Genetic and pharmacological analysis identifies a physiological role for the AHR in epidermal differentiation

NARCIS (Netherlands)

Bogaard, E.H. van den; Podolsky, M.A.; Smits, J.P.H.; Cui, X.; John, C.; Gowda, K.; Desai, D.; Amin, S.G.; Schalkwijk, J.; Perdew, G.H.; Glick, A.B.

2015-01-01

Stimulation of the aryl hydrocarbon receptor (AHR) by xenobiotics is known to affect epidermal differentiation and skin barrier formation. The physiological role of endogenous AHR signaling in keratinocyte differentiation is not known. We used murine and human skin models to address the hypothesis

A dioxin-like compound induces hyperplasia and branching morphogenesis in mouse mammary gland, through alterations in TGF-β1 and aryl hydrocarbon receptor signaling.

Science.gov (United States)

Miret, Noelia; Rico-Leo, Eva; Pontillo, Carolina; Zotta, Elsa; Fernández-Salguero, Pedro; Randi, Andrea

2017-11-01

Hexachlorobenzene (HCB) is a widespread environmental pollutant and a dioxin-like compound that binds weakly to the aryl hydrocarbon receptor (AhR). Because AhR and transforming growth factor β1 (TGF-β1) converge to regulate common signaling pathways, alterations in this crosstalk might contribute to developing preneoplastic lesions. The aim of this study was to evaluate HCB action on TGF-β1 and AhR signaling in mouse mammary gland, through AhR+/+ and AhR-/- models. Results showed a differential effect in mouse mammary epithelial cells (NMuMG), depending on the dose: 0.05μM HCB induced cell migration and TGF-β1 signaling, whereas 5μM HCB reduced cell migration, promoted cell cycle arrest and stimulated the dioxin response element (DRE) -dependent pathway. HCB (5μM) enhanced α-smooth muscle actin expression and decreased TGF-β receptor II mRNA levels in immortalized mouse mammary fibroblasts AhR+/+, resembling the phenotype of transformed cells. Accordingly, their conditioned medium was able to enhance NMuMG cell migration. Assays in C57/Bl6 mice showed HCB (3mg/kg body weight) to enhance ductal hyperplasia, cell proliferation, estrogen receptor α nuclear localization, branch density, and the number of terminal end buds in mammary gland from AhR+/+ mice. Primary culture of mammary epithelial cells from AhR+/+ mice showed reduced AhR mRNA levels after HCB exposure (0.05 and 5μM). Interestingly, AhR-/- mice exhibited an increase in ductal hyperplasia and mammary growth in the absence of HCB treatment, thus revealing the importance of AhR in mammary development. Our findings show that environmental HCB concentrations modulate AhR and TGF-β1 signaling, which could contribute to altered mammary branching morphogenesis, likely leading to preneoplastic lesions and retaining terminal end buds. Copyright © 2017. Published by Elsevier Inc.

ITE Suppresses Angiogenic Responses in Human Artery and Vein Endothelial Cells: Differential Roles of AhR.

Science.gov (United States)

Li, Yan; Wang, Kai; Zou, Qing-Yun; Jiang, Yi-Zhou; Zhou, Chi; Zheng, Jing

2017-12-01

Aryl hydrocarbon receptor (AhR), a ligand-activated transcription factor is involved in regulation of many essential biological processes including vascular development and angiogenesis. 2-(1'H-indole-3'-carbonyl)-thiazole-4-carboxylic acid methyl ester (ITE) is an AhR ligand, which regulates immune responses and cancer cell growth. However, the roles of the ITE/AhR pathway in mediating placental angiogenesis remains elusive. Here, we determined if ITE affected placental angiogenic responses via AhR in human umbilical vein (HUVECs) and artery endothelial (HUAECs) cells in vitro. We observed that ITE dose- and time-dependently inhibited proliferation and viability of HUAECs and HUVECs, whereas it inhibited migration of HUAECs, but not HUVECs. While AhR siRNA significantly suppressed AhR protein expression in HUVECs and HUAECs, it attenuated the ITE-inhibited angiogenic responses of HUAECs, but not HUVECs. Collectively, ITE suppressed angiogenic responses of HUAECs and HUVECs, dependent and independent of AhR, respectively. These data suggest that ITE may regulate placental angiogenesis. Copyright © 2017 Elsevier Inc. All rights reserved.

Non-Smad signaling pathways.

Science.gov (United States)

Mu, Yabing; Gudey, Shyam Kumar; Landström, Maréne

2012-01-01

Transforming growth factor-beta (TGFβ) is a key regulator of cell fate during embryogenesis and has also emerged as a potent driver of the epithelial-mesenchymal transition during tumor progression. TGFβ signals are transduced by transmembrane type I and type II serine/threonine kinase receptors (TβRI and TβRII, respectively). The activated TβR complex phosphorylates Smad2 and Smad3, converting them into transcriptional regulators that complex with Smad4. TGFβ also uses non-Smad signaling pathways such as the p38 and Jun N-terminal kinase (JNK) mitogen-activated protein kinase (MAPK) pathways to convey its signals. Ubiquitin ligase tumor necrosis factor (TNF)-receptor-associated factor 6 (TRAF6) and TGFβ-associated kinase 1 (TAK1) have recently been shown to be crucial for the activation of the p38 and JNK MAPK pathways. Other TGFβ-induced non-Smad signaling pathways include the phosphoinositide 3-kinase-Akt-mTOR pathway, the small GTPases Rho, Rac, and Cdc42, and the Ras-Erk-MAPK pathway. Signals induced by TGFβ are tightly regulated and specified by post-translational modifications of the signaling components, since they dictate the subcellular localization, activity, and duration of the signal. In this review, we discuss recent findings in the field of TGFβ-induced responses by non-Smad signaling pathways.

AhR and SHP regulate phosphatidylcholine and S-adenosylmethionine levels in the one-carbon cycle.

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Kim, Young-Chae; Seok, Sunmi; Byun, Sangwon; Kong, Bo; Zhang, Yang; Guo, Grace; Xie, Wen; Ma, Jian; Kemper, Byron; Kemper, Jongsook Kim

2018-02-07

Phosphatidylcholines (PC) and S-adenosylmethionine (SAM) are critical determinants of hepatic lipid levels, but how their levels are regulated is unclear. Here, we show that Pemt and Gnmt, key one-carbon cycle genes regulating PC/SAM levels, are downregulated after feeding, leading to decreased PC and increased SAM levels, but these effects are blunted in small heterodimer partner (SHP)-null or FGF15-null mice. Further, aryl hydrocarbon receptor (AhR) is translocated into the nucleus by insulin/PKB signaling in the early fed state and induces Pemt and Gnmt expression. This induction is blocked by FGF15 signaling-activated SHP in the late fed state. Adenoviral-mediated expression of AhR in obese mice increases PC levels and exacerbates steatosis, effects that are blunted by SHP co-expression or Pemt downregulation. PEMT, AHR, and PC levels are elevated in simple steatosis patients, but PC levels are robustly reduced in steatohepatitis-fibrosis patients. This study identifies AhR and SHP as new physiological regulators of PC/SAM levels.

Perturbation effect of reduced graphene oxide quantum dots (rGOQDs) on aryl hydrocarbon receptor (AhR) pathway in zebrafish.

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Zhang, Jing-Hui; Sun, Tai; Niu, Aping; Tang, Yu-Mei; Deng, Shun; Luo, Wei; Xu, Qun; Wei, Dapeng; Pei, De-Sheng

2017-07-01

Graphene quantum dots (GQDs) has been widely used in enormous fields, however, the inherent molecular mechanism of GQDs for potential risks in biological system is still elusive to date. In this study, the outstanding reduced graphene quantum dots (rGOQDs) with the QY as high as 24.62% were successfully synthesized by the improved Hummers method and DMF hydrothermal treatment approach. The rGOQDs were N-doped photoluminescent nanomaterials with functional groups on the surface. The fluorescent bio-imaging was performed by exposing zebrafish in different concentrations of the as-prepared rGOQDs, and the distribution of rGOQDs was successfully observed. Moreover, the developmental toxicity and genotoxicity were evaluated to further investigate the potential hazard of rGOQDs. The result indicated that rGOQDs were responsible for the dose-dependent abnormalities on the development of zebrafish. Since the real-time polymerase chain reaction (RT-PCR) results showed that the expression of cyp1a was the highest expression in the selected genes and significantly up-regulated 8.49 fold in zebrafish, the perturbation of rGOQDs on aryl hydrocarbon receptor (AhR) pathway was investigated by using the Tg(cyp1a:gfp) zebrafish for the first time. The results demonstrated that rGOQDs significantly increased the green fluorescent protein (GFP) expression promoted by cyp1a in a dose-dependent manner, which was also further confirmed by the western blotting. This study offered an opportunity to reveal the potential hazards of in vivo bio-probes, which provided a valuable reference for investigating the graphene-based materials on the disturbance of AhR pathway in biological organisms. Copyright © 2017 Elsevier Ltd. All rights reserved.

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

Lifescience Database Archive (English)

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

AHR-11797: a novel benzodiazepine antagonist

International Nuclear Information System (INIS)

Johnson, D.N.; Kilpatrick, B.F.; Hannaman, P.K.

1986-01-01

AHR-11797(5,6-dihydro-6-methyl-1-phenyl- 3 H-pyrrolo[3,2,1-ij]quinazolin-3-one) displaced 3 H-flunitrazepam (IC 50 = 82 nM) and 3 H-Ro 15-1877 (IC 50 = 104 nM) from rat brain synaptosomes. AHR-11797 did not protect mice from seizures induced by maximal electroshock or subcutaneous Metrazol (scMET), nor did it induce seizures in doses up to the lethal dose. However, at 31.6 mg/kg, IP, it significantly increased the anticonvulsant ED 50 of chlordiazepoxide (CDPX) from 1.9 to 31.6 mg/kg, IP. With 56.7 mg/kg, IP, of AHR-11797, CDPX was inactive in doses up to 100 mg/kg, IP. AHR-11797 did not significantly increase punished responding in the Geller and Seifter conflict procedure, but it did attenuate the effects of diazepam. Although the compound is without anticonvulsant or anxiolytic activity, it did have muscle relaxant properties. AHR-11797 blocked morphine-induced Straub tail in mice (ED 50 = 31 mg/kg, IP) and it selectively suppressed the polysnaptic linguomandibular reflex in barbiturate-anesthetized cats. The apparent muscle relaxant activity of AHR-11797 suggests that different receptor sites are involved for muscle relaxant vs. anxiolytic/anticonvulsant activities of the benzodiazepines

AHR and CYP1A expression link historical contamination events to modern day developmental effects in the American alligator.

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Hale, Matthew D; Galligan, Thomas M; Rainwater, Thomas R; Moore, Brandon C; Wilkinson, Philip M; Guillette, Louis J; Parrott, Benjamin B

2017-11-01

The aryl hydrocarbon receptor (AHR) is a ligand-activated transcription factor that initiates a transcriptional pathway responsible for the expression of CYP1A subfamily members, key to the metabolism of xenobiotic compounds. Toxic planar halogenated aromatic hydrocarbons, including dioxin and PCBs, are capable of activating the AHR, and while dioxin and PCB inputs into the environment have been dramatically curbed following strict regulatory efforts in the United States, they persist in the environment and exposures remain relevant today. Little is known regarding the effects that long-term chronic exposures to dioxin or dioxin-like compounds might have on the development and subsequent health of offspring from exposed individuals, nor is much known regarding AHR expression in reptilians. Here, we characterize AHR and CYP1A gene expression in embryonic and juvenile specimen of a long-lived, apex predator, the American alligator (Alligator mississippiensis), and investigate variation in gene expression profiles in offspring collected from sites conveying differential exposures to environmental contaminants. Both age- and tissue-dependent patterning of AHR isoform expression are detected. We characterize two downstream transcriptional targets of the AHR, CYP1A1 and CYP1A2, and describe conserved elements of their genomic architecture. When comparisons across different sites are made, hepatic expression of CYP1A2, a direct target of the AHR, appears elevated in embryos from a site associated with a dioxin point source and previously characterized PCB contamination. Elevated CYP1A2 expression is not persistent, as site-specific variation was absent in juveniles originating from field-collected eggs but reared under lab conditions. Our results illustrate the patterning of AHR gene expression in a long-lived environmental model species, and indicate a potential contemporary influence of historical contamination. This research presents a novel opportunity to link

Baicalein induces G1 arrest in oral cancer cells by enhancing the degradation of cyclin D1 and activating AhR to decrease Rb phosphorylation

Energy Technology Data Exchange (ETDEWEB)

Cheng, Ya-Hsin, E-mail: yhcheng@mail.cmu.edu.tw [Department of Physiology, School of Medicine, China Medical University, Taichung 40402, Taiwan, ROC (China); Li, Lih-Ann; Lin, Pinpin; Cheng, Li-Chuan [Division of Environmental Health and Occupational Medicine, National Health Research Institutes, Zhunan, Miaoli 35053, Taiwan, ROC (China); Hung, Chein-Hui [Graduate Institute of Clinical Medicine Sciences, Chang Gung University, Puizi City, Chiayi 613, Taiwan, ROC (China); Chang, Nai Wen [Department of Biochemistry, School of Medicine, China Medical University, Taichung, Taiwan, ROC (China); Lin, Chingju [Department of Physiology, School of Medicine, China Medical University, Taichung 40402, Taiwan, ROC (China)

2012-09-15

Baicalein is a flavonoid, known to have anti-inflammatory and anti-cancer effects. As an aryl hydrocarbon receptor (AhR) ligand, baicalein at high concentrations blocks AhR-mediated dioxin toxicity. Because AhR had been reported to play a role in regulating the cell cycle, we suspected that the anti-cancer effect of baicalein is associated with AhR. This study investigated the molecular mechanism involved in the anti-cancer effect of baicalein in oral cancer cells HSC-3, including whether such effect would be AhR-mediated. Results revealed that baicalein inhibited cell proliferation and increased AhR activity in a dose-dependent manner. Cell cycle was arrested at the G1 phase and the expression of CDK4, cyclin D1, and phosphorylated retinoblastoma (pRb) was decreased. When the AhR was suppressed by siRNA, the reduction of pRb was partially reversed, accompanied by a decrease of cell population at G1 phase and an increase at S phase, while the reduction of cyclin D1 and CDK4 did not change. This finding suggests that the baicalein activation of AhR is indeed associated with the reduction of pRb, but is independent of the reduction of cyclin D1 and CDK4. When cells were pre-treated with LiCl, the inhibitor of GSK-3β, the decrease of cyclin D1 was blocked and the reduction of pRb was recovered. The data indicates that in HSC-3 the reduction of pRb is both mediated by baicalein through activation of AhR and facilitation of cyclin D1 degradation, which causes cell cycle arrest at the G1 phase, and results in the inhibition of cell proliferation. -- Highlights: ► Baicalein causes the G1 phase arrest by decreasing Rb phosphorylation. ► Baicalein modulates AhR-mediated cell proliferation. ► Both AhR activation and cyclin D1 degradation results in hypophosphorylation of Rb. ► Baicalein facilitates cyclin D1 degradation by signalling the GSK-3β pathway.

Hexachlorobenzene modulates the crosstalk between the aryl hydrocarbon receptor and transforming growth factor-β1 signaling, enhancing human breast cancer cell migration and invasion

International Nuclear Information System (INIS)

Miret, Noelia; Pontillo, Carolina; Ventura, Clara; Carozzo, Alejandro; Chiappini, Florencia

2016-01-01

Highlights: • HCB enhances TGF-β1 expression and activation levels in breast cancer cells. • HCB activates TGF-β1 pathways: Smad3, JNK and p38. • The HCB- induced migration and invasion involves TGF-β1 signaling pathways. • HCB modulates AhR levels and activation. • HCB enhances TGF-β1 mRNA expression in an AhR-dependent manner. - Abstract: Given the number of women affected by breast cancer, considerable interest has been raised in understanding the relationships between environmental chemicals and disease onset. Hexachlorobenzene (HCB) is a dioxin-like compound that is widely distributed in the environment and is a weak ligand of the aryl hydrocarbon receptor (AhR). We previously demonstrated that HCB acts as an endocrine disruptor capable of stimulating cell proliferation, migration, invasion, and metastasis in different breast cancer models. In addition, increasing evidence indicates that transforming growth factor-β1 (TGF-β1) can contribute to tumor maintenance and progression. In this context, this work investigated the effect of HCB (0.005, 0.05, 0.5, and 5 μM) on TGF-β1 signaling and AhR/TGF-β1 crosstalk in the human breast cancer cell line MDA-MB-231 and analyzed whether TGF-β1 pathways are involved in HCB-induced cell migration and invasion. RT-qPCR results indicated that HCB reduces AhR mRNA expression through TGF-β1 signaling but enhances TGF-β1 mRNA levels involving AhR signaling. Western blot analysis demonstrated that HCB could increase TGF-β1 protein levels and activation, as well as Smad3, JNK, and p38 phosphorylation. In addition, low and high doses of HCB were determined to exert differential effects on AhR protein levels, localization, and activation, with a high dose (5 μM) inducing AhR nuclear translocation and AhR-dependent CYP1A1 expression. These findings also revealed that c-Src and AhR are involved in HCB-mediated activation of Smad3. HCB enhances cell migration (scratch motility assay) and invasion (Transwell

The aryl hydrocarbon receptor (AHR) transcription factor regulates megakaryocytic polyploidization.

Science.gov (United States)

Lindsey, Stephan; Papoutsakis, Eleftherios T

2011-02-01

We propose that the aryl hydrocarbon receptor (AHR) is a novel transcriptional regulator of megakaryopoietic polyploidization. Functional evidence was obtained that AHR impacts in vivo megakaryocytic differentiation and maturation; compared to wild-type mice, AHR-null mice had lower platelet counts, fewer numbers of newly synthesized platelets, increased bleeding times and lower-ploidy megakaryocytes (Mks). AHR mRNA increased 3·6-fold during ex vivo megakaryocytic differentiation, but reduced or remained constant during parallel isogenic granulocytic or erythroid differentiation. We interrogated the role of AHR in megakaryopoiesis using a validated Mk model of megakaryopoiesis, the human megakaryoblastic leukaemia CHRF cell line. Upon CHRF Mk differentiation, AHR mRNA and protein levels increased, AHR protein shifted from the cytoplasm to the nucleus and AHR binding to its consensus DNA binding sequence increased. Protein and mRNA levels of the AHR transcriptional target HES1 also increased. Mk differentiation of CHRF cells where AHR or HES1 was knocked-down using RNAi resulted in lower ploidy distributions and cells that were incapable of reaching ploidy classes ≥16n. AHR knockdown also resulted in increased DNA synthesis of lower ploidy cells, without impacting apoptosis. Together, these data support a role for AHR in Mk polyploidization and in vivo platelet function, and warrant further detailed investigations. © 2011 Blackwell Publishing Ltd.

Retroactive signaling in short signaling pathways.

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Jacques-Alexandre Sepulchre

Full Text Available In biochemical signaling pathways without explicit feedback connections, the core signal transduction is usually described as a one-way communication, going from upstream to downstream in a feedforward chain or network of covalent modification cycles. In this paper we explore the possibility of a new type of signaling called retroactive signaling, offered by the recently demonstrated property of retroactivity in signaling cascades. The possibility of retroactive signaling is analysed in the simplest case of the stationary states of a bicyclic cascade of signaling cycles. In this case, we work out the conditions for which variables of the upstream cycle are affected by a change of the total amount of protein in the downstream cycle, or by a variation of the phosphatase deactivating the same protein. Particularly, we predict the characteristic ranges of the downstream protein, or of the downstream phosphatase, for which a retroactive effect can be observed on the upstream cycle variables. Next, we extend the possibility of retroactive signaling in short but nonlinear signaling pathways involving a few covalent modification cycles.

Transcriptomic assessment of resistance to effects of an aryl hydrocarbon receptor (AHR agonist in embryos of Atlantic killifish (Fundulus heteroclitus from a marine Superfund site

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Franks Diana G

2011-05-01

Full Text Available Abstract Background Populations of Atlantic killifish (Fundulus heteroclitus have evolved resistance to the embryotoxic effects of polychlorinated biphenyls (PCBs and other halogenated and nonhalogenated aromatic hydrocarbons that act through an aryl hydrocarbon receptor (AHR-dependent signaling pathway. The resistance is accompanied by reduced sensitivity to induction of cytochrome P450 1A (CYP1A, a widely used biomarker of aromatic hydrocarbon exposure and effect, but whether the reduced sensitivity is specific to CYP1A or reflects a genome-wide reduction in responsiveness to all AHR-mediated changes in gene expression is unknown. We compared gene expression profiles and the response to 3,3',4,4',5-pentachlorobiphenyl (PCB-126 exposure in embryos (5 and 10 dpf and larvae (15 dpf from F. heteroclitus populations inhabiting the New Bedford Harbor, Massachusetts (NBH Superfund site (PCB-resistant and a reference site, Scorton Creek, Massachusetts (SC; PCB-sensitive. Results Analysis using a 7,000-gene cDNA array revealed striking differences in responsiveness to PCB-126 between the populations; the differences occur at all three stages examined. There was a sizeable set of PCB-responsive genes in the sensitive SC population, a much smaller set of PCB-responsive genes in NBH fish, and few similarities in PCB-responsive genes between the two populations. Most of the array results were confirmed, and additional PCB-regulated genes identified, by RNA-Seq (deep pyrosequencing. Conclusions The results suggest that NBH fish possess a gene regulatory defect that is not specific to one target gene such as CYP1A but rather lies in a regulatory pathway that controls the transcriptional response of multiple genes to PCB exposure. The results are consistent with genome-wide disruption of AHR-dependent signaling in NBH fish.

Binding Mode and Structure-Activity Relationships of ITE as an Aryl Hydrocarbon Receptor (AhR) Agonist.

Science.gov (United States)

Dolciami, Daniela; Gargaro, Marco; Cerra, Bruno; Scalisi, Giulia; Bagnoli, Luana; Servillo, Giuseppe; Fazia, Maria Agnese Della; Puccetti, Paolo; Quintana, Francisco J; Fallarino, Francesca; Macchiarulo, Antonio

2018-02-06

Discovered as a modulator of the toxic response to environmental pollutants, aryl hydrocarbon receptor (AhR) has recently gained attention for its involvement in various physiological and pathological pathways. AhR is a ligand-dependent transcription factor activated by a large array of chemical compounds, which include metabolites of l-tryptophan (l-Trp) catabolism as endogenous ligands of the receptor. Among these, 2-(1'H-indole-3'-carbonyl)thiazole-4-carboxylic acid methyl ester (ITE) has attracted interest in the scientific community, being endowed with nontoxic, immunomodulatory, and anticancer AhR-mediated functions. So far, no information about the binding mode and interactions of ITE with AhR is available. In this study, we used docking and molecular dynamics to propose a putative binding mode of ITE into the ligand binding pocket of AhR. Mutagenesis studies were then instrumental in validating the proposed binding mode, identifying His 285 and Tyr 316 as important key residues for ligand-dependent receptor activation. Finally, a set of ITE analogues was synthesized and tested to further probe molecular interactions of ITE to AhR and characterize the relevance of specific functional groups in the chemical structure for receptor activity. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Acromegaly Is More Severe in Patients With AHR or AIP Gene Variants Living in Highly Polluted Areas.

Science.gov (United States)

Cannavo, S; Ragonese, M; Puglisi, S; Romeo, P D; Torre, M L; Alibrandi, A; Scaroni, C; Occhi, G; Ceccato, F; Regazzo, D; De Menis, E; Sartorato, P; Arnaldi, G; Trementino, L; Trimarchi, F; Ferrau, F

2016-04-01

An increased prevalence of acromegaly was found some years ago in a highly polluted area in North-Eastern Sicily, where high concentration of nonmethane hydrocarbons, volatile organic compounds, and cadmium was found. Aryl hydrocarbon receptor (AHR) pathway has a key role in detoxification of these compounds and in tumorigenesis. We correlated the occurrence of AHR and/or AHR-interacting protein (AIP) gene variants with acromegaly severity according to pollution exposition. This was an observational, perspective study conducted over 7 years in four Italian referral centers for pituitary diseases in which 210 patients with acromegaly were enrolled between 2008 and 2015. Genetic screening of patients for AHR and AIP variants. Clinical, biochemical, and radiological data of patients with and without AIP and/or AHR gene variants, living in polluted (high-risk for health, [HR]) or nonpolluted (NP) areas of five Italian regions were evaluated and compared. Among the 23 patients from HR areas, nine showed AHR or AIP variants. Mean IGF-I levels and pituitary tumor diameter were significantly higher in these nine patients (HR/VAR+) than in the other 14 (HR/VAR−) and in the 187 from NP areas (44 NP/VAR+). Somatostatin analogs significantly decreased mean GH and IGF-I levels in patients from NP areas and in HR/VAR− (GH P acromegaly, increased pituitary tumor size, and somatostatin analog resistance in patients living in HR areas.

Interplay between Dioxin-Mediated Signaling and Circadian Clock: A Possible Determinant in Metabolic Homeostasis

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Chun Wang

2014-07-01

Full Text Available The rotation of the earth on its axis creates the environment of a 24 h solar day, which organisms on earth have used to their evolutionary advantage by integrating this timing information into their genetic make-up in the form of a circadian clock. This intrinsic molecular clock is pivotal for maintenance of synchronized homeostasis between the individual organism and the external environment to allow coordinated rhythmic physiological and behavioral function. Aryl hydrocarbon receptor (AhR is a master regulator of dioxin-mediated toxic effects, and is, therefore, critical in maintaining adaptive responses through regulating the expression of phase I/II drug metabolism enzymes. AhR expression is robustly rhythmic, and physiological cross-talk between AhR signaling and circadian rhythms has been established. Increasing evidence raises a compelling argument that disruption of endogenous circadian rhythms contributes to the development of disease, including sleep disorders, metabolic disorders and cancers. Similarly, exposure to environmental pollutants through air, water and food, is increasingly cited as contributory to these same problems. Thus, a better understanding of interactions between AhR signaling and the circadian clock regulatory network can provide critical new insights into environmentally regulated disease processes. This review highlights recent advances in the understanding of the reciprocal interactions between dioxin-mediated AhR signaling and the circadian clock including how these pathways relate to health and disease, with emphasis on the control of metabolic function.

Modularized TGFbeta-Smad Signaling Pathway

Science.gov (United States)

Li, Yongfeng; Wang, M.; Carra, C.; Cucinotta, F. A.

2011-01-01

The Transforming Growth Factor beta (TGFbeta) signaling pathway is a prominent regulatory signaling pathway controlling various important cellular processes. It can be induced by several factors, including ionizing radiation. It is regulated by Smads in a negative feedback loop through promoting increases in the regulatory Smads in the cell nucleus, and subsequent expression of inhibitory Smad, Smad7 to form a ubiquitin ligase with Smurf targeting active TGF receptors for degradation. In this work, we proposed a mathematical model to study the radiation-induced Smad-regulated TGF signaling pathway. By modularization, we are able to analyze each module (subsystem) and recover the nonlinear dynamics of the entire network system. Meanwhile the excitability, a common feature observed in the biological systems, along the TGF signaling pathway is discussed by mathematical analysis and numerical simulation.

Aberrant Signaling Pathways in Glioma

International Nuclear Information System (INIS)

Nakada, Mitsutoshi; Kita, Daisuke; Watanabe, Takuya; Hayashi, Yutaka; Teng, Lei; Pyko, Ilya V.; Hamada, Jun-Ichiro

2011-01-01

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

Modularized Smad-regulated TGFβ signaling pathway.

Science.gov (United States)

Li, Yongfeng; Wang, Minli; Carra, Claudio; Cucinotta, Francis A

2012-12-01

The transforming Growth Factor β (TGFβ) signaling pathway is a prominent regulatory signaling pathway controlling various important cellular processes. TGFβ signaling can be induced by several factors including ionizing radiation. The pathway is regulated in a negative feedback loop through promoting the nuclear import of the regulatory Smads and a subsequent expression of inhibitory Smad7, that forms ubiquitin ligase with Smurf2, targeting active TGFβ receptors for degradation. In this work, we proposed a mathematical model to study the Smad-regulated TGFβ signaling pathway. By modularization, we are able to analyze mathematically each component subsystem and recover the nonlinear dynamics of the entire network system. Meanwhile the excitability, a common feature observed in the biological systems, in the TGFβ signaling pathway is discussed and supported as well by numerical simulation, indicating the robustness of the model. Published by Elsevier Inc.

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

Lifescience Database Archive (English)

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

Fisetin-treatment alleviates airway inflammation through inhbition of MyD88/NF-κB signaling pathway.

Science.gov (United States)

Huang, Wei; Li, Ming-Li; Xia, Ming-Yue; Shao, Jian-Ying

2018-07-01

Asthma is a common chronic airway inflammation disease and is considered as a major public health problem. Fisetin (3,3',4',7-tetrahydroxyflavone) is a naturally occurring flavonoid abundantly found in different vegetables and fruits. Fisetin has been reported to exhibit various positive biological effects, including anti-proliferative, anticancer, anti-oxidative and neuroprotective effects. We evaluated the effects of fisetin on allergic asthma regulation in mice. Mice were first sensitized, then airway-challenged with ovalbumin (OVA). Whether fisetin treatment attenuated OVA-induced airway inflammation was examined via inflammation inhibition through MyD88-related NF-κB (p65) signaling pathway. Mice were divided into the control (Con), OVA-induced asthma (Mod), 40 (FL) and 50 (FH) mg/kg fisetin-treated OVA-induced asthma groups. Our results found that OVA-induced airway inflammation in mice caused a significant inflammatory response via the activation of MyD88 and NF-κB signaling pathways, leading to release of pro-inflammatory cytokines. In contrast, fisetin-treated mice after OVA induction inhibited activation of MyD88 and NF-κB signaling pathways, resulting in downregulation of pro-inflammatory cytokine secretion. Further, fisetin significantly ameliorated the airway hyperresponsiveness (AHR) towards methacholine (Mch). In addition, fisetin reduced the number of eosinophil, monocyte, neutrophil and total white blood cell in the bronchoalveolar lavage fluid (BALF) of OVA-induced mice. The serum and BALF samples obtained from the OVA-induced mice with fisetin showed lower levels of pro-inflammatory cytokines. The results of our study illustrated that fisetin may be a new promising candidate to inhibit airway inflammation response induced by OVA.

Hyaluronan signaling during ozone-induced lung injury requires TLR4, MyD88, and TIRAP.

Directory of Open Access Journals (Sweden)

Zhuowei Li

Full Text Available Ozone exposure is associated with exacerbation of reactive airways disease. We have previously reported that the damage-associated molecular pattern, hyaluronan, is required for the complete biological response to ambient ozone and that hyaluronan fragments signal through toll-like receptor 4 (TLR4. In this study, we further investigated the role of TLR4 adaptors in ozone-induced airway hyperresponsiveness (AHR and the direct response to hyaluronan fragments (HA. Using a murine model of AHR, C57BL/6J, TLR4-/-, MyD88-/-, and TIRAP-/- mice were characterized for AHR after exposure to either ozone (1 ppm × 3 h or HA fragments. Animals were characterized for AHR with methacholine challenge, cellular inflammation, lung injury, and production of pro-inflammatory cytokines. Ozone-exposed C57BL/6J mice developed cellular inflammation, lung injury, pro-inflammatory cytokines, and AHR, while mice deficient in TLR4, MyD88 or TIRAP demonstrated both reduced AHR and reduced levels of pro-inflammatory cytokines including TNFα, IL-1β, MCP-1, IL-6 and KC. The level of hyaluronan was increased after inhalation of ozone in each strain of mice. Direct challenge of mice to hyaluronan resulted in AHR in C57BL/6J mice, but not in TLR4-/-, MyD88-/-, or TIRAP-/- mice. HA-induced cytokine production in wild-type mice was significantly reduced in TLR4-/-, MyD88-/-, or TIRAP-/- mice. In conclusion, our findings support that ozone-induced airway hyperresponsiveness is dependent on the HA-TLR4-MyD88-TIRAP signaling pathway.

Novel cellular targets of AhR underlie alterations in neutrophilic inflammation and iNOS expression during influenza virus infection

Science.gov (United States)

Head Wheeler, Jennifer L.; Martin, Kyle C.; Lawrence, B. Paige

2012-01-01

The underlying reasons for variable clinical outcomes from respiratory viral infections remain uncertain. Several studies suggest that environmental factors contribute to this variation, but limited knowledge of cellular and molecular targets of these agents hampers our ability to quantify or modify their contribution to disease and improve public health. The aryl hydrocarbon receptor (AhR) is an environment sensing transcription factor that binds many anthropogenic and natural chemicals. The immunomodulatory properties of AhR ligands are best characterized with extensive studies of changes in CD4+ T cell responses. Yet, AhR modulates other aspects of immune function. We previously showed that during influenza virus infection, AhR activation modulates neutrophil accumulation in the lung, and this contributes to increased mortality in mice. Enhanced levels of inducible nitric oxide synthase (iNOS) in infected lungs are observed during the same timeframe as AhR-mediated increased pulmonary neutrophilia. In this study, we evaluated whether these two consequences of AhR activation are causally linked. Reciprocal inhibition of AhR-mediated elevations in iNOS and pulmonary neutrophilia reveal that, although they are contemporaneous, they are not causally related. We show using Cre/loxP technology that elevated iNOS levels and neutrophil number in the infected lung result from separate, AhR-dependent signaling in endothelial and respiratory epithelial cells, respectively. Studies using mutant mice further reveal that AhR-mediated alterations in these innate responses to infection require a functional nuclear localization signal and DNA binding domain. Thus, gene targets of AhR in non-hematopoietic cells are important new considerations for understanding AhR-mediated changes in innate anti-viral immunity. PMID:23233726

DMPD: When signaling pathways collide: positive and negative regulation of toll-likereceptor signal transduction. [Dynamic Macrophage Pathway CSML Database

Lifescience Database Archive (English)

Full Text Available 18631453 When signaling pathways collide: positive and negative regulation of toll-...uction. PubmedID 18631453 Title When signaling pathways collide: positive and neg...l) Show When signaling pathways collide: positive and negative regulation of toll-likereceptor signal transd...likereceptor signal transduction. O'Neill LA. Immunity. 2008 Jul 18;29(1):12-20. (.png) (.svg) (.html) (.csm

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

Science.gov (United States)

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

2014-01-01

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

Fibroblast growth factor (Fgf) 21 is a novel target gene of the aryl hydrocarbon receptor (AhR)

Energy Technology Data Exchange (ETDEWEB)

Cheng, Xingguo, E-mail: chengx@stjohns.edu [Department of Pharmaceutical Sciences, St. John' s University, 8000 Utopia Parkway, Queens, NY 11439 (United States); Vispute, Saurabh G. [Department of Pharmaceutical Sciences, St. John' s University, 8000 Utopia Parkway, Queens, NY 11439 (United States); Liu, Jie [Department of Internal Medicine, University of Kansas Medical Center, 3901 Rainbow Boulevard, Kansas City, KS 66160 (United States); Cheng, Christine; Kharitonenkov, Alexei [Lilly Research Laboratories, Division of Eli Lilly and Co., Indianapolis, IN 46285 (United States); Klaassen, Curtis D., E-mail: curtisklaassenphd@gmail.com [Department of Internal Medicine, University of Kansas Medical Center, 3901 Rainbow Boulevard, Kansas City, KS 66160 (United States)

2014-07-01

The toxic effects of dioxins, such as 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), mainly through activation of the aryl hydrocarbon receptor (AhR) are well documented. Fibroblast growth factor (Fgf) 21 plays critical roles in metabolic adaptation to fasting by increasing lipid oxidation and ketogenesis in the liver. The present study was performed to determine whether activation of the AhR induces Fgf21 expression. In mouse liver, TCDD increased Fgf21 mRNA in both dose- and time-dependent manners. In addition, TCDD markedly increased Fgf21 mRNA expression in cultured mouse and human hepatocytes. Moreover, TCDD increased mRNA (in liver) and protein levels (in both liver and serum) of Fgf21 in wild-type mice, but not in AhR-null mice. Chromatin immunoprecipitation assays showed that TCDD increased AhR protein binding to the Fgf21 promoter (− 105/+ 1 base pair). Fgf21-null mice administered 200 μg/kg of TCDD died within 20 days, whereas wild-type mice receiving the same treatment were still alive at one month after administration. This indicates that TCDD-induced Fgf21 expression protects against TCDD toxicity. Diethylhexylphthalate (DEHP) pretreatment attenuated TCDD-induced Fgf21 expression in mouse liver and white adipose tissue, which may explain a previous report that DEHP pretreatment decreases TCDD-induced wasting. In conclusion, Fgf21 appears to be a target gene of AhR-signaling pathway in mouse and human liver. - Highlights: • TCDD induced Fgf21 expression at both mRNA and protein levels. • Fgf21 induction by TCDD is AhR-dependent. • DEHP attenuated TCDD-induced Fgf21 expression.

Fibroblast growth factor (Fgf) 21 is a novel target gene of the aryl hydrocarbon receptor (AhR)

International Nuclear Information System (INIS)

Cheng, Xingguo; Vispute, Saurabh G.; Liu, Jie; Cheng, Christine; Kharitonenkov, Alexei; Klaassen, Curtis D.

2014-01-01

The toxic effects of dioxins, such as 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), mainly through activation of the aryl hydrocarbon receptor (AhR) are well documented. Fibroblast growth factor (Fgf) 21 plays critical roles in metabolic adaptation to fasting by increasing lipid oxidation and ketogenesis in the liver. The present study was performed to determine whether activation of the AhR induces Fgf21 expression. In mouse liver, TCDD increased Fgf21 mRNA in both dose- and time-dependent manners. In addition, TCDD markedly increased Fgf21 mRNA expression in cultured mouse and human hepatocytes. Moreover, TCDD increased mRNA (in liver) and protein levels (in both liver and serum) of Fgf21 in wild-type mice, but not in AhR-null mice. Chromatin immunoprecipitation assays showed that TCDD increased AhR protein binding to the Fgf21 promoter (− 105/+ 1 base pair). Fgf21-null mice administered 200 μg/kg of TCDD died within 20 days, whereas wild-type mice receiving the same treatment were still alive at one month after administration. This indicates that TCDD-induced Fgf21 expression protects against TCDD toxicity. Diethylhexylphthalate (DEHP) pretreatment attenuated TCDD-induced Fgf21 expression in mouse liver and white adipose tissue, which may explain a previous report that DEHP pretreatment decreases TCDD-induced wasting. In conclusion, Fgf21 appears to be a target gene of AhR-signaling pathway in mouse and human liver. - Highlights: • TCDD induced Fgf21 expression at both mRNA and protein levels. • Fgf21 induction by TCDD is AhR-dependent. • DEHP attenuated TCDD-induced Fgf21 expression

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

Lifescience Database Archive (English)

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

Hypoxia perturbs aryl hydrocarbon receptor signaling and CYP1A1 expression induced by PCB 126 in human skin and liver-derived cell lines

Energy Technology Data Exchange (ETDEWEB)

Vorrink, Sabine U. [Interdisciplinary Graduate Program in Human Toxicology, The University of Iowa, Iowa City, IA (United States); Department of Radiation Oncology, The University of Iowa, Iowa City, IA (United States); Severson, Paul L. [Department of Pharmacology and Toxicology, The University of Arizona, Tucson, AZ (United States); Kulak, Mikhail V. [Department of Surgery, The University of Iowa, Iowa City, IA (United States); Futscher, Bernard W. [Department of Pharmacology and Toxicology, The University of Arizona, Tucson, AZ (United States); Domann, Frederick E., E-mail: frederick-domann@uiowa.edu [Interdisciplinary Graduate Program in Human Toxicology, The University of Iowa, Iowa City, IA (United States); Department of Radiation Oncology, The University of Iowa, Iowa City, IA (United States); Department of Surgery, The University of Iowa, Iowa City, IA (United States)

2014-02-01

The aryl hydrocarbon receptor (AhR) is an important mediator of toxic responses after exposure to xenobiotics including 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and dioxin-like polychlorinated biphenyls (PCBs). Activation of AhR responsive genes requires AhR dimerization with the aryl hydrocarbon receptor nuclear translocator (ARNT), a heterodimeric partner also shared by the hypoxia-inducible factor-1α (HIF-1α) protein. TCDD-stimulated AhR transcriptional activity can be influenced by hypoxia; however, it less well known whether hypoxia interferes with AhR transcriptional transactivation in the context of PCB-mediated AhR activation in human cells. Elucidation of this interaction is important in liver hepatocytes which extensively metabolize ingested PCBs and experience varying degrees of oxygen tension during normal physiologic function. This study was designed to assess the effect of hypoxia on AhR transcriptional responses after exposure to 3,3′,4,4′,5-pentachlorobiphenyl (PCB 126). Exposure to 1% O{sub 2} prior to PCB 126 treatment significantly inhibited CYP1A1 mRNA and protein expression in human HepG2 and HaCaT cells. CYP1A1 transcriptional activation was significantly decreased upon PCB 126 stimulation under conditions of hypoxia. Additionally, hypoxia pre-treatment reduced PCB 126 induced AhR binding to CYP1 target gene promoters. Importantly, ARNT overexpression rescued cells from the inhibitory effect of hypoxia on XRE-luciferase reporter activity. Therefore, the mechanism of interference of the signaling crosstalk between the AhR and hypoxia pathways appears to be at least in part dependent on ARNT availability. Our results show that AhR activation and CYP1A1 expression induced by PCB 126 were significantly inhibited by hypoxia and hypoxia might therefore play an important role in PCB metabolism and toxicity. - Highlights: • Significant crosstalk exists between AhR and HIF-1α signaling. • Hypoxia perturbs PCB 126 induced AhR function and

ERβ induces the differentiation of cultured osteoblasts by both Wnt/β-catenin signaling pathway and estrogen signaling pathways

Energy Technology Data Exchange (ETDEWEB)

Yin, Xinhua [Department of Spine Surgery, Xiangya Hospital of Central South University, Changsha (China); Wang, Xiaoyuan [Department of Nephrology, Xi An Honghui Hospital, Xi an (China); Hu, Xiongke; Chen, Yong; Zeng, Kefeng [Department of Spine Surgery, Xiangya Hospital of Central South University, Changsha (China); Zhang, Hongqi, E-mail: zhq9699@126.com [Department of Spine Surgery, Xiangya Hospital of Central South University, Changsha (China)

2015-07-01

Although 17β-estradial (E2) is known to stimulate bone formation, the underlying mechanisms are not fully understood. Recent studies have implicated the Wnt/β-catenin pathway as a major signaling cascade in bone biology. The interactions between Wnt/β-catenin signaling pathway and estrogen signaling pathways have been reported in many tissues. In this study, E2 significantly increased the expression of β-catenin by inducing phosphorylations of GSK3β at serine 9. ERβ siRNAs were transfected into MC3T3-E1 cells and revealed that ERβ involved E2-induced osteoblasts proliferation and differentiation via Wnt/β-catenin signaling. The osteoblast differentiation genes (BGP, ALP and OPN) and proliferation related gene (cyclin D1) expression were significantly induced by E2-mediated ERβ. Furthermore immunofluorescence and immunoprecipitation analysis demonstrated that E2 induced the accumulation of β-catenin protein in the nucleus which leads to interaction with T-cell-specific transcription factor/lymphoid enhancer binding factor (TCF/LEF) transcription factors. Taken together, these findings suggest that E2 promotes osteoblastic proliferation and differentiation by inducing proliferation-related and differentiation-related gene expression via ERβ/GSK-3β-dependent Wnt/β-catenin signaling pathway. Our findings provide novel insights into the mechanisms of action of E2 in osteoblastogenesis. - Highlights: • 17β-estradial (E2) promotes GSK3-β phosphorylation. • E2 activates the Wnt/β-catenin signaling pathway. • The Wnt/β-catenin signaling pathway interacts with estrogen signaling pathways. • E2-mediated ER induced osteoblast differentiation and proliferation related genes expression.

ERβ induces the differentiation of cultured osteoblasts by both Wnt/β-catenin signaling pathway and estrogen signaling pathways

International Nuclear Information System (INIS)

Yin, Xinhua; Wang, Xiaoyuan; Hu, Xiongke; Chen, Yong; Zeng, Kefeng; Zhang, Hongqi

2015-01-01

Although 17β-estradial (E2) is known to stimulate bone formation, the underlying mechanisms are not fully understood. Recent studies have implicated the Wnt/β-catenin pathway as a major signaling cascade in bone biology. The interactions between Wnt/β-catenin signaling pathway and estrogen signaling pathways have been reported in many tissues. In this study, E2 significantly increased the expression of β-catenin by inducing phosphorylations of GSK3β at serine 9. ERβ siRNAs were transfected into MC3T3-E1 cells and revealed that ERβ involved E2-induced osteoblasts proliferation and differentiation via Wnt/β-catenin signaling. The osteoblast differentiation genes (BGP, ALP and OPN) and proliferation related gene (cyclin D1) expression were significantly induced by E2-mediated ERβ. Furthermore immunofluorescence and immunoprecipitation analysis demonstrated that E2 induced the accumulation of β-catenin protein in the nucleus which leads to interaction with T-cell-specific transcription factor/lymphoid enhancer binding factor (TCF/LEF) transcription factors. Taken together, these findings suggest that E2 promotes osteoblastic proliferation and differentiation by inducing proliferation-related and differentiation-related gene expression via ERβ/GSK-3β-dependent Wnt/β-catenin signaling pathway. Our findings provide novel insights into the mechanisms of action of E2 in osteoblastogenesis. - Highlights: • 17β-estradial (E2) promotes GSK3-β phosphorylation. • E2 activates the Wnt/β-catenin signaling pathway. • The Wnt/β-catenin signaling pathway interacts with estrogen signaling pathways. • E2-mediated ER induced osteoblast differentiation and proliferation related genes expression

Non-Smad pathways in TGF-β signaling

OpenAIRE

Zhang, Ying E

2009-01-01

Transforming growth factor-β utilizes a multitude of intracellular signaling pathways in addition to Smads to regulate a wide array of cellular functions. These non-canonical, non-Smad pathways are activated directly by ligand-occupied receptors to reinforce, attenuate, or otherwise modulate downstream cellular responses. These non-Smad pathways include various branches of MAP kinase pathways, Rho-like GTPase signaling pathways, and phosphatidylinositol-3-kinase/AKT pathways. This review focu...

The anticonvulsant action of AHR-11748 on kindled amygdaloid seizures in rats.

Science.gov (United States)

Albertson, T E; Walby, W F

1987-03-01

The anticonvulsant effectiveness of AHR-11748 (3-[3-(trifluoromethyl)phenoxy]-1-azetidinecarboxamide) was evaluated in the kindled amygdaloid seizure model in rats. Doses of AHR-11748 that did not cause prestimulation toxicity significantly attenuated elicited afterdischarge durations and the severity of the accompanying behavioral convulsive response in previously kindled rats. AHR-11748 (25-100 mg/kg i.p.) was evaluated at 30 min in previously kindled rats using both threshold (20 microA increments) and suprathreshold (400 microA) paradigms. AHR-11748 (50-100.mg/kg) reduced suprathreshold elicited after discharges and seizure severity. Utilizing a suprathreshold kindling paradigm, the maximum anticonvulsant effectiveness for the 100 mg/kg i.p. dose of AHR-11748 was seen at 180 min. AHR-11748 significantly elevated seizure thresholds only at the 100 mg/kg dose. AHR-11748 (25-100 mg/kg) significantly reduced the severity of threshold elicited seizures. When AHR-11748 (50 and 100 mg/kg i.p.) was administered daily during kindling acquisition, the number of daily trials necessary to complete kindling significantly increased. A reduction in both the duration and the severity of the responses induced by the daily stimulations during the acquisition period was seen with AHR-11748 treatment. This study has demonstrated that AHR-11748 significantly modifies both the acquisition of kindling and the fully kindled amygdaloid seizures at doses that do not cause behavioral toxicity.

A dominant negative zebrafish Ahr2 partially protects developing zebrafish from dioxin toxicity.

Directory of Open Access Journals (Sweden)

Kevin A Lanham

Full Text Available The toxicity by 2,3,7,8 tetrachlorodibenzo-p-dioxin (TCDD is thought to be caused by activation of the aryl hydrocarbon receptor (AHR. However, our understanding of how AHR activation by TCDD leads to toxic effects is poor. Ideally we would like to manipulate AHR activity in specific tissues and at specific times. One route to this is expressing dominant negative AHRs (dnAHRs. This work describes the construction and characterization of dominant negative forms of the zebrafish Ahr2 in which the C-terminal transactivation domain was either removed, or replaced with the inhibitory domain from the Drosophila engrailed repressor protein. One of these dnAhr2s was selected for expression from the ubiquitously active e2fα promoter in transgenic zebrafish. We found that these transgenic zebrafish expressing dnAhr2 had reduced TCDD induction of the Ahr2 target gene cyp1a, as measured by 7-ethoxyresorufin-O-deethylase activity. Furthermore, the cardiotoxicity produced by TCDD, pericardial edema, heart malformation, and reduced blood flow, were all mitigated in the zebrafish expressing the dnAhr2. These results provide in vivo proof-of-principle results demonstrating the effectiveness of dnAHRs in manipulating AHR activity in vivo, and demonstrating that this approach can be a means for blocking TCDD toxicity.

Critical nodes in signalling pathways

DEFF Research Database (Denmark)

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

2006-01-01

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

Cerebral insulin, insulin signaling pathway, and brain angiogenesis.

Science.gov (United States)

Zeng, Yi; Zhang, Le; Hu, Zhiping

2016-01-01

Insulin performs unique non-metabolic functions within the brain. Broadly speaking, two major areas of these functions are those related to brain endothelial cells and the blood-brain barrier (BBB) function, and those related to behavioral effects, like cognition in disease states (Alzheimer's disease, AD) and in health. Recent studies showed that both these functions are associated with brain angiogenesis. These findings raise interesting questions such as how they are linked to each other and whether modifying brain angiogenesis by targeting certain insulin signaling pathways could be an effective strategy to treat dementia as in AD, or even to help secure healthy longevity. The two canonical downstream pathways involved in mediating the insulin signaling pathway, the phosphoinositide-3 kinase (PI3K), and mitogen-activated protein kinase (MAPK) cascades, in the brain are supposed to be similar to those in the periphery. PI3K and MAPK pathways play important roles in angiogenesis. Both are involved in stimulating hypoxia inducible factor (HIF) in angiogenesis and could be activated by the insulin signaling pathway. This suggests that PI3K and MAPK pathways might act as cross-talk between the insulin signaling pathway and the angiogenesis pathway in brain. But the cerebral insulin, insulin signaling pathway, and the detailed mechanism in the connection of insulin signaling pathway, brain angiogenesis pathway, and healthy aging or dementias are still mostly not clear and need further studies.

Hedgehog signaling pathway in neuroblastoma differentiation.

Science.gov (United States)

Souzaki, Ryota; Tajiri, Tatsuro; Souzaki, Masae; Kinoshita, Yoshiaki; Tanaka, Sakura; Kohashi, Kenichi; Oda, Yoshinao; Katano, Mitsuo; Taguchi, Tomoaki

2010-12-01

The hedgehog (Hh) signaling pathway is activated in some adult cancers. On the other hand, the Hh signaling pathway plays an important role in the development of the neural crest in embryos. The aim of this study is to show the activation of Hh signaling pathway in neuroblastoma (NB), a pediatric malignancy arising from neural crest cells, and to reveal the meaning of the Hh signaling pathway in NB development. This study analyzed the expression of Sonic hedgehog (Shh), GLI1, and Patched 1 (Ptch1), transactivators of Hh signaling pathway, by immunohistochemistry in 82 NB and 10 ganglioneuroblastoma cases. All 92 cases were evaluated for the status of MYCN amplification. Of the 92 cases, 67 (73%) were positive for Shh, 62 cases (67%) were positive for GLI1, and 73 cases (79%) were positive for Ptch1. Only 2 (10%) of the 20 cases with MYCN amplification were positive for Shh and GLI1, and 4 cases (20%) were positive for Ptch1 (MYCN amplification vs no MYCN amplification, P ≦ .01). The percentage of GLI1-positive cells in the cases with INSS stage 1 without MYCN amplification was significantly higher than that with INSS stage 4. Of 72 cases without MYCN amplification, 60 were GLI1-positive. Twelve cases were GLI1-negative, and the prognosis of the GLI1-positive cases was significantly better than that of the GLI1-negative cases (P = .015). Most of NBs without MYCN amplification were positive for Shh, GLI1, and Ptch1. In the cases without MYCN amplification, the high expression of GLI1 was significantly associated with early clinical stage and a good prognosis of the patients. In contrast to adult cancers, the activation of the Hh signaling pathway in NB may be associated with the differentiation of the NB. Copyright © 2010 Elsevier Inc. All rights reserved.

UAV State Estimation Modeling Techniques in AHRS

Science.gov (United States)

Razali, Shikin; Zhahir, Amzari

2017-11-01

Autonomous unmanned aerial vehicle (UAV) system is depending on state estimation feedback to control flight operation. Estimation on the correct state improves navigation accuracy and achieves flight mission safely. One of the sensors configuration used in UAV state is Attitude Heading and Reference System (AHRS) with application of Extended Kalman Filter (EKF) or feedback controller. The results of these two different techniques in estimating UAV states in AHRS configuration are displayed through position and attitude graphs.

Antagonism between Hedgehog and Wnt signaling pathways regulates tumorigenicity.

Science.gov (United States)

Ding, Mei; Wang, Xin

2017-12-01

The crosstalk of multiple cellular signaling pathways is crucial in animal development and tissue homeostasis, and its dysregulation may result in tumor formation and metastasis. The Hedgehog (Hh) and Wnt signaling pathways are both considered to be essential regulators of cell proliferation, differentiation and oncogenesis. Recent studies have indicated that the Hh and Wnt signaling pathways are closely associated and involved in regulating embryogenesis and cellular differentiation. Hh signaling acts upstream of the Wnt signaling pathway, and negative regulates Wnt activity via secreted frizzled-related protein 1 (SFRP1), and the Wnt/β-catenin pathway downregulates Hh activity through glioma-associated oncogene homolog 3 transcriptional regulation. This evidence suggests that the imbalance of Hh and Wnt regulation serves a crucial role in cancer-associated processes. The activation of SFRP1, which inhibits Wnt, has been demonstrated to be an important cross-point between the two signaling pathways. The present study reviews the complex interaction between the Hh and Wnt signaling pathways in embryogenesis and tumorigenicity, and the role of SFRP1 as an important mediator associated with the dysregulation of the Hh and Wnt signaling pathways.

Aryl hydrocarbon receptor pathway activation enhances gastric cancer cell invasiveness likely through a c-Jun-dependent induction of matrix metalloproteinase-9

Directory of Open Access Journals (Sweden)

Song Xin

2009-04-01

Full Text Available Abstract Background Abberant aryl hydrocarbon receptor (AhR expression and AhR pathway activation are involved in gastric carcinogenesis. However, the relationship between AhR pathway activation and gastric cancer progression is still unclear. In present study, we used 2,3,7,8-tetrachlorodibenzo-para-dioxin (TCDD, a classic and most potent ligand of AhR, to activate AhR pathway and investigated the effect of AhR pathway activation on human gastric cancer AGS cell invasion and explored the corresponding mechanism. Results To determine whether AhR pathway can be activated in AGS cells, we examined the expression of CYP1A1, a classic target gene of AhR pathway, following TCDD exposure. RT-PCR and western blot analysis showed that both CYP1A1 mRNA and protein expression were increased in a dose-dependent manner following TCDD treatment and AhR antagonist resveratrol (RSV could reverse this TCDD-induced CYP1A1 expression. To determine whether TCDD treatment of AGS cells results in an induction of MMP-9 expression, we detected MMP-9 mRNA using RT-PCR and detected MMP-9 enzymatic activity using gelatin zymography. The results showed that both MMP-9 mRNA expression and enzymatic activity were gradually increased with the concentration increase of TCDD in media and these changes could be reversed by RSV treatment in a dose-dependent manner. To examine whether AhR activation-induced MMP-9 expression and activity in AGS cells results in increased migration and invasion, we performed wound healing migration assay and transwell migration and invasion assay. After TCDD treatment, the migration distance and the migration and invasion abilities of AGS cells were increased with a dose-dependent manner. To demonstrate AhR activation-induced MMP-9 expression is mediated by c-Jun, siRNA transfection was performed to silence c-Jun mRNA in AGS cells. The results showed that MMP-9 mRNA expression and activity in untreated control AGS cells were very weak; After TCDD

Teratogenic impact of dioxin-activated AHR in laboratory animals

Science.gov (United States)

AHR and ARNT are expressed in mouse and human palatal shelves and in the urinary tract of the mouse fetus. AHR expression, translocation to the nucleus, binding to DRE, and activation are required for mediation of TCDD-induction of CP and HN. Although the human palate requires a ...

Evolutionary conservation of plant gibberellin signalling pathway components

Directory of Open Access Journals (Sweden)

Reski Ralf

2007-11-01

Full Text Available Abstract Background: Gibberellins (GA are plant hormones that can regulate germination, elongation growth, and sex determination. They ubiquitously occur in seed plants. The discovery of gibberellin receptors, together with advances in understanding the function of key components of GA signalling in Arabidopsis and rice, reveal a fairly short GA signal transduction route. The pathway essentially consists of GID1 gibberellin receptors that interact with F-box proteins, which in turn regulate degradation of downstream DELLA proteins, suppressors of GA-controlled responses. Results: Arabidopsis sequences of the gibberellin signalling compounds were used to screen databases from a variety of plants, including protists, for homologues, providing indications for the degree of conservation of the pathway. The pathway as such appears completely absent in protists, the moss Physcomitrella patens shares only a limited homology with the Arabidopsis proteins, thus lacking essential characteristics of the classical GA signalling pathway, while the lycophyte Selaginella moellendorffii contains a possible ortholog for each component. The occurrence of classical GA responses can as yet not be linked with the presence of homologues of the signalling pathway. Alignments and display in neighbour joining trees of the GA signalling components confirm the close relationship of gymnosperms, monocotyledonous and dicotyledonous plants, as suggested from previous studies. Conclusion: Homologues of the GA-signalling pathway were mainly found in vascular plants. The GA signalling system may have its evolutionary molecular onset in Physcomitrella patens, where GAs at higher concentrations affect gravitropism and elongation growth.

Comparison of the Reactor Core Characteristics of the AHR and the OPAL

Energy Technology Data Exchange (ETDEWEB)

Seo, Chul Gyo; Lee, Byung Chul; Park, C.; Chae, Hee Taek

2008-09-15

The AHR (Advanced HANARO research Reactor) was designed using the experiences from the design, operation and utilization of HANARO. Its neutronic performance was compared to that of the OPAL with a 20 MW power which started its operation recently in Australia. As the OPAL does not have any in-core irradiation hole, a modified core model of the AHR, in which an in-core irradiation hole was changed into a fuel channel, was used for the comparison. For a clean, unperturbed core condition with all fresh fuels in the core and no irradiation holes in the reflector region, the maximum thermal neutron flux (E{sub n}<0.625 eV) in the AHR reaches 4.41x10{sup 14} n/cm{sup 2} s and that in the OPAL reaches 3.96x10{sup 14} n/cm{sup 2}s in the reflector region. The maximum flux in the AHR is 10.3% higher than that in the OPAL. The thermal flux region above 4.0x10{sup 14} n/cm{sup 2}s is widely distributed in the reflector of the AHR, but is not observed at all in the reflector of the OPAL. The uranium loading of the AHR core is 45.7 kgU, which is 16.3% higher than the 39.3 kgU of OPAL. For a clean core state, the excess reactivity of the AHR is higher than that of the OPAL. The assembly-average discharge burnup in the OPAL is estimated to be 49.1%U-235 whereas that in the AHR is 62.4%U-235. The difference for the discharge burnup is significant. For the conditions with the same cycle length of 30 days, the number of fuel assemblies consumed in the AHR is only 3/4 that of the OPAL.

Radioresistance-related signaling pathways in nasopharyngeal carcinoma cells

International Nuclear Information System (INIS)

Guo Ya; Zhu Xiaodong; Qu Song; Su Fang; Wang Qi; Zhang Wei

2011-01-01

Objective: To study the difference of gene expression profile between the radioresistant human nasopharyngeal carcinoma cell line CNE-2R and CNE-2, and to screen the signaling pathway associated with radioresistance of nasopharyngeal carcinoma. Methods: The radioresistant nasopharyngeal carcinoma cell line CNE-2R was constructed from the original cell line CNE-2. CNE-2R and CNE-2 cells were cultured and administered with 60 Co γ-ray irradiation at the dose of 400 cGy for 15 times. Human-6v 3.0 whole genome expression profile was used to screen the differentially expressed genes. Bioinformatic analysis was used to identify the pathways related to radioresistance. Results: The number of the differentially expressed genes that were found in these 2 experiments was 374. The Kegg pathway and Biocarta pathway analysis of the differentially expressed genes showed the biological importance of Toll-like receptor signaling pathway and IL-1 R-mediated signal transduction pathway to the radioresistance of the CNE-2R cells and the significant differences of 13 genes in these 2 pathways,including JUN, MYD88, CCL5, CXCL10, STAT1, LY96, FOS, CCL3, IL-6, IL-8, IL-1α, IL-1β, and IRAK2 (t=13.47-66.57, P<0.05). Conclusions: Toll-like receptor signaling pathway and IL-1R-mediated signal transduction pathway might be related to the occurrence of radioresistance. (authors)

Regulation of zebrafish CYP3A65 transcription by AHR2

International Nuclear Information System (INIS)

Chang, Chin-Teng; Chung, Hsin-Yu; Su, Hsiao-Ting; Tseng, Hua-Pin; Tzou, Wen-Shyong; Hu, Chin-Hwa

2013-01-01

CYP3A proteins are the most abundant CYPs in the liver and intestines, and they play a pivotal role in drug metabolism. In mammals, CYP3A genes are induced by various xenobiotics through processes mediated by PXR. We previously identified zebrafish CYP3A65 as a CYP3A ortholog that is constitutively expressed in gastrointestinal tissues, and is upregulated by treatment with dexamethasone, rifampicin or tetrachlorodibenzo-p-dioxin (TCDD). However, the underlying mechanism of TCDD-mediated CYP3A65 transcription is unclear. Here we generated two transgenic zebrafish, Tg(CYP3A65S:EGFP) and Tg(CYP3A65L:EGFP), which contain 2.1 and 5.4 kb 5′ flanking sequences, respectively, of the CYP3A65 gene upstream of EGFP. Both transgenic lines express EGFP in larval gastrointestinal tissues in a pattern similar to that of the endogenous CYP3A65 gene. Moreover, EGFP expression can be significantly induced by TCDD exposure during the larval stage. In addition, EGFP expression can be stimulated by kynurenine, a putative AHR ligand produced during tryptophan metabolism. AHRE elements in the upstream regulatory region of the CYP3A65 gene are indispensible for basal and TCDD-induced transcription. Furthermore, the AHR2 DNA and ligand-binding domains are required to mediate effective CYP3A65 transcription. AHRE sequences are present in the promoters of many teleost CYP3 genes, but not of mammalian CYP3 genes, suggesting that AHR/AHR2-mediated transcription is likely a common regulatory mechanism for teleost CYP3 genes. It may also reflect the different environments that terrestrial and aquatic organisms encounter. - Highlights: • Tg(CYP3A65:EGFP) and CYP3A65 exhibits identical expression pattern. • CYP3A65 can be significantly induced by TCDD or kynurenine. • The AHRE elements are required to mediate CYP3A65 transcription. • The AHR2 DNA and ligand-binding domains are required for CYP3A65 transcription. • AHRE elements are present in many teleost CYP3 genes, but not in

Regulation of zebrafish CYP3A65 transcription by AHR2

Energy Technology Data Exchange (ETDEWEB)

Chang, Chin-Teng; Chung, Hsin-Yu; Su, Hsiao-Ting; Tseng, Hua-Pin [Institute of Bioscience and Biotechnology, National Taiwan Ocean University, Keelung, Taiwan (China); Tzou, Wen-Shyong [Institute of Bioscience and Biotechnology, National Taiwan Ocean University, Keelung, Taiwan (China); Center of Excellence for Marine Bioenvironment and Biotechnology, National Taiwan Ocean University, Keelung, Taiwan (China); Hu, Chin-Hwa, E-mail: chhu@mail.ntou.edu.tw [Institute of Bioscience and Biotechnology, National Taiwan Ocean University, Keelung, Taiwan (China); Center of Excellence for Marine Bioenvironment and Biotechnology, National Taiwan Ocean University, Keelung, Taiwan (China)

2013-07-15

CYP3A proteins are the most abundant CYPs in the liver and intestines, and they play a pivotal role in drug metabolism. In mammals, CYP3A genes are induced by various xenobiotics through processes mediated by PXR. We previously identified zebrafish CYP3A65 as a CYP3A ortholog that is constitutively expressed in gastrointestinal tissues, and is upregulated by treatment with dexamethasone, rifampicin or tetrachlorodibenzo-p-dioxin (TCDD). However, the underlying mechanism of TCDD-mediated CYP3A65 transcription is unclear. Here we generated two transgenic zebrafish, Tg(CYP3A65S:EGFP) and Tg(CYP3A65L:EGFP), which contain 2.1 and 5.4 kb 5′ flanking sequences, respectively, of the CYP3A65 gene upstream of EGFP. Both transgenic lines express EGFP in larval gastrointestinal tissues in a pattern similar to that of the endogenous CYP3A65 gene. Moreover, EGFP expression can be significantly induced by TCDD exposure during the larval stage. In addition, EGFP expression can be stimulated by kynurenine, a putative AHR ligand produced during tryptophan metabolism. AHRE elements in the upstream regulatory region of the CYP3A65 gene are indispensible for basal and TCDD-induced transcription. Furthermore, the AHR2 DNA and ligand-binding domains are required to mediate effective CYP3A65 transcription. AHRE sequences are present in the promoters of many teleost CYP3 genes, but not of mammalian CYP3 genes, suggesting that AHR/AHR2-mediated transcription is likely a common regulatory mechanism for teleost CYP3 genes. It may also reflect the different environments that terrestrial and aquatic organisms encounter. - Highlights: • Tg(CYP3A65:EGFP) and CYP3A65 exhibits identical expression pattern. • CYP3A65 can be significantly induced by TCDD or kynurenine. • The AHRE elements are required to mediate CYP3A65 transcription. • The AHR2 DNA and ligand-binding domains are required for CYP3A65 transcription. • AHRE elements are present in many teleost CYP3 genes, but not in

Signal Transduction Pathways that Regulate CAB Gene Expression

Energy Technology Data Exchange (ETDEWEB)

Chory, Joanne

2004-12-31

The process of chloroplast differentiation, involves the coordinate regulation of many nuclear and chloroplast genes. The cues for the initiation of this developmental program are both extrinsic (e.g., light) and intrinsic (cell-type and plastid signals). During this project period, we utilized a molecular genetic approach to select for Arabidopsis mutants that did not respond properly to environmental light conditions, as well as mutants that were unable to perceive plastid damage. These latter mutants, called gun mutants, define two retrograde signaling pathways that regulate nuclear gene expression in response to chloroplasts. A major finding was to identify a signal from chloroplasts that regulates nuclear gene transcription. This signal is the build-up of Mg-Protoporphyrin IX, a key intermediate of the chlorophyll biosynthetic pathway. The signaling pathways downstream of this signal are currently being studied. Completion of this project has provided an increased understanding of the input signals and retrograde signaling pathways that control nuclear gene expression in response to the functional state of chloroplasts. These studies should ultimately influence our abilities to manipulate plant growth and development, and will aid in the understanding of the developmental control of photosynthesis.

Signal Transduction Pathways that Regulate CAB Gene Expression

Energy Technology Data Exchange (ETDEWEB)

Chory, Joanne

2006-01-16

The process of chloroplast differentiation, involves the coordinate regulation of many nuclear and chloroplast genes. The cues for the initiation of this developmental program are both extrinsic (e.g., light) and intrinsic (cell-type and plastid signals). During this project period, we utilized a molecular genetic approach to select for Arabidopsis mutants that did not respond properly to environmental light conditions, as well as mutants that were unable to perceive plastid damage. These latter mutants, called gun mutants, define two retrograde signaling pathways that regulate nuclear gene expression in response to chloroplasts. A major finding was to identify a signal from chloroplasts that regulates nuclear gene transcription. This signal is the build-up of Mg-Protoporphyrin IX, a key intermediate of the chlorophyll biosynthetic pathway. The signaling pathways downstream of this signal are currently being studied. Completion of this project has provided an increased understanding of the input signals and retrograde signaling pathways that control nuclear gene expression in response to the functional state of chloroplasts. These studies should ultimately influence our abilities to manipulate plant growth and development, and will aid in the understanding of the developmental control of photosynthesis.

Modelling and Analysis of Biochemical Signalling Pathway Cross-talk

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Robin Donaldson

2010-02-01

Full Text Available Signalling pathways are abstractions that help life scientists structure the coordination of cellular activity. Cross-talk between pathways accounts for many of the complex behaviours exhibited by signalling pathways and is often critical in producing the correct signal-response relationship. Formal models of signalling pathways and cross-talk in particular can aid understanding and drive experimentation. We define an approach to modelling based on the concept that a pathway is the (synchronising parallel composition of instances of generic modules (with internal and external labels. Pathways are then composed by (synchronising parallel composition and renaming; different types of cross-talk result from different combinations of synchronisation and renaming. We define a number of generic modules in PRISM and five types of cross-talk: signal flow, substrate availability, receptor function, gene expression and intracellular communication. We show that Continuous Stochastic Logic properties can both detect and distinguish the types of cross-talk. The approach is illustrated with small examples and an analysis of the cross-talk between the TGF-b/BMP, WNT and MAPK pathways.

Signaling pathways regulating murine pancreatic development

DEFF Research Database (Denmark)

Serup, Palle

2012-01-01

The recent decades have seen a huge expansion in our knowledge about pancreatic development. Numerous lineage-restricted transcription factor genes have been identified and much has been learned about their function. Similarly, numerous signaling pathways important for pancreas development have...... been identified and the specific roles have been investigated by genetic and cell biological methods. The present review presents an overview of the principal signaling pathways involved in regulating murine pancreatic growth, morphogenesis, and cell differentiation....

Signaling Pathways in Cardiac Myocyte Apoptosis

Science.gov (United States)

Xia, Peng; Liu, Yuening

2016-01-01

Cardiovascular diseases, the number 1 cause of death worldwide, are frequently associated with apoptotic death of cardiac myocytes. Since cardiomyocyte apoptosis is a highly regulated process, pharmacological intervention of apoptosis pathways may represent a promising therapeutic strategy for a number of cardiovascular diseases and disorders including myocardial infarction, ischemia/reperfusion injury, chemotherapy cardiotoxicity, and end-stage heart failure. Despite rapid growth of our knowledge in apoptosis signaling pathways, a clinically applicable treatment targeting this cellular process is currently unavailable. To help identify potential innovative directions for future research, it is necessary to have a full understanding of the apoptotic pathways currently known to be functional in cardiac myocytes. Here, we summarize recent progress in the regulation of cardiomyocyte apoptosis by multiple signaling molecules and pathways, with a focus on the involvement of these pathways in the pathogenesis of heart disease. In addition, we provide an update regarding bench to bedside translation of this knowledge and discuss unanswered questions that need further investigation. PMID:28101515

Computational identification of signalling pathways in Plasmodium falciparum.

Science.gov (United States)

Oyelade, Jelili; Ewejobi, Itunu; Brors, Benedikt; Eils, Roland; Adebiyi, Ezekiel

2011-06-01

Malaria is one of the world's most common and serious diseases causing death of about 3 million people each year. Its most severe occurrence is caused by the protozoan Plasmodium falciparum. Reports have shown that the resistance of the parasite to existing drugs is increasing. Therefore, there is a huge and urgent need to discover and validate new drug or vaccine targets to enable the development of new treatments for malaria. The ability to discover these drug or vaccine targets can only be enhanced from our deep understanding of the detailed biology of the parasite, for example how cells function and how proteins organize into modules such as metabolic, regulatory and signal transduction pathways. It has been noted that the knowledge of signalling transduction pathways in Plasmodium is fundamental to aid the design of new strategies against malaria. This work uses a linear-time algorithm for finding paths in a network under modified biologically motivated constraints. We predicted several important signalling transduction pathways in Plasmodium falciparum. We have predicted a viable signalling pathway characterized in terms of the genes responsible that may be the PfPKB pathway recently elucidated in Plasmodium falciparum. We obtained from the FIKK family, a signal transduction pathway that ends up on a chloroquine resistance marker protein, which indicates that interference with FIKK proteins might reverse Plasmodium falciparum from resistant to sensitive phenotype. We also proposed a hypothesis that showed the FIKK proteins in this pathway as enabling the resistance parasite to have a mechanism for releasing chloroquine (via an efflux process). Furthermore, we also predicted a signalling pathway that may have been responsible for signalling the start of the invasion process of Red Blood Cell (RBC) by the merozoites. It has been noted that the understanding of this pathway will give insight into the parasite virulence and will facilitate rational vaccine design

Intricacies of hedgehog signaling pathways: A perspective in tumorigenesis

International Nuclear Information System (INIS)

Kar, Swayamsiddha; Deb, Moonmoon; Sengupta, Dipta; Shilpi, Arunima; Bhutia, Sujit Kumar; Patra, Samir Kumar

2012-01-01

The hedgehog (HH) signaling pathway is a crucial negotiator of developmental proceedings in the embryo governing a diverse array of processes including cell proliferation, differentiation, and tissue patterning. The overall activity of the pathway is significantly curtailed after embryogenesis as well as in adults, yet it retains many of its functional capacities. However, aberration in HH signaling mediates the initiation, proliferation and continued sustenance of malignancy in different tissues to varying degrees through different mechanisms. In this review, we provide an overview of the role of constitutively active aberrant HH signaling pathway in different types of human cancer and the underlying molecular and genetic mechanisms that drive tumorigenesis in that particular tissue. An insight into the various modes of anomalous HH signaling in different organs will provide a comprehensive knowledge of the pathway in these tissues and open a window for individually tailored, tissue-specific therapeutic interventions. The synergistic cross talking of HH pathway with many other regulatory molecules and developmentally inclined signaling pathways may offer many avenues for pharmacological advances. Understanding the molecular basis of abnormal HH signaling in cancer will provide an opportunity to inhibit the deregulated pathway in many aggressive and therapeutically challenging cancers where promising options are not available.

Intricacies of hedgehog signaling pathways: A perspective in tumorigenesis

Energy Technology Data Exchange (ETDEWEB)

Kar, Swayamsiddha; Deb, Moonmoon; Sengupta, Dipta; Shilpi, Arunima; Bhutia, Sujit Kumar [Epigenetics and Cancer Research Laboratory, Biochemistry and Molecular Biology Group, Department of Life Science, National Institute of Technology, Rourkela, Odisha 769008 (India); Patra, Samir Kumar, E-mail: samirp@nitrkl.ac.in [Epigenetics and Cancer Research Laboratory, Biochemistry and Molecular Biology Group, Department of Life Science, National Institute of Technology, Rourkela, Odisha 769008 (India)

2012-10-01

The hedgehog (HH) signaling pathway is a crucial negotiator of developmental proceedings in the embryo governing a diverse array of processes including cell proliferation, differentiation, and tissue patterning. The overall activity of the pathway is significantly curtailed after embryogenesis as well as in adults, yet it retains many of its functional capacities. However, aberration in HH signaling mediates the initiation, proliferation and continued sustenance of malignancy in different tissues to varying degrees through different mechanisms. In this review, we provide an overview of the role of constitutively active aberrant HH signaling pathway in different types of human cancer and the underlying molecular and genetic mechanisms that drive tumorigenesis in that particular tissue. An insight into the various modes of anomalous HH signaling in different organs will provide a comprehensive knowledge of the pathway in these tissues and open a window for individually tailored, tissue-specific therapeutic interventions. The synergistic cross talking of HH pathway with many other regulatory molecules and developmentally inclined signaling pathways may offer many avenues for pharmacological advances. Understanding the molecular basis of abnormal HH signaling in cancer will provide an opportunity to inhibit the deregulated pathway in many aggressive and therapeutically challenging cancers where promising options are not available.

AhrC and Eep Are Biofilm Infection-Associated Virulence Factors in Enterococcus faecalis

Science.gov (United States)

Guiton, Pascale S.; Barnes, Aaron M. T.; Manias, Dawn A.; Chuang-Smith, Olivia N.; Kohler, Petra L.; Spaulding, Adam R.; Hultgren, Scott J.; Schlievert, Patrick M.; Dunny, Gary M.

2013-01-01

Enterococcus faecalis is part of the human intestinal microbiome and is a prominent cause of health care-associated infections. The pathogenesis of many E. faecalis infections, including endocarditis and catheter-associated urinary tract infection (CAUTI), is related to the ability of clinical isolates to form biofilms. To identify chromosomal genetic determinants responsible for E. faecalis biofilm-mediated infection, we used a rabbit model of endocarditis to test strains with transposon insertions or in-frame deletions in biofilm-associated loci: ahrC, argR, atlA, opuBC, pyrC, recN, and sepF. Only the ahrC mutant was significantly attenuated in endocarditis. We demonstrate that the transcriptional regulator AhrC and the protease Eep, which we showed previously to be an endocarditis virulence factor, are also required for full virulence in murine CAUTI. Therefore, AhrC and Eep can be classified as enterococcal biofilm-associated virulence factors. Loss of ahrC caused defects in early attachment and accumulation of biofilm biomass. Characterization of ahrC transcription revealed that the temporal expression of this locus observed in wild-type cells promotes initiation of early biofilm formation and the establishment of endocarditis. This is the first report of AhrC serving as a virulence factor in any bacterial species. PMID:23460519

Comparison of the Reactor Core Characteristics of the AHR and the OPAL

International Nuclear Information System (INIS)

Seo, Chul Gyo; Lee, Byung Chul; Park, C.; Chae, Hee Taek

2008-09-01

The AHR (Advanced HANARO research Reactor) was designed using the experiences from the design, operation and utilization of HANARO. Its neutronic performance was compared to that of the OPAL with a 20 MW power which started its operation recently in Australia. As the OPAL does not have any in-core irradiation hole, a modified core model of the AHR, in which an in-core irradiation hole was changed into a fuel channel, was used for the comparison. For a clean, unperturbed core condition with all fresh fuels in the core and no irradiation holes in the reflector region, the maximum thermal neutron flux (E n 14 n/cm 2 s and that in the OPAL reaches 3.96x10 14 n/cm 2 s in the reflector region. The maximum flux in the AHR is 10.3% higher than that in the OPAL. The thermal flux region above 4.0x10 14 n/cm 2 s is widely distributed in the reflector of the AHR, but is not observed at all in the reflector of the OPAL. The uranium loading of the AHR core is 45.7 kgU, which is 16.3% higher than the 39.3 kgU of OPAL. For a clean core state, the excess reactivity of the AHR is higher than that of the OPAL. The assembly-average discharge burnup in the OPAL is estimated to be 49.1%U-235 whereas that in the AHR is 62.4%U-235. The difference for the discharge burnup is significant. For the conditions with the same cycle length of 30 days, the number of fuel assemblies consumed in the AHR is only 3/4 that of the OPAL

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

Lifescience Database Archive (English)

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

SPV: a JavaScript Signaling Pathway Visualizer.

Science.gov (United States)

Calderone, Alberto; Cesareni, Gianni

2018-03-24

The visualization of molecular interactions annotated in web resources is useful to offer to users such information in a clear intuitive layout. These interactions are frequently represented as binary interactions that are laid out in free space where, different entities, cellular compartments and interaction types are hardly distinguishable. SPV (Signaling Pathway Visualizer) is a free open source JavaScript library which offers a series of pre-defined elements, compartments and interaction types meant to facilitate the representation of signaling pathways consisting of causal interactions without neglecting simple protein-protein interaction networks. freely available under Apache version 2 license; Source code: https://github.com/Sinnefa/SPV_Signaling_Pathway_Visualizer_v1.0. Language: JavaScript; Web technology: Scalable Vector Graphics; Libraries: D3.js. sinnefa@gmail.com.

Benzo[a]pyrene impedes self-renewal and differentiation of mesenchymal stem cells and influences fracture healing.

Science.gov (United States)

Zhou, Yiqing; Jiang, Rong; An, Liqin; Wang, Hong; Cheng, Sicheng; Qiong, Shi; Weng, Yaguang

2017-06-01

Mesenchymal stem cells (MSCs) are implicated in the bone-forming process during fracture repair. Benzo[a]pyrene (BaP)-a cigarette smoke component and powerful motivator of the aryl hydrocarbon receptor (Ahr)-unfavorably influences bone condition and osteoblast differentiation. The first thing we noticed decreases self-renewal and differentiation of human bone marrow mesenchymal stem (hBM-MSCs) from smokers and activates Ahr signaling in MSCs by up-regulating the Ahr target gene cytochrome P450 (CYP) 1B1 expression. In vitro studies, we employed C3H10T1/2 and bone marrow mesenchymal stem cells (BM-MSCs) with BaP and discovered that BaP impaired innate properties of MSCs. Further investigation into MSCs showed that exposure to BaP activated Ahr signaling and inhibited TGF-β1/SMAD4 and TGF-β1/ERK/AKT signaling pathways. Corresponding with the outcomes, tibial fracture calluses produced by BaP-administered rats appeared to delay healing. This effect of BaP was abrogated by resveratrol, a natural Ahr antagonist, in vitro and in vivo. These data demonstrated that Ahr may play a key role in BaP-impaired innate properties by inhibiting SMAD-dependent signaling pathways TGF-β1/SMAD4 and SMAD-independent TGF-β1/ERK/AKT signaling pathways. Furthermore, resveratrol inhibited MSCs from adverse effects caused by BaP. Copyright © 2017. Published by Elsevier B.V.

Aryl Hydrocarbon Receptor (AhR Modulates Cockroach Allergen-Induced Immune Responses through Active TGFβ1 Release

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Yufeng Zhou

2014-01-01

Full Text Available Background. Aryl hydrocarbon receptor (AhR, a multifunctional regulator that senses and responds to environmental stimuli, plays a role in normal cell development and immune regulation. Recent evidence supports a significant link between environmental exposure and AhR in the development of allergic diseases. We sought to investigate whether AhR plays a role in mediating cockroach allergen-induced allergic immune responses. Methods. AhR expression in human lung fibroblasts from asthmatic and healthy individuals and in cockroach extract (CRE treated human lung fibroblasts (WI-38 was examined. The role of AhR in modulating CRE induced TGFβ1 production was investigated by using AhR agonist, TCDD, antagonist CH122319, and knockdown of AhR. The role of latent TGFβ1 binding protein-1 (LTBP1 in mediating TCDD induced active TGFβ1 release was also examined. Results. AhR expression was higher in airway fibroblasts from asthmatic subjects as compared to healthy controls. AhR in fibroblasts was activated by TCDD with an increased expression of cyp1a1 and cyp1b1. Increased AhR expression was observed in CRE-treated fibroblasts. Importantly, CRE induced TGFβ1 production in fibroblasts was significantly enhanced by TCDD but inhibited by CH122319. Reduced TGFβ1 production was further confirmed in fibroblasts with AhR knockdown. Moreover, AhR knockdown inhibited CRE induced fibroblast differentiation. Furthermore, TCDD induced active TGFβ1 release was significantly inhibited by LTBP1 knockdown. Conclusion. These results provide evidence for the role of AhR in modulating cockroach allergen-induced immune responses through controlling the active TGFβ1 release, suggesting a possible synergistic effect between exposure to allergens and environmental chemicals on the development of allergic diseases.

Research advances in Hedgehog signaling pathway in hepatocellular carcinoma

Directory of Open Access Journals (Sweden)

LIU Jia

2015-02-01

Full Text Available Hedgehog (Hh signaling pathway is present in many animals and plays an important role in regulating embryonic development and differentiation. Aberrant activation of Hh signaling contributes to the pathogenesis of many malignancies. Recent studies have shown that dysregulated Hh signaling pathway participates in the tumorigenesis, tumor invasion, and metastasis of hepatocellular carcinoma (HCC. Investigation of the relationship between Hh signaling pathway and HCC will help elucidate the molecular mechanism of pathogenesis of HCC and provide a new insight into the development of novel anticancer therapy and therapeutic target.

Wnt and the Wnt signaling pathway in bone development and disease

Science.gov (United States)

Wang, Yiping; Li, Yi-Ping; Paulson, Christie; Shao, Jian-Zhong; Zhang, Xiaoling; Wu, Mengrui; Chen, Wei

2014-01-01

Wnt signaling affects both bone modeling, which occurs during development, and bone remodeling, which is a lifelong process involving tissue renewal. Wnt signals are especially known to affect the differentiation of osteoblasts. In this review, we summarize recent advances in understanding the mechanisms of Wnt signaling, which is divided into two major branches: the canonical pathway and the noncanonical pathway. The canonical pathway is also called the Wnt/β-catenin pathway. There are two major noncanonical pathways: the Wnt-planar cell polarity pathway (Wnt-PCP pathway) and the Wnt-calcium pathway (Wnt-Ca2+ pathway). This review also discusses how Wnt ligands, receptors, intracellular effectors, transcription factors, and antagonists affect both the bone modeling and bone remodeling processes. We also review the role of Wnt ligands, receptors, intracellular effectors, transcription factors, and antagonists in bone as demonstrated in mouse models. Disrupted Wnt signaling is linked to several bone diseases, including osteoporosis, van Buchem disease, and sclerosteosis. Studying the mechanism of Wnt signaling and its interactions with other signaling pathways in bone will provide potential therapeutic targets to treat these bone diseases. PMID:24389191

DMPD: Multiple signaling pathways leading to the activation of interferon regulatoryfactor 3. [Dynamic Macrophage Pathway CSML Database

Lifescience Database Archive (English)

Full Text Available 12213596 Multiple signaling pathways leading to the activation of interferon regula...(.html) (.csml) Show Multiple signaling pathways leading to the activation of interferon regulatoryfactor 3.... PubmedID 12213596 Title Multiple signaling pathways leading to the activation of

Interaction Dynamics Determine Signaling and Output Pathway Responses

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Klement Stojanovski

2017-04-01

Full Text Available The understanding of interaction dynamics in signaling pathways can shed light on pathway architecture and provide insights into targets for intervention. Here, we explored the relevance of kinetic rate constants of a key upstream osmosensor in the yeast high-osmolarity glycerol-mitogen-activated protein kinase (HOG-MAPK pathway to signaling output responses. We created mutant pairs of the Sln1-Ypd1 complex interface that caused major compensating changes in the association (kon and dissociation (koff rate constants (kinetic perturbations but only moderate changes in the overall complex affinity (Kd. Yeast cells carrying a Sln1-Ypd1 mutant pair with moderate increases in kon and koff displayed a lower threshold of HOG pathway activation than wild-type cells. Mutants with higher kon and koff rates gave rise to higher basal signaling and gene expression but impaired osmoadaptation. Thus, the kon and koff rates of the components in the Sln1 osmosensor determine proper signaling dynamics and osmoadaptation.

The Fog signaling pathway: Insights into signaling in morphogenesis

Science.gov (United States)

Manning, Alyssa J.; Rogers, Stephen L.

2014-01-01

Epithelia form the building blocks of many tissue and organ types. Epithelial cells often form a contiguous 2-dimensional sheet that is held together by strong adhesions. The mechanical properties conferred by these adhesions allow the cells to undergo dramatic three-dimensional morphogenetic movements while maintaining cell–cell contacts during embryogenesis and post-embryonic development. The Drosophila Folded gastrulation pathway triggers epithelial cell shape changes that drive gastrulation and tissue folding and is one of the most extensively studied examples of epithelial morphogenesis. This pathway has yielded key insights into the signaling mechanisms and cellular machinery involved in epithelial remodeling. In this review, we discuss principles of morphogenesis and signaling that have been discovered through genetic and cell biological examination of this pathway. We also consider various regulatory mechanisms and the system's relevance to mammalian development. We propose future directions that will continue to broaden our knowledge of morphogenesis across taxa. PMID:25127992

Interaction of TGFβ and BMP signaling pathways during chondrogenesis.

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Bettina Keller

2011-01-01

Full Text Available TGFβ and BMP signaling pathways exhibit antagonistic activities during the development of many tissues. Although the crosstalk between BMP and TGFβ signaling pathways is well established in bone development, the relationship between these two pathways is less well defined during cartilage development and postnatal homeostasis. We generated hypomorphic mouse models of cartilage-specific loss of BMP and TGFβ signaling to assess the interaction of these pathways in postnatal growth plate homeostasis. We further used the chondrogenic ATDC5 cell line to test effects of BMP and TGFβ signaling on each other's downstream targets. We found that conditional deletion of Smad1 in chondrocytes resulted in a shortening of the growth plate. The addition of Smad5 haploinsufficiency led to a more severe phenotype with shorter prehypertrophic and hypertrophic zones and decreased chondrocyte proliferation. The opposite growth plate phenotype was observed in a transgenic mouse model of decreased chondrocytic TGFβ signaling that was generated by expressing a dominant negative form of the TGFβ receptor I (ΔTβRI in cartilage. Histological analysis demonstrated elongated growth plates with enhanced Ihh expression, as well as an increased proliferation rate with altered production of extracellular matrix components. In contrast, in chondrogenic ATDC5 cells, TGFβ was able to enhance BMP signaling, while BMP2 significantly reduces levels of TGF signaling. In summary, our data demonstrate that during endochondral ossification, BMP and TGFβ signaling can have antagonistic effects on chondrocyte proliferation and differentiation in vivo. We also found evidence of direct interaction between the two signaling pathways in a cell model of chondrogenesis in vitro.

Signaling flux redistribution at toll-like receptor pathway junctions.

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Kumar Selvarajoo

Full Text Available Various receptors on cell surface recognize specific extracellular molecules and trigger signal transduction altering gene expression in the nucleus. Gain or loss-of-function mutations of one molecule have shown to affect alternative signaling pathways with a poorly understood mechanism. In Toll-like receptor (TLR 4 signaling, which branches into MyD88- and TRAM-dependent pathways upon lipopolysaccharide (LPS stimulation, we investigated the gain or loss-of-function mutations of MyD88. We predict, using a computational model built on the perturbation-response approach and the law of mass conservation, that removal and addition of MyD88 in TLR4 activation, enhances and impairs, respectively, the alternative TRAM-dependent pathway through signaling flux redistribution (SFR at pathway branches. To verify SFR, we treated MyD88-deficient macrophages with LPS and observed enhancement of TRAM-dependent pathway based on increased IRF3 phosphorylation and induction of Cxcl10 and Ifit2. Furthermore, increasing the amount of MyD88 in cultured cells showed decreased TRAM binding to TLR4. Investigating another TLR4 pathway junction, from TRIF to TRAF6, RIP1 and TBK1, the removal of MyD88-dependent TRAF6 increased expression of TRAM-dependent Cxcl10 and Ifit2. Thus, we demonstrate that SFR is a novel mechanism for enhanced activation of alternative pathways when molecules at pathway junctions are removed. Our data suggest that SFR may enlighten hitherto unexplainable intracellular signaling alterations in genetic diseases where gain or loss-of-function mutations are observed.

Linking proteins to signaling pathways for experiment design and evaluation.

Directory of Open Access Journals (Sweden)

Illés J Farkas

Full Text Available Biomedical experimental work often focuses on altering the functions of selected proteins. These changes can hit signaling pathways, and can therefore unexpectedly and non-specifically affect cellular processes. We propose PathwayLinker, an online tool that can provide a first estimate of the possible signaling effects of such changes, e.g., drug or microRNA treatments. PathwayLinker minimizes the users' efforts by integrating protein-protein interaction and signaling pathway data from several sources with statistical significance tests and clear visualization. We demonstrate through three case studies that the developed tool can point out unexpected signaling bias in normal laboratory experiments and identify likely novel signaling proteins among the interactors of known drug targets. In our first case study we show that knockdown of the Caenorhabditis elegans gene cdc-25.1 (meant to avoid progeny may globally affect the signaling system and unexpectedly bias experiments. In the second case study we evaluate the loss-of-function phenotypes of a less known C. elegans gene to predict its function. In the third case study we analyze GJA1, an anti-cancer drug target protein in human, and predict for this protein novel signaling pathway memberships, which may be sources of side effects. Compared to similar services, a major advantage of PathwayLinker is that it drastically reduces the necessary amount of manual literature searches and can be used without a computational background. PathwayLinker is available at http://PathwayLinker.org. Detailed documentation and source code are available at the website.

AhR transcription serum activity of Inuit´s across Greenlandic districts

DEFF Research Database (Denmark)

Long, Manhai; Deutch, Bente; Bonefeld-Jørgensen, Eva Cecilie

2007-01-01

. The individual is exposed to a complex mixture of POPs being life-long beginning during critical developmental windows. Exposure to POPs elicits a number of species- and tissue-specific toxic responses, many of which involve the aryl hydrocarbon receptor (AhR). The aim of this study was to compare the actual...... was similar in the different districts. For the combined data the order of the median AhR-TEQ was Tasiilaq > Nuuk > Sisimiut > Qaanaaq possibly being related to the different composition of POPs. In overall, the AhR transactivity was inversely correlated to the levels of sum POPs, age and /or intake of marine......-PCBs; ii) The inverse association between the integrated serum AhR transactivity and sum of POPs might be explained by the higher level of compounds antagonizing the AhR function probably due to selective POP bioaccumulation in the food chain....

Depressive-like effect of prenatal exposure to DDT involves global DNA hypomethylation and impairment of GPER1/ESR1 protein levels but not ESR2 and AHR/ARNT signaling.

Science.gov (United States)

Kajta, Malgorzata; Wnuk, Agnieszka; Rzemieniec, Joanna; Litwa, Ewa; Lason, Wladyslaw; Zelek-Molik, Agnieszka; Nalepa, Irena; Rogóż, Zofia; Grochowalski, Adam; Wojtowicz, Anna K

2017-07-01

Several lines of evidence suggest that exposures to Endocrine Disrupting Chemicals (EDCs) such as pesticides increase the risks of neuropsychiatric disorders. Despite extended residual persistence of dichlorodiphenyltrichloroethane (DDT) in the environment, the mechanisms of perinatal actions of DDT that could account for adult-onset of depression are largely unknown. This study demonstrated the isomer-specific induction of depressive-like behavior and impairment of Htr1a/serotonin signaling in one-month-old mice that were prenatally exposed to DDT. The effects were reversed by the antidepressant citalopram as evidenced in the forced swimming (FST) and tail suspension (TST) tests in the male and female mice. Prenatally administered DDT accumulated in mouse brain as determined with gas chromatography and tandem mass spectrometry, led to global DNA hypomethylation, and altered the levels of methylated DNA in specific genes. The induction of depressive-like behavior and impairment of Htr1a/serotonin signaling were accompanied by p,p'-DDT-specific decrease in the levels of estrogen receptors i.e. ESR1 and/or GPER1 depending on sex. In contrast, o,p'-DDT did not induce depressive-like effects and exhibited quite distinct pattern of biochemical alterations that was related to aryl hydrocarbon receptor (AHR), its nuclear translocator ARNT, and ESR2. Exposure to o,p'-DDT increased AHR expression in male and female brains, and reduced expression levels of ARNT and ESR2 in the female brains. The evolution of p,p'-DDT-induced depressive-like behavior was preceded by attenuation of Htr1a and Gper1/GPER1 expression as observed in the 7-day-old mouse pups. Because p,p'-DDT caused sex- and age-independent attenuation of GPER1, we suggest that impairment of GPER1 signaling plays a key role in the propagation of DDT-induced depressive-like symptoms. Copyright © 2017 Elsevier Ltd. All rights reserved.

Oscillatory Dynamics of the Extracellular Signal-regulated Kinase Pathway

Energy Technology Data Exchange (ETDEWEB)

Shankaran, Harish; Wiley, H. S.

2010-12-01

The extracellular signal-regulated kinase (ERK) pathway is a central signaling pathway in development and disease and is regulated by multiple negative and positive feedback loops. Recent studies have shown negative feedback from ERK to upstream regulators can give rise to biochemical oscillations with a periodicity of between 15-30 minutes. Feedback due to the stimulated transcription of negative regulators of the ERK pathway can also give rise to transcriptional oscillations with a periodicity of 1-2h. The biological significance of these oscillations is not clear, but recent evidence suggests that transcriptional oscillations participate in developmental processes, such as somite formation. Biochemical oscillations are more enigmatic, but could provide a mechanism for encoding different types of inputs into a common signaling pathway.

Interleukins and their signaling pathways in the Reactome biological pathway database.

Science.gov (United States)

Jupe, Steve; Ray, Keith; Roca, Corina Duenas; Varusai, Thawfeek; Shamovsky, Veronica; Stein, Lincoln; D'Eustachio, Peter; Hermjakob, Henning

2018-04-01

much molecular detail as possible and are linked to literature citations that contain supporting experimental details. All newly created events undergo a peer-review process before they are added to the database and made available on the associated Web site. New content is added quarterly. The 63rd release of Reactome in December 2017 contains 10,996 human proteins participating in 11,426 events in 2,179 pathways. In addition, analytic tools allow data set submission for the identification and visualization of pathway enrichment and representation of expression profiles as an overlay on Reactome pathways. Protein-protein and compound-protein interactions from several sources, including custom user data sets, can be added to extend pathways. Pathway diagrams and analytic result displays can be downloaded as editable images, human-readable reports, and files in several standard formats that are suitable for computational reuse. Reactome content is available programmatically through a REpresentational State Transfer (REST)-based content service and as a Neo4J graph database. Signaling pathways for IL-1 to IL-38 are hierarchically classified within the pathway "signaling by interleukins." The classification used is largely derived from Akdis et al. The addition to Reactome of a complete set of the known human interleukins, their receptors, and established signaling pathways linked to annotations of relevant aspects of immune function provides a significant computationally accessible resource of information about this important family. This information can be extended easily as new discoveries become accepted as the consensus in the field. A key aim for the future is to increase coverage of gene expression changes induced by interleukin signaling. Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.

Wnt pathway in Dupuytren disease: connecting profibrotic signals.

Science.gov (United States)

van Beuge, Marike M; Ten Dam, Evert-Jan P M; Werker, Paul M N; Bank, Ruud A

2015-12-01

A role of Wnt signaling in Dupuytren disease, a fibroproliferative disease of the hand and fingers, has not been fully elucidated. We examined a large set of Wnt pathway components and signaling targets and found significant dysregulation of 41 Wnt-related genes in tissue from the Dupuytren nodules compared with patient-matched control tissue. A large proportion of genes coding for Wnt proteins themselves was downregulated. However, both canonical Wnt targets and components of the noncanonical signaling pathway were upregulated. Immunohistochemical analysis revealed that protein expression of Wnt1-inducible secreted protein 1 (WISP1), a known Wnt target, was increased in nodules compared with control tissue, but knockdown of WISP1 using small interfering RNA (siRNA) in the Dupuytren myofibroblasts did not confirm a functional role. The protein expression of noncanonical pathway components Wnt5A and VANGL2 as well as noncanonical coreceptors Ror2 and Ryk was increased in nodules. On the contrary, the strongest downregulated genes in this study were 4 antagonists of Wnt signaling (DKK1, FRZB, SFRP1, and WIF1). Downregulation of these genes in the Dupuytren tissue was mimicked in vitro by treating normal fibroblasts with transforming growth factor β1 (TGF-β1), suggesting cross talk between different profibrotic pathways. Furthermore, siRNA-mediated knockdown of these antagonists in normal fibroblasts led to increased nuclear translocation of Wnt target β-catenin in response to TGF-β1 treatment. In conclusion, we have shown extensive dysregulation of Wnt signaling in affected tissue from Dupuytren disease patients. Components of both the canonical and the noncanonical pathways are upregulated, whereas endogenous antagonists are downregulated, possibly via interaction with other profibrotic pathways. Copyright © 2015 Elsevier Inc. All rights reserved.

Signaling pathway networks mined from human pituitary adenoma proteomics data

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Zhan Xianquan

2010-04-01

Full Text Available Abstract Background We obtained a series of pituitary adenoma proteomic expression data, including protein-mapping data (111 proteins, comparative proteomic data (56 differentially expressed proteins, and nitroproteomic data (17 nitroproteins. There is a pressing need to clarify the significant signaling pathway networks that derive from those proteins in order to clarify and to better understand the molecular basis of pituitary adenoma pathogenesis and to discover biomarkers. Here, we describe the significant signaling pathway networks that were mined from human pituitary adenoma proteomic data with the Ingenuity pathway analysis system. Methods The Ingenuity pathway analysis system was used to analyze signal pathway networks and canonical pathways from protein-mapping data, comparative proteomic data, adenoma nitroproteomic data, and control nitroproteomic data. A Fisher's exact test was used to test the statistical significance with a significance level of 0.05. Statistical significant results were rationalized within the pituitary adenoma biological system with literature-based bioinformatics analyses. Results For the protein-mapping data, the top pathway networks were related to cancer, cell death, and lipid metabolism; the top canonical toxicity pathways included acute-phase response, oxidative-stress response, oxidative stress, and cell-cycle G2/M transition regulation. For the comparative proteomic data, top pathway networks were related to cancer, endocrine system development and function, and lipid metabolism; the top canonical toxicity pathways included mitochondrial dysfunction, oxidative phosphorylation, oxidative-stress response, and ERK/MAPK signaling. The nitroproteomic data from a pituitary adenoma were related to cancer, cell death, lipid metabolism, and reproductive system disease, and the top canonical toxicity pathways mainly related to p38 MAPK signaling and cell-cycle G2/M transition regulation. Nitroproteins from a

Inferring the functional effect of gene expression changes in signaling pathways

Science.gov (United States)

Sebastián-León, Patricia; Carbonell, José; Salavert, Francisco; Sanchez, Rubén; Medina, Ignacio; Dopazo, Joaquín

2013-01-01

Signaling pathways constitute a valuable source of information that allows interpreting the way in which alterations in gene activities affect to particular cell functionalities. There are web tools available that allow viewing and editing pathways, as well as representing experimental data on them. However, few methods aimed to identify the signaling circuits, within a pathway, associated to the biological problem studied exist and none of them provide a convenient graphical web interface. We present PATHiWAYS, a web-based signaling pathway visualization system that infers changes in signaling that affect cell functionality from the measurements of gene expression values in typical expression microarray case–control experiments. A simple probabilistic model of the pathway is used to estimate the probabilities for signal transmission from any receptor to any final effector molecule (taking into account the pathway topology) using for this the individual probabilities of gene product presence/absence inferred from gene expression values. Significant changes in these probabilities allow linking different cell functionalities triggered by the pathway to the biological problem studied. PATHiWAYS is available at: http://pathiways.babelomics.org/. PMID:23748960

Phylogenetic diversity of stress signalling pathways in fungi

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Stansfield Ian

2009-02-01

Full Text Available Abstract Background Microbes must sense environmental stresses, transduce these signals and mount protective responses to survive in hostile environments. In this study we have tested the hypothesis that fungal stress signalling pathways have evolved rapidly in a niche-specific fashion that is independent of phylogeny. To test this hypothesis we have compared the conservation of stress signalling molecules in diverse fungal species with their stress resistance. These fungi, which include ascomycetes, basidiomycetes and microsporidia, occupy highly divergent niches from saline environments to plant or mammalian hosts. Results The fungi displayed significant variation in their resistance to osmotic (NaCl and sorbitol, oxidative (H2O2 and menadione and cell wall stresses (Calcofluor White and Congo Red. There was no strict correlation between fungal phylogeny and stress resistance. Rather, the human pathogens tended to be more resistant to all three types of stress, an exception being the sensitivity of Candida albicans to the cell wall stress, Calcofluor White. In contrast, the plant pathogens were relatively sensitive to oxidative stress. The degree of conservation of osmotic, oxidative and cell wall stress signalling pathways amongst the eighteen fungal species was examined. Putative orthologues of functionally defined signalling components in Saccharomyces cerevisiae were identified by performing reciprocal BLASTP searches, and the percent amino acid identities of these orthologues recorded. This revealed that in general, central components of the osmotic, oxidative and cell wall stress signalling pathways are relatively well conserved, whereas the sensors lying upstream and transcriptional regulators lying downstream of these modules have diverged significantly. There was no obvious correlation between the degree of conservation of stress signalling pathways and the resistance of a particular fungus to the corresponding stress. Conclusion Our

Signaling Pathways in Pathogenesis of Diamond Blackfan Anemia

Science.gov (United States)

2015-12-01

AWARD NUMBER: W81XWH-12-1-0590 TITLE: SIGNALING PATHWAYS IN PATHOGENESIS OF DIAMOND BLACKFAN ANEMIA PRINCIPAL INVESTIGATOR: KATHLEEN M...SUBTITLE 5a. CONTRACT NUMBER W81XWH-12-1-0590 SIGNALING PATHWAYS IN PATHOGENESIS OF DIAMOND BLACKFAN ANEMIA 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER...Unlimited 13. SUPPLEMENTARY NOTES None 14. ABSTRACT: Diamond Blackfan Anemia (DBA) is a disorder that results in pure red cell aplasia, congenital

The role of the Hedgehog signaling pathway in cancer: A comprehensive review

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Ana Marija Skoda

2018-02-01

Full Text Available The Hedgehog (Hh signaling pathway was first identified in the common fruit fly. It is a highly conserved evolutionary pathway of signal transmission from the cell membrane to the nucleus. The Hh signaling pathway plays an important role in the embryonic development. It exerts its biological effects through a signaling cascade that culminates in a change of balance between activator and repressor forms of glioma-associated oncogene (Gli transcription factors. The components of the Hh signaling pathway involved in the signaling transfer to the Gli transcription factors include Hedgehog ligands (Sonic Hh [SHh], Indian Hh [IHh], and Desert Hh [DHh], Patched receptor (Ptch1, Ptch2, Smoothened receptor (Smo, Suppressor of fused homolog (Sufu, kinesin protein Kif7, protein kinase A (PKA, and cyclic adenosine monophosphate (cAMP. The activator form of Gli travels to the nucleus and stimulates the transcription of the target genes by binding to their promoters. The main target genes of the Hh signaling pathway are PTCH1, PTCH2, and GLI1. Deregulation of the Hh signaling pathway is associated with developmental anomalies and cancer, including Gorlin syndrome, and sporadic cancers, such as basal cell carcinoma, medulloblastoma, pancreatic, breast, colon, ovarian, and small-cell lung carcinomas. The aberrant activation of the Hh signaling pathway is caused by mutations in the related genes (ligand-independent signaling or by the excessive expression of the Hh signaling molecules (ligand-dependent signaling – autocrine or paracrine. Several Hh signaling pathway inhibitors, such as vismodegib and sonidegib, have been developed for cancer treatment. These drugs are regarded as promising cancer therapies, especially for patients with refractory/advanced cancers.

Optimal structural inference of signaling pathways from unordered and overlapping gene sets.

Science.gov (United States)

Acharya, Lipi R; Judeh, Thair; Wang, Guangdi; Zhu, Dongxiao

2012-02-15

A plethora of bioinformatics analysis has led to the discovery of numerous gene sets, which can be interpreted as discrete measurements emitted from latent signaling pathways. Their potential to infer signaling pathway structures, however, has not been sufficiently exploited. Existing methods accommodating discrete data do not explicitly consider signal cascading mechanisms that characterize a signaling pathway. Novel computational methods are thus needed to fully utilize gene sets and broaden the scope from focusing only on pairwise interactions to the more general cascading events in the inference of signaling pathway structures. We propose a gene set based simulated annealing (SA) algorithm for the reconstruction of signaling pathway structures. A signaling pathway structure is a directed graph containing up to a few hundred nodes and many overlapping signal cascades, where each cascade represents a chain of molecular interactions from the cell surface to the nucleus. Gene sets in our context refer to discrete sets of genes participating in signal cascades, the basic building blocks of a signaling pathway, with no prior information about gene orderings in the cascades. From a compendium of gene sets related to a pathway, SA aims to search for signal cascades that characterize the optimal signaling pathway structure. In the search process, the extent of overlap among signal cascades is used to measure the optimality of a structure. Throughout, we treat gene sets as random samples from a first-order Markov chain model. We evaluated the performance of SA in three case studies. In the first study conducted on 83 KEGG pathways, SA demonstrated a significantly better performance than Bayesian network methods. Since both SA and Bayesian network methods accommodate discrete data, use a 'search and score' network learning strategy and output a directed network, they can be compared in terms of performance and computational time. In the second study, we compared SA and

Review of Signaling Pathways Governing MSC Osteogenic and Adipogenic Differentiation

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Aaron W. James

2013-01-01

Full Text Available Mesenchymal stem cells (MSC are multipotent cells, functioning as precursors to a variety of cell types including adipocytes, osteoblasts, and chondrocytes. Between osteogenic and adipogenic lineage commitment and differentiation, a theoretical inverse relationship exists, such that differentiation towards an osteoblast phenotype occurs at the expense of an adipocytic phenotype. This balance is regulated by numerous, intersecting signaling pathways that converge on the regulation of two main transcription factors: peroxisome proliferator-activated receptor-γ (PPARγ and Runt-related transcription factor 2 (Runx2. These two transcription factors, PPARγ and Runx2, are generally regarded as the master regulators of adipogenesis and osteogenesis. This review will summarize signaling pathways that govern MSC fate towards osteogenic or adipocytic differentiation. A number of signaling pathways follow the inverse balance between osteogenic and adipogenic differentiation and are generally proosteogenic/antiadipogenic stimuli. These include β-catenin dependent Wnt signaling, Hedgehog signaling, and NELL-1 signaling. However, other signaling pathways exhibit more context-dependent effects on adipogenic and osteogenic differentiation. These include bone morphogenic protein (BMP signaling and insulin growth factor (IGF signaling, which display both proosteogenic and proadipogenic effects. In summary, understanding those factors that govern osteogenic versus adipogenic MSC differentiation has significant implications in diverse areas of human health, from obesity to osteoporosis to regenerative medicine.

Prostate tumor progression in the TRAMP mouse. Protective effects of the aryl hydrocarbon receptor

Energy Technology Data Exchange (ETDEWEB)

Fritz, W.; Lin, T.M.; Peterson, R. [Wisconsin Univ., Madison, WI (United States)

2004-09-15

The developing male reproductive system is highly sensitive to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). TCDD binds to the aryl hydrocarbon receptor (AhR), a ligand-activated transcription factor, to produce sustained alterations in gene expression. Mice lacking the AhR (AhRKO, Ahr{sup -/-}) have permitted further characterization of the role of the AhR in mediating TCDD effects and revealed a physiological role for the AhR in normal development. We previously demonstrated that in utero and lactational TCDD exposure significantly reduced ventral, dorsolateral and anterior prostate weights, and that these effects were dependent on the AhR5. However, reductions in prostate lobe weights in untreated, AhRKO mice compared to wild-type counterparts at various ages demonstrated that the AhR signaling pathway is involved in normal development of the dorsolateral and anterior prostates, but apparently not the ventral prostate. Unaltered serum testosterone concentrations and modest reduction in serum 5{alpha}-androstane-3{alpha},17{beta}a-diol concentrations could not account for reductions in prostate weights in mice lacking AhR (Ahr{sup -/-}). Normal histology and lack of alteration in androgen receptor mRNA levels further indicate that the reduction in prostate weights is not a result of reduced androgen action in AhRKO mice. The observation that regulation of early prostate growth in mice occurs following AhR activation by TCDD, as well as by loss of AhR, suggests that the AhR may also regulate aberrant prostate growth that results from ''reawakening'' of the prostate growth regulatory signals later in life. Our objective was to determine if the AhR signaling pathway has an effect on prostate cancer development.

Microenvironment Dependent Photobiomodulation on Function-Specific Signal Transduction Pathways

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Timon Cheng-Yi Liu

2014-01-01

Full Text Available Cellular photobiomodulation on a cellular function has been shown to be homeostatic. Its function-specific pathway mechanism would be further discussed in this paper. The signal transduction pathways maintaining a normal function in its function-specific homeostasis (FSH, resisting the activation of many other irrelative signal transduction pathways, are so sparse that it can be supposed that there may be normal function-specific signal transduction pathways (NSPs. A low level laser irradiation or monochromatic light may promote the activation of partially activated NSP and/or its redundant NSP so that it may induce the second-order phase transition of a function from its dysfunctional one far from its FSH to its normal one in a function-specific microenvironment and may also induce the first-order functional phase transition of the normal function from low level to high level.

Role of Notch signalling pathway in cancer and its association with ...

Indian Academy of Sciences (India)

The Notch signalling pathway is an evolutionarily conserved cell signalling pathway involved in the development of organ- ... Abnormal Notch signalling is seen in many cancers like T-cell acute ...... Morgan T. H. 1917 The theory of the gene.

Purinergic signaling pathways in endocrine system.

Science.gov (United States)

Bjelobaba, Ivana; Janjic, Marija M; Stojilkovic, Stanko S

2015-09-01

Adenosine-5'-triphosphate is released by neuroendocrine, endocrine, and other cell types and acts as an extracellular agonist for ligand-gated P2X cationic channels and G protein-coupled P2Y receptors in numerous organs and tissues, including the endocrine system. The breakdown of ATP by ectonucleotidases not only terminates its extracellular messenger functions, but also provides a pathway for the generation of two additional agonists: adenosine 5'-diphosphate, acting via some P2Y receptors, and adenosine, a native agonist for G protein-coupled adenosine receptors, also expressed in the endocrine system. This article provides a review of purinergic signaling pathways in the hypothalamic magnocellular neurosecretory cells and neurohypophysis, hypothalamic parvocellular neuroendocrine system, adenohypophysis, and effector glands organized in five axes: hypothalamic-pituitary-gonadal, hypothalamic-pituitary-thyroid, hypothalamic-pituitary-adrenal, hypothalamic-pituitary-growth hormone, and hypothalamic-pituitary-prolactin. We attempted to summarize current knowledge of purinergic receptor subtypes expressed in the endocrine system, including their roles in intracellular signaling, hormone secretion, and other cell functions. We also briefly review the release mechanism for adenosine-5'-triphosphate by neuroendocrine, endocrine and surrounding cells, the enzymes involved in adenosine-5'-triphosphate hydrolysis to adenosine-5'-diphosphate and adenosine, and the relevance of this pathway for sequential activation of receptors and termination of signaling. Published by Elsevier B.V.

Purinergic Signaling Pathways in Endocrine System

Science.gov (United States)

Bjelobaba, Ivana; Janjic, Marija M.; Stojilkovic, Stanko S.

2015-01-01

Adenosine-5′-triphosphate is released by neuroendocrine, endocrine, and other cell types and acts as an extracellular agonist for ligand-gated P2X cationic channels and G protein-coupled P2Y receptors in numerous organs and tissues, including the endocrine system. The breakdown of ATP by ectonucleotidases not only terminates its extracellular messenger functions, but also provides a pathway for the generation of two additional agonists: adenosine 5′-diphosphate, acting via some P2Y receptors, and adenosine, a native agonist for G protein-coupled adenosine receptors, also expressed in the endocrine system. This article provides a review of purinergic signaling pathways in the hypothalamic magnocellular neurosecretory cells and neurohypophysis, hypothalamic parvocellular neuroendocrine system, adenohypophysis, and effector glands organized in five axes: hypothalamic-pituitary-gonadal, hypothalamic-pituitary-thyroid, hypothalamic-pituitary-adrenal, hypothalamic-pituitary-growth hormone, and hypothalamic-pituitary-prolactin. We attempted to summarize current knowledge of purinergic receptor subtypes expressed in the endocrine system, including their roles in intracellular signaling, hormone secretion, and other cell functions. We also briefly review the release mechanism for adenosine-5′-triphosphate by neuroendocrine, endocrine and surrounding cells, the enzymes involved in adenosine-5′-triphosphate hydrolysis to adenosine-5′-diphosphate and adenosine, and the relevance of this pathway for sequential activation of receptors and termination of signaling. PMID:25960051

Intercellular signaling pathways active during intervertebral disc growth, differentiation, and aging.

Science.gov (United States)

Dahia, Chitra Lekha; Mahoney, Eric J; Durrani, Atiq A; Wylie, Christopher

2009-03-01

Intervertebral discs at different postnatal ages were assessed for active intercellular signaling pathways. To generate a spatial and temporal map of the signaling pathways active in the postnatal intervertebral disc (IVD). The postnatal IVD is a complex structure, consisting of 3 histologically distinct components, the nucleus pulposus, fibrous anulus fibrosus, and endplate. These differentiate and grow during the first 9 weeks of age in the mouse. Identification of the major signaling pathways active during and after the growth and differentiation period will allow functional analysis using mouse genetics and identify targets for therapy for individual components of the disc. Antibodies specific for individual cell signaling pathways were used on cryostat sections of IVD at different postnatal ages to identify which components of the IVD were responding to major classes of intercellular signal, including sonic hedgehog, Wnt, TGFbeta, FGF, and BMPs. We present a spatial/temporal map of these signaling pathways during growth, differentiation, and aging of the disc. During growth and differentiation of the disc, its different components respond at different times to different intercellular signaling ligands. Most of these are dramatically downregulated at the end of disc growth.

TCDD-induced transcriptional profiles in different mouse strains that have an identical AhR genotype

Energy Technology Data Exchange (ETDEWEB)

Wu, Qing; Suzuki, Junko S.; Tohyama, Chiharu; Ohsako, Seiichiroh [Environmental Health Sciences Division, National Institute for Environmental Studies, Onogawa, Tsukuba (Japan); Takei, Teiji [Environmental Health and Safety Division, Ministry of the Environment, Kasumigaseki, Tokyo (Japan); Lin, Tinmin; Peterson, R.E. [Wisconsin Univ., Wisconsin, MA (United States). School of Pharmacy and Molecular and Environmental Toxicology Center

2004-09-15

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) is an environmental contaminant that is known to cause hepatotoxicity, teratogenicity and carcinogenicity. A characteristic feature in the toxicity of TCDD is exceptionally large differences in susceptibility among animal species or even strains belonging to the same species. These strain differences in susceptibility to TCDD have now been elucidated to be due to the difference in ligand binding affinity or transcriptional activity of the aryl hydrocarbon receptor (AhR). Actually the C57BL/6 type AhR (AhR{sup b}) showed 6-fold higher ligand binding affinity than the DBA/2 type AhR (AhR{sup d}). The H/W rat AhR has a C-terminal truncation of the transactivating domain compared to the L-E rat AhR. On the other hand, there is considerable species variability in response sensitivity to TCDD that cannot be ascribed simply to polymorphisms of the AhR gene. A non-AhR gene susceptibility loci for hepatic porphyria has been observed in mice treated with iron compounds prior to TCDD injection by using a quantitative trait locus analysis of an F2 intercross between susceptible C57BL/6 and resistant DBA/2 stains. In the rat, a gene B with Han/Wistar type AhR is likely to be involved in resistance to TCDD lethality. These observations suggest that other modulating genes, so-called ''modifier genes'', have profound effects on the AhR-mediated gene expression phenotype. Based on the nucleotide sequence of the AhR coding region, the BALB/c, CBA/J, and C3H/He mouse strains are clustered together on a single branch. In the present study, we try to confirm the existence of modifiers by using microarray analysis to examine hepatic gene expression after TCDD exposure in BALB/c, CBA/J, and C3H/He mice. To recognize the existence of a modifier besides the AhR, it is a prerequisite experimental condition that the analyzed strains have an identical AhR genotype. Therefore, we selected BALB/c, CBA/J, and C3H/He mice as the model

The Wnt signaling pathway in familial exudative vitreoretinopathy and Norrie disease.

Science.gov (United States)

Warden, Scott M; Andreoli, Christopher M; Mukai, Shizuo

2007-01-01

The Wnt signaling pathway is highly conserved among species and has an important role in many cell biological processes throughout the body. This signaling cascade is involved in regulating ocular growth and development, and recent findings indicate that this is particularly true in the retina. Mutations involving different aspects of the Wnt signaling pathway are being linked to several diseases of retinal development. The aim of this article is to first review the Wnt signaling pathway. We will then describe two conditions, familial exudative vitreoretinopathy (FEVR) and Norrie disease (ND), which have been shown to be caused in part by defects in the Wnt signaling cascade.

Essential oils of culinary herbs and spices display agonist and antagonist activities at human aryl hydrocarbon receptor AhR.

Science.gov (United States)

Bartoňková, Iveta; Dvořák, Zdeněk

2018-01-01

Essential oils (EOs) of culinary herbs and spices are used to flavor, color and preserve foods and drinks. Dietary intake of EOs is significant, deserving an attention of toxicologists. We examined the effects of 31 EOs of culinary herbs and spices on the transcriptional activity of human aryl hydrocarbon receptor (AhR), which is a pivotal xenobiotic sensor, having also multiple roles in human physiology. Tested EOs were sorted out into AhR-inactive ones (14 EOs) and AhR-active ones, including full agonists (cumin, jasmine, vanilla, bay leaf), partial agonists (cloves, dill, thyme, nutmeg, oregano) and antagonists (tarragon, caraway, turmeric, lovage, fennel, spearmint, star anise, anise). Major constituents (>10%) of AhR-active EOs were studied in more detail. We identified AhR partial agonists (carvacrol, ligustilide, eugenol, eugenyl acetate, thymol, ar-turmerone) and antagonists (trans-anethole, butylidine phtalide, R/S-carvones, p-cymene), which account for AhR-mediated activities of EOs of fennel, anise, star anise, caraway, spearmint, tarragon, cloves, dill, turmeric, lovage, thyme and oregano. We also show that AhR-mediated effects of some individual constituents of EOs differ from those manifested in mixtures. In conclusion, EOs of culinary herbs and spices are agonists and antagonists of human AhR, implying a potential for food-drug interactions and interference with endocrine pathways. Copyright © 2017 Elsevier Ltd. All rights reserved.

Identification of benzothiazole derivatives and polycyclic aromatic hydrocarbons as aryl hydrocarbon receptor agonists present in tire extracts.

Science.gov (United States)

He, Guochun; Zhao, Bin; Denison, Michael S

2011-08-01

Leachate from rubber tire material contains a complex mixture of chemicals previously shown to produce toxic and biological effects in aquatic organisms. The ability of these leachates to induce Ah receptor (AhR)-dependent cytochrome P4501A1 expression in fish indicated the presence of AhR active chemicals, but the responsible chemicals and their direct interaction with the AhR signaling pathway were not examined. Using a combination of AhR-based bioassays, we have demonstrated the ability of tire extract to stimulate both AhR DNA binding and AhR-dependent gene expression and confirmed that the responsible chemicals were metabolically labile. The application of CALUX (chemical-activated luciferase gene expression) cell bioassay-driven toxicant identification evaluation not only revealed that tire extract contained a variety of known AhR-active polycyclic aromatic hydrocarbons but also identified 2-methylthiobenzothiazole and 2-mercaptobenzothiazole as AhR agonists. Analysis of a structurally diverse series of benzothiazoles identified many that could directly stimulate AhR DNA binding and transiently activate the AhR signaling pathway and identified benzothiazoles as a new class of AhR agonists. In addition to these compounds, the relatively high AhR agonist activity of a large number of fractions strongly suggests that tire extract contains a large number of physiochemically diverse AhR agonists whose identities and toxicological/biological significances are unknown. Copyright © 2011 SETAC.

Cell volume homeostatic mechanisms: effectors and signalling pathways

DEFF Research Database (Denmark)

Hoffmann, E K; Pedersen, Stine Helene Falsig

2011-01-01

. Later work addressed the mechanisms through which cellular signalling pathways regulate the volume regulatory effectors or flux pathways. These studies were facilitated by the molecular identification of most of the relevant channels and transporters, and more recently also by the increased...

Insulin signaling pathways in lepidopteran steroidogenesis

Directory of Open Access Journals (Sweden)

Wendy eSmith

2014-02-01

Full Text Available Molting and metamorphosis are stimulated by the secretion of ecdysteroid hormones from the prothoracic glands. Insulin-like hormones have been found to enhance prothoracic gland activity, providing a mechanism to link molting to nutritional state. In silk moths (Bombyx mori, the prothoracic glands are directly stimulated by insulin and the insulin-like hormone bombyxin. Further, in Bombyx , the neuropeptide prothoracicotropic hormone (PTTH appears to act at least in part through the insulin-signaling pathway. In the prothoracic glands of Manduca sexta, while insulin stimulates the phosphorylation of the insulin receptor and Akt, neither insulin nor bombyxin II stimulate ecdysone secretion. Involvement of the insulin-signaling pathway in Manduca prothoracic glands was explored using two inhibitors of phosphatidylinositol-3-kinase (PI3K, LY294002 and wortmannin. PI3K inhibitors block the phosphorylation of Akt and 4EBP but have no effect on ecdysone secretion, or on the phosphorylation of the MAPkinase, ERK. Inhibitors that block phosphorylation of ERK, including the MEK inhibitor U0126, and high doses of the RSK inhibitor SL0101, effectively inhibit ecdysone secretion. The results highlight differences between the two lepidopteran insects most commonly used to directly study ecdysteroid secretion. In Bombyx, the PTTH and insulin-signaling pathways intersect; both insulin and PTTH enhance the phosphorylation of Akt and stimulate ecdysteroid secretion, and inhibition of PI3K reduces ecdysteroid secretion. By contrast, in Manduca, the action of PTTH is distinct from insulin. The results highlight species differences in the roles of translational regulators such as 4EBP, and members of the MAPkinase pathway such as ERK and RSK, in the effects of nutritionally-sensitive hormones such as insulin on ecdysone secretion and molting.

Oncogenic Signaling Pathways in The Cancer Genome Atlas

NARCIS (Netherlands)

Sanchez-Vega, Francisco; Mina, Marco; Armenia, Joshua; Chatila, Walid K.; Luna, Augustin; La, Konnor C.; Dimitriadoy, Sofia; Liu, David L.; Kantheti, Havish S.; Saghafinia, Sadegh; Chakravarty, Debyani; Daian, Foysal; Gao, Qingsong; Bailey, Matthew H.; Liang, Wen Wei; Foltz, Steven M.; Shmulevich, Ilya; Ding, Li; Heins, Zachary J.; Ochoa, Angelica; Gross, Benjamin E.; Gao, Jianjiong; Zhang, Hongxin; Kundra, Ritika; Kandoth, Cyriac; Bahceci, Istemi; Dervishi, Leonard; Dogrusoz, Ugur; Zhou, Wanding; Shen, Hui; Laird, Peter W.; Way, Gregory P.; Greene, Casey S.; Liang, Han; Xiao, Yonghong; Wang, Chen; Iavarone, Antonio; Berger, Alice H.; Bivona, Trever G.; Lazar, Alexander J.; Hammer, Gary D.; Giordano, Thomas; Kwong, Lawrence N.; McArthur, Grant; Huang, Chenfei; Tward, Aaron D.; Frederick, Mitchell J.; McCormick, Frank; Meyerson, Matthew; Caesar-Johnson, Samantha J.; Demchok, John A.; Felau, Ina; Kasapi, Melpomeni; Ferguson, Martin L.; Hutter, Carolyn M.; Sofia, Heidi J.; Tarnuzzer, Roy; Wang, Zhining; Yang, Liming; Zenklusen, Jean C.; Zhang, Jiashan (Julia); Chudamani, Sudha; Liu, Jia; Lolla, Laxmi; Naresh, Rashi; Pihl, Todd; Sun, Qiang; Wan, Yunhu; Wu, Ye; Cho, Juok; DeFreitas, Timothy; Frazer, Scott; Gehlenborg, Nils; Getz, Gad; Heiman, David I.; Kim, Jaegil; Lawrence, Michael S.; Lin, Pei; Meier, Sam; Noble, Michael S.; Saksena, Gordon; Voet, Doug; Zhang, Hailei; Bernard, Brady; Chambwe, Nyasha; Dhankani, Varsha; Knijnenburg, Theo; Kramer, Roger; Leinonen, Kalle; Liu, Yuexin; Miller, Michael; Reynolds, Sheila; Shmulevich, Ilya; Thorsson, Vesteinn; Zhang, Wei; Akbani, Rehan; Broom, Bradley M.; Hegde, Apurva M.; Ju, Zhenlin; Kanchi, Rupa S.; Korkut, Anil; Li, Jun; Liang, Han; Ling, Shiyun; Liu, Wenbin; Lu, Yiling; Mills, Gordon B.; Ng, Kwok Shing; Rao, Arvind; Ryan, Michael; Wang, Jing; Weinstein, John N.; Zhang, Jiexin; Abeshouse, Adam; Armenia, Joshua; Chakravarty, Debyani; Chatila, Walid K.; de Bruijn, Ino; Gao, Jianjiong; Gross, Benjamin E.; Heins, Zachary J.; Kundra, Ritika; La, Konnor; Ladanyi, Marc; Luna, Augustin; Nissan, Moriah G.; Ochoa, Angelica; Phillips, Sarah M.; Reznik, Ed; Sanchez-Vega, Francisco; Sander, Chris; Schultz, Nikolaus; Sheridan, Robert; Sumer, S. Onur; Sun, Yichao; Taylor, Barry S.; Wang, Jioajiao; Zhang, Hongxin; Anur, Pavana; Peto, Myron; Spellman, Paul; Benz, Christopher; Stuart, Joshua M.; Wong, Christopher K.; Yau, Christina; Hayes, D. Neil; Parker, Joel S.; Wilkerson, Matthew D.; Ally, Adrian; Balasundaram, Miruna; Bowlby, Reanne; Brooks, Denise; Carlsen, Rebecca; Chuah, Eric; Dhalla, Noreen; Holt, Robert; Jones, Steven J.M.; Kasaian, Katayoon; Lee, Darlene; Ma, Yussanne; Marra, Marco A.; Mayo, Michael; Moore, Richard A.; Mungall, Andrew J.; Mungall, Karen; Robertson, A. Gordon; Sadeghi, Sara; Schein, Jacqueline E.; Sipahimalani, Payal; Tam, Angela; Thiessen, Nina; Tse, Kane; Wong, Tina; Berger, Ashton C.; Beroukhim, Rameen; Cherniack, Andrew D.; Cibulskis, Carrie; Gabriel, Stacey B.; Gao, Galen F.; Ha, Gavin; Meyerson, Matthew; Schumacher, Steven E.; Shih, Juliann; Kucherlapati, Melanie H.; Kucherlapati, Raju S.; Baylin, Stephen; Cope, Leslie; Danilova, Ludmila; Bootwalla, Moiz S.; Lai, Phillip H.; Maglinte, Dennis T.; Van Den Berg, David J.; Weisenberger, Daniel J.; Auman, J. Todd; Balu, Saianand; Bodenheimer, Tom; Fan, Cheng; Hoadley, Katherine A.; Hoyle, Alan P.; Jefferys, Stuart R.; Jones, Corbin D.; Meng, Shaowu; Mieczkowski, Piotr A.; Mose, Lisle E.; Perou, Amy H.; Perou, Charles M.; Roach, Jeffrey; Shi, Yan; Simons, Janae V.; Skelly, Tara; Soloway, Matthew G.; Tan, Donghui; Veluvolu, Umadevi; Fan, Huihui; Hinoue, Toshinori; Laird, Peter W.; Shen, Hui; Zhou, Wanding; Bellair, Michelle; Chang, Kyle; Covington, Kyle; Creighton, Chad J.; Dinh, Huyen; Doddapaneni, Harsha Vardhan; Donehower, Lawrence A.; Drummond, Jennifer; Gibbs, Richard A.; Glenn, Robert; Hale, Walker; Han, Yi; Hu, Jianhong; Korchina, Viktoriya; Lee, Sandra; Lewis, Lora; Li, Wei; Liu, Xiuping; Morgan, Margaret; Morton, Donna; Muzny, Donna; Santibanez, Jireh; Sheth, Margi; Shinbrot, Eve; Wang, Linghua; Wang, Min; Wheeler, David A.; Xi, Liu; Zhao, Fengmei; Hess, Julian; Appelbaum, Elizabeth L.; Bailey, Matthew; Cordes, Matthew G.; Ding, Li; Fronick, Catrina C.; Fulton, Lucinda A.; Fulton, Robert S.; Kandoth, Cyriac; Mardis, Elaine R.; McLellan, Michael D.; Miller, Christopher A.; Schmidt, Heather K.; Wilson, Richard K.; Crain, Daniel; Curley, Erin; Gardner, Johanna; Lau, Kevin; Mallery, David; Morris, Scott; Paulauskis, Joseph; Penny, Robert; Shelton, Candace; Shelton, Troy; Sherman, Mark; Thompson, Eric; Yena, Peggy; Bowen, Jay; Gastier-Foster, Julie M.; Gerken, Mark; Leraas, Kristen M.; Lichtenberg, Tara M.; Ramirez, Nilsa C.; Wise, Lisa; Zmuda, Erik; Corcoran, Niall; Costello, Tony; Hovens, Christopher; Carvalho, Andre L.; de Carvalho, Ana C.; Fregnani, José H.; Longatto-Filho, Adhemar; Reis, Rui M.; Scapulatempo-Neto, Cristovam; Silveira, Henrique C.S.; Vidal, Daniel O.; Burnette, Andrew; Eschbacher, Jennifer; Hermes, Beth; Noss, Ardene; Singh, Rosy; Anderson, Matthew L.; Castro, Patricia D.; Ittmann, Michael; Huntsman, David; Kohl, Bernard; Le, Xuan; Thorp, Richard; Andry, Chris; Duffy, Elizabeth R.; Lyadov, Vladimir; Paklina, Oxana; Setdikova, Galiya; Shabunin, Alexey; Tavobilov, Mikhail; McPherson, Christopher; Warnick, Ronald; Berkowitz, Ross; Cramer, Daniel; Feltmate, Colleen; Horowitz, Neil; Kibel, Adam; Muto, Michael; Raut, Chandrajit P.; Malykh, Andrei; Barnholtz-Sloan, Jill S.; Barrett, Wendi; Devine, Karen; Fulop, Jordonna; Ostrom, Quinn T.; Shimmel, Kristen; Wolinsky, Yingli; Sloan, Andrew E.; De Rose, Agostino; Giuliante, Felice; Goodman, Marc; Karlan, Beth Y.; Hagedorn, Curt H.; Eckman, John; Harr, Jodi; Myers, Jerome; Tucker, Kelinda; Zach, Leigh Anne; Deyarmin, Brenda; Hu, Hai; Kvecher, Leonid; Larson, Caroline; Mural, Richard J.; Somiari, Stella; Vicha, Ales; Zelinka, Tomas; Bennett, Joseph; Iacocca, Mary; Rabeno, Brenda; Swanson, Patricia; Latour, Mathieu; Lacombe, Louis; Têtu, Bernard; Bergeron, Alain; McGraw, Mary; Staugaitis, Susan M.; Chabot, John; Hibshoosh, Hanina; Sepulveda, Antonia; Su, Tao; Wang, Timothy; Potapova, Olga; Voronina, Olga; Desjardins, Laurence; Mariani, Odette; Roman-Roman, Sergio; Sastre, Xavier; Stern, Marc Henri; Cheng, Feixiong; Signoretti, Sabina; Berchuck, Andrew; Bigner, Darell; Lipp, Eric; Marks, Jeffrey; McCall, Shannon; McLendon, Roger; Secord, Angeles; Sharp, Alexis; Behera, Madhusmita; Brat, Daniel J.; Chen, Amy; Delman, Keith; Force, Seth; Khuri, Fadlo; Magliocca, Kelly; Maithel, Shishir; Olson, Jeffrey J.; Owonikoko, Taofeek; Pickens, Alan; Ramalingam, Suresh; Shin, Dong M.; Sica, Gabriel; Van Meir, Erwin G.; Zhang, Hongzheng; Eijckenboom, Wil; Gillis, Ad; Korpershoek, Esther; Looijenga, Leendert; Oosterhuis, Wolter; Stoop, Hans; van Kessel, Kim E.; Zwarthoff, Ellen C.; Calatozzolo, Chiara; Cuppini, Lucia; Cuzzubbo, Stefania; DiMeco, Francesco; Finocchiaro, Gaetano; Mattei, Luca; Perin, Alessandro; Pollo, Bianca; Chen, Chu; Houck, John; Lohavanichbutr, Pawadee; Hartmann, Arndt; Stoehr, Christine; Stoehr, Robert; Taubert, Helge; Wach, Sven; Wullich, Bernd; Kycler, Witold; Murawa, Dawid; Wiznerowicz, Maciej; Chung, Ki; Edenfield, W. Jeffrey; Martin, Julie; Baudin, Eric; Bubley, Glenn; Bueno, Raphael; De Rienzo, Assunta; Richards, William G.; Kalkanis, Steven; Mikkelsen, Tom; Noushmehr, Houtan; Scarpace, Lisa; Girard, Nicolas; Aymerich, Marta; Campo, Elias; Giné, Eva; Guillermo, Armando López; Van Bang, Nguyen; Hanh, Phan Thi; Phu, Bui Duc; Tang, Yufang; Colman, Howard; Evason, Kimberley; Dottino, Peter R.; Martignetti, John A.; Gabra, Hani; Juhl, Hartmut; Akeredolu, Teniola; Stepa, Serghei; Hoon, Dave; Ahn, Keunsoo; Kang, Koo Jeong; Beuschlein, Felix; Breggia, Anne; Birrer, Michael; Bell, Debra; Borad, Mitesh; Bryce, Alan H.; Castle, Erik; Chandan, Vishal; Cheville, John; Copland, John A.; Farnell, Michael; Flotte, Thomas; Giama, Nasra; Ho, Thai; Kendrick, Michael; Kocher, Jean Pierre; Kopp, Karla; Moser, Catherine; Nagorney, David; O'Brien, Daniel; O'Neill, Brian Patrick; Patel, Tushar; Petersen, Gloria; Que, Florencia; Rivera, Michael; Roberts, Lewis; Smallridge, Robert; Smyrk, Thomas; Stanton, Melissa; Thompson, R. Houston; Torbenson, Michael; Yang, Ju Dong; Zhang, Lizhi; Brimo, Fadi; Ajani, Jaffer A.; Gonzalez, Ana Maria Angulo; Behrens, Carmen; Bondaruk, Jolanta; Broaddus, Russell; Czerniak, Bogdan; Esmaeli, Bita; Fujimoto, Junya; Gershenwald, Jeffrey; Guo, Charles; Lazar, Alexander J.; Logothetis, Christopher; Meric-Bernstam, Funda; Moran, Cesar; Ramondetta, Lois; Rice, David; Sood, Anil; Tamboli, Pheroze; Thompson, Timothy; Troncoso, Patricia; Tsao, Anne; Wistuba, Ignacio; Carter, Candace; Haydu, Lauren; Hersey, Peter; Jakrot, Valerie; Kakavand, Hojabr; Kefford, Richard; Lee, Kenneth; Long, Georgina; Mann, Graham; Quinn, Michael; Saw, Robyn; Scolyer, Richard; Shannon, Kerwin; Spillane, Andrew; Stretch, Jonathan; Synott, Maria; Thompson, John; Wilmott, James; Al-Ahmadie, Hikmat; Chan, Timothy A.; Ghossein, Ronald; Gopalan, Anuradha; Levine, Douglas A.; Reuter, Victor; Singer, Samuel; Singh, Bhuvanesh; Tien, Nguyen Viet; Broudy, Thomas; Mirsaidi, Cyrus; Nair, Praveen; Drwiega, Paul; Miller, Judy; Smith, Jennifer; Zaren, Howard; Park, Joong Won; Hung, Nguyen Phi; Kebebew, Electron; Linehan, W. Marston; Metwalli, Adam R.; Pacak, Karel; Pinto, Peter A.; Schiffman, Mark; Schmidt, Laura S.; Vocke, Cathy D.; Wentzensen, Nicolas; Worrell, Robert; Yang, Hannah; Moncrieff, Marc; Goparaju, Chandra; Melamed, Jonathan; Pass, Harvey; Botnariuc, Natalia; Caraman, Irina; Cernat, Mircea; Chemencedji, Inga; Clipca, Adrian; Doruc, Serghei; Gorincioi, Ghenadie; Mura, Sergiu; Pirtac, Maria; Stancul, Irina; Tcaciuc, Diana; Albert, Monique; Alexopoulou, Iakovina; Arnaout, Angel; Bartlett, John; Engel, Jay; Gilbert, Sebastien; Parfitt, Jeremy; Sekhon, Harman; Thomas, George; Rassl, Doris M.; Rintoul, Robert C.; Bifulco, Carlo; Tamakawa, Raina; Urba, Walter; Hayward, Nicholas; Timmers, Henri; Antenucci, Anna; Facciolo, Francesco; Grazi, Gianluca; Marino, Mirella; Merola, Roberta; de Krijger, Ronald; Gimenez-Roqueplo, Anne Paule; Piché, Alain; Chevalier, Simone; McKercher, Ginette; Birsoy, Kivanc; Barnett, Gene; Brewer, Cathy; Farver, Carol; Naska, Theresa; Pennell, Nathan A.; Raymond, Daniel; Schilero, Cathy; Smolenski, Kathy; Williams, Felicia; Morrison, Carl; Borgia, Jeffrey A.; Liptay, Michael J.; Pool, Mark; Seder, Christopher W.; Junker, Kerstin; Omberg, Larsson; Dinkin, Mikhail; Manikhas, George; Alvaro, Domenico; Bragazzi, Maria Consiglia; Cardinale, Vincenzo; Carpino, Guido; Gaudio, Eugenio; Chesla, David; Cottingham, Sandra; Dubina, Michael; Moiseenko, Fedor; Dhanasekaran, Renumathy; Becker, Karl Friedrich; Janssen, Klaus Peter; Slotta-Huspenina, Julia; Abdel-Rahman, Mohamed H.; Aziz, Dina; Bell, Sue; Cebulla, Colleen M.; Davis, Amy; Duell, Rebecca; Elder, J. Bradley; Hilty, Joe; Kumar, Bahavna; Lang, James; Lehman, Norman L.; Mandt, Randy; Nguyen, Phuong; Pilarski, Robert; Rai, Karan; Schoenfield, Lynn; Senecal, Kelly; Wakely, Paul; Hansen, Paul; Lechan, Ronald; Powers, James; Tischler, Arthur; Grizzle, William E.; Sexton, Katherine C.; Kastl, Alison; Henderson, Joel; Porten, Sima; Waldmann, Jens; Fassnacht, Martin; Asa, Sylvia L.; Schadendorf, Dirk; Couce, Marta; Graefen, Markus; Huland, Hartwig; Sauter, Guido; Schlomm, Thorsten; Simon, Ronald; Tennstedt, Pierre; Olabode, Oluwole; Nelson, Mark; Bathe, Oliver; Carroll, Peter R.; Chan, June M.; Disaia, Philip; Glenn, Pat; Kelley, Robin K.; Landen, Charles N.; Phillips, Joanna; Prados, Michael; Simko, Jeffry; Smith-McCune, Karen; VandenBerg, Scott; Roggin, Kevin; Fehrenbach, Ashley; Kendler, Ady; Sifri, Suzanne; Steele, Ruth; Jimeno, Antonio; Carey, Francis; Forgie, Ian; Mannelli, Massimo; Carney, Michael; Hernandez, Brenda; Campos, Benito; Herold-Mende, Christel; Jungk, Christin; Unterberg, Andreas; von Deimling, Andreas; Bossler, Aaron; Galbraith, Joseph; Jacobus, Laura; Knudson, Michael; Knutson, Tina; Ma, Deqin; Milhem, Mohammed; Sigmund, Rita; Godwin, Andrew K.; Madan, Rashna; Rosenthal, Howard G.; Adebamowo, Clement; Adebamowo, Sally N.; Boussioutas, Alex; Beer, David; Giordano, Thomas; Mes-Masson, Anne Marie; Saad, Fred; Bocklage, Therese; Landrum, Lisa; Mannel, Robert; Moore, Kathleen; Moxley, Katherine; Postier, Russel; Walker, Joan; Zuna, Rosemary; Feldman, Michael; Valdivieso, Federico; Dhir, Rajiv; Luketich, James; Pinero, Edna M.Mora; Quintero-Aguilo, Mario; Carlotti, Carlos Gilberto; Dos Santos, Jose Sebastião; Kemp, Rafael; Sankarankuty, Ajith; Tirapelli, Daniela; Catto, James; Agnew, Kathy; Swisher, Elizabeth; Creaney, Jenette; Robinson, Bruce; Shelley, Carl Simon; Godwin, Eryn M.; Kendall, Sara; Shipman, Cassaundra; Bradford, Carol; Carey, Thomas; Haddad, Andrea; Moyer, Jeffey; Peterson, Lisa; Prince, Mark; Rozek, Laura; Wolf, Gregory; Bowman, Rayleen; Fong, Kwun M.; Yang, Ian; Korst, Robert; Rathmell, W. Kimryn; Fantacone-Campbell, J. Leigh; Hooke, Jeffrey A.; Kovatich, Albert J.; Shriver, Craig D.; DiPersio, John; Drake, Bettina; Govindan, Ramaswamy; Heath, Sharon; Ley, Timothy; Van Tine, Brian; Westervelt, Peter; Rubin, Mark A.; Lee, Jung Il; Aredes, Natália D.; Mariamidze, Armaz; Van Allen, Eliezer M.; Cherniack, Andrew D.; Ciriello, Giovanni; Sander, Chris; Schultz, Nikolaus

2018-01-01

Genetic alterations in signaling pathways that control cell-cycle progression, apoptosis, and cell growth are common hallmarks of cancer, but the extent, mechanisms, and co-occurrence of alterations in these pathways differ between individual tumors and tumor types. Using mutations, copy-number

YAP regulates neuronal differentiation through Sonic hedgehog signaling pathway

International Nuclear Information System (INIS)

Lin, Yi-Ting; Ding, Jing-Ya; Li, Ming-Yang; Yeh, Tien-Shun; Wang, Tsu-Wei; Yu, Jenn-Yah

2012-01-01

Tight regulation of cell numbers by controlling cell proliferation and apoptosis is important during development. Recently, the Hippo pathway has been shown to regulate tissue growth and organ size in Drosophila. In mammalian cells, it also affects cell proliferation and differentiation in various tissues, including the nervous system. Interplay of several signaling cascades, such as Notch, Wnt, and Sonic Hedgehog (Shh) pathways, control cell proliferation during neuronal differentiation. However, it remains unclear whether the Hippo pathway coordinates with other signaling cascades in regulating neuronal differentiation. Here, we used P19 cells, a mouse embryonic carcinoma cell line, as a model to study roles of YAP, a core component of the Hippo pathway, in neuronal differentiation. P19 cells can be induced to differentiate into neurons by expressing a neural bHLH transcription factor gene Ascl1. Our results showed that YAP promoted cell proliferation and inhibited neuronal differentiation. Expression of Yap activated Shh but not Wnt or Notch signaling activity during neuronal differentiation. Furthermore, expression of Yap increased the expression of Patched homolog 1 (Ptch1), a downstream target of the Shh signaling. Knockdown of Gli2, a transcription factor of the Shh pathway, promoted neuronal differentiation even when Yap was over-expressed. We further demonstrated that over-expression of Yap inhibited neuronal differentiation in primary mouse cortical progenitors and Gli2 knockdown rescued the differentiation defect in Yap over-expressing cells. In conclusion, our study reveals that Shh signaling acts downstream of YAP in regulating neuronal differentiation. -- Highlights: ► YAP promotes cell proliferation and inhibits neuronal differentiation in P19 cells. ► YAP promotes Sonic hedgehog signaling activity during neuronal differentiation. ► Knockdown of Gli2 rescues the Yap-overexpression phenotype in P19 cells. ► Knockdown of Gli2 rescues the Yap

YAP regulates neuronal differentiation through Sonic hedgehog signaling pathway

Energy Technology Data Exchange (ETDEWEB)

Lin, Yi-Ting; Ding, Jing-Ya [Department of Life Sciences and Institute of Genome Sciences, National Yang-Ming University, Taipei 112, Taiwan (China); Li, Ming-Yang [Department of Life Science, National Taiwan Normal University, Taipei 116, Taiwan (China); Yeh, Tien-Shun [Department of Anatomy and Cell Biology, National Yang-Ming University, Taipei 112, Taiwan (China); Wang, Tsu-Wei [Department of Life Science, National Taiwan Normal University, Taipei 116, Taiwan (China); Yu, Jenn-Yah [Department of Life Sciences and Institute of Genome Sciences, National Yang-Ming University, Taipei 112, Taiwan (China); Brain Research Center, National Yang-Ming University, Taipei 112, Taiwan (China)

2012-09-10

Tight regulation of cell numbers by controlling cell proliferation and apoptosis is important during development. Recently, the Hippo pathway has been shown to regulate tissue growth and organ size in Drosophila. In mammalian cells, it also affects cell proliferation and differentiation in various tissues, including the nervous system. Interplay of several signaling cascades, such as Notch, Wnt, and Sonic Hedgehog (Shh) pathways, control cell proliferation during neuronal differentiation. However, it remains unclear whether the Hippo pathway coordinates with other signaling cascades in regulating neuronal differentiation. Here, we used P19 cells, a mouse embryonic carcinoma cell line, as a model to study roles of YAP, a core component of the Hippo pathway, in neuronal differentiation. P19 cells can be induced to differentiate into neurons by expressing a neural bHLH transcription factor gene Ascl1. Our results showed that YAP promoted cell proliferation and inhibited neuronal differentiation. Expression of Yap activated Shh but not Wnt or Notch signaling activity during neuronal differentiation. Furthermore, expression of Yap increased the expression of Patched homolog 1 (Ptch1), a downstream target of the Shh signaling. Knockdown of Gli2, a transcription factor of the Shh pathway, promoted neuronal differentiation even when Yap was over-expressed. We further demonstrated that over-expression of Yap inhibited neuronal differentiation in primary mouse cortical progenitors and Gli2 knockdown rescued the differentiation defect in Yap over-expressing cells. In conclusion, our study reveals that Shh signaling acts downstream of YAP in regulating neuronal differentiation. -- Highlights: Black-Right-Pointing-Pointer YAP promotes cell proliferation and inhibits neuronal differentiation in P19 cells. Black-Right-Pointing-Pointer YAP promotes Sonic hedgehog signaling activity during neuronal differentiation. Black-Right-Pointing-Pointer Knockdown of Gli2 rescues the Yap

Pan-cancer analysis of TCGA data reveals notable signaling pathways

International Nuclear Information System (INIS)

Neapolitan, Richard; Horvath, Curt M.; Jiang, Xia

2015-01-01

A signal transduction pathway (STP) is a network of intercellular information flow initiated when extracellular signaling molecules bind to cell-surface receptors. Many aberrant STPs have been associated with various cancers. To develop optimal treatments for cancer patients, it is important to discover which STPs are implicated in a cancer or cancer-subtype. The Cancer Genome Atlas (TCGA) makes available gene expression level data on cases and controls in ten different types of cancer including breast cancer, colon adenocarcinoma, glioblastoma, kidney renal papillary cell carcinoma, low grade glioma, lung adenocarcinoma, lung squamous cell carcinoma, ovarian carcinoma, rectum adenocarcinoma, and uterine corpus endometriod carcinoma. Signaling Pathway Impact Analysis (SPIA) is a software package that analyzes gene expression data to identify whether a pathway is relevant in a given condition. We present the results of a study that uses SPIA to investigate all 157 signaling pathways in the KEGG PATHWAY database. We analyzed each of the ten cancer types mentioned above separately, and we perform a pan-cancer analysis by grouping the data for all the cancer types. In each analysis several pathways were found to be markedly more significant than all the other pathways. We call them notable. Research has already established a connection between many of these pathways and the corresponding cancer type. However, some of our discovered pathways appear to be new findings. Altogether there were 37 notable findings in the separate analyses, 26 of them occurred in 7 pathways. These 7 pathways included the 4 notable pathways discovered in the pan-cancer analysis. So, our results suggest that these 7 pathways account for much of the mechanisms of cancer. Furthermore, by looking at the overlap among pathways, we identified possible regions on the pathways where the aberrant activity is occurring. We obtained 37 notable findings concerning 18 pathways. Some of them appear to be

Targeting Apoptosis Signaling Pathways for Anticancer Therapy

Energy Technology Data Exchange (ETDEWEB)

Fulda, Simone, E-mail: simone.fulda@kgu.de [Institute for Experimental Cancer Research in Pediatrics, Goethe-University, Frankfurt (Germany)

2011-08-29

Treatment approaches for cancer, for example chemotherapy, radiotherapy, or immunotherapy, primarily act by inducing cell death in cancer cells. Consequently, the inability to trigger cell death pathways or alternatively, evasion of cancer cells to the induction of cell death pathways can result in resistance of cancers to current treatment protocols. Therefore, in order to overcome treatment resistance a better understanding of the underlying mechanisms that regulate cell death and survival pathways in cancers and in response to cancer therapy is necessary to develop molecular-targeted therapies. This strategy should lead to more effective and individualized treatment strategies that selectively target deregulated signaling pathways in a tumor type- and patient-specific manner.

Targeting Apoptosis Signaling Pathways for Anticancer Therapy

International Nuclear Information System (INIS)

Fulda, Simone

2011-01-01

Treatment approaches for cancer, for example chemotherapy, radiotherapy, or immunotherapy, primarily act by inducing cell death in cancer cells. Consequently, the inability to trigger cell death pathways or alternatively, evasion of cancer cells to the induction of cell death pathways can result in resistance of cancers to current treatment protocols. Therefore, in order to overcome treatment resistance a better understanding of the underlying mechanisms that regulate cell death and survival pathways in cancers and in response to cancer therapy is necessary to develop molecular-targeted therapies. This strategy should lead to more effective and individualized treatment strategies that selectively target deregulated signaling pathways in a tumor type- and patient-specific manner.

Clinical Implications of Hedgehog Pathway Signaling in Prostate Cancer

Directory of Open Access Journals (Sweden)

Daniel L. Suzman

2015-09-01

Full Text Available Activity in the Hedgehog pathway, which regulates GLI-mediated transcription, is important in organogenesis and stem cell regulation in self-renewing organs, but is pathologically elevated in many human malignancies. Mutations leading to constitutive activation of the pathway have been implicated in medulloblastoma and basal cell carcinoma, and inhibition of the pathway has demonstrated clinical responses leading to the approval of the Smoothened inhibitor, vismodegib, for the treatment of advanced basal cell carcinoma. Aberrant Hedgehog pathway signaling has also been noted in prostate cancer with evidence suggesting that it may render prostate epithelial cells tumorigenic, drive the epithelial-to-mesenchymal transition, and contribute towards the development of castration-resistance through autocrine and paracrine signaling within the tumor microenvironment and cross-talk with the androgen pathway. In addition, there are emerging clinical data suggesting that inhibition of the Hedgehog pathway may be effective in the treatment of recurrent and metastatic prostate cancer. Here we will review these data and highlight areas of active clinical research as they relate to Hedgehog pathway inhibition in prostate cancer.

Integrin and GPCR Crosstalk in the Regulation of ASM Contraction Signaling in Asthma.

Science.gov (United States)

Teoh, Chun Ming; Tam, John Kit Chung; Tran, Thai

2012-01-01

Airway hyperresponsiveness (AHR) is one of the cardinal features of asthma. Contraction of airway smooth muscle (ASM) cells that line the airway wall is thought to influence aspects of AHR, resulting in excessive narrowing or occlusion of the airway. ASM contraction is primarily controlled by agonists that bind G protein-coupled receptor (GPCR), which are expressed on ASM. Integrins also play a role in regulating ASM contraction signaling. As therapies for asthma are based on symptom relief, better understanding of the crosstalk between GPCRs and integrins holds good promise for the design of more effective therapies that target the underlying cellular and molecular mechanism that governs AHR. In this paper, we will review current knowledge about integrins and GPCRs in their regulation of ASM contraction signaling and discuss the emerging concept of crosstalk between the two and the implication of this crosstalk on the development of agents that target AHR.

FENO and AHR mannitol in patients referred to an out-of-hospital asthma clinic

DEFF Research Database (Denmark)

Backer, Vibeke; Sverrild, Asger; Porsbjerg, Celeste

2014-01-01

between FENO and AHR to mannitol in unselected individuals with possible asthma. METHODS: A real-life study on patients with possible asthma referred to a specialized asthma clinic. Data on asthma history, FEV(1), FENO, atopy, smoking, treatment and AHR to mannitol were collected. RESULTS: In 217...

Targeting Wnt signaling in colorectal cancer. A Review in the Theme: Cell Signaling: Proteins, Pathways and Mechanisms

Science.gov (United States)

Novellasdemunt, Laura; Antas, Pedro

2015-01-01

The evolutionarily conserved Wnt signaling pathway plays essential roles during embryonic development and tissue homeostasis. Notably, comprehensive genetic studies in Drosophila and mice in the past decades have demonstrated the crucial role of Wnt signaling in intestinal stem cell maintenance by regulating proliferation, differentiation, and cell-fate decisions. Wnt signaling has also been implicated in a variety of cancers and other diseases. Loss of the Wnt pathway negative regulator adenomatous polyposis coli (APC) is the hallmark of human colorectal cancers (CRC). Recent advances in high-throughput sequencing further reveal many novel recurrent Wnt pathway mutations in addition to the well-characterized APC and β-catenin mutations in CRC. Despite attractive strategies to develop drugs for Wnt signaling, major hurdles in therapeutic intervention of the pathway persist. Here we discuss the Wnt-activating mechanisms in CRC and review the current advances and challenges in drug discovery. PMID:26289750

Estrogenic and AhR activities in dissolved phase and suspended solids from wastewater treatment plants.

Science.gov (United States)

Dagnino, Sonia; Gomez, Elena; Picot, Bernadette; Cavaillès, Vincent; Casellas, Claude; Balaguer, Patrick; Fenet, Hélène

2010-05-15

The distribution of estrogen receptor (ERalpha) and Aryl Hydrocarbon Receptor (AhR) activities between the dissolved phase and suspended solids were investigated during wastewater treatment. Three wastewater treatment plants with different treatment technologies (waste stabilization ponds (WSPs), trickling filters (TFs) and activated sludge supplemented with a biofilter system (ASB)) were sampled. Estrogenic and AhR activities were detected in both phases in influents and effluents. Estrogenic and AhR activities in wastewater influents ranged from 41.8 to 79 ng/L E(2) Eq. and from 37.9 to 115.5 ng/L TCDD Eq. in the dissolved phase and from 5.5 to 88.6 ng/g E(2) Eq. and from 15 to 700 ng/g TCDD Eq. in the suspended solids. For both activities, WSP showed greater or similar removal efficiency than ASB and both were much more efficient than TF which had the lowest removal efficiency. Moreover, our data indicate that the efficiency of removal of ER and AhR activities from the suspended solid phase was mainly due to removal of suspended solids. Indeed, ER and AhR activities were detected in the effluent suspended solid phase indicating that suspended solids, which are usually not considered in these types of studies, contribute to environmental contamination by endocrine disrupting compounds and should therefore be routinely assessed for a better estimation of the ER and AhR activities released in the environment. Copyright 2010 Elsevier B.V. All rights reserved.

Balancing act: matching growth with environment by the TOR signalling pathway.

Science.gov (United States)

Henriques, Rossana; Bögre, László; Horváth, Beátrix; Magyar, Zoltán

2014-06-01

One of the most fundamental aspects of growth in plants is its plasticity in relation to fluctuating environmental conditions. Growth of meristematic cells relies predominantly on protein synthesis, one of the most energy-consuming activities in cells, and thus is tightly regulated in accordance with the available nutrient and energy supplies. The Target of Rapamycin (TOR) signalling pathway takes a central position in this regulation. The core of the TOR signalling pathway is conserved throughout evolution, and can be traced back to the last eukaryotic common ancestor. In plants, a single complex constitutes the TOR signalling pathway. Manipulating the components of the TOR complex in Arabidopsis highlighted its common role as a major regulator of protein synthesis and metabolism, that is also involved in other biological functions such as cell-wall integrity, regulation of cell proliferation, and cell size. TOR, as an integral part of the auxin signalling pathway, connects hormonal and nutrient pathways. Downstream of TOR, S6 kinase and the ribosomal S6 protein have been shown to mediate several of these responses, although there is evidence of other complex non-linear TOR signalling pathway structures. © The Author 2014. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

POSTRANSLATIONAL MODIFICATIONS OF P53: UPSTREAM SIGNALING PATHWAYS.

Energy Technology Data Exchange (ETDEWEB)

ANDERSON,C.W.APPELLA,E.

2003-10-23

The p53 tumor suppressor is a tetrameric transcription factor that is posttranslational modified at >20 different sites by phosphorylation, acetylation, or sumoylation in response to various cellular stress conditions. Specific posttranslational modifications, or groups of modifications, that result from the activation of different stress-induced signaling pathways are thought to modulate p53 activity to regulate cell fate by inducing cell cycle arrest, apoptosis, or cellular senescence. Here we review recent progress in characterizing the upstream signaling pathways whose activation in response to various genotoxic and non-genotoxic stresses result in p53 posttranslational modifications.

Transcriptome analysis of the Lactococcus lactis ArgR and AhrC regulons

DEFF Research Database (Denmark)

Larsen, Rasmus; van Hijum, Sacha A. F. T.; Martinussen, Jan

2008-01-01

In previous studies, we have shown that direct protein-protein. interaction between the two regulators ArgR and AhrC in Lactococcus lactis is required for arginine-dependent repression of the biosynthetic argC promoter and the activation of the catabolic arcA promoter. Here, we establish the global...... ArgR and AhrC regulons by transcriptome analyses and show that both regulators are dedicated to the control of arginine metabolism in L. lactis....

Inhibition of the adrenomedullin/nitric oxide signaling pathway in early diabetic retinopathy.

Science.gov (United States)

Blom, Jan J; Giove, Thomas J; Favazza, Tara L; Akula, James D; Eldred, William D

2011-06-01

The nitric oxide (NO) signaling pathway is integrally involved in visual processing and changes in the NO pathway are measurable in eyes of diabetic patients. The small peptide adrenomedullin (ADM) can activate a signaling pathway to increase the enzyme activity of neuronal nitric oxide synthase (nNOS). ADM levels are elevated in eyes of diabetic patients and therefore, ADM may play a role in the pathology of diabetic retinopathy. The goal of this research was to test the effects of inhibiting the ADM/NO signaling pathway in early diabetic retinopathy. Inhibition of this pathway decreased NO production in high-glucose retinal cultures. Treating diabetic mice with the PKC β inhibitor ruboxistaurin for 5 weeks lowered ADM mRNA levels and ADM-like immunoreactivity and preserved retinal function as assessed by electroretinography. The results of this study indicate that inhibiting the ADM/NO signaling pathway prevents neuronal pathology and functional losses in early diabetic retinopathy.

Suppression of WIF-1 through promoter hypermethylation causes accelerated proliferation of the aryl hydrocarbon receptor (AHR) overexpressing MCF10AT1 breast cancer cells

International Nuclear Information System (INIS)

Wu, Dalei; Wong, Patrick; Li, Wen; Vogel, Christoph F.; Matsumura, Fumio

2011-01-01

Highlights: → 5-Aza-2'-deoxycytidine (AZ) causes proliferation suppression and ERα recovery. → AZ down-regulates Wnt/β-catenin pathway mainly by increasing WIF-1 expression. → Both ERα and AhR have some effects on DNA methylation in breast cancer cells. → Artificial overexpression of ERα in ER negative cells increases WIF-1 expression. → WIF-1 promoter hypermethylation is one of the major causes for accelerated proliferation. -- Abstract: The cause for increased cell proliferation in AHR overexpressing breast cancer cells still remains unknown. Here we studied the molecular basis of aggressive cell proliferation of an AHR overexpressing and ERα functionally down-regulated MCF10AT1 cell line, designated as P20E, in comparison to a matched sub-line, P20C with normal AHR expression and ERα function. We found that a 4-day treatment of P20E cells with 5-aza-2'-deoxycytidine (AZ) caused a significant suppression of cell proliferation. Such an effect of AZ was accompanied with the significant recovery of ERα function. Among diagnostic markers of AZ-induced cellular changes we found conspicuous up-regulation of mRNA expression of Wnt inhibitory factor-1 (WIF-1), particularly in P20E. The possibility of AZ-induced demethylation on the promoter of WIF-1 gene was confirmed through methylation specific PCR assay. Such AZ-induced changes in P20E cells were also accompanied with the decrease in the binding of nuclear proteins to the 32 P labeled TRE (TCF response element) and the reduced accumulation of β-catenin protein in the cell nucleus, indicating the importance of Wnt/β-catenin pathway in maintaining the increased cell proliferation in P20E line over P20C line. The importance of WIF-1 in this regard has been validated by transfecting cells with siRNA against WIF-1, which caused an increase in cell proliferation. Moreover, artificial overexpression of ERα in both P20E as well as MDA-MB-231 cells increased the mRNA expression of WIF-1. Together these

PSFC: a Pathway Signal Flow Calculator App for Cytoscape [version 2; referees: 2 approved

Directory of Open Access Journals (Sweden)

Lilit Nersisyan

2017-04-01

Full Text Available Cell signaling pathways are sequences of biochemical reactions that propagate an input signal, such as a hormone binding to a cell-surface receptor, into the cell to trigger a reactive process. Assessment of pathway activities is crucial for determining which pathways play roles in disease versus normal conditions. To date various pathway flow/perturbation assessment tools are available, however they are constrained to specific algorithms and specific data types. There are no accepted standards for evaluation of pathway activities or simulation of flow propagation events in pathways, and the results of different software are difficult to compare. Here we present Pathway Signal Flow Calculator (PSFC, a Cytoscape app for calculation of a pathway signal flow based on the pathway topology and node input data. The app provides a rich framework for customization of different signal flow algorithms to allow users to apply various approaches within a single computational framework.

A rapid and reagent-free bioassay for the detection of dioxin-like compounds and other aryl hydrocarbon receptor (AhR) agonists using autobioluminescent yeast.

Science.gov (United States)

Xu, Tingting; Young, Anna; Marr, Enolia; Sayler, Gary; Ripp, Steven; Close, Dan

2018-02-01

An autonomously bioluminescent Saccharomyces cerevisiae BLYAhS bioreporter was developed in this study for the simple and rapid detection of dioxin-like compounds (DLCs) and aryl hydrocarbon receptor (AhR) agonists. This recombinant yeast reporter was based on a synthetic bacterial luciferase reporter gene cassette (lux) that can produce the luciferase as well as the enzymes capable of self-synthesizing the requisite substrates for bioluminescent production from endogenous cellular metabolites. As a result, bioluminescent signal production is generated continuously and autonomously without cell lysis or exogenous reagent addition. By linking the expression of the autobioluminescent lux reporter cassette to AhR activation via the use of a dioxin-responsive promoter, the S. cerevisiae BLYAhS bioreporter emitted a bioluminescent signal in response to DLC exposure in a dose-responsive manner. The model dioxin, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), could be detected within 4 h with a half maximal effective concentration (EC 50 ) of ~ 8.1 nM and a lower detection limit of 500 pM. The autobioluminescent response of BLYAhS to other AhR agonists, including 2,3,7,8-tetrachlorodibenzofuran (TCDF), polychlorinated bisphenyl congener 126 (PCB-126) and 169 (PCB-169), 1,2,3,6,7,8-hexachlorodibenzo-p-dioxin (HxCDD), 1,2,3,4,6,7,8-heptachlorodibenzo-p-dioxin (HpCDD), benzo[a]pyrene (BaP), and β-naphthoflavone (bNF), were also characterized in this study. The non-destructive and reagent-free nature of the BLYAhS reporter assay facilitated near-continuous, automated signal acquisition without additional hands-on effort and cost, providing a simple and cost-effective method for rapid DLC detection.

Disruption of Ah Receptor Signaling during Mouse Development Leads to Abnormal Cardiac Structure and Function in the Adult.

Directory of Open Access Journals (Sweden)

Vinicius S Carreira

Full Text Available The Developmental Origins of Health and Disease (DOHaD Theory proposes that the environment encountered during fetal life and infancy permanently shapes tissue physiology and homeostasis such that damage resulting from maternal stress, poor nutrition or exposure to environmental agents may be at the heart of adult onset disease. Interference with endogenous developmental functions of the aryl hydrocarbon receptor (AHR, either by gene ablation or by exposure in utero to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD, a potent AHR ligand, causes structural, molecular and functional cardiac abnormalities and altered heart physiology in mouse embryos. To test if embryonic effects progress into an adult phenotype, we investigated whether Ahr ablation or TCDD exposure in utero resulted in cardiac abnormalities in adult mice long after removal of the agent. Ten-months old adult Ahr-/- and in utero TCDD-exposed Ahr+/+ mice showed sexually dimorphic abnormal cardiovascular phenotypes characterized by echocardiographic findings of hypertrophy, ventricular dilation and increased heart weight, resting heart rate and systolic and mean blood pressure, and decreased exercise tolerance. Underlying these effects, genes in signaling networks related to cardiac hypertrophy and mitochondrial function were differentially expressed. Cardiac dysfunction in mouse embryos resulting from AHR signaling disruption seems to progress into abnormal cardiac structure and function that predispose adults to cardiac disease, but while embryonic dysfunction is equally robust in males and females, the adult abnormalities are more prevalent in females, with the highest severity in Ahr-/- females. The findings reported here underscore the conclusion that AHR signaling in the developing heart is one potential target of environmental factors associated with cardiovascular disease.

Dissection of the insulin signaling pathway via quantitative phosphoproteomics

DEFF Research Database (Denmark)

Krüger, Marcus; Kratchmarova, Irina; Blagoev, Blagoy

2008-01-01

spectrum of the tyrosine phosphorylation cascade, we have defined the tyrosine-phosphoproteome of the insulin signaling pathway, using high resolution mass spectrometry in combination with phosphotyrosine immunoprecipitation and stable isotope labeling by amino acids in cell culture (SILAC......The insulin signaling pathway is of pivotal importance in metabolic diseases, such as diabetes, and in cellular processes, such as aging. Insulin activates a tyrosine phosphorylation cascade that branches to create a complex network affecting multiple biological processes. To understand the full...

An Assessment of Technical and Production Risks of Candidate Low-Cost Attitude/Heading Reference Systems(AHRS)

Science.gov (United States)

Yuchnovicz, Daniel; Burgess, Malcolm; Hammers, William

1999-01-01

This report provides an assessment of technical and production risks of candidate low-cost attitude/heading reference systems (AHRS) for use in the Advanced General Aviation Transport Experiments (AGATE) airplanes. A low-cost AHRS is a key component of modem "glass cockpit" flight displays for General Aviation (GA) aircraft. The technical capabilities of several candidate low-cost AHRS were examined and described along with the technical issues involved with using all solid-state components for attitude measurement. An economic model was developed which describes the expected profit, rate of return, and volume requirements for the manufacture of low-cost AHRS for GA aircraft in the 2000 to 2020 time frame. The model is the result of interviews with GA airframe manufacturers, avionics manufacturers and historical analysis of avionics of similar complexity. The model shows that a manufacturer will break even after three years of AHRS production, realizing an 18 percent rate of return (23 percent profit) on an investment of $3.5M over the 20 year period. A start-up production estimate showed costs of $6-12M for a new company to build and certify an AHRS from scratch, considered to be a high-risk proposition, versus $0.25-0.75M for an experienced avionics manufacturer to manufacture a design under license, a low-risk proposition.

TCDD dysregulation of 13 AHR-target genes in rat liver

International Nuclear Information System (INIS)

Watson, John D.; Prokopec, Stephenie D.; Smith, Ashley B.; Okey, Allan B.; Pohjanvirta, Raimo; Boutros, Paul C.

2014-01-01

Despite several decades of research, the complete mechanism by which 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and other xenobiotic agonists of the aryl hydrocarbon receptor (AHR) cause toxicity remains unclear. While it has been shown that the AHR is required for all major manifestations of toxicity, the specific downstream changes involved in the development of toxic phenotypes remain unknown. Here we examine a panel of 13 genes that are AHR-regulated in many species and tissues. We profiled their hepatic mRNA abundances in two rat strains with very different sensitivities to TCDD: the TCDD-sensitive Long–Evans (Turku/AB; L–E) and the TCDD-resistant Han/Wistar (Kuopio; H/W). We evaluated doses ranging from 0 to 3000 μg/kg at 19 h after TCDD exposure and time points ranging from 1.5 to 384 h after exposure to 100 μg/kg TCDD. Twelve of 13 genes responded to TCDD in at least one strain, and seven of these showed statistically significant inter-strain differences in the time course analysis (Aldh3a1, Cyp1a2, Cyp1b1, Cyp2a1, Fmo1, Nfe2l2 and Nqo1). Cyp2s1 did not respond to TCDD in either rat strain. Five genes exhibited biphasic responses to TCDD insult (Ahrr, Aldh3a1, Cyp1b1, Nfe2l2 and Nqo1), suggesting a secondary event, such as association with additional transcriptional modulators. Of the 12 genes that responded to TCDD during the dose–response analysis, none had an ED 50 equivalent to that of Cyp1a1, the most sensitive gene in this study, while nine genes responded to doses at least 10–100 fold higher, in at least one strain (Ahrr (L–E), Aldh3a1 (both), Cyp1a2 (both), Cyp1b1 (both), Cyp2a1 (L–E), Inmt (both), Nfe2l2 (L–E), Nqo1 (L–E) and Tiparp (both)). These data shed new light on the association of the AHR target genes with TCDD toxicity, and in particular the seven genes exhibiting strain-specific differences represent strong candidate mediators of Type-II toxicities. - Highlights: • NanoString measured hepatic mRNA molecules following

TCDD dysregulation of 13 AHR-target genes in rat liver

Energy Technology Data Exchange (ETDEWEB)

Watson, John D., E-mail: john.watson@oicr.on.ca [Ontario Institute for Cancer Research, Department of Informatics and Bio-computing Program, Toronto (Canada); Prokopec, Stephenie D., E-mail: stephenie.prokopec@oicr.on.ca [Ontario Institute for Cancer Research, Department of Informatics and Bio-computing Program, Toronto (Canada); Smith, Ashley B., E-mail: ashleyblaines@gmail.com [Ontario Institute for Cancer Research, Department of Informatics and Bio-computing Program, Toronto (Canada); Okey, Allan B., E-mail: allan.okey@utoronto.ca [Department of Pharmacology and Toxicology, University of Toronto, Toronto (Canada); Pohjanvirta, Raimo, E-mail: raimo.pohjanvirta@helsinki.fi [Laboratory of Toxicology, National Institute for Health and Welfare, Kuopio (Finland); Department of Food Hygiene and Environmental Health, University of Helsinki, Helsinki (Finland); Boutros, Paul C., E-mail: paul.boutros@oicr.on.ca [Ontario Institute for Cancer Research, Department of Informatics and Bio-computing Program, Toronto (Canada); Department of Pharmacology and Toxicology, University of Toronto, Toronto (Canada); Department of Medical Biophysics, University of Toronto, Toronto (Canada)

2014-02-01

Despite several decades of research, the complete mechanism by which 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and other xenobiotic agonists of the aryl hydrocarbon receptor (AHR) cause toxicity remains unclear. While it has been shown that the AHR is required for all major manifestations of toxicity, the specific downstream changes involved in the development of toxic phenotypes remain unknown. Here we examine a panel of 13 genes that are AHR-regulated in many species and tissues. We profiled their hepatic mRNA abundances in two rat strains with very different sensitivities to TCDD: the TCDD-sensitive Long–Evans (Turku/AB; L–E) and the TCDD-resistant Han/Wistar (Kuopio; H/W). We evaluated doses ranging from 0 to 3000 μg/kg at 19 h after TCDD exposure and time points ranging from 1.5 to 384 h after exposure to 100 μg/kg TCDD. Twelve of 13 genes responded to TCDD in at least one strain, and seven of these showed statistically significant inter-strain differences in the time course analysis (Aldh3a1, Cyp1a2, Cyp1b1, Cyp2a1, Fmo1, Nfe2l2 and Nqo1). Cyp2s1 did not respond to TCDD in either rat strain. Five genes exhibited biphasic responses to TCDD insult (Ahrr, Aldh3a1, Cyp1b1, Nfe2l2 and Nqo1), suggesting a secondary event, such as association with additional transcriptional modulators. Of the 12 genes that responded to TCDD during the dose–response analysis, none had an ED{sub 50} equivalent to that of Cyp1a1, the most sensitive gene in this study, while nine genes responded to doses at least 10–100 fold higher, in at least one strain (Ahrr (L–E), Aldh3a1 (both), Cyp1a2 (both), Cyp1b1 (both), Cyp2a1 (L–E), Inmt (both), Nfe2l2 (L–E), Nqo1 (L–E) and Tiparp (both)). These data shed new light on the association of the AHR target genes with TCDD toxicity, and in particular the seven genes exhibiting strain-specific differences represent strong candidate mediators of Type-II toxicities. - Highlights: • NanoString measured hepatic mRNA molecules

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

Directory of Open Access Journals (Sweden)

Paul eScholz

2016-03-01

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

JAK/STAT signaling pathway-mediated immune response in silkworm (Bombyx mori) challenged by Beauveria bassiana.

Science.gov (United States)

Geng, Tao; Lv, Ding-Ding; Huang, Yu-Xia; Hou, Cheng-Xiang; Qin, Guang-Xing; Guo, Xi-Jie

2016-12-20

Innate immunity was critical in insects defensive system and able to be induced by Janus kinase/signal transducer and activator of transcription cascade transduction (JAK/STAT) signaling pathway. Currently, it had been identified many JAK/STAT signaling pathway-related genes in silkworm, but little function was known on insect innate immunity. To explore the roles of JAK/STAT pathway in antifungal immune response in silkworm (Bombyx mori) against Beauveria bassiana infection, the expression patterns of B. mori C-type lectin 5 (BmCTL5) and genes encoding 6 components of JAK/STAT signaling pathway in silkworm challenged by B. bassiana were analyzed using quantitative real time PCR. Meanwhile the activation of JAK/STAT signaling pathway by various pathogenic micro-organisms and the affect of JAK/STAT signaling pathway inhibitors on antifungal activity in silkworm hemolymph was also detected. Moreover, RNAi assay of BmCTL5 and the affect on expression levels of signaling factors were also analyzed. We found that JAK/STAT pathway could be obviously activated in silkworm challenged with B. bassiana and had no response to bacteria and B. mori cytoplasmic polyhedrosis virus (BmCPV). However, the temporal expression patterns of JAK/STAT signaling pathway related genes were significantly different. B. mori downstream receptor kinase (BmDRK) might be a positive regulator of JAK/STAT signaling pathway in silkworm against B. bassiana infection. Moreover, antifungal activity assay showed that the suppression of JAK/STAT signaling pathway by inhibitors could significantly inhibit the antifungal activity in hemolymph and resulted in increased sensitivity of silkworm to B. bassiana infection, indicating that JAK/STAT signaling pathway might be involved in the synthesis and secretion of antifungal substances. The results of RNAi assays suggested that BmCTL5 might be one pattern recognition receptors for JAK/STAT signaling pathway in silkworm. These findings yield insights for better

Interaction of Diuron and Related Substituted Phenylureas with the Ah Receptor Pathway

Science.gov (United States)

Zhao, Bin; Baston, David S.; Hammock, Bruce; Denison, Michael S.

2011-01-01

The aryl hydrocarbon receptor (AhR) is a ligand-dependent transcription factor that mediates many of the biological and toxicological actions of structurally diverse chemicals, including the ubiquitous environmental contaminant 2,3,7,8-tetrachlorodibenzo-p-dioxin. Here, we have examined the ability of diuron, a widely used herbicide, and several structurally related substituted phenylureas to bind to and activate/inhibit the AhR and AhR signal transduction. Diuron induced CYP1A1 mRNA levels in mouse hepatoma (Hepa1c1c7) cells and AhR-dependent luciferase reporter gene expression in stably transfected mouse, rat, guinea pig, and human cell lines. In addition, ligand binding and gel retardation analysis demonstrated the ability of diuron to competitively bind to and stimulate AhR transformation and DNA binding in vitro and in intact cells. Several structurally related substituted phenylureas competitively bound to the guinea pig hepatic cytosolic AhR, inhibited 2,3,7,8-tetrachlorodibenzo-p-dioxin-induced AhR-dependent luciferase reporter gene expression in a species-specific manner and stimulated AhR transformation and DNA binding, consistent with their role as partial AhR agonists. These results demonstrate not only that diuron and related substituted phenylureas are AhR ligands but also that exposure to these chemicals could induce/inhibit AhR-dependent biological effects. PMID:16788953

Autonomous rexinoid death signaling is suppressed by converging signaling pathways in immature leukemia cells.

Science.gov (United States)

Benoit, G R; Flexor, M; Besançon, F; Altucci, L; Rossin, A; Hillion, J; Balajthy, Z; Legres, L; Ségal-Bendirdjian, E; Gronemeyer, H; Lanotte, M

2001-07-01

On their own, retinoid X receptor (RXR)-selective ligands (rexinoids) are silent in retinoic acid receptor (RAR)-RXR heterodimers, and no selective rexinoid program has been described as yet in cellular systems. We report here on the rexinoid signaling capacity that triggers apoptosis of immature promyelocytic NB4 cells as a default pathway in the absence of survival factors. Rexinoid-induced apoptosis displays all features of bona fide programmed cell death and is inhibited by RXR, but not RAR antagonists. Several types of survival signals block rexinoid-induced apoptosis. RARalpha agonists switch the cellular response toward differentiation and induce the expression of antiapoptosis factors. Activation of the protein kinase A pathway in the presence of rexinoid agonists induces maturation and blocks immature cell apoptosis. Addition of nonretinoid serum factors also blocks cell death but does not induce cell differentiation. Rexinoid-induced apoptosis is linked to neither the presence nor stability of the promyelocytic leukemia-RARalpha fusion protein and operates also in non-acute promyelocytic leukemia cells. Together our results support a model according to which rexinoids activate in certain leukemia cells a default death pathway onto which several other signaling paradigms converge. This pathway is entirely distinct from that triggered by RAR agonists, which control cell maturation and postmaturation apoptosis.

An algorithm for modularization of MAPK and calcium signaling pathways: comparative analysis among different species.

Science.gov (United States)

Nayak, Losiana; De, Rajat K

2007-12-01

Signaling pathways are large complex biochemical networks. It is difficult to analyze the underlying mechanism of such networks as a whole. In the present article, we have proposed an algorithm for modularization of signal transduction pathways. Unlike studying a signaling pathway as a whole, this enables one to study the individual modules (less complex smaller units) easily and hence to study the entire pathway better. A comparative study of modules belonging to different species (for the same signaling pathway) has been made, which gives an overall idea about development of the signaling pathways over the taken set of species of calcium and MAPK signaling pathways. The superior performance, in terms of biological significance, of the proposed algorithm over an existing community finding algorithm of Newman [Newman MEJ. Modularity and community structure in networks. Proc Natl Acad Sci USA 2006;103(23):8577-82] has been demonstrated using the aforesaid pathways of H. sapiens.

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

Lifescience Database Archive (English)

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

The node-weighted Steiner tree approach to identify elements of cancer-related signaling pathways.

Science.gov (United States)

Sun, Yahui; Ma, Chenkai; Halgamuge, Saman

2017-12-28

Cancer constitutes a momentous health burden in our society. Critical information on cancer may be hidden in its signaling pathways. However, even though a large amount of money has been spent on cancer research, some critical information on cancer-related signaling pathways still remains elusive. Hence, new works towards a complete understanding of cancer-related signaling pathways will greatly benefit the prevention, diagnosis, and treatment of cancer. We propose the node-weighted Steiner tree approach to identify important elements of cancer-related signaling pathways at the level of proteins. This new approach has advantages over previous approaches since it is fast in processing large protein-protein interaction networks. We apply this new approach to identify important elements of two well-known cancer-related signaling pathways: PI3K/Akt and MAPK. First, we generate a node-weighted protein-protein interaction network using protein and signaling pathway data. Second, we modify and use two preprocessing techniques and a state-of-the-art Steiner tree algorithm to identify a subnetwork in the generated network. Third, we propose two new metrics to select important elements from this subnetwork. On a commonly used personal computer, this new approach takes less than 2 s to identify the important elements of PI3K/Akt and MAPK signaling pathways in a large node-weighted protein-protein interaction network with 16,843 vertices and 1,736,922 edges. We further analyze and demonstrate the significance of these identified elements to cancer signal transduction by exploring previously reported experimental evidences. Our node-weighted Steiner tree approach is shown to be both fast and effective to identify important elements of cancer-related signaling pathways. Furthermore, it may provide new perspectives into the identification of signaling pathways for other human diseases.

DMPD: TLR signaling. [Dynamic Macrophage Pathway CSML Database

Lifescience Database Archive (English)

Full Text Available 2007 Feb 1. (.png) (.svg) (.html) (.csml) Show TLR signaling. PubmedID 17275323 Title TLR signaling. Author...s Kawai T, Akira S. Publication Semin Immunol. 2007 Feb;19(1):24-32. Epub 2007 Feb 1. Pathway - PNG File (.png) SVG File (.svg) HTML... File (.html) CSML File (.csml) Open .csml file with CIOP

Rapidly exploring structural and dynamic properties of signaling networks using PathwayOracle

Directory of Open Access Journals (Sweden)

Ram Prahlad T

2008-08-01

Full Text Available Abstract Background In systems biology the experimentalist is presented with a selection of software for analyzing dynamic properties of signaling networks. These tools either assume that the network is in steady-state or require highly parameterized models of the network of interest. For biologists interested in assessing how signal propagates through a network under specific conditions, the first class of methods does not provide sufficiently detailed results and the second class requires models which may not be easily and accurately constructed. A tool that is able to characterize the dynamics of a signaling network using an unparameterized model of the network would allow biologists to quickly obtain insights into a signaling network's behavior. Results We introduce PathwayOracle, an integrated suite of software tools for computationally inferring and analyzing structural and dynamic properties of a signaling network. The feature which differentiates PathwayOracle from other tools is a method that can predict the response of a signaling network to various experimental conditions and stimuli using only the connectivity of the signaling network. Thus signaling models are relatively easy to build. The method allows for tracking signal flow in a network and comparison of signal flows under different experimental conditions. In addition, PathwayOracle includes tools for the enumeration and visualization of coherent and incoherent signaling paths between proteins, and for experimental analysis – loading and superimposing experimental data, such as microarray intensities, on the network model. Conclusion PathwayOracle provides an integrated environment in which both structural and dynamic analysis of a signaling network can be quickly conducted and visualized along side experimental results. By using the signaling network connectivity, analyses and predictions can be performed quickly using relatively easily constructed signaling network models

Metformin inhibits 7,12-dimethylbenz[a]anthracene-induced breast carcinogenesis and adduct formation in human breast cells by inhibiting the cytochrome P4501A1/aryl hydrocarbon receptor signaling pathway

Energy Technology Data Exchange (ETDEWEB)

Maayah, Zaid H. [Department of Pharmacology and Toxicology, College of Pharmacy, King Saud University, Riyadh 11451 (Saudi Arabia); Ghebeh, Hazem [Stem Cell & Tissue Re-Engineering, King Faisal Specialist Hospital and Research Center, Riyadh 11211 (Saudi Arabia); Alhaider, Abdulqader A. [Department of Pharmacology and Toxicology, College of Pharmacy, King Saud University, Riyadh 11451 (Saudi Arabia); Camel Biomedical Research Unit, College of Pharmacy and Medicine, King Saud University, Riyadh 11451 (Saudi Arabia); El-Kadi, Ayman O.S. [Faculty of Pharmacy & Pharmaceutical Sciences, University of Alberta, Edmonton (Canada); Soshilov, Anatoly A.; Denison, Michael S. [Department of Environmental Toxicology, University of California at Davis, Davis, CA 95616 (United States); Ansari, Mushtaq Ahmad [Department of Pharmacology and Toxicology, College of Pharmacy, King Saud University, Riyadh 11451 (Saudi Arabia); Korashy, Hesham M., E-mail: hkorashy@ksu.edu.sa [Department of Pharmacology and Toxicology, College of Pharmacy, King Saud University, Riyadh 11451 (Saudi Arabia)

2015-04-15

Recent studies have established that metformin (MET), an oral anti-diabetic drug, possesses antioxidant activity and is effective against different types of cancer in several carcinogen-induced animal models and cell lines. However, whether MET can protect against breast cancer has not been reported before. Therefore, the overall objectives of the present study are to elucidate the potential chemopreventive effect of MET in non-cancerous human breast MCF10A cells and explore the underlying mechanism involved, specifically the role of cytochrome P4501A1 (CYP1A1)/aryl hydrocarbon receptor (AhR) pathway. Transformation of the MCF10A cells into initiated breast cancer cells with DNA adduct formation was conducted using 7,12-dimethylbenz[a]anthracene (DMBA), an AhR ligand. The chemopreventive effect of MET against DMBA-induced breast carcinogenesis was evidenced by the capability of MET to restore the induction of the mRNA levels of basic excision repair genes, 8-oxoguanine DNA glycosylase (OGG1) and apurinic/apyrimidinic endonuclease1 (APE1), and the level of 8-hydroxy-2-deoxyguanosine (8-OHdG). Interestingly, the inhibition of DMBA-induced DNA adduct formation was associated with proportional decrease in CYP1A1 and in NAD(P)H:quinone oxidoreductase 1 (NQO1) gene expression. Mechanistically, the involvements of AhR and nuclear factor erythroid 2-related factor-2 (Nrf2) in the MET-mediated inhibition of DMBA-induced CYP1A1 and NQO1 gene expression were evidenced by the ability of MET to inhibit DMBA-induced xenobiotic responsive element and antioxidant responsive element luciferase reporter gene expression which suggests an AhR- and Nrf2-dependent transcriptional control. However, the inability of MET to bind to AhR suggests that MET is not an AhR ligand. In conclusion, the present work shows a strong evidence that MET inhibits the DMBA-mediated carcinogenicity and adduct formation by inhibiting the expression of CYP1A1 through an AhR ligand-independent mechanism

Metformin inhibits 7,12-dimethylbenz[a]anthracene-induced breast carcinogenesis and adduct formation in human breast cells by inhibiting the cytochrome P4501A1/aryl hydrocarbon receptor signaling pathway

International Nuclear Information System (INIS)

Maayah, Zaid H.; Ghebeh, Hazem; Alhaider, Abdulqader A.; El-Kadi, Ayman O.S.; Soshilov, Anatoly A.; Denison, Michael S.; Ansari, Mushtaq Ahmad; Korashy, Hesham M.

2015-01-01

Recent studies have established that metformin (MET), an oral anti-diabetic drug, possesses antioxidant activity and is effective against different types of cancer in several carcinogen-induced animal models and cell lines. However, whether MET can protect against breast cancer has not been reported before. Therefore, the overall objectives of the present study are to elucidate the potential chemopreventive effect of MET in non-cancerous human breast MCF10A cells and explore the underlying mechanism involved, specifically the role of cytochrome P4501A1 (CYP1A1)/aryl hydrocarbon receptor (AhR) pathway. Transformation of the MCF10A cells into initiated breast cancer cells with DNA adduct formation was conducted using 7,12-dimethylbenz[a]anthracene (DMBA), an AhR ligand. The chemopreventive effect of MET against DMBA-induced breast carcinogenesis was evidenced by the capability of MET to restore the induction of the mRNA levels of basic excision repair genes, 8-oxoguanine DNA glycosylase (OGG1) and apurinic/apyrimidinic endonuclease1 (APE1), and the level of 8-hydroxy-2-deoxyguanosine (8-OHdG). Interestingly, the inhibition of DMBA-induced DNA adduct formation was associated with proportional decrease in CYP1A1 and in NAD(P)H:quinone oxidoreductase 1 (NQO1) gene expression. Mechanistically, the involvements of AhR and nuclear factor erythroid 2-related factor-2 (Nrf2) in the MET-mediated inhibition of DMBA-induced CYP1A1 and NQO1 gene expression were evidenced by the ability of MET to inhibit DMBA-induced xenobiotic responsive element and antioxidant responsive element luciferase reporter gene expression which suggests an AhR- and Nrf2-dependent transcriptional control. However, the inability of MET to bind to AhR suggests that MET is not an AhR ligand. In conclusion, the present work shows a strong evidence that MET inhibits the DMBA-mediated carcinogenicity and adduct formation by inhibiting the expression of CYP1A1 through an AhR ligand-independent mechanism

Binding of 2,3,7,8-tetrachlorodibenzo-p-dioxin to the AhR from various species is essentially irreversible

Energy Technology Data Exchange (ETDEWEB)

Bohonowych, J.; Denison, M. [California Univ., Davis, CA (United States)

2004-09-15

Halogenated aromatic hydrocarbons (HAHs) are a diverse group of widespread, persistent and toxic environmental contaminants that includes the polychlorinated dibenzo-p-dioxins and related chemicals. Exposure to these compounds results in a variety of biochemical and toxic effects, the majority of which are mediated by the aryl hydrocarbon receptor (AhR). 2,3,7,8- Tetrachlorodibenzo-p-dioxin (TCDD) is the most potent activator of the AhR and AhR-dependent effects. Interestingly, while a related class of compounds, the polycyclic aromatic hydrocarbons (PAHs), can bind to and activate the AhR, and produce many of the same biological effects as HAHs, they do not cause HAH-like toxicity. This can be due to differences between these two classes of compounds with respect to their AhR binding affinity, metabolic stability, and/or gene expression. PAHs have a lower affinity for the AhR5 and, unlike TCDD, can be readily metabolized by cytochrome P450 enzymes. In addition to its high affinity for the AhR, TCDD has been shown to stabilize the rat AhR receptor against thermal inactivation and to persistently bind the rat receptor. This persistent occupancy may also contribute to the differential toxicity of HAHs and PAHs. In addition to its biological and toxicological implications, the apparent lack of significant dissociation of TCDD from the AhR also impacts the design and interpretation of competitive binding experiments which assume traditional receptor-ligand equilibrium binding kinetics where binding is reversible and equilibrium of ligand:receptor complex is reached when rates of association and dissociation are equal. In this study we have further examined whether this persistent occupancy is a characteristic of the AhR among different species.

Porcine Circovirus-Like Virus P1 Inhibits Wnt Signaling Pathway in Vivo and in Vitro.

Science.gov (United States)

Zhu, Xuejiao; Wen, Libin; Sheng, Shaoyang; Wang, Wei; Xiao, Qi; Qu, Meng; Hu, Yiyi; Liu, Chuanmin; He, Kongwang

2018-01-01

Porcine circovirus-like virus P1 is an important pathogen of the current pig industry, the infection mechanism is not entirely clear. Wnt signaling pathway plays an important role in the growth of young animals and infection of some viruses. This study was designed to demonstrate the effects of P1 infection on the Wnt signaling pathway. In vivo experiments, we demonstrated the down-regulatory effects of P1 infection in piglets and mice on the downstream components expression levels of Wnt signaling pathway, and the effects of Wnt signaling pathway activation on the pathogenesis of P1. In vitro studies, we found P1 infection down-regulated protein level of β-catenin and mRNA level of mmp2, prevented the β-catenin from entering into nucleus, abolished the TCF/LEF promoter activity, proved that P1 could inhibit the activation of Wnt signaling pathway in vitro . Finally, we found that VP1 of P1 virus also had the inhibitory effects on Wnt signaling pathway in vitro , elucidated the mechanism of P1's inhibitory effects on the Wnt signaling pathway and offered the possibility that the suppression of Wnt signaling pathway was involved in the post-weaning multisystemic wasting syndrome (PMWS), laying a foundation for elucidating the pathogenesis of P1.

Disruption of contact inhibition in rat liver epithelial cells by various types of AhR ligands

Energy Technology Data Exchange (ETDEWEB)

Vondracek, J.; Chramostova, K.; Kozubik, A. [Institute of Biophysics, Brno (Czech Republic); Krcmar, P.; Machala, M. [Veterinary Research Institute, Brno (Czech Republic)

2004-09-15

The maintenance of a balance between cell gain and cell loss is essential for proper liver function. The exact role of aryl hydrocarbon receptor (AhR) in regulating cell proliferation and apoptosis of liver cells remains unclear, since ligand-dependent activation of AhR has been shown to induce cell cycle arrest, proliferation, differentiation or apoptosis, depending on the cellular model used. AhR can directly interact with retinoblastoma protein in hepatic cells, forming protein complexes that can efficiently block cell cycle progression by inducing G1 arrest, or to induce the expression of inhibitors of cyclin-dependent kinases, such as p271. On the other hand, it has been suggested that AhR could play a stimulatory role in cell proliferation, either directly or by mediating a release from contact inhibition. It is now generally accepted that progenitor cells exist in the liver, are activated in various liver diseases and can form a potential target cell population for both tumor initiating and tumor promoting chemicals4. 2,3,7,8-tetrachlorodibenzo-pdioxin (TCDD) has been found to release rat liver epithelial cells from contact inhibition by upregulating cyclin A expression and cyclin A/cdk2 activity. Our previous studies have shown that a number of AhR ligands5,6 can stimulate proliferation of confluent of rat liver epithelial ''stem-like'' WB-F344 cells. Such mechanism could play a role in liver tumor promotion. In the present study, we used flavonoid compounds that have been reported to act either as pure agonists, such as beta-naphthoflavone (BNF), or as partial/complete antagonists of AhR - alpha-naphthoflavone (ANF) and 3'-methoxy-4'-nitroflavone (3'M4'NF), in order to investigate effects of AhR agonists/antagonists on confluent rat liver epithelial cells. The present study aimed to investigate the effects of model flavonoids on the release of rat liver epithelial cells from contact inhibition, and on inducibility of

Evolution and Design Governing Signal Precision and Amplification in a Bacterial Chemosensory Pathway.

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Mathilde Guzzo

2015-08-01

Full Text Available Understanding the principles underlying the plasticity of signal transduction networks is fundamental to decipher the functioning of living cells. In Myxococcus xanthus, a particular chemosensory system (Frz coordinates the activity of two separate motility systems (the A- and S-motility systems, promoting multicellular development. This unusual structure asks how signal is transduced in a branched signal transduction pathway. Using combined evolution-guided and single cell approaches, we successfully uncoupled the regulations and showed that the A-motility regulation system branched-off an existing signaling system that initially only controlled S-motility. Pathway branching emerged in part following a gene duplication event and changes in the circuit structure increasing the signaling efficiency. In the evolved pathway, the Frz histidine kinase generates a steep biphasic response to increasing external stimulations, which is essential for signal partitioning to the motility systems. We further show that this behavior results from the action of two accessory response regulator proteins that act independently to filter and amplify signals from the upstream kinase. Thus, signal amplification loops may underlie the emergence of new connectivity in signal transduction pathways.

The AhR Ligand, TCDD, Regulates Androgen Receptor Activity Differently in Androgen-Sensitive versus Castration-Resistant Human Prostate Cancer Cells

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Maryam Ghotbaddini

2015-07-01

Full Text Available The reported biological effects of TCDD include induction of drug metabolizing enzymes, wasting syndrome and tumor promotion. TCDD elicits most of its effects through binding the aryl hydrocarbon receptor (AhR. TCDD induced degradation of AhR has been widely reported and requires ubiquitination of the protein. The rapid depletion of AhR following TCDD activation serves as a mechanism to modulate AhR mediated gene induction. In addition to inducing AhR degradation, TCDD has been reported to induce degradation of hormone receptors. The studies reported here, evaluate the effect of TCDD exposure on androgen receptor (AR expression and activity in androgen-sensitive LNCaP and castration-resistant C4-2 prostate cancer cells. Our results show that TCDD exposure does not induce AhR or AR degradation in C4-2 cells. However, both AhR and AR are degraded in LNCaP cells following TCDD exposure. In addition, TCDD enhances AR phosphorylation and induces expression of AR responsive genes in LNCaP cells. Our data reveals that TCDD effect on AR expression and activity differs in androgen-sensitive and castration-resistant prostate cancer cell models.

[Cell signaling pathways interaction in cellular proliferation: Potential target for therapeutic interventionism].

Science.gov (United States)

Valdespino-Gómez, Víctor Manuel; Valdespino-Castillo, Patricia Margarita; Valdespino-Castillo, Víctor Edmundo

2015-01-01

Nowadays, cellular physiology is best understood by analysing their interacting molecular components. Proteins are the major components of the cells. Different proteins are organised in the form of functional clusters, pathways or networks. These molecules are ordered in clusters of receptor molecules of extracellular signals, transducers, sensors and biological response effectors. The identification of these intracellular signaling pathways in different cellular types has required a long journey of experimental work. More than 300 intracellular signaling pathways have been identified in human cells. They participate in cell homeostasis processes for structural and functional maintenance. Some of them participate simultaneously or in a nearly-consecutive progression to generate a cellular phenotypic change. In this review, an analysis is performed on the main intracellular signaling pathways that take part in the cellular proliferation process, and the potential use of some components of these pathways as target for therapeutic interventionism are also underlined. Copyright © 2015 Academia Mexicana de Cirugía A.C. Published by Masson Doyma México S.A. All rights reserved.

Gene Expression Profiling Identifies Downregulation of the Neurotrophin-MAPK Signaling Pathway in Female Diabetic Peripheral Neuropathy Patients.

Science.gov (United States)

Luo, Lin; Zhou, Wen-Hua; Cai, Jiang-Jia; Feng, Mei; Zhou, Mi; Hu, Su-Pei; Xu, Jin; Ji, Lin-Dan

2017-01-01

Diabetic peripheral neuropathy (DPN) is a common complication of diabetes mellitus (DM). It is not diagnosed or managed properly in the majority of patients because its pathogenesis remains controversial. In this study, human whole genome microarrays identified 2898 and 4493 differentially expressed genes (DEGs) in DM and DPN patients, respectively. A further KEGG pathway analysis indicated that DPN and DM share four pathways, including apoptosis, B cell receptor signaling pathway, endocytosis, and Toll-like receptor signaling pathway. The DEGs identified through comparison of DPN and DM were significantly enriched in MAPK signaling pathway, NOD-like receptor signaling pathway, and neurotrophin signaling pathway, while the "neurotrophin-MAPK signaling pathway" was notably downregulated. Seven DEGs from the neurotrophin-MAPK signaling pathway were validated in additional 78 samples, and the results confirmed the initial microarray findings. These findings demonstrated that downregulation of the neurotrophin-MAPK signaling pathway may be the major mechanism of DPN pathogenesis, thus providing a potential approach for DPN treatment.

Signaling Pathways in Leiomyoma: Understanding Pathobiology and Implications for Therapy

Science.gov (United States)

Borahay, Mostafa A; Al-Hendy, Ayman; Kilic, Gokhan S; Boehning, Darren

2015-01-01

Uterine leiomyomas are the most common tumors of the female genital tract, affecting 50% to 70% of females by the age of 50. Despite their prevalence and enormous medical and economic impact, no effective medical treatment is currently available. This is, in part, due to the poor understanding of their underlying pathobiology. Although they are thought to start as a clonal proliferation of a single myometrial smooth muscle cell, these early cytogenetic alterations are considered insufficient for tumor development and additional complex signaling pathway alterations are crucial. These include steroids, growth factors, transforming growth factor-beta (TGF-β)/Smad; wingless-type (Wnt)/β-catenin, retinoic acid, vitamin D, and peroxisome proliferator-activated receptor γ (PPARγ). An important finding is that several of these pathways converge in a summative way. For example, mitogen-activated protein kinase (MAPK) and Akt pathways seem to act as signal integrators, incorporating input from several signaling pathways, including growth factors, estrogen and vitamin D. This underlines the multifactorial origin and complex nature of these tumors. In this review, we aim to dissect these pathways and discuss their interconnections, aberrations and role in leiomyoma pathobiology. We also aim to identify potential targets for development of novel therapeutics. PMID:25879625

Immunological characterization of the aryl hydrocarbon receptor (AHR) knockout rat in the presence and absence of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)

International Nuclear Information System (INIS)

Phadnis-Moghe, Ashwini S.; Chen, Weimin; Li, Jinpeng; Crawford, Robert B.; Bach, Anthony; D’Ingillo, Shawna; Kovalova, Natalia; Suarez-Martinez, Jose E.; Kaplan, Barbara L.F.; Harrill, Joshua A.; Budinsky, Robert; Rowlands, J. Craig; Thomas, Russell S.

2016-01-01

The aryl hydrocarbon receptor (AHR) has been extensively characterized for the essential role it plays in mediating the toxic responses elicited by 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). Despite similarities across animal species, species-specific differences exist in the profile of toxicity and sensitivity to TCDD owing, in part, to differences in the AHR. Newer reports have implicated the importance of AHR in the development and regulation of the immune system. Our present studies seek to further explore the essential role of AHR in lymphoid tissue composition, B cell function and the immunological responses after TCDD administration using the recently established AHR KO rats. Comprehensive immune cell phenotyping showed a decrease in the CD8 + T cell, CD11c + populations and an increase in NKT cells in 3-week-old AHR KO rats compared to the WT controls. The lipopolysaccharide-induced IgM response and proliferation was markedly suppressed in the WT but not in the AHR KO B cells in the presence of TCDD. However, the percentage of LPS-activated IgM + B cells was significantly higher in the AHR KO B cells as compared to that of WT suggesting the role of AHR in regulating the IgM response. The use of an AHR antagonist further alluded to the endogenous role of AHR in regulating B cell responses in the rat. Overall, the studies report for the first time, comprehensive immune cell phenotyping of the AHR KO rat and the endogenous role of AHR in the regulation of B cell function in the rat.

Signaling pathways in a Citrus EST database

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Angela Mehta

2007-01-01

Full Text Available Citrus spp. are economically important crops, which in Brazil are grown mainly in the State of São Paulo. Citrus cultures are attacked by several pathogens, causing severe yield losses. In order to better understand this culture, the Millenium Project (IAC Cordeirópolis was launched in order to sequence Citrus ESTs (expressed sequence tags from different tissues, including leaf, bark, fruit, root and flower. Plants were submitted to biotic and abiotic stresses and investigated under different development stages (adult vs. juvenile. Several cDNA libraries were constructed and the sequences obtained formed the Citrus ESTs database with almost 200,000 sequences. Searches were performed in the Citrus database to investigate the presence of different signaling pathway components. Several of the genes involved in the signaling of sugar, calcium, cytokinin, plant hormones, inositol phosphate, MAPKinase and COP9 were found in the citrus genome and are discussed in this paper. The results obtained may indicate that similar mechanisms described in other plants, such as Arabidopsis, occur in citrus. Further experimental studies must be conducted in order to understand the different signaling pathways present.

Investigation of radiation-induced multilayered signalling response of the inflammatory pathway

International Nuclear Information System (INIS)

Babini, G.; Ugolini, M.; Morini, J.; Baiocco, G.; Ottolenghi, A.; Mariotti, L.; Tabarelli de Fatis, P.; Liotta, M.

2015-01-01

Ionising radiation exposure of cells might induce the perturbation of cell functions and, in particular, the activation or inhibition of several important pathways. This perturbation can cause the deregulation of both intra- and extra-cellular signalling cascades (such as the inflammatory pathway) and alter not only the behaviour of directly exposed cells but also the neighbouring nonirradiated ones, through the so-called bystander effect. The aim of the present work was to investigate the complex nonlinear interactions between the inflammatory pathway and other strictly interlaced signalling pathways, such as Erk1/2 and Akt/PKB, focusing on the radiation-induced perturbation of such pathways in the dose range of 0 -2 Gy. The results show how radiation affects these interconnected pathways and how confounding factors, such as the change of culture medium, can hide radiation-induced perturbations. (authors)

Dioxin activation of CYP1A5 promoter/enhancer regions from two avian species, common cormorant (Phalacrocorax carbo) and chicken (Gallus gallus): Association with aryl hydrocarbon receptor 1 and 2 isoforms

International Nuclear Information System (INIS)

Lee, Jin-Seon; Kim, Eun-Young; Iwata, Hisato

2009-01-01

The present study focuses on the molecular mechanism and interspecies differences in susceptibility of avian aryl hydrocarbon receptor (AHR)-cytochrome P4501A (CYP1A) signaling pathway. By the cloning of 5'-flanking regions of CYP1A5 gene from common cormorant (Phalacrocorax carbo) and chicken (Gallus gallus), seven putative xenobiotic response elements (XREs) were identified within 2.7 kb upstream region of common cormorant CYP1A5 (ccCYP1A5), and six XREs were found within 0.9 kb of chicken CYP1A5 (ckCYP1A5). Analysis of sequential deletion and mutagenesis of the binding sites in avian CYP1A5 genes by in vitro reporter gene assays revealed that two XREs at -613 bp and -1585 bp in ccCYP1A5, and one XRE at -262 bp in ckCYP1A5 conferred TCDD-responsiveness. The binding of AHR1 with AHR nuclear translocator 1 (ARNT1) to the functional XRE in a TCDD-dependent manner was verified with gel shift assays, suggesting that avian CYP1A5 is induced by TCDD through AHR1/ARNT1 signaling pathway as well as mammalian CYP1A1 but through a distinct pathway from mammalian CYP1A2, an ortholog of the CYP1A5. TCDD-EC 50 for the transcriptional activity in both cormorant AHR1- and AHR2-ccCYP1A5 reporter construct was 10-fold higher than that in chicken AHR1-ckCYP1A5 reporter construct. In contrast, chicken AHR2 showed no TCDD-dependent response. The TCDD-EC 50 for CYP1A5 transactivation was altered by switching AHR1 between the two avian species, irrespective of the species from which the regulatory region of CYP1A5 gene originates. Therefore, the structural difference in AHR, not the CYP1A5 regulatory region may be a major factor to account for the dioxin susceptibility in avian species

In silico predictive studies of mAHR congener binding using homology modelling and molecular docking.

Science.gov (United States)

Panda, Roshni; Cleave, A Suneetha Susan; Suresh, P K

2014-09-01

The aryl hydrocarbon receptor (AHR) is one of the principal xenobiotic, nuclear receptor that is responsible for the early events involved in the transcription of a complex set of genes comprising the CYP450 gene family. In the present computational study, homology modelling and molecular docking were carried out with the objective of predicting the relationship between the binding efficiency and the lipophilicity of different polychlorinated biphenyl (PCB) congeners and the AHR in silico. Homology model of the murine AHR was constructed by several automated servers and assessed by PROCHECK, ERRAT, VERIFY3D and WHAT IF. The resulting model of the AHR by MODWEB was used to carry out molecular docking of 36 PCB congeners using PatchDock server. The lipophilicity of the congeners was predicted using the XLOGP3 tool. The results suggest that the lipophilicity influences binding energy scores and is positively correlated with the same. Score and Log P were correlated with r = +0.506 at p = 0.01 level. In addition, the number of chlorine (Cl) atoms and Log P were highly correlated with r = +0.900 at p = 0.01 level. The number of Cl atoms and scores also showed a moderate positive correlation of r = +0.481 at p = 0.01 level. To the best of our knowledge, this is the first study employing PatchDock in the docking of AHR to the environmentally deleterious congeners and attempting to correlate structural features of the AHR with its biochemical properties with regards to PCBs. The result of this study are consistent with those of other computational studies reported in the previous literature that suggests that a combination of docking, scoring and ranking organic pollutants could be a possible predictive tool for investigating ligand-mediated toxicity, for their subsequent validation using wet lab-based studies. © The Author(s) 2012.

Porcine Circovirus-Like Virus P1 Inhibits Wnt Signaling Pathway in Vivo and in Vitro

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Xuejiao Zhu

2018-03-01

Full Text Available Porcine circovirus-like virus P1 is an important pathogen of the current pig industry, the infection mechanism is not entirely clear. Wnt signaling pathway plays an important role in the growth of young animals and infection of some viruses. This study was designed to demonstrate the effects of P1 infection on the Wnt signaling pathway. In vivo experiments, we demonstrated the down-regulatory effects of P1 infection in piglets and mice on the downstream components expression levels of Wnt signaling pathway, and the effects of Wnt signaling pathway activation on the pathogenesis of P1. In vitro studies, we found P1 infection down-regulated protein level of β-catenin and mRNA level of mmp2, prevented the β-catenin from entering into nucleus, abolished the TCF/LEF promoter activity, proved that P1 could inhibit the activation of Wnt signaling pathway in vitro. Finally, we found that VP1 of P1 virus also had the inhibitory effects on Wnt signaling pathway in vitro, elucidated the mechanism of P1’s inhibitory effects on the Wnt signaling pathway and offered the possibility that the suppression of Wnt signaling pathway was involved in the post-weaning multisystemic wasting syndrome (PMWS, laying a foundation for elucidating the pathogenesis of P1.

Differential and directional estrogenic signaling pathways induced by enterolignans and their precursors.

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Yun Zhu

Full Text Available Mammalian lignans or enterolignans are metabolites of plant lignans, an important category of phytochemicals. Although they are known to be associated with estrogenic activity, cell signaling pathways leading to specific cell functions, and especially the differences among lignans, have not been explored. We examined the estrogenic activity of enterolignans and their precursor plant lignans and cell signaling pathways for some cell functions, cell cycle and chemokine secretion. We used DNA microarray-based gene expression profiling in human breast cancer MCF-7 cells to examine the similarities, as well as the differences, among enterolignans, enterolactone and enterodiol, and their precursors, matairesinol, pinoresinol and sesamin. The profiles showed moderate to high levels of correlation (R values: 0.44 to 0.81 with that of estrogen (17β-estradiol or E2. Significant correlations were observed among lignans (R values: 0.77 to 0.97, and the correlations were higher for cell functions related to enzymes, signaling, proliferation and transport. All the enterolignans/precursors examined showed activation of the Erk1/2 and PI3K/Akt pathways, indicating the involvement of rapid signaling through the non-genomic estrogen signaling pathway. However, when their effects on specific cell functions, cell cycle progression and chemokine (MCP-1 secretion were examined, positive effects were observed only for enterolactone, suggesting that signals are given in certain directions at a position closer to cell functions. We hypothesized that, while estrogen signaling is initiated by the enterolignans/precursors examined, their signals are differentially and directionally modulated later in the pathways, resulting in the differences at the cell function level.

Analysis of the AHR gene proximal promoter GGGGC-repeat polymorphism in lung, breast, and colon cancer

International Nuclear Information System (INIS)

Spink, Barbara C.; Bloom, Michael S.; Wu, Susan; Sell, Stewart; Schneider, Erasmus; Ding, Xinxin; Spink, David C.

2015-01-01

The aryl hydrocarbon receptor (AhR) regulates expression of numerous genes, including those of the CYP1 gene family. With the goal of determining factors that control AHR gene expression, our studies are focused on the role of the short tandem repeat polymorphism, (GGGGC) n , located in the proximal promoter of the human AHR gene. When luciferase constructs containing varying GGGGC repeats were transfected into cancer cell lines derived from the lung, colon, and breast, the number of GGGGC repeats affected AHR promoter activity. The number of GGGGC repeats was determined in DNA from 327 humans and from 38 samples representing 5 species of non-human primates. In chimpanzees and 3 species of macaques, only (GGGGC) 2 alleles were observed; however, in western gorilla, (GGGGC) n alleles with n = 2, 4, 5, 6, 7, and 8 were identified. In all human populations examined, the frequency of (GGGGC) n was n = 4 > 5 ≫ 2, 6. When frequencies of the (GGGGC) n alleles in DNA from patients with lung, colon, or breast cancer were evaluated, the occurrence of (GGGGC) 2 was found to be 8-fold more frequent among lung cancer patients in comparison with its incidence in the general population, as represented by New York State neonates. Analysis of matched tumor and non-tumor DNA samples from the same individuals provided no evidence of microsatellite instability. These studies indicate that the (GGGGC) n short tandem repeats are inherited, and that the (GGGGC) 2 allele in the AHR proximal promoter region should be further investigated with regard to its potential association with lung cancer susceptibility. - Highlights: • The AHR proximal promoter contains a polymorphism, (GGGGC) n , where n = 4 > 5 ≫ 2, 6 • Matched tumor and non-tumor DNA did not show (GGGGC) n microsatellite instability • AHR promoter activity of a construct with (GGGGC) 2 was lower than that of (GGGGC) 4 • The frequency of (GGGGC) 2 in lung cancer patients was 8-fold higher than in neonates • The

Non Linear Programming (NLP) formulation for quantitative modeling of protein signal transduction pathways.

Science.gov (United States)

Mitsos, Alexander; Melas, Ioannis N; Morris, Melody K; Saez-Rodriguez, Julio; Lauffenburger, Douglas A; Alexopoulos, Leonidas G

2012-01-01

Modeling of signal transduction pathways plays a major role in understanding cells' function and predicting cellular response. Mathematical formalisms based on a logic formalism are relatively simple but can describe how signals propagate from one protein to the next and have led to the construction of models that simulate the cells response to environmental or other perturbations. Constrained fuzzy logic was recently introduced to train models to cell specific data to result in quantitative pathway models of the specific cellular behavior. There are two major issues in this pathway optimization: i) excessive CPU time requirements and ii) loosely constrained optimization problem due to lack of data with respect to large signaling pathways. Herein, we address both issues: the former by reformulating the pathway optimization as a regular nonlinear optimization problem; and the latter by enhanced algorithms to pre/post-process the signaling network to remove parts that cannot be identified given the experimental conditions. As a case study, we tackle the construction of cell type specific pathways in normal and transformed hepatocytes using medium and large-scale functional phosphoproteomic datasets. The proposed Non Linear Programming (NLP) formulation allows for fast optimization of signaling topologies by combining the versatile nature of logic modeling with state of the art optimization algorithms.

Non Linear Programming (NLP formulation for quantitative modeling of protein signal transduction pathways.

Directory of Open Access Journals (Sweden)

Alexander Mitsos

Full Text Available Modeling of signal transduction pathways plays a major role in understanding cells' function and predicting cellular response. Mathematical formalisms based on a logic formalism are relatively simple but can describe how signals propagate from one protein to the next and have led to the construction of models that simulate the cells response to environmental or other perturbations. Constrained fuzzy logic was recently introduced to train models to cell specific data to result in quantitative pathway models of the specific cellular behavior. There are two major issues in this pathway optimization: i excessive CPU time requirements and ii loosely constrained optimization problem due to lack of data with respect to large signaling pathways. Herein, we address both issues: the former by reformulating the pathway optimization as a regular nonlinear optimization problem; and the latter by enhanced algorithms to pre/post-process the signaling network to remove parts that cannot be identified given the experimental conditions. As a case study, we tackle the construction of cell type specific pathways in normal and transformed hepatocytes using medium and large-scale functional phosphoproteomic datasets. The proposed Non Linear Programming (NLP formulation allows for fast optimization of signaling topologies by combining the versatile nature of logic modeling with state of the art optimization algorithms.

Herpes simplex virus triggers activation of calcium-signaling pathways

Science.gov (United States)

Cheshenko, Natalia; Del Rosario, Brian; Woda, Craig; Marcellino, Daniel; Satlin, Lisa M.; Herold, Betsy C.

2003-01-01

The cellular pathways required for herpes simplex virus (HSV) invasion have not been defined. To test the hypothesis that HSV entry triggers activation of Ca2+-signaling pathways, the effects on intracellular calcium concentration ([Ca2+]i) after exposure of cells to HSV were examined. Exposure to virus results in a rapid and transient increase in [Ca2+]i. Pretreatment of cells with pharmacological agents that block release of inositol 1,4,5-triphosphate (IP3)–sensitive endoplasmic reticulum stores abrogates the response. Moreover, treatment of cells with these pharmacological agents inhibits HSV infection and prevents focal adhesion kinase (FAK) phosphorylation, which occurs within 5 min after viral infection. Viruses deleted in glycoprotein L or glycoprotein D, which bind but do not penetrate, fail to induce a [Ca2+]i response or trigger FAK phosphorylation. Together, these results support a model for HSV infection that requires activation of IP3-responsive Ca2+-signaling pathways and that is associated with FAK phosphorylation. Defining the pathway of viral invasion may lead to new targets for anti-viral therapy. PMID:14568989

Evaluation of Notch and Hypoxia Signaling Pathways in Chemically ...

African Journals Online (AJOL)

Hepatocellular carcinoma (HCC) is a common worldwide malignancy. Notch signaling pathway contributes to the genesis of diverse cancers, however, its role in HCC is unclear. Hypoxia is a common feature of HCC. Signal integration between Notch and hypoxia may be involved in HCC. The aim of this study was to ...

Construction of large signaling pathways using an adaptive perturbation approach with phosphoproteomic data.

Science.gov (United States)

Melas, Ioannis N; Mitsos, Alexander; Messinis, Dimitris E; Weiss, Thomas S; Rodriguez, Julio-Saez; Alexopoulos, Leonidas G

2012-04-01

Construction of large and cell-specific signaling pathways is essential to understand information processing under normal and pathological conditions. On this front, gene-based approaches offer the advantage of large pathway exploration whereas phosphoproteomic approaches offer a more reliable view of pathway activities but are applicable to small pathway sizes. In this paper, we demonstrate an experimentally adaptive approach to construct large signaling pathways from phosphoproteomic data within a 3-day time frame. Our approach--taking advantage of the fast turnaround time of the xMAP technology--is carried out in four steps: (i) screen optimal pathway inducers, (ii) select the responsive ones, (iii) combine them in a combinatorial fashion to construct a phosphoproteomic dataset, and (iv) optimize a reduced generic pathway via an Integer Linear Programming formulation. As a case study, we uncover novel players and their corresponding pathways in primary human hepatocytes by interrogating the signal transduction downstream of 81 receptors of interest and constructing a detailed model for the responsive part of the network comprising 177 species (of which 14 are measured) and 365 interactions.

Dietary influence on MAPK-signaling pathways and risk of colon and rectal cancer.

Science.gov (United States)

Slattery, Martha L; Lundgreen, Abbie; Wolff, Roger K

2013-01-01

Mitogen-activated protein kinase (MAPK) pathways regulate cellular functions including cell proliferation, differentiation, migration, and apoptosis. Associations between genes in the DUSP, ERK1/2, JNK, and p38 MAPK-signaling pathways and dietary factors associated with growth factors, inflammation, and oxidative stress and risk of colon and rectal cancer were evaluated. Data include colon cases (n = 1555) and controls (n = 1956) and rectal cases (n = 754) and controls (n = 959). Statistically significant interactions were observed for the MAPK-signaling pathways after adjustment for multiple comparisons. DUSP genes interacted with carbohydrates, mutagen index, calories, calcium, vitamin D, lycopene, dietary fats, folic acid, and selenium. MAPK1, MAPK3, MAPK1, and RAF1 within the ERK1/2 MAPK-signaling pathway interacted with dietary fats and cruciferous vegetables. Within the JNK MAPK-signaling pathway, interactions between MAP3K7 and protein, vitamin C, iron, folic acid, carbohydrates, and cruciferous vegetables; MAP3K10 and folic acid; MAP3K9 and lutein/zeaxanthin; MAPK8 and calcium; MAP3K3 and calcium and lutein; MAP3K1 and cruciferous vegetables. Interaction within the p38-signaling pathway included MAPK14 with calories, carbohydrates saturated fat, selenium, vitamin C; MAP3K2 and carbohydrates, and folic acid. These data suggest that dietary factors involved in inflammation and oxidative stress interact with MAPK-signaling genes to alter risk of colorectal cancer.

Discovery and characterization of a potent Wnt and hedgehog signaling pathways dual inhibitor.

Science.gov (United States)

Ma, Haikuo; Chen, Qin; Zhu, Fang; Zheng, Jiyue; Li, Jiajun; Zhang, Hongjian; Chen, Shuaishuai; Xing, Haimei; Luo, Lusong; Zheng, Long Tai; He, Sudan; Zhang, Xiaohu

2018-04-10

Embryonic stem cell pathways such as hedgehog and Wnt pathways are central to the tumorigenic properties of cancer stem cells (CSC). Since CSCs are characterized by their ability to self-renew, form differentiated progeny, and develop resistance to anticancer therapies, targeting the Wnt and hedgehog signaling pathways has been an important strategy for cancer treatment. Although molecules targeting either Wnt or hedgehog are common, to the best of our knowledge, those targeting both pathways have not been documented. Here we report a small molecule (compound 1) that inhibits both Wnt (IC 50  = 0.5 nM) and hedgehog (IC 50  = 71 nM) pathways based on reporter gene assays. We further identified that the molecular target of 1 for Wnt pathway inhibition was porcupine (a member of the membrane-bound O-acyltransferase family of proteins), a post-translational modification node in Wnt signaling; while the target of 1 mitigating hedgehog pathway was Smoothened, a key G protein coupled receptor (GPCR) mediating hedgehog signal transduction. Preliminary analysis of structure-activity-relationship identified key functional elements for hedgehog/Wnt inhibition. In in vivo studies, compound 1 demonstrated good oral exposure and bioavailability while eliciting no overt toxicity in mice. An important consideration in cancer treatment is the potential therapeutic escape through compensatory activation of an interconnected pathway when only one signaling pathway is inhibited. Toward this end, compound 1 may not only lead to the development of new therapeutics for Wnt and hedgehog related cancers, but may also help to develop potential cancer treatment which needs to target Wnt and hedgehog signaling simultaneously. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

Sex and hedgehog: roles of genes in the hedgehog signaling pathway in mammalian sexual differentiation.

Science.gov (United States)

Franco, Heather L; Yao, Humphrey H-C

2012-01-01

The chromosome status of the mammalian embryo initiates a multistage process of sexual development in which the bipotential reproductive system establishes itself as either male or female. These events are governed by intricate cell-cell and interorgan communication that is regulated by multiple signaling pathways. The hedgehog signaling pathway was originally identified for its key role in the development of Drosophila, but is now recognized as a critical developmental regulator in many species, including humans. In addition to its developmental roles, the hedgehog signaling pathway also modulates adult organ function, and misregulation of this pathway often leads to diseases, such as cancer. The hedgehog signaling pathway acts through its morphogenetic ligands that signal from ligand-producing cells to target cells over a specified distance. The target cells then respond in a graded manner based on the concentration of the ligands that they are exposed to. Through this unique mechanism of action, the hedgehog signaling pathway elicits cell fate determination, epithelial-mesenchymal interactions, and cellular homeostasis. Here, we review current findings on the roles of hedgehog signaling in the sexually dimorphic development of the reproductive organs with an emphasis on mammals and comparative evidence in other species.

Conservation and divergence of chemical defense system in the tunicate Oikopleura dioica revealed by genome wide response to two xenobiotics

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Yadetie Fekadu

2012-02-01

Full Text Available Abstract Background Animals have developed extensive mechanisms of response to xenobiotic chemical attacks. Although recent genome surveys have suggested a broad conservation of the chemical defensome across metazoans, global gene expression responses to xenobiotics have not been well investigated in most invertebrates. Here, we performed genome survey for key defensome genes in Oikopleura dioica genome, and explored genome-wide gene expression using high density tiling arrays with over 2 million probes, in response to two model xenobiotic chemicals - the carcinogenic polycyclic aromatic hydrocarbon benzo[a]pyrene (BaP the pharmaceutical compound Clofibrate (Clo. Results Oikopleura genome surveys for key genes of the chemical defensome suggested a reduced repertoire. Not more than 23 cytochrome P450 (CYP genes could be identified, and neither CYP1 family genes nor their transcriptional activator AhR was detected. These two genes were present in deuterostome ancestors. As in vertebrates, the genotoxic compound BaP induced xenobiotic biotransformation and oxidative stress responsive genes. Notable exceptions were genes of the aryl hydrocarbon receptor (AhR signaling pathway. Clo also affected the expression of many biotransformation genes and markedly repressed genes involved in energy metabolism and muscle contraction pathways. Conclusions Oikopleura has the smallest number of CYP genes among sequenced animal genomes and lacks the AhR signaling pathway. However it appears to have basic xenobiotic inducible biotransformation genes such as a conserved genotoxic stress response gene set. Our genome survey and expression study does not support a role of AhR signaling pathway in the chemical defense of metazoans prior to the emergence of vertebrates.

Structure of the C-terminal effector-binding domain of AhrC bound to its corepressor l-arginine

International Nuclear Information System (INIS)

Garnett, James A.; Baumberg, Simon; Stockley, Peter G.; Phillips, Simon E. V.

2007-01-01

The crystal structure of the C-terminal domain hexameric core of AhrC, with bound corepressor (l-arginine), has been solved at 1.95 Å resolution. Binding of l-arginine results in a rotation between the two trimers of the hexamer, leading to the activation of the DNA-binding state. The arginine repressor/activator protein (AhrC) from Bacillus subtilis belongs to a large family of multifunctional transcription factors that are involved in the regulation of bacterial arginine metabolism. AhrC interacts with operator sites in the promoters of arginine biosynthetic and catabolic operons, acting as a transcriptional repressor at biosynthetic sites and an activator of transcription at catabolic sites. AhrC is a hexamer of identical subunits, each having two domains. The C-terminal domains form the core of the protein and are involved in oligomerization and l-arginine binding. The N-terminal domains lie on the outside of the compact core and play a role in binding to 18 bp DNA operators called ARG boxes. The C-terminal domain of AhrC has been expressed, purified and characterized, and also crystallized as a hexamer with the bound corepressor l-arginine. Here, the crystal structure refined to 1.95 Å is presented

Characterizing the role of endothelin-1 in the progression of cardiac hypertrophy in aryl hydrocarbon receptor (AhR) null mice

International Nuclear Information System (INIS)

Lund, Amie K.; Goens, M. Beth; Nunez, Bethany A.; Walker, Mary K.

2006-01-01

The aryl hydrocarbon receptor (AhR) is a ligand-activated transcription factor characterized to play a role in detection and adaptation to environmental stimuli. Genetic deletion of AhR results in hypertension, and cardiac hypertrophy and fibrosis, associated with elevated plasma angiotensin II (Ang II) and endothelin-1 (ET-1), thus AhR appears to contribute to cardiovascular homeostasis. In these studies, we tested the hypothesis that ET-1 mediates cardiovascular pathology in AhR null mice via ET A receptor activation. First, we determine the time courses of cardiac hypertrophy, and of plasma and tissue ET-1 expression in AhR wildtype and null mice. AhR null mice exhibited increases in heart-to-body weight ratio and age-related expression of cardiac hypertrophy markers, β-myosin heavy chain (β-MHC), and atrial natriuretic factor (ANF), which were significant at 2 months. Similarly, plasma and tissue ET-1 expression was significantly elevated at 2 months and increased further with age. Second, AhR null mice were treated with ET A receptor antagonist, BQ-123 (100 nmol/kg/day), for 7, 28, or 58 days and blood pressure, cardiac fibrosis, and cardiac hypertrophy assessed, respectively. BQ-123 for 7 days significantly reduced mean arterial pressure in conscious, catheterized mice. BQ-123 for 28 days significantly reduced the histological appearance of cardiac fibrosis. Treatment for 58 days significantly reduced cardiac mass, assessed by heart weight, echocardiography, and β-MHC and ANF expression; and reduced cardiac fibrosis as determined by osteopontin and collagen I mRNA expression. These findings establish ET-1 and the ET A receptor as primary determinants of hypertension and cardiac pathology in AhR null mice

[The function of transcription factor P63 and its signaling pathway during limb development].

Science.gov (United States)

Ma, Wei; Tian, Wen

2014-08-01

The development of human limb is controlled by several transcription factors and signaling pathways, which are organized in precise time- and space-restricted manners. Recent studies showed that P63 and its signaling pathway play important roles in this process. Transcription factor P63, one member of the P53 family, is characterized by a similar amino acid domain, plays a crucial role in the development of limb and ectoderm differentiation, especially with its DNA binding domain, and sterile alpha motif domains. Mutated P63 gene may produce abnormal transcription factor P63 which can affect the signaling pathway. Furthermore, defective signaling protein in structure and/or quantity is synthesized though the pathway. Eventually, members of the signaling protein family are involved in the regulation of differentiation and development of stem cell, which causes deformity of limbs. In brief, three signaling pathways are related to the digit formation along three axes, including SHH-ZPA, FGFs-AER and Lmx1B-Wnt7a-En1. Each contains numerous signaling molecules which are integrated in self-regulatory modules that assure the acquisition or the correct digit complements. These finding has brought new clues for deciphering the etiology of congenital limb malformation and may provide alternatives for both prevention and treatment.

Role of CSL-dependent and independent Notch signaling pathways in cell apoptosis.

Science.gov (United States)

Zeng, Chong; Xing, Rui; Liu, Jing; Xing, Feiyue

2016-01-01

Apoptosis is a normally biological phenomenon in various organisms, involving complexly molecular mechanisms with a series of signaling processes. Notch signaling is found evolutionarily conserved in many species, playing a critical role in embryonic development, normal tissue homeostasis, angiogenesis and immunoregulation. The focus of this review is on currently novel advances about roles of CSL-dependent and independent Notch signaling pathways in cell apoptosis. The CSL can bind Notch intracellular domain (NIC) to act as a switch in mediating transcriptional activation or inactivation of the Notch signaling pathway downstream genes in the nucleus. It shows that CSL-dependent signaling regulates the cell apoptosis through Hes-1-PTEN-AKT-mTOR signaling, but rather the CSL-independent signaling mediates the cell apoptosis possibly via NIC-mTORC2-AKT-mTOR signaling, providing a new insight into apoptotic mechanisms.

Network features and pathway analyses of a signal transduction cascade

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Ryoji Yanashima

2009-05-01

Full Text Available The scale-free and small-world network models reflect the functional units of networks. However, when we investigated the network properties of a signaling pathway using these models, no significant differences were found between the original undirected graphs and the graphs in which inactive proteins were eliminated from the gene expression data. We analyzed signaling networks by focusing on those pathways that best reflected cellular function. Therefore, our analysis of pathways started from the ligands and progressed to transcription factors and cytoskeletal proteins. We employed the Python module to assess the target network. This involved comparing the original and restricted signaling cascades as a directed graph using microarray gene expression profiles of late onset Alzheimer's disease. The most commonly used method of shortest-path analysis neglects to consider the influences of alternative pathways that can affect the activation of transcription factors or cytoskeletal proteins. We therefore introduced included k-shortest paths and k-cycles in our network analysis using the Python modules, which allowed us to attain a reasonable computational time and identify k-shortest paths. This technique reflected results found in vivo and identified pathways not found when shortest path or degree analysis was applied. Our module enabled us to comprehensively analyse the characteristics of biomolecular networks and also enabled analysis of the effects of diseases considering the feedback loop and feedforward loop control structures as an alternative path.

Analysis of the AHR gene proximal promoter GGGGC-repeat polymorphism in lung, breast, and colon cancer

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Spink, Barbara C. [Wadsworth Center, New York State Department of Health, Albany, NY 12201 (United States); Bloom, Michael S. [Department of Environmental Health Sciences, School of Public Health, University at Albany, State University of New York, Albany, NY 12201 (United States); Wu, Susan [Wadsworth Center, New York State Department of Health, Albany, NY 12201 (United States); Sell, Stewart; Schneider, Erasmus [Wadsworth Center, New York State Department of Health, Albany, NY 12201 (United States); Department of Biomedical Sciences, School of Public Health, University at Albany, State University of New York, Albany, NY 12201 (United States); Ding, Xinxin [Wadsworth Center, New York State Department of Health, Albany, NY 12201 (United States); Department of Environmental Health Sciences, School of Public Health, University at Albany, State University of New York, Albany, NY 12201 (United States); Department of Biomedical Sciences, School of Public Health, University at Albany, State University of New York, Albany, NY 12201 (United States); Spink, David C., E-mail: spink@wadsworth.org [Wadsworth Center, New York State Department of Health, Albany, NY 12201 (United States); Department of Environmental Health Sciences, School of Public Health, University at Albany, State University of New York, Albany, NY 12201 (United States)

2015-01-01

The aryl hydrocarbon receptor (AhR) regulates expression of numerous genes, including those of the CYP1 gene family. With the goal of determining factors that control AHR gene expression, our studies are focused on the role of the short tandem repeat polymorphism, (GGGGC){sub n}, located in the proximal promoter of the human AHR gene. When luciferase constructs containing varying GGGGC repeats were transfected into cancer cell lines derived from the lung, colon, and breast, the number of GGGGC repeats affected AHR promoter activity. The number of GGGGC repeats was determined in DNA from 327 humans and from 38 samples representing 5 species of non-human primates. In chimpanzees and 3 species of macaques, only (GGGGC){sub 2} alleles were observed; however, in western gorilla, (GGGGC){sub n} alleles with n = 2, 4, 5, 6, 7, and 8 were identified. In all human populations examined, the frequency of (GGGGC){sub n} was n = 4 > 5 ≫ 2, 6. When frequencies of the (GGGGC){sub n} alleles in DNA from patients with lung, colon, or breast cancer were evaluated, the occurrence of (GGGGC){sub 2} was found to be 8-fold more frequent among lung cancer patients in comparison with its incidence in the general population, as represented by New York State neonates. Analysis of matched tumor and non-tumor DNA samples from the same individuals provided no evidence of microsatellite instability. These studies indicate that the (GGGGC){sub n} short tandem repeats are inherited, and that the (GGGGC){sub 2} allele in the AHR proximal promoter region should be further investigated with regard to its potential association with lung cancer susceptibility. - Highlights: • The AHR proximal promoter contains a polymorphism, (GGGGC){sub n}, where n = 4 > 5 ≫ 2, 6 • Matched tumor and non-tumor DNA did not show (GGGGC){sub n} microsatellite instability • AHR promoter activity of a construct with (GGGGC){sub 2} was lower than that of (GGGGC){sub 4} • The frequency of (GGGGC){sub 2} in lung

AHR-related activities in a creosote-adapted population of adult atlantic killifish, Fundulus heteroclitus, two decades post-EPA superfund status at the Atlantic Wood Site, Portsmouth, VA USA

Energy Technology Data Exchange (ETDEWEB)

Wojdylo, Josephine V. [Department of Biological Sciences, Environmental Toxicology Graduate Program, Clemson University, Clemson, SC 29634 (United States); Vogelbein, Wolfgang [The College of William & Mary, Gloucester Point, VA 23062 (United States); Bain, Lisa J. [Department of Biological Sciences, Environmental Toxicology Graduate Program, Clemson University, Clemson, SC 29634 (United States); Rice, Charles D., E-mail: cdrice@clemson.edu [Department of Biological Sciences, Environmental Toxicology Graduate Program, Clemson University, Clemson, SC 29634 (United States)

2016-08-15

state of chronic inflammation. Overall, these findings suggest that adult AW fish are responsive to AHR signaling, and do express CYP1A and AHR2 proteins in intestines at a level above what was observed in the reference population.

Effect of PCB 126 on aryl hydrocarbon receptor 1 (AHR1) and AHR1 nuclear translocator 1 (ARNT1) mRNA expression and CYP1 monooxygenase activity in chicken (Gallus domesticus) ovarian follicles.

Science.gov (United States)

Wójcik, Dagmara; Antos, Piotr A; Katarzyńska, Dorota; Hrabia, Anna; Sechman, Andrzej

2015-12-03

The aim of the experiment was to study the in vitro effect of 3,3',4,4',5-pentachlorobiphenyl (PCB 126; a coplanar PCB congener) on aryl hydrocarbon receptor (AHR1) and AHR1 nuclear translocator (ARNT1) mRNA expression and the activity of CYP1 family monooxygenases in chicken ovarian follicles. White (1-4 mm) and yellowish (4-8 mm) prehierarchical follicles as well as fragments of the theca and granulosa layers of the 3 largest preovulatory follicles (F3-F1) were incubated in a medium supplemented with 0 (control group), 1, 10 or 100 nM PCB 126. The incubation was carried out for 6 h or 24 h for determination of mRNA expression of AHR1 and ARNT1 genes (real-time qPCR) and CYP1 monooxygenase activity (EROD and MROD fluorometric assays), respectively. It was found that chicken ovarian follicles express mRNA of AHR1 and ARNT1 genes. A modulatory effect of PCB 126 on AHR1 and ARNT1 expression depended not only on the biphenyl concentration but also on the follicular layer and the maturational state of the follicle. EROD and MROD activities appeared predominantly in the granulosa layer of the yellow preovulatory follicles. PCB 126 induced these activities in a dose-dependent manner in all ovarian follicles. The obtained results suggest that ovarian follicles, especially the granulosa layer, are involved in the detoxification process of PCBs in the laying hen. Taking this finding into consideration it can be suggested that the granulosa layer of the yellow hierarchical follicles plays a key role in the protective mechanism which reduces the amount of transferred dioxin-like compounds into the yolk of the oocyte. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Curcumin and emodin down-regulate TGF-β signaling pathway in human cervical cancer cells.

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Pooja Chandrakant Thacker

Full Text Available Cervical cancer is the major cause of cancer related deaths in women, especially in developing countries and Human Papilloma Virus infection in conjunction with multiple deregulated signaling pathways leads to cervical carcinogenesis. TGF-β signaling in later stages of cancer is known to induce epithelial to mesenchymal transition promoting tumor growth. Phytochemicals, curcumin and emodin, are effective as chemopreventive and chemotherapeutic compounds against several cancers including cervical cancer. The main objective of this work was to study the effect of curcumin and emodin on TGF-β signaling pathway and its functional relevance to growth, migration and invasion in two cervical cancer cell lines, SiHa and HeLa. Since TGF-β and Wnt/β-catenin signaling pathways are known to cross talk having common downstream targets, we analyzed the effect of TGF-β on β-catenin (an important player in Wnt/β-catenin signaling and also studied whether curcumin and emodin modulate them. We observed that curcumin and emodin effectively down regulate TGF-β signaling pathway by decreasing the expression of TGF-β Receptor II, P-Smad3 and Smad4, and also counterbalance the tumorigenic effects of TGF-β by inhibiting the TGF-β-induced migration and invasion. Expression of downstream effectors of TGF-β signaling pathway, cyclinD1, p21 and Pin1, was inhibited along with the down regulation of key mesenchymal markers (Snail and Slug upon curcumin and emodin treatment. Curcumin and emodin were also found to synergistically inhibit cell population and migration in SiHa and HeLa cells. Moreover, we found that TGF-β activates Wnt/β-catenin signaling pathway in HeLa cells, and curcumin and emodin down regulate the pathway by inhibiting β-catenin. Taken together our data provide a mechanistic basis for the use of curcumin and emodin in the treatment of cervical cancer.

Insulin-like growth factor-1 suppresses the Myostatin signaling pathway during myogenic differentiation

International Nuclear Information System (INIS)

Retamales, A.; Zuloaga, R.; Valenzuela, C.A.; Gallardo-Escarate, C.; Molina, A.; Valdés, J.A.

2015-01-01

Myogenic differentiation is a complex and well-coordinated process for generating mature skeletal muscle fibers. This event is autocrine/paracrine regulated by growth factors, principally Myostatin (MSTN) and Insulin-like Growth Factor-1 (IGF-1). Myostatin, a member of the transforming growth factor-β superfamily, is a negative regulator of skeletal muscle growth in vertebrates that exerts its inhibitory function by activating Smad transcription factors. In contrast, IGF-1 promotes the differentiation of skeletal myoblasts by activating the PI3K/Akt signaling pathway. This study reports on a novel functional crosstalk between the IGF-1 and MSTN signaling pathways, as mediated through interaction between PI3K/Akt and Smad3. Stimulation of skeletal myoblasts with MSTN resulted in a transient increase in the pSmad3:Smad3 ratio and Smad-dependent transcription. Moreover, MSTN inhibited myod gene expression and myoblast fusion in an Activin receptor-like kinase/Smad3-dependent manner. Preincubation of skeletal myoblasts with IGF-1 blocked MSTN-induced Smad3 activation, promoting myod expression and myoblast differentiation. This inhibitory effect of IGF-1 on the MSTN signaling pathway was dependent on IGF-1 receptor, PI3K, and Akt activities. Finally, immunoprecipitation assay analysis determined that IGF-1 pretreatment increased Akt and Smad3 interaction. These results demonstrate that the IGF-1/PI3K/Akt pathway may inhibit MSTN signaling during myoblast differentiation, providing new insight to existing knowledge on the complex crosstalk between both growth factors. - Highlights: • IGF-1 inhibits Myostatin canonical signaling pathway through IGF-1R/PI3K/Akt pathway. • IGF-1 promotes myoblast differentiation through a direct blocking of Myostatin signaling pathway. • IGF-1 induces the interaction of Akt with Smad3 in skeletal myoblast

Insulin-like growth factor-1 suppresses the Myostatin signaling pathway during myogenic differentiation

Energy Technology Data Exchange (ETDEWEB)

Retamales, A.; Zuloaga, R.; Valenzuela, C.A. [Laboratorio de Biotecnología Molecular, Facultad de Ciencias Biológicas, Universidad Andrés Bello, Santiago (Chile); Gallardo-Escarate, C. [Laboratory of Biotechnology and Aquatic Genomics, Universidad de Concepción, Concepción (Chile); Interdisciplinary Center for Aquaculture Research (INCAR), P.O. Box 160-C, Concepción (Chile); Molina, A. [Laboratorio de Biotecnología Molecular, Facultad de Ciencias Biológicas, Universidad Andrés Bello, Santiago (Chile); Interdisciplinary Center for Aquaculture Research (INCAR), P.O. Box 160-C, Concepción (Chile); Valdés, J.A., E-mail: jvaldes@unab.cl [Laboratorio de Biotecnología Molecular, Facultad de Ciencias Biológicas, Universidad Andrés Bello, Santiago (Chile); Interdisciplinary Center for Aquaculture Research (INCAR), P.O. Box 160-C, Concepción (Chile)

2015-08-21

Myogenic differentiation is a complex and well-coordinated process for generating mature skeletal muscle fibers. This event is autocrine/paracrine regulated by growth factors, principally Myostatin (MSTN) and Insulin-like Growth Factor-1 (IGF-1). Myostatin, a member of the transforming growth factor-β superfamily, is a negative regulator of skeletal muscle growth in vertebrates that exerts its inhibitory function by activating Smad transcription factors. In contrast, IGF-1 promotes the differentiation of skeletal myoblasts by activating the PI3K/Akt signaling pathway. This study reports on a novel functional crosstalk between the IGF-1 and MSTN signaling pathways, as mediated through interaction between PI3K/Akt and Smad3. Stimulation of skeletal myoblasts with MSTN resulted in a transient increase in the pSmad3:Smad3 ratio and Smad-dependent transcription. Moreover, MSTN inhibited myod gene expression and myoblast fusion in an Activin receptor-like kinase/Smad3-dependent manner. Preincubation of skeletal myoblasts with IGF-1 blocked MSTN-induced Smad3 activation, promoting myod expression and myoblast differentiation. This inhibitory effect of IGF-1 on the MSTN signaling pathway was dependent on IGF-1 receptor, PI3K, and Akt activities. Finally, immunoprecipitation assay analysis determined that IGF-1 pretreatment increased Akt and Smad3 interaction. These results demonstrate that the IGF-1/PI3K/Akt pathway may inhibit MSTN signaling during myoblast differentiation, providing new insight to existing knowledge on the complex crosstalk between both growth factors. - Highlights: • IGF-1 inhibits Myostatin canonical signaling pathway through IGF-1R/PI3K/Akt pathway. • IGF-1 promotes myoblast differentiation through a direct blocking of Myostatin signaling pathway. • IGF-1 induces the interaction of Akt with Smad3 in skeletal myoblast.

High-frequency deregulated expression of Wnt signaling pathway members in breast carcinomas.

Science.gov (United States)

Khan, Zahid; Arafah, Maha; Shaik, Jilani Purusottapatnam; Mahale, Alka; Alanazi, Mohammad Saud

2018-01-01

Breast carcinoma is the most common malignancy and leading cause of cancer-related deaths in women worldwide including Saudi Arabia. Breast cancer in Saudi women develops at a much early age with median age of onset of 49 years compared to 62 years observed in patients from USA. Aberrations in wingless and integration site growth factor (Wnt) signaling pathway have been pathologically implicated in development of breast cancers and hence its role was examined in Saudi patients. We immunohistochemically examined various components of Wnt signaling pathway including β-catenin, tumor suppressor proteins, adenomatous polyposis coli (APC), and Axin, expression of naturally occurring pathway antagonists such as Dickkopf Wnt signaling pathway inhibitor 3 (DKK3), FRP2, and WIF1, as well as Wnt target cyclin D1 and c-Myc to establish if the pathway is constitutively activated in breast cancers arising in Saudi women. Cytoplasmic β-catenin, indicative of activation of the pathway, was observed in 24% of cases. Expression of APC and Axin, which are components of β-catenin destruction complex, was lost in 5% and 10% of tumors, respectively. Additionally, Wnt signaling inhibitors DKK3, FRP2, and Wnt inhibitory factor 1 (WIF1) were not expressed in 8%, 14%, and 5% breast tumors, respectively. Overall, accumulation of cytoplasmic β-catenin and downregulation of other Wnt pathway proteins (APC/Axin/DKK3/FRP2/WIF1) were found in approximately half of the breast cancers (47%) in our cohort. Consistent with this, analysis of Wnt target genes demonstrated moderate-to-strong expression of c-Myc in 58% and cyclin D1 in 50% of breast cancers. Deregulation of Wnt pathway was not associated with age of onset of the disease, tumor grade, and triple-negative status of breast cancers. High level of deregulated expression of Wnt pathway proteins suggests its important role in pathogenesis of breast cancers arising in Saudi women who may benefit from development of therapeutic drugs

[Review for treatment effect and signaling pathway regulation of kidney-tonifying traditional Chinese medicine on osteoporosis].

Science.gov (United States)

Xiao, Ya-Ping; Zeng, Jie; Jiao, Lin-Na; Xu, Xiao-Yu

2018-01-01

The treatment effect and signaling pathway regulation effects of kidney-tonifying traditional Chinese medicine on osteoporosis have been widely studied, but there is no systematic summary currently. This review comprehensively collected and analyzed the traditional Chinese medicines on the treatment and signaling pathway regulation of osteoporosis in recent ten years, such as Epimedii Folium, Drynariae Rhizoma, Cnidii Fructus, Eucommiae Cortex, Psoraleae Fructus and Dipsaci Radix. Based on the existing findings, the following conclusions were obtained: ①kidney-tonifying traditional Chinese medicine treated osteoporosis mainly through BMP-Smads, Wnt/ β -catenin, MAPK, PI3K/AKT signaling pathway to promote osteoblast bone formation and through OPG/RANKL/ RANK, estrogen, CTSK signaling pathway to inhibit osteoclasts of bone resorption. Epimedii Folium, Drynariae Rhizoma, Cnidii Fructus and Psoraleae Fructus up-regulated the expression of key proteins and genes of BMP-Smads and Wnt/ β -catenin signaling pathways to promote bone formation. Epimedii Folium, Drynariae Rhizoma, Cnidii Fructus, Eucommiae Cortex, Psoraleae Fructus and Dipsaci Radix inhibited the bone resorption by mediating the OPG/RANKL/RANK signaling pathway. ②Kidney-tonifying traditional Chinese medicine prevented and treated osteoporosis through a variety of ways: icariin in Epimedii Folium, naringin in Drynariae Rhizoma, osthole in Cnidii Fructus and psoralen in Psoraleae Fructus can regulate BMP-Smads, Wnt/ β -catenin signaling pathway to promote bone formation, but also activate OPG/RANKL/RANK, CTSK and other signaling pathways to inhibit bone resorption. ③The crosstalk of the signaling pathways and the animal experiments of the traditional Chinese medicine on the prevention and treatment of osteoporosis as well as their multi-target mechanism and comprehensive regulation need further clarification. Copyright© by the Chinese Pharmaceutical Association.

Tissue-specific expression of aryl hydrocarbon receptor and putative developmental regulatory modules in Baltic salmon yolk-sac fry

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Vuori, Kristiina A. [Centre of Excellence in Evolutionary Genetics and Physiology, Department of Biology, University of Turku, FI-20014 Turku (Finland)], E-mail: kristiina.vuori@utu.fi; Nordlund, Eija [Department of Information Technology, University of Turku, and Turku Centre for Computer Science (TUCS), FI-20014 Turku (Finland); Kallio, Jenny [Centre of Excellence in Evolutionary Genetics and Physiology, Department of Biology, University of Turku, FI-20014 Turku (Finland); Salakoski, Tapio [Department of Information Technology, University of Turku, and Turku Centre for Computer Science (TUCS), FI-20014 Turku (Finland); Nikinmaa, Mikko [Centre of Excellence in Evolutionary Genetics and Physiology, Department of Biology, University of Turku, FI-20014 Turku (Finland)

2008-04-08

The aryl hydrocarbon receptor (AhR) is an ancient protein that is conserved in vertebrates and invertebrates, indicating its important function throughout evolution. AhR has been studied largely because of its role in toxicology-gene expression via AhR is induced by many aromatic hydrocarbons in mammals. Recently, however, it has become clear that AhR is involved in various aspects of development such as cell proliferation and differentiation, and cell motility and migration. The mechanisms by which AhR regulates these various functions remain poorly understood. Across-species comparative studies of AhR in invertebrates, non-mammalian vertebrates and mammals may help to reveal the multiple functions of AhR. Here, we have studied AhR during larval development of Baltic salmon (Salmon salar). Our results indicate that AhR protein is expressed in nervous system, liver and muscle tissues. We also present putative regulatory modules and module-matching genes, produced by chromatin immunoprecipitation (ChIP) cloning and in silico analysis, which may be associated with evolutionarily conserved functions of AhR during development. For example, the module NFKB-AHRR-CREB found from salmon ChIP sequences is present in human ULK3 (regulating formation of granule cell axons in mouse and axon outgrowth in Caernohabditis elegans) and SRGAP1 (GTPase-activating protein involved in the Slit/Robo pathway) promoters. We suggest that AhR may have an evolutionarily conserved role in neuronal development and nerve cell targeting, and in Wnt signaling pathway.

Tissue-specific expression of aryl hydrocarbon receptor and putative developmental regulatory modules in Baltic salmon yolk-sac fry

International Nuclear Information System (INIS)

Vuori, Kristiina A.; Nordlund, Eija; Kallio, Jenny; Salakoski, Tapio; Nikinmaa, Mikko

2008-01-01

The aryl hydrocarbon receptor (AhR) is an ancient protein that is conserved in vertebrates and invertebrates, indicating its important function throughout evolution. AhR has been studied largely because of its role in toxicology-gene expression via AhR is induced by many aromatic hydrocarbons in mammals. Recently, however, it has become clear that AhR is involved in various aspects of development such as cell proliferation and differentiation, and cell motility and migration. The mechanisms by which AhR regulates these various functions remain poorly understood. Across-species comparative studies of AhR in invertebrates, non-mammalian vertebrates and mammals may help to reveal the multiple functions of AhR. Here, we have studied AhR during larval development of Baltic salmon (Salmon salar). Our results indicate that AhR protein is expressed in nervous system, liver and muscle tissues. We also present putative regulatory modules and module-matching genes, produced by chromatin immunoprecipitation (ChIP) cloning and in silico analysis, which may be associated with evolutionarily conserved functions of AhR during development. For example, the module NFKB-AHRR-CREB found from salmon ChIP sequences is present in human ULK3 (regulating formation of granule cell axons in mouse and axon outgrowth in Caernohabditis elegans) and SRGAP1 (GTPase-activating protein involved in the Slit/Robo pathway) promoters. We suggest that AhR may have an evolutionarily conserved role in neuronal development and nerve cell targeting, and in Wnt signaling pathway

Conceptual Layout of an AHR Building and Facilities

International Nuclear Information System (INIS)

Ryu, Jeong-Soo; Chae, Hee-Taek; Park, Cheol

2007-01-01

A research reactor has been widely utilized in various fields such as industry, engineering, medicine, life science, environment etc., and now application fields are gradually being expanded together with the development of technology. The utilization of research reactor is related to necessary and essential technologies of IT, NT, BT, ET and ST. KAERI has considerable experiences on research reactor technology through the TRIGA MK II, TRIGA MK III, and the HANARO. They have largely contributed to the development of nuclear technology and lead to the nuclear industry. Through the design, construction, operation and utilization of these research reactors, lots of human resources have been developed and the basic and applied technologies in nuclear research fields have been developed step by step. In particular, the HANARO (High-flux Advanced Neutron Application Reactor) of 30MWth, which began to operate from 1995, is a landmark and a nuclear milestone in Korea. The design, construction and operation of the HANARO has allowed for a large progress in the research reactor technology. The active uses of many experimental facilities in the HANARO have enhanced the advancement of nuclear technology and spread the benefits of nuclear R and D results. KAERI is preparing for another leap, i.e., incorporating the experience and nuclear technology accumulated during the design, construction, operation and utilization of the HANARO. KAERI also has human resources who have comprehensive experiences in the design, construction, commissioning, operation and utilization of a research reactor through the HANARO project. Hence, based on such considerable experience and human resource, an advanced HANARO research reactor (AHR) is being developed by KAERI for the future needs of research reactors. Its overall concept is basically similar with the HANARO, but a much improved one. The AHR will be a light water cooled and heavy water moderated and reflected pool type research reactor with

Calcium-Dependent Protein Kinases in Phytohormone Signaling Pathways

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Wuwu Xu

2017-11-01

Full Text Available Calcium-dependent protein kinases (CPKs/CDPKs are Ca2+-sensors that decode Ca2+ signals into specific physiological responses. Research has reported that CDPKs constitute a large multigene family in various plant species, and play diverse roles in plant growth, development, and stress responses. Although numerous CDPKs have been exhaustively studied, and many of them have been found to be involved in plant hormone biosynthesis and response mechanisms, a comprehensive overview of the manner in which CDPKs participate in phytohormone signaling pathways, regulating nearly all aspects of plant growth, has not yet been undertaken. In this article, we reviewed the structure of CDPKs and the mechanism of their subcellular localization. Some CDPKs were elucidated to influence the intracellular localization of their substrates. Since little work has been done on the interaction between CDPKs and cytokinin signaling pathways, or on newly defined phytohormones such as brassinosteroids, strigolactones and salicylic acid, this paper mainly focused on discussing the integral associations between CDPKs and five plant hormones: auxins, gibberellins, ethylene, jasmonates, and abscisic acid. A perspective on future work is provided at the end.

Characterization testing of a 40 AHR bipolar nickel-hydrogen battery

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Brewer, Jeffrey C.; Manzo, Michelle A.; Gemeiner, Russel P.

1989-01-01

Extensive characterization testing has been done on a second 40 amp-hour (Ahr), 10-cell bipolar nickel-hydrogen (Ni-H2) battery to study the effects of such operating parameters as charge and discharge rates, temperature, and pressure, on capacity, Ahr and watt-hour (Whr) efficiencies, end-of-charge (EOC) and mid-point discharge voltages. Testing to date has produced many interesting results, with the battery performing well throughout all of the test matrix except during the high-rate (5C and 10C) discharges, where poorer than expected results were observed. The exact cause of this poor performance is, as yet, unknown. Small scale 2 x 2 inch battery tests are to be used in studying this problem. Low earth orbit (LEO) cycle life testing at a 40 percent depth of discharge (DOD) and 10 C is scheduled to follow the characterization testing.

Dynamics and control of the ERK signaling pathway: Sensitivity, bistability, and oscillations.

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Arkun, Yaman; Yasemi, Mohammadreza

2018-01-01

Cell signaling is the process by which extracellular information is transmitted into the cell to perform useful biological functions. The ERK (extracellular-signal-regulated kinase) signaling controls several cellular processes such as cell growth, proliferation, differentiation and apoptosis. The ERK signaling pathway considered in this work starts with an extracellular stimulus and ends with activated (double phosphorylated) ERK which gets translocated into the nucleus. We model and analyze this complex pathway by decomposing it into three functional subsystems. The first subsystem spans the initial part of the pathway from the extracellular growth factor to the formation of the SOS complex, ShC-Grb2-SOS. The second subsystem includes the activation of Ras which is mediated by the SOS complex. This is followed by the MAPK subsystem (or the Raf-MEK-ERK pathway) which produces the double phosphorylated ERK upon being activated by Ras. Although separate models exist in the literature at the subsystems level, a comprehensive model for the complete system including the important regulatory feedback loops is missing. Our dynamic model combines the existing subsystem models and studies their steady-state and dynamic interactions under feedback. We establish conditions under which bistability and oscillations exist for this important pathway. In particular, we show how the negative and positive feedback loops affect the dynamic characteristics that determine the cellular outcome.

Regulation of Cell Wall Biogenesis in Saccharomyces cerevisiae: The Cell Wall Integrity Signaling Pathway

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Levin, David E.

2011-01-01

The yeast cell wall is a strong, but elastic, structure that is essential not only for the maintenance of cell shape and integrity, but also for progression through the cell cycle. During growth and morphogenesis, and in response to environmental challenges, the cell wall is remodeled in a highly regulated and polarized manner, a process that is principally under the control of the cell wall integrity (CWI) signaling pathway. This pathway transmits wall stress signals from the cell surface to the Rho1 GTPase, which mobilizes a physiologic response through a variety of effectors. Activation of CWI signaling regulates the production of various carbohydrate polymers of the cell wall, as well as their polarized delivery to the site of cell wall remodeling. This review article centers on CWI signaling in Saccharomyces cerevisiae through the cell cycle and in response to cell wall stress. The interface of this signaling pathway with other pathways that contribute to the maintenance of cell wall integrity is also discussed. PMID:22174182

Endothelial Mechanotransduction, Redox Signaling and the Regulation of Vascular Inflammatory Pathways

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Shampa Chatterjee

2018-06-01

Full Text Available The endothelium that lines the interior of blood vessels is directly exposed to blood flow. The shear stress arising from blood flow is “sensed” by the endothelium and is “transduced” into biochemical signals that eventually control vascular tone and homeostasis. Sensing and transduction of physical forces occur via signaling processes whereby the forces associated with blood flow are “sensed” by a mechanotransduction machinery comprising of several endothelial cell elements. Endothelial “sensing” involves converting the physical cues into cellular signaling events such as altered membrane potential and activation of kinases, which are “transmission” signals that cause oxidant production. Oxidants produced are the “transducers” of the mechanical signals? What is the function of these oxidants/redox signals? Extensive data from various studies indicate that redox signals initiate inflammation signaling pathways which in turn can compromise vascular health. Thus, inflammation, a major response to infection or endotoxins, can also be initiated by the endothelium in response to various flow patterns ranging from aberrant flow to alteration of flow such as cessation or sudden increase in blood flow. Indeed, our work has shown that endothelial mechanotransduction signaling pathways participate in generation of redox signals that affect the oxidant and inflammation status of cells. Our goal in this review article is to summarize the endothelial mechanotransduction pathways that are activated with stop of blood flow and with aberrant flow patterns; in doing so we focus on the complex link between mechanical forces and inflammation on the endothelium. Since this “inflammation susceptible” phenotype is emerging as a trigger for pathologies ranging from atherosclerosis to rejection post-organ transplant, an understanding of the endothelial machinery that triggers these processes is very crucial and timely.

Bipolar cell gap junctions serve major signaling pathways in the human retina.

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Kántor, Orsolya; Varga, Alexandra; Nitschke, Roland; Naumann, Angela; Énzsöly, Anna; Lukáts, Ákos; Szabó, Arnold; Németh, János; Völgyi, Béla

2017-08-01

Connexin36 (Cx36) constituent gap junctions (GJ) throughout the brain connect neurons into functional syncytia. In the retina they underlie the transmission, averaging and correlation of signals prior conveying visual information to the brain. This is the first study that describes retinal bipolar cell (BC) GJs in the human inner retina, whose function is enigmatic even in the examined animal models. Furthermore, a number of unique features (e.g. fovea, trichromacy, midget system) necessitate a reexamination of the animal model results in the human retina. Well-preserved postmortem human samples of this study are allowed to identify Cx36 expressing BCs neurochemically. Results reveal that both rod and cone pathway interneurons display strong Cx36 expression. Rod BC inputs to AII amacrine cells (AC) appear in juxtaposition to AII GJs, thus suggesting a strategic AII cell targeting by rod BCs. Cone BCs serving midget, parasol or koniocellular signaling pathways display a wealth of Cx36 expression to form homologously coupled arrays. In addition, they also establish heterologous GJ contacts to serve an exchange of information between parallel signaling streams. Interestingly, a prominent Cx36 expression was exhibited by midget system BCs that appear to maintain intimate contacts with bistratified BCs serving other pathways. These findings suggest that BC GJs in parallel signaling streams serve both an intra- and inter-pathway exchange of signals in the human retina.

Stem cell maintenance by manipulating signaling pathways: past, current and future

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Chen, Xi; Ye, Shoudong; Ying, Qi-Long

2015-01-01

Pluripotent stem cells only exist in a narrow window during early embryonic development, whereas multipotent stem cells are abundant throughout embryonic development and are retainedin various adult tissues and organs. While pluripotent stem cell lines have been established from several species, including mouse, rat, and human, it is still challenging to establish stable multipotent stem cell lines from embryonic or adult tissues. Based on current knowledge, we anticipate that by manipulating extrinsic and intrinsic signaling pathways, most if not all types of stem cells can be maintained in a long-term culture. In this article, we summarize current culture conditions established for the long-term maintenance of authentic pluripotent and multipotent stem cells and the signaling pathways involved. We also discuss the general principles of stem cell maintenance and propose several strategies on the establishment of novel stem cell lines through manipulation of signaling pathways. [BMB Reports 2015; 48(12): 668-676] PMID:26497581

Diphenylarsinic acid, a chemical warfare-related neurotoxicant, promotes liver carcinogenesis via activation of aryl hydrocarbon receptor signaling and consequent induction of oxidative DAN damage in rats

International Nuclear Information System (INIS)

Wei, Min; Yamada, Takanori; Yamano, Shotaro; Kato, Minoru; Kakehashi, Anna; Fujioka, Masaki; Tago, Yoshiyuki; Kitano, Mistuaki; Wanibuchi, Hideki

2013-01-01

Diphenylarsinic acid (DPAA), a chemical warfare-related neurotoxic organic arsenical, is present in the groundwater and soil in some regions of Japan due to illegal dumping after World War II. Inorganic arsenic is carcinogenic in humans and its organic arsenic metabolites are carcinogenic in animal studies, raising serious concerns about the carcinogenicity of DPAA. However, the carcinogenic potential of DPAA has not yet been evaluated. In the present study we found that DPAA significantly enhanced the development of diethylnitrosamine-induced preneoplastic lesions in the liver in a medium-term rat liver carcinogenesis assay. Evaluation of the expression of cytochrome P450 (CYP) enzymes in the liver revealed that DPAA induced the expression of CYP1B1, but not any other CYP1, CYP2, or CYP3 enzymes, suggesting that CYP1B1 might be the enzyme responsible for the metabolic activation of DPAA. We also found increased oxidative DNA damage, possibly due to elevated CYP1B1 expression. Induction of CYP1B1 has generally been linked with the activation of AhR, and we found that DPAA activates the aryl hydrocarbon receptor (AhR). Importantly, the promotion effect of DPAA was observed only at a dose that activated the AhR, suggesting that activation of AhR and consequent induction of AhR target genes and oxidative DNA damage plays a vital role in the promotion effects of DPAA. The present study provides, for the first time, evidence regarding the carcinogenicity of DPAA and indicates the necessity of comprehensive evaluation of its carcinogenic potential using long-term carcinogenicity studies. - Highlights: • DPAA, an environmental neurotoxicant, promotes liver carcinogenesis in rats. • DPAA is an activator of AhR signaling pathway. • DPAA promoted oxidative DNA damage in rat livers. • AhR target gene CYP 1B1 might be involved in the metabolism of DPAA

Diphenylarsinic acid, a chemical warfare-related neurotoxicant, promotes liver carcinogenesis via activation of aryl hydrocarbon receptor signaling and consequent induction of oxidative DAN damage in rats

Energy Technology Data Exchange (ETDEWEB)

Wei, Min; Yamada, Takanori; Yamano, Shotaro; Kato, Minoru; Kakehashi, Anna; Fujioka, Masaki; Tago, Yoshiyuki; Kitano, Mistuaki; Wanibuchi, Hideki, E-mail: wani@med.osaka-cu.ac.jp

2013-11-15

Diphenylarsinic acid (DPAA), a chemical warfare-related neurotoxic organic arsenical, is present in the groundwater and soil in some regions of Japan due to illegal dumping after World War II. Inorganic arsenic is carcinogenic in humans and its organic arsenic metabolites are carcinogenic in animal studies, raising serious concerns about the carcinogenicity of DPAA. However, the carcinogenic potential of DPAA has not yet been evaluated. In the present study we found that DPAA significantly enhanced the development of diethylnitrosamine-induced preneoplastic lesions in the liver in a medium-term rat liver carcinogenesis assay. Evaluation of the expression of cytochrome P450 (CYP) enzymes in the liver revealed that DPAA induced the expression of CYP1B1, but not any other CYP1, CYP2, or CYP3 enzymes, suggesting that CYP1B1 might be the enzyme responsible for the metabolic activation of DPAA. We also found increased oxidative DNA damage, possibly due to elevated CYP1B1 expression. Induction of CYP1B1 has generally been linked with the activation of AhR, and we found that DPAA activates the aryl hydrocarbon receptor (AhR). Importantly, the promotion effect of DPAA was observed only at a dose that activated the AhR, suggesting that activation of AhR and consequent induction of AhR target genes and oxidative DNA damage plays a vital role in the promotion effects of DPAA. The present study provides, for the first time, evidence regarding the carcinogenicity of DPAA and indicates the necessity of comprehensive evaluation of its carcinogenic potential using long-term carcinogenicity studies. - Highlights: • DPAA, an environmental neurotoxicant, promotes liver carcinogenesis in rats. • DPAA is an activator of AhR signaling pathway. • DPAA promoted oxidative DNA damage in rat livers. • AhR target gene CYP 1B1 might be involved in the metabolism of DPAA.

Necrotrophic pathogens use the salicylic acid signaling pathway to promote disease development in tomato.

Science.gov (United States)

Rahman, Taha Abd El; Oirdi, Mohamed El; Gonzalez-Lamothe, Rocio; Bouarab, Kamal

2012-12-01

Plants use different immune pathways to combat pathogens. The activation of the jasmonic acid (JA)-signaling pathway is required for resistance against necrotrophic pathogens; however, to combat biotrophic pathogens, the plants activate mainly the salicylic acid (SA)-signaling pathway. SA can antagonize JA signaling and vice versa. NPR1 (noninducible pathogenesis-related 1) is considered a master regulator of SA signaling. NPR1 interacts with TGA transcription factors, ultimately leading to the activation of SA-dependent responses. SA has been shown to promote disease development caused by the necrotrophic pathogen Botrytis cinerea through NPR1, by suppressing the expression of two JA-dependent defense genes, proteinase inhibitors I and II. We show here that the transcription factor TGA1.a contributes to disease development caused by B. cinerea in tomato by suppressing the expression of proteinase inhibitors I and II. Finally, we present evidence that the SA-signaling pathway contributes to disease development caused by another necrotrophic pathogen, Alternaria solani, in tomato. Disease development promoted by SA through NPR1 requires the TGA1.a transcription factor. These data highlight how necrotrophs manipulate the SAsignaling pathway to promote their disease in tomato.

DMPD: TLR signaling. [Dynamic Macrophage Pathway CSML Database

Lifescience Database Archive (English)

Full Text Available kira S. Publication Cell Death Differ. 2006 May;13(5):816-25. Pathway - PNG File (.png) SVG File (.svg) HTML File (.html...16410796 TLR signaling. Kawai T, Akira S. Cell Death Differ. 2006 May;13(5):816-25. (.png) (.svg) (.html

Downstream reporter gene imaging for signal transduction pathway of dopamine type 2 receptor

International Nuclear Information System (INIS)

Le, Uyenchi N.; Min, Jung Joon; Moon, Sung Min; Bom, Hee Seung

2004-01-01

The Dopamine 2 receptor (D2R) signal pathway regulates gene expression by phosphorylation of proteins including cAMP reponse element-binding protein (CREB), a transcription factor. In this study, we developed a reporter strategy using the GAL4 fusion CREB to assess the phosphorylation of CREB, one of the targets of the D2R signal transduction pathway. We used three plasmids: GAL4 fusion transactivator (pCMV-CREB), firefly luciferase reporter with GAL4 binding sites (pG5-FLUC), and D2R plasmid (pCMV-D2R). Group 1 293T cells were transiently transfected with pCMV-CREB and pG5-FLUC, and group 2 cells were transfected with all three plasmids. Transfected cells were stimulated with different concentrations of dopamine (0-200 M). For animal studies, group 1 and 2 cells (1x10 6 ) were subcutaneously injected on the left and right thigh of six nude mice, respectively. Dopamine stimiulation was performed with intraperitoneal injection of L-DOPA incombination with carbidopa, a peripheral DOPA decarboxylase inhibitor. Bioluminescence optical imaging studies were performed before and after L-DOPA injection. In cell culture studies, group 1 cells showed strong luciferase activity which implies direct activation of the signaling pathway due to growth factors contained in culture medium. Group 2 cells showed strong luciferase activity and a further increase after administration of dopamine. In animal studies, group 1 and 2 cells showed bioluminescence signal before L-DOPA injection, but signal from group 2 cells significantly increased 12 h after L-DOPA injection. The signal from group 1 cells disappeared thereafter, but group 2 cells continued to show signal until 36 h of L-DOPA injection. This study demonstrates imaging of the D2R signal transduction pathway and should be useful for noninvasive imaging of downstream effects of G-coupled protein pathways

Creating and analyzing pathway and protein interaction compendia for modelling signal transduction networks

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Kirouac Daniel C

2012-05-01

Full Text Available Abstract Background Understanding the information-processing capabilities of signal transduction networks, how those networks are disrupted in disease, and rationally designing therapies to manipulate diseased states require systematic and accurate reconstruction of network topology. Data on networks central to human physiology, such as the inflammatory signalling networks analyzed here, are found in a multiplicity of on-line resources of pathway and interactome databases (Cancer CellMap, GeneGo, KEGG, NCI-Pathway Interactome Database (NCI-PID, PANTHER, Reactome, I2D, and STRING. We sought to determine whether these databases contain overlapping information and whether they can be used to construct high reliability prior knowledge networks for subsequent modeling of experimental data. Results We have assembled an ensemble network from multiple on-line sources representing a significant portion of all machine-readable and reconcilable human knowledge on proteins and protein interactions involved in inflammation. This ensemble network has many features expected of complex signalling networks assembled from high-throughput data: a power law distribution of both node degree and edge annotations, and topological features of a “bow tie” architecture in which diverse pathways converge on a highly conserved set of enzymatic cascades focused around PI3K/AKT, MAPK/ERK, JAK/STAT, NFκB, and apoptotic signaling. Individual pathways exhibit “fuzzy” modularity that is statistically significant but still involving a majority of “cross-talk” interactions. However, we find that the most widely used pathway databases are highly inconsistent with respect to the actual constituents and interactions in this network. Using a set of growth factor signalling networks as examples (epidermal growth factor, transforming growth factor-beta, tumor necrosis factor, and wingless, we find a multiplicity of network topologies in which receptors couple to downstream

Halobenzoquinone-Induced Alteration of Gene Expression Associated with Oxidative Stress Signaling Pathways.

Science.gov (United States)

Li, Jinhua; Moe, Birget; Liu, Yanming; Li, Xing-Fang

2018-06-05

Halobenzoquinones (HBQs) are emerging disinfection byproducts (DBPs) that effectively induce reactive oxygen species and oxidative damage in vitro. However, the impacts of HBQs on oxidative-stress-related gene expression have not been investigated. In this study, we examined alterations in the expression of 44 genes related to oxidative-stress-induced signaling pathways in human uroepithelial cells (SV-HUC-1) upon exposure to six HBQs. The results show the structure-dependent effects of HBQs on the studied gene expression. After 2 h of exposure, the expression levels of 9 to 28 genes were altered, while after 8 h of exposure, the expression levels of 29 to 31 genes were altered. Four genes ( HMOX1, NQO1, PTGS2, and TXNRD1) were significantly upregulated by all six HBQs at both exposure time points. Ingenuity pathway analysis revealed that the Nrf2 pathway was significantly responsive to HBQ exposure. Other canonical pathways responsive to HBQ exposure included GSH redox reductions, superoxide radical degradation, and xenobiotic metabolism signaling. This study has demonstrated that HBQs significantly alter the gene expression of oxidative-stress-related signaling pathways and contributes to the understanding of HBQ-DBP-associated toxicity.

Comparison of growth factor signalling pathway utilisation in cultured normal melanocytes and melanoma cell lines

International Nuclear Information System (INIS)

Kim, Ji Eun; Stones, Clare; Joseph, Wayne R; Leung, Euphemia; Finlay, Graeme J; Shelling, Andrew N; Phillips, Wayne A; Shepherd, Peter R; Baguley, Bruce C

2012-01-01

The phosphatidylinositol-3-kinase (PI3K-PKB), mitogen activated protein kinase (MEK-ERK) and the mammalian target of rapamycin (mTOR- p70S6K), are thought to regulate many aspects of tumour cell proliferation and survival. We have examined the utilisation of these three signalling pathways in a number of cell lines derived from patients with metastatic malignant melanoma of known PIK3CA, PTEN, NRAS and BRAF mutational status. Western blotting was used to compare the phosphorylation status of components of the PI3K-PKB, MEK-ERK and mTOR-p70S6K signalling pathways, as indices of pathway utilisation. Normal melanocytes could not be distinguished from melanoma cells on the basis of pathway utilisation when grown in the presence of serum, but could be distinguished upon serum starvation, where signalling protein phosphorylation was generally abrogated. Surprisingly, the differential utilisation of individual pathways was not consistently associated with the presence of an oncogenic or tumour suppressor mutation of genes in these pathways. Utilisation of the PI3K-PKB, MEK-ERK and mTOR-p70S6K signalling pathways in melanoma, as determined by phosphorylation of signalling components, varies widely across a series of cell lines, and does not directly reflect mutation of genes coding these components. The main difference between cultured normal melanocytes and melanoma cells is not the pathway utilisation itself, but rather in the serum dependence of pathway utilisation

Interleukin 4 signals through two related pathways.

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Pernis, A; Witthuhn, B; Keegan, A D; Nelms, K; Garfein, E; Ihle, J N; Paul, W E; Pierce, J H; Rothman, P

1995-08-15

The interleukin 4 (IL-4) signaling pathway involves activation, by tyrosine phosphorylation, of two distinct substrates, a signal-transducing factor (STF-IL4) and the IL-4-induced phosphotyrosine substrate (4PS). It is not known whether the IL-4-mediated activation of these substrates occurs via related or distinct signaling pathways. We report that 32D cells, an IL-3-dependent myeloid progenitor cell line in which no phosphorylated 4PS is found, activate high levels of STF-IL4 in response to IL-4. Consistent with the known requirement for 4PS or insulin receptor substrate 1 (IRS-1) in IL-4-mediated mitogenesis, activation of STF-IL4 in 32D cells is not sufficient for IL-4-inducible c-myc expression. In addition, we have examined the ability of 32D cells transfected with different truncation mutants of the human IL-4 receptor to activate Jak-3 kinase and STF-IL4 in response to human IL-4. As in the case of 4PS/IRS-1, we have found that activation of both Jak-3 and STF-IL4 requires the presence of the IL-4 receptor region comprising aa 437-557. The finding that the same region of the IL-4 receptor is required for the induction of both 4PS/IRS-1 and STF-IL4 suggests that the IL-4-stimulated activation of these two substrates might involve common factors.

Ties that bind: the integration of plastid signalling pathways in plant cell metabolism.

Science.gov (United States)

Brunkard, Jacob O; Burch-Smith, Tessa M

2018-04-13

Plastids are critical organelles in plant cells that perform diverse functions and are central to many metabolic pathways. Beyond their major roles in primary metabolism, of which their role in photosynthesis is perhaps best known, plastids contribute to the biosynthesis of phytohormones and other secondary metabolites, store critical biomolecules, and sense a range of environmental stresses. Accordingly, plastid-derived signals coordinate a host of physiological and developmental processes, often by emitting signalling molecules that regulate the expression of nuclear genes. Several excellent recent reviews have provided broad perspectives on plastid signalling pathways. In this review, we will highlight recent advances in our understanding of chloroplast signalling pathways. Our discussion focuses on new discoveries illuminating how chloroplasts determine life and death decisions in cells and on studies elucidating tetrapyrrole biosynthesis signal transduction networks. We will also examine the role of a plastid RNA helicase, ISE2, in chloroplast signalling, and scrutinize intriguing results investigating the potential role of stromules in conducting signals from the chloroplast to other cellular locations. © 2018 The Author(s). Published by Portland Press Limited on behalf of the Biochemical Society.

AhR Activation Underlies the CYP1A Autoinduction by A-998679 in Rats

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Michael J. Liguori

2012-10-01

Full Text Available Xenobiotic-mediated induction of cytochrome P450 (CYP drug metabolizing enzymes (DMEs is frequently encountered in drug discovery and can influence disposition, pharmacokinetic, and toxicity profiles. The CYP1A subfamily of DMEs plays a central role in the biotransformation of several drugs and environmental chemicals. Autoinduction of drugs through CYP3A enzymes is a common mechanism for their enhanced clearance. However, autoinduction via CYP1A is encountered less frequently. In this report, an experimental compound, A-998679 (3-(5-pyridin-3-yl-1,2,4-oxadiazol-3-yl benzonitrile, was shown to enhance its own clearance via induction of CYP1A1 and CYP1A2. Rats were dosed for 5 days with 30, 100, and 200 mg/kg/day A-998679. During the dosing period, the compound’s plasma AUC decreased at 30 mg/kg (95% and 100 mg/kg (80%. Gene expression analysis and immunohistochemistry of the livers showed a large increase in the mRNA and protein levels of CYP1A, which was involved in the biotransformation of A-998679. Induction of CYP1A was confirmed in primary rat, human, and dog hepatocytes. The compound also weakly inhibited CYP1A2 in human liver microsomes. A-998679 activated the aryl hydrocarbon receptor (AhR in a luciferase gene reporter assay in HepG2 cells, upregulated expression of genes associated with AhR activation in rat liver, and enhanced nuclear migration of AhR in HepG2 cells. Collectively these results demonstrate that A-998679 is an AhR activator that induces CYP1A1 and CYP1A2 expression, resulting in an autoinduction phenomenon. The unique properties of A-998679, along with its novel structure distinct from classical polycyclic aromatic hydrocarbons, may warrant its further evaluation as a tool compound for use in studies involving AhR biology and CYP1A related mechanisms of drug metabolism and toxicity.

Proteomic analysis of the signaling pathway mediated by the heterotrimeric Gα protein Pga1 of Penicillium chrysogenum.

Science.gov (United States)

Carrasco-Navarro, Ulises; Vera-Estrella, Rosario; Barkla, Bronwyn J; Zúñiga-León, Eduardo; Reyes-Vivas, Horacio; Fernández, Francisco J; Fierro, Francisco

2016-10-06

The heterotrimeric Gα protein Pga1-mediated signaling pathway regulates the entire developmental program in Penicillium chrysogenum, from spore germination to the formation of conidia. In addition it participates in the regulation of penicillin biosynthesis. We aimed to advance the understanding of this key signaling pathway using a proteomics approach, a powerful tool to identify effectors participating in signal transduction pathways. Penicillium chrysogenum mutants with different levels of activity of the Pga1-mediated signaling pathway were used to perform comparative proteomic analyses by 2D-DIGE and LC-MS/MS. Thirty proteins were identified which showed differences in abundance dependent on Pga1 activity level. By modifying the intracellular levels of cAMP we could establish cAMP-dependent and cAMP-independent pathways in Pga1-mediated signaling. Pga1 was shown to regulate abundance of enzymes in primary metabolic pathways involved in ATP, NADPH and cysteine biosynthesis, compounds that are needed for high levels of penicillin production. An in vivo phosphorylated protein containing a pleckstrin homology domain was identified; this protein is a candidate for signal transduction activity. Proteins with possible roles in purine metabolism, protein folding, stress response and morphogenesis were also identified whose abundance was regulated by Pga1 signaling. Thirty proteins whose abundance was regulated by the Pga1-mediated signaling pathway were identified. These proteins are involved in primary metabolism, stress response, development and signal transduction. A model describing the pathways through which Pga1 signaling regulates different cellular processes is proposed.

CD147 regulates extrinsic apoptosis in spermatocytes by modulating NFκB signaling pathways.

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Wang, Chaoqun; Fok, Kin Lam; Cai, Zhiming; Chen, Hao; Chan, Hsiao Chang

2017-01-10

CD147 null mutant male mice are infertile with arrested spermatogenesis and increased apoptotic germ cells. Our previous studies have shown that CD147 prevents apoptosis in mouse spermatocytes but not spermatogonia. However, the underlying mechanism remains elusive. In the present study, we aim to determine the CD147-regulated apoptotic pathway in mouse spermatocytes. Our results showed that immunodepletion of CD147 triggered apoptosis through extrinsic apoptotic pathway in mouse testis and spermatocyte cell line (GC-2 cells), accompanied by activation of non-canonical NFκB signaling and suppression of canonical NFκB signaling. Furthermore, CD147 was found to interact with TRAF2, a factor known to regulate NFκB and extrinsic apoptotic signaling, and interfering CD147 led to the decrease of TRAF2. Consistently, depletion of CD147 by CRISPR/Cas9 technique in GC-2 cells down-regulated TRAF2 and resulted in cell death with suppressed canonical NFκB and activated non-canonical NFκB signaling. On the contrary, interfering of CD147 had no effect on NFκB signaling pathways as well as TRAF2 protein level in mouse spermatogonia cell line (GC-1 cells). Taken together, these results suggested that CD147 plays a key role in reducing extrinsic apoptosis in spermatocytes, but not spermatogonia, through modulating NFκB signaling pathway.

Cross-regulation of signaling pathways: An example of nuclear hormone receptors and the canonical Wnt pathway

Energy Technology Data Exchange (ETDEWEB)

Beildeck, Marcy E. [Lombardi Comprehensive Cancer Center, Georgetown University, 3970 Reservoir Road, NW, Washington, DC 20057 (United States); Gelmann, Edward P. [Columbia University, Department of Medicine, New York, NY (United States); Byers, Stephen W., E-mail: byerss@georgetown.edu [Lombardi Comprehensive Cancer Center, Georgetown University, 3970 Reservoir Road, NW, Washington, DC 20057 (United States)

2010-07-01

Predicting the potential physiological outcome(s) of any given molecular pathway is complex because of cross-talk with other pathways. This is particularly evident in the case of the nuclear hormone receptor and canonical Wnt pathways, which regulate cell growth and proliferation, differentiation, apoptosis, and metastatic potential in numerous tissues. These pathways are known to intersect at many levels: in the intracellular space, at the membrane, in the cytoplasm, and within the nucleus. The outcomes of these interactions are important in the control of stem cell differentiation and maintenance, feedback loops, and regulating oncogenic potential. The aim of this review is to demonstrate the importance of considering pathway cross-talk when predicting functional outcomes of signaling, using nuclear hormone receptor/canonical Wnt pathway cross-talk as an example.

Cross-regulation of signaling pathways: An example of nuclear hormone receptors and the canonical Wnt pathway

International Nuclear Information System (INIS)

Beildeck, Marcy E.; Gelmann, Edward P.; Byers, Stephen W.

2010-01-01

Predicting the potential physiological outcome(s) of any given molecular pathway is complex because of cross-talk with other pathways. This is particularly evident in the case of the nuclear hormone receptor and canonical Wnt pathways, which regulate cell growth and proliferation, differentiation, apoptosis, and metastatic potential in numerous tissues. These pathways are known to intersect at many levels: in the intracellular space, at the membrane, in the cytoplasm, and within the nucleus. The outcomes of these interactions are important in the control of stem cell differentiation and maintenance, feedback loops, and regulating oncogenic potential. The aim of this review is to demonstrate the importance of considering pathway cross-talk when predicting functional outcomes of signaling, using nuclear hormone receptor/canonical Wnt pathway cross-talk as an example.

Multiple intracellular signaling pathways orchestrate adipocytic differentiation of human bone marrow stromal stem cells

DEFF Research Database (Denmark)

Ayesh Hafez Ali, Dalia; Abuelreich, Sarah; Alkeraishan, Nora

2018-01-01

during adipocyte differentiation of human bone marrow stromal (mesenchymal) stem cells (hMSCs) and identified 2,589 up-regulated and 2,583 down-regulated mRNA transcripts. Pathway analysis on the up-regulated gene list untraveled enrichment in multiple signaling pathways including insulin receptor......Bone marrow adipocyte formation plays a role in bone homeostasis and whole body energy metabolism. However, the transcriptional landscape and signaling pathways associated with adipocyte lineage commitment and maturation are not fully delineated. Thus, we performed global gene expression profiling...... signaling, focal Adhesion, metapathway biotransformation, a number of metabolic pathways e.g. selenium metabolism, Benzo(a)pyrene metabolism, fatty acid, triacylglycerol, ketone body metabolism, tryptophan metabolism, and catalytic cycle of mammalian flavin-containing monooxygenase (FMOs). On the other hand...

Constraint-based modeling and kinetic analysis of the Smad dependent TGF-beta signaling pathway.

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Zhike Zi

Full Text Available BACKGROUND: Investigation of dynamics and regulation of the TGF-beta signaling pathway is central to the understanding of complex cellular processes such as growth, apoptosis, and differentiation. In this study, we aim at using systems biology approach to provide dynamic analysis on this pathway. METHODOLOGY/PRINCIPAL FINDINGS: We proposed a constraint-based modeling method to build a comprehensive mathematical model for the Smad dependent TGF-beta signaling pathway by fitting the experimental data and incorporating the qualitative constraints from the experimental analysis. The performance of the model generated by constraint-based modeling method is significantly improved compared to the model obtained by only fitting the quantitative data. The model agrees well with the experimental analysis of TGF-beta pathway, such as the time course of nuclear phosphorylated Smad, the subcellular location of Smad and signal response of Smad phosphorylation to different doses of TGF-beta. CONCLUSIONS/SIGNIFICANCE: The simulation results indicate that the signal response to TGF-beta is regulated by the balance between clathrin dependent endocytosis and non-clathrin mediated endocytosis. This model is useful to be built upon as new precise experimental data are emerging. The constraint-based modeling method can also be applied to quantitative modeling of other signaling pathways.

Signaling pathways activation profiles make better markers of cancer than expression of individual genes

OpenAIRE

Borisov, Nikolay M.; Terekhanova, Nadezhda V.; Aliper, Alexander M.; Venkova, Larisa S.; Smirnov, Philip Yu; Roumiantsev, Sergey; Korzinkin, Mikhail B.; Zhavoronkov, Alex A.; Buzdin, Anton A.

2014-01-01

Identification of reliable and accurate molecular markers remains one of the major challenges of contemporary biomedicine. We developed a new bioinformatic technique termed OncoFinder that for the first time enables to quantatively measure activation of intracellular signaling pathways basing on transcriptomic data. Signaling pathways regulate all major cellular events in health and disease. Here, we showed that the Pathway Activation Strength (PAS) value itself may serve as the biomarker for...

Sensitivity analysis of intracellular signaling pathway kinetics predicts targets for stem cell fate control.

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Alborz Mahdavi

2007-07-01

Full Text Available Directing stem cell fate requires knowledge of how signaling networks integrate temporally and spatially segregated stimuli. We developed and validated a computational model of signal transducer and activator of transcription-3 (Stat3 pathway kinetics, a signaling network involved in embryonic stem cell (ESC self-renewal. Our analysis identified novel pathway responses; for example, overexpression of the receptor glycoprotein-130 results in reduced pathway activation and increased ESC differentiation. We used a systematic in silico screen to identify novel targets and protein interactions involved in Stat3 activation. Our analysis demonstrates that signaling activation and desensitization (the inability to respond to ligand restimulation is regulated by balancing the activation state of a distributed set of parameters including nuclear export of Stat3, nuclear phosphatase activity, inhibition by suppressor of cytokine signaling, and receptor trafficking. This knowledge was used to devise a temporally modulated ligand delivery strategy that maximizes signaling activation and leads to enhanced ESC self-renewal.

C-Jun N-terminal kinase signalling pathway in response to cisplatin.

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Yan, Dong; An, GuangYu; Kuo, Macus Tien

2016-11-01

Cisplatin (cis diamminedichloroplatinum II, cDDP) is one of the most effective cancer chemotherapeutic agents and is used in the treatment of many types of human malignancies. However, inherent tumour resistance is a major barrier to effective cisplatin therapy. So far, the mechanism of cDDP resistance has not been well defined. In general, cisplatin is considered to be a cytotoxic drug, for damaging DNA and inhibiting DNA synthesis, resulting in apoptosis via the mitochondrial death pathway or plasma membrane disruption. cDDP-induced DNA damage triggers signalling pathways that will eventually decide between cell life and death. As a member of the mitogen-activated protein kinases family, c-Jun N-terminal kinase (JNK) is a signalling pathway in response to extracellular stimuli, especially drug treatment, to modify the activity of numerous proteins locating in the mitochondria or the nucleus. Recent studies suggest that JNK signalling pathway plays a major role in deciding the fate of the cell and inducing resistance to cDDP-induced apoptosis in human tumours. c-Jun N-terminal kinase regulates several important cellular functions including cell proliferation, differentiation, survival and apoptosis while activating and inhibiting substrates for phosphorylation transcription factors (c-Jun, ATF2: Activating transcription factor 2, p53 and so on), which subsequently induce pro-apoptosis and pro-survival factors expression. Therefore, it is suggested that JNK signal pathway is a double-edged sword in cDDP treatment, simultaneously being a significant pro-apoptosis factor but also being associated with increased resistance to cisplatin-based chemotherapy. This review focuses on current knowledge concerning the role of JNK in cell response to cDDP, as well as their role in cisplatin resistance. © 2016 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.

Role of endocrine disrupting chemicals on the tissue levels of AhR and sex steroid receptors in breast tumours

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Sepideh Arbabi Bidgoli

2016-09-01

Full Text Available Breast cancer affects Iranian women at least one decade younger than their counterparts in other countries and the incidence of breast fibroadenoma is growing in the last two decades in Tehran. This study aimed to compare the AhR levels in premenopausal breast cancer and breast fibroadnemo with appropriate normal groups. Possible associations of AhR with lifestyle and reproductive risk factors and other fundamental genes of breast cancer and reproductive disorders were the other major goals of present study. To conduct the comparisons all possible reproductive, environmental and lifestyle risk factors of mentioned diseases were recorded in 100 breast cancer, 100 breast fibroadenoma and compared with 400 women in normal group from 2009 to 2011. AhR overexpression in epithelial cells of premenopausal patients emphasized the susceptibility of these cells to environmental induced reproductive disorders. The AhR overexpression was contributed to ER-/PgR- immunophenotype in malignant tissues. Weight gain (after 18 and after pregnancy, long term (>5yrs OCP consumption, smoking, severe stress ,history of ovarian cysts, hormonal deregulations, living near PAHs producing sources, were correlated with increased risk of breast cancer and reproductive disorders and were correlated with elevated tissue levels of AhR. It seems that increased risk of breast cancer and other reproductive tumours in Tehran may be the result of exposure to environmental endocrine disruptors. Long term exposure to environmental estrogens can increase the tissue levels of AhR and deregulate the expression pattern of sex steroid receptors and other genes in target tissues.

Signalling pathways involved in adult heart formation revealed by gene expression profiling in Drosophila.

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Bruno Zeitouni

2007-10-01

Full Text Available Drosophila provides a powerful system for defining the complex genetic programs that drive organogenesis. Under control of the steroid hormone ecdysone, the adult heart in Drosophila forms during metamorphosis by a remodelling of the larval cardiac organ. Here, we evaluated the extent to which transcriptional signatures revealed by genomic approaches can provide new insights into the molecular pathways that underlie heart organogenesis. Whole-genome expression profiling at eight successive time-points covering adult heart formation revealed a highly dynamic temporal map of gene expression through 13 transcript clusters with distinct expression kinetics. A functional atlas of the transcriptome profile strikingly points to the genomic transcriptional response of the ecdysone cascade, and a sharp regulation of key components belonging to a few evolutionarily conserved signalling pathways. A reverse genetic analysis provided evidence that these specific signalling pathways are involved in discrete steps of adult heart formation. In particular, the Wnt signalling pathway is shown to participate in inflow tract and cardiomyocyte differentiation, while activation of the PDGF-VEGF pathway is required for cardiac valve formation. Thus, a detailed temporal map of gene expression can reveal signalling pathways responsible for specific developmental programs and provides here substantial grasp into heart formation.

Human cytomegalovirus infection dysregulates the canonical Wnt/β-catenin signaling pathway.

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Magdalena Angelova

Full Text Available Human Cytomegalovirus (HCMV is a ubiquitous herpesvirus that currently infects a large percentage of the world population. Although usually asymptomatic in healthy individuals, HCMV infection during pregnancy may cause spontaneous abortions, premature delivery, or permanent neurological disabilities in infants infected in utero. During infection, the virus exerts control over a multitude of host signaling pathways. Wnt/β-catenin signaling, an essential pathway involved in cell cycle control, differentiation, embryonic development, placentation and metastasis, is frequently dysregulated by viruses. How HCMV infection affects this critical pathway is not currently known. In this study, we demonstrate that HCMV dysregulates Wnt/β-catenin signaling in dermal fibroblasts and human placental extravillous trophoblasts. Infection inhibits Wnt-induced transcriptional activity of β-catenin and expression of β-catenin target genes in these cells. HCMV infection leads to β-catenin protein accumulation in a discrete juxtanuclear region. Levels of β-catenin in membrane-associated and cytosolic pools, as well as nuclear β-catenin, are reduced after infection; while transcription of the β-catenin gene is unchanged, suggesting enhanced degradation. Given the critical role of Wnt/β-catenin signaling in cellular processes, these findings represent a novel and important mechanism whereby HCMV disrupts normal cellular function.

Tofacitinib Represses the Janus Kinase-Signal Transducer and Activators of Transcription Signalling Pathway in Keratinocytes.

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Srivastava, Ankit; Ståhle, Mona; Pivarcsi, Andor; Sonkoly, Enikö

2018-05-08

Tofacitinib is a Janus kinase (JAK) inhibitor, which has shown efficacy in treating psoriasis. The mode of action of tofacitinib is not completely understood but it has been thought to be mediated by the inhibition of CD4+ T-cell activation. Here, we investigated whether the molecular targets of tofacitinib are expressed in keratinocytes, and whether tofacitinib can modulate the activity of the JAK/Signal Transducer and Activators of Transcription (STAT)-pathway in keratinocytes. Transcriptomic profiling of human keratinocytes treated with IL-22 in combination with tofacitinib revealed that tofacitinib could prevent the majority of IL-22-mediated gene expression changes. Pathway analysis of tofacitinib-regulated genes in keratinocytes revealed enrichment of genes involved in the JAK/STAT signalling pathway. Quantitative real-time-PCR confirmed the upregulation of S100A7 and downregulation of EGR1 expression by IL-22, which was prevented by tofacitinib pre-treatment. These results indicate a direct effect of tofacinitib on keratinocytes, which can have relevance for systemic as well as for topical treatment of psoriasis with tofacitinib.

Drosophila Nociceptive Sensitization Requires BMP Signaling via the Canonical SMAD Pathway.

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Follansbee, Taylor L; Gjelsvik, Kayla J; Brann, Courtney L; McParland, Aidan L; Longhurst, Colin A; Galko, Michael J; Ganter, Geoffrey K

2017-08-30

Nociceptive sensitization is a common feature in chronic pain, but its basic cellular mechanisms are only partially understood. The present study used the Drosophila melanogaster model system and a candidate gene approach to identify novel components required for modulation of an injury-induced nociceptive sensitization pathway presumably downstream of Hedgehog. This study demonstrates that RNAi silencing of a member of the Bone Morphogenetic Protein (BMP) signaling pathway, Decapentaplegic (Dpp), specifically in the Class IV multidendritic nociceptive neuron, significantly attenuated ultraviolet injury-induced sensitization. Furthermore, overexpression of Dpp in Class IV neurons was sufficient to induce thermal hypersensitivity in the absence of injury. The requirement of various BMP receptors and members of the SMAD signal transduction pathway in nociceptive sensitization was also demonstrated. The effects of BMP signaling were shown to be largely specific to the sensitization pathway and not associated with changes in nociception in the absence of injury or with changes in dendritic morphology. Thus, the results demonstrate that Dpp and its pathway play a crucial and novel role in nociceptive sensitization. Because the BMP family is so strongly conserved between vertebrates and invertebrates, it seems likely that the components analyzed in this study represent potential therapeutic targets for the treatment of chronic pain in humans. SIGNIFICANCE STATEMENT This report provides a genetic analysis of primary nociceptive neuron mechanisms that promote sensitization in response to injury. Drosophila melanogaster larvae whose primary nociceptive neurons were reduced in levels of specific components of the BMP signaling pathway, were injured and then tested for nocifensive responses to a normally subnoxious stimulus. Results suggest that nociceptive neurons use the BMP2/4 ligand, along with identified receptors and intracellular transducers to transition to a

Xtalk: a path-based approach for identifying crosstalk between signaling pathways

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Tegge, Allison N.; Sharp, Nicholas; Murali, T. M.

2016-01-01

Motivation: Cells communicate with their environment via signal transduction pathways. On occasion, the activation of one pathway can produce an effect downstream of another pathway, a phenomenon known as crosstalk. Existing computational methods to discover such pathway pairs rely on simple overlap statistics. Results: We present Xtalk, a path-based approach for identifying pairs of pathways that may crosstalk. Xtalk computes the statistical significance of the average length of multiple short paths that connect receptors in one pathway to the transcription factors in another. By design, Xtalk reports the precise interactions and mechanisms that support the identified crosstalk. We applied Xtalk to signaling pathways in the KEGG and NCI-PID databases. We manually curated a gold standard set of 132 crosstalking pathway pairs and a set of 140 pairs that did not crosstalk, for which Xtalk achieved an area under the receiver operator characteristic curve of 0.65, a 12% improvement over the closest competing approach. The area under the receiver operator characteristic curve varied with the pathway, suggesting that crosstalk should be evaluated on a pathway-by-pathway level. We also analyzed an extended set of 658 pathway pairs in KEGG and to a set of more than 7000 pathway pairs in NCI-PID. For the top-ranking pairs, we found substantial support in the literature (81% for KEGG and 78% for NCI-PID). We provide examples of networks computed by Xtalk that accurately recovered known mechanisms of crosstalk. Availability and implementation: The XTALK software is available at http://bioinformatics.cs.vt.edu/~murali/software. Crosstalk networks are available at http://graphspace.org/graphs?tags=2015-bioinformatics-xtalk. Contact: ategge@vt.edu, murali@cs.vt.edu Supplementary information: Supplementary data are available at Bioinformatics online. PMID:26400040

Aberrant Signaling Pathways in T-Cell Acute Lymphoblastic Leukemia

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Bongiovanni, Deborah; Saccomani, Valentina

2017-01-01

T-cell acute lymphoblastic leukemia (T-ALL) is an aggressive disease caused by the malignant transformation of immature progenitors primed towards T-cell development. Clinically, T-ALL patients present with diffuse infiltration of the bone marrow by immature T-cell blasts high blood cell counts, mediastinal involvement, and diffusion to the central nervous system. In the past decade, the genomic landscape of T-ALL has been the target of intense research. The identification of specific genomic alterations has contributed to identify strong oncogenic drivers and signaling pathways regulating leukemia growth. Notwithstanding, T-ALL patients are still treated with high-dose multiagent chemotherapy, potentially exposing these patients to considerable acute and long-term side effects. This review summarizes recent advances in our understanding of the signaling pathways relevant for the pathogenesis of T-ALL and the opportunities offered for targeted therapy. PMID:28872614

Pattern-recognition receptors: signaling pathways and dysregulation in canine chronic enteropathies-brief review.

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Heilmann, Romy M; Allenspach, Karin

2017-11-01

Pattern-recognition receptors (PRRs) are expressed by innate immune cells and recognize pathogen-associated molecular patterns (PAMPs) as well as endogenous damage-associated molecular pattern (DAMP) molecules. With a large potential for synergism or convergence between their signaling pathways, PRRs orchestrate a complex interplay of cellular mediators and transcription factors, and thus play a central role in homeostasis and host defense. Aberrant activation of PRR signaling, mutations of the receptors and/or their downstream signaling molecules, and/or DAMP/PAMP complex-mediated receptor signaling can potentially lead to chronic auto-inflammatory diseases or development of cancer. PRR signaling pathways appear to also present an interesting new avenue for the modulation of inflammatory responses and to serve as potential novel therapeutic targets. Evidence for a dysregulation of the PRR toll-like receptor (TLR)2, TLR4, TLR5, and TLR9, nucleotide-binding oligomerization domain-containing protein (NOD)2, and the receptor of advanced glycation end products (RAGE) exists in dogs with chronic enteropathies. We describe the TLR, NOD2, and RAGE signaling pathways and evaluate the current veterinary literature-in comparison to human medicine-to determine the role of TLRs, NOD2, and RAGE in canine chronic enteropathies.

The Notch Signaling Pathway Is Balancing Type 1 Innate Lymphoid Cell Immune Functions

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Thibaut Perchet

2018-06-01

Full Text Available The Notch pathway is one of the canonical signaling pathways implicated in the development of various solid tumors. During carcinogenesis, the Notch pathway dysregulation induces tumor expression of Notch receptor ligands participating to escape the immune surveillance. The Notch pathway conditions both the development and the functional regulation of lymphoid subsets. Its importance on T cell subset polarization has been documented contrary to its action on innate lymphoid cells (ILC. We aim to analyze the effect of the Notch pathway on type 1 ILC polarization and functions after disruption of the RBPJk-dependent Notch signaling cascade. Indeed, type 1 ILC comprises conventional NK (cNK cells and type 1 helper innate lymphoid cells (ILC1 that share Notch-related functional characteristics such as the IFNg secretion downstream of T-bet expression. cNK cells have strong antitumor properties. However, data are controversial concerning ILC1 functions during carcinogenesis with models showing antitumoral capacities and others reporting ILC1 inability to control tumor growth. Using various mouse models of Notch signaling pathway depletion, we analyze the effects of its absence on type 1 ILC differentiation and cytotoxic functions. We also provide clues into its role in the maintenance of immune homeostasis in tissues. We show that modulating the Notch pathway is not only acting on tumor-specific T cell activity but also on ILC immune subset functions. Hence, our study uncovers the intrinsic Notch signaling pathway in ILC1/cNK populations and their response in case of abnormal Notch ligand expression. This study help evaluating the possible side effects mediated by immune cells different from T cells, in case of multivalent forms of the Notch receptor ligand delta 1 treatments. In definitive, it should help determining the best novel combination of therapeutic strategies in case of solid tumors.

The octadecanoid signalling pathway in plants mediates a response to ultraviolet radiation

International Nuclear Information System (INIS)

Conconi, A.; Smerdon, M.J.; Howe, G.A.; Ryan, C.A.

1996-01-01

Many plant genes that respond to environmental and developmental changes are regulated by jasmonic acid, which is derived from linolenic acid via the octadecanoid pathway. Linolenic acid is an important fatty-acid constituent of membranes in most plant species and its intracellular levels increase in response to certain signals. Here we report that irradiation of tomato leaves with ultraviolet light induces the expression of several plant defensive genes that are normally activated through the octadecanoid pathway after wounding. The response to ultraviolet light is blocked by an inhibitor of the octadecanoid pathway and it does not occur in a tomato mutant defective in this pathway. The ultraviolet irradiation maximally induces the defence genes at levels where cyclobutane pyrimidine dimer formation, an indicator of DNA damage, is less than 0.2 dimers per gene. Our evidence indicates that this plant defence response to certain wavelengths of ultraviolet radiation requires the activation of the octadecanoid defence signalling pathway. (author)

An interplay between 2 signaling pathways: Melatonin-cAMP and IP3–Ca2+ signaling pathways control intraerythrocytic development of the malaria parasite Plasmodium falciparum

International Nuclear Information System (INIS)

Furuyama, Wakako; Enomoto, Masahiro; Mossaad, Ehab; Kawai, Satoru; Mikoshiba, Katsuhiko; Kawazu, Shin-ichiro

2014-01-01

Highlights: • A melatonin receptor antagonist blocked Ca 2+ oscillation in P. falciparum and inhibited parasite growth. • P. falciparum development is controlled by Ca 2+ - and cAMP-signaling pathways. • The cAMP-signaling pathway at ring form and late trophozoite stages governs parasite growth of P. falciparum. - Abstract: Plasmodium falciparum spends most of its asexual life cycle within human erythrocytes, where proliferation and maturation occur. Development into the mature forms of P. falciparum causes severe symptoms due to its distinctive sequestration capability. However, the physiological roles and the molecular mechanisms of signaling pathways that govern development are poorly understood. Our previous study showed that P. falciparum exhibits stage-specific spontaneous Calcium (Ca 2+ ) oscillations in ring and early trophozoites, and the latter was essential for parasite development. In this study, we show that luzindole (LZ), a selective melatonin receptor antagonist, inhibits parasite growth. Analyses of development and morphology of LZ-treated P. falciparum revealed that LZ severely disrupted intraerythrocytic maturation, resulting in parasite death. When LZ was added at ring stage, the parasite could not undergo further development, whereas LZ added at the trophozoite stage inhibited development from early into late schizonts. Live-cell Ca 2+ imaging showed that LZ treatment completely abolished Ca 2+ oscillation in the ring forms while having little effect on early trophozoites. Further, the melatonin-induced cAMP increase observed at ring and late trophozoite stage was attenuated by LZ treatment. These suggest that a complex interplay between IP 3 –Ca 2+ and cAMP signaling pathways is involved in intraerythrocytic development of P. falciparum

Autoimmunity and autoinflammation: A systems view on signaling pathway dysregulation profiles.

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Arsen Arakelyan

Full Text Available Autoinflammatory and autoimmune disorders are characterized by aberrant changes in innate and adaptive immunity that may lead from an initial inflammatory state to an organ specific damage. These disorders possess heterogeneity in terms of affected organs and clinical phenotypes. However, despite the differences in etiology and phenotypic variations, they share genetic associations, treatment responses and clinical manifestations. The mechanisms involved in their initiation and development remain poorly understood, however the existence of some clear similarities between autoimmune and autoinflammatory disorders indicates variable degrees of interaction between immune-related mechanisms.Our study aims at contributing to a holistic, pathway-centered view on the inflammatory condition of autoimmune and autoinflammatory diseases. We have evaluated similarities and specificities of pathway activity changes in twelve autoimmune and autoinflammatory disorders by performing meta-analysis of publicly available gene expression datasets generated from peripheral blood mononuclear cells, using a bioinformatics pipeline that integrates Self Organizing Maps and Pathway Signal Flow algorithms along with KEGG pathway topologies.The results reveal that clinically divergent disease groups share common pathway perturbation profiles. We identified pathways, similarly perturbed in all the studied diseases, such as PI3K-Akt, Toll-like receptor, and NF-kappa B signaling, that serve as integrators of signals guiding immune cell polarization, migration, growth, survival and differentiation. Further, two clusters of diseases were identified based on specifically dysregulated pathways: one gathering mostly autoimmune and the other mainly autoinflammatory diseases. Cluster separation was driven not only by apparent involvement of pathways implicated in adaptive immunity in one case, and inflammation in the other, but also by processes not explicitly related to immune

Mechanisms Underlying the Antidepressant Response of Acupuncture via PKA/CREB Signaling Pathway.

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Jiang, Huili; Zhang, Xuhui; Wang, Yu; Zhang, Huimin; Li, Jing; Yang, Xinjing; Zhao, Bingcong; Zhang, Chuntao; Yu, Miao; Xu, Mingmin; Yu, Qiuyun; Liang, Xingchen; Li, Xiang; Shi, Peng; Bao, Tuya

2017-01-01

Protein kinase A (PKA)/cAMP response element-binding (CREB) protein signaling pathway, contributing to impaired neurogenesis parallel to depressive-like behaviors, has been identified as the crucial factor involved in the antidepressant response of acupuncture. However, the molecular mechanisms associated with antidepressant response of acupuncture, neurogenesis, and depressive-like behaviors ameliorating remain unexplored. The objective was to identify the mechanisms underlying the antidepressant response of acupuncture through PKA signaling pathway in depression rats by employing the PKA signaling pathway inhibitor H89 in in vivo experiments. Our results indicated that the expression of hippocampal PKA- α and p-CREB was significantly downregulated by chronic unpredicted mild stress (CUMS) procedures. Importantly, acupuncture reversed the downregulation of PKA- α and p-CREB. The expression of PKA- α was upregulated by fluoxetine, but not p-CREB. No significant difference was found between Acu and FLX groups on the expression of PKA- α and p-CREB. Interestingly, H89 inhibited the effects of acupuncture or fluoxetine on upregulating the expression of p-CREB, but not PKA- α . There was no significant difference in expression of CREB among the groups. Conclusively, our findings further support the hypothesis that acupuncture could ameliorate depressive-like behaviors by regulating PKA/CREB signaling pathway, which might be mainly mediated by regulating the phosphorylation level of CREB.

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

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

2017-10-01

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

Concise Review: Wnt Signaling Pathways in Skin Development and Epidermal Stem Cells.

Science.gov (United States)

Veltri, Anthony; Lang, Christopher; Lien, Wen-Hui

2018-01-01

Mammalian skin and its appendages constitute the integumentary system forming a barrier between the organism and its environment. During development, skin epidermal cells divide rapidly and stratify into a multilayered epithelium, as well as invaginate downward in the underlying mesenchyme to form hair follicles (HFs). In postnatal skin, the interfollicular epidermal (IFE) cells continuously proliferate and differentiate while HFs undergo cycles of regeneration. Epidermal regeneration is fueled by epidermal stem cells (SCs) located in the basal layer of the IFE and the outer layer of the bulge in the HF. Epidermal development and SC behavior are mainly regulated by various extrinsic cues, among which Wnt-dependent signaling pathways play crucial roles. This review not only summarizes the current knowledge of Wnt signaling pathways in the regulation of skin development and governance of SCs during tissue homeostasis, but also discusses the potential crosstalk of Wnt signaling with other pathways involved in these processes. Stem Cells 2018;36:22-35. © 2017 AlphaMed Press.

Probing the canonicity of the Wnt/Wingless signaling pathway.

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Alexandra Franz

2017-04-01

Full Text Available The hallmark of canonical Wnt signaling is the transcriptional induction of Wnt target genes by the beta-catenin/TCF complex. Several studies have proposed alternative interaction partners for beta-catenin or TCF, but the relevance of potential bifurcations in the distal Wnt pathway remains unclear. Here we study on a genome-wide scale the requirement for Armadillo (Arm, Drosophila beta-catenin and Pangolin (Pan, Drosophila TCF in the Wnt/Wingless(Wg-induced transcriptional response of Drosophila Kc cells. Using somatic genetics, we demonstrate that both Arm and Pan are absolutely required for mediating activation and repression of target genes. Furthermore, by means of STARR-sequencing we identified Wnt/Wg-responsive enhancer elements and found that all responsive enhancers depend on Pan. Together, our results confirm the dogma of canonical Wnt/Wg signaling and argue against the existence of distal pathway branches in this system.

Low levels of the AhR in chronic obstructive pulmonary disease (COPD)-derived lung cells increases COX-2 protein by altering mRNA stability.

Science.gov (United States)

Zago, Michela; Sheridan, Jared A; Traboulsi, Hussein; Hecht, Emelia; Zhang, Yelu; Guerrina, Necola; Matthews, Jason; Nair, Parameswaran; Eidelman, David H; Hamid, Qutayba; Baglole, Carolyn J

2017-01-01

Heightened inflammation, including expression of COX-2, is associated with chronic obstructive pulmonary disease (COPD) pathogenesis. The aryl hydrocarbon receptor (AhR) is a ligand-activated transcription factor that is reduced in COPD-derived lung fibroblasts. The AhR also suppresses COX-2 in response to cigarette smoke, the main risk factor for COPD, by destabilizing the Cox-2 transcript by mechanisms that may involve the regulation of microRNA (miRNA). Whether reduced AhR expression is responsible for heightened COX-2 in COPD is not known. Here, we investigated the expression of COX-2 as well as the expression of miR-146a, a miRNA known to regulate COX-2 levels, in primary lung fibroblasts derived from non-smokers (Normal) and smokers (At Risk) with and without COPD. To confirm the involvement of the AhR, AhR knock-down via siRNA in Normal lung fibroblasts and MLE-12 cells was employed as were A549-AhRko cells. Basal expression of COX-2 protein was higher in COPD lung fibroblasts compared to Normal or Smoker fibroblasts but there was no difference in Cox-2 mRNA. Knockdown of AhR in lung structural cells increased COX-2 protein by stabilizing the Cox-2 transcript. There was less induction of miR-146a in COPD-derived lung fibroblasts but this was not due to the AhR. Instead, we found that RelB, an NF-κB protein, was required for transcriptional induction of both Cox-2 and miR-146a. Therefore, we conclude that the AhR controls COX-2 protein via mRNA stability by a mechanism independent of miR-146a. Low levels of the AhR may therefore contribute to the heightened inflammation common in COPD patients.

Modulation of neurotrophic signaling pathways by polyphenols

Directory of Open Access Journals (Sweden)

Moosavi F

2015-12-01

Full Text Available Fatemeh Moosavi,1,2 Razieh Hosseini,1,2 Luciano Saso,3 Omidreza Firuzi1 1Medicinal and Natural Products Chemistry Research Center, Shiraz University of Medical Sciences, Shiraz, Iran; 2Department of Pharmacology, School of Veterinary Medicine, Shiraz University, Shiraz, Iran; 3Department of Physiology and Pharmacology “Vittorio Erspamer”, Sapienza University of Rome, Rome, Italy Abstract: Polyphenols are an important class of phytochemicals, and several lines of evidence have demonstrated their beneficial effects in the context of a number of pathologies including neurodegenerative disorders such as Alzheimer’s and Parkinson’s disease. In this report, we review the studies on the effects of polyphenols on neuronal survival, growth, proliferation and differentiation, and the signaling pathways involved in these neurotrophic actions. Several polyphenols including flavonoids such as baicalein, daidzein, luteolin, and nobiletin as well as nonflavonoid polyphenols such as auraptene, carnosic acid, curcuminoids, and hydroxycinnamic acid derivatives including caffeic acid phentyl ester enhance neuronal survival and promote neurite outgrowth in vitro, a hallmark of neuronal differentiation. Assessment of underlying mechanisms, especially in PC12 neuronal-like cells, reveals that direct agonistic effect on tropomyosin receptor kinase (Trk receptors, the main receptors of neurotrophic factors including nerve growth factor (NGF and brain-derived neurotrophic factor (BDNF explains the action of few polyphenols such as 7,8-dihydroxyflavone. However, several other polyphenolic compounds activate extracellular signal-regulated kinase (ERK and phosphoinositide 3-kinase (PI3K/Akt pathways. Increased expression of neurotrophic factors in vitro and in vivo is the mechanism of neurotrophic action of flavonoids such as scutellarin, daidzein, genistein, and fisetin, while compounds like apigenin and ferulic acid increase cyclic adenosine monophosphate

Aryl hydrocarbon receptor signaling modulates antiviral immune responses: ligand metabolism rather than chemical source is the stronger predictor of outcome.

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Boule, Lisbeth A; Burke, Catherine G; Jin, Guang-Bi; Lawrence, B Paige

2018-01-29

The aryl hydrocarbon receptor (AHR) offers a compelling target to modulate the immune system. AHR agonists alter adaptive immune responses, but the consequences differ across studies. We report here the comparison of four agents representing different sources of AHR ligands in mice infected with influenza A virus (IAV): TCDD, prototype exogenous AHR agonist; PCB126, pollutant with documented human exposure; ITE, novel pharmaceutical; and FICZ, degradation product of tryptophan. All four compounds diminished virus-specific IgM levels and increased the proportion of regulatory T cells. TCDD, PCB126 and ITE, but not FICZ, reduced virus-specific IgG levels and CD8 + T cell responses. Similarly, ITE, PCB126, and TCDD reduced Th1 and Tfh cells, whereas FICZ increased their frequency. In Cyp1a1-deficient mice, all compounds, including FICZ, reduced the response to IAV. Conditional Ahr knockout mice revealed that all four compounds require AHR within hematopoietic cells. Thus, differences in the immune response to IAV likely reflect variances in quality, magnitude, and duration of AHR signaling. This indicates that binding affinity and metabolism may be stronger predictors of immune effects than a compound's source of origin, and that harnessing AHR will require finding a balance between dampening immune-mediated pathologies and maintaining sufficient host defenses against infection.

Distinct roles for aryl hydrocarbon receptor nuclear translocator and ah receptor in estrogen-mediated signaling in human cancer cell lines.

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Mark P Labrecque

Full Text Available The activated AHR/ARNT complex (AHRC regulates the expression of target genes upon exposure to environmental contaminants such as 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD. Importantly, evidence has shown that TCDD represses estrogen receptor (ER target gene activation through the AHRC. Our data indicates that AHR and ARNT act independently from each other at non-dioxin response element sites. Therefore, we sought to determine the specific functions of AHR and ARNT in estrogen-dependent signaling in human MCF7 breast cancer and human ECC-1 endometrial carcinoma cells. Knockdown of AHR with siRNA abrogates dioxin-inducible repression of estrogen-dependent gene transcription. Intriguingly, knockdown of ARNT does not effect TCDD-mediated repression of estrogen-regulated transcription, suggesting that AHR represses ER function independently of ARNT. This theory is supported by the ability of the selective AHR modulator 3',4'-dimethoxy-α-naphthoflavone (DiMNF to repress estrogen-inducible transcription. Furthermore, basal and estrogen-activated transcription of the genes encoding cathepsin-D and pS2 are down-regulated in MCF7 cells but up-regulated in ECC-1 cells in response to loss of ARNT. These responses are mirrored at the protein level with cathepsin-D. Furthermore, knock-down of ARNT led to opposite but corresponding changes in estrogen-stimulated proliferation in both MCF7 and ECC-1 cells. We have obtained experimental evidence demonstrating a dioxin-dependent repressor function for AHR and a dioxin-independent co-activator/co-repressor function for ARNT in estrogen signalling. These results provide us with further insight into the mechanisms of transcription factor crosstalk and putative therapeutic targets in estrogen-positive cancers.

Regulation of insect behavior via the insulin-signaling pathway

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Renske eErion

2013-12-01

Full Text Available The insulin/insulin-like growth factor signaling (IIS pathway is well established as a critical regulator of growth and metabolic homeostasis across the animal kingdom. Insulin-like peptides (ILPs, the functional analogs of mammalian insulin, were initially discovered in the silkmoth Bombyx mori and subsequently identified in many other insect species. Initial research focused on the role of insulin signaling in metabolism, cell proliferation, development, reproduction and aging. More recently however, increasing attention has been given to the role of insulin in the regulation of neuronal function and behavior. Here we review the role of insulin signaling in two specific insect behaviors: feeding and locomotion.

Aberrant Wnt signaling pathway in medial temporal lobe structures of Alzheimer's disease

DEFF Research Database (Denmark)

Riise, Jesper; Plath, Niels; Pakkenberg, Bente

2015-01-01

alterations of the intracellular Wnt pathway signaling components β-catenin, Gsk3β and Tcf7l1/Tcf3 and the phosphorylation state of β-catenin and Gsk3β in the hippocampus suggestive of a link between AD and aberrant canonical activity. Alterations in Gsk3β co-appeared with hippocampal kinase...... on isolated Wnt pathway components. Here, we provide the first comprehensive pathway-focused evaluation of the Wnt pathway in the entorhinal cortex and hippocampus of AD brains. Our data demonstrate altered Wnt pathway gene expression at all levels of the pathway in both medial temporal lobe regions...

Aberrant Regulation of Notch3 Signaling Pathway in Polycystic Kidney Disease.

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Idowu, Jessica; Home, Trisha; Patel, Nisha; Magenheimer, Brenda; Tran, Pamela V; Maser, Robin L; Ward, Christopher J; Calvet, James P; Wallace, Darren P; Sharma, Madhulika

2018-02-20

Polycystic kidney disease (PKD) is a genetic disorder characterized by fluid-filled cysts in the kidney and liver that ultimately leads to end-stage renal disease. Currently there is no globally approved therapy for PKD. The Notch signaling pathway regulates cellular processes such as proliferation and de-differentiation, which are cellular hallmarks of PKD. Thus we hypothesized that the Notch pathway plays a critical role in PKD. Evaluation of protein expression of Notch signaling components in kidneys of Autosomal Recessive PKD (ARPKD) and Autosomal Dominant PKD (ADPKD) mouse models and of ADPKD patients revealed that Notch pathway members, particularly Notch3, were consistently upregulated or activated in cyst-lining epithelial cells. Notch3 expression correlated with rapidly growing cysts and co-localized with the proliferation marker, PCNA. Importantly, Notch inhibition significantly decreased forskolin-induced Notch3 activation and proliferation of primary human ADPKD cells, and significantly reduced cyst formation and growth of human ADPKD cells cultured in collagen gels. Thus our data indicate that Notch3 is aberrantly activated and facilitates epithelial cell proliferation in PKD, and that inhibition of Notch signaling may prevent cyst formation and growth.

Influence of arsenate and arsenite on signal transduction pathways: an update

Energy Technology Data Exchange (ETDEWEB)

Druwe, Ingrid L.; Vaillancourt, Richard R. [The University of Arizona College of Pharmacy, Department of Pharmacology and Toxicology, Tucson, AZ (United States)

2010-08-15

Arsenic has been a recognized contaminant and toxicant, as well as a medicinal compound throughout human history. Populations throughout the world are exposed to arsenic and these exposures have been associated with a number of human cancers. Not much is known about the role of arsenic as a human carcinogen and more recently its role in non-cancerous diseases, such as cardiovascular disease, hypertension and diabetes mellitus have been uncovered. The health effects associated with arsenic are numerous and the association between arsenic exposure and human disease has intensified the search for molecular mechanisms that describe the biological activity of arsenic in humans and leads to the aforementioned disease states. Arsenic poses a human health risk due in part to the regulation of cellular signal transduction pathways and over the last few decades, some cellular mechanisms that account for arsenic toxicity, as well as, signal transduction pathways have been discovered. However, given the ubiquitous nature of arsenic in the environment, making sense of all the data remains a challenge. This review will focus on our knowledge of signal transduction pathways that are regulated by arsenic. (orig.)

Elabela-apelin receptor signaling pathway is functional in mammalian systems.

Science.gov (United States)

Wang, Zhi; Yu, Daozhan; Wang, Mengqiao; Wang, Qilong; Kouznetsova, Jennifer; Yang, Rongze; Qian, Kun; Wu, Wenjun; Shuldiner, Alan; Sztalryd, Carole; Zou, Minghui; Zheng, Wei; Gong, Da-Wei

2015-02-02

Elabela (ELA) or Toddler is a recently discovered hormone which is required for normal development of heart and vasculature through activation of apelin receptor (APJ), a G protein-coupled receptor (GPCR), in zebrafish. The present study explores whether the ELA-APJ signaling pathway is functional in the mammalian system. Using reverse-transcription PCR, we found that ELA is restrictedly expressed in human pluripotent stem cells and adult kidney whereas APJ is more widely expressed. We next studied ELA-APJ signaling pathway in reconstituted mammalian cell systems. Addition of ELA to HEK293 cells over-expressing GFP-AJP fusion protein resulted in rapid internalization of the fusion receptor. In Chinese hamster ovarian (CHO) cells over-expressing human APJ, ELA suppresses cAMP production with EC50 of 11.1 nM, stimulates ERK1/2 phosphorylation with EC50 of 14.3 nM and weakly induces intracellular calcium mobilization. Finally, we tested ELA biological function in human umbilical vascular endothelial cells and showed that ELA induces angiogenesis and relaxes mouse aortic blood vessel in a dose-dependent manner through a mechanism different from apelin. Collectively, we demonstrate that the ELA-AJP signaling pathways are functional in mammalian systems, indicating that ELA likely serves as a hormone regulating the circulation system in adulthood as well as in embryonic development.

The self-renewal signaling pathways utilized by gastric cancer stem cells.

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Fu, Ying; Li, Hui; Hao, Xishan

2017-04-01

Gastric cancer is a leading cause of cancer-related mortality worldwide. Cancer stem cells are the source of tumor recurrence and metastasis. Self-renewal is a marker of cancer stem cells and also the basis of long-lasting survival and tumor progression. Although the mechanism of gastric cancer stem cell self-renewal is not clear, there are several signaling pathways and environmental factors known to be involved. This mini review describes recent developments in the self-renewal signaling pathway of gastric cancer stem cell research. Advancements made in this field of research will likely support the development of novel therapeutic strategies for gastric cancer.

Responses of the insulin signaling pathways in the brown adipose tissue of rats following cold exposure.

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Wang, Xiaofei; Wahl, Richard

2014-01-01

The insulin signaling pathway is critical for the control of blood glucose levels. Brown adipose tissue (BAT) has also been implicated as important in glucose homeostasis. The effect of short-term cold exposure on this pathway in BAT has not been explored. We evaluated the effect of 4 hours of cold exposure on the insulin pathway in the BAT of rats. Whole genomic microarray chips were used to examine the transcripts of the pathway in BAT of rats exposed to 4°C and 22°C for 4 hours. The 4 most significantly altered pathways following 4 hours of cold exposure were the insulin signaling pathway, protein kinase A, PI3K/AKT and ERK/MAPK signaling. The insulin signaling pathway was the most affected. In the documented 142 genes of the insulin pathway, 42 transcripts (29.6%) responded significantly to this cold exposure with the least false discovery rate (Benjamini-Hochberg Multiple Testing: -log10 (p-value)  = 7.18). Twenty-seven genes (64%) were up-regulated, including the insulin receptor (Insr), insulin substrates 1 and 2 (Irs1 and Irs2). Fifteen transcripts (36%) were down-regulated. Multiple transcripts of the primary target and secondary effector targets for the insulin signaling were also up-regulated, including those for carbohydrate metabolism. Using western blotting, we demonstrated that the cold induced higher Irs2, Irs1, and Akt-p protein levels in the BAT than in the BAT of controls maintained at room temperature, and higher Akt-p protein level in the muscle. this study demonstrated that 4 hours of cold exposure stimulated the insulin signaling pathway in the BAT and muscle of overnight fasted rats. This raises the possibility that acute cold stimulation may have potential to improve glucose clearance and insulin sensitivity.

Proteomic analysis of the signaling pathway mediated by the heterotrimeric G? protein Pga1 of Penicillium chrysogenum

OpenAIRE

Carrasco-Navarro, Ulises; Vera-Estrella, Rosario; Barkla, Bronwyn J.; Z??iga-Le?n, Eduardo; Reyes-Vivas, Horacio; Fern?ndez, Francisco J.; Fierro, Francisco

2016-01-01

Background The heterotrimeric G? protein Pga1-mediated signaling pathway regulates the entire developmental program in Penicillium chrysogenum, from spore germination to the formation of conidia. In addition it participates in the regulation of penicillin biosynthesis. We aimed to advance the understanding of this key signaling pathway using a proteomics approach, a powerful tool to identify effectors participating in signal transduction pathways. Results Penicillium chrysogenum mutants with ...

AHR prevents human IL-1R1hi ILC3 differentiation to natural killer cells

Science.gov (United States)

Hughes, Tiffany; Briercheck, Edward L.; Freud, Aharon G.; Trotta, Rossana; McClory, Susan; Scoville, Steven D.; Keller, Karen; Deng, Youcai; Cole, Jordan; Harrison, Nicholas; Mao, Charlene; Zhang, Jianying; Benson, Don M.; Yu, Jianhua; Caligiuri, Michael A.

2014-01-01

SUMMARY Accumulating evidence indicates that human natural killer (NK) cells develop in secondary lymphoid tissue (SLT) through a so-called “stage 3” developmental intermediate minimally characterized by a CD34-CD117+CD94- immunophenotype that lacks mature NK cell function. This stage 3 population is heterogeneous, potentially composed of functionally distinct innate lymphoid cell (ILC) types that includes interleukin-1 receptor (IL-1R1) positive, IL-22-producing ILC3s. Whether human ILC3s are developmentally related to NK cells is a subject of ongoing investigation. Here we show that antagonism of the aryl hydrocarbon receptor (AHR) or silencing of AHR gene expression promotes differentiation of tonsillar IL-22-producing IL-1R1hi human ILC3s to CD56brightCD94+ IFN-gamma-producing cytolytic mature NK cells expressing eomesodermin (EOMES) and T-Box Protein 21 (TBX21 or TBET). Hence, AHR is a transcription factor that prevents human IL-1R1hi ILC3s from differentiating into NK cells. PMID:24953655

Obesity is mediated by differential aryl hydrocarbon receptor signaling in mice fed a Western diet.

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Kerley-Hamilton, Joanna S; Trask, Heidi W; Ridley, Christian J A; Dufour, Eric; Ringelberg, Carol S; Nurinova, Nilufer; Wong, Diandra; Moodie, Karen L; Shipman, Samantha L; Moore, Jason H; Korc, Murray; Shworak, Nicholas W; Tomlinson, Craig R

2012-09-01

Obesity is a growing worldwide problem with genetic and environmental causes, and it is an underlying basis for many diseases. Studies have shown that the toxicant-activated aryl hydrocarbon receptor (AHR) may disrupt fat metabolism and contribute to obesity. The AHR is a nuclear receptor/transcription factor that is best known for responding to environmental toxicant exposures to induce a battery of xenobiotic-metabolizing genes. The intent of the work reported here was to test more directly the role of the AHR in obesity and fat metabolism in lieu of exogenous toxicants. We used two congenic mouse models that differ at the Ahr gene and encode AHRs with a 10-fold difference in signaling activity. The two mouse strains were fed either a low-fat (regular) diet or a high-fat (Western) diet. The Western diet differentially affected body size, body fat:body mass ratios, liver size and liver metabolism, and liver mRNA and miRNA profiles. The regular diet had no significant differential effects. The results suggest that the AHR plays a large and broad role in obesity and associated complications, and importantly, may provide a simple and effective therapeutic strategy to combat obesity, heart disease, and other obesity-associated illnesses.

The ABA-INSENSITIVE-4 (ABI4) transcription factor links redox, hormone and sugar signaling pathways.

Science.gov (United States)

Foyer, Christine H; Kerchev, Pavel I; Hancock, Robert D

2012-02-01

The cellular reduction-oxidation (redox) hub processes information from metabolism and the environment and so regulates plant growth and defense through integration with the hormone signaling network. One key pathway of redox control involves interactions with ABSCISIC ACID (ABA). Accumulating evidence suggests that the ABA-INSENSITIVE-4 (ABI4) transcription factor plays a key role in transmitting information concerning the abundance of ascorbate and hence the ability of cells to buffer oxidative challenges. ABI4 is required for the ascorbate-dependent control of growth, a process that involves enhancement of salicylic acid (SA) signaling and inhibition of jasmonic acid (JA) signaling pathways. Low redox buffering capacity reinforces SA- JA- interactions through the mediation of ABA and ABI4 to fine-tune plant growth and defense in relation to metabolic cues and environmental challenges. Moreover, ABI4-mediated pathways of sugar sensitivity are also responsive to the abundance of ascorbate, providing evidence of overlap between redox and sugar signaling pathways.

Defocused low-energy shock wave activates adipose tissue-derived stem cells in vitro via multiple signaling pathways.

Science.gov (United States)

Xu, Lina; Zhao, Yong; Wang, Muwen; Song, Wei; Li, Bo; Liu, Wei; Jin, Xunbo; Zhang, Haiyang

2016-12-01

We found defocused low-energy shock wave (DLSW) could be applied in regenerative medicine by activating mesenchymal stromal cells. However, the possible signaling pathways that participated in this process remain unknown. In the present study, DLSW was applied in cultured rat adipose tissue-derived stem cells (ADSCs) to explore its effect on ADSCs and the activated signaling pathways. After treating with DLSW, the cellular morphology and cytoskeleton of ADSCs were observed. The secretions of ADSCs were detected. The expressions of ADSC surface antigens were analyzed using flow cytometry. The expressions of proliferating cell nuclear antigen and Ki67 were analyzed using western blot. The expression of CXCR2 and the migrations of ADSCs in vitro and in vivo were detected. The phosphorylation of selected signaling pathways with or without inhibitors was also detected. DLSW did not change the morphology and phenotype of ADSCs, and could promote the secretion, proliferation and migration of ADSCs. The phosphorylation levels were significantly higher in mitogen-activated protein kinases (MAPK) pathway, phosphoinositide 3-kinase (PI-3K)/AKT pathway and nuclear factor-kappa B (NF-κB) signaling pathway but not in Janus kinase/signal transducer and activator of transcription (JAK/STAT) pathway. Furthermore, ADSCs were not activated by DLSW after adding the inhibitors of these pathways simultaneously. Our results demonstrated for the first time that DLSW could activate ADSCs through MAPK, PI-3K/AKT and NF-κB signaling pathways. Combination of DLSW and agonists targeting these pathways might improve the efficacy of ADSCs in regenerative medicine in the future. Copyright © 2016 International Society for Cellular Therapy. Published by Elsevier Inc. All rights reserved.

Prevotella intermedia induces prostaglandin E2 via multiple signaling pathways.

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Guan, S-M; Fu, S-M; He, J-J; Zhang, M

2011-01-01

Prostaglandin E(2) (PGE(2)) plays important roles in the bone resorption of inflammatory diseases such as rheumatoid arthritis and periodontitis via specific prostaglandin receptors (i.e., EP1-EP4). In this study, the authors examined whether Prevotella intermedia regulates PGE(2) production and EP expression in human periodontal ligament fibroblasts (hPDLs); they also explored the potential signaling pathways involved in PGE(2) production. P. intermedia induced PGE(2) production and cyclooxygenase-2 (COX-2) expression in a dose- and time-dependent manner. Indomethacin and NS-398 completely abrogated the P. intermedia-induced PGE(2) production without modulating COX-2 expression. Specific inhibitors of extracellular signal-regulated kinase, c-Jun N-terminal kinase, p38, phosphatidylinositol 3-kinase, and protein kinase C--but not c-AMP and protein kinase A--significantly attenuated the P. intermedia-induced COX-2 and PGE(2) expression. P. intermedia reduced EP1 expression in a concentration- and time-dependent manner. The results indicate that the COX-2-dependent induction of PGE(2) by P. intermedia in hPDLs is mediated by multiple signaling pathways.

Notch pathway signaling in the skin antagonizes Merkel cell development.

Science.gov (United States)

Logan, Gregory J; Wright, Margaret C; Kubicki, Adam C; Maricich, Stephen M

2018-02-15

Merkel cells are mechanosensitive skin cells derived from the epidermal lineage whose development requires expression of the basic helix-loop-helix transcription factor Atoh1. The genes and pathways involved in regulating Merkel cell development during embryogenesis are poorly understood. Notch pathway signaling antagonizes Atoh1 expression in many developing body regions, so we hypothesized that Notch signaling might inhibit Merkel cell development. We found that conditional, constitutive overexpression of the Notch intracellular domain (NICD) in mouse epidermis significantly decreased Merkel cell numbers in whisker follicles and touch domes of hairy skin. Conversely, conditional deletion of the obligate NICD binding partner RBPj in the epidermis significantly increased Merkel cell numbers in whisker follicles, led to the development of ectopic Merkel cells outside of touch domes in hairy skin epidermis, and altered the distribution of Merkel cells in touch domes. Deletion of the downstream Notch effector gene Hes1 also significantly increased Merkel cell numbers in whisker follicles. Together, these data demonstrate that Notch signaling regulates Merkel cell production and patterning. Copyright © 2018 Elsevier Inc. All rights reserved.

Aryl hydrocarbon receptor protects lung adenocarcinoma cells against cigarette sidestream smoke particulates-induced oxidative stress

International Nuclear Information System (INIS)

Cheng, Ya-Hsin; Huang, Su-Chin; Lin, Chun-Ju; Cheng, Li-Chuan; Li, Lih-Ann

2012-01-01

Environmental cigarette smoke has been suggested to promote lung adenocarcinoma progression through aryl hydrocarbon receptor (AhR)-signaled metabolism. However, whether AhR facilitates metabolic activation or detoxification in exposed adenocarcinoma cells remains ambiguous. To address this question, we have modified the expression level of AhR in two human lung adenocarcinoma cell lines and examined their response to an extract of cigarette sidestream smoke particulates (CSSP). We found that overexpression of AhR in the CL1-5 cell line reduced CSSP-induced ROS production and oxidative DNA damage, whereas knockdown of AhR expression increased ROS level in CSSP-exposed H1355 cells. Oxidative stress sensor Nrf2 and its target gene NQO1 were insensitive to AhR expression level and CSSP treatment in human lung adenocarcinoma cells. In contrast, induction of AhR expression concurrently increased mRNA expression of xenobiotic-metabolizing genes CYP1B1, UGT1A8, and UGT1A10 in a ligand-independent manner. It appeared that AhR accelerated xenobiotic clearing and diminished associated oxidative stress by coordinate regulation of a set of phase I and II metabolizing genes. However, the AhR-signaled protection could not shield cells from constant oxidative stress. Prolonged exposure to high concentrations of CSSP induced G0/G1 cell cycle arrest via the p53–p21–Rb1 signaling pathway. Despite no effect on DNA repair rate, AhR facilitated the recovery of cells from growth arrest when CSSP exposure ended. AhR-overexpressing lung adenocarcinoma cells exhibited an increased anchorage-dependent and independent proliferation when recovery from exposure. In summary, our data demonstrated that AhR protected lung adenocarcinoma cells against CSSP-induced oxidative stress and promoted post-exposure clonogenicity. -- Highlights: ► AhR expression level influences cigarette sidestream smoke-induced ROS production. ► AhR reduces oxidative stress by coordinate regulation of

Aryl hydrocarbon receptor protects lung adenocarcinoma cells against cigarette sidestream smoke particulates-induced oxidative stress

Energy Technology Data Exchange (ETDEWEB)

Cheng, Ya-Hsin [Graduate Institute of Basic Medical Science, School of Medicine, China Medical University, Taichung 40402, Taiwan, ROC (China); Huang, Su-Chin; Lin, Chun-Ju; Cheng, Li-Chuan [Division of Environmental Health and Occupational Medicine, National Health Research Institutes, Zhunan, Miaoli 35053, Taiwan, ROC (China); Li, Lih-Ann, E-mail: lihann@nhri.org.tw [Division of Environmental Health and Occupational Medicine, National Health Research Institutes, Zhunan, Miaoli 35053, Taiwan, ROC (China)

2012-03-15

Environmental cigarette smoke has been suggested to promote lung adenocarcinoma progression through aryl hydrocarbon receptor (AhR)-signaled metabolism. However, whether AhR facilitates metabolic activation or detoxification in exposed adenocarcinoma cells remains ambiguous. To address this question, we have modified the expression level of AhR in two human lung adenocarcinoma cell lines and examined their response to an extract of cigarette sidestream smoke particulates (CSSP). We found that overexpression of AhR in the CL1-5 cell line reduced CSSP-induced ROS production and oxidative DNA damage, whereas knockdown of AhR expression increased ROS level in CSSP-exposed H1355 cells. Oxidative stress sensor Nrf2 and its target gene NQO1 were insensitive to AhR expression level and CSSP treatment in human lung adenocarcinoma cells. In contrast, induction of AhR expression concurrently increased mRNA expression of xenobiotic-metabolizing genes CYP1B1, UGT1A8, and UGT1A10 in a ligand-independent manner. It appeared that AhR accelerated xenobiotic clearing and diminished associated oxidative stress by coordinate regulation of a set of phase I and II metabolizing genes. However, the AhR-signaled protection could not shield cells from constant oxidative stress. Prolonged exposure to high concentrations of CSSP induced G0/G1 cell cycle arrest via the p53–p21–Rb1 signaling pathway. Despite no effect on DNA repair rate, AhR facilitated the recovery of cells from growth arrest when CSSP exposure ended. AhR-overexpressing lung adenocarcinoma cells exhibited an increased anchorage-dependent and independent proliferation when recovery from exposure. In summary, our data demonstrated that AhR protected lung adenocarcinoma cells against CSSP-induced oxidative stress and promoted post-exposure clonogenicity. -- Highlights: ► AhR expression level influences cigarette sidestream smoke-induced ROS production. ► AhR reduces oxidative stress by coordinate regulation of

Emerging Role and Therapeutic Implication of Wnt Signaling Pathways in Autoimmune Diseases

Science.gov (United States)

Shi, Juan; Chi, Shuhong; Xue, Jing; Yang, Jiali; Li, Feng; Liu, Xiaoming

2016-01-01

The Wnt signaling pathway plays a key role in many biological aspects, such as cellular proliferation, tissue regeneration, embryonic development, and other systemic effects. Under a physiological condition, it is tightly controlled at different layers and arrays, and a dysregulated activation of this signaling has been implicated into the pathogenesis of various human disorders, including autoimmune diseases. Despite the fact that therapeutic interventions are available for ameliorating disease manifestations, there is no curative therapy currently available for autoimmune disorders. Increasing lines of evidence have suggested a crucial role of Wnt signaling during the pathogenesis of many autoimmune diseases; in addition, some of microRNAs (miRNAs), a class of small, noncoding RNA molecules capable of transcriptionally regulating gene expression, have also recently been demonstrated to possess both physiological and pathological roles in autoimmune diseases by regulating the Wnt signaling pathway. This review summarizes currently our understanding of the pathogenic roles of Wnt signaling in several major autoimmune disorders and miRNAs, those targeting Wnt signaling in autoimmune diseases, with a focus on the implication of the Wnt signaling as potential biomarkers and therapeutic targets in immune diseases, as well as miRNA-mediated regulation of Wnt signaling activation in the development of autoimmune diseases. PMID:27110577

Emerging Role and Therapeutic Implication of Wnt Signaling Pathways in Autoimmune Diseases

Directory of Open Access Journals (Sweden)

Juan Shi

2016-01-01

Full Text Available The Wnt signaling pathway plays a key role in many biological aspects, such as cellular proliferation, tissue regeneration, embryonic development, and other systemic effects. Under a physiological condition, it is tightly controlled at different layers and arrays, and a dysregulated activation of this signaling has been implicated into the pathogenesis of various human disorders, including autoimmune diseases. Despite the fact that therapeutic interventions are available for ameliorating disease manifestations, there is no curative therapy currently available for autoimmune disorders. Increasing lines of evidence have suggested a crucial role of Wnt signaling during the pathogenesis of many autoimmune diseases; in addition, some of microRNAs (miRNAs, a class of small, noncoding RNA molecules capable of transcriptionally regulating gene expression, have also recently been demonstrated to possess both physiological and pathological roles in autoimmune diseases by regulating the Wnt signaling pathway. This review summarizes currently our understanding of the pathogenic roles of Wnt signaling in several major autoimmune disorders and miRNAs, those targeting Wnt signaling in autoimmune diseases, with a focus on the implication of the Wnt signaling as potential biomarkers and therapeutic targets in immune diseases, as well as miRNA-mediated regulation of Wnt signaling activation in the development of autoimmune diseases.

Aryl hydrocarbon receptor (AhR agonists suppress interleukin-6 expression by bone marrow stromal cells: an immunotoxicology study

Directory of Open Access Journals (Sweden)

Schlezinger Jennifer J

2003-12-01

Full Text Available Abstract Background Bone marrow stromal cells produce cytokines required for the normal growth and development of all eight hematopoietic cell lineages. Aberrant cytokine production by stromal cells contributes to blood cell dyscrasias. Consequently, factors that alter stromal cell cytokine production may significantly compromise the development of normal blood cells. We have shown that environmental chemicals, such as aromatic hydrocarbon receptor (AhR agonists, suppress B lymphopoiesis by modulating bone marrow stromal cell function. Here, we extend these studies to evaluate the potential for two prototypic AhR agonists, 7,12-dimethylbenz [a]anthracene (DMBA and 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD, to alter stromal cell cytokine responses. Methods Bone marrow stromal cells were treated with AhR agonists and bacterial lipopolysaccharide (LPS to mimic innate inflammatory cytokine responses and to study the effects of AhR ligands on those responses. Steady state cytokine RNA levels were screened by RNAse protection assays (RPA and quantified by real-time PCR. Cytokine (IL-6 protein production was measured by ELISA. NF-κB EMSAs were used to study IL-6 transcriptional regulation. Results RPAs indicated that AhR+ bone marrow stromal cells consistently up-regulated genes encoding IL-6 and LIF in response to LPS, presumably through activation of Toll-like receptor 4. Pre-treatment with low doses of DMBA or TCDD selectively abrogated IL-6 gene induction but had no effect on LIF mRNA. Real-time-PCR indicated a significant inhibition of IL-6 mRNA by AhR ligands within 1 hour of LPS challenge which was reflected in a profound down-regulation of IL-6 protein induction, with DMBA and TCDD suppressing IL-6 levels as much as 65% and 88%, respectively. This potent inhibitory effect persisted for at least 72 hours. EMSAs measuring NF-κB binding to IL-6 promoter sequences, an event known to induce IL-6 transcription, indicated a significant decrease in

Correlated cone noise decreases rod signal contributions to the post-receptoral pathways.

Science.gov (United States)

Hathibelagal, Amithavikram R; Feigl, Beatrix; Zele, Andrew J

2018-04-01

This study investigated how invisible extrinsic temporal white noise that correlates with the activity of one of the three [magnocellular (MC), parvocellular (PC), or koniocellular (KC)] post-receptoral pathways alters mesopic rod signaling. A four-primary photostimulator provided independent control of the rod and three cone photoreceptor excitations. The rod contributions to the three post-receptoral pathways were estimated by perceptually matching a 20% contrast rod pulse by independently varying the LMS (MC pathway), +L-M (PC pathway), and S-cone (KC pathway) excitations. We show that extrinsic cone noise caused a predominant decrease in the overall magnitude and ratio of the rod contributions to each pathway. Thus, the relative cone activity in the post-receptoral pathways determines the relative mesopic rod inputs to each pathway.

Homocysteine enhances MMP-9 production in murine macrophages via ERK and Akt signaling pathways

International Nuclear Information System (INIS)

Lee, Seung Jin; Lee, Yi Sle; Seo, Kyo Won; Bae, Jin Ung; Kim, Gyu Hee; Park, So Youn; Kim, Chi Dae

2012-01-01

Homocysteine (Hcy) at elevated levels is an independent risk factor of cardiovascular diseases, including atherosclerosis. In the present study, we investigated the effect of Hcy on the production of matrix metalloproteinases (MMP) in murine macrophages. Among the MMP known to regulate the activities of collagenase and gelatinase, Hcy exclusively increased the gelatinolytic activity of MMP-9 in J774A.1 cells as well as in mouse peritoneal macrophages. Furthermore, this activity was found to be correlated with Western blot findings in J774A.1 cells, which showed that MMP-9 expression was concentration- and time-dependently increased by Hcy. Inhibition of the ERK and Akt pathways led to a significant decrease in Hcy-induced MMP-9 expression, and combined treatment with inhibitors of the ERK and Akt pathways showed an additive effects. Activity assays for ERK and Akt showed that Hcy increased the phosphorylation of both, but these phosphorylation were not affected by inhibitors of the Akt and ERK pathways. In line with these findings, the molecular inhibition of ERK and Akt using siRNA did not affect the Hcy-induced phosphorylation of Akt and ERK, respectively. Taken together, these findings suggest that Hcy enhances MMP-9 production in murine macrophages by separately activating the ERK and Akt signaling pathways. -- Highlights: ► Homocysteine (Hcy) induced MMP-9 production in murine macrophages. ► Hcy induced MMP-9 production through ERK and Akt signaling pathways. ► ERK and Akt signaling pathways were activated by Hcy in murine macrophages. ► ERK and Akt pathways were additively act on Hcy-induced MMP-9 production. ► Hcy enhances MMP-9 production in macrophages via activation of ERK and Akt signaling pathways in an independent manner.

Homocysteine enhances MMP-9 production in murine macrophages via ERK and Akt signaling pathways

Energy Technology Data Exchange (ETDEWEB)

Lee, Seung Jin; Lee, Yi Sle; Seo, Kyo Won; Bae, Jin Ung; Kim, Gyu Hee; Park, So Youn; Kim, Chi Dae, E-mail: chidkim@pusan.ac.kr

2012-04-01

Homocysteine (Hcy) at elevated levels is an independent risk factor of cardiovascular diseases, including atherosclerosis. In the present study, we investigated the effect of Hcy on the production of matrix metalloproteinases (MMP) in murine macrophages. Among the MMP known to regulate the activities of collagenase and gelatinase, Hcy exclusively increased the gelatinolytic activity of MMP-9 in J774A.1 cells as well as in mouse peritoneal macrophages. Furthermore, this activity was found to be correlated with Western blot findings in J774A.1 cells, which showed that MMP-9 expression was concentration- and time-dependently increased by Hcy. Inhibition of the ERK and Akt pathways led to a significant decrease in Hcy-induced MMP-9 expression, and combined treatment with inhibitors of the ERK and Akt pathways showed an additive effects. Activity assays for ERK and Akt showed that Hcy increased the phosphorylation of both, but these phosphorylation were not affected by inhibitors of the Akt and ERK pathways. In line with these findings, the molecular inhibition of ERK and Akt using siRNA did not affect the Hcy-induced phosphorylation of Akt and ERK, respectively. Taken together, these findings suggest that Hcy enhances MMP-9 production in murine macrophages by separately activating the ERK and Akt signaling pathways. -- Highlights: ► Homocysteine (Hcy) induced MMP-9 production in murine macrophages. ► Hcy induced MMP-9 production through ERK and Akt signaling pathways. ► ERK and Akt signaling pathways were activated by Hcy in murine macrophages. ► ERK and Akt pathways were additively act on Hcy-induced MMP-9 production. ► Hcy enhances MMP-9 production in macrophages via activation of ERK and Akt signaling pathways in an independent manner.

Phosphoproteomic Analysis Identifies Signaling Pathways Regulated by Curcumin in Human Colon Cancer Cells.

Science.gov (United States)

Sato, Tatsuhiro; Higuchi, Yutaka; Shibagaki, Yoshio; Hattori, Seisuke

2017-09-01

Curcumin, a major polyphenol of the spice turmeric, acts as a potent chemopreventive and chemotherapeutic agent in several cancer types, including colon cancer. Although various proteins have been shown to be affected by curcumin, how curcumin exerts its anticancer activity is not fully understood. Phosphoproteomic analyses were performed using SW480 and SW620 human colon cancer cells to identify curcumin-affected signaling pathways. Curcumin inhibited the growth of the two cell lines in a dose-dependent manner. Thirty-nine curcumin-regulated phosphoproteins were identified, five of which are involved in cancer signaling pathways. Detailed analyses revealed that the mTORC1 and p53 signaling pathways are main targets of curcumin. Our results provide insight into the molecular mechanisms of the anticancer activities of curcumin and future molecular targets for its clinical application. Copyright© 2017, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

IDO chronic immune activation and tryptophan metabolic pathway: A potential pathophysiological link between depression and obesity.

Science.gov (United States)

Chaves Filho, Adriano José Maia; Lima, Camila Nayane Carvalho; Vasconcelos, Silvânia Maria Mendes; de Lucena, David Freitas; Maes, Michael; Macedo, Danielle

2018-01-03

Obesity and depression are among the most pressing health problems in the contemporary world. Obesity and depression share a bidirectional relationship, whereby each condition increases the risk of the other. By inference, shared pathways may underpin the comorbidity between obesity and depression. Activation of cell-mediated immunity (CMI) is a key factor in the pathophysiology of depression. CMI cytokines, including IFN-γ, TNFα and IL-1β, induce the catabolism of tryptophan (TRY) by stimulating indoleamine 2,3-dioxygenase (IDO) resulting in the synthesis of kynurenine (KYN) and other tryptophan catabolites (TRYCATs). In the CNS, TRYCATs have been related to oxidative damage, inflammation, mitochondrial dysfunction, cytotoxicity, excitotoxicity, neurotoxicity and lowered neuroplasticity. The pathophysiology of obesity is also associated with a state of aberrant inflammation that activates aryl hydrocarbon receptor (AHR), a pathway involved in the detection of intracellular or environmental changes as well as with increases in the production of TRYCATs, being KYN an agonists of AHR. Both AHR and TRYCATS are involved in obesity and related metabolic disorders. These changes in the TRYCAT pathway may contribute to the onset of neuropsychiatric symptoms in obesity. This paper reviews the role of immune activation, IDO stimulation and increased TRYCAT production in the pathophysiology of depression and obesity. Here we suggest that increased synthesis of detrimental TRYCATs is implicated in comorbid obesity and depression and is a new drug target to treat both diseases. Copyright © 2017 Elsevier Inc. All rights reserved.

Signaling Pathways Involved in Lunar Dust Induced Cytotoxicity

Science.gov (United States)

Zhang, Ye; Lam, Chiu-Wing; Scully, Robert R.; Williams, Kyle; Zalesak, Selina; Wu, Honglu; James, John T.

2014-01-01

The Moon's surface is covered by a layer of fine, reactive dust. Lunar dust contain about 1-2% of very fine dust (pathways involved in lunar dust-induced toxicity. F344 rats were exposed for 4 weeks (6h/d; 5d/wk) in nose-only inhalation chambers to concentrations of 0 (control air), 2.1, 6.1, 21, and 61 mg/m(exp 3) of lunar dust. Five rats per group were euthanized 1 day, 1 week, 1 month, and 3 months after the last inhalation exposure. The total RNAs were isolated from the blood or lung tissue after being lavaged, using the Qigen RNeasy kit. The Rat Fibrosis RT2 Profile PCR Array was used to profile the expression of 84 genes relevant to fibrosis. The genes with significant expression changes are identified and the gene expression data were further analyzed using IPA pathway analysis tool to determine the signaling pathways with significant changes.

EG-1 interacts with c-Src and activates its signaling pathway.

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Lu, Ming; Zhang, Liping; Sartippour, Maryam R; Norris, Andrew J; Brooks, Mai N

2006-10-01

EG-1 is significantly elevated in breast, colorectal, and prostate cancers. Overexpression of EG-1 stimulates cellular proliferation, and targeted inhibition blocks mouse xenograft tumor growth. To further clarify the function of EG-1, we investigated its role in c-Src activation. We observed that EG-1 overexpression results in activation of c-Src, but found no evidence that EG-1 is a direct Src substrate. EG-1 also binds to other members of the Src family. Furthermore, EG-1 shows interaction with multiple other SH3- and WW-containing molecules involved in various signaling pathways. These observations suggest that EG-1 may be involved in signaling pathways including c-Src activation.

Encoding of temporal signals by the TGF-β pathway and implications for embryonic patterning

Science.gov (United States)

Sorre, Benoit; Warmflash, Aryeh; Brivanlou, Ali H.; Siggia, Eric D.

2014-01-01

Summary Genetics and biochemistry have defined the components and wiring of the signaling pathways that pattern the embryo. Among them, the TGF-β pathway has the potential to behave as a morphogen: invitro experiments have clearly established that it can dictate cell fate in a concentration dependent manner. How morphogens convey positional information in a developing embryo, where signal levels are changing with time, is less understood. Using integrated microfluidic cell culture and time-lapse microscopy, we demonstrate here that the speed of ligand presentation has a key and previously unexpected influence on TGF-β signaling outcomes. The response to a TGF-β concentration step is transient and adaptive, slowly increasing the ligand concentration diminishes the response and well-spaced pulses of ligand combine additively resulting in greater pathway output than with constant stimulation. Our results suggest that in an embryonic context, the speed of change of ligand concentration is an instructive signal for patterning. PMID:25065773

Does a Common Pathway Transduce Symbiotic Signals in Plant-Microbe Interactions?

Science.gov (United States)

Genre, Andrea; Russo, Giulia

2016-01-01

Recent years have witnessed major advances in our knowledge of plant mutualistic symbioses such as the rhizobium-legume symbiosis (RLS) and arbuscular mycorrhizas (AM). Some of these findings caused the revision of longstanding hypotheses, but one of the most solid theories is that a conserved set of plant proteins rules the transduction of symbiotic signals from beneficial glomeromycetes and rhizobia in a so-called common symbiotic pathway (CSP). Nevertheless, the picture still misses several elements, and a few crucial points remain unclear. How does one common pathway discriminate between - at least - two symbionts? Can we exclude that microbes other than AM fungi and rhizobia also use this pathway to communicate with their host plants? We here discuss the possibility that our current view is biased by a long-lasting focus on legumes, whose ability to develop both AM and RLS is an exception among plants and a recent innovation in their evolution; investigations in non-legumes are starting to place legume symbiotic signaling in a broader perspective. Furthermore, recent studies suggest that CSP proteins act in a wider scenario of symbiotic and non-symbiotic signaling. Overall, evidence is accumulating in favor of distinct activities for CSP proteins in AM and RLS, depending on the molecular and cellular context where they act.

Nuclear Receptor Signaling Atlas: Opening Access to the Biology of Nuclear Receptor Signaling Pathways.

Science.gov (United States)

Becnel, Lauren B; Darlington, Yolanda F; Ochsner, Scott A; Easton-Marks, Jeremy R; Watkins, Christopher M; McOwiti, Apollo; Kankanamge, Wasula H; Wise, Michael W; DeHart, Michael; Margolis, Ronald N; McKenna, Neil J

2015-01-01

Signaling pathways involving nuclear receptors (NRs), their ligands and coregulators, regulate tissue-specific transcriptomes in diverse processes, including development, metabolism, reproduction, the immune response and neuronal function, as well as in their associated pathologies. The Nuclear Receptor Signaling Atlas (NURSA) is a Consortium focused around a Hub website (www.nursa.org) that annotates and integrates diverse 'omics datasets originating from the published literature and NURSA-funded Data Source Projects (NDSPs). These datasets are then exposed to the scientific community on an Open Access basis through user-friendly data browsing and search interfaces. Here, we describe the redesign of the Hub, version 3.0, to deploy "Web 2.0" technologies and add richer, more diverse content. The Molecule Pages, which aggregate information relevant to NR signaling pathways from myriad external databases, have been enhanced to include resources for basic scientists, such as post-translational modification sites and targeting miRNAs, and for clinicians, such as clinical trials. A portal to NURSA's Open Access, PubMed-indexed journal Nuclear Receptor Signaling has been added to facilitate manuscript submissions. Datasets and information on reagents generated by NDSPs are available, as is information concerning periodic new NDSP funding solicitations. Finally, the new website integrates the Transcriptomine analysis tool, which allows for mining of millions of richly annotated public transcriptomic data points in the field, providing an environment for dataset re-use and citation, bench data validation and hypothesis generation. We anticipate that this new release of the NURSA database will have tangible, long term benefits for both basic and clinical research in this field.

Nuclear Receptor Signaling Atlas: Opening Access to the Biology of Nuclear Receptor Signaling Pathways.

Directory of Open Access Journals (Sweden)

Lauren B Becnel

Full Text Available Signaling pathways involving nuclear receptors (NRs, their ligands and coregulators, regulate tissue-specific transcriptomes in diverse processes, including development, metabolism, reproduction, the immune response and neuronal function, as well as in their associated pathologies. The Nuclear Receptor Signaling Atlas (NURSA is a Consortium focused around a Hub website (www.nursa.org that annotates and integrates diverse 'omics datasets originating from the published literature and NURSA-funded Data Source Projects (NDSPs. These datasets are then exposed to the scientific community on an Open Access basis through user-friendly data browsing and search interfaces. Here, we describe the redesign of the Hub, version 3.0, to deploy "Web 2.0" technologies and add richer, more diverse content. The Molecule Pages, which aggregate information relevant to NR signaling pathways from myriad external databases, have been enhanced to include resources for basic scientists, such as post-translational modification sites and targeting miRNAs, and for clinicians, such as clinical trials. A portal to NURSA's Open Access, PubMed-indexed journal Nuclear Receptor Signaling has been added to facilitate manuscript submissions. Datasets and information on reagents generated by NDSPs are available, as is information concerning periodic new NDSP funding solicitations. Finally, the new website integrates the Transcriptomine analysis tool, which allows for mining of millions of richly annotated public transcriptomic data points in the field, providing an environment for dataset re-use and citation, bench data validation and hypothesis generation. We anticipate that this new release of the NURSA database will have tangible, long term benefits for both basic and clinical research in this field.

Toward Understanding the Role of Aryl Hydrocarbon Receptor in the Immune System: Current Progress and Future Trends

Directory of Open Access Journals (Sweden)

Hamza Hanieh

2014-01-01

Full Text Available The immune system is regulated by distinct signaling pathways that control the development and function of the immune cells. Accumulating evidence suggest that ligation of aryl hydrocarbon receptor (Ahr, an environmentally responsive transcription factor, results in multiple cross talks that are capable of modulating these pathways and their downstream responsive genes. Most of the immune cells respond to such modulation, and many inflammatory response-related genes contain multiple xenobiotic-responsive elements (XREs boxes upstream. Active research efforts have investigated the physiological role of Ahr in inflammation and autoimmunity using different animal models. Recently formed paradigm has shown that activation of Ahr by 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD or 3,3′-diindolylmethane (DIM prompts the differentiation of CD4+Foxp3+ regulatory T cells (Tregs and inhibits T helper (Th-17 suggesting that Ahr is an innovative therapeutic strategy for autoimmune inflammation. These promising findings generate a basis for future clinical practices in humans. This review addresses the current knowledge on the role of Ahr in different immune cell compartments, with a particular focus on inflammation and autoimmunity.

Characterization of Heregulin-Stimulated Signal Transduction Pathways to the Nucleus

National Research Council Canada - National Science Library

Wilson, Kristin

2000-01-01

... 40% of breast cancers and correlates with a poor prognosis for women with breast cancer. Mapping the molecular determinants of the heregulin/ErbB2 signaling pathway will be important in determining viable cellular targets for therapeutic intervention...

An interplay between 2 signaling pathways: Melatonin-cAMP and IP{sub 3}–Ca{sup 2+} signaling pathways control intraerythrocytic development of the malaria parasite Plasmodium falciparum

Energy Technology Data Exchange (ETDEWEB)

Furuyama, Wakako [National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido 080-8555 (Japan); Enomoto, Masahiro [Princess Margaret Cancer Centre, Department of Medical Biophysics, University of Toronto, M5G1L7 Toronto, Ontario (Canada); Mossaad, Ehab [National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido 080-8555 (Japan); Kawai, Satoru [Laboratory of Tropical Medicine and Parasitology, Dokkyo Medical University, Mibu, Tochigi 321-0293 (Japan); Mikoshiba, Katsuhiko [Laboratory for Developmental Neurobiology, RIKEN Brain Science Institute, Wako, Saitama 351-0198 (Japan); Kawazu, Shin-ichiro, E-mail: skawazu@obihiro.ac.jp [National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido 080-8555 (Japan)

2014-03-28

Highlights: • A melatonin receptor antagonist blocked Ca{sup 2+} oscillation in P. falciparum and inhibited parasite growth. • P. falciparum development is controlled by Ca{sup 2+}- and cAMP-signaling pathways. • The cAMP-signaling pathway at ring form and late trophozoite stages governs parasite growth of P. falciparum. - Abstract: Plasmodium falciparum spends most of its asexual life cycle within human erythrocytes, where proliferation and maturation occur. Development into the mature forms of P. falciparum causes severe symptoms due to its distinctive sequestration capability. However, the physiological roles and the molecular mechanisms of signaling pathways that govern development are poorly understood. Our previous study showed that P. falciparum exhibits stage-specific spontaneous Calcium (Ca{sup 2+}) oscillations in ring and early trophozoites, and the latter was essential for parasite development. In this study, we show that luzindole (LZ), a selective melatonin receptor antagonist, inhibits parasite growth. Analyses of development and morphology of LZ-treated P. falciparum revealed that LZ severely disrupted intraerythrocytic maturation, resulting in parasite death. When LZ was added at ring stage, the parasite could not undergo further development, whereas LZ added at the trophozoite stage inhibited development from early into late schizonts. Live-cell Ca{sup 2+} imaging showed that LZ treatment completely abolished Ca{sup 2+} oscillation in the ring forms while having little effect on early trophozoites. Further, the melatonin-induced cAMP increase observed at ring and late trophozoite stage was attenuated by LZ treatment. These suggest that a complex interplay between IP{sub 3}–Ca{sup 2+} and cAMP signaling pathways is involved in intraerythrocytic development of P. falciparum.

Signal Transduction Pathways of TNAP: Molecular Network Analyses.

Science.gov (United States)

Négyessy, László; Györffy, Balázs; Hanics, János; Bányai, Mihály; Fonta, Caroline; Bazsó, Fülöp

2015-01-01

Despite the growing body of evidence pointing on the involvement of tissue non-specific alkaline phosphatase (TNAP) in brain function and diseases like epilepsy and Alzheimer's disease, our understanding about the role of TNAP in the regulation of neurotransmission is severely limited. The aim of our study was to integrate the fragmented knowledge into a comprehensive view regarding neuronal functions of TNAP using objective tools. As a model we used the signal transduction molecular network of a pyramidal neuron after complementing with TNAP related data and performed the analysis using graph theoretic tools. The analyses show that TNAP is in the crossroad of numerous pathways and therefore is one of the key players of the neuronal signal transduction network. Through many of its connections, most notably with molecules of the purinergic system, TNAP serves as a controller by funnelling signal flow towards a subset of molecules. TNAP also appears as the source of signal to be spread via interactions with molecules involved among others in neurodegeneration. Cluster analyses identified TNAP as part of the second messenger signalling cascade. However, TNAP also forms connections with other functional groups involved in neuronal signal transduction. The results indicate the distinct ways of involvement of TNAP in multiple neuronal functions and diseases.

Pentagone internalises glypicans to fine-tune multiple signalling pathways

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Norman, Mark; Vuilleumier, Robin; Springhorn, Alexander; Gawlik, Jennifer; Pyrowolakis, George

2016-01-01

Tight regulation of signalling activity is crucial for proper tissue patterning and growth. Here we investigate the function of Pentagone (Pent), a secreted protein that acts in a regulatory feedback during establishment and maintenance of BMP/Dpp morphogen signalling during Drosophila wing development. We show that Pent internalises the Dpp co-receptors, the glypicans Dally and Dally-like protein (Dlp), and propose that this internalisation is important in the establishment of a long range Dpp gradient. Pent-induced endocytosis and degradation of glypicans requires dynamin- and Rab5, but not clathrin or active BMP signalling. Thus, Pent modifies the ability of cells to trap and transduce BMP by fine-tuning the levels of the BMP reception system at the plasma membrane. In addition, and in accordance with the role of glypicans in multiple signalling pathways, we establish a requirement of Pent for Wg signalling. Our data propose a novel mechanism by which morphogen signalling is regulated. DOI: http://dx.doi.org/10.7554/eLife.13301.001 PMID:27269283

A SNARE-protein has opposing functions in penetration resistance and defence signalling pathways

DEFF Research Database (Denmark)

Zhang, Ziguo; Feechan, Angela; Pedersen, Carsten

2007-01-01

Penetration resistance is often the first line of defence against fungal pathogens. Subsequently induced defences are mediated by the programmed cell death (PCD) reaction pathway and the salicylic acid (SA), jasmonic acid (JA) and ethylene (ET) signalling pathways. We previously demonstrated...

Semantic Mining based on graph theory and ontologies. Case Study: Cell Signaling Pathways

Directory of Open Access Journals (Sweden)

Carlos R. Rangel

2016-08-01

Full Text Available In this paper we use concepts from graph theory and cellular biology represented as ontologies, to carry out semantic mining tasks on signaling pathway networks. Specifically, the paper describes the semantic enrichment of signaling pathway networks. A cell signaling network describes the basic cellular activities and their interactions. The main contribution of this paper is in the signaling pathway research area, it proposes a new technique to analyze and understand how changes in these networks may affect the transmission and flow of information, which produce diseases such as cancer and diabetes. Our approach is based on three concepts from graph theory (modularity, clustering and centrality frequently used on social networks analysis. Our approach consists into two phases: the first uses the graph theory concepts to determine the cellular groups in the network, which we will call them communities; the second uses ontologies for the semantic enrichment of the cellular communities. The measures used from the graph theory allow us to determine the set of cells that are close (for example, in a disease, and the main cells in each community. We analyze our approach in two cases: TGF-ß and the Alzheimer Disease.

The cAMP Signaling and MAP Kinase Pathways in Plant Pathogenic Fungi

NARCIS (Netherlands)

Mehrabi, R.; Zhao, X.; Kim, Y.; Xu, J.R.

2009-01-01

The key components of the well conserved cyclic AMP signaling and MAP kinase pathways have been functionally characterized in the corn smut Ustilago maydis, rice blast fungus Magnaporthe grisea, and a few other fungal pathogens. In general, the cAMP signaling and the MAP kinase cascade homologous to

MGAT1 is a novel transcriptional target of Wnt/β-catenin signaling pathway.

Science.gov (United States)

Akiva, Izzet; Birgül Iyison, Necla

2018-01-08

The Wnt/β-catenin signaling pathway is an evolutionary conserved pathway, which has important functions in vertebrate early development, axis formation, cellular proliferation and morphogenesis. Additionally, Wnt/β-catenin signaling pathway is one of the most important intracellular pathways that controls cancer progression. To date most of the identified targets of this pathway are shown to harbor tumorigenic properties. We previously showed that Mannosyl glycoprotein acetylglucosaminyl-transferase (MGAT1) enzyme is among the Wnt/β-catenin signaling putative target genes in hepatocellular carcinoma cell lines (Huh7). MGAT1 protein levels were determined by Western Blotting from Huh7 cell lines in which Wnt/β-catenin pathway was activated by means of different approaches such as LiCl treatment and mutant β-catenin overexpression. Luciferase reporter assay was used to analyze the promoter activity of MGAT1. The mRNA levels of MGAT1 were determined by quantitative real-time PCR from Huh7 cells that were treated with either Wnt agonist or GSK-3β inhibitor. Wound healing and XTT cell proliferation assays were performed in order to determine the proliferation and migration capacities of MGAT1 overexpressing stable Huh7 cells. Finally, xenograft experiments were carried out to measure the tumor formation capacities in vivo. In this study we showed that the activation of Wnt/β-catenin pathway culminates in the upregulation of MGAT1 enzyme both at transcriptional and post-transcriptional levels. We also showed that overexpression of the β-catenin gene (CTNNB1) increased the promoter activity of MGAT1. We applied a set of complementary approaches to elucidate the functional importance of MGAT1 as a vital target of Wnt/β-catenin signaling in Huh7 cells. Our analyses related to cell proliferation and migration assays showed that in comparison to the control cells, MGAT1 expressing Huh7 cells have greater proliferative and invasive capabilities. Furthermore, the

Trichoderma Biocontrol: Signal Transduction Pathways Involved in Host Sensing and Mycoparasitism

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Susanne Zeilinger

2007-01-01

Full Text Available Fungi of the genus Trichoderma are used as biocontrol agents against several plant pathogenic fungi like Rhizoctonia spp., Pythium spp., Botrytis cinerea and Fusarium spp. which cause both soil-borne and leaf- or flower-borne diseases of agricultural plants. Plant disease control by Trichoderma is based on complex interactions between Trichoderma, the plant pathogen and the plant. Until now, two main components of biocontrol have been identified: direct activity of Trichoderma against the plant pathogen by mycoparasitism and induced systemic resistance in plants. As the mycoparasitic interaction is host-specific and not merely a contact response, it is likely that signals from the host fungus are recognised by Trichoderma and provoke transcription of mycoparasitism-related genes.In the last few years examination of signalling pathways underlying Trichoderma biocontrol started and it was shown that heterotrimeric G-proteins and mitogen-activated protein (MAP kinases affected biocontrol-relevant processes such as the production of hydrolytic enzymes and antifungal metabolites and the formation of infection structures. MAPK signalling was also found to be involved in induction of plant systemic resistance in Trichoderma virens and in the hyperosmotic stress response in Trichoderma harzianum. Analyses of the function of components of the cAMP pathway during Trichoderma biocontrol revealed that mycoparasitism-associated coiling and chitinase production as well as secondary metabolism are affected by the internal cAMP level; in addition, a cross talk between regulation of light responses and the cAMP signalling pathway was found in Trichoderma atroviride.

Intercellular signaling pathways active during and after growth and differentiation of the lumbar vertebral growth plate.

Science.gov (United States)

Dahia, Chitra Lekha; Mahoney, Eric J; Durrani, Atiq A; Wylie, Christopher

2011-06-15

Vertebral growth plates at different postnatal ages were assessed for active intercellular signaling pathways. To generate a spatial and temporal map of the major signaling pathways active in the postnatal mouse lumbar vertebral growth plate. The growth of all long bones is known to occur by cartilaginous growth plates. The growth plate is composed of layers of chondrocyets that actively proliferate, differentiate, die and, are replaced by bone. The role of major cell signaling pathways has been suggested for regulation of the fetal long bones. But not much is known about the molecular or cellular signals that control the postnatal vertebral growth plate and hence postnatal vertebral bone growth. Understanding such molecular mechanisms will help design therapeutic treatments for vertebral growth disorders such as scoliosis. Antibodies against activated downstream intermediates were used to identify cells in the growth plate responding to BMP, TGFβ, and FGF in cryosections of lumbar vertebrae from different postnatal age mice to identify the zones that were responding to these signals. Reporter mice were used to identify the chondrocytes responding to hedgehog (Ihh), and Wnt signaling. We present a spatial/temporal map of these signaling pathways during growth, and differentiation of the mouse lumbar vertebral growth plate. During growth and differentiation of the vertebral growth plate, its different components respond at different times to different intercellular signaling ligands. Response to most of these signals is dramatically downregulated at the end of vertebral growth.

GAS6/TAM Pathway Signaling in Hemostasis and Thrombosis.

Science.gov (United States)

Law, Luke A; Graham, Douglas K; Di Paola, Jorge; Branchford, Brian R

2018-01-01

The GAS6/TYRO3-AXL-MERTK (TAM) signaling pathway is essential for full and sustained platelet activation, as well as thrombus stabilization. Inhibition of this pathway decreases platelet aggregation, shape change, clot retraction, aggregate formation under flow conditions, and surface expression of activation markers. Transgenic mice deficient in GAS6, or any of the TAM family of receptors that engage this ligand, exhibit in vivo protection against arterial and venous thrombosis but do not demonstrate either spontaneous or prolonged bleeding compared to their wild-type counterparts. Comparable results are observed in wild-type mice treated with pharmacological inhibitors of the GAS6-TAM pathway. Thus, GAS6/TAM inhibition offers an attractive novel therapeutic option that may allow for a moderate reduction in platelet activation and decreased thrombosis while still permitting the primary hemostatic function of platelet plug formation.

β1-adrenergic receptors activate two distinct signaling pathways in striatal neurons

Science.gov (United States)

Meitzen, John; Luoma, Jessie I.; Stern, Christopher M.; Mermelstein, Paul G.

2010-01-01

Monoamine action in the dorsal striatum and nucleus accumbens plays essential roles in striatal physiology. Although research often focuses on dopamine and its receptors, norepinephrine and adrenergic receptors are also crucial in regulating striatal function. While noradrenergic neurotransmission has been identified in the striatum, little is known regarding the signaling pathways activated by β-adrenergic receptors in this brain region. Using cultured striatal neurons, we characterized a novel signaling pathway by which activation of β1-adrenergic receptors leads to the rapid phosphorylation of cAMP Response Element Binding Protein (CREB), a transcription-factor implicated as a molecular switch underlying long-term changes in brain function. Norepinephrine-mediated CREB phosphorylation requires β1-adrenergic receptor stimulation of a receptor tyrosine kinase, ultimately leading to the activation of a Ras/Raf/MEK/MAPK/MSK signaling pathway. Activation of β1-adrenergic receptors also induces CRE-dependent transcription and increased c-fos expression. In addition, stimulation of β1-adrenergic receptors produces cAMP production, but surprisingly, β1-adrenergic receptor activation of adenylyl cyclase was not functionally linked to rapid CREB phosphorylation. These findings demonstrate that activation of β1-adrenergic receptors on striatal neurons can stimulate two distinct signaling pathways. These adrenergic actions can produce long-term changes in gene expression, as well as rapidly modulate cellular physiology. By elucidating the mechanisms by which norepinephrine and β1-adrenergic receptor activation affects striatal physiology, we provide the means to more fully understand the role of monoamines in modulating striatal function, specifically how norepinephrine and β1-adrenergic receptors may affect striatal physiology. PMID:21143600

Eight paths of ERK1/2 signalling pathway regulating hepatocyte ...

Indian Academy of Sciences (India)

2011-12-05

Dec 5, 2011 ... This study aims at exploring which paths of ERK1/2 signalling pathway participate in the regulation of rat .... total RNA was used to synthesize the first strand of cDNA. ..... stem cells contribute to regeneration of injured liver.

Agmatine modulates melanogenesis via MITF signaling pathway.

Science.gov (United States)

Kwon, Eun-Jeong; Kim, Moon-Moo

2017-01-01

Agmatine contained in soybean is also found in Manaca, an anti-aging plant, inhabited in Amazon and induces vasodilation by the promotion of NO synthesis in blood vessel. However, the research of agmatine on melanin synthesis related to hair greying is lacking. The aim of this study was to investigate the melanogenic effect of agmatine via regulation of MITF signaling pathway in B16F1 cells. It was determined whether agmatine regulates melanin synthesis at cellular level in addition to the effect of agmatine on mushroom tyrosinase in vitro in the presence of different concentrations of agmatine. Furthermore, the effect of agmatine on the protein expressions of tyrosinase, TRP-1, TRP-2, BMP-4, BMP-6, C-KIT, p-p38, MITF and C-FOS were examined by western blot analysis. In addition, immunofluorescence staining was carried out to visualize the location of MITF expression in cell. Agmatine at 256μM or more increased melanin synthesis as well as tyrosinase activity. Moreover, whereas agmatine increased the expression levels of TRP-1, BMP-6, p-p38 and MITF, it reduced the expression level of BMP-4. It was also found that agmatine enhanced the expression level of MITF in nucleus. These results suggest that agmatine could induce melanin synthesis though the regulation of MITF transcription factor via BMP-6/p38 signaling pathway. Copyright © 2016 Elsevier B.V. All rights reserved.

Involvement of wnt signaling pathways in the metamorphosis of the bryozoan bugula neritina

KAUST Repository

Wong, Yue Him

2012-03-20

In this study, we analyzed the metamorphosis of the marine bryozoan Bugula neritina. We observed the morphogenesis of the ancestrula. We defined three distinct pre-ancestrula stages based on the anatomy of the developing polypide and the overall morphology of pre-ancestrula. We then used an annotation based enrichment analysis tool to analyze the B. neritina transcriptome and identified over-representation of genes related to Wnt signaling pathways, suggesting its involvement in metamorphosis. Finally, we studied the temporal-spatial gene expression studies of several Wnt pathway genes. We found that one of the Wnt ligand, BnWnt10, was expressed spatially opposite to the Wnt antagonist BnsFRP within the blastemas, which is the presumptive polypide. Down-stream components of the canonical Wnt signaling pathway were exclusively expressed in the blastemas. Bn?catenin and BnFz5/8 were exclusively expressed in the blastemas throughout the metamorphosis. Based on the genes expression patterns, we propose that BnWnt10 and BnsFRP may relate to the patterning of the polypide, in which the two genes served as positional signals and contributed to the polarization of the blastemas. Another Wnt ligand, BnWnt6, was expressed in the apical part of the pre-ancestrula epidermis. Overall, our findings suggest that the Wnt signaling pathway may be important to the pattern formation of polypide and the development of epidermis. © 2012 Wong et al.

Involvement of wnt signaling pathways in the metamorphosis of the bryozoan bugula neritina

KAUST Repository

Wong, Yue Him; Wang, Hao; Ravasi, Timothy; Qian, Pei-Yuan

2012-01-01

In this study, we analyzed the metamorphosis of the marine bryozoan Bugula neritina. We observed the morphogenesis of the ancestrula. We defined three distinct pre-ancestrula stages based on the anatomy of the developing polypide and the overall morphology of pre-ancestrula. We then used an annotation based enrichment analysis tool to analyze the B. neritina transcriptome and identified over-representation of genes related to Wnt signaling pathways, suggesting its involvement in metamorphosis. Finally, we studied the temporal-spatial gene expression studies of several Wnt pathway genes. We found that one of the Wnt ligand, BnWnt10, was expressed spatially opposite to the Wnt antagonist BnsFRP within the blastemas, which is the presumptive polypide. Down-stream components of the canonical Wnt signaling pathway were exclusively expressed in the blastemas. Bn?catenin and BnFz5/8 were exclusively expressed in the blastemas throughout the metamorphosis. Based on the genes expression patterns, we propose that BnWnt10 and BnsFRP may relate to the patterning of the polypide, in which the two genes served as positional signals and contributed to the polarization of the blastemas. Another Wnt ligand, BnWnt6, was expressed in the apical part of the pre-ancestrula epidermis. Overall, our findings suggest that the Wnt signaling pathway may be important to the pattern formation of polypide and the development of epidermis. © 2012 Wong et al.

Directed random walks and constraint programming reveal active pathways in hepatocyte growth factor signaling.

Science.gov (United States)

Kittas, Aristotelis; Delobelle, Aurélien; Schmitt, Sabrina; Breuhahn, Kai; Guziolowski, Carito; Grabe, Niels

2016-01-01

An effective means to analyze mRNA expression data is to take advantage of established knowledge from pathway databases, using methods such as pathway-enrichment analyses. However, pathway databases are not case-specific and expression data could be used to infer gene-regulation patterns in the context of specific pathways. In addition, canonical pathways may not always describe the signaling mechanisms properly, because interactions can frequently occur between genes in different pathways. Relatively few methods have been proposed to date for generating and analyzing such networks, preserving the causality between gene interactions and reasoning over the qualitative logic of regulatory effects. We present an algorithm (MCWalk) integrated with a logic programming approach, to discover subgraphs in large-scale signaling networks by random walks in a fully automated pipeline. As an exemplary application, we uncover the signal transduction mechanisms in a gene interaction network describing hepatocyte growth factor-stimulated cell migration and proliferation from gene-expression measured with microarray and RT-qPCR using in-house perturbation experiments in a keratinocyte-fibroblast co-culture. The resulting subgraphs illustrate possible associations of hepatocyte growth factor receptor c-Met nodes, differentially expressed genes and cellular states. Using perturbation experiments and Answer Set programming, we are able to select those which are more consistent with the experimental data. We discover key regulator nodes by measuring the frequency with which they are traversed when connecting signaling between receptors and significantly regulated genes and predict their expression-shift consistently with the measured data. The Java implementation of MCWalk is publicly available under the MIT license at: https://bitbucket.org/akittas/biosubg. © 2015 FEBS.

Molecular mechanisms of BMP-induced bone formation: Cross-talk between BMP and NF-κB signaling pathways in osteoblastogenesis

Directory of Open Access Journals (Sweden)

Eijiro Jimi

2010-02-01

Full Text Available Osteoblasts are bone-forming cells that differentiate from mesenchymal stem cells. Differentiation processes are coordinately and dynamically controlled in the mesenchymal cells by specific signal transduction pathways. Bone morphogenetic proteins (BMPs, members of the TGF-β superfamily, induce not only bone formation in vivo, but also osteoblast differentiation of mesenchymal cells in vitro. BMP signals are transduced from plasma membrane receptors to the nucleus through both Smad-dependent and -independent pathways, and are regulated by many extracellular and intercellular proteins that interact with BMPs or components of BMP signaling pathways. To understand the molecular mechanisms underlying the role of BMPs in osteoblast differentiation, it is important to elucidate the BMP signaling transduction pathways that are active during osteoblast differentiation. In this review, we summarize the BMP signaling pathways that are known to function in osteoblast development. We also describe our recent findings regarding the molecular mechanisms underlying the cross-talk between BMP/Smad and NF-κB pathways in osteoblast differentiation.

The involvement of calcium and MAP kinase signaling pathways in the production of radiation-induced bystander effects.

LENUS (Irish Health Repository)

Lyng, F M

2006-04-01

Much evidence now exists regarding radiation-induced bystander effects, but the mechanisms involved in the transduction of the signal are still unclear. The mitogen-activated protein kinase (MAPK) pathways have been linked to growth factor-mediated regulation of cellular events such as proliferation, senescence, differentiation and apoptosis. Activation of multiple MAPK pathways such as the ERK, JNK and p38 pathways have been shown to occur after exposure of cells to radiation and a variety of other toxic stresses. Previous studies have shown oxidative stress and calcium signaling to be important in radiation-induced bystander effects. The aim of the present study was to investigate MAPK signaling pathways in bystander cells exposed to irradiated cell conditioned medium (ICCM) and the role of oxidative metabolism and calcium signaling in the induction of bystander responses. Human keratinocytes (HPV-G cell line) were irradiated (0.005-5 Gy) using a cobalt-60 teletherapy unit. The medium was harvested 1 h postirradiation and transferred to recipient HPV-G cells. Phosphorylated forms of p38, JNK and ERK were studied by immunofluorescence 30 min-24 h after exposure to ICCM. Inhibitors of the ERK pathway (PD98059 and U0126), the JNK pathway (SP600125), and the p38 pathway (SB203580) were used to investigate whether bystander-induced cell death could be blocked. Cells were also incubated with ICCM in the presence of superoxide dismutase, catalase, EGTA, verapamil, nifedipine and thapsigargin to investigate whether bystander effects could be inhibited because of the known effects on calcium homeostasis. Activated forms of JNK and ERK proteins were observed after exposure to ICCM. Inhibition of the ERK pathway appeared to increase bystander-induced apoptosis, while inhibition of the JNK pathway appeared to decrease apoptosis. In addition, reactive oxygen species, such as superoxide and hydrogen peroxide, and calcium signaling were found to be important modulators of

Identification of signaling pathways associated with cancer protection in Laron syndrome.

Science.gov (United States)

Lapkina-Gendler, Lena; Rotem, Itai; Pasmanik-Chor, Metsada; Gurwitz, David; Sarfstein, Rive; Laron, Zvi; Werner, Haim

2016-05-01

The growth hormone (GH)-insulin-like growth factor-1 (IGF1) pathway emerged in recent years as a critical player in cancer biology. Enhanced expression or activation of specific components of the GH-IGF1 axis, including the IGF1 receptor (IGF1R), is consistently associated with a transformed phenotype. Recent epidemiological studies have shown that patients with Laron syndrome (LS), the best-characterized entity among the congenital IGF1 deficiencies, seem to be protected from cancer development. To identify IGF1-dependent genes and signaling pathways associated with cancer protection in LS, we conducted a genome-wide analysis using immortalized lymphoblastoid cells derived from LS patients and healthy controls of the same gender, age range, and ethnic origin. Our analyses identified a collection of genes that are either over- or under-represented in LS-derived lymphoblastoids. Gene differential expression occurs in several gene families, including cell cycle, metabolic control, cytokine-cytokine receptor interaction, Jak-STAT signaling, and PI3K-AKT signaling. Major differences between LS and healthy controls were also noticed in pathways associated with cell cycle distribution, apoptosis, and autophagy. Our results highlight the key role of the GH-IGF1 axis in the initiation and progression of cancer. Furthermore, data are consistent with the concept that homozygous congenital IGF1 deficiency may confer protection against future tumor development. © 2016 Society for Endocrinology.

The regulation of ras-raf signaling pathway on G1 phase of the irradiated cells

International Nuclear Information System (INIS)

Guo Dehuang; Dong Bo; Liu Nongle; Wen Gengyun; Luo Qingliang; Mao Bingzhi

2000-01-01

Objective: To investigate the way of ras-raf signaling pathway which regulate the G 1 phase in irradiated KG-1 cells. Methods: Blocked the GM-CSF signaling pathway by transfected DN-ras and then momentary transfected cyclin D1 into irradiated KG-1 cells, the effects of cyclin D1 on G 1 phase was examined. Results: The irradiated KG-1 cells transfected DN-ras can't recover form G 1 phase arrest even though the GM-CSF was given,momentary transfected cyclin D1 promote the irradiated KG-1 cells from G 1 arrest. Conclusion: Activation of ras-raf signaling pathway regulate the cell cycle of the irradiated KG-1 cells through promotion the expression of the cyclin D1

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

Science.gov (United States)

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

2015-10-01

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

A hepatic amino acid/mTOR/S6K-dependent signalling pathway modulates systemic lipid metabolism via neuronal signals.

Science.gov (United States)

Uno, Kenji; Yamada, Tetsuya; Ishigaki, Yasushi; Imai, Junta; Hasegawa, Yutaka; Sawada, Shojiro; Kaneko, Keizo; Ono, Hiraku; Asano, Tomoichiro; Oka, Yoshitomo; Katagiri, Hideki

2015-08-13

Metabolism is coordinated among tissues and organs via neuronal signals. Levels of circulating amino acids (AAs), which are elevated in obesity, activate the intracellular target of rapamycin complex-1 (mTORC1)/S6kinase (S6K) pathway in the liver. Here we demonstrate that hepatic AA/mTORC1/S6K signalling modulates systemic lipid metabolism via a mechanism involving neuronal inter-tissue communication. Hepatic expression of an AA transporter, SNAT2, activates the mTORC1/S6K pathway, and markedly elevates serum triglycerides (TGs), while downregulating adipose lipoprotein lipase (LPL). Hepatic Rheb or active-S6K expression have similar metabolic effects, whereas hepatic expression of dominant-negative-S6K inhibits TG elevation in SNAT2 mice. Denervation, pharmacological deafferentation and β-blocker administration suppress obesity-related hypertriglyceridemia with adipose LPL upregulation, suggesting that signals are transduced between liver and adipose tissue via a neuronal pathway consisting of afferent vagal and efferent sympathetic nerves. Thus, the neuronal mechanism uncovered here serves to coordinate amino acid and lipid levels and contributes to the development of obesity-related hypertriglyceridemia.

UTP-induced ATP release is a fine-tuned signalling pathway in osteocytes

DEFF Research Database (Denmark)

Kringelbach, Tina M.; Aslan, Derya; Novak, Ivana

2014-01-01

Osteocytes reside as a cellular network throughout the mineralised matrix of bone and are considered the primary mechanosensors of this tissue. They sense mechanical stimulation such as fluid flow and are able to regulate osteoblast and osteoclast functions on the bone surface. Previously, we fou...... signals may be propagated by P2 receptor activation and further ATP release in the osteocyte network and implicate purinergic signalling as a central signalling pathway in osteocyte mechanotransduction....

Development of steroid signaling pathways during primordial follicle formation in the human fetal ovary.

Science.gov (United States)

Fowler, Paul A; Anderson, Richard A; Saunders, Philippa T; Kinnell, Hazel; Mason, J Ian; Evans, Dean B; Bhattacharya, Siladitya; Flannigan, Samantha; Franks, Stephen; Monteiro, Ana; O'Shaughnessy, Peter J

2011-06-01

Ovarian primordial follicle formation is critical for subsequent human female fertility. It is likely that steroid, and especially estrogen, signaling is required for this process, but details of the pathways involved are currently lacking. The aim was to identify and characterize key members of the steroid-signaling pathway expressed in the second trimester human fetal ovary. We conducted an observational study of the female fetus, quantifying and localizing steroid-signaling pathway members. The study was conducted at the Universities of Aberdeen, Edinburgh, and Glasgow. Ovaries were collected from 43 morphologically normal human female fetuses from women undergoing elective termination of second trimester pregnancies. We measured mRNA transcript levels and immunolocalized key steroidogenic enzymes and steroid receptors, including those encoded by ESR2, AR, and CYP19A1. Levels of mRNA encoding the steroidogenic apparatus and steroid receptors increased across the second trimester. CYP19A1 transcript increased 4.7-fold during this period with intense immunostaining for CYP19A detected in pregranulosa cells around primordial follicles and somatic cells around oocyte nests. ESR2 was localized primarily to germ cells, but androgen receptor was exclusively expressed in somatic cells. CYP17A1 and HSD3B2 were also localized to oocytes, whereas CYP11A1 was detected in oocytes and some pregranulosa cells. The human fetal ovary expresses the machinery to produce and detect multiple steroid signaling pathways, including estrogenic signaling, with the oocyte acting as a key component. This study provides a step-change in our understanding of local dynamics of steroid hormone signaling during the key period of human primordial follicle formation.

NF-kappaB signaling: a tale of two pathways in skeletal myogenesis.

Science.gov (United States)

Bakkar, Nadine; Guttridge, Denis C

2010-04-01

NF-kappaB is a ubiquitiously expressed transcription factor that plays vital roles in innate immunity and other processes involving cellular survival, proliferation, and differentiation. Activation of NF-kappaB is controlled by an IkappaB kinase (IKK) complex that can direct either canonical (classical) NF-kappaB signaling by degrading the IkappaB inhibitor and releasing p65/p50 dimers to the nucleus, or causes p100 processing and nuclear translocation of RelB/p52 via a noncanonical (alternative) pathway. Under physiological conditions, NF-kappaB activity is transiently regulated, whereas constitutive activation of this transcription factor typically in the classical pathway is associated with a multitude of disease conditions, including those related to skeletal muscle. How NF-kappaB functions in muscle diseases is currently under intense investigation. Insight into this role of NF-kappaB may be gained by understanding at a more basic level how this transcription factor contributes to skeletal muscle cell differentiation. Recent data from knockout mice support that the classical NF-kappaB pathway functions as an inhibitor of skeletal myogenesis and muscle regeneration acting through multiple mechanisms. In contrast, alternative NF-kappaB signaling does not appear to be required for myofiber conversion, but instead functions in myotube homeostasis by regulating mitochondrial biogenesis. Additional knowledge of these signaling pathways in skeletal myogenesis should aid in the development of specific inhibitors that may be useful in treatments of muscle disorders.

Analysis of porcine granulosa cell death signaling pathways induced by vinclozolin.

Science.gov (United States)

Knet, Malgorzata; Wartalski, Kamil; Hoja-Lukowicz, Dorota; Tabarowski, Zbigniew; Slomczynska, Maria; Duda, Malgorzata

2015-10-01

Recent studies suggest that disturbing androgen-signaling pathways in porcine ovarian follicles may cause granulosa cell (GC) death. For this reason, we investigated which apoptotic pathway is initiated after GC exposure to an environmental antiandrogen, vinclozolin (Vnz), in vitro. Immunocytochemistry, Western blots, and fluorometric assays were used to quantify caspase-3 and -9 expression and activity. To elucidate the specific mechanism of Vnz action and toxicity, GCs were assessed for viability, cytotoxicity, and apoptotic activity using the ApoTox-Glo Triplex Assay. To further determine the mechanism of GC death induced by Vnz, we used the Apoptosis Antibody Array Kit. In response to Vnz stimulus, we found an increased level of caspase-3 protein expression (P ≤ 0.001) and an increase in caspase-3 proteolytic activity (P ≤ 0.001), confirming that Vnz is a potent proapoptotic factor. The strong immunoreaction of caspase-9 after Vnz treatment (P ≤ 0.001) suggests that intrinsic mitochondrial apoptosis pathway was activated during GC death. On the other hand, caspase-8, being a part of the extrinsic receptor pathway, was also activated (P ≤ 0.001). Therefore, it is possible that Vnz induces porcine granulosal apoptosis also through a parallel pathway. Activation of these two pathways was confirmed by the Apoptosis Antibody Array Kit. In conclusion, it is possible that the intrinsic signaling pathway may not act as an initial trigger for GC apoptosis but might contribute to the amplification and propagation of apoptotic cell death in the granulosa layer after treatment with this antiandrogen. Moreover, Vnz disturbs the physiological process of programmed cell death. Consequently, this could explain why atretic follicles are rapidly removed and suggests that normal function of the ovarian follicle may be destroyed. Copyright © 2015 Elsevier Inc. All rights reserved.

MiR-9-5p promotes MSC migration by activating β-catenin signaling pathway.

Science.gov (United States)

Li, Xianyang; He, Lihong; Yue, Qing; Lu, Junhou; Kang, Naixin; Xu, Xiaojing; Wang, Huihui; Zhang, Huanxiang

2017-07-01

Mesenchymal stem cells (MSCs) have the potential to treat various tissue damages, but the very limited number of cells that migrate to the damaged region strongly restricts their therapeutic applications. Full understanding of mechanisms regulating MSC migration will help to improve their migration ability and therapeutic effects. Increasing evidence shows that microRNAs play important roles in the regulation of MSC migration. In the present study, we reported that miR-9-5p was upregulated in hepatocyte growth factor -treated MSCs and in MSCs with high migration ability. Overexpression of miR-9-5p promoted MSC migration, whereas inhibition of endogenous miR-9-5p decreased MSC migration. To elucidate the underlying mechanism, we screened the target genes of miR-9-5p and report for the first time that CK1α and GSK3β, two inhibitors of β-catenin signaling pathway, were direct targets of miR-9-5p in MSCs and that overexpression of miR-9-5p upregulated β-catenin signaling pathway. In line with these data, inhibition of β-catenin signaling pathway by FH535 decreased the miR-9-5p-promoted migration of MSCs, while activation of β-catenin signaling pathway by LiCl rescued the impaired migration of MSCs triggered by miR-9-5p inhibitor. Furthermore, the formation and distribution of focal adhesions as well as the reorganization of F-actin were affected by the expression of miR-9-5p. Collectively, these results demonstrate that miR-9-5p promotes MSC migration by upregulating β-catenin signaling pathway, shedding light on the optimization of MSCs for cell replacement therapy through manipulating the expression level of miR-9-5p. Copyright © 2017 the American Physiological Society.

Crosstalk between autophagy and inflammatory signalling pathways: balancing defence and homeostasis.

Science.gov (United States)

Cadwell, Ken

2016-11-01

Autophagy has broad functions in immunity, ranging from cell-autonomous defence to coordination of complex multicellular immune responses. The successful resolution of infection and avoidance of autoimmunity necessitates efficient and timely communication between autophagy and pathways that sense the immune environment. The recent literature indicates that a variety of immune mediators induce or repress autophagy. It is also becoming increasingly clear that immune signalling cascades are subject to regulation by autophagy, and that a return to homeostasis following a robust immune response is critically dependent on this pathway. Importantly, examples of non-canonical forms of autophagy in mediating immunity are pervasive. In this article, the progress in elucidating mechanisms of crosstalk between autophagy and inflammatory signalling cascades is reviewed. Improved mechanistic understanding of the autophagy machinery offers hope for treating infectious and inflammatory diseases.

The effect of aquaporin 5 overexpression on the Ras signaling pathway

International Nuclear Information System (INIS)

Woo, Janghee; Lee, Juna; Kim, Myoung Sook; Jang, Se Jin; Sidransky, David; Moon, Chulso

2008-01-01

Human aquaporin 5 (AQP5) has been shown to be overexpressed in multiple cancers, such as pancreatic cancer and colon cancer. Furthermore, it has been reported that ectopic expression of AQP5 leads to many phenotypic changes characteristic of transformation. However, the biochemical mechanism leading to transformation in AQP5-overexpressing cells has not been clearly elucidated. In this report, the overexpression of AQP5 in NIH3T3 cells demonstrated a significant effect on Ras activity and, thus, cell proliferation. Furthermore, this influence was shown to be mediated by phosphorylation of the PKA consensus site of AQP5. This is the first evidence demonstrating an association between AQP5 and a signaling pathway, namely the Ras signal transduction pathway, which may be the basis of the oncogenic properties seen in AQP-overexpressing cells

Signaling pathway underlying the octopaminergic modulation of myogenic contraction in the cricket lateral oviduct.

Science.gov (United States)

Tamashiro, Hirotake; Yoshino, Masami

2014-12-01

Octopamine (OA), a biogenic monoamine, is a neurotransmitter and neuromodulator in invertebrates. Here, we report the effect of OA on the spontaneous rhythmic contractions (SRCs) of the lateral oviduct of the cricket Gryllus bimaculatus and the possible signaling pathway involved. Application of OA increased both the frequency and amplitude of SRCs in a dose-dependent manner. The effect of OA was inhibited by subsequent application of the OA receptor antagonist epinastine, indicating that the action of OA is mediated by OA receptor. To investigate the predominant signaling pathway underlying the action of OA, we first examined a possible involvement of the cAMP/cAMP-dependent protein kinase A (PKA) signaling pathway. Application of the membrane-permeable cAMP analog 8-Br-cAMP had little effect on SRCs and the effect of OA was not influenced by subsequent application of the PKA inhibitor H89, indicating that the cAMP/PKA signaling pathway is not the predominant pathway in the action of OA. Next, we examined a possible involvement of the second messenger inositol 1,4,5-trisphosphate in the action of OA. The effect of OA on SRCs was inhibited by subsequent application of the phosphoinositide-specific phospholipase C (PLC) inhibitor U73122, indicating that the PLC pathway is involved in the action of OA. The OA-induced increase in the frequency of SRCs was inhibited by pretreatment of the cell with the ryanodine receptor antagonist tetracaine but was not significantly affected by the IP3 receptor antagonist 2-aminoethoxydiphenyl borate (2-APB). On the other hand, the OA-induced increase in the amplitude of SRCs was inhibited by pretreatment of the cells with 2-APB but was not significantly affected by tetracaine. Taken together, these results suggest that the OA-induced excitatory effect on SRCs is mediated by the PLC signaling pathway: Ca2+ release from IP3 receptors may contribute to the modulation of the amplitude of SRCs, whereas Ca2+ release from ryanodine

NK cell activation: distinct stimulatory pathways counterbalancing inhibitory signals.

Science.gov (United States)

Bakker, A B; Wu, J; Phillips, J H; Lanier, L L

2000-01-01

A delicate balance between positive and negative signals regulates NK cell effector function. Activation of NK cells may be initiated by the triggering of multiple adhesion or costimulatory molecules, and can be counterbalanced by inhibitory signals induced by receptors for MHC class I. A common pathway of inhibitory signaling is provided by immunoreceptor tyrosine-based inhibitory motifs (ITIMs) in the cytoplasmic domains of these receptors which mediate the recruitment of SH2 domain-bearing tyrosine phosphate-1 (SHP-1). In contrast to the extensive progress that has been made regarding the negative regulation of NK cell function, our knowledge of the signals that activate NK cells is still poor. Recent studies of the activating receptor complexes have shed new light on the induction of NK cell effector function. Several NK receptors using novel adaptors with immunoreceptor tyrosine-based activation motifs (ITAMs) and with PI 3-kinase recruiting motifs have been implicated in NK cell stimulation.

Selection of personalized patient therapy through the use of knowledge-based computational models that identify tumor-driving signal transduction pathways.

Science.gov (United States)

Verhaegh, Wim; van Ooijen, Henk; Inda, Márcia A; Hatzis, Pantelis; Versteeg, Rogier; Smid, Marcel; Martens, John; Foekens, John; van de Wiel, Paul; Clevers, Hans; van de Stolpe, Anja

2014-06-01

Increasing knowledge about signal transduction pathways as drivers of cancer growth has elicited the development of "targeted drugs," which inhibit aberrant signaling pathways. They require a companion diagnostic test that identifies the tumor-driving pathway; however, currently available tests like estrogen receptor (ER) protein expression for hormonal treatment of breast cancer do not reliably predict therapy response, at least in part because they do not adequately assess functional pathway activity. We describe a novel approach to predict signaling pathway activity based on knowledge-based Bayesian computational models, which interpret quantitative transcriptome data as the functional output of an active signaling pathway, by using expression levels of transcriptional target genes. Following calibration on only a small number of cell lines or cohorts of patient data, they provide a reliable assessment of signaling pathway activity in tumors of different tissue origin. As proof of principle, models for the canonical Wnt and ER pathways are presented, including initial clinical validation on independent datasets from various cancer types. ©2014 American Association for Cancer Research.

Signaling transduction pathways involved in basophil adhesion and histamine release

DEFF Research Database (Denmark)

Sha, Quan; Poulsen, Lars K.; Gerwien, Jens

2006-01-01

Little is known about basophil with respect to the different signaling transduction pathways involved in spontaneous, cytokine or anti-IgE induced adhesion and how this compares to IgE-dependent and IgE-independent mediator secretion. The purpose of the present study was to investigate the roles...... of beta1 and beta2 integrins in basophil adhesion as well as hosphatidylinositol 3-kinase (PI3K), src-kinases and extracellular signal regulated kinase (ERK) 1/2 in basophil adhesion and histamine release (HR)....

MAPKs are essential upstream signaling pathways in proteolytic cartilage degradation--divergence in pathways leading to aggrecanase and MMP-mediated articular cartilage degradation

DEFF Research Database (Denmark)

Sondergaard, B-C; Schultz, N; Madsen, S H

2010-01-01

Matrix metalloproteinases (MMPs) and aggrecanases are essential players in cartilage degradation. However, the signaling pathways that results in MMP and/or aggrecanase synthesis and activation are not well understood. We investigated the molecular events leading to MMP- and aggrecanase-mediated ......Matrix metalloproteinases (MMPs) and aggrecanases are essential players in cartilage degradation. However, the signaling pathways that results in MMP and/or aggrecanase synthesis and activation are not well understood. We investigated the molecular events leading to MMP- and aggrecanase......-mediated cartilage degradation....

Effect of TBT and PAHs on CYP1A, AhR and Vitellogenin Gene Expression in the Japanese Eel, Anguilla japonica.

Science.gov (United States)

Choi, Min Seop; Kwon, Se Ryun; Choi, Seong Hee; Kwon, Hyuk Chu

2012-12-01

Gene expressions of cytochrome P4501A (CYP1A), aryl hydrocarbon receptor (AhR) and vitellogenin (Vg) by endocrine disruptors, benzo[α]pyrene (B[a]P) and tributyltin (TBT) were examined in cultured eel hepatocytes which were isolated from eels treated previously with B[a]P (10 mg/kg) or estradiol-17β (20 mg/kg) in vivo, and the relationship between CYP1A, AhR and Vg genes were studied. When the cultured eel hepatocytes were treated with B[a]P (10(-6)-10(-5) M) the gene expressions of CYP1A and AhR were enhanced in a concentration-dependent manner. However, when treated with TBT (10(-9)-10(-5) M) the gene expressions of CYP1A and AhR were suppressed at high concentrations (10(-6)-10(-5) M), while having no effects at low concentrations (10(-9)-10(-7) M). Gene expression of Vg was also suppressed by TBT in a concentration-dependent manner in cultured eel hepatocytes which was previously treated in vivo with estradiol-17β.

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

Science.gov (United States)

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

2015-01-01

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

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

Science.gov (United States)

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

2015-07-01

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

Signal transduction pathways involved in mechanotransduction in bone cells

International Nuclear Information System (INIS)

Liedert, Astrid; Kaspar, Daniela; Blakytny, Robert; Claes, Lutz; Ignatius, Anita

2006-01-01

Several in vivo and in vitro studies with different loading regimens showed that mechanical stimuli have an influence on proliferation and differentiation of bone cells. Prerequisite for this influence is the transduction of mechanical signals into the cell, a phenomenon that is termed mechanotransduction, which is essential for the maintenance of skeletal homeostasis in adults. Mechanoreceptors, such as the integrins, cadherins, and stretch-activated Ca 2+ channels, together with various signal transduction pathways, are involved in the mechanotransduction process that ultimately regulates gene expression in the nucleus. Mechanotransduction itself is considered to be regulated by hormones, the extracellular matrix of the osteoblastic cells and the mode of the mechanical stimulus

MicroRNA-200a suppresses the Wnt/β-catenin signaling pathway by interacting with β-catenin.

Science.gov (United States)

Su, Juan; Zhang, Anling; Shi, Zhendong; Ma, Feifei; Pu, Peiyu; Wang, Tao; Zhang, Jie; Kang, Chunsheng; Zhang, Qingyu

2012-04-01

The Wnt/β-catenin signaling pathway is crucial for human organ development and is involved in tumor progression of many cancers. Accumulating evidence suggests that the expression of β-catenin is, in part, regulated by specific microRNAs (miRNAs). The purpose of this study was to determine the expression of a recently identified epithelial to mesenchymal transition (EMT)-associated tumor suppressor microRNA (miR)-200a, in cancer cells. We also aimed to identify specific miR-200a target genes and to investigate the antitumor effects of miR-200a on the Wnt/β-catenin signaling pathway. We employed TOP/FOP flash luciferase assays to identify the effect of miR-200a on the Wnt/β-catenin pathway and we confirmed our observations using fluorescence microscopy. To determine target genes of miR-200a, a 3' untranslated region (3' UTR) luciferase assay was performed. Cell viability, invasion and wound healing assays were carried out for functional analysis after miRNA transfection. We further investigated the role of miR-200a in EMT by Western blot analysis. We found fluctuation in the expression of miR-200a that was accompanied by changes in the expression of members of the Wnt/β-catenin signaling pathway. We also determined that miR-200a can directly interact with the 3' UTR of CTNNB1 (the gene that encodes β-catenin) to suppress Wnt/β-catenin signaling. MiR-200a could also influence the biological activities of SGC790 and U251 cells. Our results demonstrate that miR-200a is a new tumor suppressor that can regulate the activity of the Wnt/β-catenin signaling pathway via two mechanisms. MiR-200a is a candidate target for tumor treatment via its regulation of the Wnt/β-catenin signaling pathway.

Combined chemical and toxicological long-term monitoring for AhR agonists with SPMD-based virtual organisms in drinking water Danjiangkou Reservoir, China.

Science.gov (United States)

Wang, Jingxian; Song, Guoqiang; Li, Aimin; Henkelmann, Bernhard; Pfister, Gerd; Tong, Anthony Z; Schramm, Karl-Werner

2014-08-01

SPMD-based virtual organisms (VOs) were employed for time-integrating, long-term sampling combined biological and chemical analyses for exposure assessment of hydrophobic organic pollutants (HOPs) in a drinking water reservoir, China. The SPMDs were deployed at four and five sites in the Danjiangkou (DJK) reservoir over two periods of 26 and 31 d to sequester the hydrophobic contaminants in water. The chosen bioassay response for the extracts of the SPMDs, the induction of 7-ethoxyresorufin-o-deethylase (EROD) was assayed using a rat hepatoma cell line (H4IIE). The known aryl hydrocarbon receptor (AhR) agonists PAHs and PCBs were analyzed by HRGC/HRMS instrument. The cause-effect relationship between the observed AhR activities and chemical concentrations of detected AhR agonists was examined. The results show that the extracts from the SPMD samples could induce AhR activity significantly, whereas the chemically derived 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) equivalent (TEQcal) was not correlated with the bioassay-derived TCDD equivalent (TEQbio). The known AhR agonists could only account for 2-10% of the observed AhR responses among which the contribution of PCBs could almost be neglected. Unidentified AhR-active compounds represented a greater proportion of the TCDD equivalent (TCDD-EQ) in SPMD samples from DJK. Based on the first assessment, the VO followed by the combination of chemical and biological analyses emerges as a resource efficient water monitoring device in ecotoxicological assessment for toxicologically relevant compounds which are readily available for uptake by resident aquatic biota in drinking water resources. Copyright © 2014 Elsevier Ltd. All rights reserved.

Deficient brain insulin signalling pathway in Alzheimer’s disease and diabetes

Science.gov (United States)

Liu, Ying; Liu, Fei; Grundke-Iqbal, Inge; Iqbal, Khalid; Gong, Cheng-Xin

2015-01-01

Brain glucose metabolism is impaired in Alzheimer’s disease (AD), the most common form of dementia. Type 2 diabetes mellitus (T2DM) is reported to increase the risk for dementia, including AD, but the underlying mechanism is not understood. Here, we investigated the brain insulin–PI3K–AKT signalling pathway in the autopsied frontal cortices from nine AD, 10 T2DM, eight T2DM–AD and seven control cases. We found decreases in the levels and activities of several components of the insulin–PI3K–AKT signalling pathway in AD and T2DM cases. The deficiency of insulin–PI3K–AKT signalling was more severe in individuals with both T2DM and AD (T2DM–AD). This decrease in insulin–PI3K–AKT signalling could lead to activation of glycogen synthase kinase-3β, the major tau kinase. The levels and the activation of the insulin–PI3K–AKT signalling components correlated negatively with the level of tau phosphorylation and positively with protein O-GlcNAcylation, suggesting that impaired insulin–PI3K–AKT signalling might contribute to neurodegeneration in AD through down-regulation of O-GlcNAcylation and the consequent promotion of abnormal tau hyperphosphorylation and neurodegeneration. The decrease in brain insulin–PI3K–AKT signalling also correlated with the activation of calpain I in the brain, suggesting that the decrease might be caused by calpain over-activation. Our findings provide novel insight into the molecular mechanism by which type 2 diabetes mellitus increases the risk for developing cognitive impairment and dementia in Alzheimer’s disease. PMID:21598254

Using answer set programming to integrate RNA expression with signalling pathway information to infer how mutations affect ageing.

Science.gov (United States)

Papatheodorou, Irene; Ziehm, Matthias; Wieser, Daniela; Alic, Nazif; Partridge, Linda; Thornton, Janet M

2012-01-01

A challenge of systems biology is to integrate incomplete knowledge on pathways with existing experimental data sets and relate these to measured phenotypes. Research on ageing often generates such incomplete data, creating difficulties in integrating RNA expression with information about biological processes and the phenotypes of ageing, including longevity. Here, we develop a logic-based method that employs Answer Set Programming, and use it to infer signalling effects of genetic perturbations, based on a model of the insulin signalling pathway. We apply our method to RNA expression data from Drosophila mutants in the insulin pathway that alter lifespan, in a foxo dependent fashion. We use this information to deduce how the pathway influences lifespan in the mutant animals. We also develop a method for inferring the largest common sub-paths within each of our signalling predictions. Our comparisons reveal consistent homeostatic mechanisms across both long- and short-lived mutants. The transcriptional changes observed in each mutation usually provide negative feedback to signalling predicted for that mutation. We also identify an S6K-mediated feedback in two long-lived mutants that suggests a crosstalk between these pathways in mutants of the insulin pathway, in vivo. By formulating the problem as a logic-based theory in a qualitative fashion, we are able to use the efficient search facilities of Answer Set Programming, allowing us to explore larger pathways, combine molecular changes with pathways and phenotype and infer effects on signalling in in vivo, whole-organism, mutants, where direct signalling stimulation assays are difficult to perform. Our methods are available in the web-service NetEffects: http://www.ebi.ac.uk/thornton-srv/software/NetEffects.

Domain altering SNPs in the human proteome and their impact on signaling pathways.

Directory of Open Access Journals (Sweden)

Yichuan Liu

Full Text Available Single nucleotide polymorphisms (SNPs constitute an important mode of genetic variations observed in the human genome. A small fraction of SNPs, about four thousand out of the ten million, has been associated with genetic disorders and complex diseases. The present study focuses on SNPs that fall on protein domains, 3D structures that facilitate connectivity of proteins in cell signaling and metabolic pathways. We scanned the human proteome using the PROSITE web tool and identified proteins with SNP containing domains. We showed that SNPs that fall on protein domains are highly statistically enriched among SNPs linked to hereditary disorders and complex diseases. Proteins whose domains are dramatically altered by the presence of an SNP are even more likely to be present among proteins linked to hereditary disorders. Proteins with domain-altering SNPs comprise highly connected nodes in cellular pathways such as the focal adhesion, the axon guidance pathway and the autoimmune disease pathways. Statistical enrichment of domain/motif signatures in interacting protein pairs indicates extensive loss of connectivity of cell signaling pathways due to domain-altering SNPs, potentially leading to hereditary disorders.

The Drosophila rolled locus encodes a MAP kinase required in the sevenless signal transduction pathway.

OpenAIRE

Biggs, W H; Zavitz, K H; Dickson, B; van der Straten, A; Brunner, D; Hafen, E; Zipursky, S L

1994-01-01

Mitogen-activated protein (MAP) kinases have been proposed to play a critical role in receptor tyrosine kinase (RTK)-mediated signal transduction pathways. Although genetic and biochemical studies of RTK pathways in Caenorhabditis elegans, Drosophila melanogaster and mammals have revealed remarkable similarities, a genetic requirement for MAP kinases in RTK signaling has not been established. During retinal development in Drosophila, the sevenless (Sev) RTK is required for development of the ...

EGF signalling pathway regulates colon cancer stem cell proliferation and apoptosis.

Science.gov (United States)

Feng, Y; Dai, X; Li, X; Wang, H; Liu, J; Zhang, J; Du, Y; Xia, L

2012-10-01

Cancer stem cells (CSCs) compose a subpopulation of cells within a tumour that can self-renew and proliferate. Growth factors such as epidermal growth factor (EGF) and basic fibroblast growth factor (b-FGF) promote cancer stem cell proliferation in many solid tumours. This study assesses whether EGF, bFGF and IGF signalling pathways are essential for colon CSC proliferation and self-renewal. Colon CSCs were cultured in serum-free medium (SFM) with one of the following growth factors: EGF, bFGF or IGF. Characteristics of CSC gene expression were evaluated by real time PCR. Tumourigenicity of CSCs was determined using a xenograft model in vivo. Effects of EGF receptor inhibitors, Gefitinib and PD153035, on CSC proliferation, apoptosis and signalling were evaluated using fluorescence-activated cell sorting and western blotting. Colon cancer cell HCT116 transformed to CSCs in SFM. Compared to other growth factors, EGF was essential to support proliferation of CSCs that expressed higher levels of progenitor genes (Musashi-1, LGR5) and lower levels of differential genes (CK20). CSCs promoted more rapid tumour growth than regular cancer cells in xenografts. EGFR inhibitors suppressed proliferation and induced apoptosis of CSCs by inhibiting autophosphorylation of EGFR and downstream signalling proteins, such as Akt kinase, extracellular signal-regulated kinase 1/2 (ERK 1/2). This study indicates that EGF signalling was essential for formation and maintenance of colon CSCs. Inhibition of the EGF signalling pathway may provide a useful strategy for treatment of colon cancer. © 2012 Blackwell Publishing Ltd.

Distinct Calcium Signaling Pathways Regulate Calmodulin Gene Expression in Tobacco1

Science.gov (United States)

van der Luit, Arnold H.; Olivari, Claudio; Haley, Ann; Knight, Marc R.; Trewavas, Anthony J.

1999-01-01

Cold shock and wind stimuli initiate Ca2+ transients in transgenic tobacco (Nicotiana plumbaginifolia) seedlings (named MAQ 2.4) containing cytoplasmic aequorin. To investigate whether these stimuli initiate Ca2+ pathways that are spatially distinct, stress-induced nuclear and cytoplasmic Ca2+ transients and the expression of a stress-induced calmodulin gene were compared. Tobacco seedlings were transformed with a construct that encodes a fusion protein between nucleoplasmin (a major oocyte nuclear protein) and aequorin. Immunocytochemical evidence indicated targeting of the fusion protein to the nucleus in these plants, which were named MAQ 7.11. Comparison between MAQ 7.11 and MAQ 2.4 seedlings confirmed that wind stimuli and cold shock invoke separate Ca2+ signaling pathways. Partial cDNAs encoding two tobacco calmodulin genes, NpCaM-1 and NpCaM-2, were identified and shown to have distinct nucleotide sequences that encode identical polypeptides. Expression of NpCaM-1, but not NpCaM-2, responded to wind and cold shock stimulation. Comparison of the Ca2+ dynamics with NpCaM-1 expression after stimulation suggested that wind-induced NpCaM-1 expression is regulated by a Ca2+ signaling pathway operational predominantly in the nucleus. In contrast, expression of NpCaM-1 in response to cold shock is regulated by a pathway operational predominantly in the cytoplasm. PMID:10557218

The signaling pathways by which the Fas/FasL system accelerates oocyte aging.

Science.gov (United States)

Zhu, Jiang; Lin, Fei-Hu; Zhang, Jie; Lin, Juan; Li, Hong; Li, You-Wei; Tan, Xiu-Wen; Tan, Jing-He

2016-02-01

In spite of great efforts, the mechanisms for postovulatory oocyte aging are not fully understood. Although our previous work showed that the FasL/Fas signaling facilitated oocyte aging, the intra-oocyte signaling pathways are unknown. Furthermore, the mechanisms by which oxidative stress facilitates oocyte aging and the causal relationship between Ca2+ rises and caspase-3 activation and between the cell cycle and apoptosis during oocyte aging need detailed investigations. Our aim was to address these issues by studying the intra-oocyte signaling pathways for Fas/FasL to accelerate oocyte aging. The results indicated that sFasL released by cumulus cells activated Fas on the oocyte by increasing reactive oxygen species via activating NADPH oxidase. The activated Fas triggered Ca2+ release from the endoplasmic reticulum by activating phospholipase C-γ pathway and cytochrome c pathway. The cytoplasmic Ca2+ rises activated calcium/calmodulin-dependent protein kinase II (CaMKII) and caspase-3. While activated CaMKII increased oocyte susceptibility to activation by inactivating maturation-promoting factor (MPF) through cyclin B degradation, the activated caspase-3 facilitated further Ca2+releasing that activates more caspase-3 leading to oocyte fragmentation. Furthermore, caspase-3 activation and fragmentation were prevented in oocytes with a high MPF activity, suggesting that an oocyte must be in interphase to undergo apoptosis.

Epidermal wound repair is regulated by the planar cell polarity signaling pathway.

Science.gov (United States)

Caddy, Jacinta; Wilanowski, Tomasz; Darido, Charbel; Dworkin, Sebastian; Ting, Stephen B; Zhao, Quan; Rank, Gerhard; Auden, Alana; Srivastava, Seema; Papenfuss, Tony A; Murdoch, Jennifer N; Humbert, Patrick O; Parekh, Vishwas; Boulos, Nidal; Weber, Thomas; Zuo, Jian; Cunningham, John M; Jane, Stephen M

2010-07-20

The mammalian PCP pathway regulates diverse developmental processes requiring coordinated cellular movement, including neural tube closure and cochlear stereociliary orientation. Here, we show that epidermal wound repair is regulated by PCP signaling. Mice carrying mutant alleles of PCP genes Vangl2, Celsr1, PTK7, and Scrb1, and the transcription factor Grhl3, interact genetically, exhibiting failed wound healing, neural tube defects, and disordered cochlear polarity. Using phylogenetic analysis, ChIP, and gene expression in Grhl3(-)(/-) mice, we identified RhoGEF19, a homolog of a RhoA activator involved in PCP signaling in Xenopus, as a direct target of GRHL3. Knockdown of Grhl3 or RhoGEF19 in keratinocytes induced defects in actin polymerization, cellular polarity, and wound healing, and re-expression of RhoGEF19 rescued these defects in Grhl3-kd cells. These results define a role for Grhl3 in PCP signaling and broadly implicate this pathway in epidermal repair. (c) 2010 Elsevier Inc. All rights reserved.

Neuroprotective effect of rapamycin on spinal cord injury via activation of the Wnt/β-catenin signaling pathway

Directory of Open Access Journals (Sweden)

Kai Gao

2015-01-01

Full Text Available The Wnt/β-catenin signaling pathway plays a crucial role in neural development, axonal guidance, neuropathic pain remission and neuronal survival. In this study, we initially examined the effect of rapamycin on the Wnt/β-catenin signaling pathway after spinal cord injury, by intraperitoneally injecting spinal cord injured rats with rapamycin over 2 days. Western blot analysis and immunofluorescence staining were used to detect the expression levels of β-catenin protein, ca-spase-3 protein and brain-derived neurotrophic factor protein, components of the Wnt/β-catenin signaling pathway. Rapamycin increased the levels of β-catenin and brain-derived neurotrophic factor in the injured spinal cord, improved the pathological morphology at the injury site, reduced the loss of motor neurons, and promoted motor functional recovery in rats after spinal cord injury. Our experimental findings suggest that the neuroprotective effect of rapamycin intervention is mediated through activation of the Wnt/β-catenin signaling pathway after spinal cord injury.

Improved Protein Arrays for Quantitative Systems Analysis of the Dynamics of Signaling Pathway Interactions

Energy Technology Data Exchange (ETDEWEB)

Yang, Chin-Rang [National Inst. of Health (NIH), Bethesda, MD (United States). National Heart, Lung and Blood Inst.

2013-12-11

Astronauts and workers in nuclear plants who repeatedly exposed to low doses of ionizing radiation (IR, <10 cGy) are likely to incur specific changes in signal transduction and gene expression in various tissues of their body. Remarkable advances in high throughput genomics and proteomics technologies enable researchers to broaden their focus from examining single gene/protein kinetics to better understanding global gene/protein expression profiling and biological pathway analyses, namely Systems Biology. An ultimate goal of systems biology is to develop dynamic mathematical models of interacting biological systems capable of simulating living systems in a computer. This Glue Grant is to complement Dr. Boothman’s existing DOE grant (No. DE-FG02-06ER64186) entitled “The IGF1/IGF-1R-MAPK-Secretory Clusterin (sCLU) Pathway: Mediator of a Low Dose IR-Inducible Bystander Effect” to develop sensitive and quantitative proteomic technology that suitable for low dose radiobiology researches. An improved version of quantitative protein array platform utilizing linear Quantum dot signaling for systematically measuring protein levels and phosphorylation states for systems biology modeling is presented. The signals are amplified by a confocal laser Quantum dot scanner resulting in ~1000-fold more sensitivity than traditional Western blots and show the good linearity that is impossible for the signals of HRP-amplification. Therefore this improved protein array technology is suitable to detect weak responses of low dose radiation. Software is developed to facilitate the quantitative readout of signaling network activities. Kinetics of EGFRvIII mutant signaling was analyzed to quantify cross-talks between EGFR and other signaling pathways.

Differential effects of omeprazole and lansoprazole enantiomers on aryl hydrocarbon receptor in human hepatocytes and cell lines.

Science.gov (United States)

Novotna, Aneta; Srovnalova, Alzbeta; Svecarova, Michaela; Korhonova, Martina; Bartonkova, Iveta; Dvorak, Zdenek

2014-01-01

Proton pump inhibitors omeprazole and lansoprazole contain chiral sulfur atom and they are administered as a racemate, i.e. equimolar mixture of S- and R-enantiomers. The enantiopure drugs esomeprazole and dexlansoprazole have been developed and introduced to clinical practice due to their improved clinical and therapeutic properties. Since omeprazole and lansoprazole are activators of aryl hydrocarbon receptor (AhR) and inducers of CYP1A genes, we examined their enantiospecific effects on AhR-CYP1A pathway in human cancer cells and primary human hepatocytes. We performed gene reporter assays for transcriptional activity of AhR, RT-PCR analyses for CYP1A1/2 mRNAs, western blots for CYP1A1/2 proteins and EROD assay for CYP1A1/2 catalytic activity. Lansoprazole and omeprazole enantiomers displayed differential effects on AhR-CYP1A1/2 pathway. In general, S-enantiomers were stronger activators of AhR and inducers of CYP1A genes as compared to R-enantiomers in lower concentrations, i.e. 1-10 µM for lansoprazole and 10-100 µM for omeprazole. In contrast, R-enantiomers were stronger AhR activators and CYP1A inducers than S-enantiomers in higher concentrations, i.e. 100 µM for lansoprazole and 250 µM for omeprazole. In conclusion, we provide the first evidence of enantiospecific effects of omeprazole and lansoprazole on AhR signaling pathway.

NAViGaTing the micronome--using multiple microRNA prediction databases to identify signalling pathway-associated microRNAs.

Directory of Open Access Journals (Sweden)

Elize A Shirdel

2011-02-01

Full Text Available MicroRNAs are a class of small RNAs known to regulate gene expression at the transcript level, the protein level, or both. Since microRNA binding is sequence-based but possibly structure-specific, work in this area has resulted in multiple databases storing predicted microRNA:target relationships computed using diverse algorithms. We integrate prediction databases, compare predictions to in vitro data, and use cross-database predictions to model the microRNA:transcript interactome--referred to as the micronome--to study microRNA involvement in well-known signalling pathways as well as associations with disease. We make this data freely available with a flexible user interface as our microRNA Data Integration Portal--mirDIP (http://ophid.utoronto.ca/mirDIP.mirDIP integrates prediction databases to elucidate accurate microRNA:target relationships. Using NAViGaTOR to produce interaction networks implicating microRNAs in literature-based, KEGG-based and Reactome-based pathways, we find these signalling pathway networks have significantly more microRNA involvement compared to chance (p<0.05, suggesting microRNAs co-target many genes in a given pathway. Further examination of the micronome shows two distinct classes of microRNAs; universe microRNAs, which are involved in many signalling pathways; and intra-pathway microRNAs, which target multiple genes within one signalling pathway. We find universe microRNAs to have more targets (p<0.0001, to be more studied (p<0.0002, and to have higher degree in the KEGG cancer pathway (p<0.0001, compared to intra-pathway microRNAs.Our pathway-based analysis of mirDIP data suggests microRNAs are involved in intra-pathway signalling. We identify two distinct classes of microRNAs, suggesting a hierarchical organization of microRNAs co-targeting genes both within and between pathways, and implying differential involvement of universe and intra-pathway microRNAs at the disease level.

MicroRNA-gene signaling pathways in pancreatic cancer

Directory of Open Access Journals (Sweden)

Alexandra Drakaki

2013-10-01

Full Text Available Pancreatic cancer is the fourth most frequent cause of cancer-related deaths and is characterized by early metastasis and pronounced resistance to chemotherapy and radiation therapy. Despite extensive esearch efforts, there is not any substantial progress regarding the identification of novel drugs against pancreatic cancer. Although the introduction of the chemotherapeutic agent gemcitabine improved clinical response, the prognosis of these patients remained extremely poor with a 5-year survival rate of 3-5%. Thus, the identification of the novel molecular pathways involved in pancreatic oncogenesis and the development of new and potent therapeutic options are highly desirable. Here, we describe how microRNAs control signaling pathways that are frequently deregulated during pancreatic oncogenesis. In addition, we provide evidence that microRNAs could be potentially used as novel pancreatic cancer therapeutics through reversal of chemotherapy and radiotherapy resistance or regulation of essential molecular pathways. Further studies should integrate the deregulated genes and microRNAs into molecular networks in order to identify the central regulators of pancreatic oncogenesis. Targeting these central regulators could lead to the development of novel targeted therapeutic approaches for pancreatic cancer patients.

Interleukin-2 signaling pathway analysis by quantitative phosphoproteomics

DEFF Research Database (Denmark)

Osinalde, Nerea; Moss, Helle; Arrizabalaga, Onetsine

2011-01-01

among which 79 were found with increased abundance in the tyrosine-phosphorylated complexes, including several previously not reported IL-2 downstream effectors. Combinatorial site-specific phosphoproteomic analysis resulted in identification of 99 phosphorylated sites mapping to the identified proteins...... with increased abundance in the tyrosine-phosphorylated complexes, of which 34 were not previously described. In addition, chemical inhibition of the identified IL-2-mediated JAK, PI3K and MAPK signaling pathways, resulted in distinct alteration on the IL-2 dependent proliferation....

Failure of signal transduction pathway of DNA damage in hereditary microcephaly

International Nuclear Information System (INIS)

Miyamoto, Tatsuo; Matsuura, Shinya

2009-01-01

Mechanisms underlying the brain size determination are considered from an aspect of DNA-damage signaling recently revealed by studies on hereditary microcephaly (M), in relation to the radiation-induced M. International Commission of Radiological Protection (ICRP) assesses the risk of M by in utero exposure as 40%/Sv, the threshold dose is about 0.2 Gy (deterministic effect), A-bomb M is conceived to be due to the exposure at 8-5 weeks of gestation, and M is induced by radiation at 10 days after fertilization in the mouse. Recent studies on causing genes of M have revealed its particular connection with signaling pathways: in ataxia-telangiectasia (AT), genes of ATM; in Seckel syndrome, of ATR (AT and Rad3-related) and pericentrin (PCNT); Nijmegen syndrome (NBS), of NBS1; NBS-like disease, of Rad50 and Mre11; AT-like disease, of Mre11; Lig4 syndrome, of Lig4; immunodeficiency combined with M, of XLF; primary M, of MCPH1, ASPM, CdkRap2, CENP-J and STIL. Single and double strand breaks of DNA respectively activate the signaling pathway of ATR where PCNT and MCPH1 participate, and pathway of ATM where NBS1, Mre11 and Rad50 do. PCNT is a major protein, pericentrin, composing the centrosome, of which defect results in the Seckel disease with spindle dysfunction. At present, M can be thus said to be of the cellular common features of failure of ATM/ATR signaling and of dysfunction of centrosome. As well, ASPM gene expression is recently reported to be suppressed by radiation. Thus future studies on M will spread to wider biological field of cell and development as well as radiation and inheritance. (K.T.)

Yeast signaling pathways in the oxidative stress response

Energy Technology Data Exchange (ETDEWEB)

Ikner, Aminah [Section of Microbiology, Division of Biological Sciences, University of California, Davis, CA 95616 (United States); Shiozaki, Kazuhiro [Section of Microbiology, Division of Biological Sciences, University of California, Davis, CA 95616 (United States)]. E-mail: kshiozaki@ucdavis.edu

2005-01-06

Oxidative stress that generates the reactive oxygen species (ROS) is one of the major causes of DNA damage and mutations. The 'DNA damage checkpoint' that arrests cell cycle and repairs damaged DNA has been a focus of recent studies, and the genetically amenable model systems provided by yeasts have been playing a leading role in the eukaryotic checkpoint research. However, means to eliminate ROS are likely to be as important as the DNA repair mechanisms in order to suppress mutations in the chromosomal DNA, and yeasts also serve as excellent models to understand how eukaryotes combat oxidative stress. In this article, we present an overview of the signaling pathways that sense oxidative stress and induce expression of various anti-oxidant genes in the budding yeast Saccharomyces cerevisiae, the fission yeast Schizosaccharomyces pombe and the pathogenic yeast Candida albicans. Three conserved signaling modules have been identified in the oxidative stress response of these diverse yeast species: the stress-responsive MAP kinase cascade, the multistep phosphorelay and the AP-1-like transcription factor. The structure and function of these signaling modules are discussed.

Yeast signaling pathways in the oxidative stress response

International Nuclear Information System (INIS)

Ikner, Aminah; Shiozaki, Kazuhiro

2005-01-01

Oxidative stress that generates the reactive oxygen species (ROS) is one of the major causes of DNA damage and mutations. The 'DNA damage checkpoint' that arrests cell cycle and repairs damaged DNA has been a focus of recent studies, and the genetically amenable model systems provided by yeasts have been playing a leading role in the eukaryotic checkpoint research. However, means to eliminate ROS are likely to be as important as the DNA repair mechanisms in order to suppress mutations in the chromosomal DNA, and yeasts also serve as excellent models to understand how eukaryotes combat oxidative stress. In this article, we present an overview of the signaling pathways that sense oxidative stress and induce expression of various anti-oxidant genes in the budding yeast Saccharomyces cerevisiae, the fission yeast Schizosaccharomyces pombe and the pathogenic yeast Candida albicans. Three conserved signaling modules have been identified in the oxidative stress response of these diverse yeast species: the stress-responsive MAP kinase cascade, the multistep phosphorelay and the AP-1-like transcription factor. The structure and function of these signaling modules are discussed

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

NARCIS (Netherlands)

Smeets, Ruben L.; Fleuren, Wilco W. M.; He, Xuehui; Vink, Paul M.; Wijnands, Frank; Gorecka, Monika; Klop, Henri; Bauerschmidt, Sussane; Garritsen, Anja; Koenen, Hans J. P. M.; Joosten, Irma; Boots, Annemieke M. H.; Alkema, Wynand

2012-01-01

Background: T lymphocytes are orchestrators of adaptive immunity. Naive T cells may differentiate into Th1, Th2, Th17 or iTreg phenotypes, depending on environmental co-stimulatory signals. To identify genes and pathways involved in differentiation of Jurkat T cells towards Th1 and Th2 subtypes we

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

NARCIS (Netherlands)

Smeets, R.L.; Fleuren, W.W.M.; He, X.; Vink, P.M.; Wijnands, F.; Gorecka, M.; Klop, H.; Bauerschmidt, S.; Garritsen, A.; Koenen, H.J.P.M.; Joosten, I.; Boots, A.M.H.; Alkema, W.

2012-01-01

BACKGROUND: T lymphocytes are orchestrators of adaptive immunity. Naive T cells may differentiate into Th1, Th2, Th17 or iTreg phenotypes, depending on environmental co-stimulatory signals. To identify genes and pathways involved in differentiation of Jurkat T cells towards Th1 and Th2 subtypes we

Possible involvement of the JAK/STAT signaling pathway in N-acetylcysteine-mediated antidepressant-like effects

OpenAIRE

Al-Samhari, Marwa M; Al-Rasheed, Nouf M; Al-Rejaie, Salim; Al-Rasheed, Nawal M; Hasan, Iman H; Mahmoud, Ayman M; Dzimiri, Nduna

2015-01-01

Advances in depression research have targeted inflammation and oxidative stress to develop novel types of treatment. The JAK/STAT signaling pathway plays pivotal roles in immune and inflammatory responses. The present study was designed to investigate the effects of N-acetylcysteine, a putative precursor of the antioxidant glutathione, in an animal model of depression, with an emphasis on the JAK/STAT signaling pathway. Fluoxetine, a classical antidepressant drug was also under investigation....

Sotos syndrome is associated with deregulation of the MAPK/ERK-signaling pathway.

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Remco Visser

Full Text Available Sotos syndrome (SoS is characterized by tall stature, characteristic craniofacial features and mental retardation. It is caused by haploinsufficiency of the NSD1 gene. In this study, our objective was to identify downstream effectors of NSD1 and to map these effectors in signaling pathways associated with growth. Genome-wide expression studies were performed on dermal fibroblasts from SoS patients with a confirmed NSD1 abnormality. To substantiate those results, phosphorylation, siRNA and transfection experiments were performed. A significant association was demonstrated with the Mitogen-Activated Protein Kinase (MAPK pathway. Members of the fibroblast growth factor family such as FGF4 and FGF13 contributed strongly to the differential expression in this pathway. In addition, a diminished activity state of the MAPK/ERK pathway was demonstrated in SoS. The Ras Interacting Protein 1 (RASIP1 was identified to exhibit upregulated expression in SoS. It was shown that RASIP1 dose-dependently potentiated bFGF induced expression of the MAPK responsive SBE reporter providing further support for a link between NSD1 and the MAPK/ERK signaling pathway. Additionally, we demonstrated NSD1 expression in the terminally differentiated hypertrophic chondrocytes of normal human epiphyseal growth plates. In short stature syndromes such as hypochondroplasia and Noonan syndrome, the activation level of the FGF-MAPK/ERK-pathway in epiphyseal growth plates is a determining factor for statural growth. In analogy, we propose that deregulation of the MAPK/ERK pathway in SoS results in altered hypertrophic differentiation of NSD1 expressing chondrocytes and may be a determining factor in statural overgrowth and accelerated skeletal maturation in SoS.

The Impact of Hedgehog Signaling Pathway on DNA Repair Mechanisms in Human Cancer

International Nuclear Information System (INIS)

Meng, Erhong; Hanna, Ann; Samant, Rajeev S.; Shevde, Lalita A.

2015-01-01

Defined cellular mechanisms have evolved that recognize and repair DNA to protect the integrity of its structure and sequence when encountering assaults from endogenous and exogenous sources. There are five major DNA repair pathways: mismatch repair, nucleotide excision repair, direct repair, base excision repair and DNA double strand break repair (including non-homologous end joining and homologous recombination repair). Aberrant activation of the Hedgehog (Hh) signaling pathway is a feature of many cancer types. The Hh pathway has been documented to be indispensable for epithelial-mesenchymal transition, invasion and metastasis, cancer stemness, and chemoresistance. The functional transcription activators of the Hh pathway include the GLI proteins. Inhibition of the activity of GLI can interfere with almost all DNA repair types in human cancer, indicating that Hh/GLI functions may play an important role in enabling tumor cells to survive lethal types of DNA damage induced by chemotherapy and radiotherapy. Thus, Hh signaling presents an important therapeutic target to overcome DNA repair-enabled multi-drug resistance and consequently increase chemotherapeutic response in the treatment of cancer

The Impact of Hedgehog Signaling Pathway on DNA Repair Mechanisms in Human Cancer

Energy Technology Data Exchange (ETDEWEB)

Meng, Erhong; Hanna, Ann; Samant, Rajeev S.; Shevde, Lalita A., E-mail: lsamant@uab.edu [Department of Pathology, Comprehensive Cancer Center, University of Alabama at Birmingham, WTI320D, 1824 6th Avenue South, Birmingham, AL 35233 (United States)

2015-07-21

Defined cellular mechanisms have evolved that recognize and repair DNA to protect the integrity of its structure and sequence when encountering assaults from endogenous and exogenous sources. There are five major DNA repair pathways: mismatch repair, nucleotide excision repair, direct repair, base excision repair and DNA double strand break repair (including non-homologous end joining and homologous recombination repair). Aberrant activation of the Hedgehog (Hh) signaling pathway is a feature of many cancer types. The Hh pathway has been documented to be indispensable for epithelial-mesenchymal transition, invasion and metastasis, cancer stemness, and chemoresistance. The functional transcription activators of the Hh pathway include the GLI proteins. Inhibition of the activity of GLI can interfere with almost all DNA repair types in human cancer, indicating that Hh/GLI functions may play an important role in enabling tumor cells to survive lethal types of DNA damage induced by chemotherapy and radiotherapy. Thus, Hh signaling presents an important therapeutic target to overcome DNA repair-enabled multi-drug resistance and consequently increase chemotherapeutic response in the treatment of cancer.

Protein conservation and variation suggest mechanisms of cell type-specific modulation of signaling pathways.

Directory of Open Access Journals (Sweden)

Martin H Schaefer

2014-06-01

Full Text Available Many proteins and signaling pathways are present in most cell types and tissues and yet perform specialized functions. To elucidate mechanisms by which these ubiquitous pathways are modulated, we overlaid information about cross-cell line protein abundance and variability, and evolutionary conservation onto functional pathway components and topological layers in the pathway hierarchy. We found that the input (receptors and the output (transcription factors layers evolve more rapidly than proteins in the intermediary transmission layer. In contrast, protein expression variability decreases from the input to the output layer. We observed that the differences in protein variability between the input and transmission layer can be attributed to both the network position and the tendency of variable proteins to physically interact with constitutively expressed proteins. Differences in protein expression variability and conservation are also accompanied by the tendency of conserved and constitutively expressed proteins to acquire somatic mutations, while germline mutations tend to occur in cell type-specific proteins. Thus, conserved core proteins in the transmission layer could perform a fundamental role in most cell types and are therefore less tolerant to germline mutations. In summary, we propose that the core signal transmission machinery is largely modulated by a variable input layer through physical protein interactions. We hypothesize that the bow-tie organization of cellular signaling on the level of protein abundance variability contributes to the specificity of the signal response in different cell types.

Research advances in sorafenib-induced apoptotic signaling pathways in liver cancer cells

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ZHANG Chaoya

2016-04-01

Full Text Available Currently, sorafenib is the multi-target inhibitor for the treatment of advanced primary liver cancer, and can effectively prolong the progression-free survival and overall survival in patients with advanced primary liver cancer. The application of sorafenib in the targeted therapy for liver cancer has become a hot topic. Major targets or signaling pathways include Raf/Mek/Erk, Jak/Stat, PI3K/Akt/mTOR, VEGFR and PDGFR, STAT, microRNA, Wnt/β-catenin, autolysosome, and tumor-related proteins, and sorafenib can regulate the proliferation, differentiation, metastasis, and apoptosis of liver cancer cells through these targets. This article reviews the current research on the action of sorafenib on these targets or signaling pathways to provide useful references for further clinical research on sorafenib.

Effects of matrine on JAK-STAT signaling transduction pathways in ...

African Journals Online (AJOL)

The current study aims to investigate the effects of matrine on the JAK-STAT signaling transduction pathways in bleomycin (BLM)-induced pulmonary fibrosis (PF) and to explore its action mechanism. A total of 72 male C57BL/6 mice were randomized into the control, model, and treatment groups. PF models were ...

Curcumin ameliorates insulin signalling pathway in brain of Alzheimer's disease transgenic mice.

Science.gov (United States)

Feng, Hui-Li; Dang, Hui-Zi; Fan, Hui; Chen, Xiao-Pei; Rao, Ying-Xue; Ren, Ying; Yang, Jin-Duo; Shi, Jing; Wang, Peng-Wen; Tian, Jin-Zhou

2016-12-01

Deficits in glucose, impaired insulin signalling and brain insulin resistance are common in the pathogenesis of Alzheimer's disease (AD); therefore, some scholars even called AD type 3 diabetes mellitus. Curcumin can reduce the amyloid pathology in AD. Moreover, it is a well-known fact that curcumin has anti-oxidant and anti-inflammatory properties. However, whether or not curcumin could regulate the insulin signal transduction pathway in AD remains unclear. In this study, we used APPswe/PS1dE9 double transgenic mice as the AD model to investigate the mechanisms and the effects of curcumin on AD. Immunohistochemical (IHC) staining and a western blot analysis were used to test the major proteins in the insulin signal transduction pathway. After the administration of curcumin for 6 months, the results showed that the expression of an insulin receptor (InR) and insulin receptor substrate (IRS)-1 decreased in the hippocampal CA1 area of the APPswe/PS1dE9 double transgenic mice, while the expression of phosphatidylinositol-3 kinase (PI3K), phosphorylated PI3K (p-PI3K), serine-threonine kinase (AKT) and phosphorylated AKT (p-AKT) increased. Among the curcumin groups, the medium-dose group was the most effective one. Thus, we believe that curcumin may be a potential therapeutic agent that can regulate the critical molecules in brain insulin signalling pathways. Furthermore, curcumin could be adopted as one of the AD treatments to improve a patient's learning and memory ability. © The Author(s) 2016.

Peroxisome Proliferator-Activated Receptor and Vitamin D Receptor Signaling Pathways in Cancer Cells

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Yasuko Kitagishi

2013-10-01

Full Text Available Peroxisome proliferator-activated receptors (PPARs are members of the superfamily of nuclear hormone receptors, which respond to specific ligands such as polyunsaturated fatty acids by altering gene expression. Three subtypes of this receptor have been discovered, each evolving to achieve different biological functions. Like other nuclear receptors, the transcriptional activity of PPARs is affected not only by ligand-stimulation, but also by cross-talk with other molecules. For example, both PPARs and the RXRs are ligand-activated transcription factors that coordinately regulate gene expression. In addition, PPARs and vitamin D receptor (VDR signaling pathways regulate a multitude of genes that are of importance for cellular functions including cell proliferation and cell differentiation. Interaction of the PPARs and VDR signaling pathways has been shown at the level of molecular cross-regulation of their transcription factor. A variety of ligands influencing the PPARs and VDR signaling pathways have been shown to reveal chemopreventive potential by mediating tumor suppressive activities in human cancers. Use of these compounds may represent a potential novel strategy to prevent cancers. This review summarizes the roles of the PPARs and the VDR in pathogenesis and progression of cancer.

Peroxisome Proliferator-Activated Receptor and Vitamin D Receptor Signaling Pathways in Cancer Cells

Energy Technology Data Exchange (ETDEWEB)

Matsuda, Satoru, E-mail: smatsuda@cc.nara-wu.ac.jp; Kitagishi, Yasuko [Department of Food Science and Nutrition, Nara Women’s University, Kita-Uoya Nishimachi, Nara 630-8506 (Japan)

2013-10-21

Peroxisome proliferator-activated receptors (PPARs) are members of the superfamily of nuclear hormone receptors, which respond to specific ligands such as polyunsaturated fatty acids by altering gene expression. Three subtypes of this receptor have been discovered, each evolving to achieve different biological functions. Like other nuclear receptors, the transcriptional activity of PPARs is affected not only by ligand-stimulation, but also by cross-talk with other molecules. For example, both PPARs and the RXRs are ligand-activated transcription factors that coordinately regulate gene expression. In addition, PPARs and vitamin D receptor (VDR) signaling pathways regulate a multitude of genes that are of importance for cellular functions including cell proliferation and cell differentiation. Interaction of the PPARs and VDR signaling pathways has been shown at the level of molecular cross-regulation of their transcription factor. A variety of ligands influencing the PPARs and VDR signaling pathways have been shown to reveal chemopreventive potential by mediating tumor suppressive activities in human cancers. Use of these compounds may represent a potential novel strategy to prevent cancers. This review summarizes the roles of the PPARs and the VDR in pathogenesis and progression of cancer.

Peroxisome Proliferator-Activated Receptor and Vitamin D Receptor Signaling Pathways in Cancer Cells

International Nuclear Information System (INIS)

Matsuda, Satoru; Kitagishi, Yasuko

2013-01-01

Peroxisome proliferator-activated receptors (PPARs) are members of the superfamily of nuclear hormone receptors, which respond to specific ligands such as polyunsaturated fatty acids by altering gene expression. Three subtypes of this receptor have been discovered, each evolving to achieve different biological functions. Like other nuclear receptors, the transcriptional activity of PPARs is affected not only by ligand-stimulation, but also by cross-talk with other molecules. For example, both PPARs and the RXRs are ligand-activated transcription factors that coordinately regulate gene expression. In addition, PPARs and vitamin D receptor (VDR) signaling pathways regulate a multitude of genes that are of importance for cellular functions including cell proliferation and cell differentiation. Interaction of the PPARs and VDR signaling pathways has been shown at the level of molecular cross-regulation of their transcription factor. A variety of ligands influencing the PPARs and VDR signaling pathways have been shown to reveal chemopreventive potential by mediating tumor suppressive activities in human cancers. Use of these compounds may represent a potential novel strategy to prevent cancers. This review summarizes the roles of the PPARs and the VDR in pathogenesis and progression of cancer

Regulatory Mechanisms of the Ihh/PTHrP Signaling Pathway in Fibrochondrocytes in Entheses of Pig Achilles Tendon

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Xuesong Han

2016-01-01

Full Text Available This study is aimed at exploring the effect of stress stimulation on the proliferation and differentiation of fibrochondrocytes in entheses mediated via the Indian hedgehog (Ihh/parathyroid hormone-related protein (PTHrP signaling pathway. Differential stress stimulation on fibrochondrocytes in entheses was imposed. Gene expression and protein levels of signaling molecules including collagen type I (Col I, Col II, Col X, Ihh, and PTHrP in the cytoplasm of fibrochondrocytes were detected. Ihh signal blocking group was set up using Ihh signaling pathway-specific blocking agent cyclopamine. PTHrP enhancement group was set up using PTHrP reagent. Ihh/PTHrP double intervention group, as well as control group, was included to study the regulatory mechanisms of the Ihh/PTHrP signaling pathway in fibrochondrocytes. Under low cyclic stress tensile (CTS, PTHrP, Col I, and Col II gene expression and protein synthesis increased. Under high CTS, Ihh and Col X gene expression and protein synthesis increased. Blocking Ihh signaling with cyclopamine resulted in reduced PTHrP gene expression and protein synthesis and increased Col X gene expression and protein synthesis. Ihh and PTHrP coregulate fibrochondrocyte proliferation and differentiation in entheses through negative feedback regulation. Fibrochondrocyte is affected by the CTS. This phenomenon is regulated by stress stimulation through the Ihh/PTHrP signaling pathway.

Regulatory Mechanisms of the Ihh/PTHrP Signaling Pathway in Fibrochondrocytes in Entheses of Pig Achilles Tendon.

Science.gov (United States)

Han, Xuesong; Zhuang, Yanfeng; Zhang, Zhihong; Guo, Lin; Wang, Wanming

2016-01-01

This study is aimed at exploring the effect of stress stimulation on the proliferation and differentiation of fibrochondrocytes in entheses mediated via the Indian hedgehog (Ihh)/parathyroid hormone-related protein (PTHrP) signaling pathway. Differential stress stimulation on fibrochondrocytes in entheses was imposed. Gene expression and protein levels of signaling molecules including collagen type I (Col I), Col II, Col X, Ihh, and PTHrP in the cytoplasm of fibrochondrocytes were detected. Ihh signal blocking group was set up using Ihh signaling pathway-specific blocking agent cyclopamine. PTHrP enhancement group was set up using PTHrP reagent. Ihh/PTHrP double intervention group, as well as control group, was included to study the regulatory mechanisms of the Ihh/PTHrP signaling pathway in fibrochondrocytes. Under low cyclic stress tensile (CTS), PTHrP, Col I, and Col II gene expression and protein synthesis increased. Under high CTS, Ihh and Col X gene expression and protein synthesis increased. Blocking Ihh signaling with cyclopamine resulted in reduced PTHrP gene expression and protein synthesis and increased Col X gene expression and protein synthesis. Ihh and PTHrP coregulate fibrochondrocyte proliferation and differentiation in entheses through negative feedback regulation. Fibrochondrocyte is affected by the CTS. This phenomenon is regulated by stress stimulation through the Ihh/PTHrP signaling pathway.

The canonical Wnt signaling pathway promotes chondrocyte differentiation in a Sox9-dependent manner

International Nuclear Information System (INIS)

Yano, Fumiko; Kugimiya, Fumitaka; Ohba, Shinsuke; Ikeda, Toshiyuki; Chikuda, Hirotaka; Ogasawara, Toru; Ogata, Naoshi; Takato, Tsuyoshi; Nakamura, Kozo; Kawaguchi, Hiroshi; Chung, Ung-il

2005-01-01

To better understand the role of the canonical Wnt signaling pathway in cartilage development, we adenovirally expressed a constitutively active (Canada) or a dominant negative (dn) form of lymphoid enhancer factor-1 (LEF-1), the main nuclear effector of the pathway, in undifferentiated mesenchymal cells, chondrogenic cells, and primary chondrocytes, and examined the expression of markers for chondrogenic differentiation and hypertrophy. caLEF-1 and LiCl, an activator of the canonical pathway, promoted both chondrogenic differentiation and hypertrophy, whereas dnLEF-1 and the gene silencing of β-catenin suppressed LiCl-promoted effects. To investigate whether these effects were dependent on Sox9, a master regulator of cartilage development, we stimulated Sox9-deficient ES cells with the pathway. caLEF-1 and LiCl promoted both chondrogenic differentiation and hypertrophy in wild-type, but not in Sox9-deficient, cells. The response of Sox9-deficient cells was restored by the adenoviral expression of Sox9. Thus, the canonical Wnt signaling pathway promotes chondrocyte differentiation in a Sox9-dependent manner

A pivotal role of the jasmonic acid signal pathway in mediating radiation-induced bystander effects in Arabidopsis thaliana

Energy Technology Data Exchange (ETDEWEB)

Wang, Ting; Xu, Wei; Deng, Chenguang; Xu, Shaoxin; Li, Fanghua; Wu, Yuejin; Wu, Lijun [Key Laboratory of Ion Beam Bioengineering, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031 (China); Key Laboratory of Environmental Toxicology and Pollution Control Technology of Anhui Province, Hefei 230031 (China); Bian, Po, E-mail: bianpo@ipp.ac.cn [Key Laboratory of Ion Beam Bioengineering, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031 (China); Key Laboratory of Environmental Toxicology and Pollution Control Technology of Anhui Province, Hefei 230031 (China)

2016-09-15

Highlights: • The JA signal pathway plays a pivotal role in mediating radiation-induced bystander effects in Arabidopsis thaliana. • The JA signal pathway is involved in both the generation of bystander signals in irradiated roots and radiation responses in bystander aerial plants. • Over-accumulation of endogenous JA enhances the radiosensitivity of plants in terms of RIBE. - Abstract: Although radiation-induced bystander effects (RIBE) in Arabidopsis thaliana have been well demonstrated in vivo, little is known about their underlying mechanisms, particularly with regard to the participating signaling molecules and signaling pathways. In higher plants, jasmonic acid (JA) and its bioactive derivatives are well accepted as systemic signal transducers that are produced in response to various environmental stresses. It is therefore speculated that the JA signal pathway might play a potential role in mediating radiation-induced bystander signaling of root-to-shoot. In the present study, pretreatment of seedlings with Salicylhydroxamic acid, an inhibitor of lipoxigenase (LOX) in JA biosynthesis, significantly suppressed RIBE-mediated expression of the AtRAD54 gene. After root irradiation, the aerial parts of A. thaliana mutants deficient in JA biosynthesis (aos) and signaling cascades (jar1-1) showed suppressed induction of the AtRAD54 and AtRAD51 genes and TSI and 180-bp repeats, which have been extensively used as endpoints of bystander genetic and epigenetic effects in plants. These results suggest an involvement of the JA signal pathway in the RIBE of plants. Using the root micro-grafting technique, the JA signal pathway was shown to participate in both the generation of bystander signals in irradiated root cells and radiation responses in the bystander aerial parts of plants. The over-accumulation of endogenous JA in mutant fatty acid oxygenation up-regulated 2 (fou2), in which mutation of the Two Pore Channel 1 (TPC1) gene up-regulates expression of the LOX

Nasopharyngeal Carcinoma Signaling Pathway: An Update on Molecular Biomarkers

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Warut Tulalamba

2012-01-01

Full Text Available Nasopharyngeal carcinoma (NPC is an uncommon cancer, which has a distinctive ethnic and geographic distribution. Etiology of NPC is considered to be related with a complex interaction of environmental and genetic factors as well as Epstein-Barr virus infection. Since NPC is located in the silent painless area, the disease is usually therefore diagnosed at the advanced stages; hence early detection of NPC is difficult. Furthermore, understanding in molecular pathogenesis is still lacking, pondering the identification of effective prognostic and diagnostic biomarkers. Dysregulation of signaling molecules in intracellular signal transduction, which regulate cell proliferation, apoptosis, and adhesion, underlines the basis of NPC pathogenesis. In this paper, the molecular signaling pathways in the NPC are discussed for the holistic view of NPC development and progression. The important insights toward NPC pathogenesis may offer strategies for identification of novel biomarkers for diagnosis and prognosis.

Up-regulation of abscisic acid signaling pathway facilitates aphid xylem absorption and osmoregulation under drought stress.

Science.gov (United States)

Guo, Huijuan; Sun, Yucheng; Peng, Xinhong; Wang, Qinyang; Harris, Marvin; Ge, Feng

2016-02-01

The activation of the abscisic acid (ABA) signaling pathway reduces water loss from plants challenged by drought stress. The effect of drought-induced ABA signaling on the defense and nutrition allocation of plants is largely unknown. We postulated that these changes can affect herbivorous insects. We studied the effects of drought on different feeding stages of pea aphids in the wild-type A17 of Medicago truncatula and ABA signaling pathway mutant sta-1. We examined the impact of drought on plant water status, induced plant defense signaling via the abscisic acid (ABA), jasmonic acid (JA), and salicylic acid (SA) pathways, and on the host nutritional quality in terms of leaf free amino acid content. During the penetration phase of aphid feeding, drought decreased epidermis/mesophyll resistance but increased mesophyll/phloem resistance of A17 but not sta-1 plants. Quantification of transcripts associated with ABA, JA and SA signaling indicated that the drought-induced up-regulation of ABA signaling decreased the SA-dependent defense but increased the JA-dependent defense in A17 plants. During the phloem-feeding phase, drought had little effect on the amino acid concentrations and the associated aphid phloem-feeding parameters in both plant genotypes. In the xylem absorption stage, drought decreased xylem absorption time of aphids in both genotypes because of decreased water potential. Nevertheless, the activation of the ABA signaling pathway increased water-use efficiency of A17 plants by decreasing the stomatal aperture and transpiration rate. In contrast, the water potential of sta-1 plants (unable to close stomata) was too low to support xylem absorption activity of aphids; the aphids on sta-1 plants had the highest hemolymph osmolarity and lowest abundance under drought conditions. Taken together this study illustrates the significance of cross-talk between biotic-abiotic signaling pathways in plant-aphid interaction, and reveals the mechanisms leading to alter

The Hippo/YAP pathway interacts with EGFR signaling and HPV oncoproteins to regulate cervical cancer progression

Science.gov (United States)

He, Chunbo; Mao, Dagan; Hua, Guohua; Lv, Xiangmin; Chen, Xingcheng; Angeletti, Peter C; Dong, Jixin; Remmenga, Steven W; Rodabaugh, Kerry J; Zhou, Jin; Lambert, Paul F; Yang, Peixin; Davis, John S; Wang, Cheng

2015-01-01

The Hippo signaling pathway controls organ size and tumorigenesis through a kinase cascade that inactivates Yes-associated protein (YAP). Here, we show that YAP plays a central role in controlling the progression of cervical cancer. Our results suggest that YAP expression is associated with a poor prognosis for cervical cancer. TGF-α and amphiregulin (AREG), via EGFR, inhibit the Hippo signaling pathway and activate YAP to induce cervical cancer cell proliferation and migration. Activated YAP allows for up-regulation of TGF-α, AREG, and EGFR, forming a positive signaling loop to drive cervical cancer cell proliferation. HPV E6 protein, a major etiological molecule of cervical cancer, maintains high YAP protein levels in cervical cancer cells by preventing proteasome-dependent YAP degradation to drive cervical cancer cell proliferation. Results from human cervical cancer genomic databases and an accepted transgenic mouse model strongly support the clinical relevance of the discovered feed-forward signaling loop. Our study indicates that combined targeting of the Hippo and the ERBB signaling pathways represents a novel therapeutic strategy for prevention and treatment of cervical cancer. PMID:26417066

Wnt and Notch signaling pathway involved in wound healing by targeting c-Myc and Hes1 separately.

Science.gov (United States)

Shi, Yan; Shu, Bin; Yang, Ronghua; Xu, Yingbin; Xing, Bangrong; Liu, Jian; Chen, Lei; Qi, Shaohai; Liu, Xusheng; Wang, Peng; Tang, Jinming; Xie, Julin

2015-06-16

Wnt and Notch signaling pathways are critically involved in relative cell fate decisions within the development of cutaneous tissues. Moreover, several studies identified the above two pathways as having a significant role during wound healing. However, their biological effects during cutaneous tissues repair are unclear. We employed a self-controlled model (Sprague-Dawley rats with full-thickness skin wounds) to observe the action and effect of Wnt/β-catenin and Notch signalings in vivo. The quality of wound repair relevant to the gain/loss-of-function Wnt/β-catenin and Notch activation was estimated by hematoxylin-and-eosin and Masson staining. Immunofluorescence analysis and Western blot analysis were used to elucidate the underlying mechanism of the regulation of Wnt and Notch signaling pathways in wound healing. Meanwhile, epidermal stem cells (ESCs) were cultured in keratinocyte serum-free medium with Jaggedl or in DAPT (N-[(3,5-difluorophenyl)acetyl]-L-alanyl-2-phenyl]glycine-1,1-dimethylethyl) to investigate whether the interruption of Notch signaling contributes to the expression of Wnt/β-catenin signaling. The results showed that in vivo the gain-of-function Wnt/β-catenin and Notch activation extended the ability to promote wound closure. We further determined that activation or inhibition of Wnt signaling and Notch signaling can affect the proliferation of ESCs, the differentiation and migration of keratinocytes, and follicle regeneration by targeting c-Myc and Hes1, which ultimately lead to enhanced or delayed wound healing. Furthermore, Western blot analysis suggested that the two pathways might interact in vivo and in vitro. These results suggest that Wnt and Notch signalings play important roles in cutaneous repair by targeting c-Myc and Hes1 separately. What's more, interaction between the above two pathways might act as a vital role in regulation of wound healing.

An alternative mode of CD43 signal transduction activates pro-survival pathways of T lymphocytes.

Science.gov (United States)

Bravo-Adame, Maria Elena; Vera-Estrella, Rosario; Barkla, Bronwyn J; Martínez-Campos, Cecilia; Flores-Alcantar, Angel; Ocelotl-Oviedo, Jose Pablo; Pedraza-Alva, Gustavo; Rosenstein, Yvonne

2017-01-01

CD43 is one of the most abundant co-stimulatory molecules on a T-cell surface; it transduces activation signals through its cytoplasmic domain, contributing to modulation of the outcome of T-cell responses. The aim of this study was to uncover new signalling pathways regulated by this sialomucin. Analysis of changes in protein abundance allowed us to identify pyruvate kinase isozyme M2 (PKM2), an enzyme of the glycolytic pathway, as an element potentially participating in the signalling cascade resulting from the engagement of CD43 and the T-cell receptor (TCR). We found that the glycolytic activity of this enzyme was not significantly increased in response to TCR+CD43 co-stimulation, but that PKM2 was tyrosine phosphorylated, suggesting that it was performing moonlight functions. We report that phosphorylation of both Y 105 of PKM2 and of Y 705 of signal transducer and activator of transcription 3 was induced in response to TCR+CD43 co-stimulation, resulting in activation of the mitogen-activated protein kinase kinase 5/extracellular signal-regulated kinase 5 (MEK5/ERK5) pathway. ERK5 and the cAMP response element binding protein (CREB) were activated, and c-Myc and nuclear factor-κB (p65) nuclear localization, as well as Bad phosphorylation, were augmented. Consistent with this, expression of human CD43 in a murine T-cell hybridoma favoured cell survival. Altogether, our data highlight novel signalling pathways for the CD43 molecule in T lymphocytes, and underscore a role for CD43 in promoting cell survival through non-glycolytic functions of metabolic enzymes. © 2016 John Wiley & Sons Ltd.

Possible involvement of the JAK/STAT signaling pathway in N-acetylcysteine-mediated antidepressant-like effects.

Science.gov (United States)

Al-Samhari, Marwa M; Al-Rasheed, Nouf M; Al-Rejaie, Salim; Al-Rasheed, Nawal M; Hasan, Iman H; Mahmoud, Ayman M; Dzimiri, Nduna

2016-03-01

Advances in depression research have targeted inflammation and oxidative stress to develop novel types of treatment. The JAK/STAT signaling pathway plays pivotal roles in immune and inflammatory responses. The present study was designed to investigate the effects of N-acetylcysteine, a putative precursor of the antioxidant glutathione, in an animal model of depression, with an emphasis on the JAK/STAT signaling pathway. Fluoxetine, a classical antidepressant drug was also under investigation. Male Wistar rats were subjected to forced swimming test and given N-acetylcysteine and fluoxetine immediately after the pre-test session, 5 h later and 1 h before the test session of the forced swimming test. N-acetylcysteine decreased immobility time (P acetylcysteine produced significant (P acetylcysteine significantly (P acetylcysteine. Therefore, depression research may target the JAK/STAT signaling pathway to provide a novel effective therapy. © 2015 by the Society for Experimental Biology and Medicine.

Integrated analysis of breast cancer cell lines reveals unique signaling pathways

Energy Technology Data Exchange (ETDEWEB)

Heiser, Laura M.; Wang, Nicholas J.; Talcott, Carolyn L.; Laderoute, Keith R.; Knapp, Merrill; Guan, Yinghui; Hu, Zhi; Ziyad, Safiyyah; Weber, Barbara L.; Laquerre, Sylvie; Jackson, Jeffrey R.; Wooster, Richard F.; Kuo, Wen-Lin; Gray, Joe W.; Spellman, Paul T.

2009-03-31

Cancer is a heterogeneous disease resulting from the accumulation of genetic defects that negatively impact control of cell division, motility, adhesion and apoptosis. Deregulation in signaling along the EGFR-MAPK pathway is common in breast cancer, though the manner in which deregulation occurs varies between both individuals and cancer subtypes. We were interested in identifying subnetworks within the EGFR-MAPK pathway that are similarly deregulated across subsets of breast cancers. To that end, we mapped genomic, transcriptional and proteomic profiles for 30 breast cancer cell lines onto a curated Pathway Logic symbolic systems model of EGFR-MEK signaling. This model was comprised of 539 molecular states and 396 rules governing signaling between active states. We analyzed these models and identified several subtype specific subnetworks, including one that suggested PAK1 is particularly important in regulating the MAPK cascade when it is over-expressed. We hypothesized that PAK1 overexpressing cell lines would have increased sensitivity to MEK inhibitors. We tested this experimentally by measuring quantitative responses of 20 breast cancer cell lines to three MEK inhibitors. We found that PAK1 over-expressing luminal breast cancer cell lines are significantly more sensitive to MEK inhibition as compared to those that express PAK1 at low levels. This indicates that PAK1 over-expression may be a useful clinical marker to identify patient populations that may be sensitive to MEK inhibitors. All together, our results support the utility of symbolic system biology models for identification of therapeutic approaches that will be effective against breast cancer subsets.

Integrated analysis of breast cancer cell lines reveals unique signaling pathways.

Science.gov (United States)

Heiser, Laura M; Wang, Nicholas J; Talcott, Carolyn L; Laderoute, Keith R; Knapp, Merrill; Guan, Yinghui; Hu, Zhi; Ziyad, Safiyyah; Weber, Barbara L; Laquerre, Sylvie; Jackson, Jeffrey R; Wooster, Richard F; Kuo, Wen Lin; Gray, Joe W; Spellman, Paul T

2009-01-01

Cancer is a heterogeneous disease resulting from the accumulation of genetic defects that negatively impact control of cell division, motility, adhesion and apoptosis. Deregulation in signaling along the EgfR-MAPK pathway is common in breast cancer, though the manner in which deregulation occurs varies between both individuals and cancer subtypes. We were interested in identifying subnetworks within the EgfR-MAPK pathway that are similarly deregulated across subsets of breast cancers. To that end, we mapped genomic, transcriptional and proteomic profiles for 30 breast cancer cell lines onto a curated Pathway Logic symbolic systems model of EgfR-MAPK signaling. This model was composed of 539 molecular states and 396 rules governing signaling between active states. We analyzed these models and identified several subtype-specific subnetworks, including one that suggested Pak1 is particularly important in regulating the MAPK cascade when it is over-expressed. We hypothesized that Pak1 over-expressing cell lines would have increased sensitivity to Mek inhibitors. We tested this experimentally by measuring quantitative responses of 20 breast cancer cell lines to three Mek inhibitors. We found that Pak1 over-expressing luminal breast cancer cell lines are significantly more sensitive to Mek inhibition compared to those that express Pak1 at low levels. This indicates that Pak1 over-expression may be a useful clinical marker to identify patient populations that may be sensitive to Mek inhibitors. All together, our results support the utility of symbolic system biology models for identification of therapeutic approaches that will be effective against breast cancer subsets.

Transforming growth factor β-induced expression of chondroitin sulfate proteoglycans is mediated through non-Smad signaling pathways.

Science.gov (United States)

Jahan, Naima; Hannila, Sari S

2015-01-01

The expression of chondroitin sulfate proteoglycans (CSPGs) by reactive astrocytes is a major factor contributing to glial scarring and regenerative failure after spinal cord injury, but the molecular mechanisms underlying CSPG expression remain largely undefined. One contributing factor is transforming growth factor β (TGFβ), which is upregulated after injury and has been shown to induce expression of CSPGs in vitro. TGFβ typically mediates its effects through the Smad2/3 signaling pathway, and it has been suggested that this pathway is responsible for CSPG expression. However, there is evidence that TGFβ can also activate non-Smad signaling pathways. In this study, we report that TGFβ-induced expression of three different CSPGs--neurocan, brevican, and aggrecan--is mediated through non-Smad signaling pathways. We observed significant increases in TGFβ-induced expression of neurocan, brevican, and aggrecan following siRNA knockdown of Smad2 or Smad4, which indicates that Smad signaling is not required for the expression of these CSPGs. In addition, we show that neurocan, aggrecan, and brevican levels are significantly reduced when TGFβ is administered in the presence of either the PI3K inhibitor LY294002 or the mTOR inhibitor rapamycin, but not the MEK1/2 inhibitor U0126. This suggests that TGFβ mediates this effect through non-Smad-dependent activation of the PI3K-Akt-mTOR signaling pathway, and targeting this pathway may therefore be an effective means of reducing CSPG expression in the injured CNS. Copyright © 2014 Elsevier Inc. All rights reserved.

The role of the stress-activated protein kinase (SAPK/JNK) signaling pathway in radiation-induced apoptosis

International Nuclear Information System (INIS)

Verheij, M.; Ruiter, G.A.; Zerp, S.F.; Bartelink, H.; Blitterswijk, W.J. van; Fuks, Z.; Haimovitz-Friedman, A.

1998-01-01

Ionizing radiation, like a variety of other cellular stress factors, initiates apoptosis, or programmed cell death, in many cell systems. This mode of radiation-induced cell kill should be distinguished from clonogenic cell death due to unrepaired DNA damage. Ionizing radiation not only exerts its effect on the nuclear DNA, but also at the plasma membrane level where it may activate multiple signal transduction pathways. One of these pathways is the stress-activated protein kinase (SAPK) cascade which transduces death signals from the cell membrane to the nucleus. This review discusses recent evidence on the critical role of this signaling system in radiation- and stress-induced apoptosis. An improved understanding of the mechanisms involved in radiation-induced apoptosis may ultimately provide novel strategies of intervention in specific signal transduction pathways to favorably alter the therapeutic ratio in the treatment of human malignancies. (Copyright (c) 1998 Elsevier Science B.V., Amsterdam. All rights reserved.)

Differences in gene expression profiles and signaling pathways in rhabdomyolysis-induced acute kidney injury.

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Geng, Xiaodong; Wang, Yuanda; Hong, Quan; Yang, Jurong; Zheng, Wei; Zhang, Gang; Cai, Guangyan; Chen, Xiangmei; Wu, Di

2015-01-01

Rhabdomyolysis is a threatening syndrome because it causes the breakdown of skeletal muscle. Muscle destruction leads to the release of myoglobin, intracellular proteins, and electrolytes into the circulation. The aim of this study was to investigate the differences in gene expression profiles and signaling pathways upon rhabdomyolysis-induced acute kidney injury (AKI). In this study, we used glycerol-induced renal injury as a model of rhabdomyolysis-induced AKI. We analyzed data and relevant information from the Gene Expression Omnibus database (No: GSE44925). The gene expression data for three untreated mice were compared to data for five mice with rhabdomyolysis-induced AKI. The expression profiling of the three untreated mice and the five rhabdomyolysis-induced AKI mice was performed using microarray analysis. We examined the levels of Cyp3a13, Rela, Aldh7a1, Jun, CD14. And Cdkn1a using RT-PCR to determine the accuracy of the microarray results. The microarray analysis showed that there were 1050 downregulated and 659 upregulated genes in the rhabdomyolysis-induced AKI mice compared to the control group. The interactions of all differentially expressed genes in the Signal-Net were analyzed. Cyp3a13 and Rela had the most interactions with other genes. The data showed that Rela and Aldh7a1 were the key nodes and had important positions in the Signal-Net. The genes Jun, CD14, and Cdkn1a were also significantly upregulated. The pathway analysis classified the differentially expressed genes into 71 downregulated and 48 upregulated pathways including the PI3K/Akt, MAPK, and NF-κB signaling pathways. The results of this study indicate that the NF-κB, MAPK, PI3K/Akt, and apoptotic pathways are regulated in rhabdomyolysis-induced AKI.

Polyclonal immune responses to antigens associated with cancer signaling pathways and new strategies to enhance cancer vaccines.

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Clay, Timothy M; Osada, Takuya; Hartman, Zachary C; Hobeika, Amy; Devi, Gayathri; Morse, Michael A; Lyerly, H Kim

2011-04-01

Aberrant signaling pathways are a hallmark of cancer. A variety of strategies for inhibiting signaling pathways have been developed, but monoclonal antibodies against receptor tyrosine kinases have been among the most successful. A challenge for these therapies is therapeutic unresponsiveness and acquired resistance due to mutations in the receptors, upregulation of alternate growth and survival pathways, or inadequate function of the monoclonal antibodies. Vaccines are able to induce polyclonal responses that can have a multitude of affects against the target molecule. We began to explore therapeutic vaccine development to antigens associated with these signaling pathways. We provide an illustrative example in developing therapeutic cancer vaccines inducing polyclonal adaptive immune responses targeting the ErbB family member HER2. Further, we will discuss new strategies to augment the clinical efficacy of cancer vaccines by enhancing vaccine immunogenicity and reversing the immunosuppressive tumor microenvironment.

Inhibition of Wnt Signaling Pathways Impairs Chlamydia trachomatis Infection in Endometrial Epithelial Cells.

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Kintner, Jennifer; Moore, Cheryl G; Whittimore, Judy D; Butler, Megan; Hall, Jennifer V

2017-01-01

Chlamydia trachomatis infections represent the predominant cause of bacterial sexually transmitted infections. As an obligate intracellular bacterium, C. trachomatis is dependent on the host cell for survival, propagation, and transmission. Thus, factors that affect the host cell, including nutrition, cell cycle, and environmental signals, have the potential to impact chlamydial development. Previous studies have demonstrated that activation of Wnt/β-catenin signaling benefits C. trachomatis infections in fallopian tube epithelia. In cervical epithelial cells chlamydiae sequester β-catenin within the inclusion. These data indicate that chlamydiae interact with the Wnt signaling pathway in both the upper and lower female genital tract (FGT). However, hormonal activation of canonical and non-canonical Wnt signaling pathways is an essential component of cyclic remodeling in another prominent area of the FGT, the endometrium. Given this information, we hypothesized that Wnt signaling would impact chlamydial infection in endometrial epithelial cells. To investigate this hypothesis, we analyzed the effect of Wnt inhibition on chlamydial inclusion development and elementary body (EB) production in two endometrial cell lines, Ishikawa (IK) and Hec-1B, in nonpolarized cell culture and in a polarized endometrial epithelial (IK)/stromal (SHT-290) cell co-culture model. Inhibition of Wnt by the small molecule inhibitor (IWP2) significantly decreased inclusion size in IK and IK/SHT-290 cultures ( p Wnt inhibition caused chlamydiae to become aberrant in morphology. EB formation was also impaired in IK, Hec-1B and IK/SHT-290 cultures regardless of whether Wnt inhibition occurred throughout, in the middle (24 hpi) or late (36 hpi) during the development cycle. Overall, these data lead us to conclude that Wnt signaling in the endometrium is a key host pathway for the proper development of C. trachomatis .

Combinatory annotation of cell membrane receptors and signalling pathways of Bombyx mori prothoracic glands

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Moulos, Panagiotis; Samiotaki, Martina; Panayotou, George; Dedos, Skarlatos G.

2016-01-01

The cells of prothoracic glands (PG) are the main site of synthesis and secretion of ecdysteroids, the biochemical products of cholesterol conversion to steroids that shape the morphogenic development of insects. Despite the availability of genome sequences from several insect species and the extensive knowledge of certain signalling pathways that underpin ecdysteroidogenesis, the spectrum of signalling molecules and ecdysteroidogenic cascades is still not fully comprehensive. To fill this gap and obtain the complete list of cell membrane receptors expressed in PG cells, we used combinatory bioinformatic, proteomic and transcriptomic analysis and quantitative PCR to annotate and determine the expression profiles of genes identified as putative cell membrane receptors of the model insect species, Bombyx mori, and subsequently enrich the repertoire of signalling pathways that are present in its PG cells. The genome annotation dataset we report here highlights modules and pathways that may be directly involved in ecdysteroidogenesis and aims to disseminate data and assist other researchers in the discovery of the role of such receptors and their ligands. PMID:27576083

Melatonin attenuates angiotensin II-induced cardiomyocyte hypertrophy through the CyPA/CD147 signaling pathway.

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Su, Hongyan; Li, Jingyuan; Chen, Tongshuai; Li, Na; Xiao, Jie; Wang, Shujian; Guo, Xiaobin; Yang, Yi; Bu, Peili

2016-11-01

Melatonin is well known for its cardioprotective effects; however, whether melatonin exerts therapeutic effects on cardiomyocyte hypertrophy remains to be investigated, as do the mechanisms underlying these effects, if they exist. Cyclophilin A (CyPA) and its corresponding receptor, CD147, which exists in a variety of cells, play crucial roles in modulating reactive oxygen species (ROS) production. In this study, we explored the role of the CyPA/CD147 signaling pathway in angiotensin II (Ang II)-induced cardiomyocyte hypertrophy and the protective effects exerted by melatonin against Ang II-induced injury in cultured H9C2 cells. Cyclosporine A, a specific CyPA/CD147 signaling pathway inhibitor, was used to manipulate CyPA/CD147 activity. H9C2 cells were then subjected to Ang II or CyPA treatment in either the absence or presence of melatonin. Our results indicate that Ang II induces cardiomyocyte hypertrophy through the CyPA/CD147 signaling pathway and promotes ROS production, which can be blocked by melatonin pretreatment in a concentration-dependent manner, in cultured H9C2 cells and that CyPA/CD147 signaling pathway inhibition protects against Ang II-induced cardiomyocyte hypertrophy. The protective effects of melatonin against Ang II-induced cardiomyocyte hypertrophy depend at least partially on CyPA/CD147 inhibition.

A MEMS-based Adaptive AHRS for Marine Satellite Tracking Antenna

DEFF Research Database (Denmark)

Wang, Yunlong; Hussain, Dil Muhammed Akbar; Soltani, Mohsen

2015-01-01

Satellite tracking is a challenging task for marine applications. An attitude determination system should estimate the wave disturbances on the ship body accurately. To achieve this, an Attitude Heading Reference System (AHRS) based on Micro-Electro-Mechanical Systems (MEMS) sensors, composed...... of three-axis gyroscope, accelerometer and magnetometer, is developed for Marine Satellite Tracking Antenna (MSTA). In this paper, the attitude determination algorithm is improved using an adaptive mechanism that tunes the attitude estimator parameters based on an estimation of ship motion frequency...

Genital Sensory Stimulation Shifts Estradiol Intraoviductal Signaling from Nongenomic to Genomic Pathways, Independently from Prolactin Surges

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C PEÑARROJA-MATUTAN0

2007-01-01

Full Text Available Estradiol (E2 accelerates oviductal egg transport through nongenomic pathways involving oviductal protein phosphorylation in non-mated rats, and through genomic pathways in mated rats. Here we investigated the ability of cervico-vaginal stimulation (CVS to switch the mode of action of E2 in the absence of other male-associated components. Pro-estrous rats were subjected to CVS with a glass rod and 12 hours later were injected subcutaneously with E2 and intrabursally with the RNA synthesis inhibitor Actinomycin D or the protein phosphorylation inhibitor H-89. The number of eggs in the oviduct, assessed 24 h later, showed that Actinomycin D, but not H-89 blocked the E2-induced egg transport acceleration. This clearly indicates that CVS alone, without other mating-associated signals, is able to shift E2 signaling from nongenomic to genomic pathways. Since mating and CVS activate a neuroendocrine reflex that causes iterative prolactin (PRL surges, the involvement of PRL pathway in this phenomenon was evaluated. Prolactin receptor mRNA and protein expression in the rat oviduct was demonstrated by RT-PCR and Western blot, but their levels were not different on day 2 of the cycle (C2 or pregnancy (P2. Activated ST AT 5a/b (phosphorylated was detected by Western blot on P2 in the ovary, but not in the oviduct, showing that mating does not stimulate this PRL signalling pathway in the oviduct. Other rats subjected to CVS in the evening of pro-estrus were treated with bromoergocriptine to suppress PRL surges. In these rats, H-89 did not block the E2-induced acceleration of egg transport suggesting that PRL surges are not essential to shift E2 signaling pathways in the oviduct. We conclude that CVS is one of the components of mating that shifts E2 signaling in the oviduct from nongenomic to genomic pathways, and this effect is independent of PRL surges elicited by mating

Modeling of coupled differential equations for cellular chemical signaling pathways: Implications for assay protocols utilized in cellular engineering.

Science.gov (United States)

O'Clock, George D

2016-08-01

Cellular engineering involves modification and control of cell properties, and requires an understanding of fundamentals and mechanisms of action for cellular derived product development. One of the keys to success in cellular engineering involves the quality and validity of results obtained from cell chemical signaling pathway assays. The accuracy of the assay data cannot be verified or assured if the effect of positive feedback, nonlinearities, and interrelationships between cell chemical signaling pathway elements are not understood, modeled, and simulated. Nonlinearities and positive feedback in the cell chemical signaling pathway can produce significant aberrations in assay data collection. Simulating the pathway can reveal potential instability problems that will affect assay results. A simulation, using an electrical analog for the coupled differential equations representing each segment of the pathway, provides an excellent tool for assay validation purposes. With this approach, voltages represent pathway enzyme concentrations and operational amplifier feedback resistance and input resistance values determine pathway gain and rate constants. The understanding provided by pathway modeling and simulation is strategically important in order to establish experimental controls for assay protocol structure, time frames specified between assays, and assay concentration variation limits; to ensure accuracy and reproducibility of results.

Aberrant signaling pathways in medulloblastomas: a stem cell connection

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Carolina Oliveira Rodini

2010-12-01

Full Text Available Medulloblastoma is a highly malignant primary tumor of the central nervous system. It represents the most frequent type of solid tumor and the leading cause of death related to cancer in early childhood. Current treatment includes surgery, chemotherapy and radiotherapy which may lead to severe cognitive impairment and secondary brain tumors. New perspectives for therapeutic development have emerged with the identification of stem-like cells displaying high tumorigenic potential and increased radio- and chemo-resistance in gliomas. Under the cancer stem cell hypothesis, transformation of neural stem cells and/or granular neuron progenitors of the cerebellum are though to be involved in medulloblastoma development. Dissecting the genetic and molecular alterations associated with this process should significantly impact both basic and applied cancer research. Based on cumulative evidences in the fields of genetics and molecular biology of medulloblastomas, we discuss the possible involvement of developmental signaling pathways as critical biochemical switches determining normal neurogenesis or tumorigenesis. From the clinical viewpoint, modulation of signaling pathways such as TGFβ, regulating neural stem cell proliferation and tumor development, might be attempted as an alternative strategy for future drug development aiming at more efficient therapies and improved clinical outcome of patients with pediatric brain cancers.

Global microRNA profiles and signaling pathways in the development of cardiac hypertrophy

Energy Technology Data Exchange (ETDEWEB)

Feng, H.J.; Ouyang, W.; Liu, J.H.; Sun, Y.G.; Hu, R.; Huang, L.H.; Xian, J.L. [Southern Medical University, Department of Nuclear Medicine, Zhujiang Hospital, Guangzhou, China, Department of Nuclear Medicine, Zhujiang Hospital, Southern Medical University, Guangzhou (China); Jing, C.F.; Zhou, M.J. [Sun Yat-Sen University, South China Sea Marine Biotechnology, National Engineering Research Center, Guangzhou, China, National Engineering Research Center, South China Sea Marine Biotechnology, Sun Yat-Sen University, Guangzhou (China)

2014-04-11

Hypertrophy is a major predictor of progressive heart disease and has an adverse prognosis. MicroRNAs (miRNAs) that accumulate during the course of cardiac hypertrophy may participate in the process. However, the nature of any interaction between a hypertrophy-specific signaling pathway and aberrant expression of miRNAs remains unclear. In this study, Spague Dawley male rats were treated with transverse aortic constriction (TAC) surgery to mimic pathological hypertrophy. Hearts were isolated from TAC and sham operated rats (n=5 for each group at 5, 10, 15, and 20 days after surgery) for miRNA microarray assay. The miRNAs dysexpressed during hypertrophy were further analyzed using a combination of bioinformatics algorithms in order to predict possible targets. Increased expression of the target genes identified in diverse signaling pathways was also analyzed. Two sets of miRNAs were identified, showing different expression patterns during hypertrophy. Bioinformatics analysis suggested the miRNAs may regulate multiple hypertrophy-specific signaling pathways by targeting the member genes and the interaction of miRNA and mRNA might form a network that leads to cardiac hypertrophy. In addition, the multifold changes in several miRNAs suggested that upregulation of rno-miR-331*, rno-miR-3596b, rno-miR-3557-5p and downregulation of rno-miR-10a, miR-221, miR-190, miR-451 could be seen as biomarkers of prognosis in clinical therapy of heart failure. This study described, for the first time, a potential mechanism of cardiac hypertrophy involving multiple signaling pathways that control up- and downregulation of miRNAs. It represents a first step in the systematic discovery of miRNA function in cardiovascular hypertrophy.

Identification of DreI as an antiviral factor regulated by RLR signaling pathway.

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Shun Li

Full Text Available BACKGROUND: Retinoic acid-inducible gene I (RIG-I-like receptors (RLRs had been demonstrated to prime interferon (IFN response against viral infection via the conserved RLR signaling in fish, and a novel fish-specific gene, the grass carp reovirus (GCRV-induced gene 2 (Gig2, had been suggested to play important role in host antiviral response. METHODOLOGY/PRINCIPAL FINDINGS: In this study, we cloned and characterized zebrafish Gig2 homolog (named Danio rerio Gig2-I, DreI, and revealed its antiviral role and expressional regulation signaling pathway. RT-PCR, Western blot and promoter activity assay indicate that DreI can be induced by poly I:C, spring viremia of carp virus (SVCV and recombinant IFN (rIFN, showing that DreI is a typical ISG. Using the pivotal signaling molecules of RLR pathway, including RIG-I, MDA5 and IRF3 from crucian carp, it is found that DreI expression is regulated by RLR cascade and IRF3 plays an important role in this regulation. Furthermore, promoter mutation assay confirms that the IFN-stimulated regulatory elements (ISRE in the 5' flanking region of DreI is essential for its induction. Finally, overexpression of DreI leads to establish a strong antiviral state against SVCV and Rana grylio virus (RGV infection in EPC (Epithelioma papulosum cyprinid cells. CONCLUSIONS/SIGNIFICANCE: These data indicate that DreI is an antiviral protein, which is regulated by RLR signaling pathway.

The hippo pathway promotes Notch signaling in regulation of cell differentiation, proliferation, and oocyte polarity.

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Jianzhong Yu

2008-03-01

Full Text Available Specification of the anterior-posterior axis in Drosophila oocytes requires proper communication between the germ-line cells and the somatically derived follicular epithelial cells. Multiple signaling pathways, including Notch, contribute to oocyte polarity formation by controlling the temporal and spatial pattern of follicle cell differentiation and proliferation. Here we show that the newly identified Hippo tumor-suppressor pathway plays a crucial role in the posterior follicle cells in the regulation of oocyte polarity. Disruption of the Hippo pathway, including major components Hippo, Salvador, and Warts, results in aberrant follicle-cell differentiation and proliferation and dramatic disruption of the oocyte anterior-posterior axis. These phenotypes are related to defective Notch signaling in follicle cells, because misexpression of a constitutively active form of Notch alleviates the oocyte polarity defects. We also find that follicle cells defective in Hippo signaling accumulate the Notch receptor and display defects in endocytosis markers. Our findings suggest that the interaction between Hippo and classic developmental pathways such as Notch is critical to spatial and temporal regulation of differentiation and proliferation and is essential for development of the body axes in Drosophila.

M2 macrophages activate WNT signaling pathway in epithelial cells: relevance in ulcerative colitis.

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Jesús Cosín-Roger

Full Text Available Macrophages, which exhibit great plasticity, are important components of the inflamed tissue and constitute an essential element of regenerative responses. Epithelial Wnt signalling is involved in mechanisms of proliferation and differentiation and expression of Wnt ligands by macrophages has been reported. We aim to determine whether the macrophage phenotype determines the expression of Wnt ligands, the influence of the macrophage phenotype in epithelial activation of Wnt signalling and the relevance of this pathway in ulcerative colitis. Human monocyte-derived macrophages and U937-derived macrophages were polarized towards M1 or M2 phenotypes and the expression of Wnt1 and Wnt3a was analyzed by qPCR. The effects of macrophages and the role of Wnt1 were analyzed on the expression of β-catenin, Tcf-4, c-Myc and markers of cell differentiation in a co-culture system with Caco-2 cells. Immunohistochemical staining of CD68, CD206, CD86, Wnt1, β-catenin and c-Myc were evaluated in the damaged and non-damaged mucosa of patients with UC. We also determined the mRNA expression of Lgr5 and c-Myc by qPCR and protein levels of β-catenin by western blot. Results show that M2, and no M1, activated the Wnt signaling pathway in co-culture epithelial cells through Wnt1 which impaired enterocyte differentiation. A significant increase in the number of CD206+ macrophages was observed in the damaged mucosa of chronic vs newly diagnosed patients. CD206 immunostaining co-localized with Wnt1 in the mucosa and these cells were associated with activation of canonical Wnt signalling pathway in epithelial cells and diminution of alkaline phosphatase activity. Our results show that M2 macrophages, and not M1, activate Wnt signalling pathways and decrease enterocyte differentiation in co-cultured epithelial cells. In the mucosa of UC patients, M2 macrophages increase with chronicity and are associated with activation of epithelial Wnt signalling and diminution in

Signaling Pathways Regulating Redox Balance in Cancer Metabolism.

Science.gov (United States)

De Santis, Maria Chiara; Porporato, Paolo Ettore; Martini, Miriam; Morandi, Andrea

2018-01-01

The interplay between rewiring tumor metabolism and oncogenic driver mutations is only beginning to be appreciated. Metabolic deregulation has been described for decades as a bystander effect of genomic aberrations. However, for the biology of malignant cells, metabolic reprogramming is essential to tackle a harsh environment, including nutrient deprivation, reactive oxygen species production, and oxygen withdrawal. Besides the well-investigated glycolytic metabolism, it is emerging that several other metabolic fluxes are relevant for tumorigenesis in supporting redox balance, most notably pentose phosphate pathway, folate, and mitochondrial metabolism. The relationship between metabolic rewiring and mutant genes is still unclear and, therefore, we will discuss how metabolic needs and oncogene mutations influence each other to satisfy cancer cells' demands. Mutations in oncogenes, i.e., PI3K/AKT/mTOR, RAS pathway, and MYC, and tumor suppressors, i.e., p53 and liver kinase B1, result in metabolic flexibility and may influence response to therapy. Since metabolic rewiring is shaped by oncogenic driver mutations, understanding how specific alterations in signaling pathways affect different metabolic fluxes will be instrumental for the development of novel targeted therapies. In the era of personalized medicine, the combination of driver mutations, metabolite levels, and tissue of origins will pave the way to innovative therapeutic interventions.

Integrated QSAR study for inhibitors of Hedgehog Signal Pathway against multiple cell lines:a collaborative filtering method.

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Gao, Jun; Che, Dongsheng; Zheng, Vincent W; Zhu, Ruixin; Liu, Qi

2012-07-31

The Hedgehog Signaling Pathway is one of signaling pathways that are very important to embryonic development. The participation of inhibitors in the Hedgehog Signal Pathway can control cell growth and death, and searching novel inhibitors to the functioning of the pathway are in a great demand. As the matter of fact, effective inhibitors could provide efficient therapies for a wide range of malignancies, and targeting such pathway in cells represents a promising new paradigm for cell growth and death control. Current research mainly focuses on the syntheses of the inhibitors of cyclopamine derivatives, which bind specifically to the Smo protein, and can be used for cancer therapy. While quantitatively structure-activity relationship (QSAR) studies have been performed for these compounds among different cell lines, none of them have achieved acceptable results in the prediction of activity values of new compounds. In this study, we proposed a novel collaborative QSAR model for inhibitors of the Hedgehog Signaling Pathway by integration the information from multiple cell lines. Such a model is expected to substantially improve the QSAR ability from single cell lines, and provide useful clues in developing clinically effective inhibitors and modifications of parent lead compounds for target on the Hedgehog Signaling Pathway. In this study, we have presented: (1) a collaborative QSAR model, which is used to integrate information among multiple cell lines to boost the QSAR results, rather than only a single cell line QSAR modeling. Our experiments have shown that the performance of our model is significantly better than single cell line QSAR methods; and (2) an efficient feature selection strategy under such collaborative environment, which can derive the commonly important features related to the entire given cell lines, while simultaneously showing their specific contributions to a specific cell-line. Based on feature selection results, we have proposed several

Integration of Signaling Pathways with the Epigenetic Machinery in the Maintenance of Stem Cells

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Luca Fagnocchi

2016-01-01

Full Text Available Stem cells balance their self-renewal and differentiation potential by integrating environmental signals with the transcriptional regulatory network. The maintenance of cell identity and/or cell lineage commitment relies on the interplay of multiple factors including signaling pathways, transcription factors, and the epigenetic machinery. These regulatory modules are strongly interconnected and they influence the pattern of gene expression of stem cells, thus guiding their cellular fate. Embryonic stem cells (ESCs represent an invaluable tool to study this interplay, being able to indefinitely self-renew and to differentiate towards all three embryonic germ layers in response to developmental cues. In this review, we highlight those mechanisms of signaling to chromatin, which regulate chromatin modifying enzymes, histone modifications, and nucleosome occupancy. In addition, we report the molecular mechanisms through which signaling pathways affect both the epigenetic and the transcriptional state of ESCs, thereby influencing their cell identity. We propose that the dynamic nature of oscillating signaling and the different regulatory network topologies through which those signals are encoded determine specific gene expression programs, leading to the fluctuation of ESCs among multiple pluripotent states or to the establishment of the necessary conditions to exit pluripotency.

Expression of aryl hydrocarbon receptor 1 (AHR1), AHR1 nuclear translocator 1 (ARNT1) and CYP1 family monooxygenase mRNAs and their activity in chicken ovarian follicles following in vitro exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD).

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Antos, Piotr A; Błachuta, Małgorzata; Hrabia, Anna; Grzegorzewska, Agnieszka K; Sechman, Andrzej

2015-09-02

The aim of this in vitro study was to determine the effect of TCDD and luteinizing hormone (LH) on mRNA expression of aryl hydrocarbon receptor 1 (AHR1), AHR1 nuclear translocator 1 (ARNT1), and the CYP1 family monooxygenases (CYP1A4, CYP1A5, CYP1B1), and to assess the basal and TCDD-induced activity of these enzymes in chicken ovarian follicles. White (WF) and yellowish (YF) prehierarchical follicles and fragments of the theca (TL) and granulosa (GL) layers of the 3 largest preovulatory follicles (F3-F1) were exposed to TCDD (10nM), ovine LH (oLH; 10ng/mL) or a combination of TCDD (10nM) and oLH (10ng/mL), and increasing doses of TCDD (0.01-100nM). AHR1 and ARNT1 mRNA transcripts were found in all examined follicles. The effect of TCDD and oLH on AHR1 and ARNT1 mRNA expression depended on the maturational state of the follicle. CYP1A4 was predominantly expressed in the GL of the F3-F1 follicles; in comparison with the WF, a higher level of CYP1A5 mRNA was found both in the GL and TL of F3-F1 follicles. Alternatively, the highest level of CYP1B1 mRNA was noticed in the WF follicles. In different developmental stages of the follicle TCDD and oLH induced a different CYP1 isoform. TCDD increased EROD and MROD activities in all the investigated ovarian follicles. In conclusion, AHR1 and ARNT1 mRNA expression indicate that the chicken ovary is a target tissue for dioxin and dioxin-like compounds. The expression of CYP1-family genes and TCDD-inducible EROD and MROD activities in ovarian follicles suggest the possibility of xenobiotic detoxification in the chicken ovary. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Rare variants in the neurotrophin signaling pathway implicated in schizophrenia risk.

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Kranz, Thorsten M; Goetz, Ray R; Walsh-Messinger, Julie; Goetz, Deborah; Antonius, Daniel; Dolgalev, Igor; Heguy, Adriana; Seandel, Marco; Malaspina, Dolores; Chao, Moses V

2015-10-01

Multiple lines of evidence corroborate impaired signaling pathways as relevant to the underpinnings of schizophrenia. There has been an interest in neurotrophins, since they are crucial mediators of neurodevelopment and in synaptic connectivity in the adult brain. Neurotrophins and their receptors demonstrate aberrant expression patterns in cortical areas for schizophrenia cases in comparison to control subjects. There is little known about the contribution of neurotrophin genes in psychiatric disorders. To begin to address this issue, we conducted high-coverage targeted exome capture in a subset of neurotrophin genes in 48 comprehensively characterized cases with schizophrenia-related psychosis. We herein report rare missense polymorphisms and novel missense mutations in neurotrophin receptor signaling pathway genes. Furthermore, we observed that several genes have a higher propensity to harbor missense coding variants than others. Based on this initial analysis we suggest that rare variants and missense mutations in neurotrophin genes might represent genetic contributions involved across psychiatric disorders. Copyright © 2015 Elsevier B.V. All rights reserved.

Utilizing ras signaling pathway to direct selective replication of herpes simplex virus-1.

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Weihong Pan

Full Text Available Re-engineering the tropism of viruses is an attractive translational strategy for targeting cancer cells. The Ras signal transduction pathway is a central hub for a variety of pro-oncogenic events with a fundamental role in normal and neoplastic physiology. In this work we were interested in linking Ras activation to HSV-1 replication in a direct manner in order to generate a novel oncolytic herpes virus which can target cancer cells. To establish such link, we developed a mutant HSV-1 in which the expression of ICP4 (infected cell protein-4, a viral protein necessary for replication is controlled by activation of ELK, a transcription factor down-stream of the Ras pathway and mainly activated by ERK (extracellular signal-regulated kinase, an important Ras effector pathway. This mutant HSV-1 was named as Signal-Smart 1 (SS1. A series of prostate cells were infected with the SS1 virus. Cells with elevated levels of ELK activation were preferentially infected by the SS1 virus, as demonstrated by increased levels of viral progeny, herpetic glycoprotein C and overall SS1 viral protein production. Upon exposure to SS1, the proliferation, invasiveness and colony formation capabilities of prostate cancer cells with increased ELK activation were significantly decreased (p<0.05, while the rate of apoptosis/necrosis in these cells was increased. Additionally, high Ras signaling cells infected with SS1 showed a prominent arrest in the G1 phase of the cell cycle as compared to cells exposed to parental HSV-1. The results of this study reveal the potential for re-modeling the host-herpes interaction to specifically interfere with the life of cancer cells with increased Ras signaling. SS1 also serves as a "prototype" for development of a family of signal-smart viruses which can target cancer cells on the basis of their signaling portfolio.

Signaling pathway-focused gene expression profiling in pressure overloaded hearts

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Marco Musumeci

2011-01-01

Full Text Available The β-blocker propranolol displays antihypertrophic and antifibrotic properties in the heart subjected to pressure overload. Yet the underlying mechanisms responsible for these important effects remain to be completely understood. The purpose of this study was to determine signaling pathway-focused gene expression profile associated with the antihypertrophic action of propranolol in pressure overloaded hearts. To address this question, a focused real-time PCR array was used to screen left ventricular RNA expression of 84 gene transcripts representative of 18 different signaling pathways in C57BL/6 mice subjected to transverse aortic constriction (TAC or sham surgery. On the surgery day, mice received either propranolol (80 mg/kg/day or vehicle for 14 days. TAC caused a 49% increase in the left ventricular weight-to-body weight (LVW/BW ratio without changing gene expression. Propranolol blunted LVW/BW ratio increase by approximately 50% while causing about a 3-fold increase in the expression of two genes, namely Brca1 and Cdkn2a, belonging to the TGF-beta and estrogen pathways, respectively. In conclusion, after 2 weeks of pressure overload, TAC hearts show a gene expression profile superimposable to that of sham hearts. Conversely, propranolol treatment is associated with an increased expression of genes which negatively regulate cell cycle progression. It remains to be established whether a mechanistic link between gene expression changes and the antihypertrophic action of propranolol occurs.