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

PubMed

Ghotbaddini, Maryam; Powell, Joann B

2015-07-06

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.

TCDD and omeprazole prime platelets through the aryl hydrocarbon receptor (AhR) non-genomic pathway.

PubMed

Pombo, Mónica; Lamé, Michael W; Walker, Naomi J; Huynh, Danh H; Tablin, Fern

2015-05-19

The role of the aryl hydrocarbon receptor (AhR) in hemostasis has recently gained increased attention. Here, we demonstrate, by qRT-PCR and western blot, that human platelets express both AhR mRNA and AhR protein. AhR protein levels increase in a dose dependent manner when incubated with either 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) or omeprazole. Treatment of platelets with puromycin blocks increased AhR protein synthesis in the presence of AhR activators. Additionally, treatment of platelets with either activator results in phosphorylation of p38MAPK and cPLA2, two key signaling molecules in platelet activation pathways. Using the AhR competitive inhibitors alpha naphthoflavone and CH-223191, we show that phosphorylation of p38MAPK is AhR dependent. Further, inhibition of p38MAPK blocks downstream cPLA2 phosphorylation induced by TCDD or omeprazole. Treatment with AhR activators results in platelet priming, as demonstrated by increased platelet aggregation, which is inhibited by AhR antagonists. Our data support a model of the platelet AhR non-genomic pathway in which treatment with AhR activators results in increased expression of the AhR, phosphorylation of p38MAPK and cPLA2, leading to platelet priming in response to agonist. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Bidirectional communication between the Aryl hydrocarbon Receptor (AhR) and the microbiome tunes host metabolism.

PubMed

Korecka, Agata; Dona, Anthony; Lahiri, Shawon; Tett, Adrian James; Al-Asmakh, Maha; Braniste, Viorica; D'Arienzo, Rossana; Abbaspour, Afrouz; Reichardt, Nicole; Fujii-Kuriyama, Yoshiaki; Rafter, Joseph; Narbad, Arjan; Holmes, Elaine; Nicholson, Jeremy; Arulampalam, Velmurugesan; Pettersson, Sven

2016-01-01

The ligand-induced transcription factor, aryl hydrocarbon receptor (AhR) is known for its capacity to tune adaptive immunity and xenobiotic metabolism-biological properties subject to regulation by the indigenous microbiome. The objective of this study was to probe the postulated microbiome-AhR crosstalk and whether such an axis could influence metabolic homeostasis of the host. Utilising a systems-biology approach combining in-depth 1 H-NMR-based metabonomics (plasma, liver and skeletal muscle) with microbiome profiling (small intestine, colon and faeces) of AhR knockout (AhR -/- ) and wild-type (AhR +/+ ) mice, we assessed AhR function in host metabolism. Microbiome metabolites such as short-chain fatty acids were found to regulate AhR and its target genes in liver and intestine. The AhR signalling pathway, in turn, was able to influence microbiome composition in the small intestine as evident from microbiota profiling of the AhR +/+ and AhR -/- mice fed with diet enriched with a specific AhR ligand or diet depleted of any known AhR ligands. The AhR -/- mice also displayed increased levels of corticosterol and alanine in serum. In addition, activation of gluconeogenic genes in the AhR -/- mice was indicative of on-going metabolic stress. Reduced levels of ketone bodies and reduced expression of genes involved in fatty acid metabolism in the liver further underscored this observation. Interestingly, exposing AhR -/- mice to a high-fat diet showed resilience to glucose intolerance. Our data suggest the existence of a bidirectional AhR-microbiome axis, which influences host metabolic pathways.

The neuraminidases of MDCK grown human influenza A(H3N2) viruses isolated since 1994 can demonstrate receptor binding.

PubMed

Mohr, Peter G; Deng, Yi-Mo; McKimm-Breschkin, Jennifer L

2015-04-22

The neuraminidases (NAs) of MDCK passaged human influenza A(H3N2) strains isolated since 2005 are reported to have dual functions of cleavage of sialic acid and receptor binding. NA agglutination of red blood cells (RBCs) can be inhibited by neuraminidase inhibitors (NAIs), thus distinguishing it from haemagglutinin (HA) binding. We wanted to know if viruses prior to 2005 can demonstrate this property. Pairs of influenza A(H3N2) isolates ranging from 1993-2008 passaged in parallel only in eggs or in MDCK cells were tested for inhibition of haemagglutination by various NAIs. Only viruses isolated since 1994 and cultured in MDCK cells bound chicken RBCs solely through their NA. NAI inhibition of agglutination of turkey RBCs was seen for some, but not all of these same MDCK grown viruses. Efficacy of inhibition of enzyme activity and haemagglutination differed between NAIs. For many viruses lower concentrations of oseltamivir could inhibit agglutination compared to zanamivir, although they could both inhibit enzyme activity at comparable concentrations. An E119V mutation reduced sensitivity to oseltamivir and 4-aminoDANA for both the enzyme assay and inhibition of agglutination. Sequence analysis of the NAs and HAs of some paired viruses revealed mutations in the haemagglutinin of all egg passaged viruses. For many of the paired egg and MDCK cultured viruses we found no differences in their NA sequences by Sanger sequencing. However, deep sequencing of MDCK grown isolates revealed low levels of variant populations with mutations at either D151 or T148 in the NA, suggesting mutations at either site may be able to confer this property. The NA active site of MDCK cultured human influenza A(H3N2) viruses isolated since 1994 can express dual enzyme and receptor binding functions. Binding correlated with either D151 or T148 mutations. The catalytic and receptor binding sites do not appear to be structurally identical since relative concentrations of the NAIs to inhibit

Bidirectional communication between the Aryl hydrocarbon Receptor (AhR) and the microbiome tunes host metabolism

PubMed Central

Korecka, Agata; Dona, Anthony; Lahiri, Shawon; Tett, Adrian James; Al-Asmakh, Maha; Braniste, Viorica; D’Arienzo, Rossana; Abbaspour, Afrouz; Reichardt, Nicole; Fujii-Kuriyama, Yoshiaki; Rafter, Joseph; Narbad, Arjan; Holmes, Elaine; Nicholson, Jeremy; Arulampalam, Velmurugesan; Pettersson, Sven

2016-01-01

The ligand-induced transcription factor, aryl hydrocarbon receptor (AhR) is known for its capacity to tune adaptive immunity and xenobiotic metabolism—biological properties subject to regulation by the indigenous microbiome. The objective of this study was to probe the postulated microbiome-AhR crosstalk and whether such an axis could influence metabolic homeostasis of the host. Utilising a systems-biology approach combining in-depth 1H-NMR-based metabonomics (plasma, liver and skeletal muscle) with microbiome profiling (small intestine, colon and faeces) of AhR knockout (AhR−/−) and wild-type (AhR+/+) mice, we assessed AhR function in host metabolism. Microbiome metabolites such as short-chain fatty acids were found to regulate AhR and its target genes in liver and intestine. The AhR signalling pathway, in turn, was able to influence microbiome composition in the small intestine as evident from microbiota profiling of the AhR+/+ and AhR−/− mice fed with diet enriched with a specific AhR ligand or diet depleted of any known AhR ligands. The AhR−/− mice also displayed increased levels of corticosterol and alanine in serum. In addition, activation of gluconeogenic genes in the AhR−/− mice was indicative of on-going metabolic stress. Reduced levels of ketone bodies and reduced expression of genes involved in fatty acid metabolism in the liver further underscored this observation. Interestingly, exposing AhR−/− mice to a high-fat diet showed resilience to glucose intolerance. Our data suggest the existence of a bidirectional AhR-microbiome axis, which influences host metabolic pathways. PMID:28721249

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

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

2006-04-15

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{sub 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 exhibitedmore » increases in heart-to-body weight ratio and age-related expression of cardiac hypertrophy markers, {beta}-myosin heavy chain ({beta}-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{sub 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 {beta}-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{sub A} receptor as primary determinants of hypertension and cardiac pathology in AhR null mice.« less

A human intervention study with foods containing natural Ah-receptor agonists does not significantly show AhR-mediated effects as measured in blood cells and urine.

PubMed

de Waard, Pim W J; Peijnenburg, Ad A C M; Baykus, Hakan; Aarts, Jac M M J G; Hoogenboom, Ron L A P; van Schooten, Frederik J; de Kok, Theo M C M

2008-10-22

Binding and activation of the aryl hydrocarbon receptor (AhR) is thought to be an essential step in the toxicity of the environmental pollutants dioxins and dioxin-like PCBs. However, also a number of natural compounds, referred to as NAhRAs (natural Ah-receptor agonists), which are present in, for example, fruits and vegetables, can bind and activate this receptor. To study their potential effects in humans, we first investigated the effect of the prototypical AhR agonist 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) on gene expression in ex vivo exposed freshly isolated human lymphocytes, and compared the resulting gene expression profile with those caused by the well-known NAhRA indolo[3,2-b]carbazole (ICZ), originating from cruciferous vegetables, and by a hexane extract of NAhRA-containing grapefruit juice (GJE). Only ICZ induced a gene expression profile similar to TCDD in the lymphocytes, and both significantly up-regulated CYP1B1 and TIPARP (TCDD-inducible poly (ADP-ribose) polymerase) mRNA. Next, we performed a human intervention study with NAhRA-containing cruciferous vegetables and grapefruit juice. The expression of the prototypical AhR-responsive genes CYP1A1, CYP1B1 and NQO1 in whole blood cells and in freshly isolated lymphocytes was not significantly affected. Also enzyme activities of CYP1A2, CYP2A6, N-acetyltransferase 2 (NAT2) and xanthine oxidase (XO), as judged by caffeine metabolites in urine, were unaffected, except for a small down-regulation of NAT2 activity by grapefruit juice. Examination of blood plasma with DR CALUX showed a 12% increased AhR agonist activity 3 and 24 h after consumption of cruciferous vegetables, but did not show a significant effect of grapefruit juice consumption. We conclude that intake of NAhRAs from food may result in minor AhR-related effects measurable in human blood and urine.

Ligand-dependent interactions of the Ah receptor with coactivators in a mammalian two-hybrid assay

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang Shu; Rowlands, Craig; Safe, Stephen

2008-03-01

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) is a high affinity ligand for the aryl hydrocarbon receptor (AhR). In this study, we investigated structure-dependent differences in activation of the AhR by a series of halogenated aromatic hydrocarbons. TCDD, 1,2,3,7,8-pentachlorodibenzo-p-dioxin (PeCDD), 2,3,7,8-tetrachlorodibenzofuran (TCDF), 2,3,4,7,8-pentachlorodibenzofuran (PeCDF), and 3,3',4,4',5-pentachlorobiphenyl (PCB126) induced CYP1A1-dependent activities in HEK293 human embryonic kidney, Panc1 pancreatic cancer, and Hepa1c1c7 mouse hepatoma cell lines. There was a structure-dependent difference in the efficacy of TCDF and PCB126 in HEK293 and Panc1 cells since induced CYP1A1 mRNA levels were lower than observed for the other congeners. A mammalian two-hybrid assay in cells transfected with GAL4-coactivator and AhR-VP16more » chimeras was used to investigate structure-dependent interactions of these chimeras in Panc1, HEK293, and Hepa1c1c7 cells. The reporter construct pGAL4-luc contains five tandem GAL4 response elements linked to the luciferase gene and the GAL4-coactivator chimeras express several coactivators including steroid receptor coactivator 1 (SRC-1), SRC-2 and SRC-3, the mediator coactivator TRAP220, coactivator associated arginine methyl transferase 1 (CARM-1), and peroxisome proliferator-activated receptor {gamma} coactivator 1 (PGC-1). Results of the mammalian two-hybrid studies clearly demonstrate that activation of pGAL4-luc in cells transfected with VP-AhR and GAL4-coactivator chimeras is dependent on the structure of the HAH congener, cell context, and coactivator, suggesting that the prototypical HAH congeners used in this study exhibit selective AhR modulator activity.« less

Antigenic Drift of the Pandemic 2009 A(H1N1) Influenza Virus in a Ferret Model

PubMed Central

Guarnaccia, Teagan; Carolan, Louise A.; Maurer-Stroh, Sebastian; Lee, Raphael T. C.; Job, Emma; Reading, Patrick C.; Petrie, Stephen; McCaw, James M.; McVernon, Jodie; Hurt, Aeron C.; Kelso, Anne; Mosse, Jennifer; Barr, Ian G.; Laurie, Karen L.

2013-01-01

Surveillance data indicate that most circulating A(H1N1)pdm09 influenza viruses have remained antigenically similar since they emerged in humans in 2009. However, antigenic drift is likely to occur in the future in response to increasing population immunity induced by infection or vaccination. In this study, sequential passaging of A(H1N1)pdm09 virus by contact transmission through two independent series of suboptimally vaccinated ferrets resulted in selection of variant viruses with an amino acid substitution (N156K, H1 numbering without signal peptide; N159K, H3 numbering without signal peptide; N173K, H1 numbering from first methionine) in a known antigenic site of the viral HA. The N156K HA variant replicated and transmitted efficiently between naïve ferrets and outgrew wildtype virus in vivo in ferrets in the presence and absence of immune pressure. In vitro, in a range of cell culture systems, the N156K variant rapidly adapted, acquiring additional mutations in the viral HA that also potentially affected antigenic properties. The N156K escape mutant was antigenically distinct from wildtype virus as shown by binding of HA-specific antibodies. Glycan binding assays demonstrated the N156K escape mutant had altered receptor binding preferences compared to wildtype virus, which was supported by computational modeling predictions. The N156K substitution, and culture adaptations, have been detected in human A(H1N1)pdm09 viruses with N156K preferentially reported in sequences from original clinical samples rather than cultured isolates. This study demonstrates the ability of the A(H1N1)pdm09 virus to undergo rapid antigenic change to evade a low level vaccine response, while remaining fit in a ferret transmission model of immunization and infection. Furthermore, the potential changes in receptor binding properties that accompany antigenic changes highlight the importance of routine characterization of clinical samples in human A(H1N1)pdm09 influenza surveillance

Mixed-ligand copper(II) complexes activate aryl hydrocarbon receptor AhR and induce CYP1A genes expression in human hepatocytes and human cell lines.

PubMed

Kubešová, Kateřina; Dořičáková, Aneta; Trávníček, Zdeněk; Dvořák, Zdeněk

2016-07-25

The effects of four copper(II) mixed-ligand complexes [Cu(qui1)(L)]NO3·H2O (1-3) and [Cu(qui2)(phen)]NO3 (4), where qui1=2-phenyl-3-hydroxy-4(1H)-quinolinone, Hqui2=2-(4-amino-3,5-dichlorophenyl)-N-propyl-3-hydroxy-4(1H)-quinolinone-7-carboxamide, L=1,10-phenanthroline (phen) (1), 5-methyl-1,10-phenanthroline (mphen) (2), bathophenanthroline (bphen) (3), on transcriptional activities of steroid receptors, nuclear receptors and xenoreceptors have been studied. The complexes (1-4) did not influence basal or ligand-inducible activities of glucocorticoid receptor, androgen receptor, thyroid receptor, pregnane X receptor and vitamin D receptor, as revealed by gene reporter assays. The complexes 1 and 2 dose-dependently induced luciferase activity in stable gene reporter AZ-AhR cell line, and this induction was reverted by resveratrol, indicating involvement of aryl hydrocarbon receptor (AhR) in the process. The complexes 1, 2 and 3 induced CYP1A1 mRNA in LS180 cells and CYP1A1/CYP1A2 in human hepatocytes through AhR. Electrophoretic mobility shift assay EMSA showed that the complexes 1 and 2 transformed AhR in its DNA-binding form. Collectively, we demonstrate that the complexes 1 and 2 activate AhR and induce AhR-dependent genes in human hepatocytes and cancer cell lines. In conclusion, the data presented here might be of toxicological importance, regarding the multiple roles of AhR in human physiology and pathophysiology. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Cell and region specificity of Aryl hydrocarbon Receptor (AhR) system in the testis and the epididymis.

PubMed

Wajda, A; Łapczuk, J; Grabowska, M; Pius-Sadowska, E; Słojewski, M; Laszczynska, M; Urasinska, E; Machalinski, B; Drozdzik, M

2017-04-01

Aryl hydrocarbon receptor (AhR) plays multiple important functions in adaptive responses. Exposure to AhR ligands may produce an altered metabolic activity controlled by the AhR pathways, and consequently affect drug/toxin responses, hormonal status and cellular homeostasis. This research revealed species-, cell- and region-specific pattern of the AhR system expression in the rat and human testis and epididymis, complementing the existing knowledge, especially within the epididymal segments. The study showed that AhR level in the rat and human epididymis is higher than in the testis. The downregulation of AhR expression after TCDD treatment was revealed in the spermatogenic cells at different stages and the epididymal epithelial cells, but not in the Sertoli and Leydig cells. Hence, this basic research provides information about the AhR function in the testis and epididymis, which may provide an insight into deleterious effects of drugs, hormones and environmental pollutants on male fertility. Copyright © 2017 Elsevier Inc. All rights reserved.

Crucial Role of the Aryl Hydrocarbon Receptor (AhR) in Indoxyl Sulfate-Induced Vascular Inflammation.

PubMed

Ito, Shunsuke; Osaka, Mizuko; Edamatsu, Takeo; Itoh, Yoshiharu; Yoshida, Masayuki

2016-08-01

The aryl hydrocarbon receptor (AhR), a ligand-inducible transcription factor mediating toxic effects of dioxins and uremic toxins, has recently emerged as a pathophysiological regulator of immune-inflammatory conditions. Indoxyl sulfate, a uremic toxin, is associated with cardiovascular disease in patients with chronic kidney disease and has been shown to be a ligand for AhR. The aim of this study was to investigate the potential role of AhR in indoxyl sulfate-induced leukocyte-endothelial interactions. Endothelial cell-specific AhR knockout (eAhR KO) mice were produced by crossing AhR floxed mice with Tie2 Cre mice. Indoxyl sulfate was administered for 2 weeks, followed by injection of TNF-α. Leukocyte recruitment to the femoral artery was assessed by intravital microscopy. Vascular endothelial cells were transfected with siRNA specific to AhR (siAhR) and treated with indoxyl sulfate, followed by stimulation with TNF-α. Indoxyl sulfate dramatically enhanced TNF-α-induced leukocyte recruitment to the vascular wall in control animals but not in eAhR KO mice. In endothelial cells, siAhR significantly reduced indoxyl sulfate-enhanced leukocyte adhesion as well as E-selectin expression, whereas the activation of JNK and nuclear factor-κB was not affected. A luciferase assay revealed that the region between －153 and －146 bps in the E-selectin promoter was responsible for indoxyl sulfate activity via AhR. Mutational analysis of this region revealed that activator protein-1 (AP-1) is responsible for indoxyl sulfate-triggered E-selectin expression via AhR. AhR mediates indoxyl sulfate-enhanced leukocyte-endothelial interactions through AP-1 transcriptional activity, which may constitute a new mechanism of vascular inflammation in patients with renal disease.

The aryl hydrocarbon receptor AhR links atopic dermatitis and air pollution via induction of the neurotrophic factor artemin.

PubMed

Hidaka, Takanori; Ogawa, Eisaku; Kobayashi, Eri H; Suzuki, Takafumi; Funayama, Ryo; Nagashima, Takeshi; Fujimura, Taku; Aiba, Setsuya; Nakayama, Keiko; Okuyama, Ryuhei; Yamamoto, Masayuki

2017-01-01

Atopic dermatitis is increasing worldwide in correlation with air pollution. Various organic components of pollutants activate the transcription factor AhR (aryl hydrocarbon receptor). Through the use of AhR-CA mice, whose keratinocytes express constitutively active AhR and that develop atopic-dermatitis-like phenotypes, we identified Artn as a keratinocyte-specific AhR target gene whose product (the neurotrophic factor artemin) was responsible for epidermal hyper-innervation that led to hypersensitivity to pruritus. The activation of AhR via air pollutants induced expression of artemin, alloknesis, epidermal hyper-innervation and inflammation. AhR activation and ARTN expression were positively correlated in the epidermis of patients with atopic dermatitis. Thus, AhR in keratinocytes senses environmental stimuli and elicits an atopic-dermatitis pathology. We propose a mechanism of air-pollution-induced atopic dermatitis via activation of AhR.

The tertiary structures of porcine AhR and ARNT proteins and molecular interactions within the TCDD/AhR/ARNT complex.

PubMed

Orlowska, Karina; Molcan, Tomasz; Swigonska, Sylwia; Sadowska, Agnieszka; Jablonska, Monika; Nynca, Anna; Jastrzebski, Jan P; Ciereszko, Renata E

2016-06-01

The aryl hydrocarbon receptor (AhR) is a ligand-dependent transcription factor that can be activated by structurally diverse synthetic and natural chemicals, including toxic environmental contaminant 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). In the present study, homology models of the porcine AhR-ligand binding domain (LBD) and the porcine aryl hydrocarbon receptor nuclear translocator-ligand binding domain (ARNT-LBD) were created on the basis of structures of closely related respective proteins i.e., human Hif-2α and ARNT. Molecular docking of TCDD to the porcine AhR-LBD model revealed high binding affinity (-8.8kcal/mol) between TCDD and the receptor. Moreover, formation of the TCDD/AhR-LBD complex was confirmed experimentally with the use of electrophoretic mobility shift assay (EMSA). It was found that TCDD (10nM, 2h of incubation) not only bound to the AhR in the porcine granulosa cells but also activated the receptor. The current study provides a framework for examining the key events involved in the ligand-dependent activation of the AhR. Copyright © 2016 Elsevier Inc. All rights reserved.

The aryl hydrocarbon receptor repressor - More than a simple feedback inhibitor of AhR signaling: Clues for its role in inflammation and cancer.

PubMed

Vogel, Christoph F A; Haarmann-Stemmann, Thomas

2017-02-01

The aryl hydrocarbon receptor repressor (AhRR) was first described as a specific competitive repressor of aryl hydrocarbon receptor (AhR) activity based on its ability to dimerize with the AhR nuclear translocator (ARNT) and through direct competition of AhR/ARNT and AhRR/ARNT complexes for binding to dioxin-responsive elements (DREs). Like AhR, AhRR belongs to the basic Helix-Loop-Helix/Per-ARNT-Sim (bHLH/PAS) protein family but lacks functional ligand-binding and transactivation domains. Transient transfection experiments with ARNT and AhRR mutants examining the inhibitory mechanism of AhRR suggested a more complex mechanism than the simple mechanism of negative feedback through sequestration of ARNT to regulate AhR signaling. Recently, AhRR has been shown to act as a tumor suppressor gene in several types of cancer cells. Furthermore, epidemiological studies have found epigenetic changes and silencing of AhRR associated with exposure to cigarette smoke and cancer development. Additional studies from our laboratories have demonstrated that AhRR represses other signaling pathways including NF-κB and is capable of regulating inflammatory responses. A better understanding of the regulatory mechanisms of AhRR in AhR signaling and adverse outcome pathways leading to deregulated inflammatory responses contributing to tumor promotion and other adverse health effects is expected from future studies. This review article summarizes the characteristics of AhRR as an inhibitor of AhR activity and highlights more recent findings pointing out the role of AhRR in inflammation and tumorigenesis.

Amino Acids in Hemagglutinin Antigenic Site B Determine Antigenic and Receptor Binding Differences between A(H3N2)v and Ancestral Seasonal H3N2 Influenza Viruses

PubMed Central

Wang, Xiaoquan; Ilyushina, Natalia A.; Lugovtsev, Vladimir Y.; Bovin, Nicolai V.; Couzens, Laura K.; Gao, Jin

2016-01-01

ABSTRACT Influenza A H3N2 variant [A(H3N2)v] viruses, which have caused human infections in the United States in recent years, originated from human seasonal H3N2 viruses that were introduced into North American swine in the mid-1990s, but they are antigenically distinct from both the ancestral and current circulating H3N2 strains. A reference A(H3N2)v virus, A/Minnesota/11/2010 (MN/10), and a seasonal H3N2 strain, A/Beijing/32/1992 (BJ/92), were chosen to determine the molecular basis for the antigenic difference between A(H3N2)v and the ancestral viruses. Viruses containing wild-type and mutant MN/10 or BJ/92 hemagglutinins (HAs) were constructed and probed for reactivity with ferret antisera against MN/10 and BJ/92 in hemagglutination inhibition assays. Among the amino acids that differ between the MN/10 and BJ/92 HAs, those in antigenic site A had little impact on the antigenic phenotype. Within antigenic site B, mutations at residues 156, 158, 189, and 193 of MN/10 HA to those in BJ/92 switched the MN/10 antigenic phenotype to that of BJ/92. Mutations at residues 156, 157, 158, 189, and 193 of BJ/92 HA to amino acids present in MN/10 were necessary for BJ/92 to become antigenically similar to MN/10. The HA amino acid substitutions responsible for switching the antigenic phenotype also impacted HA binding to sialyl receptors that are usually present in the human respiratory tract. Our study demonstrates that antigenic site B residues play a critical role in determining both the unique antigenic phenotype and receptor specificity of A(H3N2)v viruses, a finding that may facilitate future surveillance and risk assessment of novel influenza viruses. IMPORTANCE Influenza A H3N2 variant [A(H3N2)v] viruses have caused hundreds of human infections in multiple states in the United States since 2009. Most cases have been children who had contact with swine in agricultural fairs. These viruses originated from human seasonal H3N2 viruses that were introduced into the U

Genetic variants of dopamine D2 receptor impact heterodimerization with dopamine D1 receptor.

PubMed

Błasiak, Ewa; Łukasiewicz, Sylwia; Szafran-Pilch, Kinga; Dziedzicka-Wasylewska, Marta

2017-04-01

The human dopamine D2 receptor gene has three polymorphic variants that alter its amino acid sequence: alanine substitution by valine in position 96 (V96A), proline substitution by serine in position 310 (P310S) and serine substitution by cysteine in position 311 (S311C). Their functional role has never been the object of extensive studies, even though there is some evidence that their occurrence correlates with schizophrenia. The HEK293 cell line was transfected with dopamine D1 and D2 receptors (or genetic variants of the D2 receptor), coupled to fluorescent proteins which allowed us to measure the extent of dimerization of these receptors, using a highly advanced biophysical approach (FLIM-FRET). Additionally, Fluoro-4 AM was used to examine changes in the level of calcium release after ligand stimulation of cells expressing different combinations of dopamine receptors. Using FLIM-FRET experiments we have shown that in HEK 293 expressing dopamine receptors, polymorphic mutations in the D2 receptor play a role in dimmer formation with the dopamine D1 receptor. The association level of dopamine receptors is affected by ligand administration, with variable effects depending on polymorphic variant of the D2 dopamine receptor. We have found that the level of heteromer formation is reflected by calcium ion release after ligand stimulation and have observed variations of this effect dependent on the polymorphic variant and the ligand. The data presented in this paper support the hypothesis on the role of calcium signaling regulated by the D1-D2 heteromer which may be of relevance for schizophrenia etiology. Copyright © 2016 Institute of Pharmacology, Polish Academy of Sciences. Published by Elsevier Urban & Partner Sp. z o.o. All rights reserved.

Novel down-regulatory mechanism of the surface expression of the vasopressin V2 receptor by an alternative splice receptor variant.

PubMed

Sarmiento, José M; Añazco, Carolina C; Campos, Danae M; Prado, Gregory N; Navarro, Javier; González, Carlos B

2004-11-05

In rat kidney, two alternatively spliced transcripts are generated from the V2 vasopressin receptor gene. The large transcript (1.2 kb) encodes the canonical V2 receptor, whereas the small transcript encodes a splice variant displaying a distinct sequence corresponding to the putative seventh transmembrane domain and the intracellular C terminus of the V2 receptor. This work showed that the small spliced transcript is translated in the rat kidney collecting tubules. However, the protein encoded by the small transcript (here called the V2b splice variant) is retained inside the cell, in contrast to the preferential surface distribution of the V2 receptor (here called the V2a receptor). Cells expressing the V2b splice variant do not exhibit binding to 3H-labeled vasopressin. Interestingly, we found that expression of the splice variant V2b down-regulates the surface expression of the V2a receptor, most likely via the formation of V2a.V2b heterodimers as demonstrated by co-immunoprecipitation and fluorescence resonance energy transfer experiments between the V2a receptor and the V2b splice variant. The V2b splice variant would then be acting as a dominant negative. The effect of the V2b splice variant is specific, as it does not affect the surface expression of the G protein-coupled interleukin-8 receptor (CXCR1). Furthermore, the sequence encompassing residues 242-339, corresponding to the C-terminal domain of the V2b splice variant, also down-regulates the surface expression of the V2a receptor. We suggest that some forms of nephrogenic diabetes insipidus are due to overexpression of the splice variant V2b, which could retain the wild-type V2a receptor inside the cell via the formation of V2a.V2b heterodimers.

Novel oxytocin receptor variants in laboring women requiring high doses of oxytocin.

PubMed

Reinl, Erin L; Goodwin, Zane A; Raghuraman, Nandini; Lee, Grace Y; Jo, Erin Y; Gezahegn, Beakal M; Pillai, Meghan K; Cahill, Alison G; de Guzman Strong, Cristina; England, Sarah K

2017-08-01

Although oxytocin commonly is used to augment or induce labor, it is difficult to predict its effectiveness because oxytocin dose requirements vary significantly among women. One possibility is that women requiring high or low doses of oxytocin have variations in the oxytocin receptor gene. To identify oxytocin receptor gene variants in laboring women with low and high oxytocin dosage requirements. Term, nulliparous women requiring oxytocin doses of ≤4 mU/min (low-dose-requiring, n = 83) or ≥20 mU/min (high-dose-requiring, n = 104) for labor augmentation or induction provided consent to a postpartum blood draw as a source of genomic DNA. Targeted-amplicon sequencing (coverage >30×) with MiSeq (Illumina) was performed to discover variants in the coding exons of the oxytocin receptor gene. Baseline relevant clinical history, outcomes, demographics, and oxytocin receptor gene sequence variants and their allele frequencies were compared between low-dose-requiring and high-dose-requiring women. The Scale-Invariant Feature Transform algorithm was used to predict the effect of variants on oxytocin receptor function. The Fisher exact or χ 2 tests were used for categorical variables, and Student t tests or Wilcoxon rank sum tests were used for continuous variables. A P value < .05 was considered statistically significant. The high-dose-requiring women had greater rates of obesity and diabetes and were more likely to have undergone labor induction and required prostaglandins. High-dose-requiring women were more likely to undergo cesarean delivery for first-stage arrest and less likely to undergo cesarean delivery for nonreassuring fetal status. Targeted sequencing of the oxytocin receptor gene in the total cohort (n = 187) revealed 30 distinct coding variants: 17 nonsynonymous, 11 synonymous, and 2 small structural variants. One novel variant (A243T) was found in both the low- and high-dose-requiring groups. Three novel variants (Y106H, A240_A249del, and P197

Aryl hydrocarbon receptor (AhR)-dependent regulation of pulmonary miRNA by chronic cigarette smoke exposure.

PubMed

Rogers, Sarah; de Souza, Angela Rico; Zago, Michela; Iu, Matthew; Guerrina, Necola; Gomez, Alvin; Matthews, Jason; Baglole, Carolyn J

2017-01-12

The aryl hydrocarbon receptor (AhR) is a ligand-activated transcription factor historically known for its toxic responses to man-made pollutants such as dioxin. More recently, the AhR has emerged as a suppressor of inflammation, oxidative stress and apoptosis from cigarette smoke by mechanisms that may involve the regulation of microRNA. However, little is known about the AhR regulation of miRNA expression in the lung in response to inhaled toxicants. Therefore, we exposed Ahr -/- and Ahr +/- mice to cigarette smoke for 4 weeks and evaluated lung miRNA expression by PCR array. There was a dramatic regulation of lung miRNA by the AhR in the absence of exogenous ligand. In response to cigarette smoke, there were more up-regulated miRNA in Ahr -/- mice compared to Ahr +/- mice, including the cancer-associated miRNA miR-96. There was no significant change in the expression of the AhR regulated proteins HuR and cyclooxygenase-2 (COX-2). There were significant increases in the anti-oxidant gene sulfiredoxin 1 (Srxn1) and FOXO3a- predicted targets of miR-96. Collectively, these data support a prominent role for the AhR in regulating lung miRNA expression. Further studies to elucidate a role for these miRNA may further uncover novel biological function for the AhR in respiratory health and disease.

Divergent Ah Receptor Ligand Selectivity during Hominin Evolution

PubMed Central

Hubbard, Troy D.; Murray, Iain A.; Bisson, William H.; Sullivan, Alexis P.; Sebastian, Aswathy; Perry, George H.; Jablonski, Nina G.; Perdew, Gary H.

2016-01-01

We have identified a fixed nonsynonymous sequence difference between humans (Val381; derived variant) and Neandertals (Ala381; ancestral variant) in the ligand-binding domain of the aryl hydrocarbon receptor (AHR) gene. In an exome sequence analysis of four Neandertal and Denisovan individuals compared with nine modern humans, there are only 90 total nucleotide sites genome-wide for which archaic hominins are fixed for the ancestral nonsynonymous variant and the modern humans are fixed for the derived variant. Of those sites, only 27, including Val381 in the AHR, also have no reported variability in the human dbSNP database, further suggesting that this highly conserved functional variant is a rare event. Functional analysis of the amino acid variant Ala381 within the AHR carried by Neandertals and nonhuman primates indicate enhanced polycyclic aromatic hydrocarbon (PAH) binding, DNA binding capacity, and AHR mediated transcriptional activity compared with the human AHR. Also relative to human AHR, the Neandertal AHR exhibited 150–1000 times greater sensitivity to induction of Cyp1a1 and Cyp1b1 expression by PAHs (e.g., benzo(a)pyrene). The resulting CYP1A1/CYP1B1 enzymes are responsible for PAH first pass metabolism, which can result in the generation of toxic intermediates and perhaps AHR-associated toxicities. In contrast, the human AHR retains the ancestral sensitivity observed in primates to nontoxic endogenous AHR ligands (e.g., indole, indoxyl sulfate). Our findings reveal that a functionally significant change in the AHR occurred uniquely in humans, relative to other primates, that would attenuate the response to many environmental pollutants, including chemicals present in smoke from fire use during cooking. PMID:27486223

Temporal distribution and genetic variants in influenza A(H1N1)pdm09 virus circulating in Mexico, seasons 2012 and 2013.

PubMed

Canche-Pech, Jose Reyes; Conde-Ferraez, Laura; Puerto-Solis, Marylin; Gonzalez-Losa, Refugio; Granja-Pérez, Pilar; Villanueva-Jorge, Salha; Chan-Gasca, Maria; Gómez-Carballo, Jesus; López-Ochoa, Luisa; Jiménez-Delgadillo, Bertha; Rodríguez-Sánchez, Iram; Ramírez-Prado, Jorge; Ayora-Talavera, Guadalupe

2017-01-01

The 2012 and 2013 annual influenza epidemics in Mexico were characterized by presenting different seasonal patterns. In 2012 the A(H1N1)pdm09 virus caused a high incidence of influenza infections after a two-year period of low circulation; whereas the 2013 epidemic presented circulation of the A(H1N1)pdm09 virus throughout the year. We have characterized the molecular composition of the Hemagglutinin (HA) and Neuraminidase (NA) genes of the A(H1N1)pdm09 virus from both epidemic seasons, emphasizing the genetic characteristics of viruses isolated from Yucatan in Southern Mexico. The molecular analysis of viruses from the 2012 revealed that all viruses from Mexico were predominantly grouped in clade 7. Strikingly, the molecular characterization of viruses from 2013 revealed that viruses circulating in Yucatan were genetically different to viruses from other regions of Mexico. In fact, we identified the occurrence of two genetic variants containing relevant mutations at both the HA and NA surface antigens. There was a difference on the temporal circulation of each genetic variant, viruses containing the mutations HA-A141T / NA-N341S were detected in May, June and July; whereas viruses containing the mutations HA-S162I / NA-L206S circulated in August and September. We discuss the significance of these novel genetic changes.

Temporal distribution and genetic variants in influenza A(H1N1)pdm09 virus circulating in Mexico, seasons 2012 and 2013

PubMed Central

Canche-Pech, Jose Reyes; Conde-Ferraez, Laura; Puerto-Solis, Marylin; Gonzalez-Losa, Refugio; Granja-Pérez, Pilar; Villanueva-Jorge, Salha; Chan-Gasca, Maria; Gómez-Carballo, Jesus; López-Ochoa, Luisa; Jiménez-Delgadillo, Bertha; Rodríguez-Sánchez, Iram; Ramírez-Prado, Jorge

2017-01-01

The 2012 and 2013 annual influenza epidemics in Mexico were characterized by presenting different seasonal patterns. In 2012 the A(H1N1)pdm09 virus caused a high incidence of influenza infections after a two-year period of low circulation; whereas the 2013 epidemic presented circulation of the A(H1N1)pdm09 virus throughout the year. We have characterized the molecular composition of the Hemagglutinin (HA) and Neuraminidase (NA) genes of the A(H1N1)pdm09 virus from both epidemic seasons, emphasizing the genetic characteristics of viruses isolated from Yucatan in Southern Mexico. The molecular analysis of viruses from the 2012 revealed that all viruses from Mexico were predominantly grouped in clade 7. Strikingly, the molecular characterization of viruses from 2013 revealed that viruses circulating in Yucatan were genetically different to viruses from other regions of Mexico. In fact, we identified the occurrence of two genetic variants containing relevant mutations at both the HA and NA surface antigens. There was a difference on the temporal circulation of each genetic variant, viruses containing the mutations HA-A141T / NA-N341S were detected in May, June and July; whereas viruses containing the mutations HA-S162I / NA-L206S circulated in August and September. We discuss the significance of these novel genetic changes. PMID:29220381

Aryl hydrocarbon receptor (AhR)-dependent regulation of pulmonary miRNA by chronic cigarette smoke exposure

PubMed Central

Rogers, Sarah; de Souza, Angela Rico; Zago, Michela; Iu, Matthew; Guerrina, Necola; Gomez, Alvin; Matthews, Jason; Baglole, Carolyn J.

2017-01-01

The aryl hydrocarbon receptor (AhR) is a ligand-activated transcription factor historically known for its toxic responses to man-made pollutants such as dioxin. More recently, the AhR has emerged as a suppressor of inflammation, oxidative stress and apoptosis from cigarette smoke by mechanisms that may involve the regulation of microRNA. However, little is known about the AhR regulation of miRNA expression in the lung in response to inhaled toxicants. Therefore, we exposed Ahr−/− and Ahr+/− mice to cigarette smoke for 4 weeks and evaluated lung miRNA expression by PCR array. There was a dramatic regulation of lung miRNA by the AhR in the absence of exogenous ligand. In response to cigarette smoke, there were more up-regulated miRNA in Ahr−/− mice compared to Ahr+/− mice, including the cancer-associated miRNA miR-96. There was no significant change in the expression of the AhR regulated proteins HuR and cyclooxygenase-2 (COX-2). There were significant increases in the anti-oxidant gene sulfiredoxin 1 (Srxn1) and FOXO3a- predicted targets of miR-96. Collectively, these data support a prominent role for the AhR in regulating lung miRNA expression. Further studies to elucidate a role for these miRNA may further uncover novel biological function for the AhR in respiratory health and disease. PMID:28079158

Postnatal Expression of V2 Vasopressin Receptor Splice Variants in the Rat Cerebellum

PubMed Central

Vargas, Karina J.; Sarmiento, José M.; Ehrenfeld, Pamela; Añazco, Carolina C.; Villanueva, Carolina I.; Carmona, Pamela L.; Brenet, Marianne; Navarro, Javier; Müller-Esterl, Werner; Figueroa, Carlos D.; González, Carlos B.

2010-01-01

The V2 vasopressin receptor gene contains an alternative splice site in exon-3, which leads to the generation of two splice variants (V2a and V2b) first identified in the kidney. The open reading frame of the alternatively spliced V2b transcripten codes a truncated receptor, showing the same amino acid sequence as the canonical V2a receptor up to the 6th transmembrane segment, but displaying a distinct sequence to the corresponding 7th transmembrane segment and C-terminal domain relative to the V2a receptor. Here, we demonstrate the postnatal expression of V2a and V2b variants in the rat cerebellum. Most importantly, we showed by in situ hybridization and immunocytochemistry that both V2 splice variants were preferentially expressed in Purkinje cells, from early to late postnatal development. In addition, both variants were transiently expressed in the neuroblastic external granule cells and Bergmann fibers. These results indicate that the cellular distributions of both splice variants are developmentally regulated, and suggest that the transient expression of the V2 receptor is involved in the mechanisms of cerebellar cytodifferentiation by AVP. Finally, transfected CHO-K1 .expressing similar amounts of both V2 splice variants, as that found in the cerebellum, showed a significant reduction in the surface expression of V2a receptors, suggesting that the differential expression of the V2 splice variants regulate the vasopressin signaling in the cerebellum. PMID:19281786

Screening a mouse liver gene expression Compendium Identifies Effectors of the Aryl Hydrocarbon receptor (AhR)

EPA Science Inventory

The aryl hydrocarbon receptor (AhR) is a ligand-activated transcription factor that mediates the biological and toxic effects of 2,3, 7 ,8-tetrachlorodibenzo-p-dioxin {TCDD), dioxin-like compounds (DLC) as well as some drugs and endogenous tryptophan metabolites. Short-term act...

Role of Androgen Receptor Variants in Prostate Cancer: Report from the 2017 Mission Androgen Receptor Variants Meeting.

PubMed

Luo, Jun; Attard, Gerhardt; Balk, Steven P; Bevan, Charlotte; Burnstein, Kerry; Cato, Laura; Cherkasov, Artem; De Bono, Johann S; Dong, Yan; Gao, Allen C; Gleave, Martin; Heemers, Hannelore; Kanayama, Mayuko; Kittler, Ralf; Lang, Joshua M; Lee, Richard J; Logothetis, Christopher J; Matusik, Robert; Plymate, Stephen; Sawyers, Charles L; Selth, Luke A; Soule, Howard; Tilley, Wayne; Weigel, Nancy L; Zoubeidi, Amina; Dehm, Scott M; Raj, Ganesh V

2018-05-01

Although a number of studies have demonstrated the importance of constitutively active androgen receptor variants (AR-Vs) in prostate cancer, questions still remain about the precise role of AR-Vs in the progression of castration-resistant prostate cancer (CRPC). Key stakeholders and opinion leaders in prostate cancer convened on May 11, 2017 in Boston to establish the current state of the field of AR-Vs. The meeting "Mission Androgen Receptor Variants" was the second of its kind sponsored by the Prostate Cancer Foundation (PCF). This invitation-only event was attended by international leaders in the field and representatives from sponsoring organizations (PCF and industry sponsors). Eighteen faculty members gave short presentations, which were followed by in-depth discussions. Discussions focused on three thematic topics: (1) potential of AR-Vs as biomarkers of therapeutic resistance; (2) role of AR-Vs as functionally active CRPC progression drivers; and (3) utility of AR-Vs as therapeutic targets in CRPC. The three meeting organizers synthesized this meeting report, which is intended to summarize major data discussed at the meeting and identify key questions as well as strategies for addressing these questions. There was a critical consensus that further study of the AR-Vs is an important research focus in CRPC. Contrasting views and emphasis, each supported by data, were presented at the meeting, discussed among the participants, and synthesized in this report. This article highlights the state of knowledge and outlines the most pressing questions that need to be addressed to advance the AR-V field. Although further investigation is needed to delineate the role of androgen receptor (AR) variants in metastatic castration-resistant prostate cancer, advances in measurement science have enabled development of blood-based tests for treatment selection. Detection of AR variants (eg, AR-V7) identified a patient population with poor outcomes to existing AR

The role of aryl hydrocarbon receptor (AhR) in the pathology of pleomorphic adenoma in parotid gland.

PubMed

Drozdzik, Agnieszka; Kowalczyk, Robert; Lipski, Mariusz; Łapczuk, Joanna; Urasinska, Elzbieta; Kurzawski, Mateusz

2016-01-01

Pleomorphic adenoma (benign mixed tumor) is one of the most common salivary gland tumors. However, molecular mechanisms implicated in its development are not entirely defined. Therefore, the study aimed at definition of aryl hydrocarbon receptor (AhR) involvement in pleomorphic adenoma pathology, as the AhR controlled gene system was documented to play a role in development of various human tumors. The study was carried out in pleomorphic adenoma and control parotid gland tissues where gene expression of AHR, AhR nuclear translocator (ARNT), AhR repressor (AHRR), as well as AhR controlled genes: CYP1A1 and CYP1B1, at mRNA and protein (immunohistochemistry) levels were studied. Functional evaluation of AhR system was evaluated in HSY cells (human parotid gland adenocarcinoma cells) using 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) as AhR specific inducer. Pleomorphic adenoma specimens showed cytoplasmic and nuclear AhR expression in epithelial cells as well as in mesenchymal cells. In parotid gland AhR was expressed in cytoplasm of duct cells. Quantitative expression at mRNA level showed significantly higher expression of AHR, ARNT and CYP1B1, and comparable levels of CYP1A1 in pleomorphic adenoma tissue in comparison to healthy parotid gland. The HSY cell study revealed significantly higher expression level of AHRR in HSY as compared with MCF-7 cells (human breast adenocarcinoma cell line used as reference). Upon TCDD stimulation a drop in AHRR level in HSY cells and an increase in MCF-7 cells were observed. The HSY and MCF-7 cell proliferation rate (measured by WST-1 test) was not affected by TCDD. Summarizing both in vitro and in vivo observations it can be stated that AhR system may play a role in the pathology of pleomorphic adenoma. Copyright © 2015. Published by Elsevier Ltd.

Genetic variants of innate immune receptors and infections after liver transplantation

PubMed Central

Sanclemente, Gemma; Moreno, Asuncion; Navasa, Miquel; Lozano, Francisco; Cervera, Carlos

2014-01-01

Infection is the leading cause of complication after liver transplantation, causing morbidity and mortality in the first months after surgery. Allograft rejection is mediated through adaptive immunological responses, and thus immunosuppressive therapy is necessary after transplantation. In this setting, the presence of genetic variants of innate immunity receptors may increase the risk of post-transplant infection, in comparison with patients carrying wild-type alleles. Numerous studies have investigated the role of genetic variants of innate immune receptors and the risk of complication after liver transplantation, but their results are discordant. Toll-like receptors and mannose-binding lectin are arguably the most important studied molecules; however, many other receptors could increase the risk of infection after transplantation. In this article, we review the published studies analyzing the impact of genetic variants in the innate immune system on the development of infectious complications after liver transplantation. PMID:25170199

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

PubMed

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.

Ablating the aryl hydrocarbon receptor (AhR) in CD11c+ cells perturbs intestinal epithelium development and intestinal immunity.

PubMed

Chng, Song Hui; Kundu, Parag; Dominguez-Brauer, Carmen; Teo, Wei Ling; Kawajiri, Kaname; Fujii-Kuriyama, Yoshiaki; Mak, Tak Wah; Pettersson, Sven

2016-04-12

Diet and microbiome derived indole derivatives are known to activate the ligand induced transcription factor, the Aryl hydrocarbon Receptor (AhR). While the current understanding of AhR biology has confirmed its role in mucosal lymphocytes, its function in intestinal antigen presenting cells (APCs) is poorly understood. Here, we report that Cre-mediated deletion of AhR in CD11c-expressing cells in C57/BL6 mice is associated with altered intestinal epithelial morphogenesis in vivo. Moreover, when co-cultured with AhR-deficient DCs ex vivo, intestinal organoids showed reduced SRY (sex determining region Y)-box 9 and increased Mucin 2 expression, which correlates with reduced Paneth cells and increased goblet cell differentiation, similar to the data obtained in vivo. Further, characterization of intestinal APC subsets, devoid of AhR, revealed an expression pattern associated with aberrant intrinsic Wnt pathway regulation. At a functional level, the loss of AhR in APCs resulted in a dysfunctional epithelial barrier, associated with a more aggressive chemically induced colitis compared to wild type animals. Our results are consistent with a model whereby the AhR signalling pathway may participate in the regulation of innate immunity through intestinal epithelium development and mucosal immunity.

The roles played by highly truncated splice variants of G protein-coupled receptors

PubMed Central

2012-01-01

Alternative splicing of G protein-coupled receptor (GPCR) genes greatly increases the total number of receptor isoforms which may be expressed in a cell-dependent and time-dependent manner. This increased diversity of cell signaling options caused by the generation of splice variants is further enhanced by receptor dimerization. When alternative splicing generates highly truncated GPCRs with less than seven transmembrane (TM) domains, the predominant effect in vitro is that of a dominant-negative mutation associated with the retention of the wild-type receptor in the endoplasmic reticulum (ER). For constitutively active (agonist-independent) GPCRs, their attenuated expression on the cell surface, and consequent decreased basal activity due to the dominant-negative effect of truncated splice variants, has pathological consequences. Truncated splice variants may conversely offer protection from disease when expression of co-receptors for binding of infectious agents to cells is attenuated due to ER retention of the wild-type co-receptor. In this review, we will see that GPCRs retained in the ER can still be functionally active but also that highly truncated GPCRs may also be functionally active. Although rare, some truncated splice variants still bind ligand and activate cell signaling responses. More importantly, by forming heterodimers with full-length GPCRs, some truncated splice variants also provide opportunities to generate receptor complexes with unique pharmacological properties. So, instead of assuming that highly truncated GPCRs are associated with faulty transcription processes, it is time to reassess their potential benefit to the host organism. PMID:22938630

Nuclear Receptor Variants in Liver Disease

PubMed Central

Müllenbach, Roman; Weber, Susanne N.; Lammert, Frank

2012-01-01

This review aims to provide a snapshot of the actual state of knowledge on genetic variants of nuclear receptors (NR) involved in regulating important aspects of liver metabolism. It recapitulates recent evidence for the application of NR in genetic diagnosis of monogenic (“Mendelian”) liver disease and their use in clinical diagnosis. Genetic analysis of multifactorial liver diseases such as viral hepatitis or fatty liver disease identifies key players in disease predisposition and progression. Evidence from these analyses points towards a role of NR polymorphisms in common diseases, linking regulatory networks to complex and variable phenotypes. The new insights into NR variants also offer perspectives and cautionary advice for their use as handles towards diagnosis and treatment. PMID:22523693

Malassezia yeasts produce a collection of exceptionally potent activators of the Ah (dioxin) receptor detected in diseased human skin

PubMed Central

Magiatis, Prokopios; Pappas, Periklis; Gaitanis, George; Mexia, Nikitia; Melliou, Eleni; Galanou, Maria; Vlachos, Christophoros; Stathopoulou, Konstantina; Skaltsounis, Alexios Leandros; Marselos, Marios; Velegraki, Aristea; Denison, Michael S.; Bassukas, Ioannis D.

2013-01-01

Malassezia yeasts are commensal microorganisms which under insufficiently understood conditions can become pathogenic. We have previously shown that specific strains isolated from diseased human skin can preferentially produce agonists of the aryl hydrocarbon receptor (AhR), whose activation has been linked to certain skin diseases. Investigation of skin scale extracts from patients with Malassezia associated diseases demonstrated 10–1000 fold higher AhR activating capacity than control skin extracts. LC/MS/MS analysis of the patients’ extracts revealed the presence of indirubin, 6-formylindolo[3,2-b]carbazole (FICZ), indolo[3,2-b]carbazole (ICZ), malassezin, and pityriacitrin. The same compounds were also identified in 9/12 Malassezia species culture extracts tested, connecting their presence in skin scales with this yeast. Studying the activity of the Malassezia culture-extracts and pure metabolites in HaCaT cells by Reverse Transcriptase Real-Time PCR revealed significant alterations in mRNA levels of the endogenous AhR-responsive genes Cyp1A1, Cyp1B1 and AhRR. Indirubin and FICZ activated AhR in HaCaT and human HepG2 cells with significantly higher, yet transient, potency as compared to the prototypical AhR ligand, dioxin. In loco synthesis of these highly potent AhR inducers by Malassezia yeasts could have a significant impact on skin homeostatic mechanisms and disease development. PMID:23448877

Malassezia yeasts produce a collection of exceptionally potent activators of the Ah (dioxin) receptor detected in diseased human skin.

PubMed

Magiatis, Prokopios; Pappas, Periklis; Gaitanis, George; Mexia, Nikitia; Melliou, Eleni; Galanou, Maria; Vlachos, Christophoros; Stathopoulou, Konstantina; Skaltsounis, Alexios Leandros; Marselos, Marios; Velegraki, Aristea; Denison, Michael S; Bassukas, Ioannis D

2013-08-01

Malassezia yeasts are commensal microorganisms, which under insufficiently understood conditions can become pathogenic. We have previously shown that specific strains isolated from diseased human skin can preferentially produce agonists of the aryl hydrocarbon receptor (AhR), whose activation has been linked to certain skin diseases. Investigation of skin scale extracts from patients with Malassezia-associated diseases demonstrated 10- to 1,000-fold higher AhR-activating capacity than control skin extracts. Liquid chromatography-tandem mass spectrometry analysis of the patients' extracts revealed the presence of indirubin, 6-formylindolo[3,2-b]carbazole (FICZ), indolo[3,2-b]carbazole (ICZ), malassezin, and pityriacitrin. The same compounds were also identified in 9 out of 12 Malassezia species culture extracts tested, connecting their presence in skin scales with this yeast. Studying the activity of the Malassezia culture extracts and pure metabolites in HaCaT cells by reverse transcriptase real-time PCR revealed significant alterations in mRNA levels of the endogenous AhR-responsive genes Cyp1A1, Cyp1B1, and AhRR. Indirubin- and FICZ-activated AhR in HaCaT and human HepG2 cells with significantly higher, yet transient, potency as compared with the prototypical AhR ligand, dioxin. In loco synthesis of these highly potent AhR inducers by Malassezia yeasts could have a significant impact on skin homeostatic mechanisms and disease development.

Immuno-detection of dioxins using a recombinant protein of aryl hydrocarbon receptor (AhR) fused with sfGFP.

PubMed

Faiad, Walaa; Hanano, Abdulsamie; Kabakibi, Mohamed Maher; Abbady, Abdul Qader

2016-06-21

Dioxins are one of the most toxic groups of persistent organic pollutants. Their bioaccumulation through the food chain constitutes a potential risk for human health. Upon cell entry, dioxins bind specifically and firmly to the aryl hydrocarbon receptor (AhR), leading to the stimulation of several enzymes responsible for its detoxification. Dioxin/AhR interaction could be exploited as an affordable alternative to a variety of analytical methods for detecting dioxin contamination in the environment. In this work, the ligand binding domain (LBD) of the AhR was cloned downstream a superfolder form of the green fluorescent protein (sfGFP), resulting in the construct pRSET-sfGFP-AhR. High level of expressed sfGFP-AhR fusion protein (50 kDa) was recovered from the inclusion bodies of E. coli by simple solubilization with the Arginine, and purified by affinity chromatography via its N-terminal 6 × His tag. Its purity was confirmed by SDS-PAGE analysis and immunoblotting with anti-His or anti-GFP antibodies. Indirect ELISA revealed the ability of the sfGFP-AhR, but not the sfGFP, to bind to the immobilized dioxin with the possibility to detect such interaction by both its 6 × His and GFP tags,Competitive ELISA showed that anti-dioxin antibody was more sensitive to low dioxin concentrations than sfGFP-AhR. Nevertheless,the detection range of sfGFP-AhR fusion was much wider and the detection limit was of about 10 ppt (parts per trillion) of free dioxin in the tested artificial samples. this highly expressed and functional sfGFP-AhR fusion protein provides a promising molecular tool for detecting and quantifying different congeners of dioxins.

Lack of association between sigma receptor gene variants and schizophrenia.

PubMed

Satoh, Fumiaki; Miyatake, Ryosuke; Furukawa, Aizo; Suwaki, Hiroshi

2004-08-01

Several pharmacological studies suggest the possible involvement of sigma(1) receptors in the pathogenesis of schizophrenia. An association has been reported between schizophrenia and two variants (GC-241-240TT and Gln2Pro) in the sigma(1) receptor gene (SIGMAR1). We also previously reported that, along with T-485 A, these two variants alter SIGMAR1 function. To investigate the role of SIGMAR1 in conveying susceptibility to schizophrenia, we performed a case-control study. We initially screened for polymorphisms in the SIGMAR1 coding region using PCR-single strand conformation polymorphism analysis. The distribution of SIGMAR1 polymorphisms was analyzed in 100 schizophrenic and 104 control subjects. A novel G620A variant was detected in exon4. G620A was predicted to alter the amino acid represented by codon 211 from arginine to glutamine. Our case-control study showed no significant association between the T-485 A, GC-241-240TT, Gln2Pro, and G620A (Arg211Gln) variants and schizophrenia and clinical characteristics. These findings suggest that these SIGMAR1 variants may not affect susceptibility to schizophrenia.

Pregnane X receptor regulates the AhR/Cyp1A1 pathway and protects liver cells from benzo-[α]-pyrene-induced DNA damage.

PubMed

Cui, Hongmei; Gu, Xinsheng; Chen, Jingshu; Xie, Ying; Ke, Sui; Wu, Jing; Golovko, Andrei; Morpurgo, Benjamin; Yan, Chunhong; Phillips, Timothy D; Xie, Wen; Luo, Jianyuan; Zhou, Zhijun; Tian, Yanan

2017-06-05

Pregnane X receptor (PXR) plays an important role in protecting cells from mutagenic DNA damages induced by endogenous and exogenous toxicants. This protective function is often attributed to the PXR-regulated metabolic detoxification. Here we report a novel potential mechanism that PXR reduces benzo-[α]-pyrene(BaP)-induced DNA damage through inhibiting the transcriptional activity of aryl hydrocarbon receptor (AhR) which plays a pivotal role in the bioactivation of BaP. We have utilized three well-characterized cell lines, i.e. Hepa1c1c7, AhR +/+; Bpr lacks AhR obligatory partner ARNT; Tao, lacks AhR, to analyze pivotal role of AhR/ARNT complex in mediating the BaP-induced DNA damages using comet assay (single-cell gel electrophoresis). We found that PXR activation could significantly inhibit BaP-induced DNA damage in the HepG2 cells as well as mouse hepatocytes. Using PXR-null and wild type mouse hepatocytes we showed that PXR activation by pregnenolone 16α-carbonitrile (PCN) significantly inhibited BaP-induced DNA damage and this protective effect was abolished in PXR-null hepatocytes. Mechanistically, PXR activation inhibited expression of AhR-target genes for CYP1A1, CYP1B1 and CYP1A2 that are required for BaP biotransformation in cultured liver cells, or in the livers of C57BL/6J mice. Using an AhR-responsive reporter assay as well as chromatin immunoprecipitation assay we found that PXR activation transcriptionally represses AhR-regulated gene expression. Furthermore, we found that PXR directly bound AhR at its DNA-binding domain, and this association may play a role in preventing of the AhR from binding to its target genes as shown in the ChIP assay. Taken together, our study has revealed a novel mechanism by which PXR protects liver cells from BaP-induced DNA damage through inhibiting the BaP biotransformation. Copyright © 2017 Elsevier B.V. All rights reserved.

Newly emerging mutations in the matrix genes of the human influenza A(H1N1)pdm09 and A(H3N2) viruses reduce the detection sensitivity of real-time reverse transcription-PCR.

PubMed

Yang, Ji-Rong; Kuo, Chuan-Yi; Huang, Hsiang-Yi; Wu, Fu-Ting; Huang, Yi-Lung; Cheng, Chieh-Yu; Su, Yu-Ting; Chang, Feng-Yee; Wu, Ho-Sheng; Liu, Ming-Tsan

2014-01-01

New variants of the influenza A(H1N1)pdm09 and A(H3N2) viruses were detected in Taiwan between 2012 and 2013. Some of these variants were not detected in clinical specimens using a common real-time reverse transcription-PCR (RT-PCR) assay that targeted the conserved regions of the viral matrix (M) genes. An analysis of the M gene sequences of the new variants revealed that several newly emerging mutations were located in the regions where the primers or probes of the real-time RT-PCR assay bind; these included three mutations (G225A, T228C, and G238A) in the A(H1N1)pdm09 virus, as well as one mutation (C163T) in the A(H3N2) virus. These accumulated mismatch mutations, together with the previously identified C154T mutation of the A(H1N1)pdm09 virus and the C153T and G189T mutations of the A(H3N2) virus, result in a reduced detection sensitivity for the real-time RT-PCR assay. To overcome the loss of assay sensitivity due to mismatch mutations, we established a real-time RT-PCR assay using degenerate nucleotide bases in both the primers and probe and successfully increased the sensitivity of the assay to detect circulating variants of the human influenza A viruses. Our observations highlight the importance of the simultaneous use of different gene-targeting real-time RT-PCR assays for the clinical diagnosis of influenza.

An in silico approach to investigate the source of the controversial interpretations about the phenotypic results of the human AhR-gene G1661A polymorphism.

PubMed

Aftabi, Younes; Colagar, Abasalt Hosseinzadeh; Mehrnejad, Faramarz

2016-03-21

Aryl hydrocarbon receptor (AhR) acts as an enhancer binding ligand-activated intracellular receptor. Chromatin remodeling components and general transcription factors such as TATA-binding protein (TBP) are evoked on AhR-target genes by interaction with its flexible transactivation domain (TAD). AhR-G1661A single nucleotide polymorphism (SNP: rs2066853) causes an arginine to lysine substitution in the acidic sub-domain of TAD at position 554 (R554K). Although, numerous studies associate the SNP with some abnormalities such as cancer, other reliable investigations refuse the associations. Consequently, the interpretation of the phenotypic results of G1661A-transition has been controversial. In this study, an in silico analysis were performed to investigate the possible effects of the transition on AhR-mRNA, protein structure, interaction properties and modifications. The analysis revealed that the R554K substitution affects secondary structure and solvent accessibility of adjacent residues. Also, it causes to decreasing of the AhR stability; altering the hydropathy features of the local sequence and changing the pattern of the residues at the binding site of the TAD-acidic sub-domain. Generating of new sites for ubiquitination and acetylation for AhR-K554 variant respectively at positions 544 and 560 was predicted. Our findings intensify the idea that the AhR-G1661A transition may affects AhR-TAD interactions, especially with the TBP, which influence AhR-target genes expression. However, the previously reported flexibility of the modular TAD could act as an intervening factor, moderate the SNP effects and causes distinct outcomes in different individuals and tissues. Copyright © 2016 Elsevier Ltd. All rights reserved.

Identification of a Raloxifene Analog That Promotes AhR-Mediated Apoptosis in Cancer Cells.

PubMed

Jang, Hyo Sang; Pearce, Martin; O'Donnell, Edmond F; Nguyen, Bach Duc; Truong, Lisa; Mueller, Monica J; Bisson, William H; Kerkvliet, Nancy I; Tanguay, Robert L; Kolluri, Siva Kumar

2017-12-01

We previously reported that raloxifene, an estrogen receptor modulator, is also a ligand for the aryl hydrocarbon receptor (AhR). Raloxifene induces apoptosis in estrogen receptor-negative human cancer cells through the AhR. We performed structure-activity studies with seven raloxifene analogs to better understand the structural requirements of raloxifene for induction of AhR-mediated transcriptional activity and apoptosis. We identified Y134 as a raloxifene analog that activates AhR-mediated transcriptional activity and induces apoptosis in MDA-MB-231 human triple negative breast cancer cells. Suppression of AhR expression strongly reduced apoptosis induced by Y134, indicating the requirement of AhR for Y134-induced apoptosis. Y134 also induced apoptosis in hepatoma cells without having an effect on cell cycle regulation. Toxicity testing on zebrafish embryos revealed that Y134 has a significantly better safety profile than raloxifene. Our studies also identified an analog of raloxifene that acts as a partial antagonist of the AhR, and is capable of inhibiting AhR agonist-induced transcriptional activity. We conclude that Y134 is a promising raloxifene analog for further optimization as an anti-cancer agent targeting the AhR.

Outbreak of variant influenza A(H3N2) virus in the United States.

PubMed

Jhung, Michael A; Epperson, Scott; Biggerstaff, Matthew; Allen, Donna; Balish, Amanda; Barnes, Nathelia; Beaudoin, Amanda; Berman, Lashondra; Bidol, Sally; Blanton, Lenee; Blythe, David; Brammer, Lynnette; D'Mello, Tiffany; Danila, Richard; Davis, William; de Fijter, Sietske; Diorio, Mary; Durand, Lizette O; Emery, Shannon; Fowler, Brian; Garten, Rebecca; Grant, Yoran; Greenbaum, Adena; Gubareva, Larisa; Havers, Fiona; Haupt, Thomas; House, Jennifer; Ibrahim, Sherif; Jiang, Victoria; Jain, Seema; Jernigan, Daniel; Kazmierczak, James; Klimov, Alexander; Lindstrom, Stephen; Longenberger, Allison; Lucas, Paul; Lynfield, Ruth; McMorrow, Meredith; Moll, Maria; Morin, Craig; Ostroff, Stephen; Page, Shannon L; Park, Sarah Y; Peters, Susan; Quinn, Celia; Reed, Carrie; Richards, Shawn; Scheftel, Joni; Simwale, Owen; Shu, Bo; Soyemi, Kenneth; Stauffer, Jill; Steffens, Craig; Su, Su; Torso, Lauren; Uyeki, Timothy M; Vetter, Sara; Villanueva, Julie; Wong, Karen K; Shaw, Michael; Bresee, Joseph S; Cox, Nancy; Finelli, Lyn

2013-12-01

Variant influenza virus infections are rare but may have pandemic potential if person-to-person transmission is efficient. We describe the epidemiology of a multistate outbreak of an influenza A(H3N2) variant virus (H3N2v) first identified in 2011. We identified laboratory-confirmed cases of H3N2v and used a standard case report form to characterize illness and exposures. We considered illness to result from person-to-person H3N2v transmission if swine contact was not identified within 4 days prior to illness onset. From 9 July to 7 September 2012, we identified 306 cases of H3N2v in 10 states. The median age of all patients was 7 years. Commonly reported signs and symptoms included fever (98%), cough (85%), and fatigue (83%). Sixteen patients (5.2%) were hospitalized, and 1 fatal case was identified. The majority of those infected reported agricultural fair attendance (93%) and/or contact with swine (95%) prior to illness. We identified 15 cases of possible person-to-person transmission of H3N2v. Viruses recovered from patients were 93%-100% identical and similar to viruses recovered from previous cases of H3N2v. All H3N2v viruses examined were susceptible to oseltamivir and zanamivir and resistant to adamantane antiviral medications. In a large outbreak of variant influenza, the majority of infected persons reported exposures, suggesting that swine contact at an agricultural fair was a risk for H3N2v infection. We identified limited person-to-person H3N2v virus transmission, but found no evidence of efficient or sustained person-to-person transmission. Fair managers and attendees should be aware of the risk of swine-to-human transmission of influenza viruses in these settings.

Charge heterogeneity: Basic antibody charge variants with increased binding to Fc receptors

PubMed Central

Hintersteiner, Beate; Lingg, Nico; Zhang, Peiqing; Woen, Susanto; Hoi, Kong Meng; Stranner, Stefan; Wiederkum, Susanne; Mutschlechner, Oliver; Schuster, Manfred; Loibner, Hans; Jungbauer, Alois

2016-01-01

ABSTRACT We identified active isoforms of the chimeric anti-GD2 antibody, ch14.18, a recombinant antibody produced in Chinese hamster ovary cells, which is already used in clinical trials.1,2,3 We separated the antibody by high resolution ion-exchange chromatography with linear pH gradient elution into acidic, main and basic charge variants on a preparative scale yielding enough material for an in-depth study of the sources and the effects of microheterogeneity. The binding affinity of the charge variants toward the antigen and various cell surface receptors was studied by Biacore. Effector functions were evaluated using cellular assays for antibody-dependent cell-mediated cytotoxicity and complement-dependent cytotoxicity. Basic charge variants showed increased binding to cell surface receptor FcγRIIIa, which plays a major role in regulating effector functions. Furthermore, increased binding of the basic fractions to the neonatal receptor was observed. As this receptor mediates the prolonged half-life of IgG in human serum, this data may well hint at an increased serum half-life of these basic variants compared to their more acidic counterparts. Different glycoform patterns, C-terminal lysine clipping and N-terminal pyroglutamate formation were identified as the main structural sources for the observed isoform pattern. Potential differences in structural stability between individual charge variant fractions by nano differential scanning calorimetry could not been detected. Our in-vitro data suggests that the connection between microheterogeneity and the biological activity of recombinant antibody therapeutics deserves more attention than commonly accepted. PMID:27559765

Charge heterogeneity: Basic antibody charge variants with increased binding to Fc receptors.

PubMed

Hintersteiner, Beate; Lingg, Nico; Zhang, Peiqing; Woen, Susanto; Hoi, Kong Meng; Stranner, Stefan; Wiederkum, Susanne; Mutschlechner, Oliver; Schuster, Manfred; Loibner, Hans; Jungbauer, Alois

We identified active isoforms of the chimeric anti-GD2 antibody, ch14.18, a recombinant antibody produced in Chinese hamster ovary cells, which is already used in clinical trials. 1,2,3 We separated the antibody by high resolution ion-exchange chromatography with linear pH gradient elution into acidic, main and basic charge variants on a preparative scale yielding enough material for an in-depth study of the sources and the effects of microheterogeneity. The binding affinity of the charge variants toward the antigen and various cell surface receptors was studied by Biacore. Effector functions were evaluated using cellular assays for antibody-dependent cell-mediated cytotoxicity and complement-dependent cytotoxicity. Basic charge variants showed increased binding to cell surface receptor FcγRIIIa, which plays a major role in regulating effector functions. Furthermore, increased binding of the basic fractions to the neonatal receptor was observed. As this receptor mediates the prolonged half-life of IgG in human serum, this data may well hint at an increased serum half-life of these basic variants compared to their more acidic counterparts. Different glycoform patterns, C-terminal lysine clipping and N-terminal pyroglutamate formation were identified as the main structural sources for the observed isoform pattern. Potential differences in structural stability between individual charge variant fractions by nano differential scanning calorimetry could not been detected. Our in-vitro data suggests that the connection between microheterogeneity and the biological activity of recombinant antibody therapeutics deserves more attention than commonly accepted.

Dose- and time-dependent expression of aryl hydrocarbon receptor (AhR) and aryl hydrocarbon receptor nuclear translocator (ARNT) in PCB-, B[a]P-, and TBT-exposed intertidal copepod Tigriopus japonicus.

PubMed

Kim, Bo-Mi; Rhee, Jae-Sung; Hwang, Un-Ki; Seo, Jung Soo; Shin, Kyung-Hoon; Lee, Jae-Seong

2015-02-01

The aryl hydrocarbon receptor (AhR) and aryl hydrocarbon nuclear translocator (ARNT) genes from the copepod Tigriopus japonicus (Tj) were cloned to examine their potential functions in the invertebrate putative AhR-CYP signaling pathway. The amino acid sequences encoded by the Tj-AhR and Tj-ARNT genes showed high similarity to homologs of Daphnia and Drosophila, ranging from 68% and 70% similarity for the AhR genes to 56% for the ARNT genes. To determine whether Tj-AhR and Tj-ARNT are modulated by environmental pollutants, transcriptional expression of Tj-AhR and Tj-ARNT was analyzed in response to exposure to five concentrations of polychlorinated biphenyl (PCB 126) (control, 10, 50, 100, 500 μg L(-1)), benzo[a]pyrene (B[a]P) (control, 5, 10, 50, 100 μg L(-1)), and tributyltin (TBT) (control, 1, 5, 10, 20 μg L(-1)) 24h after exposure. A time-course experiment (0, 3, 6, 12, 24h) was performed to analyze mRNA expression patterns after exposure to PCB, B[a]P, and TBT. T. japonicus exhibited dose-dependent and time-dependent upregulation of Tj-AhR and Tj-ARNT in response to pollutant exposure, and the degree of expression was dependent on the pollutant, suggesting that pollutants such as PCB, B[a]P, and TBT modulate expression of Tj-AhR and Tj-ARNT genes in the putative AhR-CYP signaling pathway. Copyright © 2014 Elsevier Ltd. All rights reserved.

Isolation and characterization of alternatively spliced variants of the mouse sigma1 receptor gene, Sigmar1.

PubMed

Pan, Ling; Pasternak, David A; Xu, Jin; Xu, Mingming; Lu, Zhigang; Pasternak, Gavril W; Pan, Ying-Xian

2017-01-01

The sigma1 receptor acts as a chaperone at the endoplasmic reticulum, associates with multiple proteins in various cellular systems, and involves in a number of diseases, such as addiction, pain, cancer and psychiatric disorders. The sigma1 receptor is encoded by the single copy SIGMAR1 gene. The current study identifies five alternatively spliced variants of the mouse sigma1 receptor gene using a polymerase chain reaction cloning approach. All the splice variants are generated by exon skipping or alternative 3' or 5' splicing, producing the truncated sigma1 receptor. Similar alternative splicing has been observed in the human SIGMAR1 gene based on the molecular cloning or genome sequence prediction, suggesting conservation of alternative splicing of SIGMAR1 gene. Using quantitative polymerase chain reactions, we demonstrate differential expression of several splice variants in mouse tissues and brain regions. When expressed in HEK293 cells, all the splice variants fail to bind sigma ligands, implicating that each truncated region in these splice variants is important for ligand binding. However, co-immunoprecipitation (Co-IP) study in HEK293 cells co-transfected with tagged constructs reveals that all the splice variants maintain their ability to physically associate with a mu opioid receptor (mMOR-1), providing useful information to correlate the motifs/sequences necessary for their physical association. Furthermore, a competition Co-IP study showed that all the variants can disrupt in a dose-dependent manner the dimerization of the original sigma1 receptor with mMOR-1, suggesting a potential dominant negative function and providing significant insights into their function.

Serotonin is an endogenous regulator of intestinal CYP1A1 via AhR.

PubMed

Manzella, Christopher; Singhal, Megha; Alrefai, Waddah A; Saksena, Seema; Dudeja, Pradeep K; Gill, Ravinder K

2018-04-17

Aryl hydrocarbon receptor (AhR) is a nuclear receptor that controls xenobiotic detoxification via induction of cytochrome P450 1A1 (CYP1A1) and regulates immune responses in the intestine. Metabolites of L-tryptophan activate AhR, which confers protection against intestinal inflammation. We tested the hypothesis that serotonin (5-HT) is an endogenous activator of AhR in intestinal epithelial cells. Treatment of Caco-2 monolayers with 5-HT induced CYP1A1 mRNA in a time- and concentration-dependent manner and also stimulated CYP1A1 activity. CYP1A1 induction by 5-HT was dependent upon uptake via serotonin transporter (SERT). Antagonism of AhR and knockdown of AhR and its binding partner aryl hydrocarbon receptor nuclear translocator (ARNT) attenuated CYP1A1 induction by 5-HT. Activation of AhR was evident by its nuclear translocation after 5-HT treatment and by induction of an AhR-responsive luciferase reporter. In vivo studies showed a dramatic decrease in CYP1A1 expression and other AhR target genes in SERT KO ileal mucosa by microarray analysis. These results suggest that intracellular accumulation of 5-HT via SERT induces CYP1A1 expression via AhR in intestinal epithelial cells, and SERT deficiency in vivo impairs activation of AhR. Our studies provide a novel link between the serotonergic and AhR pathways which has implications in xenobiotic metabolism and intestinal inflammation.

Phytomonitoring and phytoremediation of agrochemicals and related compounds based on recombinant cytochrome P450s and aryl hydrocarbon receptors (AhRs).

PubMed

Shimazu, Sayuri; Inui, Hideyuki; Ohkawa, Hideo

2011-04-13

Molecular mechanisms of metabolism and modes of actions of agrochemicals and related compounds are important for understanding selective toxicity, biodegradability, and monitoring of biological effects on nontarget organisms. It is well-known that in mammals, cytochrome P450 (P450 or CYP) monooxygenases metabolize lipophilic foreign compounds. These P450 species are inducible, and both CYP1A1 and CYP1A2 are induced by aryl hydrocarbon receptor (AhR) combined with a ligand. Gene engineering of P450 and NADPH cytochrome P450 oxidoreductase (P450 reductase) was established for bioconversion. Also, gene modification of AhRs was developed for recombinant AhR-mediated β-glucronidase (GUS) reporter assay of AhR ligands. Recombinant P450 genes were transformed into plants for phytoremediation, and recombinant AhR-mediated GUS reporter gene expression systems were each transformed into plants for phytomonitoring. Transgenic rice plants carrying CYP2B6 metabolized the herbicide metolachlor and remarkably reduced the residues in the plants and soils under paddy field conditions. Transgenic Arabidopsis plants carrying recombinant guinea pig (g) AhR-mediated GUS reporter genes detected PCB126 at the level of 10 ng/g soils in the presence of biosurfactants MEL-B. Both phytomonitoring and phytoremediation plants were each evaluated from the standpoint of practical uses.

Isolation and characterization of alternatively spliced variants of the mouse sigma1 receptor gene, Sigmar1

PubMed Central

Pan, Ling; Pasternak, David A.; Xu, Jin; Xu, Mingming; Lu, Zhigang; Pasternak, Gavril W.

2017-01-01

The sigma1 receptor acts as a chaperone at the endoplasmic reticulum, associates with multiple proteins in various cellular systems, and involves in a number of diseases, such as addiction, pain, cancer and psychiatric disorders. The sigma1 receptor is encoded by the single copy SIGMAR1 gene. The current study identifies five alternatively spliced variants of the mouse sigma1 receptor gene using a polymerase chain reaction cloning approach. All the splice variants are generated by exon skipping or alternative 3’ or 5’ splicing, producing the truncated sigma1 receptor. Similar alternative splicing has been observed in the human SIGMAR1 gene based on the molecular cloning or genome sequence prediction, suggesting conservation of alternative splicing of SIGMAR1 gene. Using quantitative polymerase chain reactions, we demonstrate differential expression of several splice variants in mouse tissues and brain regions. When expressed in HEK293 cells, all the splice variants fail to bind sigma ligands, implicating that each truncated region in these splice variants is important for ligand binding. However, co-immunoprecipitation (Co-IP) study in HEK293 cells co-transfected with tagged constructs reveals that all the splice variants maintain their ability to physically associate with a mu opioid receptor (mMOR-1), providing useful information to correlate the motifs/sequences necessary for their physical association. Furthermore, a competition Co-IP study showed that all the variants can disrupt in a dose-dependent manner the dimerization of the original sigma1 receptor with mMOR-1, suggesting a potential dominant negative function and providing significant insights into their function. PMID:28350844

Establishment of Sf9 Transformants Constitutively Expressing PBAN Receptor Variants: Application to Functional Evaluation

PubMed Central

Lee, Jae Min; Hull, J. Joe; Kawai, Takeshi; Tsuneizumi, Kazuhide; Kurihara, Masaaki; Tanokura, Masaru; Nagata, Koji; Nagasawa, Hiromichi; Matsumoto, Shogo

2012-01-01

To facilitate further evaluation of pheromone biosynthesis activating neuropeptide receptor (PBANR) functionality and regulation, we generated cultured insect cell lines constitutively expressing green fluorescent protein chimeras of the recently identified Bombyx mori PBANR (BommoPBANR) and Pseudaletia separata PBANR (PsesePBANR) variants. Fluorescent chimeras included the BommoPBANR-A, -B, and -C variants and the PsesePBANR-B and -C variants. Cell lines expressing non-chimeric BommoPBANR-B and -C variants were also generated. Functional evaluation of these transformed cell lines using confocal laser microscopy revealed that a Rhodamine Red-labeled PBAN derivative (RR-C10PBANR2K) specifically co-localized with all of the respective PBANR variants at the plasma membrane. Near complete internalization of the fluorescent RR-C10PBANR2K ligand 30 min after binding was observed in all cell lines except those expressing the BommoPBANR-A variant, in which the ligand/receptor complex remained at the plasma membrane. Fluorescent Ca2+ imaging further showed that the BommoPBANR-A cell line exhibited drastically different Ca2+ mobilization kinetics at a number of RR-C10PBANR2K concentrations including 10 μM. These observations demonstrate a clear functional difference between the BommoPBANR-A variant and the BommoPBANR-B and -C variants in terms of receptor regulation and activation of downstream effector molecules. We also found that, contrary to previous reports, ligand-induced internalization of BommoPBANR-B and BommoPBANR-C in cell lines stably expressing these variants occurred in the absence of extracellular Ca2+. PMID:22654874

Adaptation of influenza A(H1N1)pdm09 virus in experimental mouse models.

PubMed

Prokopyeva, E A; Sobolev, I A; Prokopyev, M V; Shestopalov, A M

2016-04-01

In the present study, three mouse-adapted variants of influenza A(H1N1)pdm09 virus were obtained by lung-to-lung passages of BALB/c, C57BL/6z and CD1 mice. The significantly increased virulence and pathogenicity of all of the mouse-adapted variants induced 100% mortality in the adapted mice. Genetic analysis indicated that the increased virulence of all of the mouse-adapted variants reflected the incremental acquisition of several mutations in PB2, PB1, HA, NP, NA, and NS2 proteins. Identical amino acid substitutions were also detected in all of the mouse-adapted variants of A(H1N1)pdm09 virus, including PB2 (K251R), PB1 (V652A), NP (I353V), NA (I106V, N248D) and NS1 (G159E). Apparently, influenza A(H1N1)pdm09 virus easily adapted to the host after serial passages in the lungs, inducing 100% lethality in the last experimental group. However, cross-challenge revealed that not all adapted variants are pathogenic for different laboratory mice. Such important results should be considered when using the influenza mice model. Copyright © 2016 Elsevier B.V. All rights reserved.

AhR mediates an anti-inflammatory feedback mechanism in human Langerhans cells involving FcεRI and IDO.

PubMed

Koch, S; Stroisch, T J; Vorac, J; Herrmann, N; Leib, N; Schnautz, S; Kirins, H; Förster, I; Weighardt, H; Bieber, T

2017-11-01

Aryl hydrocarbon receptor (AhR), an important regulator of immune responses, is activated by UVB irradiation in the skin. Langerhans cells (LC) in the epidermis of patients with atopic dermatitis (AD) carry the high-affinity receptor for IgE, FcεRI, and are crucially involved in the pathogenesis of AD by inducing inflammatory responses and regulating tolerogenic processes. We investigated AhR and AhR repressor (AhRR) expression and functional consequences of AhR activation in human ex vivo skin cells and in in vitro-generated LC. Epidermal cells from healthy skin were analyzed for their expression of AhR and AhRR. LC generated from CD34 + hematopoietic stem cells (CD34LC) were treated with the UV photoproduct and AhR ligand 6-formylindolo[3,2-b]carbazole (FICZ). Cell surface receptors, transcription factors, and the tolerogenic tryptophan-degrading enzyme indoleamine 2,3-dioxygenase (IDO) were analyzed using flow cytometry and quantitative PCR. Epidermal LC and CD34LC express AhR and AhRR. AhR was also found in keratinocytes, which lack AhRR. AhR activation of LC by FICZ caused downregulation of FcεRI in CD34LC without affecting their maturation. AhR-mediated regulation of FcεRI did not involve any known transcription factors related to this receptor. Furthermore, we could show upregulation of IDO mediated by AhR engagement. Our study shows that AhR activation by FICZ reduces FcεRI and upregulates IDO expression in LC. This AhR-mediated anti-inflammatory feedback mechanism may dampen the allergen-induced inflammation in AD. © 2017 EAACI and John Wiley and Sons A/S. Published by John Wiley and Sons Ltd.

Outbreak of Variant Influenza A(H3N2) Virus in the United States

PubMed Central

Jhung, Michael A.; Epperson, Scott; Biggerstaff, Matthew; Allen, Donna; Balish, Amanda; Barnes, Nathelia; Beaudoin, Amanda; Berman, LaShondra; Bidol, Sally; Blanton, Lenee; Blythe, David; Brammer, Lynnette; D’Mello, Tiffany; Danila, Richard; Davis, William; de Fijter, Sietske; DiOrio, Mary; Durand, Lizette O.; Emery, Shannon; Fowler, Brian; Garten, Rebecca; Grant, Yoran; Greenbaum, Adena; Gubareva, Larisa; Havers, Fiona; Haupt, Thomas; House, Jennifer; Ibrahim, Sherif; Jiang, Victoria; Jain, Seema; Jernigan, Daniel; Kazmierczak, James; Klimov, Alexander; Lindstrom, Stephen; Longenberger, Allison; Lucas, Paul; Lynfield, Ruth; McMorrow, Meredith; Moll, Maria; Morin, Craig; Ostroff, Stephen; Page, Shannon L.; Park, Sarah Y.; Peters, Susan; Quinn, Celia; Reed, Carrie; Richards, Shawn; Scheftel, Joni; Simwale, Owen; Shu, Bo; Soyemi, Kenneth; Stauffer, Jill; Steffens, Craig; Su, Su; Torso, Lauren; Uyeki, Timothy M.; Vetter, Sara; Villanueva, Julie; Wong, Karen K.; Shaw, Michael; Bresee, Joseph S.; Cox, Nancy; Finelli, Lyn

2017-01-01

Background Variant influenza virus infections are rare but may have pandemic potential if person-to-person transmission is efficient. We describe the epidemiology of a multistate outbreak of an influenza A(H3N2) variant virus (H3N2v) first identified in 2011. Methods We identified laboratory-confirmed cases of H3N2v and used a standard case report form to characterize illness and exposures. We considered illness to result from person-to-person H3N2v transmission if swine contact was not identified within 4 days prior to illness onset. Results From 9 July to 7 September 2012, we identified 306 cases of H3N2v in 10 states. The median age of all patients was 7 years. Commonly reported signs and symptoms included fever (98%), cough (85%), and fatigue (83%). Sixteen patients (5.2%) were hospitalized, and 1 fatal case was identified. The majority of those infected reported agricultural fair attendance (93%) and/or contact with swine (95%) prior to illness. We identified 15 cases of possible person-to-person transmission of H3N2v. Viruses recovered from patients were 93%–100% identical and similar to viruses recovered from previous cases of H3N2v. All H3N2v viruses examined were susceptible to oseltamivir and zanamivir and resistant to adamantane antiviral medications. Conclusions In a large outbreak of variant influenza, the majority of infected persons reported exposures, suggesting that swine contact at an agricultural fair was a risk for H3N2v infection. We identified limited person-to-person H3N2v virus transmission, but found no evidence of efficient or sustained person-to-person transmission. Fair managers and attendees should be aware of the risk of swine-to-human transmission of influenza viruses in these settings. PMID:24065322

Dysregulation of Notch and ERα signaling in AhR−/− male mice

PubMed Central

Huang, Bo; Butler, Ryan; Miao, Yifei; Dai, Yubing; Wu, Wanfu; Su, Wen; Fujii-Kuriyama, Yoshiaki; Warner, Margaret; Gustafsson, Jan-Åke

2016-01-01

The aryl hydrocarbon receptor (AhR) is now recognized as an important physiological regulator in the immune and reproductive systems, and in the development of the liver and vascular system. AhR regulates cell cycle, cell proliferation, and differentiation through interacting with other signaling pathways, like estrogen receptor α (ERα), androgen receptor (AR), and Notch signaling. In the present study, we investigated Notch and estrogen signaling in AhR−/− mice. We found low fertility with degenerative changes in the testes, germ cell apoptosis, and a reduced number of early spermatids. There was no change in aromatase, AR, ERα, or ERβ expression in the testis and no detectable change in serum estrogen levels. However, expression of Notch receptors (Notch1 and Notch3) and their target Hairy and Enhancer of Split homolog 1 (HES1) was reduced. In addition, the testosterone level was slightly reduced in the serum. In the mammary fat pad, AhR appeared to regulate estrogen signaling because, in AhR−/− males, there was significant growth of the mammary ducts with high expression of ERα in the ductal epithelium. The enhanced mammary ductal growth appears to be related to overexpression of ERα accompanied by a high proliferation index, whereas the reduced fertility appears to be related defects in Notch signaling that leads to reduced expression of HES1 and, consequently, early maturation of spermatocytes and a depletion of primary spermatids. Previous reports have indicated that AhR pathway is associated with infertility in men. Our results provide a mechanistic explanation for this defect. PMID:27688768

Stabilization of the μ-opioid receptor by truncated single transmembrane splice variants through a chaperone-like action.

PubMed

Xu, Jin; Xu, Ming; Brown, Taylor; Rossi, Grace C; Hurd, Yasmin L; Inturrisi, Charles E; Pasternak, Gavril W; Pan, Ying-Xian

2013-07-19

The μ-opioid receptor gene, OPRM1, undergoes extensive alternative pre-mRNA splicing, as illustrated by the identification of an array of splice variants generated by both 5' and 3' alternative splicing. The current study reports the identification of another set of splice variants conserved across species that are generated through exon skipping or insertion that encodes proteins containing only a single transmembrane (TM) domain. Using a Tet-Off system, we demonstrated that the truncated single TM variants can dimerize with the full-length 7-TM μ-opioid receptor (MOR-1) in the endoplasmic reticulum, leading to increased expression of MOR-1 at the protein level by a chaperone-like function that minimizes endoplasmic reticulum-associated degradation. In vivo antisense studies suggested that the single TM variants play an important role in morphine analgesia, presumably through modulation of receptor expression levels. Our studies suggest the functional roles of truncated receptors in other G protein-coupled receptor families.

The crystal structure of the AhRR-ARNT heterodimer reveals the structural basis of the repression of AhR-mediated transcription.

PubMed

Sakurai, Shunya; Shimizu, Toshiyuki; Ohto, Umeharu

2017-10-27

2,3,7,8-Tetrachlorodibenzo- p -dioxin and related compounds are extraordinarily potent environmental toxic pollutants. Most of the 2,3,7,8-tetrachlorodibenzo- p -dioxin toxicities are mediated by aryl hydrocarbon receptor (AhR), a ligand-dependent transcription factor belonging to the basic helix-loop-helix (bHLH) Per-ARNT-Sim (PAS) family. Upon ligand binding, AhR forms a heterodimer with AhR nuclear translocator (ARNT) and induces the expression of genes involved in various biological responses. One of the genes induced by AhR encodes AhR repressor (AhRR), which also forms a heterodimer with ARNT and represses the activation of AhR-dependent transcription. The control of AhR activation is critical for managing AhR-mediated diseases, but the mechanisms by which AhRR represses AhR activation remain poorly understood, because of the lack of structural information. Here, we determined the structure of the AhRR-ARNT heterodimer by X-ray crystallography, which revealed an asymmetric intertwined domain organization presenting structural features that are both conserved and distinct among bHLH-PAS family members. The structures of AhRR-ARNT and AhR-ARNT were similar in the bHLH-PAS-A region, whereas the PAS-B of ARNT in the AhRR-ARNT complex exhibited a different domain arrangement in this family reported so far. The structure clearly disclosed that AhRR competitively represses AhR binding to ARNT and target DNA and further suggested the existence of an AhRR-ARNT-specific repression mechanism. This study provides a structural basis for understanding the mechanism by which AhRR represses AhR-mediated gene transcription. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

Comprehensive Analysis of Non-Synonymous Natural Variants of G Protein-Coupled Receptors.

PubMed

Kim, Hee Ryung; Duc, Nguyen Minh; Chung, Ka Young

2018-03-01

G protein-coupled receptors (GPCRs) are the largest superfamily of transmembrane receptors and have vital signaling functions in various organs. Because of their critical roles in physiology and pathology, GPCRs are the most commonly used therapeutic target. It has been suggested that GPCRs undergo massive genetic variations such as genetic polymorphisms and DNA insertions or deletions. Among these genetic variations, non-synonymous natural variations change the amino acid sequence and could thus alter GPCR functions such as expression, localization, signaling, and ligand binding, which may be involved in disease development and altered responses to GPCR-targeting drugs. Despite the clinical importance of GPCRs, studies on the genotype-phenotype relationship of GPCR natural variants have been limited to a few GPCRs such as β-adrenergic receptors and opioid receptors. Comprehensive understanding of non-synonymous natural variations within GPCRs would help to predict the unknown genotype-phenotype relationship and yet-to-be-discovered natural variants. Here, we analyzed the non-synonymous natural variants of all non-olfactory GPCRs available from a public database, UniProt. The results suggest that non-synonymous natural variations occur extensively within the GPCR superfamily especially in the N-terminus and transmembrane domains. Within the transmembrane domains, natural variations observed more frequently in the conserved residues, which leads to disruption of the receptor function. Our analysis also suggests that only few non-synonymous natural variations have been studied in efforts to link the variations with functional consequences.

Changes in flip/flop splicing of astroglial AMPA receptors in human temporal lobe epilepsy.

PubMed

Seifert, Gerald; Schröder, Wolfgang; Hinterkeuser, Stefan; Schumacher, Thekla; Schramm, Johannes; Steinhäuser, Christian

2002-01-01

Recent data suggested a role for glial cells in epilepsy. This study sought to identify and functionally characterize AMPA receptors expressed by astrocytes in human hippocampal tissue resected from patients with intractable temporal lobe epilepsy. Patch-clamp and fast application methods were combined to investigate astrocytes in situ and after fresh isolation from the stratum radiatum of the hippocampal CA1 subfield. Relying on presurgical and histopathologic analysis, we divided human specimens into two groups, Ammon's horn sclerosis (AHS) and lesion-associated epilepsy. Fast application of glutamate and kainate evoked receptor currents in all cells studied. Reversal-potential analysis revealed an intermediate Ca2+ permeability of the receptor channels that did not vary between the two groups of patients. However, preapplication of the AMPA receptor-specific modulator, cyclothiazide, disclosed differences in flip-flop splicing. This treatment considerably enhanced the receptor conductance, with potentiation being significantly stronger in cells from AHS specimens compared with lesion-associated cells, suggesting upregulation of AMPA receptor flip splice variants in astrocytes of the sclerotic tissue. Compelling evidence has been accumulated showing direct and rapid signaling between neurons and glial cells. Our data suggest that in AHS patients, neuronally released glutamate will lead to an enhanced and prolonged depolarization of astrocytes, which might be involved in seizure generation and spread in this particular condition of human temporal lobe epilepsy.

Unprecedented genomic diversity of AhR1 and AhR2 genes in Atlantic salmon (Salmo salar L.).

PubMed

Hansson, Maria C; Wittzell, Håkan; Persson, Kerstin; von Schantz, Torbjörn

2004-06-24

Aryl hydrocarbon receptor (AhR) genes encode proteins involved in mediating the toxic responses induced by several environmental pollutants. Here, we describe the identification of the first two AhR1 (alpha and beta) genes and two additional AhR2 (alpha and beta) genes in the tetraploid species Atlantic salmon (Salmo salar L.) from a cosmid library screening. Cosmid clones containing genomic salmon AhR sequences were isolated using a cDNA clone containing the coding region of the Atlantic salmon AhR2gamma as a probe. Screening revealed 14 positive clones, from which four were chosen for further analyses. One of the cosmids contained genomic AhR sequences that were highly similar to the rainbow trout (Oncorhynchus mykiss) AhR2alpha and beta genes. SMART RACE amplified two complete, highly similar but not identical AhR type 2 sequences from salmon cDNA, which from phylogenetic analyses were determined as the rainbow trout AhR2alpha and beta orthologs. The salmon AhR2alpha and beta encode proteins of 1071 and 1058 residues, respectively, and encompass characteristic AhR sequence elements like a basic-helix-loop-helix (bHLH) and two PER-ARNT-SIM (PAS) domains. Both genes are transcribed in liver, spleen and muscle tissues of adult salmon. A second cosmid contained partial sequences, which were identical to the previously characterized AhR2gamma gene. The last two cosmids contained partial genomic AhR sequences, which were more similar to other AhR type 1 fish genes than the four characterized salmon AhR2 genes. However, attempts to amplify the corresponding complete cDNA sequences of the inserts proved very difficult, suggesting that these genes are non-functional or very weakly transcribed in the examined tissues. Phylogenetic analyses of the conserved regions did, however, clearly indicate that these two AhRs belong to the AhR type 1 clade and have been assigned as the Atlantic salmon AhR1alpha and AhR1beta genes. Taken together, these findings demonstrate that

AhR-deficiency as a cause of demyelinating disease and inflammation.

PubMed

Juricek, Ludmila; Carcaud, Julie; Pelhaitre, Alice; Riday, Thorfinn T; Chevallier, Aline; Lanzini, Justine; Auzeil, Nicolas; Laprévote, Olivier; Dumont, Florent; Jacques, Sebastien; Letourneur, Frank; Massaad, Charbel; Agulhon, Cendra; Barouki, Robert; Beraneck, Mathieu; Coumoul, Xavier

2017-08-29

The Aryl hydrocarbon Receptor(AhR) is among the most important receptors which bind pollutants; however it also regulates signaling pathways independently of such exposure. We previously demonstrated that AhR is expressed during development of the central nervous system(CNS) and that its deletion leads to the occurrence of a congenital nystagmus. Objectives of the present study are to decipher the origin of these deficits, and to identify the role of the AhR in the development of the CNS. We show that the AhR-knockout phenotype develops during early infancy together with deficits in visual-information-processing which are associated with an altered optic nerve myelin sheath, which exhibits modifications in its lipid composition and in the expression of myelin-associated-glycoprotein(MAG), a cell adhesion molecule involved in myelin-maintenance and glia-axon interaction. In addition, we show that the expression of pro-inflammatory cytokines is increased in the impaired optic nerve and confirm that inflammation is causally related with an AhR-dependent decreased expression of MAG. Overall, our findings demonstrate the role of the AhR as a physiological regulator of myelination and inflammatory processes in the developing CNS. It identifies a mechanism by which environmental pollutants might influence CNS myelination and suggest AhR as a relevant drug target for demyelinating diseases.

Possible role of rare variants in Trace amine associated receptor 1 in schizophrenia.

PubMed

John, Jibin; Kukshal, Prachi; Bhatia, Triptish; Chowdari, K V; Nimgaonkar, V L; Deshpande, S N; Thelma, B K

2017-11-01

Schizophrenia (SZ) is a chronic mental illness with behavioral abnormalities. Recent common variant based genome wide association studies and rare variant detection using next generation sequencing approaches have identified numerous variants that confer risk for SZ, but etiology remains unclear propelling continuing investigations. Using whole exome sequencing, we identified a rare heterozygous variant (c.545G>T; p.Cys182Phe) in Trace amine associated receptor 1 gene (TAAR1 6q23.2) in three affected members in a small SZ family. The variant predicted to be damaging by 15 prediction tools, causes breakage of a conserved disulfide bond in this G-protein-coupled receptor. On screening this intronless gene for additional variant(s) in ~800 sporadic SZ patients, we identified six rare protein altering variants (MAF<0.001) namely p.Ser47Cys, p.Phe51Leu, p.Tyr294Ter, p.Leu295Ser in four unrelated north Indian cases (n=475); p.Ala109Thr and p.Val250Ala in two independent Caucasian/African-American patients (n=310). Five of these variants were also predicted to be damaging. Besides, a rare synonymous variant was observed in SZ patients. These rare variants were absent in north Indian healthy controls (n=410) but significantly enriched in patients (p=0.036). Conversely, three common coding SNPs (rs8192621, rs8192620 and rs8192619) and a promoter SNP (rs60266355) tested for association with SZ in the north Indian cohort were not significant (P>0.05). TAAR1 is a modulator of monoaminergic pathways and interacts with AKT signaling pathways. Substantial animal model based pharmacological and functional data implying its relevance in SZ are also available. However, this is the first report suggestive of the likely contribution of rare variants in this gene to SZ. Copyright © 2017 Elsevier B.V. All rights reserved.

Functional analysis of four naturally occurring variants of human constitutive androstane receptor.

PubMed

Ikeda, Shinobu; Kurose, Kouichi; Jinno, Hideto; Sai, Kimie; Ozawa, Shogo; Hasegawa, Ryuichi; Komamura, Kazuo; Kotake, Takeshi; Morishita, Hideki; Kamakura, Shiro; Kitakaze, Masafumi; Tomoike, Hitonobu; Tamura, Tomohide; Yamamoto, Noboru; Kunitoh, Hideo; Yamada, Yasuhide; Ohe, Yuichiro; Shimada, Yasuhiro; Shirao, Kuniaki; Kubota, Kaoru; Minami, Hironobu; Ohtsu, Atsushi; Yoshida, Teruhiko; Saijo, Nagahiro; Saito, Yoshiro; Sawada, Jun-ichi

2005-01-01

The human constitutive androstane receptor (CAR, NR1I3) is a member of the orphan nuclear receptor superfamily that plays an important role in the control of drug metabolism and disposition. In this study, we sequenced all the coding exons of the NR1I3 gene for 334 Japanese subjects. We identified three novel single nucleotide polymorphisms (SNPs) that induce non-synonymous alterations of amino acids (His246Arg, Leu308Pro, and Asn323Ser) residing in the ligand-binding domain of CAR, in addition to the Val133Gly variant, which was another CAR variant identified in our previous study. We performed functional analysis of these four naturally occurring CAR variants in COS-7 cells using a CYP3A4 promoter/enhancer reporter gene that includes the CAR responsive elements. The His246Arg variant caused marked reductions in both transactivation of the reporter gene and in the response to 6-(4-chlorophenyl)imidazo[2,1-b][1,3]thiazole-5-carbaldehyde O-(3,4-dichlorobenzyl)oxime (CITCO), which is a human CAR-specific agonist. The transactivation ability of the Leu308Pro variant was also significantly decreased, but its responsiveness to CITCO was not abrogated. The transactivation ability and CITCO response of the Val133Gly and Asn323Ser variants did not change as compared to the wild-type CAR. These data suggest that the His246Arg and Leu308Pro variants, especially His246Arg, may influence the expression of drug-metabolizing enzymes and transporters that are transactivated by CAR.

Computational analysis of the receptor binding specificity of novel influenza A/H7N9 viruses.

PubMed

Zhou, Xinrui; Zheng, Jie; Ivan, Fransiskus Xaverius; Yin, Rui; Ranganathan, Shoba; Chow, Vincent T K; Kwoh, Chee-Keong

2018-05-09

Influenza viruses are undergoing continuous and rapid evolution. The fatal influenza A/H7N9 has drawn attention since the first wave of infections in March 2013, and raised more grave concerns with its increased potential to spread among humans. Experimental studies have revealed several host and virulence markers, indicating differential host binding preferences which can help estimate the potential of causing a pandemic. Here we systematically investigate the sequence pattern and structural characteristics of novel influenza A/H7N9 using computational approaches. The sequence analysis highlighted mutations in protein functional domains of influenza viruses. Molecular docking and molecular dynamics simulation revealed that the hemagglutinin (HA) of A/Taiwan/1/2017(H7N9) strain enhanced the binding with both avian and human receptor analogs, compared with the previous A/Shanghai/02/2013(H7N9) strain. The Molecular Mechanics - Poisson Boltzmann Surface Area (MM-PBSA) calculation revealed the change of residue-ligand interaction energy and detected the residues with conspicuous binding preference. The results are novel and specific to the emerging influenza A/Taiwan/1/2017(H7N9) strain compared with A/Shanghai/02/2013(H7N9). Its enhanced ability to bind human receptor analogs, which are abundant in the human upper respiratory tract, may be responsible for the recent outbreak. Residues showing binding preference were detected, which could facilitate monitoring the circulating influenza viruses.

A Historical Perspective of Influenza A(H1N2) Virus

PubMed Central

McVernon, Jodie; Hall, Robert; Leder, Karin

2014-01-01

The emergence and transition to pandemic status of the influenza A(H1N1)A(H1N1)pdm09) virus in 2009 illustrated the potential for previously circulating human viruses to re-emerge in humans and cause a pandemic after decades of circulating among animals. Within a short time of the initial emergence of A(H1N1)pdm09 virus, novel reassortants were isolated from swine. In late 2011, a variant (v) H3N2 subtype was isolated from humans, and by 2012, the number of persons infected began to increase with limited person-to-person transmission. During 2012 in the United States, an A(H1N2)v virus was transmitted to humans from swine. During the same year, Australia recorded its first H1N2 subtype infection among swine. The A(H3N2)v and A(H1N2)v viruses contained the matrix protein from the A(H1N1)pdm09 virus, raising the possibility of increased transmissibility among humans and underscoring the potential for influenza pandemics of novel swine-origin viruses. We report on the differing histories of A(H1N2) viruses among humans and animals. PMID:24377419

A historical perspective of influenza A(H1N2) virus.

PubMed

Komadina, Naomi; McVernon, Jodie; Hall, Robert; Leder, Karin

2014-01-01

The emergence and transition to pandemic status of the influenza A(H1N1)A(H1N1)pdm09) virus in 2009 illustrated the potential for previously circulating human viruses to re-emerge in humans and cause a pandemic after decades of circulating among animals. Within a short time of the initial emergence of A(H1N1)pdm09 virus, novel reassortants were isolated from swine. In late 2011, a variant (v) H3N2 subtype was isolated from humans, and by 2012, the number of persons infected began to increase with limited person-to-person transmission. During 2012 in the United States, an A(H1N2)v virus was transmitted to humans from swine. During the same year, Australia recorded its first H1N2 subtype infection among swine. The A(H3N2)v and A(H1N2)v viruses contained the matrix protein from the A(H1N1)pdm09 virus, raising the possibility of increased transmissibility among humans and underscoring the potential for influenza pandemics of novel swine-origin viruses. We report on the differing histories of A(H1N2) viruses among humans and animals.

The regulation mechanisms of AhR by molecular chaperone complex.

PubMed

Kudo, Ikuru; Hosaka, Miki; Haga, Asami; Tsuji, Noriko; Nagata, Yuhtaroh; Okada, Hirotaka; Fukuda, Kana; Kakizaki, Yuka; Okamoto, Tomoya; Grave, Ewa; Itoh, Hideaki

2018-03-01

The AhR, so called the dioxin receptor, is a member of the nuclear receptor superfamily. The ligand-free AhR forms a cytosolic protein complex with the molecular chaperone HSP90, co-chaperone p23, and XAP2 in the cytoplasm. Following ligand binding like 2, 3, 7, 8-tetrachlorodibenzo-p-dioxin (TCDD), the AhR translocates into the nucleus. Although it has been reported that HSP90 regulates the translocation of the AhR to the nucleus, the precise activation mechanisms of the AhR have not yet been fully understood. AhR consists of the N-terminal bHLH domain containing NLS and NES, the middle PAS domain and the C-terminal transactivation domain. The PAS domain is familiar as a ligand and HSP90 binding domain. In this study, we focused on the bHLH domain that was thought to be a HSP90 binding domain. We investigated the binding properties of bHLH to HSP90. We analyzed the direct interaction of bHLH with HSP90, p23 and XAP2 using purified proteins. We found that not only the PAS domain but also the bHLH domain bound to HSP90. The bHLH domain forms complex with HSP90, p23 and XAP2. We also determined the bHLH binding domain was HSP90 N-domain. The bHLH domain makes a complex with HSP90, p23 and XAP2 via the HSP90 N-domain. Although the NLS is closed in the absence of a ligand, the structure of AhR will be changed in the presence of a ligand, which leads to NLS open, result in the nuclear translocation of AhR.

Use of natural AhR ligands as potential therapeutic modalities against inflammatory disorders

PubMed Central

Busbee, Philip B; Rouse, Michael; Nagarkatti, Mitzi; Nagarkatti, Prakash S

2014-01-01

The aim of this review is to discuss research involving ligands for the aryl hydrocarbon receptor (AhR) and their role in immunomodulation. While activation of the AhR is well known for its ability to regulate the biochemical and toxic effects of environmental chemicals, more recently an exciting discovery has been made indicating that AhR ligation can also regulate T-cell differentiation, specifically through activation of Foxp3+ regulatory T cells (Tregs) and downregulation of the proinflammatory Th17 cells. Such findings have opened new avenues of research on the possibility of targeting the AhR to treat inflammatory and autoimmune diseases. Specifically, this review will discuss the current research involving natural and dietary AhR ligands. In addition, evidence indicating the potential use of these ligands in regulating inflammation in various diseases will be highlighted. The importance of the AhR in immunological processes can be illustrated by expression of this receptor on a majority of immune cell types. In addition, AhR signaling pathways have been reported to influence a number of genes responsible for mediating inflammation and other immune responses. As interest in the AhR and its ligands increases, it seems prudent to consolidate current research on the contributions of these ligands to immune regulation during the course of inflammatory diseases. PMID:23731446

Seroprotective antibodies to 2011 variant influenza A(H3N2v) and seasonal influenza A(H3N2) among three age groups of US Department of Defense service members.

PubMed

Radin, Jennifer M; Hawksworth, Anthony W; Ortiguerra, Ryan G; Brice, Gary T

2015-01-01

In 2011, a new variant of influenza A(H3N2) emerged that contained a recombination of genes from swine H3N2 viruses and the matrix (M) gene of influenza A(H1N1)pdm09 virus. New combinations and variants of pre-existing influenza viruses are worrisome if there is low or nonexistent immunity in a population, which increases chances for an outbreak or pandemic. Sera collected in 2011 were obtained from US Department of Defense service members in three age groups: 19-21 years, 32-33 years, and 47-48 years. Pre- and post-vaccination samples were available for the youngest age group, and postvaccination samples for the two older groups. Specimens were tested using microneutralization assays for antibody titers against H3N2v (A/Indiana/10/2011) and seasonal H3N2 virus (A/Perth/16/2009). The youngest age group had significantly (p<0.05) higher geometric mean titers for H3N2v with 165 (95% confidence interval [CI]: 105-225) compared with the two older groups, aged 32-33 and 47-48 years, who had geometric mean titers of 68 (95% CI: 55-82) and 46 (95% CI: 24-65), respectively. Similarly, the youngest age group also had the highest geometric mean titers for seasonal H3N2. In the youngest age group, the proportion of patients who seroconverted after vaccination was 12% for H3N2v and 27% for seasonal H3N2. Our results were similar to previous studies that found highest seroprotection among young adults and decreasing titers among older adults. The proportion of 19- to 21-year-olds who seroconverted after seasonal vaccination was low and similar to previous findings. Improving our understanding of H3N2v immunity among different age groups in the United States can help inform vaccination plans if H3N2v becomes more transmissible in the future.

Estrogen Receptor Mutants/Variants in Human Breast Cancer.

DTIC Science & Technology

1995-12-01

Effect of dystrophin gene deletions on mRNA levels and processing in Duchenne and Becker dystrophies . Cell 1990, 63:1239-1248 4 Patriotis C, Makris A...the most common inherited disorder of platelets, Aspartylblucosaminuria, 2 an inherited lysosomal storage disorder, Duchenne and Becker muscular... dystrophies 3 or cancer progression.4m 5 Several estrogen receptor (ER) variant mRNAs have also been identified in human breast cancer biopsies.6,7,8, 9

Diversity and impact of rare variants in genes encoding the platelet G protein-coupled receptors.

PubMed

Jones, Matthew L; Norman, Jane E; Morgan, Neil V; Mundell, Stuart J; Lordkipanidzé, Marie; Lowe, Gillian C; Daly, Martina E; Simpson, Michael A; Drake, Sian; Watson, Steve P; Mumford, Andrew D

2015-04-01

Platelet responses to activating agonists are influenced by common population variants within or near G protein-coupled receptor (GPCR) genes that affect receptor activity. However, the impact of rare GPCR gene variants is unknown. We describe the rare single nucleotide variants (SNVs) in the coding and splice regions of 18 GPCR genes in 7,595 exomes from the 1,000-genomes and Exome Sequencing Project databases and in 31 cases with inherited platelet function disorders (IPFDs). In the population databases, the GPCR gene target regions contained 740 SNVs (318 synonymous, 410 missense, 7 stop gain and 6 splice region) of which 70 % had global minor allele frequency (MAF) < 0.05 %. Functional annotation using six computational algorithms, experimental evidence and structural data identified 156/740 (21 %) SNVs as potentially damaging to GPCR function, most commonly in regions encoding the transmembrane and C-terminal intracellular receptor domains. In 31 index cases with IPFDs (Gi-pathway defect n=15; secretion defect n=11; thromboxane pathway defect n=3 and complex defect n=2) there were 256 SNVs in the target regions of 15 stimulatory platelet GPCRs (34 unique; 12 with MAF< 1 % and 22 with MAF≥ 1 %). These included rare variants predicting R122H, P258T and V207A substitutions in the P2Y12 receptor that were annotated as potentially damaging, but only partially explained the platelet function defects in each case. Our data highlight that potentially damaging variants in platelet GPCR genes have low individual frequencies, but are collectively abundant in the population. Potentially damaging variants are also present in pedigrees with IPFDs and may contribute to complex laboratory phenotypes.

Association between a promoter dopamine D2 receptor gene variant and the personality trait detachment.

PubMed

Jönsson, Erik G; Cichon, Sven; Gustavsson, J Petter; Grünhage, Frank; Forslund, Kaj; Mattila-Evenden, Marja; Rylander, Gunnar; Asberg, Marie; Farde, Lars; Propping, Peter; Nöthen, Markus M

2003-04-01

Personality traits have shown considerable heritable components. Striatal dopamine D(2) receptor density, as determined by positron-emission tomography, has been associated with detached personality, as assessed by the Karolinska Scales of Personality. A putative functional promoter polymorphism in the dopamine D(2) receptor gene (DRD2), -141C ins/del, has been associated with dopamine D(2) receptor density. In this study healthy subjects (n = 235) who filled in at least one of several personality questionnaires (Karolinska Scales of Personality, Swedish Universities Scales of Personality, Health-relevant Five-factor Personality Inventory, and Temperament and Character Inventory) were analyzed with regard to the DRD2 -141C ins/del variant. There was an association (p =.001) between the DRD2 -141C ins/del variant and Karolinska Scales of Personality Detachment scale, indicating higher scores in subjects with the -141C del variant. There were also associations between the DRD2 -141C ins/del variant and a number of Karolinska Scales of Personality and Swedish Universities Scales of Personality Neuroticism-related scales, but of these only Swedish Universities Scales of Personality Lack of Assertiveness scale (p =.001) survived correction for multiple testing. These results add further support for the involvement of dopamine D(2) receptor in certain personality traits. The results should be treated with caution until replicated.

The UCL low-density lipoprotein receptor gene variant database: pathogenicity update

PubMed Central

Futema, Marta; Whittall, Ros; Taylor-Beadling, Alison; Williams, Maggie; den Dunnen, Johan T; Humphries, Steve E

2017-01-01

Background Familial hypercholesterolaemia (OMIM 143890) is most frequently caused by variations in the low-density lipoprotein receptor (LDLR) gene. Predicting whether novel variants are pathogenic may not be straightforward, especially for missense and synonymous variants. In 2013, the Association of Clinical Genetic Scientists published guidelines for the classification of variants, with categories 1 and 2 representing clearly not or unlikely pathogenic, respectively, 3 representing variants of unknown significance (VUS), and 4 and 5 representing likely to be or clearly pathogenic, respectively. Here, we update the University College London (UCL) LDLR variant database according to these guidelines. Methods PubMed searches and alerts were used to identify novel LDLR variants for inclusion in the database. Standard in silico tools were used to predict potential pathogenicity. Variants were designated as class 4/5 only when the predictions from the different programs were concordant and as class 3 when predictions were discordant. Results The updated database (http://www.lovd.nl/LDLR) now includes 2925 curated variants, representing 1707 independent events. All 129 nonsense variants, 337 small frame-shifting and 117/118 large rearrangements were classified as 4 or 5. Of the 795 missense variants, 115 were in classes 1 and 2, 605 in class 4 and 75 in class 3. 111/181 intronic variants, 4/34 synonymous variants and 14/37 promoter variants were assigned to classes 4 or 5. Overall, 112 (7%) of reported variants were class 3. Conclusions This study updates the LDLR variant database and identifies a number of reported VUS where additional family and in vitro studies will be required to confirm or refute their pathogenicity. PMID:27821657

Highly Pathogenic Influenza A(H5Nx) Viruses with Altered H5 Receptor-Binding Specificity

PubMed Central

Guo, Hongbo; de Vries, Erik; McBride, Ryan; Dekkers, Jojanneke; Peng, Wenjie; Bouwman, Kim M.; Nycholat, Corwin; Verheije, M. Helene; Paulson, James C.; van Kuppeveld, Frank J.M.

2017-01-01

Emergence and intercontinental spread of highly pathogenic avian influenza A(H5Nx) virus clade 2.3.4.4 is unprecedented. H5N8 and H5N2 viruses have caused major economic losses in the poultry industry in Europe and North America, and lethal human infections with H5N6 virus have occurred in Asia. Knowledge of the evolution of receptor-binding specificity of these viruses, which might affect host range, is urgently needed. We report that emergence of these viruses is accompanied by a change in receptor-binding specificity. In contrast to ancestral clade 2.3.4 H5 proteins, novel clade 2.3.4.4 H5 proteins bind to fucosylated sialosides because of substitutions K222Q and S227R, which are unique for highly pathogenic influenza virus H5 proteins. North American clade 2.3.4.4 virus isolates have retained only the K222Q substitution but still bind fucosylated sialosides. Altered receptor-binding specificity of virus clade 2.3.4.4 H5 proteins might have contributed to emergence and spread of H5Nx viruses. PMID:27869615

Evaluation of AhR-agonists and AhR-agonist activity in sediments of Liaohe River protected areas, China.

PubMed

Zhang, Yun; Ke, Xin; Gui, Shaofeng; Wu, Xiaoqiong; Wang, Chunyong; Zhang, Haijun

2017-02-15

A total of 9 sediment samples of Liaohe River protected areas were collected to evaluate aryl hydrocarbon receptor agonists (AhR-agonists) and AhR-agonist activity via chemical analysis and in vitro H4IIE cell bioassay. Results indicated that bioassay-derived 2,3,7,8-tetrachlorodibenzo-p-dioxin equivalents (Bio-TEQs) ranged from 89.1 to 251.1pg/g dry weight. Concentrations of 16 EPA polycyclic aromatic hydrocarbons (PAHs), 12 dioxin-like polychlorinated biphenyls (PCBs), and polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) ranged from 256.8 to 560.1ng/g, 79.2 to 416.2pg/g, and 199.6 to 538.4pg/g, respectively. According to potency balance analysis, TEQ chem s based on PAHs, PCBs, and PCDD/Fs could contribute 16.56% to 26.11% of Bio-TEQs. This could be explained by the potential existence of unidentified AhR-agonists and the potential non-additive interactions among AhR-agonists in sediment extracts. Through the different contributions to Bio-TEQs, this study confirms that PCDD/Fs were the main pollutants that induced significantly AhR-agonist activity in sediments of Liaohe River protected areas. Copyright © 2016. Published by Elsevier Ltd.

An Antagonistic Vascular Endothelial Growth Factor (VEGF) Variant Inhibits VEGF-Stimulated Receptor Autophosphorylation and Proliferation of Human Endothelial Cells

NASA Astrophysics Data System (ADS)

Siemeister, Gerhard; Schirner, Michael; Reusch, Petra; Barleon, Bernhard; Marme, Dieter; Martiny-Baron, Georg

1998-04-01

Vascular endothelial growth factor (VEGF) is a potent mitogen with a unique specificity for endothelial cells and a key mediator of aberrant endothelial cell proliferation and vascular permeability in a variety of human pathological situations, such as tumor angiogenesis, diabetic retinopathy, rheumatoid arthritis, or psoriasis. VEGF is a symmetric homodimeric molecule with two receptor binding interfaces lying on each pole of the molecule. Herein we report on the construction and recombinant expression of an asymmetric heterodimeric VEGF variant with an intact receptor binding interface at one pole and a mutant receptor binding interface at the second pole of the dimer. This VEGF variant binds to VEGF receptors but fails to induce receptor activation. In competition experiments, the heterodimeric VEGF variant antagonizes VEGF-stimulated receptor autophosphorylation and proliferation of endothelial cells. A 15-fold excess of the heterodimer was sufficient to inhibit VEGF-stimulated endothelial cell proliferation by 50%, and a 100-fold excess resulted in an almost complete inhibition. By using a rational approach that is based on the structure of VEGF, we have shown the feasibility to construct a VEGF variant that acts as an VEGF antagonist.

Dibutyl Phthalate (DBP)-Induced Apoptosis and Neurotoxicity are Mediated via the Aryl Hydrocarbon Receptor (AhR) but not by Estrogen Receptor Alpha (ERα), Estrogen Receptor Beta (ERβ), or Peroxisome Proliferator-Activated Receptor Gamma (PPARγ) in Mouse Cortical Neurons.

PubMed

Wójtowicz, Anna K; Szychowski, Konrad A; Wnuk, Agnieszka; Kajta, Małgorzata

2017-01-01

Dibutyl phthalate (di-n-butyl phthalate, DBP) is one of the most commonly used phthalate esters. DBP is widely used as a plasticizer in a variety of household industries and consumer products. Because phthalates are not chemically bound to products, they can easily leak out to enter the environment. DBP can pass through the placental and blood-brain barriers due to its chemical structure, but little is known about its mechanism of action in neuronal cells. This study demonstrated the toxic and apoptotic effects of DBP in mouse neocortical neurons in primary cultures. DBP stimulated caspase-3 and LDH activities as well as ROS formation in a concentration (10 nM-100 µM) and time-dependent (3-48 h) manner. DBP induced ROS formation at nanomolar concentrations, while it activated caspase-3 and LDH activities at micromolar concentrations. The biochemical effects of DBP were accompanied by decreased cell viability and induction of apoptotic bodies. Exposure to DBP reduced Erα and Pparγ mRNA expression levels, which were inversely correlated with protein expression of the receptors. Treatment with DBP enhanced Ahr mRNA expression, which was reflected by the increased AhR protein level observed at 3 h after exposure. ERα, ERβ, and PPARγ antagonists stimulated DBP-induced caspase-3 and LDH activities. AhR silencing demonstrated that DBP-induced apoptosis and neurotoxicity are mediated by AhR, which is consistent with the results from DBP-induced enhancement of AhR mRNA and protein expression. Our study showed that AhR is involved in DBP-induced apoptosis and neurotoxicity, while the ERs and PPARγ signaling pathways are impaired by the phthalate.

Potential involvement of placental AhR in unexplained recurrent spontaneous abortion.

PubMed

Wu, Y; Chen, X; Chang, X; Huang, Y J; Bao, S; He, Q; Li, Y; Zheng, J; Duan, T; Wang, K

2016-01-01

Recurrent spontaneous abortion (RSA) is a common complication of pregnancy. Recent studies have demonstrated that the aryl hydrocarbon receptor (AhR) might play important roles in establishing and maintaining early pregnancy. In this study, we found that placental AhR protein levels were significantly lower and placental CYP1A1 mRNA levels were higher in unexplained RSA (URSA) patients than in control subjects. The results of immunohistochemical analyzes showed that placental AhR was expressed in syncytiotrophoblast cells and that the level of AhR was markedly lower in these cells in URSA subjects than in control subjects. β-Naphthoflavone (β-NF, an AhR ligand) at 5μM significantly inhibited proliferation and migration in HTR-8/SVneo cells and was associated with the activation of AhR. Moreover, overexpressing AhR in JAR cells significantly increased CYP1A1 mRNA levels and inhibited cell migration. These results indicate that AhR is highly activated in URSA placentas and that the activation of AhR in the placenta might impair trophoblast cell proliferation and migration, possibly leading to the occurrence of URSA. Copyright © 2015 Elsevier Inc. All rights reserved.

An endogenous aryl hydrocarbon receptor (AhR) ligand, ITE induces regulatory T cells (Tregs) and ameliorates experimental colitis.

PubMed

Abron, Jessicca D; Singh, Narendra P; Mishra, Manoj K; Price, Robert L; Nagarkatti, Mitzi; Nagarkatti, Prakash S; Singh, Udai P

2018-04-19

Inflammatory bowel disease (IBD) is a chronic intestinal inflammatory condition that affects millions of people with high morbidity and health-care cost. The precise etiology of IBD is unknown, but clear evidence suggests that intestinal inflammation is caused by an excessive immune response to mucosal antigens. Recent studies have shown that activation of the aryl hydrocarbon receptor (AhR) induces regulatory T cells (Tregs) and suppresses autoimmune diseases. In the current study, we investigated if nontoxic ligand of AhR, 2-(1'H-indole-3'-carbonyl)-thiazole-4-carboxylic acid methyl ester (ITE), can attenuate dextran sodium sulphate (DSS)-induced colitis. Our studies demonstrated that in mice that received ITE treatment, in-vivo colitis pathogenesis, including a decrease in body weight, was significantly reversed along with the systemic and intestinal inflammatory cytokines. ITE increased the expression of Tregs in spleen, mesenteric lymph nodes (MLNs) and colon lamina propria lymphocytes (cLPL) of mice with colitis when compared to controls. This induction of Tregs was reversed by AhR antagonist treatment in-vitro. ITE treatment also increased dendritic cells (DCs; CD11c+) and decreased F4/80+ (macrophage) from the spleen, MLNs and cLPL in mice with colitis. ITE also reversed the systemic and intestinal frequency of CD4+T cells during colitis and suppressed inflammatory cytokines including IFN-γ, TNF-α, IL-17, IL-6 and IL-1 as well as induced IL-10 levels. These findings suggest that ITE attenuates colitis through induction of Tregs and reduction in inflammatory CD4+ T cells and cytokines. Thus, our work demonstrates that the nontoxic endogenous AhR ligand ITE, may serve as a therapeutic modality to treat IBD.

Role of Sequence Variations in AhR Gene Towards Modulating Smoking Induced Lung Cancer Susceptibility in North Indian Population: A Multiple Interaction Analysis.

PubMed

Budhwar, Sneha; Bahl, Charu; Sharma, Siddharth; Singh, Navneet; Behera, Digambar

2018-05-01

AhR, a ubiquitously expressed ligand-activated transcription factor, upon its encounter with the foreign ligands activates the transcriptional machinery of genes encoding for bio-transformation enzymes like CYP1A1 hence, mediating the metabolism of Poly aromatic hydrocarbons and nitrosamines which account for the maximally found carcinogen in cigarette smoke. Polymorphic variants of AhR play a significant role and are held responsible for disposing the individuals with greater chances of acquiring lung cancer. To study the role of AhR variants (rs2282885, rs10250822, rs7811989, rs2066853) in affect-ing lung cancer susceptibility. 297 cases and 320 controls have been genotyped using PCR-RFLP technique. In order to find out the association, unconditional logistic regression approach was used. To analyze high order in-teractions Multifactor Dimensionality Reduction and Classification and regression tree was used. Subjects carrying the variant genotype for AhR rs7811989 showed a two-fold risk (p=0.007) and a marginal risk was also seen in case of individuals carrying either single or double copy of suscep-tible allele for rs102550822 (p=0.02). Whereas the variant allele for rs2066853 showcased a strong pro-tective effect (p=0.003). SQCC individuals with mutant genotype of rs2066853 also exhibited a protec-tive effect towards lung cancer (OR=0.30, p=0.0013). The association of rs7811989 mutant genotype and rs10250822 mutant genotype was evident especially in smokers as compared to non-smokers. AhR rs2066853 showed a decreased risk in smokers with mutant genotype (p=0.002). MDR approach gave the best interaction model of AhR rs2066853 and smoking (CVC=10/10, prediction error=0.42). AhR polymorphic variations can significantly contribute towards lung cancer predisposi-tion.

AhV_aPA-induced vasoconstriction involves the IP₃Rs-mediated Ca²⁺ releasing.

PubMed

Zeng, Fuxing; Zou, Zhisong; Niu, Liwen; Li, Xu; Teng, Maikun

2013-08-01

AhV_aPA, the acidic PLA₂ purified from Agkistrodon halys pallas venom, was previously reported to possess a strong enzymatic activity and can remarkably induce a further contractile response on the 60 mM K⁺-induced contraction with an EC₅₀ in 369 nM on mouse thoracic aorta rings. In the present study, we found that the p-bromo-phenacyl-bromide (pBPB), which can completely inhibit the enzymatic activity of AhV_aPA, did not significantly reduce the contractile response on vessel rings induced by AhV_aPA, indicating that the vasoconstrictor effects of AhV_aPA are independent of the enzymatic activity. The inhibitor experiments showed that the contractile response induced by AhV_aPA is mainly attributed to the Ca²⁺ releasing from Ca²⁺ store, especially sarcoplasmic reticulum (SR). Detailed studies showed that the Ca²⁺ release from SR is related to the activation of inositol trisphosphate receptors (IP₃Rs) rather than ryanodine receptors (RyRs). Furthermore, the vasoconstrictor effect could be strongly reduced by pre-incubation with heparin, indicating that the basic amino acid residues on the surface of AhV_aPA may be involved in the interaction between AhV_aPA and the molecular receptors. These findings offer new insights into the functions of snake PLA₂ and provide a novel pathogenesis of A. halys pallas venom. Copyright © 2013 Elsevier Ltd. All rights reserved.

Identification, Characterization, and Natural Selection of Mutations Driving Airborne Transmission of A/H5N1 virus

PubMed Central

Linster, Martin; van Boheemen, Sander; de Graaf, Miranda; Schrauwen, Eefje J. A.; Lexmond, Pascal; Mänz, Benjamin; Bestebroer, Theo M.; Baumann, Jan; van Riel, Debby; Rimmelzwaan, Guus F.; Osterhaus, Albert D.M.E.; Matrosovich, Mikhail; Fouchier, Ron A. M.; Herfst, Sander

2014-01-01

SUMMARY Recently, A/H5N1 influenza viruses were shown to acquire airborne transmissibility between ferrets upon targeted mutagenesis and virus passage. The critical genetic changes in airborne A/Indonesia/5/05 were not yet identified. Here, five substitutions proved to be sufficient to determine this airborne transmission phenotype. Substitutions in PB1 and PB2 collectively caused enhanced transcription and virus replication. One substitution increased HA thermostability and lowered the pH of membrane fusion. Two substitutions independently changed HA binding preference from α2,3 linked to α2,6 linked sialic acid receptors. The loss of a glycosylation site in HA enhanced overall binding to receptors. The acquired substitutions emerged early during ferret passage as minor variants and became dominant rapidly. Identification of substitutions that are essential for airborne transmission of avian influenza viruses between ferrets and their associated phenotypes advances our fundamental understanding of virus transmission and will increase the value of future surveillance programs and public health risk assessments. PMID:24725402

Third-generation Ah receptor-responsive luciferase reporter plasmids: amplification of dioxin-responsive elements dramatically increases CALUX bioassay sensitivity and responsiveness.

PubMed

He, Guochun; Tsutsumi, Tomoaki; Zhao, Bin; Baston, David S; Zhao, Jing; Heath-Pagliuso, Sharon; Denison, Michael S

2011-10-01

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD, dioxin) and related dioxin-like chemicals are widespread and persistent environmental contaminants that produce diverse toxic and biological effects through their ability to bind to and activate the Ah receptor (AhR) and AhR-dependent gene expression. The chemically activated luciferase expression (CALUX) system is an AhR-responsive recombinant luciferase reporter gene-based cell bioassay that has been used in combination with chemical extraction and cleanup methods for the relatively rapid and inexpensive detection and relative quantitation of dioxin and dioxin-like chemicals in a wide variety of sample matrices. Although the CALUX bioassay has been validated and used extensively for screening purposes, it has some limitations when screening samples with very low levels of dioxin-like chemicals or when there is only a small amount of sample matrix for analysis. Here, we describe the development of third-generation (G3) CALUX plasmids with increased numbers of dioxin-responsive elements, and stable transfection of these new plasmids into mouse hepatoma (Hepa1c1c7) cells has produced novel amplified G3 CALUX cell bioassays that respond to TCDD with a dramatically increased magnitude of luciferase induction and significantly lower minimal detection limit than existing CALUX-type cell lines. The new G3 CALUX cell lines provide a highly responsive and sensitive bioassay system for the detection and relative quantitation of very low levels of dioxin-like chemicals in sample extracts.

Protease-Activated Receptor 4 Variant p.Tyr157Cys Reduces Platelet Functional Responses and Alters Receptor Trafficking.

PubMed

Norman, Jane E; Cunningham, Margaret R; Jones, Matthew L; Walker, Mary E; Westbury, Sarah K; Sessions, Richard B; Mundell, Stuart J; Mumford, Andrew D

2016-05-01

Protease-activated receptor 4 (PAR4) is a key regulator of platelet reactivity and is encoded by F2RL3, which has abundant rare missense variants. We aimed to provide proof of principle that rare F2LR3 variants potentially affect platelet reactivity and responsiveness to PAR1 antagonist drugs and to explore underlying molecular mechanisms. We identified 6 rare F2RL3 missense variants in 236 cardiac patients, of which the variant causing a tyrosine 157 to cysteine substitution (Y157C) was predicted computationally to have the greatest effect on PAR4 structure. Y157C platelets from 3 cases showed reduced responses to PAR4-activating peptide and to α-thrombin compared with controls, but no reduction in responses to PAR1-activating peptide. Pretreatment with the PAR1 antagonist vorapaxar caused lower residual α-thrombin responses in Y157C platelets than in controls, indicating greater platelet inhibition. HEK293 cells transfected with a PAR4 Y157C expression construct had reduced PAR4 functional responses, unchanged total PAR4 expression but reduced surface expression. PAR4 Y157C was partially retained in the endoplasmic reticulum and displayed an expression pattern consistent with defective N-glycosylation. Mutagenesis of Y322, which is the putative hydrogen bond partner of Y157, also reduced PAR4 surface expression in HEK293 cells. Reduced PAR4 responses associated with Y157C result from aberrant anterograde surface receptor trafficking, in part, because of disrupted intramolecular hydrogen bonding. Characterization of PAR4 Y157C establishes that rare F2RL3 variants have the potential to markedly alter platelet PAR4 reactivity particularly after exposure to therapeutic PAR1 antagonists. © 2016 American Heart Association, Inc.

Polycyclic Aromatic Hydrocarbons (PAHs) Mediate Transcriptional Activation of the ATP Binding Cassette Transporter ABCB6 Gene via the Aryl Hydrocarbon Receptor (AhR)*

PubMed Central

Chavan, Hemantkumar; Krishnamurthy, Partha

2012-01-01

Liver is endowed with a mechanism to induce hepatic cytochromes P450 (CYP450s) in response to therapeutic drugs and environmental contaminants, leading to increased detoxification and elimination of the xenobiotics. Each CYP450 is composed of an apoprotein moiety and a heme prosthetic group, which is required for CYP450 activity. Thus, under conditions of CYP450 induction, there is a coordinate increase in heme biosynthesis to compensate for the increased expression of CYP450s. ABCB6, a mitochondrial ATP binding cassette transporter, which regulates coproporphyrinogen transport from the cytoplasm into the mitochondria to complete heme biosynthesis, represents a previously unrecognized rate-limiting step in heme biosynthesis. However, it is not known if exposure to drugs and environmental contaminants induces ABCB6 expression, to assure an adequate and apparently coordinated supply of heme for the generation of functional cytochrome holoprotein. In the present study, we demonstrate that polycyclic aromatic hydrocarbons (PAHs), the widely distributed environmental toxicants shown to induce porphyrin accumulation causing hepatic porphyria, up-regulate ABCB6 expression in both mice and humans. Using siRNA technology and Abcb6 knock-out mice, we demonstrate that PAH-mediated increase in hepatic porphyrins is compromised in the absence of ABCB6. Moreover, in vivo studies in aryl hydrocarbon receptor (AhR) knock-out mice demonstrate that PAH induction of ABCB6 is mediated by AhR. Promoter activation studies combined with electrophoretic mobility shift assay and chromatin immunoprecipitation assay demonstrate direct interactions between the AhR binding sites in the ABCB6 promoter and the AhR receptor, implicating drug activation mechanisms for ABCB6 similar to those found in inducible cytochrome P450s. These studies are the first to describe direct transcriptional activation of both mouse and human ABCB6 by xenobiotics. PMID:22761424

Studies on the Role of The Ah Receptor (AhR) on the Etiology of Breast Cancer: A Novel Idea of Identifying this Receptor as a New Therapeutic Target

DTIC Science & Technology

2010-09-01

found that the most potent phytochemical suppressors of cell proliferation of P20E cells were curcumin (10 µM approximately 80 to 90% suppression...effectiveness of a number of phytochemicals from edible plants known to block AhR in attenuating the expression of high rates of cell proliferation...selected number of those phytochemicals , by xenografting those AhR overexpressing human breast cancer cells into athymic nude mice, and by treating

The inhibition of lung cancer cell migration by AhR-regulated autophagy

PubMed Central

Tsai, Chi-Hao; Li, Ching-Hao; Cheng, Yu-Wen; Lee, Chen-Chen; Liao, Po-Lin; Lin, Cheng-Hui; Huang, Shih-Hsuan; Kang, Jaw-Jou

2017-01-01

The aryl hydrocarbon receptor (AhR) is a ligand-activated transcription factor that is highly expressed in multiple organs and tissues. Whereas AhR mediates the metabolism of xenobiotic and endogenous compounds, its novel function in cancer epithelial-mesenchymal transition (EMT) remains controversial. Autophagy also participates in tumour progression through its functions in cell homeostasis and facilitates adaptation to EMT progression. In the present study, we found that AhR-regulated autophagy positively modulates EMT in non-small cell lung cancer cells. The motility of A549, H1299, and CL1-5 cells were correlated with different AhR expression levels. Invasive potential and cell morphology also changed when AhR protein expression was altered. Moreover, AhR levels exerted a contrasting effect on autophagy potential. Autophagy was higher in CL1-5 and H1299 cells with lower AhR levels than in A549 cells. Both AhR overexpression and autophagy inhibition decreased CL1-5 metastasis in vivo. Furthermore, AhR promoted BNIP3 ubiquitination for proteasomal degradation. AhR silencing in A549 cells also reduced BNIP3 ubiquitination. Taken together, these results provide a novel insight into the cross-linking between AhR and autophagy, we addressed the mechanistic BNIP3 modulation by endogenous AhR, which affect cancer cell EMT progression. PMID:28195146

The inhibition of lung cancer cell migration by AhR-regulated autophagy.

PubMed

Tsai, Chi-Hao; Li, Ching-Hao; Cheng, Yu-Wen; Lee, Chen-Chen; Liao, Po-Lin; Lin, Cheng-Hui; Huang, Shih-Hsuan; Kang, Jaw-Jou

2017-02-14

The aryl hydrocarbon receptor (AhR) is a ligand-activated transcription factor that is highly expressed in multiple organs and tissues. Whereas AhR mediates the metabolism of xenobiotic and endogenous compounds, its novel function in cancer epithelial-mesenchymal transition (EMT) remains controversial. Autophagy also participates in tumour progression through its functions in cell homeostasis and facilitates adaptation to EMT progression. In the present study, we found that AhR-regulated autophagy positively modulates EMT in non-small cell lung cancer cells. The motility of A549, H1299, and CL1-5 cells were correlated with different AhR expression levels. Invasive potential and cell morphology also changed when AhR protein expression was altered. Moreover, AhR levels exerted a contrasting effect on autophagy potential. Autophagy was higher in CL1-5 and H1299 cells with lower AhR levels than in A549 cells. Both AhR overexpression and autophagy inhibition decreased CL1-5 metastasis in vivo. Furthermore, AhR promoted BNIP3 ubiquitination for proteasomal degradation. AhR silencing in A549 cells also reduced BNIP3 ubiquitination. Taken together, these results provide a novel insight into the cross-linking between AhR and autophagy, we addressed the mechanistic BNIP3 modulation by endogenous AhR, which affect cancer cell EMT progression.

Induction of AhR-Mediated Gene Transcription by Coffee

PubMed Central

Ishikawa, Toshio; Takahashi, Satoshi; Morita, Koji; Okinaga, Hiroko; Teramoto, Tamio

2014-01-01

Background Aryl hydrocarbon receptor (AhR) is classically known to be activated by xenobiotics such as dioxins and polycyclic aromatic hydrocarbons (PAHs). Although it has been reported that PAHs are contained in roasted coffee beans, in general coffee beverages are not considered to be AhR activators. We tested whether exposure to coffee would activate AhR in cultured cells. Methods HepG2 cells stably expressing an AhR-responsive reporter gene were treated with coffee samples. Also, expression of CYP1A1, an endogenous AhR-responsive gene, was quantitated by RT-PCR and Western blotting in HepG2, Caco-2, and MCF-7 cells, after treatment with coffee. In order to obtain sensitive and reproducible results, all the experiments were performed with the cells placed in either phosphate-buffered saline (PBS) or pure serum, instead of routinely-used culture medium, whose intrinsic AhR-stimulating activity turned out to be so strong as to interfere with the analyses. Results All the coffee samples tested robustly stimulated AhR-mediated transcription in the reporter gene assays. Of note, to what extent coffee and other AhR agonists activated AhR was different, depending on whether the experiments were done in PBS or serum. CYP1A1 mRNA was induced by coffee, in HepG2, Caco-2, and MCF-7 cells placed in either PBS or serum. CYP1A1 protein expression, which was not detected in these cells incubated in PBS, was also increased by coffee in cells placed in serum. Conclusions By using culture medium-free experimental settings, we have shown that coffee is a strong AhR activator. Our observation may help elucidate as-yet-unrecognized effects of coffee on human health. PMID:25007155

The AhR and NF-κB/Rel Proteins Mediate the Inhibitory Effect of 2,3,7,8-Tetrachlorodibenzo-p-Dioxin on the 3′ Immunoglobulin Heavy Chain Regulatory Region

PubMed Central

Salisbury, Richard L.; Sulentic, Courtney E. W.

2015-01-01

Transcriptional regulation of the murine immunoglobulin (Ig) heavy chain gene (Igh) involves several regulatory elements including the 3′Igh regulatory region (3′IghRR), which is composed of at least 4 enhancers (hs3A, hs1.2, hs3B, and hs4). The hs1.2 and hs4 enhancers exhibit the greatest transcriptional activity and contain binding sites for several transcription factors including nuclear factor kappaB/Rel (NF-κB/Rel) proteins and the aryl hydrocarbon receptor (AhR). Interestingly, the environmental immunosuppressant 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), which potently inhibits antibody secretion, also profoundly inhibits 3′IghRR and hs1.2 enhancer activation induced by the B-lymphocyte activator lipopolysaccharide (LPS), but enhances LPS-induced activation of the hs4 enhancer. Within the hs1.2 and hs4 enhancers, the AhR binding site is in close proximity or overlaps an NF-κB/Rel binding site suggesting a potential reciprocal modulation of the 3′IghRR by AhR and NF-κB/Rel. The objective of the current study was to evaluate the role of NF-κB/Rel and the AhR on the 3′IghRR and its enhancers using the AhR ligand TCDD, the AhR antagonist CH223191, and toll-like receptor agonists LPS, Resiquimod (R848), or cytosine-phosphate-guanine-oligodeoxynucleotides (CpG). Utilizing the CH12.LX B-lymphocyte cell line and variants expressing either a 3′IghRR-regulated transgene reporter or an inducible IκBα (inhibitor kappa B-alpha protein) superrepressor (IκBαAA), we demonstrate an AhR- and NF-κB/Rel-dependent modulation of 3′IghRR and hs4 activity. Additionally, in mouse splenocytes or CH12.LX cells, binding within the hs1.2 and hs4 enhancer of the AhR and the NF-κB/Rel proteins RelA and RelB was differentially altered by the cotreatment of LPS and TCDD. These results suggest that the AhR and NF-κB/Rel protein binding profile within the 3′IghRR mediates the inhibitory effects of TCDD on Ig expression and therefore antibody levels. PMID:26377645

Normal mast cell numbers in the tissues of AhR-deficient mice.

PubMed

Pilz, Caroline; Feyerabend, Thorsten; Sonner, Jana; Redaelli, Chiara; Peter, Katharina; Kunze, Anja; Haas, Katharina; Esser, Charlotte; Schäkel, Knut; Wick, Wolfgang; Rodewald, Hans-Reimer; Lanz, Tobias V; Platten, Michael

2016-01-01

The transcription factor aryl hydrocarbon receptor (AhR) acts as an immunomodulatory molecule in several immune cell lineages. Recently, it has been implicated in development and maintenance of immune cells in barrier tissues such as skin and mucosa. To investigate its role on mast cell development and maintenance in skin, peritoneal exudate cells (PECs) and lymph nodes, we studied in depth their phenotype in AhR-deficient mice. Our findings do not provide any evidence for a suspected role of the AhR in mast cell homeostasis. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Low multiple electrode aggregometry platelet responses are not associated with non-synonymous variants in G-protein coupled receptor genes.

PubMed

Norman, Jane E; Lee, Kurtis R; Walker, Mary E; Murden, Sherina L; Harris, Jessica; Mundell, Stuart; J Murphy, Gavin; Mumford, Andrew D

2015-10-01

Multiple electrode aggregometry (MEA) improves prediction of thrombosis and bleeding in cardiac patients. However, the causes of inter-individual variation in MEA results are incompletely understood. We explore whether low MEA results are associated with platelet G-protein coupled receptor (GPCR) gene variants. The effects of P2Y12 receptor (P2Y12), thromboxane A2 receptor (TPα) and protease-activated receptor 1 (PAR1) dysfunction on the MEA ADP-test, ASPI-test and TRAP-test were determined using receptor antagonists. Cardiac surgery patients with pre-operative MEA results suggesting GPCR dysfunction were selected for P2Y12 (P2RY12), TPα (TBXA2R) and PAR1 (F2R) sequencing. In control blood samples, P2Y12, TPα or PAR1 antagonists markedly reduced ADP-test, ASPI-test and TRAP-test results respectively. In the 636 patients from a cohort of 2388 cardiac surgery patients who were not receiving aspirin or a P2Y12 blocker, the median ADP-test result was 75.1 U (range 4.8-153.2), ASPI-test 83.7 U (1.4-157.3) and TRAP-test 117.7 U (2.4-194.1), indicating a broad range of results unexplained by anti-platelet drugs. In 238 consenting patients with unexplained low MEA results, three P2RY12 variants occurred in 70/107 (65%) with suspected P2Y12 dysfunction and four TBXA2R variants occurred in 19/22 (86%) with suspected TPα dysfunction although the later group was too small to draw meaningful conclusions about variant frequency. All the variants were synonymous and unlikely to cause GPCR dysfunction. There were no F2R variants in the 109 cases with suspected PAR1 dysfunction. MEA results suggesting isolated platelet GPCR dysfunction were common in cardiac surgery patients, but were not associated with non-synonymous variants in P2RY12 or F2R. Copyright © 2015 Elsevier Ltd. All rights reserved.

Differential agonist sensitivity of glycine receptor α2 subunit splice variants

PubMed Central

Miller, Paul S; Harvey, Robert J; Smart, Trevor G

2004-01-01

The glycine receptor (GlyR) α2A and α2B splice variants differ by a dual, adjacent amino acid substitution from α2AV58,T59 to α2BI58,A59 in the N-terminal extracellular domain. Comparing the effects of the GlyR agonists, glycine, β-alanine and taurine, on the GlyR α2 isoforms, revealed a significant increase in potency for all three agonists at the α2B variant. The sensitivities of the splice variants to the competitive antagonist, strychnine, and to the biphasic modulator Zn2+, were comparable. In contrast, the allosteric inhibitor picrotoxin was more potent on GlyR α2A compared to GlyR α2B receptors. Coexpression of α2A or α2B subunits with the GlyR β subunit revealed that the higher agonist potencies observed with the α2B homomer were retained for the α2Bβ heteromer. The identical sensitivity to strychnine combined with a reduction in the maximum current induced by the partial agonist taurine at the GlyR α2A homomer, suggested that the changed sensitivity to agonists is in accordance with a modulation of agonist efficacy rather than agonist affinity. An effect on agonist efficacy was also supported by using a structural model of the GlyR, localising the region of splice variation to the proposed docking region between GlyR loop 2 and the TM2-3 loop, an area associated with channel activation. The existence of a spasmodic mouse phenotype linked to a GlyR α1A52S mutation, the equivalent position to the source of the α2 splice variation, raises the possibility that the GlyR α2 splice variants may be responsible for distinct roles in neuronal function. PMID:15302677

Investigations into the binding affinities of different human 5-HT4 receptor splice variants.

PubMed

Irving, Helen R; Tochon-Danguy, Nathalie; Chinkwo, Kenneth A; Li, Jian G; Grabbe, Carmen; Shapiro, Marina; Pouton, Colin W; Coupar, Ian M

2010-01-01

This study examined whether the drug-receptor-binding sites of 5 selected human 5-HT(4) receptor splice variants [h5-HT4(a), h5-HT4(b), h5-HT4(c), h5-HT4(d) and h5-HT4(g)] display preferential affinities towards agonists. The agonists selected on the basis of chemical diversity and clinical relevance were: 5-HT4 benzamides, renzapride, zacopride and prucalopride; the benzimidazolones, DAU 6236 and BIMU 1; the aromatic ketone, RS67333, and the indole carbazimidamide tegaserod. The rank order of affinities ranging across the splice variants was: tegaserod (pKi: 7.38-7.91) > or = Y-36912 (pKi: 7.03-7.85) = BIMU 1 (pKi: 6.92-7.78) > or = DAU 6236 (pKi: 6.79-7.99) > or = 5-HT (pKi: 5.82-7.29) > or = 5-MeOT (pKi: 5.64-6.83) > or = renzapride (pKi: 4.85-5.56). We obtained affinity values for the 5-HT4(b), (d) and (g) variants for RS67333 (pKi: 7:48-8.29), prucalopride (pKi: 6.86-7.37) and zacopride (pKi: 5.88-7.0). These results indicate that the ligands interact with the same conserved site in each splice variant. Some splice variants have a higher affinity for certain agonists and the direction of selectivity followed a common trend of lowest affinity at the (d) variant. However, this trend was not evident in functional experiments. Our findings suggest that it may be possible to design splice variant selective ligands, which may be of relevance for experimental drugs but may be difficult to develop clinically. 2010 S. Karger AG, Basel.

A novel thromboxane A2 receptor N42S variant results in reduced surface expression and platelet dysfunction.

PubMed

Nisar, Shaista P; Lordkipanidzé, Marie; Jones, Matthew L; Dawood, Ban; Murden, Sherina; Cunningham, Margaret R; Mumford, Andrew D; Wilde, Jonathan T; Watson, Steve P; Mundell, Stuart J; Lowe, Gillian C

2014-05-05

A small number of thromboxane receptor variants have been described in patients with a bleeding history that result in platelet dysfunction. We have identified a patient with a history of significant bleeding, who expresses a novel heterozygous thromboxane receptor variant that predicts an asparagine to serine substitution (N42S). This asparagine is conserved across all class A GPCRs, suggesting a vital role for receptor structure and function.We investigated the functional consequences of the TP receptor heterozygous N42S substitution by performing platelet function studies on platelet-rich plasma taken from the patient and healthy controls. We investigated the N42S mutation by expressing the wild-type (WT) and mutant receptor in human embryonic kidney (HEK) cells. Aggregation studies showed an ablation of arachidonic acid responses in the patient, whilst there was right-ward shift of the U46619 concentration response curve (CRC). Thromboxane generation was unaffected. Calcium mobilisation studies in cells lines showed a rightward shift of the U46619 CRC in N42S-expressing cells compared to WT. Radioligand binding studies revealed a reduction in BMax in platelets taken from the patient and in N42S-expressing cells, whilst cell studies confirmed poor surface expression. We have identified a novel thromboxane receptor variant, N42S, which results in platelet dysfunction due to reduced surface expression. It is associated with a significant bleeding history in the patient in whom it was identified. This is the first description of a naturally occurring variant that results in the substitution of this highly conserved residue and confirms the importance of this residue for correct GPCR function.

The AhR agonist VAF347 augments retinoic acid-induced differentiation in leukemia cells

PubMed Central

Ibabao, Christopher N.; Bunaciu, Rodica P.; Schaefer, Deanna M.W.; Yen, Andrew

2015-01-01

In binary cell-fate decisions, driving one lineage and suppressing the other are conjoined. We have previously reported that aryl hydrocarbon receptor (AhR) promotes retinoic acid (RA)-induced granulocytic differentiation of lineage bipotent HL-60 myeloblastic leukemia cells. VAF347, an AhR agonist, impairs the development of CD14+CD11b+ monocytes from granulo-monocytic (GM) stage precursors. We thus hypothesized that VAF347 propels RA-induced granulocytic differentiation and impairs D3-induced monocytic differentiation of HL-60 cells. Our results show that VAF347 enhanced RA-induced cell cycle arrest, CD11b integrin expression and neutrophil respiratory burst. Granulocytic differentiation is known to be driven by MAPK signaling events regulated by Fgr and Lyn Src-family kinases, the CD38 cell membrane receptor, the Vav1 GEF, the c-Cbl adaptor, as well as AhR, all of which are embodied in a putative signalsome. We found that the VAF347 AhR ligand regulates the signalsome. VAF347 augments RA-induced expression of AhR, Lyn, Vav1, and c-Cbl as well as p47phox. Several interactions of partners in the signalsome appear to be enhanced: Fgr interaction with c-Cbl, CD38, and with pS259c-Raf and AhR interaction with c-Cbl and Lyn. Thus, we report that, while VAF347 impedes monocytic differentiation induced by 1,25-dihydroxyvitamin D3, VAF347 promotes RA-induced differentiation. This effect seems to involve but not to be limited to Lyn, Vav1, c-Cbl, AhR, and Fgr. PMID:25941627

The AhR agonist VAF347 augments retinoic acid-induced differentiation in leukemia cells.

PubMed

Ibabao, Christopher N; Bunaciu, Rodica P; Schaefer, Deanna M W; Yen, Andrew

2015-01-01

In binary cell-fate decisions, driving one lineage and suppressing the other are conjoined. We have previously reported that aryl hydrocarbon receptor (AhR) promotes retinoic acid (RA)-induced granulocytic differentiation of lineage bipotent HL-60 myeloblastic leukemia cells. VAF347, an AhR agonist, impairs the development of CD14(+)CD11b(+) monocytes from granulo-monocytic (GM) stage precursors. We thus hypothesized that VAF347 propels RA-induced granulocytic differentiation and impairs D3-induced monocytic differentiation of HL-60 cells. Our results show that VAF347 enhanced RA-induced cell cycle arrest, CD11b integrin expression and neutrophil respiratory burst. Granulocytic differentiation is known to be driven by MAPK signaling events regulated by Fgr and Lyn Src-family kinases, the CD38 cell membrane receptor, the Vav1 GEF, the c-Cbl adaptor, as well as AhR, all of which are embodied in a putative signalsome. We found that the VAF347 AhR ligand regulates the signalsome. VAF347 augments RA-induced expression of AhR, Lyn, Vav1, and c-Cbl as well as p47(phox). Several interactions of partners in the signalsome appear to be enhanced: Fgr interaction with c-Cbl, CD38, and with pS259c-Raf and AhR interaction with c-Cbl and Lyn. Thus, we report that, while VAF347 impedes monocytic differentiation induced by 1,25-dihydroxyvitamin D3, VAF347 promotes RA-induced differentiation. This effect seems to involve but not to be limited to Lyn, Vav1, c-Cbl, AhR, and Fgr.

Pityriazepin and other potent AhR ligands isolated from Malassezia furfur yeast

PubMed Central

Mexia, Nikitia; Gaitanis, George; Velegraki, Aristea; Soshilov, Anatoly; Denison, Michael S.; Magiatis, Prokopios

2015-01-01

Malassezia furfur yeast strains isolated from diseased human skin preferentially biosynthesize indole alkaloids which can be detected in human skin and are highly potent activators of the aryl hydrocarbon receptor (AhR) and AhR-dependent gene expression. Chemical analysis of an EtOAc extract of a M. furfur strain obtained from diseased human skin and grown on L-tryptophan agar revealed several known AhR active tryptophan metabolites along with a previously unidentified compound, pityriazepin. While its structure resembled that of the known alkaloid pityriacitrin, the comprised pyridine ring had been transformed into an azepinone. The indoloazepinone scaffold of pityriazepin is extremely rare in nature and has only been reported once previously. Pityriazepin, like the other isolated compounds, was found to be a potent activator of the AhR-dependent reporter gene assays in recombinant cell lines derived from four different species, although significant species differences in relative potency was observed. The ability of pityriazepin to competitively bind to the AhR and directly stimulate AhR DNA binding classified it as a new naturally-occurring potent AhR agonist. Malassezia furfur produces an expanded collection of extremely potent naturally occurring AhR agonists, which produce their biological effects in a species-specific manner.1 PMID:25721496

Identification of ten variants associated with risk of estrogen-receptor-negative breast cancer

PubMed Central

Milne, Roger L; Kuchenbaecker, Karoline B; Michailidou, Kyriaki; Beesley, Jonathan; Kar, Siddhartha; Lindström, Sara; Hui, Shirley; Lemaçon, Audrey; Soucy, Penny; Dennis, Joe; Jiang, Xia; Rostamianfar, Asha; Finucane, Hilary; Bolla, Manjeet K; McGuffog, Lesley; Wang, Qin; Aalfs, Cora M; Adams, Marcia; Adlard, Julian; Agata, Simona; Ahmed, Shahana; Ahsan, Habibul; Aittomäki, Kristiina; Al-Ejeh, Fares; Allen, Jamie; Ambrosone, Christine B; Amos, Christopher I; Andrulis, Irene L; Anton-Culver, Hoda; Antonenkova, Natalia N; Arndt, Volker; Arnold, Norbert; Aronson, Kristan J; Auber, Bernd; Auer, Paul L; Ausems, Margreet G E M; Azzollini, Jacopo; Bacot, François; Balmaña, Judith; Barile, Monica; Barjhoux, Laure; Barkardottir, Rosa B; Barrdahl, Myrto; Barnes, Daniel; Barrowdale, Daniel; Baynes, Caroline; Beckmann, Matthias W; Benitez, Javier; Bermisheva, Marina; Bernstein, Leslie; Bignon, Yves-Jean; Blazer, Kathleen R; Blok, Marinus J; Blomqvist, Carl; Blot, William; Bobolis, Kristie; Boeckx, Bram; Bogdanova, Natalia V; Bojesen, Anders; Bojesen, Stig E; Bonanni, Bernardo; Børresen-Dale, Anne-Lise; Bozsik, Aniko; Bradbury, Angela R; Brand, Judith S; Brauch, Hiltrud; Brenner, Hermann; Bressac-de Paillerets, Brigitte; Brewer, Carole; Brinton, Louise; Broberg, Per; Brooks-Wilson, Angela; Brunet, Joan; Brüning, Thomas; Burwinkel, Barbara; Buys, Saundra S; Byun, Jinyoung; Cai, Qiuyin; Caldés, Trinidad; Caligo, Maria A; Campbell, Ian; Canzian, Federico; Caron, Olivier; Carracedo, Angel; Carter, Brian D; Castelao, J Esteban; Castera, Laurent; Caux-Moncoutier, Virginie; Chan, Salina B; Chang-Claude, Jenny; Chanock, Stephen J; Chen, Xiaoqing; Cheng, Ting-Yuan David; Chiquette, Jocelyne; Christiansen, Hans; Claes, Kathleen B M; Clarke, Christine L; Conner, Thomas; Conroy, Don M; Cook, Jackie; Cordina-Duverger, Emilie; Cornelissen, Sten; Coupier, Isabelle; Cox, Angela; Cox, David G; Cross, Simon S; Cuk, Katarina; Cunningham, Julie M; Czene, Kamila; Daly, Mary B; Damiola, Francesca; Darabi, Hatef; Davidson, Rosemarie; De Leeneer, Kim; Devilee, Peter; Dicks, Ed; Diez, Orland; Ding, Yuan Chun; Ditsch, Nina; Doheny, Kimberly F; Domchek, Susan M; Dorfling, Cecilia M; Dörk, Thilo; dos-Santos-Silva, Isabel; Dubois, Stéphane; Dugué, Pierre-Antoine; Dumont, Martine; Dunning, Alison M; Durcan, Lorraine; Dwek, Miriam; Dworniczak, Bernd; Eccles, Diana; Eeles, Ros; Ehrencrona, Hans; Eilber, Ursula; Ejlertsen, Bent; Ekici, Arif B; Engel, Christoph; Eriksson, Mikael; Fachal, Laura; Faivre, Laurence; Fasching, Peter A; Faust, Ulrike; Figueroa, Jonine; Flesch-Janys, Dieter; Fletcher, Olivia; Flyger, Henrik; Foulkes, William D; Friedman, Eitan; Fritschi, Lin; Frost, Debra; Gabrielson, Marike; Gaddam, Pragna; Gammon, Marilie D; Ganz, Patricia A; Gapstur, Susan M; Garber, Judy; Garcia-Barberan, Vanesa; García-Sáenz, José A; Gaudet, Mia M; Gauthier-Villars, Marion; Gehrig, Andrea; Georgoulias, Vassilios; Gerdes, Anne-Marie; Giles, Graham G; Glendon, Gord; Godwin, Andrew K; Goldberg, Mark S; Goldgar, David E; González-Neira, Anna; Goodfellow, Paul; Greene, Mark H; Grip, Mervi; Gronwald, Jacek; Grundy, Anne; Gschwantler-Kaulich, Daphne; Guénel, Pascal; Guo, Qi; Haeberle, Lothar; Hahnen, Eric; Haiman, Christopher A; Håkansson, Niclas; Hallberg, Emily; Hamann, Ute; Hamel, Nathalie; Hankinson, Susan; Hansen, Thomas V O; Harrington, Patricia; Hart, Steven N; Hartikainen, Jaana M; Healey, Catherine S; Hein, Alexander; Helbig, Sonja; Henderson, Alex; Heyworth, Jane; Hicks, Belynda; Hillemanns, Peter; Hodgson, Shirley; Hogervorst, Frans B; Hollestelle, Antoinette; Hooning, Maartje J; Hoover, Bob; Hopper, John L; Hu, Chunling; Huang, Guanmengqian; Hulick, Peter J; Humphreys, Keith; Hunter, David J; Imyanitov, Evgeny N; Isaacs, Claudine; Iwasaki, Motoki; Izatt, Louise; Jakubowska, Anna; James, Paul; Janavicius, Ramunas; Janni, Wolfgang; Jensen, Uffe Birk; John, Esther M; Johnson, Nichola; Jones, Kristine; Jones, Michael; Jukkola-Vuorinen, Arja; Kaaks, Rudolf; Kabisch, Maria; Kaczmarek, Katarzyna; Kang, Daehee; Kast, Karin; Keeman, Renske; Kerin, Michael J; Kets, Carolien M; Keupers, Machteld; Khan, Sofia; Khusnutdinova, Elza; Kiiski, Johanna I; Kim, Sung-Won; Knight, Julia A; Konstantopoulou, Irene; Kosma, Veli-Matti; Kristensen, Vessela N; Kruse, Torben A; Kwong, Ava; Lænkholm, Anne-Vibeke; Laitman, Yael; Lalloo, Fiona; Lambrechts, Diether; Landsman, Keren; Lasset, Christine; Lazaro, Conxi; Le Marchand, Loic; Lecarpentier, Julie; Lee, Andrew; Lee, Eunjung; Lee, Jong Won; Lee, Min Hyuk; Lejbkowicz, Flavio; Lesueur, Fabienne; Li, Jingmei; Lilyquist, Jenna; Lincoln, Anne; Lindblom, Annika; Lissowska, Jolanta; Lo, Wing-Yee; Loibl, Sibylle; Long, Jirong; Loud, Jennifer T; Lubinski, Jan; Luccarini, Craig; Lush, Michael; MacInnis, Robert J; Maishman, Tom; Makalic, Enes; Kostovska, Ivana Maleva; Malone, Kathleen E; Manoukian, Siranoush; Manson, JoAnn E; Margolin, Sara; Martens, John W M; Martinez, Maria Elena; Matsuo, Keitaro; Mavroudis, Dimitrios; Mazoyer, Sylvie; McLean, Catriona; Meijers-Heijboer, Hanne; Menéndez, Primitiva; Meyer, Jeffery; Miao, Hui; Miller, Austin; Miller, Nicola; Mitchell, Gillian; Montagna, Marco; Muir, Kenneth; Mulligan, Anna Marie; Mulot, Claire; Nadesan, Sue; Nathanson, Katherine L; Neuhausen, Susan L; Nevanlinna, Heli; Nevelsteen, Ines; Niederacher, Dieter; Nielsen, Sune F; Nordestgaard, Børge G; Norman, Aaron; Nussbaum, Robert L; Olah, Edith; Olopade, Olufunmilayo I; Olson, Janet E; Olswold, Curtis; Ong, Kai-ren; Oosterwijk, Jan C; Orr, Nick; Osorio, Ana; Pankratz, V Shane; Papi, Laura; Park-Simon, Tjoung-Won; Paulsson-Karlsson, Ylva; Lloyd, Rachel; Pedersen, Inge Søkilde; Peissel, Bernard; Peixoto, Ana; Perez, Jose I A; Peterlongo, Paolo; Peto, Julian; Pfeiler, Georg; Phelan, Catherine M; Pinchev, Mila; Plaseska-Karanfilska, Dijana; Poppe, Bruce; Porteous, Mary E; Prentice, Ross; Presneau, Nadege; Prokofieva, Darya; Pugh, Elizabeth; Pujana, Miquel Angel; Pylkäs, Katri; Rack, Brigitte; Radice, Paolo; Rahman, Nazneen; Rantala, Johanna; Rappaport-Fuerhauser, Christine; Rennert, Gad; Rennert, Hedy S; Rhenius, Valerie; Rhiem, Kerstin; Richardson, Andrea; Rodriguez, Gustavo C; Romero, Atocha; Romm, Jane; Rookus, Matti A; Rudolph, Anja; Ruediger, Thomas; Saloustros, Emmanouil; Sanders, Joyce; Sandler, Dale P; Sangrajrang, Suleeporn; Sawyer, Elinor J; Schmidt, Daniel F; Schoemaker, Minouk J; Schumacher, Fredrick; Schürmann, Peter; Schwentner, Lukas; Scott, Christopher; Scott, Rodney J; Seal, Sheila; Senter, Leigha; Seynaeve, Caroline; Shah, Mitul; Sharma, Priyanka; Shen, Chen-Yang; Sheng, Xin; Shimelis, Hermela; Shrubsole, Martha J; Shu, Xiao-Ou; Side, Lucy E; Singer, Christian F; Sohn, Christof; Southey, Melissa C; Spinelli, John J; Spurdle, Amanda B; Stegmaier, Christa; Stoppa-Lyonnet, Dominique; Sukiennicki, Grzegorz; Surowy, Harald; Sutter, Christian; Swerdlow, Anthony; Szabo, Csilla I; Tamimi, Rulla M; Tan, Yen Y; Taylor, Jack A; Tejada, Maria-Isabel; Tengström, Maria; Teo, Soo H; Terry, Mary B; Tessier, Daniel C; Teulé, Alex; Thöne, Kathrin; Thull, Darcy L; Tibiletti, Maria Grazia; Tihomirova, Laima; Tischkowitz, Marc; Toland, Amanda E; Tollenaar, Rob A E M; Tomlinson, Ian; Tong, Ling; Torres, Diana; Tranchant, Martine; Truong, Thérèse; Tucker, Kathy; Tung, Nadine; Tyrer, Jonathan; Ulmer, Hans-Ulrich; Vachon, Celine; van Asperen, Christi J; Van Den Berg, David; van den Ouweland, Ans M W; van Rensburg, Elizabeth J; Varesco, Liliana; Varon-Mateeva, Raymonda; Vega, Ana; Viel, Alessandra; Vijai, Joseph; Vincent, Daniel; Vollenweider, Jason; Walker, Lisa; Wang, Zhaoming; Wang-Gohrke, Shan; Wappenschmidt, Barbara; Weinberg, Clarice R; Weitzel, Jeffrey N; Wendt, Camilla; Wesseling, Jelle; Whittemore, Alice S; Wijnen, Juul T; Willett, Walter; Winqvist, Robert; Wolk, Alicja; Wu, Anna H; Xia, Lucy; Yang, Xiaohong R; Yannoukakos, Drakoulis; Zaffaroni, Daniela; Zheng, Wei; Zhu, Bin; Ziogas, Argyrios; Ziv, Elad; Zorn, Kristin K; Gago-Dominguez, Manuela; Mannermaa, Arto; Olsson, Håkan; Teixeira, Manuel R; Stone, Jennifer; Offit, Kenneth; Ottini, Laura; Park, Sue K; Thomassen, Mads; Hall, Per; Meindl, Alfons; Schmutzler, Rita K; Droit, Arnaud; Bader, Gary D; Pharoah, Paul D P; Couch, Fergus J; Easton, Douglas F; Kraft, Peter; Chenevix-Trench, Georgia; García-Closas, Montserrat; Schmidt, Marjanka K; Antoniou, Antonis C; Simard, Jacques

2018-01-01

Most common breast cancer susceptibility variants have been identified through genome-wide association studies (GWAS) of predominantly estrogen receptor (ER)-positive disease1. We conducted a GWAS using 21,468 ER-negative cases and 100,594 controls combined with 18,908 BRCA1 mutation carriers (9,414 with breast cancer), all of European origin. We identified independent associations at P < 5 × 10−8 with ten variants at nine new loci. At P < 0.05, we replicated associations with 10 of 11 variants previously reported in ER-negative disease or BRCA1 mutation carrier GWAS and observed consistent associations with ER-negative disease for 105 susceptibility variants identified by other studies. These 125 variants explain approximately 14% of the familial risk of this breast cancer subtype. There was high genetic correlation (0.72) between risk of ER-negative breast cancer and breast cancer risk for BRCA1 mutation carriers. These findings may lead to improved risk prediction and inform further fine-mapping and functional work to better understand the biological basis of ER-negative breast cancer. PMID:29058716

Identification of ten variants associated with risk of estrogen-receptor-negative breast cancer.

PubMed

Milne, Roger L; Kuchenbaecker, Karoline B; Michailidou, Kyriaki; Beesley, Jonathan; Kar, Siddhartha; Lindström, Sara; Hui, Shirley; Lemaçon, Audrey; Soucy, Penny; Dennis, Joe; Jiang, Xia; Rostamianfar, Asha; Finucane, Hilary; Bolla, Manjeet K; McGuffog, Lesley; Wang, Qin; Aalfs, Cora M; Adams, Marcia; Adlard, Julian; Agata, Simona; Ahmed, Shahana; Ahsan, Habibul; Aittomäki, Kristiina; Al-Ejeh, Fares; Allen, Jamie; Ambrosone, Christine B; Amos, Christopher I; Andrulis, Irene L; Anton-Culver, Hoda; Antonenkova, Natalia N; Arndt, Volker; Arnold, Norbert; Aronson, Kristan J; Auber, Bernd; Auer, Paul L; Ausems, Margreet G E M; Azzollini, Jacopo; Bacot, François; Balmaña, Judith; Barile, Monica; Barjhoux, Laure; Barkardottir, Rosa B; Barrdahl, Myrto; Barnes, Daniel; Barrowdale, Daniel; Baynes, Caroline; Beckmann, Matthias W; Benitez, Javier; Bermisheva, Marina; Bernstein, Leslie; Bignon, Yves-Jean; Blazer, Kathleen R; Blok, Marinus J; Blomqvist, Carl; Blot, William; Bobolis, Kristie; Boeckx, Bram; Bogdanova, Natalia V; Bojesen, Anders; Bojesen, Stig E; Bonanni, Bernardo; Børresen-Dale, Anne-Lise; Bozsik, Aniko; Bradbury, Angela R; Brand, Judith S; Brauch, Hiltrud; Brenner, Hermann; Bressac-de Paillerets, Brigitte; Brewer, Carole; Brinton, Louise; Broberg, Per; Brooks-Wilson, Angela; Brunet, Joan; Brüning, Thomas; Burwinkel, Barbara; Buys, Saundra S; Byun, Jinyoung; Cai, Qiuyin; Caldés, Trinidad; Caligo, Maria A; Campbell, Ian; Canzian, Federico; Caron, Olivier; Carracedo, Angel; Carter, Brian D; Castelao, J Esteban; Castera, Laurent; Caux-Moncoutier, Virginie; Chan, Salina B; Chang-Claude, Jenny; Chanock, Stephen J; Chen, Xiaoqing; Cheng, Ting-Yuan David; Chiquette, Jocelyne; Christiansen, Hans; Claes, Kathleen B M; Clarke, Christine L; Conner, Thomas; Conroy, Don M; Cook, Jackie; Cordina-Duverger, Emilie; Cornelissen, Sten; Coupier, Isabelle; Cox, Angela; Cox, David G; Cross, Simon S; Cuk, Katarina; Cunningham, Julie M; Czene, Kamila; Daly, Mary B; Damiola, Francesca; Darabi, Hatef; Davidson, Rosemarie; De Leeneer, Kim; Devilee, Peter; Dicks, Ed; Diez, Orland; Ding, Yuan Chun; Ditsch, Nina; Doheny, Kimberly F; Domchek, Susan M; Dorfling, Cecilia M; Dörk, Thilo; Dos-Santos-Silva, Isabel; Dubois, Stéphane; Dugué, Pierre-Antoine; Dumont, Martine; Dunning, Alison M; Durcan, Lorraine; Dwek, Miriam; Dworniczak, Bernd; Eccles, Diana; Eeles, Ros; Ehrencrona, Hans; Eilber, Ursula; Ejlertsen, Bent; Ekici, Arif B; Eliassen, A Heather; Engel, Christoph; Eriksson, Mikael; Fachal, Laura; Faivre, Laurence; Fasching, Peter A; Faust, Ulrike; Figueroa, Jonine; Flesch-Janys, Dieter; Fletcher, Olivia; Flyger, Henrik; Foulkes, William D; Friedman, Eitan; Fritschi, Lin; Frost, Debra; Gabrielson, Marike; Gaddam, Pragna; Gammon, Marilie D; Ganz, Patricia A; Gapstur, Susan M; Garber, Judy; Garcia-Barberan, Vanesa; García-Sáenz, José A; Gaudet, Mia M; Gauthier-Villars, Marion; Gehrig, Andrea; Georgoulias, Vassilios; Gerdes, Anne-Marie; Giles, Graham G; Glendon, Gord; Godwin, Andrew K; Goldberg, Mark S; Goldgar, David E; González-Neira, Anna; Goodfellow, Paul; Greene, Mark H; Alnæs, Grethe I Grenaker; Grip, Mervi; Gronwald, Jacek; Grundy, Anne; Gschwantler-Kaulich, Daphne; Guénel, Pascal; Guo, Qi; Haeberle, Lothar; Hahnen, Eric; Haiman, Christopher A; Håkansson, Niclas; Hallberg, Emily; Hamann, Ute; Hamel, Nathalie; Hankinson, Susan; Hansen, Thomas V O; Harrington, Patricia; Hart, Steven N; Hartikainen, Jaana M; Healey, Catherine S; Hein, Alexander; Helbig, Sonja; Henderson, Alex; Heyworth, Jane; Hicks, Belynda; Hillemanns, Peter; Hodgson, Shirley; Hogervorst, Frans B; Hollestelle, Antoinette; Hooning, Maartje J; Hoover, Bob; Hopper, John L; Hu, Chunling; Huang, Guanmengqian; Hulick, Peter J; Humphreys, Keith; Hunter, David J; Imyanitov, Evgeny N; Isaacs, Claudine; Iwasaki, Motoki; Izatt, Louise; Jakubowska, Anna; James, Paul; Janavicius, Ramunas; Janni, Wolfgang; Jensen, Uffe Birk; John, Esther M; Johnson, Nichola; Jones, Kristine; Jones, Michael; Jukkola-Vuorinen, Arja; Kaaks, Rudolf; Kabisch, Maria; Kaczmarek, Katarzyna; Kang, Daehee; Kast, Karin; Keeman, Renske; Kerin, Michael J; Kets, Carolien M; Keupers, Machteld; Khan, Sofia; Khusnutdinova, Elza; Kiiski, Johanna I; Kim, Sung-Won; Knight, Julia A; Konstantopoulou, Irene; Kosma, Veli-Matti; Kristensen, Vessela N; Kruse, Torben A; Kwong, Ava; Lænkholm, Anne-Vibeke; Laitman, Yael; Lalloo, Fiona; Lambrechts, Diether; Landsman, Keren; Lasset, Christine; Lazaro, Conxi; Le Marchand, Loic; Lecarpentier, Julie; Lee, Andrew; Lee, Eunjung; Lee, Jong Won; Lee, Min Hyuk; Lejbkowicz, Flavio; Lesueur, Fabienne; Li, Jingmei; Lilyquist, Jenna; Lincoln, Anne; Lindblom, Annika; Lissowska, Jolanta; Lo, Wing-Yee; Loibl, Sibylle; Long, Jirong; Loud, Jennifer T; Lubinski, Jan; Luccarini, Craig; Lush, Michael; MacInnis, Robert J; Maishman, Tom; Makalic, Enes; Kostovska, Ivana Maleva; Malone, Kathleen E; Manoukian, Siranoush; Manson, JoAnn E; Margolin, Sara; Martens, John W M; Martinez, Maria Elena; Matsuo, Keitaro; Mavroudis, Dimitrios; Mazoyer, Sylvie; McLean, Catriona; Meijers-Heijboer, Hanne; Menéndez, Primitiva; Meyer, Jeffery; Miao, Hui; Miller, Austin; Miller, Nicola; Mitchell, Gillian; Montagna, Marco; Muir, Kenneth; Mulligan, Anna Marie; Mulot, Claire; Nadesan, Sue; Nathanson, Katherine L; Neuhausen, Susan L; Nevanlinna, Heli; Nevelsteen, Ines; Niederacher, Dieter; Nielsen, Sune F; Nordestgaard, Børge G; Norman, Aaron; Nussbaum, Robert L; Olah, Edith; Olopade, Olufunmilayo I; Olson, Janet E; Olswold, Curtis; Ong, Kai-Ren; Oosterwijk, Jan C; Orr, Nick; Osorio, Ana; Pankratz, V Shane; Papi, Laura; Park-Simon, Tjoung-Won; Paulsson-Karlsson, Ylva; Lloyd, Rachel; Pedersen, Inge Søkilde; Peissel, Bernard; Peixoto, Ana; Perez, Jose I A; Peterlongo, Paolo; Peto, Julian; Pfeiler, Georg; Phelan, Catherine M; Pinchev, Mila; Plaseska-Karanfilska, Dijana; Poppe, Bruce; Porteous, Mary E; Prentice, Ross; Presneau, Nadege; Prokofieva, Darya; Pugh, Elizabeth; Pujana, Miquel Angel; Pylkäs, Katri; Rack, Brigitte; Radice, Paolo; Rahman, Nazneen; Rantala, Johanna; Rappaport-Fuerhauser, Christine; Rennert, Gad; Rennert, Hedy S; Rhenius, Valerie; Rhiem, Kerstin; Richardson, Andrea; Rodriguez, Gustavo C; Romero, Atocha; Romm, Jane; Rookus, Matti A; Rudolph, Anja; Ruediger, Thomas; Saloustros, Emmanouil; Sanders, Joyce; Sandler, Dale P; Sangrajrang, Suleeporn; Sawyer, Elinor J; Schmidt, Daniel F; Schoemaker, Minouk J; Schumacher, Fredrick; Schürmann, Peter; Schwentner, Lukas; Scott, Christopher; Scott, Rodney J; Seal, Sheila; Senter, Leigha; Seynaeve, Caroline; Shah, Mitul; Sharma, Priyanka; Shen, Chen-Yang; Sheng, Xin; Shimelis, Hermela; Shrubsole, Martha J; Shu, Xiao-Ou; Side, Lucy E; Singer, Christian F; Sohn, Christof; Southey, Melissa C; Spinelli, John J; Spurdle, Amanda B; Stegmaier, Christa; Stoppa-Lyonnet, Dominique; Sukiennicki, Grzegorz; Surowy, Harald; Sutter, Christian; Swerdlow, Anthony; Szabo, Csilla I; Tamimi, Rulla M; Tan, Yen Y; Taylor, Jack A; Tejada, Maria-Isabel; Tengström, Maria; Teo, Soo H; Terry, Mary B; Tessier, Daniel C; Teulé, Alex; Thöne, Kathrin; Thull, Darcy L; Tibiletti, Maria Grazia; Tihomirova, Laima; Tischkowitz, Marc; Toland, Amanda E; Tollenaar, Rob A E M; Tomlinson, Ian; Tong, Ling; Torres, Diana; Tranchant, Martine; Truong, Thérèse; Tucker, Kathy; Tung, Nadine; Tyrer, Jonathan; Ulmer, Hans-Ulrich; Vachon, Celine; van Asperen, Christi J; Van Den Berg, David; van den Ouweland, Ans M W; van Rensburg, Elizabeth J; Varesco, Liliana; Varon-Mateeva, Raymonda; Vega, Ana; Viel, Alessandra; Vijai, Joseph; Vincent, Daniel; Vollenweider, Jason; Walker, Lisa; Wang, Zhaoming; Wang-Gohrke, Shan; Wappenschmidt, Barbara; Weinberg, Clarice R; Weitzel, Jeffrey N; Wendt, Camilla; Wesseling, Jelle; Whittemore, Alice S; Wijnen, Juul T; Willett, Walter; Winqvist, Robert; Wolk, Alicja; Wu, Anna H; Xia, Lucy; Yang, Xiaohong R; Yannoukakos, Drakoulis; Zaffaroni, Daniela; Zheng, Wei; Zhu, Bin; Ziogas, Argyrios; Ziv, Elad; Zorn, Kristin K; Gago-Dominguez, Manuela; Mannermaa, Arto; Olsson, Håkan; Teixeira, Manuel R; Stone, Jennifer; Offit, Kenneth; Ottini, Laura; Park, Sue K; Thomassen, Mads; Hall, Per; Meindl, Alfons; Schmutzler, Rita K; Droit, Arnaud; Bader, Gary D; Pharoah, Paul D P; Couch, Fergus J; Easton, Douglas F; Kraft, Peter; Chenevix-Trench, Georgia; García-Closas, Montserrat; Schmidt, Marjanka K; Antoniou, Antonis C; Simard, Jacques

2017-12-01

Most common breast cancer susceptibility variants have been identified through genome-wide association studies (GWAS) of predominantly estrogen receptor (ER)-positive disease. We conducted a GWAS using 21,468 ER-negative cases and 100,594 controls combined with 18,908 BRCA1 mutation carriers (9,414 with breast cancer), all of European origin. We identified independent associations at P < 5 × 10 -8 with ten variants at nine new loci. At P < 0.05, we replicated associations with 10 of 11 variants previously reported in ER-negative disease or BRCA1 mutation carrier GWAS and observed consistent associations with ER-negative disease for 105 susceptibility variants identified by other studies. These 125 variants explain approximately 16% of the familial risk of this breast cancer subtype. There was high genetic correlation (0.72) between risk of ER-negative breast cancer and breast cancer risk for BRCA1 mutation carriers. These findings may lead to improved risk prediction and inform further fine-mapping and functional work to better understand the biological basis of ER-negative breast cancer.

Genetic variants of the unsaturated fatty acid receptor GPR120 relating to obesity in dogs

PubMed Central

MIYABE, Masahiro; GIN, Azusa; ONOZAWA, Eri; DAIMON, Mana; YAMADA, Hana; ODA, Hitomi; MORI, Akihiro; MOMOTA, Yutaka; AZAKAMI, Daigo; YAMAMOTO, Ichiro; MOCHIZUKI, Mariko; SAKO, Toshinori; TAMURA, Katsutoshi; ISHIOKA, Katsumi

2015-01-01

G protein-coupled receptor (GPR) 120 is an unsaturated fatty acid receptor, which is associated with various physiological functions. It is reported that the genetic variant of GPR120, p.Arg270His, is detected more in obese people, and this genetic variation functionally relates to obesity in humans. Obesity is a common nutritional disorder also in dogs, but the genetic factors have not ever been identified in dogs. In this study, we investigated the molecular structure of canine GPR120 and searched for candidate genetic variants which may relate to obesity in dogs. Canine GPR120 was highly homologous to those of other species, and seven transmembrane domains and two N-glycosylation sites were conserved. GPR120 mRNA was expressed in lung, jejunum, ileum, colon, hypothalamus, hippocampus, spinal cord, bone marrow, dermis and white adipose tissues in dogs, as those in mice and humans. Genetic variants of GPR120 were explored in client-owned 141 dogs, resulting in that 5 synonymous and 4 non-synonymous variants were found. The variant c.595C>A (p.Pro199Thr) was found in 40 dogs, and the gene frequency was significantly higher in dogs with higher body condition scores, i.e. 0.320 in BCS4–5 dogs, 0.175 in BCS3 dogs and 0.000 in BCS2 dogs. We conclude that c.595C>A (p.Pro199Thr) is a candidate variant relating to obesity, which may be helpful for nutritional management of dogs. PMID:25960032

Genetic variants of the unsaturated fatty acid receptor GPR120 relating to obesity in dogs.

PubMed

Miyabe, Masahiro; Gin, Azusa; Onozawa, Eri; Daimon, Mana; Yamada, Hana; Oda, Hitomi; Mori, Akihiro; Momota, Yutaka; Azakami, Daigo; Yamamoto, Ichiro; Mochizuki, Mariko; Sako, Toshinori; Tamura, Katsutoshi; Ishioka, Katsumi

2015-10-01

G protein-coupled receptor (GPR) 120 is an unsaturated fatty acid receptor, which is associated with various physiological functions. It is reported that the genetic variant of GPR120, p.Arg270His, is detected more in obese people, and this genetic variation functionally relates to obesity in humans. Obesity is a common nutritional disorder also in dogs, but the genetic factors have not ever been identified in dogs. In this study, we investigated the molecular structure of canine GPR120 and searched for candidate genetic variants which may relate to obesity in dogs. Canine GPR120 was highly homologous to those of other species, and seven transmembrane domains and two N-glycosylation sites were conserved. GPR120 mRNA was expressed in lung, jejunum, ileum, colon, hypothalamus, hippocampus, spinal cord, bone marrow, dermis and white adipose tissues in dogs, as those in mice and humans. Genetic variants of GPR120 were explored in client-owned 141 dogs, resulting in that 5 synonymous and 4 non-synonymous variants were found. The variant c.595C>A (p.Pro199Thr) was found in 40 dogs, and the gene frequency was significantly higher in dogs with higher body condition scores, i.e. 0.320 in BCS4-5 dogs, 0.175 in BCS3 dogs and 0.000 in BCS2 dogs. We conclude that c.595C>A (p.Pro199Thr) is a candidate variant relating to obesity, which may be helpful for nutritional management of dogs.

Variants of Transient Receptor Potential Melastatin Member 4 in Childhood Atrioventricular Block.

PubMed

Syam, Ninda; Chatel, Stéphanie; Ozhathil, Lijo Cherian; Sottas, Valentin; Rougier, Jean-Sébastien; Baruteau, Alban; Baron, Estelle; Amarouch, Mohamed-Yassine; Daumy, Xavier; Probst, Vincent; Schott, Jean-Jacques; Abriel, Hugues

2016-05-20

Transient receptor potential melastatin member 4 (TRPM4) is a nonselective cation channel. TRPM4 mutations have been linked to cardiac conduction disease and Brugada syndrome. The mechanisms underlying TRPM4-dependent conduction slowing are not fully understood. The aim of this study was to characterize TRPM4 genetic variants found in patients with congenital or childhood atrioventricular block. Ninety-one patients with congenital or childhood atrioventricular block were screened for candidate genes. Five rare TRPM4 genetic variants were identified and investigated. The variants were expressed heterologously in HEK293 cells. Two of the variants, A432T and A432T/G582S, showed decreased expression of the protein at the cell membrane; inversely, the G582S variant showed increased expression. Further functional characterization of these variants using whole-cell patch-clamp configuration showed a loss of function and a gain of function, respectively. We hypothesized that the observed decrease in expression was caused by a folding and trafficking defect. This was supported by the observation that incubation of these variants at lower temperature partially rescued their expression and function. Previous studies have suggested that altered SUMOylation of TRPM4 may cause a gain of function; however, we did not find any evidence that supports SUMOylation as being directly involved for the gain-of-function variant. This study underpins the role of TRPM4 in the cardiac conduction system. The loss-of-function variants A432T/G582S found in 2 unrelated patients with atrioventricular block are most likely caused by misfolding-dependent altered trafficking. The ability to rescue this variant with lower temperature may provide a novel use of pharmacological chaperones in treatment strategies. © 2016 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.

AIP mutations impair AhR signaling in pituitary adenoma patients fibroblasts and in GH3 cells.

PubMed

Lecoq, Anne-Lise; Viengchareun, Say; Hage, Mirella; Bouligand, Jérôme; Young, Jacques; Boutron, Audrey; Zizzari, Philippe; Lombès, Marc; Chanson, Philippe; Kamenický, Peter

2016-05-01

Germline mutations in the aryl hydrocarbon receptor-interacting protein (AIP) gene predispose humans to pituitary adenomas through unknown molecular mechanisms. The best-known interacting partner of AIP is the aryl hydrocarbon receptor (AhR), a transcription factor that mediates the effects of xenobiotics implicated in carcinogenesis. As 75% of AIP mutations disrupt the physical and/or functional interaction with AhR, we postulated that the tumorigenic potential of AIP mutations might result from altered AhR signaling. We evaluated the impact of AIP mutations on the AhR signaling pathway, first in fibroblasts from AIP-mutated patients with pituitary adenomas, by comparison with fibroblasts from healthy subjects, then in transfected pituitary GH3 cells. The AIP protein level in mutated fibroblasts was about half of that in cells from healthy subjects, but AhR expression was unaffected. Gene expression analyses showed significant modifications in the expression of the AhR target genes CYP1B1 and AHRR in AIP-mutated fibroblasts, both before and after stimulation with the endogenous AhR ligand kynurenine. Kynurenine increased Cyp1b1 expression to a greater extent in GH3 cells overexpressing wild type compared with cells expressing mutant AIP Knockdown of endogenous Aip in these cells attenuated Cyp1b1 induction by the AhR ligand. Both mutant AIP expression and knockdown of endogenous Aip affected the kynurenine-dependent GH secretion of GH3 cells. This study of human fibroblasts bearing endogenous heterozygous AIP mutations and transfected pituitary GH3 cells shows that AIP mutations affect the AIP protein level and alter AhR transcriptional activity in a gene- and tissue-dependent manner. © 2016 Society for Endocrinology.

Considerations for potency equivalent calculations in the Ah receptor-based CALUX bioassay: normalization of superinduction results for improved sample potency estimation.

PubMed

Baston, David S; Denison, Michael S

2011-02-15

The chemically activated luciferase expression (CALUX) system is a mechanistically based recombinant luciferase reporter gene cell bioassay used in combination with chemical extraction and clean-up methods for the detection and relative quantitation of 2,3,7,8-tetrachlorodibenzo-p-dioxin and related dioxin-like halogenated aromatic hydrocarbons in a wide variety of sample matrices. While sample extracts containing complex mixtures of chemicals can produce a variety of distinct concentration-dependent luciferase induction responses in CALUX cells, these effects are produced through a common mechanism of action (i.e. the Ah receptor (AhR)) allowing normalization of results and sample potency determination. Here we describe the diversity in CALUX response to PCDD/Fs from sediment and soil extracts and not only report the occurrence of superinduction of the CALUX bioassay, but we describe a mechanistically based approach for normalization of superinduction data that results in a more accurate estimation of the relative potency of such sample extracts. Copyright © 2010 Elsevier B.V. All rights reserved.

Considerations for potency equivalent calculations in the Ah receptor-based CALUX bioassay: Normalization of superinduction results for improved sample potency estimation

PubMed Central

Baston, David S.; Denison, Michael S.

2011-01-01

The chemically activated luciferase expression (CALUX) system is a mechanistically based recombinant luciferase reporter gene cell bioassay used in combination with chemical extraction and clean-up methods for the detection and relative quantitation of 2,3,7,8-tetrachlorodibenzo-p-dioxin and related dioxin-like halogenated aromatic hydrocarbons in a wide variety of sample matrices. While sample extracts containing complex mixtures of chemicals can produce a variety of distinct concentration-dependent luciferase induction responses in CALUX cells, these effects are produced through a common mechanism of action (i.e. the Ah receptor (AhR)) allowing normalization of results and sample potency determination. Here we describe the diversity in CALUX response to PCDD/Fs from sediment and soil extracts and not only report the occurrence of superinduction of the CALUX bioassay, but we describe a mechanistically based approach for normalization of superinduction data that results in a more accurate estimation of the relative potency of such sample extracts. PMID:21238730

A constitutively active dioxin/aryl hydrocarbon receptor induces stomach tumors

NASA Astrophysics Data System (ADS)

Andersson, Patrik; McGuire, Jacqueline; Rubio, Carlos; Gradin, Katarina; Whitelaw, Murray L.; Pettersson, Sven; Hanberg, Annika; Poellinger, Lorenz

2002-07-01

The dioxin/aryl hydrocarbon receptor (AhR) functions as a ligand-activated transcription factor regulating transcription of a battery of genes encoding xenobiotic metabolizing enzymes. Known receptor ligands are environmental pollutants including polycyclic aromatic hydrocarbons and polychlorinated dioxins. Loss-of-function (gene-disruption) studies in mice have demonstrated that the AhR is involved in toxic effects of dioxins but have not yielded unequivocal results concerning the physiological function of the receptor. Gain-of-function studies therefore were performed to unravel the biological functions of the AhR. A constitutively active AhR expressed in transgenic mice reduced the life span of the mice and induced tumors in the glandular part of the stomach, demonstrating the oncogenic potential of the AhR and implicating the receptor in regulation of cell proliferation.

Establishment of Sf9 transformants constitutively expressing PBAN receptor variants: application to functional evaluation

USDA-ARS?s Scientific Manuscript database

To facilitate further evaluation of pheromone biosynthesis activating neuropeptide receptor (PBANR) functionality and regulation, we generated cultured insect cell lines stably expressing a number of fluorescent Bombyx mori PBANR (BommoPBANR) and Pseudaletia separata PBANR (PsesePBANR) variants incl...

Distinct combinations of variant ionotropic glutamate receptors mediate thermosensation and hygrosensation in Drosophila.

PubMed

Knecht, Zachary A; Silbering, Ana F; Ni, Lina; Klein, Mason; Budelli, Gonzalo; Bell, Rati; Abuin, Liliane; Ferrer, Anggie J; Samuel, Aravinthan Dt; Benton, Richard; Garrity, Paul A

2016-09-22

Ionotropic Receptors (IRs) are a large subfamily of variant ionotropic glutamate receptors present across Protostomia. While these receptors are most extensively studied for their roles in chemosensory detection, recent work has implicated two family members, IR21a and IR25a, in thermosensation in Drosophila . Here we characterize one of the most evolutionarily deeply conserved receptors, IR93a, and show that it is co-expressed and functions with IR21a and IR25a to mediate physiological and behavioral responses to cool temperatures. IR93a is also co-expressed with IR25a and a distinct receptor, IR40a, in a discrete population of sensory neurons in the sacculus, a multi-chambered pocket within the antenna. We demonstrate that this combination of receptors is required for neuronal responses to dry air and behavioral discrimination of humidity differences. Our results identify IR93a as a common component of molecularly and cellularly distinct IR pathways important for thermosensation and hygrosensation in insects.

Deciphering Dimerization Modes of PAS Domains: Computational and Experimental Analyses of the AhR:ARNT Complex Reveal New Insights Into the Mechanisms of AhR Transformation

PubMed Central

Corrada, Dario; Soshilov, Anatoly A.; Denison, Michael S.

2016-01-01

The Aryl hydrocarbon Receptor (AhR) is a transcription factor that mediates the biochemical response to xenobiotics and the toxic effects of a number of environmental contaminants, including dioxins. Recently, endogenous regulatory roles for the AhR in normal physiology and development have also been reported, thus extending the interest in understanding its molecular mechanisms of activation. Since dimerization with the AhR Nuclear Translocator (ARNT) protein, occurring through the Helix-Loop-Helix (HLH) and PER-ARNT-SIM (PAS) domains, is needed to convert the AhR into its transcriptionally active form, deciphering the AhR:ARNT dimerization mode would provide insights into the mechanisms of AhR transformation. Here we present homology models of the murine AhR:ARNT PAS domain dimer developed using recently available X-ray structures of other bHLH-PAS protein dimers. Due to the different reciprocal orientation and interaction surfaces in the different template dimers, two alternative models were developed for both the PAS-A and PAS-B dimers and they were characterized by combining a number of computational evaluations. Both well-established hot spot prediction methods and new approaches to analyze individual residue and residue-pairwise contributions to the MM-GBSA binding free energies were adopted to predict residues critical for dimer stabilization. On this basis, a mutagenesis strategy for both the murine AhR and ARNT proteins was designed and ligand-dependent DNA binding ability of the AhR:ARNT heterodimer mutants was evaluated. While functional analysis disfavored the HIF2α:ARNT heterodimer-based PAS-B model, most mutants derived from the CLOCK:BMAL1-based AhR:ARNT dimer models of both the PAS-A and the PAS-B dramatically decreased the levels of DNA binding, suggesting this latter model as the most suitable for describing AhR:ARNT dimerization. These novel results open new research directions focused at elucidating basic molecular mechanisms underlying the

Deciphering Dimerization Modes of PAS Domains: Computational and Experimental Analyses of the AhR:ARNT Complex Reveal New Insights Into the Mechanisms of AhR Transformation.

PubMed

Corrada, Dario; Soshilov, Anatoly A; Denison, Michael S; Bonati, Laura

2016-06-01

The Aryl hydrocarbon Receptor (AhR) is a transcription factor that mediates the biochemical response to xenobiotics and the toxic effects of a number of environmental contaminants, including dioxins. Recently, endogenous regulatory roles for the AhR in normal physiology and development have also been reported, thus extending the interest in understanding its molecular mechanisms of activation. Since dimerization with the AhR Nuclear Translocator (ARNT) protein, occurring through the Helix-Loop-Helix (HLH) and PER-ARNT-SIM (PAS) domains, is needed to convert the AhR into its transcriptionally active form, deciphering the AhR:ARNT dimerization mode would provide insights into the mechanisms of AhR transformation. Here we present homology models of the murine AhR:ARNT PAS domain dimer developed using recently available X-ray structures of other bHLH-PAS protein dimers. Due to the different reciprocal orientation and interaction surfaces in the different template dimers, two alternative models were developed for both the PAS-A and PAS-B dimers and they were characterized by combining a number of computational evaluations. Both well-established hot spot prediction methods and new approaches to analyze individual residue and residue-pairwise contributions to the MM-GBSA binding free energies were adopted to predict residues critical for dimer stabilization. On this basis, a mutagenesis strategy for both the murine AhR and ARNT proteins was designed and ligand-dependent DNA binding ability of the AhR:ARNT heterodimer mutants was evaluated. While functional analysis disfavored the HIF2α:ARNT heterodimer-based PAS-B model, most mutants derived from the CLOCK:BMAL1-based AhR:ARNT dimer models of both the PAS-A and the PAS-B dramatically decreased the levels of DNA binding, suggesting this latter model as the most suitable for describing AhR:ARNT dimerization. These novel results open new research directions focused at elucidating basic molecular mechanisms underlying the

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

PubMed

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.

Pharmacological characterization of canine melancortin-4 receptor and its natural variant V213F.

PubMed

Yan, J; Tao, Y-X

2011-08-01

Dogs have become one of the most important companion animals in modern society. However, it is estimated that 20% to 40% of owned dogs are obese, suggesting that obesity has become one of the most important canine health problem. In addition, obesity in dogs also leads to type II diabetes. Because the melanocortin-4 receptor (MC4R) has been shown to be essential in maintaining energy homeostasis in several different species, including rodents and humans, we initiated studies toward elucidating the roles of MC4R in obesity pathogenesis in dogs. Canine MC4R has been cloned, and a missense variant V213F was identified. We designed primers and successfully cloned canine MC4R and generated the variant V213F by site-directed mutagenesis. The objective of this study was to investigate the pharmacological properties of canine MC4R and its natural variant V213F. We measured ligand binding and signaling properties with the use of both natural and synthetic ligands. Human MC4R was also included in the experiments for comparison. Both wild-type canine MC4R and its natural variant V213F functioned normally in terms of binding and signaling. Of the ligands we used, [Nle(4), D-Phe(7)]-α-melanocyte-stimulating hormone is the most potent ligand. We conclude that the cloned canine MC4R is a functional receptor, and the natural variant V213F does not have any functional defect and therefore is not likely to cause obesity in dogs. Copyright © 2011 Elsevier Inc. All rights reserved.

Variants at serotonin transporter and 2A receptor genes predict cooperative behavior differentially according to presence of punishment.

PubMed

Schroeder, Kari B; McElreath, Richard; Nettle, Daniel

2013-03-05

Punishment of free-riding has been implicated in the evolution of cooperation in humans, and yet mechanisms for punishment avoidance remain largely uninvestigated. Individual variation in these mechanisms may stem from variation in the serotonergic system, which modulates processing of aversive stimuli. Functional serotonin gene variants have been associated with variation in the processing of aversive stimuli and widely studied as risk factors for psychiatric disorders. We show that variants at the serotonin transporter gene (SLC6A4) and serotonin 2A receptor gene (HTR2A) predict contributions to the public good in economic games, dependent upon whether contribution behavior can be punished. Participants with a variant at the serotonin transporter gene contribute more, leading to group-level differences in cooperation, but this effect dissipates in the presence of punishment. When contribution behavior can be punished, those with a variant at the serotonin 2A receptor gene contribute more than those without it. This variant also predicts a more stressful experience of the games. The diversity of institutions (including norms) that govern cooperation and punishment may create selective pressures for punishment avoidance that change rapidly across time and space. Variant-specific epigenetic regulation of these genes, as well as population-level variation in the frequencies of these variants, may facilitate adaptation to local norms of cooperation and punishment.

Variants at serotonin transporter and 2A receptor genes predict cooperative behavior differentially according to presence of punishment

PubMed Central

Schroeder, Kari B.; McElreath, Richard; Nettle, Daniel

2013-01-01

Punishment of free-riding has been implicated in the evolution of cooperation in humans, and yet mechanisms for punishment avoidance remain largely uninvestigated. Individual variation in these mechanisms may stem from variation in the serotonergic system, which modulates processing of aversive stimuli. Functional serotonin gene variants have been associated with variation in the processing of aversive stimuli and widely studied as risk factors for psychiatric disorders. We show that variants at the serotonin transporter gene (SLC6A4) and serotonin 2A receptor gene (HTR2A) predict contributions to the public good in economic games, dependent upon whether contribution behavior can be punished. Participants with a variant at the serotonin transporter gene contribute more, leading to group-level differences in cooperation, but this effect dissipates in the presence of punishment. When contribution behavior can be punished, those with a variant at the serotonin 2A receptor gene contribute more than those without it. This variant also predicts a more stressful experience of the games. The diversity of institutions (including norms) that govern cooperation and punishment may create selective pressures for punishment avoidance that change rapidly across time and space. Variant-specific epigenetic regulation of these genes, as well as population-level variation in the frequencies of these variants, may facilitate adaptation to local norms of cooperation and punishment. PMID:23431136

DDE and PCB 153 independently induce aryl hydrocarbon receptor (AhR) expression in peripheral blood mononuclear cells.

PubMed

Gaspar-Ramírez, Octavio; Pérez-Vázquez, Francisco J; Salgado-Bustamante, Mariana; González-Amaro, Roberto; Hernandez-Castro, Berenice; Pérez-Maldonado, Ivan N

2015-01-01

Recent studies have demonstrated that compounds inducing pro-inflammatory cytokines enhance AhR expression. The aim of this study was 2-fold: (1) to determine if two pro-inflammatory compounds, dichlorodiphenyldichloroethylene (DDE) and 2,2',4,4',5,5'-hexa-chlorobiphenyl (PCB 153), independently affect AhR gene expression in peripheral blood mononuclear cells (PBMC); and (2) if affected, to determine whether the mechanism involved was due to AhR activation or to a pro-inflammatory effect of the chemicals. PBMC isolated from healthy individuals were incubated in the presence of DDE (10 µg/ml) and PCB 153 (20 ng/ml) over time and AhR and CYP1A1 expression was assessed with a real-time PCR technique. The results indicated there was over-expression of the AhR mRNA in PBMC when the cells were treated with DDE and PCB 153. No changes in expression levels of CYP1A1 mRNA were found. Importantly, when the cells were exposed to DDE and PCB 153 in the presence of an antagonist of tumor necrosis factor (TNF)-α, the over-expression of AhR was abolished; as expected, the expression of CYP1A1 was unaffected. In conclusion, these studies demonstrated for the first time an increment of AhR expression "in vitro" in PBMC treated with two pro-inflammatory environmental pollutants, DDE and PCB153. Moreover, the over-expression of AhR was dependent of TNFα induced by DDE and PCB 153 and was independent of AhR activation.

Systematic Identification of Genes Required for Expression of Androgen Receptor Splice Variants

DTIC Science & Technology

2016-08-01

engineering tool has been developed from bacterial Clustered Regularly Interspaced Short Palindromic Repeats ( CRISPR )/ CRISPR ‐Associated System (Cas...regulation of AR splice variant through CRISPR /Cas screening system. 15. SUBJECT TERMS CRISPR /Cas, Androgen receptor, castration resistance, biomarker 16...control (non-targeting) gRNAs available from Addgene (http://www.addgene.org/ CRISPR /libraries/). Generation of AR3 reporter: We used molecular cloning

Lack of association between dopamine D2 receptor gene Cys311 variant and schizophrenia

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tanaka, Toshihisa; Fukushima, Noboru; Takahashi, Makoto

Itokawa et al. reported identifying one missense nucleotide mutation from C to G resulting in a substitution of serine with cysteine at codon 311 in the third intracellular loop of the dopamine D2 receptor in schizophrenics. Arinami et al. reported finding a positive association between the Cys311 variant and schizophrenia. In response to the report by Arinami et al. we examined 106 unrelated Japanese schizophrenics and 106 normal controls to determine if there is any association of the Cys311 variant with schizophrenia. However, we found no statistically significant differences in allelic frequencies of Cys311 between schizophrenia and normal controls. Themore » present results as well as those of all previous studies except for that of Arinami et al. indicated that an association between the dopamine D2 receptor gene and schizophrenia is unlikely to exist. 24 refs., 1 fig., 1 tab.« less

Sexually dimorphic effects of oxytocin receptor gene (OXTR ) variants on Harm Avoidance.

PubMed

Stankova, Trayana; Eichhammer, Peter; Langguth, Berthold; Sand, Philipp G

2012-07-30

Recent research has suggested that oxytocin receptor gene (OXTR) variants may account for individual differences in social behavior, the effects of stress and parenting styles. Little is known, however, on a putative role of the gene in heritable temperamental traits. We addressed effects of two common OXTR variants, rs237900 and rs237902, on personality dimensions in 99 healthy subjects using the Temperament and Character Inventory. When sex was controlled for and an OXTR genotype*sex interaction term was included in the regression model, 11% of the variance in Harm Avoidance could be explained (uncorrected p ≤ 0.01). Female carriers of the minor alleles scored highest, and a novel A217T mutation emerged in the most harm avoidant male participant. Findings lend support to a modulatory effect of common OXTR variants on Harm Avoidance in healthy caucasian women and invite resequencing of the gene in anxiety phenotypes to identify more explanatory functional variation.

In-Depth Analysis of HA and NS1 Genes in A(H1N1)pdm09 Infected Patients.

PubMed

Caglioti, Claudia; Selleri, Marina; Rozera, Gabriella; Giombini, Emanuela; Zaccaro, Paola; Valli, Maria Beatrice; Capobianchi, Maria Rosaria

2016-01-01

In March/April 2009, a new pandemic influenza A virus (A(H1N1)pdm09) emerged and spread rapidly via human-to-human transmission, giving rise to the first pandemic of the 21th century. Influenza virus may be present in the infected host as a mixture of variants, referred to as quasi-species, on which natural and immune-driven selection operates. Since hemagglutinin (HA) and non-structural 1 (NS1) proteins are relevant in respect of adaptive and innate immune responses, the present study was aimed at establishing the intra-host genetic heterogeneity of HA and NS1 genes, applying ultra-deep pyrosequencing (UDPS) to nasopharyngeal swabs (NPS) from patients with confirmed influenza A(H1N1)pdm09 infection. The intra-patient nucleotide diversity of HA was significantly higher than that of NS1 (median (IQR): 37.9 (32.8-42.3) X 10-4 vs 30.6 (27.4-33.6) X 10-4 substitutions/site, p = 0.024); no significant correlation for nucleotide diversity of NS1 and HA was observed (r = 0.319, p = 0.29). Furthermore, a strong inverse correlation between nucleotide diversity of NS1 and viral load was observed (r = - 0.74, p = 0.004). For both HA and NS1, the variants appeared scattered along the genes, thus indicating no privileged mutation site. Known polymorphisms, S203T (HA) and I123V (NS1), were observed as dominant variants (>98%) in almost all patients; three HA and two NS1 further variants were observed at frequency >40%; a number of additional variants were detected at frequency <6% (minority variants), of which three HA and four NS1 variants were novel. In few patients multiple variants were observed at HA residues 203 and 222. According to the FLUSURVER tool, some of these variants may affect immune recognition and host range; however, these inferences are based on H5N1, and their extension to A(H1N1)pdm09 requires caution. More studies are necessary to address the significance of the composite nature of influenza virus quasi-species within infected patients.

Structural and Molecular Characterization of the Hemagglutinin from the Fifth Epidemic Wave A(H7N9) Influenza Viruses.

PubMed

Yang, Hua; Carney, Paul J; Chang, Jessie C; Guo, Zhu; Stevens, James

2018-05-30

The avian influenza A(H7N9) virus continues to cause human infections in China and is a major ongoing public health concern. Five epidemic waves of A(H7N9) infection have occurred since 2013, and the recent fifth epidemic wave saw the emergence of two distinct lineages with elevated numbers of human infection cases and broader geographic distribution of viral diseases compared to the first four epidemic waves. Moreover, highly pathogenic avian influenza (HPAI) A(H7N9) viruses were also isolated during the fifth epidemic wave. Here, we present a detailed structural and biochemical analysis of the surface hemagglutinin (HA) antigen from viruses isolated during this recent epidemic wave. Results highlight that when compared to the 2013 virus HAs, the fifth wave virus HAs remained a weak binder to human glycan receptor analogs. We also studied three mutations, V177K-K184T-G219S, that were recently reported to switch a 2013 A(H7N9)HA to human-type receptor specificity. Our results indicate that these mutations could also switch the H7 HA receptor preference to a predominantly human binding specificity for both fifth wave H7 HAs analyzed in this study. IMPORTANCE The A(H7N9) viruses circulating in China are of great public health concern. Herein, we report a molecular and structural study of the major surface proteins from several recent A(H7N9) influenza viruses. Our results improve the understanding of these evolving viruses and provide important information on their receptor preference that is central to ongoing pandemic risk assessment. This is a work of the U.S. Government and is not subject to copyright protection in the United States. Foreign copyrights may apply.

Infection of mice with a human influenza A/H3N2 virus induces protective immunity against lethal infection with influenza A/H5N1 virus.

PubMed

Kreijtz, J H C M; Bodewes, R; van den Brand, J M A; de Mutsert, G; Baas, C; van Amerongen, G; Fouchier, R A M; Osterhaus, A D M E; Rimmelzwaan, G F

2009-08-06

The transmission of highly pathogenic avian influenza (HPAI) A viruses of the H5N1 subtype from poultry to man and the high case fatality rate fuels the fear for a pandemic outbreak caused by these viruses. However, prior infections with seasonal influenza A/H1N1 and A/H3N2 viruses induce heterosubtypic immunity that could afford a certain degree of protection against infection with the HPAI A/H5N1 viruses, which are distantly related to the human influenza A viruses. To assess the protective efficacy of such heterosubtypic immunity mice were infected with human influenza virus A/Hong Kong/2/68 (H3N2) 4 weeks prior to a lethal infection with HPAI virus A/Indonesia/5/05 (H5N1). Prior infection with influenza virus A/Hong Kong/2/68 reduced clinical signs, body weight loss, mortality and virus replication in the lungs as compared to naive mice infected with HPAI virus A/Indonesia/5/05. Priming by infection with respiratory syncytial virus, a non-related virus did not have a beneficial effect on the outcome of A/H5N1 infections, indicating that adaptive immune responses were responsible for the protective effect. In mice primed by infection with influenza A/H3N2 virus cytotoxic T lymphocytes (CTL) specific for NP(366-374) epitope ASNENMDAM and PA(224-232) SCLENFRAYV were observed. A small proportion of these CTL was cross-reactive with the peptide variant derived from the influenza A/H5N1 virus (ASNENMEVM and SSLENFRAYV respectively) and upon challenge infection with the influenza A/H5N1 virus cross-reactive CTL were selectively expanded. These CTL, in addition to those directed to conserved epitopes, shared by the influenza A/H3N2 and A/H5N1 viruses, most likely contributed to accelerated clearance of the influenza A/H5N1 virus infection. Although also other arms of the adaptive immune response may contribute to heterosubtypic immunity, the induction of virus-specific CTL may be an attractive target for development of broad protective vaccines. Furthermore the

NcoA2-Dependent Inhibition of HIF-1α Activation Is Regulated via AhR.

PubMed

Tsai, Chi-Hao; Li, Ching-Hao; Liao, Po-Lin; Cheng, Yu-Wen; Lin, Cheng-Hui; Huang, Shih-Hsuan; Kang, Jaw-Jou

2015-12-01

High endogenous levels of aryl hydrocarbon receptor (AhR) contribute to hypoxia signaling pathway inhibition following exposure to the potent AhR ligand benzo[a]pyrene (B[a]P) and could alter cellular homeostasis and disease condition. Increasing evidence indicates that AhR might compete with AhR nuclear translocator (ARNT) for complex formation with hypoxia-inducible factor-1α (HIF-1α) for transactivation, which could alter several physiological variables. Nuclear receptor coactivator 2 (NcoA2) is a transcription coactivator that regulates transcription factor activation and inhibition of basic helix-loop-helix Per (Period)-ARNT-SIM (single-minded) (bHLH-PAS) family proteins, such as HIF-1α, ARNT, and AhR, through protein-protein interactions. In this study, we demonstrated that both hypoxia and hypoxia-mimic conditions decreased NcoA2 protein expression in HEK293T cells. Hypoxia response element (HRE) and xenobiotic-responsive element (XRE) transactivation also were downregulated with NcoA2 knockdown under hypoxic conditions. In addition, B[a]P significantly decreased NcoA2 protein expression be accompanied with AhR degradation. We next evaluated whether the absence of AhR could affect NcoA2 protein function under hypoxia-mimetic conditions. NcoA2 and HIF-1α nuclear localization decreased in both B[a]P-pretreated and AhR-knockdown HepG2 cells under hypoxia-mimic conditions. Interestingly, NcoA2 overexpression downregulated HRE transactivation by competing with HIF-1α and AhR to form protein complexes with ARNT. Both NcoA2 knockdown and overexpression inhibited endothelial cell tube formation in vitro. We also demonstrated using the in vivo plug assay that NcoA2-regulated vascularization decreased in mice. Taken together, these results revealed a biphasic role of NcoA2 between AhR and hypoxic conditions, thus providing a novel mechanism underlying the cross talk between AhR and hypoxia that affects disease development and progression. © The Author 2015

Dopamine D4 receptor, but not the ADHD-associated D4.7 variant, forms functional heteromers with the dopamine D2S receptor in the brain

PubMed Central

González, Sergio; Rangel-Barajas, Claudia; Peper, Marcela; Lorenzo, Ramiro; Moreno, Estefanía; Ciruela, Francisco; Borycz, Janusz; Ortiz, Jordi; Lluís, Carme; Franco, Rafael; McCormick, Peter J.; Volkow, Nora D.; Rubinstein, Marcelo; Floran, Benjamin; Ferré, Sergi

2011-01-01

Polymorphic variants of the dopamine D4 receptor have been consistently associated with attention-deficit hyperactivity disorder (ADHD). However the functional significance of the risk polymorphism (variable number of tandem repeats in exon 3) is still unclear. Here we show that whereas the most frequent 4-repeat (D4.4) and the 2-repeat (D4.2) variants form functional heteromers with the short isoform of the dopamine D2 receptor (D2S), the 7-repeat risk allele (D4.7) does not. D2 receptor activation in the D2S-D4 receptor heteromer potentiates D4 receptor-mediated MAPK signaling in transfected cells and in the striatum, which did not occur in cells expressing D4.7 or in the striatum of knock-in mutant mice carrying the 7 repeats of the human D4.7 in the third intracellular loop of the D4 receptor. In the striatum D4 receptors are localized in cortico-striatal glutamatergic terminals, where they selectively modulate glutamatergic neurotransmission by interacting with D2S receptors. This interaction shows the same qualitative characteristics than the D2S-D4 receptor heteromer-mediated MAPK signaling and D2S receptor activation potentiates D4 receptor-mediated inibition of striatal glutamate release. It is therefore postulated that dysfunctional D2S-D4.7 heteromers may impair presynaptic dopaminergic control of corticostriatal glutamatergic neurotransmission and explain functional deficits associated with ADHD. PMID:21844870

Melanocortin-1 receptor gene variants affect pain and µ-opioid analgesia in mice and humans

PubMed Central

Mogil, J; Ritchie, J; Smith, S; Strasburg, K; Kaplan, L; Wallace, M; Romberg, R; Bijl, H; Sarton, E; Fillingim, R; Dahan, A

2005-01-01

Background: A recent genetic study in mice and humans revealed the modulatory effect of MC1R (melanocortin-1 receptor) gene variants on κ-opioid receptor mediated analgesia. It is unclear whether this gene affects basal pain sensitivity or the efficacy of analgesics acting at the more clinically relevant µ-opioid receptor. Objective: To characterise sensitivity to pain and µ-opioid analgesia in mice and humans with non-functional melanocortin-1 receptors. Methods: Comparisons of spontaneous mutant C57BL/6-Mc1re/e mice to C57BL/6 wildtype mice, followed by a gene dosage study of pain and morphine-6-glucuronide (M6G) analgesia in humans with MC1R variants. Results: C57BL/6-Mc1re/e mutant mice and human redheads—both with non-functional MC1Rs—display reduced sensitivity to noxious stimuli and increased analgesic responsiveness to the µ-opioid selective morphine metabolite, M6G. In both species the differential analgesia is likely due to pharmacodynamic factors, as plasma levels of M6G are similar across genotype. Conclusions: Genotype at MC1R similarly affects pain sensitivity and M6G analgesia in mice and humans. These findings confirm the utility of cross species translational strategies in pharmacogenetics. PMID:15994880

Anti-neuraminidase antibodies against pandemic A/H1N1 influenza viruses in healthy and influenza-infected individuals.

PubMed

Desheva, Yulia; Sychev, Ivan; Smolonogina, Tatiana; Rekstin, Andrey; Ilyushina, Natalia; Lugovtsev, Vladimir; Samsonova, Anastasia; Go, Aleksey; Lerner, Anna

2018-01-01

The main objective of the study was to evaluate neuraminidase inhibiting (NI) antibodies against A/H1N1pdm09 influenza viruses in the community as a whole and after infection. We evaluated NI serum antibodies against A/California/07/09(H1N1)pdm and A/South Africa/3626/2013(H1N1)pdm in 134 blood donors of different ages using enzyme-linked lectin assay and in 15 paired sera from convalescents with laboratory confirmed influenza. The neuraminidase (NA) proteins of both A/H1N1pdm09 viruses had minimal genetic divergence, but demonstrated different enzymatic and antigenic properties. 5.2% of individuals had NI antibody titers ≥1:20 against A/South Africa/3626/2013(H1N1)pdm compared to 53% of those who were positive to A/California/07/2009(H1N1)pdm NA. 2% of individuals had detectable NI titers against A/South Africa/3626/13(H1N1)pdm and 47.3% were positive to A/California/07/2009(H1N1)pdm NA among participants negative to hemagglutinin (HA) of A/H1N1pdm09 but positive to seasonal A/H1N1. The lowest NI antibody levels to both A/H1N1pdm09 viruses were detected in individuals born between 1956 and 1968. Our data suggest that NI antibodies against A/South Africa/3626/13 (H1N1)pdm found in the blood donors could have resulted from direct infection with a new antigenic A/H1N1pdm09 variant rather than from cross-reaction as a result of contact with previously circulating seasonal A/H1N1 variants. The immune responses against HA and NA were formed simultaneously right after natural infection with A/H1N1pdm09. NI antibodies correlated with virus-neutralizing antibodies when acquired shortly after influenza infection. A group of middle-aged patients with the lowest level of anti-NA antibodies against A/California/07/2009 (H1N1)pdm was identified, indicating the highest-priority vaccination against A/H1N1pdm09 viruses.

Anti-neuraminidase antibodies against pandemic A/H1N1 influenza viruses in healthy and influenza-infected individuals

PubMed Central

Sychev, Ivan; Smolonogina, Tatiana; Rekstin, Andrey; Ilyushina, Natalia; Lugovtsev, Vladimir; Samsonova, Anastasia; Go, Aleksey; Lerner, Anna

2018-01-01

The main objective of the study was to evaluate neuraminidase inhibiting (NI) antibodies against A/H1N1pdm09 influenza viruses in the community as a whole and after infection. We evaluated NI serum antibodies against A/California/07/09(H1N1)pdm and A/South Africa/3626/2013(H1N1)pdm in 134 blood donors of different ages using enzyme-linked lectin assay and in 15 paired sera from convalescents with laboratory confirmed influenza. The neuraminidase (NA) proteins of both A/H1N1pdm09 viruses had minimal genetic divergence, but demonstrated different enzymatic and antigenic properties. 5.2% of individuals had NI antibody titers ≥1:20 against A/South Africa/3626/2013(H1N1)pdm compared to 53% of those who were positive to A/California/07/2009(H1N1)pdm NA. 2% of individuals had detectable NI titers against A/South Africa/3626/13(H1N1)pdm and 47.3% were positive to A/California/07/2009(H1N1)pdm NA among participants negative to hemagglutinin (HA) of A/H1N1pdm09 but positive to seasonal A/H1N1. The lowest NI antibody levels to both A/H1N1pdm09 viruses were detected in individuals born between 1956 and 1968. Our data suggest that NI antibodies against A/South Africa/3626/13 (H1N1)pdm found in the blood donors could have resulted from direct infection with a new antigenic A/H1N1pdm09 variant rather than from cross-reaction as a result of contact with previously circulating seasonal A/H1N1 variants. The immune responses against HA and NA were formed simultaneously right after natural infection with A/H1N1pdm09. NI antibodies correlated with virus-neutralizing antibodies when acquired shortly after influenza infection. A group of middle-aged patients with the lowest level of anti-NA antibodies against A/California/07/2009 (H1N1)pdm was identified, indicating the highest-priority vaccination against A/H1N1pdm09 viruses. PMID:29742168

Characterization and pharmacological analysis of two adipokinetic hormone receptor variants of the tsetse fly, Glossina morsitans morsitans.

PubMed

Caers, Jelle; Janssen, Tom; Van Rompay, Liesbeth; Broeckx, Valérie; Van Den Abbeele, Jan; Gäde, Gerd; Schoofs, Liliane; Beets, Isabel

2016-03-01

Adipokinetic hormones (AKH) are well known regulators of energy metabolism in insects. These neuropeptides are produced in the corpora cardiaca and perform their hormonal function by interacting with specific G protein-coupled receptors (GPCRs) at the cell membranes of target tissues, mainly the fat body. Here, we investigated the sequences, spatial and temporal distributions, and pharmacology of AKH neuropeptides and receptors in the tsetse fly, Glossina morsitans morsitans. The open reading frames of two splice variants of the Glomo-akh receptor (Glomo-akhr) gene and of the AKH neuropeptide encoding genes, gmmhrth and gmmakh, were cloned. Both tsetse AKHR isoforms show strong sequence conservation when compared to other insect AKHRs. Glomo-AKH prepropeptides also have the typical architecture of AKH precursors. In an in vitro Ca(2+) mobilization assay, Glomo-AKH neuropeptides activated each receptor isoform up to nanomolar concentrations. We identified structural features of tsetse AKH neuropeptides essential for receptor activation in vitro. Gene expression profiles suggest a function for AKH signaling in regulating Glossina energy metabolism, where AKH peptides are released from the corpora cardiaca and activate receptors mainly expressed in the fat body. This analysis of the ligand-receptor coupling, expression, and pharmacology of the two Glomo-AKHR variants facilitates further elucidation of the function of AKH in G. m. morsitans. Copyright © 2015 Elsevier Ltd. All rights reserved.

Distinct combinations of variant ionotropic glutamate receptors mediate thermosensation and hygrosensation in Drosophila

PubMed Central

Knecht, Zachary A; Silbering, Ana F; Ni, Lina; Klein, Mason; Budelli, Gonzalo; Bell, Rati; Abuin, Liliane; Ferrer, Anggie J; Samuel, Aravinthan DT; Benton, Richard; Garrity, Paul A

2016-01-01

Ionotropic Receptors (IRs) are a large subfamily of variant ionotropic glutamate receptors present across Protostomia. While these receptors are most extensively studied for their roles in chemosensory detection, recent work has implicated two family members, IR21a and IR25a, in thermosensation in Drosophila. Here we characterize one of the most evolutionarily deeply conserved receptors, IR93a, and show that it is co-expressed and functions with IR21a and IR25a to mediate physiological and behavioral responses to cool temperatures. IR93a is also co-expressed with IR25a and a distinct receptor, IR40a, in a discrete population of sensory neurons in the sacculus, a multi-chambered pocket within the antenna. We demonstrate that this combination of receptors is required for neuronal responses to dry air and behavioral discrimination of humidity differences. Our results identify IR93a as a common component of molecularly and cellularly distinct IR pathways important for thermosensation and hygrosensation in insects. DOI: http://dx.doi.org/10.7554/eLife.17879.001 PMID:27656904

The role of ghrelin and ghrelin-receptor gene variants and promoter activity in type 2 diabetes.

PubMed

Garcia, Edwin A; King, Peter; Sidhu, Kally; Ohgusu, Hideko; Walley, Andrew; Lecoeur, Cecile; Gueorguiev, Maria; Khalaf, Sahira; Davies, Derek; Grossman, Ashley B; Kojima, Masayasu; Petersenn, Stephan; Froguel, Phillipe; Korbonits, Márta

2009-08-01

Ghrelin and its receptor play an important role in glucose metabolism and energy homeostasis, and therefore they are functional candidates for genes carrying susceptibility alleles for type 2 diabetes. We assessed common genetic variation of the ghrelin (GHRL; five single nucleotide polymorphisms (SNP)) and the ghrelin-receptor (GHSR) genes (four SNPs) in 610 Caucasian patients with type 2 diabetes and 820 controls. In addition, promoter reporter assays were conducted to model the regulatory regions of both genes. Neither GHRL nor GHSR gene SNPs were associated with type 2 diabetes. One of the ghrelin haplotypes showed a marginal protective role in type 2 diabetes. We observed profound differences in the regulation of the GHRL gene according to promoter sequence variants. There are three different GHRL promoter haplotypes represented in the studied cohort causing up to 45% difference in the level of gene expression, while the promoter region of GHSR gene is primarily represented by a single haplotype. The GHRL and GHSR gene variants are not associated with type 2 diabetes, although GHRL promoter variants have significantly different activities.

Activation of AhR-mediated toxicity pathway by emerging ...

EPA Pesticide Factsheets

Polychlorinated diphenyl sulfides (PCDPSs) are a group of environmental pollutants for which limited toxicological information is available. This study tested the hypothesis that PCDPSs could activate the mammalian aryl hydrocarbon receptor (AhR) mediated toxicity pathways. Eighteen PCDPSs were tested in the H4IIE-luc transactivation assay, with 13/18 causing concentration-dependent AhR activation. Potencies of several congeners were similar to those of mono-ortho substituted polychlorinated biphenyls. A RNA sequencing (RNA-seq)-based transcriptomic analysis was performed on H4IIE cells treated with two PCDPS congeners, 2,2',3,3',4,5,6-hepta-CDPS, and 2,4,4',5-tetra-CDPS. Results of RNA-seq revealed a remarkable modulation on a relatively short gene list by exposure to the tested concentrations of PCDPSs, among which, Cyp1 responded with the greatest fold up-regulation. Both the identities of the modulated transcripts and the associated pathways were consistent with targets and pathways known to be modulated by other types of AhR agonists and there was little evidence for significant off-target effects within the cellular context of the H4IIE bioassay. The results suggest AhR activation as a toxicologically relevant mode of action for PCDPSs suggests the utility of AhR-related toxicity pathways for predicting potential hazards associated with PCDPS exposure in mammals and potentially other vertebrates. Polychlorinated diphenyl sulfides (PCDPSs) are a group of en

Antibody production of wild-type and enzyme V279F variants of PAF-AH as a risk factor for Cardiovascular disease

NASA Astrophysics Data System (ADS)

Ramadhani, Anggia N.; Puspitarini, Sapti; Sari, Anissa N.; Widodo

2017-11-01

Coronary artery disease (CAD) has emerged as a leading cause of death in Indonesia nowadays. WHO data in 2012 revealed that 37% of the Indonesian population died from this disease. CAD occurs because of endothelial dysfunction in the arteries. Lipoprotein-associated phospholipase A2 (Lp-PLA2), also known as platelet-activating factor acetylhydrolase (PAF-AH), is a phospholipase A2 enzyme, encoded by the PLA2G7 gene. This protein is predicted to be involved in inflammatory phospholipid metabolism so it can be used as a biomarker of CAD in the early phase. Thus, the purpose of this research is to discover the difference in antibody production between wild-type and mutant V279F. The PAF-AH enzyme was isolated from mice lymphocyte cells in order to develop this enzyme as a biomarker of cardiovascular disease. PAF-AH migrates at 55kDa according to SDS-PAGE analysis. Flow cytometry analysis showed that mutant PAF-AH (V279F) is more antigenic than wild-type PAF-AH. The missense mutation of V279F PAF-AH means this enzyme cannot catabolize the acetyl group at the sn-2 position of PAF.

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

PubMed

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.

Vitamin D receptor variants in 192 patients with schizophrenia and other psychiatric diseases.

PubMed

Yan, Jin; Feng, Jinong; Craddock, Nick; Jones, Ian R; Cook, Edwin H; Goldman, David; Heston, Leonard L; Chen, Jiesheng; Burkhart, Patricia; Li, Wenyan; Shibayama, Akane; Sommer, Steve S

Intriguing parallels have been noted previously between the biology of Vitamin D and the epidemiology of schizophrenia. We have scanned the Vitamin D receptor (VDR) gene by DOVAM-S (Detection of Virtually All Mutations-SSCP), a robotically enhanced multiplexed scanning method. In total, 100 patients with schizophrenia (86 Caucasians and 14 African-Americans) were scanned. In addition, pilot experiments were performed in patients with bipolar disorder (BPD) (24), autism (24), attention deficit hyperactivity disorder (ADHD) (24), and alcoholism (20). A total of 762 kb of the VDR genomic sequence was scanned. R208N and V339I were each found in one African-American patient, while absent in 35 African-American controls without schizophrenia (2/14 versus 0/35, P=0.08). Within the power of the study (> or =1.6-fold relative risk), the common M1T variant is not associated with schizophrenia. In the 92 scanned patients with other psychiatric diseases, R173S was found in a single patient with bipolar disorder. In conclusion, we describe three novel structural variants of the Vitamin D receptor. Further study is required to clarify their role, if any, in psychiatric disease.

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

EPA Science Inventory

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

Renoprotective impact of estrogen receptor α and its splice variants in female mice with type 1 diabetes.

PubMed

Irsik, Debra L; Romero-Aleshire, Melissa Jill; Chavez, Erin M; Fallet, Rachel W; Brooks, Heddwen L; Carmines, Pamela K; Lane, Pascale H

2018-04-18

Estrogen has been implicated in the regulation of growth and immune function in the kidney, which expresses the full-length estrogen receptor α (ERα66), its ERα splice variants, and estrogen receptor β (ERβ). Thus, we hypothesized that these splice variants may inhibit glomerular enlargement that occurs early in type 1 diabetes (T1D). T1D was induced by streptozotocin (STZ) injection in 8-12 wk-old female mice lacking ERα66 (ERα66KO) or all ERα variants (αERKO), and their wild-type (WT) littermates. Basal renal ERα36 protein expression was reduced in the ERα66KO model and was downregulated by T1D in WT mice. T1D did not alter ERα46 or ERβ in WT-STZ; however, ERα46 was decreased modestly in ERα66KO. Renal hypertrophy was evident in all diabetic mice. F4/80-positive immunostaining was reduced in ERα66KO, compared with WT and αERKO mice, but was higher in STZ than in WT mice across all genotypes. Glomerular area was greater in WT and αERKO than in ERα66KO mice, with T1D-induced glomerular enlargement apparent in WT-STZ and αERKO-STZ, but not in ERα66KO-STZ. Proteinuria and hyperfiltration were evident in ERα66KO-STZ and αERKO-STZ, but not in WT-STZ mice. These data indicate that ERα splice variants may exert an inhibitory influence on glomerular enlargement and macrophage infiltration during T1D; however, effects of splice variants are masked in the presence of the full-length ERα66, suggesting that ERα66 acts in opposition to its splice variants to influence these parameters. In contrast, hyperfiltration and proteinuria in T1D are attenuated via an ERα66-dependent mechanism that is unaffected by splice variant status.

AhR transcriptional activity in serum of Inuits across Greenlandic districts

PubMed Central

Long, Manhai; Deutch, Bente; Bonefeld-Jorgensen, Eva C

2007-01-01

Background Human exposure to lipophilic persistent organic pollutants (POPs) including polychlorinated dibenzo-p-dioxins/furans (PCDDs/PCDFs), polychlorinated biphenyls (PCBs) and organochlorine pesticide is ubiquitous. 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 level of integrated AhR transcriptional activity in the lipophilic serum fraction containing the actual POP mixture among Inuits from different districts in Greenland, and to evaluate whether the AhR transactivity is correlated to the bio-accumulated POPs and/or lifestyle factors. Methods The study included 357 serum samples from the Greenlandic districts: Nuuk and Sisimiut (South West Coast), Qaanaaq (North Coast) and Tasiilaq (East Coast). The bio-accumulated serum POPs were extracted by ethanol: hexane and clean-up on Florisil columns. Effects of the serum extract on the AhR transactivity was determined using the Hepa 1.12cR mouse hepatoma cell line carrying an AhR-luciferase reporter gene, and the data was evaluated for possible association to the serum levels of 14 PCB congeners, 10 organochlorine pesticide residues and/or lifestyle factors. Results In total 85% of the Inuit samples elicited agonistic AhR transactivity in a district dependent pattern. The median level of the AhR-TCDD equivalent (AhR-TEQ) of the separate genders 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 food. Conclusion i) We observed that the proportion of dioxin like (DL) compounds in the POP mixture was the

Platelet dysfunction associated with the novel Trp29Cys thromboxane A₂ receptor variant.

PubMed

Mumford, A D; Nisar, S; Darnige, L; Jones, M L; Bachelot-Loza, C; Gandrille, S; Zinzindohoue, F; Fischer, A-M; Mundell, S J; Gaussem, P

2013-03-01

Genetic variations that affect the structure of the thromboxane A2 receptor (TP receptor) provide insights into the function of this key platelet and vascular receptor, but are very rare in unselected populations. To determine the functional consequences of the TP receptor Trp29Cys (W29C) substitution. We performed a detailed phenotypic analysis of an index case (P1) with reduced platelet aggregation and secretion responses to TP receptor pathway activators, and a heterozygous TP receptor W29C substitution. An analysis of the variant W29C TP receptor expressed in heterologous cells was performed. Total TP receptor expression in platelets from P1 was similar to that of controls, but there was reduced maximum binding and reduced affinity of binding to the TP receptor antagonist [(3) H]SQ29548. HEK293 cells transfected with W29C TP receptor cDNA showed similar total TP receptor expression to wild-type (WT) controls. However, the TP receptor agonist U46619 was less potent at inducing rises in cytosolic free Ca(2+) in HEK293 cells expressing the W29C TP receptor than in WT controls, indicating reduced receptor function. Immunofluorescence microscopy and cell surface ELISA showed intracellular retention and reduced cell surface expression of the W29C TP receptor in HEK293 cells. Consistent with the platelet phenotype, both maximum binding and the affinity of binding of [(3) H]SQ29548 to the W29C TP receptor were reduced compared to WT controls. These findings extend the phenotypic description of the very rare disorder TP receptor deficiency, and show that the W29C substitution reduces TP receptor function by reducing surface receptor expression and by disrupting ligand binding. © 2012 International Society on Thrombosis and Haemostasis.

Enhanced thyroid hormone breakdown in hepatocytes by mutual induction of the constitutive androstane receptor (CAR, NR1I3) and arylhydrocarbon receptor by benzo[a]pyrene and phenobarbital.

PubMed

Schraplau, Anne; Schewe, Bettina; Neuschäfer-Rube, Frank; Ringel, Sebastian; Neuber, Corinna; Kleuser, Burkhard; Püschel, Gerhard P

2015-02-03

Xenobiotics may interfere with the hypothalamic-pituitary-thyroid endocrine axis by inducing enzymes that inactivate thyroid hormones and thereby reduce the metabolic rate. This induction results from an activation of xeno-sensing nuclear receptors. The current study shows that benzo[a]pyrene, a frequent contaminant of processed food and activator of the arylhydrocarbon receptor (AhR) activated the promoter and induced the transcription of the nuclear receptor constitutive androstane receptor (CAR, NR1I3) in rat hepatocytes. Likewise, phenobarbital induced the AhR transcription. This mutual induction of the nuclear receptors enhanced the phenobarbital-dependent induction of the prototypic CAR target gene Cyp2b1 as well as the AhR-dependent induction of UDP-glucuronosyltransferases. In both cases, the induction by the combination of both xenobiotics was more than the sum of the induction by either substance alone. By inducing the AhR, phenobarbital enhanced the benzo[a]pyrene-dependent reduction of thyroid hormone half-life and the benzo[a]pyrene-dependent increase in the rate of thyroid hormone glucuronide formation in hepatocyte cultures. CAR ligands might thus augment the endocrine disrupting potential of AhR activators by an induction of the AhR. Copyright © 2014. Published by Elsevier Ireland Ltd.

The insulin-sensitivity sulphonylurea receptor variant is associated with thyrotoxic paralysis.

PubMed

Rolim, Ana Luiza R; Lindsey, Susan C; Kunii, Ilda S; Crispim, Felipe; Moisés, Regina Célia M S; Maciel, Rui M B; Dias-da-Silva, Magnus R

2014-10-01

Thyrotoxicosis is the most common cause of the acquired flaccid muscle paralysis in adults called thyrotoxic periodic paralysis (TPP) and is characterised by transient hypokalaemia and hypophosphataemia under high thyroid hormone levels that is frequently precipitated by carbohydrate load. The sulphonylurea receptor 1 (SUR1 (ABCC8)) is an essential regulatory subunit of the β-cell ATP-sensitive K(+) channel that controls insulin secretion after feeding. Additionally, the SUR1 Ala1369Ser variant appears to be associated with insulin sensitivity. We examined the ABCC8 gene at the single nucleotide level using PCR-restriction fragment length polymorphism (RFLP) analysis to determine its allelic variant frequency and calculated the frequency of the Ala1369Ser C-allele variant in a cohort of 36 Brazilian TPP patients in comparison with 32 controls presenting with thyrotoxicosis without paralysis (TWP). We verified that the frequency of the alanine 1369 C-allele was significantly higher in TPP patients than in TWP patients (61.1 vs 34.4%, odds ratio (OR)=3.42, P=0.039) and was significantly more common than the minor allele frequency observed in the general population from the 1000 Genomes database (61.1 vs 29.0%, OR=4.87, P<0.005). Additionally, the C-allele frequency was similar between TWP patients and the general population (34.4 vs 29%, OR=1.42, P=0.325). We have demonstrated that SUR1 alanine 1369 variant is associated with allelic susceptibility to TPP. We suggest that the hyperinsulinaemia that is observed in TPP may be linked to the ATP-sensitive K(+)/SUR1 alanine variant and, therefore, contribute to the major feedforward precipitating factors in the pathophysiology of TPP. © 2014 Society for Endocrinology.

Apoptotic cell-induced AhR activity is required for immunological tolerance and suppression of systemic lupus erythematosus in mice and humans.

PubMed

Shinde, Rahul; Hezaveh, Kebria; Halaby, Marie Jo; Kloetgen, Andreas; Chakravarthy, Ankur; da Silva Medina, Tiago; Deol, Reema; Manion, Kieran P; Baglaenko, Yuriy; Eldh, Maria; Lamorte, Sara; Wallace, Drew; Chodisetti, Sathi Babu; Ravishankar, Buvana; Liu, Haiyun; Chaudhary, Kapil; Munn, David H; Tsirigos, Aristotelis; Madaio, Michael; Gabrielsson, Susanne; Touma, Zahi; Wither, Joan; De Carvalho, Daniel D; McGaha, Tracy L

2018-06-01

The transcription factor AhR modulates immunity at multiple levels. Here we report that phagocytes exposed to apoptotic cells exhibited rapid activation of AhR, which drove production of the cytokine IL-10. Activation of AhR was dependent on interactions between apoptotic-cell DNA and the pattern-recognition receptor TLR9 that was required for the prevention of immune responses to DNA and histones in vivo. Moreover, disease progression in mouse systemic lupus erythematosus (SLE) correlated with strength of the AhR signal, and the disease course could be altered by modulation of AhR activity. Deletion of AhR in the myeloid lineage caused systemic autoimmunity in mice, and an enhanced AhR transcriptional signature correlated with disease in patients with SLE. Thus, AhR activity induced by apoptotic cell phagocytes maintains peripheral tolerance.

A truncated human peroxisome proliferator-activated receptor alpha splice variant with dominant negative activity.

PubMed

Gervois, P; Torra, I P; Chinetti, G; Grötzinger, T; Dubois, G; Fruchart, J C; Fruchart-Najib, J; Leitersdorf, E; Staels, B

1999-09-01

The peroxisome proliferator-activated receptor alpha (PPARalpha) plays a key role in lipid and lipoprotein metabolism. However, important inter- and intraspecies differences exist in the response to PPARalpha activators. This incited us to screen for PPARalpha variants with different signaling functions. In the present study, using a RT-PCR approach a variant human PPARalpha mRNA species was identified, which lacks the entire exon 6 due to alternative splicing. This deletion leads to the introduction of a premature stop codon, resulting in the formation of a truncated PPARalpha protein (PPARalphatr) lacking part of the hinge region and the entire ligand-binding domain. RNase protection analysis demonstrated that PPARalphatr mRNA is expressed in several human tissues and cells, representing between 20-50% of total PPARalpha mRNA. By contrast, PPARalphatr mRNA could not be detected in rodent tissues. Western blot analysis using PPARalpha-specific antibodies demonstrated the presence of an immunoreactive protein migrating at the size of in vitro produced PPARalphatr protein both in human hepatoma HepG2 cells and in human hepatocytes. Both in the presence or absence of 9-cis-retinoic acid receptor, PPARalphatr did not bind to DNA in gel shift assays. Immunocytochemical analysis of transfected CV-1 cells indicated that, whereas transfected PPARalphawt was mainly nuclear localized, the majority of PPARalphatr resided in the cytoplasm, with presence in the nucleus depending on cell culture conditions. Whereas a chimeric PPARalphatr protein containing a nuclear localization signal cloned at its N-terminal localized into the nucleus and exhibited strong negative activity on PPARalphawt transactivation function, PPARalphatr interfered with PPARalphatr transactivation function only under culture conditions inducing its nuclear localization. Cotransfection of the coactivator CREB-binding protein relieved the transcriptional repression of PPARalphawt by PPARalphatr, suggesting

Relationships between serum-induced AhR bioactivity or mitochondrial inhibition and circulating polychlorinated biphenyls (PCBs).

PubMed

Park, Wook Ha; Kang, Sora; Lee, Hong Kyu; Salihovic, Samira; Bavel, Bert van; Lind, P Monica; Pak, Youngmi Kim; Lind, Lars

2017-08-24

Metabolic syndrome and mitochondrial dysfunction have been linked to elevated serum levels of persistent organic pollutants (POPs). However, it is not clear which specific POPs contribute to aryl hydrocarbon receptor (AhR)-dependent bioactivity or inhibit mitochondrial function in human subjects. Here, we measured the cumulative bioactivity of AhR ligand mixture (AhR bioactivity) and the effects on mitochondrial function (ATP concentration) in recombinant Hepa1c1c7 cells incubated with raw serum samples obtained from 911 elderly subjects in the Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS) cohort. Plasma concentrations of 30 POPs and plastic chemicals have previously been determined in the same PIVUS subjects. Linear regression analysis demonstrated that total toxic equivalence (TEQ) values and polychlorinated biphenyls (PCBs) were significantly correlated with AhR bioactivity (positively) and ATP concentration (negatively). Serum AhR bioactivities were positively associated with some PCBs, regardless of their dioxin-like properties, but only dioxin-like PCBs stimulated AhR bioactivity. By contrast, PCBs mediated a reduction in ATP content independently of their dioxin-like properties. This study suggests that AhR bioactivity and ATP concentrations in serum-treated cells may be valuable surrogate biomarkers of POP exposure and could be useful for the estimation of the effects of POPs on human health.

Excessive activation of AhR signaling disrupts neuronal migration in the hippocampal CA1 region in the developing mouse.

PubMed

Kimura, Eiki; Kubo, Ken-Ichiro; Endo, Toshihiro; Nakajima, Kazunori; Kakeyama, Masaki; Tohyama, Chiharu

2017-01-01

The aryl hydrocarbon receptor (AhR) avidly binds dioxin, a ubiquitous environmental contaminant. Disruption of downstream AhR signaling has been reported to alter neuronal development, and rodent offspring exposed to dioxin during gestation and lactation showed abnormalities in learning and memory, emotion, and social behavior. However, the mechanism behind the disrupted AhR signaling and developmental neurotoxicity induced by xenobiotic ligands remains elusive. Therefore, we studied how excessive AhR activation affects neuronal migration in the hippocampal CA1 region of the developing mouse brain. We transfected constitutively active (CA)-AhR, AhR, or control vector plasmids into neurons via in utero electroporation on gestational day 14 and analyzed neuronal positioning in the hippocampal CA1 region of offspring on postnatal day 14. CA-AhR transfection affected neuronal positioning, whereas no change was observed in AhR-transfected or control hippocampus. These results suggest that constitutively activated AhR signaling disrupts neuronal migration during hippocampal development. Further studies are needed to investigate whether such developmental disruption in the hippocampus leads to the abnormal cognition and behavior of rodent offspring upon maternal exposure to AhR xenobiotic ligands.

Hexachlorobenzene induces cell proliferation, and aryl hydrocarbon receptor expression (AhR) in rat liver preneoplastic foci, and in the human hepatoma cell line HepG2. AhR is a mediator of ERK1/2 signaling, and cell cycle regulation in HCB-treated HepG2 cells.

PubMed

de Tomaso Portaz, Ana Clara; Caimi, Giselle Romero; Sánchez, Marcela; Chiappini, Florencia; Randi, Andrea S; Kleiman de Pisarev, Diana L; Alvarez, Laura

2015-10-02

Hexachlorobenzene (HCB) is a widespread environmental pollutant, and a liver tumor promoter in rodents. Depending on the particular cell lines studied, exposure to these compounds may lead to cell proliferation, terminal differentiation, or apoptosis. The aryl hydrocarbon receptor (AhR) is a ligand-activated transcription factor that is involved in drug and xenobiotic metabolism. AhR can also modulate a variety of cellular and physiological processes that can affect cell proliferation and cell fate determination. The mechanisms by which AhR ligands, both exogenous and endogenous, affect these processes involve multiple interactions between AhR and other signaling pathways. In the present study, we examined the effect of HCB on cell proliferation and AhR expression, using an initiation-promotion hepatocarcinogenesis protocol in rat liver and in the human-derived hepatoma cell line, HepG2. Female Wistar rats were initiated with a single dose of 100 mg/kg of diethylnitrosamine (DEN) at the start of the experiment. Two weeks later, daily dosing of 100 mg/kg HCB was maintained for 10 weeks. Partial hepatectomy was performed 3 weeks after initiation. The number and area of glutathione S-transferase-P (GST-P)-positive foci, in the rat liver were used as biomarkers of liver precancerous lesions. Immunohistochemical staining showed an increase in proliferating cell nuclear antigen (PCNA)-positive cells, along with enhanced AhR protein expression in hepatocytes within GST-P-positive foci of (DEN HCB) group, when compared to DEN. In a similar manner, Western blot analysis demonstrated that HCB induced PCNA and AhR protein expression in HepG2 cells. Flow cytometry assay indicated that the cells were accumulated at S and G2/M phases of the cell cycle. HCB increased cyclin D1 protein levels and ERK1/2 phosphorylation in a dose-dependent manner. Treatment of cells with a selective MEK1 inhibitor, prevented HCB-stimulatory effect on PCNA and cyclinD1, indicating that these effects

Religion priming differentially increases prosocial behavior among variants of the dopamine D4 receptor (DRD4) gene

PubMed Central

Kim, Heejung S.; Mojaverian, Taraneh; Kelley, Lauren D. S.; Park, In Young; Janušonis, Skirmantas

2013-01-01

Building on gene–environment interaction (G × E) research, this study examines how the dopamine D4 receptor (DRD4) gene interacts with a situational prime of religion to influence prosocial behavior. Some DRD4 variants tend to be more susceptible to environmental influences, whereas other variants are less susceptible. Thus, certain life environments may be associated with acts of prosociality for some DRD4 variants but not others. Given that religion can act as an environmental influence that increases prosocial behavior, environmental input in the form of religion priming may have G × E effects. Results showed that participants with DRD4 susceptibility variants were more prosocial when implicitly primed with religion than not primed with religion, whereas participants without DRD4 susceptibility variants were not impacted by priming. This research has implications for understanding why different people may behave prosocially for different reasons and also integrates G × E research with experimental psychology. PMID:22198971

Religion priming differentially increases prosocial behavior among variants of the dopamine D4 receptor (DRD4) gene.

PubMed

Sasaki, Joni Y; Kim, Heejung S; Mojaverian, Taraneh; Kelley, Lauren D S; Park, In Young; Janusonis, Skirmantas

2013-02-01

Building on gene-environment interaction (G × E) research, this study examines how the dopamine D4 receptor (DRD4) gene interacts with a situational prime of religion to influence prosocial behavior. Some DRD4 variants tend to be more susceptible to environmental influences, whereas other variants are less susceptible. Thus, certain life environments may be associated with acts of prosociality for some DRD4 variants but not others. Given that religion can act as an environmental influence that increases prosocial behavior, environmental input in the form of religion priming may have G × E effects. Results showed that participants with DRD4 susceptibility variants were more prosocial when implicitly primed with religion than not primed with religion, whereas participants without DRD4 susceptibility variants were not impacted by priming. This research has implications for understanding why different people may behave prosocially for different reasons and also integrates G × E research with experimental psychology.

Rare variant in scavenger receptor BI raises HDL cholesterol and increases risk of coronary heart disease.

PubMed

Zanoni, Paolo; Khetarpal, Sumeet A; Larach, Daniel B; Hancock-Cerutti, William F; Millar, John S; Cuchel, Marina; DerOhannessian, Stephanie; Kontush, Anatol; Surendran, Praveen; Saleheen, Danish; Trompet, Stella; Jukema, J Wouter; De Craen, Anton; Deloukas, Panos; Sattar, Naveed; Ford, Ian; Packard, Chris; Majumder, Abdullah al Shafi; Alam, Dewan S; Di Angelantonio, Emanuele; Abecasis, Goncalo; Chowdhury, Rajiv; Erdmann, Jeanette; Nordestgaard, Børge G; Nielsen, Sune F; Tybjærg-Hansen, Anne; Schmidt, Ruth Frikke; Kuulasmaa, Kari; Liu, Dajiang J; Perola, Markus; Blankenberg, Stefan; Salomaa, Veikko; Männistö, Satu; Amouyel, Philippe; Arveiler, Dominique; Ferrieres, Jean; Müller-Nurasyid, Martina; Ferrario, Marco; Kee, Frank; Willer, Cristen J; Samani, Nilesh; Schunkert, Heribert; Butterworth, Adam S; Howson, Joanna M M; Peloso, Gina M; Stitziel, Nathan O; Danesh, John; Kathiresan, Sekar; Rader, Daniel J

2016-03-11

Scavenger receptor BI (SR-BI) is the major receptor for high-density lipoprotein (HDL) cholesterol (HDL-C). In humans, high amounts of HDL-C in plasma are associated with a lower risk of coronary heart disease (CHD). Mice that have depleted Scarb1 (SR-BI knockout mice) have markedly elevated HDL-C levels but, paradoxically, increased atherosclerosis. The impact of SR-BI on HDL metabolism and CHD risk in humans remains unclear. Through targeted sequencing of coding regions of lipid-modifying genes in 328 individuals with extremely high plasma HDL-C levels, we identified a homozygote for a loss-of-function variant, in which leucine replaces proline 376 (P376L), in SCARB1, the gene encoding SR-BI. The P376L variant impairs posttranslational processing of SR-BI and abrogates selective HDL cholesterol uptake in transfected cells, in hepatocyte-like cells derived from induced pluripotent stem cells from the homozygous subject, and in mice. Large population-based studies revealed that subjects who are heterozygous carriers of the P376L variant have significantly increased levels of plasma HDL-C. P376L carriers have a profound HDL-related phenotype and an increased risk of CHD (odds ratio = 1.79, which is statistically significant). Copyright © 2016, American Association for the Advancement of Science.

AH-64E Apache New Build (AH-64E New Build)

DTIC Science & Technology

2015-12-01

night, obscured battlefield and adverse weather conditions. The AH-64E enables the Joint Air/Ground Maneuver Team to dominate the battle space by...capability over the AH-64A and AH-64D. It is capable of being employed day or night in adverse weather and obscurants , and can effectively engage and...80 Survivability Safe operation (minutes) 30 30 30 Met Objective 30 Survive Band IV MANPADS IR Missile Engagement IAW JROCM 086-10 IAW JROCM 086-10 IAW

5-HT1a activation in PO/AH area induces therapeutic hypothermia in a rat model of intracerebral hemorrhage

PubMed Central

Liang, Tan; Chen, Qianwei; Li, Qiang; Li, Rongwei; Tang, Jun; Hu, Rong; Zhong, Jun; Ge, Hongfei; Liu, Xin; Hua, Feng

2017-01-01

Therapeutic hypothermia is widely applied as a neuroprotective measure on intracerebral hemorrhage (ICH). However, several clinical trials regarding physical hypothermia encountered successive failures because of its side-effects in recent years. Increasing evidences indicate that chemical hypothermia that targets hypothalamic 5-HT1a has potential to down-regulate temperature set point without major side-effects. Thus, this study examined the efficacy and safety of 5-HT1a stimulation in PO/AH area for treating ICH rats. First, the relationship between head temperature and clinical outcomes was investigated in ICH patients and rat models, respectively. Second, the expression and distribution of 5-HT1a receptor in PO/AH area was explored by using whole-cell patch and confocal microscopy. In the meantime, the whole-cell patch was subsequently applied to investigate the involvement of 5-HT1a receptors in temperature regulation. Third, we compared the efficacy between traditional PH and 5-HT1a activation-induced hypothermia for ICH rats. Our data showed that more severe perihematomal edema (PHE) and neurological deficits was associated with increased head temperature following ICH. 5-HT1a receptor was located on warm-sensitive neurons in PO/AH area and 8-OH-DPAT (5-HT1a receptor agonist) significantly enhanced the firing rate of warm-sensitive neurons. 8-OH-DPAT treatment provided a steadier reduction in brain temperature without a withdrawal rebound, which also exhibited a superior neuroprotective effect on ICH-induced neurological dysfunction, white matter injury and BBB damage compared with physical hypothermia. These findings suggest that chemical hypothermia targeting 5-HT1a receptor in PO/AH area could act as a novel therapeutic manner against ICH, which may provide a breakthrough for therapeutic hypothermia. PMID:29088731

Re-Evaluation of the PBAN Receptor Molecule: Characterization of PBANR Variants Expressed in the Pheromone Glands of Moths

PubMed Central

Lee, Jae Min; Hull, J. Joe; Kawai, Takeshi; Goto, Chie; Kurihara, Masaaki; Tanokura, Masaru; Nagata, Koji; Nagasawa, Hiromichi; Matsumoto, Shogo

2011-01-01

Sex pheromone production in most moths is initiated following pheromone biosynthesis activating neuropeptide receptor (PBANR) activation. PBANR was initially cloned from pheromone glands (PGs) of Helicoverpa zea and Bombyx mori. The B. mori PBANR is characterized by a relatively long C-terminus that is essential for ligand-induced internalization, whereas the H. zea PBANR has a shorter C-terminus that lacks features present in the B. mori PBANR critical for internalization. Multiple PBANRs have been reported to be concurrently expressed in the larval CNS of Heliothis virescens. In the current study, we sought to examine the prevalence of multiple PBANRs in the PGs of three moths and to ascertain their potential functional relevance. Multiple PBANR variants (As, A, B, and C) were cloned from the PGs of all species examined with PBANR-C the most highly expressed. Alternative splicing of the C-terminal coding sequence of the PBAN gene gives rise to the variants, which are distinguishable only by the length and composition of their respective C-terminal tails. Transient expression of fluorescent PBANR chimeras in insect cells revealed that PBANR-B and PBANR-C localized exclusively to the cell surface while PBANR-As and PBANR-A exhibited varying degrees of cytosolic localization. Similarly, only the PBANR-B and PBANR-C variants underwent ligand-induced internalization. Taken together, our results suggest that PBANR-C is the principal receptor molecule involved in PBAN signaling regardless of moth species. The high GC content of the C-terminal coding sequence in the B and C variants, which makes amplification using conventional polymerases difficult, likely accounts for previous “preferential” amplification of PBANR-A like receptors from other species. PMID:22654850

Characterization of Transient Receptor Potential Vanilloid-1 (TRPV1) Variant Activation by Coal Fly Ash Particles and Associations with Altered Transient Receptor Potential Ankyrin-1 (TRPA1) Expression and Asthma*

PubMed Central

Stockmann, Chris; Romero, Erin G.; Lu, Zhenyu; Shapiro, Darien; Stone, Bryan L.; Fassl, Bernhard; Nkoy, Flory; Uchida, Derek A.; Ward, Robert M.; Veranth, John M.; Reilly, Christopher A.

2016-01-01

Transient receptor potential (TRP) channels are activated by environmental particulate materials. We hypothesized that polymorphic variants of transient receptor potential vanilloid-1 (TRPV1) would be uniquely responsive to insoluble coal fly ash compared with the prototypical soluble agonist capsaicin. Furthermore, these changes would manifest as differences in lung cell responses to these agonists and perhaps correlate with changes in asthma symptom control. The TRPV1-I315M and -T469I variants were more responsive to capsaicin and coal fly ash. The I585V variant was less responsive to coal fly ash particles due to reduced translation of protein and an apparent role for Ile-585 in activation by particles. In HEK-293 cells, I585V had an inhibitory effect on wild-type TRPV1 expression, activation, and internalization/agonist-induced desensitization. In normal human bronchial epithelial cells, IL-8 secretion in response to coal fly ash treatment was reduced for cells heterozygous for TRPV1-I585V. Finally, both the I315M and I585V variants were associated with worse asthma symptom control with the effects of I315M manifesting in mild asthma and those of the I585V variant manifesting in severe, steroid-insensitive individuals. This effect may be due in part to increased transient receptor potential ankyrin-1 (TRPA1) expression by lung epithelial cells expressing the TRPV1-I585V variant. These findings suggest that specific molecular interactions control TRPV1 activation by particles, differential activation, and desensitization of TRPV1 by particles and/or other agonists, and cellular changes in the expression of TRPA1 as a result of I585V expression could contribute to variations in asthma symptom control. PMID:27758864

Characterization of Transient Receptor Potential Vanilloid-1 (TRPV1) Variant Activation by Coal Fly Ash Particles and Associations with Altered Transient Receptor Potential Ankyrin-1 (TRPA1) Expression and Asthma.

PubMed

Deering-Rice, Cassandra E; Stockmann, Chris; Romero, Erin G; Lu, Zhenyu; Shapiro, Darien; Stone, Bryan L; Fassl, Bernhard; Nkoy, Flory; Uchida, Derek A; Ward, Robert M; Veranth, John M; Reilly, Christopher A

2016-11-25

Transient receptor potential (TRP) channels are activated by environmental particulate materials. We hypothesized that polymorphic variants of transient receptor potential vanilloid-1 (TRPV1) would be uniquely responsive to insoluble coal fly ash compared with the prototypical soluble agonist capsaicin. Furthermore, these changes would manifest as differences in lung cell responses to these agonists and perhaps correlate with changes in asthma symptom control. The TRPV1-I315M and -T469I variants were more responsive to capsaicin and coal fly ash. The I585V variant was less responsive to coal fly ash particles due to reduced translation of protein and an apparent role for Ile-585 in activation by particles. In HEK-293 cells, I585V had an inhibitory effect on wild-type TRPV1 expression, activation, and internalization/agonist-induced desensitization. In normal human bronchial epithelial cells, IL-8 secretion in response to coal fly ash treatment was reduced for cells heterozygous for TRPV1-I585V. Finally, both the I315M and I585V variants were associated with worse asthma symptom control with the effects of I315M manifesting in mild asthma and those of the I585V variant manifesting in severe, steroid-insensitive individuals. This effect may be due in part to increased transient receptor potential ankyrin-1 (TRPA1) expression by lung epithelial cells expressing the TRPV1-I585V variant. These findings suggest that specific molecular interactions control TRPV1 activation by particles, differential activation, and desensitization of TRPV1 by particles and/or other agonists, and cellular changes in the expression of TRPA1 as a result of I585V expression could contribute to variations in asthma symptom control. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

A Commonly Carried Genetic Variant in the Delta Opioid Receptor Gene, OPRD1, is Associated with Smaller Regional Brain Volumes: Replication in Elderly and Young Populations

PubMed Central

Roussotte, Florence F.; Jahanshad, Neda; Hibar, Derrek P.; Sowell, Elizabeth R.; Kohannim, Omid; Barysheva, Marina; Hansell, Narelle K.; McMahon, Katie L.; de Zubicaray, Greig I.; Montgomery, Grant W.; Martin, Nicholas G.; Wright, Margaret J.; Toga, Arthur W.; Jack, Clifford R.; Weiner, Michael W.; Thompson, Paul M.

2014-01-01

Delta opioid receptors are implicated in a variety of psychiatric and neurological disorders. These receptors play a key role in the reinforcing properties of drugs of abuse, and polymorphisms in OPRD1 (the gene encoding delta opioid receptors) are associated with drug addiction. Delta opioid receptors are also involved in protecting neurons against hypoxic and ischemic stress. Here, we first examined a large sample of 738 elderly participants with neuroimaging and genetic data from the Alzheimer’s Disease Neuroimaging Initiative. We hypothesized that common variants in OPRD1 would be associated with differences in brain structure, particularly in regions relevant to addictive and neurodegenerative disorders. One very common variant (rs678849) predicted differences in regional brain volumes. We replicated the association of this single-nucleotide polymorphism with regional tissue volumes in a large sample of young participants in the Queensland Twin Imaging study. Although the same allele was associated with reduced volumes in both cohorts, the brain regions affected differed between the two samples. In healthy elderly, exploratory analyses suggested that the genotype associated with reduced brain volumes in both cohorts may also predict cerebrospinal fluid levels of neurodegenerative biomarkers, but this requires confirmation. If opiate receptor genetic variants are related to individual differences in brain structure, genotyping of these variants may be helpful when designing clinical trials targeting delta opioid receptors to treat neurological disorders. PMID:23427138

Rechargeable Li/Li(x)CoO(2) 100 Ah/600 Ah Battery With Integral Smart Charge Control

DTIC Science & Technology

1999-03-01

Rechargeable Li/LixCo02100 Ah/600 Ah Battery with Integral Smart Charge Control By Charles J. Kelly ^ (Alliant Techsystems, Inc., Alliant Power...Rechargeable Li/LixCo02100 Ah/600 Ah Battery with Integral Smart Charge Control By Charles J. Kelly (Alliant Techsystems, Inc., Alliant Power Sources...AND SUBTITLE Rechargeable Li/LixCo02100 Ah/600 Ah Battery with Integral Smart Charge Control 6 AUTHOR(S) C. J. Kelly (Alliant Power Sources Co

Molecular identification and functional expression of mu 3, a novel alternatively spliced variant of the human mu opiate receptor gene.

PubMed

Cadet, Patrick; Mantione, Kirk J; Stefano, George B

2003-05-15

Studies from our laboratory have revealed a novel mu opiate receptor, mu 3, which is expressed in both vascular tissues and leukocytes. The mu 3 receptor is selective for opiate alkaloids and is insensitive to opioid peptides. We now identify the mu 3 receptor at the molecular level using a 441-bp conserved region of the mu 1 receptor. Sequence analysis of the isolated cDNA suggests that it is a novel, alternatively spliced variant of the mu opiate receptor gene. To determine whether protein expressed from this cDNA exhibits the biochemical characteristics expected of the mu 3 receptor, the cDNA clone was expressed in a heterologous system. At the functional level, COS-1 cells transfected with the mu 3 receptor cDNA exhibited dose-dependent release of NO following treatment with morphine, but not opioid peptides (i.e., Met-enkephalin). Naloxone was able to block the effect of morphine on COS-1 transfected cells. Nontransfected COS-1 cells did not produce NO in the presence of morphine or the opioid peptides at similar concentrations. Receptor binding analysis with [(3)H]dihydromorphine further supports the opiate alkaloid selectivity and opioid peptide insensitivity of this receptor. These data suggest that this new mu opiate receptor cDNA encodes the mu 3 opiate receptor, since it exhibits biochemical characteristics known to be unique to this receptor (opiate alkaloid selective and opioid peptide insensitive). Furthermore, using Northern blot, RT-PCR, and sequence analysis, we have demonstrated the expression of this new mu variant in human vascular tissue, mononuclear cells, polymorphonuclear cells, and human neuroblastoma cells.

AhR activation increases IL-2 production by alloreactive CD4+ T cells initiating the differentiation of mucosal-homing Tim3+ Lag3+ Tr1 cells.

PubMed

Ehrlich, Allison K; Pennington, Jamie M; Tilton, Susan; Wang, Xisheng; Marshall, Nikki B; Rohlman, Diana; Funatake, Castle; Punj, Sumit; O'Donnell, Edmond; Yu, Zhen; Kolluri, Siva K; Kerkvliet, Nancy I

2017-11-01

Activation of the aryl hydrocarbon receptor (AhR) by immunosuppressive ligands promotes the development of regulatory T (Treg) cells. Although AhR-induced Foxp3 + Treg cells have been well studied, much less is known about the development and fate of AhR-induced Type 1 Treg (AhR-Tr1) cells. In the current study, we identified the unique transcriptional and functional changes in murine CD4 + T cells that accompany the differentiation of AhR-Tr1 cells during the CD4 + T-cell-dependent phase of an allospecific cytotoxic T lymphocyte (allo-CTL) response. AhR activation increased the expression of genes involved in T-cell activation, immune regulation and chemotaxis, as well as a global downregulation of genes involved in cell cycling.  Increased IL-2 production was responsible for the early AhR-Tr1 activation phenotype previously characterized as CD25 + CTLA4 + GITR + on day 2. The AhR-Tr1 phenotype was further defined by the coexpression of the immunoregulatory receptors Lag3 and Tim3 and non-overlapping expression of CCR4 and CCR9. Consistent with the increased expression of CCR9, real-time imaging showed enhanced migration of AhR-Tr1 cells to the lamina propria of the small intestine and colon. The discovery of mucosal imprinting of AhR-Tr1 cells provides an additional mechanism by which therapeutic AhR ligands can control immunopathology. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Receptor homodimerization plays a critical role in a novel dominant negative P2RY12 variant identified in a family with severe bleeding.

PubMed

Mundell, S J; Rabbolini, D; Gabrielli, S; Chen, Q; Aungraheeta, R; Hutchinson, J L; Kilo, T; Mackay, J; Ward, C M; Stevenson, W; Morel-Kopp, M-C

2018-01-01

Essentials Three dominant variants for the autosomal recessive bleeding disorder type-8 have been described. To date, there has been no phenotype/genotype correlation explaining their dominant transmission. Proline plays an important role in P2Y12R ligand binding and signaling defects. P2Y12R homodimer formation is critical for the receptor function and signaling. Background Although inherited platelet disorders are still underdiagnosed worldwide, advances in molecular techniques are improving disease diagnosis and patient management. Objective To identify and characterize the mechanism underlying the bleeding phenotype in a Caucasian family with an autosomal dominant P2RY12 variant. Methods Full blood counts, platelet aggregometry, flow cytometry and western blotting were performed before next-generation sequencing (NGS). Detailed molecular analysis of the identified variant of the P2Y12 receptor (P2Y12R) was subsequently performed in mammalian cells overexpressing receptor constructs. Results All three referred individuals had markedly impaired ADP-induced platelet aggregation with primary wave only, despite normal total and surface P2Y12R expression. By NGS, a single P2RY12:c.G794C substitution (p.R265P) was identified in all affected individuals, and this was confirmed by Sanger sequencing. Mammalian cell experiments with the R265P-P2Y12R variant showed normal receptor surface expression versus wild-type (WT) P2Y12R. Agonist-stimulated R265P-P2Y12R function (both signaling and surface receptor loss) was reduced versus WT P2Y12R. Critically, R265P-P2Y12R acted in a dominant negative manner, with agonist-stimulated WT P2Y12R activity being reduced by variant coexpression, suggesting dramatic loss of WT homodimers. Importantly, platelet P2RY12 cDNA cloning and sequencing in two affected individuals also revealed three-fold mutant mRNA overexpression, decreasing even further the likelihood of WT homodimer formation. R265 located within extracellular loop 3 (EL3) is

Stimulation of in vivo hepatic uptake and in vitro hepatic binding of (/sup 125/I)2-lodo-3,7,8-trichlorodibenzo-p-dioxin by the administration of agonist for the Ah receptor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Poland, A.; Teitelbaum, P.; Glover, E.

1989-07-01

(125I)2-lodo-3,7,8-trichlorodibenzo-p-dioxin ((125I)Cl3DpD), a radiolabeled, isosteric, analogue of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), was synthesized and used to study in vivo tissue localization and in vivo tissue binding. Twenty-four hours after the administration of a tracer dose (1 X 10(-10) mol/kg) of (125I) Cl3DpD to C57BL/6J mice, the hepatic concentration of radioactivity was 1-2% of the administered dose, whereas in mice pretreated with TCDD (1 X 10(-7) mol/kg), the hepatic accumulation of radiolabel was 25-30% of that administered. Liver homogenate from TCDD-treated mice bound 4 to 10 times more (125I)Cl3DpD than homogenate from control mice. The enhancement of in vivo uptake and in vitromore » tissue binding of (125I)Cl3DpD by TCDD administration was confined to liver and was not observed in other tissues examined, kidney, lung, spleen, small intestines, and muscle. The administration of TCDD to C57BL/6J mice produces dose-related stimulation of in vivo hepatic uptake of (125I)Cl3DpD, binding of radioligand to liver homogenate, and hepatic aryl hydrocarbon hydroxylase activity, with the dose for half-maximal stimulation, ED50, varying from 1.5 to 4.0 x 10(-9) mol/kg. In congenic C57BL/6J (Ahd/Ahd) mice, which express the lower affinity Ah receptor, the ED50 values for all three responses were shifted to approximately 10-fold higher doses. 3,3',4,4',5,5'-Hexabromobiphenyl, a weak agonist for the Ah receptor produced a dose-related stimulation of these three responses in C57BL/6J mice (ED50 values of approximately 5 X 10(-7) mol/kg), but was without effect in C57BL/6J (Ahd/Ahd) mice. Stimulation of vivo hepatic uptake and in vitro liver homogenate binding of (125I)Cl3DpD was produced by administration of Ah agonists, such as 2,3,7,8-tetrachlorodibenzofuran and beta-naphthoflavone, but inactive congeners and other compounds that do not act via the Ah receptor.« less

Tapinarof Is a Natural AhR Agonist that Resolves Skin Inflammation in Mice and Humans.

PubMed

Smith, Susan H; Jayawickreme, Channa; Rickard, David J; Nicodeme, Edwige; Bui, Thi; Simmons, Cathy; Coquery, Christine M; Neil, Jessica; Pryor, William M; Mayhew, David; Rajpal, Deepak K; Creech, Katrina; Furst, Sylvia; Lee, James; Wu, Dalei; Rastinejad, Fraydoon; Willson, Timothy M; Viviani, Fabrice; Morris, David C; Moore, John T; Cote-Sierra, Javier

2017-10-01

Tapinarof (GSK2894512) is a naturally derived topical treatment with demonstrated efficacy for patients with psoriasis and atopic dermatitis, although the biologic target and mechanism of action had been unknown. We demonstrate that the anti-inflammatory properties of tapinarof are mediated through activation of the aryl hydrocarbon receptor (AhR). We show that tapinarof binds and activates AhR in multiple cell types, including cells of the target tissue-human skin. In addition, tapinarof moderates proinflammatory cytokine expression in stimulated peripheral blood CD4+ T cells and ex vivo human skin, and impacts barrier gene expression in primary human keratinocytes; both of these processes are likely to be downstream of AhR activation based on current evidence. That the anti-inflammatory properties of tapinarof derive from AhR agonism is conclusively demonstrated using the mouse model of imiquimod-induced psoriasiform skin lesions. Topical treatment of AhR-sufficient mice with tapinarof leads to compound-driven reductions in erythema, epidermal thickening, and tissue cytokine levels. In contrast, tapinarof has no impact on imiquimod-induced skin inflammation in AhR-deficient mice. In summary, these studies identify tapinarof as an AhR agonist and confirm that its efficacy is dependent on AhR. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Ethanol modulates the VR-1 variant amiloride-insensitive salt taste receptor. I. Effect on TRC volume and Na+ flux.

PubMed

Lyall, Vijay; Heck, Gerard L; Phan, Tam-Hao T; Mummalaneni, Shobha; Malik, Shahbaz A; Vinnikova, Anna K; DeSimone, John A

2005-06-01

The effect of ethanol on the amiloride- and benzamil (Bz)-insensitive salt taste receptor was investigated by the measurement of intracellular Na(+) activity ([Na(+)](i)) in polarized rat fungiform taste receptor cells (TRCs) using fluorescence imaging and by chorda tympani (CT) taste nerve recordings. CT responses were monitored during lingual stimulation with ethanol solutions containing NaCl or KCl. CT responses were recorded in the presence of Bz (a specific blocker of the epithelial Na(+) channel [ENaC]) or the vanilloid receptor-1 (VR-1) antagonists capsazepine or SB-366791, which also block the Bz-insensitive salt taste receptor, a VR-1 variant. CT responses were recorded at 23 degrees C or 42 degrees C (a temperature at which the VR-1 variant salt taste receptor activity is maximally enhanced). In the absence of permeable cations, ethanol induced a transient decrease in TRC volume, and stimulating the tongue with ethanol solutions without added salt elicited only transient phasic CT responses that were insensitive to elevated temperature or SB-366791. Preshrinking TRCs in vivo with hypertonic mannitol (0.5 M) attenuated the magnitude of the phasic CT response, indicating that in the absence of mineral salts, transient phasic CT responses are related to the ethanol-induced osmotic shrinkage of TRCs. In the presence of mineral salts, ethanol increased the Bz-insensitive apical cation flux in TRCs without a change in cell volume, increased transepithelial electrical resistance across the tongue, and elicited CT responses that were similar to salt responses, consisting of both a transient phasic component and a sustained tonic component. Ethanol increased the Bz-insensitive NaCl CT response. This effect was further enhanced by elevating the temperature from 23 degrees C to 42 degrees C, and was blocked by SB-366791. We conclude that in the presence of mineral salts, ethanol modulates the Bz-insensitive VR-1 variant salt taste receptor.

Intracellular Localization and Trafficking of Serine Proteinase AhSub and Cysteine Proteinase AhCP of Acanthamoeba healyi

PubMed Central

Moon, E.-K.; Lee, S.-T.; Chung, D.-I.; Kong, H.-H.

2006-01-01

Proteinases have been proposed to play important roles in pathogenesis and various biologic actions in Acanthamoeba. Although genetic characteristics of several proteases of Acanthamoeba have been reported, the intracellular localization and trafficking of these enzymes has yet to be studied. In the present study, we analyzed the intracellular localization and trafficking of two proteinases, AhSub and AhCP, of Acanthamoeba healyi by transient transfection. Full-length AhSub-enhanced green fluorescent protein (EGFP) fusion protein was found in intracellular vesicle-like structures of transfected amoebae. Time-lapse photographs confirmed the secretion of the fluorescent material of the vesicle toward the extracellular space. The mutated AhSub, of which the pre or prepro region was deleted, was found to localize diffusely throughout the cytoplasm of the amoeba rather than concentrated in the secretory vesicle. Transfection of the construct containing the pre region only showed the same localization and trafficking of the full-length AhSub. A cysteine proteinase AhCP-EGFP fusion protein showed similar localization in the vesicle-like structure in the amoeba. However, using Lyso Tracker analysis, these vesicular structures of AhCP were confirmed to be lysosomes rather than secretory vesicles. The AhCP construct with a deletion of the prepro region showed a dispersed distribution of fluorescence in the cytoplasm of the cells. These results indicated that AhSub and AhCP would play different roles in Acanthameoba biology and that the pre region of AhSub and pro region of AhCP are important for proper intracellular localization and trafficking of each proteinase. PMID:16400174

Functional and phenotypic effects of AhR activation in inflammatory dendritic cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bankoti, Jaishree; Center for Environmental Health Sciences, University of Montana, Missoula, MT; Rase, Ben

2010-07-15

Aryl hydrocarbon receptor (AhR) activation by 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) induces immune suppression. Dendritic cells (DCs) are key antigen presenting cells governing T cell activation and differentiation. However, the consequences of AhR activation in DCs are not fully defined. We hypothesized that AhR activation alters DC differentiation and generates dysfunctional DCs. To test this hypothesis, inflammatory bone marrow-derived DCs (BMDCs) from C57Bl/6 mice were generated in the presence of vehicle or TCDD. TCDD decreased CD11c expression but increased MHC class II, CD86 and CD25 expression on the BMDCs. The effects of TCDD were strictly AhR-dependent but not exclusively DRE-mediated. Similar effects weremore » observed with two natural AhR ligands, 6-formylindolo[3,2-b]carbazole (FICZ) and 2-(1H-Indol-3-ylcarbonyl)-4-thiazolecarboxylic acid (ITE). TCDD increased LPS- and CpG-induced IL-6 and TNF-{alpha} production by BMDCs but decreased their NO production. TCDD decreased CpG-induced IL-12p70 production by BMDCs but did not affect their secretion of IL-10. TCDD downregulated LPS- and CpG-induced NF-kB p65 levels and induced a trend towards upregulation of RelB levels in the BMDCs. AhR activation by TCDD modulated BMDC uptake of both soluble and particulate antigens. Induction of indoleamine-2,3-dioxygenase (IDO) and TGF-{beta}3 has been implicated in the generation of regulatory T cells following AhR activation. TCDD increased IDO1, IDO2 and TGF-{beta}3 mRNA levels in BMDCs as compared to vehicle. Despite the induction of regulatory mediators, TCDD-treated BMDCs failed to suppress antigen-specific T cell activation. Thus, AhR activation can directly alter the differentiation and innate functions of inflammatory DCs without affecting their ability to successfully interact with T cells.« less

AH-64E Apache Remanufacture (AH-64E Remanufacture)

DTIC Science & Technology

2015-12-01

Support Operations to Major Combat Operations, when required, in day, night, obscured battlefield and adverse weather conditions. The AH-64E enables the...adverse weather and obscurants , and can effectively engage and destroy advanced threat weapon systems on the air-land battlefield. Tactically, the AH-64E...Objective 30 Survive Band IV MANPADS IR Missile Engagement IAW JROCM 086-10 IAW JROCM 086-10 IAW JROCM 086-10 Met Objective IAW JROCM 086-10 Force Protection

T-cell expression of AhR inhibits the maintenance of pTreg cells in the gastrointestinal tract in acute GVHD.

PubMed

Dant, Trisha A; Lin, Kaifeng L; Bruce, Danny W; Montgomery, Stephanie A; Kolupaev, Oleg V; Bommiasamy, Hemamalini; Bixby, Lisa M; Woosley, John T; McKinnon, Karen P; Gonzalez, Frank J; Blazar, Bruce R; Vincent, Benjamin G; Coghill, James M; Serody, Jonathan S

2017-07-20

The aryl hydrocarbon receptor (AhR) is a ligand-activated transcription factor that affects the function and development of immune cells. Here, we show that recipient mice receiving AhR -/- T cells have improved survival and decreased acute graft-versus-host disease (aGVHD) in 2 different murine allogeneic bone marrow transplant (BMT) models. We also show that CD4 + T cells lacking AhR demonstrate reduced accumulation in secondary lymphoid tissue because of low levels of proliferation 4 days after BMT. Additionally, we found a significant increase in the quantity of peripherally induced regulatory donor T (pT reg ) cells in the colon of recipients transplanted with AhR -/- T cells 14 days after transplant. Blockade of AhR using a clinically available AhR antagonist greatly enhanced the in vitro generation of inducible T reg (iT reg ) cells from naïve CD4 + human T cells. We have identified AhR as a novel target on donor T cells that is critical to the pathogenesis of aGVHD.

Gain-of-function glutamate receptor interacting protein 1 variants alter GluA2 recycling and surface distribution in patients with autism

PubMed Central

Mejias, Rebeca; Adamczyk, Abby; Anggono, Victor; Niranjan, Tejasvi; Thomas, Gareth M.; Sharma, Kamal; Skinner, Cindy; Schwartz, Charles E.; Stevenson, Roger E.; Fallin, M. Daniele; Kaufmann, Walter; Pletnikov, Mikhail; Valle, David; Huganir, Richard L.; Wang, Tao

2011-01-01

Glutamate receptor interacting protein 1 (GRIP1) is a neuronal scaffolding protein that interacts directly with the C termini of glutamate receptors 2/3 (GluA2/3) via its PDZ domains 4 to 6 (PDZ4–6). We found an association (P < 0.05) of a SNP within the PDZ4-6 genomic region with autism by genotyping autistic patients (n = 480) and matched controls (n = 480). Parallel sequencing identified five rare missense variants within or near PDZ4–6 only in the autism cohort, resulting in a higher cumulative mutation load (P = 0.032). Two variants correlated with a more severe deficit in reciprocal social interaction in affected sibling pairs from proband families. These variants were associated with altered interactions with GluA2/3 and faster recycling and increased surface distribution of GluA2 in neurons, suggesting gain-of-function because GRIP1/2 deficiency showed opposite phenotypes. Grip1/2 knockout mice exhibited increased sociability and impaired prepulse inhibition. These results support a role for GRIP in social behavior and implicate GRIP1 variants in modulating autistic phenotype. PMID:21383172

Truncated G protein-coupled mu opioid receptor MOR-1 splice variants are targets for highly potent opioid analgesics lacking side effects.

PubMed

Majumdar, Susruta; Grinnell, Steven; Le Rouzic, Valerie; Burgman, Maxim; Polikar, Lisa; Ansonoff, Michael; Pintar, John; Pan, Ying-Xian; Pasternak, Gavril W

2011-12-06

Pain remains a pervasive problem throughout medicine, transcending all specialty boundaries. Despite the extraordinary insights into pain and its mechanisms over the past few decades, few advances have been made with analgesics. Most pain remains treated by opiates, which have significant side effects that limit their utility. We now describe a potent opiate analgesic lacking the traditional side effects associated with classical opiates, including respiratory depression, significant constipation, physical dependence, and, perhaps most important, reinforcing behavior, demonstrating that it is possible to dissociate side effects from analgesia. Evidence indicates that this agent acts through a truncated, six-transmembrane variant of the G protein-coupled mu opioid receptor MOR-1. Although truncated splice variants have been reported for a number of G protein-coupled receptors, their functional relevance has been unclear. Our evidence now suggests that truncated variants can be physiologically important through heterodimerization, even when inactive alone, and can comprise new therapeutic targets, as illustrated by our unique opioid analgesics with a vastly improved pharmacological profile.

A common variant at the TERT-CLPTM1L locus is associated with estrogen receptor-negative breast cancer.

PubMed

Haiman, Christopher A; Chen, Gary K; Vachon, Celine M; Canzian, Federico; Dunning, Alison; Millikan, Robert C; Wang, Xianshu; Ademuyiwa, Foluso; Ahmed, Shahana; Ambrosone, Christine B; Baglietto, Laura; Balleine, Rosemary; Bandera, Elisa V; Beckmann, Matthias W; Berg, Christine D; Bernstein, Leslie; Blomqvist, Carl; Blot, William J; Brauch, Hiltrud; Buring, Julie E; Carey, Lisa A; Carpenter, Jane E; Chang-Claude, Jenny; Chanock, Stephen J; Chasman, Daniel I; Clarke, Christine L; Cox, Angela; Cross, Simon S; Deming, Sandra L; Diasio, Robert B; Dimopoulos, Athanasios M; Driver, W Ryan; Dünnebier, Thomas; Durcan, Lorraine; Eccles, Diana; Edlund, Christopher K; Ekici, Arif B; Fasching, Peter A; Feigelson, Heather S; Flesch-Janys, Dieter; Fostira, Florentia; Försti, Asta; Fountzilas, George; Gerty, Susan M; Giles, Graham G; Godwin, Andrew K; Goodfellow, Paul; Graham, Nikki; Greco, Dario; Hamann, Ute; Hankinson, Susan E; Hartmann, Arndt; Hein, Rebecca; Heinz, Judith; Holbrook, Andrea; Hoover, Robert N; Hu, Jennifer J; Hunter, David J; Ingles, Sue A; Irwanto, Astrid; Ivanovich, Jennifer; John, Esther M; Johnson, Nicola; Jukkola-Vuorinen, Arja; Kaaks, Rudolf; Ko, Yon-Dschun; Kolonel, Laurence N; Konstantopoulou, Irene; Kosma, Veli-Matti; Kulkarni, Swati; Lambrechts, Diether; Lee, Adam M; Marchand, Loïc Le; Lesnick, Timothy; Liu, Jianjun; Lindstrom, Sara; Mannermaa, Arto; Margolin, Sara; Martin, Nicholas G; Miron, Penelope; Montgomery, Grant W; Nevanlinna, Heli; Nickels, Stephan; Nyante, Sarah; Olswold, Curtis; Palmer, Julie; Pathak, Harsh; Pectasides, Dimitrios; Perou, Charles M; Peto, Julian; Pharoah, Paul D P; Pooler, Loreall C; Press, Michael F; Pylkäs, Katri; Rebbeck, Timothy R; Rodriguez-Gil, Jorge L; Rosenberg, Lynn; Ross, Eric; Rüdiger, Thomas; Silva, Isabel dos Santos; Sawyer, Elinor; Schmidt, Marjanka K; Schulz-Wendtland, Rüdiger; Schumacher, Fredrick; Severi, Gianluca; Sheng, Xin; Signorello, Lisa B; Sinn, Hans-Peter; Stevens, Kristen N; Southey, Melissa C; Tapper, William J; Tomlinson, Ian; Hogervorst, Frans B L; Wauters, Els; Weaver, JoEllen; Wildiers, Hans; Winqvist, Robert; Van Den Berg, David; Wan, Peggy; Xia, Lucy Y; Yannoukakos, Drakoulis; Zheng, Wei; Ziegler, Regina G; Siddiq, Afshan; Slager, Susan L; Stram, Daniel O; Easton, Douglas; Kraft, Peter; Henderson, Brian E; Couch, Fergus J

2011-10-30

Estrogen receptor (ER)-negative breast cancer shows a higher incidence in women of African ancestry compared to women of European ancestry. In search of common risk alleles for ER-negative breast cancer, we combined genome-wide association study (GWAS) data from women of African ancestry (1,004 ER-negative cases and 2,745 controls) and European ancestry (1,718 ER-negative cases and 3,670 controls), with replication testing conducted in an additional 2,292 ER-negative cases and 16,901 controls of European ancestry. We identified a common risk variant for ER-negative breast cancer at the TERT-CLPTM1L locus on chromosome 5p15 (rs10069690: per-allele odds ratio (OR) = 1.18 per allele, P = 1.0 × 10(-10)). The variant was also significantly associated with triple-negative (ER-negative, progesterone receptor (PR)-negative and human epidermal growth factor-2 (HER2)-negative) breast cancer (OR = 1.25, P = 1.1 × 10(-9)), particularly in younger women (<50 years of age) (OR = 1.48, P = 1.9 × 10(-9)). Our results identify a genetic locus associated with estrogen receptor negative breast cancer subtypes in multiple populations.

Serum Soluble Transferrin Receptor Concentrations Are Elevated in Congolese Children with Glucose-6-Phosphate Dehydrogenase Variants, but Not Sickle Cell Variants or α-Thalassemia.

PubMed

Barker, Mikaela K; Henderson, Amanda M; Naguib, Karimah; Vercauteren, Suzanne M; Devlin, Angela M; Albert, Arianne Y; Bahizire, Esto; Tugirimana, Pierrot L; Akilimali, Pierre Z; Boy, Erick; Green, Tim J; Karakochuk, Crystal D

2017-09-01

Background: Anemia is common in Congolese children, and inherited blood disorders may be a contributing cause. The presence of sickle cell variants, X-linked glucose-6-phosphate dehydrogenase (G6PD) deficiency and α-thalassemia, has been previously reported. G6PD A- deficiency is characterized by the co-inheritance of G6PD 376 and 202 variants and is common in sub-Saharan Africa. Objective: We aimed to measure the associations between inherited blood disorders and hemoglobin, ferritin, and soluble transferrin receptor (sTfR) concentrations in Congolese children. Methods: Venous blood was collected from 744 children aged 6-59 mo from 2 provinces. We measured biomarkers of nutritional and inflammation status and malaria. Pyrosequencing was used to detect sickle cell variants. Polymerase chain reaction was used to detect G6PD variants and α-thalassemia deletions. Results: Overall, 11% of children had a sickle cell variant, 19% of boys were G6PD A- hemizygotes, 12% and 10% of girls were G6PD A- hetero- or homozygotes, respectively, and 12% of children had α-thalassemia. Multivariable linear regression models (adjusted for age, province, altitude, malaria, and biomarkers of nutritional and inflammation status) showed that G6PD A- hemizygous boys and G6PD 376 homozygous girls had higher sTfR concentrations [geometric mean ratios (95% CIs): 1.20 (1.03, 1.39) and 1.25 (1.02, 1.53), respectively] than children with no G6PD variants. Hemoglobin and ferritin concentrations were not independently associated with any of the inherited blood disorder genotypes. Conclusions: We found that 2 G6PD variant genotypes were associated with elevated sTfR concentrations, which limits the accuracy of sTfR as a biomarker of iron status in this population. © 2017 American Society for Nutrition.

Muscle strength is associated with vitamin D receptor gene variants.

PubMed

Bozsodi, Arpad; Boja, Sara; Szilagyi, Agnes; Somhegyi, Annamaria; Varga, Peter Pal; Lazary, Aron

2016-11-01

Vitamin D receptor (VDR) is an important candidate gene in muscle function. Scientific reports on the effect of its genetic variants on muscle strength are contradictory likely due to the inconsistent study designs. Hand grip strength (HGS) is a highly heritable phenotype of muscle strength but only limited studies are available on its genetic background. Association between VDR polymorphisms and HGS has been poorly investigated and previous reports are conflicting. We studied the effect of VDR gene variants on HGS in a sample of 706 schoolchildren. Genomic DNA was extracted from saliva samples and six candidate single nucleotide polymorphisms (SNPs) across the VDR gene were genotyped with Sequenom MassARRAY technique. HGS was measured with a digital dynamometer in both hands. Single marker and haplotype associations were adjusted for demographic parameters. Three SNPs, rs4516035 (A1012G; p = 0.009), rs1544410 (BsmI; p = 0.010), and rs731236 (TaqI; p = 0.038) and a 3' UTR haploblock constructed by three SNPs (Bsml-Taq1-rs10783215; p < 0.005) showed significantly associations with HGS of the dominant hand. In the non-dominant hand, the effects of the A1012G (p = 0.034) and the 3' UTR haploblock (p < 0.01) on HGS were also significant. Since the promoter SNP (A10112G) and the 3' UTR haplotype were proved to be associated with the expression and the stability of the VDR mRNA in earlier studies, VDR variants can be supposed to have a direct effect on muscle strength. The individual genetic patterns can also explain the inconsistency of the previously published clinical results on the association between vitamin D and muscle function. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 34:2031-2037, 2016. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

Discovery of a new mechanism for regulation of plant triacylglycerol metabolism: The peanut diacylglycerol acyltransferase-1 gene family transcriptome is highly enriched in alternative splicing variants.

PubMed

Zheng, Ling; Shockey, Jay; Guo, Feng; Shi, Lingmin; Li, Xinguo; Shan, Lei; Wan, Shubo; Peng, Zhenying

2017-12-01

Triacylglycerols (TAGs) are the most important energy storage form in oilseed crops. Diacylglycerol acyltransferase (DGAT) catalyzes the rate-limiting step of the Kennedy pathway of TAG biosynthesis. To date, little is known about the regulation of DGAT activity in peanut (Arachis hypogaea), an agronomically important oilseed crop that is cultivated in many parts of the world. In this study, seven distinct forms of type 1 DGAT (AhDGAT1.1-AhDGAT1.7) were identified, cloned, and characterized. Comparisons of the nucleotide sequences and gene structures revealed many different splicing variants of AhDGAT1, some of which displayed different organ-specific expression patterns. A representative gene (AhDGAT1.1) was transformed into wild-type tobacco and was shown to increase seed fatty acid (FA) content by 14.7%-20.9%. All seven AhDGAT1s were expressed in TAG-deficient Saccharomyces cerevisiae strain H1246; the five longest AhDGAT1 variants generated high levels of acyltransferase activity and complemented the free fatty acid lethality phenotype in this strain. The alternative splicing that gives rise to AhDGAT1.2 and AhDGAT1.4 creates predicted protein C-terminal truncations. The proteins encoded by these two variants were not active and did not complement the fatty acid sensitivity in H1246. These results were verified by visualization of intracellular lipid droplets using Nile Red staining. Collectively, the results presented here represent the first comprehensive analysis of the peanut DGAT1 gene family, which, unlike in other published plant DGAT1 sequences, shows widespread alternative splicing that may affect the expression patterns and enzyme activities of some members of the gene family. Copyright © 2017. Published by Elsevier GmbH.

Evaluation of the ecotoxicity of sediments from Yangtze river estuary and contribution of priority PAHs to ah receptor--mediated activities.

PubMed

Liu, Li; Chen, Ling; Shao, Ying; Zhang, Lili; Floehr, Tilman; Xiao, Hongxia; Yan, Yan; Eichbaum, Kathrin; Hollert, Henner; Wu, Lingling

2014-01-01

In this study, in vitro bioassays were performed to assess the ecotoxicological potential of sediments from Yangtze River estuary. The cytotoxicity and aryl hydrocarbon receptor (AhR)-mediated toxicity of sediment extracts with rainbow trout (Oncorhynchus mykiss) liver cells were determined by neutral red retention and 7-ethoxyresorufin-O-deethylase assays. The cytotoxicity and AhR-mediated activity of sediments from the Yangtze River estuary ranged from low level to moderate level compared with the ecotoxicity of sediments from other river systems. However, Yangtze River releases approximately 14 times greater water discharge compared with Rhine, a major river in Europe. Thus, the absolute pollution mass transfer of Yangtze River may be detrimental to the environmental quality of estuary and East China Sea. Effect-directed analysis was applied to identify substances causing high dioxin-like activities. To identify unknown substances contributing to dioxin-like potencies of whole extracts, we fractionated crude extracts by open column chromatography. Non-polar paraffinic components (F1), weakly and moderately polar components (F2), and highly polar substances (F3) were separated from each crude extract of sediments. F2 showed the highest dioxin-like activities. Based on the results of mass balance calculation of chemical toxic equivalent concentrations (TEQs), our conclusion is that priority polycyclic aromatic hydrocarbons indicated a low portion of bio-TEQs ranging from 1% to 10% of crude extracts. Further studies should be conducted to identify unknown pollutants.

Evaluation of the Ecotoxicity of Sediments from Yangtze River Estuary and Contribution of Priority PAHs to Ah Receptor-Mediated Activities

PubMed Central

Liu, Li; Chen, Ling; Shao, Ying; Zhang, Lili; Floehr, Tilman; Xiao, Hongxia; Yan, Yan; Eichbaum, Kathrin; Hollert, Henner; Wu, Lingling

2014-01-01

In this study, in vitro bioassays were performed to assess the ecotoxicological potential of sediments from Yangtze River estuary. The cytotoxicity and aryl hydrocarbon receptor (AhR)-mediated toxicity of sediment extracts with rainbow trout (Oncorhynchus mykiss) liver cells were determined by neutral red retention and 7-ethoxyresorufin-O-deethylase assays. The cytotoxicity and AhR-mediated activity of sediments from the Yangtze River estuary ranged from low level to moderate level compared with the ecotoxicity of sediments from other river systems. However, Yangtze River releases approximately 14 times greater water discharge compared with Rhine, a major river in Europe. Thus, the absolute pollution mass transfer of Yangtze River may be detrimental to the environmental quality of estuary and East China Sea. Effect-directed analysis was applied to identify substances causing high dioxin-like activities. To identify unknown substances contributing to dioxin-like potencies of whole extracts, we fractionated crude extracts by open column chromatography. Non-polar paraffinic components (F1), weakly and moderately polar components (F2), and highly polar substances (F3) were separated from each crude extract of sediments. F2 showed the highest dioxin-like activities. Based on the results of mass balance calculation of chemical toxic equivalent concentrations (TEQs), our conclusion is that priority polycyclic aromatic hydrocarbons indicated a low portion of bio-TEQs ranging from 1% to 10% of crude extracts. Further studies should be conducted to identify unknown pollutants. PMID:25111307

Preferential association of a functional variant in complement receptor 2 with antibodies to double-stranded DNA

PubMed Central

Zhao, Jian; Giles, Brendan M; Taylor, Rhonda L; Yette, Gabriel A; Lough, Kara M; Ng, Han Leng; Abraham, Lawrence J; Wu, Hui; Kelly, Jennifer A; Glenn, Stuart B; Adler, Adam J; Williams, Adrienne H; Comeau, Mary E; Ziegler, Julie T; Marion, Miranda; Alarcón-Riquelme, Marta E; Alarcón, Graciela S; Anaya, Juan-Manuel; Bae, Sang-Cheol; Kim, Dam; Lee, Hye-Soon; Criswell, Lindsey A; Freedman, Barry I; Gilkeson, Gary S; Guthridge, Joel M; Jacob, Chaim O; James, Judith A; Kamen, Diane L; Merrill, Joan T; Sivils, Kathy Moser; Niewold, Timothy B; Petri, Michelle A; Ramsey-Goldman, Rosalind; Reveille, John D; Scofield, R Hal; Stevens, Anne M; Vilá, Luis M; Vyse, Timothy J; Kaufman, Kenneth M; Harley, John B; Langefeld, Carl D; Gaffney, Patrick M; Brown, Elizabeth E; Edberg, Jeffrey C; Kimberly, Robert P; Ulgiati, Daniela; Tsao, Betty P; Boackle, Susan A

2016-01-01

Objectives Systemic lupus erythematosus (SLE; OMIM 152700) is characterised by the production of antibodies to nuclear antigens. We previously identified variants in complement receptor 2 (CR2/CD21) that were associated with decreased risk of SLE. This study aimed to identify the causal variant for this association. Methods Genotyped and imputed genetic variants spanning CR2 were assessed for association with SLE in 15 750 case-control subjects from four ancestral groups. Allele-specific functional effects of associated variants were determined using quantitative real-time PCR, quantitative flow cytometry, electrophoretic mobility shift assay (EMSA) and chromatin immunoprecipitation (ChIP)-PCR. Results The strongest association signal was detected at rs1876453 in intron 1 of CR2 (pmeta=4.2×10−4, OR 0.85), specifically when subjects were stratified based on the presence of dsDNA autoantibodies (case-control pmeta=7.6×10−7, OR 0.71; case-only pmeta=1.9×10−4, OR 0.75). Although allele-specific effects on B cell CR2 mRNA or protein levels were not identified, levels of complement receptor 1 (CR1/CD35) mRNA and protein were significantly higher on B cells of subjects harbouring the minor allele (p=0.0248 and p=0.0006, respectively). The minor allele altered the formation of several DNA protein complexes by EMSA, including one containing CCCTC-binding factor (CTCF), an effect that was confirmed by ChIP-PCR. Conclusions These data suggest that rs1876453 in CR2 has long-range effects on gene regulation that decrease susceptibility to lupus. Since the minor allele at rs1876453 is preferentially associated with reduced risk of the highly specific dsDNA autoantibodies that are present in preclinical, active and severe lupus, understanding its mechanisms will have important therapeutic implications. PMID:25180293

Analysis of PAC1 receptor gene variants in Caucasian and African American infants dying of sudden infant death syndrome.

PubMed

Barrett, Karlene T; Rodikova, Ekaterina; Weese-Mayer, Debra E; Rand, Casey M; Marazita, Mary L; Cooper, Margaret E; Berry-Kravis, Elizabeth M; Bech-Hansen, N Torben; Wilson, Richard J A

2013-12-01

Stress peptide, pituitary adenylate cyclase-activating polypeptide (PACAP), has been implicated in sudden infant death syndrome (SIDS). The aim of this exploratory study was to determine whether variants in the gene encoding the PACAP-specific receptor, PAC1, are associated with SIDS in Caucasian and African American infants. Polymerase chain reaction and Sanger DNA sequencing was used to compare variants in the 5'-untranslated region, exons and intron-exon boundaries of the PAC1 gene in 96 SIDS cases and 96 race- and gender-matched controls. The intron 3 variant, A/G: rs758995 (variant 'h'), and the intron 6 variant, C/T: rs10081254 (variant 'n'), were significantly associated with SIDS in Caucasians and African Americans, respectively (p < 0.05). Also associated with SIDS were interactions between the variants rs2302475 (variant 'i') in PAC1 and rs8192597 and rs2856966 in PACAP among Caucasians (p < 0.02) and rs2267734 (variant 'q') in PAC1 and rs1893154 in PACAP among African Americans (p < 0.01). However, none of these differences survived post hoc analysis. Overall, this study does not support a strong association between variants in the PAC1 gene and SIDS; however, a number of potential associations between race-specific variants and SIDS were identified that warrant targeted investigations in future studies. ©2013 Foundation Acta Paediatrica. Published by John Wiley & Sons Ltd.

Linking Ah receptor mediated effects of sediments and impacts on fish to key pollutants in the Yangtze Three Gorges Reservoir, China - A comprehensive perspective.

PubMed

Floehr, Tilman; Scholz-Starke, Björn; Xiao, Hongxia; Hercht, Hendrik; Wu, Lingling; Hou, Junli; Schmidt-Posthaus, Heike; Segner, Helmut; Kammann, Ulrike; Yuan, Xingzhong; Roß-Nickoll, Martina; Schäffer, Andreas; Hollert, Henner

2015-12-15

The Three Gorges Reservoir (TGR), created in consequence of the Yangtze River's impoundment by the Three Gorges Dam, faces numerous anthropogenic impacts that challenge its unique ecosystem. Organic pollutants, particularly aryl hydrocarbon receptor (AhR) agonists, have been widely detected in the Yangtze River, but only little research was yet done on AhR-mediated activities. Hence, in order to assess effects of organic pollution, with particular focus on AhR-mediated activities, several sites in the TGR area were examined applying the "triad approach". It combines chemical analysis, in vitro, in vivo and in situ investigations to a holistic assessment. Sediments and the benthic fish species Pelteobagrus vachellii were sampled in 2011/2012, respectively, to identify relevant endpoints. Sediment was tested in vitro with the ethoxyresorufin-O-deethylase (EROD) induction assay, and in vivo with the Fish Embryo Toxicity Test and Sediment Contact Assay with Danio rerio. Activities of phase I (EROD) and phase II (glutathione-S-transferase) biotransformation enzymes, pollutant metabolites and histopathological alterations were studied in situ in P. vachellii. EROD induction was tested in vitro and in situ to evaluate possible relationships. Two sites, near Chongqing and Kaixian city, were identified as regional hot-spots and further investigated in 2013. The sediments induced in the in vitro/in vivo bioassays AhR-mediated activities and embryotoxic/teratogenic effects - particularly on the cardiovascular system. These endpoints could be significantly correlated to each other and respective chemical data. However, particle-bound pollutants showed only low bioavailability. The in situ investigations suggested a rather poor condition of P. vachellii, with histopathological alterations in liver and excretory kidney. Fish from Chongqing city exhibited significant hepatic EROD induction and obvious parasitic infestations. The polycyclic aromatic hydrocarbon (PAH) metabolite 1

Cynaropicrin attenuates UVB-induced oxidative stress via the AhR-Nrf2-Nqo1 pathway.

PubMed

Takei, Kenjiro; Hashimoto-Hachiya, Akiko; Takahara, Masakazu; Tsuji, Gaku; Nakahara, Takeshi; Furue, Masutaka

2015-04-16

Due to its antioxidant and anti-inflammatory activities, artichoke (Cynara scolymus) has been used as folk medicine to treat various diseases. Cynaropicrin (Cyn), a sesquiterpene lactone, is the major bioactive phytochemical in the artichoke; however, its pharmacological mechanism remains unknown. Because some phytochemicals exert their antioxidant activity by activating aryl hydrocarbon receptor (AhR), leading to subsequent induction of the antioxidant pathway including nuclear factor E2-related factor 2 (Nrf2) and quinone oxidoreductase 1 (Nqo1), we investigated whether Cyn also activates the AhR-Nrf2-Nqo1 pathway. Cyn indeed induced the activation (nuclear translocation) of AhR, leading to nuclear translocation of Nrf2 and dose-dependent upregulation of Nrf2 and Nqo1 mRNAs in human keratinocytes. The Cyn-induced AhR-Nrf2-Nqo1 activation was AhR- and Nrf2-dependent, as demonstrated by the observation that it was absent in keratinocytes transfected by siRNA against either AhR or Nrf2. In accordance with these findings, Cyn actively inhibited generation of reactive oxygen species from keratinocytes irradiated with ultraviolet B (UVB) in a Nrf2-dependent manner. Cyn also inhibited the production of proinflammatory cytokines such as interleukin 6 and tumor necrosis factor-α from UVB-treated keratinocytes. Our findings demonstrate that Cyn is a potent activator of the AhR-Nrf2-Nqo1 pathway, and could therefore be applied to prevention of UVB-induced photo aging. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

PAF levels and PAF-AH activities in placentas from normal and preeclamptic pregnancies.

PubMed

Gu, Y; Burlison, S A; Wang, Y

2006-01-01

The aim of this study was to determine: (1) platelet-activating factor (PAF) levels and PAF-acetylhydrolase (PAF-AH) activities in normal and preeclamptic placentas; (2) lipid peroxide production by placental tissues stimulated with PAF. Placentas were obtained immediately after delivery from normal and preeclamptic pregnancies. Tissue pieces were snap frozen in liquid nitrogen and stored at -70 degrees C. One gram of tissue from each placenta was used for PAF extraction and for total RNA isolation. PAF was measured by PAF [3H] scintillation proximity assay (SPA) system. Trophoblast PAF-AH activity was determined by enzyme-linked immunosorbent assay (ELISA). mRNA expression for PAF receptor was assessed by RNase protection assay (RPA). Normal placental explants were incubated with PAF at concentrations of 1 and 10 microg/ml for 48 h. Lipid peroxide productions of 8-isoprostane and malondialdehyde (MDA) were measured by ELISA and thiobarbituric acid reaction, respectively. Data were presented as mean+/-SE and analyzed by nonparametric Mann-Whitney U test and ANOVA. A p level less than 0.05 was considered statistically significant. (1) The mean tissue level for PAF was elevated, but not statistically different, in preeclamptic (n=7) than in normal (n=8) placentas, 6.45+/-1.05 versus 4.47+/-0.60 ng/g, p=0.42. (2) PAF-AH activity was higher in trophoblasts from preeclamptic (n=7) placentas than that in trophoblasts from normal (n=8) placentas, 0.69+/-0.16 versus 0.38+/-0.03 micromol/min/microg protein, p<0.05. (3) The relative mRNA expression for PAF receptor was not different between normal (0.70+/-0.08) and preeclamptic (0.76+/-0.13) placental tissues, p=0.60. (4) Productions of 8-isoprostane and MDA were not increased in tissues with PAF in culture, 8-isoprostane: 0.37+/-0.09 ng/mg (control) versus 0.32+/-0.09 ng/mg (1 microg/ml) and 0.37+/-0.07 ng/mg (10 microg/ml), p>0.5; MDA: 0.62+/-0.05 nmol/mg (control) versus 0.68+/-0.04 nmol/mg (1 microg/ml) and 0

Sensory Gating and Alpha-7 Nicotinic Receptor Gene Allelic Variants in Schizoaffective Disorder, Bipolar Type

PubMed Central

Martin, Laura F.; Leonard, Sherry; Hall, Mei-Hua; Tregellas, Jason R.; Freedman, Robert; Olincy, Ann

2011-01-01

Objectives Single nucleotide allelic variants in the promoter region of the chromosome 15 alpha-7 acetylcholine nicotinic receptor gene (CHRNA7) are associated with both schizophrenia and the P50 auditory evoked potential sensory gating deficit. The purpose of this study was to determine if CHRNA7 promoter allelic variants are also associated with abnormal P50 ratios in persons with schizoaffective disorder, bipolar type. Methods P50 auditory evoked potentials were recorded in a paired stimulus paradigm in 17 subjects with schizoaffective disorder, bipolar type. The P50 test to conditioning ratio was used as the measure of sensory gating. Mutation screening of the CHRNA7 promoter region was performed on the subjects’ DNA samples. Comparisons to previously obtained data from persons with schizophrenia and controls were made. Results Subjects with schizophrenia, regardless of allele status, had an abnormal mean P50 ratio. Subjects with schizoaffective disorder, bipolar type and a variant allele had an abnormal mean P50 ratio, whereas those schizoaffective subjects with the common alleles had a normal mean P50 ratio. Normal control subjects had a normal mean ratio, but controls with variant alleles had higher P50 ratios. Conclusions In persons with bipolar type schizoaffective disorder, CHRNA7 promoter region allelic variants are linked to the capacity to inhibit the P50 auditory evoked potential and thus are associated with a type of illness genetically and biologically more similar to schizophrenia. PMID:17192894

Targeted resequencing identifies defective variants of decoy receptor 3 in pediatric-onset inflammatory bowel disease.

PubMed

Cardinale, C J; Wei, Z; Panossian, S; Wang, F; Kim, C E; Mentch, F D; Chiavacci, R M; Kachelries, K E; Pandey, R; Grant, S F A; Baldassano, R N; Hakonarson, H

2013-10-01

Genome-wide association studies have implicated common variation at the 20q13 locus in inflammatory bowel disease, particularly for the pediatric Crohn's form. This locus harbors tumor necrosis factor receptor superfamily (TNFRSF6B), encoding a secreted protein, decoy receptor 3 (DcR3), which binds to and neutralizes pro-inflammatory cytokines of the tumor necrosis factor superfamily. We sought to further the evidence of DcR3's role in pediatric IBD by identifying missense mutations with functional significance within TNFRSF6B. We sequenced the exons of the gene in 528 Caucasian pediatric IBD cases and 549 Caucasian healthy controls to establish the frequency of such events in each population. Sequencing revealed that our IBD cohort harbored a greater number of missense variants, yielding an odds ratio of 3.9 (P-value=0.005). Using functional assays, we established that the frequency of mutants defective in secretion from cultured cells was greater in the Crohn's category than in the controls, yielding an odds ratio of 7.1 (P-value=0.004). These results suggest that rare defective variants in TNFRSF6B have a role in the pathogenesis of some cases of IBD and that interventions targeting this group of tumor necrosis factor-family members may benefit patients with IBD.

Interim estimates of divergence date and vaccine strain match of human influenza A(H3N2) virus from systematic influenza surveillance (2010-2015) in Hangzhou, southeast of China.

PubMed

Li, Jun; Zhou, Yin-yan; Kou, Yu; Yu, Xin-fen; Zheng, Zhi-bei; Yang, Xu-hui; Wang, Hao-qiu

2015-11-01

In the post-pandemic period 2010-2015, seasonal influenza A(H3N2) virus predominated in Hangzhou, southeast of China, with an increased activity and semi-annual seasons. This study utilized HA virus gene segment sequences to analyze the divergence date and vaccine strain match of human influenza A(H3N2) virus from systematic influenza surveillance in Hangzhou. Virological and serological analyses of 124 representative A(H3N2) viruses from prospective studies of systematic surveillance samples were conducted to quantify the genetic and antigenic characteristics and their vaccine strain match. Bayesian phylogenetic inference showed that two separate subgroups 3C.3 and 3C.2 probably diverged from group 3C in early 2012 and then evolved into groups 3C.3a and 3C.2a, respectively, in the 2014/15 influenza season. Furthermore, high amino acid substitution rates of the HA1 subunit were found in A(H3N2) group 3C.2a variants, indicating that increased antigenic drift of A(H3N2) group 3C.2a virus is associated with a vaccine mismatch to the 2015/16 vaccine reference strain Switzerland/9715293/2013 (group 3C.3a). A portion of the group 3C.2a isolates are not covered by the current A(H3N2) vaccine strain. These findings offer insights into the emergence of group 3C.2a variants with epidemic potential in the imminent influenza seasons. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

Expression of profibrotic growth factors and their receptors by mouse lung macrophages and fibroblasts under conditions of acute viral inflammation in influenza A/H5N1 virus.

PubMed

Anikina, A G; Shkurupii, V A; Potapova, O V; Kovner, A V; Shestopalov, A M

2014-04-01

Morphological signs of early interstitial fibrosis, developing under conditions of acute viral inflammation (postinfection days 1-14), were observed in C57Bl/6 mice infected with influenza A/H5N1 A/goose/Krasnoozerskoye/627/05 virus. The development of fibrosis was confirmed by an increase in the number of lung cells expressing TNF-α. These changes were recorded in the presence of a many-fold increase in the counts of macrophages and fibroblasts expressing FGF, EGF, and their receptors.

Epidermal growth factor receptor and variant III targeted immunotherapy

PubMed Central

Congdon, Kendra L.; Gedeon, Patrick C.; Suryadevara, Carter M.; Caruso, Hillary G.; Cooper, Laurence J.N.; Heimberger, Amy B.; Sampson, John H.

2014-01-01

Immunotherapeutic approaches to cancer have shown remarkable promise. A critical barrier to successfully executing such immune-mediated interventions is the selection of safe yet immunogenic targets. As patient deaths have occurred when tumor-associated antigens shared by normal tissue have been targeted by strong cellular immunotherapeutic platforms, route of delivery, target selection and the immune-mediated approach undertaken must work together to maximize efficacy with safety. Selected tumor-specific targets can spare potential toxicity to normal tissue; however, they are far less common than tumor-associated antigens and may not be present on all patients. In the context of immunotherapy for high-grade glioma, 2 of the most prominently studied antigens are the tumor-associated epidermal growth factor receptor and its tumor-specific genetic deletion variant III. In this review, we will summarize the immune-mediated strategies employed against these targets as well as the caveats particular to these approaches. PMID:25342601

Region-specific expression and hormonal regulation of the first exon variants of rat prolactin receptor mRNA in rat brain and anterior pituitary gland.

PubMed

Nogami, H; Hoshino, R; Ogasawara, K; Miyamoto, S; Hisano, S

2007-08-01

Recent studies have revealed the occurrence of five first exon variants of the rat prolactin receptor mRNA, suggesting that multiple promoters direct prolactin receptor transcription in response to different regulatory factors. In the present study, regional expression of these first exon variants, as well as two prolactin receptor subtypes generated by alternative splicing, was examined in the brains and anterior pituitary glands of female rats. Expression of the long-form was detected in the choroid plexus, hypothalamus, hippocampus, cerebral cortex and anterior pituitary gland, whereas the short form was detected only in the choroid plexus. E1-3 mRNA, a first exon variant, was detected in the choroid plexus, hypothalamus, and anterior pituitary gland, whereas E1-4 was detected only in the choroid plexus. Other variants were not detectable by the polymerase chain reaction protocol employed in this study. Ovariectomy increased the short form in the choroid plexus and the E1-3 expression in the choroid plexus and pituitary gland, but changes in the long-form and E1-4 expression were minimal. Replacement of oestrogens and prolactin suggest that oestrogens down-regulate E1-3 expression in the choroid plexus and pituitary gland, and that the negative effect of oestrogen is mediated by prolactin in the pituitary gland. The present results revealed the region-specific promoter usage in prolactin receptor mRNA transcription, as well as the involvement of oestrogens in the regulation of E1-3 mRNA expression in the brain and pituitary gland.

Neutral endopeptidase-resistant C-type natriuretic peptide variant represents a new therapeutic approach for treatment of fibroblast growth factor receptor 3-related dwarfism.

PubMed

Wendt, Daniel J; Dvorak-Ewell, Melita; Bullens, Sherry; Lorget, Florence; Bell, Sean M; Peng, Jeff; Castillo, Sianna; Aoyagi-Scharber, Mika; O'Neill, Charles A; Krejci, Pavel; Wilcox, William R; Rimoin, David L; Bunting, Stuart

2015-04-01

Achondroplasia (ACH), the most common form of human dwarfism, is caused by an activating autosomal dominant mutation in the fibroblast growth factor receptor-3 gene. Genetic overexpression of C-type natriuretic peptide (CNP), a positive regulator of endochondral bone growth, prevents dwarfism in mouse models of ACH. However, administration of exogenous CNP is compromised by its rapid clearance in vivo through receptor-mediated and proteolytic pathways. Using in vitro approaches, we developed modified variants of human CNP, resistant to proteolytic degradation by neutral endopeptidase, that retain the ability to stimulate signaling downstream of the CNP receptor, natriuretic peptide receptor B. The variants tested in vivo demonstrated significantly longer serum half-lives than native CNP. Subcutaneous administration of one of these CNP variants (BMN 111) resulted in correction of the dwarfism phenotype in a mouse model of ACH and overgrowth of the axial and appendicular skeletons in wild-type mice without observable changes in trabecular and cortical bone architecture. Moreover, significant growth plate widening that translated into accelerated bone growth, at hemodynamically tolerable doses, was observed in juvenile cynomolgus monkeys that had received daily subcutaneous administrations of BMN 111. BMN 111 was well tolerated and represents a promising new approach for treatment of patients with ACH. Copyright © 2015 by The American Society for Pharmacology and Experimental Therapeutics.

A novel thromboxane A2 receptor D304N variant that abrogates ligand binding in a patient with a bleeding diathesis.

PubMed

Mumford, Andrew D; Dawood, Ban B; Daly, Martina E; Murden, Sherina L; Williams, Michael D; Protty, Majd B; Spalton, Jennifer C; Wheatley, Mark; Mundell, Stuart J; Watson, Steve P

2010-01-14

We investigated the cause of mild mucocutaneous bleeding in a 14-year-old male patient (P1). Platelet aggregation and ATP secretion induced by arachidonic acid and the thromboxane A(2) receptor (TxA(2)R) agonist U46619 were reduced in P1 compared with controls, whereas the responses to other platelet agonists were retained. P1 was heterozygous for a transversion within the TBXA2R gene predictive of a D304N substitution in the TxA(2)R. In Chinese hamster ovary-K1 cells expressing the variant D304N TxA(2)R, U46619 did not increase cytosolic free Ca(2+) concentration, indicating loss of receptor function. The TxA(2)R antagonist [(3)H]-SQ29548 showed an approximate 50% decrease in binding to platelets from P1 but absent binding to Chinese hamster ovary-K1 cells expressing variant D304N TxA(2)R. This is the second naturally occurring TxA(2)R variant to be associated with platelet dysfunction and the first in which loss of receptor function is associated with reduced ligand binding. D304 lies within a conserved NPXXY motif in transmembrane domain 7 of the TxA(2)R that is a key structural element in family A G protein-coupled receptors. Our demonstration that the D304N substitution causes clinically significant platelet dysfunction by reducing ligand binding establishes the importance of the NPXXY motif for TxA(2)R function in vivo.

Androgen receptor splice variants circumvent AR blockade by microtubule-targeting agents

PubMed Central

Zhang, Guanyi; Liu, Xichun; Li, Jianzhuo; Ledet, Elisa; Alvarez, Xavier; Qi, Yanfeng; Fu, Xueqi; Sartor, Oliver; Dong, Yan; Zhang, Haitao

2015-01-01

Docetaxel-based chemotherapy is established as a first-line treatment and standard of care for patients with metastatic castration-resistant prostate cancer. However, half of the patients do not respond to treatment and those do respond eventually become refractory. A better understanding of the resistance mechanisms to taxane chemotherapy is both urgent and clinical significant, as taxanes (docetaxel and cabazitaxel) are being used in various clinical settings. Sustained signaling through the androgen receptor (AR) has been established as a hallmark of CRPC. Recently, splicing variants of AR (AR-Vs) that lack the ligand-binding domain (LBD) have been identified. These variants are constitutively active and drive prostate cancer growth in a castration-resistant manner. In taxane-resistant cell lines, we found the expression of a major variant, AR-V7, was upregulated. Furthermore, ectopic expression of two clinically relevant AR-Vs (AR-V7 and ARV567es), but not the full-length AR (AR-FL), reduced the sensitivities to taxanes in LNCaP cells. Treatment with taxanes inhibited the transcriptional activity of AR-FL, but not those of AR-Vs. This could be explained, at least in part, due to the inability of taxanes to block the nuclear translocation of AR-Vs. Through a series of deletion constructs, the microtubule-binding activity was mapped to the LBD of AR. Finally, taxane-induced cytoplasm sequestration of AR-FL was alleviated when AR-Vs were present. These findings provide evidence that constitutively active AR-Vs maintain the AR signaling axis by evading the inhibitory effects of microtubule-targeting agents, suggesting that these AR-Vs play a role in resistance to taxane chemotherapy. PMID:26160840

Characteristics of a Widespread Community Cluster of H275Y Oseltamivir-Resistant A(H1N1)pdm09 Influenza in Australia

PubMed Central

Hurt, A. C.; Hardie, K.; Wilson, N. J.; Deng, Y. M.; Osbourn, M.; Leang, S. K.; Lee, R. T. C.; Iannello, P.; Gehrig, N.; Shaw, R.; Wark, P.; Caldwell, N.; Givney, R. C.; Xue, L.; Maurer-Stroh, S.; Dwyer, D. E.; Wang, B.; Smith, D. W.; Levy, A.; Booy, R.; Dixit, R.; Merritt, T.; Kelso, A.; Dalton, C.; Durrheim, D.; Barr, I. G.

2012-01-01

Background. Oseltamivir resistance in A(H1N1)pdm09 influenza is rare, particularly in untreated community cases. Sustained community transmission has not previously been reported. Methods. Influenza specimens from the Asia–Pacific region were collected through sentinel surveillance, hospital, and general practitioner networks. Clinical and epidemiological information was collected on patients infected with oseltamivir-resistant viruses. Results. Twenty-nine (15%) of 191 A(H1N1)pdm09 viruses collected between May and September 2011 from Hunter New England (HNE), Australia, contained the H275Y neuraminidase substitution responsible for oseltamivir resistance. Only 1 patient had received oseltamivir before specimen collection. The resistant strains were genetically very closely related, suggesting the spread of a single variant. Ninety percent of cases lived within 50 kilometers. Three genetically similar oseltamivir-resistant variants were detected outside of HNE, including 1 strain from Perth, approximately 4000 kilometers away. Computational analysis predicted that neuraminidase substitutions V241I, N369K, and N386S in these viruses may offset the destabilizing effect of the H275Y substitution. Conclusions This cluster represents the first widespread community transmission of H275Y oseltamivir-resistant A(H1N1)pdm09 influenza. These cases and data on potential permissive mutations suggest that currently circulating A(H1N1)pdm09 viruses retain viral fitness in the presence of the H275Y mutation and that widespread emergence of oseltamivir-resistant strains may now be more likely. PMID:22561367

Bioactive terpenoids and flavonoids from ginkgo biloba extract induce the expression of hepatic drug-metabolizing enzymes through Pregnane X receptor, Constitutive androstane receptor, and Aryl hydrocarbon receptor-mediated pathways

PubMed Central

Li, Linhao; Stanton, Joseph D; Tolson, Antonia H; Luo, Yuan; Wang, Hongbing

2008-01-01

Purpose The objective of the current study is to investigate the hypothesis that bioactive terpenoids and flavonoids of Ginkgo biloba extract (GBE) induce human hepatic drug metabolizing enzymes (DMEs) and transporters through the selective activation of pregnane X receptor (PXR), constitutive androstane receptor (CAR), and aryl hydrocarbon receptor (AhR). Methods Human primary hepatocyte (HPH), and HepG2 cells are used as in vitro models for enzyme induction and nuclear receptor activation studies. A combination of real-time RT-PCR, transient transfection, and cell-based reporter assays were employed. Results In human primary hepatocytes, real-time PCR analysis showed induction of CYP2B6, CYP3A4, UGT1A1, MDR1, and MRP2 by EGb 761, ginkgolide A (GA) and ginkgolide B (GB), but not by bilobalide (BB) or the flavonoids (quercetin, kaempferol and tamarixetin) of GBE. Cell-based reporter assays in HepG2 revealed that GA and GB are potent activators of PXR; quercetin and kaempferol activate PXR, CAR, and AhR, whereas BB exerts no effects on these xenobiotic receptors. Notably, the flavonoids induced the expression of UGT1A1 and CYP1A2 in HepG2 cells but not in HPH. Conclusion Our results indicate that terpenoids and flavonoids of GBE exhibit differential induction of DMEs through the selective activation of PXR, CAR, and AhR. PMID:19034627

Variant ionotropic glutamate receptors as chemosensory receptors in Drosophila

PubMed Central

Benton, Richard; Vannice, Kirsten S.; Gomez-Diaz, Carolina; Vosshall, Leslie B.

2009-01-01

Summary Ionotropic glutamate receptors (iGluRs) mediate neuronal communication at synapses throughout vertebrate and invertebrate nervous systems. We have characterized a novel family of iGluR-related genes in Drosophila, which we name Ionotropic Receptors (IRs). These receptors do not belong to the well-described Kainate, AMPA, or NMDA classes of iGluRs, and have divergent ligand-binding domains that lack their characteristic glutamate-interacting residues. IRs are expressed in a combinatorial fashion in sensory neurons that respond to many distinct odors but do not express either insect odorant receptors (ORs) or gustatory receptors (GRs). IR proteins accumulate in sensory dendrites and not at synapses. Mis-expression of IRs induces novel odor responses in ectopic neurons. Together, these results lead us to propose that the IRs comprise a novel family of chemosensory receptors. Conservation of IR/iGluR-related proteins in bacteria, plants, and animals suggests that this receptor family represents an evolutionarily ancient mechanism for sensing both internal and external chemical cues. PMID:19135896

The AhR is involved in the regulation of LoVo cell proliferation through cell cycle-associated proteins.

PubMed

Yin, Jiuheng; Sheng, Baifa; Han, Bin; Pu, Aimin; Yang, Kunqiu; Li, Ping; Wang, Qimeng; Xiao, Weidong; Yang, Hua

2016-05-01

Some ingredients in foods can activate the aryl hydrocarbon receptor (AhR) and arrest cell proliferation. In this study, we hypothesized that 6-formylindolo [3, 2-b] carbazole (FICZ) arrests the cell cycle in LoVo cells (a colon cancer line) through the AhR. The AhR agonist FICZ and the AhR antagonist CH223191 were used to treat LoVo cells. Real-time PCR and Western blot analyses were performed to detect the expression of the AhR, CYP1A1, CDK4, cyclinD1, cyclin E, CDK2, P27, and pRb. The distribution and activation of the AhR were detected with immunofluorescence. A 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) assay and flow cytometric analysis were performed to measure cell viability, cell cycle stage, and apoptosis. Our results show that FICZ inhibited LoVo cell proliferation by inducing G1 cell cycle arrest but had no effect on epithelial apoptosis. Further analysis found that FICZ downregulated cyclinD1 and upregulated p27 expression to arrest Rb phosphorylation. The downregulation of cyclinD1 and upregulation of p27 were abolished by co-treatment with CH223191. We conclude that the AhR, when activated by FICZ (an endogenous AhR ligand), can arrest the cell cycle and block LoVo cell proliferation. © 2016 International Federation for Cell Biology.

Truncated G protein-coupled mu opioid receptor MOR-1 splice variants are targets for highly potent opioid analgesics lacking side effects

PubMed Central

Majumdar, Susruta; Grinnell, Steven; Le Rouzic, Valerie; Burgman, Maxim; Polikar, Lisa; Ansonoff, Michael; Pintar, John; Pan, Ying-Xian; Pasternak, Gavril W.

2011-01-01

Pain remains a pervasive problem throughout medicine, transcending all specialty boundaries. Despite the extraordinary insights into pain and its mechanisms over the past few decades, few advances have been made with analgesics. Most pain remains treated by opiates, which have significant side effects that limit their utility. We now describe a potent opiate analgesic lacking the traditional side effects associated with classical opiates, including respiratory depression, significant constipation, physical dependence, and, perhaps most important, reinforcing behavior, demonstrating that it is possible to dissociate side effects from analgesia. Evidence indicates that this agent acts through a truncated, six-transmembrane variant of the G protein-coupled mu opioid receptor MOR-1. Although truncated splice variants have been reported for a number of G protein-coupled receptors, their functional relevance has been unclear. Our evidence now suggests that truncated variants can be physiologically important through heterodimerization, even when inactive alone, and can comprise new therapeutic targets, as illustrated by our unique opioid analgesics with a vastly improved pharmacological profile. PMID:22106286

Pure non-dioxin-like PCB congeners suppress induction of AhR-dependent endpoints in rat liver cells.

PubMed

Brenerová, Petra; Hamers, Timo; Kamstra, Jorke H; Vondráček, Jan; Strapáčová, Simona; Andersson, Patrik L; Machala, Miroslav

2016-02-01

The relative potencies of non-ortho-substituted coplanar polychlorinated biphenyl (PCB) congeners to activate the aryl hydrocarbon receptor (AhR) and to cause the AhR-dependent toxic events are essential for their risk assessment. Since some studies suggested that abundant non-dioxin-like PCB congeners (NDL-PCBs) may alter the AhR activation by PCB mixtures and possibly cause non-additive effects, we evaluated potential suppressive effects of NDL-PCBs on AhR activation, using a series of 24 highly purified NDL-PCBs. We investigated their impact on the model AhR agonist-induced luciferase reporter gene expression in rat hepatoma cells and on induction of CYP1A1/1B1 mRNAs and deregulation of AhR-dependent cell proliferation in rat liver epithelial cells. PCBs 128, 138, and 170 significantly suppressed AhR activation (with IC50 values from 1.4 to 5.6 μM), followed by PCBs 28, 47, 52, and 180; additionally, PCBs 122, 153, and 168 showed low but still significant potency to reduce luciferase activity. Detection of CYP1A1 mRNA levels in liver epithelial cells largely confirmed these results for the most abundant NDL-PCBs, whereas the other AhR-dependent events (CYP1B1 mRNA expression, induction of cell proliferation in confluent cells) were less sensitive to NDL-PCBs, thus indicating a more complex regulation of these endpoints. The present data suggest that some NDL-PCBs could modulate overall dioxin-like effects in complex mixtures.

High doses of recombinant mannan-binding lectin inhibit the binding of influenza A(H1N1)pdm09 virus with cells expressing DC-SIGN.

PubMed

Yu, Lei; Shang, Shiqiang; Tao, Ran; Wang, Caiyun; Zhang, Li; Peng, Hao; Chen, Yinghu

2017-07-01

The pandemic influenza A (H1N1)pdm09 virus continues to be a threat to human health. Low doses of mannan-binding lectin (MBL) (<1 μg/mL) were shown not to protect against influenza A(H1N1)pdm09 infection. However, the effect of high doses of MBL has not been investigated. Dendritic cell-specific intercellular adhesion molecule-3 grabbing non-integrin (DC-SIGN) has been proposed as an alternative receptor for influenza A(H1N1)pdm09 virus. In this study, we examined the expression of DC-SIGN on DCs as well as on acute monocytic leukemia cell line, THP-1. High doses of recombinant or human MBL inhibited binding of influenza A(H1N1)pdm09 to both these cell types in the presence of complement derived from bovine serum. Further, anti-DC-SIGN monoclonal antibody inhibited binding of influenza A(H1N1)pdm09 to both DC-SIGN-expressing DCs and THP-1 cells. This study demonstrates that high doses of MBL can inhibit binding of influenza A(H1N1)pdm09 virus to DC-SIGN-expressing cells in the presence of complement. Our results suggest that DC-SIGN may be an alternative receptor for influenza A(H1N1)pdm09 virus. © 2017 APMIS. Published by John Wiley & Sons Ltd.

Lupinalbin A as the most potent estrogen receptor α- and aryl hydrocarbon receptor agonist in Eriosema laurentii de Wild. (Leguminosae).

PubMed

Ateba, Sylvin Benjamin; Njamen, Dieudonné; Medjakovic, Svjetlana; Zehl, Martin; Kaehlig, Hanspeter; Jungbauer, Alois; Krenn, Liselotte

2014-08-09

Eriosema laurentii De Wild. (Leguminosae) is a plant used in Cameroon against infertility and gynecological or menopausal complaints. In our previous report, a methanol extract of its aerial parts was shown to exhibit estrogenic and aryl hydrocarbon receptor agonistic activities in vitro and to prevent menopausal symptoms in ovariectomized Wistar rats. In order to determine the major estrogen receptor α (ERα) agonists in the extract, an activity-guided fractionation was performed using the ERα yeast screen. To check whether the ERα active fractions/compounds also accounted for the aryl hydrocarbon receptor (AhR) agonistic activity of the crude methanol extract, they were further tested on the AhR yeast screen. This study led to the identification of 2'-hydroxygenistein, lupinalbin A and genistein as major estrogenic principles of the extract. 2'-hydroxygenistein and lupinalbin A were, for the first time, also shown to possess an AhR agonistic activity, whereas genistein was not active in this assay. In addition, it was possible to deduce structure-activity relationships. These results suggest that the identified compounds are the major active principles responsible for the estrogenic and AhR agonistic activities of the crude methanol extract of the aerial parts of Eriosema laurentii.

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

PubMed

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.

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

PubMed Central

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

Prevalence of Influenza A(H1N1)pdm09 Virus Resistant to Oseltamivir in Shiraz, Iran, During 2012 - 2013.

PubMed

Khodadad, Nastaran; Moattari, Afagh; Shamsi Shahr Abadi, Mahmoud; Kadivar, Mohammad Rahim; Sarvari, Jamal; Tavakoli, Forough; Pirbonyeh, Neda; Emami, Amir

2015-08-01

Oseltamivir has been used as a drug of choice for the prophylaxis and treatment of human influenza A(H1N1)pdm09 infection across the world. However, the most frequently identified oseltamivir resistant virus, influenza A(H1N1)pdm09, exhibit the H275Y substitution in NA gene. This study aimed to determine the prevalence and phylogenetic relationships of oseltamivir resistance in influenza A(H1N1)pdm09 viruses isolated in Shiraz, Iran. Throat swab samples were collected from 200 patients with influenza-like disease from December 2012 until February 2013. A total of 77 influenza A(H1N1)pdm09 positive strains were identified by real-time polymerase chain reaction (PCR). Oseltamivir resistance was detected using quantal assay and nested-PCR method. The NA gene sequencing was conducted to detect oseltamivir-resistant mutants and establish the phylogeny of the prevalent influenza variants. Our results revealed that A(H1N1)pdm09 viruses present in these samples were susceptible to oseltamivir, and contained 5 site specific mutations (V13G, V106I, V241I, N248D, and N369K) in NA gene. These mutations correlated with increasing expression and enzymatic activity of NA protein in the influenza A(H1N1)pdm09 viruses, which were closely related to a main influenza A(H1N1)pdm09 cluster isolated around the world. A(H1N1)pdm09 viruses, identified in this study in Shiraz, Iran, contained 5 site specific mutations and were susceptible to oseltamivir.

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

PubMed

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.

Functional variants of the dopamine receptor D2 gene modulate prefronto-striatal phenotypes in schizophrenia.

PubMed

Bertolino, Alessandro; Fazio, Leonardo; Caforio, Grazia; Blasi, Giuseppe; Rampino, Antonio; Romano, Raffaella; Di Giorgio, Annabella; Taurisano, Paolo; Papp, Audrey; Pinsonneault, Julia; Wang, Danxin; Nardini, Marcello; Popolizio, Teresa; Sadee, Wolfgang

2009-02-01

Dopamine D2 receptor signalling is strongly implicated in the aetiology of schizophrenia. We have recently characterized the function of three DRD2 SNPs: rs12364283 in the promoter affecting total D2 mRNA expression; rs2283265 and rs1076560, respectively in introns 5 and 6, shifting mRNA splicing to two functionally distinct isoforms, the short form of D2 (D2S) and the long form (D2L). These two isoforms differentially contribute to dopamine signalling in prefrontal cortex and in striatum. We performed a case-control study to determine association of these variants and of their main haplotypes with several schizophrenia-related phenotypes. We demonstrate that the minor allele in the intronic variants is associated with reduced expression of %D2S of total mRNA in post-mortem prefrontal cortex, and with impaired working memory behavioural performance, both in patients and controls. However, the fMRI results show opposite effects in patients compared with controls: enhanced engagement of prefronto-striatal pathways in controls and reduced activity in patients. Moreover, the promoter variant is also associated with working memory activity in prefrontal cortex and striatum of patients, and less robustly with negative symptoms scores. Main haplotypes formed by the three DRD2 variants showed significant associations with these phenotypes consistent with those of the individual SNPs. Our results indicate that the three functional DRD2 variants modulate schizophrenia phenotypes possibly by modifying D2S/D2L ratios in the context of different total D2 density.

Functional variants of the dopamine receptor D2 gene modulate prefronto-striatal phenotypes in schizophrenia

PubMed Central

Fazio, Leonardo; Caforio, Grazia; Blasi, Giuseppe; Rampino, Antonio; Romano, Raffaella; Di Giorgio, Annabella; Taurisano, Paolo; Papp, Audrey; Pinsonneault, Julia; Wang, Danxin; Nardini, Marcello; Popolizio, Teresa; Sadee, Wolfgang

2009-01-01

Dopamine D2 receptor signalling is strongly implicated in the aetiology of schizophrenia. We have recently characterized the function of three DRD2 SNPs: rs12364283 in the promoter affecting total D2 mRNA expression; rs2283265 and rs1076560, respectively in introns 5 and 6, shifting mRNA splicing to two functionally distinct isoforms, the short form of D2 (D2S) and the long form (D2L). These two isoforms differentially contribute to dopamine signalling in prefrontal cortex and in striatum. We performed a case–control study to determine association of these variants and of their main haplotypes with several schizophrenia-related phenotypes. We demonstrate that the minor allele in the intronic variants is associated with reduced expression of %D2S of total mRNA in post-mortem prefrontal cortex, and with impaired working memory behavioural performance, both in patients and controls. However, the fMRI results show opposite effects in patients compared with controls: enhanced engagement of prefronto-striatal pathways in controls and reduced activity in patients. Moreover, the promoter variant is also associated with working memory activity in prefrontal cortex and striatum of patients, and less robustly with negative symptoms scores. Main haplotypes formed by the three DRD2 variants showed significant associations with these phenotypes consistent with those of the individual SNPs. Our results indicate that the three functional DRD2 variants modulate schizophrenia phenotypes possibly by modifying D2S/D2L ratios in the context of different total D2 density. PMID:18829695

Binding affinity of the L-742,001 inhibitor to the endonuclease domain of A/H1N1/PA influenza virus variants: Molecular simulation approaches

NASA Astrophysics Data System (ADS)

Nguyen, Hung; Nguyen, Hoang Linh; Linh, Huynh Quang; Nguyen, Minh Tho

2018-01-01

The steered molecular dynamics (SMD), molecular mechanics Poisson-Boltzmann surface area (MM-PBSA) and free energy perturbation (FEP) methods were used to determine the binding affinity of the L-742,001 inhibitor to the endonuclease domain of the A/H1N1/PA influenza viruses (including wild type (WT) and three mutations I79L, E119D and F105S for both pH1N1 PA and PR8 PA viruses). Calculated results showed that the L-742,001 inhibitor not only binds to the PR8 PAs (1934 A influenza virus) better than to the pH1N1 PAs (2009 A influenza virus) but also more strongly interacts with the WT endonuclease domain than with three mutant variants for both pH1N1 PA and PR8 PA viruses. The binding affinities obtained by the SMD, MM-PBSA and FEP methods attain high correlation with available experimental data. Here the FEP method appears to provide a more accurate determination of the binding affinity than the SMD and MM-PBSA counterparts.

Autism gene variant causes hyperserotonemia, serotonin receptor hypersensitivity, social impairment and repetitive behavior

PubMed Central

Veenstra-VanderWeele, Jeremy; Muller, Christopher L.; Iwamoto, Hideki; Sauer, Jennifer E.; Owens, W. Anthony; Shah, Charisma R.; Cohen, Jordan; Mannangatti, Padmanabhan; Jessen, Tammy; Thompson, Brent J.; Ye, Ran; Kerr, Travis M.; Carneiro, Ana M.; Crawley, Jacqueline N.; Sanders-Bush, Elaine; McMahon, Douglas G.; Ramamoorthy, Sammanda; Daws, Lynette C.; Sutcliffe, James S.; Blakely, Randy D.

2012-01-01

Fifty years ago, increased whole-blood serotonin levels, or hyperserotonemia, first linked disrupted 5-HT homeostasis to Autism Spectrum Disorders (ASDs). The 5-HT transporter (SERT) gene (SLC6A4) has been associated with whole blood 5-HT levels and ASD susceptibility. Previously, we identified multiple gain-of-function SERT coding variants in children with ASD. Here we establish that transgenic mice expressing the most common of these variants, SERT Ala56, exhibit elevated, p38 MAPK-dependent transporter phosphorylation, enhanced 5-HT clearance rates and hyperserotonemia. These effects are accompanied by altered basal firing of raphe 5-HT neurons, as well as 5HT1A and 5HT2A receptor hypersensitivity. Strikingly, SERT Ala56 mice display alterations in social function, communication, and repetitive behavior. Our efforts provide strong support for the hypothesis that altered 5-HT homeostasis can impact risk for ASD traits and provide a model with construct and face validity that can support further analysis of ASD mechanisms and potentially novel treatments. PMID:22431635

Autism gene variant causes hyperserotonemia, serotonin receptor hypersensitivity, social impairment and repetitive behavior.

PubMed

Veenstra-VanderWeele, Jeremy; Muller, Christopher L; Iwamoto, Hideki; Sauer, Jennifer E; Owens, W Anthony; Shah, Charisma R; Cohen, Jordan; Mannangatti, Padmanabhan; Jessen, Tammy; Thompson, Brent J; Ye, Ran; Kerr, Travis M; Carneiro, Ana M; Crawley, Jacqueline N; Sanders-Bush, Elaine; McMahon, Douglas G; Ramamoorthy, Sammanda; Daws, Lynette C; Sutcliffe, James S; Blakely, Randy D

2012-04-03

Fifty years ago, increased whole-blood serotonin levels, or hyperserotonemia, first linked disrupted 5-HT homeostasis to Autism Spectrum Disorders (ASDs). The 5-HT transporter (SERT) gene (SLC6A4) has been associated with whole blood 5-HT levels and ASD susceptibility. Previously, we identified multiple gain-of-function SERT coding variants in children with ASD. Here we establish that transgenic mice expressing the most common of these variants, SERT Ala56, exhibit elevated, p38 MAPK-dependent transporter phosphorylation, enhanced 5-HT clearance rates and hyperserotonemia. These effects are accompanied by altered basal firing of raphe 5-HT neurons, as well as 5HT(1A) and 5HT(2A) receptor hypersensitivity. Strikingly, SERT Ala56 mice display alterations in social function, communication, and repetitive behavior. Our efforts provide strong support for the hypothesis that altered 5-HT homeostasis can impact risk for ASD traits and provide a model with construct and face validity that can support further analysis of ASD mechanisms and potentially novel treatments.

Whole-Genome Characterization of a Novel Human Influenza A(H1N2) Virus Variant, Brazil

PubMed Central

Born, Priscila Silva; Matos, Aline Rocha; Motta, Fernando Couto; Caetano, Braulia Costa; Debur, Maria do Carmo; Riediger, Irina Nastassja; Brown, David; Siqueira, Marilda M.

2017-01-01

We report the characterization of a novel reassortant influenza A(H1N2) virus not previously reported in humans. Recovered from a a pig farm worker in southeast Brazil who had influenza-like illness, this virus is a triple reassortant containing gene segments from subtypes H1N2 (hemagglutinin), H3N2 (neuraminidase), and pandemic H1N1 (remaining genes). PMID:27983507

Whole-Genome Characterization of a Novel Human Influenza A(H1N2) Virus Variant, Brazil.

PubMed

Resende, Paola Cristina; Born, Priscila Silva; Matos, Aline Rocha; Motta, Fernando Couto; Caetano, Braulia Costa; Debur, Maria do Carmo; Riediger, Irina Nastassja; Brown, David; Siqueira, Marilda M

2017-01-01

We report the characterization of a novel reassortant influenza A(H1N2) virus not previously reported in humans. Recovered from a a pig farm worker in southeast Brazil who had influenza-like illness, this virus is a triple reassortant containing gene segments from subtypes H1N2 (hemagglutinin), H3N2 (neuraminidase), and pandemic H1N1 (remaining genes).

An introduction to the molecular basics of aryl hydrocarbon receptor biology.

PubMed

Abel, Josef; Haarmann-Stemmann, Thomas

2010-11-01

Depending on their chemical structure and properties, environmental chemicals and other xenobiotics that enter the cell can affect cellular function by either nonselective binding to cellular macromolecules or by interference with cellular receptors, which would initiate a more defined cell biological response. One of these intracellular chemosensor molecules is the aryl hydrocarbon receptor (AhR), a transcription factor of the bHLH/PAS family that is known to mediate the biochemical and toxic effects of dioxins, polyaromatic hydrocarbons and related compounds. Numerous investigations have revealed that the AhR is not only a master regulator of drug metabolism activated by anthropogenic chemicals, but is also triggered by natural and endogenous ligands and can influence cell biological endpoints such as growth and differentiation. Cutting-edge research has identified new intriguing functions of the AhR, such as during proteasomal degradation of steroid hormone receptors, the cellular UVB stress response and the differentiation of certain T-cell subsets. In this review we provide both a survey of the fundamental basics of AhR biology and an insight into new functional aspects of AhR signaling to further stimulate research on this intriguing transcription factor at the interface between toxicology, cell biology and immunology.

Introducing the "TCDD-inducible AhR-Nrf2 gene battery".

PubMed

Yeager, Ronnie L; Reisman, Scott A; Aleksunes, Lauren M; Klaassen, Curtis D

2009-10-01

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) induces genes via the transcription factor aryl hydrocarbon receptor (AhR), including Cyp1a1, NAD(P)H:quinone oxidoreductase 1 (Nqo1), UDP-glucuronosyltransferase 1a6 (Ugt1a6), and glutathione S-transferase a1 (Gsta1). These genes are referred to as the "AhR gene battery." However, Nqo1 is also considered a prototypical target gene of the transcription factor nuclear factor erythroid 2-related factor 2 (Nrf2). In mice, TCDD induction of Nrf2 and Nrf2 target, Nqo1, is dependent on AhR, and thus TCDD induction of drug-processing genes may be routed through an AhR-Nrf2 sequence. There has been speculation that Nrf2 may be involved in the TCDD induction of drug-processing genes; however, the data are not definitive. Therefore, to address whether TCDD induction of Nqo1, Ugts, and Gsts is dependent on Nrf2, we conducted the definitive experiment by administering TCDD (50 mug/kg, ip) to Nrf2-null and wild-type (WT) mice and collecting livers 24 h later to quantify the mRNA of drug-processing genes. TCDD induction of Cyp1a1 and Ugt1a1 was similar in WT and Nrf2-null mice, whereas TCDD induction of Ugt1a5 and 1a9 was blunted in Nrf2-null mice. TCDD induced Nqo1, Ugt1a6, 2b34, 2b35, 2b36, UDP-glucuronic acid-synthesizing gene UDP-glucose dehydrogenase, and Gsta1, m1, m2, m3, m6, p2, t2, and microsomal Gst1 in WT mice but not in Nrf2-null mice. Therefore, the present study demonstrates the novel finding that Nrf2 is required for TCDD induction of classical AhR battery genes Nqo1, Ugt1a6, and Gsta1, as well as most Ugt and Gst isoforms in livers of mice.

4-Nitrophenol exposure alters the AhR signaling pathway and related gene expression in the rat liver.

PubMed

Li, Ruonan; Song, Meiyan; Li, Zhi; Li, Yansen; Watanabe, Gen; Nagaoka, Kentaro; Taya, Kazuyoshi; Li, Chunmei

2017-02-01

4-Nitrophenol (PNP) is well known as an environmental endocrine disruptor. The aim of this study was to clarify the mechanism of PNP-induced liver damage and determine the regulatory involvement of the aryl hydrocarbon receptor (AhR) signaling pathway and associated gene expression. Immature male Wistar-Imamichi rats (28 days old) were randomly divided into control and PNP groups, which consisted of 1- and 3-day exposure (1 DE and 3 DE, respectively) and 3-day exposure followed by 3-day recovery (3 DE + 3 DR), groups. Each group was administered the vehicle or PNP (200 mg kg -1 body weight). The body and liver weight were significantly decreased in the 3 DE group. The mRNA expression levels of estrogen receptor-α (ERα), glutathione S-transferase (GST) and AhR exhibited a significant increase in the 1 DE group whereas, in contrast, that of cytochrome P450 (CYP) 1A1 decreased significantly in the 3 DE +3 DR group. AhR and CYP1A1 proteins were detected in the cytoplasm of hepatocytes of the 1 DE and 3 DE +3 DR groups whereas the ERα protein was found in the hepatocyte nuclei of the 1 DE and 3 DE groups. The present study demonstrates that PNP activated the AhR signaling pathway and regulated related CYP1A1 and GST gene expression in the liver. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

A comparison between the blocking actions of 2-(4-phenylpiperidino) cyclohexanol (AH 5183) and its N-methyl quaternary analogue (AH 5954)

PubMed Central

Marshall, I. G.

1970-01-01

1. The neuromuscular blocking activities of AH 5183 (2-(4-phenylpiperidino) cyclohexanol) and its N-methyl quaternary analogue (AH 5954) were compared in rapidly stimulated nerve-skeletal muscle preparations of the rat, chicken and cat. 2. The evidence indicated that in isolated preparations the neuromuscular block produced by both AH 5183 and AH 5954 was primarily pre-junctional in origin. That produced by AH 5954 was readily reversible either by washing the tissue or by reducing the stimulation frequency, whereas that produced by AH 5183 was difficult to reverse in these ways. 3. Low doses of AH 5954 sensitized the rat hemidiaphragm preparation to the neuromuscular blocking action of choline. The neuromuscular block produced by choline was reversible by tetraethylammonium but not by neostigmine. This suggested that the blocking action of choline is at least partly pre-junctional in nature. 4. In anaesthetized cats AH 5954 possessed a biphasic neuromuscular blocking action. The initial phase was rapid in onset, suggestive of a post-junctional action, whereas the second phase was prolonged and reversible by choline, suggestive of a prejunctional inhibitory action on the choline transport mechanism. AH 5183 produced no initial blocking action and was irreversible by choline. 5. Both AH 5183 and AH 5954 possessed local anaesthetic and α-adrenoceptor blocking actions. These actions and the neuromuscular blocking action were affected to different degrees by quaternization, suggesting that the three main actions of the two drugs are independent. 6. It was concluded that AH 5954 and AH 5183 act at different pre-junctional sites at the neuromuscular junction, AH 5954 acting extraneuronally by inhibiting choline transport and AH 5183 intraneuronally at the level of the synaptic vesicle membrane. PMID:4395087

Natural co-infection of influenza A/H3N2 and A/H1N1pdm09 viruses resulting in a reassortant A/H3N2 virus.

PubMed

Rith, Sareth; Chin, Savuth; Sar, Borann; Y, Phalla; Horm, Srey Viseth; Ly, Sovann; Buchy, Philippe; Dussart, Philippe; Horwood, Paul F

2015-12-01

Despite annual co-circulation of different subtypes of seasonal influenza, co-infections between different viruses are rarely detected. These co-infections can result in the emergence of reassortant progeny. We document the detection of an influenza co-infection, between influenza A/H3N2 with A/H1N1pdm09 viruses, which occurred in a 3 year old male in Cambodia during April 2014. Both viruses were detected in the patient at relatively high viral loads (as determined by real-time RT-PCR CT values), which is unusual for influenza co-infections. As reassortment can occur between co-infected influenza A strains we isolated plaque purified clonal viral populations from the clinical material of the patient infected with A/H3N2 and A/H1N1pdm09. Complete genome sequences were completed for 7 clonal viruses to determine if any reassorted viruses were generated during the influenza virus co-infection. Although most of the viral sequences were consistent with wild-type A/H3N2 or A/H1N1pdm09, one reassortant A/H3N2 virus was isolated which contained an A/H1N1pdm09 NS1 gene fragment. The reassortant virus was viable and able to infect cells, as judged by successful passage in MDCK cells, achieving a TCID50 of 10(4)/ml at passage number two. There is no evidence that the reassortant virus was transmitted further. The co-infection occurred during a period when co-circulation of A/H3N2 and A/H1N1pdm09 was detected in Cambodia. It is unclear how often influenza co-infections occur, but laboratories should consider influenza co-infections during routine surveillance activities. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.

Relationship between variant forms of estrogen receptor RNA and an apoptosis-related RNA, TRPM-2, with survival in patients with breast cancer.

PubMed

Rennie, P S; Mawji, N R; Coldman, A J; Godolphin, W; Jones, E C; Vielkind, J R; Bruchovsky, N

1993-12-15

Although smaller variant forms of estrogen receptor (ER) messenger RNA (mRNA) have been detected in breast tumors, neither their prevalence nor their prognostic significance have been evaluated. Similarly, TRPM-2 mRNA, the product of a gene induced principally during the onset of apoptosis, is present in mouse and human breast cancer cell lines, but whether it also occurs in primary breast tumors and is related to disease outcome is unknown. The relative expression and transcript size of ER mRNA and TRPM-2 mRNA in 126 primary breast tumors were measured by Northern analysis and compared with tumor grade, hormone receptor status, extent of tumor necrosis, and survival. In ER-positive tumors, 64% of the tumors had only the normal 6.5 kb ER mRNA, an additional 9% had the normal plus smaller ER mRNA, and 2% had variant forms. Only 8% of ER-negative tumors had ER mRNA transcripts. There were significant relationships between the occurrence of ER mRNA and low tumor grade, ER-positive receptor status, and better survival. In contrast, TRPM-2 mRNA was found in only 17% of breast tumors, none of which could be grouped with respect to grade, hormone receptor status, or survival. The presence of smaller variant forms of ER mRNA either alone or in association with the normal ER transcript is not indicative of an unfavorable prognosis, whereas TRPM-2 mRNA occurs in many primary breast tumors, but has no apparent relationship to survival.

Virulent variants emerging in mice infected with the apathogenic prototype strain of the parvovirus minute virus of mice exhibit a capsid with low avidity for a primary receptor.

PubMed

Rubio, Mari-Paz; López-Bueno, Alberto; Almendral, José M

2005-09-01

The mechanisms involved in the emergence of virulent mammalian viruses were investigated in the adult immunodeficient SCID mouse infected by the attenuated prototype strain of the parvovirus Minute Virus of Mice (MVMp). Cloned MVMp intravenously inoculated in mice consistently evolved during weeks of subclinical infection to variants showing altered plaque phenotypes. All the isolated large-plaque variants spread systemically from the oronasal cavity and replicated in major organs (brain, kidney, liver), in sharp contrast to the absolute inability of the MVMp and small-plaque variants to productively invade SCID organs by this natural route of infection. The virulent variants retained the MVMp capacity to infect mouse fibroblasts, consistent with the lack of genetic changes across the 220-to-335 amino acid sequence of VP2, a capsid domain containing main determinants of MVM tropism. However, the capsid of the virulent variants shared a lower affinity than the wild type for a primary receptor used in the cytotoxic infection. The capsid gene of a virulent variant engineered in the MVMp background endowed the recombinant virus with a large-plaque phenotype, lower affinity for the receptor, and productive invasiveness by the oronasal route in SCID mice, eventually leading to 100% mortality. In the analysis of virulence in mice, both MVMp and the recombinant virus similarly gained the bloodstream 1 to 2 days postoronasal inoculation and remained infectious when adsorbed to blood cells in vitro. However, the wild-type MVMp was cleared from circulation a few days afterwards, in contrast to the viremia of the recombinant virus, which was sustained for life. Significantly, attachment to an abundant receptor of primary mouse kidney epithelial cells by both viruses could be quantitatively competed by wild-type MVMp capsids, indicating that virulence is not due to an extended receptor usage in target tissues. We conclude that the selection of capsid-receptor interactions of

Virulent Variants Emerging in Mice Infected with the Apathogenic Prototype Strain of the Parvovirus Minute Virus of Mice Exhibit a Capsid with Low Avidity for a Primary Receptor

PubMed Central

Rubio, Mari-Paz; López-Bueno, Alberto; Almendral, José M.

2005-01-01

The mechanisms involved in the emergence of virulent mammalian viruses were investigated in the adult immunodeficient SCID mouse infected by the attenuated prototype strain of the parvovirus Minute Virus of Mice (MVMp). Cloned MVMp intravenously inoculated in mice consistently evolved during weeks of subclinical infection to variants showing altered plaque phenotypes. All the isolated large-plaque variants spread systemically from the oronasal cavity and replicated in major organs (brain, kidney, liver), in sharp contrast to the absolute inability of the MVMp and small-plaque variants to productively invade SCID organs by this natural route of infection. The virulent variants retained the MVMp capacity to infect mouse fibroblasts, consistent with the lack of genetic changes across the 220-to-335 amino acid sequence of VP2, a capsid domain containing main determinants of MVM tropism. However, the capsid of the virulent variants shared a lower affinity than the wild type for a primary receptor used in the cytotoxic infection. The capsid gene of a virulent variant engineered in the MVMp background endowed the recombinant virus with a large-plaque phenotype, lower affinity for the receptor, and productive invasiveness by the oronasal route in SCID mice, eventually leading to 100% mortality. In the analysis of virulence in mice, both MVMp and the recombinant virus similarly gained the bloodstream 1 to 2 days postoronasal inoculation and remained infectious when adsorbed to blood cells in vitro. However, the wild-type MVMp was cleared from circulation a few days afterwards, in contrast to the viremia of the recombinant virus, which was sustained for life. Significantly, attachment to an abundant receptor of primary mouse kidney epithelial cells by both viruses could be quantitatively competed by wild-type MVMp capsids, indicating that virulence is not due to an extended receptor usage in target tissues. We conclude that the selection of capsid-receptor interactions of

Dioxin Receptor Expression Inhibits Basal and Transforming Growth Factor β-induced Epithelial-to-mesenchymal Transition*

PubMed Central

Rico-Leo, Eva M.; Alvarez-Barrientos, Alberto; Fernandez-Salguero, Pedro M.

2013-01-01

Recent studies have emphasized the role of the dioxin receptor (AhR) in maintaining cell morphology, adhesion, and migration. These novel AhR functions depend on the cell phenotype, and although AhR expression maintains mesenchymal fibroblasts migration, it inhibits keratinocytes motility. These observations prompted us to investigate whether AhR modulates the epithelial-to-mesenchymal transition (EMT). For this, we have used primary AhR+/+ and AhR−/− keratinocytes and NMuMG cells engineered to knock down AhR levels (sh-AhR) or to express a constitutively active receptor (CA-AhR). Both AhR−/− keratinocytes and sh-AhR NMuMG cells had increased migration, reduced levels of epithelial markers E-cadherin and β-catenin, and increased expression of mesenchymal markers Snail, Slug/Snai2, vimentin, fibronectin, and α-smooth muscle actin. Consistently, AhR+/+ and CA-AhR NMuMG cells had reduced migration and enhanced expression of epithelial markers. AhR activation by the agonist FICZ (6-formylindolo[3,2-b]carbazole) inhibited NMuMG migration, whereas the antagonist α-naphthoflavone induced migration as did AhR knockdown. Exogenous TGFβ exacerbated the promigratory mesenchymal phenotype in both AhR-expressing and AhR-depleted cells, although the effects on the latter were more pronounced. Rescuing AhR expression in sh-AhR cells reduced Snail and Slug/Snai2 levels and cell migration and restored E-cadherin levels. Interference of AhR in human HaCaT cells further supported its role in EMT. Interestingly, co-immunoprecipitation and immunofluorescence assays showed that AhR associates in common protein complexes with E-cadherin and β-catenin, suggesting the implication of AhR in cell-cell adhesion. Thus, basal or TGFβ-induced AhR down-modulation could be relevant in the acquisition of a motile EMT phenotype in both normal and transformed epithelial cells. PMID:23382382

Involvement of the cytokine-IDO1-AhR loop in zinc oxide nanoparticle-induced acute pulmonary inflammation.

PubMed

Ho, Chia-Chi; Lee, Hui-Ling; Chen, Chao-Yu; Luo, Yueh-Hsia; Tsai, Ming-Hsien; Tsai, Hui-Ti; Lin, Pinpin

2017-04-01

Zinc oxide nanoparticles (ZnONPs) are widely used in our daily life, such as in sunscreens and electronic nanodevices. However, pulmonary exposure to ZnONPs causes acute pulmonary inflammation, which is considered as an initial event for various respiratory diseases. Thus, elucidation of the underlying cellular mechanisms of ZnONPs can help us in predicting their potential effects in respiratory diseases. In this study, we observed that ZnONPs increased proinflammatory cytokines, accompanied with an increased expression of aryl hydrocarbon receptor (AhR) and its downstream target cytochrome P450 1A1 (CYP1A1) in macrophages in vitro and in mouse lung epithelia in vivo. Moreover, zinc nitrate, but not silica or titanium dioxide nanoparticles (NPs), had similar effects on macrophages, indicating that the zinc element or ion released from ZnONPs is likely responsible for the activation of the AhR pathway. Cotreatment with an AhR antagonist or AhR knockout reduced ZnONPs-induced cytokine secretion in macrophages or mice, respectively. Furthermore, kynurenine (KYN), an endogenous AhR agonist and a tryptophan metabolite catalyzed by indoleamine 2,3-dioxygenase (IDO), was increased in the serums of mice that aspirated ZnONPs. Consistently, ZnONPs increased IDO1 expression in lung cells in vitro and in vivo. Finally, AhR knockout reduced ZnONPs-induced pulmonary inflammation, cytokine secretion and KYN production in mice, suggesting that AhR activation is involved in ZnONPs-induced cytokine secretion and pulmonary inflammation. In summary, we demonstrated that the pulmonary exposure of ZnONPs stimulated the cytokine-IDO1-AhR loop in the lungs, which has been implied to play roles in immune dysfunctions.

12 CFR Appendixes A-H to Subpart A... - Appendixes A-H to Subpart A of Part 702

Code of Federal Regulations, 2010 CFR

2010-01-01

... 12 Banks and Banking 6 2010-01-01 2010-01-01 false Appendixes A-H to Subpart A of Part 702 A Appendixes A-H to Subpart A of Part 702 Banks and Banking NATIONAL CREDIT UNION ADMINISTRATION REGULATIONS AFFECTING CREDIT UNIONS PROMPT CORRECTIVE ACTION Net Worth Classification Pt. 702, Apps. Appendixes A-H to...

Activation of aryl hydrocarbon receptor reduces carbendazim-induced cell death

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wei, Kuo-Liang

Carbendazim inhibits microtubule assembly, thus blocking mitosis and inhibiting cancer cell proliferation. Accordingly, carbendazim is being explored as an anticancer drug. Data show that carbendazim increased mRNA and protein expressions and promoter activity of CYP1A1. In addition, carbendazim activated transcriptional activity of the aryl hydrocarbon response element, and induced nuclear translocation of the aryl hydrocarbon receptor (AhR), a sign the AhR is activated. Carbendazim-induced CYP1A1 expression was blocked by AhR antagonists, and was abolished in AhR signal-deficient cells. Results demonstrated that carbendazim activated the AhR, thereby stimulating CYP1A1 expression. In order to understand whether AhR-induced metabolic enzymes turn carbendazim intomore » less-toxic metabolites, Hoechst 33342 staining to reveal carbendazim-induced nuclear changes and flow cytometry to reveal the subG{sub 0}/G{sub 1} population were applied to monitor carbendazim-induced cell apoptosis. Carbendazim induced less apoptosis in Hepa-1c1c7 cells than in AhR signal-deficient Hepa-1c1c7 mutant cells. Pretreatment with β-NF, an AhR agonist that highly induces CYP1A1 expression, decreased carbendazim-induced cell death. In addition, the lower the level of AhR was, the lower the vitality present in carbendazim-treated cells, including hepatoma cells and their derivatives with AhR RNA interference, also embryonic kidney cells, bladder carcinoma cells, and AhR signal-deficient Hepa-1c1c7 cells. In summary, carbendazim is an AhR agonist. The toxicity of carbendazim was lower in cells with the AhR signal. This report provides clues indicating that carbendazim is more potent at inducing cell death in tissues without than in those with the AhR signal, an important reference for applying carbendazim in cancer chemotherapy. - Highlights: • Carbendazim induced transcriptional activity of the aryl hydrocarbon response element. • Carbendazim induced nuclear translocation of the

Pathobiological features of a novel, highly pathogenic avian influenza A(H5N8) virus

PubMed Central

Kim, Young-Il; Pascua, Philippe Noriel Q; Kwon, Hyeok-Il; Lim, Gyo-Jin; Kim, Eun-Ha; Yoon, Sun-Woo; Park, Su-Jin; Kim, Se Mi; Choi, Eun-Ji; Si, Young-Jae; Lee, Ok-Jun; Shim, Woo-Sub; Kim, Si-Wook; Mo, In-Pil; Bae, Yeonji; Lim, Yong Taik; Sung, Moon Hee; Kim, Chul-Joong; Webby, Richard J; Webster, Robert G; Choi, Young Ki

2014-01-01

The endemicity of highly pathogenic avian influenza (HPAI) A(H5N1) viruses in Asia has led to the generation of reassortant H5 strains with novel gene constellations. A newly emerged HPAI A(H5N8) virus caused poultry outbreaks in the Republic of Korea in 2014. Because newly emerging high-pathogenicity H5 viruses continue to pose public health risks, it is imperative that their pathobiological properties be examined. Here, we characterized A/mallard duck/Korea/W452/2014 (MDk/W452(H5N8)), a representative virus, and evaluated its pathogenic and pandemic potential in various animal models. We found that MDk/W452(H5N8), which originated from the reassortment of wild bird viruses harbored by migratory waterfowl in eastern China, replicated systemically and was lethal in chickens, but appeared to be attenuated, albeit efficiently transmitted, in ducks. Despite predominant attachment to avian-like virus receptors, MDk/W452(H5N8) also exhibited detectable human virus-like receptor binding and replicated in human respiratory tract tissues. In mice, MDk/W452(H5N8) was moderately pathogenic and had limited tissue tropism relative to previous HPAI A(H5N1) viruses. It also induced moderate nasal wash titers in inoculated ferrets; additionally, it was recovered in extrapulmonary tissues and one of three direct-contact ferrets seroconverted without shedding. Moreover, domesticated cats appeared to be more susceptible than dogs to virus infection. With their potential to become established in ducks, continued circulation of A(H5N8) viruses could alter the genetic evolution of pre-existing avian poultry strains. Overall, detailed virological investigation remains a necessity given the capacity of H5 viruses to evolve to cause human illness with few changes in the viral genome. PMID:26038499

Pathobiological features of a novel, highly pathogenic avian influenza A(H5N8) virus.

PubMed

Kim, Young-Il; Pascua, Philippe Noriel Q; Kwon, Hyeok-Il; Lim, Gyo-Jin; Kim, Eun-Ha; Yoon, Sun-Woo; Park, Su-Jin; Kim, Se Mi; Choi, Eun-Ji; Si, Young-Jae; Lee, Ok-Jun; Shim, Woo-Sub; Kim, Si-Wook; Mo, In-Pil; Bae, Yeonji; Lim, Yong Taik; Sung, Moon Hee; Kim, Chul-Joong; Webby, Richard J; Webster, Robert G; Choi, Young Ki

2014-10-01

The endemicity of highly pathogenic avian influenza (HPAI) A(H5N1) viruses in Asia has led to the generation of reassortant H5 strains with novel gene constellations. A newly emerged HPAI A(H5N8) virus caused poultry outbreaks in the Republic of Korea in 2014. Because newly emerging high-pathogenicity H5 viruses continue to pose public health risks, it is imperative that their pathobiological properties be examined. Here, we characterized A/mallard duck/Korea/W452/2014 (MDk/W452(H5N8)), a representative virus, and evaluated its pathogenic and pandemic potential in various animal models. We found that MDk/W452(H5N8), which originated from the reassortment of wild bird viruses harbored by migratory waterfowl in eastern China, replicated systemically and was lethal in chickens, but appeared to be attenuated, albeit efficiently transmitted, in ducks. Despite predominant attachment to avian-like virus receptors, MDk/W452(H5N8) also exhibited detectable human virus-like receptor binding and replicated in human respiratory tract tissues. In mice, MDk/W452(H5N8) was moderately pathogenic and had limited tissue tropism relative to previous HPAI A(H5N1) viruses. It also induced moderate nasal wash titers in inoculated ferrets; additionally, it was recovered in extrapulmonary tissues and one of three direct-contact ferrets seroconverted without shedding. Moreover, domesticated cats appeared to be more susceptible than dogs to virus infection. With their potential to become established in ducks, continued circulation of A(H5N8) viruses could alter the genetic evolution of pre-existing avian poultry strains. Overall, detailed virological investigation remains a necessity given the capacity of H5 viruses to evolve to cause human illness with few changes in the viral genome.

Identification of novel subgroup A variants with enhanced receptor binding and replicative capacity in primary isolates of anaemogenic strains of feline leukaemia virus.

PubMed

Stewart, Hazel; Adema, Karen W; McMonagle, Elizabeth L; Hosie, Margaret J; Willett, Brian J

2012-05-31

The development of anaemia in feline leukaemia virus (FeLV)-infected cats is associated with the emergence of a novel viral subgroup, FeLV-C. FeLV-C arises from the subgroup that is transmitted, FeLV-A, through alterations in the amino acid sequence of the receptor binding domain (RBD) of the envelope glycoprotein that result in a shift in the receptor usage and the cell tropism of the virus. The factors that influence the transition from subgroup A to subgroup C remain unclear, one possibility is that a selective pressure in the host drives the acquisition of mutations in the RBD, creating A/C intermediates with enhanced abilities to interact with the FeLV-C receptor, FLVCR. In order to understand further the emergence of FeLV-C in the infected cat, we examined primary isolates of FeLV-C for evidence of FeLV-A variants that bore mutations consistent with a gradual evolution from FeLV-A to FeLV-C. Within each isolate of FeLV-C, we identified variants that were ostensibly subgroup A by nucleic acid sequence comparisons, but which bore mutations in the RBD. One such mutation, N91D, was present in multiple isolates and when engineered into a molecular clone of the prototypic FeLV-A (Glasgow-1), enhanced replication was noted in feline cells. Expression of the N91D Env on murine leukaemia virus (MLV) pseudotypes enhanced viral entry mediated by the FeLV-A receptor THTR1 while soluble FeLV-A Env bearing the N91D mutation bound more efficiently to mouse or guinea pig cells bearing the FeLV-A and -C receptors. Long-term in vitro culture of variants bearing the N91D substitution in the presence of anti-FeLV gp70 antibodies did not result in the emergence of FeLV-C variants, suggesting that additional selective pressures in the infected cat may drive the subsequent evolution from subgroup A to subgroup C. Our data support a model in which variants of FeLV-A, bearing subtle differences in the RBD of Env, may be predisposed towards enhanced replication in vivo and subsequent

Ethanol modulates the VR-1 variant amiloride-insensitive salt taste receptor. II. Effect on chorda tympani salt responses.

PubMed

Lyall, Vijay; Heck, Gerard L; Phan, Tam-Hao T; Mummalaneni, Shobha; Malik, Shahbaz A; Vinnikova, Anna K; Desimone, John A

2005-06-01

The effect of ethanol on the amiloride- and benzamil (Bz)-insensitive salt taste receptor was investigated by direct measurement of intracellular Na(+) activity ([Na(+)](i)) using fluorescence imaging in polarized fungiform taste receptor cells (TRCs) and by chorda tympani (CT) taste nerve recordings. CT responses to KCl and NaCl were recorded in Sprague-Dawley rats, and in wild-type (WT) and vanilloid receptor-1 (VR-1) knockout mice (KO). CT responses were monitored in the presence of Bz, a specific blocker of the epithelial Na(+) channel (ENaC). CT responses were also recorded in the presence of agonists (resiniferatoxin and elevated temperature) and antagonists (capsazepine and SB-366791) of VR-1 that similarly modulate the Bz-insensitive VR-1 variant salt taste receptor. In the absence of mineral salts, ethanol induced a transient decrease in TRC volume and elicited only transient phasic CT responses. In the presence of mineral salts, ethanol increased the apical cation flux in TRCs without a change in volume, increased transepithelial electrical resistance across the tongue, and elicited CT responses that were similar to salt responses, consisting of both a phasic component and a sustained tonic component. At concentrations <50%, ethanol enhanced responses to KCl and NaCl, while at ethanol concentrations >50%, those CT responses were inhibited. Resiniferatoxin and elevated temperature increased the sensitivity of the CT response to ethanol in salt-containing media, and SB-366791 inhibited the effect of ethanol, resiniferatoxin, and elevated temperature on the CT responses to mineral salts. VR-1 KO mice demonstrated no Bz-insensitive CT response to NaCl and no sensitivity to ethanol. We conclude that ethanol increases salt taste sensitivity by its direct action on the Bz-insensitive VR-1 variant salt taste receptor.

Effects of artificial sweeteners on the AhR- and GR-dependent CYP1A1 expression in primary human hepatocytes and human cancer cells.

PubMed

Kamenickova, Alzbeta; Pecova, Michaela; Bachleda, Petr; Dvorak, Zdenek

2013-12-01

Food constituents may cause a phenomenon of food-drug interactions. In the current study, we examined the effects of artificial sweeteners (aspartame, acesulfame, cyclamate, saccharin) on the aryl hydrocarbon receptor (AhR) and glucocorticoid receptor (GR)-dependent expression of CYP1A1 in human hepatocytes, hepatic HepG2 and intestinal LS174T cancer cell lines. Sweeteners were tested in concentrations up to those occurring in non-alcoholic beverages. Basal and ligand-inducible AhR- and GR-dependent reporter gene activation in stably transfected HepG2 and HeLa cells, respectively, were not affected by either of the sweeteners tested after 24h of incubation. The expression of CYP1A1 mRNA and protein in primary cultures of human hepatocytes and in LS174T and HepG2 cells was not induced by any of the tested sweeteners. Overall, aspartame, acesulfame, saccharin and cyclamate had no effects on CYP1A1 expression and transcriptional activities of AhR and GR. These data imply the safety of artificial sweeteners in terms of interference with AhR, GR and CYP1A1. Copyright © 2013 Elsevier Ltd. All rights reserved.

Swine-to-Human Transmission of Influenza A(H3N2) Virus at Agricultural Fairs, Ohio, USA, 2012

PubMed Central

Nelson, Sarah W.; Page, Shannon L.; Nolting, Jacqueline M.; Killian, Mary L.; Sreevatsan, Srinand; Slemons, Richard D.

2014-01-01

Agricultural fairs provide an opportunity for bidirectional transmission of influenza A viruses. We sought to determine influenza A virus activity among swine at fairs in the United States. As part of an ongoing active influenza A virus surveillance project, nasal swab samples were collected from exhibition swine at 40 selected Ohio agricultural fairs during 2012. Influenza A(H3N2) virus was isolated from swine at 10 of the fairs. According to a concurrent public health investigation, 7 of the 10 fairs were epidemiologically linked to confirmed human infections with influenza A(H3N2) variant virus. Comparison of genome sequences of the subtype H3N2 isolates recovered from humans and swine from each fair revealed nucleotide identities of >99.7%, confirming zoonotic transmission between swine and humans. All influenza A(H3N2) viruses isolated in this study, regardless of host species or fair, were >99.5% identical, indicating that 1 virus strain was widely circulating among exhibition swine in Ohio during 2012. PMID:25148572

Epidermal growth factor receptor and variant III targeted immunotherapy.

PubMed

Congdon, Kendra L; Gedeon, Patrick C; Suryadevara, Carter M; Caruso, Hillary G; Cooper, Laurence J N; Heimberger, Amy B; Sampson, John H

2014-10-01

Immunotherapeutic approaches to cancer have shown remarkable promise. A critical barrier to successfully executing such immune-mediated interventions is the selection of safe yet immunogenic targets. As patient deaths have occurred when tumor-associated antigens shared by normal tissue have been targeted by strong cellular immunotherapeutic platforms, route of delivery, target selection and the immune-mediated approach undertaken must work together to maximize efficacy with safety. Selected tumor-specific targets can spare potential toxicity to normal tissue; however, they are far less common than tumor-associated antigens and may not be present on all patients. In the context of immunotherapy for high-grade glioma, 2 of the most prominently studied antigens are the tumor-associated epidermal growth factor receptor and its tumor-specific genetic deletion variant III. In this review, we will summarize the immune-mediated strategies employed against these targets as well as the caveats particular to these approaches. © The Author(s) 2014. Published by Oxford University Press on behalf of the Society for Neuro-Oncology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Involvement of estrogen receptor variant ER-alpha36, not GPR30, in nongenomic estrogen signaling.

PubMed

Kang, Lianguo; Zhang, Xintian; Xie, Yan; Tu, Yaping; Wang, Dong; Liu, Zhenming; Wang, Zhao-Yi

2010-04-01

Accumulating evidence suggested that an orphan G protein-coupled receptor (GPR)30, mediates nongenomic responses to estrogen. The present study was performed to investigate the molecular mechanisms underlying GPR30 function. We found that knockdown of GPR30 expression in breast cancer SK-BR-3 cells down-regulated the expression levels of estrogen receptor (ER)-alpha36, a variant of ER-alpha. Introduction of a GPR30 expression vector into GPR30 nonexpressing cells induced endogenous ER-alpha36 expression, and cotransfection assay demonstrated that GPR30 activated the promoter activity of ER-alpha36 via an activator protein 1 binding site. Both 17beta-estradiol (E2) and G1, a compound reported to be a selective GPR30 agonist, increased the phosphorylation levels of the MAPK/ERK1/2 in SK-BR-3 cells, which could be blocked by an anti-ER-alpha36-specific antibody against its ligand-binding domain. G1 induced activities mediated by ER-alpha36, such as transcription activation activity of a VP16-ER-alpha36 fusion protein and activation of the MAPK/ERK1/2 in ER-alpha36-expressing cells. ER-alpha36-expressing cells, but not the nonexpressing cells, displayed high-affinity, specific E2 and G1 binding, and E2- and G1-induced intracellular Ca(2+) mobilization only in ER-alpha36 expressing cells. Taken together, our results demonstrated that previously reported activities of GPR30 in response to estrogen were through its ability to induce ER-alpha36 expression. The selective G protein-coupled receptor (GPR)30 agonist G1 actually interacts with ER-alpha36. Thus, the ER-alpha variant ER-alpha36, not GPR30, is involved in nongenomic estrogen signaling.

Increased arylhydrocarbon receptor expression offers a potential therapeutic target for pancreatic cancer.

PubMed

Koliopanos, Alexander; Kleeff, Jörg; Xiao, Yi; Safe, Stephen; Zimmermann, Arthur; Büchler, Markus W; Friess, Helmut

2002-09-05

The arylhydrocarbon receptor (AhR) was initially identified as a member of the adaptive metabolic and toxic response pathway to polycyclic aromatic hydrocarbons and to halogenated dibenzo-p-dioxins and dibenzofurans. In the present study, we sought to determine the functional significance of the AhR pathway in pancreatic carcinogenesis. AhR expression was analysed by Northern blotting. The exact site of AhR expression was analysed by in situ hybridization and immunohistochemistry. The effects of TCDD and four selective AhR agonists on pancreatic cancer cell lines were investigated by growth assays, apoptosis assays, and induction of the cyclin-dependent kinase inhibitor p21. There was strong AhR mRNA expression in 14 out of 15 pancreatic cancer samples, weak expression in chronic pancreatitis tissues, and faint expression in all normal pancreata. In pancreatic cancer tissues, AhR mRNA and protein expression were localized in the cytoplasm of pancreatic cancer cells. TCDD and the four AhR agonists inhibited pancreatic cancer cell growth in a dose-dependent manner, and decreased anchorage-independent cell growth. DAPI staining did not reveal nuclear fragmentation and CYP1A1 and was not induced by TCDD and AhR agonists. In contrast, TCDD and AhR agonists induced the expression of the cyclin-dependent kinase inhibitor p21. In conclusion, the relatively non-toxic AhR agonists caused growth inhibition in pancreatic cancer cells with high AhR expression levels via cell cycle arrest. In addition, almost all human pancreatic cancer tissues expressed this receptor at high levels, suggesting that these or related compounds may play a role in the therapy of pancreatic cancer in the future.

Aryl hydrocarbon receptor

PubMed Central

Kiss, Elina A.; Vonarbourg, Cedric

2012-01-01

Intestinal homeostasis results from a complex mutualism between gut microbiota and host cells. Defining the molecular network regulating such mutualism is currently of increasing interest, as its deregulation is reported to lead to increased susceptibility to infections, chronic inflammatory bowel diseases and cancer. Until now, the focus has been on the mechanism, by which the composition of indigenous microbiota shapes the immune system. In a recent study, we have shown that dietary compounds have also the ability to affect innate immune system. This regulation involves aryl hydrocarbon receptor (AhR), a sensor of plant-derived phytochemicals, which mediates the maintenance of Retinoic acid related orphan receptor γ t-expressing innate lymphoid cells (RORγt+ ILC) in the gut and consequently formation of postnatal lymphoid follicles. Thus, AhR represents the first evidence of a molecular link between diet and immunity at intestinal mucosal surfaces. PMID:22909905

Lenalidomide enhances the function of chimeric antigen receptor T cells against the epidermal growth factor receptor variant III by enhancing immune synapses.

PubMed

Kuramitsu, S; Ohno, M; Ohka, F; Shiina, S; Yamamichi, A; Kato, A; Tanahashi, K; Motomura, K; Kondo, G; Kurimoto, M; Senga, T; Wakabayashi, T; Natsume, A

2015-10-01

The epidermal growth factor receptor variant III (EGFRvIII) is exclusively expressed on the cell surface in ~50% of glioblastoma multiforme (GBM). This variant strongly and persistently activates the phosphatidylinositol 3-kinase-Akt signaling pathway in a ligand-independent manner resulting in enhanced tumorigenicity, cellular motility and resistance to chemoradiotherapy. Our group generated a recombinant single-chain variable fragment (scFv) antibody specific to the EGFRvIII, referred to as 3C10-scFv. In the current study, we constructed a lentiviral vector transducing the chimeric antigen receptor (CAR) that consisted of 3C10-scFv, CD3ζ, CD28 and 4-1BB (3C10-CAR). The 3C10-CAR-transduced peripheral blood mononuclear cells (PBMCs) and CD3(+) T cells specifically lysed the glioma cells that express EGFRvIII. Moreover, we demonstrated that CAR CD3(+) T cells migrated to the intracranial xenograft of GBM in the mice treated with 3C10-CAR PBMCs. An important and novel finding of our study was that a thalidomide derivative lenalidomide induced 3C10-CAR PBMC proliferation and enhanced the persistent antitumor effect of the cells in vivo. Lenalidomide also exhibited enhanced immunological synapses between the effector cells and the target cells as determined by CD11a and F-actin polymerization. Collectively, lentiviral-mediated transduction of CAR effectors targeting the EGFRvIII showed specific efficacy, and lenalidomide even intensified CAR cell therapy by enhanced formation of immunological synapses.

Two-stage AMPA receptor trafficking in classical conditioning and selective role for glutamate receptor subunit 4 (tGluA4) flop splice variant

PubMed Central

Zheng, Zhaoqing; Sabirzhanov, Boris

2012-01-01

Previously, we proposed a two-stage model for an in vitro neural correlate of eyeblink classical conditioning involving the initial synaptic incorporation of glutamate receptor A1 (GluA1)-containing α-amino-3-hydroxy-5-methylisoxazole-4-propionic acid type receptors (AMPARs) followed by delivery of GluA4-containing AMPARs that support acquisition of conditioned responses. To test specific elements of our model for conditioning, selective knockdown of GluA4 AMPAR subunits was used using small-interfering RNAs (siRNAs). Recently, we sequenced and characterized the GluA4 subunit and its splice variants from pond turtles, Trachemys scripta elegans (tGluA4). Analysis of the relative abundance of mRNA expression by real-time RT-PCR showed that the flip/flop variants of tGluA4, tGluA4c, and a novel truncated variant tGluA4trc1 are major isoforms in the turtle brain. Here, transfection of in vitro brain stem preparations with anti-tGluA4 siRNA suppressed conditioning, tGluA4 mRNA and protein expression, and synaptic delivery of tGluA4-containing AMPARs but not tGluA1 subunits. Significantly, transfection of abducens motor neurons by nerve injections of tGluA4 flop rescue plasmid prior to anti-tGluA4 siRNA application restored conditioning and synaptic incorporation of tGluA4-containing AMPARs. In contrast, treatment with rescue plasmids for tGluA4 flip or tGluA4trc1 failed to rescue conditioning. Finally, treatment with a siRNA directed against GluA1 subunits inhibited conditioning and synaptic delivery of tGluA1-containing AMPARs and importantly, those containing tGluA4. These data strongly support our two-stage model of conditioning and our hypothesis that synaptic incorporation of tGluA4-containing AMPARs underlies the acquisition of in vitro classical conditioning. Furthermore, they suggest that tGluA4 flop may have a critical role in conditioning mechanisms compared with the other tGluA4 splice variants. PMID:22490558

Aryl hydrocarbon receptor and intestinal immunity.

PubMed

Lamas, Bruno; Natividad, Jane M; Sokol, Harry

2018-04-07

Aryl hydrocarbon receptor (AhR) is a member of the basic helix-loop-helix-(bHLH) superfamily of transcription factors, which are associated with cellular responses to environmental stimuli, such as xenobiotics and oxygen levels. Unlike other members of bHLH, AhR is the only bHLH transcription factor that is known to be ligand activated. Early AhR studies focused on understanding the role of AhR in mediating the toxicity and carcinogenesis properties of the prototypic ligand 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). In recent years, however, it has become apparent that, in addition to its toxicological involvement, AhR is highly receptive to a wide array of endogenous and exogenous ligands, and that its activation leads to a myriad of key host physiological functions. In this study, we review the current understanding of the functions of AhR in the mucosal immune system with a focus on its role in intestinal barrier function and intestinal immune cells, as well as in intestinal homeostasis.

AhR and Arnt differentially regulate NF-κB signaling and chemokine responses in human bronchial epithelial cells

PubMed Central

2014-01-01

Background The aryl hydrocarbon receptor (AhR) has gradually emerged as a regulator of inflammation in the lung and other tissues. AhR may interact with the p65-subunit of the nuclear factor (NF)-κB transcription factors, but reported outcomes of AhR/NF-κB-interactions are conflicting. Some studies suggest that AhR possess pro-inflammatory activities while others suggest that AhR may be anti-inflammatory. The present study explored the impact of AhR and its binding partner AhR nuclear translocator (Arnt) on p65-activation and two differentially regulated chemokines, CXCL8 (IL-8) and CCL5 (RANTES), in human bronchial epithelial cells (BEAS-2B). Results Cells were exposed to CXCL8- and CCL5-inducing chemicals, 1-nitropyrene (1-NP) and 1-aminopyrene (1-AP) respectively, or the synthetic double-stranded RNA analogue, polyinosinic-polycytidylic acid (Poly I:C) which induced both chemokines. Only CXCL8, and not CCL5, appeared to be p65-dependent. Yet, constitutively active unligated AhR suppressed both CXCL8 and CCL5, as shown by siRNA knock-down and the AhR antagonist α-naphthoflavone. Moreover, AhR suppressed activation of p65 by TNF-α and Poly I:C as assessed by luciferase-assay and p65-phosphorylation at serine 536, without affecting basal p65-activity. In contrast, Arnt suppressed only CXCL8, but did not prevent the p65-activation directly. However, Arnt suppressed expression of the NF-κB-subunit RelB which is under transcriptional regulation by p65. Furthermore, AhR-ligands alone at high concentrations induced a moderate CXCL8-response, without affecting CCL5, but suppressed both CXCL8 and CCL5-responses by Poly I:C. Conclusion AhR and Arnt may differentially and independently regulate chemokine-responses induced by both inhaled pollutants and pulmonary infections. Constitutively active, unligated AhR suppressed the activation of p65, while Arnt may possibly interfere with the action of activated p65. Moreover, ligand-activated AhR suppressed CXCL8 and CCL5

Low density lipoprotein receptor related protein-1 and 6 gene variants and ischemic stroke risk

PubMed Central

Harriott, Andrea M.; Heckman, Michael G.; Rayaprolu, Sruti; Soto-Ortolaza, Alexandra I.; Diehl, Nancy N.; Kanekiyo, Takahisa; Liu, Chia-Chen; Bu, Guojun; Malik, Rainer; Cole, John W.; Meschia, James F.; Ross, Owen A.

2015-01-01

Background Low density lipoprotein receptor related proteins-1 and 6 have been implicated in cerebral ischemia. In addition, genetic variation in LRP1 and LRP6 has been linked with various factors that are related to risk of ischemic stroke. The aim of this study was to examine the association of LRP1 and LRP6 gene variants with risk of ischemic stroke as part of the Ischemic Stroke Genetics Study (ISGS). Methods We included a Caucasian series (434 stroke patients, 319 controls) and an African American series (161 stroke patients, 116 controls). Fourteen LRP6 variants and 3 LRP1 variants were genotyped and assessed for association with ischemic stroke. Results In the Caucasian series, significant associations with ischemic stroke were observed for LRP6 rs2075241 (OR:0.42, P=0.023), rs2302685 (OR:0.44, P=0.049), rs7975614 (OR: 0.07, P=0.017), rs10492120 (OR: 0.62, P=0.036), and rs10743980 (OR: 0.66, P=0.037). Risk of ischemic stroke was significantly lower for carriers of any of these five protective LRP6 variants (24.0% of subjects) compared to non-carriers (OR:0.57, P=0.003). The protective association for LRP6 rs2075241 was observed at a similar magnitude across ischemic stroke subtypes, while the effects of rs23022685, rs10492120, and rs10743980 were most apparent for cardioembolic and large vessel stroke. In the African American series, LRP1 rs11172113 was associated with an increased risk of stroke (OR:1.89, P=0.006). Conclusions The results of our preliminary study provide evidence that LRP6 and LRP1 variants may be associated with risk of ischemic stroke. Validation in larger studies is warranted. PMID:26031789

Crystal Structure of Serine Racemase that Produces Neurotransmitter variant:small-caps">d-Serine for Stimulation of the NMDA Receptor

NASA Astrophysics Data System (ADS)

Goto, Masaru

variant:small-caps">d-Serine is an endogenous coagonist for the N-methyl-variant:small-caps">d-aspartate receptor and is involved in excitatory neurotransmission in the brain. Mammalian pyridoxal 5’-phosphate-dependent serine racemase, which is localized in the mammalian brain, catalyzes the racemization of variant:small-caps">l-serine to yield variant:small-caps">d-serine and vice versa. We have determined the structures of three forms of the mammalian enzyme homolog from Schizosaccharomyces pombe. Lys57 and Ser82 located on the protein and solvent sides, respectively, with respect to the cofactor plane, are acid-base catalysts that shuttle protons to the substrate. The modified enzyme, which has a unique lysino-variant:small-caps">d-alanyl residue at the active site, also binds the substrate serine in the active site, suggesting that the lysino-variant:small-caps">d-alanyl residue acts as a catalytic base in the same manner as Lys57 of the wild type enzyme.

A Rare Variant Identified Within the GluN2B C-Terminus in a Patient with Autism Affects NMDA Receptor Surface Expression and Spine Density.

PubMed

Liu, Shuxi; Zhou, Liang; Yuan, Hongjie; Vieira, Marta; Sanz-Clemente, Antonio; Badger, John D; Lu, Wei; Traynelis, Stephen F; Roche, Katherine W

2017-04-12

NMDA receptors (NMDARs) are ionotropic glutamate receptors that are crucial for neuronal development and higher cognitive processes. NMDAR dysfunction is involved in a variety of neurological and psychiatric diseases; however, the mechanistic link between the human pathology and NMDAR dysfunction is poorly understood. Rare missense variants within NMDAR subunits have been identified in numerous patients with mental or neurological disorders. We specifically focused on the GluN2B NMDAR subunit, which is highly expressed in the hippocampus and cortex throughout development. We analyzed several variants located in the GluN2B C terminus and found that three variants in patients with autism (S1415L) or schizophrenia (L1424F and S1452F) (S1413L, L1422F, and S1450F in rodents, respectively) displayed impaired binding to membrane-associated guanylate kinase (MAGUK) proteins. In addition, we observed a deficit in surface expression for GluN2B S1413L. Furthermore, there were fewer dendritic spines in GluN2B S1413L-expressing neurons. Importantly, synaptic NMDAR currents in neurons transfected with GluN2B S1413L in GluN2A/B-deficient mouse brain slices revealed only partial rescue of synaptic current amplitude. Functional properties of GluN2B S1413L in recombinant systems revealed no change in receptor properties, consistent with synaptic defects being the result of reduced trafficking and targeting of GluN2B S1413L to the synapse. Therefore, we find that GluN2B S1413L displays deficits in NMDAR trafficking, synaptic currents, and spine density, raising the possibility that this mutation may contribute to the phenotype in this autism patient. More broadly, our research demonstrates that the targeted study of certain residues in NMDARs based on rare variants identified in patients is a powerful approach to studying receptor function. SIGNIFICANCE STATEMENT We have used a "bedside-to-bench" approach to investigate the functional regulation of NMDA receptors (NMDARs). Using

Introduction and enzootic of A/H5N1 in Egypt: Virus evolution, pathogenicity and vaccine efficacy ten years on.

PubMed

Abdelwhab, E M; Hassan, M K; Abdel-Moneim, A S; Naguib, M M; Mostafa, A; Hussein, I T M; Arafa, A; Erfan, A M; Kilany, W H; Agour, M G; El-Kanawati, Z; Hussein, H A; Selim, A A; Kholousy, S; El-Naggar, H; El-Zoghby, E F; Samy, A; Iqbal, M; Eid, A; Ibraheem, E M; Pleschka, S; Veits, J; Nasef, S A; Beer, M; Mettenleiter, T C; Grund, C; Ali, M M; Harder, T C; Hafez, H M

2016-06-01

It is almost a decade since the highly pathogenic H5N1 avian influenza virus (A/H5N1) of clade 2.2.1 was introduced to Egypt in 2005, most likely, via wild birds; marking the longest endemic status of influenza viruses in poultry outside Asia. The endemic A/H5N1 in Egypt still compromises the poultry industry, poses serious hazards to public health and threatens to become potentially pandemic. The control strategies adopted for A/H5N1 in Egyptian poultry using diverse vaccines in commercialized poultry neither eliminated the virus nor did they decrease its evolutionary rate. Several virus clades have evolved, a few of them disappeared and others prevailed. Disparate evolutionary traits in both birds and humans were manifested by accumulation of clade-specific mutations across viral genomes driven by a variety of selection pressures. Viruses in vaccinated poultry populations displayed higher mutation rates at the immunogenic epitopes, promoting viral escape and reducing vaccine efficiency. On the other hand, viruses isolated from humans displayed changes in the receptor binding domain, which increased the viral affinity to bind to human-type glycan receptors. Moreover, viral pathogenicity exhibited several patterns in different hosts. This review aims to provide an overview of the viral evolution, pathogenicity and vaccine efficacy of A/H5N1 in Egypt during the last ten years. Copyright © 2016 Elsevier B.V. All rights reserved.

Serotonin (5-HT) receptor 5A sequence variants affect human plasma triglyceride levels

PubMed Central

Zhang, Y.; Smith, E. M.; Baye, T. M.; Eckert, J. V.; Abraham, L. J.; Moses, E. K.; Kissebah, A. H.; Martin, L. J.

2010-01-01

Neurotransmitters such as serotonin (5-hydroxytryptamine, 5-HT) work closely with leptin and insulin to fine-tune the metabolic and neuroendocrine responses to dietary intake. Losing the sensitivity to excess food intake can lead to obesity, diabetes, and a multitude of behavioral disorders. It is largely unclear how different serotonin receptor subtypes respond to and integrate metabolic signals and which genetic variations in these receptor genes lead to individual differences in susceptibility to metabolic disorders. In an obese cohort of families of Northern European descent (n = 2,209), the serotonin type 5A receptor gene, HTR5A, was identified as a prominent factor affecting plasma levels of triglycerides (TG), supported by our data from both genome-wide linkage and targeted association analyses using 28 publicly available and 12 newly discovered single nucleotide polymorphisms (SNPs), of which 3 were strongly associated with plasma TG levels (P < 0.00125). Bayesian quantitative trait nucleotide (BQTN) analysis identified a putative causal promoter SNP (rs3734967) with substantial posterior probability (P = 0.59). Functional analysis of rs3734967 by electrophoretic mobility shift assay (EMSA) showed distinct binding patterns of the two alleles of this SNP with nuclear proteins from glioma cell lines. In conclusion, sequence variants in HTR5A are strongly associated with high plasma levels of TG in a Northern European population, suggesting a novel role of the serotonin receptor system in humans. This suggests a potential brain-specific regulation of plasma TG levels, possibly by alteration of the expression of HTR5A. PMID:20388841

Coding variants in NOD-like receptors: An association study on risk and survival of colorectal cancer.

PubMed

Huhn, Stefanie; da Silva Filho, Miguel I; Sanmuganantham, Tharmila; Pichulik, Tica; Catalano, Calogerina; Pardini, Barbara; Naccarati, Alessio; Polakova-Vymetálkova, Veronika; Jiraskova, Katerina; Vodickova, Ludmila; Vodicka, Pavel; Löffler, Markus W; Courth, Lioba; Wehkamp, Jan; Din, Farhat V N; Timofeeva, Maria; Farrington, Susan M; Jansen, Lina; Hemminki, Kari; Chang-Claude, Jenny; Brenner, Hermann; Hoffmeister, Michael; Dunlop, Malcolm G; Weber, Alexander N R; Försti, Asta

2018-01-01

Nod-like receptors (NLRs) are important innate pattern recognition receptors and regulators of inflammation or play a role during development. We systematically analysed 41 non-synonymous single nucleotide polymorphisms (SNPs) in 21 NLR genes in a Czech discovery cohort of sporadic colorectal cancer (CRC) (1237 cases, 787 controls) for their association with CRC risk and survival. Five SNPs were found to be associated with CRC risk and eight with survival at 5% significance level. In a replication analysis using data of two large genome-wide association studies (GWASs) from Germany (DACHS: 1798 cases and 1810 controls) and Scotland (2210 cases and 9350 controls) the associations found in the Czech discovery set were not confirmed. However, expression analysis in human gut-related tissues and immune cells revealed that the NLRs associated with CRC risk or survival in the discovery set were expressed in primary human colon or rectum cells, CRC tissue and/or cell lines, providing preliminary evidence for a potential involvement of NLRs in general in CRC development and/or progression. Most interesting was the finding that the enigmatic development-related NLRP5 (also known as MATER) was not expressed in normal colon tissue but in colon cancer tissue and cell lines. Future studies may show whether regulatory variants instead of coding variants might affect the expression of NLRs and contribute to CRC risk and survival.

Genomic signature analysis of the recently emerged highly pathogenic A(H5N8) avian influenza virus: implying an evolutionary trend for bird-to-human transmission.

PubMed

Xu, Wei; Dai, Yanyan; Hua, Chen; Wang, Qian; Zou, Peng; Deng, Qiwen; Jiang, Shibo; Lu, Lu

2017-12-01

In early 2014, a novel subclade (2.3.4.4) of the highly pathogenic avian influenza (HPAI) A(H5N8) virus caused the first outbreak in domestic ducks and migratory birds in South Korea. Since then, it has spread to 44 countries and regions. To date, no human infections with A(H5N8) virus have been reported, but the possibility cannot be excluded. By analyzing the genomic signatures of A(H5N8) strains, we found that among the 47 species-associated signature positions, three positions exhibited human-like signatures (HLS), including PA-404S, PB2-613I and PB2-702R and that mutation trend of host signatures of avian A(H5N8) is different before and after 2014. About 82% of A(H5N8) isolates collected after January of 2014 carried the 3 HLS (PA-404S/PB2-613I/PB2-702R) in combination, while none of isolates collected before 2014 had this combination. Furthermore, the HA protein had S137A and S227R substitutions in the receptor-binding site and A160T in the glycosylation site, potentially increasing viral ability to bind human-type receptors. Based on these findings, the newly emerged HPAI A(H5N8) isolates show an evolutionary trend toward gaining more HLS and, along with it, the potential for bird-to-human transmissibility. Therefore, more extensive surveillance of this rapidly spreading HPAI A(H5N8) and preparedness against its potential pandemic are urgently needed. Copyright © 2017. Published by Elsevier Masson SAS.

Genetic variants of adiponectin receptor 2 are associated with increased adiponectin levels and decreased triglyceride/VLDL levels in patients with metabolic syndrome.

PubMed

Broedl, Uli C; Lehrke, Michael; Fleischer-Brielmaier, Elisabeth; Tietz, Anne B; Nagel, Jutta M; Göke, Burkhard; Lohse, Peter; Parhofer, Klaus G

2006-05-15

Adiponectin acts as an antidiabetic, antiinflammatory and antiatherogenic adipokine. These effects are assumed to be mediated by the recently discovered adiponectin receptors AdipoR1 and AdipoR2. The purpose of this study was to determine whether variations in the AdipoR1 and AdipoR2 genes may contribute to insulin resistance, dyslipidemia and inflammation. We sequenced all seven coding exons of both genes in 20 unrelated German subjects with metabolic syndrome and tested genetic variants for association with glucose, lipid and inflammatory parameters. We identified three AdipoR2 variants (+795G/A, +870C/A and +963C/T) in perfect linkage disequilibrium (r2 = 1) with a minor allele frequency of 0.125. This haplotype was associated with higher plasma adiponectin levels and decreased fasting triglyceride, VLDL-triglyceride and VLDL-cholesterol levels. No association, however, was observed between the AdipoR2 SNP cluster and glucose metabolism. To our knowledge, this is the first study to identify an association between genetic variants of the adiponectin receptor genes and plasma adiponectin levels. Furthermore, our data suggest that AdipoR2 may play an important role in triglyceride/VLDL metabolism.

The aryl hydrocarbon receptor is required for normal gonadotropin responsiveness in the mouse ovary.

PubMed

Barnett, Kimberly R; Tomic, Dragana; Gupta, Rupesh K; Babus, Janice K; Roby, Katherine F; Terranova, Paul F; Flaws, Jodi A

2007-08-15

The aryl hydrocarbon receptor (AHR) mediates the toxicity of a variety of environmental chemicals. Although little is known about the physiological role of the AHR, studies suggest that it plays an important role in regulating ovulation because Ahr deficient (AhRKO) mice have a reduced number of ovulations compared to wild-type (WT) mice. The reasons for the reduced ability of AhRKO mice to ovulate are unknown. Normal ovulation, however, requires estrous cyclicity, appropriate luteinizing hormone (LH) and follicle-stimulating hormone (FSH) levels, and LH and FSH responsiveness. Thus, the purpose of this study was to test the hypothesis that Ahr deletion regulates ovulation by altering cyclicity, FSH and LH levels, follicle-stimulating hormone receptor (Fshr) and luteinizing hormone receptor (Lhcgr) levels and/or gonadotropin responsiveness. The data indicate that AhRKO and WT mice have similar levels of FSH and LH, but AhRKO mice have reduced Fshr and Lhcgr mRNA levels compared to WT mice. Furthermore, AhRKO ovaries contain fewer corpora lutea compared to WT ovaries after 5 IU equine chorionic gonadotropin (eCG) treatment. Lastly, both AhRKO and WT mice ovulate a similar number of eggs in response to 5 IU human chorionic gonadotropin (hCG), but AhRKO mice ovulate fewer eggs than WT mice in response to 2.5 IU and 1.25 IU hCG. Collectively, these data indicate that AhRKO follicles have a reduced capacity to ovulate compared to WT follicles and that this is due to reduced responsiveness to gonadotropins. Thus, in addition to mediating toxicity of environmental chemicals, the Ahr is required for normal ovulation.

The aryl hydrocarbon receptor is required for normal gonadotropin responsiveness in the mouse ovary

DOE Office of Scientific and Technical Information (OSTI.GOV)

Barnett, Kimberly R.; Tomic, Dragana; Gupta, Rupesh K.

2007-08-15

The aryl hydrocarbon receptor (AHR) mediates the toxicity of a variety of environmental chemicals. Although little is known about the physiological role of the AHR, studies suggest that it plays an important role in regulating ovulation because Ahr deficient (AhRKO) mice have a reduced number of ovulations compared to wild-type (WT) mice. The reasons for the reduced ability of AhRKO mice to ovulate are unknown. Normal ovulation, however, requires estrous cyclicity, appropriate luteinizing hormone (LH) and follicle-stimulating hormone (FSH) levels, and LH and FSH responsiveness. Thus, the purpose of this study was to test the hypothesis that Ahr deletion regulatesmore » ovulation by altering cyclicity, FSH and LH levels, follicle-stimulating hormone receptor (Fshr) and luteinizing hormone receptor (Lhcgr) levels and/or gonadotropin responsiveness. The data indicate that AhRKO and WT mice have similar levels of FSH and LH, but AhRKO mice have reduced Fshr and Lhcgr mRNA levels compared to WT mice. Furthermore, AhRKO ovaries contain fewer corpora lutea compared to WT ovaries after 5 IU equine chorionic gonadotropin (eCG) treatment. Lastly, both AhRKO and WT mice ovulate a similar number of eggs in response to 5 IU human chorionic gonadotropin (hCG), but AhRKO mice ovulate fewer eggs than WT mice in response to 2.5 IU and 1.25 IU hCG. Collectively, these data indicate that AhRKO follicles have a reduced capacity to ovulate compared to WT follicles and that this is due to reduced responsiveness to gonadotropins. Thus, in addition to mediating toxicity of environmental chemicals, the Ahr is required for normal ovulation.« less

Trivalent inactivated influenza vaccine effective against influenza A(H3N2) variant viruses in children during the 2014/15 season, Japan

PubMed Central

Sugaya, Norio; Shinjoh, Masayoshi; Kawakami, Chiharu; Yamaguchi, Yoshio; Yoshida, Makoto; Baba, Hiroaki; Ishikawa, Mayumi; Kono, Mio; Sekiguchi, Shinichiro; Kimiya, Takahisa; Mitamura, Keiko; Fujino, Motoko; Komiyama, Osamu; Yoshida, Naoko; Tsunematsu, Kenichiro; Narabayashi, Atsushi; Nakata, Yuji; Sato, Akihiro; Taguchi, Nobuhiko; Fujita, Hisayo; Toki, Machiko; Myokai, Michiko; Ookawara, Ichiro; Takahashi, Takao

2016-01-01

The 2014/15 influenza season in Japan was characterised by predominant influenza A(H3N2) activity; 99% of influenza A viruses detected were A(H3N2). Subclade 3C.2a viruses were the major epidemic A(H3N2) viruses, and were genetically distinct from A/New York/39/2012(H3N2) of 2014/15 vaccine strain in Japan, which was classified as clade 3C.1. We assessed vaccine effectiveness (VE) of inactivated influenza vaccine (IIV) in children aged 6 months to 15 years by test-negative case–control design based on influenza rapid diagnostic test. Between November 2014 and March 2015, a total of 3,752 children were enrolled: 1,633 tested positive for influenza A and 42 for influenza B, and 2,077 tested negative. Adjusted VE was 38% (95% confidence intervals (CI): 28 to 46) against influenza virus infection overall, 37% (95% CI: 27 to 45) against influenza A, and 47% (95% CI: -2 to 73) against influenza B. However, IIV was not statistically significantly effective against influenza A in infants aged 6 to 11 months or adolescents aged 13 to 15 years. VE in preventing hospitalisation for influenza A infection was 55% (95% CI: 42 to 64). Trivalent IIV that included A/New York/39/2012(H3N2) was effective against drifted influenza A(H3N2) virus, although vaccine mismatch resulted in low VE. PMID:27784529

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

PubMed

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.

Novel Highly Pathogenic Avian A(H5N2) and A(H5N8) Influenza Viruses of Clade 2.3.4.4 from North America Have Limited Capacity for Replication and Transmission in Mammals

PubMed Central

Kaplan, Bryan S.; Russier, Marion; Jeevan, Trushar; Marathe, Bindumadhav; Govorkova, Elena A.; Russell, Charles J.; Kim-Torchetti, Mia; Choi, Young Ki; Brown, Ian; Saito, Takehiko; Stallknecht, David E.; Krauss, Scott

2016-01-01

ABSTRACT Highly pathogenic influenza A(H5N8) viruses from clade 2.3.4.4 were introduced to North America by migratory birds in the fall of 2014. Reassortment of A(H5N8) viruses with avian viruses of North American lineage resulted in the generation of novel A(H5N2) viruses with novel genotypes. Through sequencing of recent avian influenza viruses, we identified PB1 and NP gene segments very similar to those in the viruses isolated from North American waterfowl prior to the introduction of A(H5N8) to North America, highlighting these bird species in the origin of reassortant A(H5N2) viruses. While they were highly virulent and transmissible in poultry, we found A(H5N2) viruses to be low pathogenic in mice and ferrets, and replication was limited in both hosts compared with those of recent highly pathogenic avian influenza (HPAI) H5N1 viruses. Molecular characterization of the hemagglutinin protein from A(H5N2) viruses showed that the receptor binding preference, cleavage, and pH of activation were highly adapted for replication in avian species and similar to those of other 2.3.4.4 viruses. In addition, North American and Eurasian clade 2.3.4.4 H5NX viruses replicated to significantly lower titers in differentiated normal human bronchial epithelial cells than did seasonal human A(H1N1) and highly pathogenic A(H5N1) viruses isolated from a human case. Thus, despite their having a high impact on poultry, our findings suggest that the recently emerging North American A(H5N2) viruses are not expected to pose a substantial threat to humans and other mammals without further reassortment and/or adaptation and that reassortment with North American viruses has not had a major impact on viral phenotype. IMPORTANCE Highly pathogenic H5 influenza viruses have been introduced into North America from Asia, causing extensive morbidity and mortality in domestic poultry. The introduced viruses have reassorted with North American avian influenza viruses, generating viral genotypes

Novel Highly Pathogenic Avian A(H5N2) and A(H5N8) Influenza Viruses of Clade 2.3.4.4 from North America Have Limited Capacity for Replication and Transmission in Mammals.

PubMed

Kaplan, Bryan S; Russier, Marion; Jeevan, Trushar; Marathe, Bindumadhav; Govorkova, Elena A; Russell, Charles J; Kim-Torchetti, Mia; Choi, Young Ki; Brown, Ian; Saito, Takehiko; Stallknecht, David E; Krauss, Scott; Webby, Richard J

2016-01-01

Highly pathogenic influenza A(H5N8) viruses from clade 2.3.4.4 were introduced to North America by migratory birds in the fall of 2014. Reassortment of A(H5N8) viruses with avian viruses of North American lineage resulted in the generation of novel A(H5N2) viruses with novel genotypes. Through sequencing of recent avian influenza viruses, we identified PB1 and NP gene segments very similar to those in the viruses isolated from North American waterfowl prior to the introduction of A(H5N8) to North America, highlighting these bird species in the origin of reassortant A(H5N2) viruses. While they were highly virulent and transmissible in poultry, we found A(H5N2) viruses to be low pathogenic in mice and ferrets, and replication was limited in both hosts compared with those of recent highly pathogenic avian influenza (HPAI) H5N1 viruses. Molecular characterization of the hemagglutinin protein from A(H5N2) viruses showed that the receptor binding preference, cleavage, and pH of activation were highly adapted for replication in avian species and similar to those of other 2.3.4.4 viruses. In addition, North American and Eurasian clade 2.3.4.4 H5NX viruses replicated to significantly lower titers in differentiated normal human bronchial epithelial cells than did seasonal human A(H1N1) and highly pathogenic A(H5N1) viruses isolated from a human case. Thus, despite their having a high impact on poultry, our findings suggest that the recently emerging North American A(H5N2) viruses are not expected to pose a substantial threat to humans and other mammals without further reassortment and/or adaptation and that reassortment with North American viruses has not had a major impact on viral phenotype. IMPORTANCE Highly pathogenic H5 influenza viruses have been introduced into North America from Asia, causing extensive morbidity and mortality in domestic poultry. The introduced viruses have reassorted with North American avian influenza viruses, generating viral genotypes not seen on

Alternative splicing and the progesterone receptor in breast cancer

PubMed Central

Cork, David MW; Lennard, Thomas WJ; Tyson-Capper, Alison J

2008-01-01

Progesterone receptor status is a marker for hormone responsiveness and disease prognosis in breast cancer. Progesterone receptor negative tumours have generally been shown to have a poorer prognosis than progesterone receptor positive tumours. The observed loss of progesterone receptor could be through a range of mechanisms, including the generation of alternatively spliced progesterone receptor variants that are not detectable by current screening methods. Many progesterone receptor mRNA variants have been described with deletions of various whole, multiple or partial exons that encode differing protein functional domains. These variants may alter the progestin responsiveness of a tissue and contribute to the abnormal growth associated with breast cancer. Absence of specific functional domains from these spliced variants may also make them undetectable or indistinguishable from full length progesterone receptor by conventional antibodies. A comprehensive investigation into the expression profile and activity of progesterone receptor spliced variants in breast cancer is required to advance our understanding of tumour hormone receptor status. This, in turn, may aid the development of new biomarkers of disease prognosis and improve adjuvant treatment decisions. PMID:18557990

Sequence variants of Toll-like receptor 4 and susceptibility to prostate cancer.

PubMed

Chen, Yen-Ching; Giovannucci, Edward; Lazarus, Ross; Kraft, Peter; Ketkar, Shamika; Hunter, David J

2005-12-15

Chronic inflammation has been hypothesized to be a risk factor for prostate cancer. The Toll-like receptor 4 (TLR4) presents the bacterial lipopolysaccharide (LPS), which interacts with ligand-binding protein and CD14 (LPS receptor) and activates expression of inflammatory genes through nuclear factor-kappaB and mitogen-activated protein kinase signaling. A previous case-control study found a modest association of a polymorphism in the TLR4 gene [11381G/C, GG versus GC/CC: odds ratio (OR), 1.26] with risk of prostate cancer. We assessed if sequence variants of TLR4 were associated with the risk of prostate cancer. In a nested case-control design within the Health Professionals Follow-up Study, we identified 700 participants with prostate cancer diagnosed after they had provided a blood specimen in 1993 and before January 2000. Controls were 700 age-matched men without prostate cancer who had had a prostate-specific antigen test after providing a blood specimen. We genotyped 16 common (>5%) single nucleotide polymorphisms (SNP) discovered in a resequencing study spanning TLR4 to test for association between sequence variation in TLR4 and prostate cancer. Homozygosity for the variant alleles of eight SNPs was associated with a statistically significantly lower risk of prostate cancer (TLR4_1893, TLR4_2032, TLR4_2437, TLR4_7764, TLR4_11912, TLR4_16649, TLR4_17050, and TLR4_17923), but the TLR4_15844 polymorphism corresponding to 11381G/C was not associated with prostate cancer (GG versus CG/CC: OR, 1.01; 95% confidence interval, 0.79-1.29). Six common haplotypes (cumulative frequency, 81%) were observed; the global test for association between haplotypes and prostate cancer was statistically significant (chi(2) = 14.8 on 6 degrees of freedom; P = 0.02). Two common haplotypes were statistically significantly associated with altered risk of prostate cancer. Inherited polymorphisms of the innate immune gene TLR4 are associated with risk of prostate cancer.

Structural modeling of the AhR:ARNT complex in the bHLH-PASA-PASB region elucidates the key determinants of dimerization.

PubMed

Corrada, Dario; Denison, Michael S; Bonati, Laura

2017-05-02

Elucidation of the dimerization process of the aryl hydrocarbon receptor (AhR) with the AhR nuclear translocator (ARNT) is crucial for understanding the mechanisms underlying the functional activity of AhR, including mediation of the toxicity of environmental contaminants. In this work, for the first time a structural model of the AhR:ARNT dimer encompassing the entire bHLH-PASA-PASB domain region is proposed. It is developed by using a template-based modeling approach, relying on the recently available crystallographic structures of two dimers of homologous systems in the bHLH-PAS family of proteins: the CLOCK:BMAL1 and the HIF2α:ARNT heterodimers. The structural and energetic characteristics of the modeled AhR:ARNT protein-protein interface are determined by evaluating the variations in solvent accessible surface area, the total binding free energy and the per-residue free energy contributions obtained by the MM-GBSA method and the Energy Decomposition Analysis. The analyses of the intricate network of inter-domain interactions at the dimerization interfaces provide insights into the key determinants of dimerization. These are confirmed by comparison of the computational findings with the available experimental mutagenesis and functional analysis data. The results presented here on the AhR:ARNT dimer structure and interactions provide a framework to start analyzing the mechanism of AhR transformation into its functional DNA binding form.

Leptin and leptin-related gene polymorphisms, obesity, and influenza A/H1N1 vaccine-induced immune responses in older individuals.

PubMed

Ovsyannikova, Inna G; White, Sarah J; Larrabee, Beth R; Grill, Diane E; Jacobson, Robert M; Poland, Gregory A

2014-02-07

Obesity is a risk factor for complicated influenza A/H1N1 disease and poor vaccine immunogenicity. Leptin, an adipocyte-derived hormone/cytokine, has many immune regulatory functions and therefore could explain susceptibility to infections and poor vaccine outcomes. We recruited 159 healthy adults (50-74 years old) who were immunized with inactivated TIV influenza vaccine that contained A/California/7/2009/H1N1 virus. We found a strong correlation between leptin concentration and BMI (r=0.55, p<0.0001), but no association with hemagglutination antibody inhibition (HAI), B-cell, or granzyme B responses. We found a slight correlation between leptin concentration and an immunosenescence marker (TREC: T-cell receptor excision circles) level (r=0.23, p=0.01). We found eight SNPs in the LEP/LEPR/GHRL genes that were associated with leptin levels and four SNPs in the PTPN1/LEPR/STAT3 genes associated with peripheral blood TREC levels (p<0.05). Heterozygosity of the synonymous variant rs2230604 in the PTPN1 gene was associated with a significantly lower (531 vs. 259, p=0.005) TREC level, as compared to the homozygous major variant. We also found eight SNPs in the LEP/PPARG/CRP genes associated with variations in influenza-specific HAI and B-cell responses (p<0.05). Our results suggest that specific allelic variations in the leptin-related genes may influence adaptive immune responses to influenza vaccine. Copyright © 2013 Elsevier Ltd. All rights reserved.

Leptin and Leptin-Related Gene Polymorphisms, Obesity, and Influenza A/H1N1 Vaccine–Induced Immune Responses in Older Individuals

PubMed Central

Ovsyannikova, Inna G.; White, Sarah J.; Larrabee, Beth R.; Grill, Diane E.; Jacobson, Robert M.; Poland, Gregory A.

2014-01-01

Obesity is a risk factor for complicated influenza A/H1N1 disease and poor vaccine immunogenicity. Leptin, an adipocyte-derived hormone/cytokine, has many immune regulatory functions and therefore could explain susceptibility to infections and poor vaccine outcomes. We recruited 159 healthy adults (5074 years old) who were immunized with inactivated TIV influenza vacci–ne that contained A/California/7/2009/H1N1 virus. We found a strong correlation between leptin concentration and BMI (r=0.55, p<0.0001), but no association with hemagglutination antibody inhibition (HAI), B-cell, or granzyme B responses. We found a slight correlation between leptin concentration and an immunosenescence marker (TREC: T-cell receptor excision circles) level (r=0.23, p=0.01). We found eight SNPs in the LEP/LEPR/GHRL genes that were associated with leptin levels and four SNPs in the PTPN1/LEPR/STAT3 genes associated with peripheral blood TREC levels (p<0.05). Heterozygosity of the synonymous variant rs2230604 in the PTPN1 gene was associated with a significantly lower (531 vs. 259, p = 0.005) TREC level, as compared to the homozygous major variant. We also found eight SNPs in the LEP/PPARG/CRP genes associated with variations in influenza-specific HAI and B-cell responses (p<0.05). Our results suggest that specific allelic variations in the leptin-related genes may influence adaptive immune responses to influenza vaccine. PMID:24360890

Antigenic and genomic characterization of human influenza A and B viruses circulating in Argentina after the introduction of influenza A(H1N1)pdm09.

PubMed

Russo, Mara L; Pontoriero, Andrea V; Benedetti, Estefania; Czech, Andrea; Avaro, Martin; Periolo, Natalia; Campos, Ana M; Savy, Vilma L; Baumeister, Elsa G

2014-12-01

This study was conducted as part of the Argentinean Influenza and other Respiratory Viruses Surveillance Network, in the context of the Global Influenza Surveillance carried out by the World Health Organization (WHO). The objective was to study the activity and the antigenic and genomic characteristics of circulating viruses for three consecutive seasons (2010, 2011 and 2012) in order to investigate the emergence of influenza viral variants. During the study period, influenza virus circulation was detected from January to December. Influenza A and B, and all current subtypes of human influenza viruses, were present each year. Throughout the 2010 post-pandemic season, influenza A(H1N1)pdm09, unexpectedly, almost disappeared. The haemagglutinin (HA) of the A(H1N1)pdm09 viruses studied were segregated in a different genetic group to those identified during the 2009 pandemic, although they were still antigenically closely related to the vaccine strain A/California/07/2009. Influenza A(H3N2) viruses were the predominant strains circulating during the 2011 season, accounting for nearly 76 % of influenza viruses identified. That year, all HA sequences of the A(H3N2) viruses tested fell into the A/Victoria/208/2009 genetic clade, but remained antigenically related to A/Perth/16/2009 (reference vaccine recommended for this three-year period). A(H3N2) viruses isolated in 2012 were antigenically closely related to A/Victoria/361/2011, recommended by the WHO as the H3 component for the 2013 Southern Hemisphere formulation. B viruses belonging to the B/Victoria lineage circulated in 2010. A mixed circulation of viral variants of both B/Victoria and B/Yamagata lineages was detected in 2012, with the former being predominant. A(H1N1)pdm09 viruses remained antigenically closely related to the vaccine virus A/California/7/2009; A(H3N2) viruses continually evolved into new antigenic clusters and both B lineages, B/Victoria/2/87-like and B/Yamagata/16/88-like viruses, were observed

The RNA helicase DDX39B and its paralog DDX39A regulate androgen receptor splice variant AR-V7 generation.

PubMed

Nakata, Daisuke; Nakao, Shoichi; Nakayama, Kazuhide; Araki, Shinsuke; Nakayama, Yusuke; Aparicio, Samuel; Hara, Takahito; Nakanishi, Atsushi

2017-01-29

Mounting evidence suggests that constitutively active androgen receptor (AR) splice variants, typified by AR-V7, are associated with poor prognosis and resistance to androgen deprivation therapy in prostate cancer patients. However, mechanisms governing the generation of AR splice variants are not fully understood. In this study, we aimed to investigate the dynamics of AR splice variant generation using the JDCaP prostate cancer model that expresses AR splice variants under androgen depletion. Microarray analysis of JDCaP xenografts before and after expression of AR splice variants suggested that dysregulation of RNA processing pathways is likely involved in AR splice variant generation. To explore factors contributing to generation of AR-V7 mRNA, we conducted a focused RNA interference screen in AR-V7-positive JDCaP-hr cells using an shRNA library targeting spliceosome-related genes. This screen identified DDX39B as a regulator of AR-V7 mRNA expression. Simultaneous knockdown of DDX39B and its paralog DDX39A drastically and selectively downregulated AR-V7 mRNA expression in multiple AR-V7-positive prostate cancer cell lines. DDX39B was upregulated in relapsed JDCaP xenografts expressing AR splice variants, suggesting its role in expression of AR splice variants. Taken together, our findings offer insight into the mechanisms of AR splice variant generation and identify DDX39 as a potential drug target for the treatment of AR splice variant-positive prostate cancer. Copyright © 2016 Elsevier Inc. All rights reserved.

Minireview: Toward the Establishment of a Link between Melatonin and Glucose Homeostasis: Association of Melatonin MT2 Receptor Variants with Type 2 Diabetes

PubMed Central

Karamitri, Angeliki; Renault, Nicolas; Clement, Nathalie; Guillaume, Jean-Luc

2013-01-01

The existence of interindividual variations in G protein-coupled receptor sequences has been recognized early on. Recent advances in large-scale exon sequencing techniques are expected to dramatically increase the number of variants identified in G protein-coupled receptors, giving rise to new challenges regarding their functional characterization. The current minireview will illustrate these challenges based on the MTNR1B gene, which encodes the melatonin MT2 receptor, for which exon sequencing revealed 40 rare nonsynonymous variants in the general population and in type 2 diabetes (T2D) cohorts. Functional characterization of these MT2 mutants revealed 14 mutants with loss of Gi protein activation that associate with increased risk of T2D development. This repertoire of disease-associated mutants is a rich source for structure-activity studies and will help to define the still poorly understood role of melatonin in glucose homeostasis and T2D development in humans. Defining the functional defects in carriers of rare MT2 mutations will help to provide personalized therapies to these patients in the future. PMID:23798576

Structure–activity correlations of variant forms of the B pentamer of Escherichia coli type II heat-labile enterotoxin LT-IIb with Toll-like receptor 2 binding

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cody, Vivian, E-mail: cody@hwi.buffalo.edu; University at Buffalo, 700 Ellicott Street, Buffalo, NY 14203; Pace, Jim

2012-12-01

Structural data for the S74D variant of the pentameric B subunit of type II heat-labile enterotoxin of Escherichia coli reveal a smaller pore opening that may explain its reduced Toll-like receptor binding affinity compared to that of the wild type enterotoxin. The explanation for the enhanced Toll-like receptor binding affinity of the S74A variant is more complex than simply being attributed to the pore opening. The pentameric B subunit of the type II heat-labile enterotoxin of Escherichia coli (LT-IIb-B{sub 5}) is a potent signaling molecule capable of modulating innate immune responses. It has previously been shown that LT-IIb-B{sub 5}, butmore » not the LT-IIb-B{sub 5} Ser74Asp variant [LT-IIb-B{sub 5}(S74D)], activates Toll-like receptor (TLR2) signaling in macrophages. Consistent with this, the LT-IIb-B{sub 5}(S74D) variant failed to bind TLR2, in contrast to LT-IIb-B{sub 5} and the LT-IIb-B{sub 5} Thr13Ile [LT-IIb-B{sub 5}(T13I)] and LT-IIb-B{sub 5} Ser74Ala [LT-IIb-B{sub 5}(S74A)] variants, which displayed the highest binding activity to TLR2. Crystal structures of the Ser74Asp, Ser74Ala and Thr13Ile variants of LT-IIb-B{sub 5} have been determined to 1.90, 1.40 and 1.90 Å resolution, respectively. The structural data for the Ser74Asp variant reveal that the carboxylate side chain points into the pore, thereby reducing the pore size compared with that of the wild-type or the Ser74Ala variant B pentamer. On the basis of these crystallographic data, the reduced TLR2-binding affinity of the LT-IIb-B{sub 5}(S74D) variant may be the result of the pore of the pentamer being closed. On the other hand, the explanation for the enhanced TLR2-binding activity of the LT-IIb-B{sub 5}(S74A) variant is more complex as its activity is greater than that of the wild-type B pentamer, which also has an open pore as the Ser74 side chain points away from the pore opening. Data for the LT-IIb-B{sub 5}(T13I) variant show that four of the five variant side chains point to the

Effects of 4-nitrophenol on expression of the ER-α and AhR signaling pathway-associated genes in the small intestine of rats.

PubMed

Tang, Juan; Song, Meiyan; Watanabe, Gen; Nagaoka, Kentaro; Rui, Xiaoli; Li, ChunMei

2016-09-01

4-Nitrophenol (PNP) is a persistent organic pollutant that was proven to be an environmental endocrine disruptor. The aim of this study was to evaluate the role of the estrogen receptor-α (ER-α) and aryl hydrocarbon receptor (AhR) signaling pathway in regulating the damage response to PNP in the small intestine of rats. Wistar-Imamichi male rats (21 d) were randomly divided into two groups: the control group and PNP group. Each group had three processes that were gavaged with PNP or vehicle daily: single dose (1 d), repeated dose (3 consecutive days) (3 d), and repeated dose with recovery (3 consecutive days and 3 recovery days) (6 d). The weight of the body, the related viscera, and small intestine were examined. Histological parameters of the small intestine and the quantity of mucus proteins secreted by small goblet cells were determined using HE staining and PAS staining. The mRNA expression of AhR, ER-α, CYP1A1, and GST was measured by real-time qPCR. In addition, we also analyzed the AhR, ER-α, and CYP1A1 expression in the small intestine by immunohistochemical staining. The small intestines histologically changed in the PNP-treated rat and the expression of AhR, CYP1A1, and GST was increased. While ER-α was significantly decreased in the small intestine, simultaneously, when rats were exposed to a longer PNP treatment, the damages disappeared. Our results demonstrate that PNP has an effect on the expression of AhR signaling pathway genes, AhR, CYP1A1, and GST, and ER-α in the rat small intestine. Copyright © 2016 Elsevier Ltd. All rights reserved.

AhIRT1 and AhNRAMP1 metal transporter expression correlates with Cd uptake in peanuts under iron deficiency

PubMed Central

Xia, Shenglan; Deng, Rubo; Liu, Caifeng; Shi, Gangrong

2017-01-01

Fe deficiency may increase Cd accumulation in peanuts. However, the mechanisms are not yet fully understood. In the present study, two contrasting peanut cultivars, Luhua 8 (low seed-Cd cultivar) and Zhenghong 3 (high seed-Cd cultivar) were used to investigate the effect of Fe deficiency on the uptake and accumulation of cadmium (Cd) by hydroponic experiments. Under Fe-sufficient conditions, compared with Luhua 8, Zhenghong 3 had higher specific root length (SRL) and proportion of fine roots with a lower Km for Cd and showed slightly higher expression of AhIRT1 and AhNRAMP1 in the roots. These traits may be responsible for high capacity for Cd accumulation in Zhenghong 3. Under Fe deficiency, the increase of Cd accumulation was much larger in Zhenghong 3 than in Luhua 8. Kinetics studies revealed that the Vmax for Cd influx was 1.56-fold higher in Fe-deficient plants than in Fe-sufficient plants for Zhenghong 3, versus 0.48-fold higher for Luhua 8. Moreover, the increased expression levels of AhIRT1 and AhNRAMP1 induced by Fe deficiency was higher in Zhenghong 3 than in Luhua 8. Yeast complementation assays suggested that the AhIRT1 and AhNRAMP1 may function as transporters involved in Cd uptake. In conclusion, the different Cd accumulation between the two cultivars under Fe deficiency may be correlated with Vmax value for Cd uptake and the expression levels of AhIRT1 and AhNRAMP1 in the roots. PMID:28981520

Cloning and functional analysis of P2X1b, a new variant in rat optic nerve that regulates the P2X1 receptor in a use-dependent manner.

PubMed

Rangel-Yescas, Gisela E; Vazquez-Cuevas, Francisco G; Garay, Edith; Arellano, Rogelio O

2012-01-01

P2X receptors are trimeric, ATP-gated cation channels. In mammals seven P2X subtypes have been reported (P2X1-P2X7), as well as several variants generated by alternative splicing. Variants confer to the homomeric or heteromeric channels distinct functional and/or pharmacological properties. Molecular biology, biochemical, and functional analysis by electrophysiological methods were used to identify and study a new variant of the P2X1 receptor named P2X1b. This new variant, identified in rat optic nerve, was also expressed in other tissues. P2X1b receptors lack amino acids 182 to 208 of native P2X1, a region that includes residues that are highly conserved among distinct P2X receptors. When expressed in Xenopus oocytes, P2X1b was not functional as a homomer; however, when co-expressed with P2X1, it downregulated the electrical response generated by ATP compared with that of oocytes expressing P2X1 alone, and it seemed to form heteromeric channels with a modestly enhanced ATP potency. A decrease in responses to ATP in oocytes co-expressing different ratios of P2X1b to P2X1 was completely eliminated by overnight pretreatment with apyrase. Thus, it is suggested that P2X1b regulates, through a use-dependent mechanism, the availability, in the plasma membrane, of receptor channels that can be operated by ATP.

Novel cell-based assay reveals associations of circulating serum AhR-ligands with metabolic syndrome and mitochondrial dysfunction.

PubMed

Park, Wook-Ha; Jun, Dae Won; Kim, Jin Taek; Jeong, Jae Hoon; Park, Hyokeun; Chang, Yoon-Seok; Park, Kyong Soo; Lee, Hong Kyu; Pak, Youngmi Kim

2013-01-01

Serum concentrations of environmental pollutants have been positively correlated with diabetes and metabolic syndrome in epidemiologic studies. In turn, abnormal mitochondrial function has been associated with the diseases. The relationships between these variables, however, have not been studied. We developed novel cell-based aryl hydrocarbon receptor (AhR) agonist bioassay system without solvent extraction process and analyzed whether low-dose circulating AhR ligands in human serum are associated with parameters of metabolic syndrome and mitochondrial function. Serum AhR ligand activities were measured as serum 2,3,7,8-tetrachlorodibenzo-p-dioxin equivalent (sTCDDeq) in pM using 10 μL human sera from 97 Korean participants (47 with glucose intolerance and 50 matched controls, average age of 46.6 ± 9.9 years, 53 male and 45 female). sTCDDeq were higher in participants with glucose intolerance than normal controls and were positively associated (P < 0.01) with obesity, blood pressure, serum triglyceride, and fasting glucose, but not with HDL-cholesterol. Body mass index was in a positive linear relationship with serum AhR ligands in healthy participants. When myoblast cells were incubated with human sera, ATP generating power of mitochondria became impaired in an AhR ligand concentration-dependent manner. Our results support that circulating AhR ligands may directly reduce mitochondrial function in tissues, leading to weight gain, glucose intolerance, and metabolic syndrome. Our rapid cell-based assay using minute volume of human serum may provide one of the best monitoring systems for circulating AhR ligands, good clinical biomarkers for the progress of disease and therapeutic efficacy. Copyright © 2013 International Union of Biochemistry and Molecular Biology, Inc.

Adenosine A(2A) receptor gene (ADORA2A) variants may increase autistic symptoms and anxiety in autism spectrum disorder.

PubMed

Freitag, Christine M; Agelopoulos, Konstantin; Huy, Ellen; Rothermundt, Matthias; Krakowitzky, Petra; Meyer, Jobst; Deckert, Jürgen; von Gontard, Alexander; Hohoff, Christa

2010-01-01

Autism spectrum disorders (ASDs) are heterogeneous disorders presenting with increased rates of anxiety. The adenosine A(2A) receptor gene (ADORA2A) is associated with panic disorder and is located on chromosome 22q11.23. Its gene product, the adenosine A(2A) receptor, is strongly expressed in the caudate nucleus, which also is involved in ASD. As autistic symptoms are increased in individuals with 22q11.2 deletion syndrome, and large 22q11.2 deletions and duplications have been observed in ASD individuals, in this study, 98 individuals with ASD and 234 control individuals were genotyped for eight single-nucleotide polymorphisms in ADORA2A. Nominal association with the disorder was observed for rs2236624-CC, and phenotypic variability in ASD symptoms was influenced by rs3761422, rs5751876 and rs35320474. In addition, association of ADORA2A variants with anxiety was replicated for individuals with ASD. Findings point toward a possible mediating role of ADORA2A variants on phenotypic expression in ASD that need to be replicated in a larger sample.

Progressive antigenic drift and phylogeny of human influenza A(H3N2) virus over five consecutive seasons (2009-2013) in Hangzhou, China.

PubMed

Shao, Tie-Juan; Li, Jun; Yu, Xin-Fen; Kou, Yu; Zhou, Yin-Yan; Qian, Xin

2014-12-01

Vaccine efficacy (VE) can be affected by progressive antigenic drift or any new reassortment of influenza viruses. To effectively track the evolution of human influenza A(H3N2) virus circulating in Hangzhou, China, a total of 65 clinical specimens were selected randomly from outpatients infected by A(H3N2) viruses during the study period from November 2009 to December 2013. The results of reduced VE and antigenic drift of the correspondent epitopes (C-D-E to A-B) suggest that the current vaccine provides suboptimal protection against the A(H3N2) strains circulating recently. Phylogenetic analysis of the entire HA and NA sequences demonstrated that these two genes underwent independent evolutionary pathways during recent seasons. The H3-based phylogenetic tree showed that a special strain A/Hangzhou/A289/2012 fell in a cluster among viruses with reduced VE predominantly circulating in 2013. Our findings underscore a possible early warning for the circulation of A(H3N2) variants with antigenic drift during the previous seasons. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

Role of aryl hydrocarbon receptor in mesenchymal stromal cell activation: A minireview.

PubMed

de Almeida, Danilo Candido; Evangelista, Laura Sibele Martins; Câmara, Niels Olsen Saraiva

2017-09-26

Mesenchymal stromal cells (MSCs) possess great therapeutic advantages due to their ability to produce a diverse array of trophic/growth factors related to cytoprotection and immunoregulation. MSC activation via specific receptors is a crucial event for these cells to exert their immunosuppressive response. The aryl-hydrocarbon receptor (AhR) is a sensitive molecule for external signals and it is expressed in MSCs and, upon positive activation, may potentially regulate the MSC-associated immunomodulatory function. Consequently, signalling pathways linked to AhR activation can elucidate some of the molecular cascades involved in MSC-mediated immunosuppression. In this minireview, we have noted some important findings concerning MSC regulation via AhR, highlighting that its activation is associated with improvement in migration and immunoregulation, as well as an increase in pro-regenerative potential. Thus, AhR-mediated MSC activation can contribute to new perspectives on MSC-based therapies, particularly those directed at immune-associated disorders.

Individual differences in flow proneness are linked to a dopamine D2 receptor gene variant.

PubMed

Gyurkovics, Mate; Kotyuk, Eszter; Katonai, Eniko Rozsa; Horvath, Erzsebet Zsofia; Vereczkei, Andrea; Szekely, Anna

2016-05-01

Flow is a special mental state characterized by deep concentration that occurs during the performance of optimally challenging tasks. In prior studies, proneness to experience flow has been found to be moderately heritable. In the present study, we investigated whether individual differences in flow proneness are related to a polymorphism of the dopamine D2 receptor coding gene (DRD2 C957T rs6277). This polymorphism affects striatal D2 receptor availability, a factor that has been shown to be related to flow proneness. To our knowledge, this is the first study to investigate the association between this trait and a specific gene variant. In a sample of 236 healthy Hungarian adults, we found that CC homozygotes report higher flow proneness than do T allele carriers, but only during mandatory activities (i.e., studying and working), not during leisure time. We discuss implications of this result, e.g., the potential mediators of the relationship. Copyright © 2016 Elsevier Inc. All rights reserved.

Novel roles for AhR and ARNT in the regulation of alcohol dehydrogenases in human hepatic cells.

PubMed

Attignon, Eléonore A; Leblanc, Alix F; Le-Grand, Béatrice; Duval, Caroline; Aggerbeck, Martine; Rouach, Hélène; Blanc, Etienne B

2017-01-01

The mechanisms by which pollutants participate in the development of diverse pathologies are not completely understood. The pollutant 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) activates the AhR (aryl hydrocarbon receptor) signaling pathway. We previously showed that TCDD (25 nM, 30 h) decreased the expression of several alcohol metabolism enzymes (cytochrome P450 2E1, alcohol dehydrogenases ADH1, 4 and 6) in differentiated human hepatic cells (HepaRG). Here, we show that, as rapidly as 8 h after treatment (25 nM TCDD) ADH expression decreased 40 % (p < 0.05). ADH1 and 4 protein levels decreased 40 and 27 %, respectively (p < 0.05), after 72 h (25 nM TCDD). The protein half-lives were not modified by TCDD which suggests transcriptional regulation of expression. The AhR antagonist CH-223191 or AhR siRNA reduced the inhibitory effect of 25 nM TCDD on ADH1A, 4 and 6 expression 50-100 % (p < 0.05). The genomic pathway (via the AhR/ARNT complex) and not the non-genomic pathway involving c-SRC mediated these effects. Other AhR ligands (3-methylcholanthrene and PCB 126) decreased ADH1B, 4 and 6 mRNAs by more than 78 and 55 %, respectively (p < 0.01). TCDD also regulated the expression of ADH4 in the HepG2 human hepatic cell line, in primary human hepatocytes and in C57BL/6J mouse liver. In conclusion, activation of the AhR/ARNT signaling pathway by AhR ligands represents a novel mechanism for regulating the expression of ADHs. These effects may be implicated in the toxicity of AhR ligands as well as in the alteration of ethanol or retinol metabolism and may be associated further with higher risk of liver diseases or/and alcohol abuse disorders.

The Cannabinoid Receptor 2 Q63R Variant Modulates the Relationship between Childhood Obesity and Age at Menarche.

PubMed

Bellini, Giulia; Grandone, Anna; Torella, Marco; Miraglia del Giudice, Emanuele; Nobili, Bruno; Perrone, Laura; Maione, Sabatino; Rossi, Francesca

2015-01-01

The ovary is an important site where gene variants modulate pubertal timing. The cannabinoid receptor 2 (CB2) is expressed in the ovary, plays a role in folliculogenesis and ovulation, and can be modulated by estrogens. Obesity is strictly associated with early menarche and is characterized by sex hormone and endocannabinoid derangement. In this study, we investigated the role of the CB2 receptor in determining the age at menarche in obese girls. We studied a cohort of 240 obese girls (age 11.9±3 years; BMI z-score 2.8±0.8). The age at menarche (if it had already occurred) was recorded at the time of the visit or via phonecall. The CNR2 rs35761398 polymorphism, which leads to the CB2 Q63R variant, was detected by the TaqMan assay. In total, 105 patients were homozygous for the R63-coding allele (RR), 113 were QR and 22 were QQ. Variance analysis revealed a significantly earlier age of menarche in subjects carrying the Q63 allele, which was also found after adjusting for BMI z-score (11±1.2 vs. 11.6±1.2 years, p = 0.0003). Logistic regression analysis demonstrated that patients homozygous for the Q allele had a 2.2-fold higher risk (odds ratio = 2.2; CI1.1-3.4; p = 0.02) of presenting with an early menarche (age at menarche <12 years). We demonstrated for the first time the association between the CB2 Q63R functional variant and the age at menarche in a cohort of Italian obese girls.

Activation of the aryl hydrocarbon receptor sensitises human keratinocytes for CD95L- and TRAIL-induced apoptosis

PubMed Central

Stolpmann, K; Brinkmann, J; Salzmann, S; Genkinger, D; Fritsche, E; Hutzler, C; Wajant, H; Luch, A; Henkler, F

2012-01-01

In this study, we have analysed the apoptotic effects of the ubiquitous environmental toxin benzo[a]pyrene (BP) in HaCaT cells and human keratinocytes. Although prolonged exposure to BP was not cytotoxic on its own, a strong enhancement of CD95 (Fas)-mediated apoptosis was observed with BP at concentrations activating the aryl hydrocarbon receptor (AhR). Importantly, the ultimately mutagenic BP-metabolite, that is, (+)-anti-BP-7,8-diol-9,10-epoxide (BPDE), failed to enhance CD95-mediated cell death, suggesting that the observed pro-apoptotic effect of BP is neither associated with DNA adducts nor DNA-damage related signalling. CD95-induced apoptosis was also enhanced by β-naphtoflavone, a well-known agonist of the AhR that does not induce DNA damage, thus suggesting a crucial role for AhR activation. Consistently, BP failed to sensitise for CD95L-induced apoptosis in AhR knockdown HaCaT cells. Furthermore, inhibition of CYP1A1 and/or 1B1 expression did not affect the pro-apoptotic crosstalk. Exposure to BP did not increase expression of CD95, but led to augmented activation of caspase-8. Enhancement of apoptosis was also observed with the TRAIL death receptors that activate caspase-8 and apoptosis by similar mechanisms as CD95. Together, these observations indicate an interference of AhR signalling with the activity of receptor-associated signalling intermediates that are shared by CD95 and TRAIL receptors. Our data thus suggest that AhR agonists can enhance cytokine-mediated adversity upon dermal exposure. PMID:22951985

Tumor-Repopulating Cells Induce PD-1 Expression in CD8+ T Cells by Transferring Kynurenine and AhR Activation.

PubMed

Liu, Yuying; Liang, Xiaoyu; Dong, Wenqian; Fang, Yi; Lv, Jiadi; Zhang, Tianzhen; Fiskesund, Roland; Xie, Jing; Liu, Jinyan; Yin, Xiaonan; Jin, Xun; Chen, Degao; Tang, Ke; Ma, Jingwei; Zhang, Huafeng; Yu, Jing; Yan, Jun; Liang, Huaping; Mo, Siqi; Cheng, Feiran; Zhou, Yabo; Zhang, Haizeng; Wang, Jing; Li, Jingnan; Chen, Yang; Cui, Bing; Hu, Zhuo-Wei; Cao, Xuetao; Xiao-Feng Qin, F; Huang, Bo

2018-03-12

Despite the clinical successes fostered by immune checkpoint inhibitors, mechanisms underlying PD-1 upregulation in tumor-infiltrating T cells remain an enigma. Here, we show that tumor-repopulating cells (TRCs) drive PD-1 upregulation in CD8 + T cells through a transcellular kynurenine (Kyn)-aryl hydrocarbon receptor (AhR) pathway. Interferon-γ produced by CD8 + T cells stimulates release of high levels of Kyn produced by TRCs, which is transferred into adjacent CD8 + T cells via the transporters SLC7A8 and PAT4. Kyn induces and activates AhR and thereby upregulates PD-1 expression. This Kyn-AhR pathway is confirmed in both tumor-bearing mice and cancer patients and its blockade enhances antitumor adoptive T cell therapy efficacy. Thus, we uncovered a mechanism of PD-1 upregulation with potential tumor immunotherapeutic applications. Copyright © 2018 Elsevier Inc. All rights reserved.

Germline prokineticin receptor 2 (PROKR2) variants associated with central hypogonadism cause differental modulation of distinct intracellular pathways.

PubMed

Libri, Domenico Vladimiro; Kleinau, Gunnar; Vezzoli, Valeria; Busnelli, Marta; Guizzardi, Fabiana; Sinisi, Antonio Agostino; Pincelli, Angela Ida; Mancini, Antonio; Russo, Gianni; Beck-Peccoz, Paolo; Loche, Sandro; Crivellaro, Claudio; Maghnie, Mohamad; Krausz, Csilla; Persani, Luca; Bonomi, Marco

2014-03-01

Defects of prokineticin pathway affect the neuroendocrine control of reproduction, but their role in the pathogenesis of central hypogonadism remains undefined, and the functional impact of the missense PROKR2 variants has been incompletely characterized. In a series of 246 idiopathic central hypogonadism patients, we found three novel (p.V158I, p.V334M, and p.N15TfsX30) and six already known (p.L173R, p.T260M, p.R268C, p.V274D, p.V331M, and p.H20MfsX23) germline variants in the PROKR2 gene. We evaluated the effects of seven missense alterations on two different prokineticin receptor 2 (PROKR2)-dependent pathways: inositol phosphate-Ca(2+) (Gq coupling) and cAMP (Gs coupling). PROKR2 variants were found in 16 patients (6.5%). Expression levels of variants p.V158I and p.V331M were moderately reduced, whereas they were markedly impaired in the remaining cases, except p.V334M, which was significantly overexpressed. The variants p.T260M, p.R268C, and p.V331M showed no remarkable changes in cAMP response (EC50) whereas the IP signaling appeared more profoundly affected. In contrast, cAMP accumulation cannot be stimulated through the p.L173R and p.V274D, but IP EC50 was similar to wt inp.L173R and increased by 10-fold in p.V274D. The variant p.V334M led to a 3-fold increase of EC50 for both cAMP and IP. Our study shows that single PROKR2 missense allelic variants can either affect both signaling pathways differently or selectively. Thus, the integrity of both PROKR2-dependent cAMP and IP signals should be evaluated for a complete functional testing of novel identified allelic variants.

Sun Exposure, Vitamin D Receptor Genetic Variants, and Risk of Breast Cancer in the Agricultural Health Study

PubMed Central

Satagopan, Jaya; Sima, Camelia S.; Orlow, Irene; Mujumdar, Urvi; Coble, Joseph; Roy, Pampa; Yoo, Sarah; Sandler, Dale P.; Alavanja, Michael C.

2013-01-01

Background: Epidemiologic evidence suggests a negative relation between sunlight exposure and breast cancer risk. The hypothesized mechanism is sunlight-induced cutaneous synthesis of vitamin D. Objectives: Our goal was to examine sun exposure and its interaction with vitamin D receptor (VDR) gene variants on breast cancer risk. Methods: We examined sun exposure and breast cancer incidence among 31,021 private pesticide applicators’ wives, including 578 cases, enrolled in the prospective Agricultural Health Study cohort and followed 8.6 years on average. We estimated interactions between sun exposure, VDR variants, and breast cancer in a nested case–control study comprising 293 cases and 586 matched controls. Information on sun exposure was obtained by questionnaire at cohort enrollment. Relative risks were estimated using Cox proportional hazards regression for the cohort data and conditional logistic regression for the nested case–control data. Results: We observed a small decrease in breast cancer risk in association with usual sun exposure of ≥ 1 hr/day (versus < 1 hr/day) 10 years before the start of follow-up among all participants [hazard ratio (HR) = 0.8; 95% CI: 0.6, 1.0]. The association appeared to be slightly stronger in relation to estrogen receptor–positive tumors (HR = 0.7; 95% CI: 0.5, 0.9) than estrogen receptor–negative tumors (HR = 1.1; 95% CI: 0.6, 2.1). The HR for joint exposure ≥ 1 hr/day of sunlight and one VDR haplotype was less than expected given negative HRs for each individual exposure (interaction p-value = 0.07). Conclusion: Our results suggest that sun exposure may be associated with reduced risk of breast cancer, but we did not find clear evidence of modification by VDR variants. Larger studies are warranted, particularly among populations in whom low levels of usual sun exposure can be more precisely characterized. Citation: Engel LS, Satagopan J, Sima CS, Orlow I, Mujumdar U, Coble J, Roy P, Yoo S, Sandler DP

Indole-3-Carbinol Promotes Goblet-Cell Differentiation Regulating Wnt and Notch Signaling Pathways AhR-Dependently.

PubMed

Park, Joo-Hung; Lee, Jeong-Min; Lee, Eun-Jin; Hwang, Won-Bhin; Kim, Da-Jeong

2018-04-30

Using an in vitro model of intestinal organoids derived from intestinal crypts, we examined effects of indole-3-carbinol (I3C), a phytochemical that has anticancer and aryl hydrocarbon receptor (AhR)-activating abilities and thus is sold as a dietary supplement, on the development of intestinal organoids and investigated the underlying mechanisms. I3C inhibited the in vitro development of mouse intestinal organoids. Addition of α-naphthoflavone, an AhR antagonist or AhR siRNA transfection, suppressed I3C function, suggesting that I3C-mediated interference with organoid development is AhR-dependent. I3C increased the expression of Muc2 and lysozyme, lineage-specific genes for goblet cells and Paneth cells, respectively, but inhibits the expression of IAP, a marker gene for enterocytes. In the intestines of mice treated with I3C, the number of goblet cells was reduced, but the number of Paneth cells and the depth and length of crypts and villi were not changed. I3C increased the level of active nonphosphorylated β-catenin, but suppressed the Notch signal. As a result, expression of Hes1, a Notch target gene and a transcriptional repressor that plays a key role in enterocyte differentiation, was reduced, whereas expression of Math1, involved in the differentiation of secretory lineages, was increased. These results provide direct evidence for the role of AhR in the regulation of the development of intestinal stem cells and indicate that such regulation is likely mediated by regulation of Wnt and Notch signals.

Common low-density lipoprotein receptor p.G116S variant has a large effect on plasma low-density lipoprotein cholesterol in circumpolar inuit populations.

PubMed

Dubé, Joseph B; Wang, Jian; Cao, Henian; McIntyre, Adam D; Johansen, Christopher T; Hopkins, Scarlett E; Stringer, Randa; Hosseinzadeh, Siyavash; Kennedy, Brooke A; Ban, Matthew R; Young, T Kue; Connelly, Philip W; Dewailly, Eric; Bjerregaard, Peter; Boyer, Bert B; Hegele, Robert A

2015-02-01

Inuit are considered to be vulnerable to cardiovascular disease because their lifestyles are becoming more Westernized. During sequence analysis of Inuit individuals at extremes of lipid traits, we identified 2 nonsynonymous variants in low-density lipoprotein receptor (LDLR), namely p.G116S and p.R730W. Genotyping these variants in 3324 Inuit from Alaska, Canada, and Greenland showed they were common, with allele frequencies 10% to 15%. Only p.G116S was associated with dyslipidemia: the increase in LDL cholesterol was 0.54 mmol/L (20.9 mg/dL) per allele (P=5.6×10(-49)), which was >3× larger than the largest effect sizes seen with other common variants in other populations. Carriers of p.G116S had a 3.02-fold increased risk of hypercholesterolemia (95% confidence interval, 2.34-3.90; P=1.7×10(-17)), but did not have classical familial hypercholesterolemia. In vitro, p.G116S showed 60% reduced ligand-binding activity compared with wild-type receptor. In contrast, p.R730W was associated with neither LDL cholesterol level nor altered in vitro activity. LDLR p.G116S is thus unique: a common dysfunctional variant in Inuit whose large effect on LDL cholesterol may have public health implications. © 2014 American Heart Association, Inc.

A novel contact assay for testing aryl hydrocarbon receptor (AhR)-mediated toxicity of chemicals and whole sediments in zebrafish (Danio rerio) embryos.

PubMed

Schiwy, Sabrina; Bräunig, Jennifer; Alert, Henriette; Hollert, Henner; Keiter, Steffen H

2015-11-01

The European Water Framework Directive aims to achieve a good ecological and chemical status in surface waters until 2015. Sediment toxicology plays a major role in this intention as sediments can act as a secondary source of pollution. In order to fulfill this legal obligation, there is an urgent need to develop whole-sediment exposure protocols, since sediment contact assays represent the most realistic scenario to simulate in situ exposure conditions. Therefore, in the present study, a vertebrate sediment contact assay to determine aryl hydrocarbon receptor (AhR)-mediated activity of particle-bound pollutants was developed. Furthermore, the activity and the expression of the CYP1 family in early life stages of zebrafish after exposure to freeze-dried sediment samples were investigated. In order to validate the developed protocol, effects of β-naphthoflavone and three selected sediment on zebrafish embryos were investigated. Results documented clearly AhR-mediated toxicity after exposure to β-naphthoflavone (β-NF) and to the sediment from the Vering canal. Upregulation of mRNA levels was observed for all investigated sediment samples. The highest levels of all investigated cyp genes (cyp1a, cyp1b1, cyp1c1, and cyp1c2) were recorded after exposure to the sediment sample of the Vering canal. In conclusion, the newly developed sediment contact assay can be recommended for the investigation of dioxin-like activities of single substances and the bioavailable fraction of complex environmental samples. Moreover, the exposure of whole zebrafish embryos to native (freeze-dried) sediment samples represents a highly realistic and ecologically relevant exposure scenario.

Variant ionotropic receptors are expressed in olfactory sensory neurons of coeloconic sensilla on the antenna of the desert locust (Schistocerca gregaria).

PubMed

Guo, Mei; Krieger, Jürgen; Große-Wilde, Ewald; Mißbach, Christine; Zhang, Long; Breer, Heinz

2013-01-01

The behaviour of the desert locust, Schistocera gregaria, is largely directed by volatile olfactory cues. The relevant odorants are detected by specialized antennal sensory neurons which project their sensory dendrites into hair-like structures, the sensilla. Generally, the responsiveness of the antennal chemosensory cells is determined by specific receptors which may be either odorant receptors (ORs) or variant ionotropic receptors (IRs). Previously, we demonstrated that in locust the co-receptor for ORs (ORco) is only expressed in cells of sensilla basiconica and sensilla trichodea, suggesting that cells in sensilla coeloconica may express different types of chemosensory receptors. In this study, we have identified the genes of S. gregaria which encode homologues of co-receptors for the variant ionotropic receptors, the subtypes IR8a and IR25a. It was found that both subtypes, SgreIR8a and SgreIR25a, are expressed in the antennae of all five nymphal stages and in adults. Attempts to assign the relevant cell types by means of in situ hybridization revealed that SgreIR8a and SgreIR25a are expressed in cells of sensilla coeloconica. Double fluorescence in situ hybridization experiments disclosed that the two IR-subtypes are co-expressed in some cells of this sensillum type. Expression of SgreIR25a was also found in some of the sensilla chaetica, however, neither SgreIR25a nor SgreIR8a was found to be expressed in sensilla basiconica and sensilla trichodea. This observation was substantiated by the results of double FISH experiments demonstrating that cells expressing SgreIR8a or SgreIR25a do not express ORco. These results support the notion that the antenna of the desert locust employs two different populations of OSNs to sense odors; cells which express IRs in sensilla coeloconica and cells which express ORs in sensilla basiconica and sensilla trichodea.

Outbreak of Influenza A(H3N2) Variant Virus Infections Among Persons Attending Agricultural Fairs Housing Infected Swine - Michigan and Ohio, July-August 2016.

PubMed

Schicker, Rebekah S; Rossow, John; Eckel, Seth; Fisher, Nicolas; Bidol, Sally; Tatham, Lilith; Matthews-Greer, Janice; Sohner, Kevin; Bowman, Andrew S; Avrill, James; Forshey, Tony; Blanton, Lenee; Davis, C Todd; Schiltz, John; Skorupski, Susan; Berman, LaShondra; Jang, Yunho; Bresee, Joseph S; Lindstrom, Stephen; Trock, Susan C; Wentworth, David; Fry, Alicia M; de Fijter, Sietske; Signs, Kimberly; DiOrio, Mary; Olsen, Sonja J; Biggerstaff, Matthew

2016-10-28

On August 3, 2016, the Ohio Department of Health Laboratory reported to CDC that a respiratory specimen collected on July 28 from a male aged 13 years who attended an agricultural fair in Ohio during July 22-29, 2016, and subsequently developed a respiratory illness, tested positive by real-time reverse transcription-polymerase chain reaction (rRT-PCR) for influenza A(H3N2) variant* (H3N2v). The respiratory specimen was collected as part of routine influenza surveillance activities. The next day, CDC was notified of a child aged 9 years who was a swine exhibitor at an agricultural fair in Michigan who became ill on July 29, 2016, and tested positive for H3N2v virus at the Michigan Department of Health and Human Services Laboratory. Investigations by Michigan and Ohio health authorities identified 18 human infections linked to swine exhibits at agricultural fairs. To minimize transmission of influenza viruses from infected swine to visitors, agricultural fair organizers should consider prevention measures such as shortening the time swine are on the fairgrounds, isolating ill swine, maintaining a veterinarian on call, providing handwashing stations, and prohibiting food and beverages in animal barns. Persons at high risk for influenza-associated complications should be discouraged from entering swine barns.

Ecstacy-induced delayed rhabdomyolysis and neuroleptic malignant syndrome in a patient with a novel variant in the ryanodine receptor type 1 gene.

PubMed

Russell, T; Riazi, S; Kraeva, N; Steel, A C; Hawryluck, L A

2012-09-01

We present the case of a 20-year-old woman who developed rhabdomyolysis, disseminated intravascular coagulopathy and multi-organ failure induced by ecstasy. Following initial improvement, she developed delayed rhabdomyolysis then haloperidol-induced neuroleptic malignant syndrome, which was treated with a total of 50 mg.kg(-1) dantrolene. Subsequent genetic testing revealed a novel potentially pathogenic variant in the ryanodine receptor type 1 gene. However, caffeine-halothane contracture testing of the patient's mother who carried the same gene variant was negative for malignant hyperthermia. Anaesthesia © 2012 The Association of Anaesthetists of Great Britain and Ireland.

Variant Ionotropic Receptors in the Malaria Vector Mosquito Anopheles gambiae Tuned to Amines and Carboxylic Acids

PubMed Central

Pitts, R. Jason; Derryberry, Stephen L.; Zhang, Zhiwei; Zwiebel, Laurence J.

2017-01-01

The principal Afrotropical human malaria vector mosquito, Anopheles gambiae, remains a significant threat to global health. A critical component in the transmission of malaria is the ability of An. gambiae females to detect and respond to human-derived chemical kairomones in their search for blood meal hosts. The basis for host odor responses resides in olfactory receptor neurons (ORNs) that express chemoreceptors encoded by large gene families, including the odorant receptors (ORs) and the variant ionotropic receptors (IRs). While ORs have been the focus of extensive investigation, functional IR complexes and the chemical compounds that activate them have not been identified in An. gambiae. Here we report the transcriptional profiles and functional characterization of three An. gambiae IR (AgIr) complexes that specifically respond to amines or carboxylic acids - two classes of semiochemicals that have been implicated in mediating host-seeking by adult females but are not known to activate An. gambiae ORs (AgOrs). Our results suggest that AgIrs play critical roles in the detection and behavioral responses to important classes of host odors that are underrepresented in the AgOr chemical space. PMID:28067294

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

PubMed

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.

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

PubMed Central

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

2012-01-01

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. PMID:25949102

Adaptive changes in global gene expression profile of lung carcinoma A549 cells acutely exposed to distinct types of AhR ligands.

PubMed

Procházková, Jiřina; Strapáčová, Simona; Svržková, Lucie; Andrysík, Zdeněk; Hýžďalová, Martina; Hrubá, Eva; Pěnčíková, Kateřina; Líbalová, Helena; Topinka, Jan; Kléma, Jiří; Espinosa, Joaquín M; Vondráček, Jan; Machala, Miroslav

2018-08-01

Exposure to persistent ligands of aryl hydrocarbon receptor (AhR) has been found to cause lung cancer in experimental animals, and lung adenocarcinomas are often associated with enhanced AhR expression and aberrant AhR activation. In order to better understand the action of toxic AhR ligands in lung epithelial cells, we performed global gene expression profiling and analyze TCDD-induced changes in A549 transcriptome, both sensitive and non-sensitive to CH223191 co-treatment. Comparison of our data with results from previously reported microarray and ChIP-seq experiments enabled us to identify candidate genes, which expression status reflects exposure of lung cancer cells to TCDD, and to predict processes, pathways (e.g. ER stress, Wnt/β-cat, IFNɣ, EGFR/Erbb1), putative TFs (e.g. STAT, AP1, E2F1, TCF4), which may be implicated in adaptive response of lung cells to TCDD-induced AhR activation. Importantly, TCDD-like expression fingerprint of selected genes was observed also in A549 cells exposed acutely to both toxic (benzo[a]pyrene, benzo[k]fluoranthene) and endogenous AhR ligands (2-(1H-Indol-3-ylcarbonyl)-4-thiazolecarboxylic acid methyl ester and 6-formylindolo[3,2-b]carbazole). Overall, our results suggest novel cellular candidates, which could help to improve monitoring of AhR-dependent transcriptional activity during acute exposure of lung cells to distinct types of environmental pollutants. Copyright © 2018 Elsevier B.V. All rights reserved.

Joint association of nicotinic acetylcholine receptor variants with abdominal obesity in American Indians: the Strong Heart Family Study.

PubMed

Zhu, Yun; Yang, Jingyun; Yeh, Fawn; Cole, Shelley A; Haack, Karin; Lee, Elisa T; Howard, Barbara V; Zhao, Jinying

2014-01-01

Cigarette smoke is a strong risk factor for obesity and cardiovascular disease. The effect of genetic variants involved in nicotine metabolism on obesity or body composition has not been well studied. Though many genetic variants have previously been associated with adiposity or body fat distribution, a single variant usually confers a minimal individual risk. The goal of this study is to evaluate the joint association of multiple variants involved in cigarette smoke or nicotine dependence with obesity-related phenotypes in American Indians. To achieve this goal, we genotyped 61 tagSNPs in seven genes encoding nicotine acetylcholine receptors (nAChRs) in 3,665 American Indians participating in the Strong Heart Family Study. Single SNP association with obesity-related traits was tested using family-based association, adjusting for traditional risk factors including smoking. Joint association of all SNPs in the seven nAChRs genes were examined by gene-family analysis based on weighted truncated product method (TPM). Multiple testing was controlled by false discovery rate (FDR). Results demonstrate that multiple SNPs showed weak individual association with one or more measures of obesity, but none survived correction for multiple testing. However, gene-family analysis revealed significant associations with waist circumference (p = 0.0001) and waist-to-hip ratio (p = 0.0001), but not body mass index (p = 0.20) and percent body fat (p = 0.29), indicating that genetic variants are jointly associated with abdominal, but not general, obesity among American Indians. The observed combined genetic effect is independent of cigarette smoking per se. In conclusion, multiple variants in the nAChR gene family are jointly associated with abdominal obesity in American Indians, independent of general obesity and cigarette smoking per se.

Identification and functional characterization of three novel human melanocortin-4 receptor gene variants in an obese Chinese population.

PubMed

Rong, Rong; Tao, Ya-Xiong; Cheung, Bernard M Y; Xu, Aimin; Cheung, Grace C N; Lam, Karen S L

2006-08-01

Mutations in the melanocortin-4 receptor gene (MC4R) are the most common monogenic form of human obesity. However, the contribution of MC4R mutations to obesity in Chinese has not been investigated. We studied the frequency of MC4R mutations in an obese southern Chinese population and the functional consequences of the novel variants identified. We screened for MC4R mutations in 227 obese [body mass index (BMI) 35.29 +/- 5.75 kg/m2] and 100 lean (BMI 21.57 +/- 0.29 kg/m2) southern Chinese subjects using PCR-direct sequencing. In vitro functional studies, including cell surface expression, ligand binding, and cyclic adenosine monophosphate (cAMP) accumulation, were performed to examine the functional properties of three novel missense mutations. Apart from two previously reported polymorphisms, V103I and -176 A > C, three novel missense heterozygous variants (Y35C, C40R and M218T) were identified. The polymorphisms -176 A > C and Y35C were detected in both obese and normal subjects with similar frequency. C40R was identified only in an obese subject. Pedigree analysis revealed M218T carriers in both lean and obese subjects. The prevalence of V103I carriers in normal-weight controls was significantly higher than that in obese subjects (5.3%vs. 1.3%, P < 0.05). In vitro functional studies showed that all three novel missense variants have normal functions. Two known polymorphisms and three novel variants of the MC4R were identified. No overt functional defects were observed for the three novel MC4R variants, suggesting that they might not be the cause of obesity in variant carriers.

Dopamine D3 receptor Ser9Gly variant is associated with impulse control disorders in Parkinson's disease patients.

PubMed

Krishnamoorthy, Soumya; Rajan, Roopa; Banerjee, Moinak; Kumar, Hardeep; Sarma, Gangadhara; Krishnan, Syam; Sarma, Sankara; Kishore, Asha

2016-09-01

Impulse control disorders (ICD) are reported to occur at variable frequencies in different ethnic groups. Genetic vulnerability is suspected to underlie the individual risk for ICD. We investigated whether the allelic variants of dopamine (DRD3), glutamate (GRIN2B) and serotonin (HTR2A) receptors are linked to ICD in Indian Parkinson's disease (PD) patients. We conducted a prospective, case-control study which included PD patients (70 with ICD, 100 without ICD categorized after direct psychiatric interview of patient and caregiver) and 285 healthy controls. Single nucleotide polymorphism (SNP) variants of DRD3 p.S9G (rs6280), GRIN2B c.2664C>T (rs1806201) and HTR2A c.102T>C (rs6313) were genotyped. Multivariate regression analysis revealed that DRD3 p.Ser9Gly (rs6280) heterozygous variant CT (OR = 2.22, 95% CI: 1.03-4.86, p = 0.041), higher daily Levodopa equivalent doses (LED) of drugs (for 100 mg LED, OR = 1.14, 95% CI: 1.01-1.29, p = 0.041), current dopamine agonist but not Levodopa use (OR = 2.16, 95% CI: 1.03-4.55, p = 0.042) and age of onset of motor symptoms under 50 years (OR 2.09, 95% CI: 1.05-4.18, p = 0.035) were independently associated with ICD. DRD3 p.Ser9Gly (rs6280) CT genotype is associated with ICD in Indian PD patients and this association is novel. Enhanced D3 receptor affinity due to gain-of-function conferred by the glycine residues could impair reward-risk assessment in the mesolimbic system and contribute to development of impulsive behaviour, in carriers of this genotype. Copyright © 2016. Published by Elsevier Ltd.

Assessment of Molecular, Antigenic, and Pathological Features of Canine Influenza A(H3N2) Viruses That Emerged in the United States

PubMed Central

Pulit-Penaloza, Joanna A.; Simpson, Natosha; Yang, Hua; Creager, Hannah M.; Jones, Joyce; Carney, Paul; Belser, Jessica A.; Yang, Genyan; Chang, Jessie; Zeng, Hui; Thor, Sharmi; Jang, Yunho; Killian, Mary Lea; Jenkins-Moore, Melinda; Janas-Martindale, Alicia; Dubovi, Edward; Wentworth, David E.; Stevens, James; Tumpey, Terrence M.; Davis, C. Todd; Maines, Taronna R.

2017-01-01

Background A single subtype of canine influenza virus (CIV), A(H3N8), was circulating in the United States until a new subtype, A(H3N2), was detected in Illinois in spring 2015. Since then, this CIV has caused thousands of infections in dogs in multiple states. Methods In this study, genetic and antigenic properties of the new CIV were evaluated. In addition, structural and glycan array binding features of the recombinant hemagglutinin were determined. Replication kinetics in human airway cells and pathogenesis and transmissibility in animal models were also assessed. Results A(H3N2) CIVs maintained molecular and antigenic features related to low pathogenicity avian influenza A(H3N2) viruses and were distinct from A(H3N8) CIVs. The structural and glycan array binding profile confirmed these findings and revealed avian-like receptor-binding specificity. While replication kinetics in human airway epithelial cells was on par with that of seasonal influenza viruses, mild-to-moderate disease was observed in infected mice and ferrets, and the virus was inefficiently transmitted among cohoused ferrets. Conclusions Further adaptation is needed for A(H3N2) CIVs to present a likely threat to humans. However, the potential for coinfection of dogs and possible reassortment of human and other animal influenza A viruses presents an ongoing risk to public health. PMID:28934454

Relation among cytochrome P450, AH-active PCB congeners and dioxin equivalents in pipping black-crowned night-heron embryos

USGS Publications Warehouse

Rattner, B.A.; Hatfield, J.S.; Melancon, M.J.; Custer, T.W.; Tillitt, D.E.

1994-01-01

Pipping black-crowned night-heron (Nycticorax nycticorax) embryos were collected from a relatively uncontaminated site (next to Chincoteague National Wildlife Refuge, VA) and three polluted sites (Cat Island, Green Bay, Lake Michigan, WI; Bair Island, San Francisco Bay, CA; West Marin Island, San Francisco Bay, CA). Hepatic cytochrome P-450-associated monooxygenases and cytochrome P-450 proteins, induced up to 85-fold relative to the reference site, were associated with concentrations of total polychlorinated biphenyls (PCBs) and 11 PCB congeners that are presumed to express toxicity through the arylhydrocarbon (Ah) receptor. Multiple regression revealed that up to 86% of the variation of cytochrome P450 measurements was accounted for by variation in the concentration of these PCB congeners. Toxic equivalents (TEQs) of sample extracts, predicted mathematically (summed product of PCB congener concentrations and toxic equivalency factors), and dioxin equivalents (TCDD-EQs), derived by bioassay (ethoxyresorufin-O-dealkylase activity of treated H4IIE rat hepatoma cells), were greatest in Cat Island samples. Cytochrome P450-associated monooxygenases and cytochrome P450 proteins were related to TEQs and TCDD-EQs; adjusted r-2 often exceeded 0.5 for the relation among mathematically predicted TEQs and cytochrome P450 measurements. These data extend previous observations in heron embryos of an association between P450 and total PCB burdens to include Ah-active PCB congeners, and presumably other compounds, which interact similarly with the Ah receptor. Benzyloxyresorufin O-dealkylase, ethoxyresorufin O-dealkylase, and cytochrome P450 1A appear to be the most reliable measures of exposure to Ah-active PCB congeners in black-crowned night-heron embryos. These findings provide further evidence that cytochrome P450-associated parameters have considerable value as a biomarker for assessing environmental contamination of wetlands.

Integrated in silico and in vivo approaches to investigate effects of BDE-99 mediated by the nuclear receptors on developing zebrafish.

PubMed

Zhang, Li; Jin, Yaru; Han, Zhihua; Liu, Hongling; Shi, Laihao; Hua, Xiaoxue; Doering, Jon A; Tang, Song; Giesy, John P; Yu, Hongxia

2018-03-01

One of the most abundant polybrominated diphenyl ethers (PBDEs) is 2,2',4,4',5-pentabromodiphenyl ether (BDE-99), which persists and potentially bioaccumulates in aquatic wildlife. Previous studies in mammals have shown that BDE-99 affects development and disrupts certain endocrine functions through signaling pathways mediated by nuclear receptors. However, fewer studies have investigated the potential of BDE-99 to interact with nuclear receptors in aquatic vertebrates such as fish. In the present study, interactions between BDE-99 and nuclear receptors were investigated by in silico and in vivo approaches. This PBDE was able to dock into the ligand-binding domain of zebrafish aryl hydrocarbon receptor 2 (AhR2) and pregnane X receptor (PXR). It had a significant effect on the transcriptional profiles of genes associated with AhR or PXR. Based on the developed cytoscape of all zebrafish genes, it was also inferred that AhR and PXR could interact via cross-talk. In addition, both the in silico and in vivo approaches found that BDE-99 affected peroxisome proliferator-activated receptor alpha (PPARα), glucocorticoid receptor, and thyroid receptor. Collectively, our results demonstrate for the first time detailed in silico evidence that BDE-99 can bind to and interact with zebrafish AhR and PXR. These findings can be used to elaborate the molecular mechanism of BDE-99 and guide more objective environmental risk assessments. Environ Toxicol Chem 2018;37:780-787. © 2017 SETAC. © 2017 SETAC.

Association analysis of bitter receptor genes in five isolated populations identifies a significant correlation between TAS2R43 variants and coffee liking.

PubMed

Pirastu, Nicola; Kooyman, Maarten; Traglia, Michela; Robino, Antonietta; Willems, Sara M; Pistis, Giorgio; d'Adamo, Pio; Amin, Najaf; d'Eustacchio, Angela; Navarini, Luciano; Sala, Cinzia; Karssen, Lennart C; van Duijn, Cornelia; Toniolo, Daniela; Gasparini, Paolo

2014-01-01

Coffee, one of the most popular beverages in the world, contains many different physiologically active compounds with a potential impact on people's health. Despite the recent attention given to the genetic basis of its consumption, very little has been done in understanding genes influencing coffee preference among different individuals. Given its markedly bitter taste, we decided to verify if bitter receptor genes (TAS2Rs) variants affect coffee liking. In this light, 4066 people from different parts of Europe and Central Asia filled in a field questionnaire on coffee liking. They have been consequently recruited and included in the study. Eighty-eight SNPs covering the 25 TAS2R genes were selected from the available imputed ones and used to run association analysis for coffee liking. A significant association was detected with three SNP: one synonymous and two functional variants (W35S and H212R) on the TAS2R43 gene. Both variants have been shown to greatly reduce in vitro protein activity. Surprisingly the wild type allele, which corresponds to the functional form of the protein, is associated to higher liking of coffee. Since the hTAS2R43 receptor is sensible to caffeine, we verified if the detected variants produced differences in caffeine bitter perception on a subsample of people coming from the FVG cohort. We found a significant association between differences in caffeine perception and the H212R variant but not with the W35S, which suggests that the effect of the TAS2R43 gene on coffee liking is mediated by caffeine and in particular by the H212R variant. No other significant association was found with other TAS2R genes. In conclusion, the present study opens new perspectives in the understanding of coffee liking. Further studies are needed to clarify the role of the TAS2R43 gene in coffee hedonics and to identify which other genes and pathways are involved in its genetics.

Association Analysis of Bitter Receptor Genes in Five Isolated Populations Identifies a Significant Correlation between TAS2R43 Variants and Coffee Liking

PubMed Central

Pirastu, Nicola; Kooyman, Maarten; Traglia, Michela; Robino, Antonietta; Willems, Sara M.; Pistis, Giorgio; d’Adamo, Pio; Amin, Najaf; d’Eustacchio, Angela; Navarini, Luciano; Sala, Cinzia; Karssen, Lennart C.; van Duijn, Cornelia; Toniolo, Daniela; Gasparini, Paolo

2014-01-01

Coffee, one of the most popular beverages in the world, contains many different physiologically active compounds with a potential impact on people’s health. Despite the recent attention given to the genetic basis of its consumption, very little has been done in understanding genes influencing coffee preference among different individuals. Given its markedly bitter taste, we decided to verify if bitter receptor genes (TAS2Rs) variants affect coffee liking. In this light, 4066 people from different parts of Europe and Central Asia filled in a field questionnaire on coffee liking. They have been consequently recruited and included in the study. Eighty-eight SNPs covering the 25 TAS2R genes were selected from the available imputed ones and used to run association analysis for coffee liking. A significant association was detected with three SNP: one synonymous and two functional variants (W35S and H212R) on the TAS2R43 gene. Both variants have been shown to greatly reduce in vitro protein activity. Surprisingly the wild type allele, which corresponds to the functional form of the protein, is associated to higher liking of coffee. Since the hTAS2R43 receptor is sensible to caffeine, we verified if the detected variants produced differences in caffeine bitter perception on a subsample of people coming from the FVG cohort. We found a significant association between differences in caffeine perception and the H212R variant but not with the W35S, which suggests that the effect of the TAS2R43 gene on coffee liking is mediated by caffeine and in particular by the H212R variant. No other significant association was found with other TAS2R genes. In conclusion, the present study opens new perspectives in the understanding of coffee liking. Further studies are needed to clarify the role of the TAS2R43 gene in coffee hedonics and to identify which other genes and pathways are involved in its genetics. PMID:24647340

Atrazine affects kidney and adrenal hormones (AHs) related genes expressions of rare minnow (Gobiocypris rarus).

PubMed

Yang, Lihua; Zha, Jinmiao; Li, Wei; Li, Zhaoli; Wang, Zijian

2010-05-05

Atrazine, one of the most widely used herbicides, has been proved to interfere with sexual hormones. However few studies have considered the effects of atrazine on adrenal hormones (AH). In this study, rare minnow (Gobiocypris rarus) was exposed to 0, 3, 10, 33, 100 and 333microg/l atrazine for 28 days. The histopathology of kidney and gill was examined and the expressions of AHs-related genes including Na(+),K(+)-ATPase, glucocorticoid receptor (gr), heat shock protein 70 (hsp70), and heat shock protein 90 (hsp90) in kidney and gill were quantitatively determined. Histopathological observation revealed obvious lesions in gill including hyperplasia, necrosis in epithelium region, aneurysm and lamellar fusion at concentrations as low as 10microg/l. The observed lesions in kidney included extensive expansion in the lumen, degenerative and necrotic changes of the tubular epithelia, shrinkage of the glomerulus as well as increase of the Bowman's space at concentrations as low as 10microg/l. The expressions of Na(+),K(+)-ATPase, gr, hsp70 and hsp90 in the kidney of females were significantly decreased at all concentrations. For males, the expressions of hsp90 in the kidney of all treated groups were significantly down-regulated, while gr at all concentrations and hsp70 at 10, 33, 100microg/l were significantly up-regulated. However in the gill, the expressions of these genes were not significantly different from the control. These results indicated that exposure to atrazine caused impairments of kidney and gill of fish at environmental related concentrations. Histopathological lesions could partly attribute to the changes of the expressions of AHs-related genes in kidney. We concluded also that atrazine is a potential AHs-disruptor and AHs-related genes in kidney of fish could be used as sensitive molecular biomarkers.

Integration of Genome-Wide Computation DRE Search, AhR ChIP-chip and Gene Expression Analyses of TCDD-Elicited Responses in the Mouse Liver

PubMed Central

2011-01-01

Background The aryl hydrocarbon receptor (AhR) is a ligand-activated transcription factor (TF) that mediates responses to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). Integration of TCDD-induced genome-wide AhR enrichment, differential gene expression and computational dioxin response element (DRE) analyses further elucidate the hepatic AhR regulatory network. Results Global ChIP-chip and gene expression analyses were performed on hepatic tissue from immature ovariectomized mice orally gavaged with 30 μg/kg TCDD. ChIP-chip analysis identified 14,446 and 974 AhR enriched regions (1% false discovery rate) at 2 and 24 hrs, respectively. Enrichment density was greatest in the proximal promoter, and more specifically, within ± 1.5 kb of a transcriptional start site (TSS). AhR enrichment also occurred distal to a TSS (e.g. intergenic DNA and 3' UTR), extending the potential gene expression regulatory roles of the AhR. Although TF binding site analyses identified over-represented DRE sequences within enriched regions, approximately 50% of all AhR enriched regions lacked a DRE core (5'-GCGTG-3'). Microarray analysis identified 1,896 number of TCDD-responsive genes (|fold change| ≥ 1.5, P1(t) > 0.999). Integrating this gene expression data with our ChIP-chip and DRE analyses only identified 625 differentially expressed genes that involved an AhR interaction at a DRE. Functional annotation analysis of differentially regulated genes associated with AhR enrichment identified overrepresented processes related to fatty acid and lipid metabolism and transport, and xenobiotic metabolism, which are consistent with TCDD-elicited steatosis in the mouse liver. Conclusions Details of the AhR regulatory network have been expanded to include AhR-DNA interactions within intragenic and intergenic genomic regions. Moreover, the AhR can interact with DNA independent of a DRE core suggesting there are alternative mechanisms of AhR-mediated gene regulation. PMID:21762485

Allergic responses and aryl hydrocarbon receptor novel pathway of mast cell activation.

PubMed

Sibilano, Riccardo; Pucillo, Carlo E; Gri, Giorgia

2015-01-01

The activation of the transcription factor aryl hydrocarbon receptor (AhR) is modulated by a wide variety of xenobiotics and ligands deriving from products of metabolism. The study of the contribution of AhR to allergic diseases has gained much interest in recent years. Here we discuss the role that environmental factors and metabolic products, particularly acting on AhR-expressing mast cells (MCs), could have in the development of local allergic/atopic response. Thus, this review will cover: a brief overview of the AhR mechanism of action in the immune system; a description of different AhR ligands and their effects to IgE-mediated MC activation in the allergic response, with particular attention to the role of IL-17; a discussion about the potential involvement of AhR in immune tolerance; and a conclusion on human diseases in which direct AhR activation of MC might have a major impact. Copyright © 2014 Elsevier Ltd. All rights reserved.

Investigation of an Outbreak of Variant Influenza A(H3N2) Virus Infection Associated With an Agricultural Fair-Ohio, August 2012.

PubMed

Greenbaum, Adena; Quinn, Celia; Bailer, Jennifer; Su, Su; Havers, Fiona; Durand, Lizette O; Jiang, Victoria; Page, Shannon; Budd, Jeremy; Shaw, Michael; Biggerstaff, Matthew; de Fijter, Sietske; Smith, Kathleen; Reed, Carrie; Epperson, Scott; Brammer, Lynnette; Feltz, Dave; Sohner, Kevin; Ford, Jared; Jain, Seema; Gargiullo, Paul; Weiss, Edward; Burg, Pat; DiOrio, Mary; Fowler, Brian; Finelli, Lyn; Jhung, Michael A

2015-11-15

In 2012, one third of cases in a multistate outbreak of variant influenza A(H3N2) virus ([H3N2]v) infection occurred in Ohio. We conducted an investigation of (H3N2)v cases associated with agricultural Fair A in Ohio. We surveyed Fair A swine exhibitors and their household members. Confirmed cases had influenza-like illness (ILI) and a positive laboratory test for (H3N2)v, and probable cases had ILI. We calculated attack rates. We determined risk factors for infection, using multivariable log-binomial regression. We identified 20 confirmed and 94 probable cases associated with Fair A. Among 114 cases, the median age was 10 years, there were no hospitalizations or deaths, and 82% had swine exposure. In the exhibitor household cohort of 359 persons (83 households), we identified 6 confirmed cases (2%) and 40 probable cases (11%). An age of <10 years was a significant risk factor (P < .01) for illness. One instance of likely human-to-human transmission was identified. In this (H3N2)v outbreak, no evidence of sustained human-to-human (H3N2)v transmission was found. Our risk factor analysis contributed to the development of the recommendation that people at increased risk of influenza-associated complications, including children aged <5 years, avoid swine barns at fairs during the 2012 fair season. Published by Oxford University Press on behalf of the Infectious Diseases Society of America 2015. This work is written by (a) US Government employee(s) and is in the public domain in the US.

Natural variants of cytotoxic epitopes are T-cell receptor antagonists for antiviral cytotoxic T cells

NASA Astrophysics Data System (ADS)

Bertoletti, Antonio; Sette, Alessandro; Chisari, Francis V.; Penna, Amalia; Levrero, Massimo; Carli, Marco De; Fiaccadori, Franco; Ferrari, Carlo

1994-06-01

IT has been suggested that mutations within immunodominant cytotoxic T-lymphocyte (CTL) epitopes may be exploited by viruses to evade protective immune responses critical for clearance1-4. Viral escape could originate from passive mechanisms, such as mutations within crucial CTL epitopes, either affecting major histocompatibility complex binding or T-cell antigen receptor (TCR) recognition. Additionally, it has recently been shown that substitutions of TCR contact sites can yield analogue peptides that can still interact with the T-cell receptor but be unable to deliver a full stimulatory signal, thus inducing anergy5 or acting as an antagonist for the TCR6-8. We report here that hepatitis B virus isolates derived from two chronically infected patients display variant epitopes that act as natural TCR antagonists with the capacity to inhibit the CTL response to the wild-type epitope. During natural infection, TCR antagonist mutations of CTL epitopes could contribute to the development of viral persistence, especially if the antiviral CTL response is monospecific or the epitope is strongly immunodominant.

[Molecular analyses of human influenza viruses. Circulation of new variants since 1995/96].

PubMed

Biere, B; Schweiger, B

2008-09-01

The evolution of influenza viruses is increasingly pursued by molecular analyses that complement classical methods. The analyses focus on the two surface proteins hemagglutinin (HA) and neuraminidase (NA) which determine the viral antigenic profile. Influenza A(H3N2) viruses are exceptionally variable, so that usually at least two virus variants cocirculate at the same time. Together with influenza B viruses they caused approximately 90% of influenza virus infections in Germany during the last 12 seasons, while influenza A(H1N1) viruses only played a subordinate part. Unexpectedly, reassorted viruses of subtype A(H1N2) appeared during the seasons 2001/02 and 2002/03, but were isolated only rarely and gained no epidemiological significance. Furthermore, during the season 2001/02 influenza B viruses of the Victoria-lineage reappeared in Germany and other countries of the northern hemisphere after 10 years of absence. These viruses reassorted with the cocirculating Yamagata-like influenza B viruses, as could be seen by the appearance of viruses with a Victoria-like HA and a Yamagata-like NA.

Aryl Hydrocarbon Receptor Protects Lungs from Cockroach Allergen-Induced Inflammation by Modulating Mesenchymal Stem Cells.

PubMed

Xu, Ting; Zhou, Yufeng; Qiu, Lipeng; Do, Danh C; Zhao, Yilin; Cui, Zhuang; Wang, Heng; Liu, Xiaopeng; Saradna, Arjun; Cao, Xu; Wan, Mei; Gao, Peisong

2015-12-15

Exposure to cockroach allergen leads to allergic sensitization and increased risk of developing asthma. Aryl hydrocarbon receptor (AhR), a receptor for many common environmental contaminants, can sense not only environmental pollutants but also microbial insults. Mesenchymal stem cells (MSCs) are multipotent progenitor cells with the capacity to modulate immune responses. In this study, we investigated whether AhR can sense cockroach allergens and modulate allergen-induced lung inflammation through MSCs. We found that cockroach allergen-treated AhR-deficient (AhR(-/-)) mice showed exacerbation of lung inflammation when compared with wild-type (WT) mice. In contrast, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), an AhR agonist, significantly suppressed allergen-induced mouse lung inflammation. MSCs were significantly reduced in cockroach allergen-challenged AhR(-/-) mice as compared with WT mice, but increased in cockroach allergen-challenged WT mice when treated with TCDD. Moreover, MSCs express AhR, and AhR signaling can be activated by cockroach allergen with increased expression of its downstream genes cyp1a1 and cyp1b1. Furthermore, we tracked the migration of i.v.-injected GFP(+) MSCs and found that cockroach allergen-challenged AhR(-/-) mice displayed less migration of MSCs to the lungs compared with WT. The AhR-mediated MSC migration was further verified by an in vitro Transwell migration assay. Epithelial conditioned medium prepared from cockroach extract-challenged epithelial cells significantly induced MSC migration, which was further enhanced by TCDD. The administration of MSCs significantly attenuated cockroach allergen-induced inflammation, which was abolished by TGF-β1-neutralizing Ab. These results suggest that AhR plays an important role in protecting lungs from allergen-induced inflammation by modulating MSC recruitment and their immune-suppressive activity. Copyright © 2015 by The American Association of Immunologists, Inc.

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

PubMed

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.

RESULTS FROM THE AHS PESTICIDE EXPOSURE STUDY

EPA Science Inventory

The Agricultural Health Study/Pesticide Exposure Study (AHS/PES) measured exposures resulting from agricultural use of 2,4-D and chlorpyrifos for a subset of applicators in the AHS cohort. Through on-farm measurements and observations, data collected in the exposure study will...

Vitamin D receptor variants and uncontrolled asthma.

PubMed

Hutchinson, K; Kerley, C P; Faul, J; Greally, P; Coghlan, D; Louw, M; Elnazir, B; Rochev, Y

2017-11-28

Background. Asthma is a common childhood respiratory disease, affecting around 20% of Irish children. In other populations, vitamin D receptor (VDR) polymorphisms have been associated with asthma risk. We aimed to investigate the association between 2 VDR polymorphisms and uncontrolled paediatric asthma. Methods. 44 asthmatic children and 57 healthy volunteers were studied. The VDR TaqI gene variant in exon 9 (T/C) (rs731236) and ApaI (rs7975232) in intron 8 (C/T) were determined, using TaqMan® Assays. The lung function, serum 25-hydroxyvitamin D (25OHD) levels and other biomarkers of allergy, immunity, airway and systemic inflammation were as-sessed. Results. The distribution of T and C alleles and genotype frequencies differed significantly between asthmatics and controls for both polymorphisms (p < 0.05). A significant association was found between both TaqI [OR = 2.37, 95% CI (1.27 - 4.45), p = 0.007] and ApaI polymorphisms, and asthma risk [OR = 2.93, 95% CI (1.62 - 5.3), p = 0.0004]. No association was observed between genotypes and 25OHD levels, lung function and other biomarkers, with the exception of Interleukin-10 (IL-10) and white blood cells count (WBC). IL-10 levels were lower in asthmatics with TC genotype for TaqI polymorphism (p < 0.01) and were higher in patients with TT genotype for ApaI (p < 0.01). WBC were higher in patients with TC and CC genotypes for TaqI (p < 0.05) and lower in TT genotype for ApaI (p < 0.05). Conclusion. TaqI and ApaI polymorphisms are associated with asthma in Irish children. Further studies are warranted to investigate the importance of decreased IL-10 levels in paediatric asthmatics with specific genotypes.

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

PubMed Central

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

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. PMID:28749959

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

PubMed

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.

AhR-mediated gene expression in the developing mouse telencephalon.

PubMed

Gohlke, Julia M; Stockton, Pat S; Sieber, Stella; Foley, Julie; Portier, Christopher J

2009-11-01

We hypothesize that TCDD-induced developmental neurotoxicity is modulated through an AhR-dependent interaction with key regulatory neuronal differentiation pathways during telencephalon development. To test this hypothesis we examined global gene expression in both dorsal and ventral telencephalon tissues in E13.5 AhR-/- and wildtype mice exposed to TCDD or vehicle. Consistent with previous biochemical, pathological and behavioral studies, our results suggest TCDD initiated changes in gene expression in the developing telencephalon are primarily AhR-dependent, as no statistically significant gene expression changes are evident after TCDD exposure in AhR-/- mice. Based on a gene regulatory network for neuronal specification in the developing telencephalon, the present analysis suggests differentiation of GABAergic neurons in the ventral telencephalon is compromised in TCDD exposed and AhR-/- mice. In addition, our analysis suggests Sox11 may be directly regulated by AhR based on gene expression and comparative genomics analyses. In conclusion, this analysis supports the hypothesis that AhR has a specific role in the normal development of the telencephalon and provides a mechanistic framework for neurodevelopmental toxicity of chemicals that perturb AhR signaling.

The Fifth Influenza A(H7N9) Epidemic: A Family Cluster of Infection in Suzhou City of China, 2016.

PubMed

Wang, Jiajia; Su, Nan; Dong, Zefeng; Liu, Cheng; Cui, Pengwei; Huang, Jian-An; Chen, Cheng; Zhu, Yehan; Chen, Liling

2018-05-05

Influenza A(H7N9) virus is known for its high pathogenicity in human. A family cluster of influenza A(H7N9) virus infection was identified in Suzhou, China. This study aimed to investigate the possibility of human-to-human transmission of the virus and examine the virologic features of this family cluster. The clinical and epidemiologic data of two patients in the family cluster of influenza A(H7N9) virus infection were collected. Viral RNA in samples derived from the two patients, their close contacts, and the environments with likely influenza A(H7N9) virus transmission were tested by real-time reverse transcriptase polymerase chain reaction (rRT-PCR) assay. Hemagglutination inhibition (HI) assay was used to detect virus-specific antibodies. Genetic sequencing and phylogenetic analysis were also performed. The index patient (Case 1), a 66-year old man, was virologically diagnosed of influenza A(H7N9) virus infection 12days after experiencing influenza-like symptoms, then died of multi-organ failure. His 39-year old daughter (Case 2), denying any other exposure to influenza A(H7N9) virus, became infected with influenza A(H7N9) virus following taking care of her father during his illness. Sequencing viral genomes isolated from the two patients showed nearly identical nucleotide sequence, and genetically resembled the viral genome isolated from a chicken in the wet market where the index patient once visited. All three influenza A(H7N9) viruses shared S138A, G186V, Q226L mutations in HA (H3) protein and a single basic amino acid (PEIPKGR↓G) at the cleavage site. Human-to-human transmission of influenza A(H7N9) virus most likely occurred in this household. The three-amino-acid mutations in HA protein were discovered in this study, which might have increased the binding affinity of influenza A(H7N9) virus to the receptor on trachea epithelial cells to facilitate viral transmission among humans. Copyright © 2018. Published by Elsevier Ltd.

Red Clover Aryl Hydrocarbon Receptor (AhR) and Estrogen Receptor (ER) Agonists Enhance Genotoxic Estrogen Metabolism

PubMed Central

2017-01-01

Many women consider botanical dietary supplements (BDSs) as safe alternatives to hormone therapy for menopausal symptoms. However, the effect of BDSs on breast cancer risk is largely unknown. In the estrogen chemical carcinogenesis pathway, P450 1B1 metabolizes estrogens to 4-hydroxylated catechols, which are oxidized to genotoxic quinones that initiate and promote breast cancer. In contrast, P450 1A1 catalyzed 2-hydroxylation represents a detoxification pathway. The current study evaluated the effects of red clover, a popular BDS used for women’s health, and its isoflavones, biochanin A (BA), formononetin (FN), genistein (GN), and daidzein (DZ), on estrogen metabolism. The methoxy estrogen metabolites (2-MeOE1, 4-MeOE1) were measured by LC-MS/MS, and CYP1A1 and CYP1B1 gene expression was analyzed by qPCR. Nonmalignant ER-negative breast epithelial cells (MCF-10A) and ER-positive breast cancer cells (MCF-7) were derived from normal breast epithelial tissue and ER+ breast cancer tissue. Red clover extract (RCE, 10 μg/mL) and isoflavones had no effect on estrogen metabolism in MCF-10A cells. However, in MCF-7 cells, RCE treatments downregulated CYP1A1 expression and enhanced genotoxic metabolism (4-MeOE1/CYP1B1 > 2-MeOE1/CYP1A1). Experiments with the isoflavones showed that the AhR agonists (BA, FN) preferentially induced CYP1B1 expression as well as 4-MeOE1. In contrast, the ER agonists (GN, DZ) downregulated CYP1A1 expression likely through an epigenetic mechanism. Finally, the ER antagonist ICI 182,780 potentiated isoflavone-induced XRE-luciferase reporter activity and reversed GN and DZ induced downregulation of CYP1A1 expression. Overall, these studies show that red clover and its isoflavones have differential effects on estrogen metabolism in “normal” vs breast cancer cells. In breast cancer cells, the AhR agonists stimulate genotoxic metabolism, and the ER agonists downregulate the detoxification pathway. These data may suggest that especially breast

Rats fed soy protein isolate (SPI) have impaired hepatic CYP1A1 induction by polycyclic aromatic hydrocarbons as a result of interference with aryl hydrocarbon receptor signaling

DOE Office of Scientific and Technical Information (OSTI.GOV)

Singhal, Rohit; Badger, Thomas M.; Arkansas Children's Nutrition Center, Little Rock, AR 72202

2008-03-01

Consumption of soy diets has been found to reduce cancer incidence in animals and is associated with reduced cancer risk in humans. Previously, we have demonstrated that female Sprague-Dawley rats fed purified AIN-93G diets with soy protein isolate (SPI) as the sole protein source had reduced CYP1A1 induction and basal aryl hydrocarbon receptor (AhR) levels relative to those fed the same diet containing casein (CAS). In the present study, the molecular mechanisms underlying reduced AhR expression have been studied. The SPI-effect on AhR was not observed after feeding diets containing the purified soy isoflavones genistein or daidzein. Rat hepatoma FGC-4more » cells were treated with the serum obtained from rats fed CAS- or SPI-containing diets. Reduced AhR levels (P < 0.05) were observed after 24 h exposure to SPI-serum without any changes in the overall expression of chaperone proteins-HSP90 and XAP2. SPI-serum-stimulated AhR degradation was inhibited by treating the cells with the proteasome inhibitor, MG132, and was observed to be preceded by ubiquitination of the receptor. A reduced association of XAP2 with the immunoprecipitated AhR complex was observed. SPI-serum-mediated AhR degradation was preceded by nuclear translocation of the receptor. However, the translocated receptor was found to be unable to heterodimerize with ARNT or to bind to XRE elements on the CYP1A1 enhancer. These data suggest that feeding SPI-containing diets antagonizes AhR signaling by a novel mechanism which differs from those established for known AhR antagonists.« less

The human pregnane X receptor: genomic structure and identification and functional characterization of natural allelic variants.

PubMed

Zhang, J; Kuehl, P; Green, E D; Touchman, J W; Watkins, P B; Daly, A; Hall, S D; Maurel, P; Relling, M; Brimer, C; Yasuda, K; Wrighton, S A; Hancock, M; Kim, R B; Strom, S; Thummel, K; Russell, C G; Hudson, J R; Schuetz, E G; Boguski, M S

2001-10-01

The pregnane X receptor (PXR)/steroid and xenobiotic receptor (SXR) transcriptionally activates cytochrome P4503A4 (CYP3A4) when ligand activated by endobiotics and xenobiotics. We cloned the human PXR gene and analysed the sequence in DNAs of individuals whose CYP3A phenotype was known. The PXR gene spans 35 kb, contains nine exons, and mapped to chromosome 13q11-13. Thirty-eight single nucleotide polymorphisms (SNPs) were identified including six SNPs in the coding region. Three of the coding SNPs are non-synonymous creating new PXR alleles [PXR*2, P27S (79C to T); PXR*3, G36R (106G to A); and PXR*4, R122Q (4321G to A)]. The frequency of PXR*2 was 0.20 in African Americans and was never found in Caucasians. Hepatic expression of CYP3A4 protein was not significantly different between African Americans homozygous for PXR*1 compared to those with one PXR*2 allele. PXR*4 was a rare variant found in only one Caucasian person. Homology modelling suggested that R122Q, (PXR*4) is a direct DNA contact site variation in the third alpha-helix in the DNA binding domain. Compared with PXR*1, and variants PXR*2 and PXR*3, only the variant PXR*4 protein had significantly decreased affinity for the PXR binding sequence in electromobility shift assays and attenuated ligand activation of the CYP3A4 reporter plasmids in transient transfection assays. However, the person heterozygous for PXR*4 is normal for CYP3A4 metabolism phenotype. The relevance of each of the 38 PXR SNPs identified in DNA of individuals whose CYP3A basal and rifampin-inducible CYP3A4 expression was determined in vivo and/or in vitro was demonstrated by univariate statistical analysis. Because ligand activation of PXR and upregulation of a system of drug detoxification genes are major determinants of drug interactions, it will now be useful to extend this work to determine the association of these common PXR SNPs to human variation in induction of other drug detoxification gene targets.

Functional characterization of four naturally occurring variants of human pregnane X receptor (PXR): one variant causes dramatic loss of both DNA binding activity and the transactivation of the CYP3A4 promoter/enhancer region.

PubMed

Koyano, Satoru; Kurose, Kouichi; Saito, Yoshiro; Ozawa, Shogo; Hasegawa, Ryuichi; Komamura, Kazuo; Ueno, Kazuyuki; Kamakura, Shiro; Kitakaze, Masafumi; Nakajima, Toshiharu; Matsumoto, Kenji; Akasawa, Akira; Saito, Hirohisa; Sawada, Jun-Ichi

2004-01-01

Metabolism of administered drugs is determined by expression and activity of many drug-metabolizing enzymes, such as the cytochrome P450 (P450s) family members. Pregnane X receptor (PXR) is a master transcriptional regulator of many drug/xenobiotic-metabolizing enzymes, including P450s and drug transporters. In this study, we describe the functional analysis of four naturally occurring human PXR (hPXR) variants (R98C, R148Q, R381W, and I403V) that we have recently identified. By a reporter gene assay using the CYP3A4 promoter/enhancer reporter in COS-7 or HepG2 cells, it was found that the R98C variant failed to transactivate the CYP3A4 reporter. The R381W and I403V variants also showed varying degrees of reduction in transactivation, depending on the dose of PXR activators, rifampicin, clotrimazole, and paclitaxel. The transcriptional activities of the R148Q variant were not significantly different from that of the wild-type hPXR. The electrophoretic mobility shift assay revealed that only the R98C variant lacked DNA binding. Furthermore, the cellular localization of the hPXR proteins was analyzed. All four variants as well as the wild-type hPXR localized exclusively to the nucleus, regardless of the presence or absence of rifampicin. These data suggest that the R98C, R381W, and I403V hPXR variants, especially R98C, may influence the expression of drug-metabolizing enzymes and transporters, which are transactivated by PXR.

An endogenous aryl hydrocarbon receptor ligand inhibits proliferation and migration of human ovarian cancer cells

PubMed Central

Jiang, Yi-Zhou; Dai, Cai-Feng; Patankar, Manish S.; Song, Jia-Sheng; Zheng, Jing

2013-01-01

The aryl hydrocarbon receptor (AhR), a ligand-activated transcription factor mediates many biological processes. Herein, we investigated if 2-(1′H-indole-3′-carbonyl)-thiazole-4-carboxylic acid methyl ester (ITE, an endogenous AhR ligand) regulated proliferation and migration of human ovarian cancer cells via AhR. We found that AhR was widely present in many histotypes of ovarian cancer tissues. ITE suppressed OVCAR-3 cell proliferation and SKOV-3 cell migration in vitro, which were blocked by AhR knockdown. ITE also suppressed OVCAR-3 cell growth in mice. These data suggest that the ITE might potentially be used for therapeutic intervention for at least a subset of human ovarian cancer. PMID:23851185

Predominant mucosal expression of 5-HT4(+h) receptor splice variants in pig stomach and colon

PubMed Central

Priem, Evelien KV; De Maeyer, Joris H; Vandewoestyne, Mado; Deforce, Dieter; Lefebvre, Romain A

2013-01-01

epithelial and circular smooth muscle cell layer of pig colon descendens and of the epithelial cell layer of pig gastric fundus, also showed 5-HT4 receptor and GAPDH mRNA expression. No 5-HT4 receptor mRNA expression was detected in gastric LMPC-isolated EC cells from IHC stained tissues, which cells were positive for GAPDH. CONCLUSION: Porcine GI mucosa predominantly expresses 5-HT4(+h) receptor splice variants, suggesting their contribution to the 5-HT4 receptor-mediated mucosal effects of 5-HT. PMID:23840113

A liver X receptor (LXR)-{beta} alternative splicing variant (LXRBSV) acts as an RNA co-activator of LXR-{beta}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hashimoto, Koshi, E-mail: khashi@med.gunma-u.ac.jp; Ishida, Emi; Matsumoto, Shunichi

2009-12-25

We report the isolation and functional characterization of a novel transcriptional co-activator, termed LXRBSV. LXRBSV is an alternative splicing variant of liver X receptor (LXR)-{beta} LXRBSV has an intronic sequence between exons 2 and 3 in the mouse LXR-{beta} gene. The LXRBSV gene is expressed in various tissues including the liver and brain. We sub-cloned LXRBSV into pSG5, a mammalian expression vector, and LXRBSV in pSG5 augmented human Sterol Response Element Binding Protein (SREBP)-1c promoter activity in HepG2 cells in a ligand (TO901317) dependent manner. The transactivation mediated by LXRBSV is selective for LXR-{beta}. The LXRBSV protein was deduced tomore » be 64 amino acids in length; however, a GAL4-LXRBSV fusion protein was not able to induce transactivation. Serial deletion constructs of LXRBSV demonstrated that the intronic sequence inserted in LXRBSV is required for its transactivation activity. An ATG mutant of LXRBSV was able to induce transactivation as wild type. Furthermore, LXRBSV functions in the presence of cycloheximide. Taken together, we have concluded that LXRBSV acts as an RNA transcript not as a protein. In the current study, we have demonstrated for the first time that an alternative splicing variant of a nuclear receptor acts as an RNA co-activator.« less

Polymorphic variants of neurotransmitter receptor genes may affect sexual function in aging males: data from the HALS study.

PubMed

Jóźków, Paweł; Słowińska-Lisowska, Małgorzata; Łaczmański, Łukasz; Mędraś, Marek

2013-01-01

Human behavior is influenced by a number of brain neurotransmitters. Central dopamine, serotonin and melanocortin systems have special importance for male sexual function. We searched for associations between male aging symptoms and polymorphic sites of serotonin (5-HTR1B), melanocortin (MC4R) and dopamine (DRD2, DRD4) receptors. In a population-based sample, genotyping of 5-HTR1B (polymorphism: G861C), MC4R (polymorphisms: C-2745T, Val103Ile), DRD2 (polymorphism: C313T) and DRD4 (polymorphism: 48-bp VNTR) was performed in 387 healthy men. The Aging Males' Symptoms (AMS) scale was used to evaluate specific ailments of aging men. We analyzed answers to questions from the AMS scale. Five points of the questionnaire addressed sexual symptoms of the aging male: feeling of passing one's peak, decrease in beard growth, decrease in ability/frequency to perform sexually, decrease in the number of morning erections, and decrease in sexual desire/libido (lacking pleasure in sex, lacking desire for sexual intercourse). Relations between reported symptoms and variants of the polymorphic sites of the studied genes were assessed. After adjusting for confounding factors (education, arterial hypertension, physical activity, weight, waist circumference) an association between the sexual dimension of AMS and genetic variants of 5-HTR1B G861C (p = 0.04) was observed. Variability of neurotransmitter receptor genes may be associated with sexual symptoms of aging in men. Copyright © 2013 S. Karger AG, Basel.

Investigation of the role of interleukin-1 receptor antagonist VNTR variant on the Behçet’s disease

PubMed Central

Dursun, Gül; Demir, Helin Deniz; Karakuş, Nevin; Demir, Osman; Yiğit, Serbülent

2018-01-01

Objective Behçet’s disease (BD), a chronic multisystem inflammatory disorder, is mainly characterized by relapsing periods of a wide range of clinical symptoms. Several cytokine genes may play important roles in the pathogenesis of BD. Therefore, interleukin-1 receptor antagonist (IL-1Ra) gene 86bp variable number tandem repeat (VNTR) variant was investigated in patients with BD in a Turkish population. Methods One hundred nine patients (60 females, 49 males; the mean age±standard deviation [SD] was 36.56±9.571 years) with BD and one hundred healthy individuals (54 females, 46 males; the mean age±SD was 36.64±2.294 years) were examined in the study. For genotyping, polymerase chain reaction-restriction fragment length polymorphism analysis was employed. Data were analyzed using Statistical Package for Social Sciences (SPSS) 22.0 (IBM Corp.; Armonk, NY, USA) (p<0.05) Results The genotype distribution and allele frequencies of the IL-1Ra VNTR variant did not differ significantly between the patients and the controls (p>0.05). The frequency of the a1/a1, a1/a2 genotypes and a1, a2 alleles were the most common both in patients and healthy controls (p=0.37, p=0.26, and p=0.53, respectively). Also, no statistically significant difference was found between the IL-1Ra VNTR variant genotypes and clinical characteristics (p>0.05). Conclusion The results of this study do not support an association between the IL-1Ra VNTR variant and the risk of BD in a Turkish population. However, further studies of this variant with larger sample sizes and different ethnicities are required for confirmation. PMID:29657871

Whole genome sequencing of an African American family highlights toll like receptor 6 variants in Kawasaki disease susceptibility.

PubMed

Kim, Jihoon; Shimizu, Chisato; Kingsmore, Stephen F; Veeraraghavan, Narayanan; Levy, Eric; Ribeiro Dos Santos, Andre M; Yang, Hai; Flatley, Jay; Hoang, Long Truong; Hibberd, Martin L; Tremoulet, Adriana H; Harismendy, Olivier; Ohno-Machado, Lucila; Burns, Jane C

2017-01-01

Kawasaki disease (KD) is the most common acquired pediatric heart disease. We analyzed Whole Genome Sequences (WGS) from a 6-member African American family in which KD affected two of four children. We sought rare, potentially causative genotypes by sequentially applying the following WGS filters: sequence quality scores, inheritance model (recessive homozygous and compound heterozygous), predicted deleteriousness, allele frequency, genes in KD-associated pathways or with significant associations in published KD genome-wide association studies (GWAS), and with differential expression in KD blood transcriptomes. Biologically plausible genotypes were identified in twelve variants in six genes in the two affected children. The affected siblings were compound heterozygous for the rare variants p.Leu194Pro and p.Arg247Lys in Toll-like receptor 6 (TLR6), which affect TLR6 signaling. The affected children were also homozygous for three common, linked (r2 = 1) intronic single nucleotide variants (SNVs) in TLR6 (rs56245262, rs56083757 and rs7669329), that have previously shown association with KD in cohorts of European descent. Using transcriptome data from pre-treatment whole blood of KD subjects (n = 146), expression quantitative trait loci (eQTL) analyses were performed. Subjects homozygous for the intronic risk allele (A allele of TLR6 rs56245262) had differential expression of Interleukin-6 (IL-6) as a function of genotype (p = 0.0007) and a higher erythrocyte sedimentation rate at diagnosis. TLR6 plays an important role in pathogen-associated molecular pattern recognition, and sequence variations may affect binding affinities that in turn influence KD susceptibility. This integrative genomic approach illustrates how the analysis of WGS in multiplex families with a complex genetic disease allows examination of both the common disease-common variant and common disease-rare variant hypotheses.

NF-κB and androgen receptor variant expression correlate with human BPH progression.

PubMed

Austin, David C; Strand, Douglas W; Love, Harold L; Franco, Omar E; Jang, Alex; Grabowska, Magdalena M; Miller, Nicole L; Hameed, Omar; Clark, Peter E; Fowke, Jay H; Matusik, Robert J; Jin, Ren J; Hayward, Simon W

2016-04-01

Benign prostatic hyperplasia (BPH) is a common, chronic progressive disease. Inflammation is associated with prostatic enlargement and resistance to 5α-reductase inhibitor (5ARI) therapy. Activation of the nuclear factor-kappa B (NF-κB) pathway is linked to both inflammation and ligand-independent prostate cancer progression. NF-κB activation and androgen receptor variant (AR-V) expression were quantified in transition zone tissue samples from patients with a wide range of AUASS from incidental BPH in patients treated for low grade, localized peripheral zone prostate cancer to advanced disease requiring surgical intervention. To further investigate these pathways, human prostatic stromal and epithelial cell lines were transduced with constitutively active or kinase dead forms of IKK2 to regulate canonical NF-κB activity. The effects on AR full length (AR-FL) and androgen-independent AR-V expression as well as cellular growth and differentiation were assessed. Canonical NF-κB signaling was found to be upregulated in late versus early stage BPH, and to be strongly associated with non-insulin dependent diabetes mellitus. Elevated expression of AR-variant 7 (AR-V7), but not other AR variants, was found in advanced BPH samples. Expression of AR-V7 significantly correlated with the patient AUASS and TRUS volume. Forced activation of canonical NF-κB in human prostatic epithelial and stromal cells resulted in elevated expression of both AR-FL and AR-V7, with concomitant ligand-independent activation of AR reporters. Activation of NF-κB and over expression of AR-V7 in human prostatic epithelial cells maintained cell viability in the face of 5ARI treatment. Activation of NF-κB and AR-V7 in the prostate is associated with increased disease severity. AR-V7 expression is inducible in human prostate cells by forced activation of NF-κB resulting in resistance to 5ARI treatment, suggesting a potential mechanism by which patients may become resistant to 5ARI therapy. �

Variant Amino Acid Residues Alter the Enzyme Activity of Peanut Type 2 Diacylglycerol Acyltransferases

PubMed Central

Zheng, Ling; Shockey, Jay; Bian, Fei; Chen, Gao; Shan, Lei; Li, Xinguo; Wan, Shubo; Peng, Zhenying

2017-01-01

Diacylglycerol acyltransferase (DGAT) catalyzes the final step in triacylglycerol (TAG) biosynthesis via the acyl-CoA-dependent acylation of diacylglycerol. This reaction is a major control point in the Kennedy pathway for biosynthesis of TAG, which is the most important form of stored metabolic energy in most oil-producing plants. In this study, Arachis hypogaea type 2 DGAT (AhDGAT2) genes were cloned from the peanut cultivar ‘Luhua 14.’ Sequence analysis of 11 different peanut cultivars revealed a gene family of 8 peanut DGAT2 genes (designated AhDGAT2a-h). Sequence alignments revealed 21 nucleotide differences between the eight ORFs, but only six differences result in changes to the predicted amino acid (AA) sequences. A representative full-length cDNA clone (AhDGAT2a) was characterized in detail. The biochemical effects of altering the AhDGAT2a sequence to include single variable AA residues were tested by mutagenesis and functional complementation assays in transgenic yeast systems. All six mutant variants retained enzyme activity and produced lipid droplets in vivo. The N6D and A26P mutants also displayed increased enzyme activity and/or total cellular fatty acid (FA) content. N6D mutant mainly increased the content of palmitoleic acid, and A26P mutant mainly increased the content of palmitic acid. The A26P mutant grew well both in the presence of oleic and C18:2, but the other mutants grew better in the presence of C18:2. AhDGAT2 is expressed in all peanut organs analyzed, with high transcript levels in leaves and flowers. These levels are comparable to that found in immature seeds, where DGAT2 expression is most abundant in other plants. Over-expression of AhDGAT2a in tobacco substantially increased the FA content of transformed tobacco seeds. Expression of AhDGAT2a also altered transcription levels of endogenous tobacco lipid metabolic genes in transgenic tobacco, apparently creating a larger carbon ‘sink’ that supports increased FA levels. PMID

Growth Inhibition by Testosterone in an Androgen Receptor Splice Variant-Driven Prostate Cancer Model.

PubMed

Nakata, Daisuke; Nakayama, Kazuhide; Masaki, Tsuneo; Tanaka, Akira; Kusaka, Masami; Watanabe, Tatsuya

2016-12-01

Castration resistance creates a significant problem in the treatment of prostate cancer. Constitutively active splice variants of androgen receptor (AR) have emerged as drivers for resistance to androgen deprivation therapy, including the next-generation androgen-AR axis inhibitors abiraterone and enzalutamide. In this study, we describe the characteristics of a novel castration-resistant prostate cancer (CRPC) model, designated JDCaP-hr (hormone refractory). JDCaP-hr was established from an androgen-dependent JDCaP xenograft model after surgical castration. The expression of AR and its splice variants in JDCaP-hr was evaluated by immunoblotting and quantitative reverse transcription-polymerase chain reaction. The effects of AR antagonists and testosterone on JDCaP-hr were evaluated in vivo and in vitro. The roles of full-length AR (AR-FL) and AR-V7 in JDCaP-hr cell growth were evaluated using RNA interference. JDCaP-hr acquired a C-terminally truncated AR protein during progression from the parental JDCaP. The expression of AR-FL and AR-V7 mRNA was upregulated by 10-fold in JDCaP-hr compared with that in JDCaP, indicating that the JDCaP and JDCaP-hr models simulate castration resistance with some clinical features, such as overexpression of AR and its splice variants. The AR antagonist bicalutamide did not affect JDCaP-hr xenograft growth, and importantly, testosterone induced tumor regression. In vitro analysis demonstrated that androgen-independent prostate-specific antigen secretion and cell proliferation of JDCaP-hr were predominantly mediated by AR-V7. JDCaP-hr cell growth displayed a bell-shaped dependence on testosterone, and it was suppressed by physiological concentrations of testosterone. Testosterone induced rapid downregulation of both AR-FL and AR-V7 expression at physiological concentrations and suppressed expression of the AR target gene KLK3. Our findings support the clinical value of testosterone therapy, including bipolar androgen therapy, in the

Risk of Guillain–Barré syndrome following pandemic influenza A(H1N1) 2009 vaccination in Germany†

PubMed Central

Prestel, Jürgen; Volkers, Peter; Mentzer, Dirk; Lehmann, Helmar C; Hartung, Hans-Peter; Keller-Stanislawski, Brigitte

2014-01-01

Purpose A prospective, epidemiologic study was conducted to assess whether the 2009 pandemic influenza A(H1N1) vaccination in Germany almost exclusively using an AS03-adjuvanted vaccine (Pandemrix) impacts the risk of Guillain–Barré syndrome (GBS) and its variant Fisher syndrome (FS). Methods Potential cases of GBS/FS were reported by 351 participating hospitals throughout Germany. The self-controlled case series methodology was applied to all GBS/FS cases fulfilling the Brighton Collaboration (BC) case definition (levels 1–3 of diagnostic certainty) with symptom onset between 1 November 2009 and 30 September 2010 reported until end of December 2010. Results Out of 676 GBS/FS reports, in 30 cases, GBS/FS (BC levels 1–3) occurred within 150 days following influenza A(H1N1) vaccination. The relative incidence of GBS/FS within the primary risk period (days 5–42 post-vaccination) compared with the control period (days 43–150 post-vaccination) was 4.65 (95%CI [2.17, 9.98]). Similar results were found when stratifying for infections within 3 weeks prior to onset of GBS/FS and when excluding cases with additional seasonal influenza vaccination. The overall result of temporally adjusted analyses supported the primary finding of an increased relative incidence of GBS/FS following influenza A(H1N1) vaccination. Conclusions The results indicate an increased risk of GBS/FS in temporal association with pandemic influenza A(H1N1) vaccination in Germany. © 2014 The Authors. Pharmacoepidemiology and Drug Safety published by John Wiley & Sons, Ltd. PMID:24817531

Genetic drift of influenza A(H3N2) viruses during two consecutive seasons in 2011-2013 in Corsica, France.

PubMed

Fantoni, Anais; Arena, Christophe; Corrias, Laura; Salez, Nicolas; de Lamballerie, Xavier Nicolas; Amoros, Jean Pierre; Blanchon, Thierry; Varesi, Laurent; Falchi, Alessandra

2014-04-01

The 2011-2012 and 2012-2013 post-pandemic influenza outbreaks were characterized by variability in the A(H3N2) influenza viruses, resulting in low to moderate vaccine effectiveness (VE). The aim of this study was to investigate the molecular evolution and vaccine strain match of the A(H3N2) influenza viruses, having been circulated throughout the population of the French Corsica Island in 2011-2012 and again in 2012-2013. Clinical samples from 31 patients with confirmed A(H3N2) influenza viruses were collected by general practitioners (GPs) over these two consecutive seasons. An analysis of genetic distance and antigenic drift was conducted. Based on a hemagglutinin (HA) aminoacid sequence analysis, the Corsican A(H3N2) viruses fell into the A/Victoria/208/2009 genetic clade, group 3. All influenza viruses were characterized by at least four fixed amino acid mutations which were: N145S (epitope A); Q156H and V186G (epitope B) Y219S (epitope D), with respect to the A/Perth/16/2009 (reference vaccine strain for the 2011-2012) and the A/Victoria/361/2011 (reference vaccine strain for the 2012-2013). Using the p(epitope) model, the percentages of the perfect match VE estimated against circulated strains declined within and between seasons, with estimations of <50%. Overall, these results seem to indicate an antigenic drift of the A(H3N2) influenza viruses which were circulated in Corsica. These findings highlight the importance of the continuous and careful surveillance of genetic changes in the HA domain during seasonal influenza epidemics, in order to provide information on newly emerging genetic variants. © 2013 Wiley Periodicals, Inc.

Blocking oxytocin receptors inhibits vaginal marking to male odors in female Syrian hamsters.

PubMed

Martinez, Luis A; Albers, H Elliott; Petrulis, Aras

2010-12-02

In Syrian hamsters (Mesocricetus auratus), precopulatory behaviors such as vaginal scent marking are essential for attracting a suitable mate. Vaginal marking is dependent on forebrain areas implicated in the neural regulation of reproductive behaviors in rodents, including the medial preoptic/anterior hypothalamus (MPOA-AH). Within MPOA-AH, the neuropeptide oxytocin (OT) acts to facilitate copulation (lordosis), as well as ultrasonic vocalizations towards males. It is not known, however, if OT in this area also facilitates vaginal marking. In the present study, a specific oxytocin receptor antagonist (OTA) was injected into MPOA-AH of intact female Syrian hamsters to determine if oxytocin receptor-dependent signaling is critical for the normal expression of vaginal marking elicited by male, female, and clean odors. OTA injections significantly inhibited vaginal marking in response to male odors compared with vehicle injections. There was no effect of OTA on marking in response to either female or clean odors. When injected into the bed nucleus of the stria terminalis (BNST), a nearby region to MPOA-AH, OTA was equally effective in decreasing marking. Finally, the effects of OTA appear to be specific to vaginal marking, as OTA injections in MPOA-AH or BNST did not alter general locomotor activity, flank marking, or social odor investigation. Considered together, these results suggest that OT in MPOA-AH and/or BNST normally facilitates male odor-induced vaginal marking, providing further evidence that OT generally supports prosocial interactions among conspecifics. Copyright © 2010 Elsevier Inc. All rights reserved.

Oculomotor Deficits in Aryl Hydrocarbon Receptor Null Mouse

PubMed Central

Chevallier, Aline; Mialot, Antoine; Petit, Jean-Maurice; Fernandez-Salguero, Pedro; Barouki, Robert

2013-01-01

The Aryl hydrocarbon Receptor or AhR, a ligand-activated transcription factor, is known to mediate the toxic and carcinogenic effects of various environmental pollutants such as 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD). Recent studies in Caenorhabditis elegans and Drosophila melanogaster show that the orthologs of the AhR are expressed exclusively in certain types of neurons and are implicated in the development and the homeostasis of the central nervous system. While physiological roles of the AhR were demonstrated in the mammalian heart, liver and gametogenesis, its ontogenic expression and putative neural functions remain elusive. Here, we report that the constitutive absence of the AhR in adult mice (AhR−/−) leads to abnormal eye movements in the form of a spontaneous pendular horizontal nystagmus. To determine if the nystagmus is of vestibular, visual, or cerebellar origin, gaze stabilizing reflexes, namely vestibulo-ocular and optokinetic reflexes (VOR and OKR), were investigated. The OKR is less effective in the AhR−/− mice suggesting a deficit in the visuo-motor circuitry, while the VOR is mildly affected. Furthermore, the AhR is expressedin the retinal ganglion cells during the development, however electroretinograms revealed no impairment of retinal cell function. The structure of the cerebellum of the AhR−/− mice is normal which is compatible with the preserved VOR adaptation, a plastic process dependent on cerebellar integrity. Finally, intoxication with TCDD of control adults did not lead to any abnormality of the oculomotor control. These results demonstrate that the absence of the AhR leads to acquired central nervous system deficits in the adults. Given the many common features between both AhR mouse and human infantile nystagmus syndromes, the AhR−/− mice might give insights into the developmental mechanisms which lead to congenital eye disorders. PMID:23301081

Cellular responses to oxidative stress: the [Ah] gene battery as a paradigm.

PubMed Central

Nebert, D W; Petersen, D D; Fornace, A J

1990-01-01

A major source of oxidative stress in animals is plant stress metabolites, also termed phytoalexins. The aromatic hydrocarbon-responsive [Ah] gene battery is considered here as a model system in which we can study metabolically coordinated enzymes that respond to phytoalexin-induced oxidative stress. In the mouse, the [Ah] battery comprises at least six genes: two Phase I genes, CYP1A1 and CYP1A2; and four Phase II genes, Nmo-1, Aldh-1, Ugt-1, and Gt-1. All six genes appear to be regulated positively by inducers such as 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and other ligands of the Ah receptor. In the absence of foreign inducer, the control of Nmo-1 gene expression is independent of the control of CYP1A1 and CYP1A2 gene expression. The radiation deletion homozygote c14CoS/c14CoS mouse is lacking about 1.1 centiMorgans of chromosome 7. Although having no detectable CYP1A1 or CYP1A2 activation, the untreated c14CoS/c14CoS mouse exhibits markedly elevated transcripts of the Nmo-1 gene and three growth arrest- and DNA damage-inducible (gadd) genes. These data suggest that the missing region on chromosome 7 in the c14CoS/c14CoS mouse contains a gene(s), which we propose to call Nmo-1n, encoding a trans-acting factor(s) that is a negative effector of the Nmo-1 and gadd genes. The three other [Ah] battery Phase II genes behave similarly to Nmo-1 in the c14CoS/c14CoS mouse. This coordinated response to oxidative stress and DNA damage, by way of the release of a mammalian battery of genes from negative control, bears an interesting resemblance to the SOS response in bacteria. PMID:2272308

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

PubMed

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.

Pathophysiological consequences of receptor mistraffic: Tales from the platelet P2Y12 receptor.

PubMed

Cunningham, Margaret R; Aungraheeta, Riyaad; Mundell, Stuart J

2017-07-05

Genetic variations in G protein-coupled receptor (GPCR) genes can disrupt receptor function in a wide variety of human genetic diseases, including platelet bleeding disorders. Platelets are critical for haemostasis with inappropriate platelet activation leading to the development of arterial thrombosis, which can result in heart attack and stroke whilst decreased platelet activity is associated with an increased risk of bleeding. GPCRs expressed on the surface of platelets play key roles in regulating platelet activity and therefore function. Receptors include purinergic receptors (P2Y 1 and P2Y 12 ), proteinase-activated receptor (PAR1 and PAR4) and thromboxane receptors (TPα), among others. Pharmacological blockade of these receptors forms a powerful therapeutic tool in the treatment and prevention of arterial thrombosis. With the advance of genomic technologies, there has been a substantial increase in the identification of naturally occurring rare and common GPCR variants. These variants include single-nucleotide polymorphisms (SNPs) and insertion or deletions that have the potential to alter GPCR expression or function. A number of defects in platelet GPCRs that disrupt receptor function have now been characterized in patients with mild bleeding disorders. This review will focus on rare, function-disrupting variants of platelet GPCRs with particular emphasis upon mutations in the P2Y 12 receptor gene that affect receptor traffic to modulate platelet function. Further this review will outline how the identification and characterization of function-disrupting GPCR mutations provides an essential link in translating our detailed understanding of receptor traffic and function in cell line studies into relevant human biological systems. Copyright © 2017. Published by Elsevier B.V.

Variants in the dopamine-4-receptor gene promoter are not associated with sensation seeking in skiers.

PubMed

Thomson, Cynthia J; Rajala, Amelia K; Carlson, Scott R; Rupert, Jim L

2014-01-01

Sensation seeking is a personality trait that has been associated with disinhibited behaviours including substance use and gambling, but also with high-risk sport practices including skydiving, paragliding, and downhill skiing. Twin studies have shown that sensation seeking is moderately heritable, and candidate genes encoding components involved in dopaminergic transmission have been investigated as contributing to this type of behaviour. To determine whether variants in the regulatory regions of the dopamine-4-receptor gene (DRD4) influenced sport-specific sensation seeking, we analyzed five polymorphisms (-1106T/C, -906T/C, -809G/A, -291C/T, 120-bp duplication) in the promoter region of the gene in a cohort of skiers and snowboarders (n = 599) that represented a broad range of sensation seeking behaviours. We grouped subjects by genotype at each of the five loci and compared impulsive sensation seeking and domain-specific (skiing) sensation seeking between groups. There were no significant associations between genotype(s) and general or domain-specific sensation seeking in the skiers and snowboarders, suggesting that while DRD4 has previously been implicated in sensation seeking, the promoter variants investigated in this study do not contribute to sensation seeking in this athlete population.

Decreased agonist sensitivity of human GABA(A) receptors by an amino acid variant, isoleucine to valine, in the alpha1 subunit.

PubMed

Westh-Hansen, S E; Rasmussen, P B; Hastrup, S; Nabekura, J; Noguchi, K; Akaike, N; Witt, M R; Nielsen, M

1997-06-25

Recombinant human GABA(A) receptors were investigated in vitro by coexpression of cDNAs coding for alpha1, beta2, and gamma2 subunits in the baculovirus/Sf-9 insect cell system. We report that a single amino acid exchange (isoleucine 121 to valine 121) in the N-terminal, extracellular part of the alpha1 subunit induces a marked decrease in agonist GABA(A) receptor ligand sensitivity. The potency of muscimol and GABA to inhibit the binding of the GABA(A) receptor antagonist [3H]SR 95531 (2-(3-carboxypropyl)-3-amino-6-(4-methoxyphenyl)pyridazinium bromide) was higher in receptor complexes of alpha1(ile 121) beta2gamma2 than in those of alpha1(val 121) beta2gamma2 (IC50 values were 32-fold and 26-fold lower for muscimol and GABA, respectively). The apparent affinity of the GABA(A) receptor antagonist bicuculline methiodide to inhibit the binding of [3H]SR 95531 did not differ between the two receptor complex variants. Electrophysiological measurements of GABA induced whole-cell Cl- currents showed a ten-fold decrease in the GABA(A) receptor sensitivity of alpha1 (val 121) beta2gamma2 as compared to alpha1(ile 121) beta2gamma2 receptor complexes. Thus, a relatively small change in the primary structure of the alpha1 subunit leads to a decrease selective for GABA(A) receptor sensitivity to agonist ligands, since no changes were observed in a GABA(A) receptor antagonist affinity and benzodiazepine receptor binding.

Common Commercial and Consumer Products Contain Activators of the Aryl Hydrocarbon (Dioxin) Receptor

PubMed Central

Zhao, Bin; Bohonowych, Jessica E. S.; Timme-Laragy, Alicia; Jung, Dawoon; Affatato, Alessandra A.; Rice, Robert H.; Di Giulio, Richard T.; Denison, Michael S.

2013-01-01

Activation of the Ah receptor (AhR) by halogenated aromatic hydrocarbons (HAHs), such as 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD, dioxin), can produce a wide variety of toxic and biological effects. While recent studies have shown that the AhR can bind and be activated by structurally diverse chemicals, how widespread of these AhR agonists are in environmental, biological and synthetic materials remains to be determined. Using AhR-based assays, we demonstrate the presence of potent AhR agonists in a variety of common commercial and consumer items. Solvent extracts of paper, rubber and plastic products contain chemicals that can bind to and stimulate AhR DNA binding and/or AhR-dependent gene expression in hepatic cytosol, cultured cell lines, human epidermis and zebrafish embryos. In contrast to TCDD and other persistent dioxin-like HAHs, activation of AhR-dependent gene expression by these extracts was transient, suggesting that the agonists are metabolically labile. Solvent extracts of rubber products produce AhR-dependent developmental toxicity in zebrafish in vivo, and inhibition of expression of the metabolic enzyme CYP1A, significantly increased their toxic potency. Although the identity of the responsible AhR-active chemicals and their toxicological impact remain to be determined, our data demonstrate that AhR active chemicals are widely distributed in everyday products. PMID:23441220

Polychlorinated biphenyls (PCBs) contamination and aryl hydrocarbon receptor (AhR) agonist activity of Omega-3 polyunsaturated fatty acid supplements: implications for daily intake of dioxins and PCBs.

PubMed

Bourdon, J A; Bazinet, T M; Arnason, T T; Kimpe, L E; Blais, J M; White, P A

2010-11-01

Omega-3 polyunsaturated fatty acid (n-3 PUFA) rich oils derived primarily from fish are frequently consumed as supplements. Due to the tendency of persistent organic pollutants (POPs) to accumulate in exposed organisms, n-3 PUFA supplements can contain sufficient POPs to present a risk to consumers. Here we investigated PCB concentrations and aryl hydrocarbon receptor (AhR) agonist activity in 17 n-3 PUFA supplements available in Canada. PCBs ranged from <0.8 to 793 ng g(-1) oil, with salmon- and seal-derived products yielding the highest values. AhR agonist activity from a reporter gene assay ranged from 1.3 to 72.2 pg TEQ g(-1) oil, with salmon and tuna yielding the highest values. When consumed at the recommended doses and as a supplement to the average Canadian diet, seal-derived oil can contribute to exceedance of the tolerable daily intake of 20 ng PCBs kg-BW(-1)day(-1), and salmon-, tuna-, and sea herring-derived oils can contribute to exceedance of the tolerable daily intake limit of 2.3 pg TEQ kg-BW(-1)day(-1). The beneficial properties of fish and n-3 PUFA supplements, and the results of this study suggest that it is prudent to consume supplements derived from small, cold-water fatty fish. Further research will be necessary to draw firm conclusions. Crown Copyright © 2010. Published by Elsevier Ltd. All rights reserved.

Towards Targeting the Aryl Hydrocarbon Receptor in Cystic Fibrosis

PubMed Central

Paolicelli, Giuseppe; De Luca, Antonella; Renga, Giorgia; Borghi, Monica; Pariano, Marilena; Stincardini, Claudia; Scaringi, Lucia; Ricci, Maurizio; Romani, Luigina

2018-01-01

Tryptophan (trp) metabolism is an important regulatory component of gut mucosal homeostasis and the microbiome. Metabolic pathways targeting the trp can lead to a myriad of metabolites, of both host and microbial origins, some of which act as endogenous low-affinity ligands for the aryl hydrocarbon receptor (AhR), a cytosolic, ligand-operated transcription factor that is involved in many biological processes, including development, cellular differentiation and proliferation, xenobiotic metabolism, and the immune response. Low-level activation of AhR by endogenous ligands is beneficial in the maintenance of immune health and intestinal homeostasis. We have defined a functional node whereby certain bacteria species contribute to host/microbial symbiosis and mucosal homeostasis. A microbial trp metabolic pathway leading to the production of indole-3-aldehyde (3-IAld) by lactobacilli provided epithelial protection while inducing antifungal resistance via the AhR/IL-22 axis. In this review, we highlight the role of AhR in inflammatory lung diseases and discuss the possible therapeutic use of AhR ligands in cystic fibrosis. PMID:29670460

Testing Update on 20 and 25-Ah Lithium Ion Cells

NASA Technical Reports Server (NTRS)

Bruce, Gregg C.; Mardikian, Pamella; Edwards, Sherri; Bugga, Kumar; Chin, Keith; Smart, Marshall; Surampudi, Subbarao

2003-01-01

Eagle-Picher Energy Products has worked on lithium ion batteries for approximately 8 years. During that period EPEPC developed and delivered several cell sizes on a program funded by the USAF and Canadian DND. Designs are wound cylindrical cells from 7 to 40-Ah. Most cells delivered were approximately 25-Ah due to requirements of Mars missions. Several iterations of cells were manufactured and delivered for evaluation. The first design was 20-Ah, Design I, and the second was a 25-Ah, Design II.

Aa Ah Nak

ERIC Educational Resources Information Center

Tha, Na Gya; Wus, Thay

2017-01-01

In this article, Aa Ah Nak, the authors' methodology presents not only various reflections but also diverse contradictions about the Aa Nii language as well as language revitalization. This article explores language foundation and how the Aa Nii language revitalization is inextricably linked to the genocide and resulting historic trauma pervasive…

The chemokine receptor CXCR3 and its splice variant are expressed in human airway epithelial cells.

PubMed

Kelsen, Steven G; Aksoy, Mark O; Yang, Yi; Shahabuddin, Syed; Litvin, Judith; Safadi, Fayez; Rogers, Thomas J

2004-09-01

Activation of the chemokine receptor CXCR3 by its cognate ligands induces several differentiated cellular responses important to the growth and migration of a variety of hematopoietic and structural cells. In the human respiratory tract, human airway epithelial cells (HAEC) release the CXCR3 ligands Mig/CXCL9, IP-10/CXCL10, and I-TAC/CXCL11. Simultaneous expression of CXCR3 by HAEC would have important implications for the processes of airway inflammation and repair. Accordingly, in the present study we sought to determine whether HAEC also express the classic CXCR3 chemokine receptor CXCR3-A and its splice variant CXCR3-B and hence may respond in autocrine fashion to its ligands. We found that cultured HAEC (16-HBE and tracheocytes) constitutively expressed CXCR3 mRNA and protein. CXCR3 mRNA levels assessed by expression array were approximately 35% of beta-actin expression. In contrast, CCR3, CCR4, CCR5, CCR8, and CX3CR1 were <5% beta-actin. Both CXCR3-A and -B were expressed. Furthermore, tracheocytes freshly harvested by bronchoscopy stained positively for CXCR3 by immunofluorescence microscopy, and 68% of cytokeratin-positive tracheocytes (i.e., the epithelial cell population) were positive for CXCR3 by flow cytometry. In 16-HBE cells, CXCR3 receptor density was approximately 78,000 receptors/cell when assessed by competitive displacement of 125I-labeled IP-10/CXCL10. Finally, CXCR3 ligands induced chemotactic responses and actin reorganization in 16-HBE cells. These findings indicate constitutive expression by HAEC of a functional CXC chemokine receptor, CXCR3. Our data suggest the possibility that autocrine activation of CXCR3 expressed by HAEC may contribute to airway inflammation and remodeling in obstructive lung disease by regulating HAEC migration.

An endogenous aryl hydrocarbon receptor ligand inhibits proliferation and migration of human ovarian cancer cells.

PubMed

Wang, Kai; Li, Yan; Jiang, Yi-Zhou; Dai, Cai-Feng; Patankar, Manish S; Song, Jia-Sheng; Zheng, Jing

2013-10-28

The aryl hydrocarbon receptor (AhR), a ligand-activated transcription factor mediates many biological processes. Herein, we investigated if 2-(1'H-indole-3'-carbonyl)-thiazole-4-carboxylic acid methyl ester (ITE, an endogenous AhR ligand) regulated proliferation and migration of human ovarian cancer cells via AhR. We found that AhR was widely present in many histotypes of ovarian cancer tissues. ITE suppressed OVCAR-3 cell proliferation and SKOV-3 cell migration in vitro, which were blocked by AhR knockdown. ITE also suppressed OVCAR-3 cell growth in mice. These data suggest that the ITE might potentially be used for therapeutic intervention for at least a subset of human ovarian cancer. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Rules of co-occurring mutations characterize the antigenic evolution of human influenza A/H3N2, A/H1N1 and B viruses.

PubMed

Chen, Haifen; Zhou, Xinrui; Zheng, Jie; Kwoh, Chee-Keong

2016-12-05

The human influenza viruses undergo rapid evolution (especially in hemagglutinin (HA), a glycoprotein on the surface of the virus), which enables the virus population to constantly evade the human immune system. Therefore, the vaccine has to be updated every year to stay effective. There is a need to characterize the evolution of influenza viruses for better selection of vaccine candidates and the prediction of pandemic strains. Studies have shown that the influenza hemagglutinin evolution is driven by the simultaneous mutations at antigenic sites. Here, we analyze simultaneous or co-occurring mutations in the HA protein of human influenza A/H3N2, A/H1N1 and B viruses to predict potential mutations, characterizing the antigenic evolution. We obtain the rules of mutation co-occurrence using association rule mining after extracting HA1 sequences and detect co-mutation sites under strong selective pressure. Then we predict the potential drifts with specific mutations of the viruses based on the rules and compare the results with the "observed" mutations in different years. The sites under frequent mutations are in antigenic regions (epitopes) or receptor binding sites. Our study demonstrates the co-occurring site mutations obtained by rule mining can capture the evolution of influenza viruses, and confirms that cooperative interactions among sites of HA1 protein drive the influenza antigenic evolution.

Molecular characterization of the vitellogenin receptor from the tick, Amblyomma hebraeum (Acari: Ixodidae).

PubMed

Smith, Alexander D; Reuben Kaufman, W

2013-12-01

We have identified the full-length cDNA encoding a vitellogenin receptor (VgR) from the African bont tick Amblyomma hebraeum Koch (1844). VgRs are members of the low-density lipoprotein receptor superfamily that promote the uptake of the yolk protein vitellogenin (Vg), from the haemolymph. The AhVgR (GenBank accession No. JX846592) is 5703 bp, and encodes an 1801 aa protein with a 196.5 kDa molecular mass following cleavage of a 22 aa signal peptide. Phylogenetic analysis indicates that AhVgR is highly similar to other tick VgRs. AhVgR is expressed in only the ovary of mated, engorged females, and is absent in all other female tissues and in both fed and unfed males. Unfed, adult females injected with a VgR-dsRNA probe to knock-down VgR expression experienced a significant delay in ovary development and started oviposition significantly later than controls. These results indicate that the expression of AhVgR is important for the uptake of Vg and subsequent maturation of the oocytes. Copyright © 2013 Elsevier Ltd. All rights reserved.

Omeprazole Attenuates Hyperoxic Injury in H441 Cells via Aryl hydrocarbon Receptor

PubMed Central

Shivanna, Binoy; Chu, Chun; Welty, Stephen E.; Jiang, Weiwu; Wang, Lihua; Moorthy, Bhagavatula

2014-01-01

Hyperoxia contributes to the development of bronchopulmonary dysplasia in premature infants. Earlier we observed that aryl hydrocarbon receptor (AhR)-deficient mice are more susceptible to hyperoxic lung injury than AhR-sufficient mice, and this phenomenon was associated with a lack of expression of cytochrome P450 1A enzymes. Omeprazole, a proton pump inhibitor, used in humans with gastric acid related disorders, activates AhR in hepatocytes in vitro. However, the effects of omeprazole on AhR activation in the lungs and its impact on hyperoxia-induced ROS generation and inflammation are unknown. In this study, we tested the hypothesis that omeprazole attenuates hyperoxia-induced cytotoxicity, ROS generation, and expression of monocyte chemoattractant protein-1 (MCP-1) in the human lung derived H441 cells via AhR activation. Experimental groups included cells transfected with AhR small interfering RNA (siRNA). Hyperoxia resulted in significant increases in cytotoxicity, ROS generation, and MCP-1 production, which were significantly attenuated with the functional activation of AhR by omeprazole. The protective effects of omeprazole on cytotoxicity, ROS production, and MCP-1 production were lost in H441 cells whose AhR gene was silenced by AhR siRNA. These findings support the hypothesis that omeprazole protects against hyperoxic injury in vitro via AhR activation that is associated with decreased ROS generation and expression of MCP-1. PMID:21906671

Suppression of aberrant choroidal neovascularization through activation of the aryl hydrocarbon receptor.

PubMed

Choudhary, Mayur; Safe, Stephen; Malek, Goldis

2018-05-01

The aryl hydrocarbon receptor (AhR) is a ligand activated transcription factor, initially discovered for its role in regulating xenobiotic metabolism. There is extensive evidence supporting a multi-faceted role for AhR, modulating physiological pathways important in cell health and disease. Recently we demonstrated that the AhR plays a role in the pathogenesis of age-related macular degeneration (AMD), the leading cause of vision loss in the elderly. We found that loss of AhR exacerbates choroidal neovascular (CNV) lesion formation in a murine model. Herein we tested the therapeutic impact of AhR activation on CNV lesion formation and factors associated with aberrant neovascularization. We screened a panel of synthetic drugs and endogenous AhR ligands, assessed their ability to activate AhR in choroidal endothelial cells, and inhibit angiogenesis in vitro. Drugs with an anti-angiogenic profile were then administered to a murine model of CNV. Two compounds, leflunomide and flutamide, significantly inhibited CNV formation concurrent with positive modifying effects on angiogenesis, inflammation, extracellular matrix remodeling, and fibrosis. These results validate the role of the AhR pathway in regulating CNV pathogenesis, identify mechanisms of AhR-based therapies in the eye, and argue in favor of developing AhR as a drug target for the treatment of neovascular AMD. Copyright © 2018 Elsevier B.V. All rights reserved.

Further association study on dopamine D2 receptor variant S311C in Schizophrenia and affective disorders

DOE Office of Scientific and Technical Information (OSTI.GOV)

Arinami, Tadao; Hamaguchi, Hideo; Itokawa, Masanari

The dopamine D2 receptor gene is a candidate gene for schizophrenia because the potency of certain neuroleptics correlates with their affinity for this receptor. Case-control studies in 291 schizophrenics, 78 patients with affective disorders, and 579 controls on an association of a molecular variant of S311C of the dopamine D2 receptor with psychiatric disorders were conducted. The frequency of individuals with S311C was significantly higher in schizophrenics with the absence of negative symptoms (17.1%, P < 0.00001), but similar in schizophrenics with the presence of negative symptoms (5.7%, P = 0.46) when compared with the controls (4.1%). The frequency ofmore » S311C was significantly higher in familiar schizophrenics from one local area but not in those from other areas. It was significant that S311C was frequently present in patients with mood-incongruent psychotic affective disorders (33.3%, P < 0.0001), but not in those with other affective disorders. These data suggest that S311C might be one of the genetic factors for symptomatic dimensions of delusions and hallucinations and might be involved in underlying clinical heterogeneity in schizophrenia and affective disorders. 48 refs., 3 tabs.« less

[AR-V7 Androgen Receptor Variant as a Predictor of Response to Androgen-receptor Targeting Agents Used to Treat Castration-refractory Metastatic Prostate Cancer].

PubMed

Büchler, Tomáš; Bobek, Vladimír; Kološtová, Katarína

2017-01-01

Several systemic treatment options are currently available for patients with metastatic castration-refractory prostate cancer (mCRPC), including the androgen-receptor targeting agents (ARTA) enzalutamide and abiraterone, the taxanes docetaxel and cabazitaxel, and the radioisotope drug 223-radium dichloride. In some patients with mCRCP, alternative splicing of androgen receptor (AR) mRNA occurs, resulting in the formation of a truncated AR lacking the androgen-binding domain. These receptors activate downstream signalling pathways even without the ligand. Recent studies show that the presence of the AR-V7 (ARV - AR variants) splicing variant is associated with resistance to ARTA. Bec>ause the presence of AR-V7 does not affect the efficacy of other systemic therapies used in mCRCPs, particularly taxanes, AR-V7 is a candidate predictive biomarker for the individualisation of mCRCP treatment. Two types of assays based on mRNA or abnormal protein detection are used to detect AR-V7 in circulating tumour cells. To describe the current status of AR-V7 testing in mCRPC and possible applications of this method for predicting outcomes of ARTA therapy. The percentage of CTC AR-V7+ in ARTA-naive men is relatively low at baseline, but in patients pretreated with ARTA, the prevalence of AR-V7 increases to 19-34%. Given the relatively high expected prevalence, AR-V7 testing may be economically feasible in this population. The proportion of AR-V7+ patients responding to ARTA retreatment appears to be very low, at only 4.8%. AR-V7 testing could thus be useful if an ARTA switch is considered in a patient progressing onto an ARTA drug. Both protein-based tests and mRNA-based tests are currently undergoing clinical validation in prospective studies, with results expected within a year.Key words: prostate cancer - abiraterone - enzalutamide - alternative splicing - drug resistanceSubmitted: 30. 8. 2017Accepted: 5. 11. 2017 doc. MUDr. Tomáš Büchler, Ph.D. received honorary lectures

An improved cyan fluorescent protein variant useful for FRET.

PubMed

Rizzo, Mark A; Springer, Gerald H; Granada, Butch; Piston, David W

2004-04-01

Many genetically encoded biosensors use Förster resonance energy transfer (FRET) between fluorescent proteins to report biochemical phenomena in living cells. Most commonly, the enhanced cyan fluorescent protein (ECFP) is used as the donor fluorophore, coupled with one of several yellow fluorescent protein (YFP) variants as the acceptor. ECFP is used despite several spectroscopic disadvantages, namely a low quantum yield, a low extinction coefficient and a fluorescence lifetime that is best fit by a double exponential. To improve the characteristics of ECFP for FRET measurements, we used a site-directed mutagenesis approach to overcome these disadvantages. The resulting variant, which we named Cerulean (ECFP/S72A/Y145A/H148D), has a greatly improved quantum yield, a higher extinction coefficient and a fluorescence lifetime that is best fit by a single exponential. Cerulean is 2.5-fold brighter than ECFP and replacement of ECFP with Cerulean substantially improves the signal-to-noise ratio of a FRET-based sensor for glucokinase activation.

Comparing introduction to Europe of highly pathogenic avian influenza viruses A(H5N8) in 2014 and A(H5N1) in 2005.

PubMed

Adlhoch, C; Gossner, C; Koch, G; Brown, I; Bouwstra, R; Verdonck, F; Penttinen, P; Harder, T

2014-12-18

Since the beginning of November 2014, nine outbreaks of highly pathogenic avian influenza virus (HPAIV) A(H5N8) in poultry have been detected in four European countries. In this report, similarities and differences between the modes of introduction of HPAIV A(H5N1) and A(H5N8) into Europe are described. Experiences from outbreaks of A(H5N1) in Europe demonstrated that early detection to control HPAIV in poultry has proven pivotal to minimise the risk of zoonotic transmission and prevention of human cases.

A targeted genotyping approach enhances identification of variants in taste receptor and appetite/reward genes of potential functional importance for obesity-related porcine traits.

PubMed

Cirera, S; Clop, A; Jacobsen, M J; Guerin, M; Lesnik, P; Jørgensen, C B; Fredholm, M; Karlskov-Mortensen, P

2018-04-01

Taste receptors (TASRs) and appetite and reward (AR) mechanisms influence eating behaviour, which in turn affects food intake and risk of obesity. In a previous study, we used next generation sequencing to identify potentially functional mutations in TASR and AR genes and found indications for genetic associations between identified variants and growth and fat deposition in a subgroup of animals (n = 38) from the UNIK resource pig population. This population was created for studying obesity and obesity-related diseases. In the present study we validated results from our previous study by investigating genetic associations between 24 selected single nucleotide variants in TASR and AR gene variants and 35 phenotypes describing obesity and metabolism in the entire UNIK population (n = 564). Fifteen variants showed significant association with specific obesity-related phenotypes after Bonferroni correction. Six of the 15 genes, namely SIM1, FOS, TAS2R4, TAS2R9, MCHR2 and LEPR, showed good correlation between known biological function and associated phenotype. We verified a genetic association between potentially functional variants in TASR/AR genes and growth/obesity and conclude that the combination of identification of potentially functional variants by next generation sequencing followed by targeted genotyping and association studies is a powerful and cost-effective approach for increasing the power of genetic association studies. © 2018 Stichting International Foundation for Animal Genetics.

Triclosan activates aryl hydrocarbon receptor (AhR)-dependent apoptosis and affects Cyp1a1 and Cyp1b1 expression in mouse neocortical neurons.

PubMed

Szychowski, Konrad A; Wnuk, Agnieszka; Kajta, Małgorzata; Wójtowicz, Anna K

2016-11-01

Triclosan (TCS) is an antimicrobial agent that is used extensively in personal care and in sanitizing products, such as soaps, toothpastes, and hair products. A number of studies have revealed the presence of TCS in human tissues, such as fat, liver and brain, in addition to blood and breast milk. The aim of the present study was to investigate the impact of TCS on AhR and Cyp1a1/Cyp1b1 signaling in mouse neocortical neurons in primary cultures. In addition to the use of selective ligands and siRNAs, expression levels of mRNA and proteins as well as caspase-3 activity, reactive oxygen species (ROS) formation, and lactate dehydrogenase (LDH) release have been measured. We also studied the involvement of the AhR in TCS-induced LDH release and caspase-3 activation as well as the effect of TCS on ROS generation. Cultures of neocortical neurons were prepared from Swiss mouse embryos on day 15/16 of gestation. The cells were cultured in phenol red-free Neurobasal medium with B27 and glutamine, and the neurons were exposed to 1 and 10µM TCS. Our experiments showed that the expression of AhR and Cyp1a1 mRNA decreased in cells exposed to 10µM TCS for 3 or 6h. In the case of Cyp1b1, mRNA expression remained unchanged compared with the control group following 3h of exposure to TCS, but after 6h, the mRNA expression of Cyp1b1 was decreased. Our results confirmed that the AhR is involved in the TCS mechanism of action, and our data demonstrated that after the cells were transfected with AhR siRNA, the cytotoxic and pro-apoptotic properties of TCS were decreased. The decrease in Cyp1a1 mRNA and protein expression levels accompanied by a decrease in its activity. The stimulation of Cyp1a1 activity produced by the application of an AhR agonist (βNF) was attenuated by TCS, whereas the addition of AhR antagonist (αNF) reversed the inhibitory effects of TCS. In our experiments, TCS diminished Cyp1b1 mRNA and enhanced its protein expression. In case of Cyp1a1 we observed

Activation of estrogen receptor signaling by the dioxin-like aryl hydrocarbon receptor agonist, 3,3',4,4',5-Pentachlorobiphenyl (PCB126) in salmon in vitro system

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mortensen, Anne Skjetne; Arukwe, Augustine

2008-03-01

Available toxicological evidence indicates that environmental contaminants with strong affinity to the aryl hydrocarbon receptor (AhR) have anti-estrogenic properties in both mammalian and non-mammalian in vivo and in vitro studies. The primary objective of the present study was to investigate the interactions between the AhR and estrogen receptor (ER) in salmon in vitro system. Two separate experiments were performed and gene expression patterns were analyzed using real-time PCR, while protein analysis was done by immunoblotting. Firstly, salmon primary hepatocytes were exposed to the dioxin-like PCB126 at 1, 10 and 50 pM and ER agonist nonylphenol (NP) at 5 and 10more » {mu}M, singly or in combination. Our data showed increased levels of ER-mediated gene expression (vitellogenin: Vtg, zona radiata protein: Zr-protein, ER{alpha}, ER{beta} and vigilin) as well as increased cellular ER{alpha} protein levels after treatment with NP and PCB126, singly or in combination. PCB126 treatment alone produced, as expected, increased transcription of AhR nuclear translocator (Arnt), CYP1A1 and AhR repressor (AhRR) mRNA, and these responses were reduced in the presence of NP concentrations. PCB126 exposure alone did not produce significant effect on AhR2{alpha} mRNA but increased (at 1 and 50 pM) and decreased (at 10 pM) AhR2{beta} mRNA below control level. For AhR2{delta} and AhR2{gamma} isotypes, PCB126 (at 1 pM) produced significant decreases (total inhibition for AhR2{gamma}) of mRNA levels but was indifferent at 10 and 50 pM, compared to control. NP exposure alone produced concentration-dependent significant decrease of AhR2{beta} mRNA. In contrast, while 5 {mu}M NP produced an indifferent effect on AhR2{delta} and AhR2{gamma}, 10 {mu}M NP produced significant decrease (total inhibition for AhR2{gamma}) and the presence of NP produced apparent PCB126 concentration-specific modulation of all AhR isotypes. A second experiment was performed to evaluate the involvement of ER

Growth suppression of Leydig TM3 cells mediated by aryl hydrocarbon receptor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Iseki, Minoru; Department of Regulation Biology, Faculty of Science, Saitama University, Saitama; Ikuta, Togo

2005-06-17

Exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin induces developmental toxicity in reproductive organs. To elucidate the function of AhR, we generated stable transformants of TM3 cells overexpressing wild-type aryl hydrocarbon receptor (AhR) or its mutants which carried mutations in nuclear localization signal or nuclear export signal. In the presence of 3-methylcholanthrene (MC), proliferation of the cells transfected with wild-type AhR was completely suppressed, whereas cells expressing AhR mutants proliferated in a manner equivalent to control TM3 cells, suggesting AhR-dependent growth inhibition. The suppression was associated with up-regulation of cyclin-dependent kinase inhibitor p21{sup Cip1}, which was abolished by pretreatment with actinomycin D. A p38 MAPKmore » specific inhibitor, SB203580, blocked the increase of p21{sup Cip1} mRNA in response to MC. Treatment with indigo, another AhR ligand, failed to increase of p21{sup Cip1} mRNA, although up-regulation of mRNA for CYP1A1 was observed. These data suggest AhR in Leydig cells mediates growth inhibition by inducing p21{sup Cip1}.« less

New Trends in Aryl Hydrocarbon Receptor Biology.

PubMed

Mulero-Navarro, Sonia; Fernandez-Salguero, Pedro M

2016-01-01

Traditionally considered as a critical intermediate in the toxic and carcinogenic response to dioxin (2,3,7,8-tetrachlorodibenzo-p-dioxin, TCDD), the Aryl hydrocarbon/Dioxin receptor (AhR) has proven to be also an important regulator of cell physiology and organ homeostasis. AhR has become an interesting and actual area of research mainly boosted by a significant number of recent studies analyzing its contribution to the proper functioning of the immune, hepatic, cardiovascular, vascular and reproductive systems. At the cellular level, AhR establishes functional interactions with signaling pathways governing cell proliferation and cell cycle, cell morphology, cell adhesion and cell migration. Two exciting new aspects in AhR biology deal with its implication in the control of cell differentiation and its more than likely involvement in cell pluripotency and stemness. In fact, it is possible that AhR could help modulate the balance between differentiation and pluripotency in normal and transformed tumor cells. At the molecular level, AhR regulates an increasingly large array of physiologically relevant genes either by traditional transcription-dependent mechanisms or by unforeseen processes involving genomic insulators, chromatin dynamics and the transcription of mobile genetic elements. AhR is also closely related to epigenetics, not only from the point of view of target gene expression but also with respect to its own regulation by promoter methylation. It is reasonable to consider that deregulation of these many functions could have a causative role, or at least contribute to, human disease. Consequently, several laboratories have proposed that AhR could be a valuable tool as diagnostic marker and/or therapeutic target in human pathologies. An additional point of interest is the possibility of regulating AhR activity by endogenous non-toxic low weight molecules agonist or antagonist molecules that could be present or included in the diet. In this review, we will

Do Androgen Receptor Splice Variants Facilitate Growth of Bone Metastases

DTIC Science & Technology

2016-11-01

therapy is expression of constitutively active AR splice variants, which lack the carboxyl terminal hormone binding domain. The best characterized...resistance is expression of constitutively active AR splice variants, which lack the carboxyl terminal hormone binding domain. Of these, the most...removes hormone , but also many other factors. We plan to retest the effects of AR-V7 in the complete medium to determine whether effects would be

Variants in the Dopamine-4-Receptor Gene Promoter Are Not Associated with Sensation Seeking in Skiers

PubMed Central

Thomson, Cynthia J.; Rajala, Amelia K.; Carlson, Scott R.; Rupert, Jim L.

2014-01-01

Sensation seeking is a personality trait that has been associated with disinhibited behaviours including substance use and gambling, but also with high-risk sport practices including skydiving, paragliding, and downhill skiing. Twin studies have shown that sensation seeking is moderately heritable, and candidate genes encoding components involved in dopaminergic transmission have been investigated as contributing to this type of behaviour. To determine whether variants in the regulatory regions of the dopamine-4-receptor gene (DRD4) influenced sport-specific sensation seeking, we analyzed five polymorphisms (−1106T/C, −906T/C, −809G/A, −291C/T, 120-bp duplication) in the promoter region of the gene in a cohort of skiers and snowboarders (n = 599) that represented a broad range of sensation seeking behaviours. We grouped subjects by genotype at each of the five loci and compared impulsive sensation seeking and domain-specific (skiing) sensation seeking between groups. There were no significant associations between genotype(s) and general or domain-specific sensation seeking in the skiers and snowboarders, suggesting that while DRD4 has previously been implicated in sensation seeking, the promoter variants investigated in this study do not contribute to sensation seeking in this athlete population. PMID:24691022

HIV-1 and Its gp120 Inhibits the Influenza A(H1N1)pdm09 Life Cycle in an IFITM3-Dependent Fashion

PubMed Central

Mesquita, Milene; Fintelman-Rodrigues, Natalia; Sacramento, Carolina Q.; Abrantes, Juliana L.; Costa, Eduardo; Temerozo, Jairo R.; Siqueira, Marilda M.; Bou-Habib, Dumith Chequer; Souza, Thiago Moreno L.

2014-01-01

HIV-1-infected patients co-infected with A(H1N1)pdm09 surprisingly presented benign clinical outcome. The knowledge that HIV-1 changes the host homeostatic equilibrium, which may favor the patient resistance to some co-pathogens, prompted us to investigate whether HIV-1 infection could influence A(H1N1)pdm09 life cycle in vitro. We show here that exposure of A(H1N1)pdm09-infected epithelial cells to HIV-1 viral particles or its gp120 enhanced by 25% the IFITM3 content, resulting in a decrease in influenza replication. This event was dependent on toll-like receptor 2 and 4. Moreover, knockdown of IFITM3 prevented HIV-1 ability to inhibit A(H1N1)pdm09 replication. HIV-1 infection also increased IFITM3 levels in human primary macrophages by almost 100%. Consequently, the arrival of influenza ribonucleoproteins (RNPs) to nucleus of macrophages was inhibited, as evaluated by different approaches. Reduction of influenza RNPs entry into the nucleus tolled A(H1N1)pdm09 life cycle in macrophages earlier than usual, limiting influenza's ability to induce TNF-α. As judged by analysis of the influenza hemagglutin (HA) gene from in vitro experiments and from samples of HIV-1/A(H1N1)pdm09 co-infected individuals, the HIV-1-induced reduction of influenza replication resulted in delayed viral evolution. Our results may provide insights on the mechanisms that may have attenuated the clinical course of Influenza in HIV-1/A(H1N1)pdm09 co-infected patients during the recent influenza form 2009/2010. PMID:24978204

HIV-1 and its gp120 inhibits the influenza A(H1N1)pdm09 life cycle in an IFITM3-dependent fashion.

PubMed

Mesquita, Milene; Fintelman-Rodrigues, Natalia; Sacramento, Carolina Q; Abrantes, Juliana L; Costa, Eduardo; Temerozo, Jairo R; Siqueira, Marilda M; Bou-Habib, Dumith Chequer; Souza, Thiago Moreno L

2014-01-01

HIV-1-infected patients co-infected with A(H1N1)pdm09 surprisingly presented benign clinical outcome. The knowledge that HIV-1 changes the host homeostatic equilibrium, which may favor the patient resistance to some co-pathogens, prompted us to investigate whether HIV-1 infection could influence A(H1N1)pdm09 life cycle in vitro. We show here that exposure of A(H1N1)pdm09-infected epithelial cells to HIV-1 viral particles or its gp120 enhanced by 25% the IFITM3 content, resulting in a decrease in influenza replication. This event was dependent on toll-like receptor 2 and 4. Moreover, knockdown of IFITM3 prevented HIV-1 ability to inhibit A(H1N1)pdm09 replication. HIV-1 infection also increased IFITM3 levels in human primary macrophages by almost 100%. Consequently, the arrival of influenza ribonucleoproteins (RNPs) to nucleus of macrophages was inhibited, as evaluated by different approaches. Reduction of influenza RNPs entry into the nucleus tolled A(H1N1)pdm09 life cycle in macrophages earlier than usual, limiting influenza's ability to induce TNF-α. As judged by analysis of the influenza hemagglutin (HA) gene from in vitro experiments and from samples of HIV-1/A(H1N1)pdm09 co-infected individuals, the HIV-1-induced reduction of influenza replication resulted in delayed viral evolution. Our results may provide insights on the mechanisms that may have attenuated the clinical course of Influenza in HIV-1/A(H1N1)pdm09 co-infected patients during the recent influenza form 2009/2010.

Estrogen receptor-Beta variants are associated with increased risk of Alzheimer's disease in women with down syndrome.

PubMed

Zhao, Qi; Lee, Joseph H; Pang, Deborah; Temkin, Alexis; Park, Naeun; Janicki, Sarah C; Zigman, Warren B; Silverman, Wayne; Tycko, Benjamin; Schupf, Nicole

2011-01-01

Genetic variants that affect estrogen activity may influence the risk of Alzheimer's disease (AD). We examined the relation of polymorphisms in the gene for the estrogen receptor-beta (ESR2) to the risk of AD in women with Down syndrome. Two hundred and forty-nine women with Down syndrome, 31-70 years of age and nondemented at baseline, were followed at 14- to 18-month intervals for 4 years. Women were genotyped for 13 single-nucleotide polymorphisms (SNPs) in the ESR2 gene, and their association with AD incidence was examined. Among postmenopausal women, we found a 2-fold increase in the risk of AD for women carrying 1 or 2 copies of the minor allele at 3 SNPs in introns seven (rs17766755) and six (rs4365213 and rs12435857) and 1 SNP in intron eight (rs4986938) of ESR2. These findings support a role for estrogen and its major brain receptors in modulating susceptibility to AD in women. Copyright © 2011 S. Karger AG, Basel.

The Roles of Hemagglutinin Phe-95 in Receptor Binding and Pathogenicity of Influenza B Virus

PubMed Central

Ni, Fengyun; Mbawuike, Innocent Nnadi; Kondrashkina, Elena; Wang, Qinghua

2014-01-01

Diverged ~4,000 years ago, influenza B virus has several important differences from influenza A virus, including lower receptor-binding affinity and highly restricted host range. Based on our prior structural studies, we hypothesized that a single-residue difference in the receptor-binding site of hemagglutinin (HA), Phe-95 in influenza B virus versus Tyr-98 in influenza A/H1~H15, is possibly a key determinant for the low receptor-binding affinity. Here we demonstrate that the mutation Phe95→Tyr in influenza B virus HA restores all three hydrogen bonds made by Tyr-98 in influenza A/H3 HA and has the potential to enhance receptor binding. However, the full realization of this potential is influenced by the local environment into which the mutation is introduced. The binding and replication of the recombinant viruses correlate well with the receptor-binding capabilities of HA. These results are discussed in relation to the roles of Phe-95 in receptor binding and pathogenicity of influenza B virus. PMID:24503069

Thyroid hormone receptor alpha gene variants increase the risk of developing obesity and show gene-diet interactions.

PubMed

Fernández-Real, J M; Corella, D; Goumidi, L; Mercader, J M; Valdés, S; Rojo Martínez, G; Ortega, F; Martinez-Larrad, M-T; Gómez-Zumaquero, J M; Salas-Salvadó, J; Martinez González, M A; Covas, M I; Botas, P; Delgado, E; Cottel, D; Ferrieres, J; Amouyel, P; Ricart, W; Ros, E; Meirhaeghe, A; Serrano-Rios, M; Soriguer, F; Estruch, R

2013-11-01

Thyroid hormone receptor-beta resistance has been associated with metabolic traits. THRA gene sequencing of an obese woman (index case) who presented as empirical thyroid hormone receptor-α (THRA) resistance, disclosed a polymorphism (rs12939700) in a critical region involved in TRα alternative processing. THRA gene variants were evaluated in three independent europid populations (i) in two population cohorts at baseline (n=3417 and n=2265), 6 years later (n=2139) and (ii) in 4734 high cardiovascular risk subjects (HCVR, PREDIMED trial). The minor allele of the index case polymorphism (rs12939700), despite having a very low frequency (4%), was significantly associated with higher body mass index (BMI) (P=0.042) in HCVR subjects. A more frequent THRA polymorphism (rs1568400) was associated with higher BMI in subjects from the population (P=0.00008 and P=0.05) after adjusting for several confounders. Rs1568400 was also strongly associated with fasting triglycerides (P dominant=3.99 × 10(-5)). In the same sample, 6 years later, age and sex-adjusted risk of developing obesity was significantly increased in GG homozygotes (odds ratio 2.93 (95% confidence interval, 1.05-6.95)). In contrast, no association between rs1568400 and BMI was observed in HCVR subjects, in whom obesity was highly prevalent. This might be explained by the presence of an interaction (P <0.001) among the rs1568400 variant, BMI and saturated fat intake. Only when saturated fat intake was high (>24.5 g d(-1)), GG carriers showed a significantly higher BMI than A carriers after controlling for energy intake and physical activity. THRA gene polymorphisms are associated with obesity development. This is a novel observation linking the THRA locus to metabolic phenotypes.

Fatal intoxications associated with the designer opioid AH-7921.

PubMed

Kronstrand, R; Thelander, G; Lindstedt, D; Roman, M; Kugelberg, F C

2014-10-01

AH-7921 (3,4-dichloro-N-[(1-dimethylamino)cyclohexylmethyl]benzamide) is a designer opioid with ∼80% of morphine's µ-agonist activity. Over a 6-month period, we encountered nine deaths where AH-7921 was involved and detected in blood from the deceased. Shortly after the last death, on August 1 2013, AH-7921 was scheduled as a narcotic and largely disappeared from the illicit market in Sweden. AH-7921 was measured by a selective liquid chromatography-MS-MS method and the concentrations of AH-7921 ranged from 0.03 to 0.99 µg/g blood. Six of our cases had other drugs of abuse on board and most had other medications such as benzodiazepines, antidepressants and analgesics. However, the other medicinal drugs encountered were present in postmortem therapeutic concentrations and unlikely to have contributed to death. In addition to the parent compound, we identified six possible metabolites where two N-demethylated dominated and four mono-hydroxylated were found in trace amounts in the blood. In conclusion, deaths with AH-7921 seem to occur both at low and high concentrations, probably a result of different tolerance to the drug. Hence, it is reasonable to assume that no sharp dividing line exists between lethal and non-lethal concentrations. Further, poly-drug use did not seem to be a major contributing factor for the fatal outcome. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

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

PubMed

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.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cheng, Ya-Hsin, E-mail: yhcheng@mail.cmu.edu.tw; Li, Lih-Ann; Lin, Pinpin

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 phasemore » 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.« less

A variant on promoter of the cannabinoid receptor 1 gene (CNR1) moderates the effect of valence on working memory.

PubMed

Fairfield, Beth; Mammarella, Nicola; Franzago, Marica; Di Domenico, Alberto; Stuppia, Liborio; Gatta, Valentina

2018-02-01

Cannabinoid receptor 1 gene (CNR1) variants have been related to affective information processing and, in particular, to stress release. Here, we aimed to examine whether the endocannabinoid system via CNR1 signaling modulates affective working memory, the memory system that transiently maintains and manipulates emotionally charged material. We focused on rs2180619 (A > G) polymorphism and examined genotype data collected from 231 healthy females. Analyses showed how a general positivity bias in working memory (i.e., better memory for positive words) emerged as task strings lengthened only in carriers of the major allele (AA/AG). Differently, GG carriers showed better memory for affective items in general (i.e., positive and negative words). These findings are some of the first to directly highlight the role of variant on promoter of the CNR1 gene in affective working memory and to evidence a differentiation among CNR1 genotypes in terms of larger difficulties in disengaging from negative stimuli in GG carriers.

Regulatory effects of dioxin-like and non-dioxin-like PCBs and other AhR ligands on the antioxidant enzymes paraoxonase 1/2/3.

PubMed

Shen, Hua; Robertson, Larry W; Ludewig, Gabriele

2016-02-01

Paraoxonase 1 (PON1), an antioxidant enzyme, is believed to play a critical role in many diseases, including cancer. PCBs are widespread environmental contaminants known to induce oxidative stress and cancer and to produce changes in gene expression of various pro-oxidant and antioxidant enzymes. Thus, it appeared of interest to explore whether PCBs may modulate the activity and/or gene expression of PON1 as well. In this study, we compared the effects of dioxin-like and non-dioxin-like PCBs and of various aryl hydrocarbon receptor (AhR) ligands on PON1 regulation and activity in male and female Sprague-Dawley rats. Our results demonstrate that (i) the non-dioxin-like PCB154, PCB155, and PCB184 significantly reduced liver and serum PON1 activities, but only in male rats; (ii) the non-dioxin-like PCB153, the most abundant PCB in many matrices, did not affect PON1 messenger RNA (mRNA) level in the liver but significantly decreased serum PON1 activity in male rats; (iii) PCB126, an AhR ligand and dioxin-like PCB, increased both PON1 activities and gene expression; and (iv) even though three tested AhR ligands induced CYP1A in several tissues to a similar extent, they displayed differential effects on the three PONs and AhR, i.e., PCB126 was an efficacious inducer of PON1, PON2, PON3, and AhR in the liver, while 3-methylcholantrene induced liver AhR and lung PON3, and 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), the most potent AhR agonist, increased only PON3 in the lung, at the doses and exposure times used in these studies. These results show that PCBs may have an effect on the antioxidant protection by paraoxonases in exposed populations and that regulation of gene expression through AhR is highly diverse.

Allosteric alterations in the androgen receptor and activity in prostate cancer.

PubMed

Uo, Takuma; Plymate, Stephen R; Sprenger, Cynthia C

2017-09-01

Organisms have evolved to generate biological complexity in their proteome and transcriptome from a limited number of genes. This concept holds true for the androgen receptor, which displays a diversity of inclusion/exclusion events in its structural motifs as a mechanism of resistance to the most forefront anti-androgen therapies. More than 20 androgen receptor variants that lack various portions of ligand-binding domain have been identified in human prostate cancer (PCa) samples. Most of the variants are inactive on their own, with a few exceptions displaying constitutive activity. The full-length receptor and one or more variants can be co-expressed in the same cell under many circumstances, which raises the question of how these variants physically and functionally interact with the full-length receptor or one another in the course of PCa progression. To address this issue, in this review, we will characterize and discuss androgen receptor variants, including the novel variants discovered in the last couple of years (i) individually, (ii) with respect to their physical and functional interaction with one another and (iii) in clinical relevance. Here, we also introduce the very recent understanding of AR-Vs obtained through successful development of some AR-V-specific antibodies as well as identification of novel AR-Vs by data mining approaches. © 2017 Society for Endocrinology.

Ligand independent aryl hydrocarbon receptor inhibits lung cancer cell invasion by degradation of Smad4.

PubMed

Lee, Chen-Chen; Yang, Wen-Hao; Li, Ching-Hao; Cheng, Yu-Wen; Tsai, Chi-Hao; Kang, Jaw-Jou

2016-07-01

The aryl hydrocarbon receptor (AhR) is a ligand-dependent-activated transcriptional factor that regulates the metabolism of xenobiotic and endogenous compounds. Although AhR plays a crucial role in air toxicant-induced carcinogenesis, AhR expression was shown to negatively regulate tumorigenesis. Therefore, in the present study, we investigated the effect of AhR without ligand treatment on cancer invasion in lung cancer cell lines. Lung cancer cells expressing lower levels of AhR showed higher invasion ability (H1299 cells) compared with cells expressing higher levels of AhR (A549 cells). Overexpression of AhR in H1299 cells inhibited the invasion ability. We found that vimentin expression was inhibited in AhR-overexpressing H1299 cells. Additionally, the expression of EMT-related transcriptional factors Snail and ID-1 decreased. Interestingly, we found that Smad4 degradation was induced in AhR-overexpressing H1299 cells. Our data showed that AhR could interact with Jun-activation domain binding protein (Jab1) and Smad4, which may cause degradation of Smad4 by the proteasome. Our data suggest that AhR affects the transforming growth factor-β signaling pathway by inducing Smad4 degradation by the proteasome and suppressing tumor metastasis via epithelial to mesenchymal transition reduction in lung cancer cells. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Detrimental effects of melanocortin-1 receptor (MC1R) variants on the clinical outcomes of BRAF V600 metastatic melanoma patients treated with BRAF inhibitors.

PubMed

Guida, Michele; Strippoli, Sabino; Ferretta, Anna; Bartolomeo, Nicola; Porcelli, Letizia; Maida, Immacolata; Azzariti, Amalia; Tommasi, Stefania; Grieco, Claudia; Guida, Stefania; Albano, Anna; Lorusso, Vito; Guida, Gabriella

2016-11-01

Melanocortin-1 receptor (MC1R) plays a key role in skin pigmentation, and its variants are linked with a higher melanoma risk. The influence of MC1R variants on the outcomes of patients with metastatic melanoma (MM) treated with BRAF inhibitors (BRAFi) is unknown. We studied the MC1R status in a cohort of 53 consecutive BRAF-mutated patients with MM treated with BRAFi. We also evaluated the effect of vemurafenib in four V600 BRAF melanoma cell lines with/without MC1R variants. We found a significant correlation between the presence of MC1R variants and worse outcomes in terms of both overall response rate (ORR; 59% versus 95%, P = 0.011 univariate, P = 0.028 multivariate analysis) and progression-free survival (PFS) shorter than 6 months (72% versus 33%, P = 0.012 univariate, P = 0.027 multivariate analysis). No difference in overall survival (OS) was reported, probably due to subsequent treatments. Data in vitro showed a significant different phosphorylation of Erk1/2 and p38 MAPK during treatment, associated with a greater increase in vemurafenib IC50 in MC1R variant cell lines. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Detecting Spread of Avian Influenza A(H7N9) Virus Beyond China

PubMed Central

Havers, Fiona; Iuliano, A. Danielle; Davis, C. Todd; Sar, Borann; Sovann, Ly; Chin, Savuth; Corwin, Andrew L.; Vongphrachanh, Phengta; Douangngeun, Bounlom; Lindblade, Kim A.; Chittaganpitch, Malinee; Kaewthong, Viriya; Kile, James C.; Nguyen, Hien T.; Pham, Dong V.; Donis, Ruben O.; Widdowson, Marc-Alain

2015-01-01

During February 2013–March 2015, a total of 602 human cases of low pathogenic avian influenza A(H7N9) were reported; no autochthonous cases were reported outside mainland China. In contrast, since highly pathogenic avian influenza A(H5N1) reemerged during 2003 in China, 784 human cases in 16 countries and poultry outbreaks in 53 countries have been reported. Whether the absence of reported A(H7N9) outside mainland China represents lack of spread or lack of detection remains unclear. We compared epidemiologic and virologic features of A(H5N1) and A(H7N9) and used human and animal influenza surveillance data collected during April 2013–May 2014 from 4 Southeast Asia countries to assess the likelihood that A(H7N9) would have gone undetected during 2014. Surveillance in Vietnam and Cambodia detected human A(H5N1) cases; no A(H7N9) cases were detected in humans or poultry in Southeast Asia. Although we cannot rule out the possible spread of A(H7N9), substantial spread causing severe disease in humans is unlikely. PMID:25897654

Opioid Receptors: Toward Separation of Analgesic from Undesirable Effects

PubMed Central

Law, P.Y.; Reggio, Patricia H.; Loh, H.H.

2013-01-01

The use of opioid analgesics for pain has always been hampered by their many side effects; in particular, the addictive liability associated with chronic use. Recently, attempts to develop analgesic agents with reduced side effects have targeted either the putative opioid receptor splice variants or the receptor heterooligomers. This review discusses the potential for receptor splice variant- and the hetero-oligomer-based discovery of new opioid analgesics. We also examine an alternative approach of using receptor mutants for pain management. Finally, we discuss the role of the biased agonism observed and the recently reported opioid receptor crystal structures in guiding the future development of opioid analgesics PMID:23598157

BREEDING AND GENETICS SYMPOSIUM:Breeding heat tolerant dairy cattle: the case for introgression of the "slick" prolactin receptor variant into dairy breeds.

PubMed

Davis, S R; Spelman, R J; Littlejohn, M D

2017-04-01

Increasing environmental temperatures are a threat to the sustainability of livestock production and, because of the high metabolic demands of lactation, to dairy production in particular. Summer heat waves in temperate climates reduce feed intake, milk production, and cow comfort. In extreme heat events, there is an increase in cow mortality. In tropical climates, dairy cattle are mostly (zebu) type or zebu crossbred with temperate dairy breeds. Crossbreeding is undertaken to combine the heat tolerance and tick resistance of zebu with the productivity of temperate dairy breeds. In the absence of improved heat tolerance, milk production and fertility of temperate cattle is severely impaired. We have recently identified a key role for the prolactin pathway in regulating heat tolerance. A de novo mutation in prolactin that impairs prolactin activity was discovered in hairy and heat intolerant, New Zealand dairy cattle. The phenotypes produced were remarkably similar to those seen in fescue toxicosis, a syndrome seen in grazing cattle in the U.S. where ingestion of ergovaline, a fungal toxin from infected pasture, inhibits prolactin secretion. Recognition of the role of prolactin in hairy cattle led us to identify a deletion in exon 10 of the long-form of the prolactin receptor in Senepol cattle that causes truncation of the protein and determines the slick coat and heat tolerance traits found in this , beef breed. The short form of the prolactin receptor is predicted to be unaffected by the deletion. Knowledge of this dominant mutation has provided the impetus to begin a crossbreeding program to investigate performance and heat tolerance of temperate dairy cattle carrying the slick, prolactin receptor variant. The perceived opportunity is to introgress this variant into temperate dairy cattle to enable performance and welfare improvement in hot climates. Heat tolerance of cattle with slick coats appears to be mostly associated with coat type although sweating ability

PREDAC-H3: a user-friendly platform for antigenic surveillance of human influenza a(H3N2) virus based on hemagglutinin sequences.

PubMed

Peng, Yousong; Yang, Lei; Li, Honglei; Zou, Yuanqiang; Deng, Lizong; Wu, Aiping; Du, Xiangjun; Wang, Dayan; Shu, Yuelong; Jiang, Taijiao

2016-08-15

Timely surveillance of the antigenic dynamics of the influenza virus is critical for accurate selection of vaccine strains, which is important for effective prevention of viral spread and infection. Here, we provide a computational platform, called PREDAC-H3, for antigenic surveillance of human influenza A(H3N2) virus based on the sequence of surface protein hemagglutinin (HA). PREDAC-H3 not only determines the antigenic variants and antigenic cluster (grouped for similar antigenicity) to which the virus belongs, based on HA sequences, but also allows visualization of the spatial distribution and temporal dynamics of antigenic clusters of viruses isolated from around the world, thus assisting in antigenic surveillance of human influenza A(H3N2) virus. It is publicly available from: http://biocloud.hnu.edu.cn/influ411/html/index.php : yshu@cnic.org.cn or taijiao@moon.ibp.ac.cn. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

The aryl hydrocarbon receptor modulates acute and late mast cell responses.

PubMed

Sibilano, Riccardo; Frossi, Barbara; Calvaruso, Marco; Danelli, Luca; Betto, Elena; Dall'Agnese, Alessandra; Tripodo, Claudio; Colombo, Mario P; Pucillo, Carlo E; Gri, Giorgia

2012-07-01

The aryl hydrocarbon receptor (AhR) is a ligand-dependent transcription factor whose activity is modulated by xenobiotics as well as physiological ligands. These compounds may modulate inflammatory responses and contribute to the rising prevalence of allergic diseases observed in industrialized countries. Mast cells (MCs), located within tissues at the boundary of the external environment, represent a potential target of AhR ligands. In this study, we report that murine and human MCs constitutively express AhR, and its activation by the high-affinity ligand 6-formylindolo[3,2-b]carbazole (FICZ) determines a boost in degranulation. On the contrary, repeated exposure to FICZ inhibits MC degranulation. Accordingly, histamine release, in an in vivo passive systemic anaphylactic model, is exacerbated by a single dose and is attenuated by repetitive stimulation of AhR. FICZ-exposed MCs produce reactive oxygen species and IL-6 in response to cAMP-dependent signals. Moreover, AhR-activated MCs produce IL-17, a critical player in chronic inflammation and autoimmunity, suggesting a novel pathway for MC activation in the pathogenesis of these diseases. Indeed, histological analysis of patients with chronic obstructive pulmonary disease revealed an enrichment in AhR/IL-6 and AhR/IL-17 double-positive MCs within bronchial lamina propria. Thus, tissue-resident MCs could translate external chemical challenges through AhR by modulating allergic responses and contributing to the generation of inflammation-related diseases.

Increased aryl hydrocarbon receptor expression in patients with allergic rhinitis.

PubMed

Wei, P; Hu, G-H; Kang, H-Y; Yao, H-B; Kou, W; Liu, H; Hong, S-L

2014-02-01

A predominant Th17 population is a marker of allergic rhinitis (AR). As a ligand-activated transcription factor, the aryl hydrocarbon receptor (AhR) plays a vital role in promoting or inhibiting the development of specific Th cells. However, its role in AR remains undefined. To analyze the potential role of AhR in the pathogenesis of AR. In total, 30 AR patients and 13 healthy controls were recruited for this study and AR patients had clinical features, as demonstrated by rhinoconjunctivitis quality of life questionnaires, total symptom scores and visual analog scale scores. The expression of AhR, IL-17 and IL-22 and the presence of Th17 cells in peripheral blood mononuclear cells were measured before and after treatment with the nontoxic AhR ligand 2-(1'H-indole-3'-carbonyl)-thiazole-4-carboxylic acid methyl ester (ITE). Pretreatment ITE studies revealed that all AR patients had a significant increase in AhR expression compared with controls and AhR expression positively correlated with clinical parameters. After ITE intervention, a severe reduction in the differentiation of Th17 cells and the production of IL-17 and IL-22 was noted in both AR patients and normal subjects. Simultaneously, a dramatic enhancement of AhR expression was also observed in all healthy controls, but not in AR patients. The results suggested that the AhR may be one of the mechanisms underlying the Th17 response during the pathogenesis of AR and AhR levels were closely related to clinical severity in all AR patients. Additionally, ITE may represent a new drug candidate in the treatment of AR.

SLC6A19 is a novel putative gene, induced by dioxins via AhR in human hepatoma HepG2 cells.

PubMed

Tian, Wenjing; Fu, Hualing; Xu, Tuan; Xu, Sherry Li; Guo, Zhiling; Tian, Jijing; Tao, Wuqun; Xie, Heidi Qunhui; Zhao, Bin

2018-06-01

The aryl hydrocarbon receptor (AhR) plays an important role in mediating dioxins toxicity. Currently, genes of P450 families are major research interests in studies on AhR-mediated gene alterations caused by dioxins. Genes related to other metabolic pathways or processes may be also responsive to dioxin exposures. Amino acid transporter B0AT1 (encoded by SLC6A19) plays a decisive role in neutral amino acid transport which is present in kidney, intestine and liver. However, effects of dioxins on its expression are still unknown. In the present study, we focused on the effects of dioxin and dioxin-like compounds on SLC6A19 expression in HepG2 cells. We identified SLC6A19 as a novel putative target gene of AhR activation in HepG2 cells. 2, 3, 7, 8-tetrachlorodibenzo-p-dioxin (TCDD) increased the expression of SLC6A19 in time- and concentration-dependent manners. Using AhR antagonist CH223191 and/or siRNA assays, we demonstrated that certain AhR agonists upregulated SLC6A19 expression via AhR, including TCDD, 1,2,3,7,8-pentachlorodibenzo-p-dioxin (1,2,3,7,8-PeCDD), 2,3,4,7,8- pentachlorodibenzofuran (2,3,4,7,8-PeCDF) and PCB126. In addition, the expression of B0AT1 was also significantly induced by TCDD in HepG2 cells. Our study suggested that dioxins might affect the transcription and translation of SLC6A19 in HepG2 cells, which might be a novel putative gene to assess dioxins' toxicity in amino acid transport and metabolism in liver. Copyright © 2018 Elsevier Ltd. All rights reserved.

Variants in human papillomavirus receptor and associated genes are associated with type-specific HPV infection and lesion progression of the cervix

PubMed Central

Chen, Tingting; Yang, Shizhou; Huang, Yongjie; Hong, Die; Li, Yang; Chen, Xiaojing; Wang, Xinyu; Cheng, Xiaodong; Lu, Weiguo; Xie, Xing

2016-01-01

Human papillomavirus (HPV) infects cervical epithelial cells through cellular membrane receptors, and then induces the initiation and progression of cervical cancer. Single nucleotide polymorphisms (SNPs) may impact the susceptibility and outcome of diseases, but it's still unknown whether variant in HPV receptor and associated genes is associated with type-specific HPV infection and cervical lesion progression. We examined 96 SNPs in 8 genes which may participate in the HPV infection process in 875 samples with HPV negative or single HPV16, 18, 52, 58 positive from 3299 cervical exfoliated cell samples, by Illumina BeadXpress VeraCode platform, and analyzed the correlation between the SNPs and type-specific HPV infection and cervical lesions progression. We found rs28384376 in EGFR and rs12034979 in HSPG2 significantly correlated to HPV16 infection; rs2575738, rs2575712, rs2575735 in SDC2 and rs6697265 in HSPG2 significantly correlated to HPV18 infection; rs10510097 in FGFR2, rs12718946 in EGFR significantly correlated to HPV52 infection; rs4947972 in EGFR, rs2981451 in FGFR2, rs2575735 in SDC2 significantly correlated to HPV58 infection. And rs3135772, rs1047057 and rs2556537 in FGFR2, rs12034979 in HSPG2, rs16894821 in SDC2 significantly correlated to cervical lesion progression induced by HPV16 infection; rs6697265 and rs6680566 in HSPG2, rs16860426 in ITGA6 by HPV18 infection; rs878949 in HSPG2, rs12718946 and rs12668175 in EGFR by HPV52 infection; no SNP by HPV58 infection. Our findings suggest that HPV receptor and associated gene variants may influence the susceptibilities to HPV type-specific infection and cervical lesion progression, which might have a potential application value in cervical cancer screening and therapy. PMID:27223085

Third-Generation Ah Receptor–Responsive Luciferase Reporter Plasmids: Amplification of Dioxin-Responsive Elements Dramatically Increases CALUX Bioassay Sensitivity and Responsiveness

PubMed Central

He, Guochun; Tsutsumi, Tomoaki; Zhao, Bin; Baston, David S.; Zhao, Jing; Heath-Pagliuso, Sharon; Denison, Michael S.

2011-01-01

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD, dioxin) and related dioxin-like chemicals are widespread and persistent environmental contaminants that produce diverse toxic and biological effects through their ability to bind to and activate the Ah receptor (AhR) and AhR-dependent gene expression. The chemically activated luciferase expression (CALUX) system is an AhR-responsive recombinant luciferase reporter gene–based cell bioassay that has been used in combination with chemical extraction and cleanup methods for the relatively rapid and inexpensive detection and relative quantitation of dioxin and dioxin-like chemicals in a wide variety of sample matrices. Although the CALUX bioassay has been validated and used extensively for screening purposes, it has some limitations when screening samples with very low levels of dioxin-like chemicals or when there is only a small amount of sample matrix for analysis. Here, we describe the development of third-generation (G3) CALUX plasmids with increased numbers of dioxin-responsive elements, and stable transfection of these new plasmids into mouse hepatoma (Hepa1c1c7) cells has produced novel amplified G3 CALUX cell bioassays that respond to TCDD with a dramatically increased magnitude of luciferase induction and significantly lower minimal detection limit than existing CALUX-type cell lines. The new G3 CALUX cell lines provide a highly responsive and sensitive bioassay system for the detection and relative quantitation of very low levels of dioxin-like chemicals in sample extracts. PMID:21775728

Prevalence of melanocortin receptor 4 (MC4R) V103I gene variant and its association with obesity among the Kampar Health Clinic cohort, Perak, Malaysia.

PubMed

Chua, H N; Fan, S H; Say, Y H

2012-04-01

This study investigated the prevalence of the Melanocortin receptor 4 (MC4R) V1031 gene variant and its association with obesity among a cohort of 254 patients (101 males; 118 obese) attending the Kampar Health Clinic. Genotyping revealed the mutated I allele frequency of 0.02, no homozygous mutated (II), and similar distribution of V and I alleles across BMI groups, genders and ethnic groups. No significant difference was found for the means of anthropometric measurements between alleles. Prevalence of this gene variant among the Malaysian cohort was similar with previous populations (2-4% of mutated allele carrier), but was not associated with obesity.

Decreased expression of the aryl hydrocarbon receptor in ocular Behcet's disease.

PubMed