we identified a second pathway with features of macropinocytosis, which is a receptor-independent fluid uptake mechanism by cells. Each pathway contributes approximately the same amount of cell wall trafficking, but the PAFr pathway is silent, while the new pathway appears to contribute to the host inflammatory response to CW insult. Copyright © 2017

  19. Mitogen-activated protein kinase signaling pathways promote low-density lipoprotein receptor-related protein 1-mediated internalization of beta-amyloid protein in primary cortical neurons.

    Science.gov (United States)

    Yang, Wei-Na; Ma, Kai-Ge; Qian, Yi-Hua; Zhang, Jian-Shui; Feng, Gai-Feng; Shi, Li-Li; Zhang, Zhi-Chao; Liu, Zhao-Hui

    2015-07-01

    Mounting evidence suggests that the pathological hallmarks of Alzheimer's disease (AD) are caused by the intraneuronal accumulation of beta-amyloid protein (Aβ). Reuptake of extracellular Aβ is believed to contribute significantly to the intraneuronal Aβ pool in the early stages of AD. Published reports have claimed that the low-density lipoprotein receptor-related protein 1 (LRP1) mediates Aβ1-42 uptake and lysosomal trafficking in GT1-7 neuronal cells and mouse embryonic fibroblast non-neuronal cells. However, there is no direct evidence supporting the role of LRP1 in Aβ internalization in primary neurons. Our recent study indicated that p38 MAPK and ERK1/2 signaling pathways are involved in regulating α7 nicotinic acetylcholine receptor (α7nAChR)-mediated Aβ1-42 uptake in SH-SY5Y cells. This study was designed to explore the regulation of MAPK signaling pathways on LRP1-mediated Aβ internalization in neurons. We found that extracellular Aβ1-42 oligomers could be internalized into endosomes/lysosomes and mitochondria in cortical neurons. Aβ1-42 and LRP1 were also found co-localized in neurons during Aβ1-42 internalization, and they could form Aβ1-42-LRP1 complex. Knockdown of LRP1 expression significantly decreased neuronal Aβ1-42 internalization. Finally, we identified that p38 MAPK and ERK1/2 signaling pathways regulated the internalization of Aβ1-42 via LRP1. Therefore, these results demonstrated that LRP1, p38 MAPK and ERK1/2 mediated the internalization of Aβ1-42 in neurons and provided evidence that blockade of LRP1 or inhibitions of MAPK signaling pathways might be a potential approach to lowering brain Aβ levels and served a potential therapeutic target for AD. Copyright © 2015 Elsevier Ltd. All rights reserved.

  20. Stress Signals, Mediated by Membranous Glucocorticoid Receptor, Activate PLC/PKC/GSK-3β/β-catenin Pathway to Inhibit Wound Closure.

    Science.gov (United States)

    Jozic, Ivan; Vukelic, Sasa; Stojadinovic, Olivera; Liang, Liang; Ramirez, Horacio A; Pastar, Irena; Tomic Canic, Marjana

    2017-05-01

    Glucocorticoids (GCs), key mediators of stress signals, are also potent wound healing inhibitors. To understand how stress signals inhibit wound healing, we investigated the role of membranous glucocorticoid receptor (mbGR) by using cell-impermeable BSA-conjugated dexamethasone. We found that mbGR inhibits keratinocyte migration and wound closure by activating a Wnt-like phospholipase (PLC)/ protein kinase C (PKC) signaling cascade. Rapid activation of mbGR/PLC/PKC further leads to activation of known biomarkers of nonhealing found in patients, β-catenin and c-myc. Conversely, a selective inhibitor of PKC, calphostin C, blocks mbGR/PKC pathway, and rescues GC-mediated inhibition of keratinocyte migration in vitro and accelerates wound epithelialization of human wounds ex vivo. This novel signaling mechanism may have a major impact on understanding how stress response via GC signaling regulates homeostasis and its role in development and treatments of skin diseases, including wound healing. To test tissue specificity of this nongenomic signaling mechanism, we tested retinal and bronchial human epithelial cells and fibroblasts. We found that mbGR/PLC/PKC signaling cascade exists in all cell types tested, suggesting a more general role. The discovery of this nongenomic signaling pathway, in which glucocorticoids activate Wnt pathway via mbGR, provides new insights into how stress-mediated signals may activate growth signals in various epithelial and mesenchymal tissues. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  1. Mediating pathways between parental socio-economic position and allostatic load in mid-life: Findings from the 1958 British birth cohort.

    Science.gov (United States)

    Barboza Solís, Cristina; Fantin, Romain; Castagné, Raphaële; Lang, Thierry; Delpierre, Cyrille; Kelly-Irving, Michelle

    2016-09-01

    Understanding how human environments affect our health by "getting under the skin" and penetrating the cells, organs and physiological systems of our bodies is a key tenet in public health research. Here, we examine the idea that early life socioeconomic position (SEP) can be biologically embodied, potentially leading to the production of health inequalities across population groups. Allostatic load (AL), a composite measure of overall physiological wear-and-tear, could allow for a better understanding of the potential biological pathways playing a role in the construction of the social gradient in adult health. We investigate the factors mediating the link between two components of parental SEP, maternal education (ME) and parental occupation (PO), and AL at 44 years. Data was used from 7573 members of the 1958 British birth cohort follow-up to age 44. AL was constructed using 14 biomarkers representing four physiological systems. We assessed the contribution of financial/materialist, psychological/psychosocial, educational, and health behaviors/BMI pathways over the life course, in mediating the associations between ME, PO and AL. ME and PO were mediated by three pathways: educational, material/financial, and health behaviors, for both men and women. A better understanding of embodiment processes leading to disease development may contribute to developing adapted public policies aiming to reduce health inequalities. Copyright © 2016. Published by Elsevier Ltd.

  2. Xylopine Induces Oxidative Stress and Causes G2/M Phase Arrest, Triggering Caspase-Mediated Apoptosis by p53-Independent Pathway in HCT116 Cells

    Directory of Open Access Journals (Sweden)

    Luciano de Souza Santos

    2017-01-01

    Full Text Available Xylopine is an aporphine alkaloid that has cytotoxic activity to cancer cells. In this study, the underlying mechanism of xylopine cytotoxicity was assessed in human colon carcinoma HCT116 cells. Xylopine displayed potent cytotoxicity in different cancer cell lines in monolayer cultures and in a 3D model of cancer multicellular spheroids formed from HCT116 cells. Typical morphology of apoptosis, cell cycle arrest in the G2/M phase, increased internucleosomal DNA fragmentation, loss of the mitochondrial transmembrane potential, and increased phosphatidylserine externalization and caspase-3 activation were observed in xylopine-treated HCT116 cells. Moreover, pretreatment with a caspase-3 inhibitor (Z-DEVD-FMK, but not with a p53 inhibitor (cyclic pifithrin-α, reduced xylopine-induced apoptosis, indicating induction of caspase-mediated apoptosis by the p53-independent pathway. Treatment with xylopine also caused an increase in the production of reactive oxygen/nitrogen species (ROS/RNS, including hydrogen peroxide and nitric oxide, but not superoxide anion, and reduced glutathione levels were decreased in xylopine-treated HCT116 cells. Application of the antioxidant N-acetylcysteine reduced the ROS levels and xylopine-induced apoptosis, indicating activation of ROS-mediated apoptosis pathway. In conclusion, xylopine has potent cytotoxicity to different cancer cell lines and is able to induce oxidative stress and G2/M phase arrest, triggering caspase-mediated apoptosis by the p53-independent pathway in HCT116 cells.

  3. Curcumin inhibits urothelial tumor development by suppressing IGF2 and IGF2-mediated PI3K/AKT/mTOR signaling pathway.

    Science.gov (United States)

    Tian, Binqiang; Zhao, Yingmei; Liang, Tao; Ye, Xuxiao; Li, Zuowei; Yan, Dongliang; Fu, Qiang; Li, Yonghui

    2017-08-01

    We have previously reported that curcumin inhibits urothelial tumor development in a rat bladder carcinogenesis model. In this study, we report that curcumin inhibits urothelial tumor development by suppressing IGF2 and IGF2-mediated PI3K/AKT/mTOR signaling pathway. Curcumin inhibits IGF2 expression at the transcriptional level and decreases the phosphorylation levels of IGF1R and IRS-1 in bladder cancer cells and N-methyl-N-nitrosourea (MNU)-induced urothelial tumor tissue. Ectopic expression of IGF2 and IGF1R, but not IGF1, in bladder cancer cells restored this process, suggesting that IGF2 is a target of curcumin. Moreover, introduction of constitutively active AKT1 abolished the inhibitory effect of curcumin on cell proliferation, migration, and restored the phosphorylation levels of 4E-BP1 and S6K1, suggesting that curcumin functions via suppressing IGF2-mediated AKT/mTOR signaling pathway. In summary, our results reveal that suppressing IGF2 and IGF2-mediated PI3K/AKT/mTOR signaling pathway is one of the mechanisms of action of curcumin. Our findings suggest a new therapeutic strategy against human bladder cancer caused by aberrant activation of IGF2, which are useful for translational application of curcumin.

  4. Prostaglandin E2 and the protein kinase A pathway mediate arachidonic acid induction of c-fos in human prostate cancer cells

    Science.gov (United States)

    Chen, Y.; Hughes-Fulford, M.

    2000-01-01

    Arachidonic acid (AA) is the precursor for prostaglandin E2 (PGE2) synthesis and increases growth of prostate cancer cells. To further elucidate the mechanisms involved in AA-induced prostate cell growth, induction of c-fos expression by AA was investigated in a human prostate cancer cell line, PC-3. c-fos mRNA was induced shortly after addition of AA, along with a remarkable increase in PGE2 production. c-fos expression and PGE2 production induced by AA was blocked by a cyclo-oxygenase inhibitor, flurbiprofen, suggesting that PGE2 mediated c-fos induction. Protein kinase A (PKA) inhibitor H-89 abolished induction of c-fos expression by AA, and partially inhibited PGE2 production. Protein kinase C (PKC) inhibitor GF109203X had no significant effect on c-fos expression or PGE2 production. Expression of prostaglandin (EP) receptors, which mediate signal transduction from PGE2 to the cells, was examined by reverse transcription polymerase chain reaction in several human prostate cell lines. EP4 and EP2, which are coupled to the PKA signalling pathway, were expressed in all cells tested. Expression of EP1, which activates the PKC pathway, was not detected. The current study showed that induction of the immediate early gene c-fos by AA is mediated by PGE2, which activates the PKA pathway via the EP2/4 receptor in the PC-3 cells.

  5. Androgen receptor-mediated regulation of the anti-atherogenic enzyme CYP27A1 involves the JNK/c-jun pathway.

    Science.gov (United States)

    Norlin, Maria; Pettersson, Hanna; Tang, Wanjin; Wikvall, Kjell

    2011-02-15

    CYP27A1, an enzyme with several important roles in cholesterol homeostasis and vitamin D₃ metabolism, has been ascribed anti-atherogenic properties. This study addresses an important problem regarding how this enzyme, involved in cholesterol metabolism in the liver and peripheral tissues, is regulated. Our results identify the human CYP27A1 gene as a new target for the JNK/c-jun pathway. Initial experiments showed that an inhibitor of c-Jun N-terminal kinase (JNK) downregulated basal CYP27A1 promoter activity whereas overexpression of JNK slightly enhanced promoter activity. Androgen receptor (AR)-mediated upregulation of mRNA levels and endogenous enzyme activity was recently reported. In the present study, the AR antagonist nilutamide blocked the androgen induction of CYP27A1. The present data revealed that inhibition of the JNK/c-jun pathway abolishes the AR-mediated effect on CYP27A1 transcription and enzyme activity, whereas overexpression of JNK markedly increased androgenic upregulation of CYP27A1. In conclusion, the current results indicate involvement of the JNK/c-jun pathway in AR-mediated upregulation of human CYP27A1. The link to JNK signaling is interesting since inflammatory processes may upregulate CYP27A1 to clear cholesterol from peripheral tissues. Copyright © 2010 Elsevier Inc. All rights reserved.

  6. Comparative Transcriptome Analysis Reveals that a Ubiquitin-Mediated Proteolysis Pathway Is Important for Primary and Secondary Hair Follicle Development in Cashmere Goats.

    Science.gov (United States)

    Ji, Xiao-Yang; Wang, Jian-Xun; Liu, Bin; Zheng, Zhu-Qing; Fu, Shao-Yin; Tarekegn, Getinet Mekuriaw; Bai, Xue; Bai, Yong-Sheng; Li, Heng; Zhang, Wen-Guang

    2016-01-01

    The fleece of cashmere goats contains two distinct populations of fibers, a short and fine non-medullated insulating cashmere fiber and a long and coarse medullated guard hair. The former is produced by secondary follicles (SFs) and the later by primary follicles (PFs). Evidence suggests that the induction of PFs and SFs may require different signaling pathways. The regulation of BMP2/4 signaling by noggin and Edar signaling via Downless genes are essential for the induction of SFs and PFs, respectively. However, these differently expressed genes of the signaling pathway cannot directly distinguish between the PFs and SFs. In this study, we selected RNA samples from 11 PFs and 7 SFs that included 145,525 exons. The pathway analysis of 4512 differentially expressed exons revealed that the most statistically significant metabolic pathway was related to the ubiquitin-mediated proteolysis pathway (UMPP) (Pcashmere goats, a large number of differentially expressed exons were identified using a high-throughput sequencing approach. This study suggests that UMPP activation is a prominent signaling pathway for distinguishing the PFs and SFs of cashmere goats. It is also a meaningful contribution to the theoretical basis of the biological study of the HFs of cashmere goats and other mammals.

  7. FPPS mediates TGF-β1-induced non-small cell lung cancer cell invasion and the EMT process via the RhoA/Rock1 pathway.

    Science.gov (United States)

    Lin, Lin; Li, Ming; Lin, Lei; Xu, Xiaolin; Jiang, Gening; Wu, Liang

    2018-02-05

    Farnesyl pyrophosphate synthase (FPPS), a key enzyme in the mevalonate pathway, was recently shown to play a role in cancer progression. However, its role in non-small cell lung cancer (NSCLC) metastasis and the underlying mechanism remain unclear. In this study, FPPS expression was significantly correlated with TNM stage, and metastasis. Inhibition or knockdown of FPPS blocked TGF-β1-induced cell invasion and epithelial-to-mesenchymal transition (EMT) process. FPPS expression of FPPS was induced by TGF-β1 and FPPS promoted cell invasion and EMT via the RhoA/Rock1 pathway. In conclusion, FPPS mediates TGF-β1-induced lung cancer cell invasion and EMT via the RhoA/Rock1 pathway. These findings suggest new treatment strategies to reduce mortality associated with metastasis in patients with NSCLC. Copyright © 2018 Elsevier Inc. All rights reserved.

  8. Divergent pathways to influence: Cognition and behavior differentially mediate the effects of optimism on physical and mental quality of life in Chinese university students.

    Science.gov (United States)

    Ramsay, Jonathan E; Yang, Fang; Pang, Joyce S; Lai, Ching-Man; Ho, Roger Cm; Mak, Kwok-Kei

    2015-07-01

    Previous research has indicated that both cognitive and behavioral variables mediate the positive effect of optimism on quality of life; yet few attempts have been made to accommodate these constructs into a single explanatory framework. Adopting Fredrickson's broaden-and-build perspective, we examined the relationships between optimism, self-rated health, resilience, exercise, and quality of life in 365 Chinese university students using path analysis. For physical quality of life, a two-stage model, in which the effects of optimism were sequentially mediated by cognitive and behavioral variables, provided the best fit. A one-stage model, with full mediation by cognitive variables, provided the best fit for mental quality of life. This suggests that optimism influences physical and mental quality of life via different pathways. © The Author(s) 2013.

  9. Distinguishing Pathways from Negative Emotions to Suicide Ideation and to Suicide Attempt: the Differential Mediating Effects of Nonsuicidal Self-Injury.

    Science.gov (United States)

    Zhang, Xu; Ren, Yaxuan; You, Jianing; Huang, Chao; Jiang, Yongqiang; Lin, Min-Pei; Leung, Freedom

    2017-11-01

    Negative emotion (NE) is one of the most widely examined risk factors for suicide ideation (SI) and suicide attempt (SA). However, little is known about the possibly different mechanisms underlying the pathways from NE to these two different suicide phenomena. Nonsuicidal self-injury (NSSI) is related to both negative emotions and suicidality. Thus, the present study aimed to test the differential roles of NSSI in the pathways from NE (specified by depression, anxiety, and stress) to SI and from NE to SA. This study hypothesized that NSSI served as a mediator in the relationship from NE to SA, but not in the relationship from NE to SI. We assessed the study variables among 3600 Chinese students (56.6% females, mean age = 14.63 years) for 3times at 6-month intervals. Structural equation modeling was used to test the hypotheses. Results partly supported the hypothesized longitudinal mediation model, such that NSSI fully mediated the relation from NE to SA in females, while partially mediated the relation from NE to SI in both females and males. Findings of this study may help to better understand the distinct mechanisms underlying the relationships from NE to SI and SA. Moreover, our finding regarding gender differences suggests the different emphases in suicide prevention and intervention programs across genders.

  10. Molecular pathway profiling of T lymphocyte signal transduction pathways; Th1 and Th2 genomic fingerprints are defined by TCR and CD28-mediated signaling

    NARCIS (Netherlands)

    Smeets, Ruben L.; Fleuren, Wilco W. M.; He, Xuehui; Vink, Paul M.; Wijnands, Frank; Gorecka, Monika; Klop, Henri; Bauerschmidt, Sussane; Garritsen, Anja; Koenen, Hans J. P. M.; Joosten, Irma; Boots, Annemieke M. H.; Alkema, Wynand

    2012-01-01

    Background: T lymphocytes are orchestrators of adaptive immunity. Naive T cells may differentiate into Th1, Th2, Th17 or iTreg phenotypes, depending on environmental co-stimulatory signals. To identify genes and pathways involved in differentiation of Jurkat T cells towards Th1 and Th2 subtypes we

  11. Molecular pathway profiling of T lymphocyte signal transduction pathways; Th1 and Th2 genomic fingerprints are defined by TCR and CD28-mediated signaling.

    NARCIS (Netherlands)

    Smeets, R.L.; Fleuren, W.W.M.; He, X.; Vink, P.M.; Wijnands, F.; Gorecka, M.; Klop, H.; Bauerschmidt, S.; Garritsen, A.; Koenen, H.J.P.M.; Joosten, I.; Boots, A.M.H.; Alkema, W.

    2012-01-01

    BACKGROUND: T lymphocytes are orchestrators of adaptive immunity. Naive T cells may differentiate into Th1, Th2, Th17 or iTreg phenotypes, depending on environmental co-stimulatory signals. To identify genes and pathways involved in differentiation of Jurkat T cells towards Th1 and Th2 subtypes we

  12. Stat-6 signaling pathway and not Interleukin-1 mediates multi-walled carbon nanotube-induced lung fibrosis in mice: insights from an adverse outcome pathway framework

    DEFF Research Database (Denmark)

    Nikota, Jake; Banville, Allyson; Goodwin, Laura Rose

    2017-01-01

    Background: The accumulation of MWCNTs in the lung environment leads to inflammation and the development of disease similar to pulmonary fibrosis in rodents. Adverse Outcome Pathways (AOPs) are a framework for defining and organizing the key events that comprise the biological changes leading...

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

    Science.gov (United States)

    Marudhupandiyan, Shanmugam; Balamurugan, Krishnaswamy

    2017-06-01

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

  14. Lung epithelial cell-derived extracellular vesicles activate macrophage-mediated inflammatory responses via ROCK1 pathway.

    Science.gov (United States)

    Moon, H-G; Cao, Y; Yang, J; Lee, J H; Choi, H S; Jin, Y

    2015-12-10

    Despite decades of research, the pathogenesis of acute respiratory distress syndrome (ARDS) remains poorly understood, thus impeding the development of effective treatment. Diffuse alveolar damage (DAD) and lung epithelial cell death are prominent features of ARDS. Lung epithelial cells are the first line of defense after inhaled stimuli, such as in the case of hyperoxia. We hypothesized that lung epithelial cells release 'messenger' or signaling molecules to adjacent or distant macrophages, thereby initiating or propagating inflammatory responses after noxious insult. We found that, after hyperoxia, a large amount of extracellular vesicles (EVs) were generated and released into bronchoalveolar lavage fluid (BALF). These hyperoxia-induced EVs were mainly derived from live lung epithelial cells as the result of hyperoxia-associated endoplasmic reticulum (ER) stress. These EVs were remarkably different from epithelial 'apoptotic bodies', as reflected by the significantly smaller size and differentially expressed protein markers. These EVs fall mainly in the size range of the exosomes and smaller microvesicles (MVs) (50-120 nm). The commonly featured protein markers of apoptotic bodies were not found in these EVs. Treating alveolar macrophages with hyperoxia-induced, epithelial cell-derived EVs led to an increased secretion of pro-inflammatory cytokines and macrophage inflammatory protein 2 (MIP-2). Robustly increased macrophage and neutrophil influx was found in the lung tissue of the mice intranasally treated with hyperoxia-induced EVs. It was determined that EV-encapsulated caspase-3 was largely responsible for the alveolar macrophage activation via the ROCK1 pathway. Caspase-3-deficient EVs induced less cytokine/MIP-2 release, reduced cell counts in BALF, less neutrophil infiltration and less inflammation in lung parenchyma, both in vitro and in vivo. Furthermore, the serum circulating EVs were increased and mainly derived from lung epithelial cells after

  15. Cadmium-induced apoptosis in primary rat cerebral cortical neurons culture is mediated by a calcium signaling pathway.

    Directory of Open Access Journals (Sweden)

    Yan Yuan

    Full Text Available Cadmium (Cd is an extremely toxic metal, capable of severely damaging several organs, including the brain. Studies have shown that Cd disrupts intracellular free calcium ([Ca(2+]i homeostasis, leading to apoptosis in a variety of cells including primary murine neurons. Calcium is a ubiquitous intracellular ion which acts as a signaling mediator in numerous cellular processes including cell proliferation, differentiation, and survival/death. However, little is known about the role of calcium signaling in Cd-induced apoptosis in neuronal cells. Thus we investigated the role of calcium signaling in Cd-induced apoptosis in primary rat cerebral cortical neurons. Consistent with known toxic properties of Cd, exposure of cerebral cortical neurons to Cd caused morphological changes indicative of apoptosis and cell death. It also induced elevation of [Ca(2+]i and inhibition of Na(+/K(+-ATPase and Ca(2+/Mg(2+-ATPase activities. This Cd-induced elevation of [Ca(2+]i was suppressed by an IP3R inhibitor, 2-APB, suggesting that ER-regulated Ca(2+ is involved. In addition, we observed elevation of reactive oxygen species (ROS levels, dysfunction of cytochrome oxidase subunits (COX-I/II/III, depletion of mitochondrial membrane potential (ΔΨm, and cleavage of caspase-9, caspase-3 and poly (ADP-ribose polymerase (PARP during Cd exposure. Z-VAD-fmk, a pan caspase inhibitor, partially prevented Cd-induced apoptosis and cell death. Interestingly, apoptosis, cell death and these cellular events induced by Cd were blocked by BAPTA-AM, a specific intracellular Ca(2+ chelator. Furthermore, western blot analysis revealed an up-regulated expression of Bcl-2 and down-regulated expression of Bax. However, these were not blocked by BAPTA-AM. Thus Cd toxicity is in part due to its disruption of intracellular Ca(2+ homeostasis, by compromising ATPases activities and ER-regulated Ca(2+, and this elevation in Ca(2+ triggers the activation of the Ca(2+-mitochondria apoptotic

  16. Fucoidan extract induces apoptosis in MCF-7 cells via a mechanism involving the ROS-dependent JNK activation and mitochondria-mediated pathways.

    Directory of Open Access Journals (Sweden)

    Zhongyuan Zhang

    Full Text Available BACKGROUND: Fucoidan extract (FE, an enzymatically digested compound with a low molecular weight, is extracted from brown seaweed. As a natural compound with various actions, FE is attractive, especially in Asian countries, for improving the therapeutic efficacy and safety of cancer treatment. The present study was carried out to investigate the anti-tumor properties of FE in human carcinoma cells and further examine the underlying mechanisms of its activities. METHODOLOGY/PRINCIPAL FINDING: FE inhibits the growth of MCF-7, MDA-MB-231, HeLa, and HT1080 cells. FE-mediated apoptosis in MCF-7 cancer cells is accompanied by DNA fragmentation, nuclear condensation, and phosphatidylserine exposure. FE induces mitochondrial membrane permeabilization (MMP through loss of mitochondrial membrane potential (ΔΨm and regulation of the expression of Bcl-2 family members. Release of apoptosis-inducing factor (AIF and cytochrome c precedes MMP. AIF release causes DNA fragmentation, the final stage of apoptosis, via a caspase-independent mitochondrial pathway. Additionally, FE was found to induce phosphorylation of c-Jun N-terminal kinase (JNK, p38, and extracellular signal-regulated kinase (ERK 1/2, and apoptosis was found to be attenuated by inhibition of JNK. Furthermore, FE-mediated apoptosis was found to involve the generation of reactive oxygen species (ROS, which are responsible for the decrease of ΔΨm and phosphorylation of JNK, p38, and ERK1/2 kinases. CONCLUSIONS/SIGNIFICANCE: These data suggest that FE activates a caspase-independent apoptotic pathway in MCF-7 cancer cells through activation of ROS-mediated MAP kinases and regulation of the Bcl-2 family protein-mediated mitochondrial pathway. They also provide evidence that FE deserves further investigation as a natural anticancer and cancer preventive agent.

  17. Genomic and transcriptome analyses reveal that MAPK- and phosphatidylinositol-signaling pathways mediate tolerance to 5-hydroxymethyl-2-furaldehyde for industrial yeast Saccharomyces cerevisiae.

    Science.gov (United States)

    Zhou, Qian; Liu, Z Lewis; Ning, Kang; Wang, Anhui; Zeng, Xiaowei; Xu, Jian

    2014-10-09

    The industrial yeast Saccharomyces cerevisiae is a traditional ethanologenic agent and a promising biocatalyst for advanced biofuels production using lignocellulose materials. Here we present the genomic background of type strain NRRL Y-12632 and its transcriptomic response to 5-hydroxymethyl-2-furaldehyde (HMF), a commonly encountered toxic compound liberated from lignocellulosic-biomass pretreatment, in dissecting the genomic mechanisms of yeast tolerance. Compared with the genome of laboratory model strain S288C, we identified more than 32,000 SNPs in Y-12632 with 23,000 missense and nonsense SNPs. Enriched sequence mutations occurred for genes involved in MAPK- and phosphatidylinositol (PI)- signaling pathways in strain Y-12632, with 41 and 13 genes containing non-synonymous SNPs, respectively. Many of these mutated genes displayed consistent up-regulated signature expressions in response to challenges of 30 mM HMF. Analogous single-gene deletion mutations of these genes showed significantly sensitive growth response on a synthetic medium containing 20 mM HMF. Our results suggest at least three MAPK-signaling pathways, especially for the cell-wall integrity pathway, and PI-signaling pathways to be involved in mediation of yeast tolerance against HMF in industrial yeast Saccharomyces cerevisiae. Higher levels of sequence variations were also observed for genes involved in purine and pyrimidine metabolism pathways.

  18. Lactobacillus casei triggers a TLR mediated RACK-1 dependent p38 MAPK pathway in Caenorhabditis elegans to resist Klebsiella pneumoniae infection.

    Science.gov (United States)

    Kamaladevi, Arumugam; Balamurugan, Krishnaswamy

    2016-07-13

    In the present study, the effect of Lactic Acid Bacteria (LAB) was investigated at the molecular level using the model organism Caenorhabditis elegans against Klebsiella pneumoniae. Out of the 13 LAB screened, Lactobacillus casei displayed excellent protective efficacy by prolonging the survival of K. pneumoniae-infected nematodes. Pretreatment with L. casei significantly decreased bacterial colonization and rescued K. pneumoniae-infected C. elegans from various physiological impairments. The concomitant upregulation of key immune genes that regulate the TLR, RACK-1 as well as the p38 MAPK pathway rather than the IIS and ERK pathway suggested that the plausible immunomodulatory mechanism of L. casei could be by triggering the TLR, RACK-1 and p38 MAPK pathway. Furthermore, the hyper-susceptibility of L. casei treated loss-of-function mutants of the tol-1, RACK-1 and p38 MAPK pathway (sek-1 and pmk-1) to K. pneumoniae infection and gene expression analysis suggested that L. casei triggered a TLR mediated RACK-1 dependent p38 MAPK pathway to increase host resistance and protect nematodes against K. pneumoniae infection.

  19. Dissecting Bacterial Cell Wall Entry and Signaling in Eukaryotic Cells: an Actin-Dependent Pathway Parallels Platelet-Activating Factor Receptor-Mediated Endocytosis

    Directory of Open Access Journals (Sweden)

    Lip Nam Loh

    2017-01-01

    Full Text Available The Gram-positive bacterial cell wall (CW peptidoglycan-teichoic acid complex is released into the host environment during bacterial metabolism or death. It is a highly inflammatory Toll-like receptor 2 (TLR2 ligand, and previous in vivo studies have demonstrated its ability to recapitulate pathological features of pneumonia and meningitis. We report that an actin-dependent pathway is involved in the internalization of the CW by epithelial and endothelial cells, in addition to the previously described platelet-activating factor receptor (PAFr-dependent uptake pathway. Unlike the PAFr-dependent pathway, which is mediated by clathrin and dynamin and does not lead to signaling, the alternative pathway is sensitive to 5-(N-ethyl-N-isopropyl amiloride (EIPA and engenders Rac1, Cdc42, and phosphatidylinositol 3-kinase (PI3K signaling. Upon internalization by this macropinocytosis-like pathway, CW is trafficked to lysosomes. Intracellular CW trafficking is more complex than previously recognized and suggests multiple points of interaction with and without innate immune signaling.

  20. DMPD: Macrophage activation through CCR5- and CXCR4-mediated gp120-elicited signalingpathways. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 12960231 Macrophage activation through CCR5- and CXCR4-mediated gp120-elicited sign...82. Epub 2003 Jul 22. (.png) (.svg) (.html) (.csml) Show Macrophage activation through CCR5- and CXCR4-media...ted gp120-elicited signalingpathways. PubmedID 12960231 Title Macrophage activation through CCR

  1. Glucagon-Like Peptide-1 (GLP-1) Receptor Agonist Liraglutide Alters Bone Marrow Exosome-Mediated miRNA Signal Pathways in Ovariectomized Rats with Type 2 Diabetes.

    Science.gov (United States)

    Li, Jin; Fu, Ling-Zhi; Liu, Lu; Xie, Fen; Dai, Ru-Chun

    2017-11-14

    BACKGROUND Compared with normal postmenopausal women, estrogen deficiency and hyperglycemia in postmenopausal women with type 2 diabetes (T2DM) lead to more severe bone property degradation. Liraglutide, a glucagon-like peptide-1 (GLP-1) receptor agonist, has been reported to improve bone condition among people with T2DM but the precise mechanisms remain unclear. Exosomes work as mediators in cell-to-cell communication, delivering functional miRNAs between cells. We aimed to explore the role of exosomes in T2DM-related bone metabolic disorders and the bone protective mechanisms of liraglutide. MATERIAL AND METHODS We made comparative analyses of bone marrow-derived exosomal miRNAs from ovariectomized (OVX) control rats, OVX + T2DM rats, and OVX + T2DM + liraglutide-treated rats. miRNA profiles were generated using high-throughput sequencing. Target gene prediction and pathway analysis were performed to investigate the signal pathway alterations. Three miRNAs were randomly chosen to validate their absolute expression levels by real-time quantitative PCR. RESULTS Bone marrow-derived exosomal miRNAs were different with respect to miRNA numbers, species, and expression levels. miRNA spectra varied under T2DM condition and after liraglutide treatment. By bioinformatics analysis, we found T2DM and liraglutide administration lead to significant changes in exosomal miRNAs which targeted to insulin secretion and insulin-signaling pathway. Wnt signaling pathway alteration was the critical point regarding bone metabolism. CONCLUSIONS Our findings show the selective packaging of functional miRNA cargoes into exosomes due to T2DM and liraglutide treatment. Bone marrow exosome-mediated Wnt signaling pathway alteration may play a part in the bone protective effect of liraglutide.

  2. TNF-α Modulation of Intestinal Tight Junction Permeability Is Mediated by NIK/IKK-α Axis Activation of the Canonical NF-κB Pathway

    Science.gov (United States)

    Al-Sadi, Rana; Guo, Shuhong; Ye, Dongmei; Rawat, Manmeet; Ma, Thomas Y.

    2017-01-01

    Tumor necrosis factor (TNF)-α, a key mediator of intestinal inflammation, causes an increase in intestinal epithelial tight junction (TJ) permeability by activating myosin light chain kinase (MLCK; official name MYLK3) gene. However, the precise signaling cascades that mediate the TNF-α–induced activation of MLCK gene and increase in TJ permeability remain unclear. Our aims were to delineate the upstream signaling mechanisms that regulate the TNF-α modulation of intestinal TJ barrier function with the use of in vitro and in vivo intestinal epithelial model systems. TNF-α caused a rapid activation of both canonical and noncanonical NF-κB pathway. NF-κB–inducing kinase (NIK) and mitogen-activated protein kinase kinase-1 (MEKK-1) were activated in response to TNF-α. NIK mediated the TNF-α activation of inhibitory κB kinase (IKK)-α, and MEKK1 mediated the activation of IKK complex, including IKK-β. NIK/IKK-α axis regulated the activation of both NF-κB p50/p65 and RelB/p52 pathways. Surprisingly, the siRNA induced knockdown of NIK, but not MEKK-1, prevented the TNF-α activation of both NF-κB p50/p65 and RelB/p52 and the increase in intestinal TJ permeability. Moreover, NIK/IKK-α/NF-κB p50/p65 axis mediated the TNF-α–induced MLCK gene activation and the subsequent MLCK increase in intestinal TJ permeability. In conclusion, our data show that NIK/IKK-α/regulates the activation of NF-κB p50/p65 and plays an integral role in the TNF-α–induced activation of MLCK gene and increase in intestinal TJ permeability. PMID:26948423

  3. Maternal high-salt diet altered PKC/MLC20 pathway and increased ANG II receptor-mediated vasoconstriction in adult male rat offspring.

    Science.gov (United States)

    Li, Weisheng; Lv, Juanxiu; Wu, Jue; Zhou, Xiuwen; Jiang, Lin; Zhu, Xiaolin; Tu, Qing; Tang, Jiaqi; Liu, Yanping; He, Axin; Zhong, Yuan; Xu, Zhice

    2016-07-01

    High-salt diet (HSD) is associated with cardiovascular diseases. This study aims at ascertaining the influence of maternal HSD on offspring's angiotensin II (ANG II)-mediated vasoconstriction and the underlying mechanisms. In comparison to a normal-salt diet, HSD used in pregnancy in rats changed the ultrastructures of the coronary artery (CA) in 5-month-old male offspring, and increased ANG II-mediated CA contractility. Measurement of [Ca(2+) ]i in CA using fluorescent fura-2, a Ca(2+) indicator, showed that ANG II-mediated increases in [Ca(2+) ]i were the same between HSD and normal-salt diet groups, but the ratio of diameter change/[Ca(2+) ]i induced by ANG II were significantly higher in HSD groups. Angiotensin II receptor type 1, not angiotensin II receptor type 2, caused ANG II-mediated vasoconstriction. Protein kinase C (PKC) inhibitor GF109203X attenuated the ANG II-mediated vasoconstriction, PKC agonist phorbol12,13-dibutyrate produced a greater contraction. There was an increase in PKCβ mRNA and the corresponding protein abundance in the offspring, whereas other PKC subunits PKCα, PKCδ, and PKCε did not change. Moreover, 20 kDa myosin light chain phosphorylation levels were increased in HSD group. Maternal HSD affected the developmental programing for the offspring CA, with increased ANG II-mediated vasoconstrictions. The angiotensin II receptor type 1-PKC-20 kDa myosin light chain phosphorylation pathway was the possible mediated cellular mechanism. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Pathway Markers for Pro-resolving Lipid Mediators in Maternal and Umbilical Cord Blood: A Secondary Analysis of the Mothers, Omega-3, and Mental Health Study.

    Science.gov (United States)

    Mozurkewich, Ellen L; Greenwood, Matthew; Clinton, Chelsea; Berman, Deborah; Romero, Vivian; Djuric, Zora; Qualls, Clifford; Gronert, Karsten

    2016-01-01

    The omega-3 fatty acids docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) are precursors to immune regulatory and specialized pro-resolving mediators (SPM) of inflammation termed resolvins, maresins, and protectins. Evidence for lipid mediator formation in vivo can be gained through evaluation of their 5-lipoxygenase (LOX) and 15-LOX metabolic pathway precursors and downstream metabolites. We performed a secondary blood sample analysis from 60 participants in the Mothers, Omega-3, and Mental Health study to determine whether SPM and SPM precursors are augmented by dietary EPA- and DHA-rich fish oil supplementation compared to soy oil placebo. We also aimed to study whether SPM and their precursors differ in early and late pregnancy or between maternal and umbilical cord blood. We found that compared to placebo supplementation, EPA- and DHA-rich fish oil supplementation increased SPM precursor 17-hydroxy docosahexaenoic acid (17-HDHA) concentrations in maternal and umbilical cord blood (P = 0.02). We found that the D-series resolvin pathway marker 17-HDHA increased significantly between enrollment and late pregnancy (P = 0.049). Levels of both 14-HDHA, a maresin pathway marker, and 17-HDHA were significantly greater in umbilical cord blood than in maternal blood (P < 0.001, both).

  5. Visfatin is involved in TNFα-mediated insulin resistance via an NAD(+)/Sirt1/PTP1B pathway in 3T3-L1 adipocytes.

    Science.gov (United States)

    Gouranton, Erwan; Romier, Béatrice; Marcotorchino, Julie; Tourniaire, Franck; Astier, Julien; Peiretti, Franck; Landrier, Jean-François

    2014-07-01

    Tumor necrosis factor α (TNFα) is a well-known mediator of inflammation in the context of obesity in adipose tissue. Its action appears to be directly linked to perturbations of the insulin pathway, leading to the development of insulin resistance. Visfatin has been suspected to be linked to insulin sensitivity, but the mechanism involved is still partly unknown. The aim of this study was to evaluate the role of visfatin in the impairment of the insulin pathway by TNFα activity in 3T3-L1 adipocytes and to unveil the mechanisms involved in such impairment. We demonstrated in 3T3-L1 adipocytes that visfatin was involved in TNFα-mediated insulin resistance in adipocytes. Indeed, after TNFα treatment in 3T3-L1 cells, visfatin was downregulated, leading to decreased nicotinamide adenine dinucleotide (NAD(+)) concentrations in cells. This decrease was followed by a decrease in Sirt1 activity, which was linked to an increase in PTP1B expression. The modulation of PTP1B by visfatin was likely responsible for the observed decreases in glucose uptake and Akt phosphorylation in 3T3-L1 adipocytes. Here, we demonstrated a complete pathway involving visfatin, NAD(+), Sirt1, and PTP1B that led to the perturbation of insulin signaling by TNFα in 3T3-L1 adipocytes.

  6. Pathway markers for pro-resolving lipid mediators in maternal and umbilical cord blood: A Secondary analysis of the Mothers, Omega-3, & Mental Health Study

    Directory of Open Access Journals (Sweden)

    Ellen L Mozurkewich

    2016-09-01

    Full Text Available The omega-3 fatty acids docosahexaenoic acid (DHA and eicosapentaenoic acid (EPA are precursors to immune regulatory and specialized pro-resolving mediators (SPM of inflammation termed resolvins, maresins, and protections. Evidence for lipid mediator formation in vivo can be gained through evaluation of their 5-lipoxygenase (LOX and 15-LOX metabolic pathway precursors and downstream metabolites: We performed a secondary blood sample analysis from 60 participants in the Mothers, Omega-3, and Mental Health study to determine whether SPM and SPM precursors are augmented by dietary EPA- and DHA-rich fish oil supplementation compared to soy oil placebo. We also aimed to study whether SPM and their precursors differ in early and late pregnancy or between maternal and umbilical cord blood. We found that compared to placebo supplementation, EPA- and DHA- rich fish oil supplementation increased SPM precursor 17-HDHA concentrations in maternal and umbilical cord blood (P=0.02 We found that the D-series resolvin pathway marker 17-HDHA increased significantly between enrollment and late pregnancy (P=0.049. Levels of both 14-HDHA, a maresin pathway marker, and 17-HDHA were significantly greater in umbilical cord blood than in maternal blood (P<0.001, both.

  7. Schisandra chinensis regulates drug metabolizing enzymes and drug transporters via activation of Nrf2-mediated signaling pathway

    Directory of Open Access Journals (Sweden)

    He JL

    2014-12-01

    increase in the intracellular level of glutathione and total glutathione S-transferase content. SCE significantly elevated the messenger ribonucleic acid and protein levels of P-glycoprotein and multidrug resistance-associated protein 2 and 4, whereas the expression of organic anion transporting peptide 1A2 and 1B1 was significantly downregulated by SCE. Knockdown of Nrf2 by small interfering ribonucleic acid attenuated the regulatory effect of SCE on these DMEs and drug transporters. SCE significantly upregulated Nrf2 and promoted the translocation of Nrf2 from cytoplasm to the nuclei. Additionally, SCE significantly suppressed the expression of cytosolic Kelch-like ECH-associated protein 1 (the repressor of Nrf2 and remarkably increased Nrf2 stability in HepG2 cells. Taken together, our findings suggest that the hepatoprotective effects of SCE may be partially ascribed to the modulation of DMEs and drug transporters via Nrf2-mediated signaling pathway. SCE may alter the pharmacokinetics of other coadministered drugs that are substrates of these DMEs and transporters and thus cause unfavorable herb–drug interactions. Keywords: Nrf2, Keap1, HepG2 cell, drug metabolizing enzyme, drug transporter, P-gp, MRP, OATP, Schisandra chinensis

  8. Early activation of FGF and nodal pathways mediates cardiac specification independently of Wnt/beta-catenin signaling.

    Directory of Open Access Journals (Sweden)

    Lee J Samuel

    2009-10-01

    Full Text Available Cardiac induction, the first step in heart development in vertebrate embryos, is thought to be initiated by anterior endoderm during gastrulation, but what the signals are and how they act is unknown. Several signaling pathways, including FGF, Nodal, BMP and Wnt have been implicated in cardiac specification, in both gain- and loss-of-function experiments. However, as these pathways regulate germ layer formation and patterning, their specific roles in cardiac induction have been difficult to define.To investigate the mechanisms of cardiac induction directly we devised an assay based on conjugates of anterior endoderm from early gastrula stage Xenopus embryos as the inducing tissue and pluripotent ectodermal explants as the responding tissue. We show that the anterior endoderm produces a specific signal, as skeletal muscle is not induced. Cardiac inducing signal needs up to two hours of interaction with the responding tissue to produce an effect. While we found that the BMP pathway was not necessary, our results demonstrate that the FGF and Nodal pathways are essential for cardiogenesis. They were required only during the first hour of cardiogenesis, while sustained activation of ERK was required for at least four hours. Our results also show that transient early activation of the Wnt/beta-catenin pathway has no effect on cardiogenesis, while later activation of the pathway antagonizes cardiac differentiation.We have described an assay for investigating the mechanisms of cardiac induction by anterior endoderm. The assay was used to provide evidence for a direct, early and transient requirement of FGF and Nodal pathways. In addition, we demonstrate that Wnt/beta-catenin pathway plays no direct role in vertebrate cardiac specification, but needs to be suppressed just prior to differentiation.

  9. Comparative Transcriptome Analysis Reveals that a Ubiquitin-Mediated Proteolysis Pathway Is Important for Primary and Secondary Hair Follicle Development in Cashmere Goats.

    Directory of Open Access Journals (Sweden)

    Xiao-Yang Ji

    Full Text Available The fleece of cashmere goats contains two distinct populations of fibers, a short and fine non-medullated insulating cashmere fiber and a long and coarse medullated guard hair. The former is produced by secondary follicles (SFs and the later by primary follicles (PFs. Evidence suggests that the induction of PFs and SFs may require different signaling pathways. The regulation of BMP2/4 signaling by noggin and Edar signaling via Downless genes are essential for the induction of SFs and PFs, respectively. However, these differently expressed genes of the signaling pathway cannot directly distinguish between the PFs and SFs.In this study, we selected RNA samples from 11 PFs and 7 SFs that included 145,525 exons. The pathway analysis of 4512 differentially expressed exons revealed that the most statistically significant metabolic pathway was related to the ubiquitin-mediated proteolysis pathway (UMPP (P<3.32x 10-7. In addition, the 51 exons of the UMPP that were differentially expressed between the different types of hair follicle (HFs were compared by cluster analysis. This resulted in the PFs and SFs being divided into two classes. The expression level of two selected exons was analyzed by qRT-PCR, and the results indicated that the expression patterns were consistent with the deep sequencing results obtained by RNA-Seq.Based on the comparative transcriptome analysis of 18 HFs from cashmere goats, a large number of differentially expressed exons were identified using a high-throughput sequencing approach. This study suggests that UMPP activation is a prominent signaling pathway for distinguishing the PFs and SFs of cashmere goats. It is also a meaningful contribution to the theoretical basis of the biological study of the HFs of cashmere goats and other mammals.

  10. Glucagon-Like Peptide-1 Protects Human Islets against Cytokine-Mediated β-Cell Dysfunction and Death: A Proteomic Study of the Pathways Involved

    DEFF Research Database (Denmark)

    Rondas, Dieter; Bugliani, Marco; D’Hertog, Wannes

    2013-01-01

    of human islets of Langerhans treated with cytokines (IL-1β and IFN-γ) in the presence or absence of GLP-1 by 2D difference gel electrophoresis and subsequent protein interaction network analysis to understand the molecular pathways involved in GLP-1-mediated β-cell protection. Co-incubation of cytokine......-exposed human islets while protecting them against cytokine-mediated cell death and dysfunction. These data illustrate the beneficial effects of GLP-1 on human islets under immune attack, leading to a better understanding of the underlying mechanisms involved, a prerequisite for improving therapies for diabetic......Glucagon-like peptide-1 (GLP-1) has been shown to protect pancreatic β-cells against cytokine-induced dysfunction and destruction. The mechanisms through which GLP-1 exerts its effects are complex and still poorly understood. The aim of this study was to analyze the protein expression profiles...

  11. Chemical genomic-based pathway analyses for epidermal growth factor-mediated signaling in migrating cancer cells.

    Directory of Open Access Journals (Sweden)

    Shigeyuki Magi

    Full Text Available To explore the diversity and consistency of the signaling pathways that regulate tumor cell migration, we chose three human tumor cell lines that migrated after treatment with EGF. We then quantified the effect of fifteen inhibitors on the levels of expression or the phosphorylation levels of nine proteins that were induced by EGF stimulation in each of these cell lines. Based on the data obtained in this study and chemical-biological assumptions, we deduced cell migration pathways in each tumor cell line, and then compared them. As a result, we found that both the MEK/ERK and JNK/c-Jun pathways were activated in all three migrating cell lines. Moreover, GSK-3 and p38 were found to regulate PI3K/Akt pathway in only EC109 cells, and JNK was found to crosstalk with p38 and Fos related pathway in only TT cells. Taken together, our analytical system could easily distinguish between the common and cell type-specific pathways responsible for tumor cell migration.

  12. Parallel neural pathways in higher visual centers of the Drosophila brain that mediate wavelength-specific behavior

    Directory of Open Access Journals (Sweden)

    Hideo eOtsuna

    2014-02-01

    Full Text Available Compared with connections between the retinae and primary visual centers, relatively less is known in both mammals and insects about the functional segregation of neural pathways connecting primary and higher centers of the visual processing cascade. Here, using the Drosophila visual system as a model, we demonstrate two levels of parallel computation in the pathways that connect primary visual centers of the optic lobe to computational circuits embedded within deeper centers in the central brain. We show that a seemingly simple achromatic behavior, namely phototaxis, is under the control of several independent pathways, each of which is responsible for navigation towards unique wavelengths. Silencing just one pathway is enough to disturb phototaxis towards one characteristic monochromatic source, whereas phototactic behavior towards white light is not affected. The response spectrum of each demonstrable pathway is different from that of individual photoreceptors, suggesting subtractive computations. A choice assay between two colors showed that these pathways are responsible for navigation towards, but not for the detection itself of, the monochromatic light. The present study provides novel insights about how visual information is separated and processed in parallel to achieve robust control of an innate behavior.

  13. Escitalopram attenuates β-amyloid-induced tau hyperphosphorylation in primary hippocampal neurons through the 5-HT1A receptor mediated Akt/GSK-3β pathway.

    Science.gov (United States)

    Wang, Yan-Juan; Ren, Qing-Guo; Gong, Wei-Gang; Wu, Di; Tang, Xiang; Li, Xiao-Li; Wu, Fang-Fang; Bai, Feng; Xu, Lin; Zhang, Zhi-Jun

    2016-03-22

    Tau hyperphosphorylation is an important pathological feature of Alzheimer's disease (AD). To investigate whether escitalopram could inhibit amyloid-β (Aβ)-induced tau hyperphosphorylation and the underlying mechanisms, we treated the rat primary hippocampal neurons with Aβ1-42 and examined the effect of escitalopram on tau hyperphosphorylation. Results showed that escitalopram decreased Aβ1-42-induced tau hyperphosphorylation. In addition, escitalopram activated the Akt/GSK-3β pathway, and the PI3K inhibitor LY294002 blocked the attenuation of tau hyperphosphorylation induced by escitalopram. Moreover, the 5-HT1A receptor agonist 8-OH-DPAT also activated the Akt/GSK-3β pathway and decreased Aβ1-42-induced tau hyperphosphorylation. Furthermore, the 5-HT1A receptor antagonist WAY-100635 blocked the activation of Akt/GSK-3β pathway and the attenuation of tau hyperphosphorylation induced by escitalopram. Finally, escitalopram improved Aβ1-42 induced impairment of neurite outgrowth and spine density, and reversed Aβ1-42 induced reduction of synaptic proteins. Our results demonstrated that escitalopram attenuated Aβ1-42-induced tau hyperphosphorylation in primary hippocampal neurons through the 5-HT1A receptor mediated Akt/GSK-3β pathway.

  14. The Regulation of Lipid Deposition by Insulin in Goose Liver Cells Is Mediated by the PI3K-AKT-mTOR Signaling Pathway.

    Directory of Open Access Journals (Sweden)

    Chunchun Han

    Full Text Available We previously showed that the fatty liver formations observed in overfed geese are accompanied by the activation of the PI3K-Akt-mTOR pathway and an increase in plasma insulin concentrations. Recent studies have suggested a crucial role for the PI3K-Akt-mTOR pathway in regulating lipid metabolism; therefore, we hypothesized that insulin affects goose hepatocellular lipid metabolism through the PI3K-Akt-mTOR signaling pathway.Goose primary hepatocytes were isolated and treated with serum-free media supplemented with PI3K-Akt-mTOR pathway inhibitors (LY294002, rapamycin, and NVP-BEZ235, respectively and 50 or 150 nmol/L insulin.Insulin induced strong effects on lipid accumulation as well as the mRNA and protein levels of genes involved in lipogenesis, fatty acid oxidation, and VLDL-TG assembly and secretion in primary goose hepatocytes. The stimulatory effect of insulin on lipogenesis was significantly decreased by treatment with PI3K-Akt-mTOR inhibitors. These inhibitors also rescued the insulin-induced down-regulation of fatty acid oxidation and VLDL-TG assembly and secretion.These findings suggest that the stimulatory effect of insulin on lipid deposition is mediated by PI3K-Akt-mTOR regulation of lipogenesis, fatty acid oxidation, and VLDL-TG assembly and secretion in goose hepatocytes.

  15. Calmodulin Mediates DNA Repair Pathways Involving H2AX in Response to Low-Dose Radiation Exposure of RAW 264.7 Macrophages

    Energy Technology Data Exchange (ETDEWEB)

    Smallwood, Heather S.; Lopez Ferrer, Daniel; Eberlein, P. Elis; Watson, David J.; Squier, Thomas C.

    2009-02-05

    Understanding the molecular mechanisms that modulate macrophage radioresistance is necessary for the development of effective radiation therapies, as tumor-associated macrophages promote both angiogenesis and matrix remodeling that, in turn, enhance metastasis. In this respect, we have identified a dose-dependent increase in the abundance of the calcium regulatory protein calmodulin (CaM) in RAW 264.7 macrophages upon irradiation. CaM overexpression results in increased macrophage survival following radiation exposure, acting to diminish the sensitivity to low-dose exposures. Increases in CaM abundance also result in an increase in the number of phosphorylated histone H2AX protein complexes associated with DNA repair following macrophage irradiation, with no change in the extent of double-stranded DNA damage. In comparison, when NFκB-dependent pathways are inhibited, through the expression of a dominant-negative IκB construct, there is no significant increase in phosphorylated H2AX upon irradiation. These results indicate that the molecular basis for the up-regulation of histone H2AX mediated DNA-repair pathways is not the result of nonspecific NFκB-dependent pathways or a specific threshold of DNA damage. Rather, increases in CaM abundance act to minimize the low-dose hypersensitivity to radiation to enhance macrophage radioresistance through processes that include the upregulation of DNA repair pathways involving histone protein H2AX phosphorylation.

  16. Evidence for a role of Collapsin response mediator protein-2 in signaling pathways that regulate the proliferation of non-neuronal cells

    International Nuclear Information System (INIS)

    Tahimic, Candice Ginn T.; Tomimatsu, Nozomi; Nishigaki, Ryuichi; Fukuhara, Akiko; Toda, Tosifusa; Kaibuchi, Kozo; Shiota, Goshi; Oshimura, Mitsuo; Kurimasa, Akihiro

    2006-01-01

    Collapsin response mediator protein-2 or Crmp-2 plays a critical role in the establishment of neuronal polarity. In this study, we present evidence that apart from its functions in neurodevelopment, Crmp-2 is also involved in pathways that regulate the proliferation of non-neuronal cells through its phosphorylation by regulatory proteins. We show that Crmp-2 undergoes dynamic phosphorylation changes in response to contact inhibition-induced quiescence and that hyperphosphorylation of Crmp-2 occurs in a tumor. We further suggest that de-regulation of Crmp-2 phosphorylation levels at certain amino acid residues may lead to aberrant cell proliferation and consequently, tumorigenesis

  17. ATX and LPA receptor 3 are coordinately up-regulated in lipopolysaccharide-stimulated THP-1 cells through PKR and SPK1-mediated pathways.

    Science.gov (United States)

    Li, Song; Xiong, Chaoyang; Zhang, Junjie

    2012-03-23

    Lysophosphatidic acid (LPA) is an important phospholipid mediator in inflammation and immunity. Previously, we showed that autotaxin (ATX), the enzyme producing LPA from lysophosphatidylcholine (LPC), is induced by LPS in THP-1 cells via the activation of PKR, JNK and p38 MAPK. In this study, we find that ATX and LPA receptor 3 (LPA(3)) are coordinately up-regulated in LPS-stimulated THP-1 cells. PKR-mediated activation of JNK1 and p38 MAPK is required for both ATX and LPA(3) up-regulation. SPK1-mediated activation of the PI3K-AKT-β-catenin pathway is essential for ATX induction, while SPK1-mediated ERK activation is required for LPA(3) up-regulation. Either ATX or LPA(3) knockdown inhibited CCL8 induction by LPS, suggesting that ATX and LPA(3) are involved in CCL8 induction during the inflammatory process against bacterial infection. Copyright © 2012 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.

  18. Blocking RhoA/ROCK inhibits the pathogenesis of pemphigus vulgaris by suppressing oxidative stress and apoptosis through TAK1/NOD2-mediated NF-κB pathway.

    Science.gov (United States)

    Liang, Junqin; Zeng, Xuewen; Halifu, Yilinuer; Chen, Wenjing; Hu, Fengxia; Wang, Peng; Zhang, Huan; Kang, Xiaojing

    2017-12-01

    Oxidative stress and apoptosis play critical roles in pemphigus vulgaris (PV). The main aim of the present study was to investigate the effects of RhoA/ROCK signaling on UVB-induced oxidative damage, and to delineate the molecular mechanisms involved in the UVB-mediated inflammatory and apoptotic response. In HaCaT cells, we observed that blockage of RhoA/ROCK signaling with the inhibitor CT04 or Y27632 greatly inhibited the UVB-mediated increase in intracellular reactive oxygen species (ROS). Additionally, inhibition of RhoA/ROCK signaling reduced UVB-induced apoptosis, as exemplified by a reduction in DNA fragmentation, and also elevated anti-apoptotic Bcl-2 protein, concomitant with reduced levels of pro-apoptotic protein Bax, caspase-3 cleavage and decreased PARP-1 protein. The release of inflammatory mediators TNF-α, IL-1β, and IL-6 was also attenuated. Mechanically, we observed that blockage of RhoA/ROCK repressed the TAK1/NOD2-mediated NF-κB pathway in HaCaT cells exposed to UVB. Taken together, these data reveal that RhoA/ROCK signaling is one of the regulators contributing to oxidative damage and apoptosis in human keratinocytes, suggesting that RhoA/ROCK signaling has strong potential to be used as a useful therapeutic target in skin diseases including PV.

  19. Nuclear export of cutaneous HPV8 E7 oncoprotein is mediated by a leucine-rich nuclear export signal via a CRM1 pathway

    International Nuclear Information System (INIS)

    Onder, Zeynep; Chang, Vivian; Moroianu, Junona

    2015-01-01

    We recently determined that the nuclear import of cutaneous beta genus HPV8 E7 oncoprotein it is mediated by its zinc-binding domain via direct hydrophobic interactions with the FG nucleoporins Nup62 and Nup153 (Onder and Moroianu, 2014). Here we investigated the nuclear export of HPV8 E7 oncoprotein using confocal microscopy after transfections of HeLa cells with EGFP–8cE7 and mutant plasmids and treatment with Ratjadone A nuclear export inhibitor. We determined that HPV8 E7 contains a leucine-rich nuclear export signal (NES), 76 IRTFQELLF 84 , within its zinc-binding domain that mediates its nuclear export via a CRM1 pathway. We found that HPV8 E7 interacts with CRM1 and that the hydrophobic amino acid residues I76, F79 and L82 of the NES are essential for this interaction and for nuclear export of HPV8 E7 oncoprotein. - Highlights: • HPV8 E7 has a leucine-rich NES within its zinc-binding domain that mediates its nuclear export. • CRM1 nuclear export receptor interacts with HPV8 E7 and mediates its export. • Identification of the critical hydrophobic amino acids of the NES of HPV8 E7

  20. A Longitudinal Study of Depressive Symptoms, Neuropsychological Functioning, and Medical Responsibility in Youth With Spina Bifida: Examining Direct and Mediating Pathways.

    Science.gov (United States)

    Stern, Alexa; Driscoll, Colleen F Bechtel; Ohanian, Diana; Holmbeck, Grayson N

    2018-02-10

    Given the increased risk for cognitive deficits and development of depressive symptoms in youth with spina bifida (SB), this study aimed to examine two pathways through which depressive symptoms and neuropsychological dysfunction may be associated with medical autonomy in this population: (1) depressive symptoms as predictors of medical autonomy as mediated by attention/executive functioning (the cognitive scarring model), and (2) attention/executive functioning as predictors of medical autonomy as mediated by depressive symptoms (the cognitive vulnerability model). Participants were recruited as part of a larger, longitudinal study, and included 114 youth with SB (M age = 10.96 at Time 1), their parents, and teachers. Neuropsychological constructs included attention, working memory, and planning/organizing abilities, which were measured with questionnaire and performance-based data. Depressive symptoms and medical responsibility were assessed via questionnaires from multiple respondents. Bootstrapped mediation analyses revealed that teacher-reported depressive symptoms significantly mediated the relations between neuropsychological functioning (i.e., attention and working memory) and medical responsibility (all p's responsibility. One way in which neurocognitive dysfunction may hinder the development of medical autonomy in youth with SB is through an increased risk for depressive symptoms. © The Author(s) 2018. Published by Oxford University Press on behalf of the Society of Pediatric Psychology. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com

  1. Nuclear export of cutaneous HPV8 E7 oncoprotein is mediated by a leucine-rich nuclear export signal via a CRM1 pathway

    Energy Technology Data Exchange (ETDEWEB)

    Onder, Zeynep; Chang, Vivian; Moroianu, Junona, E-mail: moroianu@bc.edu

    2015-01-01

    We recently determined that the nuclear import of cutaneous beta genus HPV8 E7 oncoprotein it is mediated by its zinc-binding domain via direct hydrophobic interactions with the FG nucleoporins Nup62 and Nup153 (Onder and Moroianu, 2014). Here we investigated the nuclear export of HPV8 E7 oncoprotein using confocal microscopy after transfections of HeLa cells with EGFP–8cE7 and mutant plasmids and treatment with Ratjadone A nuclear export inhibitor. We determined that HPV8 E7 contains a leucine-rich nuclear export signal (NES), {sub 76}IRTFQELLF{sub 84}, within its zinc-binding domain that mediates its nuclear export via a CRM1 pathway. We found that HPV8 E7 interacts with CRM1 and that the hydrophobic amino acid residues I76, F79 and L82 of the NES are essential for this interaction and for nuclear export of HPV8 E7 oncoprotein. - Highlights: • HPV8 E7 has a leucine-rich NES within its zinc-binding domain that mediates its nuclear export. • CRM1 nuclear export receptor interacts with HPV8 E7 and mediates its export. • Identification of the critical hydrophobic amino acids of the NES of HPV8 E7.

  2. A Fever in Acute Aortic Dissection is Caused by Endogenous Mediators that Influence the Extrinsic Coagulation Pathway and Do Not Elevate Procalcitonin.

    Science.gov (United States)

    Inoue Arita, Yoshie; Akutsu, Koichi; Yamamoto, Takeshi; Kawanaka, Hidekazu; Kitamura, Mitsunobu; Murata, Hiroshige; Miyachi, Hideki; Hosokawa, Yusuke; Tanaka, Keiji; Shimizu, Wataru

    2016-01-01

    Objective A fever is observed in approximately one-third of cases of acute aortic dissection (AAD); however, the causes remain unclear. We investigated the mechanism of a fever in AAD by measuring the serum concentrations of inflammatory markers, mediators of coagulation and fibrinolysis, and procalcitonin, a marker of bacterial infection. Methods We retrospectively studied 43 patients with medically treated AAD without apparent infection. Patients were divided into those with (Group A; n=19) and without (Group B; n=24) a maximum body temperature >38°C. We established which patients fulfilled the criteria for systemic inflammatory response syndrome (SIRS), and its relationship with a fever was examined. Mediators of inflammation, coagulation and fibrinolysis were compared by a univariate analysis. Factors independently associated with a fever were established by a multivariate analysis. Results The criteria for SIRS were fulfilled in a greater proportion of patients in Group A (79%) than in Group B (42%, p=0.001). There was no difference in the procalcitonin concentration between Groups A and B (0.15±0.17 ng/mL vs. 0.11±0.12 ng/mL, respectively; p=0.572). Serum procalcitonin concentrations lay within the normal range in all patients in whom it was measured, which showed that the fever was caused by endogenous mediators. On the multivariate analysis, there was a borderline significant relationship between a fever and the prothrombin time-International Normalized Ratio (p=0.065), likely reflecting the extrinsic pathway activity initiated by tissue factor. Conclusion Our findings suggest that a fever in AAD could be caused by SIRS, provoked by endogenous mediators that influence the extrinsic coagulation pathway without elevating the serum procalcitonin concentration.

  3. Bacillus thuringiensis Crystal Protein Cry6Aa Triggers Caenorhabditis elegans Necrosis Pathway Mediated by Aspartic Protease (ASP-1.

    Directory of Open Access Journals (Sweden)

    Fengjuan Zhang

    2016-01-01

    Full Text Available Cell death plays an important role in host-pathogen interactions. Crystal proteins (toxins are essential components of Bacillus thuringiensis (Bt biological pesticides because of their specific toxicity against insects and nematodes. However, the mode of action by which crystal toxins to induce cell death is not completely understood. Here we show that crystal toxin triggers cell death by necrosis signaling pathway using crystal toxin Cry6Aa-Caenorhabditis elegans toxin-host interaction system, which involves an increase in concentrations of cytoplasmic calcium, lysosomal lyses, uptake of propidium iodide, and burst of death fluorescence. We find that a deficiency in the necrosis pathway confers tolerance to Cry6Aa toxin. Intriguingly, the necrosis pathway is specifically triggered by Cry6Aa, not by Cry5Ba, whose amino acid sequence is different from that of Cry6Aa. Furthermore, Cry6Aa-induced necrosis pathway requires aspartic protease (ASP-1. In addition, ASP-1 protects Cry6Aa from over-degradation in C. elegans. This is the first demonstration that deficiency in necrosis pathway confers tolerance to Bt crystal protein, and that Cry6A triggers necrosis represents a newly added necrosis paradigm in the C. elegans. Understanding this model could lead to new strategies for nematode control.

  4. Sulforaphane induces apoptosis in T24 human urinary bladder cancer cells through a reactive oxygen species-mediated mitochondrial pathway: the involvement of endoplasmic reticulum stress and the Nrf2 signaling pathway.

    Science.gov (United States)

    Jo, Guk Heui; Kim, Gi-Young; Kim, Wun-Jae; Park, Kun Young; Choi, Yung Hyun

    2014-10-01

    Sulforaphane, a naturally occurring isothiocyanate found in cruciferous vegetables, has received a great deal of attention because of its ability to inhibit cell proliferation and induce apoptosis in cancer cells. In this study, we investigated the anticancer activity of sulforaphane in the T24 human bladder cancer line, and explored its molecular mechanism of action. Our results showed that treatment with sulforaphane inhibited cell viability and induced apoptosis in T24 cells in a concentration-dependent manner. Sulforaphane-induced apoptosis was associated with mitochondria dysfunction, cytochrome c release and Bcl-2/Bax dysregulation. Furthermore, the increased activity of caspase-9 and -3, but not caspase-8, was accompanied by the cleavage of poly ADP-ribose polymerase, indicating the involvement of the mitochondria-mediated intrinsic apoptotic pathway. Concomitant with these changes, sulforaphane triggered reactive oxygen species (ROS) generation, which, along with the blockage of sulforaphane-induced loss of mitochondrial membrane potential and apoptosis, was strongly attenuated by the ROS scavenger N-acetyl-L-cysteine. Furthermore, sulforaphane was observed to activate endoplasmic reticulum (ER) stress and the nuclear factor-E2-related factor-2 (Nrf2) signaling pathway, as demonstrated by the upregulation of ER stress‑related proteins, including glucose-regulated protein 78 and C/EBP-homologous protein, and the accumulation of phosphorylated Nrf2 proteins in the nucleus and induction of heme oxygenase-1 expression, respectively. Taken together, these results demonstrate that sulforaphane has antitumor effects against bladder cancer cells through an ROS-mediated intrinsic apoptotic pathway, and suggest that ER stress and Nrf2 may represent strategic targets for sulforaphane-induced apoptosis.

  5. Sleep as a Mediator in the Pathway Linking Environmental Factors to Hypertension: A Review of the Literature

    Directory of Open Access Journals (Sweden)

    Oluwaseun A. Akinseye

    2015-01-01

    Full Text Available Environmental factors, such as noise exposure and air pollution, are associated with hypertension. These environmental factors also affect sleep quality. Given the growing evidence linking sleep quality with hypertension, the purpose of this review is to investigate the role of sleep as a key mediator in the association between hypertension and environmental factors. Through this narrative review of the extant literature, we highlight that poor sleep quality mediates the relationship between environmental factors and hypertension. The conceptual model proposed in this review offers opportunities to address healthcare disparities in hypertension among African Americans by highlighting the disparate impact that the predictors (environmental factors and mediator (sleep have on the African-American community. Understanding the impact of these factors is crucial since the main outcome variable (hypertension severely burdens the African-American community.

  6. Functional interaction between hMYH and hTRADD in the TNF-α-mediated survival and death pathways of HeLa cells

    Energy Technology Data Exchange (ETDEWEB)

    Vy Tran, An Hue; Hahm, Soo-Hyun; Han, Se Hee [Department of Advanced Technology Fusion, Konkuk University, Hwayang-dong, Gwangjin-gu, Seoul 143-701 (Korea, Republic of); Chung, Ji Hyung [Department of Applied Bioscience, College of Life Science, CHA University, Gyeonggi-do 463-836 (Korea, Republic of); Park, Geon Tae [Cornell University, Ithaca, NY 14850 (United States); Han, Ye Sun, E-mail: yshan@konkuk.ac.kr [College of Global Integrated Studies, Division of Interdisciplinary Studies, Konkuk University, Hwayang-dong, Gwangjin-gu, Seoul 143-701 (Korea, Republic of)

    2015-07-15

    Highlights: • We determine the interaction between hMYH and hTRADD. • We examine changes in the level of hMYH–hTRADD interaction under TNF-α treatment. • hTRADD–hMYH association is involved in the nuclear translocation of NFκB. • hTRADD–hMYH complex influences the TNFR1–TRADD association. - Abstract: The tumor necrosis factor (TNF) signaling pathway is a classical immune system pathway that plays a key role in regulating cell survival and apoptosis. The TNF receptor-associated death domain (TRADD) protein is recruited to the death domain of TNF receptor 1 (TNFR1), where it interacts with TNF receptor-associated factor 2 (TRAF2) and receptor-interacting protein (RIP) for the induction of apoptosis, necrosis, nuclear factor kappa-light-chain-enhancer of activated B cells (NFκB), and mitogen-activated protein (MAP) kinase activation. In this study, we found that the human MutY homolog (hMYH) interacted with human TRADD (hTRADD) via the C-terminal domain of hMYH. Moreover, under conditions promoting TNF-α-induced cell death or survival in HeLa cells, this interaction was weakened or enhanced, respectively. The interaction between hMYH and hTRADD was important for signaling pathways mediated by TNF-α. Our results also suggested that the hTRADD–hMYH association was involved in the nuclear translocation of NFκB and formation of the TNFR1–TRADD complex. Thus, this study identified a novel mechanism through which the hMYH–hTRADD interaction may affect the TNF-α signaling pathway. Implications: In HeLa cells, the hTRADD–hMYH interaction functioned in both cell survival and apoptosis pathways following TNF-α stimulation.

  7. 2-Methoxy-6-Acetyl-7-Methyljuglone (MAM) Induces iNOS/NO-mediated DNA Damage Response through Activation of MAPKs Pathways.

    Science.gov (United States)

    Niu, Yanan; Yuan, Renyikun; Gao, Hongwei; Kong, Qi; Lu, Jin-Jian; Chen, Xiuping

    2018-04-10

    There are inconsistent reports about the role of nitric oxide (NO) in cancer progression and prevention. Quinones demonstrate significant anti-cancer activities both in vitro and in vivo. Here, we reported that 2-methoxy-6-acetyl-7-methyljuglone (MAM), a natural naphthoquinone isolated from Polygonum cuspidatum Sieb. et Zucc, induced inducible nitric oxide synthase (iNOS)/NO-mediated DNA damage response through activation of MAPKs pathways in BEL-7402 and A549 cells. MAM induced DNA damage by activating ATM/Chk2. MAM increased iNOS expression, NO production, and MAPKs (JNK1/2, ERK1/2, and p38MAPK) phosphorylation in concentration- and time- dependent manners. Furthermore, iNOS inhibitor 1400W, iNOS siRNA, and NO scavenger hemoglobin (Hb) could significantly reversed MAM-induced DNA damage, ATM/Chk2 activation, NO production, and cell death. In addition, MAPKs inhibitors (SP600125, U0126, and SB203580) reversed MAM-induced cell death and ATM/Chk2 activation. MAM-induced cell death was partially reversed by 1400W and Hb but enhanced by L-arginine. Collectively, these results suggested that MAM induced iNOS/NO activation and generation mediated by MAPKs pathways, which resulted in DNA damage. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  8. Brain heterotrimeric Gαi₂-subunit protein-gated pathways mediate central sympathoinhibition to maintain fluid and electrolyte homeostasis during stress.

    Science.gov (United States)

    Kapusta, Daniel R; Pascale, Crissey L; Wainford, Richard D

    2012-07-01

    Fluid and electrolyte homeostasis is integral to blood pressure regulation. However, the central molecular mechanisms regulating the neural control of sodium excretion remain unclear. We have demonstrated that brain Gαi(2)-subunit protein pathways mediate the natriuretic response to α(2)-adrenoreceptor activation in vivo. Consequently, we examined the role of brain Gαi(2) proteins in the neural mechanisms facilitating fluid and electrolyte homeostasis in response to acute [i.v. volume expansion (VE)] or chronic stressful stimuli (dietary sodium restriction vs. supplementation) in conscious Sprague-Dawley rats. Selective oligodeoxynucleotide (ODN)-mediated down-regulation of brain Gαi(2) proteins, but not a scrambled ODN, abolished the renal sympathoinhibitory response and attenuated the natriuresis to VE. In scrambled ODN-treated rats, chronic changes in dietary sodium intake evoked an endogenous, hypothalamic paraventricular nucleus (PVN)-specific, decrease (sodium deficiency) or increase (sodium excess) in PVN Gαi(2) proteins; plasma norepinephrine levels were inversely related to dietary sodium content. Finally, in rats treated with an ODN to prevent high salt-induced up-regulation of brain Gαi(2) proteins, animals exhibited sodium retention, global sympathoexcitation, and elevated blood pressure. Collectively, these data demonstrate that PVN Gαi(2) protein pathways play an endogenous role in maintaining fluid and electrolyte balance by controlling the influence the sympathetic nervous system has on the renal handling of sodium.

  9. Osteitis fibrosa is mediated by Platelet-Derived Growth Factor-A via a phosphoinositide 3-kinase-dependent signaling pathway in a rat model for chronic hyperparathyroidism.

    Science.gov (United States)

    Lowry, Malcolm B; Lotinun, Sutada; Leontovich, Alexey A; Zhang, Minzhi; Maran, Avudaiappan; Shogren, Kristen L; Palama, Brett K; Marley, Kevin; Iwaniec, Urszula T; Turner, Russell T

    2008-11-01

    Abnormal secretion of PTH by the parathyroid glands contributes to a variety of common skeletal disorders. Prior studies implicate platelet-derived growth factor-A (PDGF-A) as an important mediator of selective PTH actions on bone. The present studies used targeted gene profiling and small-molecule antagonists directed against candidate gene products to elucidate the roles of specific PTH-regulated genes and signaling pathways. A group of 29 genes in rats continuously infused with PTH and cotreated with the PDGF receptor antagonist trapidil were differentially expressed compared with PTH treatment alone. Several of the identified genes were functionally clustered as regulators of fibroblast differentiation and extracellular matrix modeling, including the matrix cross-linking enzyme lysyl oxidase (LOX). Treatment with beta-aminopropionitrile, an irreversible inhibitor of LOX activity, dramatically reduced diffuse mineralization but had no effect on PTH-induced fibrosis. In contrast, the receptor tyrosine kinase inhibitor Gleevec and the phosphoinositide 3-kinase inhibitor wortmannin each reduced bone marrow fibrosis. In summary, the present studies support the hypotheses that PTH-induced bone marrow fibrosis is mediated by PDGF-A via a phosphoinositide 3-kinase-dependent signaling pathway and that increased LOX gene expression plays a key role in abnormal mineralization, a hallmark of chronic hyperparathyroidism.

  10. Fcγ-receptor IIa-mediated Src Signaling Pathway Is Essential for the Antibody-Dependent Enhancement of Ebola Virus Infection.

    Directory of Open Access Journals (Sweden)

    Wakako Furuyama

    2016-12-01

    Full Text Available Antibody-dependent enhancement (ADE of Ebola virus (EBOV infection has been demonstrated in vitro, raising concerns about the detrimental potential of some anti-EBOV antibodies. ADE has been described for many viruses and mostly depends on the cross-linking of virus-antibody complexes to cell surface Fc receptors, leading to enhanced infection. However, little is known about the molecular mechanisms underlying this phenomenon. Here we show that Fcγ-receptor IIa (FcγRIIa-mediated intracellular signaling through Src family protein tyrosine kinases (PTKs is required for ADE of EBOV infection. We found that deletion of the FcγRIIa cytoplasmic tail abolished EBOV ADE due to decreased virus uptake into cellular endosomes. Furthermore, EBOV ADE, but not non-ADE infection, was significantly reduced by inhibition of the Src family protein PTK pathway, which was also found to be important to promote phagocytosis/macropinocytosis for viral uptake into endosomes. We further confirmed a significant increase of the Src phosphorylation mediated by ADE. These data suggest that antibody-EBOV complexes bound to the cell surface FcγRIIa activate the Src signaling pathway that leads to enhanced viral entry into cells, providing a novel perspective for the general understanding of ADE of virus infection.

  11. Effect of leonurine hydrochloride on endothelin and the endothelin receptor-mediated signal pathway in medically-induced incomplete abortion in rats.

    Science.gov (United States)

    Li, Xia; Yuan, Feng-Lai; Zhao, Yi-Qing; Lu, Wei-Guo; Li, Cheng-Wan; He, Chun-Hui

    2013-07-01

    Endothelin (ET) is involved in uterine contractions. Our previous study showed that leonurine hydrochloride (LH) inhibits abnormal bleeding caused by incomplete abortion through an increase in uterine contractions in rats. The present study was conducted to show that LH treatment regulates the ET-mediated signal pathway in abortion in rats. Early pregnancies in rats had incomplete abortions induced using mifepristone in combination with misoprostol. After the abortions, the rats were treated with LH orally for 7 days and surgery was performed. The sinistro-uterus was dissected for measurement of ET and nitric oxide (NO); the dextro-uterus was stored at -80°C for ET receptor (ETA and ETB) analysis. Myometrial cells from the dextro-uterus were cultured for measurement of phospholipase C (PLC) activity, intra-cellular Ca(2+) concentration ([Ca(2+)]i), and protein kinase C (PKC) activity. In in vivo experiments, LH treatment elevated the ET level and ET/NO ratio in rats with induced abortions and up-regulated ETA mRNA expression (Pabortions by modulating the ET receptor-mediated signal pathway. Copyright © 2013. Published by Elsevier Ireland Ltd.

  12. PHP14 regulates hepatic stellate cells migration in liver fibrosis via mediating TGF-β1 signaling to PI3Kγ/AKT/Rac1 pathway.

    Science.gov (United States)

    Xu, Anjian; Li, Yanmeng; Zhao, Wenshan; Hou, Fei; Li, Xiaojin; Sun, Lan; Chen, Wei; Yang, Aiting; Wu, Shanna; Zhang, Bei; Yao, Jingyi; Wang, Huan; Huang, Jian

    2018-02-01

    Hepatic fibrosis is characterized by the activation of hepatic stellate cells (HSCs). Migration of the activated HSCs to the site of injury is one of the key characteristics during the wound healing process. We have previously demonstrated that 14 kDa phosphohistidine phosphatase (PHP14) is involved in migration and lamellipodia formation of HSCs. However, the role of PHP14 in liver fibrosis remains unknown. In this study, we first assessed PHP14 expression and distribution in liver fibrotic tissues using western blot, immunohistochemistry, and double immunofluorescence staining. Next, we investigated the role of PHP14 in liver fibrosis and, more specifically, the migration of HSCs by Transwell assay and 3D collagen matrices assay. Finally, we explored the possible molecular mechanisms of the effects of PHP14 on these processes. Our results show that the PHP14 expression is up-regulated in fibrotic liver and mainly in HSCs. Importantly, TGF-β1 can induce PHP14 expression in HSCs accompanied with the activation of HSCs. Consistent with the previous study, PHP14 promotes HSCs migration, especially, promotes 3D floating collagen matrices contraction but inhibits stressed-released matrices contraction. Mechanistically, the PI3Kγ/AKT/Rac1 pathway is involved in migration regulated by PHP14. Moreover, PHP14 specifically mediates the TGF-β1 signaling to PI3Kγ/AKT pathway and regulates HSC migration, and thus participates in liver fibrosis. Our study identified the role of PHP14 in liver fibrosis, particularly HSC migration, and suggested a novel mediator of transducting TGF-β1 signaling to PI3Kγ/AKT/Rac1 pathway. PHP14 is up-regulated in fibrotic liver and activated hepatic stellate cells. The expression of PHP14 is induced by TGF-β1. The migration of hepatic stellate cells is regulated by PHP14. PHP14 is a mediator of TGF-β1 signaling to PI3Kγ/AKT/Rac1 pathway in hepatic stellate cells.

  13. Human T-Cell Leukemia Virus Type 1 Tax-Deregulated Autophagy Pathway and c-FLIP Expression Contribute to Resistance against Death Receptor-Mediated Apoptosis

    Science.gov (United States)

    Wang, Weimin; Zhou, Jiansuo; Shi, Juan; Zhang, Yaxi; Liu, Shilian

    2014-01-01

    ABSTRACT The human T-cell leukemia virus type 1 (HTLV-1) Tax protein is considered to play a central role in the process that leads to adult T-cell leukemia/lymphoma (ATL) and HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). HTLV-1 Tax-expressing cells show resistance to apoptosis induced by Fas ligand (FasL) and tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL). The regulation of Tax on the autophagy pathway in HeLa cells and peripheral T cells was recently reported, but the function and underlying molecular mechanism of the Tax-regulated autophagy are not yet well defined. Here, we report that HTLV-1 Tax deregulates the autophagy pathway, which plays a protective role during the death receptor (DR)-mediated apoptosis of human U251 astroglioma cells. The cellular FLICE-inhibitory protein (c-FLIP), which is upregulated by Tax, also contributes to the resistance against DR-mediated apoptosis. Both Tax-induced autophagy and Tax-induced c-FLIP expression require Tax-induced activation of IκB kinases (IKK). Furthermore, Tax-induced c-FLIP expression is regulated through the Tax-IKK-NF-κB signaling pathway, whereas Tax-triggered autophagy depends on the activation of IKK but not the activation of NF-κB. In addition, DR-mediated apoptosis is correlated with the degradation of Tax, which can be facilitated by the inhibitors of autophagy. IMPORTANCE Our study reveals that Tax-deregulated autophagy is a protective mechanism for DR-mediated apoptosis. The molecular mechanism of Tax-induced autophagy is also illuminated, which is different from Tax-increased c-FLIP. Tax can be degraded via manipulation of autophagy and TRAIL-induced apoptosis. These results outline a complex regulatory network between and among apoptosis, autophagy, and Tax and also present evidence that autophagy represents a new possible target for therapeutic intervention for the HTVL-1 related diseases. PMID:24352466

  14. Removal efficiency and economic cost comparison of hydrated electron-mediated reductive pathways for treatment of bromate

    DEFF Research Database (Denmark)

    Nawaz, Shah; Shah, Noor S.; Khan, Javed Ali

    2017-01-01

    Bromate, a potential carcinogen, is a well known highly persistent and environmentally recalcitrant contaminant. UV-254/sulfite-based advanced reductive pathways (ARPs) were proposed to eliminate bromate successfully from water. Experiments with N2, N2O, 2-chlorophenol, inorganic ions, and differ...

  15. Mediated Pathways from Maternal Depression and Early Parenting to Children's Executive Function and Externalizing Behaviour Problems

    Science.gov (United States)

    Baker, Claire; Kuhn, Laura

    2018-01-01

    Structural equation models were used to examine pathways from maternal depression and early parenting to children's executive function (EF) and externalizing behaviours in the first nationally representative study to obtain direct assessments of children's kindergarten EF skills (i.e., the Early Childhood Longitudinal Study Kindergarten Class of…

  16. Effect of aspirin on the Wnt/beta-catenin pathway is mediated via protein phosphatase 2A

    NARCIS (Netherlands)

    Bos, C. L.; Kodach, L. L.; van den Brink, G. R.; Diks, S. H.; van Santen, M. M.; Richel, D. J.; Peppelenbosch, M. P.; Hardwick, J. C. H.

    2006-01-01

    Nonsteroidal anti-inflammatory drugs show chemopreventive efficacy in colon cancer, but the mechanism behind this remains unclear. Elucidating this mechanism is seen as vital to the development of new chemopreventive agents. We studied the effects of aspirin on the oncogenic Wnt/beta-catenin pathway

  17. Metabolic pathway interruption: CRISPR/Cas9-mediated knockout of tryptophan 2,3-oxygenase in Tribolium castaneum

    Science.gov (United States)

    The Tribolium castaneum vermilion gene encodes tryptophan 2,3-dioxygenase, a pivotal enzyme in the ommochrome pathway that is responsible for the black eye color. T. castaneum strains with a loss-of-function mutation, vermilion white (vw), lack both the promoter and the first 80% of the vermilion co...

  18. B Cell Receptor-Mediated Internalization of Salmonella: A Novel Pathway for Autonomous B Cell Activation and Antibody Production

    NARCIS (Netherlands)

    Souwer, Yuri; Griekspoor, Alexander; Jorritsma, Tineke; de Wit, Jelle; Janssen, Hans; Neefjes, Jacques; van Ham, S. Marieke

    2009-01-01

    The present paradigm is that primary B cells are nonphagocytosing cells. In this study, we demonstrate that human primary B cells are able to internalize bacteria when the bacteria are recognized by the BCR. BCR-mediated internalization of Salmonella typhimurium results in B cell differentiation and

  19. Two Distinct Mediated Pathways to Disordered Eating in Response to Weight Stigmatization and Their Application to Prevention Programs

    Science.gov (United States)

    Simone, Melissa; Lockhart, Ginger

    2016-01-01

    Objective: Disordered eating behaviors among undergraduate women are common and, thus, are an important public health concern. Weight stigmatization, stress, and social withdrawal are often associated with disordered eating behaviors; however, it is unclear whether stress and social withdrawal act as mediators between weight stigmatization and…

  20. Intracellular collagen degradation mediated by uPARAP/Endo180 is a major pathway of extracellular matrix turnover during malignancy

    DEFF Research Database (Denmark)

    Curino, Alejandro C; Engelholm, Lars H; Yamada, Susan S

    2005-01-01

    We recently reported that uPARAP/Endo180 can mediate the cellular uptake and lysosomal degradation of collagen by cultured fibroblasts. Here, we show that uPARAP/Endo180 has a key role in the degradation of collagen during mammary carcinoma progression. In the normal murine mammary gland, uPARAP/...

  1. Is Self-Objectification Related to Interoceptive Awareness? An Examination of Potential Mediating Pathways to Disordered Eating Attitudes

    Science.gov (United States)

    Myers, Taryn A.; Crowther, Janis H.

    2008-01-01

    Although there has been considerable empirical support for Objectification Theory (Fredrickson & Roberts, 1997), findings have been mixed regarding self-objectification's relationship to interoceptive awareness, an awareness of one's internal physical and emotional states. We examined whether interoceptive awareness mediated the relationship…

  2. PKCa and PKCd regulate ADAM17-mediated ectodomain shedding of heparin binding-EGF through separate pathways

    DEFF Research Database (Denmark)

    Kveiborg, Marie; Instrell, Rachael; Rowlands, Christina

    2011-01-01

    a cell-based system of PMA-induced PKC activation coupled with shedding of heparin binding (HB)-EGF. In agreement with previous studies, we demonstrated that PMA triggers a rapid ADAM17-mediated release of HB-EGF. However, PMA-treatment also results in a protease-independent loss of cell surface HB...

  3. Ursolic acid-mediated changes in glycolytic pathway promote cytotoxic autophagy and apoptosis in phenotypically different breast cancer cells.

    Science.gov (United States)

    Lewinska, Anna; Adamczyk-Grochala, Jagoda; Kwasniewicz, Ewa; Deregowska, Anna; Wnuk, Maciej

    2017-06-01

    Plant-derived pentacyclic triterpenotids with multiple biological activities are considered as promising candidates for cancer therapy and prevention. However, their mechanisms of action are not fully understood. In the present study, we have analyzed the effects of low dose treatment (5-20 µM) of ursolic acid (UA) and betulinic acid (BA) on breast cancer cells of different receptor status, namely MCF-7 (ER + , PR +/- , HER2 - ), MDA-MB-231 (ER - , PR - , HER2 - ) and SK-BR-3 (ER - , PR - , HER2 + ). UA-mediated response was more potent than BA-mediated response. Triterpenotids (5-10 µM) caused G0/G1 cell cycle arrest, an increase in p21 levels and SA-beta-galactosidase staining that was accompanied by oxidative stress and DNA damage. UA (20 µM) also diminished AKT signaling that affected glycolysis as judged by decreased levels of HK2, PKM2, ATP and lactate. UA-induced energy stress activated AMPK that resulted in cytotoxic autophagy and apoptosis. UA-mediated elevation in nitric oxide levels and ATM activation may also account for AMPK activation-mediated cytotoxic response. Moreover, UA-promoted apoptosis was associated with decreased pERK1/2 signals and the depolarization of mitochondrial membrane potential. Taken together, we have shown for the first time that UA at low micromolar range may promote its anticancer action by targeting glycolysis in phenotypically distinct breast cancer cells.

  4. DMPD: Protein kinase C epsilon: a new target to control inflammation andimmune-mediated disorders. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 14643884 Protein kinase C epsilon: a new target to control inflammation andimmune-m...g) (.html) (.csml) Show Protein kinase C epsilon: a new target to control inflammation andimmune-mediated di...sorders. PubmedID 14643884 Title Protein kinase C epsilon: a new target to control inflammation

  5. Transcriptome analyses and virus induced gene silencing identify genes in the Rpp4-mediated Asian soybean rust resistance pathway

    Science.gov (United States)

    Rpp4 (Resistance to Phakopsora pachyrhizi 4) confers resistance to P. pachyrhizi, the causal agent of Asian soybean rust (ASR). By combining expression profiling and virus induced gene silencing (VIGS), we are developing a genetic framework for Rpp4-mediated resistance. We measured gene expression i...

  6. PI3K/Akt is involved in brown adipogenesis mediated by growth differentiation factor-5 in association with activation of the Smad pathway

    Energy Technology Data Exchange (ETDEWEB)

    Hinoi, Eiichi; Iezaki, Takashi; Fujita, Hiroyuki; Watanabe, Takumi; Odaka, Yoshiaki; Ozaki, Kakeru; Yoneda, Yukio, E-mail: yyoneda@p.kanazawa-u.ac.jp

    2014-07-18

    Highlights: • Akt is preferentially phosphorylated in BAT and sWAT of aP2-GDF5 mice. • PI3K/Akt signaling is involved in GDF5-induced brown adipogenesis. • PI3K/Akt signaling regulates GDF5-induced Smad5 phosphorylation. - Abstract: We have previously demonstrated promotion by growth differentiation factor-5 (GDF5) of brown adipogenesis for systemic energy expenditure through a mechanism relevant to activating the bone morphological protein (BMP) receptor/mothers against decapentaplegic homolog (Smad)/peroxisome proliferator-activated receptor gamma co-activator 1α (PGC-1α) pathway. Here, we show the involvement of the phosphatidylinositol 3-kinase (PI3K)/Akt pathway in brown adipogenesis mediated by GDF5. Overexpression of GDF5 in cells expressing adipocyte protein-2 markedly accelerated the phosphorylation of Smad1/5/8 and Akt in white and brown adipose tissues. In brown adipose tissue from heterozygous GDF5{sup Rgsc451} mutant mice expressing a dominant-negative (DN) GDF5 under obesogenic conditions, the basal phosphorylation of Smad1/5/8 and Akt was significantly attenuated. Exposure to GDF5 not only promoted the phosphorylation of both Smad1/5/8 and Akt in cultured brown pre-adipocytes, but also up-regulated Pgc1a and uncoupling protein-1 expression in a manner sensitive to the PI3K/Akt inhibitor Ly294002 as well as retroviral infection with DN-Akt. GDF5 drastically promoted BMP-responsive luciferase reporter activity in a Ly294002-sensitive fashion. Both Ly294002 and DN-Akt markedly inhibited phosphorylation of Smad5 in the nuclei of brown pre-adipocytes. These results suggest that PI3K/Akt signals play a role in the GDF5-mediated brown adipogenesis through a mechanism related to activation of the Smad pathway.

  7. Surface-bound capsular polysaccharide of type Ia group B Streptococcus mediates C1 binding and activation of the classic complement pathway

    International Nuclear Information System (INIS)

    Levy, N.J.; Kasper, D.L.

    1986-01-01

    The role of surface-bound type Ia group B Streptococcus (GBS) capsular polysaccharide in anti-body-independent binding of C1 and activation of the classic component pathway was investigated. In a radiolabeled bacterial-polymorphonuclear leukocyte (PMN) association assay, a measure of bacterial opsonization, preincubation of 3 H-type Ia GBS with purified F(ab') 2 to the organism blocked the association of the bacteria with PMN', and the inhibitory effect was dose dependent. The specificity of F(ab') 2 blocking was shown after adsorption of F(ab') 2 with type Ia polysaccharide-sensitized erythrocytes. Polysaccharide-adsorbed F(ab') 2 had a 70% decrease in ability to block the association of bacteria with PMN. Neuraminidase digestion removed 80% of the terminal sialic acid residues from the native polysaccharide. These neuraminidase-digested organisms had a 72% decrease in binding and transfer of purified C1 compared with non-enzyme-treated organisms. Type Ia capsular polysaccharide bound to sheep erythrocytes promoted classic complement pathway-mediated hemolysis of the cells. The role of C1 inhibitor (INH) in modulation of C1 activation by the organisms was investigated. The possibility existed that the C1 INH could be bound by the bacteria, allowing C1 activation to occur in the fluid phase. The inhibitor was purified from human serum, and its activity was measured before and after incubation with type Ia GBS. The organisms had no effect on C1 INH activity. Thus surface-bound capsular polysacchardie of type Ia GBS mediates C1 binding and classic pathway activation, and this does not involve the C1 INH

  8. Impaired pentose phosphate pathway in the development of 3D MCF-7 cells mediated intracellular redox disturbance and multi-cellular resistance without drug induction.

    Science.gov (United States)

    Wang, Wenjie; Cai, Qingyun; Zhou, Fang; Liu, Jiali; Jin, Xiaoliang; Ni, Ping; Lu, Meng; Wang, Guangji; Zhang, Jingwei

    2018-05-01

    Although metabolic reprogramming and redox imbalance are widely reported to be involved in chemo-resistance in cancer treatment, much more attention was paid to anti-cancer drug induced effect. Our previous studies showed that cancer cells can develop P-gp overexpression-mediated intrinsic drug resistance in the formation of 3D MCF-7 multi-cellular layers (MCLs) without any drug induction. However, whether metabolic reprogramming and redox imbalance functioned during this progress remained unrevealed. In our present study, LC-Q/TOF-MS and GC-MS were used in combination for analysing intracellular metabolites. The contribution of pentose phosphate pathway (PPP) and its related redox status were checked by chemical interfering and silencing/over-expression of glucose-6-phosphate dehydrogenase (G6PD). The downstream products of G6PD were assayed by quantitative real-time PCR, western blot and flow cytometry. Results showed that not only G6PD expression but also G6PD activity was significantly lowered along with 3D MCF-7 cells culture time. Impaired PPP disturbed redox-cycling, generated reactive oxygen species (ROS), which triggered cell cycle arrest and caused the switch to Chk2/p53/NF-κB pathway-mediated P-gp induction. Our results provided a new attempt to associate intrinsic small molecule metabolites (impaired PPP) communicating with cell signalling pathways through disturbed intracellular redox status to elucidate multi-cellular resistance (MCR) in 3D MCF-7 cells, which improved the understanding of the mechanisms of P-gp up-regulation in MCR with metabolomic and related redox status support. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

  9. Icariin and icaritin stimulate the proliferation of SKBr3 cells through the GPER1-mediated modulation of the EGFR-MAPK signaling pathway.

    Science.gov (United States)

    Ma, Hai-Rong; Wang, Jie; Chen, Yiu-Fai; Chen, Hua; Wang, Wei-Shan; Aisa, Haji Akber

    2014-06-01

    Icariin (ICA) and icaritin (ICT), with a similar structure to genistein, are the important bioactive components of the genus Epimedium, and regulate many cellular processes. In the present study, using the estrogen receptor (ER)-negative breast cancer cell line, SKBr3, as a model, we examined the hypothesis that ICA and ICT at low concentrations stimulate SKBr3 cell proliferation in vitro through the functional membrane, G protein‑coupled estrogen receptor 1 (GPER1), mediated by the epithelial growth factor receptor (EGFR)‑mitogen-activated protein kinase (MAPK) signaling pathway. MTT assay revealed that ICA and ICT at doses of 1 nM to 1 µM markedly stimulated SKBr3 cell proliferation in a dose-dependent manner. The ICA- and ICT-stimulated cell growth was completely suppressed by the GPER1 antagonist, G-15, indicating that the ICA‑ and ICT-stimulated cell proliferation was mediated by GPER1 activation. Semi-quantitative RT-PCR analysis revealed that treatment with ICA and ICT enhanced the transcription of c-fos, a proliferation-related early gene. The ICA- and ICT-stimulated mRNA expression was markedly attenuated by G-15, AG-1478 (an EGFR antagonist) or PD98059 (a MAPK inhibitor). Our data also demonstrated that ICA and ICT increased the phosphorylation of ERK1/2. The ICA- and ICT-stimulated ERK1/2 phosphorylation was blocked by pre-treatment of the cells with G-15 and AG-1478 or PD 98059. Flow cytometric analysis confirmed that the ICA- and ICT-stimulated SKBr3 cell proliferation involved the GPER1-mediated modulation of the EGFR‑MAPK signaling pathway. To the best of our knowledge, our current findings demonstrate for the first time that ICA and ICT promote the progression of ER-negative breast cancer through the activation of membrane GPER1.

  10. Response rate of fibrosarcoma cells to cytotoxic drugs on the expression level correlates to the therapeutic response rate of fibrosarcomas and is mediated by regulation of apoptotic pathways

    International Nuclear Information System (INIS)

    Lehnhardt, Marcus; Mueller, Oliver; Klein-Hitpass, Ludger; Kuhnen, Cornelius; Homann, Heinz Herbert; Daigeler, Adrien; Steinau, Hans Ulrich; Roehrs, Sonja; Schnoor, Laura; Steinstraesser, Lars

    2005-01-01

    Because of the high resistance rate of fibrosarcomas against cytotoxic agents clinical chemotherapy of these tumors is not established. A better understanding of the diverse modes of tumor cell death following cytotoxic therapies will provide a molecular basis for new chemotherapeutic strategies. In this study we elucidated the response of a fibrosarcoma cell line to clinically used cytostatic agents on the level of gene expression. HT1080 fibrosarcoma cells were exposed to the chemotherapeutic agents doxorubicin, actinomycin D or vincristine. Total RNA was isolated and the gene expression patterns were analyzed by microarray analysis. Expression levels for 46 selected candidate genes were validated by quantitative real-time PCR. The analysis of the microarray data resulted in 3.309 (actinomycin D), 1.019 (doxorubicin) and 134 (vincristine) probesets that showed significant expression changes. For the RNA synthesis blocker actinomycin D, 99.4% of all differentially expressed probesets were under-represented. In comparison, probesets down-regulated by doxorubicin comprised only 37.4% of all genes effected by this agent. Closer analysis of the differentially regulated genes revealed that doxorubicin induced cell death of HT1080 fibrosarcoma cells mainly by regulating the abundance of factors mediating the mitochondrial (intrinsic) apoptosis pathway. Furthermore doxorubicin influences other pathways and crosstalk to other pathways (including to the death receptor pathway) at multiple levels. We found increased levels of cytochrome c, APAF-1 and members of the STAT-family (STAT1, STAT3), while Bcl-2 expression was decreased. Caspase-1, -3, -6, -8, and -9 were increased indicating that these proteases are key factors in the execution of doxorubicin mediated apoptosis. This study demonstrates that chemotherapy regulates the expression of apoptosis-related factors in fibrosarcoma cells. The number and the specific pattern of the genes depend on the used cytotoxic drug

  11. Indirubin Inhibits LPS-Induced Inflammation via TLR4 Abrogation Mediated by the NF-kB and MAPK Signaling Pathways.

    Science.gov (United States)

    Lai, Jin-Lun; Liu, Yu-Hui; Liu, Chang; Qi, Ming-Pu; Liu, Rui-Ning; Zhu, Xi-Fang; Zhou, Qiu-Ge; Chen, Ying-Yu; Guo, Ai-Zhen; Hu, Chang-Min

    2017-02-01

    Indirubin plays an important role in the treatment of many chronic diseases and exhibits strong anti-inflammatory activity. However, the molecular mode of action during mastitis prophylaxis remains poorly understood. In this study, a lipopolysaccharide (LPS)-induced mastitis mouse model showed that indirubin attenuated histopathological changes in the mammary gland, local tissue necrosis, and neutrophil infiltration. Moreover, indirubin significantly downregulated the production of interleukin (IL)-1β, IL-6, and tumor necrosis factor-α (TNF-α). We explored the mechanism whereby indirubin exerts protective effects against LPS-induced inflammation of mouse mammary epithelial cells (MMECs). The addition of different concentrations of indirubin before exposure of cells to LPS for 1 h significantly attenuated inflammation and reduced the concentrations of the three inflammatory cytokines in a dose-dependent manner. Indirubin downregulated LPS-induced cyclooxygenase-2 (COX-2) and Toll-like receptor 4 (TLR4) expression, inhibited phosphorylation of the LPS-induced nuclear transcription factor-kappa B (NF-kB) P65 protein and its inhibitor IkBα of the NF-kB signaling pathway. Furthermore, indirubin suppressed phosphorylation of P38, extracellular signal-regulated kinase (ERK), and c-Jun NH 2 -terminal kinase (JNK) of the mitogen-activated protein kinase (MAPK) signal pathways. Thus, indirubin effectively suppressed LPS-induced inflammation via TLR4 abrogation mediated by the NF-kB and MAPK signaling pathways and may be useful for mastitis prophylaxis.

  12. Rmi1 functions in S phase-mediated cohesion establishment via a pathway involving the Ctf18-RFC complex and Mrc1.

    Science.gov (United States)

    Lai, Mong Sing; Seki, Masayuki; Tada, Shusuke; Enomoto, Takemi

    2012-10-26

    Saccharomyces cerevisiae RecQ helicase (Sgs1) combines with DNA topoisomerase III (Top3) and RecQ-mediated genome instability 1 (Rmi1) to form an evolutionarily conserved complex that is required for processing homologous recombination intermediates and restarting collapsed replication forks. It was previously reported that Rmi1 contributes to sister chromatid cohesion; however, the underlying molecular mechanism has been unclear. In the present study, Rmi1 was found to be enriched at the region close to an early-firing replication origin when replication forks were arrested near their origins in the presence of hydroxyurea. Genetic analyses revealed that Rmi1 promoted sister chromatid cohesion in a process that was distinct from both the cohesion establishment pathway involving Ctf4, Csm3, and Chl1 and the pathway involving the acetylation of Smc3. On the other hand, Rmi1 seemed to function in a pathway involving the Ctf18-RFC complex and Mrc1, which were previously predicted to regulate leading-strand DNA replication. Copyright © 2012 Elsevier Inc. All rights reserved.

  13. The Bone Marrow-Mediated Protection of Myeloproliferative Neoplastic Cells to Vorinostat and Ruxolitinib Relies on the Activation of JNK and PI3K Signalling Pathways.

    Directory of Open Access Journals (Sweden)

    Bruno A Cardoso

    Full Text Available The classical BCR-ABL-negative Myeloproliferative Neoplasms (MPN are a group of heterogeneous haematological diseases characterized by constitutive JAK-STAT pathway activation. Targeted therapy with Ruxolitinib, a JAK1/2-specific inhibitor, achieves symptomatic improvement but does not eliminate the neoplastic clone. Similar effects are seen with histone deacetylase inhibitors (HDACi, albeit with poorer tolerance. Here, we show that bone marrow (BM stromal cells (HS-5 protected MPN-derived cell lines (SET-2; HEL and UKE-1 and MPN patient-derived BM cells from the cytotoxic effects of Ruxolitinib and the HDACi Vorinostat. This protective effect was mediated, at least in part, by the secretion of soluble factors from the BM stroma. In addition, it correlated with the activation of signalling pathways important for cellular homeostasis, such as JAK-STAT, PI3K, JNK, MEK-ERK and NF-κB. Importantly, the pharmacological inhibition of JNK and PI3K pathways completely abrogated the BM protective effect on MPN cell lines and MPN patient samples. Our findings shed light on mechanisms of tumour survival and may indicate novel therapeutic approaches for the treatment of MPN.

  14. The Bone Marrow-Mediated Protection of Myeloproliferative Neoplastic Cells to Vorinostat and Ruxolitinib Relies on the Activation of JNK and PI3K Signalling Pathways

    Science.gov (United States)

    Cardoso, Bruno A.; Belo, Hélio; Barata, João T.; Almeida, António M.

    2015-01-01

    The classical BCR-ABL-negative Myeloproliferative Neoplasms (MPN) are a group of heterogeneous haematological diseases characterized by constitutive JAK-STAT pathway activation. Targeted therapy with Ruxolitinib, a JAK1/2-specific inhibitor, achieves symptomatic improvement but does not eliminate the neoplastic clone. Similar effects are seen with histone deacetylase inhibitors (HDACi), albeit with poorer tolerance. Here, we show that bone marrow (BM) stromal cells (HS-5) protected MPN-derived cell lines (SET-2; HEL and UKE-1) and MPN patient-derived BM cells from the cytotoxic effects of Ruxolitinib and the HDACi Vorinostat. This protective effect was mediated, at least in part, by the secretion of soluble factors from the BM stroma. In addition, it correlated with the activation of signalling pathways important for cellular homeostasis, such as JAK-STAT, PI3K, JNK, MEK-ERK and NF-κB. Importantly, the pharmacological inhibition of JNK and PI3K pathways completely abrogated the BM protective effect on MPN cell lines and MPN patient samples. Our findings shed light on mechanisms of tumour survival and may indicate novel therapeutic approaches for the treatment of MPN. PMID:26623653

  15. Advanced oxidation protein products induce chondrocyte apoptosis via receptor for advanced glycation end products-mediated, redox-dependent intrinsic apoptosis pathway.

    Science.gov (United States)

    Wu, Qian; Zhong, Zhao-Ming; Zhu, Si-Yuan; Liao, Cong-Rui; Pan, Ying; Zeng, Ji-Huan; Zheng, Shuai; Ding, Ruo-Ting; Lin, Qing-Song; Ye, Qing; Ye, Wen-Bin; Li, Wei; Chen, Jian-Ting

    2016-01-01

    Pro-inflammatory cytokine-induced chondrocyte apoptosis is a primary cause of cartilage destruction in the progression of rheumatoid arthritis (RA). Advanced oxidation protein products (AOPPs), a novel pro-inflammatory mediator, have been confirmed to accumulate in patients with RA. However, the effect of AOPPs accumulation on chondrocyte apoptosis and the associated cellular mechanisms remains unclear. The present study demonstrated that the plasma formation of AOPPs was enhanced in RA rats compared with normal. Then, chondrocyte were treated with AOPPs-modified rat serum albumin (AOPPs-RSA) in vitro. Exposure of chondrocyte to AOPPs activated nicotinamide adenine dinucleotide phosphate (NADPH) oxidase and increased expression of NADPH oxidase subunits, which was mediated by receptor for advanced glycation end products (RAGE), but not scavenger receptor CD36. Moreover, AOPPs challenge triggered NADPH oxidase-dependent ROS generation which induced mitochondrial dysfunction and endoplasmic reticulum stress resulted in activation of caspase family that eventually lead to apoptosis. Lastly, blockade of RAGE, instead of CD36, largely attenuated these signals. Our study demonstrated first time that AOPPs induce chondrocyte apoptosis via RAGE-mediated and redox-dependent intrinsic apoptosis pathway in vitro. These data implicates that AOPPs may represent a novel pathogenic factor that contributes to RA progression. Targeting AOPPs-triggered cellular mechanisms might emerge as a promising therapeutic option for patients with RA.

  16. The perlecan heparan sulfate proteoglycan mediates cellular uptake of HIV-1 Tat through a pathway responsible for biological activity

    International Nuclear Information System (INIS)

    Cell surface heparan sulfate proteoglycans (HSPGs) mediate internalization of HIV-1 Tat. Herein, we report that human WiDr cells, which express perlecan but no other HSPGs, can internalize 125 I-labeled Tat with minimal lysosomal degradation. Pre-treatment of cells with heparitinase almost completely abolished 125 I-Tat surface binding, while the use of an HIV-1 long terminal repeat (LTR) promoter-reporter construct demonstrated that transactivation was potently blocked by pretreatment of cells with heparitinase, indicating an essential role for perlecan in the biologic effects of Tat. We conclude that the perlecan mediates Tat uptake and is required for HIV-1 LTR-directed transactivation in this human cell type

  17. DNA ligase C1 mediates the LigD-independent nonhomologous end-joining pathway of Mycobacterium smegmatis.

    Science.gov (United States)

    Bhattarai, Hitesh; Gupta, Richa; Glickman, Michael S

    2014-10-01

    Nonhomologous end joining (NHEJ) is a recently described bacterial DNA double-strand break (DSB) repair pathway that has been best characterized for mycobacteria. NHEJ can religate transformed linear plasmids, repair ionizing radiation (IR)-induced DSBs in nonreplicating cells, and seal I-SceI-induced chromosomal DSBs. The core components of the mycobacterial NHEJ machinery are the DNA end binding protein Ku and the polyfunctional DNA ligase LigD. LigD has three autonomous enzymatic modules: ATP-dependent DNA ligase (LIG), DNA/RNA polymerase (POL), and 3' phosphoesterase (PE). Although genetic ablation of ku or ligD abolishes NHEJ and sensitizes nonreplicating cells to ionizing radiation, selective ablation of the ligase activity of LigD in vivo only mildly impairs NHEJ of linearized plasmids, indicating that an additional DNA ligase can support NHEJ. Additionally, the in vivo role of the POL and PE domains in NHEJ is unclear. Here we define a LigD ligase-independent NHEJ pathway in Mycobacterium smegmatis that requires the ATP-dependent DNA ligase LigC1 and the POL domain of LigD. Mycobacterium tuberculosis LigC can also support this backup NHEJ pathway. We also demonstrate that, although dispensable for efficient plasmid NHEJ, the activities of the POL and PE domains are required for repair of IR-induced DSBs in nonreplicating cells. These findings define the genetic requirements for a LigD-independent NHEJ pathway in mycobacteria and demonstrate that all enzymatic functions of the LigD protein participate in NHEJ in vivo. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

  18. Afferent Pathway-Mediated Effect of α1 Adrenergic Antagonist, Tamsulosin, on the Neurogenic Bladder After Spinal Cord Injury.

    Science.gov (United States)

    Han, Jin-Hee; Kim, Sung-Eun; Ko, Il-Gyu; Kim, Jayoung; Kim, Khae Hawn

    2017-09-01

    The functions of the lower urinary tract (LUT), such as voiding and storing urine, are dependent on complex central neural networks located in the brain, spinal cord, and peripheral ganglia. Thus, the functions of the LUT are susceptible to various neurologic disorders including spinal cord injury (SCI). SCI at the cervical or thoracic levels disrupts voluntary control of voiding and the normal reflex pathways coordinating bladder and sphincter functions. In this context, it is noteworthy that α1-adrenoceptor blockers have been reported to relieve voiding symptoms and storage symptoms in elderly men with benign prostatic hyperplasia (BPH). Tamsulosin, an α1-adrenoceptor blocker, is also considered the most effective regimen for patients with LUT symptoms such as BPH and overactive bladder (OAB). In the present study, the effects of tamsulosin on the expression of c-Fos, nerve growth factor (NGF), and nicotinamide adenine dinucleotide phosphate-diaphorase (NADPH-d) in the afferent micturition areas, including the pontine micturition center (PMC), the ventrolateral periaqueductal gray matter (vlPAG), and the spinal cord (L5), of rats with an SCI were investigated. SCI was found to remarkably upregulate the expression of c-Fos, NGF, and NADPH-d in the afferent pathway of micturition, the dorsal horn of L5, the vlPAG, and the PMC, resulting in the symptoms of OAB. In contrast, tamsulosin treatment significantly suppressed these neural activities and the production of nitric oxide in the afferent pathways of micturition, and consequently, attenuated the symptoms of OAB. Based on these results, tamsulosin, an α1-adrenoceptor antagonist, could be used to attenuate bladder dysfunction following SCI. However, further studies are needed to elucidate the exact mechanism and effects of tamsulosin on the afferent pathways of micturition.

  19. RNA silencing of Mcl-1 enhances ABT-737-mediated apoptosis in melanoma: role for a caspase-8-dependent pathway.

    Science.gov (United States)

    Keuling, Angela M; Felton, Kathleen E A; Parker, Arabesque A M; Akbari, Majid; Andrew, Susan E; Tron, Victor A

    2009-08-17

    Malignant melanoma is resistant to almost all conventional forms of chemotherapy. Recent evidence suggests that anti-apoptotic proteins of the Bcl-2 family are overexpressed in melanoma and may contribute to melanoma's striking resistance to apoptosis. ABT-737, a small-molecule inhibitor of Bcl-2, Bcl-xl and Bcl-w, has demonstrated efficacy in several forms of leukemia, lymphoma as well as solid tumors. However, overexpression of Mcl-1, a frequent observance in melanoma, is known to confer ABT-737 resistance. Here we report that knockdown of Mcl-1 greatly reduces cell viability in combination with ABT-737 in six different melanoma cell lines. We demonstrate that the cytotoxic effect of this combination treatment is due to apoptotic cell death involving not only caspase-9 activation but also activation of caspase-8, caspase-10 and Bid, which are normally associated with the extrinsic pathway of apoptosis. Caspase-8 (and caspase-10) activation is abrogated by inhibition of caspase-9 but not by inhibitors of the death receptor pathways. Furthermore, while caspase-8/-10 activity is required for the full induction of cell death with treatment, the death receptor pathways are not. Finally, we demonstrate that basal levels of caspase-8 and Bid correlate with treatment sensitivity. Our findings suggest that the combination of ABT-737 and Mcl-1 knockdown represents a promising, new treatment strategy for malignant melanoma. We also report a death receptor-independent role for extrinsic pathway proteins in treatment response and suggest that caspase-8 and Bid may represent potential markers of treatment sensitivity.

  20. RNA silencing of Mcl-1 enhances ABT-737-mediated apoptosis in melanoma: role for a caspase-8-dependent pathway.

    Directory of Open Access Journals (Sweden)

    Angela M Keuling

    Full Text Available BACKGROUND: Malignant melanoma is resistant to almost all conventional forms of chemotherapy. Recent evidence suggests that anti-apoptotic proteins of the Bcl-2 family are overexpressed in melanoma and may contribute to melanoma's striking resistance to apoptosis. ABT-737, a small-molecule inhibitor of Bcl-2, Bcl-xl and Bcl-w, has demonstrated efficacy in several forms of leukemia, lymphoma as well as solid tumors. However, overexpression of Mcl-1, a frequent observance in melanoma, is known to confer ABT-737 resistance. METHODOLOGY/PRINCIPAL FINDINGS: Here we report that knockdown of Mcl-1 greatly reduces cell viability in combination with ABT-737 in six different melanoma cell lines. We demonstrate that the cytotoxic effect of this combination treatment is due to apoptotic cell death involving not only caspase-9 activation but also activation of caspase-8, caspase-10 and Bid, which are normally associated with the extrinsic pathway of apoptosis. Caspase-8 (and caspase-10 activation is abrogated by inhibition of caspase-9 but not by inhibitors of the death receptor pathways. Furthermore, while caspase-8/-10 activity is required for the full induction of cell death with treatment, the death receptor pathways are not. Finally, we demonstrate that basal levels of caspase-8 and Bid correlate with treatment sensitivity. CONCLUSIONS/SIGNIFICANCE: Our findings suggest that the combination of ABT-737 and Mcl-1 knockdown represents a promising, new treatment strategy for malignant melanoma. We also report a death receptor-independent role for extrinsic pathway proteins in treatment response and suggest that caspase-8 and Bid may represent potential markers of treatment sensitivity.

  1. The mediational pathway among parenting styles, attachment styles and self-regulation with addiction susceptibility of adolescents*

    OpenAIRE

    Zeinali, Ali; Sharifi, Hassanpasha; Enayati, Mirsalahadine; Asgari, Parviz; Pasha, Gohlamreza

    2011-01-01

    Background: The purpose of present study was to create and test a model that illustrates variables that influence the development of addiction susceptibility and determine how different styles of parenting may indirectly influence the addiction susceptibility of children through the mediators of attachment style and self-regulation. Methods: Using random cluster sampling, 508 adolescent high school boys and girls aged 14-19 years were enrolled. Data were analyzed using structural equation...

  2. Steric Switching from Photochemical to Thermal Reaction Pathways for Enhanced Efficiency in Metal-Mediated Nitrogen Fixation.

    Science.gov (United States)

    Duman, Leila M; Farrell, Wesley S; Zavalij, Peter Y; Sita, Lawrence R

    2016-11-16

    Programmed manipulation of the subtle interplay of nonbonded steric interactions within a supporting ligand environment has been used for the conversion of a photochemically driven chemical cycle for group 6 metal-mediated nitrogen fixation into a thermally promoted process with increased energy efficiency and atom economy for key transformations involving N≡N bond cleavage and N-atom functionalization of coordinated N 2 .

  3. MicroRNA mediated network motifs in autoimmune diseases and its crosstalk between genes, functions and pathways.

    Science.gov (United States)

    Prabahar, Archana; Natarajan, Jeyakumar

    2017-01-01

    Autoimmune diseases (AIDs) are incurable but suppressible diseases whose molecular mechanisms are yet to be elucidated. In this work, we selected five systemic autoimmune diseases such as Rheumatoid Arthritis (RA), Type 1 Diabetes (T1D), Inflammatory Bowel Disease (IBD), Autoimmune Thyroid Disease (ATD) and Systemic Lupus Erythematosus (SLE). Heterogeneous data such as miRNA, transcription factor (TF), target genes and protein-protein interactions involved in these AIDs were integrated to understand their roles at different functional levels of miRNA such as transcription initiation, gene regulatory network formation and post transcriptional regulation. To understand the functional characteristics of these complex biological networks, they can be simplified as network motifs (sub networks) and motif-motif interacting pairs (MMIs). The network motif patterns and motif-motif interacting pairs that occur for the selected five diseases were identified. To further understand the functional association between AIDs, functions and pathways were determined using gene set enrichment analysis and five selected immune signaling pathways (ISPs). The crosstalk within AIDs and between the immune signaling pathways (ISPs) could provide novel insights in deciphering disease mechanisms. This study represents the first investigation of miRNA-TF regulatory network for AIDs and its association with ISPs using sub-network motifs. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. Acacetin protects against cardiac remodeling after myocardial infarction by mediating MAPK and PI3K/Akt signal pathway

    Directory of Open Access Journals (Sweden)

    Wei Chang

    2017-12-01

    Full Text Available Since inhibiting cardiac remodeling is a critical treatment goal after myocardial infarction (MI, many drugs have been evaluated for this purpose. Acacetin is a flavonoid compound that has been shown to have anti-cancer, anti-mutagenic, anti-inflammatory and anti-peroxidative effects. In this study, we investigated whether acacetin is able to exert a protective effect against MI. One week after anterior wall standard MI surgeries or sham surgeries were performed in mice, acacetin was administered via gavage for two weeks. The results of echocardiographic and hemodynamic evaluation revealed that cardiac dysfunction significantly improved after acacetin treatment. H&E staining indicated that the ratio of the infarct size and the cardiomyocyte cross-sectional area was decreased by acacetin. Masson's staining detected that the fibrotic area ratio was evidently lower in the acacetin-treated MI group. TUNEL assays showed that acacetin ameliorated cardiomyocyte apoptosis after MI. RT-qPCR analysis showed that levels of hypertrophic and fibrotic markers were significantly decreased after acacetin treatment. Western blot analysis of various signaling pathway proteins showed that acacetin targets the MAPK and PI3K/Akt signaling pathways. Collectively, acacetin improves mouse left ventricular function and attenuates cardiac remodeling by inhibiting of the MAPK and PI3K/Akt signaling pathway.

  5. Andrographolide sodium bisulfate-induced apoptosis and autophagy in human proximal tubular endothelial cells is a ROS-mediated pathway.

    Science.gov (United States)

    Lu, Hong; Zhang, Xin-Yue; Wang, Yi-Qi; Zheng, Xiao-Liang; Yin-Zhao; Xing, Wen-Min; Zhang, Qin

    2014-03-01

    The nephrotoxic mechanisms of andrographolide sodium bisulfate (ASB) remain largely unknown. This study attempted to explore the mechanism of ASB-induced nephrotoxicity using human proximal tubular endothelial cells (HK-2). For this study HK-2 cells were treated with rising concentrations of ASB. Their survival rate was detected using MTT assay and ultrastructure was observed with electron microscopy. L-Lactate dehydrogenase (LDH) assay was followed by examination of mitochondrial membrane potential (MMP). Reactive oxygen species (ROS) was detected using different methods and apoptosis/autophage related proteins were detected using immunoblotting. We found that ASB inhibited HK-2 cell proliferation and decreased cell survival rate in a time and dose-dependent manner (Papoptosis and autophagy were observed. MMP gradually decreased and ROS was induced. The expression of JNK and Beclin-1 increased and activation of the JNK signaling pathway were seen. Apoptosis was induced via the mitochondrial-dependent caspase-3 and caspase-9 pathway, and autophagy related protein Beclin-1 was enhanced by ASB. The data show that ASB induces high levels of ROS generation in HK-2 cells and activates JNK signaling. Furthermore, ASB induces cell apoptosis via the caspase-dependent mitochondrial pathway, and induces cellular autophagy, in part by enhancing Beclin-1 protein expression. Copyright © 2014 Elsevier B.V. All rights reserved.

  6. Hydrogen sulfide postconditioning protects isolated rat hearts against ischemia and reperfusion injury mediated by the JAK2/STAT3 survival pathway

    Directory of Open Access Journals (Sweden)

    Heng-Fei Luan

    2012-10-01

    Full Text Available The JAK2/STAT3 signal pathway is an important component of survivor activating factor enhancement (SAFE pathway. The objective of the present study was to determine whether the JAK2/STAT3 signaling pathway participates in hydrogen sulfide (H2S postconditioning, protecting isolated rat hearts from ischemic-reperfusion injury. Male Sprague-Dawley rats (230-270 g were divided into 6 groups (N = 14 per group: time-matched perfusion (Sham group, ischemia/reperfusion (I/R group, NaHS postconditioning group, NaHS with AG-490 group, AG-490 (5 µM group, and dimethyl sulfoxide (DMSO; <0.2% group. Langendorff-perfused rat hearts, with the exception of the Sham group, were subjected to 30 min of ischemia followed by 90 min of reperfusion after 20 min of equilibrium. Heart rate, left ventricular developed pressure (LVDP, left ventricular end-diastolic pressure (LVEDP, and the maximum rate of increase or decrease of left ventricular pressure (± dp/dt max were recorded. Infarct size was determined using triphenyltetrazolium chloride (TTC staining. Myocardial TUNEL staining was used as the in situ cell death detection method and the percentage of TUNEL-positive nuclei to all nuclei counted was used as the apoptotic index. The expression of STAT3, bcl-2 and bax was determined by Western blotting. After reperfusion, compared to the I/R group, H2S significantly improved functional recovery and decreased infarct size (23.3 ± 3.8 vs 41.2 ± 4.7%, P < 0.05 and apoptotic index (22.1 ± 3.6 vs 43.0 ± 4.8%, P < 0.05. However, H2S-mediated protection was abolished by AG-490, the JAK2 inhibitor. In conclusion, H2S postconditioning effectively protects isolated I/R rat hearts via activation of the JAK2/STAT3 signaling pathway.

  7. Lipopolysaccharide inhibits colonic biotin uptake via interference with membrane expression of its transporter: a role for a casein kinase 2-mediated pathway.

    Science.gov (United States)

    Lakhan, Ram; Said, Hamid M

    2017-04-01

    Biotin (vitamin B7), an essential micronutrient for normal cellular functions, is obtained from both dietary sources as well as gut microbiota. Absorption of biotin in both the small and large intestine is via a carrier-mediated process that involves the sodium-dependent multivitamin transporter (SMVT). Although different physiological and molecular aspects of intestinal biotin uptake have been delineated, nothing is known about the effect of LPS on the process. We addressed this issue using in vitro (human colonic epithelial NCM460 cells) and in vivo (mice) models of LPS exposure. Treating NCM460 cells with LPS was found to lead to a significant inhibition in carrier-mediated biotin uptake. Similarly, administration of LPS to mice led to a significant inhibition in biotin uptake by native colonic tissue. Although no changes in total cellular SMVT protein and mRNA levels were observed, LPS caused a decrease in the fraction of SMVT expressed at the cell surface. A role for casein kinase 2 (CK2) (whose activity was also inhibited by LPS) in mediating the endotoxin effects on biotin uptake and on membrane expression of SMVT was suggested by findings that specific inhibitors of CK2, as well as mutating the putative CK2 phosphorylation site (Thr 78 Ala) in the SMVT protein, led to inhibition in biotin uptake and membrane expression of SMVT. This study shows for the first time that LPS inhibits colonic biotin uptake via decreasing membrane expression of its transporter and that these effects likely involve a CK2-mediated pathway.

  8. Enhanced tolerance against early and late apoptotic oxidative stress in mammalian neurons through nicotinamidase and sirtuin mediated pathways.

    Science.gov (United States)

    Chong, Zhao Zhong; Maiese, Kenneth

    2008-08-01

    Focus upon therapeutic strategies that intersect between pathways that govern cellular metabolism and cellular survival may offer the greatest impact for the treatment of a number of neurodegenerative and metabolic disorders, such as diabetes mellitus. In this regard, we investigated the role of a Drosophila nicotinamidase (DN) in mammalian SH-SY5Y neuronal cells during oxidative stress. We demonstrate that during free radical exposure to nitric oxide generators DN neuronal expression significantly increased cell survival and blocked cellular membrane injury. Furthermore, DN neuronal expression prevented both apoptotic late DNA degradation and early phosphatidylserine exposure that may serve to modulate inflammatory cell activation in vivo. Nicotinamidase activity that limited nicotinamide cellular concentrations appeared to be necessary for DN neuroprotection, since application of progressive nicotinamide concentrations could abrogate the benefits of DN expression during oxidative stress. Pathways that involved sirtuin activation and SIRT1 were suggested to be vital, at least in part, for DN to confer protection through a series of studies. First, application of resveratrol increased cell survival during oxidative stress either alone or in conjunction with the expression of DN to a similar degree, suggesting that DN may rely upon SIRT1 activation to foster neuronal protection. Second, the overexpression of either SIRT1 or DN in neurons prevented apoptotic injury specifically in neurons expressing these proteins during oxidative stress, advancing the premise that DN and SIRT1 may employ similar pathways for neuronal protection. Third, inhibition of sirtuin activity with sirtinol was detrimental to neuronal survival during oxidative stress and prevented neuronal protection during overexpression of DN or SIRT1, further supporting that SIRT1 activity may be necessary for DN neuroprotection during oxidative stress. Implementation of further work to elucidate the

  9. Combined inhibition of p38 and Akt signaling pathways abrogates cyclosporine A-mediated pathogenesis of aggressive skin SCCs

    International Nuclear Information System (INIS)

    Arumugam, Aadithya; Walsh, Stephanie B.; Xu, Jianmin; Afaq, Farrukh; Elmets, Craig A.; Athar, Mohammad

    2012-01-01

    Highlights: ► p38 and Akt are the crucial molecular targets in the pathogenesis of SCCs in OTRs. ► Combined inhibition of these targets diminished tumor growth by 90%. ► Inhibition of these targets act through downregulating mTOR signaling pathway. -- Abstract: Non-melanoma skin cancers (NMSCs) are the most common neoplasm in organ transplant recipients (OTRs). These cancers are more invasive and metastatic as compared to those developed in normal cohorts. Previously, we have shown that immunosuppressive drug, cyclosporine A (CsA) directly alters tumor phenotype of cutaneous squamous cell carcinomas (SCCs) by activating TGF-β and TAK1/TAB1 signaling pathways. Here, we identified novel molecular targets for the therapeutic intervention of these SCCs. We observed that combined blockade of Akt and p38 kinases-dependent signaling pathways in CsA-promoted human epidermoid carcinoma A431 xenograft tumors abrogated their growth by more than 90%. This diminution in tumor growth was accompanied by a significant decrease in proliferation and an increase in apoptosis. The residual tumors following the combined treatment with Akt inhibitor triciribine and p38 inhibitors SB-203580 showed significantly diminished expression of phosphorylated Akt and p38 and these tumors were less invasive and highly differentiated. Diminished tumor invasiveness was associated with the reduced epithelial–mesenchymal transition as ascertained by the enhanced E-cadherin and reduced vimentin and N-cadherin expression. Consistently, these tumors also manifested reduced MMP-2/9. The decreased p-Akt expression was accompanied by a significant reduction in p-mTOR. These data provide first important combinatorial pharmacological approach to block the pathogenesis of CsA-induced highly aggressive cutaneous neoplasm in OTRs.

  10. Combined inhibition of p38 and Akt signaling pathways abrogates cyclosporine A-mediated pathogenesis of aggressive skin SCCs

    Energy Technology Data Exchange (ETDEWEB)

    Arumugam, Aadithya; Walsh, Stephanie B.; Xu, Jianmin; Afaq, Farrukh [Department of Dermatology, University of Alabama at Birmingham, Birmingham, AL 35294-0019 (United States); Elmets, Craig A. [Department of Dermatology, University of Alabama at Birmingham, Birmingham, AL 35294-0019 (United States); Skin Diseases Research Center, University of Alabama at Birmingham, Birmingham, AL 35294 (United States); Athar, Mohammad, E-mail: mathar@uab.edu [Department of Dermatology, University of Alabama at Birmingham, Birmingham, AL 35294-0019 (United States); Skin Diseases Research Center, University of Alabama at Birmingham, Birmingham, AL 35294 (United States)

    2012-08-24

    Highlights: Black-Right-Pointing-Pointer p38 and Akt are the crucial molecular targets in the pathogenesis of SCCs in OTRs. Black-Right-Pointing-Pointer Combined inhibition of these targets diminished tumor growth by 90%. Black-Right-Pointing-Pointer Inhibition of these targets act through downregulating mTOR signaling pathway. -- Abstract: Non-melanoma skin cancers (NMSCs) are the most common neoplasm in organ transplant recipients (OTRs). These cancers are more invasive and metastatic as compared to those developed in normal cohorts. Previously, we have shown that immunosuppressive drug, cyclosporine A (CsA) directly alters tumor phenotype of cutaneous squamous cell carcinomas (SCCs) by activating TGF-{beta} and TAK1/TAB1 signaling pathways. Here, we identified novel molecular targets for the therapeutic intervention of these SCCs. We observed that combined blockade of Akt and p38 kinases-dependent signaling pathways in CsA-promoted human epidermoid carcinoma A431 xenograft tumors abrogated their growth by more than 90%. This diminution in tumor growth was accompanied by a significant decrease in proliferation and an increase in apoptosis. The residual tumors following the combined treatment with Akt inhibitor triciribine and p38 inhibitors SB-203580 showed significantly diminished expression of phosphorylated Akt and p38 and these tumors were less invasive and highly differentiated. Diminished tumor invasiveness was associated with the reduced epithelial-mesenchymal transition as ascertained by the enhanced E-cadherin and reduced vimentin and N-cadherin expression. Consistently, these tumors also manifested reduced MMP-2/9. The decreased p-Akt expression was accompanied by a significant reduction in p-mTOR. These data provide first important combinatorial pharmacological approach to block the pathogenesis of CsA-induced highly aggressive cutaneous neoplasm in OTRs.

  11. Hesperidin inhibits HeLa cell proliferation through apoptosis mediated by endoplasmic reticulum stress pathways and cell cycle arrest

    International Nuclear Information System (INIS)

    Wang, Yaoxian; Yu, Hui; Zhang, Jin; Gao, Jing; Ge, Xin; Lou, Ge

    2015-01-01

    Hesperidin (30, 5, 9-dihydroxy-40-methoxy-7-orutinosyl flavanone) is a flavanone that is found mainly in citrus fruits and has been shown to have some anti-neoplastic effects. The aim of the present study was to investigate the effect of hesperidin on apoptosis in human cervical cancer HeLa cells and to identify the mechanism involved. Cells were treated with hesperidin (0, 20, 40, 60, 80, and 100 μM) for 24, 48, or 72 h and relative cell viability was assessed using the 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay. Hesperidin inhibited the proliferation of HeLa cells in a concentration- and time-dependent manner. Hesperidin-induced apoptosis in HeLa cells was characterized by increased nuclear condensation and DNA fragmentation. Furthermore, increased levels of GADD153/CHOP and GRP78 indicated hesperidin-induced apoptosis in HeLa cells involved a caspase-dependent pathway, presumably downstream of the endoplasmic reticulum stress pathway. Both of these proteins are hallmarks of endoplasmic reticulum stress. Hesperidin also promoted the formation of reactive oxygen species, mobilization of intracellular Ca 2+ , loss of mitochondrial membrane potential (ΔΨm), increased release of cytochrome c and apoptosis-inducing factor from mitochondria, and promoted capase-3 activation. It also arrested HeLa cells in the G0/G1 phase in the cell cycle by downregulating the expression of cyclinD1, cyclinE1, and cyclin-dependent kinase 2 at the protein level. The effect of hesperidin was also verified on the human colon cancer cell HT-29 cells. We concluded that hesperidin inhibited HeLa cell proliferation through apoptosis involving endoplasmic reticulum stress pathways and cell cycle arrest

  12. UV induced foot duplication in regenerating hydra is mediated by metalloproteinases and modulation of the Wnt pathway.

    Science.gov (United States)

    Krishnapati, Lakshmi-Surekha; Londhe, Rohini; Deoli, Vaishali; Barve, Apurva; Ghaskadbi, Saroj; Ghaskadbi, Surendra

    2016-01-01

    We have shown earlier that irradiation with UV induces duplication of foot in regenerating middle pieces of hydra. The present study was undertaken to elucidate the underlying mechanism(s) leading to this curious phenomenon. UV irradiation induced duplicated foot in about 30% of regenerating middle pieces. Metalloproteinases are important in foot formation, while Wnt pathway genes are important in head formation in hydra. The effect of UV irradiation on expression of these genes was studied by in situ hybridization and q-PCR. In whole polyps and middle pieces, UV irradiation led to up-regulation of HMP2 and HMMP, the two metalloproteinases involved in foot formation in hydra. HMP2 expression was significantly increased starting from 30 min post exposure to UV at 254 nm (500 J/m(2)), while HMMP showed significant up-regulation 6 h post UV exposure onwards. In middle pieces, increased expression of both metalloproteinases was observed only at 48 h. In whole polyps as well as in middle pieces, expression of Wnt3 and β-catenin was detected within 30 min of UV exposure and was accompanied by up-regulation of GSK3β, DKK3 and DKK1/2/4, inhibitors of the Wnt pathway. These conditions likely lead to inactivation of Wnt signaling. We therefore conclude that duplication of foot due to UV irradiation in regenerating middle pieces of hydra is a combined effect of up-regulation of metalloproteinases and inactivation of the Wnt pathway. Our results suggest that UV irradiation can be employed as a tool to understand patterning mechanisms during foot formation in hydra.

  13. Identifying Signalling Pathways Regulated by GPRC5B in β-Cells by CRISPR-Cas9-Mediated Genome Editing

    Directory of Open Access Journals (Sweden)

    Patricio Atanes

    2018-01-01

    Full Text Available Background/Aims: CRISPR-Cas9, a RNA-guided targeted genome editing tool, has revolutionized genetic engineering by offering the ability to precisely modify DNA. GPRC5B is an orphan receptor belonging to the group C family of G protein-coupled receptors (GPCRs. In this study, we analysed the functional roles of the Gprc5b receptor in MIN6 β-cells using CRISPR-Cas9 and transient over-expression of Gprc5b. Methods: The optimal transfection reagent for use in MIN6 β-cells was determined by analysing efficiency of GFP plasmid delivery by cell sorting. A MIN6 β-cell line in which Gprc5b expression was knocked down (Gprc5b KD was generated using CRISPR-Cas9 technology. Gprc5b receptor mRNA expression, proliferation, apoptosis, Cignal 45-Pathway Reporter Array signalling and western blot assays were carried out using Gpcr5b KD MIN6 β-cells that had been transiently transfected with different concentrations of mouse Gprc5b plasmid to over-express Gprc5b. Results: JetPRIME® was the best candidate for MIN6 β-cell transfection, providing approximately 30% transfection efficiency. CRISPR-Cas9 technology targeting Gprc5b led to stable knock-down of this receptor in MIN6 β-cells and its re-expression induced proliferation and potentiated cytokine- and palmitate-induced apoptosis. The Cignal 45 Reporter analysis indicated Gprc5b-dependent regulation of apoptotic and proliferative pathways, and western blotting confirmed activation of signalling via TGF-β and IFNγ. Conclusion: This study provides evidence of CRISPR-Cas9 technology being used to down-regulate Gprc5b expression in MIN6 β-cells. This strategy allowed us to identify signalling pathways linking GPRC5B receptor expression to β-cell proliferation and apoptosis.

  14. Procarcinogenic effects of cyclosporine A are mediated through the activation of TAK1/TAB1 signaling pathway

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Jianmin; Walsh, Stephanie B.; Verney, Zoe M. [Department of Dermatology, University of Alabama at Birmingham, AL 35294 (United States); Kopelovich, Levy [Division of Cancer Prevention, National Cancer Institute, Bethesda, MD (United States); Elmets, Craig A. [Department of Dermatology, University of Alabama at Birmingham, AL 35294 (United States); Skin Diseases Research Center, University of Alabama at Birmingham, AL 35294 (United States); Athar, Mohammad, E-mail: mathar@uab.edu [Department of Dermatology, University of Alabama at Birmingham, AL 35294 (United States); Skin Diseases Research Center, University of Alabama at Birmingham, AL 35294 (United States)

    2011-05-13

    Research highlights: {yields} Organ transplant recipients are highly susceptible to early skin cancer development. {yields} CsA-mediated TGFB1-dependent TAK1/TAB1 signaling augments invasive tumor growth. {yields} CsA enhances accumulation of upstream kinases, ZMP, AMPK and IRAK to activate TAK1. {yields} TAK1 mediates enhanced proliferation and reduced apoptosis via CsA-dependent NF{kappa}B. -- Abstract: Cyclosporine A (CsA) is an immunosuppressive drug commonly used for maintaining chronic immune suppression in organ transplant recipients. It is known that patients receiving CsA manifest increased growth of aggressive non-melanoma skin cancers. However, the underlying mechanism by which CsA augments tumor growth is not fully understood. Here, we show that CsA augments the growth of A431 epidermoid carcinoma xenograft tumors by activating tumor growth factor {beta}-activated kinase1 (TAK1). The activation of TAK1 by CsA occurs at multiple levels by kinases ZMP, AMPK and IRAK. TAK1 forms heterodimeric complexes with TAK binding protein 1 and 2 (TAB1/TAB2) which in term activate nuclear factor {kappa}B (NF{kappa}B) and p38 MAP kinase. Transcriptional activation of NF{kappa}B is evidenced by IKK{beta}-mediated phosphorylation-dependent degradation of I{kappa}B and consequent nuclear translocation of p65. This also leads to enhancement in the expression of its transcriptional target genes cyclin D1, Bcl2 and COX-2. Similarly, activation of p38 leads to enhanced inflammation-related signaling shown by increased phosphorylation of MAPKAPK2 and which in turn phosphorylates its substrate HSP27. Activation of both NF{kappa}B and p38 MAP kinase provide mitogenic stimuli to augment the growth of SCCs.

  15. Oxidative stress induced by palytoxin in human keratinocytes is mediated by a H{sup +}-dependent mitochondrial pathway

    Energy Technology Data Exchange (ETDEWEB)

    Pelin, Marco, E-mail: marco.pelin@phd.units.it [Department of Life Science, University of Trieste, Via L. Giorgieri 7/9, 34127 Trieste (Italy); Ponti, Cristina, E-mail: cponti@units.it [Department of Life Science, University of Trieste, Via L. Giorgieri 7/9, 34127 Trieste (Italy); Sosa, Silvio, E-mail: silvio.sosa@econ.units.it [Department of Life Science, University of Trieste, Via L. Giorgieri 7/9, 34127 Trieste (Italy); Gibellini, Davide, E-mail: davide.gibellini@unibo.it [Department of Haematology and Oncological Sciences, University of Bologna, Via Massarenti 9, 40138 Bologna (Italy); Florio, Chiara, E-mail: florioc@units.it [Department of Life Science, University of Trieste, Via L. Giorgieri 7/9, 34127 Trieste (Italy); Tubaro, Aurelia, E-mail: tubaro@units.it [Department of Life Science, University of Trieste, Via L. Giorgieri 7/9, 34127 Trieste (Italy)

    2013-01-01

    In the last decades, massive blooms of palytoxin (PLTX)-producing Ostreopsis cf. ovata have been observed along Mediterranean coasts, usually associated to human respiratory and cutaneous problems. At the molecular level, PLTX induces a massive intracellular Na{sup +} influx due to the transformation of Na{sup +}/K{sup +} ATPase in a cationic channel. Recently, we have demonstrated that Na{sup +} overload is the crucial step in mediating overproduction of reactive oxygen species (ROS) and cell death in human HaCaT keratinocytes, tentatively explaining PLTX-induced skin irritant effects. In the present study the molecular mechanisms of ROS production induced by PLTX-mediated Na{sup +} intracellular overload have been investigated. In HaCaT cells, PLTX exposure caused accumulation of superoxide anion, but not of nitric oxide or peroxynitrite/hydroxyl radicals. Even if RT-PCR and western blot analysis revealed an early NOX-2 and iNOS gene and protein over-expressions, their active involvement seemed to be only partial since selective inhibitors did not completely reduce O{sub 2}{sup −} production. A significant role of other enzymes (COX-1, COX-2, XO) was not evidenced. Nigericin, that counteracts Na{sup +}-mediated H{sup +}-imbalance, dissipating ΔpH across mitochondrial inner membrane, and the uncouplers DNP significantly reduced O{sub 2}{sup −} production. These inhibitions were synergistic when co-exposed with complex-I inhibitor rotenone. These results suggest a novel mechanism of O{sub 2}{sup −} production induced by PLTX-mediated ionic imbalance. Indeed, the H{sup +} intracellular overload that follows PLTX-induced intracellular Na{sup +} accumulation, could enhance ΔpH across mitochondrial inner membrane, that seems to be the driving force for O{sub 2}{sup −} production by reversing mitochondrial electron transport. Highlights: ► PLTX induces superoxide (O{sub 2}{sup −}) production by reversing mitochondrial transport chain. ► The mechanism of

  16. IgE mediates killing of intracellular Toxoplasma gondii by human macrophages through CD23-dependent, interleukin-10 sensitive pathway.

    Directory of Open Access Journals (Sweden)

    Ioannis Vouldoukis

    Full Text Available BACKGROUND: In addition to helminthic infections, elevated serum IgE levels were observed in many protozoal infections, while their contribution during immune response to these pathogens remained unclear. As IgE/antigen immune complexes (IgE-IC bind to human cells through FcεRI or FcεRII/CD23 surface molecules, the present study aimed to identify which functional receptor may be involved in IgE-IC interaction with human macrophages, the major effector cell during parasite infection. METHODOLOGY/PRINCIPAL FINDINGS: Human monocyte-derived macrophages were infected with Toxoplasma gondii before being incubated with IgE-IC. IgE receptors were then identified using appropriate blocking antibodies. The activation of cells and parasiticidal activity were evaluated by mediator quantification and direct counting of infected macrophages. RNAs were extracted and cell supernatants were also collected for their content in tumor necrosis factor (TNF-α, interleukin-10 (IL-10 and nitrites. Sera from symptomatic infected patients were also tested for their content of IgE, IL-10 and nitrites, and compared to values found in healthy donors. Results showed that IgE-IC induced intracellular elimination of parasites by human macrophages. IgE-mediated effect was FcεRI-independent, but required cross-linking of surface FcεRII/CD23, cell activation and the generation of nitric oxide (NO. Although TNF-α was shown to be produced during cell activation, this cytokine had minor contribution in this phenomenon while endogenous and exogenous IL-10 down-regulated parasite killing. Inverse relationship was found between IL-10 and NO expression by infected human macrophages at both mRNA and mediator levels. The relationship between these in vitro data and in vivo levels of various factors in T. gondii infected patients supports the involvement of CD23 antigen and IL-10 expression in disease control. CONCLUSION: Thus, IgE may be considered as immune mediator during

  17. Both p53-PUMA/NOXA-Bax-mitochondrion and p53-p21cip1 pathways are involved in the CDglyTK-mediated tumor cell suppression

    International Nuclear Information System (INIS)

    Yu, Zhendong; Wang, Hao; Zhang, Libin; Tang, Aifa; Zhai, Qinna; Wen, Jianxiang; Yao, Li; Li, Pengfei

    2009-01-01

    CDglyTK fusion suicide gene has been well characterized to effectively kill tumor cells. However, the exact mechanism and downstream target genes are not fully understood. In our study, we found that CDglyTK/prodrug treatment works more efficiently in p53 wild-type (HONE1) cells than in p53 mutant (CNE1) cells. We then used adenovirus-mediated gene delivery system to either knockdown or overexpress p53 and its target genes in these cells. Consistent results showed that both p53-PUMA/NOXA/Bcl2-Bax and p53-p21 pathways contribute to the CDglyTK induced tumor cell suppression. Our work for the first time addressed the role of p53 related genes in the CDglyTK/prodrug system.

  18. Phosphorylation of threonine residues on Shc promotes ligand binding and mediates crosstalk between MAPK and Akt pathways in breast cancer cells

    KAUST Repository

    Suen, K.M.

    2017-12-06

    Scaffold proteins play important roles in regulating signalling network fidelity, the absence of which is often the basis for diseases such as cancer. In the present work, we show that the prototypical scaffold protein Shc is phosphorylated by the extracellular signal-regulated kinase, Erk. In addition, Shc threonine phosphorylation is specifically up-regulated in two selected triple-negative breast cancer (TNBC) cell lines. To explore how Erk-mediated threonine phosphorylation on Shc might play a role in the dysregulation of signalling events, we investigated how Shc affects pathways downstream of EGF receptor. Using an in vitro model and biophysical analysis, we show that Shc threonine phosphorylation is responsible for elevated Akt and Erk signalling, potentially through the recruitment of the 14-3-3 ζ and Pin-1 proteins.

  19. Grape seed proanthocyanidins (GSPs inhibit the growth of cervical cancer by inducing apoptosis mediated by the mitochondrial pathway.

    Directory of Open Access Journals (Sweden)

    Qing Chen

    Full Text Available Grape seed proanthocyanidins (GSPs, a biologically active component of grape seeds, have been reported to possess a wide array of pharmacological and biochemical properties. Recently, the inhibitory effects of GSPs on various cancers have been reported, but their effects on cervical cancer remain unclear. Here, we explored the effect of GSPs on cervical cancer using in vitro and in vivo models. In vitro, the treatment of HeLa and SiHa cells with GSPs resulted in a significant inhibition of cell viability. Further investigation indicated that GSPs led to the dose-dependent induction of apoptosis in cancer cells. The underlying mechanism was associated with increased expression of the pro-apoptotic protein Bak-1, decreased expression of the anti-apoptotic protein Bcl-2, the loss of mitochondrial membrane potential, and the activation of caspase-3, suggesting that GSPs induced cervical cancer cell apoptosis through the mitochondrial pathway. In addition, the administration of GSPs (0.1%, 0.2%, and 0.4%, w/v as a supplement in drinking water significantly inhibited the tumor growth of HeLa and SiHa cells in athymic nude mice, and the number of apoptotic cells in those tumors was also increased significantly. Taken together, our studies demonstrated that GSPs could inhibit the growth of cervical cancer by inducing apoptosis through the mitochondrial pathway, which provides evidence indicating that GSPs may be a potential chemopreventive and/or chemotherapeutic agent for cervical cancer.

  20. Plant Oxygen Sensing Is Mediated by the N-End Rule Pathway: A Milestone in Plant Anaerobiosis

    Science.gov (United States)

    Sasidharan, Rashmi; Mustroph, Angelika

    2011-01-01

    Like all aerobic organisms, plants require molecular oxygen for respiratory energy production. In plants, hypoxic conditions can occur during natural events (e.g., flooding), during developmental processes (e.g., seed germination), and in cells of compact tissues with high metabolic rates. Plant acclimation responses to hypoxia involve a modulation of gene expression leading to various biochemical, physiological, and morphological changes that stave off eventual anoxia. In contrast with the animal kingdom, a direct oxygen-sensing mechanism in plants has been elusive so far. However, two recent independent studies show that oxygen sensing in plants operates via posttranslational regulation of key hypoxia response transcription factors by the N-end rule pathway. The N-end rule is an evolutionarily conserved pathway for protein degradation that relates the fate of a protein with the identity of its N-terminal residues. Results from these studies demonstrate that oxygen-dependent modification and targeted proteolysis of members of the ethylene response factor group VII transcription factor family regulate hypoxia-responsive gene expression in Arabidopsis thaliana. The discovery of this plant hypoxia-sensing mechanism sets the stage for further research on plant homeostatic response to oxygen, which could be relevant to understanding plant distributions in flood-prone ecosystems and improving hypoxia tolerance of crops. PMID:22207573

  1. Naringin prevents ovariectomy-induced osteoporosis and promotes osteoclasts apoptosis through the mitochondria-mediated apoptosis pathway

    Energy Technology Data Exchange (ETDEWEB)

    Li, Fengbo [Tianjin Institute of Orthopedics in Traditional Chinese and Western Medicine, No. 155, Munan Road, Tianjin TJ 300050 (China); Graduate School of Tianjin Medical University, No. 22, Qixiangtai Street, Heping District, Tianjin 300070 (China); Sun, Xiaolei; Ma, Jianxiong [Tianjin Institute of Orthopedics in Traditional Chinese and Western Medicine, No. 155, Munan Road, Tianjin TJ 300050 (China); Ma, Xinlong, E-mail: gengxiao502@163.com [Tianjin Institute of Orthopedics in Traditional Chinese and Western Medicine, No. 155, Munan Road, Tianjin TJ 300050 (China); Zhao, Bin; Zhang, Yang; Tian, Peng [Tianjin Institute of Orthopedics in Traditional Chinese and Western Medicine, No. 155, Munan Road, Tianjin TJ 300050 (China); Li, Yanjun [Graduate School of Tianjin Medical University, No. 22, Qixiangtai Street, Heping District, Tianjin 300070 (China); Han, Zhe [Tianjin Institute of Orthopedics in Traditional Chinese and Western Medicine, No. 155, Munan Road, Tianjin TJ 300050 (China)

    2014-09-26

    Highlights: • Naringin possesses many pharmacological activities, promotes the proliferation of osteoblast. • Undecalcified histological obtain dynamic parameters of callus formation and remodeling. • Naringin regulate osteoclast apoptosis by mitochondrial pathway. - Abstract: Naringin, the primary active compound of the traditional Chinese medicine Rhizoma drynariae, possesses many pharmacological activities. The present study is an effort to explore the anti-osteoporosis potential of naringin in vivo and in vitro. In vivo, we used ovariectomized rats to clarify the mechanisms by which naringin anti-osteoporosis. In vitro, we used osteoclasts to investigate naringin promotes osteoclasts apoptosis. Naringin was effective at enhancing BMD, trabecular thickness, bone mineralization, and mechanical strength in a dose-dependent manner. The result of RT-PCR analysis revealed that naringin down-regulated the mRNA expression levels of BCL-2 and up-regulated BAX, caspase-3 and cytochrome C. In addition, naringin significantly reduced the bone resorption area in vitro. These findings suggest that naringin promotes the apoptosis of osteoclasts by regulating the activity of the mitochondrial apoptosis pathway and prevents OVX-induced osteoporosis in rats.

  2. Naringin prevents ovariectomy-induced osteoporosis and promotes osteoclasts apoptosis through the mitochondria-mediated apoptosis pathway

    International Nuclear Information System (INIS)

    Li, Fengbo; Sun, Xiaolei; Ma, Jianxiong; Ma, Xinlong; Zhao, Bin; Zhang, Yang; Tian, Peng; Li, Yanjun; Han, Zhe

    2014-01-01

    Highlights: • Naringin possesses many pharmacological activities, promotes the proliferation of osteoblast. • Undecalcified histological obtain dynamic parameters of callus formation and remodeling. • Naringin regulate osteoclast apoptosis by mitochondrial pathway. - Abstract: Naringin, the primary active compound of the traditional Chinese medicine Rhizoma drynariae, possesses many pharmacological activities. The present study is an effort to explore the anti-osteoporosis potential of naringin in vivo and in vitro. In vivo, we used ovariectomized rats to clarify the mechanisms by which naringin anti-osteoporosis. In vitro, we used osteoclasts to investigate naringin promotes osteoclasts apoptosis. Naringin was effective at enhancing BMD, trabecular thickness, bone mineralization, and mechanical strength in a dose-dependent manner. The result of RT-PCR analysis revealed that naringin down-regulated the mRNA expression levels of BCL-2 and up-regulated BAX, caspase-3 and cytochrome C. In addition, naringin significantly reduced the bone resorption area in vitro. These findings suggest that naringin promotes the apoptosis of osteoclasts by regulating the activity of the mitochondrial apoptosis pathway and prevents OVX-induced osteoporosis in rats

  3. The MicroRNA390/TAS3 Pathway Mediates Symbiotic Nodulation and Lateral Root Growth1[OPEN

    Science.gov (United States)

    Bustos-Sanmamed, Pilar; Mysore, Kirankumar S.

    2017-01-01

    Legume roots form two types of postembryonic organs, lateral roots and symbiotic nodules. Nodule formation is the result of the interaction of legumes with rhizobia and requires the mitotic activation and differentiation of root cells as well as an independent, but coordinated, program that allows infection by rhizobia. MicroRNA390 (miR390) is an evolutionarily conserved microRNA that targets the Trans-Acting Short Interference RNA3 (TAS3) transcript. Cleavage of TAS3 by ARGONAUTE7 results in the production of trans-acting small interference RNAs, which target mRNAs encoding AUXIN RESPONSE FACTOR2 (ARF2), ARF3, and ARF4. Here, we show that activation of the miR390/TAS3 regulatory module by overexpression of miR390 in Medicago truncatula promotes lateral root growth but prevents nodule organogenesis, rhizobial infection, and the induction of two key nodulation genes, Nodulation Signaling Pathway1 (NSP1) and NSP2. Accordingly, inactivation of the miR390/TAS3 module, either by expression of a miR390 target mimicry construct or mutations in ARGONAUTE7, enhances nodulation and rhizobial infection, alters the spatial distribution of the nodules, and increases the percentage of nodules with multiple meristems. Our results revealed a key role of the miR390/TAS3 pathway in legumes as a modulator of lateral root organs, playing opposite roles in lateral root and nodule development. PMID:28663332

  4. Piroxicam and C-phycocyanin mediated apoptosis in 1,2-dimethylhydrazine dihydrochloride induced colon carcinogenesis: exploring the mitochondrial pathway.

    Science.gov (United States)

    Saini, Manpreet Kaur; Sanyal, Sankar Nath; Vaiphei, Kim

    2012-04-01

    Apoptosis is a synchronized procedure of cell death that is regulated by caspases and proapoptotic proteins. During apoptosis, translocation of cytochrome c, an electron carrier, from mitochondria into the cytosol is regulated by Bcl-2 family members. Cytochrome c in association with an apoptotic protease activating factor (Apaf), a proapoptotic protein essential for cell differentiation and procaspase-9 form the apoptosome complex, which consecutively activates effector caspase, caspase-3, and coordinate the implementation of apoptosis. In the current study, an attempt has been made to gain insight into piroxicam, a traditional nonsteroidal antiinflammatory drug and c-phycocyanin, a biliprotein from Spirulina platensis (cyanobacterium) mediated apoptosis in DMH-induced colon cancer. Male Sprague-Dawley rats were segregated into 5 groups: control, DMH, DMH + piroxicam, DMH + c-phycocyanin, and DMH + piroxicam + c-phycocyanin. Results illustrated that piroxicam and c-phycocyanin treatments stimulate cytochrome c release by downregulating the Bcl-2 (an antiapoptotic protein) expression significantly, while promoting the level of Bax (a proapoptotic protein), thereby activating caspases (caspases-9 and -3) and Apaf-1. The outcomes of the present study clearly signify that piroxicam and c-phycocyanin may mediate mitochondrial-dependent apoptosis in DMH-induced colon cancer. Moreover, apoptosis induction was more apparent in the combination regimen of piroxicam and c-phycocyanin than the individual drugs alone.

  5. Helicobacter pylori-derived Heat shock protein 60 enhances angiogenesis via a CXCR2-mediated signaling pathway

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Chen-Si [Department of Biological Science and Technology, National Chiao-Tung University, Hsin-Chu, Taiwan (China); School of Veterinary Medicine, National Taiwan University, Taipei, Taiwan (China); He, Pei-Juin; Hsu, Wei-Tung [Department of Biological Science and Technology, National Chiao-Tung University, Hsin-Chu, Taiwan (China); Wu, Ming-Shiang [Department of Internal Medicine, College of Medicine, National Taiwan University, Taipei, Taiwan (China); Wu, Chang-Jer [Department of Food Science, National Taiwan Ocean University, Keelung, Taiwan (China); Shen, Hsiao-Wei [Institute of Molecular Medicine and Bioengineering, National Chiao-Tung University, Hsin-Chu, Taiwan (China); Hwang, Chia-Hsiang [Yung-Shin Pharmaceutical Industry Co., Ltd., Tachia, Taichung, Taiwan (China); Lai, Yiu-Kay [Department of Life Science, Institute of Biotechnology, National Tsing Hua University, Hsin-Chu, Taiwan (China); Tsai, Nu-Man [School of Medical Laboratory and Biotechnology, Chung Shan Medical University, Taichung, Taiwan (China); Liao, Kuang-Wen, E-mail: kitchhen@yahoo.com.tw [Institute of Molecular Medicine and Bioengineering, National Chiao-Tung University, Hsin-Chu, Taiwan (China)

    2010-06-25

    Helicobacter pylori is a potent carcinogen associated with gastric cancer malignancy. Recently, H. pylori Heat shock protein 60 (HpHSP60) has been reported to promote cancer development by inducing chronic inflammation and promoting tumor cell migration. This study demonstrates a role for HpHSP60 in angiogenesis, a necessary precursor to tumor growth. We showed that HpHSP60 enhanced cell migration and tube formation, but not cell proliferation, in human umbilical vein endothelial cells (HUVECs). HpHSP60 also indirectly promoted HUVEC proliferation when HUVECs were co-cultured with supernatants collected from HpHSP60-treated AGS or THP-1 cells. The angiogenic array showed that HpHSP60 dramatically induced THP-1 cells and HUVECs to produce the chemotactic factors IL-8 and GRO. Inhibition of CXCR2, the receptor for IL-8 and GRO, or downstream PLC{beta}2/Ca2+-mediated signaling, significantly abolished HpHSP60-induced tube formation. In contrast, suppression of MAP K or PI3 K signaling did not affect HpHSP60-mediated tubulogenesis. These data suggest that HpHSP60 enhances angiogenesis via CXCR2/PLC{beta}2/Ca2+ signal transduction in endothelial cells.

  6. Apigenin inhibits release of inflammatory mediators by blocking the NF-κB activation pathways in the HMC-1 cells.

    Science.gov (United States)

    Kang, Ok-Hwa; Lee, John-Hwa; Kwon, Dong-Yeul

    2011-09-01

    Apigenin is a plant flavonoid and a pharmacologically active agent that has been isolated from several plant species. However, the molecular mechanism of apigenin-mediated immune modulation has not been fully understood. One of the possible mechanisms of its protective effects is the down-regulation of inflammatory responses. In this study, we used cells from the human mast cell line (HMC-1) to investigate this effect. Apigenin significantly inhibits the inductive effect of phorbol 12-myristate 13-acetate (PMA) plus A23187 on the production of inflammatory cytokines such as tumor necrosis factor (TNF)-α, interleukin (IL)-8, IL-6, and granulocyte-macrophage colony-stimulating factor (GM-CSF). Moreover, apigenin attenuated the cyclooxygenase (COX)-2 expression and intracellular Ca(2+) level. In activated HMC-1 cells, apigenin inhibited the PMA plus A23187-induced activation of nuclear factor (NF)-κB, IκB degradation, and luciferase activity. Furthermore, apigenin suppressed the expression of TNF-α, IL-8, IL-6, GM-CSF, and COX-2 by decreasing the intracellular Ca(2+) level and inhibiting NF-κB activation. These results indicate that apigenin has a potential regulatory effect on inflammatory reactions that are mediated by mast cells.

  7. Physiological crosstalk between the AC/PKA and PLC/PKC pathways modulates melatonin-mediated, monochromatic-light-induced proliferation of T-lymphocytes in chickens.

    Science.gov (United States)

    Guo, Qingyun; Wang, Zixu; Dong, Yulan; Cao, Jing; Chen, Yaoxing

    2017-09-01

    Previous study has demonstrated that melatonin plays a critical role in monochromatic-light-induced lymphocyte proliferation in response to T cell mitogen concanavalin A (ConA). However, its intracellular mechanism is still unclear. In this study, we investigate the intracellular signal pathways of melatonin receptor-mediated T-lymphocyte proliferation in the spleens of chicks exposed to different light wavelengths. Results showed that green light enhanced T-lymphocyte proliferation by 2.46-6.83% and increased splenic mRNA and protein expressions of melatonin receptor subtypes (Mel1a, Mel1b and Mel1c) by 16.05-40.43% compared with the white, red and blue light groups. However, pinealectomy resulted in a decrease in T-lymphocyte proliferation and melatonin receptor expression with no statistically significant differences between the different light groups. In vitro experiments showed that the Mel1b selective antagonist 4P-PDOT, the Mel1c selective antagonist prazosin and the mitogen-activated protein kinase kinase-1 (MEK-1) inhibitor PD98059 suppressed both melatonin-induced lymphocyte proliferation in response to ConA and melatonin- and ConA-stimulated extracellular signal-regulated kinase 1/2 (ERK1/2) activity but that the Mel1a/Mel1b non-selective antagonist luzindole did not. In addition, pretreatment with forskolin (FSK, the adenylyl cyclase activator), H89 (the PKA inhibitor), U73122 (the PLC inhibitor) or Go6983 (the broad spectrum PKC inhibitor) markedly attenuated melatonin- and ConA-stimulated T-lymphocyte proliferation and ERK1/2 activity. These results demonstrate that melatonin mediates green-light-induced T-lymphocyte proliferation via the Mel1b and Mel1c receptors by triggering crosstalk between the cAMP/PKA and PLC/PKC signal pathways followed by ERK1/2 activation.

  8. The mitogen-activated protein kinase pathway mediates growth arrest or E1A-dependent apoptosis in SKBR3 human breast cancer cells.

    Science.gov (United States)

    Blagosklonny, M V

    1998-11-09

    Previously, we have shown that phorbol ester (PMA) induces p21(WAF1/CIP1)-dependent growth arrest in SKBr3 breast cancer and LNCaP prostate cancer cells. Here, I demonstrate that inhibition of Raf-1 kinase by dominant-negative Raf-1 or pharmacological depletion of Raf-1 prevented PMA-mediated induction of p21(WAF1/CIP1). Similarly, PD98059, a specific inhibitor of MEK, abolished p21(WAF1/CIP1) induction and PMA-induced growth arrest. Like PMA, the H-ras oncogene, another activator of the Raf-1/MEK/MAPK pathway, transactivated p21(WAF1/CIP1) in SKBr3 cells. I further investigated PMA-induced growth arrest following infection of SKBr3 cells with 12S E1A-expressing adenovirus. Although high levels of E1A oncoprotein prevented both PMA-induced p21(WAF1/CIP1) and growth arrest, smaller amounts of E1A abrogated growth arrest without down-regulation of p21(WAF1/CIP1). Therefore, E1A can stimulate proliferation downstream of p21(WAF1/CIP1). Albeit less effective than full activity, either Rb- or p300-binding activity of E1A was sufficient for the abrogation of PMA-mediated growth arrest. E1A-driven proliferation of PMA-treated SKBr3 cells was accompanied by apoptosis. New therapeutic approaches can be envisioned that would utilize stimulation of the Raf-1/MEK/MAPK pathway to inhibit growth of PMA-sensitive cancer cells.

  9. Histamine 1 receptor-Gβγ-cAMP/PKA-CFTR pathway mediates the histamine-induced resetting of the suprachiasmatic circadian clock.

    Science.gov (United States)

    Kim, Yoon Sik; Kim, Young-Beom; Kim, Woong Bin; Lee, Seung Won; Oh, Seog Bae; Han, Hee-Chul; Lee, C Justin; Colwell, Christopher S; Kim, Yang In

    2016-05-06

    Recent evidence indicates that histamine, acting on histamine 1 receptor (H1R), resets the circadian clock in the mouse suprachiasmatic nucleus (SCN) by increasing intracellular Ca(2+) concentration ([Ca(2+)]i) through the activation of CaV1.3 L-type Ca(2+) channels and Ca(2+)-induced Ca(2+) release from ryanodine receptor-mediated internal stores. In the current study, we explored the underlying mechanisms with various techniques including Ca(2+)- and Cl(-)-imaging and extracellular single-unit recording. Our hypothesis was that histamine causes Cl(-) efflux through cystic fibrosis transmembrane conductance regulator (CFTR) to elicit membrane depolarization needed for the activation of CaV1.3 Ca(2+) channels in SCN neurons. We found that histamine elicited Cl(-) efflux and increased [Ca(2+)]i in dissociated mouse SCN cells. Both of these events were suppressed by bumetanide [Na(+)-K(+)-2Cl(-) cotransporter isotype 1 (NKCC1) blocker], CFTRinh-172 (CFTR inhibitor), gallein (Gβγ protein inhibitor) and H89 [protein kinase A (PKA) inhibitor]. By itself, H1R activation with 2-pyridylethylamine increased the level of cAMP in the SCN and this regulation was prevented by gallein. Finally, histamine-evoked phase shifts of the circadian neural activity rhythm in the mouse SCN slice were blocked by bumetanide, CFTRinh-172, gallein or H89 and were not observed in NKCC1 or CFTR KO mice. Taken together, these results indicate that histamine recruits the H1R-Gβγ-cAMP/PKA pathway in the SCN neurons to activate CaV1.3 channels through CFTR-mediated Cl(-) efflux and ultimately to phase-shift the circadian clock. This pathway and NKCC1 may well be potential targets for agents designed to treat problems resulting from the disturbance of the circadian system.

  10. Spatane diterpinoid from the brown algae, Stoechospermum marginatum induces apoptosis via ROS induced mitochondrial mediated caspase dependent pathway in murine B16F10 melanoma cells.

    Science.gov (United States)

    Velatooru, Loka Reddy; Baggu, Chinna Babu; Janapala, Venkateswara Rao

    2016-12-01

    Spatane diterpinoids isolated from the brown marine algae Stoechospermum marginatum were known to have cytotoxic effects in human cancerous cell lines and murine melanoma cells; the underling apoptotic mechanism of diterpinoids still remains unclear so far. Thus, in the present study, the apoptotic mechanism of a spatane diterpinoid, 5(R), 19-diacetoxy-15,18(R and S), dihydro spata-13, 16(E)-diene (DDSD) was investigated mainly in B16F10 melanoma cells because they were most susceptible to DDSD than THP1, U937, COLO205, and HL60 cells. The treatment of B6F10 cells with DDSD resulted in morphological alterations, nuclear condensation, and DNA fragmentation, which leads to cell growth inhibition in a concentration-dependent manner. Data indicate that DDSD induced the generation of ROS, consequentially caused alteration in Bax/Bcl-2 ratio that disrupted the inner mitochondrial transmembrane potential (ΔΨm) resulting in cytochrome c redistribution to the cytoplasm and activation of caspase-mediated apoptotic pathway. Flow cytometric analysis clearly indicated that the DDSD inducing phosphatidylserine externalization and mediated "S-phase" arrest in cell cycle. In addition, results also found that DDSD induced apoptosis through deregulating PI3K/AKT signaling pathway. The anti-tumor activity of DDSD was evaluated in C57BL/6 mice bearing B16F10 melanoma. It effectively inhibited tumor growth (volume and weight) in a dose dependent manner, yet without apparent toxic effects. Morphology and apoptotic status of tumor tissues in the treated mice were assessed by microscopy and TUNEL assay, respectively. Our study shows a therapeutic potential of DDSD for the treatment of malignant melanoma and a new source of anticancer drugs. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  11. Attenuation of TNFSF10/TRAIL-induced apoptosis by an autophagic survival pathway involving TRAF2- and RIPK1/RIP1-mediated MAPK8/JNK activation

    Science.gov (United States)

    He, Weiyang; Wang, Qiong; Xu, Jennings; Xu, Xiuling; Padilla, Mabel T.; Ren, Guosheng; Gou, Xin; Lin, Yong

    2012-01-01

    Although it is known that tumor necrosis factor-related apoptosis-inducing ligand (TNFSF10/TRAIL) induces autophagy, the mechanism by which autophagy is activated by TNFSF10 is still elusive. In this report, we show evidence that TRAF2- and RIPK1-mediated MAPK8/JNK activation is required for TNFSF10-induced cytoprotective autophagy. TNFSF10 activated autophagy rapidly in cancer cell lines derived from lung, bladder and prostate tumors. Blocking autophagy with either pharmacological inhibitors or siRNAs targeting the key autophagy factors BECN1/Beclin 1 or ATG7 effectively increased TNFSF10-induced apoptotic cytotoxicity, substantiating a cytoprotective role for TNFSF10-induced autophagy. Blocking MAPK8 but not NFκB effectively blocked autophagy, suggesting that MAPK8 is the main pathway for TNFSF10-induced autophagy. In addition, blocking MAPK8 effectively inhibited degradation of BCL2L1/Bcl-xL and reduction of the autophagy-suppressing BCL2L1–BECN1complex. Knockdown of TRAF2 or RIPK1 effectively suppressed TNFSF10-induced MAPK8 activation and autophagy. Furthermore, suppressing autophagy inhibited expression of antiapoptosis factors BIRC2/cIAP1, BIRC3/cIAP2, XIAP and CFLAR/c-FLIP and increased the formation of TNFSF10-induced death-inducing signaling complex (DISC). These results reveal a critical role for the MAPK8 activation pathway through TRAF2 and RIPK1 for TNFSF10-induced autophagy that blunts apoptosis in cancer cells. Thus, suppression of MAPK8-mediated autophagy could be utilized for sensitizing cancer cells to therapy with TNFSF10. PMID:23051914

  12. Terminalia arjuna prevents Interleukin-18-induced atherosclerosis via modulation of NF-κB/PPAR-γ-mediated pathway in Apo E-/- mice.

    Science.gov (United States)

    Bhat, Owais Mohammad; Kumar, P Uday; Rao, K Rajender; Ahmad, Ashfaq; Dhawan, Veena

    2018-04-01

    Terminalia arjuna is a medicinal plant well known as a cardiotonic in Ayurvedic system of medicine. We hypothesized that aqueous stem bark extract of T. arjuna (TAE) may inhibit IL-18-induced atherosclerosis via NF-κB/PPAR-γ-mediated pathway in Apo E-/- mice. 12-week-old, male Apo E-/- mice divided into four groups (n = 6/group) fed with normal chow-diet were employed: GP I: phosphate buffer saline (PBS) (2 month); GP II: rIL-18 (1 month) followed by PBS (1 month); GP III: rIL-18 (1 month) followed by TAE (1 month); GP IV: rIL-18 (1 month) followed by atorvastatin (1 month). IL-18 treatment induced a significant increase (p < 0.001) in pro-inflammatory marker (IL-18) (170 ± 9.16 vs. 1178.66 ± 8.08, pg/ml), and downregulated cholesterol efflux gene (PPAR-γ) by ~0.6-fold vs. 1.00 in IL-18-treated mice as compared to the control animals, respectively. TAE treatment to both groups caused a significant reduction in IL-18 to 281.66 ± 9.60 vs. 1178.66 ± 8.08 (pg/ml), upregulated cholesterol efflux gene by ~1.5- vs. 0.6-fold in TAE-treated group, decreased atherogenic lipids, and percentage atherosclerotic lesion area, demonstrating comparable effects with atorvastatin. Our data demonstrate that TAE protects against IL-18-induced atherosclerosis via NF-κB/PPAR-γ-mediated pathway.

  13. Effects of interleukin-7/interleukin-7 receptor on RANKL-mediated osteoclast differentiation and ovariectomy-induced bone loss by regulating c-Fos/c-Jun pathway.

    Science.gov (United States)

    Zhao, Ji-Jun; Wu, Zhao-Feng; Yu, Ying-Hao; Wang, Ling; Cheng, Li

    2018-04-16

    To explore the effects of IL-7/IL-7R on the RANKL-mediated osteoclast differentiation in vitro and OVX-induced bone loss in vivo. BMMs and RAW264.7 were transfected with IL-7, IL-7R siRNA, c-Fos siRNA, and c-jun siRNA and later stimulated by RANKL. TRAP and toluidine blue staining were used to observe osteoclast formation and bone resorption, respectively. HE and TRAP staining were used to detect trabecular bone microstructure and osteoclasts of mice, respectively. qRT-PCR and Western blot analysis were used to examine expression. IL-7 unregulated the expression of CTSK, NFATc1, MMP9, and the phosphorylation of p38 and Akt by activating the c-Fos/c-Jun pathway, which increased osteoclast numbers and bone resorption in RANKL-stimulated macrophages. While IL-7R siRNA and c-Fos siRNA decreased the expression, as well as and the phosphorylation of p38 and Akt.IL-7 decreased the BMD and OPG expression in OVX-induced mice and increased the TRAP positive cells, the mRNA expression of c-fos, c-jun, and RANKL, which was contradictory to IL-7R siRNA, and c-Fos siRNA. Furthermore, IL-7R siRNA and c-Fos siRNA caused thicker trabeculae, increased trabecular number, and decreased osteolysis in OVX mice. IL-7/IL-7R can promote RANKL-mediated osteoclast formation and bone resorption by activating the c-Fos/c-Jun pathway, as well as inducing bone loss in OVX mice. © 2018 Wiley Periodicals, Inc.

  14. Sugar-induced cephalic-phase insulin release is mediated by a T1r2+T1r3-independent taste transduction pathway in mice

    Science.gov (United States)

    Stano, Sarah; Holter, Marlena; Azenkot, Tali; Goldman, Olivia; Margolskee, Robert F.; Vasselli, Joseph R.; Sclafani, Anthony

    2015-01-01

    Sensory stimulation from foods elicits cephalic phase responses, which facilitate digestion and nutrient assimilation. One such response, cephalic-phase insulin release (CPIR), enhances glucose tolerance. Little is known about the chemosensory mechanisms that activate CPIR. We studied the contribution of the sweet taste receptor (T1r2+T1r3) to sugar-induced CPIR in C57BL/6 (B6) and T1r3 knockout (KO) mice. First, we measured insulin release and glucose tolerance following oral (i.e., normal ingestion) or intragastric (IG) administration of 2.8 M glucose. Both groups of mice exhibited a CPIR following oral but not IG administration, and this CPIR improved glucose tolerance. Second, we examined the specificity of CPIR. Both mouse groups exhibited a CPIR following oral administration of 1 M glucose and 1 M sucrose but not 1 M fructose or water alone. Third, we studied behavioral attraction to the same three sugar solutions in short-term acceptability tests. B6 mice licked more avidly for the sugar solutions than for water, whereas T1r3 KO mice licked no more for the sugar solutions than for water. Finally, we examined chorda tympani (CT) nerve responses to each of the sugars. Both mouse groups exhibited CT nerve responses to the sugars, although those of B6 mice were stronger. We propose that mice possess two taste transduction pathways for sugars. One mediates behavioral attraction to sugars and requires an intact T1r2+T1r3. The other mediates CPIR but does not require an intact T1r2+T1r3. If the latter taste transduction pathway exists in humans, it should provide opportunities for the development of new treatments for controlling blood sugar. PMID:26157055

  15. Sugar-induced cephalic-phase insulin release is mediated by a T1r2+T1r3-independent taste transduction pathway in mice.

    Science.gov (United States)

    Glendinning, John I; Stano, Sarah; Holter, Marlena; Azenkot, Tali; Goldman, Olivia; Margolskee, Robert F; Vasselli, Joseph R; Sclafani, Anthony

    2015-09-01

    Sensory stimulation from foods elicits cephalic phase responses, which facilitate digestion and nutrient assimilation. One such response, cephalic-phase insulin release (CPIR), enhances glucose tolerance. Little is known about the chemosensory mechanisms that activate CPIR. We studied the contribution of the sweet taste receptor (T1r2+T1r3) to sugar-induced CPIR in C57BL/6 (B6) and T1r3 knockout (KO) mice. First, we measured insulin release and glucose tolerance following oral (i.e., normal ingestion) or intragastric (IG) administration of 2.8 M glucose. Both groups of mice exhibited a CPIR following oral but not IG administration, and this CPIR improved glucose tolerance. Second, we examined the specificity of CPIR. Both mouse groups exhibited a CPIR following oral administration of 1 M glucose and 1 M sucrose but not 1 M fructose or water alone. Third, we studied behavioral attraction to the same three sugar solutions in short-term acceptability tests. B6 mice licked more avidly for the sugar solutions than for water, whereas T1r3 KO mice licked no more for the sugar solutions than for water. Finally, we examined chorda tympani (CT) nerve responses to each of the sugars. Both mouse groups exhibited CT nerve responses to the sugars, although those of B6 mice were stronger. We propose that mice possess two taste transduction pathways for sugars. One mediates behavioral attraction to sugars and requires an intact T1r2+T1r3. The other mediates CPIR but does not require an intact T1r2+T1r3. If the latter taste transduction pathway exists in humans, it should provide opportunities for the development of new treatments for controlling blood sugar. Copyright © 2015 the American Physiological Society.

  16. 9-Hydroxypheophorbide α-mediated photodynamic therapy induces matrix metalloproteinase-2 (MMP-2) and MMP-9 down-regulation in Hep-2 cells via ROS-mediated suppression of the ERK pathway.

    Science.gov (United States)

    Zhang, Huankang; Shen, Bo; Swinarska, Joanna T; Li, Wen; Xiao, Kuanlin; He, Peijie

    2014-03-01

    Photodynamic therapy (PDT) is a promising treatment modality for malignant diseases through the generation of reactive oxygen species (ROS). In this study, we assessed the change of migration and invasion of HEp-2 cells after sublethal doses of 9-hydroxypheophorbide α (9-HPbD)-mediated PDT in vitro, and explored the role of ROS in 9-HPbD-PDT-induced anti-metastatic effects in HEp-2 cells. Following PDT, ROS were measured by a fluorescence microscope in both the presence and absence of glutathione (GSH) pretreatment. Wound healing assay, cell migration assay, and matrigel invasion assay were used to evaluate the cellular migration and invasion. Western blot was performed to investigate the signaling pathways that may have been involved. ROS were rapidly generated in 9-HPbD-loaded HEp-2 laryngeal cancer cells by the activation of a diode laser and were significantly inhibited by a 6-h GSH pretreatment. Wound healing assay, cell migration assay, and matrigel invasion assay showed that sublethal PDT significantly suppressed the migration and invasion of HEp-2 cells. GSH decreased the ability of PDT to inhibit the invasion of HEp-2 cells. Western blot analysis showed that PDT significantly inhibited the phosphorylation of MEK1/2 and ERK1/2, and significantly suppressed the expression of MMP-2 and MMP-9 after 24h following the implementation of sublethal PDT, and these efficacies of PDT could be abrogated by GSH pretreatment. 9-HPbD-PDT attenuated the migration and invasion of HEp-2 cells in vitro, which may be related to the down-regulated expression of MMP-2 and MMP-9 via ROS-mediated-inhibition of phosphorylation in the ERK/MEK signaling pathway. Copyright © 2014. Published by Elsevier B.V.

  17. Genomic ancestry and the social pathways leading to major depression in adulthood: the mediating effect of socioeconomic position and discrimination.

    Science.gov (United States)

    Loret de Mola, Christian; Hartwig, Fernando Pires; Gonçalves, Helen; Quevedo, Luciana de Avila; Pinheiro, Ricardo; Gigante, Denise Petrucci; Motta, Janaína Vieira Dos Santos; Pereira, Alexandre C; Barros, Fernando C; Horta, Bernardo Lessa

    2016-09-05

    Evidence suggests that there is an association between ethnicity/skin color and depression; however, many contextual and individual variables, like sense of discrimination and socioeconomic position (SEP), might influence the direction of this association. We assessed the association between African ancestry and major depression among young adults that have been followed-up since birth in a Southern Brazilian city, and the mediating effect of SEP and discrimination. In 1982, all hospital deliveries in Pelotas (Southern Brazil) were identified; liveborns were examined and their mothers interviewed (n = 5914). In 2012-13, at 30 years of age, we used the Mini International Neuropsychiatric Interview (MINI) for major depression diagnosis. In addition, DNA samples were genotyped for approximately 2.5 million single nucleotide polymorphisms (SNPs) using Illumina (CA, USA) HumanOmni2.5-8v1 array. Genomic ancestry estimation was based on approximately 370 000 single nucleotide polymorphisms (SNPs) mutually available for the Pelotas cohort and selected samples (used as reference panels) of the HapMap and Human Genome Diversity (HGDP). We estimated prevalence ratios (PR) using Poisson regression models and evaluated the association between percentage of African ancestry and major depression. We used G-computation for mediation analysis. At 30 years, 3576 individuals were evaluated for major depression (prevalence = 7.9 %). Only individuals in the highest SEP, who had a percentage of African ancestry between >5-30 % and >30 % had a prevalence of major depression 2.16 (PR = 2.16 95 % CI [1.05-4.45]) and 2.74 (PR = 2.74 95 % CI [1.06-7.06]) times higher, than those with 5 % or less, respectively. Among these subjects, sense of discrimination by skin color, captured 84 % of the association between African ancestry and major depression. SEP is an important effect modifier of the positive association between African ancestry and major depression. In addition

  18. α-Terpineol induces fatty liver in mice mediated by the AMP-activated kinase and sterol response element binding protein pathway.

    Science.gov (United States)

    Choi, You-Jin; Sim, Woo-Cheol; Choi, Hyun Kyu; Lee, Seung-Ho; Lee, Byung-Hoon

    2013-05-01

    The use of herbal medicines in disease prevention and treatment is growing rapidly worldwide, without careful consideration of safety issues. α-Terpineol is a monoterpene alcoholic component of Melaleuca alternifolia, Salvia officinalis and Carthamus tinctorius that is used widely as a flavor and essential oil in food. The present study showed that α-terpineol induces fatty liver via the AMP-activated protein kinase (AMPK)-mTOR-sterol regulatory element-binding protein-1 (SREBP-1) pathway. α-Terpineol-treated hepatocytes had significantly increased neutral lipid accumulation. α-Terpineol suppressed AMPK phosphorylation, and increased p70S6 kinase (p70S6K) phosphorylation and SREBP-1 activation. It also increased luciferase activity in cells transfected with LXRE-tk-Luc and SRE-tk-Luc. Inhibition of mTOR signaling by co-treatment with rapamycin or co-transfection with dominant negative p70S6K blocked completely the effects of α-terpineol. α-Terpineol oral administration to mice for 2weeks led to decreased AMPK phosphorylation and increased SREBP-1 activation in the liver, followed by hepatic lipid accumulation. Conversely, rapamycin co-treatment reversed α-terpineol-induced SREBP-1 activation and fatty liver in mice. These data provide evidence that α-terpineol causes fatty liver, an effect mediated by the AMPK/mTOR/SREBP-1 pathway. Copyright © 2013 Elsevier Ltd. All rights reserved.

  19. Nicotine promotes cell proliferation via α7-nicotinic acetylcholine receptor and catecholamine-synthesizing enzymes-mediated pathway in human colon adenocarcinoma HT-29 cells

    International Nuclear Information System (INIS)

    Wong, Helen Pui Shan; Yu Le; Lam, Emily Kai Yee; Tai, Emily Kin Ki; Wu, William Ka Kei; Cho, Chi Hin

    2007-01-01

    Cigarette smoking has been implicated in colon cancer. Nicotine is a major alkaloid in cigarette smoke. In the present study, we showed that nicotine stimulated HT-29 cell proliferation and adrenaline production in a dose-dependent manner. The stimulatory action of nicotine was reversed by atenolol and ICI 118,551, a β 1 - and β 2 -selective antagonist, respectively, suggesting the role of β-adrenoceptors in mediating the action. Nicotine also significantly upregulated the expression of the catecholamine-synthesizing enzymes [tyrosine hydroxylase (TH), dopamine-β-hydroxylase (DβH) and phenylethanolamine N-methyltransferase]. Inhibitor of TH, a rate-limiting enzyme in the catecholamine-biosynthesis pathway, reduced the actions of nicotine on cell proliferation and adrenaline production. Expression of α7-nicotinic acetylcholine receptor (α7-nAChR) was demonstrated in HT-29 cells. Methyllycaconitine, an α7-nAChR antagonist, reversed the stimulatory actions of nicotine on cell proliferation, TH and DβH expression as well as adrenaline production. Taken together, through the action on α7-nAChR nicotine stimulates HT-29 cell proliferation via the upregulation of the catecholamine-synthesis pathway and ultimately adrenaline production and β-adrenergic activation. These data reveal the contributory role α7-nAChR and β-adrenoceptors in the tumorigenesis of colon cancer cells and partly elucidate the carcinogenic action of cigarette smoke on colon cancer

  20. Supplementation of American ginseng berry extract mitigated cisplatin-evoked nephrotoxicity by suppressing ROS-mediated activation of MAPK and NF-κB signaling pathways.

    Science.gov (United States)

    Ma, Zhi-Na; Liu, Zhi; Wang, Zi; Ren, Shen; Tang, Shan; Wang, Ying-Ping; Xiao, Sheng-Yuan; Chen, Chen; Li, Wei

    2017-12-01

    Nephrotoxicity induced by cisplatin in 30% of all cisplatin treated patients seriously limits its clinical implication as a widely used anticancer agent, and may even cause patients to alter or give up cisplatin therapy. The purpose of this study is to test a protective effect of American ginseng berry extract (AGBE) on cisplatin-induced nephrotoxicity in mice. In this study, the histopathological changes and elevated levels of serum creatinine (CRE) and urea nitrogen (BUN) caused by cisplatin were significantly diminished by AGBE treatment. Oxidative stress caused by cisplatin, evidenced by increases in kidney tissues malondialdehyde (MDA) content, cytochrome P450 E1 (CYP2E1), renal 4-hydroxynonenal (4-HNE) levels and decreases of glutathione (GSH) and superoxide dismutase (SOD) contents, was significantly ameliorated by AGBE pretreatment. The expression levels of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) were inhibited by AGBE treatment, suggesting a suppression of inflammatory response. Additionally, AGBE clearly inhibited cisplatin-induced activations of nuclear factor-kappa B (NF-κB) and mitogen activated protein kinase (MAPK) signal pathways. Supplementation of cisplatin-intoxicated mice with AGBE also significantly reduced apoptotic protein levels of Bax, cleaved caspase-3, cytochrome c and increased anti-apoptotic protein Bcl-2. These findings highlight nephroprotective effect of AGBE against cisplatin-evoked nephrotoxicity through ROS-mediated MAPK and NF-κB signaling pathways. Copyright © 2017. Published by Elsevier Ltd.

  1. Induction of matrix metalloproteinase-2 by tenascin-X deficiency is mediated through the c-Jun N-terminal kinase and protein tyrosine kinase phosphorylation pathway

    International Nuclear Information System (INIS)

    Matsumoto, Ken-ichi; Minamitani, Takeharu; Orba, Yasuko; Sato, Mami; Sawa, Hirofumi; Ariga, Hiroyoshi

    2004-01-01

    The results of our previous study showed that tumor invasion and metastasis are promoted in extracellular matrix (ECM) tenascin-X-deficient (TNX-/-) mice via increased expression of matrix metalloproteinases (MMPs). However, little is known about the relationship between TNX deficiency and activation of MMP genes. In this study, we investigated the molecular mechanism by which TNX deficiency activates the MMP-2 gene. We examined the intracellular signaling pathways that regulate gene expression of the proteinase in isolated fibroblasts. Results of gelatin zymography showed that MMP-2 was induced to a greater extent in TNX-/- fibroblasts embedded in type I collagen than in wild-type fibroblasts. RT-PCR analysis revealed that the increased level of MMP-2 expression was caused at the transcription level. Conversely, stable overexpression of TNX in a fibroblast cell line reduced MMP-2 expression and suppressed MMP-2 promoter activity. In addition, treatment of TNX-/- fibroblasts with SP600125, a c-Jun N-terminal kinase (JNK) inhibitor, and genistein, a tyrosine kinase inhibitor, suppressed the increased level of proMMP-2 and increased MMP-2 promoter activity in TNX-/- fibroblasts. Furthermore, increased activation of JNK and tyrosine phosphorylation of certain proteins were observed in TNX-/- fibroblasts. These findings suggest that induction of MMP-2 by TNX deficiency is mediated, at least in part, through the JNK and protein tyrosine kinase phosphorylation pathway

  2. Versican G1 domain enhances adenoviral-mediated transgene expression and can be modulated by inhibitors of the Janus kinase (JAK)/STAT and Src family kinase pathways.

    Science.gov (United States)

    Akinfenwa, Patricia Y; Bond, Wesley S; Ildefonso, Cristhian J; Hurwitz, Mary Y; Hurwitz, Richard L

    2017-09-01

    To examine the biochemical influences that may contribute to the success of gene therapy for ocular disorders, the role of versican, a vitreous component, in adenoviral-mediated transgene expression was examined. Versican is a large chondroitin sulfate-containing, hyaluronic acid-binding proteoglycan present in the extracellular matrix and in ocular vitreous body. Y79 retinoblastoma cells and CD44-negative SK-N-DZ neuroblastoma cells transduced with adenoviral vectors in the presence of versican respond with an activation of transgene expression. Proteolysis of versican generates a hyaluronan-binding G1 domain. The addition of recombinant versican G1 to SK-N-DZ cells results in a similar activation of transgene expression, and treatment with dasatinib, an inhibitor of Src family kinases, also mimics the effects of versican. Enhancement is accompanied by an increase in signal transducer and activator of transcription 5 (STAT5) phosphorylation and is abrogated by treatment with C188-9, a STAT3/5 inhibitor, or with ruxolitinib, a Janus kinase 1/2 (JAK1/2) inhibitor. These data implicate versican G1 in enhancing adenoviral vector transgene expression in a hyaluronic acid-CD44 independent manner that is down-regulated by inhibitors of the JAK/STAT pathway and enhanced by inhibitors of the Src kinase pathway. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

  3. MyD88 and STING Signaling Pathways Are Required for IRF3-Mediated IFN-β Induction in Response to Brucella abortus Infection

    Science.gov (United States)

    de Almeida, Leonardo A.; Carvalho, Natalia B.; Oliveira, Fernanda S.; Lacerda, Thais L. S.; Vasconcelos, Anilton C.; Nogueira, Lucas; Bafica, Andre; Silva, Aristóbolo M.; Oliveira, Sergio C.

    2011-01-01

    Type I interferons (IFNs) are cytokines that orchestrate diverse immune responses to viral and bacterial infections. Although typically considered to be most important molecules in response to viruses, type I IFNs are also induced by most, if not all, bacterial pathogens. In this study, we addressed the role of type I IFN signaling during Brucella abortus infection, a facultative intracellular bacterial pathogen that causes abortion in domestic animals and undulant fever in humans. Herein, we have shown that B. abortus induced IFN-β in macrophages and splenocytes. Further, IFN-β induction by Brucella was mediated by IRF3 signaling pathway and activates IFN-stimulated genes via STAT1 phosphorylation. In addition, IFN-β expression induced by Brucella is independent of TLRs and TRIF signaling but MyD88-dependent, a pathway not yet described for Gram-negative bacteria. Furthermore, we have identified Brucella DNA as the major bacterial component to induce IFN-β and our study revealed that this molecule operates through a mechanism dependent on RNA polymerase III to be sensed probably by an unknown receptor via the adaptor molecule STING. Finally, we have demonstrated that IFN-αβR KO mice are more resistant to infection suggesting that type I IFN signaling is detrimental to host control of Brucella. This resistance phenotype is accompanied by increased IFN-γ and NO production by IFN-αβR KO spleen cells and reduced apoptosis. PMID:21829705

  4. MyD88 and STING signaling pathways are required for IRF3-mediated IFN-β induction in response to Brucella abortus infection.

    Directory of Open Access Journals (Sweden)

    Leonardo A de Almeida

    Full Text Available Type I interferons (IFNs are cytokines that orchestrate diverse immune responses to viral and bacterial infections. Although typically considered to be most important molecules in response to viruses, type I IFNs are also induced by most, if not all, bacterial pathogens. In this study, we addressed the role of type I IFN signaling during Brucella abortus infection, a facultative intracellular bacterial pathogen that causes abortion in domestic animals and undulant fever in humans. Herein, we have shown that B. abortus induced IFN-β in macrophages and splenocytes. Further, IFN-β induction by Brucella was mediated by IRF3 signaling pathway and activates IFN-stimulated genes via STAT1 phosphorylation. In addition, IFN-β expression induced by Brucella is independent of TLRs and TRIF signaling but MyD88-dependent, a pathway not yet described for Gram-negative bacteria. Furthermore, we have identified Brucella DNA as the major bacterial component to induce IFN-β and our study revealed that this molecule operates through a mechanism dependent on RNA polymerase III to be sensed probably by an unknown receptor via the adaptor molecule STING. Finally, we have demonstrated that IFN-αβR KO mice are more resistant to infection suggesting that type I IFN signaling is detrimental to host control of Brucella. This resistance phenotype is accompanied by increased IFN-γ and NO production by IFN-αβR KO spleen cells and reduced apoptosis.

  5. The induction of apoptosis in HepG-2 cells by ruthenium(II) complexes through an intrinsic ROS-mediated mitochondrial dysfunction pathway.

    Science.gov (United States)

    Zeng, Chuan-Chuan; Lai, Shang-Hai; Yao, Jun-Hua; Zhang, Cheng; Yin, Hui; Li, Wei; Han, Bing-Jie; Liu, Yun-Jun

    2016-10-21

    Four new ruthenium(II) polypyridyl complexes [Ru(N-N)2(dhbn)](ClO4)2 (N-N = dmb: 4,4'-dimethyl-2,2'-bipyridine 1; bpy = 2,2'-bipyridine 2; phen = 1,10-phenanthroline 3; dmp = 2,9-dimethyl-1,10-phenanthroline 4) were synthesized and characterized. The cytotoxicity in vitro of the ligand and complexes toward HepG-2, HeLa, MG-63 and A549 were assayed by MTT method. The IC50 values of the complexes against the above cells range from 17.7 ± 1.1 to 45.1 ± 2.8 μM. The cytotoxic activity of the complexes against HepG-2 cells follows the order of 4 > 2 > 3 > 1. Ligand shows no cytotoxic activity against the selected cell lines. Cellular uptake, apoptosis, comet assay, reactive oxygen species, mitochondrial membrane potential, cell cycle arrest, and the expression of proteins involved in apoptosis pathway induced by the complexes were investigated. The results indicate that complexes 1-4 induce apoptosis in HepG-2 cells through an intrinsic ROS-mediated mitochondrial dysfunction pathway. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  6. DNA-PKcs Negatively Regulates Cyclin B1 Protein Stability through Facilitating Its Ubiquitination Mediated by Cdh1-APC/C Pathway.

    Science.gov (United States)

    Shang, Zeng-Fu; Tan, Wei; Liu, Xiao-Dan; Yu, Lan; Li, Bing; Li, Ming; Song, Man; Wang, Yu; Xiao, Bei-Bei; Zhong, Cai-Gao; Guan, Hua; Zhou, Ping-Kun

    2015-01-01

    The catalytic subunit of DNA-dependent protein kinase (DNA-PKcs) is a critical component of the non-homologous end-joining pathway of DNA double-stranded break repair. DNA-PKcs has also been shown recently functioning in mitotic regulation. Here, we report that DNA-PKcs negatively regulates the stability of Cyclin B1 protein through facilitating its ubiquitination mediated by Cdh1 / E 3 ubiquitin ligase APC/C pathway. Loss of DNA-PKcs causes abnormal accumulation of Cyclin B1 protein. Cyclin B1 degradation is delayed in DNA-PKcs-deficient cells as result of attenuated ubiquitination. The impact of DNA-PKcs on Cyclin B1 stability relies on its kinase activity. Our study further reveals that DNA-PKcs interacts with APC/C core component APC2 and its co-activator Cdh1. The destruction of Cdh1 is accelerated in the absence of DNA-PKcs. Moreover, overexpression of exogenous Cdh1 can reverse the increase of Cyclin B1 protein in DNA-PKcs-deficient cells. Thus, DNA-PKcs, in addition to its direct role in DNA damage repair, functions in mitotic progression at least partially through regulating the stability of Cyclin B1 protein.

  7. gef Gene Expression in MCF-7 Breast Cancer Cells is Associated with a Better Prognosis and Induction of Apoptosis by p53-Mediated Signaling Pathway

    Science.gov (United States)

    Boulaiz, Houria; Álvarez, Pablo J.; Prados, Jose; Marchal, Juan; Melguizo, Consolación; Carrillo, Esmeralda; Peran, Macarena; Rodríguez, Fernando; Ramírez, Alberto; Ortíz, Raúl; Aránega, Antonia

    2011-01-01

    Breast cancer research has developed rapidly in the past few decades, leading to longer survival times for patients and opening up the possibility of developing curative treatments for advanced breast cancer. Our increasing knowledge of the biological pathways associated with the progression and development of breast cancer, alongside the failure of conventional treatments, has prompted us to explore gene therapy as an alternative therapeutic strategy. We previously reported that gef gene from E. coli has shown considerable cytotoxic effects in breast cancer cells. However, its action mechanism has not been elucidated. Indirect immunofluorescence technique using flow cytometry and immunocytochemical analysis were used to detect breast cancer markers: estrogen (ER) and progesterone (PR) hormonal receptors, human epidermal growth factor receptor-2 proto-oncogene (c-erbB-2), ki-67 antigen and p53 protein. gef gene induces an increase in ER and PR expressions and a decrease in ki-67 and c-erbB-2 gene expressions, indicating a better prognosis and response to treatment and a longer disease-free interval and survival. It also increased p53 expression, suggesting that gef-induced apoptosis is regulated by a p53-mediated signaling pathway. These findings support the hypothesis that the gef gene offers a new approach to gene therapy in breast cancer. PMID:22174609

  8. Child effortful control as a mediator of parenting practices on externalizing behavior: evidence for a sex-differentiated pathway across the transition from preschool to school.

    Science.gov (United States)

    Chang, Hyein; Olson, Sheryl L; Sameroff, Arnold J; Sexton, Holly R

    2011-01-01

    An explanatory model for children's development of disruptive behavior across the transition from preschool to school was tested. It was hypothesized that child effortful control would mediate the effects of parenting on children's externalizing behavior and that child sex would moderate these relations. Participants were 241 children (123 boys) and their parents and teachers. Three dimensions of parenting, warm responsiveness, induction, and corporal punishment, were assessed via maternal report when children were 3 years old. Child effortful control at age 3 was measured using laboratory tasks and a mother-report questionnaire. Mothers and teachers contributed ratings of child externalizing behavior at age 6. Results showed that the hypothesized model fit the data well and that the pattern of associations between constructs differed for boys and girls. For boys, parental warm responsiveness and corporal punishment had significant indirect effects on children's externalizing behavior three years later, mediated by child effortful control. Such relations were not observed for girls. These findings support a sex-differentiated pathway to externalizing behavior across the transition from preschool to school.

  9. Sphk1 mediates neuroinflammation and neuronal injury via TRAF2/NF-κB pathways in activated microglia in cerebral ischemia reperfusion.

    Science.gov (United States)

    Su, Danying; Cheng, Yuefeng; Li, Shi; Dai, Dawei; Zhang, Wei; Lv, Manhua

    2017-04-15

    Sphingosine kinase 1 (Sphk1), a key enzyme responsible for phosphorylating sphingosine into sphingosine1-phosphate (S1P), plays an important role in mediating post-stroke neuroinflammation. However, the pathway and mechanism of the Sphk1-mediated inflammatory response remains unknown. In this study, we found that suppression of Sphk1 decreased IL17 production and relieved neuronal damage induced by microglia in cerebral ischemia reperfusion (IR) or in an in vitro oxygen-glucose deprivation reperfusion (OGDR) system. Inhibition of Sphk1 with an inhibitor or siRNA decreased tumor necrosis factor receptor-associated factor 2 (TRAF2) and nuclear factor-kappa B (NF-κB) sequentially in microglia in response to IR or OGDR. Moreover, we also found that after suppression of TRAF2 or NF-κB by siRNA in microglia, reductions in the downstream molecules NF-κB and IL-17 and in neuronal apoptosis were observed in response to OGDR. Taken together, we hypothesize that Sphk1, TRAF2 and NF-κB form an axis that leads to increased IL-17 and neuronal apoptosis. This axis may be a potential therapeutic target to control neuroinflammation in brain IR. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Selective regulation of YB-1 mRNA translation by the mTOR signaling pathway is not mediated by 4E-binding protein.

    Science.gov (United States)

    Lyabin, D N; Ovchinnikov, L P

    2016-03-02

    The Y-box binding protein 1 (YB-1) is a key regulator of gene expression at the level of both translation and transcription. The mode of its action on cellular events depends on its subcellular distribution and the amount in the cell. So far, the regulatory mechanisms of YB-1 synthesis have not been adequately studied. Our previous finding was that selective inhibition of YB-1 mRNA translation was caused by suppression of activity of the mTOR signaling pathway. It was suggested that this event may be mediated by phosphorylation of the 4E-binding protein (4E-BP). Here, we report that 4E-BP alone can only slightly inhibit YB-1 synthesis both in the cell and in vitro, although it essentially decreases binding of the 4F-group translation initiation factors to mRNA. With inhibited mTOR kinase, the level of mRNA binding to the eIF4F-group factors was decreased, while that to 4E-BP1 was increased, as was observed for both mTOR kinase-sensitive mRNAs and those showing low sensitivity. This suggests that selective inhibition of translation of YB-1 mRNA, and probably some other mRNAs as well, by mTOR kinase inhibitors is not mediated by the action of the 4E-binding protein upon functions of the 4F-group translation initiation factors.

  11. Blueberry and malvidin inhibit cell cycle progression and induce mitochondrial-mediated apoptosis by abrogating the JAK/STAT-3 signalling pathway.

    Science.gov (United States)

    Baba, Abdul Basit; Nivetha, Ramesh; Chattopadhyay, Indranil; Nagini, Siddavaram

    2017-11-01

    Blueberries, a rich source of anthocyanins have attracted considerable attention as functional foods that confer immense health benefits including anticancer properties. Herein, we assessed the potential of blueberry and its major constituent malvidin to target STAT-3, a potentially druggable oncogenic transcription factor with high therapeutic index. We demonstrate that blueberry abrogates the JAK/STAT-3 pathway and modulates downstream targets that influence cell proliferation and apoptosis in a hamster model of oral oncogenesis. Further, we provide mechanistic evidence that blueberry and malvidin function as STAT-3 inhibitors in the oral cancer cell line SCC131. Blueberry and malvidin suppressed STAT-3 phosphorylation and nuclear translocation thereby inducing cell cycle arrest and mitochondrial-mediated apoptosis. However, the combination of blueberry and malvidin with the STAT-3 inhibitor S3I-201 was more efficacious in STAT-3 inhibition relative to single agents. The present study has provided leads for the development of novel combinations of compounds that can serve as inhibitors of STAT-mediated oncogenic signalling. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Cyclin-dependent kinase 5-mediated phosphorylation of CHIP promotes the tAIF-dependent death pathway in rotenone-treated cortical neurons.

    Science.gov (United States)

    Kim, Chiho; Lee, Juhyung; Ko, Yeon Uk; Oh, Young J

    2018-01-01

    Cyclin-dependent kinase 5 (Cdk5) is a proline-directed serine/threonine kinase. Its dysregulation has been implicated in various neurodegenerative diseases. We previously reported that phosphorylation of the C-terminus of the Hsc70-interacting protein (CHIP) by Cdk5 promotes truncated apoptosis-inducing factor (tAIF)-mediated neuronal death induced by oxidative stress. Here, we determined whether this Cdk5-dependent cell death signaling pathway is present in experimental models of Parkinson's disease. First, we showed that rotenone activates Cdk5 in primary cultures of cortical neurons and causes tAIF-dependent neuronal cell death. This event was attenuated by negative regulation of endogenous Cdk5 activity by the pharmacological Cdk5 inhibitor, roscovitine, or by lentiviral knockdown of Cdk5. Cdk5 phosphorylates CHIP at Ser20 in rotenone-treated neurons. Consequently, overexpression of CHIP S20A , but not CHIP WT , attenuates tAIF-induced cell death in rotenone-treated cortical neurons. Taken together, these results indicate that phosphorylation of CHIP at Ser20 by Cdk5 activation inhibits CHIP-mediated tAIF degradation, thereby contributing to tAIF-induced neuronal cell death following rotenone treatment. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Hepatitis C Virus Mediated Changes in miRNA-449a Modulates Inflammatory Biomarker YKL40 through Components of the NOTCH Signaling Pathway

    Science.gov (United States)

    Sarma, Nayan J.; Tiriveedhi, Venkataswarup; Subramanian, Vijay; Shenoy, Surendra; Crippin, Jeffrey S.; Chapman, William C.; Mohanakumar, Thalachallour

    2012-01-01

    Liver disease due to hepatitis C virus (HCV) infection is an important health problem worldwide. HCV induced changes in microRNAs (miRNA) are shown to mediate inflammation leading to liver fibrosis. Gene expression analyses identified dysregulation of miRNA-449a in HCV patients but not in alcoholic and non-alcoholic liver diseases. By sequence analysis of the promoter for YKL40, an inflammatory marker upregulated in patients with chronic liver diseases with fibrosis, adjacent binding sites for nuclear factor of Kappa B/P65 and CCAAT/enhancer-binding protein alpha (CEBPα) were identified. P65 interacted with CEBPα to co-operatively activate YKL40 expression through sequence specific DNA binding. In vitro analysis demonstrated that tumor necrosis factor alpha (TNFα) mediated YKL40 expression is regulated by miRNA-449a and its target NOTCH1 in human hepatocytes.NOTCH1 facilitated nuclear localization of P65 in response to TNFα. Further, HCV patients demonstrated upregulation of NOTCH1 along with downregulation of miRNA-449a. Taken together it is demonstrated that miRNA-449a plays an important role in modulating expression of YKL40 through targeting the components of the NOTCH signaling pathway following HCV infection. Therefore, defining transcriptional regulatory mechanisms which control inflammatory responses and fibrosis will be important towards developing strategies to prevent hepatic fibrosis especially following HCV recurrence in liver transplant recipients. PMID:23226395

  14. Sensitization of cancer cells to radiation by selenadiazole derivatives by regulation of ROS-mediated DNA damage and ERK and AKT pathways

    Energy Technology Data Exchange (ETDEWEB)

    Xie, Qiang [Department of Chemistry, Jinan University, Guangzhou 510632 (China); Wu Jing Zong Dui Hospital of Guangdong Province, Guangzhou (China); Zhou, Yangliang; Lan, Guoqiang; Yang, Liye; Zheng, Wenjie; Liang, Yuanwei [Department of Chemistry, Jinan University, Guangzhou 510632 (China); Chen, Tianfeng, E-mail: tchentf@jnu.edu.cn [Department of Chemistry, Jinan University, Guangzhou 510632 (China)

    2014-06-20

    Highlights: • Selenadiazole derivatives could be used as an effective and low toxic sensitizer for radiotherapy. • Selenadiazole derivatives enhances radiation-induced growth inhibition on A375 cells through induction of G2/M arrest. • ROS-mediated signaling pathways play important roles in radiosensitization of selenadiazole derivatives. - Abstract: X-ray-based radiotherapy represents one of the most effective ways in treating human cancers. However, radioresistance and side effect remain as the most challenging issue. This study describes the design and application of novel selenadiazole derivatives as radiotherapy sensitizers to enhance X-ray-induced inhibitory effects on A375 human melanoma and Hela human cervical carcinoma cells. The results showed that, pretreatment of the cells with selenadiazole derivatives dramatically enhance X-ray-induced growth inhibition and colony formation. Flow cytometry analysis indicates that the sensitization by selenadiazole derivatives was mainly caused by induction of G2/M cell cycle arrest. Results of Western blotting demonstrated that the combined treatment-induced A375 cells growth inhibition was achieved by triggering reactive oxygen species-mediated DNA damage involving inactivation of AKT and MAPKs. Further investigation revealed that selenadiazole derivative in combination with X-ray could synergistically inhibit the activity of thioredoxin reductase-1 in A375 cells. Taken together, these results suggest that selenadiazole derivatives can act as novel radiosensitizer with potential application in combating human cancers.

  15. Constitutive impaired TCR/CD3-mediated activation of T cells in IDDM patients co-exist with normal co-stimulation pathways.

    Science.gov (United States)

    Nervi, S; Atlan-Gepner, C; Fossat, C; Vialettes, B

    1999-09-01

    IDDM is a T cell-mediated autoimmune disease which is paradoxically associated with T cell functional deficiencies. The proliferative response of PBMC under CD3-, Vbeta2-, Vbeta8- and Vbeta7-stimulation was investigated in IDDM and NIDDM patients, non-diabetic first-degree relatives and control subjects. Despite normal surface expression of the TCR/CD3 complex, the TCR/CD3-mediated proliferation of PBMC from IDDM patients was significantly impaired compared to control subjects (PMHC genotype, to metabolic disturbances or to presence of specific autoantibodies. Inefficient activation of T cells was not related to a lower capacity of CD28 to transduce co-stimulative signals because proliferative responses under CD2/CD28 stimulations were similar in IDDM and control groups. The IL-2/IL-2 receptor system was functional because unstimulated PBMC proliferated in response to increasing amounts of IL-2. Nevertheless, despite normal expression of CD25, addition of IL-2 did not normalize the proliferative defect linked to IDDM. In conclusion, excluding a faulty co-stimulation pathway, these results are in favour of a constitutive defect in the CD3/TCR transduction machinery, increasing sensitivity to apoptosis or anergy in T cells from IDDM patients. Copyright 1999 Academic Press.

  16. Nuclear export of cutaneous HPV8 E7 oncoprotein is mediated by a leucine-rich nuclear export signal via a CRM1 pathway.

    Science.gov (United States)

    Onder, Zeynep; Chang, Vivian; Moroianu, Junona

    2015-01-01

    We recently determined that the nuclear import of cutaneous beta genus HPV8 E7 oncoprotein it is mediated by its zinc-binding domain via direct hydrophobic interactions with the FG nucleoporins Nup62 and Nup153 (Onder and Moroianu, 2014). Here we investigated the nuclear export of HPV8 E7 oncoprotein using confocal microscopy after transfections of HeLa cells with EGFP-8cE7 and mutant plasmids and treatment with Ratjadone A nuclear export inhibitor. We determined that HPV8 E7 contains a leucine-rich nuclear export signal (NES), 76IRTFQELLF84, within its zinc-binding domain that mediates its nuclear export via a CRM1 pathway. We found that HPV8 E7 interacts with CRM1 and that the hydrophobic amino acid residues I76, F79 and L82 of the NES are essential for this interaction and for nuclear export of HPV8 E7 oncoprotein. Copyright © 2014 Elsevier Inc. All rights reserved.

  17. Presynaptic adenosine receptor-mediated regulation of diverse thalamocortical short-term plasticity in the mouse whisker pathway

    Directory of Open Access Journals (Sweden)

    Giovanni eFerrati

    2016-02-01

    Full Text Available Short-term synaptic plasticity (STP sets the sensitivity of a synapse to incoming activity and determines the temporal patterns that it best transmits. In driver thalamocortical (TC synaptic populations, STP is dominated by depression during stimulation from rest. However, during ongoing stimulation, lemniscal TC connections onto layer 4 neurons in mouse barrel cortex express variable STP. Each synapse responds to input trains with a distinct pattern of depression or facilitation around its mean steady-state response. As a result, in common with other synaptic populations, lemniscal TC synapses express diverse rather than uniform dynamics, allowing for a rich representation of temporally varying stimuli. Here we show that this STP diversity is regulated presynaptically. Presynaptic adenosine receptors of the A1R type, but not kainate receptors, modulate STP behavior. Blocking the receptors does not eliminate diversity, indicating that diversity is related to heterogeneous expression of multiple mechanisms in the pathway from presynaptic calcium influx to neurotransmitter release.

  18. Interplay between FMRP and lncRNA TUG1 regulates axonal development through mediating SnoN-Ccd1 pathway.

    Science.gov (United States)

    Guo, Ye; Chen, Xu; Xing, Ruxiao; Wang, Min; Zhu, Xiaojuan; Guo, Weixiang

    2018-02-01

    LncRNAs have recently emerged to influence the pathogenesis of fragile X syndrome (FXS), which is caused by the functional loss of fragile X mental retardation protein (FMRP). However, the interaction between FMRP and lncRNAs on regulating neuronal development remains elusive. Here, we reported that FMRP directly interacted with lncRNA TUG1, and decreased its stability. Furthermore, TUG1 bond to transcriptional regulator, SnoN, and negatively modulated SnoN-Ccd1 pathway to specifically control axonal development. These observations suggested interplay between FMRP and lncRNAs might contribute to the pathogenesis of FXS. © The Author(s) 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  19. Singly protonated dehydronorcantharidin silver coordination polymer induces apoptosis of lung cancer cells via reactive oxygen species-mediated mitochondrial pathway.

    Science.gov (United States)

    Li, Senpeng; Zhang, Shuo; Jin, Xing; Tan, Xuejie; Lou, Jianfang; Zhang, Xiumei; Zhao, Yunxue

    2014-10-30

    Silver complexes have been shown to possess antimicrobial and anticancer properties. Ag-SP-DNC, a novel silver and singly protonated dehydronorcantharidin complex, was synthesized in our previous study. In this study, we offer evidence that Ag-SP-DNC elicits a reactive oxygen species (ROS)-mediated mitochondrial apoptosis in lung cancer cells. Ag-SP-DNC inhibited the growth of A549 cells by inducing G2/M phase cell cycle arrest and apoptosis. Ag-SP-DNC induced apoptosis was associated with the levels of intracellular ROS. The further study revealed that Ag-SP-DNC disrupted the mitochondrial membrane potential, induced the caspase-3 activation and led to the translocation of apoptosis inducing factor and endonucleaseG to the nucleus. These findings have important implications for the development of silver complexes for anticancer applications. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  20. Brazilian green propolis induced apoptosis in human lung cancer A549 cells through mitochondrial-mediated pathway.

    Science.gov (United States)

    Frión-Herrera, Yahima; Díaz-García, Alexis; Ruiz-Fuentes, Jenny; Rodríguez-Sánchez, Hermis; Sforcin, José Maurício

    2015-10-01

    Propolis effect on the growth and apoptosis of human lung adenocarcinoma (A549 cells) was investigated as well as its mechanisms. Cells were incubated with propolis for 72 h, and 3-(4,5- dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and lactate dehydrogenase assays were employed to assess cell viability and the inhibitory concentration (IC). Apoptosis was detected by Acridine Orange/Ethidium Bromide and 4',6-diamidino-2-phenylindole staining after 24 and 48 h of incubation with ¼ IC50 of propolis by testing the mitochondrial membrane potential (ΔΨm) and the expression of apoptosis-related genes (p53, Caspase-3, Bax, Bcl-2, Bcl-XL , Noxa, Puma and p21) by reverse transcription polymerase chain reaction. Propolis displayed antiproliferative and cytotoxic effects on A549 cells in a dose- and time-dependent manner, but it did not suppress the growth of normal Vero cells. An enhanced apoptosis was seen in A549 propolis-treated cells after 48 h compared with the control cells. Propolis decreased mitochondrial membrane potential by overexpression of pro-apoptotic genes (Bax and Noxa) and reduction of the antiapoptotic gene Bcl-XL . The expression level of other genes remained unchanged (p53, Caspse-3 and Bax), whereas p21 expression was increased. Propolis induced caspase-independent apoptosis through a p53-independent mitochondrial pathway, and cell cycle arrest by upregulation of p21. Although propolis induces apoptosis mainly by p53-independent manner, it may be induced by another pathway, and new insights may arise for preventing or treating lung cancer. © 2015 Royal Pharmaceutical Society.

  1. Aspartame and Soft Drink-Mediated Neurotoxicity in Rats: Implication of Oxidative Stress, Apoptotic Signaling Pathways, Electrolytes and Hormonal Levels.

    Science.gov (United States)

    Lebda, Mohamed A; Sadek, Kadry M; El-Sayed, Yasser S

    2017-10-01

    A significant association between fructose corn syrup in sweetened beverages consumption and increased risk of detrimental central nervous system effects has been recently reported. We hypothesized that the aspartame and soft drink induced disturbances in energy production and endocrine function, which play a role in the induction of brain damage. Therefore, we aimed to assess the effect of aspartame and soft drink on brain function and the link between energy status in the brain, oxidative stress and molecular pathways of apoptosis. Thirty rats were randomly assigned to drink water, aspartame (240 mg/kg orally) and cola soft drinks (free access) daily for two months. Subchronic intake of aspartame and soft drink significantly disrupted the brain energy production, as indicated by inhibited serum and brain creatine kinase, specifically in soft drink-received rats. Moreover, they substantially altered serum electrolytes (increased Ca and Na, and depleted Cu, Fe, Zn and K levels), and accordingly the related hormonal status (increased T4 and PTH, and lowered T3 and aldosterone levels), particularly in soft drink-received rats reflecting brain damage. Additionally, significant increment of acetylcholine esterase activity concomitant with the reduction of antioxidant molecules (SOD, CAT, GSH-Px and GSH), and induction of malondialdehyde level are precisely indicative of oxidative brain damage. Brain mRNA transcripts of target genes showed that aspartame and soft drink induced upregulation of BAX, Casp3, P27 and Mdm2 (1.5-fold) and down-regulation of Bcl2, suggesting an activation of cellular apoptosis. Collectively, subchronic aspartame and soft drink-induced brain damage in rats may be driven via a mechanism that involves energy production disruption, electrolytes and hormonal imbalance, increased oxidative stress and activation of molecular pathway of neuronal apoptosis.

  2. The LIM-only protein FHL2 mediates ras-induced transformation through cyclin D1 and p53 pathways.

    Directory of Open Access Journals (Sweden)

    Charlotte Labalette

    Full Text Available BACKGROUND: Four and a half LIM-only protein 2 (FHL2 has been implicated in multiple signaling pathways that regulate cell growth and tissue homeostasis. We reported previously that FHL2 regulates cyclin D1 expression and that immortalized FHL2-null mouse embryo fibroblasts (MEFs display reduced levels of cyclin D1 and low proliferative activity. METHODOLOGY/PRINCIPAL FINDINGS: Here we address the contribution of FHL2 in cell transformation by investigating the effects of oncogenic Ras in FHL2-null context. We show that H-RasV12 provokes cell cycle arrest accompanied by accumulation of p53 and p16(INK4a in immortalized FHL2(-/- MEFs. These features contrast sharply with Ras transforming activity in wild type cell lines. We further show that establishment of FHL2-null cell lines differs from conventional immortalization scheme by retaining functional p19(ARF/p53 checkpoint that is required for cell cycle arrest imposed by Ras. However, after serial passages of Ras-expressing FHL2(-/- cells, dramatic increase in the levels of D-type cyclins and Rb phosphorylation correlates with the onset of cell proliferation and transformation without disrupting the p19(ARF/p53 pathway. Interestingly, primary FHL2-null cells overexpressing cyclin D1 undergo a classical immortalization process leading to loss of the p19(ARF/p53 checkpoint and susceptibility to Ras transformation. CONCLUSIONS/SIGNIFICANCE: Our findings uncover a novel aspect of cellular responses to mitogenic stimulation and illustrate a critical role of FHL2 in the signalling network that implicates Ras, cyclin D1 and p53.

  3. Ecological Trade-offs between Migration and Reproduction Are Mediated by the Nutrition-Sensitive Insulin-Signaling Pathway.

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    Lin, Xinda; Yao, Yun; Wang, Bo; Emlen, Douglas J; Lavine, Laura Corley

    2016-01-01

    Crowding and changes in food availability are two critical environmental conditions that impact an animal's trajectory toward either migration or reproduction. Many insects facing this challenge have evolved wing polyphenisms. When conditions favor reproduction, wing polyphenic species produce adults that either have no wings or short, non-functional wings. Facultative wing growth reflects a physiological and evolutionary trade-off between migration and reproduction, triggered by environmental conditions. How environmental cues are transduced to produce these alternative forms, and their associated ecological shift from migration to reproduction, remains an important unsolved problem in evolutionary ecology. The brown planthopper, a wing polymorphic insect exhibiting strong trade-offs in investment between migration and reproduction, is one of the most serious rice pests in Asia. In this study, we investigated the function of four genes in the insulin-signaling pathway known to couple nutrition with growth, PI3 Kinase (PI3K), PDK1, Akt (Protein Kinase B), and the forkhead gene FOXO. Using a combination of RNA interference and pharmacological inhibitor treatment, we show that all four genes contribute to tissue level regulation of wing polymorphic development in this insect. As predicted, silencing of the NlPI3K, NlAkt and NlPDK1 through dsRNA and with the pharmacological inhibitor Perifosine resulted in short-winged brown planthoppers, whereas knockdown of NlFOXO resulted in long-winged planthoppers. Morphometric analyses confirm that phenotypes from our manipulations mimic what would be found in nature, i.e., major parameters such as bristle number, wing area and body weight are not significantly different from non-experimental animals. Taken together, these data implicate the insulin-signaling pathway in the transduction of environmental factors into condition-dependent patterns of wing growth in insects.

  4. Pentacyclic Triterpenoids Inhibit IKKβ Mediated Activation of NF-κB Pathway: In Silico and In Vitro Evidences.

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    Kalpesh R Patil

    Full Text Available Pentacyclic Triterpenoids (PTs and their analogues as well as derivatives are emerging as important drug leads for various diseases. They act through a variety of mechanisms and a majority of them inhibit the nuclear factor kappa-beta (NF-κB signaling pathway. In this study, we examined the effects of the naturally occurring PTs on IκB kinase-β (IKKβ, which has great scientific relevance in the NF-κB signaling pathway. On virtual screening, 109 PTs were screened through the PASS (prediction of activity spectra of substances software for prediction of NF-κB inhibitory activity followed by docking on the NEMO/IKKβ association complex (PDB: 3BRV and testing for compliance with the softened Lipinski's Rule of Five using Schrodinger (LLC, New York, USA. Out of the projected 45 druggable PTs, Corosolic Acid (CA, Asiatic Acid (AA and Ursolic Acid (UA were assayed for IKKβ kinase activity in the cell free medium. The UA exhibited a potent IKKβ inhibitory effect on the hotspot kinase assay with IC50 of 69 μM. Whereas, CA at 50 μM concentration markedly reduced the NF-κB luciferase activity and phospho-IKKβ protein expressions. The PTs tested, attenuated the expression of the NF-κB cascade proteins in the LPS-stimulated RAW 264.7 cells, prevented the phosphorylation of the IKKα/β and blocked the activation of the Interferon-gamma (IFN-γ. The results suggest that the IKKβ inhibition is the major mechanism of the PTs-induced NF-κB inhibition. PASS predictions along with in-silico docking against the NEMO/IKKβ can be successfully applied in the selection of the prospective NF-κB inhibitory downregulators of IKKβ phosphorylation.

  5. Luteoloside attenuates anoxia/reoxygenation-induced cardiomyocytes injury via mitochondrial pathway mediated by 14-3-3η protein.

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    Liu, Zhantu; Yang, Lili; Huang, Jiyi; Xu, Ping; Zhang, Zeyu; Yin, Dong; Liu, Jichun; He, Huan; He, Ming

    2018-02-21

    Ischemia/reperfusion (I/R) injury is the major cause of acute cardiovascular disease worldwide. 14-3-3η protein has been demonstrated to protect myocardium against I/R injury. Luteoloside (Lut), a flavonoid found in many Chinese herbs, exerts myocardial protection effects. However, the mechanism remains unclear. We hypothesize that the cardioprotective role of Lut is exerted by regulating the 14-3-3η signal pathway. To investigate our hypothesis, an in vitro I/R model was generated in H9C2 cardiomyocytes by anoxia/reoxygenation (A/R) treatment. The effects of Lut on cardiomyocytes with A/R injury were assessed by determining the cell viability, lactate dehydrogenase levels, intracellular reactive oxygen species levels, mitochondrial permeability transition pores (mPTP) openness, caspase-3 activity, and apoptosis rate. The effects on protein expression were tested using western blot analysis. Lut attenuated A/R-induced injury to cardiomyocytes by increasing the expression of 14-3-3η protein and cell viability; decreasing levels of lactate dehydrogenase, reactive oxygen species, mPTP openness, caspase-3 activity, and low apoptosis rate were observed. However, the cardioprotective effects of Lut were blocked by AD14-3-3ηRNAi, an adenovirus knocking down the intracellular 14-3-3η expression. In conclusion, to our knowledge, this is the first study to demonstrate that Lut protected cardiomyocytes from A/R-induced injury via the regulation of 14-3-3η signaling pathway. Copyright © 2018 John Wiley & Sons, Ltd.

  6. Cornuside inhibits mast cell-mediated allergic response by down-regulating MAPK and NF-κB signaling pathways

    Energy Technology Data Exchange (ETDEWEB)

    Li, Liangchang [Department of Anatomy, Histology and Embryology, School of Basic Medical Sciences, Yanbian University, Yanji, 133002 (China); Jin, Guangyu [Yanbian University Hospital, Medicine College, Yanbian University, Yanji, 133000 (China); Jiang, Jingzhi [Department of Anatomy, Histology and Embryology, School of Basic Medical Sciences, Yanbian University, Yanji, 133002 (China); Zheng, Mingyu; Jin, Yan [College of Pharmacy, Yanbian University, Yanji, 133002 (China); Lin, Zhenhua [Department of Pathology & Cancer Research Center, Yanbian University Medical College, Yanji, 133002 (China); Li, Guangzhao [Department of Anatomy, Histology and Embryology, School of Basic Medical Sciences, Yanbian University, Yanji, 133002 (China); Choi, Yunho, E-mail: why76@jbnu.ac.kr [Department of Anatomy, Medical School, Institute for Medical Sciences, Chonbuk National University, Jeonju, 561-756 (Korea, Republic of); Yan, Guanghai, E-mail: ghyan2015@sina.com [Department of Anatomy, Histology and Embryology, School of Basic Medical Sciences, Yanbian University, Yanji, 133002 (China)

    2016-04-29

    Aims: The present study is to investigate the effect of cornuside on mast cell-mediated allergic response, as well as its possible mechanisms of action. Methods: To test the anti-allergic effects of cornuside in vivo, local extravasati