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Sample records for early activated pathways

  1. Role of Magnesium Chelatase Activity in the Early Steps of the Tetrapyrrole Biosynthetic Pathway1

    PubMed Central

    Papenbrock, Jutta; Mock, Hans-Peter; Tanaka, Ryouichi; Kruse, Elisabeth; Grimm, Bernhard

    2000-01-01

    Magnesium-protoporphyrin IX chelatase (Mg-chelatase) is located at the branchpoint of tetrapyrrole biosynthesis, at which point protoporphyrin IX is distributed for the synthesis of chlorophyll and heme. We investigated the regulatory contribution of Mg-chelatase to the flow of metabolites. In plants, the enzyme complex consists of three subunits, designated CHL D, CHL I, and CHL H. Transgenic tobacco (Nicotiana tabacum) plants expressing antisense RNA for the Mg-chelatase subunit CHL H were analyzed to elucidate further the role of Mg-chelatase in the distribution of protoporphyrin IX into the branched tetrapyrrolic pathway. The transgenic plants displayed a reduced growth rate and chlorophyll deficiency. Both phenotypical properties were correlated with lower Mg-chelatase activity. Unexpectedly, less protoporphyrin IX and heme accumulated, and a decrease in 5-aminolevulinate (ALA)-synthesizing capacity and ALA dehydratase activity paralleled the progressive reduction in Mg-chelatase activity in the transformants compared with control plants. The reduced activities of the early enzymatic steps corresponded with lower levels of transcripts encoding glutamyl-tRNA reductase and ALA-dehydratase. The decreased expression and activities of early enzymes in the pathway could be explained by a feedback-controlled mechanism in response to lower Mg-chelatase activity. We discuss intercompartmental signaling that synchronizes the activities of the first steps in tetrapyrrolic metabolism with the late steps for the synthesis of end products. PMID:10759511

  2. The Developmental Pathway From Pubertal Timing to Delinquency and Sexual Activity From Early to Late Adolescence

    PubMed Central

    Negriff, Sonya; Elizabeth, J. Susman; Trickett, Penelope K.

    2013-01-01

    There is strong evidence that early pubertal timing is associated with adolescent problem behaviors. However, there has been limited investigation of the mechanisms or developmental relationships. The present study examined longitudinal models incorporating pubertal timing, delinquency, and sexual activity in a sample of 454 adolescents (9–13 years old at enrollment; 47% females). Participants were seen for three assessments approximately 1 year apart. Characteristics of friendship networks (older friends, male friends, older male friends) were examined as mediators. Structural equation modeling was used to test these associations as well as temporal relationships between sexual activity and delinquency. Results showed that early pubertal timing at Time 1 was related to more sexual activity at Time 2, which was related to higher delinquency at Time 3, a trend mediation effect. None of the friendship variables mediated these associations. Gender or maltreatment status did not moderate the meditational pathways. The results also supported the temporal sequence of sexual activity preceding increases in delinquency. These findings reveal that early maturing adolescents may actively seek out opportunities to engage in sexual activity which appears to be risk for subsequent delinquency. PMID:21191640

  3. Genes of phenylpropanoid pathway are activated in early response to Fusarium attack in flax plants.

    PubMed

    Kostyn, Kamil; Czemplik, Magdalena; Kulma, Anna; Bortniczuk, Małgorzata; Skała, Jacek; Szopa, Jan

    2012-07-01

    Fusarium is the most common flax pathogen causing serious plant diseases and in most cases leading to plant death. To protect itself, the plant activates a number of genes and metabolic pathways, both to counteract the effects of the pathogen, and to eliminate the threat. The identification of the plant genes which respond to infection is the approach, that has been used in this study. Forty-seven flax genes have been identified by means of cDNA subtraction method as those, which respond to pathogen infection. Subtracted genes were classified into several classes and the prevalence of the genes involved in the broad spectrum of antioxidants biosynthesis has been noticed. By means of semi-quantitative RT-PCR and metabolite profiling, the involvement of subtracted genes controlling phenylpropanoid pathway in flax upon infection was positively verified. We identified the key genes of the synthesis of these compounds. At the same time we determined the level of the metabolites produced in the phenylpropanoid pathway (flavonoids, phenolic acids) in early response to Fusarium attack by means of GC-MS technique. To the best of our knowledge this is the first report to describe genes and metabolites of early flax response to pathogens studied in a comprehensive way. PMID:22608524

  4. Low Dose Nicotine Attenuates Aβ Neurotoxicity through Activation Early Growth Response Gene 1 Pathway

    PubMed Central

    Zhang, Jie; Qiu, Jinhua; Du, Guicheng; Qiao, Zhiliang; Jin, Guanghui; Gao, Fengguang; Zhang, Qiqing

    2015-01-01

    Epidemiological studies indicate that smoking is negatively correlated with the incidence and development of Alzheimer's disease (AD). Nicotine was reported to be the active factor. However, the detailed mechanisms still remain to be fully elucidated. Early growth response gene 1 (EGR-1) plays important roles in several important biological processes such as promoting cell growth, differentiation, anti oxidative stress, and apoptosis, but few in the pathogenesis of AD. In the present study, we show that nicotine can activate the MAPK/ERK/EGR-1 signaling pathway partially through α7 nAChR. In addition, the up-regulation of EGR-1 by nicotine can also increase the phosphorylation of CyclinD1 which contributes to the attenuation of amyloid-β (Aβ25–35) -induced neurotoxicity. Although nicotine and Aβ25–35 can activate EGR-1, the expression of EGR-1 is down-regulated following treatment with nicotine and Aβ25–35. This study demonstrates that low dose nicotine attenuates Aβ25–35-induced neurotoxicity in vitro and in vivo through activating EGR-1 pathway. PMID:25815723

  5. Early Components of the Complement Classical Activation Pathway in Human Systemic Autoimmune Diseases

    PubMed Central

    Lintner, Katherine E.; Wu, Yee Ling; Yang, Yan; Spencer, Charles H.; Hauptmann, Georges; Hebert, Lee A.; Atkinson, John P.; Yu, C. Yung

    2016-01-01

    The complement system consists of effector proteins, regulators, and receptors that participate in host defense against pathogens. Activation of the complement system, via the classical pathway (CP), has long been recognized in immune complex-mediated tissue injury, most notably systemic lupus erythematosus (SLE). Paradoxically, a complete deficiency of an early component of the CP, as evidenced by homozygous genetic deficiencies reported in human, are strongly associated with the risk of developing SLE or a lupus-like disease. Similarly, isotype deficiency attributable to a gene copy-number (GCN) variation and/or the presence of autoantibodies directed against a CP component or a regulatory protein that result in an acquired deficiency are relatively common in SLE patients. Applying accurate assay methodologies with rigorous data validations, low GCNs of total C4, and heterozygous and homozygous deficiencies of C4A have been shown as medium to large effect size risk factors, while high copy numbers of total C4 or C4A as prevalent protective factors, of European and East-Asian SLE. Here, we summarize the current knowledge related to genetic deficiency and insufficiency, and acquired protein deficiencies for C1q, C1r, C1s, C4A/C4B, and C2 in disease pathogenesis and prognosis of SLE, and, briefly, for other systemic autoimmune diseases. As the complement system is increasingly found to be associated with autoimmune diseases and immune-mediated diseases, it has become an attractive therapeutic target. We highlight the recent developments and offer a balanced perspective concerning future investigations and therapeutic applications with a focus on early components of the CP in human systemic autoimmune diseases. PMID:26913032

  6. Activation of oxidative stress-responsive signaling pathways in early splenotoxic response of aniline

    SciTech Connect

    Wang Jianling; Wang Gangduo; Ansari, G.A.S.; Khan, M. Firoze

    2008-07-15

    Aniline exposure causes toxicity to the spleen, which leads to a variety of sarcomas, and fibrosis appears to be an important preneoplastic lesion. However, early molecular mechanisms in aniline-induced toxicity to the spleen are not known. Previously, we have shown that aniline exposure results in iron overload and induction of oxidative stress in the spleen, which can cause transcriptional upregulation of fibrogenic/inflammatory cytokines via activation of oxidative stress (OS)-responsive signaling pathways. To test this mechanism, male SD rats were treated with aniline (1mmol/kg/day via gavage) for 7days, an experimental condition that precedes the appearance of fibrosis. Significant increases in both NF-{kappa}B and AP-1 binding activity was observed in the nuclear extracts of splenocytes from aniline-treated rats as determined by ELISAs, and supported by Western blot data showing increases in p-I{kappa}B{alpha}, p-p65 and p-c-Jun. To understand the upstream signaling events which could account for the activation of NF-{kappa}B and AP-1, phosphorylation patterns of I{kappa}B kinases (IKK{alpha} and IKK{beta}) and mitogen-activated protein kinases (MAPKs) were pursued. Our data showed remarkable increases in both p-IKK{alpha} and p-IKK{beta} in the splenocytes from aniline-treated rats, suggesting their role in the phosphorylation of both I{kappa}B{alpha} and p65 subunits. Furthermore, aniline exposure led to activation of all three classes of MAPKs, as evident from increased phosphorylation of extracellular-signal-regulated kinase (ERK1/2), c-Jun N-terminal kinase (JNK1/2) and p38 MAPKs, which could potentially contribute to the observed activation of both AP-1 and NF-{kappa}B. Activation of upstream signaling molecules was also associated with simultaneous increases in gene transcription of cytokines IL-1, IL-6 and TNF-{alpha}. The observed sequence of events following aniline exposure could initiate a fibrogenic and/or tumorigenic response in the spleen.

  7. Modeling and analysis of early events in T-lymphocyte antigen-activated intracellular-signaling pathways

    NASA Astrophysics Data System (ADS)

    Zheng, Yanan; Balakrishnan, Venkataramanan; Buzzard, Greg; Geahlen, Robert; Harrison, Marietta; Rundell, Ann

    2005-12-01

    The T-cell antigen-activated signaling pathway is a highly regulated intracellular biochemical system that is crucial for initiating an appropriate adaptive immune response. To improve the understanding of the complex regulatory mechanisms controlling the early events in T-cell signaling, a detailed mathematical model was developed that utilizes ordinary differential equations to describe chemical reactions of the signaling pathway. The model parameter values were constrained by experimental data on the activation of a specific signaling intermediate and indicated an initial rapid cascade of phosphorylation events followed by a comparatively slow signal downregulation. Nonlinear analysis of the model suggested that thresholding and bistability occur as a result of the embedded positive and negative feedback loops within the model. These nonlinear system properties may enhance the T-cell receptor specificity and provide sub-threshold noise filtering with switch-like behavior to ensure proper cell response. Additional analysis using a reduced second-order model led to further understanding of the observed system behavior. Moreover, the interactions between the positive and negative feedback loops enabled the model to exhibit, among a variety of other feasible dynamics, a sustained oscillation that corresponds to a stable limit cycle in the two-dimensional phase plane. Quantitative analysis in this paper has helped identify potential regulatory mechanisms in the early T-cell signaling events. This integrated approach provides a framework to quantify and discover the ensemble of interconnected T-cell antigen-activated signaling pathways from limited experimental data.

  8. Localization of p24 putative cargo receptors in the early secretory pathway depends on the biosynthetic activity of the cell.

    PubMed Central

    Kuiper, R P; Bouw, G; Janssen, K P; Rötter, J; van Herp, F; Martens, G J

    2001-01-01

    Members of the p24 family of putative cargo receptors (subdivided into p24-alpha, -beta, -gamma and -delta) are localized in the intermediate-and cis-Golgi compartments of the early secretory pathway, and are thought to play an important role in protein transport. In the present study, we wondered what effect increased biosynthetic cell activity with resulting high levels of protein transport would have on the subcellular localization of p24. We examined p24 localization in Xenopus intermediate pituitary melanotrope cells, which in black- and white-adapted animals are biosynthetically highly active and virtually inactive respectively. In addition, p24 localization was studied in Xenopus anterior pituitary cells whose activity is not changed during background adaptation. Using organelle fractionation, we found that in the inactive melanotropes and moderately active anterior pituitary cells of white-adapted animals, the p24-alpha, -beta, -gamma and -delta proteins are all located in the Golgi compartment. In the highly active melanotropes, but not in the anterior cells of black-adapted animals, the steady-state distribution of all four p24 members changed towards the intermediate compartment and subdomains of the endoplasmic reticulum (ER), most probably the ER exit sites. In the active melanotropes, the major cargo protein pro-opiomelanocortin was mostly localized to ER subdomains and partially co-localized with the p24 proteins. Furthermore, in the active cells, in vitro blocking of protein biosynthesis by cycloheximide or dispersion of the Golgi complex by brefeldin A led to a redistribution of the p24 proteins, indicating their involvement in ER-to-Golgi protein transport and extensive cycling in the early secretory pathway. We conclude that the subcellular localization of p24 proteins is dynamic and depends on the biosynthetic activity of the cell. PMID:11716771

  9. Early Activation of the Kynurenine Pathway Predicts Early Death and Long‐term Outcome in Patients Resuscitated From Out‐of‐Hospital Cardiac Arrest

    PubMed Central

    Ristagno, Giuseppe; Latini, Roberto; Vaahersalo, Jukka; Masson, Serge; Kurola, Jouni; Varpula, Tero; Lucchetti, Jacopo; Fracasso, Claudia; Guiso, Giovanna; Montanelli, Alessandro; Barlera, Simona; Gobbi, Marco; Tiainen, Marjaana; Pettilä, Ville; Skrifvars, Markus B.

    2014-01-01

    Background The kynurenine pathway (KP) is the major route of tryptophan (TRP) catabolism and is activated by inflammation and after cardiac arrest in animals. We hypothesized that the KP activation level correlates with severity of post–cardiac arrest shock, early death, and long‐term outcome. Methods and Results Plasma was obtained from 245 patients enrolled in a prospective multicenter observational study in 21 intensive care units in Finland. Time to return of spontaneous circulation, lowest systolic arterial pressure, and bicarbonate during the first 24 hours were collected. A cerebral performance category of 3 to 5 defined 12‐month poor outcome. Plasma TRP and KP metabolites, kynurenine (KYN), kynurenic acid, 3‐hydroxyanthranilic acid, and the ratio of KYN to TRP were measured by liquid chromatography and mass spectrometry. All KP metabolites at intensive care unit admission were significantly higher in cardiac arrest patients with a nonshockable rhythm compared to those with a shockable rhythm, and kynurenic acid and 3‐hydroxyanthranilic acid correlated with time to return of spontaneous circulation. Patients with higher levels of KYN, KYN to TRP, kynurenic acid, and 3‐hydroxyanthranilic acid had lower 24‐hour systolic arterial pressure and bicarbonate. All KP metabolites and the ratio of KYN to TRP, but not TRP, were significantly higher in patients who died in the intensive care unit in comparison to those who survived. Multivariable logistic regression showed that high kynurenic acid (odds ratio: 1.004; 95% confidence interval: 1.001 to 1.008; P=0.014), and 3‐hydroxyanthranilic acid (odds ratio: 1.011; 95% confidence interval: 1.001 to 1.022; P=0.03) were independently associated with 12‐month poor outcome and significantly improved risk reclassification. Conclusions KP is activated early after cardiac arrest and is associated with severity of post–cardiac arrest shock, early death, and poor long‐term outcome. PMID:25092787

  10. Microbes & neurodevelopment--Absence of microbiota during early life increases activity-related transcriptional pathways in the amygdala.

    PubMed

    Stilling, Roman M; Ryan, Feargal J; Hoban, Alan E; Shanahan, Fergus; Clarke, Gerard; Claesson, Marcus J; Dinan, Timothy G; Cryan, John F

    2015-11-01

    The mammalian amygdala is a key emotional brain region for eliciting social behaviour, critically involved in anxiety and fear-related behaviours, and hence a focus of research on neurodevelopmental and stress-related disorders such as autism and anxiety. Recently, increasing evidence implicates host-microbe interactions in the aetiology of these conditions. Germ-free (GF) mice, devoid of any microbiota throughout organismal maturation, are a well-established tool to study the effects of absence of the microbiota on host physiology. A growing body of independently replicated findings confirm that GF animals demonstrate altered anxiety-related behaviour and impaired social behaviour. However, the underlying mechanisms of this interaction and the nature of the pathways involved are only insufficiently understood. To further elucidate the molecular underpinnings of microbe-brain interaction, we therefore exploited unbiased genome-wide transcriptional profiling to determine gene expression in the amygdala of GF and GF mice that have been colonised after weaning. Using RNA-sequencing and a comprehensive downstream analysis pipeline we studied the amygdala transcriptome and found significant differences at the levels of differential gene expression, exon usage and RNA-editing. Most surprisingly, we noticed upregulation of several immediate early response genes such as Fos, Fosb, Egr2 or Nr4a1 in association with increased CREB signalling in GF mice. In addition, we found differential expression and recoding of several genes implicated in brain physiology processes such as neurotransmission, neuronal plasticity, metabolism and morphology. In conclusion, our data suggest altered baseline neuronal activity in the amygdala of germ-free animals, which is established during early life and may have implications for understanding development and treatment of neurodevelopmental disorders. PMID:26184083

  11. The Rel/NF-κB pathway and transcription of immediate early genes in T cell activation are inhibited by microgravity

    PubMed Central

    Chang, Tammy T.; Walther, Isabelle; Li, Chai-Fei; Boonyaratanakornkit, Jim; Galleri, Grazia; Meloni, Maria Antonia; Pippia, Proto; Cogoli, Augusto; Hughes-Fulford, Millie

    2012-01-01

    This study tested the hypothesis that transcription of immediate early genes is inhibited in T cells activated in μg. Immunosuppression during spaceflight is a major barrier to safe, long-term human space habitation and travel. The goals of these experiments were to prove that μg was the cause of impaired T cell activation during spaceflight, as well as understand the mechanisms controlling early T cell activation. T cells from four human donors were stimulated with Con A and anti-CD28 on board the ISS. An on-board centrifuge was used to generate a 1g simultaneous control to isolate the effects of μg from other variables of spaceflight. Microarray expression analysis after 1.5 h of activation demonstrated that μg- and 1g-activated T cells had distinct patterns of global gene expression and identified 47 genes that were significantly, differentially down-regulated in μg. Importantly, several key immediate early genes were inhibited in μg. In particular, transactivation of Rel/NF-κB, CREB, and SRF gene targets were down-regulated. Expression of cREL gene targets were significantly inhibited, and transcription of cREL itself was reduced significantly in μg and upon anti-CD3/anti-CD28 stimulation in simulated μg. Analysis of gene connectivity indicated that the TNF pathway is a major early downstream effector pathway inhibited in μg and may lead to ineffective proinflammatory host defenses against infectious pathogens during spaceflight. Results from these experiments indicate that μg was the causative factor for impaired T cell activation during spaceflight by inhibiting transactivation of key immediate early genes. PMID:22750545

  12. Huntingtons Disease Mice Infected with Toxoplasma gondii Demonstrate Early Kynurenine Pathway Activation, Altered CD8+ T-Cell Responses, and Premature Mortality.

    PubMed

    Donley, David W; Olson, Andrew R; Raisbeck, Merl F; Fox, Jonathan H; Gigley, Jason P

    2016-01-01

    Huntington's disease (HD) is a progressive neurodegenerative disorder caused by a polyglutamine-repeat expansion in the huntingtin protein. Activation of the kynurenine pathway of tryptophan degradation is implicated in the pathogenesis of HD. Indoleamine-2,3-dioxygenase (IDO) catalyzes the oxidation of tryptophan to kynurenine, the first step in this pathway. The prevalent, neuroinvasive protozoal pathogen Toxoplasma gondii (T. gondii) results in clinically silent life-long infection in immune-competent individuals. T. gondii infection results in activation of IDO which provides some protection against the parasite by depleting tryptophan which the parasite cannot synthesize. The kynurenine pathway may therefore represent a point of synergism between HD and T. gondii infection. We show here that IDO activity is elevated at least four-fold in frontal cortex and striata of non-infected N171-82Q HD mice at 14-weeks corresponding to early-advanced HD. T. gondii infection at 5 weeks resulted in elevation of cortical IDO activity in HD mice. HD-infected mice died significantly earlier than wild-type infected and HD control mice. Prior to death, infected HD mice demonstrated decreased CD8+ T-lymphocyte proliferation in brain and spleen compared to wild-type infected mice. We demonstrate for the first time that HD mice have an altered response to an infectious agent that is characterized by premature mortality, altered immune responses and early activation of IDO. Findings are relevant to understanding how T. gondii infection may interact with pathways mediating neurodegeneration in HD. PMID:27611938

  13. Blocking TGF-β Signaling Pathway Preserves Mitochondrial Proteostasis and Reduces Early Activation of PDGFRβ+ Pericytes in Aristolochic Acid Induced Acute Kidney Injury in Wistar Male Rats

    PubMed Central

    Pozdzik, Agnieszka A.; Giordano, Laetitia; Li, Gang; Antoine, Marie-Hélène; Quellard, Nathalie; Godet, Julie; De Prez, Eric; Husson, Cécile; Declèves, Anne-Emilie; Arlt, Volker M.; Goujon, Jean-Michel; Brochériou-Spelle, Isabelle; Ledbetter, Steven R.; Caron, Nathalie; Nortier, Joëlle L.

    2016-01-01

    Background The platelet-derived growth factor receptor β (PDGFRβ)+ perivascular cell activation becomes increasingly recognized as a main source of scar-associated kidney myofibroblasts and recently emerged as a new cellular therapeutic target. Aims In this regard, we first confirmed the presence of PDGFRβ+ perivascular cells in a human case of end-stage aristolochic acid nephropathy (AAN) and thereafter we focused on the early fibrosis events of transforming growth factor β (TGFβ) inhibition in a rat model of AAN. Materials and Methods Neutralizing anti-TGFβ antibody (1D11) and its control isotype (13C4) were administered (5 mg/kg, i.p.) at Days -1, 0, 2 and 4; AA (15 mg/kg, sc) was injected daily. Results At Day 5, 1D11 significantly suppressed p-Smad2/3 signaling pathway improving renal function impairment, reduced the score of acute tubular necrosis, peritubular capillaritis, interstitial inflammation and neoangiogenesis. 1D11 markedly decreased interstitial edema, disruption of tubular basement membrane loss of brush border, cytoplasmic edema and organelle ultrastructure alterations (mitochondrial disruption and endoplasmic reticulum edema) in proximal tubular epithelial cells. Moreover, 1D11 significantly inhibited p-PERK activation and attenuated dysregulation of unfolded protein response (UPR) pathways, endoplasmic reticulum and mitochondrial proteostasis in vivo and in vitro. Conclusions The early inhibition of p-Smad2/3 signaling pathway improved acute renal function impairment, partially prevented epithelial-endothelial axis activation by maintaining PTEC proteostasis and reduced early PDGFRβ+ pericytes-derived myofibroblasts accumulation. PMID:27379382

  14. Grape seed proanthocyanidin extract protects the retina against early diabetic injury by activating the Nrf2 pathway

    PubMed Central

    SUN, YAN; XIU, CAIMEI; LIU, WEI; TAO, YUAN; WANG, JIANRONG; QU, YI

    2016-01-01

    The present study aimed to investigate whether grape seed proanthocyanidin extract (GSPE) has a protective effect on diabetic retinal function. A total of 30 Wistar rats were randomly divided into three equal groups, including the control, diabetic and GSPE-treated diabetic groups. Retinal tissue was harvested and subsequently stained with hematoxylin and eosin. Superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and methane dicarboxylic aldehyde (MDA) levels were evaluated using respective assay kits; whereas nuclear erythroid 2-related factor 2 (Nrf2) and heme oxygenase (HO)-1 expression levels were assessed by immunohistochemical and western blot analysis. Cell apoptosis in the retina was determined using the terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling method. The results showed that the structure of the retina was damaged in diabetic rats, as compared with the control rats. Notably, the structure of the retina improved in the GSPE-treated diabetic group, as compared with the diabetic group. SOD and GSH-Px activities were significantly increased in the retina of rats in the GSPE-treated diabetic group, as compared with the diabetic group (P=0.011 and P=0.001, respectively). Furthermore, a significant reduction in MDA was detected (P=0.013) and the expression levels of Nrf2 and HO-1 in the bladders of rats in the GSPE-treated diabetic group were significantly increased, as compared with the diabetic group (P=0.038 and P=0.043, respectively). Apoptosis of retinal cells was significantly increased in the diabetic group, as compared with the control group (P<0.001); a significant reduction was also detected in the GSPE-treated diabetic group, as compared with the diabetic group (P=0.014). These results demonstrate that GSPE administration may protect the retina against hyperglycemic damage, possibly by ameliorating oxidative stress-mediated injury via the activation of the Nrf2 pathway. PMID:27073432

  15. Early BMP, Wnt and Ca(2+)/PKC pathway activation predicts the bone forming capacity of periosteal cells in combination with calcium phosphates.

    PubMed

    Bolander, Johanna; Chai, Yoke Chin; Geris, Liesbet; Schrooten, Jan; Lambrechts, Dennis; Roberts, Scott J; Luyten, Frank P

    2016-04-01

    The development of osteoinductive calcium phosphate- (CaP) based biomaterials has, and continues to be, a major focus in the field of bone tissue engineering. However, limited insight into the spatiotemporal activation of signalling pathways has hampered the optimisation of in vivo bone formation and subsequent clinical translation. To gain further knowledge regarding the early molecular events governing bone tissue formation, we combined human periosteum derived progenitor cells with three types of clinically used CaP-scaffolds, to obtain constructs with a distinct range of bone forming capacity in vivo. Protein phosphorylation together with gene expression for key ligands and target genes were investigated 24 hours after cell seeding in vitro, and 3 and 12 days post ectopic implantation in nude mice. A computational modelling approach was used to deduce critical factors for bone formation 8 weeks post implantation. The combined Ca(2+)-mediated activation of BMP-, Wnt- and PKC signalling pathways 3 days post implantation were able to discriminate the bone forming from the non-bone forming constructs. Subsequently, a mathematical model able to predict in vivo bone formation with 96% accuracy was developed. This study illustrates the importance of defining and understanding CaP-activated signalling pathways that are required and sufficient for in vivo bone formation. Furthermore, we demonstrate the reliability of mathematical modelling as a tool to analyse and deduce key factors within an empirical data set and highlight its relevance to the translation of regenerative medicine strategies. PMID:26901484

  16. Early Stages of Zebrafish Eye Formation Require the Coordinated Activity of Wnt11, Fz5, and the Wnt/β-Catenin Pathway

    PubMed Central

    Cavodeassi, Florencia; Carreira-Barbosa, Filipa; Young, Rodrigo M.; Concha, Miguel L.; Allende, Miguel L.; Houart, Corinne; Tada, Masazumi; Wilson, Stephen W.

    2009-01-01

    Summary During regional patterning of the anterior neural plate, a medially positioned domain of cells is specified to adopt retinal identity. These eye field cells remain coherent as they undergo morphogenetic events distinct from other prospective forebrain domains. We show that two branches of the Wnt signaling pathway coordinate cell fate determination with cell behavior during eye field formation. Wnt/β-catenin signaling antagonizes eye specification through the activity of Wnt8b and Fz8a. In contrast, Wnt11 and Fz5 promote eye field development, at least in part, through local antagonism of Wnt/β-catenin signaling. Additionally, Wnt11 regulates the behavior of eye field cells, promoting their cohesion. Together, these results allow us to postulate a model in which Wnt11 and Fz5 signaling promotes early eye development through the coordinated antagonism of signals that suppress retinal identity and promotion of coherence of eye field cells. PMID:15996547

  17. Combinatorial activity of Flamingo proteins directs convergence and extension within the early zebrafish embryo via the planar cell polarity pathway.

    PubMed

    Formstone, Caroline J; Mason, Ivor

    2005-06-15

    The seven-transmembrane protocadherin, Flamingo, functions in a number of processes during Drosophila development, including planar cell polarity (PCP). To assess the role(s) of Flamingo1/Celsr1 (Fmi1) during vertebrate embryogenesis we have exploited the zebrafish system, identifying two Fmi1 orthologues (zFmi1a and zFmi1b) and employing morpholinos to induce mis-splicing of zebrafish fmi1 mRNAs, to both imitate mutations identified in Drosophila flamingo and generate novel aberrant Flamingo proteins. We demonstrate that in the zebrafish gastrula, Fmi1 proteins function in concert with each other and with the vertebrate PCP proteins, Wnt11 and Strabismus, to mediate convergence and extension during gastrulation, without altering early dorso-ventral patterning. We show that zebrafish Fmi1a promotes extension of the entire antero-posterior axis of the zebrafish gastrula including prechordal plate and ventral diencephalic precursors. However, while we show that control over axial extension is autonomous, we find that Fmi1a is not required within lateral cells undergoing dorsal convergence. PMID:15882862

  18. Dynamic gene expression patterns in animal models of early and late heart failure reveal biphasic-bidirectional transcriptional activation of signaling pathways.

    PubMed

    Rowell, Janelle; Koitabashi, Norimichi; Kass, David A; Barth, Andreas S

    2014-10-15

    Altered cardiac gene expression in heart failure (HF) has mostly been identified by single-point analysis of end-stage disease. This may miss earlier changes in gene expression that are transient and/or directionally opposite to those observed later. Myocardial datasets from the largest microarray data repository (Gene Expression Omnibus) yielded six HF studies with time-course data. Differentially expressed transcripts between nonfailing controls, early HF (<3 days after cardiac insult) and late HF (usually >2 wk) were determined, and analysis of KEGG pathways and predicted regulatory control elements performed. We found that gene expression followed varying patterns: Downregulation of metabolic pathways occurred early and was sustained into late-stage HF. In contrast, most signaling pathways undergo a complex biphasic pattern: Calcium signaling, p53, apoptosis, and MAPK pathways displayed a bidirectional response, declining early but rising late. These profiles were compatible with specific microRNA (miRNA) and transcription regulators: Estrogen-related receptor-α and myocyte-enhancer factor-2 binding sites were overrepresented in the promoter regions of downregulated transcripts. Concurrently, there were overrepresented binding sites for E2f and ETS family members (E-Twenty Six, including Gabp, Elf1, and Ets2), serum response and interferon regulated factor in biphasic-bidirectional and late-upregulated transcripts. Binding sites for miRNAs downregulated by HF were more common in upregulated transcripts (e.g., miRNA-22,-133a/b, and -150 in early HF and miRNA-1,-9,-499 in late HF). During the development of HF, gene expression is characterized by dynamic overlapping sets of transcripts controlled by specific interrelated regulatory mechanisms. While metabolic gene classes show early and sustained downregulation in HF, signaling pathways undergo a complex biphasic pattern with early down- and more pronounced late upregulation. PMID:25159852

  19. RNA-seq liver transcriptome analysis reveals an activated MHC-I pathway and an inhibited MHC-II pathway at the early stage of vaccine immunization in zebrafish

    PubMed Central

    2012-01-01

    Background Zebrafish (Danio rerio) is a prominent vertebrate model of human development and pathogenic disease and has recently been utilized to study teleost immune responses to infectious agents threatening the aquaculture industry. In this work, to clarify the host immune mechanisms underlying the protective effects of a putative vaccine and improve its immunogenicity in the future efforts, high-throughput RNA sequencing technology was used to investigate the immunization-related gene expression patterns of zebrafish immunized with Edwardsiella tarda live attenuated vaccine. Results Average reads of 18.13 million and 14.27 million were obtained from livers of zebrafish immunized with phosphate buffered saline (mock) and E. tarda vaccine (WED), respectively. The reads were annotated with the Ensembl zebrafish database before differential expressed genes sequencing (DESeq) comparative analysis, which identified 4565 significantly differentially expressed genes (2186 up-regulated and 2379 down-regulated in WED; p<0.05). Among those, functional classifications were found in the Gene Ontology database for 3891 and in the Kyoto Encyclopedia of Genes and Genomes database for 3467. Several pathways involved in acute phase response, complement activation, immune/defense response, and antigen processing and presentation were remarkably affected at the early stage of WED immunization. Further qPCR analysis confirmed that the genes encoding the factors involved in major histocompatibility complex (MHC)-I processing pathway were up-regulated, while those involved in MHC-II pathway were down-regulated. Conclusion These data provided insights into the molecular mechanisms underlying zebrafish immune response to WED immunization and might aid future studies to develop a highly immunogenic vaccine against gram-negative bacteria in teleosts. PMID:22805612

  20. Metabolic block at early stages of the glycolytic pathway activates the Rcs phosphorelay system via increased synthesis of dTDP-glucose in Escherichia coli.

    PubMed

    El-Kazzaz, Waleed; Morita, Teppei; Tagami, Hideaki; Inada, Toshifumi; Aiba, Hiroji

    2004-02-01

    A mutational block in the early stages of the glycolytic pathway facilitates the degradation of the ptsG mRNA encoding the major glucose transporter IICBGlc in Escherichia coli. The degradation is RNase E dependent and is correlated with the accumulation of either glucose-6-P or fructose-6-P (Kimata et al., 2001, EMBO J 20: 3587-3595; Morita et al., 2003, J Biol Chem 278: 15608-15614). In this paper, we investigate additional physiological effects resulting from the accumulation of glucose-6-P caused by a mutation in pgi encoding phosphoglucose isomerase, focusing on changes in gene expression. The addition of glucose to the pgi strain caused significant growth inhibition, in particular in the mlc background. Cell growth then gradually resumed as the level of IICBGlc decreased. We found that the transcription of the cps operon, encoding a series of proteins responsible for the synthesis of colanic acid, was markedly but transiently induced under this metabolic stress. Both genetic and biochemical studies revealed that the metabolic stress induces cps transcription by activating the RcsC/YojN/RcsB signal transduction system. Overexpression of glucose-6-P dehydrogenase eliminated both growth inhibition and cps induction by reducing the glucose-6-P level. Mutations in genes responsible for the synthesis of glucose-1-P and/or dTDP-glucose eliminated the activation of the Rcs system by the metabolic stress. Taken together, we conclude that an increased synthesis of dTDP-glucose activates the Rcs phosphorelay system, presumably by affecting the synthesis of oligosaccharides for enterobacterial common antigen and O-antigen. PMID:14763984

  1. Early Events Induced by the Elicitor Cryptogein in Tobacco Cells: Involvement of a Plasma Membrane NADPH Oxidase and Activation of Glycolysis and the Pentose Phosphate Pathway.

    PubMed Central

    Pugin, A.; Frachisse, J. M.; Tavernier, E.; Bligny, R.; Gout, E.; Douce, R.; Guern, J.

    1997-01-01

    Application of the elicitor cryptogein to tobacco (cv Xanthi) is known to evoke external medium alkalinization, active oxygen species production, and phytoalexin synthesis. These are all dependent on an influx of calcium. We show here that cryptogein also induces calcium-dependent plasma membrane depolarization, chloride efflux, cytoplasm acidification, and NADPH oxidation without changes in NAD+ and ATP levels, indicating that the elicitor-activated redox system, responsible for active oxygen species production, uses NADPH in vivo. NADPH oxidation activates the functioning of the pentose phosphate pathway, leading to a decrease in glucose 6-phosphate and to the accumulation of glyceraldehyde 3-phosphate, 3- and 2-phosphoglyceric acid, and phosphoenolpyruvate. By inhibiting the pentose phosphate pathway, we demonstrate that the activation of the plasma membrane NADPH oxidase is responsible for active oxygen species production, external alkalinization, and acidification of the cytoplasm. A model is proposed for the organization of the cryptogein responses measured to date. PMID:12237354

  2. Studying MAP Kinase pathways during early development of Xenopus laevis.

    PubMed

    Keren, Aviad; Bengal, Eyal

    2010-01-01

    The following chapter describes several methods involved in the detection of MAPK activities and phosphorylated proteins during early development of Xenopus laevis. The Xenopus embryo provides a powerful platform for biochemical studies. We describe here basic methods of embryo manipulations such as egg fertilization, embryo growth and maintenance, microinjection of capped RNA and antisense morpholino oligonucleotides (AMOs), and isolation of explants. In addition, we describe methods to detect phosphorylated proteins, to analyze kinase activity, and to interfere with signaling pathways. Immunohistochemical staining performed on whole embryos or on tissue sections is an additional method for the detection of phosphorylated proteins in the developing embryo. Approaches to activate or inhibit MAPK activities including the ectopic expression of mutated isoforms of MAPK kinase, or the incubation of embryo explants with pharmacological inhibitors are described. Finally, we describe an in vitro kinase assay specifically designed for the Xenopus embryo. PMID:20811998

  3. Phospholipase D Activation Is an Early Component of the Salicylic Acid Signaling Pathway in Arabidopsis Cell Suspensions1[W][OA

    PubMed Central

    Krinke, Ondřej; Flemr, Matyáš; Vergnolle, Chantal; Collin, Sylvie; Renou, Jean-Pierre; Taconnat, Ludivine; Yu, Agnès; Burketová, Lenka; Valentová, Olga; Zachowski, Alain; Ruelland, Eric

    2009-01-01

    Salicylic acid (SA) plays a central role in defense against pathogen attack, as well as in germination, flowering, senescence, and the acquisition of thermotolerance. In this report we investigate the involvement of phospholipase D (PLD) in the SA signaling pathway. In presence of exogenous primary alcohols, the production of phosphatidic acid by PLD is diverted toward the formation of phosphatidylalcohols through a reaction called transphosphatidylation. By in vivo metabolic phospholipid labeling with 33Pi, PLD activity was found to be induced 45 min after addition of SA. We show that incubation of Arabidopsis (Arabidopsis thaliana) cell suspensions with primary alcohols inhibited the induction of two SA-responsive genes, PATHOGENESIS-RELATED1 and WRKY38, in a dose-dependent manner. This inhibitory effect was more pronounced when the primary alcohols were more hydrophobic. Secondary or tertiary alcohols had no inhibitory effect. These results provide compelling arguments for PLD activity being upstream of the induction of these genes by SA. A subsequent study of n-butanol effects on the SA-responsive transcriptome identified 1,327 genes differentially expressed upon SA treatment. Strikingly, the SA response of 380 of these genes was inhibited by n-butanol but not by tert-butanol. A detailed analysis of the regulation of these genes showed that PLD could act both positively and negatively, either on gene induction or gene repression. The overlap with the previously described phosphatidylinositol-4-kinase pathway is discussed. PMID:19304931

  4. Interleukin-24 mediates apoptosis in human B-cells through early activation of cell cycle arrest followed by late induction of the mitochondrial apoptosis pathway.

    PubMed

    Hadife, Nader; Nemos, Christophe; Frippiat, Jean-Pol; Hamadé, Tala; Perrot, Aurore; Dalloul, Ali

    2013-03-01

    Interleukin (IL)-24 has death-promoting effects on various proliferating cells including B-cells from chronic lymphocytic leukemia (CLL) and germinal center B-cells, but its molecular mechanisms are poorly understood. Using a B-cell differentiation model and mRNA profiling, we found that recombinant (r)IL-24 stimulated genes of the mitochondrial apoptotic pathway (Bax, Bid, Casp8, COX6C, COX7B) after 36 h, whereas the transcription of genes involved in DNA replication and metabolism was inhibited within 6 h. Unexpectedly, insulin-like growth factor 1 (IGF1), a hormone known to promote cell growth, was stimulated by IL-24. Activated B-cells express receptor for IGF1, to which they become sensitized and undergo apoptosis, a mechanism similar in this respect to IL-24-induced cell death. Furthermore, inhibition of the IGF1 pathway reversed the effects of IL-24. IL-24-mediated apoptosis was also antagonized by pifithrin-alpha, an inhibitor of p53 transactivation. Altogether, these results disclose sequential molecular signals generated by IL-24 in activated B-cells. PMID:22860893

  5. Pathway network analysis and an application to the ODE model of MMP2 activation in the early stage of cancer cell invasion

    NASA Astrophysics Data System (ADS)

    Minerva, D.; Kawasaki, S.; Suzuki, T.

    2015-03-01

    Cancer is known as the leading causes of death in the world, particularly in developing countries. Metastasis is believed as factor that make the situation worse. Cancer cell has the ability to invade and metastasize to a distant part of body. The mechanism of cancer cell invasion involving three molecules; MT1-MMP, TIMP2, and MMP2. The interaction of the three molecules activates MMP2 by cutting the MMP2 binding from a specific complex. The MMP2 activation leads to the release of cancer cell from its primary state towards distant part of body. In this paper, we will present the result of recent studies about MMP2 activation from mathematical point of view. We study the MMP2 activation model using law of mass action and conservation. We propose a method based on attachment and detachment rules and conservation law to analyze the ordinary differential equations system of pathway network associated with the MMP2 activation. As the result, we obtain possible way to suppress the spread of cancer cell.

  6. Neurotrophins Acting Via TRKB Receptors Activate the JAGGED1-NOTCH2 Cell-Cell Communication Pathway to Facilitate Early Ovarian Development

    PubMed Central

    Dorfman, Mauricio D.; Kerr, Bredford; Garcia-Rudaz, Cecilia; Paredes, Alfonso H.; Dissen, Gregory A.

    2011-01-01

    Tropomyosin-related kinase (TRK) receptor B (TRKB) mediates the supportive actions of neurotrophin 4/5 and brain-derived neurotrophic factor on early ovarian follicle development. Absence of TRKB receptors reduces granulosa cell (GC) proliferation and delays follicle growth. In the present study, we offer mechanistic insights into this phenomenon. DNA array and quantitative PCR analysis of ovaries from TrkB-null mice revealed that by the end of the first week of postnatal life, Jagged1, Hes1, and Hey2 mRNA abundance is reduced in the absence of TRKB receptors. Although Jagged1 encodes a NOTCH receptor ligand, Hes1 and Hey2 are downstream targets of the JAGGED1-NOTCH2 signaling system. Jagged1 is predominantly expressed in oocytes, and the abundance of JAGGED1 is decreased in TrkB−/− oocytes. Lack of TRKB receptors also resulted in reduced expression of c-Myc, a NOTCH target gene that promotes entry into the cell cycle, but did not alter the expression of genes encoding core regulators of cell-cycle progression. Selective restoration of JAGGED1 synthesis in oocytes of TrkB−/− ovaries via lentiviral-mediated transfer of the Jagged1 gene under the control of the growth differentiation factor 9 (Gdf9) promoter rescued c-Myc expression, GC proliferation, and follicle growth. These results suggest that neurotrophins acting via TRKB receptors facilitate early follicle growth by supporting a JAGGED1-NOTCH2 oocyte-to-GC communication pathway, which promotes GC proliferation via a c-MYC-dependent mechanism. PMID:22028443

  7. Quantitative proteomic analysis of HIV-1 infected CD4+ T cells reveals an early host response in important biological pathways: Protein synthesis, cell proliferation, and T-cell activation

    SciTech Connect

    Navare, Arti T.; Sova, Pavel; Purdy, David E.; Weiss, Jeffrey M.; Wolf-Yadlin, Alejandro; Korth, Marcus J.; Chang, Stewart T.; Proll, Sean C.; Jahan, Tahmina A.; Krasnoselsky, Alexei L.; Palermo, Robert E.; Katze, Michael G.

    2012-07-20

    Human immunodeficiency virus (HIV-1) depends upon host-encoded proteins to facilitate its replication while at the same time inhibiting critical components of innate and/or intrinsic immune response pathways. To characterize the host cell response on protein levels in CD4+ lymphoblastoid SUP-T1 cells after infection with HIV-1 strain LAI, we used mass spectrometry (MS)-based global quantitation with iTRAQ (isobaric tag for relative and absolute quantification). We found 266, 60 and 22 proteins differentially expressed (DE) (P-value{<=}0.05) at 4, 8, and 20 hours post-infection (hpi), respectively, compared to time-matched mock-infected samples. The majority of changes in protein abundance occurred at an early stage of infection well before the de novo production of viral proteins. Functional analyses of these DE proteins showed enrichment in several biological pathways including protein synthesis, cell proliferation, and T-cell activation. Importantly, these early changes before the time of robust viral production have not been described before.

  8. Inhibitory effects of omega-3 fatty acids on early brain injury after subarachnoid hemorrhage in rats: Possible involvement of G protein-coupled receptor 120/β-arrestin2/TGF-β activated kinase-1 binding protein-1 signaling pathway.

    PubMed

    Yin, Jia; Li, Haiying; Meng, Chengjie; Chen, Dongdong; Chen, Zhouqing; Wang, Yibin; Wang, Zhong; Chen, Gang

    2016-06-01

    Omega-3 fatty acids have been reported to improve neuron functions during aging and in patients affected by mild cognitive impairment, and mediate potent anti-inflammatory via G protein-coupled receptor 120 (GPR120) signal pathway. Neuron dysfunction and inflammatory response also contributed to the progression of subarachnoid hemorrhage (SAH)-induced early brain injury (EBI). This study was to examine the effects of omega-3 fatty acids on SAH-induced EBI. Two weeks before SAH, 30% Omega-3 fatty acids was administered by oral gavage at 1g/kg body weight once every 24h. Specific siRNA for GPR120 was exploited. Terminal deoxynucleotidyl transferase dUTP nick end labeling, fluoro-Jade B staining, and neurobehavioral scores and brain water content test showed that omega-3 fatty acids effectively suppressed SAH-induced brain cell apoptosis and neuronal degradation, behavioral impairment, and brain edema. Western blot, immunoprecipitation, and electrophoretic mobility shift assays results showed that omega-3 fatty acids effectively suppressed SAH-induced elevation of inflammatory factors, including cyclooxygenase-2, monocyte chemoattractant protein-1, and inducible nitric oxide synthase. In addition, omega-3 fatty acids could inhibit phosphorylation of transforming growth factor β activated kinase-1 (TAK1), MEK4, c-Jun N-terminal kinase, and IkappaB kinase as well as activation of nuclear factor kappa B through regulating GPR120/β-arrestin2/TAK1 binding protein-1 pathway. Furthermore, siRNA-induced GPR120 silencing blocked the protective effects of omega-3 fatty acids. Here, we show that stimulation of GPR120 with omega-3 fatty acids pretreatment causes anti-apoptosis and anti-inflammatory effects via β-arrestin2/TAK1 binding protein-1/TAK1 pathway in the brains of SAH rats. Fish omega-3 fatty acids as part of a daily diet may reduce EBI in an experimental rat model of SAH. PMID:27000704

  9. Choctaw Culture Early Education Activities.

    ERIC Educational Resources Information Center

    Brescia, William, Ed.; Reeves, Carolyn, Ed.; Skinner, Linda, Ed.

    An effort to better prepare Choctaw youngsters for kindergarten, the Choctaw Culture Early Education Program developed a resource of 58 activities adapted to meet the needs of Choctaw 3- and 4-year olds. The activities are divided into four sections pertaining to getting started, relating to five project publications (How the Flowers Came to Be,…

  10. Spaceflight Activates Lipotoxic Pathways in Mouse Liver.

    PubMed

    Jonscher, Karen R; Alfonso-Garcia, Alba; Suhalim, Jeffrey L; Orlicky, David J; Potma, Eric O; Ferguson, Virginia L; Bouxsein, Mary L; Bateman, Ted A; Stodieck, Louis S; Levi, Moshe; Friedman, Jacob E; Gridley, Daila S; Pecaut, Michael J

    2016-01-01

    Spaceflight affects numerous organ systems in the body, leading to metabolic dysfunction that may have long-term consequences. Microgravity-induced alterations in liver metabolism, particularly with respect to lipids, remain largely unexplored. Here we utilize a novel systems biology approach, combining metabolomics and transcriptomics with advanced Raman microscopy, to investigate altered hepatic lipid metabolism in mice following short duration spaceflight. Mice flown aboard Space Transportation System -135, the last Shuttle mission, lose weight but redistribute lipids, particularly to the liver. Intriguingly, spaceflight mice lose retinol from lipid droplets. Both mRNA and metabolite changes suggest the retinol loss is linked to activation of PPARα-mediated pathways and potentially to hepatic stellate cell activation, both of which may be coincident with increased bile acids and early signs of liver injury. Although the 13-day flight duration is too short for frank fibrosis to develop, the retinol loss plus changes in markers of extracellular matrix remodeling raise the concern that longer duration exposure to the space environment may result in progressive liver damage, increasing the risk for nonalcoholic fatty liver disease. PMID:27097220

  11. Spaceflight Activates Lipotoxic Pathways in Mouse Liver

    PubMed Central

    Jonscher, Karen R.; Alfonso-Garcia, Alba; Suhalim, Jeffrey L.; Orlicky, David J.; Potma, Eric O.; Ferguson, Virginia L.; Bouxsein, Mary L.; Bateman, Ted A.; Stodieck, Louis S.; Levi, Moshe; Friedman, Jacob E.; Gridley, Daila S.; Pecaut, Michael J.

    2016-01-01

    Spaceflight affects numerous organ systems in the body, leading to metabolic dysfunction that may have long-term consequences. Microgravity-induced alterations in liver metabolism, particularly with respect to lipids, remain largely unexplored. Here we utilize a novel systems biology approach, combining metabolomics and transcriptomics with advanced Raman microscopy, to investigate altered hepatic lipid metabolism in mice following short duration spaceflight. Mice flown aboard Space Transportation System -135, the last Shuttle mission, lose weight but redistribute lipids, particularly to the liver. Intriguingly, spaceflight mice lose retinol from lipid droplets. Both mRNA and metabolite changes suggest the retinol loss is linked to activation of PPARα-mediated pathways and potentially to hepatic stellate cell activation, both of which may be coincident with increased bile acids and early signs of liver injury. Although the 13-day flight duration is too short for frank fibrosis to develop, the retinol loss plus changes in markers of extracellular matrix remodeling raise the concern that longer duration exposure to the space environment may result in progressive liver damage, increasing the risk for nonalcoholic fatty liver disease. PMID:27097220

  12. Early metabolic adaptation in C57BL/6 mice resistant to high fat diet induced weight gain involves an activation of mitochondrial oxidative pathways.

    PubMed

    Boulangé, Claire L; Claus, Sandrine P; Chou, Chieh J; Collino, Sebastiano; Montoliu, Ivan; Kochhar, Sunil; Holmes, Elaine; Rezzi, Serge; Nicholson, Jeremy K; Dumas, Marc E; Martin, François-Pierre J

    2013-04-01

    We investigated the short-term (7 days) and long-term (60 days) metabolic effect of high fat diet induced obesity (DIO) and weight gain in isogenic C57BL/6 mice and examined the specific metabolic differentiation between mice that were either strong-responders (SR), or non-responders (NR) to weight gain. Mice (n = 80) were fed a standard chow diet for 7 days prior to randomization into a high-fat (HF) (n = 56) or a low-fat (LF) (n = 24) diet group. The (1)H NMR urinary metabolic profiles of LF and HF mice were recorded 7 and 60 days after the diet switch. On the basis of the body weight gain (BWG) distribution of HF group, we identified NR mice (n = 10) and SR mice (n = 14) to DIO. Compared with LF, HF feeding increased urinary excretion of glycine conjugates of β-oxidation intermediate (hexanoylglycine), branched chain amino acid (BCAA) catabolism intermediates (isovalerylglycine, α-keto-β-methylvalerate and α-ketoisovalerate) and end-products of nicotinamide adenine dinucleotide (NAD) metabolism (N1-methyl-2-pyridone-5-carboxamide, N1-methyl-4-pyridone-3-carboxamide) suggesting up-regulation of mitochondrial oxidative pathways. In the HF group, NR mice excreted relatively more hexanoylglycine, isovalerylglycine, and fewer tricarboxylic acid (TCA) cycle intermediate (succinate) in comparison to SR mice. Thus, subtle regulation of ketogenic pathways in DIO may alleviate the saturation of the TCA cycle and mitochondrial oxidative metabolism. PMID:23473242

  13. Early Distal Axonopathy of the Visual Pathway in Experimental Diabetes

    PubMed Central

    Fernandez, Diego C.; Pasquini, Laura A.; Dorfman, Damián; Aldana Marcos, Hernán J.; Rosenstein, Ruth E.

    2012-01-01

    Diabetic retinopathy is a leading cause of acquired blindness. Visual function disorders have been observed in diabetic patients with very early retinopathy or even before the onset of retinopathy. The aim of the present work was to analyze the visual pathway in an early stage of experimental diabetes. Diabetes was induced in Wistar rats by an i.p. injection of streptozotocin. A deficit in anterograde transport from the retina to the superior colliculus was observed 6 weeks after streptozotocin injection. At this time point, morphologic studies did not reveal retinal ganglion cell loss or substantial alterations in the superior colliculus. The optic nerve was morphometrically evaluated at intraorbital (unmyelinated and myelinated) and intracranial sections. In animals that had been diabetic for 6 weeks, a large increase in astrocyte reactivity occurred in the distal (but not the intraorbital) portion, which coincided with significant axon loss. Moreover, profound myelin alterations and altered morphologic features of oligodendrocyte lineage were observed at the distal (but not the proximal) optic nerve portion. The present results suggest that axoglial alterations at the distal portion of the optic nerve could be the first structural change in the diabetic visual pathway. PMID:22079928

  14. Key gravity-sensitive signaling pathways drive T cell activation.

    PubMed

    Boonyaratanakornkit, J B; Cogoli, A; Li, C-F; Schopper, T; Pippia, P; Galleri, G; Meloni, M A; Hughes-Fulford, M

    2005-12-01

    Returning astronauts have experienced altered immune function and increased vulnerability to infection during spaceflights dating back to Apollo and Skylab. Lack of immune response in microgravity occurs at the cellular level. We analyzed differential gene expression to find gravity-dependent genes and pathways. We found inhibited induction of 91 genes in the simulated freefall environment of the random positioning machine. Altered induction of 10 genes regulated by key signaling pathways was verified using real-time RT-PCR. We discovered that impaired induction of early genes regulated primarily by transcription factors NF-kappaB, CREB, ELK, AP-1, and STAT after crosslinking the T-cell receptor contributes to T-cell dysfunction in altered gravity environments. We have previously shown that PKA and PKC are key early regulators in T-cell activation. Since the majority of the genes were regulated by NF-kappaB, CREB, and AP-1, we studied the pathways that regulated these transcription factors. We found that the PKA pathway was down-regulated in vg. In contrast, PI3-K, PKC, and its upstream regulator pLAT were not significantly down-regulated by vectorless gravity. Since NF-kappaB, AP-1, and CREB are all regulated by PKA and are transcription factors predicted by microarray analysis to be involved in the altered gene expression in vectorless gravity, the data suggest that PKA is a key player in the loss of T-cell activation in altered gravity. PMID:16210397

  15. Display of cardiac activation pathways with echocardiography

    NASA Astrophysics Data System (ADS)

    Olstad, Bjoern; Brodin, Lars A.; Berg, Sevald

    1997-05-01

    The study of cardiac activation dynamics is an important factor in the characterization of the cardiac function. One such example is the localization of WPW-pathways inside the myocardium. Accurate localization of these pathways can be used to determine if the patient should be treated with catheter techniques or surgical techniques. This paper analyzes the temporal information in tissue velocity imaging with both qualitative and quantitative methods. The clinical experiments indicate that echocardiography can become an alternative technique for non-invasive electrophysiology in these kinds of applications.

  16. Bright light activates a trigeminal nociceptive pathway

    PubMed Central

    Okamoto, Keiichiro; Tashiro, Akimasa; Chang, Zheng; Bereiter, David A.

    2010-01-01

    Bright light can cause ocular discomfort and/or pain; however, the mechanism linking luminance to trigeminal nerve activity is not known. In this study we identify a novel reflex circuit necessary for bright light to excite nociceptive neurons in superficial laminae of trigeminal subnucleus caudalis (Vc/C1). Vc/C1 neurons encoded light intensity and displayed a long delay (>10 s) for activation. Microinjection of lidocaine into the eye or trigeminal root ganglion (TRG) inhibited light responses completely, whereas topical application onto the ocular surface had no effect. These findings indicated that light-evoked Vc/C1 activity was mediated by an intraocular mechanism and transmission through the TRG. Disrupting local vasomotor activity by intraocular microinjection of the vasoconstrictive agents, norepinephrine or phenylephrine, blocked light-evoked neural activity, whereas ocular surface or intra-TRG microinjection of norepinephrine had no effect. Pupillary muscle activity did not contribute since light-evoked responses were not altered by atropine. Microinjection of lidocaine into the superior salivatory nucleus diminished light-evoked Vc/C1 activity and lacrimation suggesting that increased parasympathetic outflow was critical for light-evoked responses. The reflex circuit also required input through accessory visual pathways since both Vc/C1 activity and lacrimation were prevented by local blockade of the olivary pretectal nucleus. These findings support the hypothesis that bright light activates trigeminal nerve activity through an intraocular mechanism driven by a luminance-responsive circuit and increased parasympathetic outflow to the eye. PMID:20206444

  17. Early signalling pathways in rice roots under vanadate stress.

    PubMed

    Lin, Chung-Wen; Lin, Chung-Yi; Chang, Ching-Chun; Lee, Ruey-Hua; Tsai, Tsung-Mu; Chen, Po-Yu; Chi, Wen-Chang; Huang, Hao-Jen

    2009-05-01

    Vanadate is beneficial to plant growth at low concentration. However, plant exposure to high concentrations of vanadate has been shown to arrest cell growth and lead to cell death. We are interested in understanding the signalling pathways of rice roots in response to vanadate stress. In this study, we demonstrated that vanadate induced rice root cell death and suppressed root growth. In addition, we found that vanadate induced ROS accumulation, increased lipid peroxidation and elicited a remarkable increase of MAPKs and CDPKs activities in rice roots. In contrast, pre-treatment of rice roots with ROS scavenger (sodium benzoate), serine/threonine protein phosphatase inhibitor (endothall), and CDPK antagonist (W7), reduced the vanadate-induced MAPKs activation. Furthermore, the expression of a MAPK gene (OsMPK3) and four tyrosine phosphatase genes (OsDSP3, OsDSP5, OsDSP6, and OsDSP10) were regulated by vanadate in rice roots. Collectively, these results strongly suggest that ROS, protein phosphatase, and CDPK may function in the vanadate-triggered MAPK signalling pathway cause cell death and retarded growth in rice roots. PMID:19250836

  18. Attenuation of serum inducibility of immediate early genes by oncoproteins in tyrosine kinase signaling pathways.

    PubMed Central

    Yu, C L; Prochownik, E V; Imperiale, M J; Jove, R

    1993-01-01

    Immediate early genes involved in controlling cell proliferation are rapidly and transiently induced following stimulation of susceptible cells with serum. To study how oncoproteins regulate immediate early genes, we examined serum inducibility of these genes in cells transformed by various oncoproteins. We found that induction of the immediate early gene, c-fos, by serum stimulation was markedly attenuated in four independent cell lines stably transformed by the v-Src tyrosine kinase. Cells chronically transformed by other oncoproteins implicated in tyrosine kinase signaling pathways, including v-Sis, v-Ras, and v-Raf, showed the same pattern of attenuation. In contrast, serum inducibility of c-fos was not attenuated in cells transformed by simian virus 40, which is thought to transform cells through a different pathway. Cell cycle analyses showed that proliferation of these transformed cell lines could be arrested effectively in 0.1% serum, demonstrating that the attenuation was not simply due to continuous cycling of transformed cells after serum deprivation. Moreover, serum inducibility of other immediate early genes, including c-jun, junB, egr-1, and NGFI-B, also was strikingly attenuated by these same oncoproteins. Nuclear run-on transcription assays established that this attenuation of serum inducibility occurred at the transcriptional level. Finally, flow cytometric analysis demonstrated that serum-starved v-Src-transformed cells were viable and able to progress into S phase of the cell cycle after serum stimulation, even though the induction of immediate early genes was greatly attenuated in these cells. Our results suggest that activation of immediate early genes is repressed by chronic stimulation of tyrosine kinase signaling pathways in transformed cells. Images PMID:8384301

  19. Prenatal alcohol and other early childhood adverse exposures: Direct and indirect pathways to adolescent drinking.

    PubMed

    Cornelius, Marie D; De Genna, Natacha M; Goldschmidt, Lidush; Larkby, Cynthia; Day, Nancy L

    2016-01-01

    We examined direct and indirect pathways between adverse environmental exposures during gestation and childhood and drinking in mid-adolescence. Mothers and their offspring (n=917 mother/child dyads) were followed prospectively from second trimester to a 16-year follow-up assessment. Interim assessments occurred at delivery, 6, 10, and 14years. Adverse environmental factors included gestational exposures to alcohol, tobacco, and marijuana, exposures to childhood maltreatment and violence, maternal psychological symptoms, parenting practices, economic and home environments, and demographic characteristics of the mother and child. Indirect effects of early child behavioral characteristics including externalizing, internalizing activity, attention, and impulsivity were also examined. Polytomous logistic regression analyses were used to evaluate direct effects of adverse environmental exposures with level of adolescent drinking. Structural equation modeling (SEM) was applied to simultaneously estimate the relation between early adversity variables, childhood characteristics, and drinking level at age 16 while controlling for significant covariates. Level of drinking among the adolescent offspring was directly predicted by prenatal exposure to alcohol, less parental strictness, and exposures to maltreatment and violence during childhood. Whites and offspring with older mothers were more likely to drink at higher levels. There was a significant indirect effect between childhood exposure to violence and adolescent drinking via childhood externalizing behavior problems. All other hypothesized indirect pathways were not significant. Thus most of the early adversity measures directly predicted adolescent drinking and did not operate via childhood behavioral dysregulation characteristics. These results highlight the importance of adverse environmental exposures on pathways to adolescent drinking. PMID:26994529

  20. Prenatal alcohol and other early childhood adverse exposures: Direct and indirect pathways to adolescent drinking

    PubMed Central

    Cornelius, Marie D.; De Genna, Natacha M.; Goldschmidt, Lidush; Larkby, Cynthia; Day, Nancy L.

    2016-01-01

    We examined direct and indirect pathways between adverse environmental exposures during gestation and childhood and drinking in mid-adolescence. Mothers and their offspring (n = 917 mother/child dyads) were followed prospectively from second trimester to a 16-year follow-up assessment. Interim assessments occurred at delivery, 6, 10, and 14 years. Adverse environmental factors included gestational exposures to alcohol, tobacco, and marijuana, exposures to childhood maltreatment and violence, maternal psychological symptoms, parenting practices, economic and home environments, and demographic characteristics of the mother and child. Indirect effects of early child behavioral characteristics including externalizing, internalizing activity, attention, and impulsivity were also examined. Polytomous logistic regression analyses were used to evaluate direct effects of adverse environmental exposures with level of adolescent drinking. Structural equation modeling (SEM) was applied to simultaneously estimate the relation between early adversity variables, childhood characteristics, and drinking level at age 16 while controlling for significant covariates. Level of drinking among the adolescent offspring was directly predicted by prenatal exposure to alcohol, less parental strictness, and exposures to maltreatment and violence during childhood. Whites and offspring with older mothers were more likely to drink at higher levels. There was a significant indirect effect between childhood exposure to violence and adolescent drinking via childhood externalizing behavior problems. All other hypothesized indirect pathways were not significant. Thus most of the early adversity measures directly predicted adolescent drinking and did not operate via childhood behavioral dysregulation characteristics. These results highlight the importance of adverse environmental exposures on pathways to adolescent drinking. PMID:26994529

  1. Ultrastructural features of the early secretory pathway in Trichoderma reesei.

    PubMed

    Nykänen, Marko; Birch, Debra; Peterson, Robyn; Yu, Hong; Kautto, Liisa; Gryshyna, Anna; Te'o, Junior; Nevalainen, Helena

    2016-05-01

    We have systematically analysed the ultrastructure of the early secretory pathway in the Trichoderma reesei hyphae in the wild-type QM6a, cellulase-overexpressing Rut-C30 strain and a Rut-C30 transformant BV47 overexpressing a recombinant BiP1-VenusYFP fusion protein with an endoplasmic reticulum (ER) retention signal. The hyphae were studied after 24 h of growth using transmission electron microscopy, confocal microscopy and quantitative stereological techniques. All three strains exhibited different spatial organisation of the ER at 24 h in both a cellulase-inducing medium and a minimal medium containing glycerol as a carbon source (non-cellulase-inducing medium). The wild-type displayed a number of ER subdomains including parallel tubular/cisternal ER, ER whorls, ER-isolation membrane complexes with abundant autophagy vacuoles and dense bodies. Rut-C30 and its transformant BV47 overexpressing the BiP1-VenusYFP fusion protein also contained parallel tubular/cisternal ER, but no ER whorls; also, there were very few autophagy vacuoles and an increasing amount of punctate bodies where particularly the recombinant BiP1-VenusYFP fusion protein was localised. The early presence of distinct strain-specific features such as the dominance of ER whorls in the wild type and tub/cis ER in Rut-C30 suggests that these are inherent traits and not solely a result of cellular response mechanisms by the high secreting mutant to protein overload. PMID:26699139

  2. The pathway to earthquake early warning in the US

    NASA Astrophysics Data System (ADS)

    Allen, R. M.; Given, D. D.; Heaton, T. H.; Vidale, J. E.; West Coast Earthquake Early Warning Development Team

    2013-05-01

    The development of earthquake early warning capabilities in the United States is now accelerating and expanding as the technical capability to provide warning is demonstrated and additional funding resources are making it possible to expand the current testing region to the entire west coast (California, Oregon and Washington). Over the course of the next two years we plan to build a prototype system that will provide a blueprint for a full public system in the US. California currently has a demonstrations warning system, ShakeAlert, that provides alerts to a group of test users from the public and private sector. These include biotech companies, technology companies, the entertainment industry, the transportation sector, and the emergency planning and response community. Most groups are currently in an evaluation mode, receiving the alerts and developing protocols for future response. The Bay Area Rapid Transit (BART) system is the one group who has now implemented an automated response to the warning system. BART now stops trains when an earthquake of sufficient size is detected. Research and development also continues to develop improved early warning algorithms to better predict the distribution of shaking in large earthquakes when the finiteness of the source becomes important. The algorithms under development include the use of both seismic and GPS instrumentation and integration with existing point source algorithms. At the same time, initial testing and development of algorithms in and for the Pacific Northwest is underway. In this presentation we will review the current status of the systems, highlight the new research developments, and lay out a pathway to a full public system for the US west coast. The research and development described is ongoing at Caltech, UC Berkeley, University of Washington, ETH Zurich, Southern California Earthquake Center, and the US Geological Survey, and is funded by the Gordon and Betty Moore Foundation and the US Geological

  3. Preferential sites of early DNA cleavage in apoptosis and the pathway of nuclear damage.

    PubMed

    Krystosek, A

    1999-04-01

    We have tested the specific hypothesis that the pathway of nuclear collapse in apoptosis is governed by the early attack on active chromatin at spatially restricted nuclear sites. Cell death in PC12 pheochromocytoma cells deprived of serum growth factors, in HL-60 leukemic cells treated with inhibitors of protein or RNA biosynthesis, and in U937 histiocytic lymphoma cells exposed to the cytokine tumor necrosis factor alpha showed a common mechanism in the targeting of DNA for degradation. An incorporation assay with labeled nucleotide revealed an early selective nicking in peripheral nuclear chromatin with concomitant diminution in the amount of immunoreactive lamin B protein. This was followed by a phase of more extensive cleavages, continued nuclear protein loss, chromatin collapse, and fragmentation of nuclei. The spatial restriction of early cleavages is similar to the nicking obtained by the application of exogenous DNase I to fixed nuclei of normal cells and to that obtained in the activation of the endogenous endonuclease of liver nuclei by Ca2+. These similarities suggest that, in apoptosis, activation of an endonuclease preferentially recognizing a specific chromatin configuration, such as that of active (DNase I-sensitive) genes, underlies the early spatial demarcation of cleavages. PMID:10219626

  4. Systemic Lupus Erythematosus and Deficiencies of Early Components of the Complement Classical Pathway

    PubMed Central

    Macedo, Ana Catarina Lunz; Isaac, Lourdes

    2016-01-01

    The complement system plays an important role in the innate and acquired immune response against pathogens. It consists of more than 30 proteins found in soluble form or attached to cell membranes. Most complement proteins circulate in inactive forms and can be sequentially activated by the classical, alternative, or lectin pathways. Biological functions, such as opsonization, removal of apoptotic cells, adjuvant function, activation of B lymphocytes, degranulation of mast cells and basophils, and solubilization and clearance of immune complex and cell lysis, are dependent on complement activation. Although the activation of the complement system is important to avoid infections, it also can contribute to the inflammatory response triggered by immune complex deposition in tissues in autoimmune diseases. Paradoxically, the deficiency of early complement proteins from the classical pathway (CP) is strongly associated with development of systemic lupus erythematous (SLE) – mainly C1q deficiency (93%) and C4 deficiency (75%). The aim of this review is to focus on the deficiencies of early components of the CP (C1q, C1r, C1s, C4, and C2) proteins in SLE patients. PMID:26941740

  5. Minireview: Targeting GPCR Activated ERK Pathways for Drug Discovery

    PubMed Central

    Eishingdrelo, Haifeng; Kongsamut, Sathapana

    2013-01-01

    It has become clear in recent years that multiple signal transduction pathways are employed upon GPCR activation. One of the major cellular effectors activated by GPCRs is extracellular signal-regulated kinase (ERK). Both G-protein and β-arrestin mediated signaling pathways can lead to ERK activation. However, depending on activation pathway, the subcellular destination of activated ERK1/2 may be different. G-protein -dependent ERK activation results in the translocation of active ERK to the nucleus, whereas ERK activated via an arrestin-dependent mechanism remains largely in the cytoplasm. The subcellular location of activated ERK1/2 determines the downstream signaling cascade. Many substrates of ERK1/2 are found in the nucleus: nuclear transcription factors that participate in gene transcription, cell proliferation and differentiation. ERK1/2 substrates are also found in cytosol and other cellular organelles: they may play roles in translation, mitosis, apoptosis and cross-talk with other signaling pathways. Therefore, determining specific subcellular locations of activated ERK1/2 mediated by GPCR ligands would be important in correlating signaling pathways with cellular physiological functions. While GPCR-stimulated selective ERK pathway activation has been studied in several receptor systems, exploitation of these different signaling cascades for therapeutics has not yet been seriously pursued. Many old drug candidates were identified from screens based on G-protein signaling assays, and their activity on β-arrestin signaling pathways being mostly unknown, especially regarding their subcellular ERK pathways. With today’s knowledge of complicated GPCR signaling pathways, drug discovery can no longer rely on single-pathway approaches. Since ERK activation is an important signaling pathway and associated with many physiological functions, targeting the ERK pathway, especially specific subcellular activation pathways should provide new avenues for GPCR drug

  6. "Boundary Crossing": Negotiating Understandings of Early Literacy and Numeracy Pathways

    ERIC Educational Resources Information Center

    Kennedy, Anne; Ridgway, Avis; Surman, Lynne

    2006-01-01

    This article is based on the findings of a study which examined the literacy and numeracy pathways for a group of 65 children in the year prior to school entry in Victoria, Australia. The article will discuss key features of the home and community pathways for literacy and numeracy development and learning which were identified in the study. In…

  7. Neuroinflammatory mechanisms in Parkinson's disease: Potential environmental triggers, pathways, and targets for early therapeutic intervention

    PubMed Central

    Tansey, Malú G.; McCoy, Melissa K.; Frank-Cannon, Tamy C.

    2013-01-01

    Most acute and chronic neurodegenerative conditions are accompanied by neuroinflammation; yet the exact nature of the inflammatory processes and whether they modify disease progression is not well understood. In this review, we discuss the key epidemiological, clinical, and experimental evidence implicating inflammatory processes in the progressive degeneration of the dopaminergic (DA) nigrostriatal pathway and their potential contribution to the pathophysiology of Parkinson's disease (PD). Given that interplay between genetics and environment are likely to contribute to risk for development of idiopathic PD, recent data showing interactions between products of genes linked to heritable PD that function to protect DA neurons against oxidative or proteolytic stress and inflammation pathways will be discussed. Cellular mechanisms activated or enhanced by inflammatory processes that may contribute to mitochondrial dysfunction, oxidative stress, or apoptosis of dopaminergic (DA) neurons will be reviewed, with special emphasis on tumor necrosis factor (TNF) and interleukin-1-beta (IL-1β) signaling pathways. Epigenetic factors which have the potential to trigger neuroinflammation, including environmental exposures and age-associated chronic inflammatory conditions, will be discussed as possible ‘second-hit’ triggers that may affect disease onset or progression of idiopathic PD. If inflammatory processes have an active role in nigrostriatal pathway degeneration, then evidence should exist to indicate that such processes begin in the early stages of disease and that they contribute to neuronal dysfunction and/or hasten neurodegeneration of the nigrostriatal pathway. Therapeutically, if anti-inflammatory interventions can be shown to rescue nigral DA neurons from degeneration and lower PD risk, then timely use of anti-inflammatory therapies should be investigated further in well-designed clinical trials for their ability to prevent or delay the progressive loss of

  8. Wnt pathway activation by ADP-ribosylation

    PubMed Central

    Yang, Eungi; Tacchelly-Benites, Ofelia; Wang, Zhenghan; Randall, Michael P.; Tian, Ai; Benchabane, Hassina; Freemantle, Sarah; Pikielny, Claudio; Tolwinski, Nicholas S.; Lee, Ethan; Ahmed, Yashi

    2016-01-01

    Wnt/β-catenin signalling directs fundamental processes during metazoan development and can be aberrantly activated in cancer. Wnt stimulation induces the recruitment of the scaffold protein Axin from an inhibitory destruction complex to a stimulatory signalosome. Here we analyse the early effects of Wnt on Axin and find that the ADP-ribose polymerase Tankyrase (Tnks)—known to target Axin for proteolysis—regulates Axin's rapid transition following Wnt stimulation. We demonstrate that the pool of ADP-ribosylated Axin, which is degraded under basal conditions, increases immediately following Wnt stimulation in both Drosophila and human cells. ADP-ribosylation of Axin enhances its interaction with the Wnt co-receptor LRP6, an essential step in signalosome assembly. We suggest that in addition to controlling Axin levels, Tnks-dependent ADP-ribosylation promotes the reprogramming of Axin following Wnt stimulation; and propose that Tnks inhibition blocks Wnt signalling not only by increasing destruction complex activity, but also by impeding signalosome assembly. PMID:27138857

  9. Wnt pathway activation by ADP-ribosylation.

    PubMed

    Yang, Eungi; Tacchelly-Benites, Ofelia; Wang, Zhenghan; Randall, Michael P; Tian, Ai; Benchabane, Hassina; Freemantle, Sarah; Pikielny, Claudio; Tolwinski, Nicholas S; Lee, Ethan; Ahmed, Yashi

    2016-01-01

    Wnt/β-catenin signalling directs fundamental processes during metazoan development and can be aberrantly activated in cancer. Wnt stimulation induces the recruitment of the scaffold protein Axin from an inhibitory destruction complex to a stimulatory signalosome. Here we analyse the early effects of Wnt on Axin and find that the ADP-ribose polymerase Tankyrase (Tnks)--known to target Axin for proteolysis-regulates Axin's rapid transition following Wnt stimulation. We demonstrate that the pool of ADP-ribosylated Axin, which is degraded under basal conditions, increases immediately following Wnt stimulation in both Drosophila and human cells. ADP-ribosylation of Axin enhances its interaction with the Wnt co-receptor LRP6, an essential step in signalosome assembly. We suggest that in addition to controlling Axin levels, Tnks-dependent ADP-ribosylation promotes the reprogramming of Axin following Wnt stimulation; and propose that Tnks inhibition blocks Wnt signalling not only by increasing destruction complex activity, but also by impeding signalosome assembly. PMID:27138857

  10. A Functional Genome-Wide In Vivo Screen Identifies New Regulators of Signalling Pathways during Early Xenopus Embryogenesis

    PubMed Central

    Zhang, Siwei; Li, Jingjing; Lea, Robert; Amaya, Enrique; Dorey, Karel

    2013-01-01

    Embryonic development requires exquisite regulation of several essential processes, such as patterning of tissues and organs, cell fate decisions, and morphogenesis. Intriguingly, these diverse processes are controlled by only a handful of signalling pathways, and mis-regulation in one or more of these pathways may result in a variety of congenital defects and diseases. Consequently, investigating how these signalling pathways are regulated at the molecular level is essential to understanding the mechanisms underlying vertebrate embryogenesis, as well as developing treatments for human diseases. Here, we designed and performed a large-scale gain-of-function screen in Xenopus embryos aimed at identifying new regulators of MAPK/Erk, PI3K/Akt, BMP, and TGF-β/Nodal signalling pathways. Our gain-of-function screen is based on the identification of gene products that alter the phosphorylation state of key signalling molecules, which report the activation state of the pathways. In total, we have identified 20 new molecules that regulate the activity of one or more signalling pathways during early Xenopus development. This is the first time that such a functional screen has been performed, and the findings pave the way toward a more comprehensive understanding of the molecular mechanisms regulating the activity of important signalling pathways under normal and pathological conditions. PMID:24244509

  11. Myelin-associated glycoprotein modulates apoptosis of motoneurons during early postnatal development via NgR/p75NTR receptor-mediated activation of RhoA signaling pathways

    PubMed Central

    Palandri, A; Salvador, V R; Wojnacki, J; Vivinetto, A L; Schnaar, R L; Lopez, P H H

    2015-01-01

    Myelin-associated glycoprotein (MAG) is a minor constituent of nervous system myelin, selectively expressed on the periaxonal myelin wrap. By engaging multiple axonal receptors, including Nogo-receptors (NgRs), MAG exerts a nurturing and protective effect the axons it ensheaths. Pharmacological activation of NgRs has a modulatory role on p75NTR-dependent postnatal apoptosis of motoneurons (MNs). However, it is not clear whether this reflects a physiological role of NgRs in MN development. NgRs are part of a multimeric receptor complex, which includes p75NTR, Lingo-1 and gangliosides. Upon ligand binding, this multimeric complex activates RhoA/ROCK signaling in a p75NTR-dependent manner. The aim of this study was to analyze a possible modulatory role of MAG on MN apoptosis during postnatal development. A time course study showed that Mag-null mice suffer a loss of MNs during the first postnatal week. Also, these mice exhibited increased susceptibility in an animal model of p75NTR-dependent MN apoptosis induced by nerve-crush injury, which was prevented by treatment with a soluble form of MAG (MAG-Fc). The protective role of MAG was confirmed in in vitro models of p75NTR-dependent MN apoptosis using the MN1 cell line and primary cultures. Lentiviral expression of shRNA sequences targeting NgRs on these cells abolished protection by MAG-Fc. Analysis of RhoA activity using a FRET-based RhoA biosensor showed that MAG-Fc activates RhoA. Pharmacological inhibition of p75NTR/RhoA/ROCK pathway, or overexpression of a p75NTR mutant unable to activate RhoA, completely blocked MAG-Fc protection against apoptosis. The role of RhoA/ROCK signaling was further confirmed in the nerve-crush model, where pretreatment with ROCK inhibitor Y-27632 blocked the pro-survival effect of MAG-Fc. These findings identify a new protective role of MAG as a modulator of apoptosis of MNs during postnatal development by a mechanism involving the p75NTR/RhoA/ROCK signaling pathway. Also, our results

  12. Pathways to Adolescent Internalizing: Early Attachment Insecurity as a Lasting Source of Vulnerability

    ERIC Educational Resources Information Center

    Milan, Stephanie; Zona, Kate; Snow, Stephanie

    2013-01-01

    Despite theoretical links between attachment quality in early childhood and subsequent internalizing symptoms, there is limited empirical evidence supporting direct effects. In this article, we test whether early attachment insecurity indirectly contributes to adolescent internalizing by increasing the likelihood of certain pathways leading to…

  13. Music in the Early Years: Pathways into the Social World

    ERIC Educational Resources Information Center

    Ilari, Beatriz

    2016-01-01

    Two assumptions that underlie much research in early childhood music education are that music is a social endeavor and musical participation is beneficial to children's overall social development. As members of cultural and social groups, young children engage with music in a multitude of ways and with different companions. This article examines…

  14. Sequential activation of metabolic pathways: a dynamic optimization approach.

    PubMed

    Oyarzún, Diego A; Ingalls, Brian P; Middleton, Richard H; Kalamatianos, Dimitrios

    2009-11-01

    The regulation of cellular metabolism facilitates robust cellular operation in the face of changing external conditions. The cellular response to this varying environment may include the activation or inactivation of appropriate metabolic pathways. Experimental and numerical observations of sequential timing in pathway activation have been reported in the literature. It has been argued that such patterns can be rationalized by means of an underlying optimal metabolic design. In this paper we pose a dynamic optimization problem that accounts for time-resource minimization in pathway activation under constrained total enzyme abundance. The optimized variables are time-dependent enzyme concentrations that drive the pathway to a steady state characterized by a prescribed metabolic flux. The problem formulation addresses unbranched pathways with irreversible kinetics. Neither specific reaction kinetics nor fixed pathway length are assumed.In the optimal solution, each enzyme follows a switching profile between zero and maximum concentration, following a temporal sequence that matches the pathway topology. This result provides an analytic justification of the sequential activation previously described in the literature. In contrast with the existent numerical approaches, the activation sequence is proven to be optimal for a generic class of monomolecular kinetics. This class includes, but is not limited to, Mass Action, Michaelis-Menten, Hill, and some Power-law models. This suggests that sequential enzyme expression may be a common feature of metabolic regulation, as it is a robust property of optimal pathway activation. PMID:19412635

  15. Interference of target cell catalase with an early step of the neutrophil cytolytic pathway.

    PubMed Central

    Dallegri, F; Ballestrero, A; Frumento, G; Patrone, F

    1986-01-01

    The hypochlorous acid (HOCL)-dependent lysis of human red blood cells (HRBC) targets by neutrophils, activated with opsonized zymosan particles (OPZ), was increased by inhibiting HRBC catalatic activity with aminotriazole (AT; HRBCAT). The inhibition of HRBC glutathione cycle activity with carmustine (BCNU; HRBCBCNU) had no effect. In addition, the recovery of hydrogen peroxide (H2O2) and HOCL from neutrophils, activated under conditions similar to those used for cytotoxicity assay, was reduced by the presence of HRBC and restored by replacing HRBC with HRBCAT, but not with HRBCBCNU. Linear relationships were found between the increments in the neutrophil-mediated lysis, observed by using HRBCAT instead of HRBC, and the increments in the H2O2 or HOCL recovery, detected by replacing HRBC with HRBCAT. Together these data, coupled with the results obtained by probing neutrophil cytolysis with chemical agents, suggest that the increased cytolytic efficiency displayed by neutrophils against HRBCAT, inhibited in their catalatic activity, is due to an enhanced availability of neutrophil-derived H2O2, with a consequent enhancement in the HOCL production (according to the following reaction: (formula; see text). Thus it appears that HRBC catalase restrains the neutrophil cytolytic activity, by interfering with an early step of the pathway through which neutrophils generate cytotoxins. PMID:3022971

  16. The unpredictability of prolonged activation of stress response pathways

    PubMed Central

    Lamech, Lilian T.

    2015-01-01

    In response to stress, cellular compartments activate signaling pathways that mediate transcriptional programs to promote survival and reestablish homeostasis. Manipulation of the magnitude and duration of the activation of stress responses has been proposed as a strategy to prevent or repair the damage associated with aging or degenerative diseases. However, as these pathways likely evolved to respond specifically to transient perturbations, the unpredictability of prolonged activation should be considered. PMID:26101215

  17. Early steps in bilirubin-mediated apoptosis in murine hepatoma (Hepa 1c1c7) cells are characterized by aryl hydrocarbon receptor-independent oxidative stress and activation of the mitochondrial pathway.

    PubMed

    Oakes, Garth H; Bend, John R

    2005-01-01

    Unconjugated bilirubin (UCB), the end product of heme catabolism, causes apoptosis in cells of the central nervous system, endothelial cells, and hepatotoma cells. However, the molecular mechanisms that contribute to UCB cytotoxicity remain unclear. The purpose of this study was to characterize the sequence of early events leading to UCB-mediated cytotoxicity in murine hepatoma Hepa 1c1c7 cells. In the present study, UCB (5-50 microM) was found to markedly increase the intracellular generation of reactive oxygen species (ROS) in a concentration-dependent manner, which is significantly elevated by 30 min post-treatment. This generation of ROS by UCB is not dependent on aryl hydrocarbon receptor (Ahr) signaling, as cells deficient in the Ahr (C12 cells) or the Ahr nuclear translocator protein (Arnt; C4 cells) were as efficient at generating ROS as wild type (WT) Hepa 1c1c7 cells. Mitochondrial membrane depolarization, evaluated with the lipophilic cationic dye, JC-1, occurred at least by 2 h after treatment with 50 muM UCB. Analysis of the caspase cascade demonstrated that activation of caspase-9 preceded activation of caspase-3. No conversion of procaspase-2 to active caspase-2 was detected in this study. These results demonstrate that UCB-mediated apoptosis in Hepa 1c1c7 cells is associated with increased oxidative stress and that caspase-9, and definitely not caspase-2, is the initiator caspase for apoptosis in UCB-treated Hepa 1c1c7 cells. PMID:16173058

  18. Early Risk Factors and Developmental Pathways to Chronic High Inhibition and Social Anxiety Disorder in Adolescence

    PubMed Central

    Essex, Marilyn J.; Klein, Marjorie H.; Slattery, Marcia J.; Goldsmith, H. Hill; Kalin, Ned H.

    2009-01-01

    Objective Evidence suggests that chronic high levels of behavioral inhibition are a precursor of social anxiety disorder (SAD). This study identified the early risk factors for and developmental pathways to chronic high inhibition among school-age children and its association with SAD by adolescence. Method A community sample of 238 children was followed from birth to Grade 9. Mothers, children, and teachers reported on children's behavioral inhibition from Grades 1 to 9. Lifetime history of psychiatric disorders was available for the subset of 60 (25%) children who participated in an intensive laboratory assessment at Grade 9. Four early risk factors were assessed: female gender; exposure to maternal stress during the infancy and preschool periods and at child age 4.5 years; early manifestation of behavioral inhibition, and elevated afternoon salivary cortisol levels. Results All four risk factors predicted higher and more chronic inhibition from Grade 1 to Grade 9, and together, defined two developmental pathways. The first pathway in female children was partially mediated by early evidence of behavioral inhibition and elevated cortisol levels at age 4.5 years. The second pathway began with exposure to early maternal stress and was also partially mediated by childhood cortisol levels. By Grade 9, chronic high inhibition was associated with a lifetime history of SAD. Conclusions Chronic high levels of behavioral inhibition are associated with SAD by adolescence. The identification of two developmental pathways suggests the potential importance of considering both sets of risk factors in developing preventive interventions for SAD. PMID:19917594

  19. Selenium compounds activate early barriers of tumorigenesis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Selenium chemoprevention by apoptosis has been well studied, but it is not clear whether selenium can activate early barriers of tumorigenesis, namely senescence and DNA damage response. To address this issue, we treated normal and cancerous cells with a gradient concentration of sodium selenite, me...

  20. Familial Pathways to Early-Onset Suicide Attempt

    PubMed Central

    Brent, David A.; Melhem, Nadine M.; Oquendo, Maria; Burke, Ainsley; Birmaher, Boris; Stanley, Barbara; Biernesser, Candice; Keilp, John; Kolko, David; Ellis, Steve; Porta, Giovanna; Zelazny, Jamie; Iyengar, Satish; Mann, J. John

    2015-01-01

    IMPORTANCE Suicide attempts are strong predictors of suicide, a leading cause of adolescent mortality. Suicide attempts are highly familial, although the mechanisms of familial transmission are not understood. Better delineation of these mechanisms could help frame potential targets for prevention. OBJECTIVE To examine the mechanisms and pathways by which suicidal behavior is transmitted from parent to child. DESIGN, SETTING, AND PARTICIPANTS In this prospective study conducted from July 15, 1997, through June 21, 2012, a total of 701 offspring aged 10 to 50 years (mean age, 17.7 years) of 334 clinically referred probands with mood disorders, 191 (57.2%) of whom had also made a suicide attempt, were followed up for a mean of 5.6 years. MAIN OUTCOMES AND MEASURES The primary outcome was a suicide attempt. Variables were examined at baseline, intermediate time points, and the time point proximal to the attempt. Participants were assessed by structured psychiatric assessments and self-report and by interview measures of domains hypothesized to be related to familial transmission (eg, mood disorder and impulsive aggression). RESULTS Among the 701 offspring, 44 (6.3%) had made a suicide attempt before participating in the study, and 29 (4.1%) made an attempt during study follow-up. Multivariate logistic regression revealed that proband suicide attempt was a predictor of offspring suicide attempt (odds ratio [OR], 4.79; 95% CI, 1.75–13.07), even controlling for other salient offspring variables: baseline history of mood disorder (OR, 4.20; 95% CI, 1.37–12.86), baseline history of suicide attempt (OR, 5.69; 95% CI, 1.94–16.74), and mood disorder at the time point before the attempt (OR, 11.32; 95% CI, 2.29–56.00). Path analyses were consistent with these findings, revealing a direct effect of proband attempt on offspring suicide attempt, a strong effect of offspring mood disorder at each time point, and impulsive aggression as a precursor of mood disorder

  1. RAF inhibitors that evade paradoxical MAPK pathway activation.

    PubMed

    Zhang, Chao; Spevak, Wayne; Zhang, Ying; Burton, Elizabeth A; Ma, Yan; Habets, Gaston; Zhang, Jiazhong; Lin, Jack; Ewing, Todd; Matusow, Bernice; Tsang, Garson; Marimuthu, Adhirai; Cho, Hanna; Wu, Guoxian; Wang, Weiru; Fong, Daniel; Nguyen, Hoa; Shi, Songyuan; Womack, Patrick; Nespi, Marika; Shellooe, Rafe; Carias, Heidi; Powell, Ben; Light, Emily; Sanftner, Laura; Walters, Jason; Tsai, James; West, Brian L; Visor, Gary; Rezaei, Hamid; Lin, Paul S; Nolop, Keith; Ibrahim, Prabha N; Hirth, Peter; Bollag, Gideon

    2015-10-22

    Oncogenic activation of BRAF fuels cancer growth by constitutively promoting RAS-independent mitogen-activated protein kinase (MAPK) pathway signalling. Accordingly, RAF inhibitors have brought substantially improved personalized treatment of metastatic melanoma. However, these targeted agents have also revealed an unexpected consequence: stimulated growth of certain cancers. Structurally diverse ATP-competitive RAF inhibitors can either inhibit or paradoxically activate the MAPK pathway, depending whether activation is by BRAF mutation or by an upstream event, such as RAS mutation or receptor tyrosine kinase activation. Here we have identified next-generation RAF inhibitors (dubbed 'paradox breakers') that suppress mutant BRAF cells without activating the MAPK pathway in cells bearing upstream activation. In cells that express the same HRAS mutation prevalent in squamous tumours from patients treated with RAF inhibitors, the first-generation RAF inhibitor vemurafenib stimulated in vitro and in vivo growth and induced expression of MAPK pathway response genes; by contrast the paradox breakers PLX7904 and PLX8394 had no effect. Paradox breakers also overcame several known mechanisms of resistance to first-generation RAF inhibitors. Dissociating MAPK pathway inhibition from paradoxical activation might yield both improved safety and more durable efficacy than first-generation RAF inhibitors, a concept currently undergoing human clinical evaluation with PLX8394. PMID:26466569

  2. Mitogen Activated Protein kinase signal transduction pathways in the prostate

    PubMed Central

    Maroni, Paul D; Koul, Sweaty; Meacham, Randall B; Koul, Hari K

    2004-01-01

    The biochemistry of the mitogen activated protein kinases ERK, JNK, and p38 have been studied in prostate physiology in an attempt to elucidate novel mechanisms and pathways for the treatment of prostatic disease. We reviewed articles examining mitogen-activated protein kinases using prostate tissue or cell lines. As with other tissue types, these signaling modules are links/transmitters for important pathways in prostate cells that can result in cellular survival or apoptosis. While the activation of the ERK pathway appears to primarily result in survival, the roles of JNK and p38 are less clear. Manipulation of these pathways could have important implications for the treatment of prostate cancer and benign prostatic hypertrophy. PMID:15219238

  3. TRAIL activates JNK and NF-κB through RIP1-dependent and -independent pathways.

    PubMed

    Zhang, Laiqun; Dittmer, Martin R; Blackwell, Ken; Workman, Lauren M; Hostager, Bruce; Habelhah, Hasem

    2015-02-01

    The death receptor (DR) ligand TRAIL is being evaluated in clinical trials as an anti-cancer agent; however, many studies have found that TRAIL also enhances tumor progression by activating the NF-κB pathway in apoptosis-resistant cells. Although RIP1, cFLIP and caspase-8 have been implicated in TRAIL-induced JNK and NF-κB activation, underlying mechanisms are unclear. By examining the kinetics of pathway activation in TRAIL-sensitive lymphoma cells wild-type or deficient for RIP1, TRAF2, cIAP1/2 or HOIP, we report here that TRAIL induces two phases of JNK and NF-κB activation. The early phase is activated by TRAF2- and cIAP1-mediated ubiquitination of RIP1, whereas the delayed phase is induced by caspase-dependent activation of MEKK1 independent of RIP1 and TRAF2 expression. cFLIP overexpression promotes the early phase but completely suppresses the delayed phase of pathway activation in lymphoma cells, whereas Bcl-2 overexpression promotes both the early and delayed phases of the pathways. In addition, stable overexpression of cFLIP in RIP1- or TRAF2-deficient cells confers resistance to apoptosis, but fails to mediate NF-κB activation. HOIP is not essential for, but contributes to, TRAIL-induced NF-κB activation in cFLIP-overexpressing cells. These findings not only elucidate details of the mechanisms underlying TRAIL-induced JNK and NF-κB activation, but also clarify conflicting reports in the field. PMID:25446254

  4. Deregulated tryptophan-kynurenine pathway is linked to inflammation, oxidative stress, and immune activation pathway in cardiovascular diseases

    PubMed Central

    Wang, Qiongxin; Liu, Danxia; Song, Ping; Zou, Ming-Hui

    2016-01-01

    The kynurenine (Kyn) pathway is the major route for tryptophan (Trp) metabolism, and it contributes to several fundamental biological processes. Trp is constitutively oxidized by tryptophan 2, 3-dioxygenase in liver cells. In other cell types, it is catalyzed by an alternative inducible indoleamine-pyrrole 2, 3-dioxygenase (IDO) under certain pathophysiological conditions, which consequently increases the formation of Kyn metabolites. IDO is up-regulated in response to inflammatory conditions as a novel marker of immune activation in early atherosclerosis. Besides, IDO and the IDO-related pathway are important mediators of the immunoinflammatory responses in advanced atherosclerosis. In particular, Kyn, 3-hydroxykynurenine, and quinolinic acid are positively associated with inflammation, oxidative stress (SOX), endothelial dysfunction, and carotid artery intima-media thickness values in end-stage renal disease patients. Moreover, IDO is a potential novel contributor to vessel relaxation and metabolism in systemic infections, which is also activated in acute severe heart attacks. The Kyn pathway plays a key role in the increased prevalence of cardiovascular disease by regulating inflammation, SOX, and immune activation. PMID:25961549

  5. Juvenile hormone-activated phospholipase C pathway enhances transcriptional activation by the methoprene-tolerant protein.

    PubMed

    Liu, Pengcheng; Peng, Hong-Juan; Zhu, Jinsong

    2015-04-14

    Juvenile hormone (JH) is a key regulator of a wide diversity of developmental and physiological events in insects. Although the intracellular JH receptor methoprene-tolerant protein (MET) functions in the nucleus as a transcriptional activator for specific JH-regulated genes, some JH responses are mediated by signaling pathways that are initiated by proteins associated with plasma membrane. It is unknown whether the JH-regulated gene expression depends on the membrane-mediated signal transduction. In Aedes aegypti mosquitoes, we found that JH activated the phospholipase C (PLC) pathway and quickly increased the levels of inositol 1,4,5-trisphosphate, diacylglycerol, and intracellular calcium, leading to activation and autophosphorylation of calcium/calmodulin-dependent protein kinase II (CaMKII). When abdomens from newly emerged mosquitoes were cultured in vitro, the JH-activated gene expression was repressed substantially if specific inhibitors of PLC or CaMKII were added to the medium together with JH. In newly emerged female mosquitoes, RNAi-mediated depletion of PLC or CaMKII considerably reduced the expression of JH-responsive genes, including the Krüppel homolog 1 gene (AaKr-h1) and the early trypsin gene (AaET). JH-induced loading of MET to the promoters of AaKr-h1 and AaET was weakened drastically when either PLC or CaMKII was inactivated in the cultured tissues. Therefore, the results suggest that the membrane-initiated signaling pathway modifies the DNA-binding activity of MET via phosphorylation and thus facilitates the genomic responses to JH. In summary, this study reveals an interplay of genomic and nongenomic signaling mechanisms of JH. PMID:25825754

  6. Juvenile hormone-activated phospholipase C pathway enhances transcriptional activation by the methoprene-tolerant protein

    PubMed Central

    Liu, Pengcheng; Peng, Hong-Juan; Zhu, Jinsong

    2015-01-01

    Juvenile hormone (JH) is a key regulator of a wide diversity of developmental and physiological events in insects. Although the intracellular JH receptor methoprene-tolerant protein (MET) functions in the nucleus as a transcriptional activator for specific JH-regulated genes, some JH responses are mediated by signaling pathways that are initiated by proteins associated with plasma membrane. It is unknown whether the JH-regulated gene expression depends on the membrane-mediated signal transduction. In Aedes aegypti mosquitoes, we found that JH activated the phospholipase C (PLC) pathway and quickly increased the levels of inositol 1,4,5-trisphosphate, diacylglycerol, and intracellular calcium, leading to activation and autophosphorylation of calcium/calmodulin-dependent protein kinase II (CaMKII). When abdomens from newly emerged mosquitoes were cultured in vitro, the JH-activated gene expression was repressed substantially if specific inhibitors of PLC or CaMKII were added to the medium together with JH. In newly emerged female mosquitoes, RNAi-mediated depletion of PLC or CaMKII considerably reduced the expression of JH-responsive genes, including the Krüppel homolog 1 gene (AaKr-h1) and the early trypsin gene (AaET). JH-induced loading of MET to the promoters of AaKr-h1 and AaET was weakened drastically when either PLC or CaMKII was inactivated in the cultured tissues. Therefore, the results suggest that the membrane-initiated signaling pathway modifies the DNA-binding activity of MET via phosphorylation and thus facilitates the genomic responses to JH. In summary, this study reveals an interplay of genomic and nongenomic signaling mechanisms of JH. PMID:25825754

  7. IL-17/Th17 Pathway Is Activated in Acne Lesions

    PubMed Central

    Kelhälä, Hanna-Leena; Palatsi, Riitta; Fyhrquist, Nanna; Lehtimäki, Sari; Väyrynen, Juha P.; Kallioinen, Matti; Kubin, Minna E.; Greco, Dario; Tasanen, Kaisa; Alenius, Harri; Bertino, Beatrice; Carlavan, Isabelle; Mehul, Bruno; Déret, Sophie; Reiniche, Pascale; Martel, Philippe; Marty, Carine; Blume-Peytavi, Ulrike; Voegel, Johannes J.; Lauerma, Antti

    2014-01-01

    The mechanisms of inflammation in acne are currently subject of intense investigation. This study focused on the activation of adaptive and innate immunity in clinically early visible inflamed acne lesions and was performed in two independent patient populations. Biopsies were collected from lesional and non-lesional skin of acne patients. Using Affymetrix Genechips, we observed significant elevation of the signature cytokines of the Th17 lineage in acne lesions compared to non-lesional skin. The increased expression of IL-17 was confirmed at the RNA and also protein level with real-time PCR (RT-PCR) and Luminex technology. Cytokines involved in Th17 lineage differentiation (IL-1β, IL-6, TGF-β, IL23p19) were remarkably induced at the RNA level. In addition, proinflammatory cytokines and chemokines (TNF-α, IL-8, CSF2 and CCL20), Th1 markers (IL12p40, CXCR3, T-bet, IFN-γ), T regulatory cell markers (Foxp3, IL-10, TGF-β) and IL-17 related antimicrobial peptides (S100A7, S100A9, lipocalin, hBD2, hBD3, hCAP18) were induced. Importantly, immunohistochemistry revealed significantly increased numbers of IL-17A positive T cells and CD83 dendritic cells in the acne lesions. In summary our results demonstrate the presence of IL-17A positive T cells and the activation of Th17-related cytokines in acne lesions, indicating that the Th17 pathway is activated and may play a pivotal role in the disease process, possibly offering new targets of therapy. PMID:25153527

  8. Pathway activation profiling reveals new insights into Age-related Macular Degeneration and provides avenues for therapeutic interventions

    PubMed Central

    Makarev, Evgeny; Cantor, Charles; Zhavoronkov, Alex; Buzdin, Anton; Aliper, Alexander; Csoka, Antonei Benjamin

    2014-01-01

    Age-related macular degeneration (AMD) is a major cause of blindness in older people and is caused by loss of the central region of the retinal pigment epithelium (RPE). Conventional methods of gene expression analysis have yielded important insights into AMD pathogenesis, but the precise molecular pathway alterations are still poorly understood. Therefore we developed a new software program, “AMD Medicine”, and discovered differential pathway activation profiles in samples of human RPE/choroid from AMD patients and controls. We identified 29 pathways in RPE-choroid AMD phenotypes: 27 pathways were activated in AMD compared to controls, and 2 pathways were activated in controls compared to AMD. In AMD, we identified a graded activation of pathways related to wound response, complement cascade, and cell survival. Also, there was downregulation of two pathways responsible for apoptosis. Furthermore, significant activation of pro-mitotic pathways is consistent with dedifferentiation and cell proliferation events, which occur early in the pathogenesis of AMD. Significantly, we discovered new global pathway activation signatures of AMD involved in the cell-based inflammatory response: IL-2, STAT3, and ERK. The ultimate aim of our research is to achieve a better understanding of signaling pathways involved in AMD pathology, which will eventually lead to better treatments. PMID:25543336

  9. Predictors and Pathways from Infancy to Symptoms of Anxiety and Depression in Early Adolescence

    ERIC Educational Resources Information Center

    Karevold, Evalill; Roysamb, Espen; Ystrom, Eivind; Mathiesen, Kristin S.

    2009-01-01

    Data from a prospective 11-year longitudinal survey were used to identify early predictors and pathways to symptoms of anxiety and depression at 12-13 years of age, and to examine whether there were unique predictors of anxious versus depressive symptoms. Structural equation modeling was used to explore longitudinal relations between contextual…

  10. Using ILP to Identify Pathway Activation Patterns in Systems Biology

    PubMed Central

    Neaves, Samuel R; Millard, Louise A C; Tsoka, Sophia

    2016-01-01

    We show a logical aggregation method that, combined with propositionalization methods, can construct novel structured biological features from gene expression data. We do this to gain understanding of pathway mechanisms, for instance, those associated with a particular disease. We illustrate this method on the task of distinguishing between two types of lung cancer; Squamous Cell Carcinoma (SCC) and Adenocarcinoma (AC). We identify pathway activation patterns in pathways previously implicated in the development of cancers. Our method identified a model with comparable predictive performance to the winning algorithm of a recent challenge, while providing biologically relevant explanations that may be useful to a biologist. PMID:27478883

  11. BMP pathway suppression is an early event in inflammation-driven colon neoplasmatogenesis of uPA-deficient mice.

    PubMed

    Karagiannis, George S; Afaloniati, Hara; Karamanavi, Elisavet; Poutahidis, Theofilos; Angelopoulou, Katerina

    2016-02-01

    The suppression of the bone morphogenetic protein (BMP) signaling pathway has been recently shown to promote adenoma-to-carcinoma transition in sporadic colon cancer. However, its role in the evolution of early preneoplastic changes to neoplasia remains elusive. In the present study, we aimed to investigate the gene expression levels of multiple extracellular BMP family constituents, including BMP ligands/receptors and inhibitors, during the early stages of inflammation-associated colon carcinogenesis. For that, we used the recently developed urokinase-type plasminogen activator (uPA)-deficient mouse model of colonic polypoidogenesis, in which adenomatous polyps arise several months after the induction of dextran sodium sulfate (DSS) colitis. In DSS-treated wild-type mice, the preneoplastic lesions which did not eventually evolve to adenomas resided in a colitic microenvironment characterized by a balanced upregulation of both BMP ligands, i.e., Bmp4/7 and BMP inhibitors, such as chordin, noggin, and gremlin-1. In the uPA-deficient tumor-promoting inflammatory microenvironment, however, there was a clear evidence for BMP pathway suppression. By contrast to DSS-treated wild-type controls, the inflammation-associated Bmp4 upregulation was abolished, and the BMP signaling suppression was further enhanced by a particularly high increase of gremlin-1 expression. These findings propose that BMP pathway suppression in colon cancer could be associated with very early stages of the preneoplasia-to-neoplasia sequence of events. PMID:26358253

  12. Different pathways of macrophage activation and polarization.

    PubMed

    Juhas, Ulana; Ryba-Stanisławowska, Monika; Szargiej, Patryk; Myśliwska, Jolanta

    2015-01-01

    Monocytes are short-lived cells and undergo spontaneous apoptosis every day. Inflammatory responses may induce dramatic up-regulation of monocyte survival and differentiation. When monocytes are recruited to an area of infection they may differentiate into macrophages. In different microenvironments macrophages polarize into two types. The M1 or classically activated macrophages are characterized by the high ability to produce pro-inflammatory cytokines and the production of NO through the induced synthesis of iNOS. The M2 or alternatively activated macrophages are divided into 3 subtypes, M2 a, b and c, and they have anti-inflammatory properties. Mediators of M1 macrophage TLR-dependent polarization include transcription factors such as NF-κB, AP-1, PU.1, CCAAT/enhancer-binding protein α (C/EBP-α), STAT1 as well as interferon regulatory factor 5 (IRF5), while the transcription factors which promote M2 activation include IRF4, C/EBP-β, Krüppel-like factor 4 (KLF4), STAT6 and PPARγ receptor. PMID:25983288

  13. Angiotensin II activates different calcium signaling pathways in adipocytes.

    PubMed

    Dolgacheva, Lyudmila P; Turovskaya, Maria V; Dynnik, Vladimir V; Zinchenko, Valery P; Goncharov, Nikolay V; Davletov, Bazbek; Turovsky, Egor A

    2016-03-01

    Angiotensin II (Ang II) is an important mammalian neurohormone involved in reninangiotensin system. Ang II is produced both constitutively and locally by RAS systems, including white fat adipocytes. The influence of Ang II on adipocytes is complex, affecting different systems of signal transduction from early Са(2+) responses to cell proliferation and differentiation, triglyceride accumulation, expression of adipokine-encoding genes and adipokine secretion. It is known that white fat adipocytes express all RAS components and Ang II receptors (АТ1 and АТ2). The current work was carried out with the primary white adipocytes culture, and Са(2+) signaling pathways activated by Ang II were investigated using fluorescent microscopy. Са(2+)-oscillations and transient responses of differentiated adipocytes to Ang II were registered in cells with both small and multiple lipid inclusions. Using inhibitory analysis and selective antagonists, we now show that Ang II initiates periodic Са(2+)-oscillations and transient responses by activating АТ1 and АТ2 receptors and involving branched signaling cascades: 1) Ang II → Gq → PLC → IP3 → IP3Rs → Ca(2+) 2) Gβγ → PI3Kγ → PKB 3) PKB → eNOS → NO → PKG 4) CD38 → cADPR → RyRs → Ca(2+) In these cascades, AT1 receptors play the leading role. The results of the present work open a perspective of using Ang II for correction of signal resistance of adipocytes often observed during obesity and type 2 diabetes. PMID:26850364

  14. Pathways to Early Violent Death: The Voices of Serious Violent Youth Offenders

    PubMed Central

    Richardson, Joseph B.; Brown, Jerry; Van Brakle, Michelle

    2013-01-01

    Quantitative studies have uncovered factors associated with early violent death among youth offenders detained in the juvenile justice system, but little is known about the contextual factors associated with pathways to early violent death among youths detained in adult jails. We interviewed young Black male serious violent youth offenders detained in an adult jail to understand their experience of violence. Their narratives reveal how the code of the street, informal rules that govern interpersonal violence among poor inner-city Black male youths, increases the likelihood of violent victimization. Youth offenders detained in adult jails have the lowest rate of service provision among all jail populations. We have addressed how services for youth offenders can be improved to reduce the pathways to early violent death. PMID:23678923

  15. Coordinated activation of the secretory pathway during notochord formation in the Xenopus embryo.

    PubMed

    Tanegashima, Kosuke; Zhao, Hui; Rebbert, Martha L; Dawid, Igor B

    2009-11-01

    We compared the transcriptome in the developing notochord of Xenopus laevis embryos with that of other embryonic regions. A coordinated and intense activation of a large set of secretory pathway genes was observed in the notochord, but not in notochord precursors in the axial mesoderm at early gastrula stage. The genes encoding Xbp1 and Creb3l2 were also activated in the notochord. These two transcription factors are implicated in the activation of secretory pathway genes during the unfolded protein response, where cells react to the stress of a build-up of unfolded proteins in their endoplasmic reticulum. Xbp1 and Creb3l2 are differentially expressed but not differentially activated in the notochord. Reduction of expression of Xbp1 or Creb3l2 by injection of antisense morpholinos led to strong deficits in notochord but not somitic muscle development. In addition, the expression of some, but not all, genes encoding secretory proteins was inhibited by injection of xbp1 morpholinos. Furthermore, expression of activated forms of Xbp1 or Creb3l2 in animal explants could activate a similar subset of secretory pathway genes. We conclude that coordinated activation of a battery of secretory pathway genes mediated by Xbp1 and Creb/ATF factors is a characteristic and necessary feature of notochord formation. PMID:19793890

  16. Coordinated activation of the secretory pathway during notochord formation in the Xenopus embryo

    PubMed Central

    Tanegashima, Kosuke; Zhao, Hui; Rebbert, Martha L.; Dawid, Igor B.

    2009-01-01

    Summary We compared the transcriptome in the developing notochord of Xenopus laevis embryos with that of other embryonic regions. A coordinated and intense activation of a large set of secretory pathway genes was observed in the notochord, but not in notochord precursors in the axial mesoderm at early gastrula stage. The genes encoding Xbp1 and Creb3l2 were also activated in the notochord. These two transcription factors are implicated in the activation of secretory pathway genes during the unfolded protein response, where cells react to the stress of a build-up of unfolded proteins in their endoplasmic reticulum. Xbp1 and Creb3l2 are differentially expressed but not differentially activated in the notochord. Reduction of expression of Xbp1 or Creb3l2 by injection of antisense morpholinos led to strong deficits in notochord but not somitic muscle development. In addition, the expression of some, but not all, genes encoding secretory proteins was inhibited by injection of xbp1 morpholinos. Furthermore, expression of activated forms of Xbp1 or Creb3l2 in animal explants could activate a similar subset of secretory pathway genes. We conclude that coordinated activation of a battery of secretory pathway genes mediated by Xbp1 and Creb/ATF factors is a characteristic and necessary feature of notochord formation. PMID:19793890

  17. Non-conventional trafficking of the cystic fibrosis transmembrane conductance regulator through the early secretory pathway.

    PubMed

    Yoo, Jin-San; Moyer, Bryan D; Bannykh, Sergei; Yoo, Hyeon-Mi; Riordan, John R; Balch, William E

    2002-03-29

    The mechanism(s) of cystic fibrosis transmembrane conductance regulator (CFTR) trafficking from the endoplasmic reticulum (ER) through the Golgi apparatus, the step impaired in individuals afflicted with the prevalent CFTR-DeltaF508 mutation leading to cystic fibrosis, is largely unknown. Recent morphological observations suggested that CFTR is largely absent from the Golgi in situ (Bannykh, S. I., Bannykh, G. I., Fish, K. N., Moyer, B. D., Riordan, J. R., and Balch, W. E. (2000) Traffic 1, 852-870), raising the possibility of a novel trafficking pathway through the early secretory pathway. We now report that export of CFTR from the ER is regulated by the conventional coat protein complex II (COPII) in all cell types tested. Remarkably, in a cell type-specific manner, processing of CFTR from the core-glycosylated (band B) ER form to the complex-glycosylated (band C) isoform followed a non-conventional pathway that was insensitive to dominant negative Arf1, Rab1a/Rab2 GTPases, or the SNAp REceptor (SNARE) component syntaxin 5, all of which block the conventional trafficking pathway from the ER to the Golgi. Moreover, CFTR transport through the non-conventional pathway was potently blocked by overexpression of the late endosomal target-SNARE syntaxin 13, suggesting that recycling through a late Golgi/endosomal system was a prerequisite for CFTR maturation. We conclude that CFTR transport in the early secretory pathway can involve a novel pathway between the ER and late Golgi/endosomal compartments that may influence developmental expression of CFTR on the cell surface in polarized epithelial cells. PMID:11799116

  18. Pathogen-Secreted Proteases Activate a Novel Plant Immune Pathway

    PubMed Central

    Cheng, Zhenyu; Li, Jian-Feng; Niu, Yajie; Zhang, Xue-Cheng; Woody, Owen Z.; Xiong, Yan; Djonović, Slavica; Millet, Yves; Bush, Jenifer; McConkey, Brendan J.; Sheen, Jen; Ausubel, Frederick M.

    2015-01-01

    Mitogen-Activated Protein Kinase (MAPK) cascades play central roles in innate immune signaling networks in plants and animals1,2. In plants, however, the molecular mechanisms of how signal perception is transduced to MAPK activation remain elusive1. We report that pathogen-secreted proteases activate a previously unknown signaling pathway in Arabidopsis thaliana involving the Gα, Gβ and Gγ subunits of heterotrimeric G-protein complexes, which function upstream of a MAPK cascade. In this pathway, Receptor for Activated C Kinase 1 (RACK1) functions as a novel scaffold that binds to the Gβ subunit as well as to all three tiers of the MAPK cascade, thereby linking upstream G protein signaling to downstream activation of a MAPK cascade. The protease-G protein-RACK1-MAPK cascade modules identified in these studies are distinct from previously described plant immune signaling pathways such as the one elicited by bacterial flagellin, in which G proteins function downstream of or in parallel to a MAPK cascade without the involvement of the RACK1 scaffolding protein. The discovery of the novel protease-mediated immune signaling pathway described here was facilitated by the use of the broad host range, opportunistic bacterial pathogen Pseudomonas aeruginosa. The ability of P. aeruginosa to infect both plants and animals makes it an excellent model to identify novel types of immunoregulatory strategies that account for its niche adaptation to diverse host tissues and immune systems. PMID:25731164

  19. Legionella pneumophila lipopolysaccharide activates the classical complement pathway.

    PubMed Central

    Mintz, C S; Schultz, D R; Arnold, P I; Johnson, W

    1992-01-01

    Legionella pneumophila is a gram-negative bacterium capable of entering and growing in alveolar macrophages and monocytes. Complement and complement receptors are important in the uptake of L. pneumophila by human mononuclear phagocytes. The surface molecules of L. pneumophila that activate the complement system are unknown. To identify these factors, we investigated the effects of L. pneumophila lipopolysaccharide (LPS) on the classical and alternative complement pathways of normal human serum by functional hemolytic assays. Although incubation of LPS in normal human serum at 37 degrees C resulted in the activation of both pathways, complement activation proceeded primarily through the classical pathway. Activation of the classical pathway by LPS was dependent on natural antibodies of the immunoglobulin M class that were present in various quantities in sera from different normal individuals but were absent in an immunoglobulin-deficient serum obtained from an agammaglobulinemic patient. Additional studies using sheep erythrocytes coated with LPS suggested that the antibodies recognized antigenic sites in the carbohydrate portion of LPS. The ability of LPS to interact with the complement system suggests a role for LPS in the uptake of L. pneumophila by mononuclear phagocytes. PMID:1612744

  20. Alpha-synuclein Toxicity in the Early Secretory Pathway: How It Drives Neurodegeneration in Parkinsons Disease

    PubMed Central

    Wang, Ting; Hay, Jesse C.

    2015-01-01

    Alpha-synuclein is a predominant player in the pathogenesis of Parkinson's Disease. However, despite extensive study for two decades, its physiological and pathological mechanisms remain poorly understood. Alpha-synuclein forms a perplexing web of interactions with lipids, trafficking machinery, and other regulatory factors. One emerging consensus is that synaptic vesicles are likely the functional site for alpha-synuclein, where it appears to facilitate vesicle docking and fusion. On the other hand, the dysfunctions of alpha-synuclein are more dispersed and numerous; when mutated or over-expressed, alpha-synuclein affects several membrane trafficking and stress pathways, including exocytosis, ER-to-Golgi transport, ER stress, Golgi homeostasis, endocytosis, autophagy, oxidative stress, and others. Here we examine recent developments in alpha-synuclein's toxicity in the early secretory pathway placed in the context of emerging themes from other affected pathways to help illuminate its underlying pathogenic mechanisms in neurodegeneration. PMID:26617485

  1. Reciprocal Pathways Between Autonomous Motivation and Affect: A Longitudinal Investigation of American and Chinese Early Adolescents

    PubMed Central

    Pomerantz, Eva M.; Qin, Lili

    2013-01-01

    The current research examined the reciprocal pathways between children's autonomous motivation in school and affect over early adolescence in the United States and China. Beginning in the fall of 7th grade, 825 American and Chinese children (mean age = 12.73 years) reported on their autonomous (vs. controlled) motivation as well as unpleasant and pleasant affect every six months until the end of eighth grade. In both the United States and China, there were negative reciprocal pathways between children's autonomous motivation and unpleasant affect: Over time, heightened autonomous motivation predicted dampened unpleasant affect, which in turn predicted heightened autonomous motivation. Positive reciprocal pathways between children's autonomous motivation and pleasant affect were evident over time only in China. PMID:25593503

  2. Anomaly Detection in Host Signaling Pathways for the Early Prognosis of Acute Infection.

    PubMed

    Wang, Kun; Langevin, Stanley; O'Hern, Corey S; Shattuck, Mark D; Ogle, Serenity; Forero, Adriana; Morrison, Juliet; Slayden, Richard; Katze, Michael G; Kirby, Michael

    2016-01-01

    Clinical diagnosis of acute infectious diseases during the early stages of infection is critical to administering the appropriate treatment to improve the disease outcome. We present a data driven analysis of the human cellular response to respiratory viruses including influenza, respiratory syncytia virus, and human rhinovirus, and compared this with the response to the bacterial endotoxin, Lipopolysaccharides (LPS). Using an anomaly detection framework we identified pathways that clearly distinguish between asymptomatic and symptomatic patients infected with the four different respiratory viruses and that accurately diagnosed patients exposed to a bacterial infection. Connectivity pathway analysis comparing the viral and bacterial diagnostic signatures identified host cellular pathways that were unique to patients exposed to LPS endotoxin indicating this type of analysis could be used to identify host biomarkers that can differentiate clinical etiologies of acute infection. We applied the Multivariate State Estimation Technique (MSET) on two human influenza (H1N1 and H3N2) gene expression data sets to define host networks perturbed in the asymptomatic phase of infection. Our analysis identified pathways in the respiratory virus diagnostic signature as prognostic biomarkers that triggered prior to clinical presentation of acute symptoms. These early warning pathways correctly predicted that almost half of the subjects would become symptomatic in less than forty hours post-infection and that three of the 18 subjects would become symptomatic after only 8 hours. These results provide a proof-of-concept for utility of anomaly detection algorithms to classify host pathway signatures that can identify presymptomatic signatures of acute diseases and differentiate between etiologies of infection. On a global scale, acute respiratory infections cause a significant proportion of human co-morbidities and account for 4.25 million deaths annually. The development of clinical

  3. Anomaly Detection in Host Signaling Pathways for the Early Prognosis of Acute Infection

    PubMed Central

    O’Hern, Corey S.; Shattuck, Mark D.; Ogle, Serenity; Forero, Adriana; Morrison, Juliet; Slayden, Richard; Katze, Michael G.

    2016-01-01

    Clinical diagnosis of acute infectious diseases during the early stages of infection is critical to administering the appropriate treatment to improve the disease outcome. We present a data driven analysis of the human cellular response to respiratory viruses including influenza, respiratory syncytia virus, and human rhinovirus, and compared this with the response to the bacterial endotoxin, Lipopolysaccharides (LPS). Using an anomaly detection framework we identified pathways that clearly distinguish between asymptomatic and symptomatic patients infected with the four different respiratory viruses and that accurately diagnosed patients exposed to a bacterial infection. Connectivity pathway analysis comparing the viral and bacterial diagnostic signatures identified host cellular pathways that were unique to patients exposed to LPS endotoxin indicating this type of analysis could be used to identify host biomarkers that can differentiate clinical etiologies of acute infection. We applied the Multivariate State Estimation Technique (MSET) on two human influenza (H1N1 and H3N2) gene expression data sets to define host networks perturbed in the asymptomatic phase of infection. Our analysis identified pathways in the respiratory virus diagnostic signature as prognostic biomarkers that triggered prior to clinical presentation of acute symptoms. These early warning pathways correctly predicted that almost half of the subjects would become symptomatic in less than forty hours post-infection and that three of the 18 subjects would become symptomatic after only 8 hours. These results provide a proof-of-concept for utility of anomaly detection algorithms to classify host pathway signatures that can identify presymptomatic signatures of acute diseases and differentiate between etiologies of infection. On a global scale, acute respiratory infections cause a significant proportion of human co-morbidities and account for 4.25 million deaths annually. The development of clinical

  4. Discovery of piRNAs Pathway Associated with Early-Stage Spermatogenesis in Chicken

    PubMed Central

    Chang, Guobin; Guo, Qixin; Liu, Xiangping; Bi, Yulin; Zhang, Yu; Wang, Hongzhi; Li, Zhiteng; Guo, Xiaoming; Wan, Fang; Zhang, Yang; Xu, Qi; Chen, Guohong

    2016-01-01

    Piwi-interacting RNAs (piRNAs) play a key role in spermatogenesis. Here, we describe the piRNAs profiling of primordial germ cells (PGCs), spermatogonial stem cells (SSCs), and the spermatogonium (Sp) during early-stage spermatogenesis in chicken. We obtained 31,361,989 reads from PGCs, 31,757,666 reads from SSCs, and 46,448,327 reads from Sp cells. The length distribution of piRNAs in the three samples showed peaks at 33 nt. The resulting genes were subsequently annotated against the Gene Ontology (GO) database. Five genes (RPL7A, HSPA8, Pum1, CPXM2, and PRKCA) were found to be involved in cellular processes. Interactive pathway analysis (IPA) further revealed three important pathways in early-stage spermatogenesis including the FGF, Wnt, and EGF receptor signaling pathways. The gene Pum1 was found to promote germline stem cell proliferation, but it also plays a role in spermatogenesis. In conclusion, we revealed characteristics of piRNAs during early spermatogonial development in chicken and provided the basis for future research. PMID:27045806

  5. Hepatic and Nephric NRF2 Pathway Up-Regulation, an Early Antioxidant Response, in Acute Arsenic-Exposed Mice

    PubMed Central

    Li, Jinlong; Duan, Xiaoxu; Dong, Dandan; Zhang, Yang; Li, Wei; Zhao, Lu; Nie, Huifang; Sun, Guifan; Li, Bing

    2015-01-01

    Inorganic arsenic (iAs), a proven human carcinogen, damages biological systems through multiple mechanisms, one of them being reactive oxygen species (ROS) production. NRF2 is a redox-sensitive transcription factor that positively regulates the genes of encoding antioxidant and detoxification enzymes to neutralize ROS. Although NRF2 pathway activation by iAs has been reported in various cell types, however, the experimental data in vivo are very limited and not fully elucidated in humans. The present investigation aimed to explore the hepatic and nephric NRF2 pathway upregulation in acute arsenic-exposed mice in vivo. Our results showed 10 mg/kg NaAsO2 elevated the NRF2 protein and increased the transcription of Nrf2 mRNA, as well as up-regulated NRF2 downstream targets HO-1, GST and GCLC time- and dose-dependently both in the liver and kidney. Acute NaAsO2 exposure also resulted in obvious imbalance of oxidative redox status represented by the increase of GSH and MDA, and the decrease of T-AOC. The present investigation reveals that hepatic and nephric NRF2 pathway expression is an early antioxidant defensive response upon iAs exposure. A better knowledge about the NRF2 pathway involvment in the cellular response against arsenic could help improve the strategies for reducing the cellular toxicity related to this metalloid. PMID:26473898

  6. Repeated allergen exposure reduce early phase airway response and leukotriene release despite upregulation of 5-lipoxygenase pathways

    PubMed Central

    2012-01-01

    Background Allergen induced early phase airway response and airway plasma exudation are predominantly mediated by inflammatory mast cell mediators including histamine, cysteinyl leukotrienes (cysLTs) and thromboxane A2 (TXA2). The aim of the present study was to evaluate whether repeated allergen exposure affects early phase airway response to allergen challenge. Methods A trimellitic anhydride (TMA) sensitized guinea pig model was used to investigate the effects of low dose repeated allergen exposure on cholinergic airway responsiveness, early phase airway response and plasma exudation, as well as local airway production of mast cell derived cysteinyl leukotrienes and thromboxane B2 (TXB2) after allergen challenge. Results Repeated low dose allergen exposure increased cholinergic airway responsiveness. In contrast, early phase airway response and plasma exudation in response to a high-dose allergen challenge were strongly attenuated after repeated low dose allergen exposure. Inhibition of the airway response was unspecific to exposed allergen and independent of histamine receptor blocking. Furthermore, a significant reduction of cysteinyl leukotrienes and TXB2 was found in the airways of animals repeatedly exposed to a low dose allergen. However, in vitro stimulation of airway tissue from animals repeatedly exposed to a low dose allergen with arachidonic acid and calcium ionophore (A23187) induced production of cysteinyl leukotrienes and TXB2, suggesting enhanced activity of 5-lipoxygenase and cyclooxygenase pathways. Conclusions The inhibition of the early phase airway response, cysteinyl leukotriene and TXB2 production after repeated allergen exposure may result from unresponsive effector cells. PMID:22439792

  7. Activation of the canonical Wnt/{beta}-catenin pathway enhances monocyte adhesion to endothelial cells

    SciTech Connect

    Lee, Dong Kun . E-mail: leedk@memorialhealthsource.com; Nathan Grantham, R.; Trachte, Aaron L.; Mannion, John D.; Wilson, Colleen L.

    2006-08-18

    Monocyte adhesion to vascular endothelium has been reported to be one of the early processes in the development of atherosclerosis. In an attempt to develop strategies to prevent or delay atherosclerosis progression, we analyzed effects of the Wnt/{beta}-catenin signaling pathway on monocyte adhesion to various human endothelial cells. Adhesion of fluorescein-labeled monocytes to various human endothelial cells was analyzed under a fluorescent microscope. Unlike sodium chloride, lithium chloride enhanced monocyte adhesion to endothelial cells in a dose-dependent manner. We further demonstrated that inhibitors for glycogen synthase kinase (GSK)-3{beta} or proteosome enhanced monocyte-endothelial cell adhesion. Results of semi-quantitative reverse transcriptase polymerase chain reaction (RT-PCR) indicated that activation of Wnt/{beta}-catenin pathway did not change expression levels of mRNA for adhesion molecules. In conclusion, the canonical Wnt/{beta}-catenin pathway enhanced monocyte-endothelial cell adhesion without changing expression levels of adhesion molecules.

  8. Molecular pathways: mitogen-activated protein kinase pathway mutations and drug resistance.

    PubMed

    Pritchard, Antonia L; Hayward, Nicholas K

    2013-05-01

    Receptor tyrosine kinases are a diverse family of transmembrane proteins that can activate multiple pathways upon ligation of the receptor, one of which is the series of mitogen-activated protein kinase (MAPK) signaling cascades. The MAPK pathways play critical roles in a wide variety of cancer types, from hematologic malignancies to solid tumors. Aberrations include altered expression levels and activation states of pathway components, which can sometimes be attributable to mutations in individual members. The V600E mutation of BRAF was initially described in 2002 and has been found at particularly high frequency in melanoma and certain subtypes of colorectal cancer. In the relatively short time since this discovery, a family of drugs has been developed that specifically target this mutated BRAF isoform, which, after results from phase I/II and III clinical trials, was granted U.S. Food and Drug Administration approval in August 2011. Although these drugs produce clinically meaningful increases in progression-free and overall survival, due to acquired resistance they have not improved mortality rates. New drugs targeting other members of the MAPK pathways are in clinical trials or advanced stages of development. It is hoped that combination therapies of these new drugs in conjunction with BRAF inhibitors will counteract the mechanisms of resistance and provide cures. The clinical implementation of next-generation sequencing is leading to a greater understanding of the genetic architecture of tumors, along with acquired mechanisms of drug resistance, which will guide the development of tumor-specific inhibitors and combination therapies in the future. PMID:23406774

  9. Pubertal Timing and Vulnerabilities to Depression in Early Adolescence: Differential Pathways to Depressive Symptoms by Sex

    PubMed Central

    Hamilton, Jessica L.; Hamlat, Elissa J.; Stange, Jonathan P.; Abramson, Lyn Y.; Alloy, Lauren B.

    2014-01-01

    Although research implicates pubertal processes in the emergence of the sex difference in depression during adolescence, few studies have examined how cognitive and affective vulnerabilities influence the effect of pubertal timing on depressive symptoms. The current study prospectively examined whether early pubertal timing predicted increases in depressive symptoms among adolescents with more negative cognitive styles and lower emotional clarity, and whether this risk was specific to adolescent girls. In a diverse sample of 318 adolescents, early pubertal timing predicted increases in depressive symptoms among adolescent boys and girls with more negative cognitive styles and adolescent girls with poor emotional clarity. These findings suggest that earlier pubertal maturation may heighten the risk of depression for adolescents with pre-existing vulnerabilities to depression, and that early-maturing adolescent girls with lower levels of emotional clarity may be particularly vulnerable to depressive symptoms, representing one pathway through which the sex difference in depression may emerge. PMID:24439622

  10. The Cryptococcus neoformans Alkaline Response Pathway: Identification of a Novel Rim Pathway Activator

    PubMed Central

    Ost, Kyla S.; O’Meara, Teresa R.; Huda, Naureen; Esher, Shannon K.; Alspaugh, J. Andrew

    2015-01-01

    The Rim101/PacC transcription factor acts in a fungal-specific signaling pathway responsible for sensing extracellular pH signals. First characterized in ascomycete fungi such as Aspergillus nidulans and Saccharomyces cerevisiae, the Rim/Pal pathway maintains conserved features among very distantly related fungi, where it coordinates cellular adaptation to alkaline pH signals and micronutrient deprivation. However, it also directs species-specific functions in fungal pathogens such as Cryptococcus neoformans, where it controls surface capsule expression. Moreover, disruption of the Rim pathway central transcription factor, Rim101, results in a strain that causes a hyper-inflammatory response in animal infection models. Using targeted gene deletions, we demonstrate that several genes encoding components of the classical Rim/Pal pathway are present in the C. neoformans genome. Many of these genes are in fact required for Rim101 activation, including members of the ESCRT complex (Vps23 and Snf7), ESCRT-interacting proteins (Rim20 and Rim23), and the predicted Rim13 protease. We demonstrate that in neutral/alkaline pH, Rim23 is recruited to punctate regions on the plasma membrane. This change in Rim23 localization requires upstream ESCRT complex components but does not require other Rim101 proteolysis components, such as Rim20 or Rim13. Using a forward genetics screen, we identified the RRA1 gene encoding a novel membrane protein that is also required for Rim101 protein activation and, like the ESCRT complex, is functionally upstream of Rim23-membrane localization. Homologs of RRA1 are present in other Cryptococcus species as well as other basidiomycetes, but closely related genes are not present in ascomycetes. These findings suggest that major branches of the fungal Kingdom developed different mechanisms to sense and respond to very elemental extracellular signals such as changing pH levels. PMID:25859664

  11. Sucrose activates human taste pathways differently from artificial sweetener.

    PubMed

    Frank, Guido K W; Oberndorfer, Tyson A; Simmons, Alan N; Paulus, Martin P; Fudge, Julie L; Yang, Tony T; Kaye, Walter H

    2008-02-15

    Animal models suggest that sucrose activates taste afferents differently than non-caloric sweeteners. Little information exists how artificial sweeteners engage central taste pathways in the human brain. We assessed sucrose and sucralose taste pleasantness across a concentration gradient in 12 healthy control women and applied 10% sucrose and matched sucralose during functional magnet resonance imaging. The results indicate that (1) both sucrose and sucralose activate functionally connected primary taste pathways; (2) taste pleasantness predicts left insula response; (3) sucrose elicits a stronger brain response in the anterior insula, frontal operculum, striatum and anterior cingulate, compared to sucralose; (4) only sucrose, but not sucralose, stimulation engages dopaminergic midbrain areas in relation to the behavioral pleasantness response. Thus, brain response distinguishes the caloric from the non-caloric sweetener, although the conscious mind could not. This could have important implications on how effective artificial sweeteners are in their ability to substitute sugar intake. PMID:18096409

  12. Microglial Janus kinase/signal transduction and activator of transcription 3 pathway activity directly impacts astrocyte and spinal neuron characteristics.

    PubMed

    Molet, Jenny; Mauborgne, Annie; Diallo, Mickael; Armand, Vincent; Geny, David; Villanueva, Luis; Boucher, Yves; Pohl, Michel

    2016-01-01

    After peripheral nerve injury microglial reactivity change in the spinal cord is associated with an early activation of Janus kinase (JAK)/STAT3 transduction pathway whose blockade attenuates local inflammation and pain hypersensitivity. However, the consequences of microglial JAK/STAT3-mediated signaling on neighboring cells are unknown. Using an in vitro paradigm we assessed the impact of microglial JAK/STAT3 activity on functional characteristics of astrocytes and spinal cord neurons. Purified rat primary microglia was stimulated with JAK/STAT3 classical activator interleukin-6 in the presence or absence of a selective STAT3 inhibitor and rat primary astrocytes or spinal cord neurons were exposed to microglia conditioned media (CM). JAK/STAT3 activity-generated microglial CM modulated both astrocyte and neuron characteristics. Beyond inducing mRNA expression changes in various targets of interest in astrocytes and neurons, microglia CM activated c-Jun N-terminal kinase, STAT3 and NF-κB intracellular pathways in astrocytes and promoted their proliferation. Without modifying neuronal excitability or survival, CM affected the nerve processes morphology and distribution of the post-synaptic density protein 95, a marker of glutamatergic synaptic contacts. These findings show that JAK/STAT3 activity in microglia impacts the functional characteristics of astrocytes and neurons. This suggests its participation in spinal cord tissue plasticity and remodeling occurring after peripheral nerve injury. We show that the activity of JAK/STAT3 pathway in microglial cells confers them a specific signaling modality toward neighboring cells, promoting astrocyte proliferation and changes in neuronal morphology. These in vitro data suggest that the early JAK/STAT3 activation in spinal cord microglia, associated with peripheral nerve injury, participates in functional alteration of various cell populations and in spinal tissue remodeling. PMID:26440453

  13. Adenomatous polyposis coli mutants dominantly activate Hsf1-dependent cell stress pathways through inhibition of microtubule dynamics

    PubMed Central

    Davies, Alexander E.; Kortright, Kaitlyn; Kaplan, Kenneth B.

    2015-01-01

    Cancer cells up-regulate cell stress pathways, including the protein chaperone Hsp90. Increases in Hsp90 are believed “buffer” mutant protein activities necessary for cancer phenotypes. Activation of the cell stress pathway also alters the transcriptional landscape of cells in ways that are critical for cancer progression. However, it is unclear when and how the cell stress pathway is de-regulated during cancer progression. Here we report that mutations in adenomatous polyposis coli (APC) found in colorectal cancer activate cell stress pathways in mouse intestinal crypt cells, prior to loss of heterozygosity at APC or to the appearance of canonical intestinal cancer markers. Hsp90 levels are elevated in normal APC heterozygote crypt cells and further elevated in non-cancer cells adjacent to dysplasias, suggesting that the Hsp90 stress pathway marks the “cancer-field” effect. Expression of mutant APC in normal human epithelial cells is sufficient to activate a cell stress pathway via perturbations in microtubule dynamics. Inhibition of microtubule dynamics is sufficient to activate an Hsf1-dependent increase in gene transcription and protein levels. We suggest that the early activation of this Hsf1 dependent cell stress pathway by mono-allelic mutations in APC can affect cell programming in a way that contributes to cancer onset. PMID:26320184

  14. Activated factor XI increases the procoagulant activity of the extrinsic pathway by inactivating tissue factor pathway inhibitor

    PubMed Central

    Tucker, Erik I.; Matafonov, Anton; Cheng, Qiufang; Zientek, Keith D.; Gailani, Dave; Gruber, András; McCarty, Owen J. T.

    2015-01-01

    Activation of coagulation factor XI (FXI) may play a role in hemostasis. The primary substrate of activated FXI (FXIa) is FIX, leading to FX activation (FXa) and thrombin generation. However, recent studies suggest the hemostatic role of FXI may not be restricted to the activation of FIX. We explored whether FXI could interact with and inhibit the activity of tissue factor pathway inhibitor (TFPI). TFPI is an essential reversible inhibitor of activated factor X (FXa) and also inhibits the FVIIa-TF complex. We found that FXIa neutralized both endothelium- and platelet-derived TFPI by cleaving the protein between the Kunitz (K) 1 and K2 domains (Lys86/Thr87) and at the active sites of the K2 (Arg107/Gly108) and K3 (Arg199/Ala200) domains. Addition of FXIa to plasma was able to reverse the ability of TFPI to prolong TF-initiated clotting times in FXI- or FIX-deficient plasma, as well as FXa-initiated clotting times in FX-deficient plasma. Treatment of cultured endothelial cells with FXIa increased the generation of FXa and promoted TF-dependent fibrin formation in recalcified plasma. Together, these results suggest that the hemostatic role of FXIa may be attributed not only to activation of FIX but also to promoting the extrinsic pathway of thrombin generation through inactivation of TFPI. PMID:25587039

  15. Activated factor XI increases the procoagulant activity of the extrinsic pathway by inactivating tissue factor pathway inhibitor.

    PubMed

    Puy, Cristina; Tucker, Erik I; Matafonov, Anton; Cheng, Qiufang; Zientek, Keith D; Gailani, Dave; Gruber, András; McCarty, Owen J T

    2015-02-26

    Activation of coagulation factor XI (FXI) may play a role in hemostasis. The primary substrate of activated FXI (FXIa) is FIX, leading to FX activation (FXa) and thrombin generation. However, recent studies suggest the hemostatic role of FXI may not be restricted to the activation of FIX. We explored whether FXI could interact with and inhibit the activity of tissue factor pathway inhibitor (TFPI). TFPI is an essential reversible inhibitor of activated factor X (FXa) and also inhibits the FVIIa-TF complex. We found that FXIa neutralized both endothelium- and platelet-derived TFPI by cleaving the protein between the Kunitz (K) 1 and K2 domains (Lys86/Thr87) and at the active sites of the K2 (Arg107/Gly108) and K3 (Arg199/Ala200) domains. Addition of FXIa to plasma was able to reverse the ability of TFPI to prolong TF-initiated clotting times in FXI- or FIX-deficient plasma, as well as FXa-initiated clotting times in FX-deficient plasma. Treatment of cultured endothelial cells with FXIa increased the generation of FXa and promoted TF-dependent fibrin formation in recalcified plasma. Together, these results suggest that the hemostatic role of FXIa may be attributed not only to activation of FIX but also to promoting the extrinsic pathway of thrombin generation through inactivation of TFPI. PMID:25587039

  16. Signaling pathways activated by a protease allergen in basophils

    PubMed Central

    Rosenstein, Rachel K.; Bezbradica, Jelena S.; Yu, Shuang; Medzhitov, Ruslan

    2014-01-01

    Allergic diseases represent a significant burden in industrialized countries, but why and how the immune system responds to allergens remain largely unknown. Because many clinically significant allergens have proteolytic activity, and many helminths express proteases that are necessary for their life cycles, host mechanisms likely have evolved to detect the proteolytic activity of helminth proteases, which may be incidentally activated by protease allergens. A cysteine protease, papain, is a prototypic protease allergen that can directly activate basophils and mast cells, leading to the production of cytokines, including IL-4, characteristic of the type 2 immune response. The mechanism of papain’s immunogenic activity remains unknown. Here we have characterized the cellular response activated by papain in basophils. We find that papain-induced IL-4 production requires calcium flux and activation of PI3K and nuclear factor of activated T cells. Interestingly, papain-induced IL-4 production was dependent on the immunoreceptor tyrosine-based activation motif (ITAM) adaptor protein Fc receptor γ-chain, even though the canonical ITAM signaling was not activated by papain. Collectively, these data characterize the downstream signaling pathway activated by a protease allergen in basophils. PMID:25369937

  17. Early lethality of shRNA-transgenic pigs due to saturation of microRNA pathways* #

    PubMed Central

    Dai, Zhen; Wu, Rong; Zhao, Yi-cheng; Wang, Kan-kan; Huang, Yong-ye; Yang, Xin; Xie, Zi-cong; Tu, Chang-chun; Ouyang, Hong-sheng; Wang, Tie-dong; Pang, Da-xin

    2014-01-01

    RNA interference (RNAi) is considered as a potential modality for clinical treatment and anti-virus animal breeding. Here, we investigate the feasibility of inhibiting classical swine fever virus (CSFV) replication by short hairpin RNA (shRNA) in vitro and in vivo. We generate four different shRNA-positive clonal cells and two types of shRNA-transgenic pigs. CSFV could be effectively inhibited in shRNA-positive clonal cells and tail tip fibroblasts of shRNA-transgenic pigs. Unexpectedly, an early lethality due to shRNA is observed in these shRNA-transgenic pigs. With further research on shRNA-positive clonal cells and transgenic pigs, we report a great induction of interferon (IFN)-responsive genes in shRNA-positive clonal cells, altered levels of endogenous microRNAs (miRNA), and their processing enzymes in shRNA-positive cells. What is more, abnormal expressions of miRNAs and their processing enzymes are also observed in the livers of shRNA-transgenic pigs, indicating saturation of miRNA/shRNA pathways induced by shRNA. In addition, we investigate the effects of shRNAs on the development of somatic cell nuclear transfer (SCNT) embryos. These results show that shRNA causes adverse effects in vitro and in vivo and shRNA-induced disruption of the endogenous miRNA pathway may lead to the early lethality of shRNA-transgenic pigs. We firstly report abnormalities of the miRNA pathway in shRNA-transgenic animals, which may explain the early lethality of shRNA-transgenic pigs and has important implications for shRNA-transgenic animal preparation. PMID:24793764

  18. Pathways to URM Retention: IBP's Professional Development and Mentoring Activities

    NASA Astrophysics Data System (ADS)

    Johnson, A.; Williamson Whitney, V.; Ricciardi, L.; Detrick, L.; Siegfried, D.; Fauver, A.; Ithier-Guzman, W.; Thomas, S. H.; Valaitis, S.

    2013-05-01

    As a not for profit organization, the Institute for Broadening Participation (IBP) hosts a variety of initiatives designed to increase the retention of underrepresented minority (URM) students pursuing pathways in STEM. IBP also assists with formative program evaluation design and implementation to help strengthen URM recruitment and retention elements. Successful initiatives include virtual and face-to-face components that bring together URM students with established URM and other scientists in academia, government and industry. These connections provide URMs with mentoring, networking opportunities, and professional skill development contributing to an improved retention rate of URM students. IBP's initiatives include the NASA One Stop Shopping Initiative (NASA OSSI), Pathways to Ocean Science and Engineering, and the Minorities Striving and Pursuing Higher Degrees of Success (MS PHD'S) in Earth System Science (ESS) Professional Development Program. The NASA OSSI recruits and facilitates student engagement in NASA education and employment opportunities. Pathways to Ocean Science connects and supports URM students with Ocean Science REU programs and serves as a resource for REU program directors. Pathways to Engineering has synthesized mentoring resources into an online mentoring manual for URM students that has been extensively vetted by mentoring experts throughout the country. The mentoring manual, which is organized by roles, provides undergraduates, graduates, postdocs, faculty and project directors with valuable resources. MS PHD'S, one of IBP's longest running and most successful initiatives, focuses on increasing the retention rate of URM students receiving advanced degrees in ESS. The program addresses barriers to retention in ESS including isolation, lack of preparation and professional development, and lack of mentoring. Program activities center on peer-to-peer community building, professional development exercises, networking experiences, one

  19. Contribution of the GABAergic pathway(s) to the correlated activities of chicken retinal ganglion cells.

    PubMed

    Liu, Xue; Zhou, Yi; Gong, Hai-Qing; Liang, Pei-Ji

    2007-10-26

    In the present study, the spatiotemporal pattern of chicken retinal ganglion cells' firing activity in response to full-field white light stimulation was investigated. Cross-correlation analysis showed that ganglion cells of sustained subtype fired in precise synchrony with their adjacent neurons of the same subtype (delay lag within 2 ms, narrow correlation). On the other hand, the activities of neighboring ganglion cells of transient subtype were correlated with distributed time lags (10-30 ms, medium correlation). Pharmacological studies demonstrated that the intensity of the medium correlations could be strengthened when exogenous GABA was applied and attenuated when GABA receptors were blocked by picrotoxin. Meanwhile, the GABAergic modulation on the narrow correlations was not consistent. These results suggest that, in the chicken retina, GABAergic pathway(s) are likely involved in the formation of medium correlations between ganglion cells. Neurons might fire at a lower rate but with higher level of synchronization to improve the efficiency of information transmission, with the mechanism involving the GABAergic inhibitory input. PMID:17919471

  20. Activation of the Canonical Wnt Signaling Pathway Induces Cementum Regeneration.

    PubMed

    Han, Pingping; Ivanovski, Saso; Crawford, Ross; Xiao, Yin

    2015-07-01

    Canonical Wnt signaling is important in tooth development but it is unclear whether it can induce cementogenesis and promote the regeneration of periodontal tissues lost because of disease. Therefore, the aim of this study is to investigate the influence of canonical Wnt signaling enhancers on human periodontal ligament cell (hPDLCs) cementogenic differentiation in vitro and cementum repair in a rat periodontal defect model. Canonical Wnt signaling was induced by (1) local injection of lithium chloride; (2) local injection of sclerostin antibody; and (3) local injection of a lentiviral construct overexpressing β-catenin. The results showed that the local activation of canonical Wnt signaling resulted in significant new cellular cementum deposition and the formation of well-organized periodontal ligament fibers, which was absent in the control group. In vitro experiments using hPDLCs showed that the Wnt signaling pathway activators significantly increased mineralization, alkaline phosphatase (ALP) activity, and gene and protein expression of the bone and cementum markers osteocalcin (OCN), osteopontin (OPN), cementum protein 1 (CEMP1), and cementum attachment protein (CAP). Our results show that the activation of the canonical Wnt signaling pathway can induce in vivo cementum regeneration and in vitro cementogenic differentiation of hPDLCs. PMID:25556853

  1. Pathways to Early Coital Debut for Adolescent Girls: A Recursive Partitioning Analysis

    PubMed Central

    Pearson, Matthew R.; Kholodkov, Tatyana; Henson, James M.; Impett, Emily A.

    2011-01-01

    The current study examined pathways to early coital debut among early to middle adolescent girls in the United States. In a two-year longitudinal study of 104 adolescent girls, we conducted Recursive Partitioning (RP) analyses to examine the specific factors that were related to engaging in first intercourse by the 10th grade among adolescent girls who had not yet engaged in sexual intercourse by the 8th grade. RP analyses identified subsamples of girls who had low, medium, and high likelihoods of engaging in early coital debut based on six variables (i.e., school aspirations, early physical intimacy experiences, depression, body objectification, body image, and relationship inauthenticity). For example, girls in the lowest likelihood group (3% had engaged in sex by the 10th grade) reported no prior experiences with being touched under their clothes, low body objectification, high aspirations to complete graduate education, and low depressive symptoms; girls in the highest likelihood group (75% had engaged in sex by the 10th grade) also reported no prior experiences with being touched under their clothes but had high levels of body objectification. The implications of these analyses for the development of female adolescent sexuality as well as for advances in quantitative methods are discussed. PMID:21512947

  2. Pharmacology of the intracellular pathways activated by amyloid beta protein.

    PubMed

    Balleza-Tapia, Hugo; Peña, Fernando

    2009-06-01

    Alzheimer's disease (AD) is a late-life cognitive disorder associated, among other things, to the presence of extracellular aggregates of fibrillar amyloid beta protein (Abeta). However, there is growing evidence that early stages of AD may be due to neuronal network dysfunction produced by the actions of soluble forms of Abeta. Therefore, the development of new therapeutic strategies to treat AD, at least during its first stages, may be focused on preventing or reversing, the deleterious effects that soluble Abeta exerts on neuronal circuit function. In order to do so, it is necessary to elucidate the pathophysiological processes involved in Abeta-induced neuronal network dysfunction and the molecular processes underlying such dysfunction. Over the last decades, there has been extensive research about the molecular mechanisms involved in the effects of Abeta as well as possible neuroprotective strategies against such effects. Here we are going to review some of the intracellular pathways triggered by Abeta, which involve membrane receptors such as nicotinic-R, NMDA-R, integrins, TNF-R1, RAGE, FPRL and p75NTR and their intracellular mediators such as GSK3, PKC, PI3K, Akt, FAK, MAPK family, Src family and cdk5. Several of these pathways may constitute therapeutic targets for the treatment of the Abeta-induced neuronal network dysfunction which is, at least in part, the basis for cognitive dysfunction in AD. PMID:19519498

  3. Phosphatidylinositol 3-kinase pathway activation in breast cancer brain metastases

    PubMed Central

    2011-01-01

    Introduction Activation status of the phosphatidylinositol 3-kinase (PI3K) pathway in breast cancer brain metastases (BCBMs) is largely unknown. We examined expression of phospho(p)-AKT, p-S6, and phosphatase and tensin homologue (PTEN) in BCBMs and their implications for overall survival (OS) and survival after BCBMs. Secondary analyses included PI3K pathway activation status and associations with time to distant recurrence (TTDR) and time to BCBMs. Similar analyses were also conducted among the subset of patients with triple-negative BCBMs. Methods p-AKT, p-S6, and PTEN expression was assessed with immunohistochemistry in 52 BCBMs and 12 matched primary BCs. Subtypes were defined as hormone receptor (HR)+/HER2-, HER2+, and triple-negative (TNBC). Survival analyses were performed by using a Cox model, and survival curves were estimated with the Kaplan-Meier method. Results Expression of p-AKT and p-S6 and lack of PTEN (PTEN-) was observed in 75%, 69%, and 25% of BCBMs. Concordance between primary BCs and matched BCBMs was 67% for p-AKT, 58% for p-S6, and 83% for PTEN. PTEN- was more common in TNBC compared with HR+/HER2- and HER2+. Expression of p-AKT, p-S6, and PTEN- was not associated with OS or survival after BCBMs (all, P > 0.06). Interestingly, among all patients, PTEN- correlated with shorter time to distant and brain recurrence. Among patients with TNBC, PTEN- in BCBMs was associated with poorer overall survival. Conclusions The PI3K pathway is active in most BCBMs regardless of subtype. Inhibition of this pathway represents a promising therapeutic strategy for patients with BCBMs, a group of patients with poor prognosis and limited systemic therapeutic options. Although expression of the PI3K pathway did not correlate with OS and survival after BCBM, PTEN- association with time to recurrence and OS (among patients with TNBC) is worthy of further study. PMID:22132754

  4. Traffic pattern of cystic fibrosis transmembrane regulator through the early exocytic pathway.

    PubMed

    Bannykh, S I; Bannykh, G I; Fish, K N; Moyer, B D; Riordan, J R; Balch, W E

    2000-11-01

    The pathway of transport of the cystic fibrosis transmembrane regulator (CFTR) through the early exocytic pathway has not been examined. In contrast to most membrane proteins that are concentrated during export from the ER and therefore readily detectable at elevated levels in pre-Golgi intermediates and Golgi compartments, wild-type CFTR could not be detected in these compartments using deconvolution immunofluorescence microscopy. To determine the basis for this unusual feature, we analyzed CFTR localization using quantitative immunoelectron microscopy (IEM). We found that wild-type CFTR is present in pre-Golgi compartments and peripheral tubular elements associated with the cis and trans faces of the Golgi stack, albeit at a concentration 2-fold lower than that found in the endoplasmic reticulum (ER). delta F508 CFTR, a mutant form that is not efficiently delivered to the cell surface and the most common mutation in cystic fibrosis, could also be detected at a reduced concentration in pre-Golgi intermediates and peripheral cis Golgi elements, but not in post-Golgi compartments. Our results suggest that the low level of wild-type CFTR in the Golgi region reflects a limiting step in selective recruitment by the ER export machinery, an event that is largely deficient in delta F508. We raise the possibility that novel modes of selective anterograde and retrograde traffic between the ER and the Golgi may serve to regulate CFTR function in the early secretory compartments. PMID:11208075

  5. Synaptic activity regulates AMPA receptor trafficking through different recycling pathways.

    PubMed

    Zheng, Ning; Jeyifous, Okunola; Munro, Charlotte; Montgomery, Johanna M; Green, William N

    2015-01-01

    Changes in glutamatergic synaptic strength in brain are dependent on AMPA-type glutamate receptor (AMPAR) recycling, which is assumed to occur through a single local pathway. In this study, we present evidence that AMPAR recycling occurs through different pathways regulated by synaptic activity. Without synaptic stimulation, most AMPARs recycled in dynamin-independent endosomes containing the GTPase, Arf6. Few AMPARs recycled in dynamin-dependent endosomes labeled by transferrin receptors (TfRs). AMPAR recycling was blocked by alterations in the GTPase, TC10, which co-localized with Arf6 endosomes. TC10 mutants that reduced AMPAR recycling had no effect on increased AMPAR levels with long-term potentiation (LTP) and little effect on decreased AMPAR levels with long-term depression. However, internalized AMPAR levels in TfR-containing recycling endosomes increased after LTP, indicating increased AMPAR recycling through the dynamin-dependent pathway with synaptic plasticity. LTP-induced AMPAR endocytosis is inconsistent with local recycling as a source of increased surface receptors, suggesting AMPARs are trafficked from other sites. PMID:25970033

  6. The Activation Pathway of Human Rhodopsin in Comparison to Bovine Rhodopsin.

    PubMed

    Kazmin, Roman; Rose, Alexander; Szczepek, Michal; Elgeti, Matthias; Ritter, Eglof; Piechnick, Ronny; Hofmann, Klaus Peter; Scheerer, Patrick; Hildebrand, Peter W; Bartl, Franz J

    2015-08-14

    Rhodopsin, the photoreceptor of rod cells, absorbs light to mediate the first step of vision by activating the G protein transducin (Gt). Several human diseases, such as retinitis pigmentosa or congenital night blindness, are linked to rhodopsin malfunctions. Most of the corresponding in vivo studies and structure-function analyses (e.g. based on protein x-ray crystallography or spectroscopy) have been carried out on murine or bovine rhodopsin. Because these rhodopsins differ at several amino acid positions from human rhodopsin, we conducted a comprehensive spectroscopic characterization of human rhodopsin in combination with molecular dynamics simulations. We show by FTIR and UV-visible difference spectroscopy that the light-induced transformations of the early photointermediates are very similar. Significant differences between the pigments appear with formation of the still inactive Meta I state and the transition to active Meta II. However, the conformation of Meta II and its activity toward the G protein are essentially the same, presumably reflecting the evolutionary pressure under which the active state has developed. Altogether, our results show that although the basic activation pathways of human and bovine rhodopsin are similar, structural deviations exist in the inactive conformation and during receptor activation, even between closely related rhodopsins. These differences between the well studied bovine or murine rhodopsins and human rhodopsin have to be taken into account when the influence of point mutations on the activation pathway of human rhodopsin are investigated using the bovine or murine rhodopsin template sequences. PMID:26105054

  7. Activation of the TGFβ pathway impairs endothelial to haematopoietic transition

    PubMed Central

    Vargel, Özge; Zhang, Yang; Kosim, Kinga; Ganter, Kerstin; Foehr, Sophia; Mardenborough, Yannicka; Shvartsman, Maya; Enright, Anton J.; Krijgsveld, Jeroen; Lancrin, Christophe

    2016-01-01

    The endothelial to haematopoietic transition (EHT) is a key developmental process where a drastic change of endothelial cell morphology leads to the formation of blood stem and progenitor cells during embryogenesis. As TGFβ signalling triggers a similar event during embryonic development called epithelial to mesenchymal transition (EMT), we hypothesised that TGFβ activity could play a similar role in EHT as well. We used the mouse embryonic stem cell differentiation system for in vitro recapitulation of EHT and performed gain and loss of function analyses of the TGFβ pathway. Quantitative proteomics analysis showed that TGFβ treatment during EHT increased the secretion of several proteins linked to the vascular lineage. Live cell imaging showed that TGFβ blocked the formation of round blood cells. Using gene expression profiling we demonstrated that the TGFβ signalling activation decreased haematopoietic genes expression and increased the transcription of endothelial and extracellular matrix genes as well as EMT markers. Finally we found that the expression of the transcription factor Sox17 was up-regulated upon TGFβ signalling activation and showed that its overexpression was enough to block blood cell formation. In conclusion we showed that triggering the TGFβ pathway does not enhance EHT as we hypothesised but instead impairs it. PMID:26891705

  8. Metabolic activation of efferent pathways from the rat area postrema.

    PubMed

    Gross, P M; Wainman, D S; Shaver, S W; Wall, K M; Ferguson, A V

    1990-03-01

    We used the quantitative [14C]deoxyglucose method and autoradiography to evaluate metabolic activity in 47 individual cerebral structures or subregions that are part of neural pathways emanating from the brain stem circumventricular organ, area postrema. Electrical stimulation of the dorsocentral area postrema in halothane-ventilated rats produced hypotension and increased glucose metabolism by several structures within the ascending trajectories of efferent neural projections from the nucleus. Structures in the caudal medulla oblongata, including three subnuclei of the nucleus of the solitary tract, dorsal motor nucleus of the vagus nerve, and nucleus ambiguus-A1 noradrenergic region, had increases of metabolism during stimulation of 32-62%. Pontine activation occurred specifically in the locus coeruleus and lateral parabrachial nuclei (increases of 24-36%). Magnocellular and parvocellular subdivisions of the hypothalamic paraventricular nucleus, supraoptic and suprachiasmatic nuclei, and median eminence showed increases in metabolism of 22-34%. An 89% elevation of glucose metabolism by the pituitary neural lobe resulted. The findings are evidence for functional activation of specific structures within ascending neural pathways from area postrema to forebrain mechanisms regulating blood pressure and fluid balance. PMID:2316724

  9. Activation of the TGFβ pathway impairs endothelial to haematopoietic transition.

    PubMed

    Vargel, Özge; Zhang, Yang; Kosim, Kinga; Ganter, Kerstin; Foehr, Sophia; Mardenborough, Yannicka; Shvartsman, Maya; Enright, Anton J; Krijgsveld, Jeroen; Lancrin, Christophe

    2016-01-01

    The endothelial to haematopoietic transition (EHT) is a key developmental process where a drastic change of endothelial cell morphology leads to the formation of blood stem and progenitor cells during embryogenesis. As TGFβ signalling triggers a similar event during embryonic development called epithelial to mesenchymal transition (EMT), we hypothesised that TGFβ activity could play a similar role in EHT as well. We used the mouse embryonic stem cell differentiation system for in vitro recapitulation of EHT and performed gain and loss of function analyses of the TGFβ pathway. Quantitative proteomics analysis showed that TGFβ treatment during EHT increased the secretion of several proteins linked to the vascular lineage. Live cell imaging showed that TGFβ blocked the formation of round blood cells. Using gene expression profiling we demonstrated that the TGFβ signalling activation decreased haematopoietic genes expression and increased the transcription of endothelial and extracellular matrix genes as well as EMT markers. Finally we found that the expression of the transcription factor Sox17 was up-regulated upon TGFβ signalling activation and showed that its overexpression was enough to block blood cell formation. In conclusion we showed that triggering the TGFβ pathway does not enhance EHT as we hypothesised but instead impairs it. PMID:26891705

  10. S(mu) mutation patterns suggest different progression pathways in follicular lymphoma: early direct or late from FL progenitor cells.

    PubMed

    Ruminy, Philippe; Jardin, Fabrice; Picquenot, Jean-Michel; Parmentier, Françoise; Contentin, Nathalie; Buchonnet, Gérard; Tison, Sandrine; Rainville, Vinciane; Tilly, Hervé; Bastard, Christian

    2008-09-01

    Follicular lymphoma (FL) is a B-cell malignancy characterized by the t(14;18) translocation. Although sensitive to treatment, the disease remains incurable and the reason why tumor cells invariably evade treatment, leading to clinical relapse, is still unknown. Here, we tracked the clonal history of tumor cells by studying mutations introduced by activation-induced cytidine deaminase on the switch mu region of the der(14)t(14;18) during the early phase of the class-switch recombination (CSR) process. We observed frequent intraclonal variations, suggesting that CSR often remains active after the acquisition of the fully transformed phenotype. However, mutations only rarely accumulated over time, but instead showed complex evolutionary scenarios and 2 different progression pathways. The first pathway was a direct and rapid evolution from the dominant clone. The second was indirect, arising from earlier subclones usually after years of remission. A better understanding of these mechanisms might influence the future choice of treatment strategies. PMID:18515657

  11. Mast cell degranulation activates a pain pathway underlying migraine headache

    PubMed Central

    Levy, Dan; Burstein, Rami; Kainz, Vanessa; Jakubowski, Moshe; Strassman, Andrew M.

    2007-01-01

    Intracranial headaches such as that of migraine are generally accepted to be mediated by prolonged activation of meningeal nociceptors but the mechanisms responsible for such nociceptor activation are poorly understood. In this study, we examined the hypothesis that meningeal nociceptors can be activated locally through a neuroimmune interaction with resident mast cells, granulated immune cells that densely populate the dura mater. Using in vivo electrophysiological single unit recording of meningeal nociceptors in the rat we observed that degranulation of dural mast cells using intraperitoneal administration of the basic secretagogue agent compound 48/80 (2 mg/kg) induced a prolonged state of excitation in meningeal nociceptors. Such activation was accompanied by increased expression of the phosphorylated form of the extracellular signal-regulated kinase (pERK), an anatomical marker for nociceptor activation. Mast cell - induced nociceptor interaction was also associated with downstream activation of the spinal trigeminal nucleus as indicated by an increase in c-fos expression. Our findings provide evidence linking dural mast cell degranulation to prolonged activation of the trigeminal pain pathway believed to underlie intracranial headaches such as that of migraine. PMID:17459586

  12. Genome-Wide Chromatin Landscape Transitions Identify Novel Pathways in Early Commitment to Osteoblast Differentiation

    PubMed Central

    Thompson, Bethtrice; Varticovski, Lyuba; Baek, Songjoon; Hager, Gordon L.

    2016-01-01

    Bone continuously undergoes remodeling by a tightly regulated process that involves osteoblast differentiation from Mesenchymal Stem Cells (MSC). However, commitment of MSC to osteoblastic lineage is a poorly understood process. Chromatin organization functions as a molecular gatekeeper of DNA functions. Detection of sites that are hypersensitive to Dnase I has been used for detailed examination of changes in response to hormones and differentiation cues. To investigate the early steps in commitment of MSC to osteoblasts, we used a model human temperature-sensitive cell line, hFOB. When shifted to non-permissive temperature, these cells undergo "spontaneous" differentiation that takes several weeks, a process that is greatly accelerated by osteogenic induction media. We performed Dnase I hypersensitivity assays combined with deep sequencing to identify genome-wide potential regulatory events in cells undergoing early steps of commitment to osteoblasts. Massive reorganization of chromatin occurred within hours of differentiation. Whereas ~30% of unique DHS sites were located in the promoters, the majority was outside of the promoters, designated as enhancers. Many of them were at novel genomic sites and need to be confirmed experimentally. We developed a novel method for identification of cellular networks based solely on DHS enhancers signature correlated to gene expression. The analysis of enhancers that were unique to differentiating cells led to identification of bone developmental program encompassing 147 genes that directly or indirectly participate in osteogenesis. Identification of these pathways provided an unprecedented view of genomic regulation during early steps of differentiation and changes related to WNT, AP-1 and other pathways may have therapeutic implications. PMID:26890492

  13. Genome-Wide Chromatin Landscape Transitions Identify Novel Pathways in Early Commitment to Osteoblast Differentiation.

    PubMed

    Thompson, Bethtrice; Varticovski, Lyuba; Baek, Songjoon; Hager, Gordon L

    2016-01-01

    Bone continuously undergoes remodeling by a tightly regulated process that involves osteoblast differentiation from Mesenchymal Stem Cells (MSC). However, commitment of MSC to osteoblastic lineage is a poorly understood process. Chromatin organization functions as a molecular gatekeeper of DNA functions. Detection of sites that are hypersensitive to Dnase I has been used for detailed examination of changes in response to hormones and differentiation cues. To investigate the early steps in commitment of MSC to osteoblasts, we used a model human temperature-sensitive cell line, hFOB. When shifted to non-permissive temperature, these cells undergo "spontaneous" differentiation that takes several weeks, a process that is greatly accelerated by osteogenic induction media. We performed Dnase I hypersensitivity assays combined with deep sequencing to identify genome-wide potential regulatory events in cells undergoing early steps of commitment to osteoblasts. Massive reorganization of chromatin occurred within hours of differentiation. Whereas ~30% of unique DHS sites were located in the promoters, the majority was outside of the promoters, designated as enhancers. Many of them were at novel genomic sites and need to be confirmed experimentally. We developed a novel method for identification of cellular networks based solely on DHS enhancers signature correlated to gene expression. The analysis of enhancers that were unique to differentiating cells led to identification of bone developmental program encompassing 147 genes that directly or indirectly participate in osteogenesis. Identification of these pathways provided an unprecedented view of genomic regulation during early steps of differentiation and changes related to WNT, AP-1 and other pathways may have therapeutic implications. PMID:26890492

  14. Activation of defense response pathways by OGs and Flg22 elicitors in Arabidopsis seedlings

    PubMed Central

    Denoux, Carine; Galletti, Roberta; Mammarella, Nicole; Gopalan, Suresh; Werck, Danièle; De Lorenzo, Giulia; Ferrari, Simone; Ausubel, Frederick M.; Dewdney, Julia

    2010-01-01

    We carried out transcriptional profiling analysis in 10 day-old Arabidopsis thaliana seedlings treated with oligogalacturonides (OGs), oligosaccharides derived from the plant cell wall, or the bacterial flagellin peptide Flg22, general elicitors of the basal defense response in plants. Although detected by different receptors, both OGs and Flg22 trigger a fast and transient response that is both similar and comprehensive, and characterized by activation of early stages of multiple defense signaling pathways, particularly JA-associated processes. However, the response to Flg22 is stronger in both the number of genes differentially expressed and the amplitude of change. The magnitude of induction of individual genes is in both cases dose dependent, but even at very high concentrations, OGs do not induce a response that is as comprehensive as that seen with Flg22. While high doses of either microbe-associated molecular pattern (MAMP) elicit a late response that includes activation of senescence processes, SA-dependent secretory pathway genes and PR1 expression are substantially induced only by Flg22. These results suggest a lower threshold for activation of early responses than for sustained or SA-mediated late defenses. Expression patterns of aminocyclopropane-carboxylate synthase genes also implicate ethylene biosynthesis in regulation of the late innate immune response. PMID:19825551

  15. Overexpression of the Transcription Factor Sp1 Activates the OAS-RNAse L-RIG-I Pathway

    PubMed Central

    Dupuis-Maurin, Valéryane; Brinza, Lilia; Baguet, Joël; Plantamura, Emilie; Schicklin, Stéphane; Chambion, Solène; Macari, Claire; Tomkowiak, Martine; Deniaud, Emmanuelle; Leverrier, Yann

    2015-01-01

    Deregulated expression of oncogenes or transcription factors such as specificity protein 1 (Sp1) is observed in many human cancers and plays a role in tumor maintenance. Paradoxically in untransformed cells, Sp1 overexpression induces late apoptosis but the early intrinsic response is poorly characterized. In the present work, we studied increased Sp1 level consequences in untransformed cells and showed that it turns on an early innate immune transcriptome. Sp1 overexpression does not activate known cellular stress pathways such as DNA damage response or endoplasmic reticulum stress, but induces the activation of the OAS-RNase L pathway and the generation of small self-RNAs, leading to the upregulation of genes of the antiviral RIG-I pathway at the transcriptional and translational levels. Finally, Sp1-induced intrinsic innate immune response leads to the production of the chemokine CXCL4 and to the recruitment of inflammatory cells in vitro and in vivo. Altogether our results showed that increased Sp1 level in untransformed cells constitutes a novel danger signal sensed by the OAS-RNase L axis leading to the activation of the RIG-I pathway. These results suggested that the OAS-RNase L-RIG-I pathway may be activated in sterile condition in absence of pathogen. PMID:25738304

  16. Complement Alternative Pathway Activation in Human Nonalcoholic Steatohepatitis

    PubMed Central

    Segers, Filip M.; Verdam, Froukje J.; de Jonge, Charlotte; Boonen, Bas; Driessen, Ann; Shiri-Sverdlov, Ronit; Bouvy, Nicole D.; Greve, Jan Willem M.; Buurman, Wim A.; Rensen, Sander S.

    2014-01-01

    The innate immune system plays a major role in the pathogenesis of nonalcoholic steatohepatitis (NASH). Recently we reported complement activation in human NASH. However, it remained unclear whether the alternative pathway of complement, which amplifies C3 activation and which is frequently associated with pathological complement activation leading to disease, was involved. Here, alternative pathway components were investigated in liver biopsies of obese subjects with healthy livers (n = 10) or with NASH (n = 12) using quantitative PCR, Western blotting, and immunofluorescence staining. Properdin accumulated in areas where neutrophils surrounded steatotic hepatocytes, and colocalized with the C3 activation product C3c. C3 activation status as expressed by the C3c/native C3 ratio was 2.6-fold higher (p<0.01) in subjects with NASH despite reduced native C3 concentrations (0.94±0.12 vs. 0.57±0.09; p<0.01). Hepatic properdin levels positively correlated with levels of C3c (rs = 0.69; p<0.05) and C3c/C3 activation ratio (rs = 0.59; p<0.05). C3c, C3 activation status (C3c/C3 ratio) and properdin levels increased with higher lobular inflammation scores as determined according to the Kleiner classification (C3c: p<0.01, C3c/C3 ratio: p<0.05, properdin: p<0.05). Hepatic mRNA expression of factor B and factor D did not differ between subjects with healthy livers and subjects with NASH (factor B: 1.00±0.19 vs. 0.71±0.07, p = 0.26; factor D: 1.00±0.21 vs. 0.66±0.14, p = 0.29;). Hepatic mRNA and protein levels of Decay Accelerating Factor tended to be increased in subjects with NASH (mRNA: 1.00±0.14 vs. 2.37±0.72; p = 0.22; protein: 0.51±0.11 vs. 1.97±0.67; p = 0.28). In contrast, factor H mRNA was downregulated in patients with NASH (1.00±0.09 vs. 0.71±0.06; p<0.05) and a similar trend was observed with hepatic protein levels (1.12±0.16 vs. 0.78±0.07; p = 0.08). Collectively, these data suggest a role for alternative pathway

  17. Characterization of early events involved in human dendritic cell maturation induced by sensitizers: Cross talk between MAPK signalling pathways

    SciTech Connect

    Trompezinski, Sandra; Migdal, Camille; Tailhardat, Magalie; Le Varlet, Beatrice; Courtellemont, Pascal; Haftek, Marek; Serres, Mireille

    2008-08-01

    Dendritic cells (DCs), efficient-antigen presenting cells play an important role in initiating and regulating immune responses. DC maturation following exposure to nickel or DNCB induced an up-regulation of phenotypic markers and inflammatory cytokine secretion. Early intracellular mechanisms involved in DC maturation required to be precise. To address this purpose, DCs derived from human monocytes were treated with sensitizers (nickel, DNCB or thimerosal) in comparison with an irritant (SDS). Our data confirming the up-regulation of CD86, CD54 and cytokine secretion (IL-8 and TNF{alpha}) induced by sensitizers but not by SDS, signalling transduction involved in DC maturation was investigated using these chemicals. Kinase activity measurement was assessed using two new sensitive procedures (Face{sup TM} and CBA) requiring few cells. SDS did not induce changes in signalling pathways whereas NiSO{sub 4}, DNCB and thimerosal markedly activated p38 MAPK and JNK, in contrast Erk1/2 phosphorylation was completely inhibited by DNCB or thimerosal and only activated by nickel. A pre-treatment with p38 MAPK inhibitor (SB203580) suppressed Erk1/2 inhibition induced by DNCB or thimerosal demonstrating a direct interaction between p38 MAPK and Erk1/2. A pre-treatment with an antioxidant, N-acetyl-L-cysteine (NAC) markedly reduced Erk1/2 inhibition and p38 MAPK phosphorylation induced by DNCB and thimerosal, suggesting a direct activation of p38 MAPK via an oxidative stress and a regulation of MAPK signalling pathways depending on chemicals. Because of a high sensitivity of kinase activity measurements, these procedures will be suitable for weak or moderate sensitizer screening.

  18. Ischemia in tumors induces early and sustained phosphorylation changes in stress kinase pathways but does not affect global protein levels

    SciTech Connect

    Mertins, Philipp; Yang, Feng; Liu, Tao; Mani, DR; Petyuk, Vladislav A.; Gillette, Michael; Clauser, Karl; Qiao, Jana; Gritsenko, Marina A.; Moore, Ronald J.; Levine, Douglas; Townsend, Reid; Erdmann-Gilmore, Petra; Snider, Jacqueline E.; Davies, Sherri; Ruggles, Kelly; Fenyo, David; Kitchens, R. T.; Li, Shunqiang; Olvera, Narcisco; Dao, Fanny; Rodriguez, Henry; Chan, Daniel W.; Liebler, Daniel; White, Forest; Rodland, Karin D.; Mills, Gordon; Smith, Richard D.; Paulovich, Amanda G.; Ellis, Matthew; Carr, Steven A.

    2014-07-01

    Advances in quantitative mass spectrometry (MS)-based proteomics have sparked efforts to characterize the proteomes of tumor samples to provide complementary and unique information inaccessible by genomics. Tumor samples are usually not accrued with proteomic characterization in mind, raising concerns regarding effects of undocumented sample ischemia on protein abundance and phosphosite stoichiometry. Here we report the effects of cold ischemia time on clinical ovarian cancer samples and patient-derived basal and luminal breast cancer xenografts. Tumor tissues were excised and collected prior to vascular ligation, subjected to accurately defined ischemia times up to 60 min, and analyzed by quantitative proteomics and phosphoproteomics using isobaric tags and high-performance, multidimensional LC-MS/MS. No significant changes were detected at the protein level in each tumor type after 60 minutes of ischemia, and the majority of the >25,000 phosphosites detected were also stable. However, large, reproducible increases and decreases in protein phosphorylation at specific sites were observed in up to 24% of the phosphoproteome starting as early as 5 minutes post-excision. Early and sustained activation of stress response, transcriptional regulation and cell death pathways were observed in common across tumor types. Tissue-specific changes in phosphosite stability were also observed suggesting idiosyncratic effects of ischemia in particular lineages. Our study provides insights into the information that may be obtained by proteomic characterization of tumor samples after undocumented periods of ischemia, and suggests caution especially in interpreting activation of stress pathways in such samples as they may reflect sample handling rather than tumor physiology.

  19. Sorafenib synergizes with metformin in NSCLC through AMPK pathway activation

    PubMed Central

    Groenendijk, Floris H; Mellema, Wouter W; van der Burg, Eline; Schut, Eva; Hauptmann, Michael; Horlings, Hugo M; Willems, Stefan M; van den Heuvel, Michel M; Jonkers, Jos; Smit, Egbert F; Bernards, René

    2015-01-01

    The multikinase inhibitor sorafenib is under clinical investigation for the treatment of many solid tumors, but in most cases, the molecular target responsible for the clinical effect is unknown. Furthermore, enhancing the effectiveness of sorafenib using combination strategies is a major clinical challenge. Here, we identify sorafenib as an activator of AMP-activated protein kinase (AMPK), in a manner that involves either upstream LKB1 or CAMKK2. We further show in a phase II clinical trial in KRAS mutant advanced non-small cell lung cancer (NSCLC) with single agent sorafenib an improved disease control rate in patients using the antidiabetic drug metformin. Consistent with this, sorafenib and metformin act synergistically in inhibiting cellular proliferation in NSCLC in vitro and in vivo. A synergistic effect of both drugs is also seen on phosphorylation of the AMPKα activation site. Our results provide a rationale for the synergistic antiproliferative effects, given that AMPK inhibits downstream mTOR signaling. These data suggest that the combination of sorafenib with AMPK activators could have beneficial effects on tumor regression by AMPK pathway activation. The combination of metformin or other AMPK activators and sorafenib could be tested in prospective clinical trials. PMID:25080865

  20. A structural pathway for activation of the kinesin motor ATPase

    PubMed Central

    Yun, Mikyung; Zhang, Xiaohua; Park, Cheon-Gil; Park, Hee-Won; Endow, Sharyn A.

    2001-01-01

    Molecular motors move along actin or microtubules by rapidly hydrolyzing ATP and undergoing changes in filament-binding affinity with steps of the nucleotide hydrolysis cycle. It is generally accepted that motor binding to its filament greatly increases the rate of ATP hydrolysis, but the structural changes in the motor associated with ATPase activation are not known. To identify the conformational changes underlying motor movement on its filament, we solved the crystal structures of three kinesin mutants that decouple nucleotide and microtubule binding by the motor, and block microtubule-activated, but not basal, ATPase activity. Conformational changes in the structures include a disordered loop and helices in the switch I region and a visible switch II loop, which is disordered in wild-type structures. Switch I moved closer to the bound nucleotide in two mutant structures, perturbing water-mediated interactions with the Mg2+. This could weaken Mg2+ binding and accelerate ADP release to activate the motor ATPase. The structural changes we observe define a signaling pathway within the motor for ATPase activation that is likely to be essential for motor movement on microtubules. PMID:11387196

  1. Wnt Signaling Inhibits Osteoclast Differentiation by Activating Canonical and Noncanonical cAMP/PKA Pathways

    PubMed Central

    Weivoda, Megan M; Ruan, Ming; Hachfeld, Christine M; Pederson, Larry; Howe, Alan; Davey, Rachel A; Zajac, Jeffrey D; Kobayashi, Yasuhiro; Williams, Bart O; Westendorf, Jennifer J; Khosla, Sundeep; Oursler, Merry Jo

    2016-01-01

    Although there has been extensive characterization of the Wnt signaling pathway in the osteoblast lineage, the effects of Wnt proteins on the osteoclast lineage are less well studied. We found that osteoclast lineage cells express canonical Wnt receptors. Wnt3a reduced osteoclast formation when applied to early bone-marrow macrophage (BMM) osteoclast differentiation cultures, whereas late addition did not suppress osteoclast formation. Early Wnt3a treatment inactivated the crucial transcription factor NFATc1 in osteoclast progenitors. Wnt3a led to the accumulation of nuclear β-catenin, confirming activation of canonical Wnt signaling. Reducing low-density lipoprotein receptor-related proteins (Lrp) 5 and Lrp6 protein expression prevented Wnt3a-induced inactivation of NFATc1; however, deletion of β-catenin did not block Wnt3a inactivation of NFATc1, suggesting that this effect was mediated by a noncanonical pathway. Wnt3a rapidly activated the cyclic adenosine monophosphate (cAMP)/protein kinase A (PKA) pathway and pharmacological stimulation of cAMP/PKA signaling suppressed osteoclast differentiation; Wnt3a-induced NFATc1 phosphorylation was blocked by inhibiting interactions between PKA and A-kinase anchoring proteins (AKAPs). These data indicate that Wnt3a directly suppresses osteoclast differentiation through both canonical (β-catenin) and noncanonical (cAMP/PKA) pathways in osteoclast precursors. In vivo reduction of Lrp5 and Lrp6 expressions in the early osteoclast lineage via Rank promoter Cre recombination reduced trabecular bone mass, whereas disruption of Lrp5/6 expression in late osteoclast precursors via cathepsin K (Ctsk) promoter Cre recombination did not alter the skeletal phenotype. Surprisingly, reduction of Lrp5/6 in the early osteoclast lineage decreased osteoclast numbers, as well as osteoblast numbers. Published studies have previously noted that β-catenin signaling is required for osteoclast progenitor proliferation. Our in vivo data

  2. Radiation exposure induces inflammasome pathway activation in immune cells.

    PubMed

    Stoecklein, Veit M; Osuka, Akinori; Ishikawa, Shizu; Lederer, Madeline R; Wanke-Jellinek, Lorenz; Lederer, James A

    2015-02-01

    Radiation exposure induces cell and tissue damage, causing local and systemic inflammatory responses. Because the inflammasome pathway is triggered by cell death and danger-associated molecular patterns, we hypothesized that the inflammasome may signal acute and chronic immune responses to radiation. Using a mouse radiation model, we show that radiation induces a dose-dependent increase in inflammasome activation in macrophages, dendritic cells, NK cells, T cells, and B cells as judged by cleaved caspase-1 detection in cells. Time course analysis showed the appearance of cleaved caspase-1 in cells by day 1 and sustained expression until day 7 after radiation. Also, cells showing inflammasome activation coexpressed the cell surface apoptosis marker annexin V. The role of caspase-1 as a trigger for hematopoietic cell losses after radiation was studied in caspase-1(-/-) mice. We found less radiation-induced cell apoptosis and immune cell loss in caspase-1(-/-) mice than in control mice. Next, we tested whether uric acid might mediate inflammasome activation in cells by treating mice with allopurinol and discovered that allopurinol treatment completely blocked caspase-1 activation in cells. Finally, we demonstrate that radiation-induced caspase-1 activation occurs by a Nod-like receptor family protein 3-independent mechanism because radiation-exposed Nlrp3(-/-) mice showed caspase-1 activation profiles that were indistinguishable from those of wild-type mice. In summary, our data demonstrate that inflammasome activation occurs in many immune cell types following radiation exposure and that allopurinol prevented radiation-induced inflammasome activation. These results suggest that targeting the inflammasome may help control radiation-induced inflammation. PMID:25539818

  3. Early Adolescence: Active Science for Middle Schoolers.

    ERIC Educational Resources Information Center

    Padilla, Michael; Griffin, Nancy

    1980-01-01

    Describes activities appropriate for involving middle school students as active participants in the learning process. Topics discussed include archaeology, bulletin boards, dramatizations, physics experiments using the human body, oceanography, and ecology. (CS)

  4. Conservation Seeds Activities Book. An Early Childhood Conservation Education Program.

    ERIC Educational Resources Information Center

    Griffin, Sherri

    This activities book is used with an early childhood conservation education program. The activities are presented in four color-coded sections, each section representing one of the four seasons. Each activity includes a statement of purpose, list of materials needed, instructional strategies, and a list of supplementary activities. In addition to…

  5. Phospholipid Ozonation Products Activate the 5-Lipoxygenase Pathway in Macrophages.

    PubMed

    Zemski Berry, Karin A; Murphy, Robert C

    2016-08-15

    Ozone is a highly reactive environmental toxicant that can react with the double bonds of lipids in pulmonary surfactant. This study was undertaken to investigate the proinflammatory properties of the major lipid-ozone product in pulmonary surfactant, 1-palmitoyl-2-(9'-oxo-nonanoyl)-glycerophosphocholine (16:0/9al-PC), with respect to eicosanoid production. A dose-dependent increase in the formation of 5-lipoxygenase (5-LO) products was observed in murine resident peritoneal macrophages (RPM) and alveolar macrophages (AM) upon treatment with 16:0/9al-PC. In contrast, the production of cyclooxygenase (COX) derived eicosanoids did not change from basal levels in the presence of 16:0/9al-PC. When 16:0/9al-PC and the TLR2 ligand, zymosan, were added to RPM or AM, an enhancement of 5-LO product formation along with a concomitant decrease in COX product formation was observed. Neither intracellular calcium levels nor arachidonic acid release was influenced by the addition of 16:0/9al-PC to RPM. Results from mitogen-activated protein kinase (MAPK) inhibitor studies and direct measurement of phosphorylation of MAPKs revealed that 16:0/9al-PC activates the p38 MAPK pathway in RPM, which results in the activation of 5-LO. Our results indicate that 16:0/9al-PC has a profound effect on the eicosanoid pathway, which may have implications in inflammatory pulmonary disease states where eicosanoids have been shown to play a role. PMID:27448436

  6. Role of IGF-1 pathway in lung fibroblast activation

    PubMed Central

    2013-01-01

    Background IGF-1 is elevated in pulmonary fibrosis and acute lung injury, where fibroblast activation is a prominent feature. We previously demonstrated that blockade of IGF pathway in murine model of lung fibrosis improved outcome and decreased fibrosis. We now expand that study to examine effects of IGF pathway on lung fibroblast behaviors that could contribute to fibrosis. Methods We first examined mice that express αSMA promoter upstream of GFP reporter treated with A12, a blocking antibody to IGF-1 receptor, after bleomycin induced lung injury. We then examined the effect of IGF-1 alone, or in combination with the pro-fibrotic cytokine TGFβ on expression of markers of myofibroblast activation in vitro, including αSMA, collagen α1, type 1, collagen α1, type III, and TGFβ expression. Results After bleomycin injury, we found decreased number of αSMA-GFP + cells in A12 treated mice, validated by αSMA immunofluorescent staining. We found that IGF-1, alone or in combination with TGF-β, did not affect αSMA RNA expression, promoter activity, or protein levels when fibroblasts were cultured on stiff substrate. IGF-1 stimulated Col1a1 and Col3a1 expression on stiff substrate. In contrast, IGF-1 treatment on soft substrate resulted in upregulation of αSMA gene and protein expression, as well as Col1a1 and Col3a1 transcripts. In conclusion, IGF-1 stimulates differentiation of fibroblasts into a myofibroblast phenotype in a soft matrix environment and has a modest effect on αSMA stress fiber organization in mouse lung fibroblasts. PMID:24103846

  7. Distinct molecular pathways mediate glial activation and engulfment of axonal debris after axotomy

    PubMed Central

    Ziegenfuss, Jennifer S.; Doherty, Johnna; Freeman, Marc R.

    2016-01-01

    Glial cells efficiently recognize and clear cellular debris after nervous system injury to maintain brain homeostasis, but pathways governing glial responses to neural injury remain poorly defined. We identify the Drosophila guanine-nucleotide exchange factor (GEF) complex Crk/Mbc/dCed-12, and the small GTPase Rac1 as novel modulators of glial clearance of axonal debris. We show Crk/Mbc/dCed-12 and Rac1 function in a non-redundant fashion with the Draper pathway—loss of either pathway fully suppresses clearance of axonal debris. Draper signaling is required early during glial responses, promoting glial activation, which includes increased Draper and dCed-6 expression and extension of glial membranes to degenerating axons. In contrast, the Crk/Mbc/dCed-12 complex functions at later phases promoting glial phagocytosis of axonal debris. Our work identifies new components of the glial engulfment machinery and shows that glial activation, phagocytosis of axonal debris, and termination of responses to injury are genetically separable events mediated by distinct signaling pathways. PMID:22706267

  8. The F-box-containing protein UFO and AGAMOUS participate in antagonistic pathways governing early petal development in Arabidopsis

    PubMed Central

    Durfee, Tim; Roe, Judith L.; Sessions, R. Allen; Inouye, Carla; Serikawa, Kyle; Feldmann, Kenneth A.; Weigel, Detlef; Zambryski, Patricia C.

    2003-01-01

    The UNUSUAL FLORAL ORGANS (UFO) gene is required for multiple processes in the developing Arabidopsis flower, including the proper patterning and identity of both petals and stamens. The gene encodes an F-box-containing protein, UFO, which interacts physically and genetically with the Skp1 homolog, ASK1. In this report, we describe four ufo alleles characterized by the absence of petals, which uncover another role for UFO in promoting second whorl development. This UFO-dependent pathway is required regardless of the second whorl organ to be formed, arguing that it affects a basic process acting in parallel with those establishing organ identity. However, the pathway is dispensable in the absence of AGAMOUS (AG), a known inhibitor of petal development. In situ hybridization results argue that AG is not transcribed in the petal region, suggesting that it acts non-cell-autonomously to inhibit second whorl development in ufo mutants. These results are combined into a genetic model explaining early second whorl initiation/proliferation, in which UFO functions to inhibit an AG-dependent activity. PMID:12826617

  9. The F-box-containing protein UFO and AGAMOUS participate in antagonistic pathways governing early petal development in Arabidopsis.

    PubMed

    Durfee, Tim; Roe, Judith L; Sessions, R Allen; Inouye, Carla; Serikawa, Kyle; Feldmann, Kenneth A; Weigel, Detlef; Zambryski, Patricia C

    2003-07-01

    The UNUSUAL FLORAL ORGANS (UFO) gene is required for multiple processes in the developing Arabidopsis flower, including the proper patterning and identity of both petals and stamens. The gene encodes an F-box-containing protein, UFO, which interacts physically and genetically with the Skp1 homolog, ASK1. In this report, we describe four ufo alleles characterized by the absence of petals, which uncover another role for UFO in promoting second whorl development. This UFO-dependent pathway is required regardless of the second whorl organ to be formed, arguing that it affects a basic process acting in parallel with those establishing organ identity. However, the pathway is dispensable in the absence of AGAMOUS (AG), a known inhibitor of petal development. In situ hybridization results argue that AG is not transcribed in the petal region, suggesting that it acts non-cell-autonomously to inhibit second whorl development in ufo mutants. These results are combined into a genetic model explaining early second whorl initiation/proliferation, in which UFO functions to inhibit an AG-dependent activity. PMID:12826617

  10. Molecular Pathways: Anticancer Activity by Inhibition of Nucleocytoplasmic Shuttling.

    PubMed

    Conforti, Fabio; Wang, Yisong; Rodriguez, Jose A; Alberobello, Anna Teresa; Zhang, Yu-Wen; Giaccone, Giuseppe

    2015-10-15

    A dynamic distribution between nucleus and cytoplasm (nucleocytoplasmic shuttling) is one of the control mechanisms adapted by normal cells to regulate the activity of a variety of molecules. Growing evidence suggests that dysregulation of the nucleocytoplasmic shuttling is involved in promoting abnormal cell survival, tumor progression, and drug resistance, and is associated with poor cancer prognosis. Aberrant nucleocytoplasmic shuttling in cancer cells may result from a hyperactive status of diverse signal-transduction pathways, such as the PI3K-AKT and MAPK pathways, or from alterations in the general nuclear import/export machinery. Among the large number of molecules involved in the shuttling process, exportin XPO1, also known as chromosome region maintenance 1, appears to play a particularly prominent role in pathogenesis of both hematological malignancies and solid tumors. Given the importance of nucleocytoplasmic shuttling in cancer pathogenesis and the rapidly expanding knowledge in this field, attempts have been made to develop compounds able to revert the aberrant nucleocytoplasmic shuttling. A promising new drug, KPT-330 (Selinexor), which belongs to the class of XPO1 inhibitors called selective inhibitors of nuclear export, is now being tested in phase I/II clinical trials. PMID:26324742

  11. Protein synthesis inhibitors reveal differential regulation of mitogen-activated protein kinase and stress-activated protein kinase pathways that converge on Elk-1.

    PubMed Central

    Zinck, R; Cahill, M A; Kracht, M; Sachsenmaier, C; Hipskind, R A; Nordheim, A

    1995-01-01

    Inhibitors of protein synthesis, such as anisomycin and cycloheximide, lead to superinduction of immediate-early genes. We demonstrate that these two drugs activate intracellular signaling pathways involving both the mitogen-activated protein kinase (MAPK) and stress-activated protein kinase (SAPK) cascades. The activation of either pathway correlates with phosphorylation of the c-fos regulatory transcription factor Elk-1. In HeLa cells, anisomycin stabilizes c-fos mRNA when protein synthesis is inhibited to only 50%. Under these conditions, anisomycin, in contrast to cycloheximide, rapidly induces kinase activation and efficient Elk-1 phosphorylation. However, full inhibition of translation by either drug leads to prolonged activation of SAPK activity, while MAPK induction is transient. This correlates with prolonged Elk-1 phosphorylation and c-fos transcription. Elk-1 induction and c-fos activation are also observed in KB cells, in which anisomycin strongly induces SAPKs but not MAPKs. Purified p54 SAPK alpha efficiently phosphorylates the Elk-1 C-terminal domain in vitro and comigrates with anisomycin-activated kinases in in-gel kinase assays. Thus, Elk-1 provides a potential convergence point for the MAPK and SAPK signaling pathways. The activation of signal cascades and control of transcription factor function therefore represent prominent processes in immediate-early gene superinduction. PMID:7651411

  12. Phyllosilicate weathering pathways in chlorite-talc bearing soil parent materials, D.R. Congo: early findings.

    NASA Astrophysics Data System (ADS)

    Dumon, Mathijs; Oostermeyer, Fran; Timmermans, Els; De Meulemeester, Aschwin; Mees, Florias; Van Driessche, Isabel; Erens, Hans; Bazirake Mujinya, Basile; Van Ranst, Eric

    2015-04-01

    The study of the formation and transformation of clay minerals is of the upmost importance to understand soil formation and to adjust land-use management to the land surface conditions. These clay minerals determine to a large extent the soil physical and chemical properties. It is commonly observed that over time the mineralogy of any parent material is transformed to a simple assemblage composed mostly of Al and Fe oxides and low-activity clays, e.g. kaolinite. This is especially obvious in the humid tropics, which have been protected from glacial erosion, allowing deep, highly weathered soils to form. Despite the abundant presence of kaolinite in these soils, its formation pathways are still under debate: either neoformation by dissolution-crystallisation reactions or solid-state transformation of 2:1 phyllosilicates. To elucidate this, weathering sequences in a unique 40 m core taken below a termite mound, reaching a talc-chlorite bearing substrate in the Lubumbashi area, Katanga, DR Congo are being investigated in detail using a.o. quantitative X-ray diffraction analysis, chemical characterization, micromorphology and µXRF-scanning with the main objective to improve the understanding of the formation pathways of kaolinite subgroup minerals in humid tropical environments. Based on an initial characterization of the core, two zones of interest were selected for more detailed analysis, for which the early findings will be presented. The first zone extends from ca. 9 m to 11 m below the surface is dominated by kaolinite but shows early traces of primary talc and micas. The second zone extends from 34 to 36 m below the surface and contains large amounts of chlorite, with smaller amounts of talc, micas and kaolinite.

  13. Early LPS-induced ERK activation in retinal pigment epithelium cells is dependent on PIP 2 -PLC.

    PubMed

    Mateos, Melina V; Kamerbeek, Constanza B; Giusto, Norma M; Salvador, Gabriela A

    2016-06-01

    This article presents additional data regarding the study "The phospholipase D pathway mediates the inflammatory response of the retinal pigment epithelium" [1]. The new data presented here show that short exposure of RPE cells to lipopolysaccharide (LPS) induces an early and transient activation of the extracellular signal-regulated kinase (ERK1/2). This early ERK1/2 activation is dependent on phosphatidylinositol bisphosphate-phospholipase C (PIP2-PLC). On the contrary, neither the phospholipase D 1 (PLD1) nor the PLD2 inhibition is able to modulate the early ERK1/2 activation induced by LPS in RPE cells. PMID:27006973

  14. Predicting Early Sexual Activity with Behavior Problems Exhibited at School Entry and in Early Adolescence

    ERIC Educational Resources Information Center

    Schofield, Hannah-Lise T.; Bierman, Karen L.; Heinrichs, Brenda; Nix, Robert L.

    2008-01-01

    Youth who initiate sexual intercourse in early adolescence (age 11-14) experience multiple risks, including concurrent adjustment problems and unsafe sexual practices. The current study tested two models describing the links between childhood precursors, early adolescent risk factors, and adolescent sexual activity: a cumulative model and a…

  15. Purmorphamine induces osteogenesis by activation of the hedgehog signaling pathway.

    PubMed

    Wu, Xu; Walker, John; Zhang, Jie; Ding, Sheng; Schultz, Peter G

    2004-09-01

    Previously, a small molecule, purmorphamine, was identified that selectively induces osteogenesis in multipotent mesenchymal progenitor cells. In order to gain insights into the mechanism of action of purmorphamine, high-density oligonucleotide microarrays were used to profile gene expression in multipotent mesenchymal progenitor cells treated with either purmorphamine or bone morphogenetic protein-4 (BMP-4). In contrast to BMP-4 treatment, purmorphamine activates the Hedgehog (Hh) signaling pathway, resulting in the up- and downregulation of its downstream target genes, including Gli1 and Patched. Moreover, the known Hh signaling antagonists, cyclopamine and forskolin, completely block the osteogenesis and Glimediated transcription induced by purmorphamine. These results demonstrate that purmorphamine is a small molecule agonist of Hedgehog signaling, and it may ultimately be useful in the treatment of bone-related disease and neurodegenerative disease. PMID:15380183

  16. Bisphenol A exposure pathways in early childhood: Reviewing the need for improved risk assessment models.

    PubMed

    Healy, Bridget F; English, Karin R; Jagals, Paul; Sly, Peter D

    2015-01-01

    Bisphenol A (BPA) is a plasticiser found in a number of household plastics, electronics, and food-packaging materials. Over the past 5 years, several human epidemiological studies have reported a positive association between BPA exposure and adverse health outcomes in children, including obesity, asthma, preterm birth, and neuro-behavioural disturbances. These findings are in conflict with international environmental risk assessment models, which predict daily exposure levels to BPA should not pose a risk to child health. The aim of this review is to provide an overview of the evidence for different exposure sources and potential exposure pathways of BPA in early childhood. By collating the findings from experimental models and exposure associations observed in human bio-monitoring studies, we affirm the potential for non-dietary sources to make a substantial contribution to total daily exposure in young children. Infants and toddlers have distinctive exposure sources, physiology, and metabolism of endocrine-disrupting chemicals. We recommend risk-assessment models implement new frameworks, which specifically address exposure and hazard in early childhood. This is particularly important for BPA, which is present in numerous products in the home and day-care environments, and for which animal studies report contradictory findings on its safety at environmentally relevant levels of exposure. PMID:26350983

  17. Does the ADMA/DDAH/NO pathway modulate early regression of left ventricular hypertrophy with esmolol?

    PubMed

    Quintana-Villamandos, Begoña; Delgado-Baeza, Emilio

    2016-02-01

    Hypertensive left ventricular hypertrophy (LVH) is a maladaptive response to chronic pressure overload and a strong independent risk factor for cardiovascular disease. Regression of LVH is associated with improved prognosis. Regression of LVH with antihypertensive therapy (angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, beta-blockers, calcium channel blockers, and diuretics) has been reported, although only after long-term treatment. Asymmetrical dimethylarginine (ADMA), the most potent endogenous NO synthase inhibitor, is emerging as an important cardiovascular risk factor in patients with arterial hypertension and LVH, and dimethylarginine dimethylaminohydrolase (DDAH) is the mechanism that most frequently leads to accumulation of ADMA (plasma ADMA is cleared in small part by renal excretion, although the bulk of ADMA is degraded by DDAH). Left ventricular mass is strongly modulated by the NO system. As an important inhibitor of the bioavailability of NO, ADMA is an underlying mechanism of LVH. Beta-blockers can induce regression of LVH and reduced plasma ADMA levels. Oxidative stress is increased in patients with LVH, and this in turn increases generation of ADMA. In a previous preclinical study of spontaneously hypertensive rats, we found that short-term treatment (48 h) with esmolol reverses early LVH, increases the bioavailability of NO, and improves antioxidant status in plasma. Therefore, we propose that the ADMA/DDAH/NO pathway could modulate early regression of LVH with esmolol. PMID:26826640

  18. Lhx9 gene expression during early limb development in mice requires the FGF signalling pathway.

    PubMed

    Yang, Yisheng; Wilson, Megan J

    2015-01-01

    Lhx9 is a member of the LIM-homeodomain gene family necessary for the correct development of many organs including gonads, limbs, heart and the nervous system. In the context of limb development, Lhx9 has been implicated as an integrator for Fibroblast growth factor (FGF) and Sonic hedgehog (Shh) signalling required for proximal-distal (PD) and anterior-posterior (AP) development of the limb. Three splice variants of the Lhx9 transcript are expressed during development, two of which are predicted to act in a dominant negative fashion, competing with the DNA binding version of Lhx9 for binding to cofactors via the LIM-domain. We examined the expression pattern for the three alternative splice forms of Lhx9; Lhx9α, Lhx9β and Lhx9c during early limb development. We have found that of the three Lhx9 isoforms, only Lhx9α and Lhx9c (intact homeodomain) are expressed during early limb development, each with their own distinct expression pattern. Additionally we determined that Lhx9 expression overlaps with FGF10 expression in the developing limb bud mesenchyme. Limb bud explant cultures, in the presence of signalling pathway inhibitors, also indicated that Lhx9 mRNA expression in the limb bud was dependent on FGF signalling. PMID:26220830

  19. Hedgehog-Gli pathway activation during kidney fibrosis.

    PubMed

    Fabian, Steven L; Penchev, Radostin R; St-Jacques, Benoit; Rao, Anjali N; Sipilä, Petra; West, Kip A; McMahon, Andrew P; Humphreys, Benjamin D

    2012-04-01

    The Hedgehog (Hh) signaling pathway regulates tissue patterning during development, including patterning and growth of limbs and face, but whether Hh signaling plays a role in adult kidney remains undefined. In this study, using a panel of hedgehog-reporter mice, we show that the two Hh ligands (Indian hedgehog and sonic hedgehog ligands) are expressed in tubular epithelial cells. We report that the Hh effectors (Gli1 and Gli2) are expressed exclusively in adjacent platelet-derived growth factor receptor-β-positive interstitial pericytes and perivascular fibroblasts, suggesting a paracrine signaling loop. In two models of renal fibrosis, Indian Hh ligand was upregulated with a dramatic activation of downstream Gli effector expression. Hh-responsive Gli1-positive interstitial cells underwent 11-fold proliferative expansion during fibrosis, and both Gli1- and Gli2-positive cells differentiated into α-smooth muscle actin-positive myofibroblasts. In the pericyte-like cell line 10T1/2, hedgehog ligand triggered cell proliferation, suggesting a possible role for this pathway in the regulation of cell cycle progression of myofibroblast progenitors during the development of renal fibrosis. The hedgehog antagonist IPI-926 abolished Gli1 induction in vivo but did not decrease kidney fibrosis. However, the transcriptional induction of Gli2 was unaffected by IPI-926, suggesting the existence of smoothened-independent Gli activation in this model. This study is the first detailed description of paracrine hedgehog signaling in adult kidney, which indicates a possible role for hedgehog-Gli signaling in fibrotic chronic kidney disease. PMID:22342522

  20. Hedgehog-Gli Pathway Activation during Kidney Fibrosis

    PubMed Central

    Fabian, Steven L.; Penchev, Radostin R.; St-Jacques, Benoit; Rao, Anjali N.; Sipilä, Petra; West, Kip A.; McMahon, Andrew P.; Humphreys, Benjamin D.

    2012-01-01

    The Hedgehog (Hh) signaling pathway regulates tissue patterning during development, including patterning and growth of limbs and face, but whether Hh signaling plays a role in adult kidney remains undefined. In this study, using a panel of hedgehog-reporter mice, we show that the two Hh ligands (Indian hedgehog and sonic hedgehog ligands) are expressed in tubular epithelial cells. We report that the Hh effectors (Gli1 and Gli2) are expressed exclusively in adjacent platelet-derived growth factor receptor-β-positive interstitial pericytes and perivascular fibroblasts, suggesting a paracrine signaling loop. In two models of renal fibrosis, Indian Hh ligand was upregulated with a dramatic activation of downstream Gli effector expression. Hh-responsive Gli1-positive interstitial cells underwent 11-fold proliferative expansion during fibrosis, and both Gli1- and Gli2-positive cells differentiated into α-smooth muscle actin-positive myofibroblasts. In the pericyte-like cell line 10T1/2, hedgehog ligand triggered cell proliferation, suggesting a possible role for this pathway in the regulation of cell cycle progression of myofibroblast progenitors during the development of renal fibrosis. The hedgehog antagonist IPI-926 abolished Gli1 induction in vivo but did not decrease kidney fibrosis. However, the transcriptional induction of Gli2 was unaffected by IPI-926, suggesting the existence of smoothened-independent Gli activation in this model. This study is the first detailed description of paracrine hedgehog signaling in adult kidney, which indicates a possible role for hedgehog-Gli signaling in fibrotic chronic kidney disease. PMID:22342522

  1. Promoting Physical Activity during Early Childhood

    ERIC Educational Resources Information Center

    Vidoni, Carla; Ignico, Arlene

    2011-01-01

    The prevalence of obesity in children and adolescents from low-income families in the USA has become a significant concern over the last 20 years. One of the major contributors to this problem is the lack of physical activity. The purpose of this paper is to describe initiatives designed to: (1) engage young children in physical activity during…

  2. Early Childhood: Developing Sense-activities.

    ERIC Educational Resources Information Center

    Shirah, Sue; Dorman, Mildred M.

    1989-01-01

    Described are science activities in which students concentrate on their senses and make discoveries with their eyes, ears, noses, mouths, and hands. Suggested experiments include activities involving cooking, tasting, observing, floating and sinking objects, making rain, and stringed musical instruments. (RT)

  3. Increased alveolar plasminogen activator in early asbestosis

    SciTech Connect

    Cantin, A.; Allard, C.; Begin, R.

    1989-03-01

    Alveolar macrophage-derived plasminogen activator (PA) activity is decreased in some chronic interstitial lung diseases such as idiopathic pulmonary fibrosis and sarcoidosis but increased in experimental models of acute alveolitis. Although asbestos fibers can stimulate alveolar macrophages (AM) to release PA in vitro, the effect of chronic asbestos exposure of the lower respiratory tract on lung PA activity remains unknown. The present study was designed to evaluate PA activity of alveolar macrophages and bronchoalveolar lavage (BAL) fluid in asbestos-exposed sheep and asbestos workers. Forty-three sheep were exposed to either 100 mg UICC chrysotile B asbestos in 100 ml phosphate-buffered saline (PBS) or to 100 ml PBS by tracheal infusion every 2 wk for 18 months. At Month 18, chest roentgenograms were analyzed and alveolar macrophage and extracellular fluid PA activity were measured in samples obtained by BAL. Alveolar macrophage PA activity was increased in the asbestos-exposed sheep compared to control sheep (87.2 +/- 17.3 versus 41.1 +/- 7.2 U/10(5) AM-24 h, p less than 0.05) as was the BAL fluid PA activity (674.9 +/- 168.4 versus 81.3 +/- 19.7 U/mg alb-24 h, p less than 0.01). Among the asbestos-exposed sheep, 10 had normal chest roentgenograms (Group SA) and 15 had irregular interstitial opacities (Group SB). Strikingly, whereas Group SA did not differ from the control group in BAL cellularity or PA activity, Group SB had marked increases in alveolar macrophages (p less than 0.005), AM PA activity (p less than 0.02), and BAL PA activity (p less than 0.001) compared to the control group.

  4. The phosphoinositide 3-kinase signaling pathway in normal and malignant B cells: activation mechanisms, regulation and impact on cellular functions.

    PubMed

    Pauls, Samantha D; Lafarge, Sandrine T; Landego, Ivan; Zhang, Tingting; Marshall, Aaron J

    2012-01-01

    The phosphoinositide 3-kinase (PI3K) pathway is a central signal transduction axis controlling normal B cell homeostasis and activation in humoral immunity. The p110δ PI3K catalytic subunit has emerged as a critical mediator of multiple B cell functions. The activity of this pathway is regulated at multiple levels, with inositol phosphatases PTEN and SHIP both playing critical roles. When deregulated, the PI3K pathway can contribute to B cell malignancies and autoantibody production. This review summarizes current knowledge on key mechanisms that activate and regulate the PI3K pathway and influence normal B cell functional responses including the development of B cell subsets, antigen presentation, immunoglobulin isotype switch, germinal center responses, and maintenance of B cell anergy. We also discuss PI3K pathway alterations reported in select B cell malignancies and highlight studies indicating the functional significance of this pathway in malignant B cell survival and growth within tissue microenvironments. Finally, we comment on early clinical trial results, which support PI3K inhibition as a promising treatment of chronic lymphocytic leukemia. PMID:22908014

  5. The phosphoinositide 3-kinase signaling pathway in normal and malignant B cells: activation mechanisms, regulation and impact on cellular functions

    PubMed Central

    Pauls, Samantha D.; Lafarge, Sandrine T.; Landego, Ivan; Zhang, Tingting; Marshall, Aaron J.

    2012-01-01

    The phosphoinositide 3-kinase (PI3K) pathway is a central signal transduction axis controlling normal B cell homeostasis and activation in humoral immunity. The p110δ PI3K catalytic subunit has emerged as a critical mediator of multiple B cell functions. The activity of this pathway is regulated at multiple levels, with inositol phosphatases PTEN and SHIP both playing critical roles. When deregulated, the PI3K pathway can contribute to B cell malignancies and autoantibody production. This review summarizes current knowledge on key mechanisms that activate and regulate the PI3K pathway and influence normal B cell functional responses including the development of B cell subsets, antigen presentation, immunoglobulin isotype switch, germinal center responses, and maintenance of B cell anergy. We also discuss PI3K pathway alterations reported in select B cell malignancies and highlight studies indicating the functional significance of this pathway in malignant B cell survival and growth within tissue microenvironments. Finally, we comment on early clinical trial results, which support PI3K inhibition as a promising treatment of chronic lymphocytic leukemia. PMID:22908014

  6. Activation of Shikimate, Phenylpropanoid, Oxylipins, and Auxin Pathways in Pectobacterium carotovorum Elicitors-Treated Moss.

    PubMed

    Alvarez, Alfonso; Montesano, Marcos; Schmelz, Eric; Ponce de León, Inés

    2016-01-01

    Plants have developed complex defense mechanisms to cope with microbial pathogens. Pathogen-associated molecular patterns (PAMPs) and damage-associated molecular patterns (DAMPs) are perceived by pattern recognition receptors (PRRs), leading to the activation of defense. While substantial progress has been made in understanding the activation of plant defense by PAMPs and DAMPs recognition in tracheophytes, far less information exists on related processes in early divergent plants like mosses. The aim of this study was to identify genes that were induced in P. patens in response to elicitors of Pectobacterium carotovorum subsp. carotovorum, using a cDNA suppression subtractive hybridization (SSH) method. A total of 239 unigenes were identified, including genes involved in defense responses related to the shikimate, phenylpropanoid, and oxylipin pathways. The expression levels of selected genes related to these pathways were analyzed using quantitative RT-PCR, confirming their rapid induction by P.c. carotovorum derived elicitors. In addition, P. patens induced cell wall reinforcement after elicitor treatment by incorporation of phenolic compounds, callose deposition, and elevated expression of Dirigent-like encoding genes. Small molecule defense markers and phytohormones such as cinnamic acid, 12-oxo-phytodienoic acid, and auxin levels all increased in elicitor-treated moss tissues. In contrast, salicylic acid levels decreased while abscisic acid levels remained unchanged. P. patens reporter lines harboring an auxin-inducible promoter fused to β-glucuronidase revealed GUS activity in protonemal and gametophores tissues treated with elicitors of P.c. carotovorum, consistent with a localized activation of auxin signaling. These results indicate that P. patens activates the shikimate, phenylpropanoid, oxylipins, and auxin pathways upon treatment with P.c. carotovorum derived elicitors. PMID:27047509

  7. Activation of Shikimate, Phenylpropanoid, Oxylipins, and Auxin Pathways in Pectobacterium carotovorum Elicitors-Treated Moss

    PubMed Central

    Alvarez, Alfonso; Montesano, Marcos; Schmelz, Eric; Ponce de León, Inés

    2016-01-01

    Plants have developed complex defense mechanisms to cope with microbial pathogens. Pathogen-associated molecular patterns (PAMPs) and damage-associated molecular patterns (DAMPs) are perceived by pattern recognition receptors (PRRs), leading to the activation of defense. While substantial progress has been made in understanding the activation of plant defense by PAMPs and DAMPs recognition in tracheophytes, far less information exists on related processes in early divergent plants like mosses. The aim of this study was to identify genes that were induced in P. patens in response to elicitors of Pectobacterium carotovorum subsp. carotovorum, using a cDNA suppression subtractive hybridization (SSH) method. A total of 239 unigenes were identified, including genes involved in defense responses related to the shikimate, phenylpropanoid, and oxylipin pathways. The expression levels of selected genes related to these pathways were analyzed using quantitative RT-PCR, confirming their rapid induction by P.c. carotovorum derived elicitors. In addition, P. patens induced cell wall reinforcement after elicitor treatment by incorporation of phenolic compounds, callose deposition, and elevated expression of Dirigent-like encoding genes. Small molecule defense markers and phytohormones such as cinnamic acid, 12-oxo-phytodienoic acid, and auxin levels all increased in elicitor-treated moss tissues. In contrast, salicylic acid levels decreased while abscisic acid levels remained unchanged. P. patens reporter lines harboring an auxin-inducible promoter fused to β-glucuronidase revealed GUS activity in protonemal and gametophores tissues treated with elicitors of P.c. carotovorum, consistent with a localized activation of auxin signaling. These results indicate that P. patens activates the shikimate, phenylpropanoid, oxylipins, and auxin pathways upon treatment with P.c. carotovorum derived elicitors. PMID:27047509

  8. Structural activation pathways from dynamic olfactory receptor-odorant interactions.

    PubMed

    Lai, Peter C; Singer, Michael S; Crasto, Chiquito J

    2005-11-01

    We have simulated an odor ligand's dynamic behavior in the binding region of an olfactory receptor (OR). Our short timescale computational studies (up to 200 ps) have helped identify unprecedented postdocking ligand behavior of ligands. From in vacuo molecular dynamics simulations of interactions between models of rat OR I7 and 10 aldehyde ligands, we have identified a dissociative pathway along which the ligand exits and enters the OR-binding pocket--a transit event. The ligand's transit through the receptor's binding region may mark the beginning of a signal transduction cascade leading to odor recognition. We have graphically traced the rotameric changes in key OR amino acid side chains during the transit. Our results have helped substantiate or refute previously held notions of amino acid contribution to ligand stability in the binding pocket. Our observations of ligand activity when compared to those of experimental (electroolfactogram response) OR-activation studies provide a view to predicting the stability of ligands in the binding pocket as a precursor to OR activation by the ligand. PMID:16243965

  9. Alterations in leukocyte transcriptional control pathway activity associated with major depressive disorder and antidepressant treatment.

    PubMed

    Mellon, S H; Wolkowitz, O M; Schonemann, M D; Epel, E S; Rosser, R; Burke, H B; Mahan, L; Reus, V I; Stamatiou, D; Liew, C-C; Cole, S W

    2016-01-01

    Major depressive disorder (MDD) is associated with a significantly elevated risk of developing serious medical illnesses such as cardiovascular disease, immune impairments, infection, dementia and premature death. Previous work has demonstrated immune dysregulation in subjects with MDD. Using genome-wide transcriptional profiling and promoter-based bioinformatic strategies, we assessed leukocyte transcription factor (TF) activity in leukocytes from 20 unmedicated MDD subjects versus 20 age-, sex- and ethnicity-matched healthy controls, before initiation of antidepressant therapy, and in 17 of the MDD subjects after 8 weeks of sertraline treatment. In leukocytes from unmedicated MDD subjects, bioinformatic analysis of transcription control pathway activity indicated an increased transcriptional activity of cAMP response element-binding/activating TF (CREB/ATF) and increased activity of TFs associated with cellular responses to oxidative stress (nuclear factor erythroid-derived 2-like 2, NFE2l2 or NRF2). Eight weeks of antidepressant therapy was associated with significant reductions in Hamilton Depression Rating Scale scores and reduced activity of NRF2, but not in CREB/ATF activity. Several other transcriptional regulation pathways, including the glucocorticoid receptor (GR), nuclear factor kappa-B cells (NF-κB), early growth response proteins 1-4 (EGR1-4) and interferon-responsive TFs, showed either no significant differences as a function of disease or treatment, or activities that were opposite to those previously hypothesized to be involved in the etiology of MDD or effective treatment. Our results suggest that CREB/ATF and NRF2 signaling may contribute to MDD by activating immune cell transcriptome dynamics that ultimately influence central nervous system (CNS) motivational and affective processes via circulating mediators. PMID:27219347

  10. Early Risk, Attention, and Brain Activation in Adolescents Born Preterm

    ERIC Educational Resources Information Center

    Carmody, Dennis P.; Bendersky, Margaret; Dunn, Stanley M.; DeMarco, J. Kevin; Hegyi, Thomas; Hiatt, Mark; Lewis, Michael

    2006-01-01

    The relations among early cumulative medical risk, cumulative environmental risk, attentional control, and brain activation were assessed in 15-16-year-old adolescents who were born preterm. Functional magnetic resonance imaging found frontal, temporal, and parietal cortex activation during an attention task with greater activation of the left…

  11. The JAK-STAT Pathway Controls Plasmodium vivax Load in Early Stages of Anopheles aquasalis Infection

    PubMed Central

    Bahia, Ana C.; Kubota, Marina S.; Tempone, Antonio J.; Araújo, Helena R. C.; Guedes, Bruno A. M.; Orfanó, Alessandra S.; Tadei, Wanderli P.; Ríos-Velásquez, Claudia M.; Han, Yeon S.; Secundino, Nágila F. C.; Barillas-Mury, Carolina

    2011-01-01

    Malaria affects 300 million people worldwide every year and 450,000 in Brazil. In coastal areas of Brazil, the main malaria vector is Anopheles aquasalis, and Plasmodium vivax is responsible for the majority of malaria cases in the Americas. Insects possess a powerful immune system to combat infections. Three pathways control the insect immune response: Toll, IMD, and JAK-STAT. Here we analyze the immune role of the A. aquasalis JAK-STAT pathway after P. vivax infection. Three genes, the transcription factor Signal Transducers and Activators of Transcription (STAT), the regulatory Protein Inhibitors of Activated STAT (PIAS) and the Nitric Oxide Synthase enzyme (NOS) were characterized. Expression of STAT and PIAS was higher in males than females and in eggs and first instar larvae when compared to larvae and pupae. RNA levels for STAT and PIAS increased 24 and 36 hours (h) after P. vivax challenge. NOS transcription increased 36 h post infection (hpi) while this protein was already detected in some midgut epithelial cells 24 hpi. Imunocytochemistry experiments using specific antibodies showed that in non-infected insects STAT and PIAS were found mostly in the fat body, while in infected mosquitoes the proteins were found in other body tissues. The knockdown of STAT by RNAi increased the number of oocysts in the midgut of A. aquasalis. This is the first clear evidence for the involvement of a specific immune pathway in the interaction of the Brazilian malaria vector A. aquasalis with P. vivax, delineating a potential target for the future development of disease controlling strategies. PMID:22069502

  12. The JAK-STAT pathway controls Plasmodium vivax load in early stages of Anopheles aquasalis infection.

    PubMed

    Bahia, Ana C; Kubota, Marina S; Tempone, Antonio J; Araújo, Helena R C; Guedes, Bruno A M; Orfanó, Alessandra S; Tadei, Wanderli P; Ríos-Velásquez, Claudia M; Han, Yeon S; Secundino, Nágila F C; Barillas-Mury, Carolina; Pimenta, Paulo F P; Traub-Csekö, Yara M

    2011-11-01

    Malaria affects 300 million people worldwide every year and 450,000 in Brazil. In coastal areas of Brazil, the main malaria vector is Anopheles aquasalis, and Plasmodium vivax is responsible for the majority of malaria cases in the Americas. Insects possess a powerful immune system to combat infections. Three pathways control the insect immune response: Toll, IMD, and JAK-STAT. Here we analyze the immune role of the A. aquasalis JAK-STAT pathway after P. vivax infection. Three genes, the transcription factor Signal Transducers and Activators of Transcription (STAT), the regulatory Protein Inhibitors of Activated STAT (PIAS) and the Nitric Oxide Synthase enzyme (NOS) were characterized. Expression of STAT and PIAS was higher in males than females and in eggs and first instar larvae when compared to larvae and pupae. RNA levels for STAT and PIAS increased 24 and 36 hours (h) after P. vivax challenge. NOS transcription increased 36 h post infection (hpi) while this protein was already detected in some midgut epithelial cells 24 hpi. Imunocytochemistry experiments using specific antibodies showed that in non-infected insects STAT and PIAS were found mostly in the fat body, while in infected mosquitoes the proteins were found in other body tissues. The knockdown of STAT by RNAi increased the number of oocysts in the midgut of A. aquasalis. This is the first clear evidence for the involvement of a specific immune pathway in the interaction of the Brazilian malaria vector A. aquasalis with P. vivax, delineating a potential target for the future development of disease controlling strategies. PMID:22069502

  13. Efficacy of JAK/STAT pathway inhibition in murine xenograft models of early T-cell precursor (ETP) acute lymphoblastic leukemia

    PubMed Central

    Maude, Shannon L.; Dolai, Sibasish; Delgado-Martin, Cristina; Vincent, Tiffaney; Robbins, Alissa; Selvanathan, Arthavan; Ryan, Theresa; Hall, Junior; Wood, Andrew C.; Tasian, Sarah K.; Hunger, Stephen P.; Loh, Mignon L.; Mullighan, Charles G.; Wood, Brent L.; Hermiston, Michelle L.; Grupp, Stephan A.; Lock, Richard B.

    2015-01-01

    Early T-cell precursor (ETP) acute lymphoblastic leukemia (ALL) is a recently described subtype of T-ALL characterized by a unique immunophenotype and genomic profile, as well as a high rate of induction failure. Frequent mutations in cytokine receptor and Janus kinase (JAK)/signal transducer and activator of transcription (STAT) signaling pathways led us to hypothesize that ETP-ALL is dependent on JAK/STAT signaling. Here we demonstrate aberrant activation of the JAK/STAT pathway in ETP-ALL blasts relative to non-ETP T-ALL. Moreover, ETP-ALL showed hyperactivation of STAT5 in response to interleukin-7, an effect that was abrogated by the JAK1/2 inhibitor ruxolitinib. In vivo, ruxolitinib displayed activity in 6 of 6 patient-derived murine xenograft models of ETP-ALL, with profound single-agent efficacy in 5 models. Ruxolitinib treatment decreased peripheral blast counts relative to pretreatment levels and compared with control (P < .01) in 5 of 6 ETP-ALL xenografts, with marked reduction in mean splenic blast counts (P < .01) in 6 of 6 samples. Surprisingly, both JAK/STAT pathway activation and ruxolitinib efficacy were independent of the presence of JAK/STAT pathway mutations, raising the possibility that the therapeutic potential of ruxolitinib in ETP-ALL extends beyond those cases with JAK mutations. These findings establish the preclinical in vivo efficacy of ruxolitinib in ETP-ALL, a biologically distinct subtype for which novel therapies are needed. PMID:25645356

  14. Activation of the Canonical Bone Morphogenetic Protein (BMP) Pathway during Lung Morphogenesis and Adult Lung Tissue Repair

    PubMed Central

    Sountoulidis, Alexandros; Stavropoulos, Athanasios; Giaglis, Stavros; Apostolou, Eirini; Monteiro, Rui; Chuva de Sousa Lopes, Susana M.; Chen, Huaiyong; Stripp, Barry R.; Mummery, Christine; Andreakos, Evangelos; Sideras, Paschalis

    2012-01-01

    Signaling by Bone Morphogenetic Proteins (BMP) has been implicated in early lung development, adult lung homeostasis and tissue-injury repair. However, the precise mechanism of action and the spatio-temporal pattern of BMP-signaling during these processes remains inadequately described. To address this, we have utilized a transgenic line harboring a BMP-responsive eGFP-reporter allele (BRE-eGFP) to construct the first detailed spatiotemporal map of canonical BMP-pathway activation during lung development, homeostasis and adult-lung injury repair. We demonstrate that during the pseudoglandular stage, when branching morphogenesis progresses in the developing lung, canonical BMP-pathway is active mainly in the vascular network and the sub-epithelial smooth muscle layer of the proximal airways. Activation of the BMP-pathway becomes evident in epithelial compartments only after embryonic day (E) 14.5 primarily in cells negative for epithelial-lineage markers, located in the proximal portion of the airway-tree, clusters adjacent to neuro-epithelial-bodies (NEBs) and in a substantial portion of alveolar epithelial cells. The pathway becomes activated in isolated E12.5 mesenchyme-free distal epithelial buds cultured in Matrigel suggesting that absence of reporter activity in these regions stems from a dynamic cross-talk between endoderm and mesenchyme. Epithelial cells with activated BMP-pathway are enriched in progenitors capable of forming colonies in three-dimensional Matrigel cultures. As lung morphogenesis approaches completion, eGFP-expression declines and in adult lung its expression is barely detectable. However, upon tissue-injury, either with naphthalene or bleomycin, the canonical BMP-pathways is re-activated, in bronchial or alveolar epithelial cells respectively, in a manner reminiscent to early lung development and in tissue areas where reparatory progenitor cells reside. Our studies illustrate the dynamic activation of canonical BMP-pathway during lung

  15. Enzyme Activities of Starch and Sucrose Pathways and Growth of Apical and Basal Maize Kernels 1

    PubMed Central

    Ou-Lee, Tsai-Mei; Setter, Tim Lloyd

    1985-01-01

    Apical kernels of maize (Zea mays L.) ears have smaller size and lower growth rates than basal kernels. To improve our understanding of this difference, the developmental patterns of starch-synthesis-pathway enzyme activities and accumulation of sugars and starch was determined in apical- and basal-kernel endosperm of greenhouse-grown maize (cultivar Cornell 175) plants. Plants were synchronously pollinated, kernels were sampled from apical and basal ear positions throughout kernel development, and enzyme activities were measured in crude preparations. Several factors were correlated with the higher dry matter accumulation rate and larger mature kernel size of basal-kernel endosperm. During the period of cell expansion (7 to 19 days after pollination), the activity of insoluble (acid) invertase and sucose concentration in endosperm of basal kernels exceeded that in apical kernels. Soluble (alkaline) invertase was also high during this stage but was the same in endosperm of basal and apical kernels, while glucose concentration was higher in apical-kernel endosperm. During the period of maximal starch synthesis, the activities of sucrose synthase, ADP-Glc-pyrophosphorylase, and insoluble (granule-bound) ADP-Glc-starch synthase were higher in endosperm of basal than apical kernels. Soluble ADP-Glc-starch synthase, which was maximal during the early stage before starch accumulated, was the same in endosperm from apical and basal kernels. It appeared that differences in metabolic potential between apical and basal kernels were established at an early stage in kernel development. PMID:16664503

  16. BDNF selectively regulates GABAA receptor transcription by activation of the JAK/STAT pathway.

    PubMed

    Lund, Ingrid V; Hu, Yinghui; Raol, YogendraSinh H; Benham, Rebecca S; Faris, Ramona; Russek, Shelley J; Brooks-Kayal, Amy R

    2008-01-01

    The gamma-aminobutyric acid (GABA) type A receptor (GABA(A)R) is the major inhibitory neurotransmitter receptor in the brain. Its multiple subunits show regional, developmental, and disease-related plasticity of expression; however, the regulatory networks controlling GABA(A)R subunit expression remain poorly understood. We report that the seizure-induced decrease in GABA(A)R alpha1 subunit expression associated with epilepsy is mediated by the Janus kinase (JAK)/signal transducer and activator of transcription (STAT) pathway regulated by brain-derived neurotrophic factor (BDNF). BDNF- and seizure-dependent phosphorylation of STAT3 cause the adenosine 3',5'-monophosphate (cAMP) response element-binding protein (CREB) family member ICER (inducible cAMP early repressor) to bind with phosphorylated CREB at the Gabra1:CRE site. JAK/STAT pathway inhibition prevents the seizure-induced decrease in GABA(A)R alpha1 abundance in vivo and, given that BDNF is known to increase the abundance of GABA(A)R alpha4 in a JAK/STAT-independent manner, indicates that BDNF acts through at least two distinct pathways to influence GABA(A)R-dependent synaptic inhibition. PMID:18922788

  17. Sonic Hedgehog Promotes Cementoblastic Differentiation via Activating the BMP Pathways.

    PubMed

    Bae, Won-Jung; Auh, Q-Schick; Lim, Hyun-Chang; Kim, Gyu-Tae; Kim, Hyun-Soo; Kim, Eun-Cheol

    2016-10-01

    Although sonic hedgehog (SHH), an essential molecule in embryogenesis and organogenesis, stimulates proliferation of human periodontal ligament (PDL) stem cells, the effects of recombinant human SHH (rh-SHH) on osteoblastic differentiation are unclear. To reveal the role of SHH in periodontal regeneration, expression of SHH in mouse periodontal tissues and its effects on the osteoblastic/cementoblastic differentiation in human cementoblasts were investigated. SHH is immunolocalized to differentiating cementoblasts, PDL cells, and osteoblasts of the developing mouse periodontium. Addition of rh-SHH increased cell growth, ALP activity, and mineralization nodule formation, and upregulated mRNA expression of osteoblastic and cementoblastic markers. The osteoblastic/cementoblastic differentiation of rh-SHH was abolished by the SHH inhibitor cyclopamine (Cy) and the BMP antagonist noggin. rh-SHH increased the expression of BMP-2 and -4 mRNA, as well as levels of phosphorylated Akt, ERK, p38, and JNK, and of MAPK and NF-κB activation, which were reversed by noggin, Cy, and BMP-2 siRNA. Collectively, this study is the first to demonstrate that SHH can promote cell growth and cell osteoblastic/cementoblastic differentiation via BMP pathway. Thus, SHH plays important roles in the development of periodontal tissue, and might represent a new therapeutic target for periodontitis and periodontal regeneration. PMID:27289556

  18. OASIS modulates hypoxia pathway activity to regulate bone angiogenesis

    PubMed Central

    Cui, Min; Kanemoto, Soshi; Cui, Xiang; Kaneko, Masayuki; Asada, Rie; Matsuhisa, Koji; Tanimoto, Keiji; Yoshimoto, Yuki; Shukunami, Chisa; Imaizumi, Kazunori

    2015-01-01

    OASIS/CREB3L1, an endoplasmic reticulum (ER)-resident transcription factor, plays important roles in osteoblast differentiation. In this study, we identified new crosstalk between OASIS and the hypoxia signaling pathway, which regulates vascularization during bone development. RT-PCR and real-time PCR analyses revealed significant decreases in the expression levels of hypoxia-inducible factor-1α (HIF-1α) target genes such as vascular endothelial growth factor A (VEGFA) in OASIS-deficient (Oasis−/−) mouse embryonic fibroblasts. In coimmunoprecipitation experiments, the N-terminal fragment of OASIS (OASIS-N; activated form of OASIS) bound to HIF-1α through the bZIP domain. Luciferase assays showed that OASIS-N promoted the transcription activities of a reporter gene via a hypoxia-response element (HRE). Furthermore, the expression levels of an angiogenic factor Vegfa was decreased in Oasis−/− osteoblasts. Immunostaining and metatarsal angiogenesis assay showed retarded vascularization in bone tissue of Oasis−/− mice. These results suggest that OASIS affects the expression of HIF-1α target genes through the protein interaction with HIF-1α, and that OASIS-HIF-1α complexes may play essential roles in angiogenesis during bone development. PMID:26558437

  19. Workjobs II: Number Activities for Early Childhood.

    ERIC Educational Resources Information Center

    Baratta-Lorton, Mary

    This curriculum guide presents a program of 20 open-ended math activities to be used to supplement the math programs in kindergarten, first, or second grade classrooms. The program consists of child-oriented counters and gameboards used to explore the concept of number from counting to making up and solving addition and subtraction equations. Each…

  20. American History Activators (Early American History).

    ERIC Educational Resources Information Center

    Lacey, Bill

    This document consists of a package of seven separately published "activities" or simulations that allow students to learn about and participate in many of the aspects of United States history that have influenced our present institutions and way of life. The seven units include: (1) First Americans Arrive: 11.000 BC; (2) Puritan General Court,…

  1. Early detectors of the heart's electrical activity.

    PubMed

    Breathnach, Caoimhghín S; Westphal, Wolfgang

    2006-04-01

    It was in Matteucci's rheoscopic frog in Pisa that evidence was first found for the electrical activity of the heart in 1844, and his results were confirmed and expanded 12 years later at Würzburg. The capillary electrometer gave a continuous record that could be photographed, and was used initially by Einthoven who, to obviate the onerous mathematical conversion of the electrometer record, developed the string galvanometer by the close of the century, and showed its clinical value in 1906. PMID:16650272

  2. Impacts of Activation of the Mitogen-Activated Protein Kinase Pathway in Pancreatic Cancer

    PubMed Central

    Furukawa, Toru

    2015-01-01

    Pancreatic cancer is characterized by constitutive activation of the mitogen-activated protein kinase (MAPK) pathway. Mutations of KRAS or BRAF and epigenetic abrogation of DUSP6 contribute synergistically to the constitutive activation of MAPK. Active MAPK induces the expression of a variety of genes that are thought to play roles in malignant phenotypes of pancreatic cancer. By blocking the functions of such induced genes, it is possible to attenuate the malignant phenotypes. The development of drugs targeting genes downstream of MAPK may provide a novel therapeutic option for pancreatic cancer. PMID:25699241

  3. Discovering and annotating fish early life-stage (FELS) adverse outcome pathways: Putting the research strategy into practice

    EPA Science Inventory

    In May 2012, a HESI-sponsored expert workshop yielded a proposed research strategy for systematically discovering, characterizing, and annotating fish early life-stage (FELS) adverse outcome pathways (AOPs) as well as prioritizing AOP development in light of current restrictions ...

  4. Pathways of Long-Term Effects of an Early Intervention Program on Educational Attainment: Findings from the Chicago Longitudinal Study

    ERIC Educational Resources Information Center

    Ou, Suh-Ru

    2005-01-01

    The present study investigated pathways that might explain the observed linkage between participation in early intervention programs and later educational attainment using a sample from the Chicago Longitudinal Study, an on-going investigation of low-income minority children growing up in high-poverty neighborhoods in Chicago. A review of…

  5. Pathways from Adolescent Deliberate Self-Poisoning to Early Adult Outcomes: A Six-Year Follow-Up

    ERIC Educational Resources Information Center

    Aglan, Azza; Kerfoot, Michael; Pickles, Andrew

    2008-01-01

    Background: Prospective studies show that the adult outcomes of adolescents who deliberately harm themselves are marked by high rates of adversity and psychiatric disorders. The goal of this study was to identify pathways linking childhood risk factors to early adult outcomes of suicidal adolescents. Methods: A clinical sample of 158 adolescents…

  6. Early methyl donor deficiency alters cAMP signaling pathway and neurosteroidogenesis in the cerebellum of female rat pups.

    PubMed

    El Hajj Chehadeh, Sarah; Dreumont, Natacha; Willekens, Jérèmy; Canabady-Rochelle, Laetitia; Jeannesson, Elise; Alberto, Jean-Marc; Daval, Jean-Luc; Guéant, Jean-Louis; Leininger-Muller, Brigitte

    2014-12-01

    Early deficiency of the methyl donors folate and vitamin B12 produces hyperhomocysteinemia and cognitive and motor disorders in 21-day-old rat pups from dams fed a diet deficient in methyl donors during gestation and lactation. These disorders are associated with impaired neurogenesis and altered synaptic plasticity in cerebellum. We aimed to investigate whether these disorders could be related to impaired expression of neurosteroidogenesis-associated proteins, key regulator receptors, and some steroid content in the cerebellum. The methyl donor deficiency produced a decreased concentration of folate and vitamin B12, along with accumulation of homocysteine in Purkinje cells in both sexes, whereas the S-adenosylmethionine/S-adenosylhomocysteine ratio was reduced only in females. The transcription level and protein expression of StAR, aromatase, ERα, ERβ, and LH receptors were decreased only in females, with a marked effect in Purkinje cells, as shown by immunohistochemistry. Consistently, reduced levels of estradiol and pregnenolone were measured in cerebellar extracts of females only. The decreased expression levels of the transcriptional factors CREB, phospho-CREB, and SF-1, the lesser increase of cAMP concentration, and the lower level of phospho-PKC in the cerebellum of deficient females suggest that the activation of neurosteroidogenesis via cAMP-mediated signaling pathways associated with LHR activation would be altered. In conclusion, a gestational methyl donor deficiency impairs neurosteroidogenesis in cerebellum in a sex-dependent manner. PMID:25294213

  7. Wolbachia Blocks Viral Genome Replication Early in Infection without a Transcriptional Response by the Endosymbiont or Host Small RNA Pathways.

    PubMed

    Rainey, Stephanie M; Martinez, Julien; McFarlane, Melanie; Juneja, Punita; Sarkies, Peter; Lulla, Aleksei; Schnettler, Esther; Varjak, Margus; Merits, Andres; Miska, Eric A; Jiggins, Francis M; Kohl, Alain

    2016-04-01

    The intracellular endosymbiotic bacterium Wolbachia can protect insects against viral infection, and is being introduced into mosquito populations in the wild to block the transmission of arboviruses that infect humans and are a major public health concern. To investigate the mechanisms underlying this antiviral protection, we have developed a new model system combining Wolbachia-infected Drosophila melanogaster cell culture with the model mosquito-borne Semliki Forest virus (SFV; Togaviridae, Alphavirus). Wolbachia provides strong antiviral protection rapidly after infection, suggesting that an early stage post-infection is being blocked. Wolbachia does appear to have major effects on events distinct from entry, assembly or exit as it inhibits the replication of an SFV replicon transfected into the cells. Furthermore, it causes a far greater reduction in the expression of proteins from the 3' open reading frame than the 5' non-structural protein open reading frame, indicating that it is blocking the replication of viral RNA. Further to this separation of the replicase proteins and viral RNA in transreplication assays shows that uncoupling of viral RNA and replicase proteins does not overcome Wolbachia's antiviral activity. This further suggests that replicative processes are disrupted, such as translation or replication, by Wolbachia infection. This may occur by Wolbachia mounting an active antiviral response, but the virus did not cause any transcriptional response by the bacterium, suggesting that this is not the case. Host microRNAs (miRNAs) have been implicated in protection, but again we found that host cell miRNA expression was unaffected by the bacterium and neither do our findings suggest any involvement of the antiviral siRNA pathway. We conclude that Wolbachia may directly interfere with early events in virus replication such as translation of incoming viral RNA or RNA transcription, and this likely involves an intrinsic (as opposed to an induced

  8. Wolbachia Blocks Viral Genome Replication Early in Infection without a Transcriptional Response by the Endosymbiont or Host Small RNA Pathways

    PubMed Central

    McFarlane, Melanie; Juneja, Punita; Sarkies, Peter; Lulla, Aleksei; Schnettler, Esther; Varjak, Margus; Merits, Andres; Miska, Eric A.; Jiggins, Francis M.; Kohl, Alain

    2016-01-01

    The intracellular endosymbiotic bacterium Wolbachia can protect insects against viral infection, and is being introduced into mosquito populations in the wild to block the transmission of arboviruses that infect humans and are a major public health concern. To investigate the mechanisms underlying this antiviral protection, we have developed a new model system combining Wolbachia-infected Drosophila melanogaster cell culture with the model mosquito-borne Semliki Forest virus (SFV; Togaviridae, Alphavirus). Wolbachia provides strong antiviral protection rapidly after infection, suggesting that an early stage post-infection is being blocked. Wolbachia does appear to have major effects on events distinct from entry, assembly or exit as it inhibits the replication of an SFV replicon transfected into the cells. Furthermore, it causes a far greater reduction in the expression of proteins from the 3´ open reading frame than the 5´ non-structural protein open reading frame, indicating that it is blocking the replication of viral RNA. Further to this separation of the replicase proteins and viral RNA in transreplication assays shows that uncoupling of viral RNA and replicase proteins does not overcome Wolbachia’s antiviral activity. This further suggests that replicative processes are disrupted, such as translation or replication, by Wolbachia infection. This may occur by Wolbachia mounting an active antiviral response, but the virus did not cause any transcriptional response by the bacterium, suggesting that this is not the case. Host microRNAs (miRNAs) have been implicated in protection, but again we found that host cell miRNA expression was unaffected by the bacterium and neither do our findings suggest any involvement of the antiviral siRNA pathway. We conclude that Wolbachia may directly interfere with early events in virus replication such as translation of incoming viral RNA or RNA transcription, and this likely involves an intrinsic (as opposed to an induced

  9. Bidirectional Expression of Metabolic, Structural, and Immune Pathways in Early Myopia and Hyperopia

    PubMed Central

    Riddell, Nina; Giummarra, Loretta; Hall, Nathan E.; Crewther, Sheila G.

    2016-01-01

    Myopia (short-sightedness) affects 1.45 billion people worldwide, many of whom will develop sight-threatening secondary disorders. Myopic eyes are characterized by excessive size while hyperopic (long-sighted) eyes are typically small. The biological and genetic mechanisms underpinning the retina's local control of these growth patterns remain unclear. In the present study, we used RNA sequencing to examine gene expression in the retina/RPE/choroid across 3 days of optically-induced myopia and hyperopia induction in chick. Data were analyzed for differential expression of single genes, and Gene Set Enrichment Analysis (GSEA) was used to identify gene sets correlated with ocular axial length and refraction across lens groups. Like previous studies, we found few single genes that were differentially-expressed in a sign-of-defocus dependent manner (only BMP2 at 1 day). Using GSEA, however, we are the first to show that more subtle shifts in structural, metabolic, and immune pathway expression are correlated with the eye size and refractive changes induced by lens defocus. Our findings link gene expression with the morphological characteristics of refractive error, and suggest that physiological stress arising from metabolic and inflammatory pathway activation could increase the vulnerability of myopic eyes to secondary pathologies. PMID:27625591

  10. Bidirectional Expression of Metabolic, Structural, and Immune Pathways in Early Myopia and Hyperopia.

    PubMed

    Riddell, Nina; Giummarra, Loretta; Hall, Nathan E; Crewther, Sheila G

    2016-01-01

    Myopia (short-sightedness) affects 1.45 billion people worldwide, many of whom will develop sight-threatening secondary disorders. Myopic eyes are characterized by excessive size while hyperopic (long-sighted) eyes are typically small. The biological and genetic mechanisms underpinning the retina's local control of these growth patterns remain unclear. In the present study, we used RNA sequencing to examine gene expression in the retina/RPE/choroid across 3 days of optically-induced myopia and hyperopia induction in chick. Data were analyzed for differential expression of single genes, and Gene Set Enrichment Analysis (GSEA) was used to identify gene sets correlated with ocular axial length and refraction across lens groups. Like previous studies, we found few single genes that were differentially-expressed in a sign-of-defocus dependent manner (only BMP2 at 1 day). Using GSEA, however, we are the first to show that more subtle shifts in structural, metabolic, and immune pathway expression are correlated with the eye size and refractive changes induced by lens defocus. Our findings link gene expression with the morphological characteristics of refractive error, and suggest that physiological stress arising from metabolic and inflammatory pathway activation could increase the vulnerability of myopic eyes to secondary pathologies. PMID:27625591

  11. Cognitive vulnerabilities as predictors of stress generation in early adolescence: pathway to depressive symptoms.

    PubMed

    Hamilton, Jessica L; Stange, Jonathan P; Shapero, Benjamin G; Connolly, Samantha L; Abramson, Lyn Y; Alloy, Lauren B

    2013-10-01

    Although individuals with depression have been found to experience a higher rate of stress in their lives, it remains unclear to what extent other personal characteristics may contribute to stress generation. The current study extended past research by examining the effects of two theoretically and empirically supported cognitive vulnerabilities to depression (negative cognitive style and rumination) as predictors of dependent interpersonal and achievement events, independent events, and relational peer victimization. In a diverse sample of 301 early adolescents (56 % female; M(age) = 12.82 years), we found that negative cognitive style prospectively predicted the experience of dependent interpersonal stress and relational victimization, and that rumination did not predict stress in any of the domains. Furthermore, the occurrence of intervening stress mediated the associations between negative cognitive style and subsequent depressive symptoms. Additionally, whereas negative cognitive style predicted relational victimization among both boys and girls, girls were particularly vulnerable to developing depressive symptoms following the occurrence of relational victimization. Thus, a negative cognitive style may contribute to the occurrence of stressful events, which in turn increases depressive symptoms. Girls may be particularly reactive to relational victimization, representing one pathway through which sex differences in depression may emerge. PMID:23624770

  12. Existing FDA pathways have potential to ensure early access to, and appropriate use of, specialty drugs.

    PubMed

    Kesselheim, Aaron S; Tan, Yongtian Tina; Darrow, Jonathan J; Avorn, Jerry

    2014-10-01

    Specialty drugs are notable among prescription drugs in that they offer the possibility of substantial clinical improvement, come with important risks of adverse events and mortality, can be complex to manufacture or administer, and are usually extremely costly. The Food and Drug Administration (FDA) plays a critical role in ensuring that patients who could benefit from specialty drugs have access to them in a timely fashion. In this article we review the different strategies that the FDA can use to approve and influence the post-approval prescribing of specialty drugs. When specialty drugs show promise in early clinical trials, the FDA can expedite the drugs' availability to patients through expanded access programs and expedited approval pathways that speed regulatory authorization. After approval, to ensure that specialty drugs are directed to the patients who are most likely to benefit from them, the FDA can limit the scope of the drugs' indications, encourage the development of companion diagnostic tests to indicate which patients should receive the drugs, or require that manufacturers subject them to Risk Evaluation and Mitigation Strategies to ensure that their use is appropriately limited to a restricted population that is aware of the drugs' risks and benefits. Implementing these existing regulatory approaches can promote timely patient access to specialty drugs while preventing expensive and potentially inappropriate overuse. PMID:25288421

  13. Intergenerational Influences on Early Alcohol Use: Independence from the Problem Behavior Pathway

    PubMed Central

    Kerr, David C. R.; Capaldi, Deborah M.; Pears, Katherine C.; Owen, Lee D.

    2013-01-01

    Conduct problems are a general risk factor for adolescent alcohol use. However, their role in relation to alcohol-specific risk pathways of intergenerational transmission of alcohol use is not well understood. Further, the roles of alcohol-specific contextual influences on children’s early alcohol use have been little examined. In a 20-year prospective, multimethod study of 83 fathers and their 125 children, we considered predictors of child alcohol use by age 13 years. Predictors included fathers’ adolescent antisocial behavior and alcohol use, both parents’ adult alcohol use, norms about and encouragement of child use, parental monitoring, child-reported exposure to intoxicated adults, and parent-reported child externalizing behaviors. Path models supported an association between fathers’ adolescent alcohol use and children’s use (β = .17) that was not better explained by concurrent indicators of fathers’ and children’s general problem behavior. Fathers’ and mothers’ adult alcohol use uniquely predicted child use, and exposure to intoxicated adults partially mediated the latter path. Other family risk mechanisms were not supported. However, parental alcohol use and child alcohol use were linked in expected ways with family contextual conditions known to set the stage for alcohol use problems later in adolescence. PMID:22781861

  14. No evidence for TSLP pathway activity in human breast cancer.

    PubMed

    Ghirelli, Cristina; Sadacca, Benjamin; Reyal, Fabien; Zollinger, Raphaël; Michea, Paula; Sirven, Philémon; Pattarini, Lucia; Martínez-Cingolani, Carolina; Guillot-Delost, Maude; Nicolas, André; Scholer-Dahirel, Alix; Soumelis, Vassili

    2016-08-01

    Thymic stromal lymphopoietin (TSLP) is an epithelial cell-derived cytokine that primes dendritic cells for Th2 induction. It has been implicated in different types of allergic diseases. Recent work suggested that TSLP could play an important role in the tumor microenvironment and influence tumor progression, in particular in breast cancer. In this study we systematically assessed the production of TSLP at the mRNA and protein levels in several human breast cancer cell lines, large-scale public transcriptomics data sets, and primary human breast tumors. We found that TSLP production was marginal, and concerned less than 10% of the tumors, with very low mRNA and protein levels. In most cases TSLP was undetectable and found to be expressed at lower levels in breast cancer as compared to normal breast tissue. Last, we could not detect any functional TSLP receptor (TSLPR) expression neither on hematopoietic cells nor on stromal cells within the primary tumor microenvironment. We conclude that TSLP-TSLPR pathway activity is not significantly detected within human breast cancer. Taken together, these observations do not support TSLP targeting in breast cancer. PMID:27622057

  15. Target-Cell Contact Activates a Highly Selective Capacitative Calcium Entry Pathway in Cytotoxic T Lymphocytes

    PubMed Central

    Zweifach, Adam

    2000-01-01

    Calcium influx is critical for T cell activation. Evidence has been presented that T cell receptor–stimulated calcium influx in helper T lymphocytes occurs via channels activated as a consequence of depletion of intracellular calcium stores, a mechanism known as capacitative Ca2+ entry (CCE). However, two key questions have not been addressed. First, the mechanism of calcium influx in cytotoxic T cells has not been examined. While the T cell receptor–mediated early signals in helper and cytotoxic T cells are similar, the physiology of the cells is strikingly different, raising the possibility that the mechanism of calcium influx is also different. Second, contact of T cells with antigen-presenting cells or targets involves a host of intercellular interactions in addition to those between antigen–MHC and the T cell receptor. The possibility that calcium influx pathways in addition to those activated via the T cell receptor may be activated by contact with relevant cells has not been addressed. We have used imaging techniques to show that target-cell–stimulated calcium influx in CTLs occurs primarily through CCE. We investigated the permeability of the CTL influx pathway for divalent cations, and compared it to the permeability of CCE in Jurkat human leukemic T cells. CCE in CTLs shows a similar ability to discriminate between calcium, barium, and strontium as CCE in Jurkat human leukemic T lymphocytes, where CCE is likely to mediated by Ca2+ release–activated Ca2+ current (CRAC) channels, suggesting that CRAC channels also underlie CCE in CTLs. These results are the first determination of the mechanism of calcium influx in cytotoxic T cells and the first demonstration that cell contact–mediated calcium signals in T cells occur via depletion-activated channels. PMID:10662784

  16. Secretory pathway retention of mutant prion protein induces p38-MAPK activation and lethal disease in mice.

    PubMed

    Puig, Berta; Altmeppen, Hermann C; Ulbrich, Sarah; Linsenmeier, Luise; Krasemann, Susanne; Chakroun, Karima; Acevedo-Morantes, Claudia Y; Wille, Holger; Tatzelt, Jörg; Glatzel, Markus

    2016-01-01

    Misfolding of proteins in the biosynthetic pathway in neurons may cause disturbed protein homeostasis and neurodegeneration. The prion protein (PrP(C)) is a GPI-anchored protein that resides at the plasma membrane and may be misfolded to PrP(Sc) leading to prion diseases. We show that a deletion in the C-terminal domain of PrP(C) (PrPΔ214-229) leads to partial retention in the secretory pathway causing a fatal neurodegenerative disease in mice that is partially rescued by co-expression of PrP(C). Transgenic (Tg(PrPΔ214-229)) mice show extensive neuronal loss in hippocampus and cerebellum and activation of p38-MAPK. In cell culture under stress conditions, PrPΔ214-229 accumulates in the Golgi apparatus possibly representing transit to the Rapid ER Stress-induced ExporT (RESET) pathway together with p38-MAPK activation. Here we describe a novel pathway linking retention of a GPI-anchored protein in the early secretory pathway to p38-MAPK activation and a neurodegenerative phenotype in transgenic mice. PMID:27117504

  17. Secretory pathway retention of mutant prion protein induces p38-MAPK activation and lethal disease in mice

    PubMed Central

    Puig, Berta; Altmeppen, Hermann C.; Ulbrich, Sarah; Linsenmeier, Luise; Krasemann, Susanne; Chakroun, Karima; Acevedo-Morantes, Claudia Y.; Wille, Holger; Tatzelt, Jörg; Glatzel, Markus

    2016-01-01

    Misfolding of proteins in the biosynthetic pathway in neurons may cause disturbed protein homeostasis and neurodegeneration. The prion protein (PrPC) is a GPI-anchored protein that resides at the plasma membrane and may be misfolded to PrPSc leading to prion diseases. We show that a deletion in the C-terminal domain of PrPC (PrPΔ214–229) leads to partial retention in the secretory pathway causing a fatal neurodegenerative disease in mice that is partially rescued by co-expression of PrPC. Transgenic (Tg(PrPΔ214–229)) mice show extensive neuronal loss in hippocampus and cerebellum and activation of p38-MAPK. In cell culture under stress conditions, PrPΔ214–229 accumulates in the Golgi apparatus possibly representing transit to the Rapid ER Stress-induced ExporT (RESET) pathway together with p38-MAPK activation. Here we describe a novel pathway linking retention of a GPI-anchored protein in the early secretory pathway to p38-MAPK activation and a neurodegenerative phenotype in transgenic mice. PMID:27117504

  18. Early capillary flux homogenization in response to neural activation.

    PubMed

    Lee, Jonghwan; Wu, Weicheng; Boas, David A

    2016-02-01

    This Brief Communication reports early homogenization of capillary network flow during somatosensory activation in the rat cerebral cortex. We used optical coherence tomography and statistical intensity variation analysis for tracing changes in the red blood cell flux over hundreds of capillaries nearly at the same time with 1-s resolution. We observed that while the mean capillary flux exhibited a typical increase during activation, the standard deviation of the capillary flux exhibited an early decrease that happened before the mean flux increase. This network-level data is consistent with the theoretical hypothesis that capillary flow homogenizes during activation to improve oxygen delivery. PMID:26661145

  19. Fall Activities for the Early Childhood and Special Education Classroom.

    ERIC Educational Resources Information Center

    Denton, Penny

    Designed for teachers of early childhood or special education students, this guide contains instructions and illustrations for classroom activities for the months of September, October, and November. Most of the activities involve art projects and many incorporate teaching in other subject areas such as mathematics, language arts, science, and…

  20. Sports, Physical Activity and Recreation in Early American History.

    ERIC Educational Resources Information Center

    Ballou, Ralph B.

    Sports and physical recreation activities have been part of American life since the days of the early settlers. Although the settlers were faced with problems of survival, accounts of life in the colonies in the 1600's carry mention of bowling in the streets, play with bows and arrows, and ice skating. Other activities to gain popularity before…

  1. Aging causes decreased resistance to multiple stresses and a failure to activate specific stress response pathways.

    PubMed

    Dues, Dylan J; Andrews, Emily K; Schaar, Claire E; Bergsma, Alexis L; Senchuk, Megan M; Van Raamsdonk, Jeremy M

    2016-04-01

    In this work, we examine the relationship between stress resistance and aging. We find that resistance to multiple types of stress peaks during early adulthood and then declines with age. To dissect the underlying mechanisms, we use C. elegans transcriptional reporter strains that measure the activation of different stress responses including: the heat shock response, mitochondrial unfolded protein response, endoplasmic reticulum unfolded protein response, hypoxia response, SKN-1-mediated oxidative stress response, and the DAF-16-mediated stress response. We find that the decline in stress resistance with age is at least partially due to a decreased ability to activate protective mechanisms in response to stress. In contrast, we find that any baseline increase in stress caused by the advancing age is too mild to detectably upregulate any of the stress response pathways. Further exploration of how worms respond to stress with increasing age revealed that the ability to mount a hormetic response to heat stress is also lost with increasing age. Overall, this work demonstrates that resistance to all types of stress declines with age. Based on our data, we speculate that the decrease in stress resistance with advancing age results from a genetically-programmed inactivation of stress response pathways, not accumulation of damage. PMID:27053445

  2. Aging causes decreased resistance to multiple stresses and a failure to activate specific stress response pathways

    PubMed Central

    Bergsma, Alexis L.; Senchuk, Megan M.; Van Raamsdonk, Jeremy M.

    2016-01-01

    In this work, we examine the relationship between stress resistance and aging. We find that resistance to multiple types of stress peaks during early adulthood and then declines with age. To dissect the underlying mechanisms, we use C. elegans transcriptional reporter strains that measure the activation of different stress responses including: the heat shock response, mitochondrial unfolded protein response, endoplasmic reticulum unfolded protein response, hypoxia response, SKN-1-mediated oxidative stress response, and the DAF-16-mediated stress response. We find that the decline in stress resistance with age is at least partially due to a decreased ability to activate protective mechanisms in response to stress. In contrast, we find that any baseline increase in stress caused by the advancing age is too mild to detectably upregulate any of the stress response pathways. Further exploration of how worms respond to stress with increasing age revealed that the ability to mount a hormetic response to heat stress is also lost with increasing age. Overall, this work demonstrates that resistance to all types of stress declines with age. Based on our data, we speculate that the decrease in stress resistance with advancing age results from a genetically-programmed inactivation of stress response pathways, not accumulation of damage. PMID:27053445

  3. Dose-response modeling of early molecular and cellular key events in the CAR-mediated hepatocarcinogenesis pathway.

    PubMed

    Geter, David R; Bhat, Virunya S; Gollapudi, B Bhaskar; Sura, Radhakrishna; Hester, Susan D

    2014-04-01

    Low-dose extrapolation and dose-related transitions are paramount in the ongoing debate regarding the quantification of cancer risks for nongenotoxic carcinogens. Phenobarbital (PB) is a prototypical nongenotoxic carcinogen that activates the constitutive androstane receptor (CAR) resulting in rodent liver tumors. In this study, male and female CD-1 mice administered dietary PB at 0, 0.15, 1.5, 15, 75, or 150 mg/kg-day for 2 or 7 days to characterize multiple apical and molecular endpoints below, at (∼75 mg/kg-day), and above the carcinogenic dose level of PB and examine these responses using benchmark dose modeling. Linear toxicokinetics were observed for all doses. Increased liver weight, hepatocellular hypertrophy, and mitotic figures were seen at 75 and 150 mg/kg-day. CAR activation, based on Cyp2b qPCR and pentoxyresorufin dealkylase activity, occurred at doses ≥ 1.5 mg/kg-day. The no-observable transcriptional effect level for global gene expression was 15 mg/kg-day. At 2 days, several xenobiotic metabolism and cell protective pathways were activated at lower doses and to a greater degree in females. However, hepatocellular proliferation, quantified by bromodeoxyuridine immunohistochemistry, was the most sensitive indicator of PB exposure with female mice more sensitive than males, contrary to sex-specific differences in sensitivity to hepatocarcinogenesis. Taken together, the identification of low-dose cellular and molecular transitions in the subtumorigenic dose range aids the understanding of early key events in CAR-mediated hepatocarcinogenesis. PMID:24449422

  4. Blocking HMGB1 signal pathway protects early radiation-induced lung injury.

    PubMed

    Wang, Liping; Zhang, Jing; Wang, Baozhong; Wang, Guifu; Xu, Junlong

    2015-01-01

    It has been reported that HMGB1 participated in various types of lung injury. In this study, we explored whether blocking HMGB1 has a preventive effect on the early radiation-induced lung injury and investigate the mechanism. Mice model of radiation-induced lung injury were accomplished by a single dose irradiation (15 Gy) to the whole thorax. Irradiated mice were treated with HMGB1-neutralizing antibody intraperitoneally dosed 10 μg, 50 μg, 100 μg/mouse respectively and were sacrificed after one week post-irradiation. Lung tissue slices were stained by H&E, and alveolitis was quantified by Szapiel scoring system. The level of cytokines TNF-γ in bronchoalveolar lavage fluid was detected by ELISA method. And p65NF-κB, p50NF-κB protein expression in mice lung tissues was detected by Western blot analysis. The results showed that blocking HMGB1 inhibited the inflammatory response, and thereby decreased the degree of alveolitis of irradiated lung tissue. In addition, HMGB1 antagonist can restrain the expression of type Th2 or Th17 derived inflammatory cytokines TNF-α, IL-6 and IL-17A, promote the expression of Th1 type cytokines INF-γ, and inhibit p65 NF-κB but promote p50 NF-κB activation, which promoted the resolution of the radiation-induced inflammatory response. In conclusion, blocking HMGB1 can reduce the degree of early radiation-induced lung injury, and its mechanism may be related to the promotion of p50NF-κB activation and its downstream molecules expression. Inhibiting HMGB1 may be a new target to deal with early radiation-induced lung injury. PMID:26191172

  5. Blocking HMGB1 signal pathway protects early radiation-induced lung injury

    PubMed Central

    Wang, Liping; Zhang, Jing; Wang, Baozhong; Wang, Guifu; Xu, Junlong

    2015-01-01

    It has been reported that HMGB1 participated in various types of lung injury. In this study, we explored whether blocking HMGB1 has a preventive effect on the early radiation-induced lung injury and investigate the mechanism. Mice model of radiation-induced lung injury were accomplished by a single dose irradiation (15 Gy) to the whole thorax. Irradiated mice were treated with HMGB1-neutralizing antibody intraperitoneally dosed 10 μg, 50 μg, 100 μg/mouse respectively and were sacrificed after one week post-irradiation. Lung tissue slices were stained by H&E, and alveolitis was quantified by Szapiel scoring system. The level of cytokines TNF-γ in bronchoalveolar lavage fluid was detected by ELISA method. And p65NF-κB, p50NF-κB protein expression in mice lung tissues was detected by Western blot analysis. The results showed that blocking HMGB1 inhibited the inflammatory response, and thereby decreased the degree of alveolitis of irradiated lung tissue. In addition, HMGB1 antagonist can restrain the expression of type Th2 or Th17 derived inflammatory cytokines TNF-α, IL-6 and IL-17A, promote the expression of Th1 type cytokines INF-γ, and inhibit p65 NF-κB but promote p50 NF-κB activation, which promoted the resolution of the radiation-induced inflammatory response. In conclusion, blocking HMGB1 can reduce the degree of early radiation-induced lung injury, and its mechanism may be related to the promotion of p50NF-κB activation and its downstream molecules expression. Inhibiting HMGB1 may be a new target to deal with early radiation-induced lung injury. PMID:26191172

  6. Early development of synchrony in cortical activations in the human

    PubMed Central

    Koolen, N.; Dereymaeker, A.; Räsänen, O.; Jansen, K.; Vervisch, J.; Matic, V.; Naulaers, G.; De Vos, M.; Van Huffel, S.; Vanhatalo, S.

    2016-01-01

    Early intermittent cortical activity is thought to play a crucial role in the growth of neuronal network development, and large scale brain networks are known to provide the basis for higher brain functions. Yet, the early development of the large scale synchrony in cortical activations is unknown. Here, we tested the hypothesis that the early intermittent cortical activations seen in the human scalp EEG show a clear developmental course during the last trimester of pregnancy, the period of intensive growth of cortico-cortical connections. We recorded scalp EEG from altogether 22 premature infants at post-menstrual age between 30 and 44 weeks, and the early cortical synchrony was quantified using recently introduced activation synchrony index (ASI). The developmental correlations of ASI were computed for individual EEG signals as well as anatomically and mathematically defined spatial subgroups. We report two main findings. First, we observed a robust and statistically significant increase in ASI in all cortical areas. Second, there were significant spatial gradients in the synchrony in fronto-occipital and left-to-right directions. These findings provide evidence that early cortical activity is increasingly synchronized across the neocortex. The ASI-based metrics introduced in our work allow direct translational comparison to in vivo animal models, as well as hold promise for implementation as a functional developmental biomarker in future research on human neonates. PMID:26876605

  7. Early active mobilization following UCL repair With Mitek bone anchor.

    PubMed

    Crowley, Timothy P; Stevenson, Susan; Taghizadeh, Reika; Addison, Patrick; Milner, Richard H

    2013-09-01

    Ulnar collateral ligament (UCL) injuries of the thumb are common. Surgical repair is accepted as the treatment of choice for complete rupture of the ligament. Biomechanical studies have suggested that Mitek bone anchor repairs are potentially safe and strong enough to allow early controlled active mobilization. To date, there have been no studies to compare early active mobilization following Mitek bone anchor repair to standard postoperative rehabilitation involving thumb spica immobilization for the first 4 to 6 weeks. We performed a small pilot randomized control trial to assess the outcome of this new rehabilitation technique to that of standard immobilization following UCL repair with Mitek bone anchor. Our results show that on average early active mobilization leads to an earlier return to full hand function (6 vs. 8 wk) and an earlier return to work (7 vs. 11 wk). There is no difference in the final range of motion achieved. We suggest that Mitek bone anchor repairs for UCL ruptures are robust enough to allow early active mobilization and that a larger trial is warranted to assess whether early active mobilization is superior to standard rehabilitation. PMID:23970193

  8. Early development of synchrony in cortical activations in the human.

    PubMed

    Koolen, N; Dereymaeker, A; Räsänen, O; Jansen, K; Vervisch, J; Matic, V; Naulaers, G; De Vos, M; Van Huffel, S; Vanhatalo, S

    2016-05-13

    Early intermittent cortical activity is thought to play a crucial role in the growth of neuronal network development, and large scale brain networks are known to provide the basis for higher brain functions. Yet, the early development of the large scale synchrony in cortical activations is unknown. Here, we tested the hypothesis that the early intermittent cortical activations seen in the human scalp EEG show a clear developmental course during the last trimester of pregnancy, the period of intensive growth of cortico-cortical connections. We recorded scalp EEG from altogether 22 premature infants at post-menstrual age between 30 and 44weeks, and the early cortical synchrony was quantified using recently introduced activation synchrony index (ASI). The developmental correlations of ASI were computed for individual EEG signals as well as anatomically and mathematically defined spatial subgroups. We report two main findings. First, we observed a robust and statistically significant increase in ASI in all cortical areas. Second, there were significant spatial gradients in the synchrony in fronto-occipital and left-to-right directions. These findings provide evidence that early cortical activity is increasingly synchronized across the neocortex. The ASI-based metrics introduced in our work allow direct translational comparison to in vivo animal models, as well as hold promise for implementation as a functional developmental biomarker in future research on human neonates. PMID:26876605

  9. atRA-induced apoptosis of mouse embryonic palate mesenchymal cells involves activation of MAPK pathway

    SciTech Connect

    Yu Zengli . E-mail: yuzengli@263.net; Xing Ying . E-mail: xingy@zzu.edu.cn

    2006-08-15

    Our previous studies have shown that atRA treatment resulted in cell-cycle block and growth inhibition in mouse embryonic palatal mesenchymal (MEPM). In the current study, gestation day (GD) 13 MEPM cells were used to test the hypothesis that the growth inhibition by atRA is due to apoptosis. The effects of atRA on apoptosis were assessed by performing MTT assay, Cell Death Detection ELISA and flow cytometry, respectively. Data analysis confirmed that atRA treatment induced apoptosis-like cell death, as shown by decreased cell viability and increased fragmented DNA and sub-G1 fraction. atRA-induced apoptosis was associated with upregulation of bcl-2, translocation of bax protein to the mitochondria from the cytosol, activation of caspase-3 and cytochrome c release into cytosol. atRA-induced apoptosis was abrogated by z-DEVD-fmk, a caspase-3 specific inhibitor, and z-VAD-fmk, a general caspase inhibitor, suggesting that the atRA-induced cell death of MEPM cells occurs through the cytochrome c- and caspase-3-dependent pathways. In addition, atRA treatment caused a strong and sustained activation of c-Jun N-terminal kinase (JNK) and p38 kinase (p38), as well as an early but transient activation of extracellular signal-regulated kinase (ERK). Importantly, atRA-induced DNA fragmentation and capase-3 activation were prevented by pretreatment with the JNK inhibitor (SP600125) and the p38 MAPK inhibitor (SB202190), but not by pretreatment with MEK inhibitor (U0126). From these results, we suggest that mitogen-activated protein kinase-dependent pathways is involved in the atRA-induced apoptosis of MEPM cells.

  10. Unfolded Protein Response and Activated Degradative Pathways Regulation in GNE Myopathy

    PubMed Central

    Li, Honghao; Chen, Qi; Liu, Fuchen; Zhang, Xuemei; Li, Wei; Liu, Shuping; Zhao, Yuying; Gong, Yaoqin; Yan, Chuanzhu

    2013-01-01

    Although intracellular beta amyloid (Aβ) accumulation is known as an early upstream event in the degenerative course of UDP-N-acetylglucosamine 2-epimerase/N-acetylmannosamine kinase (GNE) myopathy, the process by which Aβdeposits initiate various degradative pathways, and their relationship have not been fully clarified. We studied the possible secondary responses after amyloid beta precursor protein (AβPP) deposition including unfolded protein response (UPR), ubiquitin proteasome system (UPS) activation and its correlation with autophagy system. Eight GNE myopathy patients and five individuals with normal muscle morphology were included in this study. We performed immunofluorescence and immunoblotting to investigate the expression of AβPP, phosphorylated tau (p-tau) and endoplasmic reticulum molecular chaperones. Proteasome activities were measured by cleavage of fluorogenic substrates. The expression of proteasome subunits and linkers between proteasomal and autophagy systems were also evaluated by immunoblotting and relative quantitative real-time RT-PCR. Four molecular chaperones, glucose-regulated protein 94 (GRP94), glucose-regulated protein 78 (GRP78), calreticulin and calnexin and valosin containing protein (VCP) were highly expressed in GNE myopathy. 20S proteasome subunits, three main proteasome proteolytic activities, and the factors linking UPS and autophagy system were also increased. Our study suggests that AβPP deposition results in endoplasmic reticulum stress (ERS) and highly expressed VCP deliver unfolded proteins from endoplasmic reticulum to proteosomal system which is activated in endoplasmic reticulum associated degradation (ERAD) in GNE myopathy. Excessive ubiquitinated unfolded proteins are exported by proteins that connect UPS and autophagy to autophagy system, which is activated as an alternative pathway for degradation. PMID:23472144

  11. Activation of the Saccharomyces cerevisiae filamentation/invasion pathway by osmotic stress in high-osmolarity glycogen pathway mutants

    NASA Technical Reports Server (NTRS)

    Davenport, K. D.; Williams, K. E.; Ullmann, B. D.; Gustin, M. C.; McIntire, L. V. (Principal Investigator)

    1999-01-01

    Mitogen-activated protein kinase (MAPK) cascades are frequently used signal transduction mechanisms in eukaryotes. Of the five MAPK cascades in Saccharomyces cerevisiae, the high-osmolarity glycerol response (HOG) pathway functions to sense and respond to hypertonic stress. We utilized a partial loss-of-function mutant in the HOG pathway, pbs2-3, in a high-copy suppressor screen to identify proteins that modulate growth on high-osmolarity media. Three high-copy suppressors of pbs2-3 osmosensitivity were identified: MSG5, CAK1, and TRX1. Msg5p is a dual-specificity phosphatase that was previously demonstrated to dephosphorylate MAPKs in yeast. Deletions of the putative MAPK targets of Msg5p revealed that kss1delta could suppress the osmosensitivity of pbs2-3. Kss1p is phosphorylated in response to hyperosmotic shock in a pbs2-3 strain, but not in a wild-type strain nor in a pbs2-3 strain overexpressing MSG5. Both TEC1 and FRE::lacZ expressions are activated in strains lacking a functional HOG pathway during osmotic stress in a filamentation/invasion-pathway-dependent manner. Additionally, the cellular projections formed by a pbs2-3 mutant on high osmolarity are absent in strains lacking KSS1 or STE7. These data suggest that the loss of filamentation/invasion pathway repression contributes to the HOG mutant phenotype.

  12. Deficient activity of the alternative pathway of complement in beta thalassemia major.

    PubMed

    Corry, J M; Marshall, W C; Guthrie, L A; Peerless, A G; Johnston, R B

    1981-06-01

    Patients with thalassemia major suffer frequent and serious infections, especially after splenectomy. To explore the basis for this susceptibility, we examined activity of the complement system in sera from 24 patients. All sera had normal or increased activity of the classic complement pathway. However, six of the 24 (three with and three without splenectomy) had abnormal alternative pathway function, and mean alternative pathway activity was significantly decreased in both splenectomized and nonsplenectomized patients. Mean concentrations of C3, factor B, properdin, and immunoglobulins were normal. Defective alternative pathway function, especially in conjunction with asplenia, could contribute to the propensity to infection that exists in thalassemia. PMID:6908998

  13. Volvariella volvacea lectin activates mouse T lymphocytes by a calcium dependent pathway.

    PubMed

    Sze, S C W; Ho, J C K; Liu, W K

    2004-08-15

    The immunomodulatory lectin, Volvariella volvacea lectin (VVL), isolated from the edible mushroom, Volvariella volvacea, has been shown to stimulate the expression of Th1 cytokines and the proliferative activity of mouse splenocytes (She et al. [1998]: Biochem Biophys Res Comm 247:106-111). In order to elucidate the mechanisms underlying these activities, we conducted a kinetic analysis of the early and late activation markers in mouse T lymphocytes: (1) flow cytometric analysis of calcium influx, (2) induction of activation molecules (CD25 and CD69), (3) expression and DNA-binding activity of the nuclear factor of activated T cells (NFAT), NFkappaB, and activation protein-1 (AP-1), (4) translational production of cytokines (interleukin-2 (IL-2) and interferon-gamma (IFNgamma)), and (5) cell proliferation by expression of proliferating cell nuclear antigen (PCNA) and tritiated thymidine incorporation. All results showed that VVL induced a rapid expression of CD69, CD25, NFAT, IL-2, and PCNA in a dose- and time-dependent manner, leading to lymphocyte proliferation. These effects brought about by VVL were more potent than those stimulated by equimolar concentrations of mitogenic lectin, concanavalin A (Con A). Cell activation and proliferation were mediated through a calcium-dependent pathway as demonstrated by a VVL-induced increase of intracellular calcium influx, and a proliferation inhibition by the Ca-dependent phosphatase calcineurin blocker-cyclosporin A (CsA). Taken all data together, VVL is a lectin which activates lymphocyte through successive calcium influx, nuclear localization of NFAT transcription factor, induction of activation markers, CD25 and CD69, intracellular cytokine production, and cell proliferation. PMID:15258902

  14. CHD1 acts via the Hmgpi pathway to regulate mouse early embryogenesis.

    PubMed

    Suzuki, Shinnosuke; Nozawa, Yusuke; Tsukamoto, Satoshi; Kaneko, Takehito; Manabe, Ichiro; Imai, Hiroshi; Minami, Naojiro

    2015-07-01

    The protein CHD1 is a member of the family of ATPase-dependent chromatin remodeling factors. CHD1, which recognizes trimethylated histone H3 lysine 4, has been implicated in transcriptional activation in organisms ranging from yeast to humans. It is required for pre-mRNA maturation, maintenance of mouse embryonic stem cell pluripotency and rapid growth of the mouse epiblast. However, the function(s) of CHD1 in mouse preimplantation embryos has not yet been examined. Here, we show that loss of CHD1 function led to embryonic lethality after implantation. In mouse embryos in which Chd1 was targeted by siRNA microinjection, the expression of the key regulators of cell fate specification Pou5f1 (also known as Oct4), Nanog and Cdx2 was dramatically decreased, starting at mid-preimplantation gene activation (MGA). Moreover, expression of Hmgpi and Klf5, which regulate Pou5f1, Nanog and Cdx2, was also significantly suppressed at zygotic gene activation (ZGA). Suppression of Hmgpi expression in Chd1-knockdown embryos continued until the blastocyst stage, whereas suppression of Klf5 expression was relieved by the morula stage. Next, we rescued HMGPI expression via Hmgpi mRNA microinjection in Chd1-knockdown embryos. Consequently, Pou5f1, Nanog and Cdx2 expression was restored at MGA and live offspring were recovered. These findings indicate that CHD1 plays important roles in mouse early embryogenesis via activation of Hmgpi at ZGA. PMID:26092847

  15. Rutin-Mediated Priming of Plant Resistance to Three Bacterial Pathogens Initiating the Early SA Signal Pathway.

    PubMed

    Yang, Wei; Xu, Xiaonan; Li, Yang; Wang, Yingzi; Li, Ming; Wang, Yong; Ding, Xinhua; Chu, Zhaohui

    2016-01-01

    Flavonoids are ubiquitous in the plant kingdom and have many diverse functions, including UV protection, auxin transport inhibition, allelopathy, flower coloring and insect resistance. Here we show that rutin, a proud member of the flavonoid family, could be functional as an activator to improve plant disease resistances. Three plant species pretreated with 2 mM rutin were found to enhance resistance to Xanthomonas oryzae pv. oryzae, Ralstonia solanacearum, and Pseudomonas syringae pv. tomato strain DC3000 in rice, tobacco and Arabidopsis thaliana respectively. While they were normally propagated on the cultural medium supplemented with 2 mM rutin for those pathogenic bacteria. The enhanced resistance was associated with primed expression of several pathogenesis-related genes. We also demonstrated that the rutin-mediated priming resistance was attenuated in npr1, eds1, eds5, pad4-1, ndr1 mutants, and NahG transgenic Arabidopsis plant, while not in either snc1-11, ein2-5 or jar1 mutants. We concluded that the rutin-priming defense signal was modulated by the salicylic acid (SA)-dependent pathway from an early stage upstream of NDR1 and EDS1. PMID:26751786

  16. Comparative gene expression analysis of Dtg, a novel target gene of Dpp signaling pathway in the early Drosophila melanogaster embryo.

    PubMed

    Hodar, Christian; Zuñiga, Alejandro; Pulgar, Rodrigo; Travisany, Dante; Chacon, Carlos; Pino, Michael; Maass, Alejandro; Cambiazo, Verónica

    2014-02-10

    In the early Drosophila melanogaster embryo, Dpp, a secreted molecule that belongs to the TGF-β superfamily of growth factors, activates a set of downstream genes to subdivide the dorsal region into amnioserosa and dorsal epidermis. Here, we examined the expression pattern and transcriptional regulation of Dtg, a new target gene of Dpp signaling pathway that is required for proper amnioserosa differentiation. We showed that the expression of Dtg was controlled by Dpp and characterized a 524-bp enhancer that mediated expression in the dorsal midline, as well as, in the differentiated amnioserosa in transgenic reporter embryos. This enhancer contained a highly conserved region of 48-bp in which bioinformatic predictions and in vitro assays identified three Mad binding motifs. Mutational analysis revealed that these three motifs were necessary for proper expression of a reporter gene in transgenic embryos, suggesting that short and highly conserved genomic sequences may be indicative of functional regulatory regions in D. melanogaster genes. Dtg orthologs were not detected in basal lineages of Dipterans, which unlike D. melanogaster develop two extra-embryonic membranes, amnion and serosa, nevertheless Dtg orthologs were identified in the transcriptome of Musca domestica, in which dorsal ectoderm patterning leads to the formation of a single extra-embryonic membrane. These results suggest that Dtg was recruited as a new component of the network that controls dorsal ectoderm patterning in the lineage leading to higher Cyclorrhaphan flies, such as D. melanogaster and M. domestica. PMID:24321690

  17. Rutin-Mediated Priming of Plant Resistance to Three Bacterial Pathogens Initiating the Early SA Signal Pathway

    PubMed Central

    Li, Yang; Wang, Yingzi; Li, Ming; Wang, Yong; Ding, Xinhua; Chu, Zhaohui

    2016-01-01

    Flavonoids are ubiquitous in the plant kingdom and have many diverse functions, including UV protection, auxin transport inhibition, allelopathy, flower coloring and insect resistance. Here we show that rutin, a proud member of the flavonoid family, could be functional as an activator to improve plant disease resistances. Three plant species pretreated with 2 mM rutin were found to enhance resistance to Xanthomonas oryzae pv. oryzae, Ralstonia solanacearum, and Pseudomonas syringae pv. tomato strain DC3000 in rice, tobacco and Arabidopsis thaliana respectively. While they were normally propagated on the cultural medium supplemented with 2 mM rutin for those pathogenic bacteria. The enhanced resistance was associated with primed expression of several pathogenesis-related genes. We also demonstrated that the rutin-mediated priming resistance was attenuated in npr1, eds1, eds5, pad4-1, ndr1 mutants, and NahG transgenic Arabidopsis plant, while not in either snc1-11, ein2-5 or jar1 mutants. We concluded that the rutin-priming defense signal was modulated by the salicylic acid (SA)-dependent pathway from an early stage upstream of NDR1 and EDS1. PMID:26751786

  18. Glucocorticoids Enhance Muscle Proteolysis through a Myostatin-Dependent Pathway at the Early Stage.

    PubMed

    Wang, Ruxia; Jiao, Hongchao; Zhao, Jingpeng; Wang, Xiaojuan; Lin, Hai

    2016-01-01

    Myostatin, a member of the TGF-β superfamily of secreted proteins, is expressed primarily in skeletal muscle. It negatively regulates muscle mass and is associated with glucocorticoid-induced muscle atrophy. However, it remains unclear whether myostatin is involved in glucocorticoid-induced muscle protein turnover. The aim of the present study was to investigate the role of myostatin in protein metabolism during dexamethasone (DEX) treatment. Protein synthesis rates and the expression of the genes for myostatin, ubiquitin-proteasome atrogin-1, MuRF1, FoxO1/3a and mTOR/p70S6K were determined. The results show that DEX decreased (P<0.05) protein synthesis rates while increasing the abundance of myostatin. DEX increased (P<0.05) the level of phospho-FoxO1/3a (Thr 24/32) and the expression of MuRF1. In contrast, DEX treatment had no detectable effect on atrogin-1 protein levels (P>0.05). The phosphorylation levels of mTOR and p70S6K were decreased by DEX treatment (P<0.05). Follistatin treatment inhibited the DEX-induced increase in myostatin (P<0.05) and the activation of phosphor-FoxO1/3a (Thr 24/32) (P< 0.05) and MuRF1 (P<0.05). Follistatin treatment had no influence on the protein synthesis rate or on the phosphorylation levels of mTOR (Ser 2448) and p70S6K (Thr 389) (P> 0.05). In conclusion, the present study suggests that the myostatin signalling pathway is associated with glucocorticoid-induced muscle protein catabolism at the beginning of exposure. Myostatin is not a main pathway associated with the suppression of muscle protein synthesis by glucocorticoids. PMID:27227776

  19. Glucocorticoids Enhance Muscle Proteolysis through a Myostatin-Dependent Pathway at the Early Stage

    PubMed Central

    Wang, Ruxia; Jiao, Hongchao; Zhao, Jingpeng; Wang, Xiaojuan; Lin, Hai

    2016-01-01

    Myostatin, a member of the TGF-β superfamily of secreted proteins, is expressed primarily in skeletal muscle. It negatively regulates muscle mass and is associated with glucocorticoid-induced muscle atrophy. However, it remains unclear whether myostatin is involved in glucocorticoid-induced muscle protein turnover. The aim of the present study was to investigate the role of myostatin in protein metabolism during dexamethasone (DEX) treatment. Protein synthesis rates and the expression of the genes for myostatin, ubiquitin-proteasome atrogin-1, MuRF1, FoxO1/3a and mTOR/p70S6K were determined. The results show that DEX decreased (P<0.05) protein synthesis rates while increasing the abundance of myostatin. DEX increased (P<0.05) the level of phospho-FoxO1/3a (Thr 24/32) and the expression of MuRF1. In contrast, DEX treatment had no detectable effect on atrogin-1 protein levels (P>0.05). The phosphorylation levels of mTOR and p70S6K were decreased by DEX treatment (P<0.05). Follistatin treatment inhibited the DEX-induced increase in myostatin (P<0.05) and the activation of phosphor-FoxO1/3a (Thr 24/32) (P< 0.05) and MuRF1 (P<0.05). Follistatin treatment had no influence on the protein synthesis rate or on the phosphorylation levels of mTOR (Ser 2448) and p70S6K (Thr 389) (P> 0.05). In conclusion, the present study suggests that the myostatin signalling pathway is associated with glucocorticoid-induced muscle protein catabolism at the beginning of exposure. Myostatin is not a main pathway associated with the suppression of muscle protein synthesis by glucocorticoids. PMID:27227776

  20. A role for the mevalonate pathway in early plant symbiotic signaling

    PubMed Central

    Venkateshwaran, Muthusubramanian; Jayaraman, Dhileepkumar; Chabaud, Mireille; Genre, Andrea; Balloon, Allison J.; Maeda, Junko; Forshey, Kari; den Os, Désirée; Kwiecien, Nicholas W.; Coon, Joshua J.; Barker, David G.; Ané, Jean-Michel

    2015-01-01

    Rhizobia and arbuscular mycorrhizal fungi produce signals that are perceived by host legume receptors at the plasma membrane and trigger sustained oscillations of the nuclear and perinuclear Ca2+ concentration (Ca2+ spiking), which in turn leads to gene expression and downstream symbiotic responses. The activation of Ca2+ spiking requires the plasma membrane-localized receptor-like kinase Does not Make Infections 2 (DMI2) as well as the nuclear cation channel DMI1. A key enzyme regulating the mevalonate (MVA) pathway, 3-Hydroxy-3-Methylglutaryl CoA Reductase 1 (HMGR1), interacts with DMI2 and is required for the legume–rhizobium symbiosis. Here, we show that HMGR1 is required to initiate Ca2+ spiking and symbiotic gene expression in Medicago truncatula roots in response to rhizobial and arbuscular mycorrhizal fungal signals. Furthermore, MVA, the direct product of HMGR1 activity, is sufficient to induce nuclear-associated Ca2+ spiking and symbiotic gene expression in both wild-type plants and dmi2 mutants, but interestingly not in dmi1 mutants. Finally, MVA induced Ca2+ spiking in Human Embryonic Kidney 293 cells expressing DMI1. This demonstrates that the nuclear cation channel DMI1 is sufficient to support MVA-induced Ca2+ spiking in this heterologous system. PMID:26199419

  1. A constitutive active MAPK/ERK pathway due to BRAFV600E positively regulates AHR pathway in PTC.

    PubMed

    Occhi, Gianluca; Barollo, Susi; Regazzo, Daniela; Bertazza, Loris; Galuppini, Francesca; Guzzardo, Vincenza; Jaffrain-Rea, Marie Lise; Vianello, Federica; Ciato, Denis; Ceccato, Filippo; Watutantrige-Fernando, Sara; Bisognin, Andrea; Bortoluzzi, Stefania; Pennelli, Gianmaria; Boscaro, Marco; Scaroni, Carla; Mian, Caterina

    2015-10-13

    The aryl hydrocarbon receptor (AHR) is a ligand-activated transcription factor mediating the toxicity and tumor-promoting properties of dioxin. AHR has been reported to be overexpressed and constitutively active in a variety of solid tumors, but few data are currently available concerning its role in thyroid cancer. In this study we quantitatively explored a series of 51 paired-normal and papillary thyroid carcinoma (PTC) tissues for AHR-related genes. We identified an increased AHR expression/activity in PTC, independently from its nuclear dimerization partner and repressor but strictly related to a constitutive active MAPK/ERK pathway. The AHR up-regulation followed by an increased expression of AHR target genes was confirmed by a meta-analysis of published microarray data, suggesting a ligand-independent active AHR pathway in PTC. In-vitro studies using a PTC-derived cell line (BCPAP) and HEK293 cells showed that BRAFV600E may directly modulate AHR localization, induce AHR expression and activity in an exogenous ligand-independent manner. The AHR pathway might represent a potential novel therapeutic target for PTC in the clinical practice. PMID:26392334

  2. Inhibition of Microglia Activation as a Phenotypic Assay in Early Drug Discovery

    PubMed Central

    Figuera-Losada, Mariana; Rojas, Camilo; Slusher, Barbara S.

    2014-01-01

    Complex biological processes such as inflammation, cell death, migration, proliferation, and the release of biologically active molecules can be used as outcomes in phenotypic assays during early stages of drug discovery. Although target-based approaches have been widely used over the past decades, a disproportionate number of first-in-class drugs have been identified using phenotypic screening. This review details phenotypic assays based on inhibition of microglial activation and their utility in primary and secondary screening, target validation, and pathway elucidation. The role of microglia, both in normal as well as in pathological conditions such as chronic neurodegenerative diseases, is reviewed. Methodologies to assess microglia activation in vitro are discussed in detail, and classes of therapeutic drugs known to decrease the proinflammatory and cytotoxic responses of activated microglia are appraised, including inhibitors of glutaminase, cystine/glutamate antiporter, nuclear factor κB, and mitogen-activated protein kinases. PMID:23945875

  3. Antibody-independent activation of the classical pathway of complement by Epstein-Barr virus.

    PubMed

    Martin, H; McConnell, I; Gorick, B; Hughes-Jones, N C

    1987-03-01

    A purified preparation of Epstein-Barr virus (EBV) has been shown to activate the classical complement pathway by direct interaction with the first component of complement, C1, without the intervention of antibody. No evidence was found for activation of the alternative pathway. Following classical pathway activation the specific affinity of EBV for B cells can be presumed to be lost since the virus will become opsonized for clearance by phagocytic cells bearing complement receptors, CR1 and CR3. This activation is further evidence that complement plays a role in defence mechanisms independently of antibody activity. PMID:3038440

  4. Prediction of Pathway Activation by Xenobiotic-Responsive Transcription Factors in the Mouse Liver

    EPA Science Inventory

    Many drugs and environmentally-relevant chemicals activate xenobioticresponsive transcription factors (TF). Identification of target genes of these factors would be useful in predicting pathway activation in in vitro chemical screening. Starting with a large compendium of Affymet...

  5. Canonical Wnt Signaling Activity in Early Stages of Chick Lung Development

    PubMed Central

    daMota, Paulo; Correia-Pinto, Jorge

    2014-01-01

    Wnt signaling pathway is an essential player during vertebrate embryonic development which has been associated with several developmental processes such as gastrulation, body axis formation and morphogenesis of numerous organs, namely the lung. Wnt proteins act through specific transmembrane receptors, which activate intracellular pathways that regulate cellular processes such as cell proliferation, differentiation and death. Morphogenesis of the fetal lung depends on epithelial-mesenchymal interactions that are governed by several growth and transcription factors that regulate cell proliferation, fate, migration and differentiation. This process is controlled by different signaling pathways such as FGF, Shh and Wnt among others. Wnt signaling is recognized as a key molecular player in mammalian pulmonary development but little is known about its function in avian lung development. The present work characterizes, for the first time, the expression pattern of several Wnt signaling members, such as wnt-1, wnt-2b, wnt-3a, wnt-5a, wnt-7b, wnt-8b, wnt-9a, lrp5, lrp6, sfrp1, dkk1, β-catenin and axin2 at early stages of chick lung development. In general, their expression is similar to their mammalian counterparts. By assessing protein expression levels of active/total β-catenin and phospho-LRP6/LRP6 it is revealed that canonical Wnt signaling is active in this embryonic tissue. In vitro inhibition studies were performed in order to evaluate the function of Wnt signaling pathway in lung branching. Lung explants treated with canonical Wnt signaling inhibitors (FH535 and PK115-584) presented an impairment of secondary branch formation after 48 h of culture along with a decrease in axin2 expression levels. Branching analysis confirmed this inhibition. Wnt-FGF crosstalk assessment revealed that this interaction is preserved in the chick lung. This study demonstrates that Wnt signaling is crucial for precise chick lung branching and further supports the avian lung as a good

  6. Activation of the ATM-Snail pathway promotes breast cancer metastasis

    PubMed Central

    Sun, Mianen; Guo, Xiaojing; Qian, Xiaolong; Wang, Haibo; Yang, Chunying; Brinkman, Kathryn L.; Serrano-Gonzalez, Monica; Jope, Richard S.; Zhou, Binhua; Engler, David A.; Zhan, Ming; Wong, Stephen T.C.; Fu, Li; Xu, Bo

    2012-01-01

    The DNA damage response (DDR) is critical for the maintenance of genetic stability and serves as an anti-cancer barrier during early tumorigenesis. However, the role of the DDR in tumor progression and metastasis is less known. Here, we demonstrate that the ATM kinase, one of the critical DDR elements, is hyperactive in late stage breast tumor tissues with lymph-node metastasis and this hyperactivity correlates with elevated expression of the epithelial–mesenchymal transition marker, Snail. At the molecular level, we demonstrate that ATM regulates Snail stabilization by phosphorylation on Serine-100. Using mass spectrometry, we identified HSP90 as a critical binding protein of Snail in response to DNA damage. HSP90 binds to and stabilizes phosphorylated Snail. We further provide in vitro and in vivo evidence that activation of ATM-mediated Snail phosphorylation promotes tumor invasion and metastasis. Finally, we demonstrate that Snail Serine-100 phosphorylation is elevated in breast cancer tissues with lymph-node metastasis, indicating clinical significance of the ATM-Snail pathway. Together, our findings provide strong evidence that the ATM-Snail pathway promotes tumor metastasis, highlighting a previously undescribed role of the DDR in tumor invasion and metastasis. PMID:22923499

  7. Early microglia activation in a mouse model of chronic glaucoma

    PubMed Central

    Bosco, Alejandra; Steele, Michael R.; Vetter, Monica L.

    2014-01-01

    Changes in microglial cell activation and distribution are associated with neuronal decline in the CNS, particularly under pathological conditions. Activated microglia converge on the initial site of axonal degeneration in human glaucoma, yet, their part in its pathophysiology remains unresolved. To begin with, it is unknown whether microglia activation precedes or is a late consequence of retinal ganglion cell (RGC) neurodegeneration. Here, we address this critical element in DBA/2J (D2) mice, an established model of chronic inherited glaucoma, using as a control the congenic substrain DBA/2J Gpnmb+/SjJ (D2G), which is not affected by glaucoma. We analyzed the spatial distribution and timecourse of microglial changes in the retina, as well as within the proximal optic nerve prior to and throughout ages when neurodegeneration has been reported. Exclusively in D2 mice, we detected early microglia clustering in the inner central retina and unmyelinated optic nerve regions, with microglia activation peaking by 3 months of age. Between 5 and 8 months of age, activated microglia persisted and concentrated in the optic disc, but also localized to the retinal periphery. Collectively, our findings suggest microglia activation is an early alteration in the retina and optic nerve in D2 glaucoma, potentially contributing to disease onset or progression. Ultimately, detection of microglial activation may have value in early disease diagnosis, while modulation of microglial responses may alter disease progression. PMID:21246546

  8. Communicating and Thinking through Drawing Activity in Early Childhood

    ERIC Educational Resources Information Center

    Papandreou, Maria

    2014-01-01

    This article considers drawing as a meaning-making activity that takes place in certain sociocultural contexts to find evidence for its communicative potentials as well as the relationship between thought and drawing in early childhood. The researcher challenges traditional views about young children's drawing that focus on the result of the…

  9. Teaching Adults, Revisited: Active Learning for Early Childhood Educators

    ERIC Educational Resources Information Center

    Jones, Elizabeth

    2007-01-01

    This book follows master educator Elizabeth (Betty) Jones as she teaches an introductory course in early childhood education. She actively engages the students, encouraging them to make decisions, ask questions, and engage in collaborative problem solving--herself modeling the behaviors that should be practiced by adults working with young…

  10. Angiogenic activity of sesamin through the activation of multiple signal pathways

    SciTech Connect

    Chung, Byung-Hee; Lee, Jung Joon; Kim, Jong-Dai; Jeoung, Dooil; Lee, Hansoo; Choe, Jongseon; Ha, Kwon-Soo; Kwon, Young-Geun; Kim, Young-Myeong

    2010-01-01

    The natural product sesamin has been known to act as a potent antioxidant and prevent endothelial dysfunction. We here found that sesamin increased in vitro angiogenic processes, such as endothelial cell proliferation, migration, and tube formation, as well as neovascularization in an animal model. This compound elicited the activation of multiple angiogenic signal modulators, such as ERK, Akt, endothelial nitric oxide synthase (eNOS), NO production, FAK, and p38 MAPK, but not Src. The MEK inhibitor PD98059 and the PI3K inhibitor Wortmannin specifically inhibited sesamin-induced activation of the ERK and Akt/eNOS pathways. These inhibitors reduced angiogenic events, with high specificity for MEK/ERK-dependent cell proliferation and migration and PI3K/Akt-mediated tube formation. Moreover, inhibition of p38 MAPK effectively inhibited sesamin-induced cell migration. The angiogenic activity of sesamin was not associated with VEGF expression. Furthermore, this compound did not induce vascular permeability and upregulated ICAM-1 and VCAM-1 expression, which are hallmarks of vascular inflammation. These results suggest that sesamin stimulates angiogenesis in vitro and in vivo through the activation of MEK/ERK-, PI3K/Akt/eNOS-, p125{sup FAK}-, and p38 MAPK-dependent pathways, without increasing vascular inflammation, and may be used for treating ischemic diseases and tissue regeneration.

  11. Xylazine Activates Adenosine Monophosphate-Activated Protein Kinase Pathway in the Central Nervous System of Rats.

    PubMed

    Shi, Xing-Xing; Yin, Bai-Shuang; Yang, Peng; Chen, Hao; Li, Xin; Su, Li-Xue; Fan, Hong-Gang; Wang, Hong-Bin

    2016-01-01

    Xylazine is a potent analgesic extensively used in veterinary and animal experimentation. Evidence exists that the analgesic effect can be inhibited using adenosine 5'-monophosphate activated protein kinase (AMPK) inhibitors. Considering this idea, the aim of this study was to investigate whether the AMPK signaling pathway is involved in the central analgesic mechanism of xylazine in the rat. Xylazine was administrated via the intraperitoneal route. Sprague-Dawley rats were sacrificed and the cerebral cortex, cerebellum, hippocampus, thalamus and brainstem were collected for determination of liver kinase B1 (LKB1) and AMPKα mRNA expression using quantitative real-time polymerase chain reaction (qPCR), and phosphorylated LKB1 and AMPKα levels using western blot. The results of our study showed that compared with the control group, xylazine induced significant increases in AMPK activity in the cerebral cortex, hippocampus, thalamus and cerebellum after rats received xylazine (P < 0.01). Increased AMPK activities were accompanied with increased phosphorylation levels of LKB1 in corresponding regions of rats. The protein levels of phosphorylated LKB1 and AMPKα in these regions returned or tended to return to control group levels. However, in the brainstem, phosphorylated LKB1 and AMPKα protein levels were decreased by xylazine compared with the control (P < 0.05). In conclusion, our data indicates that xylazine alters the activities of LKB1 and AMPK in the central nervous system of rats, which suggests that xylazine affects the regulatory signaling pathway of the analgesic mechanism in the rat brain. PMID:27049320

  12. Telomerase Activity is Downregulated Early During Human Brain Development

    PubMed Central

    Ishaq, Abbas; Hanson, Peter S.; Morris, Christopher M.; Saretzki, Gabriele

    2016-01-01

    Changes in hTERT splice variant expression have been proposed to facilitate the decrease of telomerase activity during fetal development in various human tissues. Here, we analyzed the expression of telomerase RNA (hTR), wild type and α-spliced hTERT in developing human fetal brain (post conception weeks, pcw, 6–19) and in young and old cortices using qPCR and correlated it to telomerase activity measured by TRAP assay. Decrease of telomerase activity occurred early during brain development and correlated strongest to decreased hTR expression. The expression of α-spliced hTERT increased between pcw 10 and 19, while that of wild type hTERT remained unchanged. Lack of expression differences between young and old cortices suggests that most changes seem to occur early during human brain development. Using in vitro differentiation of neural precursor stem cells (NPSCs) derived at pcw 6 we found a decrease in telomerase activity but no major expression changes in telomerase associated genes. Thus, they do not seem to model the mechanisms for the decrease in telomerase activity in fetal brains. Our results suggest that decreased hTR levels, as well as transient increase in α-spliced hTERT, might both contribute to downregulation of telomerase activity during early human brain development between 6 and 17 pcw. PMID:27322326

  13. Telomerase Activity is Downregulated Early During Human Brain Development.

    PubMed

    Ishaq, Abbas; Hanson, Peter S; Morris, Christopher M; Saretzki, Gabriele

    2016-01-01

    Changes in hTERT splice variant expression have been proposed to facilitate the decrease of telomerase activity during fetal development in various human tissues. Here, we analyzed the expression of telomerase RNA (hTR), wild type and α-spliced hTERT in developing human fetal brain (post conception weeks, pcw, 6-19) and in young and old cortices using qPCR and correlated it to telomerase activity measured by TRAP assay. Decrease of telomerase activity occurred early during brain development and correlated strongest to decreased hTR expression. The expression of α-spliced hTERT increased between pcw 10 and 19, while that of wild type hTERT remained unchanged. Lack of expression differences between young and old cortices suggests that most changes seem to occur early during human brain development. Using in vitro differentiation of neural precursor stem cells (NPSCs) derived at pcw 6 we found a decrease in telomerase activity but no major expression changes in telomerase associated genes. Thus, they do not seem to model the mechanisms for the decrease in telomerase activity in fetal brains. Our results suggest that decreased hTR levels, as well as transient increase in α-spliced hTERT, might both contribute to downregulation of telomerase activity during early human brain development between 6 and 17 pcw. PMID:27322326

  14. SOX9 drives WNT pathway activation in prostate cancer

    PubMed Central

    Ma, Fen; Ye, Huihui; He, Housheng Hansen; Gerrin, Sean J.; Chen, Sen; Tanenbaum, Benjamin A.; Sowalsky, Adam G.; He, Lingfeng; Wang, Hongyun; Balk, Steven P.; Yuan, Xin

    2016-01-01

    The transcription factor SOX9 is critical for prostate development, and dysregulation of SOX9 is implicated in prostate cancer (PCa). However, the SOX9-dependent genes and pathways involved in both normal and neoplastic prostate epithelium are largely unknown. Here, we performed SOX9 ChIP sequencing analysis and transcriptome profiling of PCa cells and determined that SOX9 positively regulates multiple WNT pathway genes, including those encoding WNT receptors (frizzled [FZD] and lipoprotein receptor-related protein [LRP] family members) and the downstream β-catenin effector TCF4. Analyses of PCa xenografts and clinical samples both revealed an association between the expression of SOX9 and WNT pathway components in PCa. Finally, treatment of SOX9-expressing PCa cells with a WNT synthesis inhibitor (LGK974) reduced WNT pathway signaling in vitro and tumor growth in murine xenograft models. Together, our data indicate that SOX9 expression drives PCa by reactivating the WNT/β−catenin signaling that mediates ductal morphogenesis in fetal prostate and define a subgroup of patients who would benefit from WNT-targeted therapy. PMID:27043282

  15. Nanometer Scale Titanium Surface Texturing Are Detected by Signaling Pathways Involving Transient FAK and Src Activations

    PubMed Central

    Zambuzzi, Willian F.; Bonfante, Estevam A.; Jimbo, Ryo; Hayashi, Mariko; Andersson, Martin; Alves, Gutemberg; Takamori, Esther R.; Beltrão, Paulo J.; Coelho, Paulo G.; Granjeiro, José M.

    2014-01-01

    Background It is known that physico/chemical alterations on biomaterial surfaces have the capability to modulate cellular behavior, affecting early tissue repair. Such surface modifications are aimed to improve early healing response and, clinically, offer the possibility to shorten the time from implant placement to functional loading. Since FAK and Src are intracellular proteins able to predict the quality of osteoblast adhesion, this study evaluated the osteoblast behavior in response to nanometer scale titanium surface texturing by monitoring FAK and Src phosphorylations. Methodology Four engineered titanium surfaces were used for the study: machined (M), dual acid-etched (DAA), resorbable media microblasted and acid-etched (MBAA), and acid-etch microblasted (AAMB). Surfaces were characterized by scanning electron microscopy, interferometry, atomic force microscopy, x-ray photoelectron spectroscopy and energy dispersive X-ray spectroscopy. Thereafter, those 4 samples were used to evaluate their cytotoxicity and interference on FAK and Src phosphorylations. Both Src and FAK were investigated by using specific antibody against specific phosphorylation sites. Principal Findings The results showed that both FAK and Src activations were differently modulated as a function of titanium surfaces physico/chemical configuration and protein adsorption. Conclusions It can be suggested that signaling pathways involving both FAK and Src could provide biomarkers to predict osteoblast adhesion onto different surfaces. PMID:24999733

  16. Activation of signalling pathways during hepatocyte isolation: relevance to toxicology in vitro.

    PubMed

    Paine, Alan J; Andreakos, Evangelos

    2004-04-01

    The "Holy Grail" of in vitro toxicology is to develop assay systems that mimic the in vivo situation and hence reduce the need for toxicity tests employing experimental animals. However a major problem to be overcome with cell culture models is the rapid loss of differentiated phenotype that markedly limits extrapolation of results to the whole animal (i.e. human) situation. This limitation is most obvious in the application of hepatocyte cultures to predict pathways of metabolism mediated toxicity and results from the rapid loss of cytochrome P450 content. Here we demonstrate that changes in hepatocyte gene expression (e.g. MAP kinase and NF-kappaB activation) occur very early into the well established hepatocyte isolation procedure employing collagenase suggesting that hepatocytes are undergoing a pro-inflammatory ('acute phase') response before they are cultured. Data is presented indicating that the stimulus is, in part, due to oxidative stress but the demonstration of endotoxins in collagenase preparations is likely to exacerbate the situation. Thus appreciation of these early events during hepatocyte isolation represents the surest foundation for the successful application of cultured hepatocytes to toxicology rather than relying on traditional manipulations of hepatocyte culture medium/substratum once differentiated phenotype has already been lost. PMID:14757109

  17. Pathway modeling of microarray data: A case study of pathway activity changes in the testis following in utero exposure to dibutyl phthalate (DBP)

    SciTech Connect

    Ovacik, Meric A.; Sen, Banalata; Euling, Susan Y.; Gaido, Kevin W.; Ierapetritou, Marianthi G.; Androulakis, Ioannis P.

    2013-09-15

    Pathway activity level analysis, the approach pursued in this study, focuses on all genes that are known to be members of metabolic and signaling pathways as defined by the KEGG database. The pathway activity level analysis entails singular value decomposition (SVD) of the expression data of the genes constituting a given pathway. We explore an extension of the pathway activity methodology for application to time-course microarray data. We show that pathway analysis enhances our ability to detect biologically relevant changes in pathway activity using synthetic data. As a case study, we apply the pathway activity level formulation coupled with significance analysis to microarray data from two different rat testes exposed in utero to Dibutyl Phthalate (DBP). In utero DBP exposure in the rat results in developmental toxicity of a number of male reproductive organs, including the testes. One well-characterized mode of action for DBP and the male reproductive developmental effects is the repression of expression of genes involved in cholesterol transport, steroid biosynthesis and testosterone synthesis that lead to a decreased fetal testicular testosterone. Previous analyses of DBP testes microarray data focused on either individual gene expression changes or changes in the expression of specific genes that are hypothesized, or known, to be important in testicular development and testosterone synthesis. However, a pathway analysis may inform whether there are additional affected pathways that could inform additional modes of action linked to DBP developmental toxicity. We show that Pathway activity analysis may be considered for a more comprehensive analysis of microarray data.

  18. Silver nanoparticles/chitosan oligosaccharide/poly(vinyl alcohol) nanofiber promotes wound healing by activating TGFβ1/Smad signaling pathway

    PubMed Central

    Li, Chen-wen; Wang, Qing; Li, Jing; Hu, Min; Shi, San-jun; Li, Zi-wei; Wu, Guo-lin; Cui, Huan-huan; Li, Yuan-yuan; Zhang, Qian; Yu, Xiu-heng; Lu, Lai-chun

    2016-01-01

    Wound healing occupies a remarkable place in everyday pathology and remains a challenging clinical problem. In our previous study, we prepared a silver nanoparticle/chitosan oligosaccharide/poly(vinyl alcohol) (PVA/COS-AgNPs) nanofiber via electrospinning and revealed that it could promote wound healing; however, the healing mechanism remained unknown. Therefore, we aimed to clarify the mechanism underlying the accelerated healing effect of the PVA/COS-AgNPs nanofiber. The TGFβ1/Smad signaling pathway is actively involved in wound healing. Considering the key role of this signaling pathway in wound healing, our preliminary study showed that the TGFβ1 level was significantly increased during the early stage of wound healing. Thus, in this study, hematoxylin–eosin, Masson’s trichrome, immunofluorescent staining, hydroxyproline content, quantitative real-time polymerase chain reaction, and Western blot analyses were used to analyze the wound healing in a rat model treated with gauze, the PVA/COS-AgNPs nanofiber, and the nanofiber plus SB431542 (an inhibitor of TGFβ1 receptor kinase). The results showed that the PVA/COS-AgNPs nanofiber promoted wound healing and upregulated the expression levels of cytokines associated with the TGFβ1/Smad signaling pathway such as TGFβ1, TGFβRI, TGFβRII, collagen I, collagen III, pSmad2, and pSmad3. Inhibiting this pathway with SB431542 resulted in prevention of the PVA/COS-AgNPs nanofiber-associated salutary effects on the early stage of wound healing and relative cytokines expression. In conclusion, the wound healing effect of the PVA/COS-AgNPs nanofiber involves activation of the TGFβ1/Smad signaling pathway. PMID:26855575

  19. Silver nanoparticles/chitosan oligosaccharide/poly(vinyl alcohol) nanofiber promotes wound healing by activating TGFβ1/Smad signaling pathway.

    PubMed

    Li, Chen-wen; Wang, Qing; Li, Jing; Hu, Min; Shi, San-jun; Li, Zi-wei; Wu, Guo-lin; Cui, Huan-huan; Li, Yuan-yuan; Zhang, Qian; Yu, Xiu-heng; Lu, Lai-chun

    2016-01-01

    Wound healing occupies a remarkable place in everyday pathology and remains a challenging clinical problem. In our previous study, we prepared a silver nanoparticle/chitosan oligosaccharide/poly(vinyl alcohol) (PVA/COS-AgNPs) nanofiber via electrospinning and revealed that it could promote wound healing; however, the healing mechanism remained unknown. Therefore, we aimed to clarify the mechanism underlying the accelerated healing effect of the PVA/COS-AgNPs nanofiber. The TGFβ1/Smad signaling pathway is actively involved in wound healing. Considering the key role of this signaling pathway in wound healing, our preliminary study showed that the TGFβ1 level was significantly increased during the early stage of wound healing. Thus, in this study, hematoxylin-eosin, Masson's trichrome, immunofluorescent staining, hydroxyproline content, quantitative real-time polymerase chain reaction, and Western blot analyses were used to analyze the wound healing in a rat model treated with gauze, the PVA/COS-AgNPs nanofiber, and the nanofiber plus SB431542 (an inhibitor of TGFβ1 receptor kinase). The results showed that the PVA/COS-AgNPs nanofiber promoted wound healing and upregulated the expression levels of cytokines associated with the TGFβ1/Smad signaling pathway such as TGFβ1, TGFβRI, TGFβRII, collagen I, collagen III, pSmad2, and pSmad3. Inhibiting this pathway with SB431542 resulted in prevention of the PVA/COS-AgNPs nanofiber-associated salutary effects on the early stage of wound healing and relative cytokines expression. In conclusion, the wound healing effect of the PVA/COS-AgNPs nanofiber involves activation of the TGFβ1/Smad signaling pathway. PMID:26855575

  20. Semantic Wavelet-Induced Frequency-Tagging (SWIFT) Periodically Activates Category Selective Areas While Steadily Activating Early Visual Areas

    PubMed Central

    Koenig-Robert, Roger; VanRullen, Rufin; Tsuchiya, Naotsugu

    2015-01-01

    Primate visual systems process natural images in a hierarchical manner: at the early stage, neurons are tuned to local image features, while neurons in high-level areas are tuned to abstract object categories. Standard models of visual processing assume that the transition of tuning from image features to object categories emerges gradually along the visual hierarchy. Direct tests of such models remain difficult due to confounding alteration in low-level image properties when contrasting distinct object categories. When such contrast is performed in a classic functional localizer method, the desired activation in high-level visual areas is typically accompanied with activation in early visual areas. Here we used a novel image-modulation method called SWIFT (semantic wavelet-induced frequency-tagging), a variant of frequency-tagging techniques. Natural images modulated by SWIFT reveal object semantics periodically while keeping low-level properties constant. Using functional magnetic resonance imaging (fMRI), we indeed found that faces and scenes modulated with SWIFT periodically activated the prototypical category-selective areas while they elicited sustained and constant responses in early visual areas. SWIFT and the localizer were selective and specific to a similar extent in activating category-selective areas. Only SWIFT progressively activated the visual pathway from low- to high-level areas, consistent with predictions from standard hierarchical models. We confirmed these results with criterion-free methods, generalizing the validity of our approach and show that it is possible to dissociate neural activation in early and category-selective areas. Our results provide direct evidence for the hierarchical nature of the representation of visual objects along the visual stream and open up future applications of frequency-tagging methods in fMRI. PMID:26691722

  1. Transport through the yeast endocytic pathway occurs through morphologically distinct compartments and requires an active secretory pathway and Sec18p/N-ethylmaleimide-sensitive fusion protein.

    PubMed Central

    Hicke, L; Zanolari, B; Pypaert, M; Rohrer, J; Riezman, H

    1997-01-01

    Molecules travel through the yeast endocytic pathway from the cell surface to the lysosome-like vacuole by passing through two sequential intermediates. Immunofluorescent detection of an endocytosed pheromone receptor was used to morphologically identify these intermediates, the early and late endosomes. The early endosome is a peripheral organelle that is heterogeneous in appearance, whereas the late endosome is a large perivacuolar compartment that corresponds to the prevacuolar compartment previously shown to be an endocytic intermediate. We demonstrate that inhibiting transport through the early secretory pathway in sec mutants quickly impedes transport from the early endosome. Treatment of sensitive cells with brefeldin A also blocks transport from this compartment. We provide evidence that Sec18p/N-ethylmaleimide-sensitive fusion protein, a protein required for membrane fusion, is directly required in vivo for forward transport early in the endocytic pathway. Inhibiting protein synthesis does not affect transport from the early endosome but causes endocytosed proteins to accumulate in the late endosome. As newly synthesized proteins and the late steps of secretion are not required for early to late endosome transport, but endoplasmic reticulum through Golgi traffic is, we propose that efficient forward transport in the early endocytic pathway requires delivery of lipid from secretory organelles to endosomes. Images PMID:9017592

  2. Activation of factor XII-dependent pathways in human plasma by hematin and protoporphyrin.

    PubMed Central

    Becker, C G; Wagner, M; Kaplan, A P; Silverberg, M; Grady, R W; Liem, H; Muller-Eberhard, U

    1985-01-01

    Intravenous administration of hematin is effective in the treatment of acute exacerbations of the inducible porphyrias. In the course of such treatment, coagulopathies have occurred that are characterized by prolongation of prothrombin time, partial thromboplastin time, and formation of fibrin split products. In experiments in vitro with normal human plasma, we observed that hematin and protoporphyrin activated Factor XII-dependent pathways of coagulation and fibrinolysis, and that they generated kallikrein activity. Incubation of protoporphyrin with purified Factor XII resulted in activation as measured by amidolysis of a chromogenic substrate. Neither coproporphyrin, uroporphyrin, delta-aminolevulinic acid, porphobilinogen, or bilirubin activated Factor XII-dependent pathways. Exposure of serum containing added uroporphyrin, coproporphyrin, and protoporphyrin, but not hematin, to ultraviolet light (405 nm) resulted in activation of the classical pathway of the complement system. On the other hand, exposure of plasma containing uroporphyrin or coproporphyrin to ultraviolet light did not result in activation of Factor XII-dependent pathways. PMID:4031058

  3. Ammonium Activates Ouabain-Activated Signalling Pathway in Astrocytes: Therapeutic Potential of Ouabain Antagonist

    PubMed Central

    Song, Dan; Du, Ting

    2014-01-01

    The causal role of ammonium in hepatic encephalopathy was identified in 1930s. Astroglial cells are primary cellular elements of hepatic encephalopathy which conceptually, can be considered a toxic astrogliopathology. Previously we have reported that acute exposure to ammonium activated ouabain/Na,K-ATPase signalling pathway, which includes Src, EGF receptor, Raf, Ras, MEK and ERK1/2. Chronic incubation of astrocytes with ammonium increased production of endogenous ouabain-like compound. Ouabain antagonist canrenone abolished effects of ammonium on astrocytic swelling, ROS production, and upregulation of gene expression and function of TRPC1 and Cav1.2. However, ammonium induces multiple pathological modifications in astrocytes, and some of them may be not related to this signalling pathway. In this review, we focus on the effect of ammonium on ouabain/Na,K-ATPase signalling pathway and its involvement in ammonium-induced ROS production, cell swelling and aberration of Ca2+ signals in astrocytes. We also briefly discuss Na,K-ATPase, EGF receptor, endogenous ouabain and ouabain antagonist. PMID:25342941

  4. Developmental pathways from childhood aggression-disruptiveness, chronic peer rejection, and deviant friendships to early-adolescent rule breaking.

    PubMed

    Ettekal, Idean; Ladd, Gary W

    2015-01-01

    Childhood aggression-disruptiveness (AD), chronic peer rejection, and deviant friendships were examined as predictors of early-adolescent rule-breaking behaviors. Using a sample of 383 children (193 girls and 190 boys) who were followed from ages 6 to 14, peer rejection trajectories were identified and incorporated into a series of alternative models to assess how chronic peer rejection and deviant friendships mediate the association between stable childhood AD and early-adolescent rule breaking. There were multiple mediated pathways to rule breaking that included both behavioral and relational risk factors, and findings were consistent for boys and girls. Results have implications for better understanding the influence of multiple social processes in the continuity of antisocial behaviors from middle childhood to early adolescence. PMID:25403544

  5. Developmental Pathways from Childhood Aggression-Disruptiveness, Chronic Peer Rejection and Deviant Friendships to Early-Adolescent Rule Breaking

    PubMed Central

    Ettekal, Idean; Ladd, Gary W.

    2015-01-01

    Childhood aggression-disruptiveness, chronic peer rejection, and deviant friendships were examined as predictors of early-adolescent rule breaking behaviors. Using a sample of 383 children (193 girls and 190 boys) who were followed from ages 6 to 14, peer rejection trajectories were identified and incorporated into a series of alternative models to assess how chronic peer rejection and deviant friendships mediate the association between stable childhood aggression-disruptiveness and early-adolescent rule breaking. There were multiple mediated pathways to rule breaking that included both behavioral and relational risk factors and findings were consistent for boys and girls. Results have implications for better understanding the influence of multiple social processes in the continuity of antisocial behaviors from middle childhood to early adolescence. PMID:25403544

  6. JNK and p38 mitogen-activated protein kinase pathways contribute to porcine epidemic diarrhea virus infection.

    PubMed

    Lee, Changhee; Kim, Youngnam; Jeon, Ji Hyun

    2016-08-15

    The mitogen-activated protein kinase (MAPK) pathways, which are central building blocks in the intracellular signaling network, are often manipulated by viruses of diverse families to favor their replication. Among the MAPK family, the extracellular signal-regulated kinase (ERK) pathway is known to be modulated during the infection with porcine epidemic diarrhea virus (PEDV); however, involvement of stress-activated protein kinases (SAPKs) comprising p38 MAPK and c-Jun NH2-terminal kinase (JNK) remains to be determined. Therefore, in the present study, we investigated whether activation of p38 MAPK and JNK cascades is required for PEDV replication. Our results showed that PEDV activates p38 MAPK and JNK1/2 up to 24h post-infection, whereas, thereafter their phosphorylation levels recede to baseline levels or even fall below them. Notably, UV-irradiated inactivated PEDV, which can enter cells but cannot replicate inside them, failed to induce phosphorylation of p38 MAPK and JNK1/2 suggesting that viral biosynthesis is essential for activation of these kinases. Treatment of cells with selective p38 or JNK inhibitors markedly impaired PEDV replication in a dose-dependent manner and these antiviral effects were found to be maximal during the early times of the infection. Furthermore, direct pharmacological inhibition of p38 MAPK or JNK1/2 activation resulted in a significant reduction of viral RNA synthesis, viral protein expression, and progeny release. However, independent treatments with either SAPK inhibitor did not inhibit PEDV-induced apoptotic cell death mediated by activation of mitochondrial apoptosis-inducing factor (AIF) suggesting that SAPKs are irrelevant to the apoptosis pathway during PEDV infection. In summary, our data demonstrated critical roles of the p38 and JNK1/2 signaling pathways in facilitating successful viral infection during the post-entry steps of the PEDV life cycle. PMID:27215486

  7. Naphthazarin protects against glutamate-induced neuronal death via activation of the Nrf2/ARE pathway

    SciTech Connect

    Son, Tae Gen; Kawamoto, Elisa M.; Yu, Qian-Sheng; Greig, Nigel H.; Mattson, Mark P.; Camandola, Simonetta

    2013-04-19

    Highlights: •Naphthazarin activates the Nrf2/ARE pathway. •Naphthazarin induces Nrf2-driven genes in neurons and astrocytes. •Naphthazarin protects neurons against excitotoxicity. -- Abstract: Nuclear factor E2-related factor 2 (Nrf2)/antioxidant response element (ARE) pathway is an important cellular stress response pathway involved in neuroprotection. We previously screened several natural phytochemicals and identified plumbagin as a novel activator of the Nrf2/ARE pathway that can protect neurons against ischemic injury. Here we extended our studies to natural and synthetic derivatives of plumbagin. We found that 5,8-dimethoxy-1,4-naphthoquinone (naphthazarin) is a potent activator of the Nrf2/ARE pathway, up-regulates the expression of Nrf2-driven genes in primary neuronal and glial cultures, and protects neurons against glutamate-induced excitotoxicity.

  8. Exome capture sequencing of adenoma reveals genetic alterations in multiple cellular pathways at the early stage of colorectal tumorigenesis.

    PubMed

    Zhou, Donger; Yang, Liu; Zheng, Liangtao; Ge, Weiting; Li, Dan; Zhang, Yong; Hu, Xueda; Gao, Zhibo; Xu, Jinghong; Huang, Yanqin; Hu, Hanguang; Zhang, Hang; Zhang, Hao; Liu, Mingming; Yang, Huanming; Zheng, Lei; Zheng, Shu

    2013-01-01

    Most of colorectal adenocarcinomas are believed to arise from adenomas, which are premalignant lesions. Sequencing the whole exome of the adenoma will help identifying molecular biomarkers that can predict the occurrence of adenocarcinoma more precisely and help understanding the molecular pathways underlying the initial stage of colorectal tumorigenesis. We performed the exome capture sequencing of the normal mucosa, adenoma and adenocarcinoma tissues from the same patient and sequenced the identified mutations in additional 73 adenomas and 288 adenocarcinomas. Somatic single nucleotide variations (SNVs) were identified in both the adenoma and adenocarcinoma by comparing with the normal control from the same patient. We identified 12 nonsynonymous somatic SNVs in the adenoma and 42 nonsynonymous somatic SNVs in the adenocarcinoma. Most of these mutations including OR6X1, SLC15A3, KRTHB4, RBFOX1, LAMA3, CDH20, BIRC6, NMBR, GLCCI1, EFR3A, and FTHL17 were newly reported in colorectal adenomas. Functional annotation of these mutated genes showed that multiple cellular pathways including Wnt, cell adhesion and ubiquitin mediated proteolysis pathways were altered genetically in the adenoma and that the genetic alterations in the same pathways persist in the adenocarcinoma. CDH20 and LAMA3 were mutated in the adenoma while NRXN3 and COL4A6 were mutated in the adenocarcinoma from the same patient, suggesting for the first time that genetic alterations in the cell adhesion pathway occur as early as in the adenoma. Thus, the comparison of genomic mutations between adenoma and adenocarcinoma provides us a new insight into the molecular events governing the early step of colorectal tumorigenesis. PMID:23301059

  9. Exploring the Early Organization and Maturation of Linguistic Pathways in the Human Infant Brain.

    PubMed

    Dubois, Jessica; Poupon, Cyril; Thirion, Bertrand; Simonnet, Hina; Kulikova, Sofya; Leroy, François; Hertz-Pannier, Lucie; Dehaene-Lambertz, Ghislaine

    2016-05-01

    Linguistic processing is based on a close collaboration between temporal and frontal regions connected by two pathways: the "dorsal" and "ventral pathways" (assumed to support phonological and semantic processing, respectively, in adults). We investigated here the development of these pathways at the onset of language acquisition, during the first post-natal weeks, using cross-sectional diffusion imaging in 21 healthy infants (6-22 weeks of age) and 17 young adults. We compared the bundle organization and microstructure at these two ages using tractography and original clustering analyses of diffusion tensor imaging parameters. We observed structural similarities between both groups, especially concerning the dorsal/ventral pathway segregation and the arcuate fasciculus asymmetry. We further highlighted the developmental tempos of the linguistic bundles: The ventral pathway maturation was more advanced than the dorsal pathway maturation, but the latter catches up during the first post-natal months. Its fast development during this period might relate to the learning of speech cross-modal representations and to the first combinatorial analyses of the speech input. PMID:25924951

  10. Early effects of Aβ1-42 oligomers injection in mice: Involvement of PI3K/Akt/GSK3 and MAPK/ERK1/2 pathways.

    PubMed

    Morroni, Fabiana; Sita, Giulia; Tarozzi, Andrea; Rimondini, Roberto; Hrelia, Patrizia

    2016-11-01

    Neuronal and synaptic loss are the best pathological correlates for memory decline in Alzheimer's disease (AD). Soluble beta-amyloid oligomers (AβO) are considered to putatively play a crucial role in the early synapse loss and cognitive impairment observed in AD. Evidence suggests that oxidative stress and apoptosis are involved in the mechanism of Aβ-induced neurotoxicity and AD pathogenesis. This study aimed to explore the molecular mechanisms that contribute to the early memory deficits induced by intracerebroventricular injection of AβO in mice. Ten days after a single AβO injection memory impairments were observed, as measured by Morris water maze and novel object recognition tests. Cognitive decline was associated with increased oxidative stress, caspase-9 activation, and decreased hippocampal synaptophysin immunoreactivity. Furthermore, GSH levels were significantly higher in AβO-injected mice than in sham mice, showing that a protective mechanism might develop due to oxidative stress. Additionally, AβO-induced toxicity was aligned with an increment of the activation of Akt and ERK1/2, and reduced activity of GSK3. These findings suggest that AβO injection triggers a cascade of events that mimic the key neuropathological hallmarks of AD. Aβ acute injection helps to better understand how this peptide impairs specific signaling pathways leading to synaptic and memory dysfunctions. Thus, this model is a valid tool for investigating AD and may suggest a new way to develop neuroprotective therapies at such early stages of the disease. PMID:27498145

  11. Activation of the AMPK-ULK1 pathway plays an important role in autophagy during prion infection

    PubMed Central

    Fan, Xue-Yu; Tian, Chan; Wang, Hui; Xu, Yin; Ren, Ke; Zhang, Bao-Yun; Gao, Chen; Shi, Qi; Meng, Ge; Zhang, Lu-Bin; Zhao, Yang-Jing; Shao, Qi-Xiang; Dong, Xiao-Ping

    2015-01-01

    AMPK is a serine/threonine protein kinase that acts as a positive regulator of autophagy, by phosphorylating ULK1 at specific sites. A previous study demonstrated activation of the macroautophagic system in scrapie-infected experimental rodents and in certain human prion diseases, in which the essential negative regulator mTOR is severely inhibited. In this study, AMPK and ULK1 in the brains of hamsters infected with scrapie strain 263 K and in the scrapie-infected cell line SMB-S15 were analysed. The results showed an up-regulated trend of AMPK and AMPK-Thr172, ULK1 and ULK1-Ser555. Increases in brain AMPK and ULK1 occurred at an early stage of agent 263 K infection. The level of phosphorylated ULK1-Ser757 decreased during mid-infection and was only negligibly present at the terminal stage, a pattern that suggested a close relationship of the phosphorylated protein with altered endogenous mTOR. In addition, the level of LKB1 associated with AMPK activation was selectively increased at the early and middle stages of infection. Knockdown of endogenous ULK1 in SMB-S15 cells inhibited LC3 lipidation. These results showed that, in addition to the abolishment of the mTOR regulatory pathway, activation of the AMPK-ULK1 pathway during prion infection contributes to autophagy activation in prion-infected brain tissues. PMID:26423766

  12. Sustained behavioral effects of lithium exposure during early development in zebrafish: involvement of the Wnt-β-catenin signaling pathway.

    PubMed

    Nery, Laura R; Eltz, Natália S; Martins, Lídia; Guerim, Laura D; Pereira, Talita C; Bogo, Maurício R; Vianna, Monica R M

    2014-12-01

    Lithium has been the paradigmatic treatment for bipolar disorder since 1950s, offering prophylactic and acute efficacy against maniac and depressive episodes. Its use during early pregnancy and the perinatal period remains controversial due to reports of negative consequences on the newborn including teratogenic and neurobehavioral effects generally referred as Floppy baby syndrome. The mechanisms underlying lithium therapeutic action are still elusive but exacerbation of Wnt signaling pathway due to GSK-3 inhibition is believed to represent its main effect. In this study we evaluated the impact of lithium exposure during zebrafish embryonic and early development including behavioral and molecular characterization of Wnt-β-catenin pathway components. Wild-type zebrafish embryos were individually treated for 72 hpf with LiCl at 0.05, 0.5 and 5mM. No significant teratogenic and embryotoxic effects were observed. At the end of treatment period western blot analysis of selected Wnt-β-catenin system components showed increased β-catenin and decreased N-cadherin protein levels, without significant changes in Wnt3a, supporting GSK-3 inhibition as lithium's main target. At 10 dpf 0.5 and 5mM lithium-treated larvae showed a dose-dependent decrease in locomotion among other exploratory parameters, resembling lithium-induced Floppy baby syndrome neurobehavioral symptoms in humans. At this later period previously altered proteins returned to control levels in treated groups, suggesting that the neurobehavioral effects are a lasting consequence of lithium exposure during early development. RT-qPCR analysis of β-catenin and N-cadherin gene expression showed no effects of lithium at 3 or 10 dpf, suggesting that protein fluctuations were likely due to post-transcriptional events. Other Wnt target genes were evaluated and only discrete alterations were observed. These results suggest that zebrafish may be a valuable model for investigation of early effects of lithium that may

  13. The NRF2-KEAP1 Pathway Is an Early Responsive Gene Network in Arsenic Exposed Lymphoblastoid Cells

    PubMed Central

    Córdova, Emilio J.; Martínez-Hernández, Angélica; Uribe-Figueroa, Laura; Centeno, Federico; Morales-Marín, Mirna; Koneru, Harsha; Coleman, Matthew A.; Orozco, Lorena

    2014-01-01

    Inorganic arsenic (iAs), a major environmental contaminant, has risen as an important health problem worldwide. More detailed identification of the molecular mechanisms associated with iAs exposure would help to establish better strategies for prevention and treatment. Although chronic iAs exposures have been previously studied there is little to no information regarding the early events of exposure to iAs. To better characterize the early mechanisms of iAs exposure we conducted gene expression studies using sublethal doses of iAs at two different time-points. The major transcripts differentially regulated at 2 hrs of iAs exposure included antioxidants, detoxificants and chaperones. Moreover, after 12 hrs of exposure many of the down-regulated genes were associated with DNA replication and S phase cell cycle progression. Interestingly, the most affected biological pathway by both 2 or 12 hrs of iAs exposure were the Nrf2-Keap1 pathway, represented by the highly up-regulated HMOX1 transcript, which is transcriptionally regulated by the transcription factor Nrf2. Additional Nrf2 targets included SQSTM1 and ABCB6, which were not previously associated with acute iAs exposure. Signalling pathways such as interferon, B cell receptor and AhR route were also responsive to acute iAs exposure. Since HMOX1 expression increased early (20 min) and was responsive to low iAs concentrations (0.1 µM), this gene could be a suitable early biomarker for iAs exposure. In addition, the novel Nrf2 targets SQSTM1 and ABCB6 could play an important and previously unrecognized role in cellular protection against iAs. PMID:24516582

  14. The majority of early primordial germ cells acquire pluripotency by AKT activation.

    PubMed

    Matsui, Yasuhisa; Takehara, Asuka; Tokitake, Yuko; Ikeda, Makiko; Obara, Yuka; Morita-Fujimura, Yuiko; Kimura, Tohru; Nakano, Toru

    2014-12-01

    Primordial germ cells (PGCs) are undifferentiated germ cells in embryos, the fate of which is to become gametes; however, mouse PGCs can easily be reprogrammed into pluripotent embryonic germ cells (EGCs) in culture in the presence of particular extracellular factors, such as combinations of Steel factor (KITL), LIF and bFGF (FGF2). Early PGCs form EGCs more readily than do later PGCs, and PGCs lose the ability to form EGCs by embryonic day (E) 15.5. Here, we examined the effects of activation of the serine/threonine kinase AKT in PGCs during EGC formation; notably, AKT activation, in combination with LIF and bFGF, enhanced EGC formation and caused ∼60% of E10.5 PGCs to become EGCs. The results indicate that the majority of PGCs at E10.5 could acquire pluripotency with an activated AKT signaling pathway. Importantly, AKT activation did not fully substitute for bFGF and LIF, and AKT activation without both LIF and bFGF did not result in EGC formation. These findings indicate that AKT signal enhances and/or collaborates with signaling pathways of bFGF and of LIF in PGCs for the acquisition of pluripotency. PMID:25359722

  15. MAPK pathway activation by chronic lead-exposure increases vascular reactivity through oxidative stress/cyclooxygenase-2-dependent pathways

    SciTech Connect

    Simões, Maylla Ronacher; Aguado, Andrea; Fiorim, Jonaína; Silveira, Edna Aparecida; Azevedo, Bruna Fernandes; Toscano, Cindy Medice; Zhenyukh, Olha; Briones, Ana María; Alonso, María Jesús; Vassallo, Dalton Valentim; Salaices, Mercedes

    2015-03-01

    Chronic exposure to low lead concentration produces hypertension; however, the underlying mechanisms remain unclear. We analyzed the role of oxidative stress, cyclooxygenase-2-dependent pathways and MAPK in the vascular alterations induced by chronic lead exposure. Aortas from lead-treated Wistar rats (1st dose: 10 μg/100 g; subsequent doses: 0.125 μg/100 g, intramuscular, 30 days) and cultured aortic vascular smooth muscle cells (VSMCs) from Sprague Dawley rats stimulated with lead (20 μg/dL) were used. Lead blood levels of treated rats attained 21.7 ± 2.38 μg/dL. Lead exposure increased systolic blood pressure and aortic ring contractile response to phenylephrine, reduced acetylcholine-induced relaxation and did not affect sodium nitroprusside relaxation. Endothelium removal and L-NAME left-shifted the response to phenylephrine more in untreated than in lead-treated rats. Apocynin and indomethacin decreased more the response to phenylephrine in treated than in untreated rats. Aortic protein expression of gp91(phox), Cu/Zn-SOD, Mn-SOD and COX-2 increased after lead exposure. In cultured VSMCs lead 1) increased superoxide anion production, NADPH oxidase activity and gene and/or protein levels of NOX-1, NOX-4, Mn-SOD, EC-SOD and COX-2 and 2) activated ERK1/2 and p38 MAPK. Both antioxidants and COX-2 inhibitors normalized superoxide anion production, NADPH oxidase activity and mRNA levels of NOX-1, NOX-4 and COX-2. Blockade of the ERK1/2 and p38 signaling pathways abolished lead-induced NOX-1, NOX-4 and COX-2 expression. Results show that lead activation of the MAPK signaling pathways activates inflammatory proteins such as NADPH oxidase and COX-2, suggesting a reciprocal interplay and contribution to vascular dysfunction as an underlying mechanisms for lead-induced hypertension. - Highlights: • Lead-exposure increases oxidative stress, COX-2 expression and vascular reactivity. • Lead exposure activates MAPK signaling pathway. • ROS and COX-2 activation by

  16. Modulation of WNT/β-catenin pathway in melanoma by biologically active components derived from plants.

    PubMed

    Gajos-Michniewicz, Anna; Czyz, Malgorzata

    2016-03-01

    Metastatic melanoma is an aggressive cancer, often resistant to treatment. Therefore, it is essential to determine the molecular mechanisms leading to melanoma or underlying resistance to therapy, and the response to targeted inhibition of the RAS/BRAF/MEK/ERK pathway was a good lesson in this respect. Aberrant WNT/β-catenin pathway is observed in melanoma, and the modulators of this signaling cascade have been under investigation in the context of therapy as well as chemoprevention. Several natural compounds were recognized as being capable of targeting elements of the WNT/β-catenin pathway in various cancers, however, only a few of them can modulate this pathway in melanoma. This review examines recent research on the role of the WNT/β-catenin pathway in tumor development and maintenance, as well as summarizes the current knowledge concerning the modulation of this pathway in melanoma by active compounds of natural origin. PMID:26851176

  17. Early Childhood Education: Pathways to Quality and Equity for All Children. Australian Education Review Number 50

    ERIC Educational Resources Information Center

    Elliott, Alison

    2006-01-01

    Although a good beginning is well recognised as the foundation for future development, health and wellbeing, not only in the early years, but also throughout life, policy and practice in early education and care in Australia still lack focus and integration. Using metaphors of patchworks and crossroads, the author discusses this issue, outlining…

  18. Early Childhood Education: Pathways to Better Health. Preschool Policy Brief Issue 25

    ERIC Educational Resources Information Center

    Friedman-Krauss, Allison; Barnett, W. Steven

    2013-01-01

    The potential health benefits of early childhood education programs are quite large, especially for children living in poverty. In this report, authors Allison Friedman-Krauss and Steve Barnett set out the evidence regarding the short and long term health benefits to children from early childhood education programs, identify the features of…

  19. Comparative Proteomic Analysis Reveals Activation of Mucosal Innate Immune Signaling Pathways during Cholera

    PubMed Central

    LaRocque, Regina C.; Uddin, Taher; Krastins, Bryan; Mayo-Smith, Leslie M.; Sarracino, David; Karlsson, Elinor K.; Rahman, Atiqur; Shirin, Tahmina; Bhuiyan, Taufiqur R.; Chowdhury, Fahima; Khan, Ashraful Islam; Ryan, Edward T.; Calderwood, Stephen B.; Qadri, Firdausi

    2015-01-01

    Vibrio cholerae O1 is a major cause of acute watery diarrhea in over 50 countries. Evidence suggests that V. cholerae O1 may activate inflammatory pathways, and a recent study of a Bangladeshi population showed that variants in innate immune genes play a role in mediating susceptibility to cholera. We analyzed human proteins present in the small intestine of patients infected with V. cholerae O1 to characterize the host response to this pathogen. We collected duodenal biopsy specimens from patients with acute cholera after stabilization and again 30 days after initial presentation. Peptides extracted from biopsy specimens were sequenced and quantified using label-free mass spectrometry and SEQUEST. Twenty-seven host proteins were differentially abundant between the acute and convalescent stages of infection; the majority of these have known roles in innate defense, cytokine production, and apoptosis. Immunostaining confirmed that two proteins, WARS and S100A8, were more abundant in lamina propria cells during the acute stage of cholera. Analysis of the differentially abundant proteins revealed the activation of key regulators of inflammation by the innate immune system, including Toll-like receptor 4, nuclear factor kappa-light-chain-enhancer of activated B cells, mitogen-activated protein kinases, and caspase-dependent inflammasomes. Interleukin-12β (IL-12β) was a regulator of several proteins that were activated during cholera, and we confirmed that IL-12β was produced by lymphocytes recovered from duodenal biopsy specimens of cholera patients. Our study shows that a broad inflammatory response is generated in the gut early after onset of cholera, which may be critical in the development of long-term mucosal immunity against V. cholerae O1. PMID:25561705

  20. Comparative proteomic analysis reveals activation of mucosal innate immune signaling pathways during cholera.

    PubMed

    Ellis, Crystal N; LaRocque, Regina C; Uddin, Taher; Krastins, Bryan; Mayo-Smith, Leslie M; Sarracino, David; Karlsson, Elinor K; Rahman, Atiqur; Shirin, Tahmina; Bhuiyan, Taufiqur R; Chowdhury, Fahima; Khan, Ashraful Islam; Ryan, Edward T; Calderwood, Stephen B; Qadri, Firdausi; Harris, Jason B

    2015-03-01

    Vibrio cholerae O1 is a major cause of acute watery diarrhea in over 50 countries. Evidence suggests that V. cholerae O1 may activate inflammatory pathways, and a recent study of a Bangladeshi population showed that variants in innate immune genes play a role in mediating susceptibility to cholera. We analyzed human proteins present in the small intestine of patients infected with V. cholerae O1 to characterize the host response to this pathogen. We collected duodenal biopsy specimens from patients with acute cholera after stabilization and again 30 days after initial presentation. Peptides extracted from biopsy specimens were sequenced and quantified using label-free mass spectrometry and SEQUEST. Twenty-seven host proteins were differentially abundant between the acute and convalescent stages of infection; the majority of these have known roles in innate defense, cytokine production, and apoptosis. Immunostaining confirmed that two proteins, WARS and S100A8, were more abundant in lamina propria cells during the acute stage of cholera. Analysis of the differentially abundant proteins revealed the activation of key regulators of inflammation by the innate immune system, including Toll-like receptor 4, nuclear factor kappa-light-chain-enhancer of activated B cells, mitogen-activated protein kinases, and caspase-dependent inflammasomes. Interleukin-12β (IL-12β) was a regulator of several proteins that were activated during cholera, and we confirmed that IL-12β was produced by lymphocytes recovered from duodenal biopsy specimens of cholera patients. Our study shows that a broad inflammatory response is generated in the gut early after onset of cholera, which may be critical in the development of long-term mucosal immunity against V. cholerae O1. PMID:25561705

  1. v-Crk activates the phosphoinositide 3-kinase/AKT pathway in transformation

    PubMed Central

    Akagi, Tsuyoshi; Shishido, Tomoyuki; Murata, Kazutaka; Hanafusa, Hidesaburo

    2000-01-01

    v-Crk induces cellular tyrosine phosphorylation and transformation of chicken embryo fibroblasts (CEF). We studied the molecular mechanism of the v-Crk-induced transformation. Experiments with Src homology (SH)2 and SH3 domain mutants revealed that the induction of tyrosine phosphorylation of cellular proteins requires only the SH2 domain, but both the SH2 and SH3 domains are required for complete transformation. Analysis of three well defined signaling pathways, the mitogen-activated protein kinase (MAPK) pathway, the Jun N-terminal kinase (JNK) pathway, and the phosphoinositide 3-kinase (PI3K)/AKT pathway, demonstrated that only the PI3K/AKT pathway is constitutively activated in v-Crk-transformed CEF. Both the SH2 and SH3 domains are required for this activation of the PI3K/AKT pathway in CEF. We also found that the colony formation of CEF is strongly induced by a constitutively active PI3K mutant, and that a PI3K inhibitor, LY294002, suppresses the v-Crk-induced transformation. These results strongly suggest that constitutive activation of the PI3K/AKT pathway plays an essential role in v-Crk-induced transformation of CEF. PMID:10852971

  2. Xylazine Activates Adenosine Monophosphate-Activated Protein Kinase Pathway in the Central Nervous System of Rats

    PubMed Central

    Shi, Xing-Xing; Yin, Bai-Shuang; Yang, Peng; Chen, Hao; Li, Xin; Su, Li-Xue; Fan, Hong-Gang; Wang, Hong-Bin

    2016-01-01

    Xylazine is a potent analgesic extensively used in veterinary and animal experimentation. Evidence exists that the analgesic effect can be inhibited using adenosine 5’-monophosphate activated protein kinase (AMPK) inhibitors. Considering this idea, the aim of this study was to investigate whether the AMPK signaling pathway is involved in the central analgesic mechanism of xylazine in the rat. Xylazine was administrated via the intraperitoneal route. Sprague-Dawley rats were sacrificed and the cerebral cortex, cerebellum, hippocampus, thalamus and brainstem were collected for determination of liver kinase B1 (LKB1) and AMPKα mRNA expression using quantitative real-time polymerase chain reaction (qPCR), and phosphorylated LKB1 and AMPKα levels using western blot. The results of our study showed that compared with the control group, xylazine induced significant increases in AMPK activity in the cerebral cortex, hippocampus, thalamus and cerebellum after rats received xylazine (P < 0.01). Increased AMPK activities were accompanied with increased phosphorylation levels of LKB1 in corresponding regions of rats. The protein levels of phosphorylated LKB1 and AMPKα in these regions returned or tended to return to control group levels. However, in the brainstem, phosphorylated LKB1 and AMPKα protein levels were decreased by xylazine compared with the control (P < 0.05). In conclusion, our data indicates that xylazine alters the activities of LKB1 and AMPK in the central nervous system of rats, which suggests that xylazine affects the regulatory signaling pathway of the analgesic mechanism in the rat brain. PMID:27049320

  3. Functional Protein Pathway Activation Mapping of the Progression of Normal Skin to Squamous Cell Carcinoma

    PubMed Central

    Einspahr, Janine G.; Calvert, Valerie; Alberts, David S.; Curiel-Lewandrowski, Clara; Warneke, James; Krouse, Robert; Stratton, Steven P; Liotta, Lance; Longo, Caterina; Pellicani, Giovanni; Prasad, Anil; Sagerman, Paul; Bermudez, Yira; Deng, Jianghong; Bowden, G. Timothy; Petricoin, Emanuel F.

    2012-01-01

    Reverse Phase Protein Microarray analysis was used to identify cell-signaling derangements in squamous cell carcinoma (SCC) compared to actinic keratosis (AK) and upper inner arm (UIA). We analyzed 2 independent tissue sets with isolation and enrichment of epithelial cells by Laser Capture Microdissection. Set 1 served as a pilot and a means to identify protein pathway activation alterations that could be further validated in a second independent set. Set 1 was comprised of 4 AK, 13 SCC, and 20 UIA. Set 2 included 15 AK, 9 SCC and 20 UIA. Activation of 51 signaling proteins known to be involved in tumorigenesis were assessed for set 1 and demonstrated the MEK-ERK pathway was activated in SCC compared to AK and UIA, that EGFR and mTOR pathways were aberrantly activated in SCC. Unsupervised two-way hierarchical clustering revealed that AK and UIA shared a common signaling network activation architecture while SCC was dramatically different. Statistical analysis found that pro-survival signaling through phosphorylation of ASK and 4EBP1 as well as increased Bax and Bak expression was higher in AK compared to UIA. We expanded pathway network activation mapping in Set 2 to 101 key signaling proteins, which corroborated activation of MEK-ERK, EGFR, and mTOR pathways through discovery of a number of upstream, and downstream signaling molecules within these pathways to conclude that SCC is indeed a pathway activation-driven disease. Pathway activation mapping of SCC compared to AK revealed several interconnected networks that could be targeted with drug therapy for potential chemoprevention and therapeutic applications. PMID:22389437

  4. ASBESTOS-INDUCED ACTIVATION OF CELL SIGNALING PATHWAYS IN HUMAN BRONCHIAL EPITHELIAL CELLS

    EPA Science Inventory

    Using respiratory epithelial cells transfected with either superoxide dismutase (SOD) or catalase, the authors tested the hypothesis that the activation of the epidermal growth factor (EGF) receptor signal pathway after asbestos exposure involves an oxidative stress. Western blot...

  5. Activation of AhR-mediated toxicity pathway by emerging pollutants polychlorinated diphenyl sulfides

    EPA Science Inventory

    Polychlorinated diphenyl sulfides (PCDPSs) are a group of environmental pollutants for which limited toxicological information is available. This study tested the hypothesis that PCDPSs could activate the mammalian aryl hydrocarbon receptor (AhR) mediated toxicity pathways. Eight...

  6. Ras-GTP dimers activate the Mitogen-Activated Protein Kinase (MAPK) pathway

    PubMed Central

    Nan, Xiaolin; Tamgüney, Tanja M.; Collisson, Eric A.; Lin, Li-Jung; Pitt, Cameron; Galeas, Jacqueline; Lewis, Sophia; Gray, Joe W.; McCormick, Frank; Chu, Steven

    2015-01-01

    Rat sarcoma (Ras) GTPases regulate cell proliferation and survival through effector pathways including Raf-MAPK, and are the most frequently mutated genes in human cancer. Although it is well established that Ras activity requires binding to both GTP and the membrane, details of how Ras operates on the cell membrane to activate its effectors remain elusive. Efforts to target mutant Ras in human cancers to therapeutic benefit have also been largely unsuccessful. Here we show that Ras-GTP forms dimers to activate MAPK. We used quantitative photoactivated localization microscopy (PALM) to analyze the nanoscale spatial organization of PAmCherry1-tagged KRas 4B (hereafter referred to KRas) on the cell membrane under various signaling conditions. We found that at endogenous expression levels KRas forms dimers, and KRasG12D, a mutant that constitutively binds GTP, activates MAPK. Overexpression of KRas leads to formation of higher order Ras nanoclusters. Conversely, at lower expression levels, KRasG12D is monomeric and activates MAPK only when artificially dimerized. Moreover, dimerization and signaling of KRas are both dependent on an intact CAAX (C, cysteine; A, aliphatic; X, any amino acid) motif that is also known to mediate membrane localization. These results reveal a new, dimerization-dependent signaling mechanism of Ras, and suggest Ras dimers as a potential therapeutic target in mutant Ras-driven tumors. PMID:26080442

  7. Ras-GTP dimers activate the mitogen-activated protein kinase (MAPK) pathway

    DOE PAGESBeta

    Nan, Xiaolin; Tamgüney, Tanja M.; Collisson, Eric A.; Lin, Li -Jung; Pitt, Cameron; Galeas, Jacqueline; Lewis, Sophia; Gray, Joe W.; McCormick, Frank; Chu, Steven

    2015-06-16

    Rat sarcoma (Ras) GTPases regulate cell proliferation and survival through effector pathways including Raf-MAPK, and are the most frequently mutated genes in human cancer. Although it is well established that Ras activity requires binding to both GTP and the membrane, details of how Ras operates on the cell membrane to activate its effectors remain elusive. Efforts to target mutant Ras in human cancers to therapeutic benefit have also been largely unsuccessful. Here we show that Ras-GTP forms dimers to activate MAPK. We used quantitative photoactivated localization microscopy (PALM) to analyze the nanoscale spatial organization of PAmCherry1-tagged KRas 4B (hereafter referredmore » to KRas) on the cell membrane under various signaling conditions. We found that at endogenous expression levels KRas forms dimers, and KRasG12D, a mutant that constitutively binds GTP, activates MAPK. Overexpression of KRas leads to formation of higher order Ras nanoclusters. Conversely, at lower expression levels, KRasG12D is monomeric and activates MAPK only when artificially dimerized. Moreover, dimerization and signaling of KRas are both dependent on an intact CAAX (C, cysteine; A, aliphatic; X, any amino acid) motif that is also known to mediate membrane localization. These results reveal a new, dimerization-dependent signaling mechanism of Ras, and suggest Ras dimers as a potential therapeutic target in mutant Ras-driven tumors.« less

  8. Ras-GTP dimers activate the mitogen-activated protein kinase (MAPK) pathway

    SciTech Connect

    Nan, Xiaolin; Tamgüney, Tanja M.; Collisson, Eric A.; Lin, Li -Jung; Pitt, Cameron; Galeas, Jacqueline; Lewis, Sophia; Gray, Joe W.; McCormick, Frank; Chu, Steven

    2015-06-16

    Rat sarcoma (Ras) GTPases regulate cell proliferation and survival through effector pathways including Raf-MAPK, and are the most frequently mutated genes in human cancer. Although it is well established that Ras activity requires binding to both GTP and the membrane, details of how Ras operates on the cell membrane to activate its effectors remain elusive. Efforts to target mutant Ras in human cancers to therapeutic benefit have also been largely unsuccessful. Here we show that Ras-GTP forms dimers to activate MAPK. We used quantitative photoactivated localization microscopy (PALM) to analyze the nanoscale spatial organization of PAmCherry1-tagged KRas 4B (hereafter referred to KRas) on the cell membrane under various signaling conditions. We found that at endogenous expression levels KRas forms dimers, and KRasG12D, a mutant that constitutively binds GTP, activates MAPK. Overexpression of KRas leads to formation of higher order Ras nanoclusters. Conversely, at lower expression levels, KRasG12D is monomeric and activates MAPK only when artificially dimerized. Moreover, dimerization and signaling of KRas are both dependent on an intact CAAX (C, cysteine; A, aliphatic; X, any amino acid) motif that is also known to mediate membrane localization. These results reveal a new, dimerization-dependent signaling mechanism of Ras, and suggest Ras dimers as a potential therapeutic target in mutant Ras-driven tumors.

  9. Concurrent Activation of Striatal Direct and Indirect Pathways During Action Initiation

    PubMed Central

    Cui, Guohong; Jun, Sang Beom; Jin, Xin; Pham, Michael D.

    2014-01-01

    Summary The basal ganglia are subcortical nuclei that control voluntary actions, and are affected by a number of debilitating neurological disorders1–4. The prevailing model of basal ganglia function proposes that two orthogonal projection circuits originating from distinct populations of spiny projection neurons (SPNs) in the striatum5,6 - the so-called direct and indirect pathways - have opposing effects on movement: while activity of direct-pathway SPNs purportedly facilitates movement, activity of indirect-pathway SPNs inhibits movement1,2. This model has been difficult to test due to the lack of methods to selectively measure the activity of direct- and indirect-pathway SPNs in freely moving animals. We developed a novel in-vivo method that allowed us to specifically measure direct- and indirect-pathway SPN activity using Cre-dependent viral expression of the genetically encoded calcium indicator (GECI) GCAMP3 in the dorsal striatum of D1-Cre (direct-pathway specific6,7) and A2A-Cre (indirect-pathway specific8,9) mice10. Using fiber optics and time-correlated single photon counting (TCSPC) in mice performing an operant task, we observed transient increases in neural activity in both direct- and indirect-pathway SPNs when animals initiated actions, but not when they were inactive. Concurrent activation of SPNs from both pathways in one hemisphere preceded the initiation of contraversive movements, and predicted the occurrence of specific movements within 500 ms. These observations challenge the classical view of basal ganglia function, and may have implications for understanding the origin of motor symptoms in basal ganglia disorders. PMID:23354054

  10. On the levels of enzymatic substrate specificity: Implications for the early evolution of metabolic pathways

    NASA Technical Reports Server (NTRS)

    Lazcano, A.; Diaz-Villagomez, E.; Mills, T.; Oro, J.

    1995-01-01

    The most frequently invoked explanation for the origin of metabolic pathways is the retrograde evolution hypothesis. In contrast, according to the so-called 'patchwork' theory, metabolism evolved by the recruitment of relatively inefficient small enzymes of broad specificity that could react with a wide range of chemically related substrates. In this paper it is argued that both sequence comparisons and experimental results on enzyme substrate specificity support the patchwork assembly theory. The available evidence supports previous suggestions that gene duplication events followed by a gradual neoDarwinian accumulation of mutations and other minute genetic changes lead to the narrowing and modification of enzyme function in at least some primordial metabolic pathways.