Science.gov

Sample records for persistent enos activation

  1. Regulation of eNOS enzyme activity by posttranslational modification.

    PubMed

    Heiss, Elke H; Dirsch, Verena M

    2014-01-01

    The regulation of endothelial NO synthase (eNOS) employs multiple different cellular control mechanisms impinging on level and activity of the enzyme. This review aims at summarizing the current knowledge on the posttranslational modifications of eNOS, including acylation, nitrosylation, phosphorylation, acetylation, glycosylation and glutathionylation. Sites, mediators and impact on enzyme localization and activity of the single modifications will be discussed. Moreover, interdependence, cooperativity and competition between the different posttranslational modifications will be elaborated with special emphasis on the susceptibility of eNOS to metabolic cues.

  2. Stromal cell–derived factor 2 is critical for Hsp90-dependent eNOS activation

    PubMed Central

    Siragusa, Mauro; Fröhlich, Florian; Park, Eon Joo; Schleicher, Michael; Walther, Tobias C.; Sessa, William C.

    2016-01-01

    Endothelial nitric oxide synthase (eNOS) catalyzes the conversion of l-arginine and molecular oxygen into l-citrulline and nitric oxide (NO), a gaseous second messenger that influences cardiovascular physiology and disease. Several mechanisms regulate eNOS activity and function, including phosphorylation at Ser and Thr residues and protein-protein interactions. Combining a tandem affinity purification approach and mass spectrometry, we identified stromal cell–derived factor 2 (SDF2) as a component of the eNOS macromolecular complex in endothelial cells. SDF2 knockdown impaired agonist-stimulated NO synthesis and decreased the phosphorylation of eNOS at Ser1177, a key event required for maximal activation of eNOS. Conversely, SDF2 overexpression dose-dependently increased NO synthesis through a mechanism involving Akt and calcium (induced with ionomycin), which increased the phosphorylation of Ser1177 in eNOS. NO synthesis by iNOS (inducible NOS) and nNOS (neuronal NOS) was also enhanced upon SDF2 overexpression. We found that SDF2 was a client protein of the chaperone protein Hsp90, interacting preferentially with the M domain of Hsp90, which is the same domain that binds to eNOS. In endothelial cells exposed to vascular endothelial growth factor (VEGF), SDF2 was required for the binding of Hsp90 and calmodulin to eNOS, resulting in eNOS phosphorylation and activation. Thus, our data describe a function for SDF2 as a component of the Hsp90-eNOS complex that is critical for signal transduction in endothelial cells. PMID:26286023

  3. Stromal cell-derived factor 2 is critical for Hsp90-dependent eNOS activation.

    PubMed

    Siragusa, Mauro; Fröhlich, Florian; Park, Eon Joo; Schleicher, Michael; Walther, Tobias C; Sessa, William C

    2015-08-18

    Endothelial nitric oxide synthase (eNOS) catalyzes the conversion of l-arginine and molecular oxygen into l-citrulline and nitric oxide (NO), a gaseous second messenger that influences cardiovascular physiology and disease. Several mechanisms regulate eNOS activity and function, including phosphorylation at Ser and Thr residues and protein-protein interactions. Combining a tandem affinity purification approach and mass spectrometry, we identified stromal cell-derived factor 2 (SDF2) as a component of the eNOS macromolecular complex in endothelial cells. SDF2 knockdown impaired agonist-stimulated NO synthesis and decreased the phosphorylation of eNOS at Ser(1177), a key event required for maximal activation of eNOS. Conversely, SDF2 overexpression dose-dependently increased NO synthesis through a mechanism involving Akt and calcium (induced with ionomycin), which increased the phosphorylation of Ser(1177) in eNOS. NO synthesis by iNOS (inducible NOS) and nNOS (neuronal NOS) was also enhanced upon SDF2 overexpression. We found that SDF2 was a client protein of the chaperone protein Hsp90, interacting preferentially with the M domain of Hsp90, which is the same domain that binds to eNOS. In endothelial cells exposed to vascular endothelial growth factor (VEGF), SDF2 was required for the binding of Hsp90 and calmodulin to eNOS, resulting in eNOS phosphorylation and activation. Thus, our data describe a function for SDF2 as a component of the Hsp90-eNOS complex that is critical for signal transduction in endothelial cells. Copyright © 2015, American Association for the Advancement of Science.

  4. Fenofibrate activates AMPK and increases eNOS phosphorylation in HUVEC

    SciTech Connect

    Murakami, Hisashi; Murakami, Ryuichiro . E-mail: ryuichi@med.nagoya-u.ac.jp; Kambe, Fukushi; Cao, Xia; Takahashi, Ryotaro; Asai, Toru; Hirai, Toshihisa; Numaguchi, Yasushi; Okumura, Kenji; Seo, Hisao; Murohara, Toyoaki

    2006-03-24

    Fenofibrate improves endothelial function by lipid-lowering and anti-inflammatory effects. Additionally, fenofibrate has been demonstrated to upregulate endothelial nitric oxide synthase (eNOS). AMP-activated protein kinase (AMPK) has been reported to phosphorylate eNOS at Ser-1177 and stimulate vascular endothelium-derived nitric oxide (NO) production. We report here that fenofibrate activates AMPK and increases eNOS phosphorylation and NO production in human umbilical vein endothelial cells (HUVEC). Incubation of HUVEC with fenofibrate increased the phosphorylation of AMPK and acetyl-CoA carboxylase. Fenofibrate simultaneously increased eNOS phosphorylation and NO production. Inhibitors of protein kinase A and phosphatidylinositol 3-kinase failed to suppress the fenofibrate-induced eNOS phosphorylation. Neither bezafibrate nor WY-14643 activated AMPK in HUVEC. Furthermore, fenofibrate activated AMPK without requiring any transcriptional activities. These results indicate that fenofibrate stimulates eNOS phosphorylation and NO production through AMPK activation, which is suggested to be a novel characteristic of this agonist and unrelated to its effects on peroxisome proliferator-activated receptor {alpha}.

  5. Activation of Endothelial Nitric Oxide (eNOS) Occurs through Different Membrane Domains in Endothelial Cells

    PubMed Central

    Tran, Jason; Magenau, Astrid; Rodriguez, Macarena; Rentero, Carles; Royo, Teresa; Enrich, Carlos; Thomas, Shane R.; Grewal, Thomas; Gaus, Katharina

    2016-01-01

    Endothelial cells respond to a large range of stimuli including circulating lipoproteins, growth factors and changes in haemodynamic mechanical forces to regulate the activity of endothelial nitric oxide synthase (eNOS) and maintain blood pressure. While many signalling pathways have been mapped, the identities of membrane domains through which these signals are transmitted are less well characterized. Here, we manipulated bovine aortic endothelial cells (BAEC) with cholesterol and the oxysterol 7-ketocholesterol (7KC). Using a range of microscopy techniques including confocal, 2-photon, super-resolution and electron microscopy, we found that sterol enrichment had differential effects on eNOS and caveolin-1 (Cav1) colocalisation, membrane order of the plasma membrane, caveolae numbers and Cav1 clustering. We found a correlation between cholesterol-induced condensation of the plasma membrane and enhanced high density lipoprotein (HDL)-induced eNOS activity and phosphorylation suggesting that cholesterol domains, but not individual caveolae, mediate HDL stimulation of eNOS. Vascular endothelial growth factor (VEGF)-induced and shear stress-induced eNOS activity was relatively independent of membrane order and may be predominantly controlled by the number of caveolae on the cell surface. Taken together, our data suggest that signals that activate and phosphorylate eNOS are transmitted through distinct membrane domains in endothelial cells. PMID:26977592

  6. Activation of Endothelial Nitric Oxide (eNOS) Occurs through Different Membrane Domains in Endothelial Cells.

    PubMed

    Tran, Jason; Magenau, Astrid; Rodriguez, Macarena; Rentero, Carles; Royo, Teresa; Enrich, Carlos; Thomas, Shane R; Grewal, Thomas; Gaus, Katharina

    2016-01-01

    Endothelial cells respond to a large range of stimuli including circulating lipoproteins, growth factors and changes in haemodynamic mechanical forces to regulate the activity of endothelial nitric oxide synthase (eNOS) and maintain blood pressure. While many signalling pathways have been mapped, the identities of membrane domains through which these signals are transmitted are less well characterized. Here, we manipulated bovine aortic endothelial cells (BAEC) with cholesterol and the oxysterol 7-ketocholesterol (7KC). Using a range of microscopy techniques including confocal, 2-photon, super-resolution and electron microscopy, we found that sterol enrichment had differential effects on eNOS and caveolin-1 (Cav1) colocalisation, membrane order of the plasma membrane, caveolae numbers and Cav1 clustering. We found a correlation between cholesterol-induced condensation of the plasma membrane and enhanced high density lipoprotein (HDL)-induced eNOS activity and phosphorylation suggesting that cholesterol domains, but not individual caveolae, mediate HDL stimulation of eNOS. Vascular endothelial growth factor (VEGF)-induced and shear stress-induced eNOS activity was relatively independent of membrane order and may be predominantly controlled by the number of caveolae on the cell surface. Taken together, our data suggest that signals that activate and phosphorylate eNOS are transmitted through distinct membrane domains in endothelial cells.

  7. (−)-Epicatechin activation of endothelial cell eNOS, NO and related signaling pathways

    PubMed Central

    Ramirez-Sanchez, Israel; Maya, Lisandro; Ceballos, Guillermo; Villarreal, Francisco

    2010-01-01

    Recent reports indicate that (−)-epicatechin can exert cardioprotective actions, which may involve eNOS-mediated nitric oxide production in endothelial cells. However, the mechanism by which (−)-epicatechin activates eNOS remains unclear. In this study, we proposed to identify the intracellular pathways involved in (−)-epicatechin-induced effects on eNOS, utilizing human coronary artery endothelial cells in culture. Treatment of cells with (−)-epicatechin leads to time- and dose-dependent effects, which peaked at 10 min at 1 μmol/L. (−)-Epicatechin treatment activates eNOS via serine-633 and serine-1177 phosphorylation and threonine-495 dephosphorylation. Using specific inhibitors, we have established the participation of the PI3K pathway in eNOS activation. (−)-Epicatechin induces eNOS uncoupling from caveolin-1 and its association with calmodulin-1, suggesting the involvement of intracellular calcium. These results allowed us to propose that (−) epicatechin effects may be dependent on actions exerted at the cell membrane level. To test this hypothesis, cells were treated with the phospholipase C inhibitor U73122, which blocked (−)-epicatechin-induced eNOS activation. We also demonstrated inositol phosphate accumulation in (−)-epicatechin-treated cells. The inhibitory effects of the pre-incubation of cells with the CaMKII inhibitor KN-93 indicate that (−)-epicatechin-induced eNOS activation is at least partially mediated via the Ca2+/CaMKII pathway. The (−)-epicatechin stereoisomer catechin was only able to partially stimulate nitric oxide production in cells. Altogether, these results strongly suggest the presence of a cell surface acceptor-effector for the cacao flavanol (−)-epicatechin, which may mediate its cardiovascular effects. PMID:20404222

  8. NADPH Oxidase 4 Promotes Endothelial Angiogenesis Through eNOS Activation

    PubMed Central

    Craige, Siobhan M.; Kai, Chen; Pei, Yongmei; Chunying, Li; Xiaoyun, Huang; Christine, Chen; Shibata, Rei; Sato, Kaori; Walsh, Kenneth; Keaney, John F.

    2013-01-01

    Background Reactive Oxygen Species (ROS) serve signaling functions in the vasculature, and hypoxia has been associated with increased ROS production. NADPH oxidase 4 (Nox4) is an ROS-producing enzyme that is highly expressed in the endothelium, yet its specific role is unknown. We sought to determine the role of Nox4 in the endothelial response to hypoxia. Methods and Results Hypoxia induced Nox4 expression both in vitro and in vivo and overexpression of Nox4 was sufficient to promote endothelial proliferation, migration, and tube formation. To determine the in vivo relevance of our observations, we generated transgenic mice with endothelial-specific Nox4 overexpression using the VE-cadherin promoter (VECad-Nox4 mice). In vivo, the VECad-Nox4 mice had accelerated recovery from hind limb ischemia and enhanced aortic capillary sprouting. Because endothelial nitric oxide synthase (eNOS) is involved in endothelial angiogenic responses and eNOS is activated by ROS, we probed the effect of Nox4 on eNOS. In cultured ECs overexpressing Nox4 we observed a significant increase in eNOS protein expression and activity. To causally address the link between eNOS and Nox4 we crossed our transgenic Nox4 mice with eNOS-/- mice. Aorta from these mice did not demonstrate enhanced aortic sprouting and VECad-Nox4 mice on the eNOS-/- background did not demonstrate enhanced recovery from hind limb ischemia. Conclusions Collectively, we demonstrate that augmented endothelial Nox4 expression promotes angiogenesis and recovery from hypoxia in an eNOS-dependent manner. PMID:21788590

  9. Folic acid modulates eNOS activity via effects on posttranslational modifications and protein–protein interactions☆

    PubMed Central

    Taylor, Sarah Y.; Dixon, Hannah M.; Yoganayagam, Shobana; Price, Natalie; Lang, Derek

    2013-01-01

    Folic acid enhances endothelial function and improves outcome in primary prevention of cardiovascular disease. The exact intracellular signalling mechanisms involved remain elusive and were therefore the subject of this study. Particular focus was placed on folic acid-induced changes in posttranslational modifications of endothelial nitric oxide synthase (eNOS). Cultured endothelial cells were exposed to folic acid in the absence or presence of phosphatidylinositol-3' kinase/Akt (PI3K/Akt) inhibitors. The phosphorylation status of eNOS was determined via western blotting. The activities of eNOS and PI3K/Akt were evaluated. The interaction of eNOS with caveolin-1, Heat-Shock Protein 90 and calmodulin was studied using co-immunoprecipitation. Intracellular localisation of eNOS was investigated using sucrose gradient centrifugation and confocal microscopy. Folic acid promoted eNOS dephosphorylation at negative regulatory sites, and increased phosphorylation at positive regulatory sites. Modulation of phosphorylation status was concomitant with increased cGMP concentrations, and PI3K/Akt activity. Inhibition of PI3K/Akt revealed specific roles for this kinase pathway in folic acid-mediated eNOS phosphorylation. Regulatory protein and eNOS protein associations were altered in favour of a positive regulatory effect in the absence of bulk changes in intracellular eNOS localisation. Folic acid-mediated eNOS activation involves the modulation of eNOS phosphorylation status at multiple residues and positive changes in important protein–protein interactions. Such intracellular mechanisms may in part explain improvements in clinical vascular outcome following folic acid treatment. PMID:23796957

  10. (−)-Epicatechin induces calcium and translocation independent eNOS activation in arterial endothelial cells

    PubMed Central

    Ramirez-Sanchez, Israel; Maya, Lisandro; Ceballos, Guillermo

    2011-01-01

    The consumption of cacao-derived (i.e., cocoa) products provides beneficial cardiovascular effects in healthy subjects as well as individuals with endothelial dysfunction such as smokers, diabetics, and postmenopausal women. The vascular actions of cocoa are related to enhanced nitric oxide (NO) production. These actions can be reproduced by the administration of the cacao flavanol (−)-epicatechin (EPI). To further understand the mechanisms behind the vascular action of EPI, we investigated the effects of Ca2+ depletion on endothelial nitric oxide (NO) synthase (eNOS) activation/phosphorylation and translocation. Human coronary artery endothelial cells were treated with EPI or with bradykinin (BK), a well-known Ca2+-dependent eNOS activator. Results demonstrate that both EPI and BK induce increases in intracellular calcium and NO levels. However, under Ca2+-free conditions, EPI (but not BK) is still capable of inducing NO production through eNOS phosphorylation at serine 615, 633, and 1177. Interestingly, EPI-induced translocation of eNOS from the plasmalemma was abolished upon Ca2+ depletion. Thus, under Ca2+-free conditions, EPI can stimulate NO synthesis independent of calmodulin binding to eNOS and of its translocation into the cytoplasm. We also examined the effect of EPI on the NO/cGMP/vasodilator-stimulated phosphoprotein (VASP) pathway activation in isolated Ca2+-deprived canine mesenteric arteries. Results demonstrate that under these conditions, EPI induces the activation of this vasorelaxation-related pathway and that this effect is inhibited by pretreatment with nitro-l-arginine methyl ester, suggesting a functional relevance for this phenomenon. PMID:21209365

  11. Activation of eNOS in endothelial cells exposed to ionizing radiation involves components of the DNA damage response pathway

    SciTech Connect

    Nagane, Masaki; Yasui, Hironobu; Sakai, Yuri; Yamamori, Tohru; Niwa, Koichi; Hattori, Yuichi; Kondo, Takashi; Inanami, Osamu

    2015-01-02

    Highlights: • eNOS activity is increased in BAECs exposed to X-rays. • ATM is involved in this increased eNOS activity. • HSP90 modulates the radiation-induced activation of ATM and eNOS. - Abstract: In this study, the involvement of ataxia telangiectasia mutated (ATM) kinase and heat shock protein 90 (HSP90) in endothelial nitric oxide synthase (eNOS) activation was investigated in X-irradiated bovine aortic endothelial cells. The activity of nitric oxide synthase (NOS) and the phosphorylation of serine 1179 of eNOS (eNOS-Ser1179) were significantly increased in irradiated cells. The radiation-induced increases in NOS activity and eNOS-Ser1179 phosphorylation levels were significantly reduced by treatment with either an ATM inhibitor (Ku-60019) or an HSP90 inhibitor (geldanamycin). Geldanamycin was furthermore found to suppress the radiation-induced phosphorylation of ATM-Ser1181. Our results indicate that the radiation-induced eNOS activation in bovine aortic endothelial cells is regulated by ATM and HSP90.

  12. Early ischaemic preconditioning requires Akt- and PKA-mediated activation of eNOS via serine1176 phosphorylation

    PubMed Central

    Yang, Changjun; Talukder, M.A. Hassan; Varadharaj, Saradhadevi; Velayutham, Murugesan; Zweier, Jay L.

    2013-01-01

    Aims The role of endothelial nitric oxide synthase (eNOS)/NO signalling is well documented in late ischaemic preconditioning (IPC); however, the role of eNOS and its activation in early IPC remains controversial. This study investigates the role of eNOS in early IPC and the signalling pathways and molecular interactions that regulate eNOS activation during early IPC. Methods and results Rat hearts were subjected to 30-min global ischaemia and reperfusion (I/R) with or without IPC (three cycles 5-min I and 5-min R) in the presence or absence of the NOS inhibitor l-NAME, phosphatidylinositol 3-kinase (PI3K) inhibitor LY294002 (LY), and protein kinase A (PKA) inhibitor H89 during IPC induction or prior endothelial permeablization. IPC improved post-ischaemic contractile function and reduced infarction compared with I/R with this being abrogated by l-NAME or endothelial permeablization. eNOSSer1176, AktSer473, and PKAThr197 phosphorylation was increased following IPC. I/R decreased eNOSSer1176 phosphorylation, whereas IPC increased it. Mass spectroscopy confirmed eNOSSer1176 phosphorylation and quantitative Western blots showed ∼24% modification of eNOSSer1176 following IPC. Immunoprecipitation demonstrated eNOS, Akt, and PKA complexation. Immunohistology showed IPC-induced Akt and PKA phosphorylation in cardiomyocytes and endothelium. With eNOS activation, IPC increased NO production as measured by electron paramagnetic resonance spin trapping and fluorescence microscopy. LY or H89 not only decreased AktSer473 or PKAThr197 phosphorylation, respectively, but also abolished IPC-induced preservation of eNOS and eNOSSer1176 phosphorylation as well as cardioprotection. Conclusion Thus, Akt- and PKA-mediated eNOS activation, with phosphorylation near the C-terminus, is critical for early IPC-induced cardioprotection, with eNOS-derived NO from the endothelium serving a critical role. PMID:22977010

  13. Phenylephrine activates eNOS Ser 1177 phosphorylation and nitric oxide signaling in renal hypertensive rat aorta.

    PubMed

    Silva, Bruno R; Pernomian, Laena; Grando, Marcella D; Bendhack, Lusiane M

    2014-09-05

    The endothelial nitric oxide synthase (eNOS) plays an important role in the control of the vascular tone. This work aimed to evaluate the role of an α1-adrenoceptor agonist phenylephrine (PE) on eNOS activity and downstream signaling pathway activation in normotensive (2K) and renal hypertensive (2K-1C) intact-endothelium rat aortas. Concentration-effect curves were performed for PE in intact-endothelium aortas from 2K and 2K-1C rats, in the absence of or in the presence of NOS or soluble guanylyl cyclase (sGC) inhibitor. Intact endothelium aortas were stimulated with PE in organ chambers and eNOS Ser(1177)/Thr(495) phosphorylation expression was evaluated by western blot. Nitric Oxide (NO) production was evaluated in isolated endothelial cells from 2K and 2K-1C rat aortas by flow-cytometry using NO selective fluorescent probe, DAF-2DA. The sGC activity/expression was also evaluated. PE-induced contractile response is lower in 2K-1C than in 2K intact-endothelium rat aorta. This is due to higher eNOS Ser(1177) phosphorylation in 2K-1C, which induces the eNOS overactivation. It was abolished by NOS or sGC inhibition. Phenylephrine reduces NO production in 2K as compared to the basal level, but it is not modified in 2K-1C. In PE-stimulated endothelial cells, the NO production is higher in 2K-1C than in 2K. Phenylephrine induces higher cGMP production in 2K-1C than in 2K, despite the lower expression of sGC in 2K-1C. Our results suggest that alpha1-adrenoceptor activation contributes to the increased activity of the enzyme eNOS by Ser(1177) phosphorylation in 2K-1C intact-endothelium aorta, which consequently decreases PE-induced contractile response.

  14. Sildenafil promotes eNOS activation and inhibits NADPH oxidase in the transgenic sickle cell mouse penis.

    PubMed

    Musicki, Biljana; Bivalacqua, Trinity J; Champion, Hunter C; Burnett, Arthur L

    2014-02-01

    Sickle cell disease (SCD)-associated vasculopathy in the penis is characterized by aberrant nitric oxide and phosphodiesterase (PDE) 5 signaling, and by increased oxidative stress. Preliminary clinical trials show that continuous treatment with PDE5 inhibitor sildenafil unassociated with sexual activity decreases priapic activity in patients with SCD. However, the mechanism of its vasculoprotective effect in the penis remains unclear. We evaluated whether continuous administration of PDE5 inhibitor sildenafil promotes eNOS function at posttranslational levels and decreases superoxide-producing enzyme NADPH oxidase activity in the sickle cell mouse penis. SCD transgenic mice were used as an animal model of SCD. WT mice served as controls. Mice received treatment with the PDE5 inhibitor sildenafil (100 mg/kg/day) or vehicle for 3 weeks. eNOS phosphorylation on Ser-1177 (positive regulatory site), eNOS interactions with heat-shock protein 90 (HSP90) (positive regulator), phosphorylated AKT (upstream mediator of eNOS phosphorylation on Ser-1177), an NADPH oxidase catalytic subunit gp91(phox), and a marker of oxidative stress (4-hydroxy-2-nonenal [HNE]) were measured by Western blot. Effect of continuous sildenafil treatment on eNOS posttranslational activation, NADPH oxidase catalytic subunit, and oxidative stress in the penis of the sickle cell mouse. Continuous treatment with sildenafil reversed (P < 0.05) the abnormalities in protein expressions of P-eNOS (Ser-1177), eNOS/HSP90 interaction, P-AKT, protein expression of gp91(phox), and 4-HNE, in the sickle cell mouse penis. Sildenafil treatment of WT mice did not affect any of these parameters. Our findings that sildenafil enhances eNOS activation and inhibits NADPH oxidase function in the sickle cell mouse penis offers a vasculoprotective molecular basis for the therapeutic effect of sildenafil in the penis in association with SCD. © 2013 International Society for Sexual Medicine.

  15. Sildenafil Promotes eNOS Activation and Inhibits NADPH Oxidase in the Transgenic Sickle Cell Mouse Penis

    PubMed Central

    Musicki, Biljana; Bivalacqua, Trinity J.; Champion, Hunter C.; Burnett, Arthur L.

    2014-01-01

    Introduction Sickle cell disease (SCD)-associated vasculopathy in the penis is characterized by aberrant nitric oxide and phosphodiesterase (PDE) 5 signaling, and by increased oxidative stress. Preliminary clinical trials show that continuous treatment with PDE5 inhibitor sildenafil unassociated with sexual activity decreases priapic activity in patients with SCD. However, the mechanism of its vasculoprotective effect in the penis remains unclear. Aims We evaluated whether continuous administration of PDE5 inhibitor sildenafil promotes eNOS function at posttranslational levels and decreases superoxide-producing enzyme NADPH oxidase activity in the sickle cell mouse penis. Methods SCD transgenic mice were used as an animal model of SCD. WT mice served as controls. Mice received treatment with the PDE5 inhibitor sildenafil (100 mg/kg/day) or vehicle for 3 weeks. eNOS phosphorylation on Ser-1177 (positive regulatory site), eNOS interactions with heat-shock protein 90 (HSP90) (positive regulator), phosphorylated AKT (upstream mediator of eNOS phosphorylation on Ser-1177), an NADPH oxidase catalytic subunit gp91(phox), and a marker of oxidative stress (4-hydroxy-2-nonenal [HNE]) were measured by Western blot. Main Outcome Measures Effect of continuous sildenafil treatment on eNOS posttranslational activation, NADPH oxidase catalytic subunit, and oxidative stress in the penis of the sickle cell mouse. Results Continuous treatment with sildenafil reversed (P < 0.05) the abnormalities in protein expressions of P-eNOS (Ser-1177), eNOS/HSP90 interaction, P-AKT, protein expression of gp91(phox), and 4-HNE, in the sickle cell mouse penis. Sildenafil treatment of WT mice did not affect any of these parameters. Conclusion Our findings that sildenafil enhances eNOS activation and inhibits NADPH oxidase function in the sickle cell mouse penis offers a vasculoprotective molecular basis for the therapeutic effect of sildenafil in the penis in association with SCD. PMID:24251665

  16. Impact of Lifestyle Intervention on HDL-Induced eNOS Activation and Cholesterol Efflux Capacity in Obese Adolescent

    PubMed Central

    Wesnigk, Jenny; De Guchtenaere, Ann; Fischer, Tina; Schuler, Gerhard; Vrints, Christiaan J.

    2016-01-01

    Background. Endothelial dysfunction occurs in obese children and adolescent and is regarded as a key step in the development of atherosclerosis. Important components for the development of endothelial dysfunction are reduced activity of endothelial nitric oxide synthase (eNOS) and an increase in cholesterol deposition in the vessel wall, due to reduced reverse cholesterol transport (RCT) activity. High density lipoprotein (HDL) exhibits antiatherosclerotic properties including modulation of eNOS activity and cholesterol efflux capacity. Lifestyle intervention programs can modify endothelial dysfunction in obese adolescents, but their impact on HDL-mediated eNOS activation and RCT is unknown so far. Methods. Obese adolescents (15 ± 1 years, BMI > 35 kg/m2) where randomized either to an intervention group (IG, n = 8; restricted diet and exercise) or to a usual care group (UC, n = 8). At the beginning and after 10 months of treatment HDL-mediated eNOS phosphorylation and cholesterol efflux capacity were evaluated. Results. Ten months of treatment resulted in a substantial weight loss (−31%), an improvement of endothelial function, and an increase in HDL-mediated eNOS-Ser1177 phosphorylation and RCT. A correlation between change in eNOS-Ser1177 phosphorylation or RCT and change in endothelial function was noted. Conclusion. A structured lifestyle intervention program improves antiatherosclerotic HDL functions, thereby positively influencing endothelial function. PMID:27965912

  17. Regulation of Endothelial Glutathione by ICAM-1 governs VEGF-A mediated eNOS Activity and Angiogenesis

    PubMed Central

    Langston, Will; Chidlow, John H.; Booth, Blake A.; Barlow, Shayne C.; Lefer, David J.; Patel, Rakesh P.; Kevil, Christopher G.

    2007-01-01

    Previous studies suggest that inflammatory cell adhesion molecules may modulate endothelial cell migration and angiogenesis through unknown mechanisms. Using a combination of in vitro and in vivo approaches, herein we reveal a novel redox sensitive mechanism by which ICAM-1 modulates endothelial GSH that controls VEGF-A induced eNOS activity, endothelial chemotaxis, and angiogenesis. In vivo disk angiogenesis assays showed attenuated VEGF-A mediated angiogenesis in ICAM-1−/− mice. Moreover, VEGF-A dependent chemotaxis, eNOS phosphorylation, and nitric oxide (NO) production were impaired in ICAM-1−/− MAEC compared to WT MAEC. Decreasing intracellular GSH in ICAM-1−/− MAEC to levels observed in WT MAEC with 150 μM buthionine sulfoximine (BSO) restored VEGF-A responses. Conversely, GSH supplementation of WT MAEC with 5 mM glutathione ethyl ester (GEE) mimicked defects observed in ICAM-1−/− cells. Deficient angiogenic responses in ICAM-1−/− cells were associated with increased expression of the lipid phosphatase, PTEN, consistent with antagonism of signaling pathways leading to eNOS activation. PTEN expression was also sensitive to GSH status, decreasing or increasing in proportion to intracellular GSH concentrations. These data suggest a novel role for ICAM-1 in modulating VEGF-A induced angiogenesis and eNOS activity through regulation of PTEN expression via modulation of intracellular GSH status. PMID:17291995

  18. Pretreatment with β-Boswellic Acid Improves Blood Stasis Induced Endothelial Dysfunction: Role of eNOS Activation

    PubMed Central

    Wang, Mingming; Chen, Minchun; Ding, Yi; Zhu, Zhihui; Zhang, Yikai; Wei, Peifeng; Wang, Jingwen; Qiao, Yi; Li, Liang; Li, Yuwen; Wen, Aidong

    2015-01-01

    Vascular endothelial cells play an important role in modulating anti-thrombus and maintaining the natural function of vascular by secreting many active substances. β-boswellic acid (β-BA) is an active triterpenoid compound from the extract of boswellia serrate. In this study, it is demonstrated that β-BA ameliorates plasma coagulation parameters, protects endothelium from blood stasis induced injury and prevents blood stasis induced impairment of endothelium-dependent vasodilatation. Moreover, it is found that β-BA significantly increases nitric oxide (NO) and cyclic guanosine 3’, 5’-monophosphate (cGMP) levels in carotid aortas of blood stasis rats. To stimulate blood stasis-like conditions in vitro, human umbilical vein endothelial cells (HUVECs) were exposed to transient oxygen and glucose deprivation (OGD). Treatment of β-BA significantly increased intracellular NO level. Western blot and immunofluorescence as well as immunohistochemistry reveal that β-BA increases phosphorylation of enzyme nitric oxide synthase (eNOS) at Ser1177. In addition, β-BA mediated endothelium-dependent vasodilatation can be markedly blocked by eNOS inhibitor L-NAME in blood stasis rats. In OGD treated HUEVCs, the protective effect of β-BA is attenuated by knockdown of eNOS. In conclusion, the above findings provide convincing evidence for the protective effects of β-BA on blood stasis induced endothelial dysfunction by eNOS signaling pathway. PMID:26482008

  19. Human red blood cells at work: identification and visualization of erythrocytic eNOS activity in health and disease.

    PubMed

    Cortese-Krott, Miriam M; Rodriguez-Mateos, Ana; Sansone, Roberto; Kuhnle, Gunter G C; Thasian-Sivarajah, Sivatharsini; Krenz, Thomas; Horn, Patrick; Krisp, Christoph; Wolters, Dirk; Heiß, Christian; Kröncke, Klaus-Dietrich; Hogg, Neil; Feelisch, Martin; Kelm, Malte

    2012-11-15

    A nitric oxide synthase (NOS)-like activity has been demonstrated in human red blood cells (RBCs), but doubts about its functional significance, isoform identity and disease relevance remain. Using flow cytometry in combination with the nitric oxide (NO)-imaging probe DAF-FM we find that all blood cells form NO intracellularly, with a rank order of monocytes > neutrophils > lymphocytes > RBCs > platelets. The observation of a NO-related fluorescence within RBCs was unexpected given the abundance of the NO-scavenger oxyhemoglobin. Constitutive normoxic NO formation was abolished by NOS inhibition and intracellular NO scavenging, confirmed by laser-scanning microscopy and unequivocally validated by detection of the DAF-FM reaction product with NO using HPLC and LC-MS/MS. Using immunoprecipitation, ESI-MS/MS-based peptide sequencing and enzymatic assay we further demonstrate that human RBCs contain an endothelial NOS (eNOS) that converts L-(3)H-arginine to L-(3)H-citrulline in a Ca(2+)/calmodulin-dependent fashion. Moreover, in patients with coronary artery disease, red cell eNOS expression and activity are both lower than in age-matched healthy individuals and correlate with the degree of endothelial dysfunction. Thus, human RBCs constitutively produce NO under normoxic conditions via an active eNOS isoform, the activity of which is compromised in patients with coronary artery disease.

  20. High salt medium activates RhoA/ROCK and downregulates eNOS expression via the upregulation of ADMA.

    PubMed

    Cao, Yu; Fang, Yuan; Mu, Jianjun; Liu, Xiaohong

    2016-07-01

    Endothelial dysfunction has an important role in the development and progression of salt-sensitive hypertension. Asymmetric dimethylarginine (ADMA), which is an endogenous inhibitor of nitric oxide synthase (NOS), has been demonstrated to be involved in the pathophysiological processes of endothelial dysfunction and salt‑sensitive hypertension. However, it is currently unclear how high salt intake may induce these processes. The present study investigated the effects of high salt medium on ADMA, endothelial NOS (eNOS) and the Ras homolog gene family, member A (RhoA)/Rho-associated protein kinase (ROCK) pathway in the EA.hy926 umbilical vein cell line. The results demonstrated that high salt medium significantly increased the concentration of ADMA, the expression of protein arginine methyltransferase 1 (PRMT‑1) and RhoA, and the activity of ROCK, and downregulated the expression of eNOS. Knockdown of PRMT-1 with small interfering RNA (siRNA) significantly abrogated the aforementioned effects. These results indicated that ADMA has a key role in high salt‑mediated activation of the RhoA/ROCK pathway and inhibition of eNOS biosynthesis. siRNA‑PRMT‑1 may be considered a novel remedy for the treatment of endothelial dysfunction.

  1. Role of PECAM-1 in the shear-stress-induced activation of Akt and the endothelial nitric oxide synthase (eNOS) in endothelial cells.

    PubMed

    Fleming, Ingrid; Fisslthaler, Beate; Dixit, Madhulika; Busse, Rudi

    2005-09-15

    The application of fluid shear stress to endothelial cells elicits the formation of nitric oxide (NO) and phosphorylation of the endothelial NO synthase (eNOS). Shear stress also elicits the enhanced tyrosine phosphorylation of endothelial proteins, especially of those situated in the vicinity of cell-cell contacts. Since a major constituent of these endothelial cell-cell contacts is the platelet endothelial cell adhesion molecule-1 (PECAM-1) we assessed the role of PECAM-1 in the activation of eNOS. In human endothelial cells, shear stress induced the tyrosine phosphorylation of PECAM-1 and enhanced the association of PECAM-1 with eNOS. Endothelial cell stimulation with shear stress elicited the phosphorylation of Akt and eNOS as well as of the AMP-activated protein kinase (AMPK). While the shear-stress-induced tyrosine phosphorylation of PECAM-1 as well as the serine phosphorylation of Akt and eNOS were abolished by the pre-treatment of cells with the tyrosine kinase inhibitor PP1 the phosphorylation of AMPK was unaffected. Down-regulation of PECAM-1 using a siRNA approach attenuated the shear-stress-induced phosphorylation of Akt and eNOS, as well as the shear-stress-induced accumulation of cyclic GMP levels while the shear-stress-induced phosphorylation of AMPK remained intact. A comparable attenuation of Akt and eNOS (but not AMPK) phosphorylation and NO production was also observed in endothelial cells generated from PECAM-1-deficient mice. These data indicate that the shear-stress-induced activation of Akt and eNOS in endothelial cells is modulated by the tyrosine phosphorylation of PECAM-1 whereas the shear-stress-induced phosphorylation of AMPK is controlled by an alternative signaling pathway.

  2. Purinergic glio-endothelial coupling during neuronal activity: role of P2Y1 receptors and eNOS in functional hyperemia in the mouse somatosensory cortex.

    PubMed

    Toth, Peter; Tarantini, Stefano; Davila, Antonio; Valcarcel-Ares, M Noa; Tucsek, Zsuzsanna; Varamini, Behzad; Ballabh, Praveen; Sonntag, William E; Baur, Joseph A; Csiszar, Anna; Ungvari, Zoltan

    2015-12-01

    Impairment of moment-to-moment adjustment of cerebral blood flow (CBF) via neurovascular coupling is thought to play a critical role in the genesis of cognitive impairment associated with aging and pathological conditions associated with accelerated cerebromicrovascular aging (e.g., hypertension, obesity). Although previous studies demonstrate that endothelial dysfunction plays a critical role in neurovascular uncoupling in these conditions, the role of endothelial NO mediation in neurovascular coupling responses is not well understood. To establish the link between endothelial function and functional hyperemia, neurovascular coupling responses were studied in mutant mice overexpressing or deficient in endothelial NO synthase (eNOS), and the role of P2Y1 receptors in purinergic glioendothelial coupling was assessed. We found that genetic depletion of eNOS (eNOS(-/-)) and pharmacological inhibition of NO synthesis significantly decreased the CBF responses in the somatosensory cortex evoked by whisker stimulation and by administration of ATP. Overexpression of eNOS enhanced NO mediation of functional hyperemia. In control mice, the selective and potent P2Y1 receptor antagonist MRS2179 attenuated both whisker stimulation-induced and ATP-mediated CBF responses, whereas, in eNOS(-/-) mice, the inhibitory effects of MRS2179 were blunted. Collectively, our findings provide additional evidence for purinergic glio-endothelial coupling during neuronal activity, highlighting the role of ATP-mediated activation of eNOS via P2Y1 receptors in functional hyperemia.

  3. p38 mitogen-activated protein kinase activates eNOS in endothelial cells by an estrogen receptor alpha-dependent pathway in response to black tea polyphenols.

    PubMed

    Anter, Elad; Chen, Kai; Shapira, Oz M; Karas, Richard H; Keaney, John F

    2005-05-27

    Black tea has been shown to improve endothelial function in patients with coronary artery disease and recent data indicate the polyphenol fraction of black tea enhances endothelial nitric oxide synthase (eNOS) activity through p38 MAP kinase (p38 MAPK) activation. Because the mechanisms for this phenomenon are not yet clear, we sought to elucidate the signaling events in response to black tea polyphenols. Bovine aortic endothelial cells (BAECs) exposed to black tea polyphenols demonstrated eNOS activation that was inhibited by the estrogen receptor (ER) antagonist ICI 182,780, and siRNA-mediated silencing of ER expression. Consistent with this observation, black tea polyphenols induced time-dependent phosphorylation of ERalpha on Ser-118 that was inhibited by ICI 182,780. Phosphorylation of ERalpha on Ser-118 was due to p38 MAP kinase (p38 MAPK) as, it was inhibited by SB203580 and overexpression of dominant-negative p38alpha MAPK. Conversely, constitutively active MKK6 induced p38 MAPK activation that recapitulated the effects of polyphenols by inducing ERalpha phosphorylation and downstream activation of Akt, and eNOS. The key role of ERalpha Ser-118 phosphorylation was confirmed in eNOS-transfected COS-7 cells, as polyphenol-induced eNOS activation required cotransfection with ERalpha subject to phosphorylation at Ser-118. This residue appeared critical for functional association of ERalpha with p38 MAPK as ERalpha with Ser-118 mutated to alanine could not form a complex with p38 MAPK. These findings suggest p38 MAP kinase-mediated eNOS activation requires ERalpha and these data uncover a new mechanism of ERalpha activation that has broad implications for NO bioactivity and endothelial cell phenotype.

  4. HMG-CoA reductase inhibitor rosuvastatin improves abnormal brain electrical activity via mechanisms involving eNOS.

    PubMed

    Seker, F B; Kilic, U; Caglayan, B; Ethemoglu, M S; Caglayan, A B; Ekimci, N; Demirci, S; Dogan, A; Oztezcan, S; Sahin, F; Yilmaz, B; Kilic, E

    2015-01-22

    Apart from its repressing effect on plasma lipid levels, 3-hydroxy-3-methyl glutaryl coenzyme A (HMG-CoA) reductase inhibitors exert neuroprotective functions in animal models of neurodegenerative disorders. In view of these promising observations, we were interested in whether HMG-CoA reductase inhibition would affect epileptiform activity in the brain. To elucidate this issue, atorvastatin, simvastatin and rosuvastatin were administered orally at a dose of 20 mg/kg each for 3 days and their anti-epileptic activities were tested and compared in rats. Epileptiform activity in the brain was induced by an intracortical penicillin G injection. Among HMG-CoA reductase inhibitors, simvastatin-treatment was less effective in terms of spike frequency as compared with atorvastatin- and rosuvastatin-treated animals. Atorvastatin treatment reduced spike frequencies and amplitudes significantly throughout the experiment. However, the most pronounced anti-epileptic effect was observed in rosuvastatin-treated animals, which was associated with improved blood-brain barrier (BBB) integrity, increased expression of endothelial nitric oxide synthase (eNOS) mRNA and decreased expressions of pro-apoptotic p53, Bax and caspase-3 mRNAs. Inhibition of eNOS activity with L-NG-Nitroarginine Methyl Ester (L-NAME) reversed the anti-epileptic effect of rosuvastatin significantly. However, L-NAME did not alter the effect of rosuvastatin on the levels of p53, Bax and caspase-3 mRNA expression. Here, we provide evidence that among HMG-CoA reductase inhibitors, rosuvastatin was the most effective statin on the reduction of epileptiform activity, which was associated with improved BBB permeability, increased expression of eNOS and decreased expressions of pro-apoptotic p53, Bax and caspase-3. Our observation also revealed that the anti-epileptic effect of rosuvastatin was dependent on the increased expression level of eNOS. The robust anti-epileptic effect encourages proof-of-concept studies with

  5. Impairment of the Ability of HDL From Patients With Metabolic Syndrome but Without Diabetes Mellitus to Activate eNOS: Correction by S1P Enrichment.

    PubMed

    Denimal, Damien; Monier, Serge; Brindisi, Marie-Claude; Petit, Jean-Michel; Bouillet, Benjamin; Nguyen, Amandine; Demizieux, Laurent; Simoneau, Isabelle; Pais de Barros, Jean-Paul; Vergès, Bruno; Duvillard, Laurence

    2017-05-01

    High-density lipoprotein (HDL) from nondiabetic patients with metabolic syndrome (MetS) displays abnormalities in their lipidome, such as triglyceride enrichment and sphingosine-1-phosphate depletion. We hypothesized that these abnormalities could impair the ability of HDL to stimulate endothelial nitric oxide synthase (eNOS). Compared with HDL from control subjects, HDL from normoglycemic patients with MetS was 39% richer in triglycerides (P<0.01) and 15% poorer in sphingosine-1-phosphate (P<0.05; n=23 in each group). eNOS activity, assessed by the conversion of L-[(3)H]arginine to L-[(3)H]citrulline, was 69% lower in human umbilical vein endothelial cells incubated with HDL from MetS patients than in cells incubated with HDL from controls (P<0.0001). In addition, the activating phosphorylation of eNOS at serine (Ser) 1177 and of Akt (protein kinase B) at Ser473 was 37% (P<0.001) and 39% (P<0.05) lower, respectively, with HDL from MetS patients. Sphingosine-1-phosphate enrichment of HDL from MetS patients restored their ability to stimulate eNOS activity (P<0.05), in relation with a significant increase in eNOS phosphorylation at Ser1177 (P<0.05) and in Akt phosphorylation at Ser473 (P=0.05). By contrast, triglyceride enrichment of HDL from control subjects did not modify eNOS activity (P=0.90) and phosphorylation at Ser1177 (P=0.87). We provide evidence that the activation of eNOS by HDL is decreased in MetS patients before the appearance of diabetes mellitus and that sphingosine-1-phosphate depletion of HDL is the main factor responsible for this defect. This has important consequences on the impairment of HDL functionality and antiatherogenic properties in these patients. © 2017 American Heart Association, Inc.

  6. Sodium nitrite exerts an antihypertensive effect and improves endothelial function through activation of eNOS in the SHR

    PubMed Central

    Ling, Wei Chih; Murugan, Dharmani Devi; Lau, Yeh Siang; Vanhoutte, Paul M.; Mustafa, Mohd Rais

    2016-01-01

    Sodium nitrite (NaNO2) induces relaxation in isolated arteries partly through an endothelium-dependent mechanism involving NO-eNOS-sGC-cGMP pathway. The present study was designed to investigate the effect of chronic NaNO2 administration on arterial systolic blood pressure (SBP) and vascular function in hypertensive rats. NaNO2 (150 mg L−1) was given in drinking water for four weeks to spontaneously (SHR) and Nω-Nitro-L-arginine methyl ester hydrochloride (L-NAME) treated hypertensive SD rats. Arterial SBP and vascular function in isolated aortae were studied. Total plasma nitrate/nitrite and vascular cyclic guanosine monophosphate (cGMP) levels were measured using commercially available assay kits. Vascular nitric oxide (NO) levels were evaluated by DAF-FM fluorescence while the proteins involved in endothelial nitric oxide synthase (eNOS) activation was determined by Western blotting. NaNO2 treatment reduced SBP, improved the impaired endothelium-dependent relaxation, increased plasma total nitrate/nitrite level and vascular tissue NO and cGMP levels in SHR. Furthermore, increased presence of phosphorylated eNOS and Hsp-90 was observed in NaNO2-treated SHR. The beneficial effect of nitrite treatment was not observed in L-NAME treated hypertensive SD rats. The present study provides evidence that chronic treatment of genetically hypertensive rats with NaNO2 improves endothelium-dependent relaxation in addition to its antihypertensive effect, partly through mechanisms involving activation of eNOS. PMID:27616322

  7. NOX4-dependent Hydrogen peroxide promotes shear stress-induced SHP2 sulfenylation and eNOS activation.

    PubMed

    Sánchez-Gómez, Francisco J; Calvo, Enrique; Bretón-Romero, Rosa; Fierro-Fernández, Marta; Anilkumar, Narayana; Shah, Ajay M; Schröder, Katrin; Brandes, Ralf P; Vázquez, Jesús; Lamas, Santiago

    2015-12-01

    Laminar shear stress (LSS) triggers signals that ultimately result in atheroprotection and vasodilatation. Early responses are related to the activation of specific signaling cascades. We investigated the participation of redox-mediated modifications and in particular the role of hydrogen peroxide (H2O2) in the sulfenylation of redox-sensitive phosphatases. Exposure of vascular endothelial cells to short periods of LSS (12 dyn/cm(2)) resulted in the generation of superoxide radical anion as detected by the formation of 2-hydroxyethidium by HPLC and its subsequent conversion to H2O2, which was corroborated by the increase in the fluorescence of the specific peroxide sensor HyPer. By using biotinylated dimedone we detected increased total protein sulfenylation in the bovine proteome, which was dependent on NADPH oxidase 4 (NOX4)-mediated generation of peroxide. Mass spectrometry analysis allowed us to identify the phosphatase SHP2 as a protein susceptible to sulfenylation under LSS. Given the dependence of FAK activity on SHP2 function, we explored the role of FAK under LSS conditions. FAK activation and subsequent endothelial NO synthase (eNOS) phosphorylation were promoted by LSS and both processes were dependent on NOX4, as demonstrated in lung endothelial cells isolated from NOX4-null mice. These results support the idea that LSS elicits redox-sensitive signal transduction responses involving NOX4-dependent generation of hydrogen peroxide, SHP2 sulfenylation, and ulterior FAK-mediated eNOS activation.

  8. Prunella vulgaris suppresses HG-induced vascular inflammation via Nrf2/HO-1/eNOS activation.

    PubMed

    Hwang, Sun Mi; Lee, Yun Jung; Yoon, Jung Joo; Lee, So Min; Kim, Jin Sook; Kang, Dae Gill; Lee, Ho Sub

    2012-01-01

    Vascular inflammation is an important factor which can promote diabetic complications. In this study, the inhibitory effects of aqueous extract from Prunella vulgaris (APV) on high glucose (HG)-induced expression of cell adhesion molecules in human umbilical vein endothelial cells (HUVEC) are reported. APV decreased HG-induced expression of intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), and E-selectin. APV also dose-dependently inhibited HG-induced adhesion of HL-60 monocytic cells. APV suppressed p65 NF-κB activation in HG-treated cells. APV significantly inhibited the formation of intracellular reactive oxygen species (ROS). HG-stimulated HUVEC secreted gelatinases, however, APV inhibited it. APV induced Akt phosphorylation as well as activation of heme oxygenase-1 (HO-1), eNOS, and nuclear factor E2-related factor 2 (Nrf2), which may protect vascular inflammation caused by HG. In conclusion, APV exerts anti-inflammatory effect via inhibition of ROS/NF-κB pathway by inducing HO-1 and eNOS expression mediated by Nrf2, thereby suggesting that Prunella vulgaris may be a possible therapeutic approach to the inhibition of diabetic vascular diseases.

  9. Cavin-2 regulates the activity and stability of endothelial nitric oxide synthase (eNOS) in angiogenesis.

    PubMed

    Boopathy, Gandhi T K; Kulkarni, Madhura; Ho, Sze Yuan; Boey, Adrian; Chua, Edmond Wei Min; Barathi, Veluchamy A; Carney, Tom J; Wang, Xiaomeng; Hong, Wanjin

    2017-09-14

    Angiogenesis is a highly regulated process for formation of new blood vessels from pre-existing ones. Angiogenesis is dysregulated in various pathologies, including age-related macular degeneration, arthritis, and cancer. Inhibiting pathological angiogenesis therefore represents a promising therapeutic strategy for treating these disorders, highlighting the need to study angiogenesis in more detail. To this end, identifying the genes essential for blood vessel formation and elucidating their function are crucial for a complete understanding of angiogenesis. Here, focusing on potential candidate genes for angiogenesis, we performed a morpholino-based genetic screen in zebrafish and identified Cavin-2, a membrane-bound phosphatidylserine-binding protein and critical organizer of caveolae (small microdomains in the plasma membrane), as a regulator of angiogenesis. Using endothelial cells, we show that Cavin-2 is required for in vitro angiogenesis and also for endothelial cell proliferation, migration, and invasion. We noted a high level of Cavin-2 expression in the neovascular tufts in the mouse model of oxygen-induced retinopathy, suggesting a role for Cavin-2 in pathogenic angiogenesis. Interestingly, we also found that Cavin-2 regulates the production of nitric oxide (NO) in endothelial cells by controlling the stability and activity of the endothelial nitric oxide synthase (eNOS) and that Cavin-2 knockdown cells produce much less NO than WT cells. Also, mass spectrometry, flow cytometry, and electron microscopy analyses indicated that Cavin-2 is secreted in endothelial microparticles (EMPs) and is required for EMP biogenesis. Taken together, our results indicate that in addition to its function in caveolae biogenesis, Cavin-2 plays a critical role in endothelial cell maintenance and function by regulating eNOS activity. Copyright © 2017, The American Society for Biochemistry and Molecular Biology.

  10. Redox-Sensitive Induction of Src/PI3-kinase/Akt and MAPKs Pathways Activate eNOS in Response to EPA:DHA 6:1

    PubMed Central

    Zgheel, Faraj; Alhosin, Mahmoud; Rashid, Sherzad; Burban, Mélanie; Auger, Cyril; Schini-Kerth, Valérie B.

    2014-01-01

    Aims Omega-3 fatty acid products containing eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) have vasoprotective effects, in part, by stimulating the endothelial formation of nitric oxide (NO). This study determined the role of the EPA:DHA ratio and amount, and characterized the mechanism leading to endothelial NO synthase (eNOS) activation. Methods and Results EPA:DHA 6∶1 and 9∶1 caused significantly greater endothelium-dependent relaxations in porcine coronary artery rings than EPA:DHA 3∶1, 1∶1, 1∶3, 1∶6, 1∶9, EPA and DHA alone, and EPA:DHA 6∶1 with a reduced EPA + DHA amount, which were inhibited by an eNOS inhibitor. Relaxations to EPA:DHA 6∶1 were insensitive to cyclooxygenase inhibition, and reduced by inhibitors of either oxidative stress, Src kinase, PI3-kinase, p38 MAPK, MEK, or JNK. EPA:DHA 6∶1 induced phosphorylation of Src, Akt, p38 MAPK, ERK, JNK and eNOS; these effects were inhibited by MnTMPyP. EPA:DHA 6∶1 induced the endothelial formation of ROS in coronary artery sections as assessed by dihydroethidium, and of superoxide anions and hydrogen peroxide in cultured endothelial cells as assessed by electron spin resonance with the spin probe CMH, and the Amplex Red based assay, respectively. Conclusion Omega-3 fatty acids cause endothelium-dependent NO-mediated relaxations in coronary artery rings, which are dependent on the EPA:DHA ratio and amount, and involve an intracellular activation of the redox-sensitive PI3-kinase/Akt and MAPKs pathways to activate eNOS. PMID:25133540

  11. A2B adenosine receptor contributes to penile erection via PI3K/AKT signaling cascade-mediated eNOS activation

    PubMed Central

    Wen, Jiaming; Grenz, Almut; Zhang, Yujin; Dai, Yingbo; Kellems, Rodney E.; Blackburn, Michael R.; Eltzschig, Holger K.; Xia, Yang

    2011-01-01

    Normal penile erection is under the control of multiple factors and signaling pathways. Although adenosine signaling is implicated in normal and abnormal penile erection, the exact role and the underlying mechanism for adenosine signaling in penile physiology remain elusive. Here we report that shear stress leads to increased adenosine release from endothelial cells. Subsequently, we determined that ecto-5′-nucleotidase (CD73) is a key enzyme required for the production of elevated adenosine from ATP released by shear-stressed endothelial cells. Mechanistically, we demonstrate that shear stress-mediated elevated adenosine functions through the adenosine A2B receptor (A2BR) to activate the PI3K/AKT signaling cascade and subsequent increased endothelial nitric oxide synthase (eNOS) phosphorylation. These in vitro studies led us to discover further that adenosine was induced during sustained penile erection and contributes to PI3K/AKT activation and subsequent eNOS phosphorylation via A2BR signaling in intact animal. Finally, we demonstrate that lowering adenosine in wild-type mice or genetic deletion of A2BR in mutant mice significantly attenuated PI3K/AKT activation, eNOS phosphorylation, and subsequent impaired penile erection featured with the reduction of ratio of maximal intracavernosal pressure to systemic arterial pressure from 0.49 ± 0.03 to 0.41 ± 0.05 and 0.38 ± 0.04, respectively (both P<0.05). Overall, using biochemical, cellular, genetic, and physiological approaches, our findings reveal that adenosine is a novel molecule signaling via A2BR activation, contributing to penile erection via PI3K/AKT-dependent eNOS activation. These studies suggest that this signaling pathway may be a novel therapeutic target for erectile disorders.—Wen, J., Grenz, A., Zhang, Y., Dai, Y., Kellems, R. E., Blackburn, M. R., Eltzschig, H. K., Xia, Y. A2B adenosine receptor contributes to penile erection via PI3K/AKT signaling cascade-mediated eNOS activation. PMID

  12. Ibuprofen arginate retains eNOS substrate activity and reverses endothelial dysfunction: implications for the COX-2/ADMA axis.

    PubMed

    Kirkby, Nicholas S; Tesfai, Abel; Ahmetaj-Shala, Blerina; Gashaw, Hime H; Sampaio, Walkyria; Etelvino, Gisele; Leão, Nádia Miricéia; Santos, Robson A; Mitchell, Jane A

    2016-12-01

    Nonsteroidal antiinflammatory drugs, including ibuprofen, are among the most commonly used medications and produce their antiinflammatory effects by blocking cyclooxygenase (COX)-2. Their use is associated with increased risk of heart attacks caused by blocking COX-2 in the vasculature and/or kidney, with our recent work implicating the endogenous NOS inhibitor asymmetric dimethylarginine (ADMA), a cardiotoxic hormone whose effects can be prevented by l-arginine. The ibuprofen salt ibuprofen arginate (Spididol) was created to increase solubility but we suggest that it could also augment the NO pathway through codelivery of arginine. Here we investigated the idea that ibuprofen arginate can act to simultaneously inhibit COX-2 and preserve the NO pathway. Ibuprofen arginate functioned similarly to ibuprofen sodium for inhibition of mouse/human COX-2, but only ibuprofen arginate served as a substrate for NOS. Ibuprofen arginate but not ibuprofen sodium also reversed the inhibitory effects of ADMA and N(G)-nitro-l-arginine methyl ester on inducible NOS (macrophages) and endothelial NOS in vitro (aorta) and in vivo (blood pressure). These observations show that ibuprofen arginate provides, in one preparation, a COX-2 inhibitor and NOS substrate that could act to negate the harmful cardiovascular consequences mediated by blocking renal COX-2 and increased ADMA. While remarkably simple, our findings are potentially game-changing in the nonsteroidal antiinflammatory drug arena.-Kirkby, N. S., Tesfai, A., Ahmetaj-Shala, B., Gashaw, H. H., Sampaio, W., Etelvino, G., Leão, N. M., Santos, R. A., Mitchell, J. A. Ibuprofen arginate retains eNOS substrate activity and reverses endothelial dysfunction: implications for the COX-2/ADMA axis. © The Author(s).

  13. MiR-21 is induced in endothelial cells by shear stress and modulates apoptosis and eNOS activity

    SciTech Connect

    Weber, Martina; Baker, Meredith B.; Moore, Jeffrey P.; Searles, Charles D.

    2010-03-19

    Mechanical forces associated with blood flow play an important role in regulating vascular signaling and gene expression in endothelial cells (ECs). MicroRNAs (miRNAs) are a class of noncoding RNAs that posttranscriptionally regulate the expression of genes involved in diverse cell functions, including differentiation, growth, proliferation, and apoptosis. miRNAs are known to have an important role in modulating EC biology, but their expression and functions in cells subjected to shear stress conditions are unknown. We sought to determine the miRNA expression profile in human ECs subjected to unidirectional shear stress and define the role of miR-21 in shear stress-induced changes in EC function. TLDA array and qRT-PCR analysis performed on HUVECs exposed to prolonged unidirectional shear stress (USS, 24 h, 15 dynes/cm{sup 2}) identified 13 miRNAs whose expression was significantly upregulated (p < 0.05). The miRNA with the greatest change was miR-21; it was increased 5.2-fold (p = 0.002) in USS-treated versus control cells. Western analysis demonstrated that PTEN, a known target of miR-21, was downregulated in HUVECs exposed to USS or transfected with pre-miR-21. Importantly, HUVECs overexpressing miR-21 had decreased apoptosis and increased eNOS phosphorylation and nitric oxide (NO{sup {center_dot}}) production. These data demonstrate that shear stress forces regulate the expression of miRNAs in ECs, and that miR-21 influences endothelial biology by decreasing apoptosis and activating the NO{sup {center_dot}} pathway. These studies advance our understanding of the mechanisms by which shear stress forces modulate vascular homeostasis.

  14. Ibuprofen arginate retains eNOS substrate activity and reverses endothelial dysfunction: implications for the COX-2/ADMA axis

    PubMed Central

    Kirkby, Nicholas S.; Tesfai, Abel; Ahmetaj-Shala, Blerina; Gashaw, Hime H.; Sampaio, Walkyria; Etelvino, Gisele; Leão, Nádia Miricéia; Santos, Robson A.; Mitchell, Jane A.

    2016-01-01

    Nonsteroidal antiinflammatory drugs, including ibuprofen, are among the most commonly used medications and produce their antiinflammatory effects by blocking cyclooxygenase (COX)-2. Their use is associated with increased risk of heart attacks caused by blocking COX-2 in the vasculature and/or kidney, with our recent work implicating the endogenous NOS inhibitor asymmetric dimethylarginine (ADMA), a cardiotoxic hormone whose effects can be prevented by l-arginine. The ibuprofen salt ibuprofen arginate (Spididol) was created to increase solubility but we suggest that it could also augment the NO pathway through codelivery of arginine. Here we investigated the idea that ibuprofen arginate can act to simultaneously inhibit COX-2 and preserve the NO pathway. Ibuprofen arginate functioned similarly to ibuprofen sodium for inhibition of mouse/human COX-2, but only ibuprofen arginate served as a substrate for NOS. Ibuprofen arginate but not ibuprofen sodium also reversed the inhibitory effects of ADMA and NG-nitro-l-arginine methyl ester on inducible NOS (macrophages) and endothelial NOS in vitro (aorta) and in vivo (blood pressure). These observations show that ibuprofen arginate provides, in one preparation, a COX-2 inhibitor and NOS substrate that could act to negate the harmful cardiovascular consequences mediated by blocking renal COX-2 and increased ADMA. While remarkably simple, our findings are potentially game-changing in the nonsteroidal antiinflammatory drug arena.—Kirkby, N. S., Tesfai, A., Ahmetaj-Shala, B., Gashaw, H. H., Sampaio, W., Etelvino, G., Leão, N. M., Santos, R. A., Mitchell, J. A. Ibuprofen arginate retains eNOS substrate activity and reverses endothelial dysfunction: implications for the COX-2/ADMA axis. PMID:27601438

  15. eNOS activation induced by a polyphenol-rich grape skin extract in porcine coronary arteries.

    PubMed

    Madeira, Socorro Vanesca Frota; Auger, Cyril; Anselm, Eric; Chataigneau, Marta; Chataigneau, Thierry; Soares de Moura, Roberto; Schini-Kerth, Valérie B

    2009-01-01

    Drinking red wine is associated with a decreased mortality from coronary heart diseases. This study examined whether polyphenols contained in a grape skin extract (GSE) triggered the endothelial formation of nitric oxide (NO) and investigated the underlying mechanism. Vascular reactivity was assessed in organ chambers using porcine coronary artery rings in the presence of indomethacin (a cyclooxygenase inhibitor) and charybdotoxin plus apamin (inhibitors of endothelium-derived hyperpolarizing factor-mediated responses). The phosphorylation level of Src, Akt and endothelial NO synthase (eNOS) were assessed by Western blot analysis, and the formation of reactive oxygen species (ROS) was investigated using dihydroethidine and dichlorodihydrofluorescein. GSE-induced endothelium-dependent relaxations were abolished by N(G)-nitro-L-arginine (an eNOS inhibitor) and ODQ (a soluble guanylyl cyclase inhibitor), and they were reduced by MnTMPyP, polyethyleneglycol catalase, PP2 (an inhibitor of Src kinase) and wortmannin (an inhibitor of phosphoinositide 3-kinase). GSE caused phosphorylation of Src, which was prevented by MnTMPyP. It also caused phosphorylation of Akt and eNOS, which were prevented by MnTMPyP, polyethyleneglycol catalase, PP2, wortmannin and LY294002. GSE elicited the formation of ROS in native and cultured endothelial cells, which was prevented by MnTMPyP. GSE causes endothelium-dependent NO-mediated relaxations of coronary arteries. This effect involves the intracellular formation of ROS in endothelial cells leading to the Src kinase/phosphoinositide 3-kinase/Akt-dependent phosphorylation of eNOS.

  16. Functional significance of differential eNOS translocation

    PubMed Central

    Sánchez, Fabiola A.; Savalia, Nirav B.; Durán, Ricardo G.; Lal, Brajesh K.; Boric, Mauricio P.; Durán, Walter N.

    2006-01-01

    Nitric oxide (NO) regulates flow and permeability. ACh and platelet-activating factor (PAF) lead to endothelial NO synthase (eNOS) phosphorylation and NO release. While ACh causes only vasodilation, PAF induces vasoconstriction and hyperpermeability. The key differential signaling mechanisms for discriminating between vasodilation and hyperpermeability are unknown. We tested the hypothesis that differential translocation may serve as a regulatory mechanism of eNOS to determine specific vascular responses. We used ECV-304 cells permanently transfected with eNOS-green fluorescent protein (ECVeNOS-GFP) and demonstrated that the agonists activate eNOS and reproduce their characteristic endothelial permeability effects in these cells. We evaluated eNOS localization by lipid raft analysis and immunofluorescence microscopy. After PAF and ACh, eNOS moves away from caveolae. eNOS distributes both in the plasma membrane and Golgi in control cells. ACh (10−5 M, 10−4 M) translocated eNOS preferentially to the trans-Golgi network (TGN) and PAF (10−7 M) preferentially to the cytosol. We suggest that PAF-induced eNOS translocation preferentially to cytosol reflects a differential signaling mechanism related to changes in permeability, whereas ACh-induced eNOS translocation to the TGN is related to vasodilation. PMID:16679407

  17. Grape juice causes endothelium-dependent relaxation via a redox-sensitive Src- and Akt-dependent activation of eNOS.

    PubMed

    Anselm, Eric; Chataigneau, Marta; Ndiaye, Mamadou; Chataigneau, Thierry; Schini-Kerth, Valérie B

    2007-01-15

    An enhanced endothelial formation of nitric oxide (NO) and endothelium-derived hyperpolarizing factor (EDHF), is thought to contribute to the protective effect of moderate consumption of red wine on coronary diseases. The present study has characterized endothelium-dependent relaxations to Concord grape juice (CGJ), a non-alcoholic rich source of grape-derived polyphenols, in the coronary artery. Porcine coronary artery rings were suspended in organ chambers for the measurement of changes in isometric tension in the presence of indomethacin. NO formation was assessed by electron spin resonance spectroscopy, and the phosphorylation of Src, Akt and endothelial NO synthase (eNOS) by Western blot analysis in cultured endothelial cells. Endothelium-dependent relaxations to CGJ were slightly but significantly reduced by L-NA, not affected by charybdotoxin (CTX) plus apamin (APA, two inhibitors of EDHF-mediated responses) whereas the combination of L-NA, CTX plus APA reduced maximal relaxation to about 50%. In the presence of CTX plus APA, relaxations to CGJ were markedly reduced by the membrane permeant mimetic of superoxide dismutase (SOD), MnTMPyP, the membrane permeant analogue of catalase polyethyleneglycol-catalase (PEG-catalase), PP2, an inhibitor of Src kinase, and by wortmannin, an inhibitor of the PI3-kinase. CGJ stimulated the formation of reactive oxygen species and the N(omega)-nitro-L-arginine-, PP2- and wortmannin-sensitive formation of NO in endothelial cells. The formation of NO was associated with a redox-sensitive and time-dependent phosphorylation of Src, Akt and eNOS. CGJ induces endothelium-dependent relaxations of coronary arteries, which involve a NO-mediated component and also, to a minor extent, an EDHF-mediated component. In addition, CGJ-induced NO formation is due to the redox-sensitive activation of Src kinase with the subsequent PI3-kinase/Akt-dependent phosphorylation of eNOS.

  18. Effects of chronic treatment with the eNOS stimulator Impaza on penis length and sexual behaviors in rats with a high baseline of sexual activity.

    PubMed

    Chu, X; Zhavbert, E S; Dugina, J L; Kheyfets, I A; Sergeeva, S A; Epstein, O I; Agmo, A

    2014-01-01

    Endothelial nitric oxide synthase (eNOS) has an important role in erection, and it also affects aspects of sexual behavior. In this experiment, we determined whether a compound enhancing the activity of eNOS, Impaza, could stimulate any aspect of sexual behavior and increase penis length in rats with a high baseline of sexual activity. For comparison, the PDE5 inhibitor sildenafil was included. Male rats were orally treated with Impaza or sildenafil for 28 days. Impaza (3 ml kg(-1)) was given daily while sildenafil (3 mg kg(-1)) was given twice weekly. Tests for sexual incentive motivation and copulatory behavior were performed just before drug treatment and at days 7, 14 and 28 of treatment. In addition, the length of the protruding penis at mount, intromission and ejaculation was measured. Impaza but not sildenafil increased penis length at mount after 14 and 28 days of treatment. The compounds failed to modify sexual incentive motivation or copulatory behavior. It is suggested that Impaza enhanced intracavernous pressure, as such a pressure increase is the most likely explanation for enhanced penis length at mount. This effect, together with an absence of motivational actions, suggests that Impaza may be the most valuable treatment for erectile dysfunction.

  19. Intact mitochondrial Ca2+ uniport is essential for agonist-induced activation of endothelial nitric oxide synthase (eNOS)

    PubMed Central

    Charoensin, Suphachai; Eroglu, Emrah; Opelt, Marissa; Bischof, Helmut; Madreiter-Sokolowski, Corina T.; Kirsch, Andrijana; Depaoli, Maria R.; Frank, Saša; Schrammel, Astrid; Mayer, Bernd; Waldeck-Weiermair, Markus; Graier, Wolfgang F.; Malli, Roland

    2017-01-01

    Mitochondrial Ca2+ uptake regulates diverse endothelial cell functions and has also been related to nitric oxide (NO•) production. However, it is not entirely clear if the organelles support or counteract NO• biosynthesis by taking up Ca2+. The objective of this study was to verify whether or not mitochondrial Ca2+ uptake influences Ca2+-triggered NO• generation by endothelial NO• synthase (eNOS) in an immortalized endothelial cell line (EA.hy926), respective primary human umbilical vein endothelial cells (HUVECs) and eNOS-RFP (red fluorescent protein) expressing human embryonic kidney (HEK293) cells. We used novel genetically encoded fluorescent NO• probes, the geNOps, and Ca2+ sensors to monitor single cell NO• and Ca2+ dynamics upon cell treatment with ATP, an inositol 1,4,5-trisphosphate (IP3)-generating agonist. Mitochondrial Ca2+ uptake was specifically manipulated by siRNA-mediated knock-down of recently identified key components of the mitochondrial Ca2+ uniporter machinery. In endothelial cells and the eNOS-RFP expressing HEK293 cells we show that reduced mitochondrial Ca2+ uptake upon the knock-down of the mitochondrial calcium uniporter (MCU) protein and the essential MCU regulator (EMRE) yield considerable attenuation of the Ca2+-triggered NO• increase independently of global cytosolic Ca2+ signals. The knock-down of mitochondrial calcium uptake 1 (MICU1), a gatekeeper of the MCU, increased both mitochondrial Ca2+ sequestration and Ca2+-induced NO• signals. The positive correlation between mitochondrial Ca2+ elevation and NO• production was independent of eNOS phosphorylation at serine1177. Our findings emphasize that manipulating mitochondrial Ca2+ uptake may represent a novel strategy to control eNOS-mediated NO• production. PMID:27923677

  20. Wall stretch and thromboxane A₂ activate NO synthase (eNOS) in pulmonary arterial smooth muscle cells via H₂O₂ and Akt-dependent phosphorylation.

    PubMed

    Kim, Hae Jin; Yoo, Hae Young; Jang, Ji Hyun; Lin, Hai Yue; Seo, Eun Yeong; Zhang, Yin Hua; Kim, Sung Joon

    2016-04-01

    Pulmonary arteries (PAs) have high compliance, buffering the wide ranges of blood flow. Here, we addressed a hypothesis that PA smooth muscle cells (PASMCs) express nitric oxide synthases (NOS) that might be activated by mechanical stress and vasoactive agonists. In the myograph study of endothelium-denuded rat PAs, NOS inhibition (L-NAME) induced strong contraction (96 % of 80 mM KCl-induced contraction (80K)) in the presence of 5 nM U46619 (thromboxane A2 (TXA2) analogue) with relatively high basal stretch (2.94 mN, S(+)). With lower basal stretch (0.98 mN, S(-)), however, L-NAME application following U46619 (TXA2/L-NAME) induced weak contraction (27 % of 80K). Inhibitors of nNOS and iNOS had no such effect in S(+) PAs. In endothelium-denuded S(+) mesenteric and renal arteries, TXA2/L-NAME-induced contraction was only 18 and 21 % of 80K, respectively. Expression of endothelial-type NOS (eNOS) in rat PASMCs was confirmed by RT-PCR and immunohistochemistry. Even in S(-) PAs, pretreatment with H2O2 (0.1-10 μM) effectively increased the sensitivity to TXA2/L-NAME (105 % of 80K). Vice versa, NADPH oxidase inhibitors, reactive oxygen species scavengers, or an Akt inhibitor (SC-66) suppressed TXA2/L-NAME-induced contraction in S(+) PAs. In a human PASMC line, immunoblot analysis showed the following: (1) eNOS expression, (2) Ser(1177) phosphorylation by U46619 and H2O2, and (3) Akt activation (Ser(473) phosphorylation) by U46619. In the cell-attached patch clamp study, H2O2 facilitated membrane stretch-activated cation channels in rat PASMCs. Taken together, the muscular eNOS in PAs can be activated by TXA2 and mechanical stress via H2O2 and Akt-mediated signaling, which may counterbalance the contractile signals from TXA2 and mechanical stimuli.

  1. Long persistence effects of geomagnetic activity

    NASA Astrophysics Data System (ADS)

    Wrenn, Gordon L.

    1990-03-01

    The identification of the physical processes which perturb the dynamic equilibrium of the charged particle populations in the terrestrial magnetosphere is investigated. A planetary index was used and it was proved that the introduction of a persistence factor for a derived index, a time weighted accumulation of recent values, gives a better correlation with an estimation of characteristic persistence times in order to establish the temporal response of observed effects in relation to available measures of geomagnetic activity. The analysis procedure was illustrated by results pertaining to ionospheric foF2, cold plasma concentration at geosynchronous orbit and ring current strength.

  2. Natural product extract of Dicksonia sellowiana induces endothelium-dependent relaxations by a redox-sensitive Src- and Akt-dependent activation of eNOS in porcine coronary arteries.

    PubMed

    Rattmann, Yanna D; Anselm, Eric; Kim, Jong-Hun; Dal-Ros, Stéphanie; Auger, Cyril; Miguel, Obdulio G; Santos, Adair R S; Chataigneau, Thierry; Schini-Kerth, Valérie B

    2012-01-01

    The consumption of polyphenol-rich food is associated with a decreased mortality from coronary diseases. This study examined whether a standardized hydroalcoholic extract of Dicksonia sellowiana (HEDS) triggered endothelium-dependent relaxations in porcine coronary artery rings and characterized the underlying mechanism. The phosphorylation level of Src, Akt and eNOS was assessed by Western blot analysis, the formation of reactive oxygen species by dihydroethidine staining and the level of eNOS Ser1177 phosphorylation by immunohistochemical staining in sections of coronary arteries. HEDS-induced endothelium-dependent relaxations were strongly reduced by Nω-nitro-L-arginine, an eNOS inhibitor, and by its combination with charybdotoxin plus apamin, inhibitors of endothelium-derived hyperpolarizing factor-mediated responses. These relaxations were markedly reduced by MnTMPyP (a membrane-permeant mimetic of superoxide dismutase), polyethylene glycol catalase (PEG-catalase; a membrane-permeant analog of catalase), and by wortmannin (an inhibitor of PI3-kinase). HEDS-induced sustained phosphorylation of Akt and eNOS in endothelial cells was abolished by MnTMPyP, PEG-catalase and wortmannin. Oral administration of HEDS induced a significant decrease of mean arterial pressure in spontaneously hypertensive rats. These findings indicate that HEDS caused endothelium-dependent relaxations of coronary artery rings through the redox-sensitive activation of the endothelial PI3-kinase/Akt pathway leading to the subsequent activation of eNOS by phosphorylation. HEDS also has antihypertensive properties. Copyright © 2012 S. Karger AG, Basel.

  3. Electrodermal activity in patients with persistent insomnia.

    PubMed

    Broman; Hetta

    1994-09-01

    In order to evaluate daytime arousal in patients with persistent insomnia, electrodermal activity (EDA) was measured in a habituation paradigm (21 tones, 80 dB, 1 s) in forty patients with persistent insomnia and in twenty normal subjects. Results showed that the patients had higher EDA than the controls implying a higher arousal level in the patients. Among the patients the distribution of trials to a habituation criterion was bimodal and patients were separated into habituators (n = 24) and non-habituators (n = 16). Non-habituators had significantly higher EDA than habituators and they also had a shorter nocturnal sleep time. Thus, daytime arousal was, significantly related to nocturnal sleep in the patients. Both patients with Psychophysiological Insomnia and Insomnia Associated with Psychiatric Disorders had higher EDA than the controls, and EDA was also significantly related to sleep in both groups. Results lend further support for the notion of an excessive daytime arousal, which may serve as a common predisposing factor in the initiation or maintenance of persistent insomnia.

  4. CRLI induces vascular smooth muscle relaxation and suggests a dual mechanism of eNOS activation by legume lectins via muscarinic receptors and shear stress.

    PubMed

    Rocha, Bruno A M; Barroso-Neto, Ito L; Teixeira, Claudener S; Santiago, Mayara Q; Pires, Alana F; Souza, Luiz A G; Nascimento, Kyria S; Sampaio, Alexandre H; Delatorre, Plinio; Assreuy, Ana M S; Cavada, Benildo S

    2015-01-01

    Lectins are proteins able to recognize carbohydrates, without modifying their structure, via the carbohydrate-recognition domain (CRD). Here, the three-dimensional structure of the mannose-binding lectin isolated from Cymbosema roseum (CRLI) was determined with X-man molecule modeled into the carbohydrate recognition domain. CRLI relaxant activity in thoracic rat aorta was also investigated, and based on the results, a molecular docking of CRLI with heparan sulfate was performed to investigate the possible interaction with mechanoreceptors involved in vasorelaxation. CRLI (IC₅₀=12.4 μg mL(-)(1)) elicited vasorelaxant response (96%) in endothelialized rat aorta contracted with phenylephrine. Endothelium-derived relaxant factors, extracellular calcium (Ca(2+)e) and muscarinic receptors were also evaluated as putative participants in the CRLI relaxant effect. CRLI relaxant effect was blocked by L-NAME, a nonselective inhibitor of nitric oxide synthase (NOS), and partially inhibited in a calcium-free solution (0Ca) and by atropine, but it remained unchanged in the presence of indomethacin and TEA. In summary, our data suggest interaction between CRLI and muscarinic receptors located in vascular endothelial cells leading to NOS activation triggered by a mechanism that involves Ca(2+)e along with the ability of CRLI to interact with heparan sulfate, a highly rated mechanoreceptor involved in eNOS activation. Copyright © 2014. Published by Elsevier Inc.

  5. BET Bromodomain Suppression Inhibits VEGF-induced Angiogenesis and Vascular Permeability by Blocking VEGFR2-mediated Activation of PAK1 and eNOS

    PubMed Central

    Huang, Mingcheng; Qiu, Qian; Xiao, Youjun; Zeng, Shan; Zhan, Mingying; Shi, Maohua; Zou, Yaoyao; Ye, Yujin; Liang, Liuqin; Yang, Xiuyan; Xu, Hanshi

    2016-01-01

    The tyrosine kinase receptor vascular endothelial growth factor receptor 2 (VEGFR2) is a critical modulator of angiogenesis. Increasing evidence indicate the important role of bromodomain and extra-terminal domain (BET) of chromatin adaptors in regulating tumor growth and inflammatory response. However, whether BET proteins have a role in angiogenesis and endothelial permeability is unclear. In this study, we observed that treatment with JQ1, a specific BET inhibitor, suppressed in vitro tube formation of human umbilical vein endothelial cells (HUVECs) and in vivo angiogenesis in a Matrigel plug and oxygen-induced retinopathy neovascularization. JQ1 attenuated the VEGF-induced decrease in TEER in HUVECs and prevented Evans blue dye leakage in the VEGF-induced Miles assay in athymic Balb/c nude mice. BET inhibition with JQ1 or shRNA for Brd2 or Brd4 suppressed VEGF-induced migration, proliferation, and stress fiber formation of HUVECs. Furthermore, BET inhibition suppressed phosphorylation of VEGFR2 and PAK1, as well as eNOS activation in VEGF-stimulated HUVECs. Inhibition with VEGFR2 and PAK1 also reduced migration and proliferation, and attenuated the VEGF-induced decrease in TEER. Thus, our observations suggest the important role of BET bromodomain in regulating VEGF-induced angiogenesis. Strategies that target the BET bromodomain may provide a new therapeutic approach for angiogenesis-related diseases. PMID:27044328

  6. Long-term persistence of solar activity

    NASA Technical Reports Server (NTRS)

    Ruzmaikin, Alexander; Feynman, Joan; Robinson, Paul

    1994-01-01

    We examine the question of whether or not the non-periodic variations in solar activity are caused by a white-noise, random process. The Hurst exponent, which characterizes the persistence of a time series, is evaluated for the series of C-14 data for the time interval from about 6000 BC to 1950 AD. We find a constant Hurst exponent, suggesting that solar activity in the frequency range from 100 to 3000 years includes an important continuum component in addition to the well-known periodic variations. The value we calculate, H approximately 0.8, is significantly larger than the value of 0.5 that would correspond to variations produced by a white-noise process. This value is in good agreement with the results for the monthly sunspot data reported elsewhere, indicating that the physics that produces the continuum is a correlated random process and that it is the same type of process over a wide range of time interval lengths.

  7. Long-term persistence of solar activity

    NASA Technical Reports Server (NTRS)

    Ruzmaikin, Alexander; Feynman, Joan; Robinson, Paul

    1994-01-01

    We examine the question of whether or not the non-periodic variations in solar activity are caused by a white-noise, random process. The Hurst exponent, which characterizes the persistence of a time series, is evaluated for the series of C-14 data for the time interval from about 6000 BC to 1950 AD. We find a constant Hurst exponent, suggesting that solar activity in the frequency range from 100 to 3000 years includes an important continuum component in addition to the well-known periodic variations. The value we calculate, H approximately 0.8, is significantly larger than the value of 0.5 that would correspond to variations produced by a white-noise process. This value is in good agreement with the results for the monthly sunspot data reported elsewhere, indicating that the physics that produces the continuum is a correlated random process and that it is the same type of process over a wide range of time interval lengths.

  8. Degassing Processes at Persistently Active Explosive Volcanoes

    NASA Astrophysics Data System (ADS)

    Smekens, Jean-Francois

    Among volcanic gases, sulfur dioxide (SO2) is by far the most commonly measured. More than a monitoring proxy for volcanic degassing, SO 2 has the potential to alter climate patterns. Persistently active explosive volcanoes are characterized by short explosive bursts, which often occur at periodic intervals numerous times per day, spanning years to decades. SO 2 emissions at those volcanoes are poorly constrained, in large part because the current satellite monitoring techniques are unable to detect or quantify plumes of low concentration in the troposphere. Eruption plumes also often show high concentrations of ash and/or aerosols, which further inhibit the detection methods. In this work I focus on quantifying volcanic gas emissions at persistently active explosive volcanoes and their variations over short timescales (minutes to hours), in order to document their contribution to natural SO2 flux as well as investigate the physical processes that control their behavior. In order to make these measurements, I first develop and assemble a UV ground-based instrument, and validate it against an independently measured source of SO2 at a coal-burning power plant in Arizona. I establish a measurement protocol and demonstrate that the instrument measures SO 2 fluxes with < 20 % error. Using the same protocol, I establish a record of the degassing patterns at Semeru volcano (Indonesia), a volcano that has been producing cycles of repeated explosions with periods of minutes to hours for the past several decades. Semeru produces an average of 21-71 tons of SO2 per day, amounting to a yearly output of 8-26 Mt. Using the Semeru data, along with a 1-D transient numerical model of magma ascent, I test the validity of a model in which a viscous plug at the top of the conduit produces cycles of eruption and gas release. I find that it can be a valid hypothesis to explain the observed patterns of degassing at Semeru. Periodic behavior in such a system occurs for a very narrow range

  9. Persistent neural activity in head direction cells

    NASA Technical Reports Server (NTRS)

    Taube, Jeffrey S.; Bassett, Joshua P.; Oman, C. M. (Principal Investigator)

    2003-01-01

    Many neurons throughout the rat limbic system discharge in relation to the animal's directional heading with respect to its environment. These so-called head direction (HD) cells exhibit characteristics of persistent neural activity. This article summarizes where HD cells are found, their major properties, and some of the important experiments that have been conducted to elucidate how this signal is generated. The number of HD and angular head velocity cells was estimated for several brain areas involved in the generation of the HD signal, including the postsubiculum, anterior dorsal thalamus, lateral mammillary nuclei and dorsal tegmental nucleus. The HD cell signal has many features in common with what is known about how neural integration is accomplished in the oculomotor system. The nature of the HD cell signal makes it an attractive candidate for using neural network models to elucidate the signal's underlying mechanisms. The conditions that any network model must satisfy in order to accurately represent how the nervous system generates this signal are highlighted and areas where key information is missing are discussed.

  10. Wetting Transitions Displayed by Persistent Active Particles

    NASA Astrophysics Data System (ADS)

    Sepúlveda, Néstor; Soto, Rodrigo

    2017-08-01

    A lattice model for active matter is studied numerically, showing that it displays wetting transitions between three distinctive phases when in contact with an impenetrable wall. The particles in the model move persistently, tumbling with a small rate α , and interact via exclusion volume only. When increasing the tumbling rates α , the system transits from total wetting to partial wetting and unwetting phases. In the first phase, a wetting film covers the wall, with increasing heights when α is reduced. The second phase is characterized by wetting droplets on the wall with a periodic spacing between them. Finally, the wall dries with few particles in contact with it. These phases present nonequilibrium transitions. The first transition, from partial to total wetting, is continuous and the fraction of dry sites vanishes continuously when decreasing the tumbling rate α . For the second transition, from partial wetting to dry, the mean droplet distance diverges logarithmically when approaching the critical tumbling rate, with saturation due to finite-size effects.

  11. Wetting Transitions Displayed by Persistent Active Particles.

    PubMed

    Sepúlveda, Néstor; Soto, Rodrigo

    2017-08-18

    A lattice model for active matter is studied numerically, showing that it displays wetting transitions between three distinctive phases when in contact with an impenetrable wall. The particles in the model move persistently, tumbling with a small rate α, and interact via exclusion volume only. When increasing the tumbling rates α, the system transits from total wetting to partial wetting and unwetting phases. In the first phase, a wetting film covers the wall, with increasing heights when α is reduced. The second phase is characterized by wetting droplets on the wall with a periodic spacing between them. Finally, the wall dries with few particles in contact with it. These phases present nonequilibrium transitions. The first transition, from partial to total wetting, is continuous and the fraction of dry sites vanishes continuously when decreasing the tumbling rate α. For the second transition, from partial wetting to dry, the mean droplet distance diverges logarithmically when approaching the critical tumbling rate, with saturation due to finite-size effects.

  12. Persistent neural activity in head direction cells

    NASA Technical Reports Server (NTRS)

    Taube, Jeffrey S.; Bassett, Joshua P.; Oman, C. M. (Principal Investigator)

    2003-01-01

    Many neurons throughout the rat limbic system discharge in relation to the animal's directional heading with respect to its environment. These so-called head direction (HD) cells exhibit characteristics of persistent neural activity. This article summarizes where HD cells are found, their major properties, and some of the important experiments that have been conducted to elucidate how this signal is generated. The number of HD and angular head velocity cells was estimated for several brain areas involved in the generation of the HD signal, including the postsubiculum, anterior dorsal thalamus, lateral mammillary nuclei and dorsal tegmental nucleus. The HD cell signal has many features in common with what is known about how neural integration is accomplished in the oculomotor system. The nature of the HD cell signal makes it an attractive candidate for using neural network models to elucidate the signal's underlying mechanisms. The conditions that any network model must satisfy in order to accurately represent how the nervous system generates this signal are highlighted and areas where key information is missing are discussed.

  13. Redox regulation of ischemic preconditioning is mediated by the differential activation of caveolins and their association with eNOS and GLUT-4.

    PubMed

    Koneru, Srikanth; Penumathsa, Suresh Varma; Thirunavukkarasu, Mahesh; Samuel, Samson Mathews; Zhan, Lijun; Han, Zhihua; Maulik, Gautam; Das, Dipak K; Maulik, Nilanjana

    2007-05-01

    Reactive oxygen species (ROS) generated during ischemia-reperfusion (I/R) enhance myocardial injury, but brief periods of myocardial ischemia followed by reperfusion [ischemic preconditioning (IP)] induce cardioprotection. Ischemia is reported to stimulate glucose uptake through the translocation of GLUT-4 from the intracellular vesicles to the sarcolemma. In the present study we demonstrated involvement of ROS in IP-mediated GLUT-4 translocation along with increased expression of caveolin (Cav)-3, phospho (p)-endothelial nitric oxide synthase (eNOS), p-Akt, and decreased expression of Cav-1. The rats were divided into the following groups: 1) control sham, 2) N-acetyl-L-cysteine (NAC, free radical scavenger) sham (NS), 3) I/R, 4) IP + I/R (IP), and 5) NAC + IP (IPN). IP was performed by four cycles of 4 min of ischemia and 4 min of reperfusion followed by 30 min of ischemia and 3, 24, 48 h of reperfusion, depending on the protocol. Increased mRNA expression of GLUT-4 and Cav-3 was observed after 3 h of reperfusion in the IP group compared with other groups. IP increased expression of GLUT-4, Cav-3, and p-AKT and p-eNOS compared with I/R. Coimmunoprecipitation demonstrated decreased association of Cav-1/eNOS in the IP group compared with the I/R group. Significant GLUT-4 and Cav-3 association was also observed in the IP group. This association was disrupted when NAC was used in conjunction with IP. It clearly documents a significant role of ROS signaling in Akt/eNOS/Cav-3-mediated GLUT-4 translocation and association in IP myocardium. In conclusion, we demonstrated a novel redox mechanism in IP-induced eNOS and GLUT-4 translocation and the role of caveolar paradox in making the heart euglycemic during the process of ischemia, leading to myocardial protection in a clinically relevant rat ischemic model.

  14. MicroRNA-27b plays a role in pulmonary arterial hypertension by modulating peroxisome proliferator-activated receptor γ dependent Hsp90-eNOS signaling and nitric oxide production

    SciTech Connect

    Bi, Rui; Bao, Chunrong; Jiang, Lianyong; Liu, Hao; Yang, Yang; Mei, Ju; Ding, Fangbao

    2015-05-01

    Pulmonary artery endothelial dysfunction is associated with pulmonary arterial hypertension (PAH). Based on recent studies showing that microRNA (miR)-27b is aberrantly expressed in PAH, we hypothesized that miR-27b may contribute to pulmonary endothelial dysfunction and vascular remodeling in PAH. The effect of miR-27b on pulmonary endothelial dysfunction and the underlying mechanism were investigated in human pulmonary artery endothelial cells (HPAECs) in vitro and in a monocrotaline (MCT)-induced model of PAH in vivo. miR-27b expression was upregulated in MCT-induced PAH and inversely correlated with the levels of peroxisome proliferator-activated receptor (PPAR)-γ, and miR-27b inhibition attenuated MCT-induced endothelial dysfunction and remodeling and prevented PAH associated right ventricular hypertrophy and systolic pressure in rats. PPARγ was confirmed as a direct target of miR-27b in HPAECs and shown to mediate the effect of miR-27b on the disruption of endothelial nitric oxide synthase (eNOS) coupling to Hsp90 and the suppression of NO production associated with the PAH phenotype. We showed that miR-27b plays a role endothelial function and NO release and elucidated a potential mechanism by which miR-27b regulates Hsp90-eNOS and NO signaling by modulating PPARγ expression, providing potential therapeutic targets for the treatment of PAH. - Highlights: • miR-27b plays a role in endothelial function and NO release. • miR-27b inhibition ameliorates MCT-induced endothelial dysfunction and PAH. • miR-27b targets PPARγ in HPAECs. • miR-27b regulates PPARγ dependent Hsp90-eNOS and NO signaling.

  15. 3-Methylcholanthrene/Aryl-Hydrocarbon Receptor-Mediated Hypertension Through eNOS Inactivation.

    PubMed

    Chang, Chih-Cheng; Hsu, Yung-Ho; Chou, Hsiu-Chu; Lee, Yuan-Chii G; Juan, Shu-Hui

    2017-05-01

    Endothelial nitric oxide synthase (eNOS) modulates vascular blood pressure and is predominantly expressed in endothelial cells and activated through the protein kinase B (Akt/PKB)-dependent pathway. We previously reported that 3-methylcholanthrene (3MC) activates the aryl hydrocarbon receptor (AhR) and reduces PI3K/Akt phosphorylation. This study investigated the mechanism underlying the downregulatory effects of 3-MC on nitric oxide (NO) production occurring through the AhR/RhoA/Akt-mediated mechanism. The mechanism underlying the effects of 3-MC on eNOS activity and blood pressure was examined in vitro and in vivo through genetic and pharmacological approaches. Results indicated that 3-MC modified heat shock protein 90 (HSP90), caveolin-1, dynein, and eNOS mRNA and protein expression through the AhR/RhoA-dependent mechanism in mouse cerebral vascular endothelial cells (MCVECs) and that 3-MC reduced eNOS phosphorylation through the AhR/RhoA-mediated inactivation of Akt1. The upregulation of dynein expression was associated with decreased eNOS dimer formation (eNOS dimer; an activated form of the enzyme). Coimmunoprecipitation assay results indicated that 3-MC significantly reduced the interaction between eNOS and its regulatory proteins, including Akt1 and HSP90, but increased the interaction between eNOS and caveolin-1. Immunofluorescence and Western blot analysis revealed that 3-MC reduced the amount of membrane-bound activated eNOS, and a modified Griess assay revealed that 3-MC concomitantly reduced NO production. However, simvastatin reduced 3-MC-mediated murine hypertension. Our study results indicate that AhR, RhoA, and eNOS have major roles in blood pressure regulation. Statin intervention might provide a potential therapeutic approach for reducing hypertension caused by 3-MC. J. Cell. Physiol. 232: 1020-1029, 2017. © 2016 Wiley Periodicals, Inc.

  16. Analyzing persister physiology with fluorescence activated cell sorting

    PubMed Central

    Orman, Mehmet A.; Henry, Theresa C.; DeCoste, Christina J.; Brynildsen, Mark P.

    2016-01-01

    Bacterial persisters are phenotypic variants that exhibit an impressive ability to tolerate antibiotics. Persisters are hypothesized to cause relapse infections, and therefore, understanding their physiology may lead to novel therapeutics to treat recalcitrant infections. However, persisters have yet to be isolated due to their low abundance, transient nature, and similarity to the more highly abundant viable but non-culturable cells (VBNCs), resulting in limited knowledge of their phenotypic state. This technical hurdle has been addressed through the use of fluorescence activated cell sorting (FACS) and quantification of persister levels in the resulting sorted fractions. These assays provide persister phenotype distributions, which can be compared to the phenotype distributions of the entire population, and can also be used to examine persister heterogeneity. Here we describe two detailed protocols for analysis of persister physiology with FACS. One protocol assays the metabolic state of persisters using a fluorescent metabolic stain, whereas the other assays the growth state of persisters with use of a fluorescent protein. PMID:26468102

  17. Reversal of SIN-1-induced eNOS dysfunction by the spin trap, DMPO, in bovine aortic endothelial cells via eNOS phosphorylation

    PubMed Central

    Das, Amlan; Gopalakrishnan, Bhavani; Druhan, Lawrence J; Wang, Tse-Yao; De Pascali, Francesco; Rockenbauer, Antal; Racoma, Ira; Varadharaj, Saradhadevi; Zweier, Jay L; Cardounel, Arturo J; Villamena, Frederick A

    2014-01-01

    Background and Purpose Nitric oxide (NO) derived from eNOS is mostly responsible for the maintenance of vascular homeostasis and its decreased bioavailability is characteristic of reactive oxygen species (ROS)-induced endothelial dysfunction (ED). Because 5,5-dimethyl-1-pyrroline-N-oxide (DMPO), a commonly used spin trap, can control intracellular nitroso-redox balance by scavenging ROS and donating NO, it was employed as a cardioprotective agent against ED but the mechanism of its protection is still not clear. This study elucidated the mechanism of protection by DMPO against SIN-1-induced oxidative injury to bovine aortic endothelial cells (BAEC). Experimental Approach BAEC were treated with SIN-1, as a source of peroxynitrite anion (ONOO−), and then incubated with DMPO. Cytotoxicity following SIN-1 alone and cytoprotection by adding DMPO was assessed by MTT assay. Levels of ROS and NO generation from HEK293 cells transfected with wild-type and mutant eNOS cDNAs, tetrahydrobiopterin bioavailability, eNOS activity, eNOS and Akt kinase phosphorylation were measured. Key Results Post-treatment of cells with DMPO attenuated SIN-1-mediated cytotoxicity and ROS generation, restoration of NO levels via increased in eNOS activity and phospho-eNOS levels. Treatment with DMPO alone significantly increased NO levels and induced phosphorylation of eNOS Ser1179 via Akt kinase. Transfection studies with wild-type and mutant human eNOS confirmed the dual role of eNOS as a producer of superoxide anion (O2−) with SIN-1 treatment, and a producer of NO in the presence of DMPO. Conclusion and Implications Post-treatment with DMPO of oxidatively challenged cells reversed eNOS dysfunction and could have pharmacological implications in the treatment of cardiovascular diseases. PMID:24405159

  18. Persistent Focal Behavior and Physical Activity Performance

    ERIC Educational Resources Information Center

    Erfle, Stephen E.

    2014-01-01

    This article examines the proclivity and performance attributes of focal students across time and activities using data from 9,345 students. Three systematic focal behavior partitions are examined: Across activities, across time, and across activities and time. A student's performance is focal if it ends in 0 or 5 for push-ups and 0 for curl-ups.…

  19. Persistent Focal Behavior and Physical Activity Performance

    ERIC Educational Resources Information Center

    Erfle, Stephen E.

    2014-01-01

    This article examines the proclivity and performance attributes of focal students across time and activities using data from 9,345 students. Three systematic focal behavior partitions are examined: Across activities, across time, and across activities and time. A student's performance is focal if it ends in 0 or 5 for push-ups and 0 for curl-ups.…

  20. Exercise-induced cardioprotection: a role for eNOS uncoupling and NO metabolites.

    PubMed

    Farah, C; Kleindienst, A; Bolea, G; Meyer, G; Gayrard, S; Geny, B; Obert, P; Cazorla, O; Tanguy, S; Reboul, Cyril

    2013-11-01

    Exercise is an efficient strategy for myocardial protection against ischemia-reperfusion (IR) injury. Although endothelial nitric oxide synthase (eNOS) is phosphorylated and activated during exercise, its role in exercise-induced cardioprotection remains unknown. This study investigated whether modulation of eNOS activation during IR could participate in the exercise-induced cardioprotection against IR injury. Hearts isolated from sedentary or exercised rats (5 weeks training) were perfused with a Langendorff apparatus and IR performed in the presence or absence of NOS inhibitors [N-nitro-L-arginine methyl ester, L-NAME or N5-(1-iminoethyl)-L-ornithine, L-NIO] or tetrahydrobiopterin (BH₄). Exercise training protected hearts against IR injury and this effect was abolished by L-NAME or by L-NIO treatment, indicating that exercise-induced cardioprotection is eNOS dependent. However, a strong reduction of eNOS phosphorylation at Ser1177 (eNOS-PSer1177) and of eNOS coupling during early reperfusion was observed in hearts from exercised rats (which showed higher eNOS-PSer1177 and eNOS dimerization at baseline) in comparison to sedentary rats. Despite eNOS uncoupling, exercised hearts had more S-nitrosylated proteins after early reperfusion and also less nitro-oxidative stress, indexed by lower malondialdehyde content and protein nitrotyrosination compared to sedentary hearts. Moreover, in exercised hearts, stabilization of eNOS dimers by BH4 treatment increased nitro-oxidative stress and then abolished the exercise-induced cardioprotection, indicating that eNOS uncoupling during IR is required for exercise-induced myocardial cardioprotection. Based on these results, we hypothesize that in the hearts of exercised animals, eNOS uncoupling associated with the improved myocardial antioxidant capacity prevents excessive NO synthesis and limits the reaction between NO and O₂·- to form peroxynitrite (ONOO⁻), which is cytotoxic.

  1. Internalization of eNOS via caveolae regulates PAF-induced inflammatory hyperpermeability to macromolecules.

    PubMed

    Sánchez, Fabiola A; Kim, David D; Durán, Ricardo G; Meininger, Cynthia J; Durán, Walter N

    2008-10-01

    Endothelial nitric oxide (NO) synthase (eNOS) is thought to regulate microvascular permeability via NO production. We tested the hypotheses that the expression of eNOS and eNOS endocytosis by caveolae are fundamental for appropriate signaling mechanisms in inflammatory endothelial permeability to macromolecules. We used bovine coronary postcapillary venular endothelial cells (CVECs) because these cells are derived from the microvascular segment responsible for the transport of macromolecules in inflammation. We stimulated CVECs with platelet-activating factor (PAF) at 100 nM and measured eNOS phosphorylation, NO production, and CVEC monolayer permeability to FITC-dextran 70 KDa (Dx-70). PAF translocated eNOS from plasma membrane to cytosol, induced changes in the phosphorylation state of the enzyme, and increased NO production from 4.3+/-3.8 to 467+/-22.6 nM. PAF elevated CVEC monolayer permeability to FITC-Dx-70 from 3.4+/-0.3 x 10(-6) to 8.5+/-0.4 x 10(-6) cm/s. The depletion of endogenous eNOS with small interfering RNA abolished PAF-induced hyperpermeability, demonstrating that the expression of eNOS is required for inflammatory hyperpermeability responses. The inhibition of the caveolar internalization by blocking caveolar scission using transfection of dynamin dominant-negative mutant, dyn2K44A, inhibited PAF-induced hyperpermeability to FITC-Dx-70. We interpret these data as evidence that 1) eNOS is required for hyperpermeability to macromolecules and 2) the internalization of eNOS via caveolae is an important mechanism in the regulation of endothelial permeability. We advance the novel concept that eNOS internalization to cytosol is a signaling mechanism for the onset of microvascular hyperpermeability in inflammation.

  2. Persistence

    NASA Astrophysics Data System (ADS)

    Moore, John W.

    1998-11-01

    Eudora Welty, the famous writer, was once asked what should be done by society or government to encourage young writers. Her response, which surprised the questioner, and me when I heard it, was "Nothing". Welty contended that a person who was really a writer would be persistent enough to overcome whatever obstacles were in the way, needing no interference or support from others.

  3. Persistent Aeolian Activity at Endeavour Crater, Mars

    NASA Astrophysics Data System (ADS)

    Chojnacki, M.; Michaels, T. I.; Fenton, L. K.

    2013-12-01

    Long-term monitoring of sites that are known to have active dunes and ripples is generally limited to 3 Mars-Years (MY). Here, we discuss new results of dune activity and albedo change in Endeavour crater (EC), Meridiani Planum (MP) that record eight MY of aeolian activity. MP dune fields often show large yearly variations in albedo; EC darkened by ~12% in TES albedo between MY 24 and 26 (from 0.14 to 0.12). THEMIS VIS albedo of dunes did not change significantly from MY 26 to 29, but did decrease notably (~15 %) in MY 30. These darkening events are most likely related to aeolian-driven dust cleaning (e.g., removal by saltating sand, dust devils). For example, the Opportunity rover (poised on the western rim of EC) observed evidence for a MY 31 dune field dust-clearing event. HiRISE monitoring of MP has shown it be one of the most active regions outside of north polar latitudes. Paired images of western EC taken 3 MY apart show clear evidence for dune modification that include: ripple migration, change in dune perimeters, exposure of previously buried light-toned rock, and/or burial of rock by sand (Fig. 1a-1b). Dune slip face movement is evident for most dunes, where crests and aprons advanced (2-7 m) in the downwind direction (to the SSE) at rates of 0.7-2.3 m per MY. Small dome dunes in the eastern EC were found to have a large degree of aeolian activity (e.g., deflation and/or translation) by an earlier study that used MGS-MRO images (MY 24-30). New MY 31 images validate earlier observations, showing clear evidence for bedform deflation where dunes often occupy less area (~50%) than in earlier MY 29 images (Fig. 1c-1d). Areal removal rates are on par with earlier estimates. Bedform modification and sand streamer orientation appear to be caused by a NNW wind regime, consistent with earlier observations, mesoscale modeling, and the transport direction of barchans to the west. Dunes in EC are now known to be periodically (consistently?) active from over a decade

  4. Eno-Osher schemes for Euler equations

    NASA Technical Reports Server (NTRS)

    Vandervegt, Jacobus J.

    1992-01-01

    The combination of the Osher approximate Riemann solver for the Euler equations and various ENO schemes is discussed for one-dimensional flow. The three basic approaches, viz. the ENO scheme using primitive variable reconstruction, either with Cauchy-Kowalewski procedure for time integration or the TVD Runge-Kutta scheme, and the flux-ENO method are tested on different shock tube cases. The shock tube cases were chosen to present a serious challenge to the ENO schemes in order to test their ability to capture flow discontinuities, such as shocks. Also the effect of the ordering of the eigen values, viz. natural or reversed ordering, in the Osher scheme is investigated. The ENO schemes are tested up to fifth order accuracy in space and time. The ENO-Osher scheme using the Cauchy-Kowalewski procedure for time integration is found to be the most accurate and robust compared with the other methods and is also computationally efficient. The tests showed that the ENO schemes perform reasonably well, but have problems in cases where two discontinuities are close together. In that case there are not enough points in the smooth part of the flow to create a non-oscillatory interpolation.

  5. Stable cellular senescence is associated with persistent DDR activation.

    PubMed

    Fumagalli, Marzia; Rossiello, Francesca; Mondello, Chiara; d'Adda di Fagagna, Fabrizio

    2014-01-01

    The DNA damage response (DDR) is activated upon DNA damage generation to promote DNA repair and inhibit cell cycle progression in the presence of a lesion. Cellular senescence is a permanent cell cycle arrest characterized by persistent DDR activation. However, some reports suggest that DDR activation is a feature only of early cellular senescence that is then lost with time. This challenges the hypothesis that cellular senescence is caused by persistent DDR activation. To address this issue, we studied DDR activation dynamics in senescent cells. Here we show that normal human fibroblasts retain DDR markers months after replicative senescence establishment. Consistently, human fibroblasts from healthy aged donors display markers of DDR activation even three years in culture after entry into replicative cellular senescence. However, by extending our analyses to different human cell strains, we also observed an apparent DDR loss with time following entry into cellular senescence. This though correlates with the inability of these cell strains to survive in culture upon replicative or irradiation-induced cellular senescence. We propose a model to reconcile these results. Cell strains not suffering the prolonged in vitro culture stress retain robust DDR activation that persists for years, indicating that under physiological conditions persistent DDR is causally involved in senescence establishment and maintenance. However, cell strains unable to maintain cell viability in vitro, due to their inability to cope with prolonged cell culture-associated stress, show an only-apparent reduction in DDR foci which is in fact due to selective loss of the most damaged cells.

  6. Tyrosine phosphorylation of eNOS regulates myocardial survival after an ischaemic insult: role of PYK2.

    PubMed

    Bibli, Sofia-Iris; Zhou, Zongmin; Zukunft, Sven; Fisslthaler, Beate; Andreadou, Ioanna; Szabo, Csaba; Brouckaert, Peter; Fleming, Ingrid; Papapetropoulos, Andreas

    2017-07-01

    Endothelial nitric oxide (NO) synthase (eNOS) is known to play a cardioprotective protective. However, the molecular mechanisms regulating eNOS activity during ischaemia/reperfusion (I/R) injury are incompletely understood. eNOS is a substrate for several kinases that positively or negatively affect its enzymatic activity. Herein, we sought to correlate eNOS phosphorylation status with cardiomyocyte survival and we investigated the contribution of the proline-rich tyrosine kinase 2 (PYK2)/eNOS axis to the regulation of myocardial infarct size in vivo. Exposure of H9c2 cardiomyocytes to H2O2 lead to PYK2 phosphorylation on its activator site (Y402) and eNOS phosphorylation on the inhibitor site Y656 and the activator site S1176. Both H2O2-induced eNOS phosphorylation events were abolished by PYK2 pharmacological inhibition or gene knockdown. Activity assays demonstrated that phosphorylation of the tyrosine inhibitory site exerts a dominant effect over S1176. In cardiomyocytes subjected to oxidative stress or oxygen-glucose deprivation, inhibition of PYK2 limited cell injury; this effect was prevented by inhibition of NO production. In vivo, ischaemia-reperfusion induced an early activation of PYK2, leading to eNOS phosphorylation on Y656, which, in turn, reduced NO output, as judged by the low tissue levels of its downstream effector cGMP. Moreover, pharmacological blockade of PYK2 alleviated eNOS inhibition and prevented cardiac damage following I/R injury in wild-type, but not in eNOS KO mice. The current studies demonstrate that PYK2 is a pivotal regulator of eNOS function in myocardial infarction and identify PYK2 as a novel therapeutic target for cardioprotection.

  7. Antiepileptic Activity of Preferential Inhibitors of Persistent Sodium Current

    PubMed Central

    Anderson, Lyndsey L.; Thompson, Christopher H.; Hawkins, Nicole A.; Nath, Ravi D.; Petersohn, Adam A.; Rajamani, Sridharan; Bush, William S.; Frankel, Wayne N.; Vanoye, Carlos G.; Kearney, Jennifer A.; George, Alfred L.

    2014-01-01

    Objective Evidence from basic neurophysiology and molecular genetics has implicated persistent sodium current conducted by voltage-gated sodium (NaV) channels as a contributor to the pathogenesis of epilepsy. Many antiepileptic drugs target NaV channels and modulate neuronal excitability mainly by a use-dependent block of transient sodium current, although suppression of persistent current may also contribute to the efficacy of these drugs. We hypothesized that a drug or compound capable of preferential inhibition of persistent sodium current would have antiepileptic activity. Methods We examined the antiepileptic activity of two selective persistent sodium current blockers ranolazine, an FDA-approved drug for treatment of angina pectoris, and GS967, a novel compound with more potent effects on persistent current, in the epileptic Scn2aQ54 mouse model. We also examined the effect of GS967 in the maximal electroshock model and evaluated effects of the compound on neuronal excitability, propensity for hilar neuron loss, development of mossy fiber sprouting and survival of Scn2aQ54 mice. Results We found that ranolazine was capable of reducing seizure frequency by ~50% in Scn2aQ54 mice. The more potent persistent current blocker GS967 reduced seizure frequency by greater than 90% in Scn2aQ54 mice and protected against induced seizures in the maximal electroshock model. GS967 greatly attenuated abnormal spontaneous action potential firing in pyramidal neurons acutely isolated from Scn2aQ54 mice. In addition to seizure suppression in vivo, GS967 treatment greatly improved the survival of Scn2aQ54 mice, prevented hilar neuron loss, and suppressed the development of hippocampal mossy fiber sprouting. Significance Our findings indicate that the selective persistent sodium current blocker GS967 has potent antiepileptic activity and this compound could inform development of new agents. PMID:24862204

  8. Role of Prefrontal Persistent Activity in Working Memory

    PubMed Central

    Riley, Mitchell R.; Constantinidis, Christos

    2016-01-01

    The prefrontal cortex is activated during working memory, as evidenced by fMRI results in human studies and neurophysiological recordings in animal models. Persistent activity during the delay period of working memory tasks, after the offset of stimuli that subjects are required to remember, has traditionally been thought of as the neural correlate of working memory. In the last few years several findings have cast doubt on the role of this activity. By some accounts, activity in other brain areas, such as the primary visual and posterior parietal cortex, is a better predictor of information maintained in visual working memory and working memory performance; dynamic patterns of activity may convey information without requiring persistent activity at all; and prefrontal neurons may be ill-suited to represent non-spatial information about the features and identity of remembered stimuli. Alternative interpretations about the role of the prefrontal cortex have thus been suggested, such as that it provides a top-down control of information represented in other brain areas, rather than maintaining a working memory trace itself. Here we review evidence for and against the role of prefrontal persistent activity, with a focus on visual neurophysiology. We show that persistent activity predicts behavioral parameters precisely in working memory tasks. We illustrate that prefrontal cortex represents features of stimuli other than their spatial location, and that this information is largely absent from early cortical areas during working memory. We examine memory models not dependent on persistent activity, and conclude that each of those models could mediate only a limited range of memory-dependent behaviors. We review activity decoded from brain areas other than the prefrontal cortex during working memory and demonstrate that these areas alone cannot mediate working memory maintenance, particularly in the presence of distractors. We finally discuss the discrepancy between

  9. Deficient eNOS phosphorylation is a mechanism for diabetic vascular dysfunction contributing to increased stroke size

    PubMed Central

    Li, Qian; Atochin, Dmitriy; Kashiwagi, Satoshi; Earle, John; Wang, Annie; Mandeville, Emiri; Hayakawa, Kazuhide; d'Uscio, Livius V.; Lo, Eng H.; Katusic, Zvonimir; Sessa, William; Huang, Paul

    2013-01-01

    Background and Purpose Phosphorylation of eNOS, an important post-translational modulator of its enzymatic activity, is reduced in diabetes. We hypothesized that modulation of eNOS phosphorylation could overcome diabetic vascular dysfunction and improves the outcome to stroke. Methods We used the db/db mouse model of type 2 diabetes. We mated db/db mice with eNOS knockin mice that carry single-amino acid mutations at the S1176 phosphorylation site; the phosphomimetic SD mutation shows increased eNOS enzymatic activity, while the unphosphorylatable SA mutation shows decreased eNOS activity. We characterized the vascular anatomy, baseline physiologic parameters and vascular reactivity. We used the middle cerebral artery occlusion model of stroke and measured infarct volume and neurological deficits. Results db/db mice showed diminished eNOS phosphorylation at S1176. eNOS SD and SA mutations do not change the vascular anatomy at the Circle of Willis, brain capillary density, heart rate, or arterial blood gases of db/db mice. The eNOS SD mutation, but not the SA mutation, lowers blood pressure and improves vascular reactivity to acetylcholine in db/db mice. The eNOS SD mutation reduces stroke size and neurologic deficit following middle cerebral artery occlusion. Conclusion Diminished eNOS phosphorylation is a mechanism of vascular dysfunction in db/db mice. We show here that modulation of the eNOS S1176 phosphorylation site in db/db mice is associated with improved vascular reactivity and improved outcome to stroke following middle cerebral artery occlusion. PMID:23988642

  10. Numerical experiments on the accuracy of ENO and modified ENO schemes

    NASA Technical Reports Server (NTRS)

    Shu, Chi-Wang

    1990-01-01

    Further numerical experiments are made assessing an accuracy degeneracy phenomena. A modified essentially non-oscillatory (ENO) scheme is proposed, which recovers the correct order of accuracy for all the test problems with smooth initial conditions and gives comparable results with the original ENO schemes for discontinuous problems.

  11. Relationships between caveolae and eNOS: everything in proximity and the proximity of everything.

    PubMed

    Goligorsky, Michael S; Li, Hong; Brodsky, Sergey; Chen, Jun

    2002-07-01

    Caveolae, flask-shaped invaginations of the plasma membrane occupying up to 30% of cell surface in capillaries, represent a predominant location of endothelial nitric oxide synthase (eNOS) in endothelial cells. The caveolar coat protein caveolin forms high-molecular-weight, Triton-insoluble complexes through oligomerization mediated by interactions between NH2-terminal residues 61-101. eNOS is targeted to caveolae by cotranslational N-myristoylation and posttranslational palmitoylation. Caveolin-1 coimmunoprecipitates with eNOS; interaction with eNOS occurs via the caveolin-1 scaffolding domain and appears to result in the inhibition of NOS activity. The inhibitory conformation of eNOS is reversed by the addition of excess Ca2+/calmodulin and by Akt-induced phosphorylation of eNOS. Here, we shall dissect the system using the classic paradigm of a reflex loop: 1) the action of afferent elements, such as fluid shear stress and its putative caveolar sensor, on caveolae; 2) the ways in which afferent signals may affect the central element, the activation of the eNOS-nitric oxide system; and 3) several resultant well-established and novel physiologically important effector mechanisms, i.e., vasorelaxation, angiogenesis, membrane fluidity, endothelial permeability, deterrance of inflammatory cells, and prevention of platelet aggregation.

  12. Insights into the arginine paradox: evidence against the importance of subcellular location of arginase and eNOS.

    PubMed

    Elms, Shawn; Chen, Feng; Wang, Yusi; Qian, Jin; Askari, Bardia; Yu, Yanfang; Pandey, Deepesh; Iddings, Jennifer; Caldwell, Ruth B; Fulton, David J R

    2013-09-01

    Reduced production of nitric oxide (NO) is one of the first indications of endothelial dysfunction and precedes overt cardiovascular disease. Increased expression of Arginase has been proposed as a mechanism to account for diminished NO production. Arginases consume l-arginine, the substrate for endothelial nitric oxide synthase (eNOS), and l-arginine depletion is thought to competitively reduce eNOS-derived NO. However, this simple relationship is complicated by the paradox that l-arginine concentrations in endothelial cells remain sufficiently high to support NO synthesis. One mechanism proposed to explain this is compartmentalization of intracellular l-arginine into distinct, poorly interchangeable pools. In the current study, we investigated this concept by targeting eNOS and Arginase to different intracellular locations within COS-7 cells and also BAEC. We found that supplemental l-arginine and l-citrulline dose-dependently increased NO production in a manner independent of the intracellular location of eNOS. Cytosolic arginase I and mitochondrial arginase II reduced eNOS activity equally regardless of where in the cell eNOS was expressed. Similarly, targeting arginase I to disparate regions of the cell did not differentially modify eNOS activity. Arginase-dependent suppression of eNOS activity was reversed by pharmacological inhibitors and absent in a catalytically inactive mutant. Arginase did not directly interact with eNOS, and the metabolic products of arginase or downstream enzymes did not contribute to eNOS inhibition. Cells expressing arginase had significantly lower levels of intracellular l-arginine and higher levels of ornithine. These results suggest that arginases inhibit eNOS activity by depletion of substrate and that the compartmentalization of l-arginine does not play a major role.

  13. Pathologic Heterogeneity Persists in Early Active Multiple Sclerosis Lesions

    PubMed Central

    Metz, Imke; Weigand, Stephen D; Popescu, Bogdan F G; Frischer, Josa M; Parisi, Joseph E; Guo, Yong; Lassmann, Hans; Brück, Wolfgang; Lucchinetti, Claudia F.

    2014-01-01

    Objective Multiple sclerosis (MS) lesions demonstrate immunopathological heterogeneity in patterns of demyelination. Previous cross-sectional studies reported immunopatterns of demyelination were identical among multiple active demyelinating lesions from the same individual, but differed between individuals, leading to the hypothesis of intraindividual pathological homogeneity and interindividual heterogeneity. Other groups suggested a time-dependent heterogeneity of lesions. The objective of our present study was to analyze tissue samples collected longitudinally to determine whether patterns of demyelination persist over time within a given patient. Methods Archival tissue samples derived from patients with pathologically confirmed CNS inflammatory demyelinating disease who had undergone either diagnostic serial biopsy or biopsy followed by autopsy, were analyzed immunohistochemically. Inclusion criteria was the presence of early active demyelinating lesions - required for immunopattern classification - obtained from the same patient at two or more time points. Results Among 1321 surgical biopsies consistent with MS, 22 cases met study inclusion criteria. Twenty-one patients (95%) showed a persistence of immunopathological patterns in tissue sampled from different time points. This persistence was demonstrated for all major patterns of demyelination. A single patient showed features suggestive of both pattern II and pattern III on biopsy, but only pattern II among all active lesions examined at autopsy. Interpretation These findings continue to support the concept of patient-dependent immunopathological heterogeneity in early MS and suggest that the mechanisms and targets of tissue injury may differ among patient subgroups. These observations have potentially significant implications for individualized therapeutic approaches. PMID:24771535

  14. Vascular nitric oxide: Beyond eNOS.

    PubMed

    Zhao, Yingzi; Vanhoutte, Paul M; Leung, Susan W S

    2015-10-01

    As the first discovered gaseous signaling molecule, nitric oxide (NO) affects a number of cellular processes, including those involving vascular cells. This brief review summarizes the contribution of NO to the regulation of vascular tone and its sources in the blood vessel wall. NO regulates the degree of contraction of vascular smooth muscle cells mainly by stimulating soluble guanylyl cyclase (sGC) to produce cyclic guanosine monophosphate (cGMP), although cGMP-independent signaling [S-nitrosylation of target proteins, activation of sarco/endoplasmic reticulum calcium ATPase (SERCA) or production of cyclic inosine monophosphate (cIMP)] also can be involved. In the blood vessel wall, NO is produced mainly from l-arginine by the enzyme endothelial nitric oxide synthase (eNOS) but it can also be released non-enzymatically from S-nitrosothiols or from nitrate/nitrite. Dysfunction in the production and/or the bioavailability of NO characterizes endothelial dysfunction, which is associated with cardiovascular diseases such as hypertension and atherosclerosis.

  15. A central role of eNOS in the protective effect of wine against metabolic syndrome.

    PubMed

    Leighton, Federico; Miranda-Rottmann, Soledad; Urquiaga, Inés

    2006-01-01

    The positive health effects derived from moderate wine consumption are pleiotropic. They appear as improvements in cardiovascular risk factors such as plasma lipids, haemostatic mechanisms, endothelial function and antioxidant defences. The active principles would be ethanol and mainly polyphenols. Results from our and other laboratories support the unifying hypothesis that the improvements in risk factors after red wine consumption are mediated by endothelial nitric oxide synthase (eNOS). Many genes are involved, but the participation of eNOS would be a constant feature. The metabolic syndrome is a cluster of metabolic risk factors associated with high risk of cardiovascular disease (CVD). The National Cholesterol Education Programmmes Adult Treatment Panel III (NCEPATP III) clinical definition of the metabolic syndrome requires the presence of at least three risk factors, from among abdominal obesity, high plasma triacylglycerols, low plasma HDL, high blood pressure and high fasting plasma glucose. The molecular mechanisms responsible for the metabolic syndrome are not known. Since metabolic syndrome apparently affects 10-30% of the population in the world, research on its pathogenesis and control is needed. The recent finding that eNOS knockout mice present a cluster of cardiovascular risk factors comparable to those of the metabolic syndrome suggests that defects in eNOS function may cause human metabolic syndrome. These mice are hypertensive, insulin resistant and dyslipidemic. Further support for a pathogenic role of eNOS comes from the finding in humans that eNOS polymorphisms associate with insulin resistance and diabetes, with hypertension, with inflammatory and oxidative stress markers and with albuminuria. So, the data sustain the hypothesis that eNOS enhancement should reduce metabolic syndrome incidence and its consequences. Therefore red wine, since it enhances eNOS function, should be considered as a potential tool for the control of metabolic

  16. Post-translational Regulation of Endothelial Nitric Oxide Synthase (eNOS) by Estrogens in the Rat Vagina

    PubMed Central

    Musicki, Biljana; Liu, Tongyun; Strong, Travis D.; Lagoda, Gwen A.; Bivalacqua, Trinity J.; Burnett, Arthur L.

    2010-01-01

    Introduction Estrogens control vaginal blood flow during female sexual arousal mostly through nitric oxide (NO). Although vascular effects of estrogens are attributed to an increase in endothelial NO production, the mechanisms of endothelial NO synthase (eNOS) regulation by estrogens in the vagina are largely unknown. Aims Our hypothesis was that estrogens regulate eNOS post-translationally in the vagina, providing a mechanism to affect NO bioavailability without changes in eNOS protein expression. Methods We measured eNOS phosphorylation and eNOS interaction with caveolin-1 and heat shock protein 90 (HSP90) in the distal and proximal vagina of female rats at diestrus, 7 days after ovariectomy and 2 days after replacement of ovariectomized rats with estradiol-17β (15 μg). Main Outcome Measures Molecular mechanisms of eNOS regulation by estrogen in the rat vagina. Results We localized phospho-eNOS (Ser-1177) immunohistochemically to the endothelium lining blood vessels and vaginal sinusoids. Estrogen withdrawal decreased phosphorylation of eNOS on its positive regulatory site (Ser-1177) and increased eNOS binding to its negative regulator caveolin-1 (without affecting eNOS/HSP90 interaction), and they were both normalized by estradiol replacement. Protein expressions of phosphorylated Akt (protein kinase B) and extracellular signal-regulated protein kinase 1/2 (ERK1/2) were not affected by estrogen status, suggesting that the effect of estrogens on eNOS (Ser-1177) phosphorylation was not mediated by activated AKT or ERK1/2. eNOS phosphorylation on its negative regulatory site (Ser-114) was increased in the vagina by estrogen withdrawal and normalized by estradiol replacement, implying that the maintenance of low phosphorylation of eNOS on this site by estradiol may limit eNOS interaction with caveolin-1 and preserve the enzyme's activity. Total eNOS, inducible NOS, caveolin-1, and HSP90 protein expressions were not affected by ovariectomy or estradiol replacement

  17. Persistent dynamic attractors in activity patterns of cultured neuronal networks

    NASA Astrophysics Data System (ADS)

    Wagenaar, Daniel A.; Nadasdy, Zoltan; Potter, Steve M.

    2006-05-01

    Three remarkable features of the nervous system—complex spatiotemporal patterns, oscillations, and persistent activity—are fundamental to such diverse functions as stereotypical motor behavior, working memory, and awareness. Here we report that cultured cortical networks spontaneously generate a hierarchical structure of periodic activity with a strongly stereotyped population-wide spatiotemporal structure demonstrating all three fundamental properties in a recurring pattern. During these “superbursts,” the firing sequence of the culture periodically converges to a dynamic attractor orbit. Precursors of oscillations and persistent activity have previously been reported as intrinsic properties of the neurons. However, complex spatiotemporal patterns that are coordinated in a large population of neurons and persist over several hours—and thus are capable of representing and preserving information—cannot be explained by known oscillatory properties of isolated neurons. Instead, the complexity of the observed spatiotemporal patterns implies large-scale self-organization of neurons interacting in a precise temporal order even in vitro, in cultures usually considered to have random connectivity.

  18. Synaptic mechanisms of persistent reverberatory activity in neuronal networks.

    PubMed

    Lau, Pak-Ming; Bi, Guo-Qiang

    2005-07-19

    For brain functions such as working memory and motor planning, neuronal circuits are able to sustain persistent activity after transient inputs. Theoretical studies have suggested that persistent activity can exist in recurrently connected networks as active reverberation. However, the actual cellular processes underlying such reverberation are not well understood. In this study, we investigated the basic synaptic mechanisms responsible for reverberatory activity in small networks of rat hippocampal neurons in vitro. We found that brief stimulation of one neuron in a network could evoke, in an all-or-none fashion, reverberatory activity lasting for seconds. The reverberation was likely to arise from recurrent excitation because it was eliminated by partial inhibition of alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA)-type glutamate receptors (but not by blockade of NMDA receptors). In contrast, blocking inhibitory transmission with bicuculline enhanced the reverberation. Furthermore, paired-pulse stimuli with interpulse intervals of 200-400 ms were more effective than single pulses in triggering reverberation, apparently by eliciting higher levels of asynchronous transmitter release. Suppressing asynchronous release by EGTA-AM abolished reverberation, whereas elevating asynchronous release by strontium substantially enhanced reverberation. Finally, manipulating calcium uptake into or release from intracellular stores also modulated the level of reverberation. Thus, the oft-overlooked asynchronous phase of synaptic transmission plays a central role in the emergent phenomenon of network reverberation.

  19. Synaptic mechanisms of persistent reverberatory activity in neuronal networks

    PubMed Central

    Lau, Pak-Ming; Bi, Guo-Qiang

    2005-01-01

    For brain functions such as working memory and motor planning, neuronal circuits are able to sustain persistent activity after transient inputs. Theoretical studies have suggested that persistent activity can exist in recurrently connected networks as active reverberation. However, the actual cellular processes underlying such reverberation are not well understood. In this study, we investigated the basic synaptic mechanisms responsible for reverberatory activity in small networks of rat hippocampal neurons in vitro. We found that brief stimulation of one neuron in a network could evoke, in an all-or-none fashion, reverberatory activity lasting for seconds. The reverberation was likely to arise from recurrent excitation because it was eliminated by partial inhibition of α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA)-type glutamate receptors (but not by blockade of NMDA receptors). In contrast, blocking inhibitory transmission with bicuculline enhanced the reverberation. Furthermore, paired-pulse stimuli with interpulse intervals of 200–400 ms were more effective than single pulses in triggering reverberation, apparently by eliciting higher levels of asynchronous transmitter release. Suppressing asynchronous release by EGTA-AM abolished reverberation, whereas elevating asynchronous release by strontium substantially enhanced reverberation. Finally, manipulating calcium uptake into or release from intracellular stores also modulated the level of reverberation. Thus, the oft-overlooked asynchronous phase of synaptic transmission plays a central role in the emergent phenomenon of network reverberation. PMID:16006530

  20. Space chimp Enos returns to Patrick Air Force Base

    NASA Technical Reports Server (NTRS)

    1961-01-01

    Enos the chimpanzee that orbited the earth twice in a Mercury spacecraft arrives back at Patrick Air Force Base. Enos landed some 220 nautical miles south of Bermuda and was picked up up by the U.S.S. Stormes.

  1. Space chimp Enos returns to Patrick Air Force Base

    NASA Technical Reports Server (NTRS)

    1961-01-01

    Enos the chimpanzee that orbited the earth twice in a Mercury spacecraft arrives back at Patrick Air Force Base. Enos landed some 220 nautical miles south of Bermuda and was picked up up by the U.S.S. Stormes.

  2. Active rejection of persistent disturbances in flexible space structures

    NASA Technical Reports Server (NTRS)

    Hwang, Cheng-Neng; Jayasuriya, Suhada; Parlos, Alexander G.; Sunkel, John W.

    1990-01-01

    A dynamic compensator for active rejection of persistent disturbances in flexible space structures is designed on the principle of the H(infinity)-optimization of the sensitivity transfer function matrix. A general state space solution is formulated to the multiinput multioutput H(infinity)-optimal control problem, allowing the use of the H(infinity)-optimal synthesis algorithm for the state-space models of space structures that result from model order reduction. Disturbances encountered in flexible space structures, such as shuttle docking, are investigated using the high-mode and the reduced-order models of a cantilevered two-bay truss, demonstrating the applicability of the H(infinity)-optimal approach.

  3. Liposomal tetrahydrobiopterin preserves eNOS coupling in the post-ischemic heart conferring in vivo cardioprotection.

    PubMed

    Xie, Lin; Talukder, M A Hassan; Sun, Jian; Varadharaj, Saradhadevi; Zweier, Jay L

    2015-09-01

    Tetrahydrobiopterin (BH4) is an essential cofactor of nitric oxide synthase (NOS), and reduced BH4 availability leads to endothelial NOS (eNOS) uncoupling and increased reactive oxygen species (ROS) generation. Questions remain regarding the functional state of eNOS and role of BH4 availability in the process of in vivo myocardial ischemia-reperfusion (I/R) injury. Rats were subjected to 60min of in vivo left coronary artery occlusion and varying periods of reperfusion with or without pre-ischemic liposomal BH4 supplementation (1mg/kg, iv). Myocardial infarction was correlated with cardiac BH4 content, eNOS protein level, NOS enzyme activity, and ROS generation. In the vehicle group, 60-min ischemia drastically reduced myocardial BH4 content in the area at risk (AAR) compared to non-ischemic (NI) area and the level remained lower during early reperfusion followed by recovery after 24-h reperfusion. Total eNOS, activated eNOS protein level (eNOS Ser1177 phosphorylation) and NOS activity were also significantly reduced during ischemia and/or early reperfusion, but recovered after 24-h reperfusion. With liposomal BH4 treatment, BH4 levels were identical in the AAR and NI area during ischemia and/or early reperfusion, and were significantly higher than with vehicle. BH4 pre-treatment preserved eNOS Ser1177 phosphorylation and NOS activity in the AAR, and significantly reduced myocardial ROS generation and infarction compared to vehicle. These findings provide direct evidence that in vivo I/R induces eNOS dysfunction secondary to BH4 depletion, and that pre-ischemic liposomal BH4 administration preserves eNOS function conferring cardioprotection with reduced oxidative stress. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. Long-term persistence of solar activity. [Abstract only

    NASA Technical Reports Server (NTRS)

    Ruzmaikin, Alexander; Feynman, Joan; Robinson, Paul

    1994-01-01

    The solar irradiance has been found to change by 0.1% over the recent solar cycle. A change of irradiance of about 0.5% is required to effect the Earth's climate. How frequently can a variation of this size be expected? We examine the question of the persistence of non-periodic variations in solar activity. The Huerst exponent, which characterizes the persistence of a time series (Mandelbrot and Wallis, 1969), is evaluated for the series of C-14 data for the time interval from about 6000 BC to 1950 AD (Stuiver and Pearson, 1986). We find a constant Huerst exponent, suggesting that solar activity in the frequency range of from 100 to 3000 years includes an important continuum component in addition to the well-known periodic variations. The value we calculate, H approximately equal to 0.8, is significantly larger than the value of 0.5 that would correspond to variations produced by a white-noise process. This value is in good agreement with the results for the monthly sunspot data reported elsewhere, indicating that the physics that produces the continuum is a correlated random process (Ruzmaikin et al., 1992), and that is is the same type of process over a wide range of time interval lengths. We conclude that the time period over which an irradiance change of 0.5% can be expected to occur is significantly shorter than that which would be expected for variations produced by a white-noise process.

  5. Long-term persistence of solar activity. [Abstract only

    NASA Technical Reports Server (NTRS)

    Ruzmaikin, Alexander; Feynman, Joan; Robinson, Paul

    1994-01-01

    The solar irradiance has been found to change by 0.1% over the recent solar cycle. A change of irradiance of about 0.5% is required to effect the Earth's climate. How frequently can a variation of this size be expected? We examine the question of the persistence of non-periodic variations in solar activity. The Huerst exponent, which characterizes the persistence of a time series (Mandelbrot and Wallis, 1969), is evaluated for the series of C-14 data for the time interval from about 6000 BC to 1950 AD (Stuiver and Pearson, 1986). We find a constant Huerst exponent, suggesting that solar activity in the frequency range of from 100 to 3000 years includes an important continuum component in addition to the well-known periodic variations. The value we calculate, H approximately equal to 0.8, is significantly larger than the value of 0.5 that would correspond to variations produced by a white-noise process. This value is in good agreement with the results for the monthly sunspot data reported elsewhere, indicating that the physics that produces the continuum is a correlated random process (Ruzmaikin et al., 1992), and that is is the same type of process over a wide range of time interval lengths. We conclude that the time period over which an irradiance change of 0.5% can be expected to occur is significantly shorter than that which would be expected for variations produced by a white-noise process.

  6. Persistently active cannabinoid receptors mute a subpopulation of hippocampal interneurons.

    PubMed

    Losonczy, Attila; Biró, Agota A; Nusser, Zoltan

    2004-02-03

    Cortical information processing requires an orchestrated interaction between a large number of pyramidal cells and albeit fewer, but highly diverse GABAergic interneurons (INs). The diversity of INs is thought to reflect functional and structural specializations evolved to control distinct network operations. Consequently, specific cortical functions may be selectively modified by altering the input-output relationship of unique IN populations. Here, we report that persistently active cannabinoid receptors, the site of action of endocannabinoids, and the psychostimulants marijuana and hashish, switch off the output (mute) of a unique class of hippocampal INs. In paired recordings between cholecystokinin-immunopositive, mossy fiber-associated INs, and their target CA3 pyramidal cells, no postsynaptic currents could be evoked with single presynaptic action potentials or with repetitive stimulations at frequencies <25 Hz. Cannabinoid receptor antagonists converted these "mute" synapses into high-fidelity ones. The selective muting of specific GABAergic INs, achieved by persistent presynaptic cannabinoid receptor activation, provides a state-dependent switch in cortical networks.

  7. Persistently active neurons in human medial frontal and medial temporal lobe support working memory.

    PubMed

    Kamiński, Jan; Sullivan, Shannon; Chung, Jeffrey M; Ross, Ian B; Mamelak, Adam N; Rutishauser, Ueli

    2017-04-01

    Persistent neural activity is a putative mechanism for the maintenance of working memories. Persistent activity relies on the activity of a distributed network of areas, but the differential contribution of each area remains unclear. We recorded single neurons in the human medial frontal cortex and medial temporal lobe while subjects held up to three items in memory. We found persistently active neurons in both areas. Persistent activity of hippocampal and amygdala neurons was stimulus-specific, formed stable attractors and was predictive of memory content. Medial frontal cortex persistent activity, on the other hand, was modulated by memory load and task set but was not stimulus-specific. Trial-by-trial variability in persistent activity in both areas was related to memory strength, because it predicted the speed and accuracy by which stimuli were remembered. This work reveals, in humans, direct evidence for a distributed network of persistently active neurons supporting working memory maintenance.

  8. Persistently active neurons in human medial frontal and medial temporal lobe support working memory

    PubMed Central

    Kamiński, J; Sullivan, S; Chung, JM; Ross, IB; Mamelak, AN; Rutishauser, U

    2017-01-01

    Persistent neural activity is a putative mechanism for the maintenance of working memories. Persistent activity relies on the activity of a distributed network of areas, but the differential contribution of each area remains unclear. We recorded single neurons in the human medial frontal cortex and the medial temporal lobe while subjects held up to three items in memory. We found persistently active neurons in both areas. Persistent activity of hippocampal and amygdala neurons was stimulus-specific, formed stable attractors, and was predictive of memory content. Medial frontal cortex persistent activity, on the other hand, was modulated by memory load and task set but was not stimulus-specific. Trial-by-trial variability in persistent activity in both areas was related to memory strength, because it predicted the speed and accuracy by which stimuli were remembered. This work reveals, in humans, direct evidence for a distributed network of persistently active neurons supporting working memory maintenance. PMID:28218914

  9. Significant negative correlations between capillary expressed eNOS and Alzheimer lesion burden.

    PubMed

    Jeynes, Brian; Provias, John

    2009-10-09

    Nitric oxide [NO] is known to have vasoregulatory, neuroprotective and blood-brain barrier (BBB) related transport functions in the human CNS. Altered NO levels are suspected of contributing to neurodegenerative disorders, including Alzheimer's disease (AD). NO is produced as a result of the activity of one or more of three isoforms of nitrogen oxide synthase (NOS). In this study we compared Alzheimer and normative comparison brain samples, from temporal and calcarine cortices, with respect to the interactive correlation between eNOS, iNOS and nNOS isoform positive capillaries and the presence of neurofibrillary tangles (NFTs) and senile plaques (SPs). Cortical samples were taken from the superior temporal and calcarine cortices of 10 confirmed AD and 10 non-demented comparison group (CG) brains. Contiguous coronal sections were stained using immunohistochemistry techniques to stain for tau protein, beta amyloid (A beta) n-termini ([40 and 42]), eNOS, iNOS and nNOS. The densities of NFTs, SPs, and eNOS, iNOS and nNOS positive capillaries were recorded. Non-parametric statistical analyses were applied to the data. Our results demonstrate a significant negative correlation between the presence of eNOS positive capillaries and NFTs and SPs in both cortices in AD brains. Our results support the view that eNOS activity should be targeted for further investigation, and that factors involved in the regulation of NO production may be amenable to therapeutic intervention.

  10. PGC-1α dictates endothelial function through regulation of eNOS expression

    PubMed Central

    Craige, Siobhan M.; Kröller-Schön, Swenja; Li, Chunying; Kant, Shashi; Cai, Shenghe; Chen, Kai; Contractor, Mayur M.; Pei, Yongmei; Schulz, Eberhard; Keaney, John F.

    2016-01-01

    Endothelial dysfunction is a characteristic of many vascular related diseases such as hypertension. Peroxisome proliferator activated receptor gamma, coactivator 1α (PGC-1α) is a unique stress sensor that largely acts to promote adaptive responses. Therefore, we sought to define the role of endothelial PGC-1α in vascular function using mice with endothelial specific loss of function (PGC-1α EC KO) and endothelial specific gain of function (PGC-1α EC TG). Here we report that endothelial PGC-1α is suppressed in angiotensin-II (ATII)-induced hypertension. Deletion of endothelial PGC-1α sensitized mice to endothelial dysfunction and hypertension in response to ATII, whereas PGC-1α EC TG mice were protected. Mechanistically, PGC-1α promotes eNOS expression and activity, which is necessary for protection from ATII-induced dysfunction as mice either treated with an eNOS inhibitor (LNAME) or lacking eNOS were no longer responsive to transgenic endothelial PGC-1α expression. Finally, we determined that the orphan nuclear receptor, estrogen related receptor α (ERRα) is required to coordinate the PGC-1α -induced eNOS expression. In conclusion, endothelial PGC-1α expression protects from vascular dysfunction by promoting NO• bioactivity through ERRα induced expression of eNOS. PMID:27910955

  11. eNOS genotype modifies the effect of leisure-time physical activity on serum triglyceride levels in a Japanese population

    PubMed Central

    2012-01-01

    Background Nitric oxide is a key molecule not only in the cardiovascular system, but also in the metabolic-endocrine system. The purpose of this study was to examine possible associations of the NOS3 T-786C polymorphism (rs2070744) with serum lipid levels on the basis of lifestyle factors for tailoring prevention of dyslipidemia. Methods For this cross-sectional study, a total of 2226 subjects aged 35 to 69 years (1084 men and 1142 women) were selected from Japanese participants in the Japan Multi-Institutional Collaborative Cohort (J-MICC) Study. They were recruited in eight areas throughout Japan between February 2004 and November 2008. Results In a stratified analysis by leisure-time physical activity, the likelihood of hypertriglyceridemia (serum triglyceride levels ≥ 150 mg/dL) among subjects with the C allele was significantly lower than those without it in the active group (OR = 0.43, 95% CI = 0.22-0.84 in the fasting group), but not in the sedentary group. A gene-environment interaction between the T-786C polymorphism and leisure-time physical activity for hypertriglyceridemia was significant (P = 0.007 in the fasting group). Additionally, serum triglyceride levels (mean ± SD) across leisure-time physical activity classes decreased significantly only in the TC + CC genotype group (111 ± 60 mg/dL for sedentary, 95 ± 48 mg/dL for moderately active, 88 ± 44 mg/dL for very active, P for trend = 0.008 in the fasting group), but not in the TT genotype group. Total cholesterol, high-density lipoprotein (HDL) cholesterol, and non-HDL cholesterol levels had no significant association with the polymorphism. Conclusions This study suggests that the NOS3 T-786C polymorphism modifies the effect of leisure-time physical activity on serum triglyceride levels. PMID:23122449

  12. In Vitro Activation of eNOS by Mangifera indica (Careless™) and Determination of an Effective Dosage in a Randomized, Double-Blind, Human Pilot Study on Microcirculation.

    PubMed

    Gerstgrasser, Alexandra; Röchter, Sigrid; Dressler, Dirk; Schön, Christiane; Reule, Claudia; Buchwald-Werner, Sybille

    2016-03-01

    Mangifera indica fruit preparation (Careless™) activates the evolutionary conserved metabolic sensors sirtuin 1 and adenosine monophosphate-activated protein kinase, which have been identified as playing a key role in microcirculation and endothelial function. Here, an acute effect of a single dose of 100 mg or 300 mg Careless™ on microcirculation was investigated in a randomized, double-blind, crossover pilot study in ten healthy women to determine the effective dosage. Microcirculation and endothelial function were assessed by the Oxygen-to-see system and pulse amplitude tonometry (EndoPAT™), respectively. Cutaneous blood flow was increased over time by 100 mg (54% over pre-values, p = 0.0157) and 300 mg (35% over pre-value, p = 0.209) Careless™. The EndoPAT™ reactive hyperemia response was slightly improved 3 h after intake compared to pretesting with 300 mg Careless™. Furthermore, activation of endothelial nitric oxide synthase, as an important regulator for endothelial function, was tested in vitro in primary human umbilical vein endothelial cells. Careless™, after simulation of digestion, increased the activated form of endothelial nitric oxide synthase dose-dependently by 23% (300 µg/mL), 42% (1500 µg/mL), and 60% (3000 µg/mL) compared to the untreated control. In conclusion, the study suggests moderate beneficial effects of Careless™ on microcirculation, which is at least partly mediated by endothelial nitric oxide synthase activation.

  13. Effect of Learning Activity on Students' Motivation, Physical Activity Levels and Effort/Persistence

    ERIC Educational Resources Information Center

    Gao, Zan; Lee, Amelia M.; Xiang, Ping; Kosma, Maria

    2011-01-01

    The type of learning activity offered in physical education may influence students' motivational beliefs, physical activity participation and effort/persistence in class. However, most empirical studies have focused on the individual level rather than on the learner-content interactions. Accordingly, the potential effects of learning activities on…

  14. Is targeting eNOS a key mechanistic insight of cardiovascular defensive potentials of statins?

    PubMed

    Balakumar, Pitchai; Kathuria, Sonam; Taneja, Gaurav; Kalra, Sanjeev; Mahadevan, Nanjaian

    2012-01-01

    Statins are widely used in the treatment of dyslipidemia and associated cardiovascular abnormalities including atherosclerosis, hypertension and coronary heart disease. Needless to mention, statins have cholesterol-lowering effects by means of inhibiting 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA) reductase, a rate-limiting enzyme of cholesterol biosynthesis. Besides cholesterol-lowering effects, statins possess pleiotropic anti-inflammatory, anti-oxidant, anti-platelet and anti-fibrotic properties, which may additionally play imperative roles in statins-mediated cardiovascular protection. However, the precise mechanisms involved in the cardiovascular defensive potential of statins have not completely been elucidated. Intriguingly, a considerable number of studies demonstrated the potential modulatory role of statins on endothelial nitric oxide synthase (eNOS), a key enzyme involved in the regulation of cardiovascular function by generating endothelium-derived relaxing factor (often represented 'nitric oxide'). Worthy of note is that vascular generation of nitric oxide has beneficial anti-inflammatory, anti-platelet and vasodilatory actions. The upregulation of eNOS by statins is mediated through inhibition of synthesis of isoprenoids and subsequent prevention of isoprenylation of small GTPase Rho, whereas statin-induced activation of eNOS is mediated through activation of phosphotidylinositol-3-kinase (PI3K)/protein kinase B (PKB/Akt) signals. Additionally, statins enhance eNOS activation by abrogating caveolin-1 expression in vascular endothelium. In light of this view-point, we suggest in this review that eNOS upregulation and activation, in part, could play a fundamental role in the cardiovascular defensive potential of statins. The eNOS modulatory role of statins may have an imperative influence on the functional regulation of cardiovascular system and may offer new perspectives for the better use of statins in ameliorating cardiovascular disorders.

  15. The Akt1-eNOS axis illustrates the specificity of kinase-substrate relationships in vivo.

    PubMed

    Schleicher, Michael; Yu, Jun; Murata, Takahisa; Derakhshan, Berhad; Atochin, Dimitriy; Qian, Li; Kashiwagi, Satoshi; Di Lorenzo, Annarita; Harrison, Kenneth D; Huang, Paul L; Sessa, William C

    2009-08-04

    Akt1 is critical for many in vivo functions; however, the cell-specific substrates responsible remain to be defined. Here, we examine the importance of endothelial nitric oxide synthase (eNOS) as an Akt1 substrate by generating Akt1-deficient mice (Akt1(-/-) mice) carrying knock-in mutations (serine to aspartate or serine to alanine substitutions) of the critical Akt1 phosphorylation site on eNOS (serine 1176) that render the enzyme "constitutively active" or "less active." The eNOS mutations did not influence several phenotypes in Akt1(-/-) mice; however, the defective postnatal angiogenesis characteristic of Akt1(-/-) mice was rescued by crossing the Akt1(-/-) mice with mice carrying the constitutively active form of eNOS, but not by crossing with mice carrying the less active eNOS mutant. This genetic rescue resulted in the stabilization of hypoxia-inducible factor 1alpha (HIF-1alpha) and increased production of HIF-1alpha-responsive genes in vivo and in vitro. Thus, Akt1 regulates angiogenesis largely through phosphorylation of eNOS and NO-dependent signaling.

  16. Liposomal Tetrahydrobiopterin Preserves eNOS Coupling in the Post-ischemic Heart Conferring in vivo Cardioprotection

    PubMed Central

    Xie, Lin; Talukder, M A Hassan; Sun, Jian; Varadharaj, Saradhadevi; Zweier, Jay L.

    2015-01-01

    Tetrahydrobiopterin (BH4) is an essential cofactor of nitric oxide synthase (NOS), and reduced BH4 availability leads to endothelial NOS (eNOS) uncoupling and increased reactive oxygen species (ROS) generation. Questions remain regarding the functional state of eNOS and role of BH4 availability in the process of in vivo myocardial ischemia-reperfusion (I/R) injury. Rats were subjected to 60-minutes of in vivo left coronary artery occlusion and varying periods of reperfusion with or without pre-ischemic liposomal BH4 supplementation (1 mg/kg, iv). Myocardial infarction was correlated with cardiac BH4 content, eNOS protein level, NOS enzyme activity, and ROS generation. In the vehicle group, 60-min ischemia drastically reduced myocardial BH4 content in the area at risk (AAR) compared to non-ischemic (NI) area and the level remained lower during early reperfusion followed by recovery after 24-hr reperfusion. Activated eNOS protein level (eNOS Ser1177 phosphorylation) and NOS activity were also significantly reduced during ischemia and/or early reperfusion, but recovered after 24-hr reperfusion. With liposomal BH4 treatment, BH4 levels were identical in the AAR and NI area during ischemia and/or early reperfusion, and were significantly higher than with vehicle. BH4 pre-treatment preserved eNOS Ser1177 phosphorylation and NOS activity in the AAR, and significantly reduced myocardial ROS generation and infarction compared to vehicle. These findings provide direct evidence that in vivo I/R induces eNOS dysfunction secondary to BH4 depletion, and that pre-ischemic liposomal BH4 administration preserves eNOS function conferring cardioprotection with reduced oxidative stress. PMID:26116866

  17. Fundamental bound on the persistence and capacity of short-term memory stored as graded persistent activity.

    PubMed

    Koyluoglu, Onur Ozan; Pertzov, Yoni; Manohar, Sanjay; Husain, Masud; Fiete, Ila R

    2017-09-07

    It is widely believed that persistent neural activity underlies short-term memory. Yet, as we show, the degradation of information stored directly in such networks behaves differently from human short-term memory performance. We build a more general framework where memory is viewed as a problem of passing information through noisy channels whose degradation characteristics resemble those of persistent activity networks. If the brain first encoded the information appropriately before passing the information into such networks, the information can be stored substantially more faithfully. Within this framework, we derive a fundamental lower-bound on recall precision, which declines with storage duration and number of stored items. We show that human performance, though inconsistent with models involving direct (uncoded) storage in persistent activity networks, can be well-fit by the theoretical bound. This finding is consistent with the view that if the brain stores information in patterns of persistent activity, it might use codes that minimize the effects of noise, motivating the search for such codes in the brain.

  18. eNOS polymorphisms and clinical outcome in advanced HCC patients receiving sorafenib: final results of the ePHAS study.

    PubMed

    Casadei Gardini, Andrea; Marisi, Giorgia; Faloppi, Luca; Scarpi, Emanuela; Foschi, Francesco Giuseppe; Iavarone, Massimo; Lauletta, Gianfranco; Corbelli, Jody; Valgiusti, Martina; Facchetti, Floriana; Della Corte, Cristina; Neri, Luca Maria; Tamberi, Stefano; Cascinu, Stefano; Scartozzi, Mario; Amadori, Dino; Nanni, Oriana; Tenti, Elena; Ulivi, Paola; Frassineti, Giovanni Luca

    2016-05-10

    Sorafenib may reduce endothelial nitric oxide synthase (eNOS) activity by inhibiting vascular endothelial growth factor receptors (VEGF-R), leading to a decrease in nitric oxide production. In the Italian multicenter ePHAS (eNOS polymorphisms in HCC and sorafenib) study, we analyzed the role of eNOS polymorphisms in relation to clinical outcome in patients with hepatocellular carcinoma (HCC) receiving sorafenib. Our retrospective study included a training cohort of 41 HCC patients and a validation cohort of 87 HCC patients, all undergoing sorafenib treatment. Three eNOS polymorphisms (eNOS -786T>C, eNOS VNTR 27bp 4a/b and eNOS+894G>T) were analyzed by direct sequencing or Real Time PCR in relation to progression-free survival (PFS) and overall survival (OS) (log-rank test). In univariate analysis, training cohort patients homozygous for eNOS haplotype (HT1:T-4b at eNOS-786/eNOS VNTR) had a lower median PFS (2.6 vs. 5.8 months, P < 0.0001) and OS (3.2 vs.14.6 months, P = 0.024) than those with other haplotypes. In the validation set, patients homozygous for HT1 had a lower median PFS (2.0 vs. 6.7 months, P < 0.0001) and OS (6.4 vs.18.0 months, P < 0.0001) than those with other haplotypes. Multivariate analysis confirmed this haplotype as the only independent prognostic factor. Our results suggest that haplotype HT1 in the eNOS gene may be capable of identifying a subset of HCC patients who are resistant to sorafenib.

  19. eNOS polymorphisms and clinical outcome in advanced HCC patients receiving sorafenib: final results of the ePHAS study

    PubMed Central

    Faloppi, Luca; Scarpi, Emanuela; Foschi, Francesco Giuseppe; Iavarone, Massimo; Lauletta, Gianfranco; Corbelli, Jody; Valgiusti, Martina; Facchetti, Floriana; Corte, Cristina della; Neri, Luca Maria; Tamberi, Stefano; Cascinu, Stefano; Scartozzi, Mario; Amadori, Dino; Nanni, Oriana; Tenti, Elena

    2016-01-01

    Sorafenib may reduce endothelial nitric oxide synthase (eNOS) activity by inhibiting vascular endothelial growth factor receptors (VEGF-R), leading to a decrease in nitric oxide production. In the Italian multicenter ePHAS (eNOS polymorphisms in HCC and sorafenib) study, we analyzed the role of eNOS polymorphisms in relation to clinical outcome in patients with hepatocellular carcinoma (HCC) receiving sorafenib. Our retrospective study included a training cohort of 41 HCC patients and a validation cohort of 87 HCC patients, all undergoing sorafenib treatment. Three eNOS polymorphisms (eNOS -786T>C, eNOS VNTR 27bp 4a/b and eNOS+894G>T) were analyzed by direct sequencing or Real Time PCR in relation to progression-free survival (PFS) and overall survival (OS) (log-rank test). In univariate analysis, training cohort patients homozygous for eNOS haplotype (HT1:T-4b at eNOS-786/eNOS VNTR) had a lower median PFS (2.6 vs. 5.8 months, P < 0.0001) and OS (3.2 vs.14.6 months, P = 0.024) than those with other haplotypes. In the validation set, patients homozygous for HT1 had a lower median PFS (2.0 vs. 6.7 months, P < 0.0001) and OS (6.4 vs.18.0 months, P < 0.0001) than those with other haplotypes. Multivariate analysis confirmed this haplotype as the only independent prognostic factor. Our results suggest that haplotype HT1 in the eNOS gene may be capable of identifying a subset of HCC patients who are resistant to sorafenib. PMID:27058899

  20. eNOS Deficiency Predisposes Podocytes to Injury in Diabetes

    PubMed Central

    Yuen, Darren A.; Stead, Bailey E.; Zhang, Yanling; White, Kathryn E.; Kabir, M. Golam; Thai, Kerri; Advani, Suzanne L.; Connelly, Kim A.; Takano, Tomoko; Zhu, Lei; Cox, Alison J.; Kelly, Darren J.; Gibson, Ian W.; Takahashi, Takamune; Harris, Raymond C.

    2012-01-01

    Endothelial nitric oxide synthase (eNOS) deficiency may contribute to the pathogenesis of diabetic nephropathy in both experimental models and humans, but the underlying mechanism is not fully understood. Here, we studied two common sequelae of endothelial dysfunction in diabetes: glomerular capillary growth and effects on neighboring podocytes. Streptozotocin-induced diabetes increased glomerular capillary volume in both C57BL/6 and eNOS−/− mice. Inhibiting the vascular endothelial growth factor receptor attenuated albuminuria in diabetic C57BL/6 mice but not in diabetic eNOS−/− mice, even though it inhibited glomerular capillary enlargement in both. In eNOS−/− mice, an acute podocytopathy and heavy albuminuria occurred as early as 2 weeks after inducing diabetes, but treatment with either captopril or losartan prevented these effects. In vitro, serum derived from diabetic eNOS−/− mice augmented actin filament rearrangement in cultured podocytes. Furthermore, conditioned medium derived from eNOS−/− glomerular endothelial cells exposed to both high glucose and angiotensin II activated podocyte RhoA. Taken together, these results suggest that the combined effects of eNOS deficiency and hyperglycemia contribute to podocyte injury, highlighting the importance of communication between endothelial cells and podocytes in diabetes. Identifying mediators of this communication may lead to the future development of therapies targeting endothelial dysfunction in albuminuric individuals with diabetes. PMID:22997257

  1. Effects of Dietary Decosahexaenoic Acid (Dha) on eNOS in Human Coronary Artery Endothelial Cells

    PubMed Central

    Stebbins, Charles L.; Stice, James P.; Hart, C. Michael; Mbai, Fiona N.; Knowlton, Anne A.

    2015-01-01

    Endothelial dysfunction occurs in heart disease, and may reduce functional capacity via attenuations in peripheral blood flow. Dietary DHA may improve this dysfunction, but the mechanism is unknown. We determined if DHA enhances expression and activity of eNOS in cultured human coronary artery endothelial cells (HCAEC). HCAEC from 4 donors were treated with 5 nM, 50 nM, or 1 μM DHA for 7 days to model chronic DHA exposure. A trend for increased expression of eNOS and phospho-eNOS was observed with 5 and 50 nM DHA. DHA also enhanced expression of two proteins instrumental in activation of eNOS; phospho-Akt (5 and 50 nM) and HSP90 (50 nM and 1 μM). VEGF-induced activation of Akt increased NOx in treated (50 nM DHA) vs. untreated HCAEC (9.2±1.0 vs. 3.3±1.1 μmols/μg protein/μl). Findings suggest that DHA enhances eNOS and Akt activity, augments HSP90 expression, and increases NO bioavailability in response to Akt kinase activation PMID:18682551

  2. Persistence of endometrial activity after radiation therapy for cervical carcinoma

    SciTech Connect

    Barnhill, D.; Heller, P.; Dames, J.; Hoskins, W.; Gallup, D.; Park, R.

    1985-12-01

    Radiation therapy is a proved treatment for cervical carcinoma; however, it destroys ovarian function and has been thought to ablate the endometrium. Estrogen replacement therapy is often prescribed for patients with cervical carcinoma after radiation therapy. A review of records of six teaching hospitals revealed 16 patients who had endometrial sampling for uterine bleeding after standard radiation therapy for cervical carcinoma. Fifteen patients underwent dilatation and curettage, and one patient underwent total abdominal hysterectomy and bilateral salpingo-oophorectomy when a dilatation and curettage was unsuccessful. Six patients had fibrosis and inflammation of the endometrial cavity, seven had proliferative endometrium, one had cystic hyperplasia, one had atypical adenomatous hyperplasia, and one had adenocarcinoma. Although the number of patients who have an active endometrium after radiation therapy for cervical carcinoma is not known, this report demonstrates that proliferative endometrium may persist, and these patients may develop endometrial hyperplasia or adenocarcinoma. Studies have indicated that patients with normal endometrial glands have an increased risk of developing endometrial adenocarcinoma if they are treated with unopposed estrogen. Patients who have had radiation therapy for cervical carcinoma should be treated with estrogen and a progestational agent to avoid endometrial stimulation from unopposed estrogen therapy.

  3. Persistence of biologically active compounds in aquatic systems: Final report

    SciTech Connect

    Boelter, A.M.; Fernandez, J.D.; Meyer, J.S.; Sanchez, D.A.; Bergman, H.L.

    1986-11-01

    Waters collected from two study sites were tested for persistence of biologically active compounds as the waters percolated through experimental media. At the first site, the Paraho Lysimeter in Anvil Points, Colorado, two leachate samples (early and late flow in Spring 1983) were collected from each of four piles of processed oil shale overlain by different thicknesses of soil. Although water quality differed among samples, six of eight lysimeter leachates tested were acutely toxic to an aquatic invertebrate, Daphnia magna, and five were acutely toxic to fathead minnows (Pimephales promelas). Water collected from a modified in situ (MIS) retort was percolated through columns containing three different types of soil. Raw leachate from the MIS spent shale was acutely toxic to an aquatic invertebrate, Ceriodaphnia dubia. The toxicity of samples from nine pore volumes of retort water percolating through a column containing a sandy soil increased with successive pore volumes, but leachate toxicity never equaled the toxicity of the retort water. In contrast, the first pore volumes of retort water or reconstituted water leached through a sandy loam soil were more toxic than the retort water; however, the second pore volumes of leachates were not toxic. First pore volume leachates of retort water percolating through a sandy clay loam soil were much less toxic than the retort water; second pore volume leachates were not toxic.

  4. Soil activity and persistence of sulcotrione and mesotrione.

    PubMed

    Maeghe, L; Desmet, E M; Bulcke, R

    2004-01-01

    clearly sensitive to mesotrione and sulcotrione whereas sugar beet, red clover and lettuce are extremely sensitive to both herbicides in both experiment types. Bioassays and field experiments provide a detailed and complete information about soil activity and persistence of both herbicides.

  5. Removal of Persistent Organic Contaminants by Electrochemically Activated Sulfate.

    PubMed

    Farhat, Ali; Keller, Jurg; Tait, Stephan; Radjenovic, Jelena

    2015-12-15

    Solutions of sulfate have often been used as background electrolytes in the electrochemical degradation of contaminants and have been generally considered inert even when high-oxidation-power anodes such as boron-doped diamond (BDD) were employed. This study examines the role of sulfate by comparing electro-oxidation rates for seven persistent organic contaminants at BDD anodes in sulfate and inert nitrate anolytes. Sulfate yielded electro-oxidation rates 10-15 times higher for all target contaminants compared to the rates of nitrate anolyte. This electrochemical activation of sulfate was also observed at concentrations as low as 1.6 mM, which is relevant for many wastewaters. Electrolysis of diatrizoate in the presence of specific radical quenchers (tert-butanol and methanol) had a similar effect on electro-oxidation rates, illustrating a possible role of the hydroxyl radical ((•)OH) in the anodic formation of sulfate radical (SO4(•-)) species. The addition of 0.55 mM persulfate increased the electro-oxidation rate of diatrizoate in nitrate from 0.94 to 9.97 h(-1), suggesting a nonradical activation of persulfate. Overall findings indicate the formation of strong sulfate-derived oxidant species at BDD anodes when polarized at high potentials. This may have positive implications in the electro-oxidation of wastewaters containing sulfate. For example, the energy required for the 10-fold removal of diatrizoate was decreased from 45.6 to 2.44 kWh m(-3) by switching from nitrate to sulfate anolyte.

  6. The NCA sodium leak channel is required for persistent motor circuit activity that sustains locomotion.

    PubMed

    Gao, Shangbang; Xie, Lin; Kawano, Taizo; Po, Michelle D; Guan, Sihui; Zhen, Mei; Pirri, Jennifer K; Alkema, Mark J

    2015-02-26

    Persistent neural activity, a sustained circuit output that outlasts the stimuli, underlies short-term or working memory, as well as various mental representations. Molecular mechanisms that underlie persistent activity are not well understood. Combining in situ whole-cell patch clamping and quantitative locomotion analyses, we show here that the Caenorhabditis elegans neuromuscular system exhibits persistent rhythmic activity, and such an activity contributes to the sustainability of basal locomotion, and the maintenance of acceleration after stimulation. The NALCN family sodium leak channel regulates the resting membrane potential and excitability of invertebrate and vertebrate neurons. Our molecular genetics and electrophysiology analyses show that the C. elegans NALCN, NCA, activates a premotor interneuron network to potentiate persistent motor circuit activity and to sustain C. elegans locomotion. Collectively, these results reveal a mechanism for, and physiological function of, persistent neural activity using a simple animal model, providing potential mechanistic clues for working memory in other systems.

  7. Chinese medicine Tongxinluo modulates vascular endothelial function by inducing eNOS expression via the PI-3K/Akt/HIF-dependent signaling pathway.

    PubMed

    Liang, Jun Qing; Wu, Kun; Jia, Zhen Hua; Liu, Chang; Ding, Jin; Huang, Shan Na; Yin, Pei Pei; Wu, Xiang Chun; Wei, Cong; Wu, Yi Ling; Wang, Hong Yang

    2011-01-27

    To investigate the molecular mechanisms whereby the Chinese medicinal compound Tongxinluo improves vascular endothelial function through studying the induction of endothelial nitric oxide synthase (eNOS) and its upstream signaling pathway. Hyperhomocysteinemia was induced in Wistar rats by a methionine-rich diet followed by Tongxinluo treatment. The aorta ring was isolated for measuring vascular dilation of aorta and eNOS expression. Human umbilical vein endothelial cells (HUVECs) were transfected with AP-1, NF-κB, HRE or eNOS reporter plasmid followed by Tongxinluo exposure. Expression of the reporter genes was measured by luciferase assay. The level of eNOS was studied by western blot and the nitric oxide content was measured using the nitrate reductase method. HUVECs were also transiently transfected with the dominant negative mutant of HIF-1, PI-3K or Akt to explore the role of HIF and PI-3K/Akt pathway in eNOS induction by Tongxinluo. Tongxinluo could significantly up-regulate the expression of eNOS in the aortic tissue and improve the endothelium-dependent vasodilation of the aorta ring. Additionally, Tongxinluo at various doses could significantly enhance the expression of HRE and eNOS reporter gene as well as up-regulate the protein level of eNOS. Meanwhile, Tongxinluo caused a dose-dependent increase in the NO content in the supernatant of HUVECs. Suppression of HIF-1 activation by DN-HIF or inhibition of PI-3K/Akt pathway by ΔP85 or DN-Akt both attenuated HRE reporter gene activation and eNOS induction by Tongxinluo. Tongxinluo, a compound Chinese traditional medicine, up-regulates the expression of eNOS via the PI-3K/Akt/HIF-dependent signaling pathway, thus improving the endothelium-dependent vasodilation. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

  8. Persistent active avoidance correlates with activity in prelimbic cortex and ventral striatum

    PubMed Central

    Bravo-Rivera, Christian; Roman-Ortiz, Ciorana; Montesinos-Cartagena, Marlian; Quirk, Gregory J.

    2015-01-01

    Persistent avoidance is a prominent symptom of anxiety disorders and is often resistant to extinction-based therapies. Little is known about the circuitry mediating persistent avoidance. Using a recently described platform-mediated active avoidance task, we assessed activity in several structures with c-Fos immuno-labeling. In Task 1, rats were conditioned to avoid a tone-signaled shock by moving to a safe platform, and then were extinguished over two days. One day later, failure to retrieve extinction correlated with increased activity in the prelimbic prefrontal cortex (PL), ventral striatum (VS), and basal amygdala (BA), and decreased activity in infralimbic prefrontal cortex (IL), consistent with pharmacological inactivation studies. In Task 2, the platform was removed during extinction training and fear (suppression of bar pressing) was extinguished to criterion over 3–5 days. The platform was then returned in a post-extinction test. Under these conditions, avoidance levels were equivalent to Experiment 1 and correlated with increased activity in PL and VS, but there was no correlation with activity in IL or BA. Thus, persistent avoidance can occur independently of deficits in fear extinction and its associated structures. PMID:26236209

  9. L-theanine promotes nitric oxide production in endothelial cells through eNOS phosphorylation.

    PubMed

    Siamwala, Jamila H; Dias, Paul M; Majumder, Syamantak; Joshi, Manoj K; Sinkar, Vilas P; Banerjee, Gautam; Chatterjee, Suvro

    2013-03-01

    Consumption of tea (Camellia sinensis) improves vascular function and is linked to lowering the risk of cardiovascular disease. Endothelial nitric oxide is the key regulator of vascular functions in endothelium. In this study, we establish that l-theanine, a non-protein amino-acid found in tea, promotes nitric oxide (NO) production in endothelial cells. l-theanine potentiated NO production in endothelial cells was evaluated using Griess reaction, NO sensitive electrode and a NO specific fluorescent probe (4-amino-5-methylamino-2',7'-difluororescein diacetate). l-Theanine induced NO production was partially attenuated in presence of l-NAME or l-NIO and completely abolished using eNOS siRNA. eNOS activation was Ca(2+) and Akt independent, as assessed by fluo-4AM and immunoblotting experiments, respectively and was associated with phosphorylation of eNOS Ser 1177. eNOS phosphorylation was inhibited in the presence of ERK1/2 inhibitor, PD-98059 and partially inhibited by PI3K inhibitor, LY-294002 and Wortmanin suggesting PI3K-ERK1/2 dependent pathway. Increased NO production was associated with vasodilation in ex ovo (chorioallantoic membrane) model. These results demonstrated that l-theanine administration in vitro activated ERK/eNOS resulting in enhanced NO production and thereby vasodilation in the artery. The results of our experiments are suggestive of l-theanine mediated vascular health benefits of tea.

  10. Stress, Coping, and Infectious Illness: Persistently Low Natural Killer Cell Activity as a Host Risk Factor.

    DTIC Science & Technology

    1988-03-14

    Persistently Low Natural Killer Cell Activity as a Host Risk Factor " 12 PERSONAL AUTHOR(S) Sandra M. Levy, Ph.D., Ronald B. Herberman, M.D., Theresa...killer (NK) cell activity. In this prevbus work, a subgroup of individuals characterized by persistently low NK activity, and self-reported depression and... depression and chronic anxiety. In a very preliminary fashion, we have also found a trend of association between this low NK activity pattern, and some

  11. Efficient implementation of weighted ENO schemes

    NASA Technical Reports Server (NTRS)

    Jiang, Guang-Shan; Shu, Chi-Wang

    1995-01-01

    In this paper, we further analyze, test, modify and improve the high order WENO (weighted essentially non-oscillatory) finite difference schemes of Liu, Osher and Chan. It was shown by Liu et al. that WENO schemes constructed from the r-th order (in L1 norm) ENO schemes are (r+1)-th order accurate. We propose a new way of measuring the smoothness of a numerical solution, emulating the idea of minimizing the total variation of the approximation, which results in a 5-th order WENO scheme for the case r = 3, instead of the 4-th order with the original smoothness measurement by Liu et al. This 5-th order WENO scheme is as fast as the 4-th order WENO scheme of Liu et al., and both schemes are about twice as fast as the 4-th order ENO schemes on vector supercomputers and as fast on serial and parallel computers. For Euler systems of gas dynamics, we suggest computing the weights from pressure and entropy instead of the characteristic values to simplify the costly characteristic procedure. The resulting WENO schemes are about twice as fast as the WENO schemes using the characteristic decompositions to compute weights, and work well for problems which do not contain strong shocks or strong reflected waves. We also prove that, for conservation laws with smooth solutions, all WENO schemes are convergent. Many numerical tests, including the 1D steady state nozzle flow problem and 2D shock entropy wave interaction problem, are presented to demonstrate the remarkable capability of the WENO schemes, especially the WENO scheme using the new smoothness measurement, in resolving complicated shock and flow structures. We have also applied Yang's artificial compression method to the WENO schemes to sharpen contact discontinuities.

  12. Mutation at the tomato excessive number of floral organs (ENO) locus impairs floral meristem development, thus promoting an increased number of floral organs and fruit size.

    PubMed

    Fernández-Lozano, Antonia; Yuste-Lisbona, Fernando J; Pérez-Martín, Fernando; Pineda, Benito; Moreno, Vicente; Lozano, Rafael; Angosto, Trinidad

    2015-03-01

    A novel tomato (Solanum lycopersicum L.) mutant affected in reproductive development, excessive number of floral organs (eno), is described in this study. The eno plants yielded flowers with a higher number of floral organs in the three innermost floral whorls and larger fruits than those found in wild-type plants. Scanning-electron microscopy study indicated that the rise in floral organ number and fruit size correlates with an increased size of floral meristem at early developmental stages. It has been reported that mutation at the FASCIATED (FAS) gene causes the development of flowers with supernumerary organs; however, complementation test and genetic mapping analyses proved that ENO is not an allele of the FAS locus. Furthermore, expression of WUSCHEL (SlWUS) and INHIBITOR OF MERISTEM ACTIVITY (IMA), the two main regulators of floral meristem activity in tomato, is altered in eno but not in fas flowers indicating that ENO could exert its function in the floral meristem independently of FAS. Interestingly, the eno mutation delayed the expression of IMA leading to a prolonged expression of SlWUS, which would explain the greater size of floral meristem. Taken together, results showed that ENO plays a significant role in the genetic pathway regulating tomato floral meristem development. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  13. Negligible effect of eNOS palmitoylation on fatty acid regulation of contraction in ventricular myocytes from healthy and hypertensive rats.

    PubMed

    Jin, Chun Li; Wu, Yu Na; Jang, Ji Hyun; Zhao, Zai Hao; Oh, Goo Taeg; Kim, Sung Joon; Zhang, Yin Hua

    2017-04-25

    S-palmitoylation is an important post-translational modification that affects the translocation and the activity of target proteins in a variety of cell types including cardiomyocytes. Since endothelial nitric oxide synthase (eNOS) is known to be palmitoylated and the activity of eNOS is essential in fatty acid-dependent β-oxidation in muscle, we aimed to test whether palmitoylation of eNOS is involved in palmitic acid (PA) regulation of left ventricular (LV) myocyte contraction from healthy (sham) and hypertensive (HTN) rats. Our results showed that PA, a predominant metabolic substrate for cardiac β-oxidation, significantly increased contraction and oxygen consumption rate (OCR) in LV myocytes from sham. Nω-nitro-L-arginine methyl ester hydrochloride (L-NAME) or eNOS gene deletion prevented PA regulation of the myocyte contraction or OCR, indicating the pivotal role of eNOS in mediating the effects of PA in cardiac myocytes. PA increased the palmitoylation of eNOS in LV myocytes and depalmitoylation with 2-bromopalmitate (2BP; 100 μM) abolished the increment. Furthermore, although PA did not increase eNOS-Ser(1177), 2BP reduced eNOS-Ser(1177) with and without PA. Intriguingly, PA-induced increases in contraction and OCR were unaffected by 2BP treatment. In HTN, PA did not affect eNOS palmitoylation, eNOS-Ser(1177), or myocyte contraction. However, 2BP diminished eNOS palmitoylation and eNOS-Ser(1177) in the presence and absence of PA but did not change myocyte contraction. Collectively, our results confirm eNOS palmitoylation in LV myocytes from sham and HTN rats and its upregulation by PA in sham. However, such post-transcriptional modification plays negligible role in PA regulation of myocyte contraction and mitochondrial activity in sham and HTN.

  14. Physical activity, restrictions in activity, and body mass index among urban children with persistent asthma.

    PubMed

    Holderness, Heather; Chin, Nancy; Ossip, Deborah J; Fagnano, Maria; Reznik, Marina; Halterman, Jill S

    2017-04-01

    Asthma and obesity are public health problems that disproportionately affect underserved children. Urban children with asthma may be limited in their participation in physical activity, further increasing their risk for overweight. To determine the prevalence of overweight and obesity among high-risk children with persistent asthma, to assess physical activity and activity restrictions by level of asthma control, and to evaluate whether activity is associated with weight status. We analyzed baseline data from 324 urban children with poorly controlled asthma (3-10 years old) enrolled in the School-Based Telemedicine Enhanced Asthma Management program in Rochester, New York. Caregivers reported their child's asthma symptoms, physical activity, and activity limitation, and height and weight were measured. Most children were black (59%), and 69% had Medicaid. Almost half (47%) of children had symptoms that indicated poorly controlled asthma, 15% were overweight, and 31% were obese. Few children (39%) participated in 1 or more hour of physical activity per day. In addition, most (85%) did not walk to and from school, 38% did not have any recess in school, and 35% reported no safe place to exercise. More children with very poorly controlled asthma symptoms, compared with children with more mild symptoms, reported limitation in gym class (58% vs 43%, P = .01) and even in mild activities (28% vs 14%, P = .004). Children with activity limitation were at significantly greater odds of being overweight or obese (odds ratio, 2.1; 95% confidence interval, 1.2-3.8). Many children with persistent asthma are overweight or obese, have limited opportunity for activity, and experience activity limitations. Efforts are needed to optimize asthma control and provide opportunity for increased physical activity in and outside school. ClinicalTrials.gov Identifier: NCT01650844. Copyright © 2017 American College of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights

  15. Active transport in complex media: Relationship between persistence and superdiffusion

    NASA Astrophysics Data System (ADS)

    Despósito, Marcelo A.; Pallavicini, Carla; Levi, Valeria; Bruno, Luciana

    2011-03-01

    We study the relationship between anomalous diffusion and persistent motion of micron-sized particles moving in a viscoelastic environment and subjected to an external noise. In the framework of a generalized Langevin equation, we compare the analytical expressions of the mean square displacement and the mean cosine of the turning angle. Both magnitudes can be easily computed from the particles trajectories, and allow us to investigate the different anomalous regimes typically obtained, for instance, in single particle tracking experiments within living cells. Finally, we analyze the directional changes occurring during the motion of pigment organelles driven by molecular motors in Xenopus laevis melanocytes, as an example of application of our model.

  16. Proteomic Analysis of Bovine Axonemes Exposed to Acute Alcohol: Role of eNOS and HSP90 in Cilia Stimulation

    PubMed Central

    Simet, Samantha M.; Pavlik, Jacqueline A.; Sisson, Joseph H.

    2012-01-01

    Background Cilia are fingerlike motor-driven organelles, which propel inhaled particles and mucus from the lung and airways. We have previously shown that brief alcohol exposure stimulates ciliary motility through an endothelial nitric oxide (eNOS)-dependent pathway localized in the ciliary metabolon. However, the signaling molecules of the ciliary metabolon involved in alcohol-triggered cilia beat frequency (CBF) stimulation upstream of eNOS activation are unknown. Methods and Results We hypothesized that brief alcohol exposure alters threonine and serine phosphorylation of proteins involved in stimulating ciliary beat frequency. Two-dimensional electrophoresis indicated both increases and deceases in the serine and threonine phosphorylation states of several proteins. One of the proteins identified was heat shock protein 90 (HSP90), which undergoes increased threonine phosphorylation after brief alcohol exposure. Because HSP90 has been shown to associate with eNOS in lung tissue, we hypothesized that HSP90 is a key component in alcohol-triggered eNOS activation and that these two proteins co-localize within the ciliary metabolon. Immunofluorescence experiments demonstrate that eNOS and HSP90 co-localize within basal bodies of the ciliary metabolon and partially translocate to the axoneme upon brief alcohol exposure. Pretreatment with geldanamycin, which disrupts HSP90 chaperone functions, prevented eNOS-HSP90 association and prevented the translocation of eNOS from the ciliary metabolon to the axoneme. Functional cilia motility studies revealed that geldanamycin blocked alcohol-stimulated ciliary motility in bovine bronchial epithelial cells and mouse tracheal rings. Conclusions Based on the HSP90 localization with eNOS, alcohol activation of HSP90 phosphorylation, and geldanamycin’s ability inhibit HSP90-eNOS association, prevent eNOS translocation to the axoneme, and block alcohol-stimulated ciliary motility, we conclude that alcohol-induced cilia stimulation

  17. ET-1 Stimulates Superoxide Production by eNOS Following Exposure of Vascular Endothelial Cells to Endotoxin.

    PubMed

    Gopalakrishna, Deepak; Pennington, Samantha; Karaa, Amel; Clemens, Mark G

    2016-07-01

    It has been shown that microcirculation is hypersensitized to endothelin1 (ET-1) following endotoxin (lipopolysaccharide [LPS]) treatment leading to an increased vasopressor response. This may be related in part to decreased activation of endothelial nitric oxide synthase (eNOS) by ET-1. eNOS can also be uncoupled to produce superoxide (O2). This aberrant eNOS activity could further contribute to the hyperconstriction and injury caused by ET-1 following LPS. We therefore tested whether LPS affects ROS production by vascular endothelial cells and whether and how this effect is altered by ET-1. Human umbilical vein endothelial cells (HUVEC) or human microvascular endothelial cells (HMEC) were subjected to a 6-h treatment with LPS (250 ng/mL) or LPS and sepiapterin (100 μM) followed by a 30-min treatment with 100 μM L-Iminoethyl Ornithine (L-NIO) an irreversible eNOS inhibitor and 30-min treatment with ET-1 (10 nM). Conversion of [H]L-arginine to [H]L-citrulline was used to measure eNOS activity. Superoxide dismutase (SOD) inhibitable reduction of Cytochrome-C, dihydro carboxy fluorescein (DCF), and Mitosox was used to estimate ROS. LT-SDS PAGE was used to assess the degree of monomerization of the eNOS homodimer. Stimulation of HUVECs with ET-1 significantly increased NO synthesis by 1.4-fold (P < 0.05). ET-1 stimulation of LPS-treated HUVECs failed to increase NO production. Western blot for eNOS protein showed no change in eNOS protein levels. LPS alone resulted in an insignificant increase in ROS production as measured by cytochrome C that was increased 4.6-fold by ET-1 stimulation (P < 0.05). L-NIO significantly decreased ET-1-induced ROS production (P < 0.05). Sepiapterin significantly decreased ROS production in both; unstimulated and ET-1-stimulated LPS-treated groups, but did not restore NO production. DCF experiments confirmed intracellular ROS while Mitosox suggested a non-mitochondrial source. ET-1 treatment following a chronic LPS stress

  18. Why people with fibromyalgia persist in activity despite the increasing pain? A Delphi Study of the content of the Clinic Scale of Persistence in Activity in Fibromyalgia.

    PubMed

    Torres, Xavier; Herrero, Maria Jesús; Martí, Mireia; Conesa, Arantxa; Valdés, Manuel; Arias, Anna; Gómez, Emili; Collado, Antonio

    2013-01-01

    There is evidence of the relevance of fear, anxiety and avoidance of activity in the maintenance of pain in fibromyalgia. Recently, an opposite pattern based on the persistence in activity has been described. To date, the cognitions that impede modifying this pattern are unknown. Therefore, the aim of this study is to reach consensus on the content of an instrument that assesses those cognitions. A Delphi method was applied to reach consensus on the content of the Clinic Scale of Persistence in Activity in Fibromyalgia (CCAP-FM). After three rounds of consultation, an acceptable consensus was reached. Those items that received an average rating of relevance lower than 5/10 and that at least the 75% of experts recommended removing were excluded. The preliminary questionnaire of persistence in activity was composed of 30 items. The consensus on the content of the CCAP-FM will allow advancing towards the assessment of the relation between the modification of the cognitions responsible for the maintenance of the persistence in activity and the clinical improvement in people with fibromyalgia. Copyright © 2011 SEP y SEPB. Published by Elsevier Espana. All rights reserved.

  19. Histone deacetylase inhibitors promote eNOS expression in vascular smooth muscle cells and suppress hypoxia-induced cell growth.

    PubMed

    Tan, Xiaoling; Feng, Lan; Huang, Xiaoyong; Yang, Yidong; Yang, Chengzhong; Gao, Yuqi

    2017-03-07

    Hypoxia stimulates excessive growth of vascular smooth muscle cells (VSMCs) contributing to vascular remodelling. Recent studies have shown that histone deacetylase inhibitors (HDIs) suppress VSMC proliferation and activate eNOS expression. However, the effects of HDI on hypoxia-induced VSMC growth and the role of activated eNOS in VSMCs are unclear. Using an EdU incorporation assay and flow cytometry analysis, we found that the HDIs, butyrate (Bur) and suberoylanilide hydroxamic acid (SAHA) significantly suppressed the proliferation of hypoxic VSMC lines and induced apoptosis. Remarkable induction of cleaved caspase 3, p21 expression and reduction of PCNA expression were also observed. Increased eNOS expression and enhanced NO secretion by hypoxic VSMC lines were detected using Bur or SAHA treatment. Knockdown of eNOS by siRNA transfection or exposure of hypoxic VSMCs to NO scavengers weakened the effects of Bur and SAHA on the growth of hypoxic VSMCs. In animal experiments, administration of Bur to Wistar rats exposed to hypobaric hypoxia for 28 days ameliorated the thickness and collagen deposition in pulmonary artery walls. Although the mean pulmonary arterial pressure (mPAP) was not obviously decreased with Bur in hypoxic rats, right ventricle hypertrophy index (RVHI) was decreased and the oxygen partial pressure of arterial blood was elevated. Furthermore, cell viability was decreased and eNOS and cleaved caspase 3 were induced in HDI-treated rat pulmonary arterial SMCs. These findings imply that HDIs prevent hypoxia-induced VSMC growth, in correlation with activated eNOS expression and activity in hypoxic VSMCs.

  20. Immune activation and HIV persistence: Implications for curative approaches to HIV infection

    PubMed Central

    Klatt, Nichole R.; Chomont, Nicolas; Douek, Daniel C.; Deeks, Steven G.

    2013-01-01

    Summary Despite complete or near-complete suppression of human immunodeficiency virus (HIV) replication with combination antiretroviral therapy, both HIV and chronic inflammation/immune dysfunction persist indefinitely. Untangling the association between the virus and the host immune environment during therapy might lead to novel interventions aimed at either curing the infection or preventing the development of inflammation-associated end-organ disease. Chronic inflammation and immune dysfunction might lead to HIV persistence by causing virus production, generating new target cells, enabling infecting of activated and resting target cells, altering the migration patterns of susceptible target cells, increasing the proliferation of infected cells, and preventing normal HIV-specific clearance mechanisms from function. Chronic HIV production or replication might contribute to persistent inflammation and immune dysfunction. The rapidly evolving data on these issues strongly suggest that a vicious cycle might exist in which HIV persistence causes inflammation that in turn contributes to HIV persistence. PMID:23772629

  1. Persistent neural activity in the prefrontal cortex: a mechanism by which BDNF regulates working memory?

    PubMed

    Galloway, Evan M; Woo, Newton H; Lu, Bai

    2008-01-01

    Working memory is the ability to maintain representations of task-relevant information for short periods of time to guide subsequent actions or make decisions. Neurons of the prefrontal cortex exhibit persistent firing during the delay period of working memory tasks. Despite extensive studies, the mechanisms underlying this persistent neural activity remain largely obscure. The neurotransmitter systems of dopamine, NMDA, and GABA have been implicated, but further investigations are necessary to establish their precise roles and relationships. Recent research has suggested a new component: brain-derived neurotrophic factor (BDNF) and its high-affinity receptor, TrkB. We review the research on persistent activity and suggest that BDNF/TrkB signaling in a distinct class of interneurons plays an important role in organizing persistent neural activity at the single-neuron and network levels.

  2. The Role of Active Learning in College Student Persistence

    ERIC Educational Resources Information Center

    Braxton, John M.; Jones, Willis A.; Hirschy, Amy S.; Hartley, Harold V., III

    2008-01-01

    Active learning, which entails any class activity that "involves students doing things and thinking about the things that they are doing," stands as an important pedagogical practice. Discussion, the types of questions faculty ask students in class, role playing, cooperative learning, debates, and the types of questions faculty ask on examinations…

  3. High concentration of glucose inhibits glomerular endothelial eNOS through a PKC mechanism.

    PubMed

    Chu, Shaoyou; Bohlen, H Glenn

    2004-09-01

    Kidney glomeruli are important targets of diabetic nephropathy. We hypothesized a high concentration of glucose could suppress glomerular endothelial nitric oxide synthase (eNOS) by a protein kinase C (PKC) mechanism, as has been found in other tissues. Mouse kidney slices (150-200 microm) were bathed in Hanks' solution with 100 microM L-arginine and exposed to either 5 or 20-30 mM D-glucose. Immunofluorescence identified only eNOS in normal mouse glomeruli. Measurements of glomerular NO concentration with NO-sensitive fluorescent dye (4,5-diaminofluorescein diacetate) using confocal microscopy and NO-sensitive microelectrodes verified that resting glomeruli had active production of NO that was inhibited by N(G)-nitro-L-arginine methyl ester. High-concentration (20-30 mM) D-glucose inhibited 60-70% of the NO production within 15-30 min; L-glucose at the same concentration did not have any effect. Inhibition of PKC-beta with 100 nM ruboxistaurin prevented eNOS suppression in high-glucose media. Activation of PKC with 100 nM phorbol ester also suppressed the glomerular NO concentration. We concluded that eNOS in the renal glomerular capillary endothelial cells is suppressed by activity of PKC at high-glucose concentrations comparable to those in diabetic animals and humans. The consequence is a rapid decline in the generation of NO in the glomerular endothelial cells in the presence of a high concentration of glucose.

  4. Impact of persistence and non-persistence in leisure time physical activity on coronary heart disease and all-cause mortality: The Copenhagen City Heart Study.

    PubMed

    Schnohr, Peter; O'Keefe, James H; Lange, Peter; Jensen, Gorm Boje; Marott, Jacob Louis

    2017-01-01

    Aims The aim of this study was to investigate the impact of persistence and non-persistence in leisure time physical activity on coronary heart disease and all-cause mortality. Methods and results In the Copenhagen City Heart Study, we prospectively followed 12,314 healthy subjects for 33 years of maximum follow-up with at least two repeated measures of physical activity. The association between persistence and non-persistence in leisure time physical activity, coronary heart disease and all-cause mortality were assessed by multivariable Cox regression analyses. Coronary heart disease mortality for persistent physical activity in leisure compared to persistent sedentary activity were: light hazard ratio (HR) 0.76; 95% confidence interval (CI) 0.63-0.92, moderate HR 0.52; 95% CI 0.41-0.67, and high physical activity HR 0.51; 95% CI, 0.30-0.88. The differences in longevity were 2.8 years for light, 4.5 years for moderate and 5.5 years for high physical activity. A substantial increase in physical activity was associated with lower coronary heart disease mortality (HR 0.75; 95% CI 0.52-1.08) corresponding to 2.4 years longer life, whereas a substantial decrease in physical activity was associated with higher coronary heart disease mortality (HR 1.61; 95% CI 1.11-2.33) corresponding to 4.2 years shorter life than the unchanged group. A similar pattern was observed for all-cause mortality. Conclusion We found inverse dose-response relationships between persistent leisure time physical activity and both coronary heart disease and all-cause mortality. A substantial increase in physical activity was associated with a significant gain in longevity, whereas a decrease in physical activity was associated with even greater loss of longevity.

  5. Geranylgeranylacetone protects against cerebral ischemia and reperfusion injury: HSP90 and eNOS phosphorylation involved.

    PubMed

    He, Dake; Song, Xiaoqing; Li, Ling

    2015-03-02

    Cerebral ischemia and reperfusion (I/R) can trigger a cytotoxic cascade with overflow of reactive oxygen species, paradoxically causing neurological dysfunction, redox imbalance, inflammation and apoptosis. The present study aims to investigate the effect of geranylgeranylacetone(GGA) on cerebral I/R injury and the underlying mechanism. The results demonstrated that cerebral I/R increased the neurological function abnormality, brain edema, inflammation and oxidative injury in rats as well as the cognitive impairment, which was significantly reversed by GGA in a dose-dependent manner. GGA also suppressed the cell injury and apoptosis caused by cerebral I/R. Moreover, the protective effect of GGA was found to involve heat shock protein 90 (HSP90) and phosphorylated endothelial nitric oxide synthase (eNOS) expression and activity. Both the HSP90 and eNOS inhibitor abolished the effect of GGA. The data showed that GGA could protect rats against cerebral I/R injury, which may be related to the induction of HSP90 and activation of eNOS. Copyright © 2014 Elsevier B.V. All rights reserved.

  6. eNOS correlates with mitochondrial biogenesis in hearts of congenital heart disease with cyanosis.

    PubMed

    Xiao, Juan; Chen, Lin; Wang, Xuefeng; Liu, Mei; Xiao, Yingbin

    2012-09-01

    Mitochondrial biogenesis program in heart appears to exhibit adaptive remodeling following biomechanical and oxidative stress. The adaptive mechanisms that protect myocardium metabolism during hypoxia are coordinated in part by nitric oxide (NO). To observe mitochondrial biogenesis and nitric oxide synthase (NOS) expression in hearts of congenital heart disease with cyanosis, discuss mitochondrial response to chronic hypoxia in myocardium. 20 patients with cyanotic (n=10) or acyanotic cardiac defects (n=10) were investigated. Samples from the right ventricular outflow tract myocardium taken during operation were studied. Morphometric analysis of mitochondria was performed with transmission electron microscope. Relative mtDNA/nDNA ratio was determined with real-time PCR. Cytochrome c oxidase subunit I (COXI), peroxisome-proliferator-activated receptor γ coactivator-1α (PGC-1α), nuclear respiratory factor 1 (NRF1), and mitochondrial transcription factor A (Tfam) transcript levels were detected by real-time fluorescent RT-PCR. COXI and nNOS, iNOS and eNOS protein levels were measured with western blot. Mitochondrial volume density (Vv) and numerical density (Nv) were significantly elevated in patients with cyanotic compared to acyanotic congenital heart disease. Elevated mtDNA and up-regulated COXI, PGC-1α, NRF1 and Tfam mRNA levels were observed in cyanotic patients. Protein levels of COXI and eNOS were significantly higher in the myocardium of cyanotic than of acyanotic patients. PGC-1α transcript levels correlated with the levels of eNOS. Mitochondrial biogenesis is activated in right ventricular outflow tract myocardium in congenital heart disease with cyanosis, which could be the adaptive response to chronic hypoxia and possibly involves eNOS up-regulation.

  7. Activated ClpP kills persisters and eradicates a chronic biofilm infection.

    SciTech Connect

    Conlon, Brian P.; Nakayasu, Ernesto S.; Fleck, Laura E.; LaFleur, Michael D.; Isabella, Vincent M.; Coleman, K.; Leonard, Steve N.; Smith, Richard D.; Adkins, Joshua N.; Lewis, Kim

    2013-11-21

    The current antibiotic crisis stems from two distinct phenomena-drug resistance, and drug tolerance. Resistance mechanisms such as drug efflux or modification prevent antibiotics from binding to their targets 1, allowing pathogens to grow. Antibiotic tolerance is the property of persister cells, phenotypic variants of regular bacteria 2. Antibiotics kill by corrupting targets, but these are inactive in dormant persisters, leading to tolerance. Persisters were first identified by Joseph Bigger in 1944, when he discovered a surviving sub-population of Staphylococcus following treatment with penicillin3. Persisters are largely responsible for recalcitrance of chronic diseases such as tuberculosis, and various infections associated with biofilms - endocarditis, osteomyelitis, infections of catheters and indwelling devices, and deep-seated infections of soft tissues 4. There are a number of redundant pathways involved in persister formation5,6 precluding development of drugs inhibiting their formation. The acyldepsipeptide antibiotic (ADEP 4) has been shown to activate the ClpP protease resulting in death of growing cells 7. Here we show that ADEP4 activated ClpP becomes a fairly non-specific protease and kills persister cells by degradation of over 400 intracellular targets. clpP mutants are resistant to ADEP4 7, but we find that they display increased susceptibility to killing by a range of conventional antibiotics. Combining ADEP4 with rifampicin leads to eradication of persisters, stationary and biofilm populations of Staphylococcus aureus in vitro and in a deep-seated murine infection. Target corruption/activation provides an approach to killing persisters and eradicating chronic infections.

  8. Role of reactive oxygen species in the signalling cascade of cyclosporine A-mediated up-regulation of eNOS in vascular endothelial cells

    PubMed Central

    López-Ongil, S; Hernández-Perera, O; Navarro-Antolín, J; Pérez de Lema, G; Rodríguez-Puyol, M; Lamas, S; Rodríguez-Puyol, D

    1998-01-01

    Cyclosporine A (CsA) increases eNOS mRNA expression in bovine cultured aortic endothelial cells (BAEC). As some effects of CsA may be mediated by reactive oxygen species (ROS), present experiments were devoted to test the hypothesis that the CsA-induced eNOS up-regulation could be dependent on an increased synthesis of ROS.CsA induced a dose-dependent increase of ROS synthesis, with the two fluorescent probes used, DHR123 (CsA 1 μM: 305±7% over control) and H2DCFDA (CsA 1 μM: 178±6% over control).Two ROS generating systems, xanthine plus xanthine oxidase (XXO) and glucose oxidase (GO), increased the expression of eNOS mRNA in BAEC, an effect which was maximal after 8 h of incubation (XXO: 168±21% of control values. GO: 208±18% of control values). The ROS-dependent increased eNOS mRNA expression was followed by an increase in eNOS activity.The effect of CsA on eNOS mRNA expression was abrogated by catalase, and superoxide dismutase (SOD). In contrast, the antioxidant PDTC augmented eNOS mRNA expression, both in basal conditions and in the presence of CsA.The potential participation of the transcription factor AP-1 was explored. Electrophoretic mobility shift assays were consistent with an increase in AP-1 DNA-binding activity in BAEC treated with CsA or glucose oxidase.The present results support a role for ROS, particularly superoxide anion and hydrogen peroxide, as mediators of the CsA-induced eNOS mRNA up-regulation. Furthermore, they situate ROS as potential regulators of gene expression in endothelial cells, both in physiological and pathophysiological situations. PMID:9647467

  9. Persistence of biologically active compounds in soil: Final report

    SciTech Connect

    Williams, S.E.

    1987-02-01

    This document describes the long-term effects of soil-applied oil shale process water on the VA fungi and Rhizobium bacteria in a native soil. Techniques include assessing the VA fungal activity at field treatment plots and using treated field soils in a bioassay to determine VA infection and Rhizobium-nodulation potentials four years after process water application. 52 refs., 32 figs., 2 tabs.

  10. Persistent neural activity during the maintenance of spatial position in working memory.

    PubMed

    Srimal, Riju; Curtis, Clayton E

    2008-01-01

    The mechanism for the short-term maintenance of information involves persistent neural activity during the retention interval, which forms a bridge between the cued memoranda and its later contingent response. Here, we used event-related functional magnetic resonance imaging to identify cortical areas with activity that persists throughout working memory delays with the goal of testing if such activity represents visuospatial attention or prospective saccade goals. We did so by comparing two spatial working memory tasks. During a memory-guided saccade (MGS) task, a location was maintained during a delay after which a saccade was generated to the remembered location. During a spatial item recognition (SIR) task identical to MGS until after the delay, a button press indicated whether a newly cued location matched the remembered location. Activity in frontal and parietal areas persisted above baseline and was greater in the hemisphere contralateral to the cued visual field. However, delay-period activity did not differ between the tasks. Notably, in the putative frontal eye field (FEF), delay period activity did not differ despite that the precise metrics of the memory-guided saccade were known during the MGS delay and saccades were never made in SIR. Persistent FEF activity may therefore represent a prioritized attentional map of space, rather than the metrics for saccades.

  11. Systematic Survey of Serine Hydrolase Activity in Mycobacterium tuberculosis Defines Changes Associated with Persistence

    SciTech Connect

    Ortega, Corrie; Anderson, Lindsey N.; Frando, Andrew; Sadler, Natalie C.; Brown, Robert W.; Smith, Richard D.; Wright, Aaron T.; Grundner, Christoph

    2016-02-01

    The transition between replication and non-replication underlies much of Mycobacterium tuberculosis (Mtb) pathogenicity, as non- or slowly replicating Mtb are responsible for persistence and poor treatment outcomes. Therapeutic targeting of non-replicating, persistent populations is a priority for tuberculosis treatment, but only few drug targets in non-replicating Mtb are currently known. Here, we directly measure the activity of the highly diverse and druggable serine hydrolases (SHs) during active replication and non-replication by activity-based proteomics. We predict serine hydrolase activity for 78 proteins, including 27 proteins with previously unknown function, and identify 37 SHs that remain active even in the absence of replication, providing a set of candidate persistence targets. Non-replication was associated with large shifts in the activity of the majority of SHs. These activity changes were largely independent of SH abundance, indicating extensive post-translational regulation. By probing a large cross-section of druggable Mtb enzyme space during replication and non-replication, we identify new SHs and suggest new persistence targets.

  12. Persistent complement activation on tumor cells in breast cancer.

    PubMed Central

    Niculescu, F.; Rus, H. G.; Retegan, M.; Vlaicu, R.

    1992-01-01

    The neoantigens of the C5b-9 complement complex, IgG, C3, C4, S-protein/vitronectin, fibronectin, and macrophages were localized on 17 samples of breast cancer and on 6 samples of benign breast tumors using polyclonal or monoclonal antibodies and the streptavidin-biotin-peroxidase technique. All the tissue samples with carcinoma in each the TNM stages presented C5b-9 deposits on the membranes of tumor cells, thin granules on cell remnants, and diffuse deposits in the necrotic areas. When chemotherapy and radiation therapy preceded surgery, C5b-9 deposits were more intense and extended. The C5b-9 deposits were absent in all the samples with benign lesions. S-protein/vitronectin was present as fibrillar deposits in the connective tissue matrix and as diffuse deposits around the tumor cells, less intense and extended than fibronectin. IgG, C3, and C4 deposits were present only in carcinoma samples. The presence of C5b-9 deposits is indicative of complement activation and its subsequent pathogenetic effects in breast cancer. Images Figure 1 PMID:1374587

  13. Calcium regulation of HCN channels supports persistent activity in a multiscale model of neocortex

    PubMed Central

    McDougal, Robert A.; Bulanova, Anna S.; Zeki, Mustafa; Lakatos, Peter; Terman, David; Hines, Michael L.; Lytton, William W.

    2016-01-01

    Neuronal persistent activity has been primarily assessed in terms of electrical mechanisms, without attention to the complex array of molecular events that also control cell excitability. We developed a multiscale neocortical model proceeding from the molecular to the network level to assess the contributions of calcium regulation of hyperpolarization-activated cyclic nucleotide-gated (HCN) channels in providing additional and complementary support of continuing activation in the network. The network contained 776 compartmental neurons arranged in the cortical layers, connected using synapses containing AMPA/NMDA/GABAA/GABAB receptors. Metabotropic glutamate receptors (mGluR) produced inositol triphosphate (IP3) which caused release of Ca2+ from endoplasmic reticulum (ER) stores, with reuptake by sarco/ER Ca2+-ATP-ase pumps (SERCA), and influence on HCN channels. Stimulus-induced depolarization led to Ca2+ influx via NMDA and voltage-gated Ca2+ channels (VGCCs). After a delay, mGluR activation led to ER Ca2+ release via IP3 receptors. These factors increased HCN channel conductance and produced firing lasting for ~1 minute. The model displayed inter-scale synergies among synaptic weights, excitation/inhibition balance, firing rates, membrane depolarization, calcium levels, regulation of HCN channels, and induction of persistent activity. The interaction between inhibition and Ca2+ at the HCN channel nexus determined a limited range of inhibition strengths for which intracellular Ca2+ could prepare population-specific persistent activity. Interactions between metabotropic and ionotropic inputs to the neuron demonstrated how multiple pathways could contribute in a complementary manner to persistent activity. Such redundancy and complementarity via multiple pathways is a critical feature of biological systems. Mediation of activation at different time scales, and through different pathways, would be expected to protect against disruption, in this case providing

  14. Calcium regulation of HCN channels supports persistent activity in a multiscale model of neocortex.

    PubMed

    Neymotin, S A; McDougal, R A; Bulanova, A S; Zeki, M; Lakatos, P; Terman, D; Hines, M L; Lytton, W W

    2016-03-01

    Neuronal persistent activity has been primarily assessed in terms of electrical mechanisms, without attention to the complex array of molecular events that also control cell excitability. We developed a multiscale neocortical model proceeding from the molecular to the network level to assess the contributions of calcium (Ca(2+)) regulation of hyperpolarization-activated cyclic nucleotide-gated (HCN) channels in providing additional and complementary support of continuing activation in the network. The network contained 776 compartmental neurons arranged in the cortical layers, connected using synapses containing AMPA/NMDA/GABAA/GABAB receptors. Metabotropic glutamate receptors (mGluR) produced inositol triphosphate (IP3) which caused the release of Ca(2+) from endoplasmic reticulum (ER) stores, with reuptake by sarco/ER Ca(2+)-ATP-ase pumps (SERCA), and influence on HCN channels. Stimulus-induced depolarization led to Ca(2+) influx via NMDA and voltage-gated Ca(2+) channels (VGCCs). After a delay, mGluR activation led to ER Ca(2+) release via IP3 receptors. These factors increased HCN channel conductance and produced firing lasting for ∼1min. The model displayed inter-scale synergies among synaptic weights, excitation/inhibition balance, firing rates, membrane depolarization, Ca(2+) levels, regulation of HCN channels, and induction of persistent activity. The interaction between inhibition and Ca(2+) at the HCN channel nexus determined a limited range of inhibition strengths for which intracellular Ca(2+) could prepare population-specific persistent activity. Interactions between metabotropic and ionotropic inputs to the neuron demonstrated how multiple pathways could contribute in a complementary manner to persistent activity. Such redundancy and complementarity via multiple pathways is a critical feature of biological systems. Mediation of activation at different time scales, and through different pathways, would be expected to protect against disruption, in

  15. Modulation of Network Excitability by Persistent Activity: How Working Memory Affects the Response to Incoming Stimuli

    PubMed Central

    Tartaglia, Elisa M.; Brunel, Nicolas; Mongillo, Gianluigi

    2015-01-01

    Persistent activity and match effects are widely regarded as neuronal correlates of short-term storage and manipulation of information, with the first serving active maintenance and the latter supporting the comparison between memory contents and incoming sensory information. The mechanistic and functional relationship between these two basic neurophysiological signatures of working memory remains elusive. We propose that match signals are generated as a result of transient changes in local network excitability brought about by persistent activity. Neurons more active will be more excitable, and thus more responsive to external inputs. Accordingly, network responses are jointly determined by the incoming stimulus and the ongoing pattern of persistent activity. Using a spiking model network, we show that this mechanism is able to reproduce most of the experimental phenomenology of match effects as exposed by single-cell recordings during delayed-response tasks. The model provides a unified, parsimonious mechanistic account of the main neuronal correlates of working memory, makes several experimentally testable predictions, and demonstrates a new functional role for persistent activity. PMID:25695777

  16. Identification of novel activity against Borrelia burgdorferi persisters using an FDA approved drug library.

    PubMed

    Feng, Jie; Wang, Ting; Shi, Wanliang; Zhang, Shuo; Sullivan, David; Auwaerter, Paul G; Zhang, Ying

    2014-07-01

    Although antibiotic treatment for Lyme disease is effective in the majority of cases, especially during the early phase of the disease, a minority of patients suffer from post-treatment Lyme disease syndrome (PTLDS). It is unclear what mechanisms drive this problem, and although slow or ineffective killing of Borrelia burgdorferi has been suggested as an explanation, there is a lack of evidence that viable organisms are present in PTLDS. Although not a clinical surrogate, insight may be gained by examining stationary-phase in vitro Borrelia burgdorferi persisters that survive treatment with the antibiotics doxycycline and amoxicillin. To identify drug candidates that can eliminate B. burgdorferi persisters more effectively, we screened an Food and Drug Administration (FDA)-approved drug library consisting of 1524 compounds against stationary-phase B. burgdorferi by using a newly developed high throughput SYBR Green I/propidium iodide (PI) assay. We identified 165 agents approved for use in other disease conditions that had more activity than doxycycline and amoxicillin against B. burgdorferi persisters. The top 27 drug candidates from the 165 hits were confirmed to have higher anti-persister activity than the current frontline antibiotics. Among the top 27 confirmed drug candidates from the 165 hits, daptomycin, clofazimine, carbomycin, sulfa drugs (e.g., sulfamethoxazole), and certain cephalosporins (e.g. cefoperazone) had the highest anti-persister activity. In addition, some drug candidates, such as daptomycin and clofazimine (which had the highest activity against non-growing persisters), had relatively poor activity or a high minimal inhibitory concentration (MIC) against growing B. burgdorferi. Our findings may have implications for the development of a more effective treatment for Lyme disease and for the relief of long-term symptoms that afflict some Lyme disease patients.

  17. Identification of novel activity against Borrelia burgdorferi persisters using an FDA approved drug library

    PubMed Central

    Feng, Jie; Wang, Ting; Shi, Wanliang; Zhang, Shuo; Sullivan, David; Auwaerter, Paul G; Zhang, Ying

    2014-01-01

    Although antibiotic treatment for Lyme disease is effective in the majority of cases, especially during the early phase of the disease, a minority of patients suffer from post-treatment Lyme disease syndrome (PTLDS). It is unclear what mechanisms drive this problem, and although slow or ineffective killing of Borrelia burgdorferi has been suggested as an explanation, there is a lack of evidence that viable organisms are present in PTLDS. Although not a clinical surrogate, insight may be gained by examining stationary-phase in vitro Borrelia burgdorferi persisters that survive treatment with the antibiotics doxycycline and amoxicillin. To identify drug candidates that can eliminate B. burgdorferi persisters more effectively, we screened an Food and Drug Administration (FDA)-approved drug library consisting of 1524 compounds against stationary-phase B. burgdorferi by using a newly developed high throughput SYBR Green I/propidium iodide (PI) assay. We identified 165 agents approved for use in other disease conditions that had more activity than doxycycline and amoxicillin against B. burgdorferi persisters. The top 27 drug candidates from the 165 hits were confirmed to have higher anti-persister activity than the current frontline antibiotics. Among the top 27 confirmed drug candidates from the 165 hits, daptomycin, clofazimine, carbomycin, sulfa drugs (e.g., sulfamethoxazole), and certain cephalosporins (e.g. cefoperazone) had the highest anti-persister activity. In addition, some drug candidates, such as daptomycin and clofazimine (which had the highest activity against non-growing persisters), had relatively poor activity or a high minimal inhibitory concentration (MIC) against growing B. burgdorferi. Our findings may have implications for the development of a more effective treatment for Lyme disease and for the relief of long-term symptoms that afflict some Lyme disease patients. PMID:26038747

  18. Vasoinhibins Prevent Bradykinin-Stimulated Endothelial Cell Proliferation by Inactivating eNOS via Reduction of both Intracellular Ca2+ Levels and eNOS Phosphorylation at Ser1179

    PubMed Central

    Thebault, Stéphanie; González, Carmen; García, Celina; Zamarripa, David Arredondo; Nava, Gabriel; Vaca, Luis; López-Casillas, Fernando; de la Escalera, Gonzalo Martínez; Clapp, Carmen

    2011-01-01

    Vasoinhibins, a family of antiangiogenic peptides derived from prolactin proteolysis, inhibit the vascular effects of several proangiogenic factors, including bradykinin (BK). Here, we report that vasoinhibins block the BK-induced proliferation of bovine umbilical vein endothelial cells. This effect is mediated by the inactivation of endothelial nitric oxide synthase (eNOS), as the NO donor DETA-NONOate reverted vasoinhibin action. It is an experimentally proven fact that the elevation of intracellular Ca2+ levels ([Ca2+]i) upon BK stimulation activates eNOS, and vasoinhibins blocked the BK-mediated activation of phospholipase C and the formation of inositol 1,4,5-triphosphate leading to a reduced release of Ca2+ from intracellular stores. The [Ca2+]i rise evoked by BK also involves the influx of extracellular Ca2+ via canonical transient receptor potential (TRPC) channels. Vasoinhibins likely interfere with TRPC-mediated Ca2+ entry since La3+, which is an enhancer of TRPC4 and TRPC5 channel activity, prevented vasoinhibins from blocking the stimulation by BK of endothelial cell NO production and proliferation, and vasoinhibins reduced the BK-induced increase of TRPC5 mRNA expression. Finally, vasoinhibins prevented the BK-induced phosphorylation of eNOS at Ser1179, a post-translational modification that facilitates Ca2+-calmodulin activation of eNOS. Together, our data show that vasoinhibins, by lowering NO production through the inhibition of both [Ca2+]i mobilization and eNOS phosphorylation, prevent the BK-induced stimulation of endothelial cell proliferation. Thus, vasoinhibins help to regulate BK effects on angiogenesis and vascular homeostasis.

  19. The in vivo activation of persistent nanophosphors for optical imaging of vascularization, tumours and grafted cells

    NASA Astrophysics Data System (ADS)

    Maldiney, Thomas; Bessière, Aurélie; Seguin, Johanne; Teston, Eliott; Sharma, Suchinder K.; Viana, Bruno; Bos, Adrie J. J.; Dorenbos, Pieter; Bessodes, Michel; Gourier, Didier; Scherman, Daniel; Richard, Cyrille

    2014-04-01

    Optical imaging for biological applications requires more sensitive tools. Near-infrared persistent luminescence nanoparticles enable highly sensitive in vivo optical detection and complete avoidance of tissue autofluorescence. However, the actual generation of persistent luminescence nanoparticles necessitates ex vivo activation before systemic administration, which prevents long-term imaging in living animals. Here, we introduce a new generation of optical nanoprobes, based on chromium-doped zinc gallate, whose persistent luminescence can be activated in vivo through living tissues using highly penetrating low-energy red photons. Surface functionalization of this photonic probe can be adjusted to favour multiple biomedical applications such as tumour targeting. Notably, we show that cells can endocytose these nanoparticles in vitro and that, after intravenous injection, we can track labelled cells in vivo and follow their biodistribution by a simple whole animal optical detection, opening new perspectives for cell therapy research and for a variety of diagnosis applications.

  20. Altered vasoreactivity in neonatal rats with pulmonary hypertension associated with bronchopulmonary dysplasia: Implication of both eNOS phosphorylation and calcium signaling

    PubMed Central

    Quignard, Jean-François; Freund-Michel, Véronique; Courtois, Arnaud; Marthan, Roger; Muller, Bernard; Guibert, Christelle; Dubois, Mathilde

    2017-01-01

    Bronchopulmonary dysplasia (BPD) consists of an arrest of pulmonary vascular and alveolar growth, with persistent hypoplasia of the pulmonary microvasculature and alveolar simplification. In 25 to 40% of the cases, BPD is complicated by pulmonary hypertension (BPD-PH) that significantly increases the risk of morbidity. In vivo studies suggest that increased pulmonary vascular tone could contribute to late PH in BPD. Nevertheless, an alteration in vasoreactivity as well as the mechanisms involved remain to be confirmed. The purpose of this study was thus to assess changes in pulmonary vascular reactivity in a murine model of BPD-PH. Newborn Wistar rats were exposed to either room air (normoxia) or 90% O2 (hyperoxia) for 14 days. Exposure to hyperoxia induced the well-known features of BPD-PH such as elevated right ventricular systolic pressure, right ventricular hypertrophy, pulmonary vascular remodeling and decreased pulmonary vascular density. Intrapulmonary arteries from hyperoxic pups showed decreased endothelium-dependent relaxation to acetylcholine without any alteration of relaxation to the NO-donor sodium nitroprusside. This functional alteration was associated with a decrease of lung eNOS phosphorylation at the Ser1177 activating site. In pups exposed to hyperoxia, serotonin and phenylephrine induced exacerbated contractile responses of intrapulmonary arteries as well as intracellular calcium response in pulmonary arterial smooth muscle cells (PASMC). Moreover, the amplitude of the store-operated Ca2+ entry (SOCE), induced by store depletion using a SERCA inhibitor, was significantly greater in PASMC from hyperoxic pups. Altogether, hyperoxia-induced BPD-PH alters the pulmonary arterial reactivity, with effects on both endothelial and smooth muscle functions. Reduced activating eNOS phosphorylation and enhanced Ca2+ signaling likely account for alterations of pulmonary arterial reactivity. PMID:28235094

  1. Activation of respiratory epithelial cells by wood smoke particles persists beyond immediate exposure.

    EPA Science Inventory

    The biological effect of particles on epithelial cells involves, in part, oxidant generation and a cascade of reactions culminating in inflammatory mediator release. Whether there is an immediate short-lived activation or continued persistent response of the cells to the particle...

  2. Activation of respiratory epithelial cells by wood smoke particles persists beyond immediate exposure.

    EPA Science Inventory

    The biological effect of particles on epithelial cells involves, in part, oxidant generation and a cascade of reactions culminating in inflammatory mediator release. Whether there is an immediate short-lived activation or continued persistent response of the cells to the particle...

  3. Differential expression of three Chlamydia trachomatis hsp60-encoding genes in active vs. persistent infections.

    PubMed

    Gérard, Hervé C; Whittum-Hudson, Judith A; Schumacher, H Ralph; Hudson, Alan P

    2004-01-01

    Real time RT-PCR was used to assess expression of the three Chlamydia trachomatis hsp60-encoding genes (Ct110, Ct604, Ct755) over time in in vitro systems of active vs. persistent infection, and in synovial samples from patients with Chlamydia-induced arthritis. In HEp-2 cells actively infected with C. trachomatis (serovar K), mRNA from Ct110 (groEL) was apparent by 8 h post-infection (p.i.) and increased more than 10-fold through 48 h p.i.; mRNA from Ct604 followed a similar pattern. Transcripts from Ct755 were abundant at 8 h p.i. and remained 2-3-fold higher than those from Ct110 at all times. In persistently infected human monocytes in culture, expression of Ct110 and Ct755 was low from 1 to 7d p.i., while mRNA from Ct604 was abundant at 1d p.i. and increased more than 3-fold from 1 to 3d p.i., as the organism transited to the persistent state. Those mRNA levels remained high through 7d p.i. Real time analyses of RNA/cDNA from synovial tissue of patients with Chlamydia-associated arthritis showed high Ct604 mRNA levels, consistent with results from the in vitro monocyte system of persistence. These data demonstrate that each chlamydial hsp60-encoding gene is expressed independently, and that the three genes are expressed differentially in active vs. persistent infection. The results further suggest that the Ct604 gene product may function importantly during chlamydial persistence.

  4. Therapeutic effect of enhancing endothelial nitric oxide synthase (eNOS) expression and preventing eNOS uncoupling

    PubMed Central

    Förstermann, Ulrich; Li, Huige

    2011-01-01

    Nitric oxide (NO) produced by the endothelium is an important protective molecule in the vasculature. It is generated by the enzyme endothelial NO synthase (eNOS). Similar to all NOS isoforms, functional eNOS transfers electrons from nicotinamide adenine dinucleotide phosphate (NADPH), via the flavins flavin adenine dinucleotide and flavin mononucleotide in the carboxy-terminal reductase domain, to the heme in the amino-terminal oxygenase domain. Here, the substrate L-arginine is oxidized to L-citrulline and NO. Cardiovascular risk factors such as diabetes mellitus, hypertension, hypercholesterolaemia or cigarette smoking reduce bioactive NO. These risk factors lead to an enhanced production of reactive oxygen species (ROS) in the vessel wall. NADPH oxidases represent major sources of this ROS and have been found upregulated in the presence of cardiovascular risk factors. NADPH-oxidase-derived superoxide avidly reacts with eNOS-derived NO to form peroxynitrite (ONOO-). The essential NOS cofactor (6R-)5,6,7,8-tetrahydrobiopterin (BH4) is highly sensitive to oxidation by this ONOO-. In BH4 deficiency, oxygen reduction uncouples from NO synthesis, thereby converting NOS to a superoxide-producing enzyme. Among conventional drugs, compounds interfering with the renin-angiotensin-aldosterone system and statins can reduce vascular oxidative stress and increase bioactive NO. In recent years, we have identified a number of small molecules that have the potential to prevent eNOS uncoupling and, at the same time, enhance eNOS expression. These include the protein kinase C inhibitor midostaurin, the pentacyclic triterpenoids ursolic acid and betulinic acid, the eNOS enhancing compounds AVE9488 and AVE3085, and the polyphenolic phytoalexin trans-resveratrol. Such compounds enhance NO production from eNOS also under pathophysiological conditions and may thus have therapeutic potential. PMID:21198553

  5. Evaluation of the persistence of micropollutants through pure-oxygen activated sludge nitrification and denitrification.

    PubMed

    Levine, Audrey D; Meyer, Michael T; Kish, George

    2006-10-01

    The persistence of pharmaceuticals, hormones, and household and industrial chemicals through a pure-oxygen activated sludge, nitrification, denitrification wastewater treatment facility was evaluated. Of the 125 micropollutants that were tested in this study, 55 compounds were detected in the untreated wastewater, and 27 compounds were detected in the disinfected effluent. The persistent compounds included surfactants, fire-retardant chemicals, pesticides, fragrance compounds, hormones, and one pharmaceutical. Physical-chemical properties of micropollutants that affected partitioning onto wastewater solids included vapor pressure and octanol-water partition coefficients.

  6. Evaluation of the persistence of micropollutants through pure-oxygen activated sludge nitrification and denitrification

    USGS Publications Warehouse

    Levine, A.D.; Meyer, M.T.; Kish, G.

    2006-01-01

    The persistence of pharmaceuticals, hormones, and household and industrial chemicals through a pure-oxygen activated sludge, nitrification, denitrification wastewater treatment facility was evaluated. Of the 125 micropollutants that were tested in this study, 55 compounds were detected in the untreated wastewater, and 27 compounds were detected in the disinfected effluent. The persistent compounds included surfactants, fire-retardant chemicals, pesticides, fragrance compounds, hormones, and one pharmaceutical. Physical-chemical properties of micropollutants that affected partitioning onto wastewater solids included vapor pressure and octanol-water partition coefficients.

  7. Bone Morphogenic Protein 4 Mediates NOX1-Dependent eNOS Uncoupling, Endothelial Dysfunction, and COX2 Induction in Type 2 Diabetes Mellitus.

    PubMed

    Youn, Ji-Youn; Zhou, Jun; Cai, Hua

    2015-08-01

    We have recently shown that angiotensin II-mediated uncoupling of endothelial nitric oxide synthase (eNOS) contributes to endothelial dysfunction in streptozotocin-induced type 1 diabetes mellitus. However, it has remained unclear whether and how eNOS uncoupling occurs in type 2 diabetes mellitus (T2DM) and the consequences of such in regulating vascular function. Here we investigated a role of bone morphogenic protein (BMP)-4 in mediating eNOS uncoupling, endothelial dysfunction, and inflammation in db/db mice. Circulating levels of BMP4 were markedly elevated in db/db mice but not in mice with type 1 diabetes mellitus, in which angiotensin II levels were significantly increased. Infusion of BMP4 antagonist noggin into db/db mice (15 μg/kg/day, 4 weeks) abolished eNOS uncoupling activity while restoring tetrahydrobiopterin (H(4)B) bioavailability. The impaired endothelium-dependent vasorelaxation in db/db aortas was significantly improved by noggin infusion. Exposure of aortic endothelial cells to BMP4 (50 ng/mL, 24 hours) resulted in eNOS uncoupling, which was attenuated by H(4)B precursor sepiapterin or small interfering RNA silencing nicotinamide adenine dinucleotide phosphate oxidase isoform 1 (NOX1). Interestingly, BMP4-dependent NOX1 up-regulation was abrogated by sepiapterin, implicating a NOX1-uncoupled eNOS-NOX1 feed-forward loop. BMP4 induction of cyclooxygenase 2 (COX2) expression and vascular cell adhesion protein 1 was found in db/db mice. Consistently, COX2 was up-regulated by BMP4 in endothelial cells, which was attenuated by sepiapterin, implicating an upstream role of eNOS uncoupling in COX2-mediated inflammatory activation. Taken together, our data for the first time reveal a novel role of BMP4 in inducing NOX1-dependent eNOS uncoupling in T2DM, which may promote development of novel therapeutics restoring endothelial function in T2DM.

  8. Quantifying a dynamic risk landscape: heterogeneous predator activity and implications for prey persistence.

    PubMed

    Schauber, Eric M; Connors, Matthew J; Goodwin, Brett J; Jones, Clive G; Ostfeld, Richard S

    2009-01-01

    Spatial heterogeneity in predation risk can ameliorate impacts on prey populations, particularly for prey of generalists. Spatially heterogeneous risk implies the existence of refugia, and the spatial scale of those refugia and their persistence over time affect whether prey can avoid predation by aggregating therein. Our objective was to quantify the magnitude, spatial scale, and temporal persistence of heterogeneity in risk of predation by white-footed mice (Peromyscus leucopus), an abundant generalist predator of gypsy moths (Lymantria dispar) and songbirds. We used track plates to measure white-footed mouse activity at > 170 trees in each of three forest plots in upstate New York during summers of 2003-2005. We quantified the mean and coefficient of variation of track activity among trees by fitting the beta-binomial distribution to data from each plot and study period. We measured temporal persistence by disattenuated autocorrelation, and spatial scale by fitting exponential variograms. Mice were much less abundant in 2005 than the other two years, leading to lower overall track activity but higher coefficient of variation among trees. Mouse track activity at individual trees was positively autocorrelated between monthly study periods in 2003 and 2004, and even between the two years, whereas temporal autocorrelation in 2005 was much weaker. Track activity showed positive spatial autocorrelation over lag distances from approximately 30 to > 1000 m. These findings indicate that mouse activity, and hence risk to their prey, varies substantially in space at spatial and temporal scales that appear responsive to mouse population dynamics. The spatial scale and temporal persistence of that variation imply that prey may benefit from returning to, or failing to disperse from, refugia.

  9. Metabolic brain activity suggestive of persistent pain in a rat model of neuropathic pain.

    PubMed

    Thompson, Scott J; Millecamps, Magali; Aliaga, Antonio; Seminowicz, David A; Low, Lucie A; Bedell, Barry J; Stone, Laura S; Schweinhardt, Petra; Bushnell, M Catherine

    2014-05-01

    Persistent pain is a central characteristic of neuropathic pain conditions in humans. Knowing whether rodent models of neuropathic pain produce persistent pain is therefore crucial to their translational applicability. We investigated the spared nerve injury (SNI) model of neuropathic pain and the formalin pain model in rats using positron emission tomography (PET) with the metabolic tracer [18F]fluorodeoxyglucose (FDG) to determine if there is ongoing brain activity suggestive of persistent pain. For the formalin model, under brief anesthesia we injected one hindpaw with 5% formalin and the FDG tracer into a tail vein. We then allowed the animals to awaken and observed pain behavior for 30min during the FDG uptake period. The rat was then anesthetized and placed in the scanner for static image acquisition, which took place between minutes 45 and 75 post-tracer injection. A single reference rat brain magnetic resonance image (MRI) was used to align the PET images with the Paxinos and Watson rat brain atlas. Increased glucose metabolism was observed in the somatosensory region associated with the injection site (S1 hindlimb contralateral), S1 jaw/upper lip and cingulate cortex. Decreases were observed in the prelimbic cortex and hippocampus. Second, SNI rats were scanned 3weeks post-surgery using the same scanning paradigm, and region-of-interest analyses revealed increased metabolic activity in the contralateral S1 hindlimb. Finally, a second cohort of SNI rats was scanned while anesthetized during the tracer uptake period, and the S1 hindlimb increase was not observed. Increased brain activity in the somatosensory cortex of SNI rats resembled the activity produced with the injection of formalin, suggesting that the SNI model may produce persistent pain. The lack of increased activity in S1 hindlimb with general anesthetic demonstrates that this effect can be blocked, as well as highlights the importance of investigating brain activity in awake and behaving rodents.

  10. Persistent ERK/MAPK Activation Promotes Lactotrope Differentiation and Diminishes Tumorigenic Phenotype

    PubMed Central

    Booth, Allyson; Trudeau, Tammy; Gomez, Crystal; Lucia, M. Scott

    2014-01-01

    The signaling pathways that govern the lactotrope-specific differentiated phenotype, and those that control lactotrope proliferation in both physiological and pathological lactotrope expansion, are poorly understood. Moreover, the specific role of MAPK signaling in lactotrope proliferation vs differentiation, whether activated phosphorylated MAPK is sufficient for prolactinoma tumor formation remain unknown. Given that oncogenic Ras mutations and persistently activated phosphorylated MAPK are found in human tumors, including prolactinomas and other pituitary tumors, a better understanding of the role of MAPK in lactotrope biology is required. Here we directly examined the role of persistent Ras/MAPK signaling in differentiation, proliferation, and tumorigenesis of rat pituitary somatolactotrope GH4 cells. We stimulated Ras/MAPK signaling in a persistent, long-term manner (over 6 d) in GH4 cells using two distinct approaches: 1) a doxycycline-inducible, oncogenic V12Ras expression system; and 2) continuous addition of exogenous epidermal growth factor. We find that long-term activation of the Ras/MAPK pathway over 6 days promotes differentiation of the bihormonal somatolactotrope GH4 precursor cell into a prolactin-secreting, lactotrope cell phenotype in vitro and in vivo with GH4 cell xenograft tumors. Furthermore, we show that persistent activation of the Ras/MAPK pathway not only fails to promote cell proliferation, but also diminishes tumorigenic characteristics in GH4 cells in vitro and in vivo. These data demonstrate that activated MAPK promotes differentiation and is not sufficient to drive tumorigenesis, suggesting that pituitary lactotrope tumor cells have the ability to evade the tumorigenic fate that is often associated with Ras/MAPK activation. PMID:25361391

  11. Metabolic brain activity suggestive of persistent pain in a rat model of neuropathic pain

    PubMed Central

    Thompson, Scott J; Millecamps, Magali; Aliaga, Antonio; Seminowicz, David A; Low, Lucie A; Bedell, Barry J; Stone, Laura S; Schweinhardt, Petra; Bushnell, M Catherine

    2014-01-01

    Persistent pain is a central characteristic of neuropathic pain conditions in humans. Knowing whether rodent models of neuropathic pain produce persistent pain is therefore crucial to their translational applicability. We investigated the Spared Nerve Injury (SNI) model of neuropathic pain and the formalin pain model in rats using Positron Emission Tomography (PET) with the metabolic tracer [18F]fluorodeoxyglucose (FDG) to determine if there is ongoing brain activity suggestive of persistent pain. For the formalin model, under brief anesthesia we injected one hindpaw with 5% formalin and the FDG tracer into a tail vein. We then allowed the animals to awaken and observed pain behavior for 30 min during the FDG uptake period. The rat was then anesthetized and placed in the scanner for static image acquisition, which took place between minutes 45 and 75 post-tracer injection. A single reference rat brain magnetic resonance image (MRI) was used to align the PET images with the Paxinos and Watson rat brain atlas. Increased glucose metabolism was observed in the somatosensory region associated with the injection site (S1 hindlimb contralateral), S1 jaw/upper lip and cingulate cortex. Decreases were observed in the prelimbic cortex and hippocampus. Second, SNI rats were scanned 3 weeks post-surgery using the same scanning paradigm, and region-of-interest analyses revealed increased metabolic activity in the contralateral S1 hindlimb. Finally, a second cohort of SNI rats were scanned while anesthetized during the tracer uptake period, and the S1 hindlimb increase was not observed. Increased brain activity in the somatosensory cortex of SNI rats resembled the activity produced with the injection of formalin, suggesting that the SNI model may produce persistent pain. The lack of increased activity in S1 hindlimb with general anesthetic demonstrates that this effect can be blocked, as well as highlights the importance of investigating brain activity in awake and behaving

  12. Maternal eNOS deficiency determines a fatty liver phenotype of the offspring in a sex dependent manner

    PubMed Central

    Hocher, Berthold; Haumann, Hannah; Rahnenführer, Jan; Reichetzeder, Christoph; Kalk, Philipp; Pfab, Thiemo; Tsuprykov, Oleg; Winter, Stefan; Hofmann, Ute; Li, Jian; Püschel, Gerhard P.; Lang, Florian; Schuppan, Detlef; Schwab, Matthias; Schaeffeler, Elke

    2016-01-01

    ABSTRACT Maternal environmental factors can impact on the phenotype of the offspring via the induction of epigenetic adaptive mechanisms. The advanced fetal programming hypothesis proposes that maternal genetic variants may influence the offspring's phenotype indirectly via epigenetic modification, despite the absence of a primary genetic defect. To test this hypothesis, heterozygous female eNOS knockout mice and wild type mice were bred with male wild type mice. We then assessed the impact of maternal eNOS deficiency on the liver phenotype of wild type offspring. Birth weight of male wild type offspring born to female heterozygous eNOS knockout mice was reduced compared to offspring of wild type mice. Moreover, the offspring displayed a sex specific liver phenotype, with an increased liver weight, due to steatosis. This was accompanied by sex specific differences in expression and DNA methylation of distinct genes. Liver global DNA methylation was significantly enhanced in both male and female offspring. Also, hepatic parameters of carbohydrate metabolism were reduced in male and female offspring. In addition, male mice displayed reductions in various amino acids in the liver. Maternal genetic alterations, such as partial deletion of the eNOS gene, can affect liver metabolism of wild type offspring without transmission of the intrinsic defect. This occurs in a sex specific way, with more detrimental effects in females. This finding demonstrates that a maternal genetic defect can epigenetically alter the phenotype of the offspring, without inheritance of the defect itself. Importantly, these acquired epigenetic phenotypic changes can persist into adulthood. PMID:27175980

  13. Protective effect of eNOS overexpression against ischemia/reperfusion injury in small-for-size liver transplantation

    PubMed Central

    Zhang, Bo; Liu, Qiu-Hua; Zhou, Cui-Jie; Hu, Ming-Zheng; Qian, Hai-Xin

    2016-01-01

    Ischemia/reperfusion (I/R) injury can occur during small-for-size liver transplantation, resulting in delayed graft function and decreased long-term graft survival. The aim of the present study was to evaluate the effects of genetic overexpression of endothelial nitric oxide synthase (eNOS) in protecting hepatocytes against I/R injury in a rat model of small-for-size liver transplantation. L02 liver cells were transfected with the eNOS gene using an adenovirus (Ad-eNOS). eNOS expression was detected using quantitative polymerase chain reaction and western blot analysis. To evaluate the effect of eNOS overexpression, L02 cells were placed in a hypoxic environment for 12 h and immediately transferred to an oxygen-enriched atmosphere. For in vivo testing, rats pretreated with Ad-eNOS or control underwent small-for-size liver transplantation. At 6 h after reperfusion, the bile quantity, serum transaminase and nitric oxide (NO) levels, and histological outcomes were evaluated. Cell apoptosis was assessed by flow cytometry or TUNEL assay. In vitro, Ad-eNOS prevented apoptosis in L02 cells with an increase in the level of NO in culture supernatant. In vivo, Ad-eNOS pre-treatment significantly increased bile production, improved abnormal transaminase levels, diminished apoptosis among liver cells, and decreased hepatocellular damage at 6 h after I/R injury. The eNOS-mediated renal protective effects might be associated with the downregulation of tumor necrosis factor-α and a reduction in macrophage activation in the early stage of reperfusion in small-for-size liver allografts. eNOS-derived NO production significantly attenuates hepatic I/R injury. Thus, eNOS overexpression constitutes a promising therapeutic approach to prevent liver I/R injury following small-for-size liver transplantation. PMID:27882135

  14. Therapy students' recommendations of physical activity for managing persistent low back pain in older adults.

    PubMed

    Ryan, Cormac G; Schofield, Patricia; Martin, Denis J

    2013-07-01

    Negative views of older adults can lead to suboptimal care. For older adults with persistent low back pain (LBP), promotion of physical activity by health care professionals is important. Health care professionals' views of older adults are influenced by their training. This study aimed to compare recommendations for physical activity for managing persistent LBP offered by students in physiotherapy and occupational therapy to an older person vs. a younger person. In a cross-sectional online survey, participants (N = 77) randomly received a vignette of either a 40-yr-old or 70-yr-old patient with persistent LBP. Other than age, the vignettes were identical. There was no difference between the younger and older vignettes in the likelihood of participants making overall appropriate physical activity recommendations--63% vs. 59%, OR (95% CI) = 1.19 (0.48-2.99), p = .71--although there was a trend toward age bias on recommendations specific to daily activity. Postqualification education may be where ageist views need to be addressed.

  15. Regulation of Persistent Activity by Background Inhibition in an In Vitro Model of a Cortical Microcircuit

    PubMed Central

    Fellous, Jean-Marc; Sejnowski, Terrence J.

    2010-01-01

    We combined in vitro intracellular recording from prefrontal cortical neurons with simulated synaptic activity of a layer 5 prefrontal microcircuit using a dynamic clamp. During simulated in vivo background conditions, the cell responded to a brief depolarization with a sequence of spikes that outlasted the depolarization, mimicking the activity of a cell recorded during the delay period of a working memory task in the behaving monkey. The onset of sustained activity depended on the number of action potentials elicited by the cue-like depolarization. Too few spikes failed to provide enough NMDA drive to elicit sustained reverberations; too many spikes activated a slow intrinsic hyperpolarization current that prevented spiking; an intermediate number of spikes produced sustained activity. When high dopamine levels were simulated by depolarizing the cell and by increasing the amount of NMDA current, the cell exhibited spontaneous ‘up-states’ that terminated by the activation of a slow intrinsic hyperpolarizing current. The firing rate during the delay period could be effectively modulated by the standard deviation of the inhibitory background synaptic noise without significant changes in the background firing rate before cue onset. These results suggest that the balance between fast feedback inhibition and slower AMPA and NMDA feedback excitation is critical in initiating persistent activity and that the maintenance of persistent activity may be regulated by the amount of correlated background inhibition. PMID:14576214

  16. Identification of Additional Anti-Persister Activity against Borrelia burgdorferi from an FDA Drug Library.

    PubMed

    Feng, Jie; Weitner, Megan; Shi, Wanliang; Zhang, Shuo; Sullivan, David; Zhang, Ying

    2015-09-16

    Lyme disease is a leading vector-borne disease in the United States. Although the majority of Lyme patients can be cured with standard 2-4 week antibiotic treatment, 10%-20% of patients continue to suffer from prolonged post-treatment Lyme disease syndrome (PTLDS). While the cause for this is unclear, persisting organisms not killed by current Lyme antibiotics may be involved. In our previous study, we screened an FDA drug library and reported 27 top hits that showed high activity against Borrelia persisters. In this study, we present the results of an additional 113 active hits that have higher activity against the stationary phase B. burgdorferi than the currently used Lyme antibiotics. Many antimicrobial agents (antibiotics, antivirals, antifungals, anthelmintics or antiparasitics) used for treating other infections were found to have better activity than the current Lyme antibiotics. These include antibacterials such as rifamycins (3-formal-rifamycin, rifaximin, rifamycin SV), thiostrepton, quinolone drugs (sarafloxacin, clinafloxacin, tosufloxacin), and cell wall inhibitors carbenicillin, tazobactam, aztreonam; antifungal agents such as fluconazole, mepartricin, bifonazole, climbazole, oxiconazole, nystatin; antiviral agents zanamivir, nevirapine, tilorone; antimalarial agents artemisinin, methylene blue, and quidaldine blue; antihelmintic and antiparasitic agents toltrazuril, tartar emetic, potassium antimonyl tartrate trihydrate, oxantel, closantel, hycanthone, pyrimethamine, and tetramisole. Interestingly, drugs used for treating other non-infectious conditions including verteporfin, oltipraz, pyroglutamic acid, pidolic acid, and dextrorphan tartrate, that act on the glutathione/γ-glutamyl pathway involved in protection against free radical damage, and also the antidepressant drug indatraline, were found to have high activity against stationary phase B. burgdorferi. Among the active hits, agents that affect cell membranes, energy production, and reactive

  17. Identification of Additional Anti-Persister Activity against Borrelia burgdorferi from an FDA Drug Library

    PubMed Central

    Feng, Jie; Weitner, Megan; Shi, Wanliang; Zhang, Shuo; Sullivan, David; Zhang, Ying

    2015-01-01

    Lyme disease is a leading vector-borne disease in the United States. Although the majority of Lyme patients can be cured with standard 2–4 week antibiotic treatment, 10%–20% of patients continue to suffer from prolonged post-treatment Lyme disease syndrome (PTLDS). While the cause for this is unclear, persisting organisms not killed by current Lyme antibiotics may be involved. In our previous study, we screened an FDA drug library and reported 27 top hits that showed high activity against Borrelia persisters. In this study, we present the results of an additional 113 active hits that have higher activity against the stationary phase B. burgdorferi than the currently used Lyme antibiotics. Many antimicrobial agents (antibiotics, antivirals, antifungals, anthelmintics or antiparasitics) used for treating other infections were found to have better activity than the current Lyme antibiotics. These include antibacterials such as rifamycins (3-formal-rifamycin, rifaximin, rifamycin SV), thiostrepton, quinolone drugs (sarafloxacin, clinafloxacin, tosufloxacin), and cell wall inhibitors carbenicillin, tazobactam, aztreonam; antifungal agents such as fluconazole, mepartricin, bifonazole, climbazole, oxiconazole, nystatin; antiviral agents zanamivir, nevirapine, tilorone; antimalarial agents artemisinin, methylene blue, and quidaldine blue; antihelmintic and antiparasitic agents toltrazuril, tartar emetic, potassium antimonyl tartrate trihydrate, oxantel, closantel, hycanthone, pyrimethamine, and tetramisole. Interestingly, drugs used for treating other non-infectious conditions including verteporfin, oltipraz, pyroglutamic acid, pidolic acid, and dextrorphan tartrate, that act on the glutathione/γ-glutamyl pathway involved in protection against free radical damage, and also the antidepressant drug indatraline, were found to have high activity against stationary phase B. burgdorferi. Among the active hits, agents that affect cell membranes, energy production, and

  18. PECAM-1 Isoforms, eNOS, and Endoglin Axis in Regulation of Angiogenesis

    PubMed Central

    Park, SunYoung; Sorenson, Christine M.; Sheibani, Nader

    2016-01-01

    Vascular development and maintenance of proper vascular function through various regulatory mechanisms are critical to our wellbeing. Delineating the regulatory processes involved in development of vascular system and function is one of the most important topics in human physiology and pathophysiology. Platelet endothelial cell adhesion molecule-1 (PECAM-1/CD31), a cell adhesion molecule with proangiogenic and proinflammatory activity, has been subject of numerous studies. Here we will review the important roles PECAM-1 and its isoforms play during angiogenesis, and its molecular mechanisms of action in the endothelium. In the endothelium, PECAM-1 not only plays a role as an adhesion molecule but also participates in intracellular signaling pathways which impact various cell adhesive mechanisms and endothelial nitric oxide (eNOS) expression and activity. In addition, recent studies from our laboratory have revealed an important relationship between PECAM-1 and endoglin expression. Endoglin is an essential molecule during angiogenesis, vascular development and integrity whose expression and activity are compromised in the absence of PECAM-1. Here we will discuss the roles PECAM-1 isoforms may play in modulation of endothelial cell adhesive mechanisms, eNOS and endoglin expression and activity, and angiogenesis. PMID:25976664

  19. Mean-driven and fluctuation-driven persistent activity in recurrent networks.

    PubMed

    Renart, Alfonso; Moreno-Bote, Rubén; Wang, Xiao-Jing; Parga, Néstor

    2007-01-01

    Spike trains from cortical neurons show a high degree of irregularity, with coefficients of variation (CV) of their interspike interval (ISI) distribution close to or higher than one. It has been suggested that this irregularity might be a reflection of a particular dynamical state of the local cortical circuit in which excitation and inhibition balance each other. In this "balanced" state, the mean current to the neurons is below threshold, and firing is driven by current fluctuations, resulting in irregular Poisson-like spike trains. Recent data show that the degree of irregularity in neuronal spike trains recorded during the delay period of working memory experiments is the same for both low-activity states of a few Hz and for elevated, persistent activity states of a few tens of Hz. Since the difference between these persistent activity states cannot be due to external factors coming from sensory inputs, this suggests that the underlying network dynamics might support coexisting balanced states at different firing rates. We use mean field techniques to study the possible existence of multiple balanced steady states in recurrent networks of current-based leaky integrate-and-fire (LIF) neurons. To assess the degree of balance of a steady state, we extend existing mean-field theories so that not only the firing rate, but also the coefficient of variation of the interspike interval distribution of the neurons, are determined self-consistently. Depending on the connectivity parameters of the network, we find bistable solutions of different types. If the local recurrent connectivity is mainly excitatory, the two stable steady states differ mainly in the mean current to the neurons. In this case, the mean drive in the elevated persistent activity state is suprathreshold and typically characterized by low spiking irregularity. If the local recurrent excitatory and inhibitory drives are both large and nearly balanced, or even dominated by inhibition, two stable states

  20. Developmental Deltamethrin Exposure Causes Persistent Changes in Dopaminergic Gene Expression, Neurochemistry, and Locomotor Activity in Zebrafish

    PubMed Central

    Kung, Tiffany S.; Richardson, Jason R.; Cooper, Keith R.; White, Lori A.

    2015-01-01

    Pyrethroids are commonly used insecticides that are considered to pose little risk to human health. However, there is an increasing concern that children are more susceptible to the adverse effects of pesticides. We used the zebrafish model to test the hypothesis that developmental exposure to low doses of the pyrethroid deltamethrin results in persistent alterations in dopaminergic gene expression, neurochemistry, and locomotor activity. Zebrafish embryos were treated with deltamethrin (0.25–0.50 μg/l), at concentrations below the LOAEL, during the embryonic period [3–72 h postfertilization (hpf)], after which transferred to fresh water until the larval stage (2-weeks postfertilization). Deltamethrin exposure resulted in decreased transcript levels of the D1 dopamine (DA) receptor (drd1) and increased levels of tyrosine hydroxylase at 72 hpf. The reduction in drd1 transcripts persisted to the larval stage and was associated with decreased D2 dopamine receptor transcripts. Larval fish, exposed developmentally to deltamethrin, had increased levels of homovanillic acid, a DA metabolite. Since the DA system is involved in locomotor activity, we measured the swim activity of larval fish following a transition to darkness. Developmental exposure to deltamethrin significantly increased larval swim activity which was attenuated by concomitant knockdown of the DA transporter. Acute exposure to methylphenidate, a DA transporter inhibitor, increased swim activity in control larva, while reducing swim activity in larva developmentally exposed to deltamethrin. Developmental exposure to deltamethrin causes locomotor deficits in larval zebrafish, which is likely mediated by dopaminergic dysfunction. This highlights the need to understand the persistent effects of low-dose neurotoxicant exposure during development. PMID:25912032

  1. Developmental Deltamethrin Exposure Causes Persistent Changes in Dopaminergic Gene Expression, Neurochemistry, and Locomotor Activity in Zebrafish.

    PubMed

    Kung, Tiffany S; Richardson, Jason R; Cooper, Keith R; White, Lori A

    2015-08-01

    Pyrethroids are commonly used insecticides that are considered to pose little risk to human health. However, there is an increasing concern that children are more susceptible to the adverse effects of pesticides. We used the zebrafish model to test the hypothesis that developmental exposure to low doses of the pyrethroid deltamethrin results in persistent alterations in dopaminergic gene expression, neurochemistry, and locomotor activity. Zebrafish embryos were treated with deltamethrin (0.25-0.50 μg/l), at concentrations below the LOAEL, during the embryonic period [3-72 h postfertilization (hpf)], after which transferred to fresh water until the larval stage (2-weeks postfertilization). Deltamethrin exposure resulted in decreased transcript levels of the D1 dopamine (DA) receptor (drd1) and increased levels of tyrosine hydroxylase at 72 hpf. The reduction in drd1 transcripts persisted to the larval stage and was associated with decreased D2 dopamine receptor transcripts. Larval fish, exposed developmentally to deltamethrin, had increased levels of homovanillic acid, a DA metabolite. Since the DA system is involved in locomotor activity, we measured the swim activity of larval fish following a transition to darkness. Developmental exposure to deltamethrin significantly increased larval swim activity which was attenuated by concomitant knockdown of the DA transporter. Acute exposure to methylphenidate, a DA transporter inhibitor, increased swim activity in control larva, while reducing swim activity in larva developmentally exposed to deltamethrin. Developmental exposure to deltamethrin causes locomotor deficits in larval zebrafish, which is likely mediated by dopaminergic dysfunction. This highlights the need to understand the persistent effects of low-dose neurotoxicant exposure during development. © The Author 2015. Published by Oxford University Press on behalf of the Society of Toxicology. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  2. Persistent cue-evoked activity of accumbens neurons after prolonged abstinence from self-administered cocaine.

    PubMed

    Ghitza, Udi E; Fabbricatore, Anthony T; Prokopenko, Volodymyr; Pawlak, Anthony P; West, Mark O

    2003-08-13

    Persistent neural processing of information regarding drug-predictive environmental stimuli may be involved in motivating drug abusers to engage in drug seeking after abstinence. The addictive effects of various drugs depend on the mesocorticolimbic dopamine system innervating the nucleus accumbens. We used single-unit recording in rats to test whether accumbens neurons exhibit responses to a discriminative stimulus (SD) tone previously paired with cocaine availability during cocaine self-administration. Presentation of the tone after 3-4 weeks of abstinence resulted in a cue-induced relapse of drug seeking under extinction conditions. Accumbens neurons did not exhibit tone-evoked activity before cocaine self-administration training but exhibited significant SD tone-evoked activity during extinction. Under extinction conditions, shell neurons exhibited significantly greater activity evoked by the SD tone than that evoked by a neutral tone (i.e., never paired with reinforcement). In contrast, core neurons responded indiscriminately to presentations of the SD tone or the neutral tone. Accumbens shell neurons exhibited significantly greater SD tone-evoked activity than did accumbens core neurons. Although the onset of SD tone-evoked activity occurred well before the earliest movements commenced (150 msec), this activity often persisted beyond the onset of tone-evoked movements. These results indicate that accumbens shell neurons exhibit persistent processing of information regarding reward-related stimuli after prolonged drug abstinence. Moreover, the accumbens shell appears to be involved in discriminating the motivational value of reward-related associative stimuli, whereas the accumbens core does not.

  3. Spatial heterogeneity in human activities favors the persistence of wolves in agroecosystems.

    PubMed

    Ahmadi, Mohsen; López-Bao, José Vicente; Kaboli, Mohammad

    2014-01-01

    As human populations expand, there is increasing demand and pressure for land. Under this scenario, behavioural flexibility and adaptation become important processes leading to the persistence of large carnivores in human-dominated landscapes such as agroecosystems. A growing interest has recently emerged on the outcome of the coexistence between wolves and humans in these systems. It has been suggested that spatial heterogeneity in human activities would be a major environmental factor modulating vulnerability and persistence of this contentious species in agroecosystems. Here, we combined information from 35 den sites detected between 2011 and 2012 in agroecosystems of western Iran (Hamedan province), a set of environmental variables measured at landscape and fine spatial scales, and generalized linear models to identify patterns of den site selection by wolves in a highly-modified agroecosystem. On a landscape level, wolves selected a mixture of rangelands with scattered dry-farms on hillsides (showing a low human use) to locate their dens, avoiding areas with high densities of settlements and primary roads. On a fine spatial scale, wolves primarily excavated dens into the sides of elevated steep-slope hills with availability of water bodies in the vicinity of den sites, and wolves were relegated to dig in places with coarse-soil particles. Our results suggest that vulnerability of wolves in human-dominated landscapes could be compensated by the existence of spatial heterogeneity in human activities. Such heterogeneity would favor wolf persistence in agroecosystems favoring a land sharing model of coexistence between wolves and people.

  4. Spatial Heterogeneity in Human Activities Favors the Persistence of Wolves in Agroecosystems

    PubMed Central

    Ahmadi, Mohsen; López-Bao, José Vicente; Kaboli, Mohammad

    2014-01-01

    As human populations expand, there is increasing demand and pressure for land. Under this scenario, behavioural flexibility and adaptation become important processes leading to the persistence of large carnivores in human-dominated landscapes such as agroecosystems. A growing interest has recently emerged on the outcome of the coexistence between wolves and humans in these systems. It has been suggested that spatial heterogeneity in human activities would be a major environmental factor modulating vulnerability and persistence of this contentious species in agroecosystems. Here, we combined information from 35 den sites detected between 2011 and 2012 in agroecosystems of western Iran (Hamedan province), a set of environmental variables measured at landscape and fine spatial scales, and generalized linear models to identify patterns of den site selection by wolves in a highly-modified agroecosystem. On a landscape level, wolves selected a mixture of rangelands with scattered dry-farms on hillsides (showing a low human use) to locate their dens, avoiding areas with high densities of settlements and primary roads. On a fine spatial scale, wolves primarily excavated dens into the sides of elevated steep-slope hills with availability of water bodies in the vicinity of den sites, and wolves were relegated to dig in places with coarse-soil particles. Our results suggest that vulnerability of wolves in human-dominated landscapes could be compensated by the existence of spatial heterogeneity in human activities. Such heterogeneity would favor wolf persistence in agroecosystems favoring a land sharing model of coexistence between wolves and people. PMID:25251567

  5. Ablation of Persistent Atrial Fibrillation Targeting Low-Voltage Areas With Selective Activation Characteristics.

    PubMed

    Jadidi, Amir S; Lehrmann, Heiko; Keyl, Cornelius; Sorrel, Jérémie; Markstein, Viktor; Minners, Jan; Park, Chan-Il; Denis, Arnaud; Jaïs, Pierre; Hocini, Mélèze; Potocnik, Clemens; Allgeier, Juergen; Hochholzer, Willibald; Herrera-Sidloky, Claudia; Kim, Steve; Omri, Youssef El; Neumann, Franz-Josef; Weber, Reinhold; Haïssaguerre, Michel; Arentz, Thomas

    2016-03-01

    Complex-fractionated atrial electrograms and atrial fibrosis are associated with maintenance of persistent atrial fibrillation (AF). We hypothesized that pulmonary vein isolation (PVI) plus ablation of selective atrial low-voltage sites may be more successful than PVI only. A total of 85 consecutive patients with persistent AF underwent high-density atrial voltage mapping, PVI, and ablation at low-voltage areas (LVA < 0.5 mV in AF) associated with electric activity lasting > 70% of AF cycle length on a single electrode (fractionated activity) or multiple electrodes around the circumferential mapping catheter (rotational activity) or discrete rapid local activity (group I). The procedural end point was AF termination. Arrhythmia freedom was compared with a control group (66 patients) undergoing PVI only (group II). PVI alone was performed in 23 of 85 (27%) patients of group I with low amount (< 10% of left atrial surface area) of atrial low voltage. Selective atrial ablation in addition to PVI was performed in 62 patients with termination of AF in 45 (73%) after 11 ± 9 minutes radiofrequency delivery. AF-termination sites colocalized within LVA in 80% and at border zones in 20%. Single-procedural arrhythmia freedom at 13 months median follow-up was achieved in 59 of 85 (69%) patients in group I, which was significantly higher than the matched control group (31/66 [47%], P < 0.001). There was no significant difference in the success rate of patients in group I with a low amount of low voltage undergoing PVI only and patients requiring PVI+selective low-voltage ablation (P = 0.42). Ablation of sites with distinct activation characteristics within/at borderzones of LVA in addition to PVI is more effective than conventional PVI-only strategy for persistent AF. PVI only seems to be sufficient to treat patients with left atrial low voltage < 10%. © 2016 American Heart Association, Inc.

  6. Effect of Exercise Training on Enos Expression, NO Production and Oxygen Metabolism in Human Placenta

    PubMed Central

    Ramírez-Vélez, Robinson; Bustamante, Juanita; Czerniczyniec, Analia; Aguilar de Plata, Ana C.; Lores-Arnaiz, Silvia

    2013-01-01

    Objective To determine the effects of combined aerobic and resistance exercise training during the second half of pregnancy on endothelial NOS expression (eNOS), nitric oxide (NO) production and oxygen metabolism in human placenta. Methods The study included 20 nulliparous in gestational week 16–20, attending prenatal care at three tertiary hospitals in Colombia who were randomly assigned into one of two groups: The exercise group (n = 10) took part in an exercise session three times a week for 12 weeks which consisted of: aerobic exercise at an intensity of 55–75% of their maximum heart rate for 60 min and 25 mins. Resistance exercise included 5 exercise groups circuit training (50 repetitions of each) using barbells (1–3 kg/exercise) and low-to-medium resistance bands. The control group (n = 10) undertook their usual physical activity. Mitochondrial and cytosol fractions were isolated from human placental tissue by differential centrifugation. A spectrophotometric assay was used to measure NO production in cytosolic samples from placental tissue and Western Blot technique to determine eNOS expression. Mitochondrial superoxide levels and hydrogen peroxide were measured to determine oxygen metabolism. Results Combined aerobic and resistance exercise training during pregnancy leads to a 2-fold increase in eNOS expression and 4-fold increase in NO production in placental cytosol (p = 0.05). Mitochondrial superoxide levels and hydrogen peroxide production rate were decreased by 8% and 37% respectively in the placental mitochondria of exercising women (p = 0.05). Conclusion Regular exercise training during the second half of pregnancy increases eNOS expression and NO production and decreases reactive oxygen species generation in human placenta. Collectively, these data demonstrate that chronic exercise increases eNOS/NO production, presumably by increasing endothelial shear stress. This adaptation may contribute to the beneficial effects of

  7. Longterm persistence of proteolytic activities in frass of Blattella germanica increases its allergenic potential.

    PubMed

    Erban, T; Hubert, J

    2011-06-01

    Chromogenic microplate assays in 96 wells were used to determine the stability of enzyme activity in frass of Blattella germanica (Blattodea: Blattellidae). Frass samples were exposed to controlled conditions [temperature 15-35 °C and/or 53-100% relative humidity (RH)] and to household conditions (apartment). Exposure times were 0 (control), 90, 183 and 276 days. Starch digestion and cellulolytic activities decreased during exposure. Non-specific proteolytic activities were affected by changes in selective proteolytic activities. Activities towards AAPpNA and SA(3) pNA strongly increased at 100% RH, indicating the possible influence of microorganisms growing on frass. Activities towards BApNA and ArgpNA decreased with increasing decomposition time, whereas activity towards ZRRpNA was not influenced by exposure time. The largest decrease in activities towards ArgpNA and BApNA occurred at temperatures of 15 °C, 30 °C and 35 °C and at 100% RH. Activities towards BApNA and ZRRpNA were very stable under different temperature and RH conditions; this was confirmed by findings showing that these activities were stable in the experimental apartment. In comparison with the control, activities towards ZRRpNA and BApNA after 276 days decreased by 1% and 19%, respectively. The longterm persistence of proteolytic activities in cockroach frass increases their allergenic hazard potential.

  8. Circadian oscillation of hippocampal MAPK activity and cAMP: implications for memory persistence

    PubMed Central

    Eckel-Mahan, Kristin L; Phan, Trongha; Han, Sung; Wang, Hongbing; Chan, Guy C-K; Scheiner, Zachary S

    2008-01-01

    The mitogen-activated protein kinase (MAPK) and cyclic adenosine monophosphate (cAMP) signal transduction pathways have critical roles in the consolidation of hippocampus-dependent memory. We found that extracellular regulated kinase 1/2 MAPK phosphorylation and cAMP underwent a circadian oscillation in the hippocampus that was paralleled by changes in Ras activity and the phosphorylation of MAPK kinase and cAMP response element-binding protein (CREB). The nadir of this activation cycle corresponded with severe deficits in hippocampus-dependent fear conditioning under both light-dark and free-running conditions. Circadian oscillations in cAMP and MAPK activity were absent in memory-deficient transgenic mice that lacked Ca2+-stimulated adenylyl cyclases. Furthermore, physiological and pharmacological interference with oscillations in MAPK phosphorylation after the cellular memory consolidation period impaired the persistence of hippocampus-dependent memory. These data suggest that the persistence of long-term memories may depend on reactivation of the cAMP/MAPK/CREB transcriptional pathway in the hippocampus during the circadian cycle. PMID:19160506

  9. Compliance, Persistence, and Preferences Regarding Osteoporosis Treatment During Active Therapy or Drug Holiday.

    PubMed

    Eliasaf, Alona; Amitai, Alina; Maram Edry, Mira; Yosselson Superstine, Shimona; Rotman Pikielny, Pnina

    2016-11-01

    Osteoporosis treatments reduce the risk of fractures by 30%-50%, but adherence after 1 year is only about 50%. Drug holiday, a period with no active treatment, is part of routine management. The objective of this study was to determine compliance and persistence with osteoporosis therapy among postmenopausal women and to assess attitudes regarding treatment resumption among patients on drug holiday. This was a prospective observational study of patients followed at a dedicated metabolic bone clinic September 2013-February 2014. Compliance was assessed by medication possession ratio (MPR; number of doses dispensed relative to the number prescribed). Persistence was defined as continuation of treatment without a >30-day gap in prescription refills. Of 150 patients (70.1 ± 8.1 years), 57% were prescribed a medication: 64% oral, mostly bisphosphonates. MPR ≥ 80% was found in 80% and <50% in 12%; it was 100% for zoledronic acid and denosumab and 97%, 85%, 83%, and 70% for raloxifene, teriparatide, oral bisphosphonates, and strontium ranelate, respectively. Of 39 patients prescribed oral bisphosphonates, 77% persisted with treatment, and 89% took them as directed. Of 64 patients on a drug holiday, 59% expressed confidence in their physician's future treatment choice, whereas 19% expressed concerns about resuming treatment. Compliance among patients attending a dedicated bone clinic was higher than that reported in the literature. High persistence and compliance may be specific to patients followed in this type of setting. This study provides new information about attitudes of patients on a drug holiday. Most were not concerned about resuming treatment and did not have a preferred medication. © 2016, The American College of Clinical Pharmacology.

  10. Fluid shear stress stimulates phosphorylation-dependent nuclear export of HDAC5 and mediates expression of KLF2 and eNOS.

    PubMed

    Wang, Weiye; Ha, Chang Hoon; Jhun, Bong Sook; Wong, Chelsea; Jain, Mukesh K; Jin, Zheng-Gen

    2010-04-08

    Fluid shear stress generated by steady laminar blood flow protects vessels from atherosclerosis. Krüppel-like factor 2 (KLF2) and endothelial nitric oxide synthase (eNOS) are fluid shear stress-responsive genes and key mediators in flow anti-inflammatory and antiatherosclerotic actions. However, the molecular mechanisms underlying flow induction of KLF2 and eNOS remain largely unknown. Here, we show a novel role of histone deacetylase 5 (HDAC5) in flow-mediated KLF2 and eNOS expression. We found for the first time that fluid shear stress stimulated HDAC5 phosphorylation and nuclear export in endothelial cells through a calcium/calmodulin-dependent pathway. Consequently, flow induced the dissociation of HDAC5 and myocyte enhancer factor-2 (MEF2) and enhanced MEF2 transcriptional activity, which leads to expression of KLF2 and eNOS. Adenoviral overexpression of a HDAC5 phosphorylation-defective mutant (Ser259/Ser498 were replaced by Ala259/Ala498, HDAC5-S/A), which shows resistance to flow-induced nuclear export, suppressed flow-mediated MEF2 transcriptional activity and expression of KLF2 and eNOS. Importantly, HDAC5-S/A attenuated the flow-inhibitory effect on monocyte adhesion to endothelial cells. Taken together, our results reveal that phosphorylation-dependent derepression of HDAC5 mediates flow-induced KLF2 and eNOS expression as well as flow anti-inflammation, and suggest that HDAC5 could be a potential therapeutic target for the prevention of atherosclerosis.

  11. Synthetic dendrimeric peptide active against biofilm and persister cells of Pseudomonas aeruginosa.

    PubMed

    Bahar, Ali Adem; Liu, Zhigang; Totsingan, Filbert; Buitrago, Carlos; Kallenbach, Neville; Ren, Dacheng

    2015-10-01

    Antimicrobial dendrimeric peptides (AMDP) are a relatively new class of agents displaying repetitive functional groups on a branched core. Previously, we have investigated the length requirement for antimicrobial activity of peptides consisting of repeated arginine (R) and tryptophan (W) side chains and found that even short linear RW repeats are active, providing a starting point for a de novo design of multivalent structures. In this study, we synthesized and tested a new synthetic dendrimer, 2D-24, for its antimicrobial activity against Pseudomonas aeruginosa, including the wild-type PAO1 and its mucoid mutant PDO300. This synthetic AMDP was found to kill planktonic cells of both PAO1 and PDO300 in a dose-dependent manner, with nearly complete killing of both strains observed when treated with 50 μM of this agent. In addition to planktonic cells, 2D-24 was also found to kill biofilm cells of both strains in a dose-dependent manner. For example, treatment with 30 μM 2D-24 led to 94.4 ± 1.4 and 93.9 ± 4.2 % killing of PAO1 and PDO300 biofilm cells, respectively. Furthermore, 2D-24 was effective in killing multidrug-tolerant persister cells of PAO1 and PDO300. While higher concentrations of 2D-24 were required to kill persister cells, combinations of 2D-24 with ciprofloxacin, tobramycin, or carbenicillin showed synergistic effects on killing persister cells of both strains. Based on hemolysis assays using sheep erythrocytes and a coculture model of PAO1 and human epithelial cells, 2D-24 was found to kill P. aeruginosa cells at concentrations that are not toxic to mammalian cells.

  12. Ketamine upregulates eNOS expression in human astroglial A172 cells: Possible role in its antidepressive properties.

    PubMed

    Yuhas, Yael; Ashkenazi, Shai; Berent, Eva; Weizman, Abraham

    2017-04-15

    Ketamine is a potent anti-depressive agent. Nitric oxide plays an essential role in neuronal transmission and cerebral blood flow and has been implicated in the pathophysiology of major depressive disorder as well as cardiovascular functioning. We investigated the effect of ketamine on eNOS expression in human A172 astroglial cells. Ketamine (50-500μM) increased eNOS expression at 4-24h in a concentration-dependent manner. This effect was mediated by NMDA receptor, Akt inhibition and ERK1/2 activation and was synergistically augmented by rapamycin. The combined effect on the vascular, immune and neuronal systems may be relevant to the rapid antidepressive effect of ketamine. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Active control synthesis for flexible space structures excited by persistent disturbances

    NASA Technical Reports Server (NTRS)

    Wie, Bong; Gonzalez, Marcelo

    1990-01-01

    Both classical and state-space synthesis methods for active control of flexible space structures in the presence of persistent disturbances are presented. The methods exploit the so-called internal model principle for asymptotic disturbance rejection. A generic example of flexible space structures is used to illustrate the simplicity of the proposed design methodologies. The concept of a disturbance rejection filter dipole is introduced from a classical control viewpoint. It is shown that the proposed design methods will invariably make use of non-minimum-phase compensation for a class of noncolocated control problems. The need for tradeoffs between performance and parameter robustness is discussed.

  14. Dopamine modulates an intrinsic mGluR5-mediated depolarization underlying prefrontal persistent activity

    PubMed Central

    Sidiropoulou, Kyriaki; Lu, Fang-Min; Fowler, Melissa A.; Xiao, Rui; Phillips, Christopher; Ozkan, Emin D.; Zhu, Michael X.; White, Francis J.; Cooper, Donald C.

    2009-01-01

    Intrinsic properties of neurons that enable them to maintain depolarized, persistently activated states in the absence of sustained input are poorly understood. In short-term memory tasks, individual prefrontal cortical (PFC) neurons are capable of maintaining persistent action potential output during delay periods between informative cues and behavioral responses. Dopamine and drugs of abuse alter PFC function and working memory possibly by modulating intrinsic neuronal properties. Here we use patch-clamp recording of layer 5 PFC pyramidal neurons to identify an action potential burst-evoked intrinsic mGluR5-mediated postsynaptic depolarization that initiates an activated state. Depolarization occurs in the absence of recurrent synaptic activity and is reduced by a postsynaptic dopamine D1/5 receptor pathway. The depolarization is substantially diminished following behavioral sensitization to cocaine; moreover the D1/5 receptor modulation is lost. We propose the burst-evoked intrinsic depolarization to be a novel form of short-term cellular memory that is modulated by dopamine and cocaine experience. PMID:19169252

  15. NMDA receptor-mediated epileptiform persistent activity requires calcium release from intracellular stores in prefrontal neurons.

    PubMed

    Gao, Wen-Jun; Goldman-Rakic, Patricia S

    2006-02-01

    Various normal and pathological forms of synchronized population activity are generated by recurrent excitation among pyramidal neurons in the neocortex. However, the intracellular signaling mechanisms underlying this activity remain poorly understood. In this study, we have examined the cellular properties of synchronized epileptiform activity in the prefrontal cortex with particular emphasis on a potential role of intracellular calcium stores. We find that the zero-magnesium-induced synchronized activity is blocked by inhibition of sarco-endoplasmic reticulum Ca(2+)-ATPases, phospholipase C (PLC), the inositol 1,4,5-trisphosphate (IP3) receptor, and the ryanodine receptor. This same activity is, however, not affected by application of metabotropic glutamatergic receptor (mGluR) agonists, nor by introduction of an mGluR antagonist. These results suggest that persistent synchronized activity in vitro is dependent upon calcium release from internal calcium stores through the activation of PLC-IP3 receptor pathway. Our findings also raise the possibility that intracellular calcium release may be involved in the generation of pathologic synchronized activity in epilepsy in vivo and in physiological forms of synchronized cortical activity.

  16. Atherosclerosis: analysis of the eNOS (T786C) gene polymorphism.

    PubMed

    Barbosa, A M; Silva, K S F; Lagares, M H; Rodrigues, D A; da Costa, I R; Morais, M P; Martins, J V M; Mascarenhas, R S; Campedelli, F L; Moura, K K V O

    2017-09-21

    The coronary arteriosclerotic disease is the most common cardiovascular disease. Atherosclerosis affects large- and medium-sized arteries leading to severe thrombosis or artery stenosis that could evolve to myocardial infarction, ischemic stroke, ischemic injury of kidneys and intestines, and several other life-threatening clinical manifestations. Nitric oxide has been shown to be a promising therapeutic agent against cardiovascular diseases. The eNOS gene assumes several important functions, including regulation of vascular tone and regional blood flow, the suppression of vascular smooth muscle cell proliferation, and modulation of leukocyte-endothelium interactions. The T786C polymorphism is an important point mutation, where thymine is changed to cytosine. T786C significantly reduces the activity of the eNOS promoter gene. Two hundred and ninety-seven peripheral blood samples were collected from patients with the previous diagnosis of atherosclerotic disease based on clinical examination and confirmed by imaging methods. Results were compared using the chi-square test and the G-test. In the present study, the TC genotype was more frequent in both case and control groups with no statistically significant difference. Comparing the relation TC/TT and CC genotypes in the case and control groups, there was no statistically significant difference. No significant difference was found when genotypes were analyzed regarding gender and smoking. Our results suggest a strong tendency of the T allele, in single or double dose, to be associated with atherosclerosis that was not confirmed by the scientific data.

  17. Melatonin and vitamin C ameliorate alcohol-induced oxidative stress and eNOS expression in rat kidney.

    PubMed

    Sönmez, Mehmet Fatih; Narin, Figen; Akkuş, Derya; Türkmen, Ayşegül Burçin

    2012-01-01

    The aim of this study was to investigate the preventive effects of melatonin and vitamin C as antioxidants on renal injury in chronic alcohol consumption. A total of 24 adult male Wistar rats weighing 200-250 g were used in the study. Rats were divided into four equal groups. Group I (control): rats were not fed on alcohol; Group II: rats were fed on alcohol; Group III: rats were fed on alcohol and 40 mg/kg vitamin C; and Group IV: rats were fed on alcohol and 4 mg/kg melatonin. Light microscopic examination revealed atrophic renal corpuscles, dilatation and congestion of the peritubular vessels, and renal corpuscles with obscure Bowman's space and a few foamy-appearing tubules due to alcohol consumption were observed. Expression of endothelial nitric oxide synthase (eNOS) was localized to glomerulus, distal, and collector tubules. eNOS staining decreased in alcohol treatment group and melatonin and vitamin C encore increased expression pattern of eNOS. Alcohol consumption increased malondialdehyde (MDA) level and superoxide dismutase (SOD) and catalase (CAT) activities significantly in the alcohol consumption groups compared with that in the control group, while in melatonin give group just MDA level was decreased statistically significant and SOD and CAT activities were also decreased numerically compared with the alcohol consumption groups. These results indicated that chronic alcohol consumption caused renal damage by increased lipid peroxidation and melatonin and vitamin C administration produced in some degree protection against alcohol-induced damage.

  18. Betaxolol stimulates eNOS production associated with LOX-1 and VEGF in Dahl salt-sensitive rats.

    PubMed

    Kobayashi, Naohiko; Yoshida, Kohtaro; Mita, Shin-ichiro; Honda, Takeaki; Hara, Kazuyoshi; Nakano, Shigefumi; Tsubokou, Yusuke; Matsuoka, Hiroaki

    2004-07-01

    Lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1) and vascular endothelial growth factor (VEGF) may play key roles in atherosclerosis, and have been shown to regulate nitric oxide (NO) production. However, the molecular mechanisms by which betaxolol, a specific beta 1-antagonist, stimulates endothelial NO synthase (eNOS) expression associated with LOX-1 and VEGF are unclear. We hypothesized that in the left ventricle of Dahl salt-sensitive (DS) rats, betaxolol reduces production of LOX-1 by suppressing NAD(P)H oxidase p47phox expression; betaxolol stimulates eNOS production associated with expression of VEGF and LOX-1; and betaxolol inhibits adhesion molecule and signal transduction, which may be involved in cardiovascular remodeling. After 5 weeks of feeding an 8% NaCl diet to 6-week-old DS rats (i.e. at 11 weeks of age), a distinct stage of concentric left ventricular hypertrophy was noted. Betaxolol (0.9 mg/kg per day) was administered to 6-week-old DS rats for 5 weeks until the onset of left ventricular hypertrophy stage. Decreased expression of eNOS and VEGF in DS rats was increased by betaxolol. Upregulated LOX-1, NAD(P)H oxidase p47phox, intercellular and vascular cell adhesion molecule-1 expression and phosphorylations of p38 mitogen-activated protein kinase and p65 nuclear factor-kappa B activity were inhibited by betaxolol. Betaxolol administration resulted in significant improvement of cardiovascular remodeling and suppression of transforming growth factor-beta 1 and type I collagen expression. These results suggest that cardioprotective effects of betaxolol may stimulate eNOS production associated with VEGF and LOX-1, and inhibit adhesion molecule and signal transduction in DS rats.

  19. Partial eNOS deficiency causes spontaneous thrombotic cerebral infarction, amyloid angiopathy and cognitive impairment.

    PubMed

    Tan, Xing-Lin; Xue, Yue-Qiang; Ma, Tao; Wang, Xiaofang; Li, Jing Jing; Lan, Lubin; Malik, Kafait U; McDonald, Michael P; Dopico, Alejandro M; Liao, Francesca-Fang

    2015-06-24

    Cerebral infarction due to thrombosis leads to the most common type of stroke and a likely cause of age-related cognitive decline and dementia. Endothelial nitric oxide synthase (eNOS) generates NO, which plays a crucial role in maintaining vascular function and exerting an antithrombotic action. Reduced eNOS expression and eNOS polymorphisms have been associated with stroke and Alzheimer's disease (AD), the most common type of dementia associated with neurovascular dysfunction. However, direct proof of such association is lacking. Since there are no reports of complete eNOS deficiency in humans, we used heterozygous eNOS(+/-) mice to mimic partial deficiency of eNOS, and determine its impact on cerebrovascular pathology and perfusion of cerebral vessels. Combining cerebral angiography with immunohistochemistry, we found thrombotic cerebral infarctions in eNOS(+/-) mice as early as 3-6 months of age but not in eNOS(+/+) mice at any age. Remarkably, vascular occlusions in eNOS(+/-) mice were found almost exclusively in three areas: temporoparietal and retrosplenial granular cortexes, and hippocampus this distribution precisely matching the hypoperfused areas identified in preclinical AD patients. Moreover, progressive cerebral amyloid angiopaphy (CAA), blood brain barrier (BBB) breakdown, and cognitive impairment were also detected in aged eNOS(+/-) mice. These data provide for the first time the evidence that partial eNOS deficiency results in spontaneous thrombotic cerebral infarctions that increase with age, leading to progressive CAA and cognitive impairments. We thus conclude that eNOS(+/-) mouse may represent an ideal model of ischemic stroke to address early and progressive damage in spontaneously-evolving chronic cerebral ischemia and thus, study vascular mechanisms contributing to vascular dementia and AD.

  20. Living Water. Eno River State Park: An Environmental Education Learning Experience Designed for the Middle Grades.

    ERIC Educational Resources Information Center

    Hartley, Scott; Woods, Martha

    This learning packet, one in a series of eight, was developed by the Eno River State Park in North Carolina for Grades 5-6 to teach about various aspects of water life on the Eno River. Loose-leaf pages are presented in nine sections that contain: (1) introductions to the North Carolina State Park System, the Eno River State Park, and to the…

  1. Correlations in background activity control persistent state stability and allow execution of working memory tasks

    PubMed Central

    Dipoppa, Mario; Gutkin, Boris S.

    2013-01-01

    Working memory (WM) requires selective information gating, active information maintenance, and rapid active updating. Hence performing a WM task needs rapid and controlled transitions between neural persistent activity and the resting state. We propose that changes in correlations in neural activity provides a mechanism for the required WM operations. As a proof of principle, we implement sustained activity and WM in recurrently coupled spiking networks with neurons receiving excitatory random background activity where background correlations are induced by a common noise source. We first characterize how the level of background correlations controls the stability of the persistent state. With sufficiently high correlations, the sustained state becomes practically unstable, so it cannot be initiated by a transient stimulus. We exploit this in WM models implementing the delay match to sample task by modulating flexibly in time the correlation level at different phases of the task. The modulation sets the network in different working regimes: more prompt to gate in a signal or clear the memory. We examine how the correlations affect the ability of the network to perform the task when distractors are present. We show that in a winner-take-all version of the model, where two populations cross-inhibit, correlations make the distractor blocking robust. In a version of the mode where no cross inhibition is present, we show that appropriate modulation of correlation levels is sufficient to also block the distractor access while leaving the relevant memory trace in tact. The findings presented in this manuscript can form the basis for a new paradigm about how correlations are flexibly controlled by the cortical circuits to execute WM operations. PMID:24155714

  2. Correlations in background activity control persistent state stability and allow execution of working memory tasks.

    PubMed

    Dipoppa, Mario; Gutkin, Boris S

    2013-01-01

    Working memory (WM) requires selective information gating, active information maintenance, and rapid active updating. Hence performing a WM task needs rapid and controlled transitions between neural persistent activity and the resting state. We propose that changes in correlations in neural activity provides a mechanism for the required WM operations. As a proof of principle, we implement sustained activity and WM in recurrently coupled spiking networks with neurons receiving excitatory random background activity where background correlations are induced by a common noise source. We first characterize how the level of background correlations controls the stability of the persistent state. With sufficiently high correlations, the sustained state becomes practically unstable, so it cannot be initiated by a transient stimulus. We exploit this in WM models implementing the delay match to sample task by modulating flexibly in time the correlation level at different phases of the task. The modulation sets the network in different working regimes: more prompt to gate in a signal or clear the memory. We examine how the correlations affect the ability of the network to perform the task when distractors are present. We show that in a winner-take-all version of the model, where two populations cross-inhibit, correlations make the distractor blocking robust. In a version of the mode where no cross inhibition is present, we show that appropriate modulation of correlation levels is sufficient to also block the distractor access while leaving the relevant memory trace in tact. The findings presented in this manuscript can form the basis for a new paradigm about how correlations are flexibly controlled by the cortical circuits to execute WM operations.

  3. CD62L+ NKT cells have prolonged persistence and antitumor activity in vivo.

    PubMed

    Tian, Gengwen; Courtney, Amy N; Jena, Bipulendu; Heczey, Andras; Liu, Daofeng; Marinova, Ekaterina; Guo, Linjie; Xu, Xin; Torikai, Hiroki; Mo, Qianxing; Dotti, Gianpietro; Cooper, Laurence J; Metelitsa, Leonid S

    2016-06-01

    Vα24-invariant natural killer T cells (NKTs) localize to tumors and have inherent antitumor properties, making them attractive chimeric antigen receptor (CAR) carriers for redirected cancer immunotherapy. However, clinical application of CAR-NKTs has been impeded, as mechanisms responsible for NKT expansion and the in vivo persistence of these cells are unknown. Here, we demonstrated that antigen-induced expansion of primary NKTs in vitro associates with the accumulation of a CD62L+ subset and exhaustion of CD62L- cells. Only CD62L+ NKTs survived and proliferated in response to secondary stimulation. When transferred to immune-deficient NSG mice, CD62L+ NKTs persisted 5 times longer than CD62L- NKTs. Moreover, CD62L+ cells transduced with a CD19-specific CAR achieved sustained tumor regression in a B cell lymphoma model. Proliferating CD62L+ cells downregulated or maintained CD62L expression when activated via T cell receptor alone or in combination with costimulatory receptors. We generated HLAnull K562 cell clones that were engineered to express CD1d and costimulatory ligands. Clone B-8-2 (HLAnullCD1dmedCD86high4-1BBLmedOX40Lhigh) induced the highest rates of NKT expansion and CD62L expression. B-8-2-expanded CAR-NKTs exhibited prolonged in vivo persistence and superior therapeutic activities in models of lymphoma and neuroblastoma. Therefore, we have identified CD62L as a marker of a distinct NKT subset endowed with high proliferative potential and have developed artificial antigen-presenting cells that generate CD62L-enriched NKTs for effective cancer immunotherapy.

  4. CD62L+ NKT cells have prolonged persistence and antitumor activity in vivo

    PubMed Central

    Tian, Gengwen; Courtney, Amy N.; Jena, Bipulendu; Heczey, Andras; Liu, Daofeng; Marinova, Ekaterina; Guo, Linjie; Xu, Xin; Torikai, Hiroki; Mo, Qianxing; Dotti, Gianpietro; Cooper, Laurence J.; Metelitsa, Leonid S.

    2016-01-01

    Vα24-invariant natural killer T cells (NKTs) localize to tumors and have inherent antitumor properties, making them attractive chimeric antigen receptor (CAR) carriers for redirected cancer immunotherapy. However, clinical application of CAR-NKTs has been impeded, as mechanisms responsible for NKT expansion and the in vivo persistence of these cells are unknown. Here, we demonstrated that antigen-induced expansion of primary NKTs in vitro associates with the accumulation of a CD62L+ subset and exhaustion of CD62L– cells. Only CD62L+ NKTs survived and proliferated in response to secondary stimulation. When transferred to immune-deficient NSG mice, CD62L+ NKTs persisted 5 times longer than CD62L– NKTs. Moreover, CD62L+ cells transduced with a CD19-specific CAR achieved sustained tumor regression in a B cell lymphoma model. Proliferating CD62L+ cells downregulated or maintained CD62L expression when activated via T cell receptor alone or in combination with costimulatory receptors. We generated HLAnull K562 cell clones that were engineered to express CD1d and costimulatory ligands. Clone B-8-2 (HLAnullCD1dmedCD86high4-1BBLmedOX40Lhigh) induced the highest rates of NKT expansion and CD62L expression. B-8-2–expanded CAR-NKTs exhibited prolonged in vivo persistence and superior therapeutic activities in models of lymphoma and neuroblastoma. Therefore, we have identified CD62L as a marker of a distinct NKT subset endowed with high proliferative potential and have developed artificial antigen-presenting cells that generate CD62L-enriched NKTs for effective cancer immunotherapy. PMID:27183388

  5. Hypercholesterolemia-induced erectile dysfunction: endothelial nitric oxide synthase (eNOS) uncoupling in the mouse penis by NAD(P)H oxidase

    PubMed Central

    Musicki, Biljana; Liu, Tongyun; Lagoda, Gwen A.; Strong, Travis D.; Sezen, Sena F.; Johnson, Justin M.; Burnett, Arthur L.

    2010-01-01

    INTRODUCTION Hypercholesterolemia induces erectile dysfunction (ED) mostly by increasing oxidative stress and impairing endothelial function in the penis, but the mechanisms regulating reactive oxygen species (ROS) production in the penis are not understood. AIMS We evaluated whether hypercholesterolemia activates nicotinamide adenine dinucleotide phosphate (NAD[P]H) oxidase in the penis, providing an initial source of ROS to induce endothelial nitric oxide synthase (eNOS) uncoupling and endothelial dysfunction resulting in ED. METHODS Low-density-lipoprotein receptor (LDLR)–null mice were fed Western diet for 4 weeks to induce early-stage hyperlipidemia. Wild type (WT) mice fed regular chow served as controls. Mice received NAD(P)H oxidase inhibitor apocynin (10 mM in drinking water) or vehicle. Erectile function was assessed in response to cavernous nerve electrical stimulation. Markers of endothelial function (phospho [P]-vasodilator-stimulated-protein [VASP]-Ser-239), oxidative stress (4-hydroxy-2-nonenal [HNE]), sources of ROS (eNOS uncoupling and NAD[P]H oxidase subunits p67phox, p47phox, and gp91phox), P-eNOS-Ser-1177, and eNOS were measured by Western blot in penes. MAIN OUTCOME MEASURES Molecular mechanisms of ROS generation and endothelial dysfunction in hypercholesterolemia-induced ED. RESULTS Erectile response was significantly (P<0.05) reduced in hypercholesterolemic LDLR-null mice compared to WT mice. Relative to WT mice, hypercholesterolemia increased (P<0.05) protein expressions of NAD(P)H oxidase subunits p67phox, p47phox and gp91phox, eNOS uncoupling, and 4-HNE-modified proteins, and reduced (P<0.05) P-VASP-Ser-239 expression in the penis. Apocynin treatment of LDLR-null mice preserved (P<0.05) maximal intracavernosal pressure, and reversed (P < 0.05) the abnormalities in protein expressions of gp67phox and gp47phox, 4-HNE, P-VASP-Ser-239, and eNOS uncoupling in the penis. Apocynin treatment of WT mice did not affect any of these parameters

  6. Dopamine suppresses persistent network activity via D1-like dopamine receptors in rat medial entorhinal cortex

    PubMed Central

    Mayne, Elizabeth W; Craig, Michael T; McBain, Chris J; Paulsen, Ole

    2013-01-01

    Cortical networks display persistent activity in the form of periods of sustained synchronous depolarizations (‘UP states’) punctuated by periods of relative hyperpolarization (‘DOWN states’), which together form the slow oscillation. UP states are known to be synaptically generated and are sustained by a dynamic balance of excitation and inhibition, with fast ionotropic glutamatergic excitatory and GABAergic inhibitory conductances increasing during the UP state. Previously, work from our group demonstrated that slow metabotropic GABA receptors also play an important role in terminating the UP state, but the effects of other neuromodulators on this network phenomenon have received little attention. Given that persistent activity is a neural correlate of working memory and that signalling through dopamine receptors has been shown to be critical for working memory tasks, we examined whether dopaminergic neurotransmission affected the slow oscillation. Here, using an in vitro model of the slow oscillation in rat medial entorhinal cortex, we showed that dopamine strongly and reversibly suppressed cortical UP states. We showed that this effect was mediated through D1-like and not D2-like dopamine receptors, and we found no evidence that tonic dopaminergic transmission affected UP states in our model. PMID:23336973

  7. Ramping ensemble activity in dorsal anterior cingulate neurons during persistent commitment to a decision

    PubMed Central

    Hayden, Benjamin Y.

    2015-01-01

    We frequently need to commit to a choice to achieve our goals; however, the neural processes that keep us motivated in pursuit of delayed goals remain obscure. We examined ensemble responses of neurons in macaque dorsal anterior cingulate cortex (dACC), an area previously implicated in self-control and persistence, in a task that requires commitment to a choice to obtain a reward. After reward receipt, dACC neurons signaled reward amount with characteristic ensemble firing rate patterns; during the delay in anticipation of the reward, ensemble activity smoothly and gradually came to resemble the postreward pattern. On the subset of risky trials, in which a reward was anticipated with 50% certainty, ramping ensemble activity evolved to the pattern associated with the anticipated reward (and not with the anticipated loss) and then, on loss trials, took on an inverted form anticorrelated with the form associated with a win. These findings enrich our knowledge of reward processing in dACC and may have broader implications for our understanding of persistence and self-control. PMID:26334016

  8. Persistent activation of autophagy in kidney tubular cells promotes renal interstitial fibrosis during unilateral ureteral obstruction

    PubMed Central

    Livingston, Man J.; Ding, Han-Fei; Huang, Shuang; Hill, Joseph A.; Yin, Xiao-Ming; Dong, Zheng

    2016-01-01

    ABSTRACT Renal fibrosis is the final, common pathway of end-stage renal disease. Whether and how autophagy contributes to renal fibrosis remains unclear. Here we first detected persistent autophagy in kidney proximal tubules in the renal fibrosis model of unilateral ureteral obstruction (UUO) in mice. UUO-associated fibrosis was suppressed by pharmacological inhibitors of autophagy and also by kidney proximal tubule-specific knockout of autophagy-related 7 (PT-Atg7 KO). Consistently, proliferation and activation of fibroblasts, as indicated by the expression of ACTA2/α-smooth muscle actin and VIM (vimentin), was inhibited in PT-Atg7 KO mice, so was the accumulation of extracellular matrix components including FN1 (fibronectin 1) and collagen fibrils. Tubular atrophy, apoptosis, nephron loss, and interstitial macrophage infiltration were all inhibited in these mice. Moreover, these mice showed a specific suppression of the expression of a profibrotic factor FGF2 (fibroblast growth factor 2). In vitro, TGFB1 (transforming growth factor β 1) induced autophagy, apoptosis, and FN1 accumulation in primary proximal tubular cells. Inhibition of autophagy suppressed FN1 accumulation and apoptosis, while enhancement of autophagy increased TGFB1-induced-cell death. These results suggest that persistent activation of autophagy in kidney proximal tubules promotes renal interstitial fibrosis during UUO. The profibrotic function of autophagy is related to the regulation on tubular cell death, interstitial inflammation, and the production of profibrotic factors. PMID:27123926

  9. eNOS gene haplotype is indirectly associated with the recovery of cardiovascular autonomic modulation from exercise.

    PubMed

    Silva, Bruno M; Barbosa, Thales C; Neves, Fabricia J; Sales, Allan K; Rocha, Natalia G; Medeiros, Renata F; Pereira, Felipe S; Garcia, Vinicius P; Cardoso, Fabiane T; Nobrega, Antonio C L

    2014-12-01

    Polymorphisms in the endothelial nitric oxide synthase (eNOS) gene decrease expression and activation of eNOS in vitro, which is associated with lower post-exercise increase in vasodilator reactivity in vivo. However, it is unknown whether such polymorphisms are associated with other eNOS-related phenotypes during recovery from exercise. Therefore, we investigated the impact of an eNOS haplotype containing polymorphic alleles at loci -786 and 894 on the recovery of cardiovascular autonomic function from exercise. Sedentary, non-obese, healthy subjects were enrolled [n = 107, age 32 ± 1 years (mean ± SEM)]. Resting autonomic modulation (heart rate variability, systolic blood pressure variability, and spontaneous baroreflex sensitivity) and vascular reactivity (forearm hyperemic response post-ischemia) were assessed at baseline, 10, 60, and 120 min after a maximal cardiopulmonary exercise test. Besides, autonomic function was assessed by heart rate recovery (HRR) immediately after peak exercise. Haplotype analysis showed that vagal modulation (i.e., HF n.u.) was significantly higher, combined sympathetic and vagal modulation (i.e., LF/HF) was significantly lower and total blood pressure variability was significantly lower post-exercise in a haplotype containing polymorphic alleles (H2) compared to a haplotype with wild type alleles (H1). HRR was similar between groups. Corroborating previous evidence, H2 had significantly lower post-exercise increase in vasodilator reactivity than H1. In conclusion, a haplotype containing polymorphic alleles at loci -786 and 894 had enhanced recovery of autonomic modulation from exercise, along with unchanged HRR, and attenuated vasodilator reactivity. Then, these results suggest an autonomic compensatory response of a direct deleterious effect of eNOS polymorphisms on the vascular function. Copyright © 2014 Elsevier B.V. All rights reserved.

  10. Resveratrol Prevented Lipopolysaccharide-Induced Endothelial Dysfunction in Rat Thoracic Aorta Through Increased eNOS Expression

    PubMed Central

    Uğurel, Seda Sultan; Kuşçu, Nilay; Özenci, Çiler Çelik; Dalaklıoğlu, Selvinaz; Taşatargil, Arda

    2016-01-01

    Background: The cardiovascular benefits of Resveratrol (RVT) have been well established by previous experimental and clinical studies. Aims: The goal of this study was to test the effectiveness of RVT administration on the impaired endothelial function induced by lipopolysaccharide (LPS), and to elucidate the role of endothelial nitric oxide synthase (eNOS)/Sirtuin 1 (SIRT1) pathway. Study Design: Animal experiment. Methods: Endotoxemia was induced by intraperitoneal injection of 10 mg/kg LPS, and the thoracic aorta was isolated six hours later. RVT was injected intraperitoneally 15 minutes before LPS administration. Six hours after LPS injection, potassium chloride (KCl), phenylephrine (Phe), acetylcholine (ACh), and sodium nitroprusside (SNP) were used to examine to vascular reactivity and endothelial function. eNOS, phospho-eNOS (p-eNOS) (Ser 1177), and SIRT1 expressions in thoracic aorta were evaluated by Western blot. Results: LPS administration significantly inhibited the relaxation response induced by ACh, while the relaxation to SNP was not significantly altered. Phe- and KCl-induced contractile responses in the thoracic aorta significantly decreased in LPS-injected group. eNOS and p-eNOS expression decreased significantly in arteries obtained from LPS group rats. The impaired vasoreactivity as well as decreased expressions of eNOS, p-eNOS, and SIRT1 in vessels from LPS-injected rats were improved by RVT treatment. Conclusion: The endothelium-dependent vasodilatation of the thoracic aorta was significantly inhibited by LPS administration, and RVT treatment may improve vascular endothelial function. The protective effect of RVT might be associated with increased eNOS expression and activity. PMID:27403381

  11. Effect of exercise training on eNOS expression, NO production and oxygen metabolism in human placenta.

    PubMed

    Ramírez-Vélez, Robinson; Bustamante, Juanita; Czerniczyniec, Analia; Aguilar de Plata, Ana C; Lores-Arnaiz, Silvia

    2013-01-01

    To determine the effects of combined aerobic and resistance exercise training during the second half of pregnancy on endothelial NOS expression (eNOS), nitric oxide (NO) production and oxygen metabolism in human placenta. The study included 20 nulliparous in gestational week 16-20, attending prenatal care at three tertiary hospitals in Colombia who were randomly assigned into one of two groups: The exercise group (n = 10) took part in an exercise session three times a week for 12 weeks which consisted of: aerobic exercise at an intensity of 55-75% of their maximum heart rate for 60 min and 25 mins. Resistance exercise included 5 exercise groups circuit training (50 repetitions of each) using barbells (1-3 kg/exercise) and low-to-medium resistance bands. The control group (n = 10) undertook their usual physical activity. Mitochondrial and cytosol fractions were isolated from human placental tissue by differential centrifugation. A spectrophotometric assay was used to measure NO production in cytosolic samples from placental tissue and Western Blot technique to determine eNOS expression. Mitochondrial superoxide levels and hydrogen peroxide were measured to determine oxygen metabolism. Combined aerobic and resistance exercise training during pregnancy leads to a 2-fold increase in eNOS expression and 4-fold increase in NO production in placental cytosol (p = 0.05). Mitochondrial superoxide levels and hydrogen peroxide production rate were decreased by 8% and 37% respectively in the placental mitochondria of exercising women (p = 0.05). Regular exercise training during the second half of pregnancy increases eNOS expression and NO production and decreases reactive oxygen species generation in human placenta. Collectively, these data demonstrate that chronic exercise increases eNOS/NO production, presumably by increasing endothelial shear stress. This adaptation may contribute to the beneficial effects of exercise on the vascular and antioxidant system and in turn

  12. Systemic right-to-left shunts, ischemic brain lesions, and persistent migraine activity.

    PubMed

    Koppen, Hille; Palm-Meinders, Inge H; Mess, Werner H; Keunen, Ruud W; Terwindt, Gisela M; Launer, Lenore J; van Buchem, Mark A; Kruit, Mark C; Ferrari, Michel D

    2016-05-03

    To assess whether migraine in the general population is associated with increased risk of systemic right-to-left shunts (RLS) and whether RLS are associated with increased prevalence of brain infarcts and persistent recurrence of migraine attacks at older age. Brain MRI and transcranial Doppler with air contrast in 166 unselected migraineurs (mean age ± SD 56 ± 7.7 years; 70% women; n = 96 migraine with aura) and 69 controls (mean age ± SD 55 ± 7.6 years; 65% women) from the general population. Participants with migraine with aura more frequently had Valsalva-induced RLS (60%), in particular large-sized, compared to controls (42%; odds ratio [OR] 2.1; 95% confidence interval [CI] 1.1-3.9; p = 0.02) and participants with migraine without aura (40%; OR 2.3; 95% CI 1.2-4.3; p = 0.01). They also more frequently had spontaneous RLS (35%) than participants with migraine without aura (17%; OR 2.6; 95% CI 1.3-5.6; p = 0.01) but not compared to controls (26%; OR 1.6; 95% CI 0.8-3.1; p = 0.2). Participants with migraine with aura and spontaneous RLS more frequently had persistent migraine activity (85%) than participants with migraine without spontaneous RLS (63%; OR 3.4; 95% CI 1.2-10.1; p = 0.03). Nine percent of participants with RLS had silent posterior circulation infarcts compared to 3% of participants without RLS (OR 2.8; 95% CI 0.9-9.3; p = 0.08), independent of migraine status. RLS were not associated with white matter lesions. RLS are more prevalent in migraineurs with aura but do not explain the increased prevalence of silent posterior circulation infarcts or white matter lesions in migraineurs. Spontaneous RLS are associated with persistent migraine. © 2016 American Academy of Neurology.

  13. DNA Methylation Mediates Persistent Epileptiform Activity In Vitro and In Vivo

    PubMed Central

    Machnes, Ziv M.; Huang, Tony C. T.; Chang, Philip K. Y.; Gill, Raminder; Reist, Nicholas; Dezsi, Gabriella; Ozturk, Ezgi; Charron, Francois; O’Brien, Terence J.; Jones, Nigel C.

    2013-01-01

    Epilepsy is a chronic brain disorder involving recurring seizures often precipitated by an earlier neuronal insult. The mechanisms that link the transient neuronal insult to the lasting state of epilepsy are unknown. Here we tested the possible role of DNA methylation in mediating long-term induction of epileptiform activity by transient kainic acid exposure using in vitro and in vivo rodent models. We analyzed changes in the gria2 gene, which encodes for the GluA2 subunit of the ionotropic glutamate, alpha-amino-3-hydroxy-5-methyl-4-isoxazole proprionic acid receptor and is well documented to play a role in epilepsy. We show that kainic acid exposure for two hours to mouse hippocampal slices triggers methylation of a 5’ regulatory region of the gria2 gene. Increase in methylation persists one week after removal of the drug, with concurrent suppression of gria2 mRNA expression levels. The degree of kainic acid-induced hypermethylation of gria2 5’ region varies between individual slices and correlates with the changes in excitability induced by kainic acid. In a rat in vivo model of post kainic acid-induced epilepsy, we show similar hypermethylation of the 5’ region of gria2. Inter-individual variations in gria2 methylation, correlate with the frequency and intensity of seizures among epileptic rats. Luciferase reporter assays support a regulatory role for methylation of gria2 5’ region. Inhibition of DNA methylation by RG108 blocked kainic acid-induced hypermethylation of gria2 5’ region in hippocampal slice cultures and bursting activity. Our results suggest that DNA methylation of such genes as gria2 mediates persistent epileptiform activity and inter-individual differences in the epileptic response to neuronal insult and that pharmacological agents that block DNA methylation inhibit epileptiform activity raising the prospect of DNA methylation inhibitors in epilepsy therapeutics. PMID:24098468

  14. Voltage-gated Na+ Channel Activity Increases Colon Cancer Transcriptional Activity and Invasion Via Persistent MAPK Signaling

    NASA Astrophysics Data System (ADS)

    House, Carrie D.; Wang, Bi-Dar; Ceniccola, Kristin; Williams, Russell; Simaan, May; Olender, Jacqueline; Patel, Vyomesh; Baptista-Hon, Daniel T.; Annunziata, Christina M.; Silvio Gutkind, J.; Hales, Tim G.; Lee, Norman H.

    2015-06-01

    Functional expression of voltage-gated Na+ channels (VGSCs) has been demonstrated in multiple cancer cell types where channel activity induces invasive activity. The signaling mechanisms by which VGSCs promote oncogenesis remain poorly understood. We explored the signal transduction process critical to VGSC-mediated invasion on the basis of reports linking channel activity to gene expression changes in excitable cells. Coincidentally, many genes transcriptionally regulated by the SCN5A isoform in colon cancer have an over-representation of cis-acting sites for transcription factors phosphorylated by ERK1/2 MAPK. We hypothesized that VGSC activity promotes MAPK activation to induce transcriptional changes in invasion-related genes. Using pharmacological inhibitors/activators and siRNA-mediated gene knockdowns, we correlated channel activity with Rap1-dependent persistent MAPK activation in the SW620 human colon cancer cell line. We further demonstrated that VGSC activity induces downstream changes in invasion-related gene expression via a PKA/ERK/c-JUN/ELK-1/ETS-1 transcriptional pathway. This is the first study illustrating a molecular mechanism linking functional activity of VGSCs to transcriptional activation of invasion-related genes.

  15. Voltage-gated Na+ Channel Activity Increases Colon Cancer Transcriptional Activity and Invasion Via Persistent MAPK Signaling.

    PubMed

    House, Carrie D; Wang, Bi-Dar; Ceniccola, Kristin; Williams, Russell; Simaan, May; Olender, Jacqueline; Patel, Vyomesh; Baptista-Hon, Daniel T; Annunziata, Christina M; Gutkind, J Silvio; Hales, Tim G; Lee, Norman H

    2015-06-22

    Functional expression of voltage-gated Na(+) channels (VGSCs) has been demonstrated in multiple cancer cell types where channel activity induces invasive activity. The signaling mechanisms by which VGSCs promote oncogenesis remain poorly understood. We explored the signal transduction process critical to VGSC-mediated invasion on the basis of reports linking channel activity to gene expression changes in excitable cells. Coincidentally, many genes transcriptionally regulated by the SCN5A isoform in colon cancer have an over-representation of cis-acting sites for transcription factors phosphorylated by ERK1/2 MAPK. We hypothesized that VGSC activity promotes MAPK activation to induce transcriptional changes in invasion-related genes. Using pharmacological inhibitors/activators and siRNA-mediated gene knockdowns, we correlated channel activity with Rap1-dependent persistent MAPK activation in the SW620 human colon cancer cell line. We further demonstrated that VGSC activity induces downstream changes in invasion-related gene expression via a PKA/ERK/c-JUN/ELK-1/ETS-1 transcriptional pathway. This is the first study illustrating a molecular mechanism linking functional activity of VGSCs to transcriptional activation of invasion-related genes.

  16. Theodore E. Woodward Award: Lactase Persistence SNPs in African Populations Regulate Promoter Activity in Intestinal Cell Culture

    PubMed Central

    Sibley, Eric; Ahn, Jong Kun

    2011-01-01

    Lactase-phlorizin hydrolase, lactase, is the intestinal enzyme responsible for the digestion of the milk sugar lactose. The majority of the world's human population experiences a decline in expression of the lactase gene by late childhood (lactase non-persistence). Individuals with lactase persistence, however, continue to express high levels of the lactase gene throughout adulthood. Lactase persistence is a heritable autosomal dominant condition and has been strongly correlated with several single nucleotide polymorphisms (SNPs) located ∼14 kb upstream of the lactase gene in different ethnic populations: -13910*T in Europeans and -13907*G, -13915*G, and -14010*C in several African populations. The coincidence of the four SNPs clustering within 100 bp strongly suggests that this region mediates the lactase non-persistence/persistence phenotype. Having previously characterized the European SNP, we aimed to determine whether the African SNPs similarly mediate a functional role in regulating the lactase promoter. Human intestinal Caco-2 cells were transfected with lactase SNP/promoter-reporter constructs and assayed for promoter activity. The -13907*G and -13915*G SNPs result in a significant enhancement of lactase promoter activity relative to the ancestral lactase non-persistence genotype. Such differential regulation by the SNPs is consistent with a causative role in the mechanism specifying the lactase persistence phenotype. PMID:21686221

  17. Theodore E. Woodward Award: lactase persistence SNPs in African populations regulate promoter activity in intestinal cell culture.

    PubMed

    Sibley, Eric; Ahn, Jong Kun

    2011-01-01

    Lactase-phlorizin hydrolase, lactase, is the intestinal enzyme responsible for the digestion of the milk sugar lactose. The majority of the world's human population experiences a decline in expression of the lactase gene by late childhood (lactase non-persistence). Individuals with lactase persistence, however, continue to express high levels of the lactase gene throughout adulthood. Lactase persistence is a heritable autosomal dominant condition and has been strongly correlated with several single nucleotide polymorphisms (SNPs) located ∼14 kb upstream of the lactase gene in different ethnic populations: -13910*T in Europeans and -13907*G, -13915*G, and -14010*C in several African populations. The coincidence of the four SNPs clustering within 100 bp strongly suggests that this region mediates the lactase non-persistence/persistence phenotype. Having previously characterized the European SNP, we aimed to determine whether the African SNPs similarly mediate a functional role in regulating the lactase promoter. Human intestinal Caco-2 cells were transfected with lactase SNP/promoter-reporter constructs and assayed for promoter activity. The -13907*G and -13915*G SNPs result in a significant enhancement of lactase promoter activity relative to the ancestral lactase non-persistence genotype. Such differential regulation by the SNPs is consistent with a causative role in the mechanism specifying the lactase persistence phenotype.

  18. The role of endothelial nitric oxide synthase (eNOS) in the pathogenesis of sinonasal polyps.

    PubMed

    Muluk, N Bayar; Arikan, O K; Atasoy, P; Kiliç, R; Yalçinozan, E Tuna

    2014-01-01

    The pathogenesis of sinonasal polyps has not been known completely. We investigated the role of endothelial Nitric Oxide Synthase (eNOS) in the pathogenesis of sinonasal polyps. Study group (Groups 1-3) consisted of nasal polyp samples of patients with sinonasal polyps; and control group consisted of inferior turbinate samples of patients without nasal polyp. In Group 1: 14 specimens from ethmoid sinus; in Group 2: 10 specimens from nasal cavity; in Group 3: 10 specimens from maxillary sinus; and in Group 4 (Control): 9 specimens from inferior turbinate were included. By immunohistochemical staining technique, eNOS Positivity Index in mucosal layers; and in the inflammatory cells were assessed. eNOS Positivity Index was higher at apical layer of epithelium; and perivascular and glandular parts of subepithelial layer. As a rate of mononuclear cells increased, eNOS positivity increased at basal part of epithelium. In eNOS Positivity Index of mononuclear cells increased ones, eNOS values also increased at glands of subepithelial layer. In nasal cavity, eNOS positivity index of all cells was significantly higher than that of the control group. Increased eNOS all cells positivity index values were seen with decreased glandular and endothelial eNOS values. In all cells group, fibroblasts were seen beside the mononuclear cells. It was observed that eNOS was not expressed in PMNC (mainly neutrophils), growing more in acute inflammatory process; and was expressed in MNCs and all cells group with fibroblasts which were the cells of chronic inflammatory process. Especially MNCs and fibroblasts may play a role in the polyp formation process. In males and in patients with longer polyp duration, eNOS values decreased. We concluded that eNOS Positivity Index was higher at apical layer of epithelium; and perivascular and glandular parts of subepithelial layer. eNOS plays role in vascular dilatation, increases in vascular permeability; increases in nasal secretion due to glandular

  19. Activation of Endocannabinoid System Is Associated with Persistent Inflammation in Human Aortic Aneurysm

    PubMed Central

    Gestrich, Christopher; Duerr, Georg D.; Heinemann, Jan C.; Meertz, Anne; Probst, Chris; Roell, Wilhelm; Schiller, Wolfgang; Zimmer, Andreas; Bindila, Laura; Lutz, Beat; Welz, Armin; Dewald, Oliver

    2015-01-01

    Human aortic aneurysms have been associated with inflammation and vascular remodeling. Since the endocannabinoid system modulates inflammation and tissue remodeling, we investigated its components in human aortic aneurysms. We obtained anterior aortic wall samples from patients undergoing elective surgery for aortic aneurysm or coronary artery disease as controls. Histological and molecular analysis (RT-qPCR) was performed, and endocannabinoid concentration was determined using LC-MRM. Patient characteristics were comparable between the groups except for a higher incidence of arterial hypertension and diabetes in the control group. mRNA level of cannabinoid receptors was significantly higher in aneurysms than in controls. Concentration of the endocannabinoid 2-arachidonoylglycerol was significantly higher, while the second endocannabinoid anandamide and its metabolite arachidonic acid and palmitoylethanolamide were significantly lower in aneurysms. Histology revealed persistent infiltration of newly recruited leukocytes and significantly higher mononuclear cell density in adventitia of the aneurysms. Proinflammatory environment in aneurysms was shown by significant upregulation of M-CSF and PPARγ but associated with downregulation of chemokines. We found comparable collagen-stained area between the groups, significantly decreased mRNA level of CTGF, osteopontin-1, and MMP-2, and increased TIMP-4 expression in aneurysms. Our data provides evidence for endocannabinoid system activation in human aortic aneurysms, associated with persistent low-level inflammation and vascular remodeling. PMID:26539497

  20. Biodegradation of persistent organics can overcome adsorption-desorption hysteresis in biological activated carbon systems.

    PubMed

    Abromaitis, V; Racys, V; van der Marel, P; Meulepas, R J W

    2016-04-01

    In Biological Activated Carbon (BAC) systems, persistent organic pollutants can be removed through a combination of adsorption, desorption and biodegradation. These processes might be affected by the presence of other organics, especially by the more abundant easily-biodegradable organics, like acetate. In this research these relations are quantified for the removal of the persistent pharmaceutical metoprolol. Acetate did not affect the adsorption and desorption of metoprolol, but it did greatly enhance the metoprolol biodegradation. At least part of the BAC biomass growing on acetate was also able to metabolise metoprolol, although metoprolol was only converted after the acetate was depleted. The presence of easily-degradable organics like acetate in the feeding water is therefore beneficial for the removal of metoprolol in BAC systems. The isotherms obtained from metoprolol adsorption and desorption experiments showed that BAC systems are subject to hysteresis; for AC bioregeneration to take place the microbial biomass has to reduce the concentration at the AC-biomass interface 2.7 times compared to the concentration at which the carbon was being loaded. However, given the threshold concentration of the MET degrading microorganisms (<0.08 μg/L) versus the average influent concentration (1.3 μg/L), bioregeneration is feasible.

  1. Identification of chicken eNOS gene and differential expression in highland versus lowland chicken breeds.

    PubMed

    Peng, J F; Ling, Y; Gou, W Y; Zhang, H; Wu, C X

    2012-09-01

    Nitric oxide (NO), an endothelium-derived relaxing factor, is synthesized from l-arginine by endothelial nitric oxide synthase (eNOS) in the endothelium. The objective of the present study was to preliminarily illuminate the expression of the eNOS gene in hypoxic adaptation of chicken embryonic development. The eNOS expression profiles between the Tibet and Shouguang chickens incubated under both normoxic and hypoxic conditions were detected by TaqMan real-time PCR. In this study, the chicken eNOS gene was found by both in silico cloning and RACE approaches. From the eNOS gene, we obtained a 3,310-bp mRNA sequence and a 10,666-bp DNA sequence and discovered that it was located on chicken chromosome 2 and had 7 unique transcripts. eNOS mRNA was detected in abundant amounts in some chick embryo organs (i.e., heart, liver, chorio-allantoic membrane, and lung), and expressed stably with the lowest levels in the brain. We observed that when exposed to hypoxia (13% O(2)) different embryo organ tissues had various sensitivities to hypoxia as determined by their eNOS expression profiles. Compared with the Shouguang chicken, the eNOS expression in the Tibet chicken was higher in the lung and liver, lower in the heart, and similar in the brain. In chorio-allantoic membranes, eNOS expression was higher in the Shouguang chicken than the Tibet chicken under hypoxic conditions, but not markedly different under normoxic conditions. The differences of eNOS expression between the 2 breeds may be relative to the hypoxic adaptation ability in Tibet chickens during embryonic development. This work will provide reference for future studies on the role of eNOS in hypoxic adaptation and response.

  2. Arsenic, cadmium and neuron specific enolase (ENO2, γ-enolase) expression in breast cancer

    PubMed Central

    2011-01-01

    Background Neuron specific enolase (ENO2, γ-enolase) has been used as a biomarker to help identify neuroendocrine differentiation in breast cancer. The goal of the present study was to determine if ENO2 expression in the breast epithelial cell is influenced by the environmental pollutants, arsenite and cadmium. Acute and chronic exposure of MCF-10A cells to As+3 and Cd+2 sufficient to allow colony formation in soft agar, was used to determine if ENO2 expression was altered by these pollutants. Results It was shown that both As+3 and Cd+2 exposure caused significant increases in ENO2 expression under conditions of both acute and chronic exposure. In contrast, ENO1, the major glycolytic enolase in non-muscle and neuronal cells, was largely unaffected by exposure to either As+3 or Cd+2. Localization studies showed that ENO2 in the MCF-10A cells transformed by As+3 or Cd+2 had both a cytoplasmic and nuclear localization. In contrast, ENO1 was localized to the cytoplasm. ENO2 localized to the cytoplasm was found to co-localized with ENO1. Conclusion The results are the first to show that ENO2 expression in breast epithelial cells is induced by acute and chronic exposure to As+3 or Cd+2. The findings also suggest a possible link between As+3 and Cd+2 exposure and neuroendocrine differentiation in tumors. Overall, the results suggest that ENO2 might be developed as a biomarker indicating acute and/or chronic environmental exposure of the breast epithelial cell to As+3 and Cd+2. PMID:22098917

  3. Sodium-activated potassium channels are functionally coupled to persistent sodium currents.

    PubMed

    Hage, Travis A; Salkoff, Lawrence

    2012-02-22

    We report a novel coupled system of sodium-activated potassium currents (I(KNa)) and persistent sodium currents (I(NaP)), the components of which are widely distributed throughout the brain. Its existence and importance has not been previously recognized. Although I(KNa) was known to exist in many cell types, the source of Na(+) which activates I(KNa) remained a mystery. We now show in single membrane patches generated from the somas of rat neurons that sodium influx through I(NaP) is sufficient for activation of K(Na) channels, without substantial contribution from the transient sodium current or bulk [Na(+)](i). I(NaP) was found to be active at cell membrane resting potentials, a finding that may explain why I(KNa) can be evoked from negative holding potentials. These results show an unanticipated role for I(NaP) in activating a negative feedback system countering the excitable effects I(NaP); the interrelatedness of I(NaP) and I(KNa) suggests new ways neurons can tune their excitability.

  4. DUOX1 mediates persistent epithelial EGFR activation, mucous cell metaplasia, and airway remodeling during allergic asthma

    PubMed Central

    Habibovic, Aida; Hristova, Milena; Heppner, David E.; Danyal, Karamatullah; Ather, Jennifer L.; Janssen-Heininger, Yvonne M.W.; Irvin, Charles G.; Poynter, Matthew E.; Lundblad, Lennart K.; Dixon, Anne E.; Geiszt, Miklos

    2016-01-01

    Chronic inflammation with mucous metaplasia and airway remodeling are hallmarks of allergic asthma, and these outcomes have been associated with enhanced expression and activation of EGFR signaling. Here, we demonstrate enhanced expression of EGFR ligands such as amphiregulin as well as constitutive EGFR activation in cultured nasal epithelial cells from asthmatic subjects compared with nonasthmatic controls and in lung tissues of mice during house dust mite–induced (HDM-induced) allergic inflammation. EGFR activation was associated with cysteine oxidation within EGFR and the nonreceptor tyrosine kinase Src, and both amphiregulin production and oxidative EGFR activation were diminished by pharmacologic or genetic inhibition of the epithelial NADPH oxidase dual oxidase 1 (DUOX1). DUOX1 deficiency also attenuated several EGFR-dependent features of HDM-induced allergic airway inflammation, including neutrophilic inflammation, type 2 cytokine production (IL-33, IL-13), mucous metaplasia, subepithelial fibrosis, and central airway resistance. Moreover, targeted inhibition of airway DUOX1 in mice with previously established HDM-induced allergic inflammation, by intratracheal administration of DUOX1-targeted siRNA or pharmacological NADPH oxidase inhibitors, reversed most of these outcomes. Our findings indicate an important function for DUOX1 in allergic inflammation related to persistent EGFR activation and suggest that DUOX1 targeting may represent an attractive strategy in asthma management. PMID:27812543

  5. DUOX1 mediates persistent epithelial EGFR activation, mucous cell metaplasia, and airway remodeling during allergic asthma.

    PubMed

    Habibovic, Aida; Hristova, Milena; Heppner, David E; Danyal, Karamatullah; Ather, Jennifer L; Janssen-Heininger, Yvonne M W; Irvin, Charles G; Poynter, Matthew E; Lundblad, Lennart K; Dixon, Anne E; Geiszt, Miklos; van der Vliet, Albert

    2016-11-03

    Chronic inflammation with mucous metaplasia and airway remodeling are hallmarks of allergic asthma, and these outcomes have been associated with enhanced expression and activation of EGFR signaling. Here, we demonstrate enhanced expression of EGFR ligands such as amphiregulin as well as constitutive EGFR activation in cultured nasal epithelial cells from asthmatic subjects compared with nonasthmatic controls and in lung tissues of mice during house dust mite-induced (HDM-induced) allergic inflammation. EGFR activation was associated with cysteine oxidation within EGFR and the nonreceptor tyrosine kinase Src, and both amphiregulin production and oxidative EGFR activation were diminished by pharmacologic or genetic inhibition of the epithelial NADPH oxidase dual oxidase 1 (DUOX1). DUOX1 deficiency also attenuated several EGFR-dependent features of HDM-induced allergic airway inflammation, including neutrophilic inflammation, type 2 cytokine production (IL-33, IL-13), mucous metaplasia, subepithelial fibrosis, and central airway resistance. Moreover, targeted inhibition of airway DUOX1 in mice with previously established HDM-induced allergic inflammation, by intratracheal administration of DUOX1-targeted siRNA or pharmacological NADPH oxidase inhibitors, reversed most of these outcomes. Our findings indicate an important function for DUOX1 in allergic inflammation related to persistent EGFR activation and suggest that DUOX1 targeting may represent an attractive strategy in asthma management.

  6. Do brain activation changes persist in athletes with a history of multiple concussions who are asymptomatic?

    PubMed

    Elbin, R J; Covassin, Tracey; Hakun, Jonathan; Kontos, Anthony P; Berger, Kevin; Pfeiffer, Karin; Ravizza, Susan

    2012-01-01

    To evaluate brain activation patterns of asymptomatic athletes with a history of two or more concussions. A paired case-control design was used to evaluate brain activation patterns during cognitive performance in 14 athletes with a history of two or more concussions and 14 age- and sex-matched controls with no previous concussion. Percentage Blood-Oxygen-Level-Dependent (BOLD) change during an N-back working memory task was assessed in all participants. Performance on the Trail-Making Test Form A and B, Symbol-Digit Modalities Test and the Immediate Post-concussion Assessment and Cognitive Test (ImPACT) was also compared between groups. As expected, brain regions activated during the performance of the N-back were equivalent between groups. The groups performed similarly on the neurocognitive measures. The history of concussion group was less accurate than controls on the 1-, 2- and 3-back conditions of the N-back. Following the complete resolution of symptoms, a history of two or more concussions is not associated with changes in regional brain activation during the performance of working memory task. Compensatory brain activation may only persist during the typically brief time athletes experience symptoms following concussion.

  7. Exendin-4 protects endothelial cells from lipoapoptosis by PKA, PI3K, eNOS, p38 MAPK, and JNK pathways.

    PubMed

    Erdogdu, Ozlem; Eriksson, Linnéa; Xu, Hua; Sjöholm, Ake; Zhang, Qimin; Nyström, Thomas

    2013-04-01

    Experimental studies have indicated that endothelial cells play an important role in maintaining vascular homeostasis. We previously reported that human coronary artery endothelial cells (HCAECs) express the glucagon-like peptide 1 (GLP1) receptor and that the stable GLP1 mimetic exendin-4 is able to activate the receptor, leading to increased cell proliferation. Here, we have studied the effect of exendin-4 and native GLP1 (7-36) on lipoapoptosis and its underlying mechanisms in HCAECs. Apoptosis was assessed by DNA fragmentation and caspase-3 activation, after incubating cells with palmitate. Nitric oxide (NO) and reactive oxidative species (ROS) were analyzed. GLP1 receptor activation, PKA-, PI3K/Akt-, eNOS-, p38 MAPK-, and JNK-dependent pathways, and genetic silencing of transfection of eNOS were also studied. Palmitate-induced apoptosis stimulated cells to release NO and ROS, concomitant with upregulation of eNOS, which required activation of p38 MAPK and JNK. Exendin-4 restored the imbalance between NO and ROS production in which ROS production decreased and NO production was further augmented. Incubation with exendin-4 and GLP1 (7-36) protected HCAECs against lipoapoptosis, an effect that was blocked by PKA, PI3K/Akt, eNOS, p38 MAPK, and JNK inhibitors. Genetic silencing of eNOS also abolished the anti-apoptotic effect afforded by exendin-4. Our results support the notion that GLP1 receptor agonists restore eNOS-induced ROS production due to lipotoxicity and that such agonists protect against lipoapoptosis through PKA-PI3K/Akt-eNOS-p38 MAPK-JNK-dependent pathways via a GLP1 receptor-dependent mechanism.

  8. Persistence of antimicrobial activity through sustained release of triclosan from pegylated silicone elastomers.

    PubMed

    McBride, Marcella C; Karl Malcolm, R; David Woolfson, A; Gorman, Sean P

    2009-12-01

    Microbial adhesion to silicone elastomer biomaterials is a major problem often resulting in infection and medical device failure. Several strategies have been employed to modulate eukaryotic cell adhesion and to hamper bacterial adherence to polymeric biomaterials. Chemical modification of the surface by grafting of polyethylene glycol (PEG) chains or the incorporation of non-antibiotic antimicrobial agents such as triclosan into the biomaterial matrix may reduce bacterial adhesion. Here, such strategies are simultaneously applied to the preparation of both condensation-cure and addition-cure silicone elastomer systems, seeking a sustained release antimicrobial device biomaterial. The influence of triclosan incorporation and degree of pegylation on antimicrobial release, surface microbial adherence and persistence (Escherichia coli and Staphylococcus epidermidis) were evaluated in vitro. Non-pegylated silicone elastomers provided an increased percentage release of triclosan extending over a relatively short duration (99% release by day 64) compared with their pegylated (4% w/w) counterparts (65% and 72% release by day 64, for condensation and addition-cure systems respectively). Viable E. coli adherence to a non-pegylated silicone elastomer containing 1% w/w triclosan was reduced by over 99% after 24 h compared to the non-pegylated silicone elastomer containing no triclosan. No viable S. epidermidis adhered to any of the triclosan-loaded (>0.1% w/w) formulations other than the control. Persistence of the antimicrobial activity of the triclosan-loaded pegylated silicone elastomers continued for at least 70 days compared to the triclosan-loaded non-pegylated elastomers (at least 49 days). Understanding how PEG affects the release of triclosan from silicone elastomers may prove useful in the development of a biomaterial providing prolonged, effective antimicrobial activity.

  9. Manipulation of persistent free radicals in biochar to activate persulfate for contaminant degradation.

    PubMed

    Fang, Guodong; Liu, Cun; Gao, Juan; Dionysiou, Dionysios D; Zhou, Dongmei

    2015-05-05

    This study investigated the effects of metals (Fe3+, Cu2+, Ni2+, and Zn2+) and phenolic compounds (PCs: hydroquinone, catechol, and phenol) loaded on biomass on the formation of persistent free radicals (PFRs) in biochar. It was found that metal and phenolic compound treatments not only increased the concentrations of PFRs in biochar but also changed the types of PFRs formed, which indicated that manipulating the amount of metals and PCs in biomass may be an efficient method to regulate PFRs in biochar. These results provided direct evidence to elucidate the mechanism of PFR formation in biochar. Furthermore, the catalytic ability of biochar toward persulfate activation for the degradation of contaminants was evaluated. The results indicated that biochar activates persulfate to produce sulfate radicals (SO4•-) and degraded polychlorinated biphenyls (PCBs) efficiently. It was found that both the concentration and type of PFRs were the dominant factors controlling the activation of persulfate by biochar and that superoxide radical anions account for 20-30% of sulfate radical generation in biochar/persulfate. This conclusion was supported by linear correlations between the concentration of PFRs consumed and the formation of SO4•- and between λ (λ=[formed sulfate radicals]/[consumed PFRs]) and g-factors. The findings of this study provide new methods to manipulate PFR concentration in biochar for the transformation of contaminants and development of new alternative activators for persulfate-based remediation of contaminated soils.

  10. A cyclic AMP-activated K+ channel in Drosophila larval muscle is persistently activated in dunce.

    PubMed

    Delgado, R; Hidalgo, P; Diaz, F; Latorre, R; Labarca, P

    1991-01-15

    Single-channel recording from longitudinal ventrolateral Drosophila larval muscle reveals the presence of a potassium-selective channel that is directly and reversibly activated by cAMP in a dose-dependent fashion. Activation is specific and it cannot be mimicked by a series of agents that include AMP, cGMP, ATP, inositol trisphosphate, and Ca2+. Channel current records obtained from larval muscle in different dunce mutants possessing abnormally high levels of cAMP show that, in the mutants, the channel displays an increased probability of opening.

  11. A cyclic AMP-activated K+ channel in Drosophila larval muscle is persistently activated in dunce.

    PubMed Central

    Delgado, R; Hidalgo, P; Diaz, F; Latorre, R; Labarca, P

    1991-01-01

    Single-channel recording from longitudinal ventrolateral Drosophila larval muscle reveals the presence of a potassium-selective channel that is directly and reversibly activated by cAMP in a dose-dependent fashion. Activation is specific and it cannot be mimicked by a series of agents that include AMP, cGMP, ATP, inositol trisphosphate, and Ca2+. Channel current records obtained from larval muscle in different dunce mutants possessing abnormally high levels of cAMP show that, in the mutants, the channel displays an increased probability of opening. PMID:1846445

  12. Persistent Immune Activation in CVID and the Role of IVIg in Its Suppression

    PubMed Central

    Paquin-Proulx, Dominic; Sandberg, Johan K.

    2014-01-01

    Common variable immunodeficiency (CVID) is one of the most common and clinically important primary immune deficiencies. CVID patients have poor humoral immunity, resulting in recurrent infections of the gastrointestinal and upper respiratory tracts, as well as increased incidence of some forms of cancers and autoimmune diseases. The treatment for CVID is IgG replacement, often given as intravenous immunoglobulins (IVIg). IVIg consists of monomeric IgG purified from pooled plasma from healthy donors and is used to treat an increasing number of conditions including autoimmune diseases. In the case of CVID, IVIg has mainly been seen as reconstitution therapy, providing patients with pathogen-specific antibodies. Recent evidence shows that IVIg has diverse effects on the immune system of CVID patients, and one important component is that IVIg alleviates the state of chronic immune activation. In this review, we will discuss causes and consequences of persistent immune activation in CVID, possible underlying mechanisms for how IVIg treatment reduces immune activation, and implications for our understanding of primary as well as acquired immune deficiencies. PMID:25566250

  13. Persistent Immune Activation in CVID and the Role of IVIg in Its Suppression.

    PubMed

    Paquin-Proulx, Dominic; Sandberg, Johan K

    2014-01-01

    Common variable immunodeficiency (CVID) is one of the most common and clinically important primary immune deficiencies. CVID patients have poor humoral immunity, resulting in recurrent infections of the gastrointestinal and upper respiratory tracts, as well as increased incidence of some forms of cancers and autoimmune diseases. The treatment for CVID is IgG replacement, often given as intravenous immunoglobulins (IVIg). IVIg consists of monomeric IgG purified from pooled plasma from healthy donors and is used to treat an increasing number of conditions including autoimmune diseases. In the case of CVID, IVIg has mainly been seen as reconstitution therapy, providing patients with pathogen-specific antibodies. Recent evidence shows that IVIg has diverse effects on the immune system of CVID patients, and one important component is that IVIg alleviates the state of chronic immune activation. In this review, we will discuss causes and consequences of persistent immune activation in CVID, possible underlying mechanisms for how IVIg treatment reduces immune activation, and implications for our understanding of primary as well as acquired immune deficiencies.

  14. Student anxiety in introductory biology classrooms: Perceptions about active learning and persistence in the major.

    PubMed

    England, Benjamin J; Brigati, Jennifer R; Schussler, Elisabeth E

    2017-01-01

    Many researchers have called for implementation of active learning practices in undergraduate science classrooms as one method to increase retention and persistence in STEM, yet there has been little research on the potential increases in student anxiety that may accompany these practices. This is of concern because excessive anxiety can decrease student performance. Levels and sources of student anxiety in three introductory biology lecture classes were investigated via an online survey and student interviews. The survey (n = 327) data revealed that 16% of students had moderately high classroom anxiety, which differed among the three classes. All five active learning classroom practices that were investigated caused student anxiety, with students voluntarily answering a question or being called on to answer a question causing higher anxiety than working in groups, completing worksheets, or answering clicker questions. Interviews revealed that student anxiety seemed to align with communication apprehension, social anxiety, and test anxiety. Additionally, students with higher general anxiety were more likely to self-report lower course grade and the intention to leave the major. These data suggest that a subset of students in introductory biology experience anxiety in response to active learning, and its potential impacts should be investigated.

  15. Student anxiety in introductory biology classrooms: Perceptions about active learning and persistence in the major

    PubMed Central

    2017-01-01

    Many researchers have called for implementation of active learning practices in undergraduate science classrooms as one method to increase retention and persistence in STEM, yet there has been little research on the potential increases in student anxiety that may accompany these practices. This is of concern because excessive anxiety can decrease student performance. Levels and sources of student anxiety in three introductory biology lecture classes were investigated via an online survey and student interviews. The survey (n = 327) data revealed that 16% of students had moderately high classroom anxiety, which differed among the three classes. All five active learning classroom practices that were investigated caused student anxiety, with students voluntarily answering a question or being called on to answer a question causing higher anxiety than working in groups, completing worksheets, or answering clicker questions. Interviews revealed that student anxiety seemed to align with communication apprehension, social anxiety, and test anxiety. Additionally, students with higher general anxiety were more likely to self-report lower course grade and the intention to leave the major. These data suggest that a subset of students in introductory biology experience anxiety in response to active learning, and its potential impacts should be investigated. PMID:28771564

  16. Differential effects of eNOS uncoupling on conduit and small arteries in GTP-cyclohydrolase I-deficient hph-1 mice

    PubMed Central

    d'Uscio, Livius V.; Smith, Leslie A.

    2011-01-01

    In the present study, we used the hph-1 mouse, which displays GTP-cyclohydrolase I (GTPCH I) deficiency, to test the hypothesis that loss of tetrahydrobiopterin (BH4) in conduit and small arteries activates compensatory mechanisms designed to protect vascular wall from oxidative stress induced by uncoupling of endothelial nitric oxide synthase (eNOS). Both GTPCH I activity and BH4 levels were reduced in the aortas and small mesenteric arteries of hph-1 mice. However, the BH4-to-7,8-dihydrobiopterin ratio was significantly reduced only in hph-1 aortas. Furthermore, superoxide anion and 3-nitrotyrosine production were significantly enhanced in aortas but not in small mesenteric arteries of hph-1 mice. In contrast to the aorta, protein expression of copper- and zinc-containing superoxide dismutase (CuZnSOD) was significantly increased in small mesenteric arteries of hph-1 mice. Protein expression of catalase was increased in both aortas and small mesenteric arteries of hph-1 mice. Further analysis of endothelial nitric oxide synthase (eNOS)/cyclic guanosine monophosphate (cGMP) signaling demonstrated that protein expression of phosphorylated Ser1177-eNOS as well as basal cGMP levels and hydrogen peroxide was increased in hph-1 aortas. Increased production of hydrogen peroxide in hph-1 mice aortas appears to be the most likely mechanism responsible for phosphorylation of eNOS and elevation of cGMP. In contrast, upregulation of CuZnSOD and catalase in resistance arteries is sufficient to protect vascular tissue from increased production of reactive oxygen species generated by uncoupling of eNOS. The results of our study suggest that anatomical origin determines the ability of vessel wall to cope with oxidative stress induced by uncoupling of eNOS. PMID:21963838

  17. Persistent activation of Nrf2 through p62 in hepatocellular carcinoma cells

    PubMed Central

    Inami, Yoshihiro; Waguri, Satoshi; Sakamoto, Ayako; Kouno, Tsuguka; Nakada, Kazuto; Hino, Okio; Watanabe, Sumio; Ando, Jin; Iwadate, Manabu; Yamamoto, Masayuki; Lee, Myung-Shik; Tanaka, Keiji

    2011-01-01

    Suppression of autophagy is always accompanied by marked accumulation of p62, a selective autophagy substrate. Because p62 interacts with the Nrf2-binding site on Keap1, which is a Cullin 3–based ubiquitin ligase adapter protein, autophagy deficiency causes competitive inhibition of the Nrf2–Keap1 interaction, resulting in stabilization of Nrf2 followed by transcriptional activation of Nrf2 target genes. Herein, we show that liver-specific autophagy-deficient mice harbor adenomas linked to both the formation of p62- and Keap1-positive cellular aggregates and induction of Nrf2 targets. Importantly, similar aggregates were identified in more than 25% of human hepatocellular carcinomas (HCC), and induction of Nrf2 target genes was recognized in most of these tumors. Gene targeting of p62 in an HCC cell line markedly abrogates the anchorage-independent growth, whereas forced expression of p62, but not a Keap1 interaction-defective mutant, resulted in recovery of the growth defect. These results indicate the involvement of persistent activation of Nrf2 through the accumulation of p62 in hepatoma development. PMID:21482715

  18. Persistent high paleosecular variation activity in southern hemisphere for at least 10 000 years

    NASA Astrophysics Data System (ADS)

    Constable, Catherine; Korte, Monika; Panovska, Sanja

    2016-11-01

    Direct observations of the geomagnetic field show that secular variation is strong in the Atlantic hemisphere, and comparatively reduced in the Pacific region. The dipole has been decaying since at least 1840 AD, driven by growth and migration of reverse flux patches in the southern hemisphere. We investigate whether anything like this modern pattern of geomagnetic secular variation persists and can be detected in global paleomagnetic field models. Synthesis of results from two new time-varying spherical harmonic models shows that geographically distinct geomagnetic secular variation extends to at least 10 000 BP. The models use the same database but differ in methodology, leading to some regional differences in results. Consistent large-scale surface features include strong average fields in the northern hemisphere and weaker fields with greater overall variability in the south. Longitudinal structure is present, with weaker average fields in the western Pacific than in the east, and prominent negative inclination anomalies extending beneath Indonesia, across Africa and to Brazil, but weaker anomalies in the central Pacific. Marginally positive inclination anomalies occur west of the Americas. Paleosecular variation activity peaks at high southern latitudes, and there is a pattern of reduced activity at equatorial and mid-latitudes beneath the Pacific. Although the dipole has exhibited both growth and decay over the interval 0-10 000 BP, our results show that geomagnetic paleosecular variation is preferentially focused in similar geographic regions to secular variation seen in the modern field.

  19. Persistent Single-Neuron Activity during Working Memory in the Human Medial Temporal Lobe.

    PubMed

    Kornblith, Simon; Quian Quiroga, Rodrigo; Koch, Christof; Fried, Itzhak; Mormann, Florian

    2017-04-03

    Working memory is an essential component of human cognition. Persistent activity related to working memory has been reported in many brain areas, including the inferior temporal and prefrontal cortex [1-8]. The medial temporal lobe (MTL) contains "concept cells" that respond invariantly to specific individuals or places whether presented as images, text, or speech [9, 10]. It is unknown, however, whether the MTL also participates in working memory processes. We thus sought to determine whether human MTL neurons respond to images held in working memory. We recorded from patients with chronically intractable epilepsy as they performed a task that required them to remember three or four sequentially presented pictures across a brief delay. 48% of visually selective neurons continued to carry image-specific information after image offset, but most ceased to encode previously presented images after a subsequent presentation of a different image. However, 8% of visually selective neurons encoded previously presented images during a final maintenance period, despite presentation of further images in the intervening interval. Population activity of stimulus-selective neurons predicted behavioral outcome in terms of correct and incorrect responses. These findings indicate that the MTL is part of a brain-wide network for working memory.

  20. Insights into the emission reductions of multiple unintentional persistent organic pollutants from industrial activities.

    PubMed

    Liu, Guorui; Zheng, Minghui; Jiang, Xiaoxu; Jin, Rong; Zhao, Yuyang; Zhan, Jiayu

    2016-02-01

    Industrial activities result in unintentional production of multiple types of persistent organic pollutants (POPs) at various concentrations. Because of the potential adverse effect of these POPs on the environment, biota and human health, methods for controlling emission of POPs are required. Development and application of techniques for controlling emissions of POPs can be a technical and economic burden for the industry involved. Therefore, from the point of view of cost-benefit analysis, reducing emissions of multiple pollutants at the same time is optimal for sustainable industrial development. Although techniques have been developed for reducing the emissions of individual POPs, such as dioxins, further work is required on multi-POP control emissions from industrial activities. This paper discusses three important aspects that need to be taken to achieve multi-POP control. These aspects include the establishment of a comprehensive system for evaluating the risk from emissions of multiple POPs, determination of indicators for total emissions of multiple POPs, and the preparation and application of functional materials to inhibit formation of multiple POPs. These discussion might be helpful for the future research on the multi-POP control in industry. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. Neurosteroid dehydroepiandrosterone sulphate inhibits persistent sodium currents in rat medial prefrontal cortex via activation of sigma-1 receptors.

    PubMed

    Cheng, Zheng-Xiang; Lan, Dan-Mei; Wu, Pei-Ying; Zhu, Yan-Hua; Dong, Yi; Ma, Lan; Zheng, Ping

    2008-03-01

    Dehydroepiandrosterone sulphate is one of the most important neurosteroids. In the present paper, we studied the effect of dehydroepiandrosterone sulphate on persistent sodium currents and its mechanism and functional consequence with whole-cell patch clamp recording method combined with a pharmacological approach in the rat medial prefrontal cortex slices. The results showed that dehydroepiandrosterone sulphate inhibited the amplitude of persistent sodium currents and the inhibitory effect was significant at 0.1 microM, reached maximum at 1 microM and decreased with the increase in the concentrations of above 1 microM. The effect of dehydroepiandrosterone sulphate on persistent sodium currents was canceled by the Gi protein inhibitor and the protein kinase C inhibitor, but not by the protein kinase A inhibitor. The effect of dehydroepiandrosterone sulphate on persistent sodium currents was also canceled by the sigma-1 receptor blockers and the sigma-1 receptor agonist could mimic the effect of dehydroepiandrosterone sulphate. Dehydroepiandrosterone sulphate had no significant influence on neuronal excitability but could significantly inhibit chemical inhibition of mitochondria-evoked increase in persistent sodium currents. These results suggest that dehydroepiandrosterone sulphate inhibits persistent sodium currents via the activation of sigma-1 receptors-Gi protein-protein kinase C-coupled signaling pathway, and the main functional consequence of this effect of DHEAS is presumably to protect neurons under ischemia.

  2. Environmentally persistent free radicals inhibit cytochrome P450 activity in rat liver microsomes.

    PubMed

    Reed, James R; Cawley, George F; Ardoin, Taylor G; Dellinger, Barry; Lomnicki, Slawomir M; Hasan, Farhana; Kiruri, Lucy W; Backes, Wayne L

    2014-06-01

    Combustion processes generate particulate matter that affects human health. When incineration fuels include components that are highly enriched in aromatic hydrocarbons (especially halogenated varieties) and redox-active metals, ultrafine particulate matter containing air-stable, environmentally persistent free radicals (EPFRs) is generated. The exposure to fine EPFRs (less than 2.5 μm in diameter) has been shown to negatively influence pulmonary and cardiovascular functions in living organisms. The goal of this study was to determine if these EPFRs have a direct effect on cytochrome P450 function. This was accomplished by direct addition of the EPFRs to rat liver microsomal preparations and measurement of several P450 activities using form-selective substrates. The EPFRs used in this study were formed by heating vapors from an organic compound (either monochlorophenol (MCP230) or 1,2-dichlorobenzene (DCB230)) and 5% copper oxide supported on silica (approximately 0.2 μm in diameter) to 230°C under vacuum. Both types of EPFRs (but not silica, physisorbed silica, or silica impregnated with copper oxide) dramatically inhibited the activities of CYP1A, CYP2B, CYP2E1, CYP2D2 and CYP3A when incubated at concentrations less than 0.1 mg/ml with microsomes and NADPH. Interestingly, at the same concentrations, the EPFRs did not inhibit HO-1 activity or the reduction of cytochrome c by NADPH-cytochrome P450 reductase. CYP2D2-selective metabolism by rat liver microsomes was examined in more detail. The inhibition of CYP2D2-selective metabolism by both DCB230- and MCP230-EPFRs appeared to be largely noncompetitive and was attenuated in the presence of catalase suggesting that reactive oxygen species may be involved in the mechanism of inhibition. Copyright © 2014 Elsevier Inc. All rights reserved.

  3. Circuits constructed from identified Aplysia neurons exhibit multiple patterns of persistent activity.

    PubMed Central

    Kleinfeld, D; Raccuia-Behling, F; Chiel, H J

    1990-01-01

    We have used identified neurons from the abdominal ganglion of the mollusc Aplysia to construct and analyze two circuits in vitro. Each of these circuits was capable of producing two patterns of persistent activity; that is, they had bistable output states. The output could be switched between the stable states by a brief, external input. One circuit consisted of cocultured L10 and left upper quadrant (LUQ) neurons that formed reciprocal, inhibitory connections. In one stable state L10 was active and the LUQ was quiescent, whereas in the other stable state L10 was quiescent and the LUQ was active. A second circuit consisted of co-cultured L7 and L12 neurons that formed reciprocal, excitatory connections. In this circuit, both cells were quiescent in one stable state and both cells fired continuously in the other state. Bistable output in both circuits resulted from the nonlinear firing characteristics of each neuron and the feedback between the two neurons. We explored how the stability of the neuronal output could be controlled by the background currents injected into each neuron. We observed a relatively well-defined range of currents for which bistability occurred, consistent with the values expected from the measured strengths of the connections and a simple model. Outside of the range, the output was stable in only a single state. These results suggest how stable patterns of output are produced by some in vivo circuits and how command neurons from higher neural centers may control the activity of these circuits. The criteria that guided us in forming our circuits in culture were derived from theoretical studies on the properties of certain neuronal network models (e.g., Hopfield, J. J. 1984. Proc. Natl. Acad. Sci. USA. 81:3088-3092). Our results show that circuits consisting of only two co-cultured neurons can exhibit bistable output states of the form hypothesized to occur in populations of neurons. Images FIGURE 3 PMID:2344460

  4. Persistent aeolian activity at Endeavour crater, Meridiani Planum, Mars; new observations from orbit and the surface

    NASA Astrophysics Data System (ADS)

    Chojnacki, Matthew; Johnson, Jeffrey R.; Moersch, Jeffrey E.; Fenton, Lori K.; Michaels, Timothy I.; Bell, James F., III

    2015-05-01

    Aeolian-driven bedform activity is now known to occur in many regions of Mars, based on surface and orbital observation of contemporary martian ripple and dune mobility events. Many of these sites have only been monitored with sufficient resolution data for the last few Mars years, when the High Resolution Imaging Science Experiment (HiRISE) began acquiring images of Mars. One exception is the well-monitored Endeavour crater in Meridiani Planum, which was one of the first known sites of unambiguous dune activity (migration and deflation). However, those early detections used lower resolution images over longer temporal baselines (versus the HIRISE data now available), leaving some measurements poorly constrained. New orbital and surface observations of Endeavour show multiple spatial (cm, m, km) and temporal (seasons, Mars year) scales of aeolian-driven surface change, which confirms earlier reports. Dome dunes in the eastern portion of the crater persistently deflate, disseminating dark sand across lighter-toned regolith and/or eroded bright dust, and likely contribute to the crater interior's episodic decreases in orbital albedo measurements. Other dome dunes are detected with the highest migration rates (4-12 m per Mars year) and volumetric sand fluxes reported yet for Mars. Estimated dune construction times or "turnover times" here and elsewhere on Mars are significantly shorter than martian obliquity cycles, implying that it is not necessary to invoke paleoclimate wind regimes to explain current dune morphologies. Located on the crater rim, the Opportunity rover detected evidence for near- and far-field aeolian-driven activity, with observations of spherules/sand movement in the rover workspace, bedform albedo alteration, and dust-lifting events. Observations of intracrater dunes show periodic shifting dark streaks that significantly constrain local wind regimes (directionality and seasonality). Constraints on wind directions from surface and orbital images

  5. Persistent CaMKII activation mediates learning-induced long-lasting enhancement of synaptic inhibition.

    PubMed

    Ghosh, Sourav; Reuveni, Iris; Lamprecht, Raphael; Barkai, Edi

    2015-01-07

    Training rats in a particularly difficult olfactory-discrimination task results in acquisition of high skill to perform the task superbly, termed "rule learning" or "learning set." Such complex learning results in enhanced intrinsic neuronal excitability of piriform cortex pyramidal neurons, and in their excitatory synaptic interconnections. These changes, while subserving memory maintenance, must be counterbalanced by modifications that prevent overspreading of activity and uncontrolled synaptic strengthening. Indeed, we have previously shown that the average amplitude of GABAA-mediated miniature IPSCs (mIPSCs) in these neurons is enhanced for several days after learning, an enhancement mediated via a postsynaptic mechanism. To unravel the molecular mechanism of this long-term inhibition enhancement, we tested the role of key second-messenger systems in maintaining such long-lasting modulation. The calcium/calmodulin-dependent kinase II (CaMKII) blocker, KN93, significantly reduced the average mIPSC amplitude in neurons from trained rats only to the average pretraining level. A similar effect was obtained by the CaMKII peptide inhibitor, tatCN21. Such reduction resulted from decreased single-channel conductance and not in the number of activated channels. The PKC inhibitor, GF109203X, reduced the average mIPSC amplitude in neurons from naive, pseudo-trained, and trained animals, and the difference between the trained and control groups remained. Such reduction resulted from a decrease in the number of activated channels. The PKA inhibitor H89 dihydrochloride did not affect the average mIPSC amplitude in neurons from any of the three groups. We conclude that learning-induced enhancement of GABAA-mediated synaptic inhibition is maintained by persistent CaMKII activation.

  6. Persistent Immune Activation and Carotid Atherosclerosis in HIV-Infected Ugandans Receiving Antiretroviral Therapy

    PubMed Central

    Siedner, Mark J.; Kim, June-Ho; Nakku, Ruth Sentongo; Bibangambah, Prossy; Hemphill, Linda; Triant, Virginia A.; Haberer, Jessica E.; Martin, Jeffrey N.; Mocello, A. Rain; Boum, Yap; Kwon, Douglas S.; Tracy, Russell P.; Burdo, Tricia; Huang, Yong; Cao, Huyen; Okello, Samson; Bangsberg, David R.; Hunt, Peter W.

    2016-01-01

    Background. Human immunodeficiency virus (HIV) infection and associated immune activation predict the risk of cardiovascular disease in resource-rich areas. Less is known about these relationships in sub-Saharan Africa. Methods. Beginning in 2005, we enrolled subjects in southwestern Uganda into a cohort at the time of antiretroviral therapy (ART) initiation. Multiple immune activation measures were assessed before and 6 months after ART initiation. Beginning in 2013, participants aged >40 years underwent metabolic profiling, including measurement of hemoglobin A1c and lipid levels and carotid ultrasonography. We fit regression models to identify traditional and HIV-specific correlates of common carotid intima media thickness (CCIMT). Results. A total of 105 participants completed carotid ultrasonography, with a median completion time of 7 years following ART initiation. Age, low-density lipoprotein cholesterol level, and pre-ART HIV load were correlated with CCIMT. No association was found between CCIMT and any pre-ART biomarkers of immune activation. However, in multivariable models adjusted for cardiovascular disease risk factors, lower absolute levels of soluble CD14 and interleukin 6 and greater declines in the CD14 level and kynurenine-tryptophan ratio after 6 months of ART predicted a lower CCIMT years later (P < .01). Conclusions. Persistent immune activation despite ART-mediated viral suppression predicts the future atherosclerotic burden among HIV-infected Ugandans. Future work should focus on clinical correlates of these relationships, to elucidate the long-term health priorities for HIV-infected people in the region. PMID:26347573

  7. Persistent perceptual delay for active head movement onset relative to sound onset with and without vision.

    PubMed

    Chung, William; Barnett-Cowan, Michael

    2017-07-25

    Knowing when the head moves is crucial information for the central nervous system to maintain a veridical representation of the self in the world for perception and action. Previous studies have shown that active head movement onset has to precede a sound by approximately 80 ms to be perceived as simultaneous, suggesting that the perceived timing of head movement is slow. However, this research was conducted with closed eyes. Given that visual information is available for most natural head movements, could perceptual delays in head movement onset be related to removing vision? Here, we examined whether visual information affects the perceived timing of active head movement onset. Participants performed a series of temporal order judgment tasks between their active head movement and an auditory tone presented at various stimulus onset asynchronies. Visual information was either absent (eyes closed) or present while either maintaining fixation on an earth or head-fixed target in the dark or in the light. Results show that head movement onset has to precede a sound by ~76 ms with eyes closed confirming previous work. The results also suggest that head movement onset must still precede a sound when fixating targets in the dark with a trend for the head having to move with less lead time with visual information and with the vestibulo-ocular reflex active or suppressed (~70 to 48 ms). Together, these results suggest that the perception of head movement onset is persistently delayed and is not fully resolved even with full field visual input.

  8. Persistent Neuronal Activity in Anterior Cingulate Cortex Correlates with Sustained Attention in Rats Regardless of Sensory Modality

    PubMed Central

    Wu, Dingcheng; Deng, Hanfei; Xiao, Xiong; Zuo, Yanfang; Sun, Jingjing; Wang, Zuoren

    2017-01-01

    The anterior cingulate cortex (ACC) has long been thought to regulate conflict between an object of attention and distractors during goal-directed sustained attention. However, it is unclear whether ACC serves to sustained attention itself. Here, we developed a task in which the time course of sustained attention could be controlled in rats. Then, using pharmacological lesion experiments, we employed it to assess function of ACC in sustained attention. We then recorded neuronal activity in ACC using multichannel extracellular recording techniques and identified specific ACC neurons persistently activated during the period of attention. Further experiments showed that target modality had minimal influence on the neuronal activity, and distracting external sensory input during the attention period did not perturb persistent neuronal activity. Additionally, minimal trial-to-trial variability in neuronal activity observed during sustained attention supports a role for ACC neurons in that behavior. Therefore, we conclude that the ACC neuronal activity correlates with sustained attention. PMID:28230158

  9. Enhanced photocatalytic activity and persistent luminescence in Zn2GeO4:Mn2+ by Eu3+ doping

    NASA Astrophysics Data System (ADS)

    Li, Hong; Wang, Yinhai; Li, Lei; Huang, Haiju; Zhao, Hui; Hu, Zhengfa

    2016-09-01

    Zn2GeO4:Mn2+,Eu3+ and Zn2GeO4:Mn2+ powders were synthesized by a high-temperature solid-state reaction. X-ray powder diffraction (XRD) and scanning electron microscopy (SEM) were used to characterize the structures and morphologies of the synthesized powders, respectively. The photocatalytic properties and long persistent luminescence performance were improved by Eu3+ doping. Thermoluminescent (TL) curves showed that the trap concentration in the material was increased with Eu3+ doping, which formed trap centers in Zn2GeO4:Mn2+. The trap centers can capture the electrons or holes and subsequently increase the separation of photogenerated electrons and holes by suppressing the recombination of captured electrons and holes; thus, resulting in an improved photocatalytic activity and a prolonged persistent luminescence. The present strategy may be used as a general method to improve the photocatalytic activity and persistent luminescence.

  10. T-13910 DNA variant associated with lactase persistence interacts with Oct-1 and stimulates lactase promoter activity in vitro.

    PubMed

    Lewinsky, Rikke H; Jensen, Tine G K; Møller, Jette; Stensballe, Allan; Olsen, Jørgen; Troelsen, Jesper T

    2005-12-15

    Two phenotypes exist in the human population with regard to expression of lactase in adults. Lactase non-persistence (adult-type hypolactasia and lactose intolerance) is characterized by a decline in the expression of lactase-phlorizin hydrolase (LPH) after weaning. In contrast, lactase-persistent individuals have a high LPH throughout their lifespan. Lactase persistence and non-persistence are associated with a T/C polymorphism at position -13,910 upstream the lactase gene. A nuclear factor binds more strongly to the T-13,910 variant associated with lactase persistence than the C-13,910 variant associated with lactase non-persistence. Oct-1 and glyceraldehyde-3-phosphate dehydrogenase were co-purified by DNA affinity purification using the sequence of the T-13,910 variant. Supershift analyses show that Oct-1 binds directly to the T-13,910 variant, and we suggest that GAPDH is co-purified due to interactions with Oct-1. Expression of Oct-1 stimulates reporter gene expression from the T and the C-13,910 variant/LPH promoter constructs only when it is co-expressed with HNF1alpha. Binding sites for other intestinal transcription factors (GATA-6, HNF4alpha, Fox and Cdx-2) were identified in the region of the -13,910 T/C polymorphism. Three of these sites are required for the enhancer activity of the -13,910 region. The data suggest that the binding of Oct-1 to the T-13,910 variant directs increased lactase promoter activity and this might provide an explanation for the lactase persistence phenotype in the human population.

  11. On the application of ENO scheme with subcell resolution to conservation laws with stiff source terms

    NASA Technical Reports Server (NTRS)

    Chang, Shih-Hung

    1991-01-01

    Two approaches are used to extend the essentially non-oscillatory (ENO) schemes to treat conservation laws with stiff source terms. One approach is the application of the Strang time-splitting method. Here the basic ENO scheme and the Harten modification using subcell resolution (SR), ENO/SR scheme, are extended this way. The other approach is a direct method and a modification of the ENO/SR. Here the technique of ENO reconstruction with subcell resolution is used to locate the discontinuity within a cell and the time evolution is then accomplished by solving the differential equation along characteristics locally and advancing in the characteristic direction. This scheme is denoted ENO/SRCD (subcell resolution - characteristic direction). All the schemes are tested on the equation of LeVeque and Yee (NASA-TM-100075, 1988) modeling reacting flow problems. Numerical results show that these schemes handle this intriguing model problem very well, especially with ENO/SRCD which produces perfect resolution at the discontinuity.

  12. PGE1 analog alprostadil induces VEGF and eNOS expression in endothelial cells.

    PubMed

    Haider, Dominik G; Bucek, Robert A; Giurgea, Aura G; Maurer, Gerald; Glogar, Helmut; Minar, Erich; Wolzt, Michael; Mehrabi, Mohammad R; Baghestanian, Mehrdad

    2005-11-01

    Endothelial nitric oxide synthase (eNOS), VEGF, and hypoxia-inducible factor 1-alpha (HIF-1alpha) are important regulators of endothelial function, which plays a role in the pathophysiology of heart failure (HF). PGE1 analog treatment in patients with HF elicits beneficial hemodynamic effects, but the precise mechanisms have not been investigated. We have investigated the effects of the PGE1 analog alprostadil on eNOS, VEGF, and HIF-1alpha expression in human umbilical vein endothelial cells (HUVEC) using RT-PCR and immunoblotting under normoxic and hypoxic conditions. In addition, we studied protein expression by immunohistochemical staining in explanted hearts from patients with end-stage HF, treated or untreated with systemic alprostadil. Alprostadil causes an upregulation of eNOS and VEGF protein and mRNA expression in HUVEC and decreases HIF-1alpha. Hypoxia potently increased eNOS, VEGF, and HIF-1alpha synthesis. The alprostadil-induced upregulation of eNOS and VEGF was prevented by inhibition of MAPKs with PD-98056 or U-0126. Consistently, the expression of eNOS and VEGF was increased, and HIF-1alpha was reduced in failing hearts treated with alprostadil. The potent effects of alprostadil on endothelial VEGF and eNOS synthesis may be useful for patients with HF where endothelial dysfunction is involved in the disease process.

  13. Mesenchymal Stem Cells Expressing eNOS and a Cav1 Mutant Inhibit Vascular Smooth Muscle Cell Proliferation in a Rat Model of Pulmonary Hypertension.

    PubMed

    Chen, Haiying; Yang, Hongli; Yue, Hongmei; Strappe, Pádraig Michael; Xia, Peng; Pan, Li; Zhang, Yingxin; Chai, Shoudong; Chen, Shuangfeng; Ma, Longle; Wang, Lexin

    2017-05-01

    This study aimed to investigate the effect of bone marrow derived mesenchymal stem cells (rBMSCs) transduced with lentiviral vectors expressing endothelial nitric oxide synthase (eNOS) and/or a mutant caveolin-1(F92A-Cav1), on the pulmonary haemodynamics and structure in a rat model of pulmonary arterial hypertension (PAH). Pulmonary arterial hypertension was induced with monocrotaline (MCT) in 60 adult male Wistar rats prior to delivery of lentiviral vector transduced rBMSCs expressing Cav1, eNOS and/or F92A-Cav1. Changes in pulmonary haemodynamics, right ventricular hypertrophy index (RVHI), and serum nitric oxide (NO) were evaluated. Ultrastructure changes in lung tissues were observed by transmission electron microscopy. Expression of Kruppel-like factor 4 (KLF4), p53, P21, eNOS, and alpha-smooth muscle actin were evaluated by real time PCR, western blotting or immunohistochemistry. Treatment of PAH rats with gene modified rBMSCs (eNOS +/- Cav1 F92A) decreased right ventricular systolic pressure and improved pulmonary haemodynamics. The protein of alpha-smooth muscle actin expression was decreased whilst KLF4, p53, P21, eNOS expression, and serum NO concentration was elevated. The survival rate of rats in the treatment groups was also improved, after 35 days of observation. Intravenous delivery of rBMSCs expressing eNOS/F92A-Cav1 to PAH rats inhibits pulmonary vascular smooth muscle cell proliferation, and improves pulmonary haemodynamics, vascular remodelling and short-term survival. Activation of KLF4-p53 signalling pathway may be involved in these beneficial effects. Copyright © 2016 Australian and New Zealand Society of Cardiac and Thoracic Surgeons (ANZSCTS) and the Cardiac Society of Australia and New Zealand (CSANZ). Published by Elsevier B.V. All rights reserved.

  14. Active Atrial Function and Atrial Scar Burden After Multiple Catheter Ablations of Persistent Atrial Fibrillation.

    PubMed

    Nührich, Jana M; Geisler, Anne C; Steven, Daniel; Hoffmann, Boris A; Schäffer, Benjamin; Lund, Gunnar; Stehning, Christian; Radunski, Ulf K; Sultan, Arian; Schwarzl, Michael; Adam, Gerhard; Willems, Stephan; Muellerleile, Kai

    2017-02-01

    Extensive and repeated substrate modification (SM) is frequently performed as an ablation strategy in persistent atrial fibrillation (persAF). The effect of these extended ablation strategies on atrial function has not been investigated sufficiently so far. The purpose was to assess atrial function by cardiac magnetic resonance (CMR) and its association with left atrial (LA) scar burden by electroanatomical voltage-mapping after multiple persAF ablation procedures. We included 16 persAF patients who had ≥2 SM procedures and a control group (CG) of 21 persAF patients without prior ablation. CMR was performed in sinus rhythm at least 4 weeks after the last cardioversion. Active left and right (RA) atrial emptying fractions (AEF) as well as peak active left atrial appendage (LAA) emptying velocities were obtained by CMR flow measurements. Furthermore, LA scar burden was quantified on electroanatomical voltage maps by the portion of points with local voltage amplitude <0.2 mV. We found median LA-AEF to be lower (13 [9-22] vs 32 [26-36] %, P < 0.001) and median LA scar burden to be higher (40 [20-68] vs nine [3-18] %, P < 0.05) in the SM group compared with the CG. Furthermore, a significant correlation was found between mean LA voltage and LA-AEF (r(2) = 0.62, P < 0.001). No significant differences were detected with respect to median RA-AEF (41 [28-48] vs 47 [35-50] %, P = 0.43) and median peak LAA emptying velocities (30 [16-40] vs 17 [13-28] cm/s, P = 0.07). Active LA function is preserved but significantly impaired and associated with ablation-related LA scar burden after multiple extensive persAF ablations. ©2016 Wiley Periodicals, Inc.

  15. The persistence of the NWA effect during the low solar activity period 2007-2009

    NASA Astrophysics Data System (ADS)

    Jakowski, N.; Hoque, M. M.; Kriegel, M.; Patidar, V.

    2015-10-01

    The ionospheric Nighttime Winter Anomaly (NWA) was first reported more than three decades ago based on total electron content (TEC) and vertical sounding data. The aim of this paper is to provide further evidence that the NWA effect is a persistent feature in the Northern Hemisphere at the American and in the Southern Hemisphere at the Asian longitude sector under low solar activity conditions. The analysis of ground-based GPS derived TEC and peak electron density data from radio occultation measurements on Formosat-3/COSMIC satellites confirms and further supports the findings published in earlier NWA papers. So it has been confirmed and further specified that the NWA appears at longitude sectors where the displacement between the geomagnetic and the geographic equator maximizes. Here NWA peaks at around 40°-50° geomagnetic midlatitude supporting the idea that wind-induced plasma uplifting in the conjugated summer hemisphere is the main driving force for the accumulation of ionospheric plasma in the topside ionosphere and plasmasphere. In parallel, the midsummer nighttime anomaly (MSNA) is caused at the local ionosphere. Simultaneously, interhemispheric coupling causes severe downward plasma fluxes in the conjugated winter hemisphere during night causing the NWA at low solar activity. With increasing solar activity, the downward plasma fluxes lose their impact due to the much stronger increasing background ionization that masks the NWA. It is assumed that MSNA and related special anomalies such as the Weddell Sea Anomaly and the Okhotsk Sea Anomaly are closely related to the NWA via enhanced wind-induced uplifting of the ionosphere.

  16. NMDA receptors are the basis for persistent network activity in neocortex slices.

    PubMed

    Castro-Alamancos, Manuel A; Favero, Morgana

    2015-06-01

    During behavioral quiescence the neocortex generates spontaneous slow oscillations that consist of Up and Down states. Up states are short epochs of persistent activity, but their underlying source is unclear. In neocortex slices of adult mice, we monitored several cellular and network variables during the transition between a traditional buffer, which does not cause Up states, and a lower-divalent cation buffer, which leads to the generation of Up states. We found that the resting membrane potential and input resistance of cortical cells did not change with the development of Up states. The synaptic efficacy of excitatory postsynaptic potentials mediated by non-NMDA receptors was slightly reduced, but this is unlikely to facilitate the generation of Up states. On the other hand, we identified two variables that are associated with the generation of Up states: an enhancement of the intrinsic firing excitability of cortical cells and an enhancement of NMDA-mediated responses evoked by electrical or optogenetic stimulation. The fact that blocking NMDA receptors abolishes Up states indicates that the enhancement in intrinsic firing excitability alone is insufficient to generate Up states. NMDA receptors have a crucial role in the generation of Up states in neocortex slices.

  17. New paradigms for understanding and step changes in treating active and chronic, persistent apicomplexan infections

    PubMed Central

    McPhillie, Martin; Zhou, Ying; El Bissati, Kamal; Dubey, Jitender; Lorenzi, Hernan; Capper, Michael; Lukens, Amanda K; Hickman, Mark; Muench, Stephen; Verma, Shiv Kumar; Weber, Christopher R.; Wheeler, Kelsey; Gordon, James; Sanders, Justin; Moulton, Hong; Wang, Kai; Kim, Taek-Kyun; He, Yuqing; Santos, Tatiana; Woods, Stuart; Lee, Patty; Donkin, David; Kim, Eric; Fraczek, Laura; Lykins, Joseph; Esaa, Farida; Alibana-Clouser, Fatima; Dovgin, Sarah; Weiss, Louis; Brasseur, Gael; Wirth, Dyann; Kent, Michael; Hood, Leroy; Meunieur, Brigitte; Roberts, Craig W.; Hasnain, S. Samar; Antonyuk, Svetlana V.; Fishwick, Colin; McLeod, Rima

    2016-01-01

    Toxoplasma gondii, the most common parasitic infection of human brain and eye, persists across lifetimes, can progressively damage sight, and is currently incurable. New, curative medicines are needed urgently. Herein, we develop novel models to facilitate drug development: EGS strain T. gondii forms cysts in vitro that induce oocysts in cats, the gold standard criterion for cysts. These cysts highly express cytochrome b. Using these models, we envisioned, and then created, novel 4-(1H)-quinolone scaffolds that target the cytochrome bc1 complex Qi site, of which, a substituted 5,6,7,8-tetrahydroquinolin-4-one inhibits active infection (IC50, 30 nM) and cysts (IC50, 4 μM) in vitro, and in vivo (25 mg/kg), and drug resistant Plasmodium falciparum (IC50, <30 nM), with clinically relevant synergy. Mutant yeast and co-crystallographic studies demonstrate binding to the bc1 complex Qi site. Our results have direct impact on improving outcomes for those with toxoplasmosis, malaria, and ~2 billion persons chronically infected with encysted bradyzoites. PMID:27412848

  18. Persistence of the activity of topical ivermectin against biting lice (Bovicola bovis).

    PubMed

    Clymer, B; Newcomb, K M; Ryan, W G; Soll, M D

    1998-08-15

    To assess the persistence of the activity of topical ivermectin against a natural challenge with biting lice (Bovicola bovis), 90 mixed-breed cattle that had been treated to remove lice, were blocked by bodyweight within sex and randomly allocated to three treatments: untreated control, doramectin at 200 micrograms/kg by subcutaneous injection, and ivermectin at 500 micrograms/kg by topical application. Forty-five pens were blocked into three groups of 15, and the blocks of pens were randomly allocated to three 14-day challenge periods starting 21, 28 and 35 days after treatment. There were five pens per treatment for each challenge period, and one B bovis-infested donor calf was introduced into each pen containing two principal calves at the start of the challenge period for that block of pens. The calves were examined thoroughly for B bovis seven, 14 and 21 days after the introduction of the donors. There were no significant differences between the control and doramectin groups for the numbers of animals infested, or the geometric mean louse counts at the final examination for any of the challenge periods. At the final examination for each challenge period, the louse counts of the cattle treated with topical ivermectin were all zero, and significantly (P < 0.05) fewer cattle treated with topical ivermectin were infested than either the controls or cattle treated with doramectin.

  19. Persistent Peripheral Inflammation Attenuates Morphine-induced Periaqueductal Gray Glial Cell Activation and Analgesic Tolerance in the Male Rat

    PubMed Central

    Eidson, Lori N.; Murphy, Anne Z.

    2014-01-01

    Morphine is among the most prevalent analgesics prescribed for chronic pain. However, prolonged morphine treatment results in the development of analgesic tolerance. An abundance of evidence has accumulated indicating that CNS glial cell activity facilitates pain transmission and opposes morphine analgesia. While the midbrain ventrolateral periaqueductal gray (vlPAG) is an important neural substrate mediating pain modulation and the development of morphine tolerance, no studies have directly assessed the role of PAG-glia. Here we test the hypothesis that morphine-induced increases in vlPAG glial cell activity contribute to the development of morphine tolerance. As morphine is primarily consumed for the alleviation of severe pain, the influence of persistent inflammatory pain was also assessed. Administration of morphine, in the absence of persistent inflammatory pain, resulted in the rapid development of morphine tolerance and was accompanied by a significant increase in vlPAG glial activation. In contrast, persistent inflammatory hyperalgesia, induced by intraplantar administration of Complete Freund’s Adjuvant (CFA), significantly attenuated the development of morphine tolerance. No significant differences were noted in vlPAG glial cell activation for CFA-treated animals versus controls. These results indicate that vlPAG glia are modulated by a persistent pain state, and implicate vlPAG glial cells as possible regulators of morphine tolerance. Perspective The development of morphine tolerance represents a significant impediment to its use in the management of chronic pain. We report that morphine tolerance is accompanied by increased glial cell activation within the vlPAG, and that the presence of a persistent pain state prevented vlPAG glial activation and attenuated morphine tolerance. PMID:23395474

  20. Teacher and Student Incremental and Entity Views of Intelligence: The Effect of Self-Regulation and Persistence Activities.

    ERIC Educational Resources Information Center

    Myers, Mark D.; Nichols, Joe D.; White, Janet

    2003-01-01

    Using self-reporting instruments, examines relationship between the teacher's view of potential student achievement and student's view. Involves self-regulated learning activities and persistence in two large urban high schools in the South. Findings suggest likely significant influence of teacher's perspective of potential student achievement on…

  1. The persistence of chronic spontaneous urticaria in childhood is associated with the urticaria activity score.

    PubMed

    Arik Yilmaz, Ebru; Karaatmaca, Betul; Cetinkaya, Pinar Gur; Soyer, Ozge; Sekerel, Bulent E; Sahiner, Umit Murat

    2017-03-01

    There is little information regarding the etiology and natural course of chronic spontaneous urticaria (CSU) in childhood. To investigate the etiology, prognosis, and the factors associated with the prognosis of CSU in children. Data from children with CSU who had been diagnosed between 1992 and 2015 were analyzed. A telephone interview was done to assess the current status of these patients. Remission was defined as the disappearance of urticaria for >6 months. A total of 222 children with CSU were evaluated. The median age of symptom onset was 8.8 years (interquartile range [IQR], 4.6-12.3 years), median duration of urticaria was 23 months (IQR, 7-48 months), and the median sum of the daily urticaria activity score of 7 consecutive days (UAS7) was 28 (IQR, 21-42). Accompanying angioedema was reported by 107 patients (48.2%), whereas 27.1% of the study population had autoantibody positivity. Autologous serum skin testing results were positive in 43 (34.1%); skin-prick testing results revealed atopy in 55 children (27.9%). Parasites (4.8%), pollen sensitization (1.5%), food allergy (0.9%), urinary tract infection (0.9%), and Hashimoto thyroiditis (0.5%) were determined as etiologic factors of CSU. The patients were followed up for a median time of 15 months (IQR, 5-36.5 months). Remission was observed in 10.6, 29.3, and 44.5% of the patients in 1, 3, and 5 years, respectively. In multivariate regression analysis, a UAS7 of >28 at admission was found to be a risk factor for persistence of urticaria (odds ratio 6.22 [95% confidence interval, 1.54-25.15; p = 0.010). The etiology of CSU in children was mostly idiopathic despite detailed investigation. In childhood, the natural course of CSU was favorable, and nearly half of the patients recovered after 5 years of disease duration. A high UAS7 at admission seemed to be a significant risk factor for the persistence of symptoms.

  2. Idiopathic Relapsing Thrombotic Thrombocytopenic Purpura with Persistent ADAMTS13 Inhibitor Activity Treated Sequentially with Plasmapheresis, Rituximab, Cyclophosphamide and Splenectomy.

    PubMed

    Musa, Faisal; Baidas, Said

    2015-01-01

    We here describe a patient with an idiopathic thrombotic thrombocytopenic purpura (TTP) secondary to an ADAMTS13 inhibitor that continued to be dependent on plasmapheresis until the patient was treated with rituximab. TTP manifestations subsided with rituximab treatment in spite of a persistently low ADAMTS13 activity and continued a detectable inhibitor activity until the patient developed an intolerance to rituximab due to an allergic reaction when cyclophosphamide was added; this resulted in a normalization of ADAMTS13 activity and the disappearance of the inhibitor. Later, the patient developed an intolerance to rituximab due to a severe allergic reaction. Soon after stopping rituximab, the ADAMTS13 activity level dipped below 5% in addition to the appearance of the ADAMTS13 inhibitor. The patient had a splenectomy after rituximab and cyclophosphamide treatment; the medication was stopped based on several case reports of a complete remission of TTP after splenectomy. We believe that the reason TTP went into remission in our patient was because of rituximab treatment, in spite of both persistently low ADAMTS13 activity and a detectable inhibitor activity due to reducing the release of von Willebrand factor large multimers from the endothelial cells. We found that ADAMTS13 activity normalized and the inhibitor activity became undetectable when cyclophosphamide was added to rituximab. We suggest adding cyclophosphamide to rituximab for the treatment of patients with persistent ADAMTS13 inhibitors in order to prolong the remission period and lower the rate of relapse.

  3. Crustal-scale active deformation along the Ecuadorian Andes using Persistent Scatterers SAR Interferometry

    NASA Astrophysics Data System (ADS)

    Champenois, J.; Baize, S.; Audin, L.; Pinel, V.; Alvarado, A.; Jomard, H.; Yepes, H. A.

    2013-12-01

    Located in the Northern Andes along the active subduction zone of the Nazca plate beneath the South American continent, Ecuador is highly exposed to seismic hazard. For the last ten years, numerous multidisciplinary studies focused on major seismicity related to the subduction, whereas few investigations concentrated on M>7 crustal seismicity in the upper plate (like 1797 Riobamba earthquake, ML 8.3, 12.000 deaths). The active faults producing these earthquakes are poorly known in term of slip rate and for some cases are even not identified yet. Additionnally, Ecuador is one of the most active volcanic areas of the northern Andean volcanic zone. Three among the nine active volcanoes are actually erupting (Reventador, Tungurahua, and Sangay). For the last 5 years, geodetic networks have been deployed in Ecuador to enhance crustal deformation monitoring, but these point-wise techniques cannot provide spatially dense maps of ground deformation and are quite expensive methods. To address this issue, we applied the Persistent Scatterers SAR Interferometry technique (StaMPS/MTI freeware developed by A. Hooper) to ENVISAT SAR data between 2003 and 2009. Using these cost-effective techniques, we are able to investigate both tectonic and volcanic surface deformations with an unprecedented spatial density of measurements. This study presents new PS-InSAR results along the Ecuadorian Andes, close to the area of Riobamba. We generated average velocity maps and consistent time-series of displacements measured along the radar line of sight. These results evidence large scale deformation localized on the Pallatanga fault system (locked fault) compatible with a model of locked strike slip fault. Moreover, these results show an important growth of the Tungurahua volcanic complex (maximum rate about 9 mm/yr) with a rapid uplift prior and post 2006 explosive eruption. We investigate the time-series of displacement for 22 images. Our results permitted to propose two crustal source

  4. Altered Spontaneous Activity in Patients with Persistent Somatoform Pain Disorder Revealed by Regional Homogeneity

    PubMed Central

    Yan, Chao; Lu, Jing; Li, Xuzhou; Tang, Chaozheng; Fan, Mingxia; Luo, Yanli

    2016-01-01

    Persistent somatoform pain disorder (PSPD) is a mental disorder un-associated with any somatic injury and can cause severe somatosensory and emotional impairments in patients. However, so far, the neuro-pathophysiological mechanism of the functional impairments in PSPD is still unclear. The present study assesses the difference in regional spontaneous activity between PSPD and healthy controls (HC) during a resting state, in order to elucidate the neural mechanisms underlying PSPD. Resting-state functional Magnetic Resonance Imaging data were obtained from 13 PSPD patients and 23 age- and gender-matched HC subjects in this study. Kendall’s coefficient of concordance was used to measure regional homogeneity (ReHo), and a two-sample t-test was subsequently performed to investigate the ReHo difference between PSPD and HC. Additionally, the correlations between the mean ReHo of each survived area and the clinical assessments were further analyzed. Compared with the HC group, patients with PSPD exhibited decreased ReHo in the bilateral primary somatosensory cortex, posterior cerebellum, and occipital lobe, while increased ReHo in the prefrontal cortex (PFC) and default mode network (including the medial PFC, right inferior parietal lobe (IPL), and left supramarginal gyrus). In addition, significant positive correlations were found between the mean ReHo of both right IPL and left supramarginal gyrus and participants’ Self-Rating Anxiety Scale (SAS) scores, and between the mean ReHo of the left middle frontal gyrus and Visual Analogue Scale (VAS) scores. Our results suggest that abnormal spontaneous brain activity in specific brain regions during a resting state may be associated with the dysfunctions in pain, memory and emotional processing commonly observed in patients with PSPD. These findings help us to understand the neural mechanisms underlying PSPD and suggest that the ReHo metric could be used as a clinical marker for PSPD. PMID:26977802

  5. Persistent Persister Misperceptions

    PubMed Central

    Kim, Jun-Seob; Wood, Thomas K.

    2016-01-01

    Persister cells survive antibiotic treatment due to their lack of metabolism, rather than through genetic change, as shown via four seminal experiments conducted by the discoverers of the phenotype (Hobby et al., 1942; Bigger, 1944). Unfortunately, over seven decades of persister cell research, the literature has been populated by misperceptions that do not withstand scrutiny. This opinion piece examines some of those misunderstandings in the literature with the hope that by shining some light on these inaccuracies, the field may be advanced and subsequent manuscripts may be reviewed more critically. PMID:28082974

  6. Reconsolidation-induced memory persistence: Participation of late phase hippocampal ERK activation.

    PubMed

    Krawczyk, M C; Navarro, N; Blake, M G; Romano, A; Feld, M; Boccia, M M

    2016-09-01

    Persistence is an attribute of long-term memories (LTM) that has recently caught researcher's attention in search for mechanisms triggered by experience that assure memory perdurability. Up-to-date, scarce evidence of relationship between reconsolidation and persistence has been described. Here, we characterized hippocampal ERK participation in LTM reconsolidation and persistence using an inhibitory avoidance task (IA) at different time points. Intra-dorsal-hippocampal (dHIP) administration of an ERK inhibitor (PD098059, PD, 1.0μg/hippocampus) 3h after retrieval did not affect reconsolidation of a strong IA, when tested 24h apart. However, the same manipulation impaired performance when animals were tested at 7d, regardless of the training's strength; and being specific to memory reactivation. To the best of our knowledge, this is the first report showing that persistence might be triggered after memory reactivation involving an ERK/MAPK-dependent process.

  7. Semibiotic Persistence

    NASA Astrophysics Data System (ADS)

    Prothmann, C.; Zauner, K.-P.

    From observation, we find four different strategies to successfully enable structures to persist over extended periods of time. If functionally relevant features are very large compared to the changes that can be effectuated by entropy, the functional structure itself has a high enough probability to erode only slowly over time. If the functionally relevant features are protected from environmental influence by sacrificial layers that absorb the impinging of the environment, deterioration can be avoided or slowed. Loss of functionality can be delayed, even for complex systems, by keeping alternate options for all required components available. Biological systems also apply information processing to actively counter the impact of entropy by mechanisms such as self-repair. The latter strategy increases the overall persistence of living systems and enables them to maintain a highly complex functional organisation during their lifetime and over generations. In contrast to the other strategies, information processing has only low material overhead. While at present engineered technology is far from achieving the self-repair of evolved systems, the semibiotic combination of biological components with conventionally engineered systems may open a path to long-term persistence of functional devices in harsh environments. We review nature's strategies for persistence, and consider early steps taken in the laboratory to import such capabilities into engineered architectures.

  8. Robustness of persistent spiking to partial synchronization in a minimal model of synaptically driven self-sustained activity

    NASA Astrophysics Data System (ADS)

    Novikov, Nikita; Gutkin, Boris

    2016-11-01

    We study the behavior of a minimal model of synaptically sustained persistent activity that consists of two quadratic integrate-and-fire neurons mutually coupled via excitatory synapses. Importantly, each of the neurons is excitable, as opposed to an oscillator; hence when uncoupled it sits at a subthreshold rest state. When the constituent neurons are mutually coupled via sufficiently strong fast excitatory synapses, the system demonstrates bistability between a fixed point (quiescent background state) and a limit cycle (memory state with synaptically driven spiking activity). Previous work showed that this persistent activity can be stopped by an excitatory input that synchronizes the network. Here we analyzed how this persistent state reacts to partial synchronization. We considered three types of progressively more complex excitatory synaptic kernels: delta pulse, square, and exponential. The first two cases were treated analytically, and the latter case numerically. Using phase-plane methods, we characterized the shape of the region, such that all orbits starting within it correspond to infinite spike trains; this constitutes the persistent activity region. In the case of instant coupling, all such active orbits were neutrally stable; in the case of noninstant coupling, the activity region contained a unique stable limit cycle (so the activity region was the basin of attraction for the limit cycle). This limit cycle corresponded to purely antiphase spiking of two neurons. Increasing synchronization shifted the system toward the border of the activity region, eventually terminating spiking activity. We calculated three measures of robustness of the active state: width of the activity region in the phase plane, critical level of synchronization that can be tolerated by the persistent spiking activity, and speed of reconvergence to the limit cycle. Our analysis revealed that the self-sustained activity is more robust to synchronization when each individual neuron

  9. Molecular characterisation and expression profiling of the ENO1 gene in the ovarian follicle of the Sichuan white goose.

    PubMed

    Kang, Bo; Jiang, Dong Mei; Bai, Lin; He, Hui; Ma, Rong

    2014-01-01

    The ENO1 gene encodes a multifunctional enzyme that has been identified as a key component of the glycolytic pathway. Our previous studies demonstrated that ENO1 gene expression was higher in the ovaries of laying geese compared with prelaying geese. However, the molecular characterisation and expression profiling of the ENO1 gene in geese tissues and ovarian follicles remain to be determined. In this study, ENO1 cDNA (1,445 bp long) of the Sichuan white goose was cloned and characterised. The ORF of ENO1 cDNA is 1,305 bp in length and encodes a 434 amino acid protein with a molecular weight of 47.27 kDa. ENO1 expression in all of the examined tissues was the highest in spleen and the lowest in breast muscle. High expression of ENO1 appeared in the kidney, liver, adrenal gland, and retina. With increasing follicle growth, ENO1 gene expression began to decrease from the small white follicle to F5, which was followed by a sharp increase in expression in F4 and then a gradual decrease in expression from F3 to F1. Furthermore, in the postovulatory follicles (POF), the levels of ENO1 gene expression decreased gradually from POF1 to POF4. In conclusion, the ENO1 transcript was widely distributed in various tissues of the Sichuan white goose, but ENO1 expression was tissue-specific. Furthermore, the results of the ENO1 expression profiling of ovarian follicles suggest that ENO1 may play an important dual role in the progress of follicular development, where ENO1 acts as a glycolytic enzyme and also mediates apoptosis.

  10. Environmentally persistent free radicals inhibit cytochrome P450 activity in rat liver microsomes

    SciTech Connect

    Reed, James R.; Cawley, George F.; Ardoin, Taylor G.; Dellinger, Barry; Lomnicki, Slawomir M.; Hasan, Farhana; Kiruri, Lucy W.; Backes, Wayne L.

    2014-06-01

    Combustion processes generate particulate matter that affects human health. When incineration fuels include components that are highly enriched in aromatic hydrocarbons (especially halogenated varieties) and redox-active metals, ultrafine particulate matter containing air-stable, environmentally persistent free radicals (EPFRs) is generated. The exposure to fine EPFRs (less than 2.5 μm in diameter) has been shown to negatively influence pulmonary and cardiovascular functions in living organisms. The goal of this study was to determine if these EPFRs have a direct effect on cytochrome P450 function. This was accomplished by direct addition of the EPFRs to rat liver microsomal preparations and measurement of several P450 activities using form-selective substrates. The EPFRs used in this study were formed by heating vapors from an organic compound (either monochlorophenol (MCP230) or 1,2-dichlorobenzene (DCB230)) and 5% copper oxide supported on silica (approximately 0.2 μm in diameter) to 230 °C under vacuum. Both types of EPFRs (but not silica, physisorbed silica, or silica impregnated with copper oxide) dramatically inhibited the activities of CYP1A, CYP2B, CYP2E1, CYP2D2 and CYP3A when incubated at concentrations less than 0.1 mg/ml with microsomes and NADPH. Interestingly, at the same concentrations, the EPFRs did not inhibit HO-1 activity or the reduction of cytochrome c by NADPH-cytochrome P450 reductase. CYP2D2-selective metabolism by rat liver microsomes was examined in more detail. The inhibition of CYP2D2-selective metabolism by both DCB230- and MCP230-EPFRs appeared to be largely noncompetitive and was attenuated in the presence of catalase suggesting that reactive oxygen species may be involved in the mechanism of inhibition. - Highlights: • Combustion of organic pollutants generates long-lived particulate radicals (EPFRs). • EPFRs inhibit metabolism by all cytochromes P450 tested in rat liver microsomes. • EPFR-mediated inhibition is related to

  11. Effects of aerobic exercise on the blood pressure, oxidative stress and eNOS gene polymorphism in pre-hypertensive older people.

    PubMed

    Zago, Anderson Saranz; Park, Joon-Young; Fenty-Stewart, Nicola; Silveira, Leonardo Reis; Kokubun, Eduardo; Brown, Michael D

    2010-11-01

    The polymorphisms of endothelial nitric oxide synthase (eNOS) are associated with reduced eNOS activity. Aerobic exercise training (AEX) may influence resting nitric oxide (NO) production, oxidative stress and blood pressure. The purpose of this study was to investigate the effect of AEX on the relationship among blood pressure, eNOS gene polymorphism and oxidative stress in pre-hypertensive older people. 118 pre-hypertensive subjects (59 ± 6 years) had blood samples collected after a 12 h overnight fast for assessing plasma NO metabolites (NOx) assays, thiobarbituric acid reactive substances (T-BARS) and superoxide dismutase activity (ecSOD). eNOS polymorphism (T-786C and G-894T) was done by standard PCR methods. All people were divided according to the genotype results (G1: TT/GG, G2: TT/GT + TT, G3: TC + CC/GG, G4: TC + CC/GT + TT). All parameters were measured before and after 6 months of AEX (70% of VO(2 max)). At baseline, no difference was found in systolic and diastolic blood pressure, ecSOD and T-BARS activity. Plasma NOx levels were significantly different between G1 (19 ± 1 μM) and G4 (14.2 ± 0.6 μM) and between G2 (20.1 ± 1.7 μM) and G4 (14.2 ± 0.6 μM). Therefore, reduced NOx concentration in G4 group occurred only when the polymorphisms were associated, suggesting that these results are more related to genetic factors than NO-scavenging effect. After AEX, the G4 increased NOx values (17.2 ± 1.2 μM) and decreased blood pressure. G1, G3 and G4 decreased T-BARS levels. These results suggest the AEX can modulate the NOx concentration, eNOS activity and the relationship among eNOS gene polymorphism, oxidative stress and blood pressure especially in C (T-786C) and T (G-894T) allele carriers.

  12. Variation in metabolic enzyme activity of persistent Haemophilus influenzae in respiratory tracts of patients with cystic fibrosis.

    PubMed

    Möller, L V; Grasselier, H; Dankert, J; van Alphen, L

    1996-08-01

    Haemophilus influenzae organisms were isolated from sputum specimens prospectively collected from 40 patients with cystic fibrosis during 2 years to study variations in the metabolic enzyme activities of persistent H. influenzae strains as determined by biotyping. In total, 97 distinct H. influenzae strains without variations in their major outer membrane protein (MOMP) patterns and 73 MOMP variants derived from 30 of these distinct strains were obtained. Twelve distinct strains and 42 MOMP variant strains were isolated at multiple time points during the study period, indicating the persistence of these strains. Among the 54 persistent H. influenzae strains, 22 (41%) strains with stable MOMP compositions showed random variations in biotypes. In 39 of 103 (38%) H. influenzae strains, biotype changes coincided with MOMP variations. Biotype variations were the result of both the loss and the acquisition of enzyme activities. The results of the study indicate that changes in metabolic enzyme activity occur randomly during the persistence of H. influenzae organisms in cystic fibrosis patients, irrespective of MOMP variations.

  13. Persistent oxidative stress following renal ischemia-reperfusion injury increases ANG II hemodynamic and fibrotic activity

    PubMed Central

    Leonard, Ellen C.; Beal, Alisa G.; Schleuter, Devin; Friedrich, Jessica

    2012-01-01

    ANG II is a potent renal vasoconstrictor and profibrotic factor and its activity is enhanced by oxidative stress. We sought to determine whether renal oxidative stress was persistent following recovery from acute kidney injury (AKI) induced by ischemia-reperfusion (I/R) injury in rats and whether this resulted in increased ANG II sensitivity. Rats were allowed to recover from bilateral renal I/R injury for 5 wk and renal blood flow responses were measured. Post-AKI rats showed significantly enhanced renal vasoconstrictor responses to ANG II relative to sham-operated controls and treatment of AKI rats with apocynin (15 mM, in the drinking water) normalized these responses. Recovery from AKI for 5 wk resulted in sustained oxidant stress as indicated by increased dihydroethidium incorporation in renal tissue slices and was normalized in apocynin-treated rats. Surprisingly, the renal mRNA expression for common NADPH oxidase subunits was not altered in kidneys following recovery from AKI; however, mRNA screening using PCR arrays suggested that post-AKI rats had decreased renal Gpx3 mRNA and an increased expression other prooxidant genes such as lactoperoxidase, myeloperoxidase, and dual oxidase-1. When rats were infused for 7 days with ANG II (100 ng·kg−1·min−1), renal fibrosis was not apparent in sham-operated control rats, but it was enhanced in post-AKI rats. The profibrotic response was significantly attenuated in rats treated with apocynin. These data suggest that there is sustained renal oxidant stress following recovery from AKI that alters both renal hemodynamic and fibrotic responses to ANG II, and may contribute to the transition to chronic kidney disease following AKI. PMID:22442209

  14. Persistent Organochlorine Pollutants with Endocrine Activity and Blood Steroid Hormone Levels in Middle-Aged Men

    PubMed Central

    Emeville, Elise; Giton, Frank; Giusti, Arnaud; Oliva, Alejandro; Fiet, Jean; Thomé, Jean-Pierre; Blanchet, Pascal; Multigner, Luc

    2013-01-01

    Background Studies relating long-term exposure to persistent organochlorine pollutants (POPs) with endocrine activities (endocrine disrupting chemicals) on circulating levels of steroid hormones have been limited to a small number of hormones and reported conflicting results. Objective We examined the relationship between serum concentrations of dehydroepiandrosterone, dehydroepiandrosterone sulphate, androstenedione, androstenediol, testosterone, free and bioavailable testosterone, dihydrotestosterone, estrone, estrone sulphate, estradiol, sex-hormone binding globulin, follicle-stimulating hormone, and luteinizing hormone as a function of level of exposure to three POPs known to interfere with hormone-regulated processes in different way: dichlorodiphenyl dichloroethene (DDE), polychlorinated biphenyl (PCB) congener 153, and chlordecone. Methods We collected fasting, morning serum samples from 277 healthy, non obese, middle-aged men from the French West Indies. Steroid hormones were determined by gas chromatography-mass spectrometry, except for dehydroepiandrosterone sulphate, which was determined by immunological assay, as were the concentrations of sex-hormone binding globulin, follicle-stimulating hormone and luteinizing hormone. Associations were assessed by multiple linear regression analysis, controlling for confounding factors, in a backward elimination procedure, in multiple bootstrap samples. Results DDE exposure was negatively associated to dihydrotestosterone level and positively associated to luteinizing hormone level. PCB 153 was positively associated to androstenedione and estrone levels. No association was found for chlordecone. Conclusions These results suggested that the endocrine response pattern, estimated by determining blood levels of steroid hormones, varies depending on the POPs studied, possibly reflecting differences in the modes of action generally attributed to these compounds. It remains to be investigated whether this response pattern

  15. Levels of HIV-1 persistence on antiretroviral therapy are not associated with markers of inflammation or activation

    PubMed Central

    Bosch, Ronald J.; Macatangay, Bernard J.; Rinaldo, Charles R.; Riddler, Sharon A.; Mellors, John W.

    2017-01-01

    Antiretroviral therapy (ART) reduces levels of HIV-1 and immune activation but both can persist despite clinically effective ART. The relationships among pre-ART and on-ART levels of HIV-1 and activation are incompletely understood, in part because prior studies have been small or cross-sectional. To address these limitations, we evaluated measures of HIV-1 persistence, inflammation, T cell activation and T cell cycling in a longitudinal cohort of 101 participants who initiated ART and had well-documented sustained suppression of plasma viremia for a median of 7 years. During the first 4 years following ART initiation, HIV-1 DNA declined by 15-fold (93%) whereas cell-associated HIV-1 RNA (CA-RNA) fell 525-fold (>99%). Thereafter, HIV-1 DNA levels continued to decline slowly (5% per year) with a half-life of 13 years. Participants who had higher HIV-1 DNA and CA-RNA before starting treatment had higher levels while on ART, despite suppression of plasma viremia for many years. Markers of inflammation and T cell activation were associated with plasma HIV-1 RNA levels before ART was initiated but there were no consistent associations between these markers and HIV-1 DNA or CA-RNA during long-term ART, suggesting that HIV-1 persistence is not driving or driven by inflammation or activation. Higher levels of inflammation, T cell activation and cycling before ART were associated with higher levels during ART, indicating that immunologic events that occurred well before ART initiation had long-lasting effects despite sustained virologic suppression. These findings should stimulate studies of viral and host factors that affect virologic, inflammatory and immunologic set points prior to ART initiation and should inform the design of strategies to reduce HIV-1 reservoirs and dampen immune activation that persists despite ART. PMID:28426825

  16. Circulating Blood eNOS Contributes to the Regulation of Systemic Blood Pressure and Nitrite Homeostasis

    PubMed Central

    Wood, Katherine C.; Cortese-Krott, Miriam M.; Kovacic, Jason C.; Noguchi, Audrey; Liu, Virginia B.; Wang, Xunde; Raghavachari, Nalini; Boehm, Manfred; Kato, Gregory J.; Kelm, Malte; Gladwin, Mark T.

    2013-01-01

    Objective Mice genetically deficient in endothelial nitric oxide synthase (eNOS−/−) are hypertensive with lower circulating nitrite levels, indicating the importance of constitutively produced nitric oxide (NO•) to blood pressure regulation and vascular homeostasis. While the current paradigm holds that this bioactivity derives specifically from expression of eNOS in endothelium, circulating blood cells also express eNOS protein. A functional red cell eNOS that modulates vascular NO• signaling has been proposed. Approach and Results To test the hypothesis that blood cells contribute to mammalian blood pressure regulation via eNOS-dependent NO• generation, we cross-transplanted WT and eNOS−/− mice, producing chimeras competent or deficient for eNOS expression in circulating blood cells. Surprisingly, we observed a significant contribution of both endothelial and circulating blood cell eNOS to blood pressure and systemic nitrite levels, the latter being a major component of the circulating NO• reservoir. These effects were abolished by the NOS inhibitor L-NAME and repristinated by the NOS substrate L-Arginine, and were independent of platelet or leukocyte depletion. Mouse erythrocytes were also found to carry an eNOS protein and convert 14C-Arginine into 14C-Citrulline in a NOS-dependent fashion. Conclusions These are the first studies to definitively establish a role for a blood borne eNOS, using cross transplant chimera models, that contributes to the regulation of blood pressure and nitrite homeostasis. This work provides evidence suggesting that erythrocyte eNOS may mediate this effect. PMID:23702660

  17. The persistence of erroneous familiarity in an epileptic male: challenging perceptual theories of déjà vu activation.

    PubMed

    O'Connor, Akira R; Moulin, Christopher J A

    2008-11-01

    We report the case of a 39-year-old, temporal lobe epileptic male, MH. Prior to complex partial seizure, experienced up to three times a day, MH often experiences an aura experienced as a persistent sensation of déjà vu. Data-driven theories of déjà vu formation suggest that partial familiarity for the perceived stimulus is responsible for the sensation. Consequently, diverting attention away from this stimulus should cause the sensation to dissipate. MH, whose sensations of déjà vu persist long enough for him to shift his perceptual focus a number of times during the experience, spontaneously reports that these shifts make no difference to the sensation experienced. This novel observation challenges data-driven theories of déjà vu formation which have been used to explain the occurrence of déjà vu in those with temporal lobe epilepsy and the general population. Clearly, in epilepsy, erratic neuronal firing is the likely contributor, and in this paper we postulate that such brain firing causes higher-order erroneous 'cognitive feelings'. We tentatively extend this account to the general population. Rather than being a reaction to familiar elements in perceptual stimuli, déjà vu is likely to be the result of a cognitive feeling borne of the erroneous activation of neural familiarity circuits such as the parahippocampal gyrus, persisting as long as this activation persists.

  18. Prelamin A Accumulation Attenuates Rac1 Activity and Increases the Intrinsic Migrational Persistence of Aged Vascular Smooth Muscle Cells

    PubMed Central

    Porter, Lauren J.; Holt, Mark R.; Soong, Daniel; Shanahan, Catherine M.; Warren, Derek T.

    2016-01-01

    Vascular smooth muscle cell (VSMC) motility is essential during both physiological and pathological vessel remodeling. Although ageing has emerged as a major risk factor in the development of cardiovascular disease, our understanding of the impact of ageing on VSMC motility remains limited. Prelamin A accumulation is known to drive VSMC ageing and we show that presenescent VSMCs, that have accumulated prelamin A, display increased focal adhesion dynamics, augmented migrational velocity/persistence and attenuated Rac1 activity. Importantly, prelamin A accumulation in proliferative VSMCs, induced by depletion of the prelamin A processing enzyme FACE1, recapitulated the focal adhesion, migrational persistence and Rac1 phenotypes observed in presenescent VSMCs. Moreover, lamin A/C-depleted VSMCs also display reduced Rac1 activity, suggesting that prelamin A influences Rac1 activity by interfering with lamin A/C function at the nuclear envelope. Taken together, these data demonstrate that lamin A/C maintains Rac1 activity in VSMCs and prelamin A disrupts lamin A/C function to reduce Rac1 activity and induce migrational persistence during VSMC ageing. PMID:27854297

  19. Transfer and persistence of DNA on the hands and the influence of activities performed.

    PubMed

    Szkuta, Bianca; Ballantyne, Kaye N; van Oorschot, Roland A H

    2017-05-01

    During the evaluation of forensic DNA evidence in court proceedings, the emphasis previously placed on the source of the DNA is progressively shifting to the consideration of the activities resulting in its deposition. While direct contact and deposition may be a likely explanation, alternative scenarios involving DNA transfer through a secondary person or medium are important to consider. Here we assessed whether non-self DNA, indirectly transferred via a handshake, could be detected on surfaces contacted by the opposing hand-shaker after 15min, and considered the variables affecting its persistence in subsequent contacts. In general, the depositor of the handprint was the major contributor to DNA profiles collected from handprints placed on glass plates. Minor contributions from the opposing hand-shaker (as a known contributor) were detected at a lower rate, decreasing as the number of contacted items increased post-handshake. Delays in deposition also affected the detection of the opposing hand-shaker, with a 15min delay between handshaking and contact resulting in the reduced presence, and corresponding LRs, of the known contributor. The handprint depositor was excluded from their own handprint on several occasions, including instances where the opposing hand-shaker was not excluded from the same profile. Several factors appeared to strongly influence the detection of both the depositor and contributing individual involved in the handshake. The relative shedding ability of the pair had the largest effect, where good shedders (whether depositor or contributor) could swamp poor to moderate shedders, while the pairing of two moderate or two poor shedders could result in the detection of both individuals. When the deposition of a handprint was delayed, the activities performed by the individual had a substantial effect on the resultant detection of the contributing profile - multiple contacts with the same items increased the likelihood that the known contributor

  20. Bactericidal activity of alpha-bromocinnamaldehyde against persisters in Escherichia coli.

    PubMed

    Shen, Qingshan; Zhou, Wei; Hu, Liangbin; Qi, Yonghua; Ning, Hongmei; Chen, Jian; Mo, Haizhen

    2017-01-01

    Persisters are tolerant to multiple antibiotics, and widely distributed in bacteria, fungi, parasites, and even cancerous human cell populations, leading to recurrent infections and relapse after therapy. In this study, we investigated the potential of cinnamaldehyde and its derivatives to eradicate persisters in Escherichia coli. The results showed that 200 μg/ml of alpha-bromocinnamaldehyde (Br-CA) was capable of killing all E. coli cells during the exponential phase. Considering the heterogeneous nature of persisters, multiple types of persisters were induced and exposed to Br-CA. Our results indicated that no cells in the ppGpp-overproducing strain or TisB-overexpressing strain survived the treatment of Br-CA although considerable amounts of persisters to ampicillin (Amp) and ciprofloxacin (Cip) were induced. Chemical induction by carbonyl cyanide m-chlorophenylhydrazone (CCCP) led to the formation of more than 10% persister to Amp and Cip in the entire population, and Br-CA still completely eradicated them. In addition, the cells in the stationary phase, which are usually highly recalcitrant to antibiotics treatment, were also completely eradicated by 400 μg/ml of Br-CA. Further studies showed that neither thiourea (hydroxyl-radical scavenger) nor DPTA (Fe3+ chelator to block the hydroxyl-radical) affected the bactericidal efficiency of the Br-CA to kill E. coli, indicating a ROS-independent bactericidal mechanism. Taken together, we concluded that Br-CA compound has a novel bactericidal mechanism and the potential to mitigate antibiotics resistance crisis.

  1. Chlamydophila (Chlamydia) pneumoniae infection of human astrocytes and microglia in culture displays an active, rather than a persistent, phenotype.

    PubMed

    Dreses-Werringloer, Ute; Gérard, Hervé C; Whittum-Hudson, Judith A; Hudson, Alan P

    2006-10-01

    The intracellular pathogen Chlamydia pneumoniae can cause persistent infections during which its morphologic, molecular, and pathogenic characteristics differ importantly from those of active infection. This bacterium was identified within astrocytes and microglia in the brain of late-onset Alzheimer disease patients. We investigated whether infection of these two host cell types displays an active or persistent growth phenotype. The human astrocytoma and microglioma cell lines U-87 MG and CHME-5 (respectively) and the human epithelial cell line HEp-2 were infected by the standard method with C pneumoniae strain AR-39. Cultures were harvested at 24, 48, and 72 hours postinfection and subjected to analysis of inclusion morphology. DNA and RNA were prepared from portions of each infected culture sample and analyzed for relative chromosome accumulation and presence or absence of several specific bacterial mRNAs. Astrocytes and microglial cells infected in vitro with C pneumoniae displayed inclusions that were indistinguishable from those characteristic of active infection of the standard HEp-2 host cell line. Real time polymerase chain reaction (PCR) showed that the relative accumulation of chlamydial chromosome over time during infection of these two cell lines also was virtually identical to that in actively infected HEp-2 cells. Reverse transcriptase PCR (RT-PCR) analyses showed that mRNA from ftsK, pyk, and other chlamydial genes whose expression is abrogated during persistent infection were easily identifiable in infected CHME-5 and U-87 MG cells. In cultured human astrocytes and microglia, C pneumoniae displays an active, not a persistent, growth phenotype. This indicates normal passage through the developmental cycle with its probable concomitant destruction by lysis of some portion of host cells at the termination of that cycle.

  2. Sildenafil Ameliorates Gentamicin-Induced Nephrotoxicity in Rats: Role of iNOS and eNOS

    PubMed Central

    Morsy, Mohamed A.; Ibrahim, Salwa A.; Amin, Entesar F.; Kamel, Maha Y.; Rifaai, Rehab A.; Hassan, Magdy K.

    2014-01-01

    Gentamicin, an aminoglycoside antibiotic, is used for the treatment of serious Gram-negative infections. However, its usefulness is limited by its nephrotoxicity. Sildenafil, a selective phosphodiesterase-5 inhibitor, was reported to prevent or decrease tissue injury. The aim of this study is to evaluate the potential protective effects of sildenafil on gentamicin-induced nephrotoxicity in rats. Male Wistar rats were injected with gentamicin (100 mg/kg/day, i.p.) for 6 days with and without sildenafil. Sildenafil administration resulted in nephroprotective effect in gentamicin-intoxicated rats as it significantly decreased serum creatinine and urea, urinary albumin, and renal malondialdehyde and nitrite/nitrate levels, with a concomitant increase in renal catalase and superoxide dismutase activities compared to gentamicin-treated rats. Moreover, immunohistochemical examination revealed that sildenafil treatment markedly reduced inducible nitric oxide synthase (iNOS) expression, while expression of endothelial nitric oxide synthase (eNOS) was markedly enhanced. The protective effects of sildenafil were verified histopathologically. In conclusion, sildenafil protects rats against gentamicin-induced nephrotoxicity possibly, in part, through its antioxidant activity, inhibition of iNOS expression, and induction of eNOS production. PMID:25120567

  3. New paradigms for understanding and step changes in treating active and chronic, persistent apicomplexan infections

    USDA-ARS?s Scientific Manuscript database

    Toxoplasma gondii, the most common parasitic infection of the human brain and eye, persists across lifetimes, can progressively damage sight, and is currently incurable. New, curative medicines are needed urgently. Herein, we developed novel models to facilitate drug development: EGS strain T. gondi...

  4. College Students' Goal Orientations, Situational Motivation and Effort/Persistence in Physical Activity Classes

    ERIC Educational Resources Information Center

    Gao, Zan; Podlog, Leslie W.; Harrison, Louis

    2012-01-01

    The purpose of this study was to examine relationships among college students' 2 x 2 goal orientations (mastery-approach [MAp], mastery-avoidance [MAv], performance-approach [PAp], performance-avoidance [PAv]), situational motivation (intrinsic motivation, identified regulation, external regulation and amotivation) and effort/persistence in…

  5. Severity of Dysfluency Correlates with Basal Ganglia Activity in Persistent Developmental Stuttering

    ERIC Educational Resources Information Center

    Giraud, Anne-Lise; Neumann, Katrin; Bachoud-Levi, Anne-Catherine; von Gudenberg, Alexander W.; Euler, Harald A.; Lanfermann, Heinrich; Preibisch, Christine

    2008-01-01

    Previous studies suggest that anatomical anomalies [Foundas, A. L., Bollich, A. M., Corey, D. M., Hurley, M., & Heilman, K. M. (2001). "Anomalous anatomy of speech-language areas in adults with persistent developmental stuttering." "Neurology," 57, 207-215; Foundas, A. L., Corey, D. M., Angeles, V., Bollich, A. M., Crabtree-Hartman, E., & Heilman,…

  6. The Persistence of Erroneous Familiarity in an Epileptic Male: Challenging Perceptual Theories of Deja Vu Activation

    ERIC Educational Resources Information Center

    O'Connor, Akira R.; Moulin, Christopher J. A.

    2008-01-01

    We report the case of a 39-year-old, temporal lobe epileptic male, MH. Prior to complex partial seizure, experienced up to three times a day, MH often experiences an aura experienced as a persistent sensation of deja vu. Data-driven theories of deja vu formation suggest that partial familiarity for the perceived stimulus is responsible for the…

  7. Persistence of Cognitive Constructs Fostered by Hands-On Science Activities in Middle School Students

    ERIC Educational Resources Information Center

    Christensen, Rhonda; Knezek, Gerald; Tyler-Wood, Tandra; Gibson, David

    2013-01-01

    The purpose of this paper is to determine whether the changes that were found to occur pre- to post intervention in students' cognitive structures (Mills, 2013; Knezek, Christensen, Tyler-Wood, & Periathiruvadi, 2013) continued to persist two years later. Major findings were: a) semantic perception of science and STEM as a career became more…

  8. The Persistence of Erroneous Familiarity in an Epileptic Male: Challenging Perceptual Theories of Deja Vu Activation

    ERIC Educational Resources Information Center

    O'Connor, Akira R.; Moulin, Christopher J. A.

    2008-01-01

    We report the case of a 39-year-old, temporal lobe epileptic male, MH. Prior to complex partial seizure, experienced up to three times a day, MH often experiences an aura experienced as a persistent sensation of deja vu. Data-driven theories of deja vu formation suggest that partial familiarity for the perceived stimulus is responsible for the…

  9. Severity of Dysfluency Correlates with Basal Ganglia Activity in Persistent Developmental Stuttering

    ERIC Educational Resources Information Center

    Giraud, Anne-Lise; Neumann, Katrin; Bachoud-Levi, Anne-Catherine; von Gudenberg, Alexander W.; Euler, Harald A.; Lanfermann, Heinrich; Preibisch, Christine

    2008-01-01

    Previous studies suggest that anatomical anomalies [Foundas, A. L., Bollich, A. M., Corey, D. M., Hurley, M., & Heilman, K. M. (2001). "Anomalous anatomy of speech-language areas in adults with persistent developmental stuttering." "Neurology," 57, 207-215; Foundas, A. L., Corey, D. M., Angeles, V., Bollich, A. M., Crabtree-Hartman, E., & Heilman,…

  10. Keeping women active: an examination of the impacts of self-efficacy, intrinsic motivation, and leadership on women's persistence in physical activity.

    PubMed

    Lloyd, Kathleen M; Little, Donna E

    2010-10-01

    Physical inactivity in women is a worldwide problem that has not only been well-documented but has provoked much government concern and policy activity. However, an even more important issue is encouraging women's persistence in physical activity. The purpose of this study was to examine the links between women's experiences of participation in a government-funded physical activity festival, their intentions to continue participation, and their participation behavior six months after the festival. Results from semi-structured, in-depth interviews with 20 women revealed that enhanced self-efficacy, intrinsic motivation, and supportive leadership had motivated the women's future intentions to participate. Follow-up surveys showed their levels of interest and participation in physical activity had been maintained. These results enhance our understanding of the relationship between key outcomes of women's physical activity participation and their persistence in physical activity.

  11. HSP70-1 is required for interleukin-5-induced angiogenic responses through eNOS pathway

    PubMed Central

    Park, Sung Lyea; Chung, Tae-Wook; Kim, Sangtae; Hwang, Byungdoo; Kim, Jung Min; Lee, Hwan Myung; Cha, Hee-Jae; Seo, Yoonhee; Choe, Soo Young; Ha, Ki-Tae; Kim, Gonhyung; Yun, Seok-Joong; Park, Sung-Soo; Choi, Yung Hyun; Kim, Bo Kyung; Kim, Won-Tae; Cha, Eun-Jong; Patterson, Cam; Kim, Wun-Jae; Moon, Sung-Kwon

    2017-01-01

    We report a pivotal role for IL-5 as an angiogenic activator. IL-5 increased proliferation, migration and colony tube formation in HUVECs associated with the phosphorylation of ERK and AKT/eNOS, and promoted microvessel sprouting from an angiogenesis animal model. The angiogenic effects were confirmed in IL-5-deficient mice and addition of IL-5 antibody. HSP70-1 was identified via expression profiling following IL-5 stimulation. A siRNA knockdown of HSP70-1 suppressed angiogenic responses and eNOS phosphorylation induced by IL-5. HSP70-1 overexpression enhanced IL-5-induced angiogenic responses. In addition, IL-5-induced neo-vascular formation was verified in both HSP70-1 knockout and HSP70-1 transgenic mice. Furthermore, transcription factor AP-1 was a main factor in IL-5-induced HSP70-1 in response to ERK and AKT signaling pathway. Angiogenic responses induced by VEGF had no effect in either HSP70-1 siRNA in vitro or HSP70-1 knockout mice. IL-5-induced angiogenic responses depended on the binding of IL-5Rα. Our data demonstrate that binding of IL-5 to IL-5Rα receptors enhances angiogenic responses by stimulating the expression of HSP70-1 via the eNOS signaling pathway. PMID:28317868

  12. New Findings in eNOS gene and Thalidomide Embryopathy Suggest pre-transcriptional effect variants as susceptibility factors.

    PubMed

    Kowalski, Thayne Woycinck; Fraga, Lucas Rosa; Tovo-Rodrigues, Luciana; Sanseverino, Maria Teresa Vieira; Hutz, Mara Helena; Schuler-Faccini, Lavínia; Vianna, Fernanda Sales Luiz

    2016-03-23

    Antiangiogenic properties of thalidomide have created an interest in the use of the drug in treatment of cancer. However, thalidomide is responsible for thalidomide embryopathy (TE). A lack of knowledge regarding the mechanisms of thalidomide teratogenesis acts as a barrier in the aim to synthesize a safer analogue of thalidomide. Recently, our group detected a higher frequency of alleles that impair the pro-angiogenic mechanisms of endothelial nitric oxide synthase (eNOS), coded by the NOS3 gene. In this study we evaluated variable number tandem repeats (VNTR) functional polymorphism in intron 4 of NOS3 in individuals with TE (38) and Brazilians without congenital anomalies (136). Haplotypes were estimated for this VNTR with previously analyzed polymorphisms, rs2070744 (-786C > T) and rs1799983 (894T > G), in promoter region and exon 7, respectively. Haplotypic distribution was different between the groups (p = 0.007). Alleles -786C (rs2070744) and 4b (VNTR), associated with decreased NOS3 expression, presented in higher frequency in TE individuals (p = 0.018; OR = 2.57; IC = 1.2-5.8). This association was not identified with polymorphism 894T > G (p = 0.079), which influences eNOS enzymatic activity. These results suggest variants in NOS3, with pre-transcriptional effects as susceptibility factors, influencing the risk TE development. This finding generates insight for a new approach to research that pursues a safer analogue.

  13. Influence of coronary artery diameter on eNOS protein content

    NASA Technical Reports Server (NTRS)

    Laughlin, M. H.; Turk, J. R.; Schrage, W. G.; Woodman, C. R.; Price, E. M.

    2003-01-01

    The purpose of this study was to test the hypothesis that the content of endothelial nitric oxide synthase (eNOS) protein (eNOS protein/g total artery protein) increases with decreasing artery diameter in the coronary arterial tree. Content of eNOS protein was determined in porcine coronary arteries with immunoblot analysis. Arteries were isolated in six size categories from each heart: large arteries [301- to 2,500-microm internal diameter (ID)], small arteries (201- to 300-microm ID), resistance arteries (151- to 200-microm ID), large arterioles (101- to 150-microm ID), intermediate arterioles (51- to 100-microm ID), and small arterioles(<50-microm ID). To obtain sufficient protein for analysis from small- and intermediate-sized arterioles, five to seven arterioles 1-2 mm in length were pooled into one sample for each animal. Results establish that the number of smooth muscle cells per endothelial cell decreases from a number of 10 to 15 in large coronary arteries to 1 in the smallest arterioles. Immunohistochemistry revealed that eNOS is located only in endothelial cells in all sizes of coronary artery and in coronary capillaries. Contrary to our hypothesis, eNOS protein content did not increase with decreasing size of coronary artery. Indeed, the smallest coronary arterioles had less eNOS protein per gram of total protein than the large coronary arteries. These results indicate that eNOS protein content is greater in the endothelial cells of conduit arteries, resistance arteries, and large arterioles than in small coronary arterioles.

  14. Influence of coronary artery diameter on eNOS protein content

    NASA Technical Reports Server (NTRS)

    Laughlin, M. H.; Turk, J. R.; Schrage, W. G.; Woodman, C. R.; Price, E. M.

    2003-01-01

    The purpose of this study was to test the hypothesis that the content of endothelial nitric oxide synthase (eNOS) protein (eNOS protein/g total artery protein) increases with decreasing artery diameter in the coronary arterial tree. Content of eNOS protein was determined in porcine coronary arteries with immunoblot analysis. Arteries were isolated in six size categories from each heart: large arteries [301- to 2,500-microm internal diameter (ID)], small arteries (201- to 300-microm ID), resistance arteries (151- to 200-microm ID), large arterioles (101- to 150-microm ID), intermediate arterioles (51- to 100-microm ID), and small arterioles(<50-microm ID). To obtain sufficient protein for analysis from small- and intermediate-sized arterioles, five to seven arterioles 1-2 mm in length were pooled into one sample for each animal. Results establish that the number of smooth muscle cells per endothelial cell decreases from a number of 10 to 15 in large coronary arteries to 1 in the smallest arterioles. Immunohistochemistry revealed that eNOS is located only in endothelial cells in all sizes of coronary artery and in coronary capillaries. Contrary to our hypothesis, eNOS protein content did not increase with decreasing size of coronary artery. Indeed, the smallest coronary arterioles had less eNOS protein per gram of total protein than the large coronary arteries. These results indicate that eNOS protein content is greater in the endothelial cells of conduit arteries, resistance arteries, and large arterioles than in small coronary arterioles.

  15. Hindlimb unweighting decreases endothelium-dependent dilation and eNOS expression in soleus not gastrocnemius

    NASA Technical Reports Server (NTRS)

    Woodman, C. R.; Schrage, W. G.; Rush, J. W.; Ray, C. A.; Price, E. M.; Hasser, E. M.; Laughlin, M. H.

    2001-01-01

    We tested the hypothesis that hindlimb unweighting (HLU) decreases endothelium-dependent vasodilation and expression of endothelial nitric oxide synthase (eNOS) and superoxide dismutase-1 (SOD-1) in arteries of skeletal muscle with reduced blood flow during HLU. Sprague-Dawley rats (300-350 g) were exposed to HLU (n = 15) or control (n = 15) conditions for 14 days. ACh-induced dilation was assessed in muscle with reduced [soleus (Sol)] or unchanged [gastrocnemius (Gast)] blood flow during HLU. eNOS and SOD-1 expression were measured in feed arteries (FA) and in first-order (1A), second-order (2A), and third-order (3A) arterioles. Dilation to infusion of ACh in vivo was blunted in Sol but not Gast. In arteries of Sol muscle, HLU decreased eNOS mRNA and protein content. eNOS mRNA content was significantly less in Sol FA (35%), 1A arterioles (25%) and 2A arterioles (18%). eNOS protein content was less in Sol FA (64%) and 1A arterioles (65%) from HLU rats. In arteries of Gast, HLU did not decrease eNOS mRNA or protein. SOD-1 mRNA expression was less in Sol 2A arterioles (31%) and 3A arterioles (29%) of HLU rats. SOD-1 protein content was less in Sol FA (67%) but not arterioles. SOD-1 mRNA and protein content were not decreased in arteries from Gast. These data indicate that HLU decreases endothelium-dependent vasodilation, eNOS expression, and SOD-1 expression primarily in arteries of Sol muscle where blood flow is reduced during HLU.

  16. Hindlimb unweighting decreases endothelium-dependent dilation and eNOS expression in soleus not gastrocnemius

    NASA Technical Reports Server (NTRS)

    Woodman, C. R.; Schrage, W. G.; Rush, J. W.; Ray, C. A.; Price, E. M.; Hasser, E. M.; Laughlin, M. H.

    2001-01-01

    We tested the hypothesis that hindlimb unweighting (HLU) decreases endothelium-dependent vasodilation and expression of endothelial nitric oxide synthase (eNOS) and superoxide dismutase-1 (SOD-1) in arteries of skeletal muscle with reduced blood flow during HLU. Sprague-Dawley rats (300-350 g) were exposed to HLU (n = 15) or control (n = 15) conditions for 14 days. ACh-induced dilation was assessed in muscle with reduced [soleus (Sol)] or unchanged [gastrocnemius (Gast)] blood flow during HLU. eNOS and SOD-1 expression were measured in feed arteries (FA) and in first-order (1A), second-order (2A), and third-order (3A) arterioles. Dilation to infusion of ACh in vivo was blunted in Sol but not Gast. In arteries of Sol muscle, HLU decreased eNOS mRNA and protein content. eNOS mRNA content was significantly less in Sol FA (35%), 1A arterioles (25%) and 2A arterioles (18%). eNOS protein content was less in Sol FA (64%) and 1A arterioles (65%) from HLU rats. In arteries of Gast, HLU did not decrease eNOS mRNA or protein. SOD-1 mRNA expression was less in Sol 2A arterioles (31%) and 3A arterioles (29%) of HLU rats. SOD-1 protein content was less in Sol FA (67%) but not arterioles. SOD-1 mRNA and protein content were not decreased in arteries from Gast. These data indicate that HLU decreases endothelium-dependent vasodilation, eNOS expression, and SOD-1 expression primarily in arteries of Sol muscle where blood flow is reduced during HLU.

  17. Upregulation of ERK1/2-eNOS via AT2 Receptors Decreases the Contractile Response to Angiotensin II in Resistance Mesenteric Arteries from Obese Rats

    PubMed Central

    Hagihara, Graziela N.; Lobato, Nubia S.; Filgueira, Fernando P.; Akamine, Eliana H.; Aragão, Danielle S.; Casarini, Dulce E.; Carvalho, Maria Helena C.; Fortes, Zuleica B.

    2014-01-01

    It has been clearly established that mitogen-activated protein kinases (MAPKS) are important mediators of angiotensin II (Ang II) signaling via AT1 receptors in the vasculature. However, evidence for a role of these kinases in changes of Ang II-induced vasoconstriction in obesity is still lacking. Here we sought to determine whether vascular MAPKs are differentially activated by Ang II in obese animals. The role of AT2 receptors was also evaluated. Male monosodium glutamate-induced obese (obese) and non-obese Wistar rats (control) were used. The circulating concentrations of Ang I and Ang II, determined by HPLC, were increased in obese rats. Ang II-induced isometric contraction was decreased in endothelium-intact resistance mesenteric arteries from obese compared with control rats and exhibited a retarded AT1 receptor antagonist response. Blocking of AT2 receptors and inhibition of either endothelial nitric oxide synthase (eNOS) or extracellular signal-regulated protein kinases 1 and 2 (ERK1/2) restored Ang II-induced contraction in obese rats. Western blot analysis revealed increased protein expression of AT2 receptors in arteries from obese rats. Basal and Ang II-induced ERK1/2 phosphorylation was also increased in obese rats. Blockade of either AT1 or AT2 receptors corrected the increased ERK1/2 phosphorylation in arteries from obese rats to levels observed in control preparations. Phosphorylation of eNOS was increased in obese rats. Incubation with the ERK1/2 inhibitor before Ang II stimulation did not affect eNOS phosphorylation in control rats; however, it corrected the increased phosphorylation of eNOS in obese rats. These results clearly demonstrate that enhanced AT2 receptor and ERK1/2-induced, NO-mediated vasodilation reduces Ang II-induced contraction in an endothelium-dependent manner in obese rats. PMID:25170617

  18. Borrelia burgdorferi aggrecanase activity: more evidence for persistent infection in Lyme disease

    PubMed Central

    Stricker, Raphael B.; Johnson, Lorraine

    2013-01-01

    Lyme disease is the most common tickborne illness in the world today. A recent study describes for the first time an enzyme produced by the spirochetal agent of Lyme disease, Borrelia burgdorferi, that cleaves aggrecan, a proteoglycan found in joints and connective tissue. Discovery of the spirochetal aggrecanase raises many questions about the pathogenesis of Lyme arthritis and lends support to the concept of persistent B. burgdorferi infection in patients with chronic Lyme disease symptoms. PMID:23967405

  19. ENO1 promotes tumor proliferation and cell adhesion mediated drug resistance (CAM-DR) in Non-Hodgkin's Lymphomas

    SciTech Connect

    Zhu, Xinghua; Miao, Xiaobing; Wu, Yaxun; Li, Chunsun; Guo, Yan; Liu, Yushan; Chen, Yali; Lu, Xiaoyun; Wang, Yuchan; He, Song

    2015-07-15

    Enolases are glycolytic enzymes responsible for the ATP-generated conversion of 2-phosphoglycerate to phosphoenolpyruvate. In addition to the glycolytic function, Enolase 1 (ENO1) has been reported up-regulation in several tumor tissues. In this study, we investigated the expression and biologic function of ENO1 in Non-Hodgkin's Lymphomas (NHLs). Clinically, by western blot analysis we observed that ENO1 expression was apparently higher in diffuse large B-cell lymphoma than in the reactive lymphoid tissues. Subsequently, immunohistochemical staining of 144 NHLs suggested that the expression of ENO1 was significantly lower in the indolent lymphomas compared with the progressive lymphomas. Further, we identified ENO1 as an independent prognostic factor, and it was significantly correlated with overall survival of NHL patients. In addition, we found that ENO1 could promote cell proliferation, regulate cell cycle associated gene and PI3K/AKT signaling pathway in NHLs. Finally, we verified that ENO1 participated in the process of lymphoma cell adhesion mediated drug resistance (CAM-DR). Adhesion to FN or HS5 cells significantly protected OCI-Ly8 and Daudi cells from cytotoxicity compared with those cultured in suspension, and these effects were attenuated when transfected with ENO1-siRNA. Based on the study, we propose that inhibition of ENO1 expression may be a novel strategy for therapy for NHLs patients, and it may be a target for drug resistance. - Highlights: • ENO1 expression is reversely correlated with clinical outcomes of patients with NHLs. • ENO1 promotes the proliferation of NHL cells. • ENO1 regulates cell adhesion mediated drug resistance.

  20. Phase Resetting Light Pulses Induce Per1 and Persistent Spike Activity in a Subpopulation of Biological Clock Neurons

    PubMed Central

    Kuhlman, Sandra J.; Silver, Rae; Le Sauter, Joseph; Bult-Ito, Abel; McMahon, Douglas G.

    2012-01-01

    The endogenous circadian clock of the mammalian suprachiasmatic nucleus (SCN) can be reset by light to synchronize the biological clock of the brain with the external environment. This process involves induction of immediate-early genes such as the circadian clock gene Period1 (Per1) and results in a stable shift in the timing of behavioral and physiological rhythms on subsequent days. The mechanisms by which gene activation permanently alters the phase of clock neuron activity are unknown. To study the relationship between acute gene activation and persistent changes in the neurophysiology of SCN neurons, we recorded from SCN neurons marked with a dynamic green fluorescent protein (GFP) reporter of Per1 gene activity. Phase-resetting light pulses resulted in Per1 induction in a distinct subset of SCN neurons that also exhibited a persistent increase in action potential frequency 3–5 hr after a light pulse. By simultaneously quantifying Per1 gene activation and spike frequency in individual neurons, we found that the degree of Per1 induction was highly correlated with neuronal spike frequency on a cell-by-cell basis. Increased neuronal activity was mediated by membrane potential depolarization as a result of a reduction in outward potassium current. Double-label immunocytochemistry revealed that vasoactive intestinal peptide (VIP)-expressing cells, but not arginine vasopressin (AVP)-expressing cells, exhibited significant Per1 induction by light pulses. Rhythmic GFP expression occurred in both VIP and AVP neurons. Our results indicate that the steps that link acute molecular events to permanent changes in clock phase involve persistent suppression of potassium current, downstream of Per1 gene induction, in a specific subset of Per1-expressing neurons enriched for VIP. PMID:12598633

  1. Cortex glial cells activation, associated with lowered mechanical thresholds and motor dysfunction, persists into adulthood after neonatal pain

    PubMed Central

    Sanada, Luciana Sayuri; Sato, Karina Laurenti; Machado, Nathalia Leilane Berto; de Cássia do Carmo, Elisabete; Sluka, Kathleen A.; Fazan, Valeria Paula Sassoli

    2014-01-01

    We investigated if changes in glial activity in cortical areas that process nociceptive stimuli persisted in adult rats after neonatal injury. Neonatal pain was induced by repetitive needle prickling on the right paw, twice per day for 15 days starting at birth. Wistar rats received either neonatal pain or tactile stimulation and were tested behaviorally for mechanical withdrawal thresholds of the paws and gait alterations, after 15 (P15) or 180 (P180) days of life. Brains from rats on P15 and P180 were immunostained for glial markers (GFAP, MCP-1, OX-42) and the following cortical areas were analyzed for immunoreactivity density: prefrontal, anterior insular, anterior cingulated, somatosensory and motor cortices. Withdrawal thresholds of the stimulated paw remained decreased on P180 after neonatal pain when compared to controls. Neonatal pain animals showed increased density for both GFAP and MCP-1 staining, but not for OX-42, in all investigated cortical areas on both experimental times (P15 and P180). Painful stimuli in the neonatal period produced pain behaviors immediately after injury that persisted in adult life, and was accompanied by increase in the glial markers density in cortical areas that process and interpret pain. Thus, long-lasting changes in cortical glial activity could be, at least in part, responsible for the persistent hyperalgesia in adult rats that suffered from neonatal pain. PMID:24667146

  2. Cortex glial cells activation, associated with lowered mechanical thresholds and motor dysfunction, persists into adulthood after neonatal pain.

    PubMed

    Sanada, Luciana Sayuri; Sato, Karina Laurenti; Machado, Nathalia Leilane Berto; Carmo, Elisabete de Cássia do; Sluka, Kathleen A; Fazan, Valeria Paula Sassoli

    2014-06-01

    We investigated if changes in glial activity in cortical areas that process nociceptive stimuli persisted in adult rats after neonatal injury. Neonatal pain was induced by repetitive needle prickling on the right paw, twice per day for 15 days starting at birth. Wistar rats received either neonatal pain or tactile stimulation and were tested behaviorally for mechanical withdrawal thresholds of the paws and gait alterations, after 15 (P15) or 180 (P180) days of life. Brains from rats on P15 and P180 were immunostained for glial markers (GFAP, MCP-1, OX-42) and the following cortical areas were analyzed for immunoreactivity density: prefrontal, anterior insular, anterior cingulated, somatosensory and motor cortices. Withdrawal thresholds of the stimulated paw remained decreased on P180 after neonatal pain when compared to controls. Neonatal pain animals showed increased density for both GFAP and MCP-1 staining, but not for OX-42, in all investigated cortical areas on both experimental times (P15 and P180). Painful stimuli in the neonatal period produced pain behaviors immediately after injury that persisted in adult life, and was accompanied by increase in the glial markers density in cortical areas that process and interpret pain. Thus, long-lasting changes in cortical glial activity could be, at least in part, responsible for the persistent hyperalgesia in adult rats that suffered from neonatal pain.

  3. Activation of endothelial nitric oxide synthase is dependent on its interaction with globular actin in human umbilical vein endothelial cells.

    PubMed

    Mi, Qiongyu; Chen, Nan; Shaifta, Yasin; Xie, Liping; Lu, Hui; Liu, Zhen; Chen, Qi; Hamid, Colleen; Becker, Silke; Ji, Yong; Ferro, Albert

    2011-09-01

    Endothelial nitric oxide synthase (eNOS) has been reported to associate with globular actin, and this association increases eNOS activity. Adenosine, histamine, salbutamol and thrombin cause activation of eNOS through widely different mechanisms. Whether these eNOS agonists can regulate eNOS activity through affecting its association with actin is unknown. As previously reported, we confirmed in cultured human umbilical vein endothelial cells (HUVEC) that histamine and thrombin increased intracellular Ca(2+) whereas adenosine and salbutamol did not, and that these four agonists caused different effects on actin filament structure. Nevertheless, despite their divergent effects on intracellular Ca(2+) and on actin filament structure, we found by immunoprecipitation that adenosine, histamine, salbutamol and thrombin all caused an increase in association between eNOS and globular actin. This increase of association was inhibited by pre-treatment with phalloidin, an actin filament stabilizer. All of these agonists also increased phosphorylation of eNOS on serine residue 1177, eNOS activity, and cyclic guanosine-3', 5'-monophosphate, and these increases were all attenuated by phalloidin. Agonist-induced phosphorylation of eNOS on serine 1177 was attenuated by Akt inhibition, whereas association of eNOS with actin was not. We also found, in HEK-293 cells transfected with the eNOS mutants eNOS-S1177A or eNOS-S1177D, that the association between eNOS and globular actin was decreased as compared to cells transfected with wild-type eNOS. We conclude that association of globular actin with eNOS plays an essential and necessary role in agonist-induced eNOS activation, through enabling its phosphorylation by Akt at serine residue 1177.

  4. Estimating the persistence of organic contaminants in indirect potable reuse systems using quantitative structure activity relationship (QSAR).

    PubMed

    Lim, Seung Joo; Fox, Peter

    2012-09-01

    Predictions from the quantitative structure activity relationship (QSAR) model EPI Suite were modified to estimate the persistence of organic contaminants in indirect potable reuse systems. The modified prediction included the effects of sorption, biodegradation, and oxidation that may occur during sub-surface transport. A retardation factor was used to simulate the mobility of adsorbed compounds during sub-surface transport to a recovery well. A set of compounds with measured persistent properties during sub-surface transport was used to validate the results of the modifications to the predictions of EPI Suite. A comparison of the predicted values and measured values was done and the residual sum of the squares showed the importance of including oxidation and sorption. Sorption was the most important factor to include in predicting the fates of organic chemicals in the sub-surface environment.

  5. Enolase isoforms activities in spermatozoa from men with normospermia and abnormospermia.

    PubMed

    Force, Andre; Viallard, Jean-L; Grizard, Genevieve; Boucher, Daniel

    2002-01-01

    Total enolase as well as enolase-alphaalpha. (ENO-alphaalpha, ubiquitous) and enolase-S (ENO-S, sperm-specific) activities were measured in total and Percoll-selected sperm from 30 normospermic fertile men and 20 abnormospermic infertile patients. The total enolase activity was significantly higher in total sperm from patients with abnormospermia compared with normospermic patients (11.1 +/- 1.9 vs. 4.8 +/- 0.5 mlU/10(7) sperm P < .05). ENO-alphaalpha activity was significantly higher in total sperm from abnormospermic men than from normospermic men (P < .05). ENO-alphaalpha activity in Percoll-selected sperm was significantly lower compared with total sperm in both group of patients; however, for the same sperm fraction ENO-alphaalpha activity did not differ between normospermic and abnormospermic men. ENO-alphaalpha activity was related to the cell contamination ratio and to the percentage of spermatozoa with abnormal morphology. Furthermore, ENO-alphaalpha was positively correlated with the percentage of immature sperm showing an excess of residual cytoplasm. ENO-S activity was significantly higher in total sperm from normospermic patients than from abnormospermic patients (P < .05). ENO-S activity in Percoll-selected sperm was not significantly different compared with total sperm in both group of patients. However, this activity was significantly lower in Percoll-selected sperm from abnormospermic men compared with normospermic men (P < .05). ENO-S activity was not related to the cell contamination ratio but was significantly correlated with the percentage of spermatozoa with normal morphology. The 2 enolase isoforms seem to reflect 2 opposite aspects of sperm cells quality: ENO-alphaalpha is associated with abnormal spermatozoa, immature spermatozoa, or both; and ENO-S is associated with normal spermatozoa. As an additional index to distinguish normal from abnormal semen, the ENO-S:ENO-alphaalpha ratio was evaluated for total and Percoll-selected sperm in both

  6. Role of endothelial nitric oxide synthase (eNOS) in chronic stress-promoted tumour growth

    PubMed Central

    Barbieri, Antonio; Palma, Giuseppe; Rosati, Alessandra; Giudice, Aldo; Falco, Antonia; Petrillo, Antonella; Petrillo, Mario; Bimonte, Sabrina; Benedetto, Maria Di; Esposito, Giuseppe; Stiuso, Paola; Abbruzzese, Alberto; Caraglia, Michele; Arra, Claudio

    2012-01-01

    Abstract Accumulating evidence suggests that chronic stress can be a cofactor for the initiation and progression of cancer. Here we evaluated the role of endothelial nitric oxide synthase (eNOS) in stress-promoted tumour growth of murine B16F10 melanoma cell line in C57BL/6 mice. Animals subjected to restraint stress showed increased levels adrenocorticotropic hormone, enlarged adrenal glands, reduced thymus weight and a 3.61-fold increase in tumour growth in respect to no-stressed animals. Tumour growth was significantly reduced in mice treated with the β-antagonist propranolol. Tumour samples obtained from stressed mice displayed high levels of vascular endothelial growth factor (VEGF) protein in immunohistochemistry. Because VEGF can induce eNOS increase, and nitric oxide is a relevant factor in angiogenesis, we assessed the levels of eNOS protein by Western blot analysis. We found a significant increase in eNOS levels in tumour samples from stressed mice, indicating an involvement of this enzyme in stress-induced tumour growth. Accordingly, chronic stress did not promote tumour growth in eNOS−/− mice. These results disclose for the first time a pivotal role for eNOS in chronic stress-induced initiation and promotion of tumour growth. PMID:21722303

  7. Extensive Ethnogenomic Diversity of Endothelial Nitric Oxide Synthase (eNOS) Polymorphisms

    PubMed Central

    Thomas, Bolaji N.; Thakur, Tanya J.; Yi, Li; Guindo, Aldiouma; Diallo, Dapa A.; Ott, Jurg

    2013-01-01

    Nitric oxide (NO) is highly reactive, produced in endothelial cells by endothelial NO synthase (eNOS) and has been implicated in sickle cell pathophysiology. We evaluated the distribution of functionally significant eNOS variants (the T786C variant in the promoter region, the Glu298Asp variant in exon 7, and the variable number of tandem repeats (VNTR) in intron 4) in Africans, African Americans and Caucasians. The C-786 variant was more common in Caucasians than in Africans and African Americans. Consistent with other findings, the Asp-298 variant had the highest frequency in Caucasians followed by African Americans, but was completely absent in Africans. The very rare intron 4 allele, eNOS 4c, was found in some Africans and African Americans, but not in Caucasians. eNOS 4d allele was present in 2 Africans. These findings suggest a consistent and widespread genomic diversity in the distribution of eNOS variants in Africans, comparative to African Americans and Caucasians. PMID:23400313

  8. TAML activator/peroxide-catalyzed facile oxidative degradation of the persistent explosives trinitrotoluene and trinitrobenzene in micellar solutions.

    PubMed

    Kundu, Soumen; Chanda, Arani; Khetan, Sushil K; Ryabov, Alexander D; Collins, Terrence J

    2013-05-21

    TAML activators are well-known for their ability to activate hydrogen peroxide to oxidize persistent pollutants in water. The trinitroaromatic explosives, 2,4,6-trinitrotoluene (TNT) and 1,3,5-trinitrobenzene (TNB), are often encountered together as persistent, toxic pollutants. Here we show that an aggressive TAML activator with peroxides boosts the effectiveness of the known surfactant/base promoted breakdown of TNT and transforms the surfactant induced nondestructive binding of base to TNB into an extensive multistep degradation process. Treatment of basic cationic surfactant solutions of either TNT or TNB with TAML/peroxide (hydrogen peroxide and tert-butylhydroperoxide, TBHP) gave complete pollutant removal for both in <1 h with >75% of the nitrogen and ≥20% of the carbon converted to nitrite/nitrate and formate, respectively. For TNT, the TAML advantage is to advance the process toward mineralization. Basic surfactant solutions of TNB gave the colored solutions typical of known Meisenheimer complexes which did not progress to degradation products over many hours. However with added TAML activator, the color was bleached quickly and the TNB starting compound was degraded extensively toward minerals within an hour. A slower surfactant-free TAML activator/peroxide process also degrades TNT/TNB effectively. Thus, TAML/peroxide amplification effectively advances TNT and TNB water treatment giving reason to explore the environmental applicability of the approach.

  9. Increased IFNα activity and differential antibody response in patients with a history of Lyme disease and persistent cognitive deficits.

    PubMed

    Jacek, Elzbieta; Fallon, Brian A; Chandra, Abhishek; Crow, Mary K; Wormser, Gary P; Alaedini, Armin

    2013-02-15

    Following antibiotic treatment for Lyme disease, some patients report persistent or relapsing symptoms of pain, fatigue, and/or cognitive deficits. Factors other than active infection, including immune abnormalities, have been suggested, but few clues regarding mechanism have emerged. Furthermore, the effect of antibiotic treatment on immune response in affected individuals remains unknown. In this study, a longitudinal analysis of specific immune markers of interest was carried out in patients with a history of Lyme disease and persistent objective memory impairment, prior to and following treatment with either ceftriaxone or placebo. IFNα activity was measured by detection of serum-induced changes in specific target genes, using a functional cell-based assay and quantitative real-time PCR. Level and pattern of antibody reactivity to brain antigens and to Borrelia burgdorferi proteins were analyzed by ELISA and immunoblotting. Sera from the patient cohort induced significantly higher expression of IFIT1 and IFI44 target genes than those from healthy controls, indicating increased IFNα activity. Antibody reactivity to specific brain and borrelial proteins was significantly elevated in affected patients. IFNα activity and antibody profile did not change significantly in response to ceftriaxone. The heightened antibody response implies enhanced immune stimulation, possibly due to prolonged exposure to the organism prior to the initial diagnosis and antibiotic treatment of Lyme disease. The increase in IFNα activity is suggestive of a mechanism contributing to the ongoing neuropsychiatric symptoms. Copyright © 2012 Elsevier B.V. All rights reserved.

  10. Molecular structure of the human muscle-specific enolase gene (ENO3).

    PubMed Central

    Peshavaria, M; Day, I N

    1991-01-01

    The single human gene for muscle-specific enolase was isolated and its structure was characterized, from which the mature mRNA transcript and encoded protein were also deduced. The gene contains 12 exons, spans approx. 6 kb and encodes a protein of 433 residues. The gene structure is similar to that found for the rat neuron-specific enolase gene, and the deduced protein aligns precisely with other enolase sequences, including the sequence of the only published crystallized enolase, yeast eno-1. The 5' boundary of the gene includes a 5' non-coding exon and is characterized by an upstream TATA-like box and CpG-rich region. This region contains potential recognition motifs for general transcriptional regulation involving Sp1, activator protein 1 and 2, CCAAT box transcription factor/nuclear factor I and cyclic AMP, and for muscle-specific transcriptional regulation involving a CC(A + T-rich)6GG box, M-CAT-box CAATCCT and two myocyte-specific enhancer-binding factor 1 boxes. Images Fig. 1. Fig. 5. PMID:1840492

  11. Persistent activation of DNA damage signaling in response to complex mixtures of PAHs in air particulate matter

    SciTech Connect

    Jarvis, Ian W.H.; Bergvall, Christoffer; Bottai, Matteo; Westerholm, Roger; Stenius, Ulla; Dreij, Kristian

    2013-02-01

    Complex mixtures of polycyclic aromatic hydrocarbons (PAHs) are present in air particulate matter (PM) and have been associated with many adverse human health effects including cancer and respiratory disease. However, due to their complexity, the risk of exposure to mixtures is difficult to estimate. In the present study the effects of binary mixtures of benzo[a]pyrene (BP) and dibenzo[a,l]pyrene (DBP) and complex mixtures of PAHs in urban air PM extracts on DNA damage signaling was investigated. Applying a statistical model to the data we observed a more than additive response for binary mixtures of BP and DBP on activation of DNA damage signaling. Persistent activation of checkpoint kinase 1 (Chk1) was observed at significantly lower BP equivalent concentrations in air PM extracts than BP alone. Activation of DNA damage signaling was also more persistent in air PM fractions containing PAHs with more than four aromatic rings suggesting larger PAHs contribute a greater risk to human health. Altogether our data suggests that human health risk assessment based on additivity such as toxicity equivalency factor scales may significantly underestimate the risk of exposure to complex mixtures of PAHs. The data confirms our previous findings with PAH-contaminated soil (Niziolek-Kierecka et al., 2012) and suggests a possible role for Chk1 Ser317 phosphorylation as a biological marker for future analyses of complex mixtures of PAHs. -- Highlights: ► Benzo[a]pyrene (BP), dibenzo[a,l]pyrene (DBP) and air PM PAH extracts were compared. ► Binary mixture of BP and DBP induced a more than additive DNA damage response. ► Air PM PAH extracts were more potent than toxicity equivalency factor estimates. ► Larger PAHs (> 4 rings) contribute more to the genotoxicity of PAHs in air PM. ► Chk1 is a sensitive marker for persistent activation of DNA damage signaling from PAH mixtures.

  12. The Fatty Acid Signaling Molecule cis-2-Decenoic Acid Increases Metabolic Activity and Reverts Persister Cells to an Antimicrobial-Susceptible State

    PubMed Central

    Morozov, Aleksey; Planzos, Penny; Zelaya, Hector M.

    2014-01-01

    Persister cells, which are tolerant to antimicrobials, contribute to biofilm recalcitrance to therapeutic agents. In turn, the ability to kill persister cells is believed to significantly improve efforts in eradicating biofilm-related, chronic infections. While much research has focused on elucidating the mechanism(s) by which persister cells form, little is known about the mechanism or factors that enable persister cells to revert to an active and susceptible state. Here, we demonstrate that cis-2-decenoic acid (cis-DA), a fatty acid signaling molecule, is able to change the status of Pseudomonas aeruginosa and Escherichia coli persister cells from a dormant to a metabolically active state without an increase in cell number. This cell awakening is supported by an increase of the persister cells' respiratory activity together with changes in protein abundance and increases of the transcript expression levels of several metabolic markers, including acpP, 16S rRNA, atpH, and ppx. Given that most antimicrobials target actively growing cells, we also explored the effect of cis-DA on enhancing antibiotic efficacy in killing persister cells due to their inability to keep a persister cell state. Compared to antimicrobial treatment alone, combinational treatments of persister cell subpopulations with antimicrobials and cis-DA resulted in a significantly greater decrease in cell viability. In addition, the presence of cis-DA led to a decrease in the number of persister cells isolated. We thus demonstrate the ability of a fatty acid signaling molecule to revert bacterial cells from a tolerant phenotype to a metabolically active, antimicrobial-sensitive state. PMID:25192989

  13. Persistent Long-Term Facilitation at an Identified Synapse Becomes Labile with Activation of Short-Term Heterosynaptic Plasticity

    PubMed Central

    Schacher, Samuel

    2014-01-01

    Short-term and long-term synaptic plasticity are cellular correlates of learning and memory of different durations. Little is known, however, how these two forms of plasticity interact at the same synaptic connection. We examined the reciprocal impact of short-term heterosynaptic or homosynaptic plasticity at sensorimotor synapses of Aplysia in cell culture when expressing persistent long-term facilitation (P-LTF) evoked by serotonin [5-hydroxytryptamine (5-HT)]. Short-term heterosynaptic plasticity induced by 5-HT (facilitation) or the neuropeptide FMRFa (depression) and short-term homosynaptic plasticity induced by tetanus [post-tetanic potentiation (PTP)] or low-frequency stimulation [homosynaptic depression (HSD)] of the sensory neuron were expressed in both control synapses and synapses expressing P-LTF in the absence or presence of protein synthesis inhibitors. All forms of short-term plasticity failed to significantly affect ongoing P-LTF in the absence of protein synthesis inhibitors. However, P-LTF reversed to control levels when either 5-HT or FMRFa was applied in the presence of rapamycin. In contrast, P-LTF was unaffected when either PTP or HSD was evoked in the presence of either rapamycin or anisomycin. These results indicate that synapses expressing persistent plasticity acquire a “new” baseline and functionally express short-term changes as naive synapses, but the new baseline becomes labile following selective activations—heterosynaptic stimuli that evoke opposite forms of plasticity—such that when presented in the presence of protein synthesis inhibitors produce a rapid reversal of the persistent plasticity. Activity-selective induction of a labile state at synapses expressing persistent plasticity may facilitate the development of therapies for reversing inappropriate memories. PMID:24695698

  14. Association Between Three eNOS Polymorphisms and Intracranial Aneurysms Risk

    PubMed Central

    Yang, Chao; Qi, Zhen-yu; Shao, Chuan; Xing, Wei-kang; Wang, Zhong

    2015-01-01

    Abstract Endothelial nitric oxide synthase (eNOS) is the catalyst of endothelial nitric oxide (NO) synthesis. Polymorphisms in the eNOS gene may influence the risk of intracranial aneurysm (IA), but the results of existing researches are still inconsistent. Thus, we performed the present meta-analysis to derive a more precise estimation between eNOS polymorphisms (T786C, G894T, 27-bp-variable number of tandem repeat [VNTR]) and IA risk. Case–control studies evaluating the association between the eNOS polymorphisms and IA risk were searched in PubMed, Ovid & Embase, Web of Science, and Chinese Wanfang datasets with the last search up to July 15, 2014. The pooled odds ratios (ORs) for the association between eNOS polymorphisms and IA and their corresponding 95% confidence intervals (CIs) were estimated using the random or fixed-effects model. Finally, 10 studies for T786C polymorphism (1819 cases and 1893 controls), 9 studies for G894T polymorphism (1393 cases and 1508 controls), and 7 studies for 27-bp-VNTR polymorphism (1281 cases and 1406 controls) were included in the meta-analyses. In the overall analysis, no evidence of association between eNOS polymorphisms and susceptibility of IA was found. When subgrouped by race descent, significantly increased risk was detected among Asians for T786C polymorphism (heterozygous comparison of codominant model: OR = 1.294, 95% CI = 1.025–1.634; dominant model: OR = 1.277, 95% CI = 1.019–1.600), but not in Caucasians or the other 2 polymorphisms. Our meta-analysis suggested that T786C polymorphism was associated with increased risk of IA among Asians, whereas G894T and 27-bp-VNTR polymorphisms might have no influence on the susceptibility of IA. PMID:25634184

  15. Genetic variants of eNOS gene may modify the susceptibility to idiopathic male infertility.

    PubMed

    Ying, Hou-Qun; Pu, Xiao-Ying; Liu, Shuo-Ran; A, Zhou-Cun

    2013-08-01

    In testis, eNOS is responsible for synthesis of nitric oxide (NO) which is an essential gas message regulator in spermatogenesis, suggesting that eNOS gene plays a role in normal spermatogenesis and the genetic variants of eNOS gene may be potential genetic risk factors of spermatogenesis impairment. In this study, the polymorphic distributions of three common polymorphism loci including T-786C, 4A4B and G894T in eNOS gene were investigated in 355 Chinese infertile patients with azoospermia or oligozoospermia and 246 healthy fertile men and a meta-analysis was carried in order to explore the possible relationship between the three loci of eNOS gene and male infertility with spermatogenesis impairment. As a result, allele -786C of T-786C (11.4% versus 6.5%, p = 0.004) and 4A of 4A4B (11.0% versus 6.3%, p = 0.005) as well as genotype TC of T-786C (22.8% versus 13.0%, p = 0.002) and AB of 4A4B (18% versus 11%, p = 0.015) were significantly associated with idiopathic male infertility. The haplotypes T-4A-G (7.4% versus 4.1%, p = 0.015) and C-4B-G (7.6% versus 4.4%, p = 0.028) could increase the susceptibility to male infertility, whereas haplotype T-4B-G (67.0% versus 75.2%, p = 0.002) might be a protective factor for male infertility. The results of meta-analysis revealed that the polymorphism of T-786C was associated with male infertility. These findings suggested that the variants of eNOS gene may modify the susceptibility to male infertility with impaired spermatogenesis.

  16. Geochemical heterogeneities and dynamics of magmas inside the plumbing system of a persistently active volcano: evidences from Stromboli

    NASA Astrophysics Data System (ADS)

    Pompilio, Massimo; Bertagnini, Antonella; Métrich, Nicole; Belhadj, Oulfa

    2010-05-01

    Shallow processes such as degassing, crystallization and magma drain-back commonly operate in the upper parts of the plumbing systems of open-conduit basaltic volcanoes, often hindering the identification of potentially important geochemical changes in the volcano systems. Stromboli, known for its long-lived persistent activity over the last 18 centuries, is a suitable subject of study for addressing this issue, since basaltic magmas presently erupting at in this volcano record both deep and shallow processes. We report petrological and geochemical data on magmas erupted by Stromboli since the beginning of the persistent activity, in order to find a correlation between magma composition and the dynamics of magma in the plumbing system. Geochemical data on deep-derived magmas erupted as pumice during paroxysmal eruptions allowed us to identify two distinct parental melts (1944- and 2003-Type). These magmas, in which geochemical differences are linked to source processes rather than crystal fractionation, have alternately fed the deep reservoir in the last two millennia several times. The chemical heterogeneities recorded in lava flows and the products of Strombolian activity testify to the extent of homogenization after magma recharges at shallow depths. Persistent heterogeneities in the shallow plumbing system have important implications for magma residence times calculated on the basis of time-series analysis. These models are based on the assumptions that the reservoir is well stirred and chemically homogeneous and that the time for the re-homogenization after recharge (or mixing) is shorter than the residence time. We argue that these models do not apply to present-day activity at Stromboli and may not apply to other open-conduit, persistently degassing basaltic volcanoes. Thus compositional variations within the shallow magma bodies provide only a biased signal of ongoing changes within the plumbing system. We conclude that source changes responsible for

  17. Persistent activation of DNA damage signaling in response to complex mixtures of PAHs in air particulate matter.

    PubMed

    Jarvis, Ian W H; Bergvall, Christoffer; Bottai, Matteo; Westerholm, Roger; Stenius, Ulla; Dreij, Kristian

    2013-02-01

    Complex mixtures of polycyclic aromatic hydrocarbons (PAHs) are present in air particulate matter (PM) and have been associated with many adverse human health effects including cancer and respiratory disease. However, due to their complexity, the risk of exposure to mixtures is difficult to estimate. In the present study the effects of binary mixtures of benzo[a]pyrene (BP) and dibenzo[a,l]pyrene (DBP) and complex mixtures of PAHs in urban air PM extracts on DNA damage signaling was investigated. Applying a statistical model to the data we observed a more than additive response for binary mixtures of BP and DBP on activation of DNA damage signaling. Persistent activation of checkpoint kinase 1 (Chk1) was observed at significantly lower BP equivalent concentrations in air PM extracts than BP alone. Activation of DNA damage signaling was also more persistent in air PM fractions containing PAHs with more than four aromatic rings suggesting larger PAHs contribute a greater risk to human health. Altogether our data suggests that human health risk assessment based on additivity such as toxicity equivalency factor scales may significantly underestimate the risk of exposure to complex mixtures of PAHs. The data confirms our previous findings with PAH-contaminated soil (Niziolek-Kierecka et al., 2012) and suggests a possible role for Chk1 Ser317 phosphorylation as a biological marker for future analyses of complex mixtures of PAHs. Copyright © 2012 Elsevier Inc. All rights reserved.

  18. High-order ENO schemes applied to two- and three-dimensional compressible flow

    NASA Technical Reports Server (NTRS)

    Shu, Chi-Wang; Erlebacher, Gordon; Zang, Thomas A.; Whitaker, David; Osher, Stanley

    1991-01-01

    High order essentially non-oscillatory (ENO) finite difference schemes are applied to the 2-D and 3-D compressible Euler and Navier-Stokes equations. Practical issues, such as vectorization, efficiency of coding, cost comparison with other numerical methods, and accuracy degeneracy effects, are discussed. Numerical examples are provided which are representative of computational problems of current interest in transition and turbulence physics. These require both nonoscillatory shock capturing and high resolution for detailed structures in the smooth regions and demonstrate the advantage of ENO schemes.

  19. Effects of cycling exercise on vigor, fatigue, and electroencephalographic activity among young adults who report persistent fatigue.

    PubMed

    Dishman, Rod K; Thom, Nathaniel J; Puetz, Timothy W; O'Connor, Patrick J; Clementz, Brett A

    2010-11-01

    We previously reported that 6 weeks of exercise training had positive effects on feelings of vigor and fatigue among college students who reported persistent fatigue. Here we examined whether transient mood changes after single sessions of exercise would mimic those chronic effects and whether they would be related to changes in brain activity measured by electroencephalography (EEG). Feelings of vigor were higher after both low- and moderate-intensity exercise during Weeks 1, 3, and 6 compared to a control condition. Feelings of fatigue were lower after low-intensity exercise during Weeks 3 and 6. Posterior theta activity accounted for about half the changes in vigor. Studies that manipulate mood, EEG activity, or both during exercise are needed to determine whether EEG changes after exercise are causally linked with mood.

  20. eNOS uncoupling in the cerebellum after BBB disruption by exposure to Phoneutria nigriventer spider venom.

    PubMed

    Soares, Edilene Siqueira; Mendonça, Monique Culturato Padilha; da Cruz-Höfling, Maria Alice

    2015-09-15

    Numerous studies have shown that the venom of Phoneutria nigriventer (PNV) armed-spider causes excitotoxic signals and blood-brain barrier breakdown (BBBb) in rats. Nitric oxide (NO) is a signaling molecule which has a role in endothelium homeostasis and vascular health. The present study investigated the relevance of endothelial NO synthase (eNOS) uncoupling to clinical neurotoxic evolution induced by PNV. eNOS immunoblotting of cerebellum lysates processed through low-temperature SDS-PAGE revealed significant increased monomerization of the enzyme at critical periods of severe envenoming (1-2 h), whereas eNOS dimerization reversal paralleled to amelioration of animals condition (5-72 h). Moreover, eNOS uncoupling was accompanied by increased expression in calcium-sensing calmodulin protein and calcium-binding calbindin-D28 protein in cerebellar neurons. It is known that greater eNOS monomers than dimers implies the inability of eNOS to produce NO leading to superoxide production and endothelial/vascular barrier dysfunction. We suggest that transient eNOS deactivation and disturbances in calcium handling reduce NO production and enhance production of free radicals thus contributing to endothelial dysfunction in the cerebellum of envenomed rats. In addition, eNOS uncoupling compromises the enzyme capacity to respond to shear stress contributing to perivascular edema and it is one of the mechanisms involved in the BBBb promoted by PNV. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. Altered Endometrial Expression of Endothelial Nitric oxide Synthase (eNOS) in women with Unexplained Recurrent Miscarriage and Infertility

    PubMed Central

    Najafi, Tohid; Novin, Marefat Ghaffari; Ghazi, Reza; Khorram, Omid

    2012-01-01

    Background Endothelial nitric oxide synthase (eNOS) has diverse roles in the female reproductive system including a role in blastocyst implantation. Aberrant expression of eNOS could therefore be significant in the pathogenesis of disorders of implantation Materials and Methods eNOS protein and mRNA levels in the endometrium of women with recurrent miscarriages, unexplained infertility, and a control group was determined by compartmental quantitative immunohistochemistry and real time RT-PCR Results eNOS was immunolocalized to all layers of the endometrium and the vascular endothelium. eNOS protein expression was higher in glandular epithelium (P=0.004) and luminal epithelium (P=0.002) but not vascular endothelium and stroma (P=0.14) in women with recurrent miscarriage. Similarly, in women with unexplained infertility eNOS expression was significantly higher (P<0.03) in luminal epithelium but not in any other compartments compared with the control group. The levels of mRNA expression as determined by real time RT-PCR confirmed the protein data demonstrating higher eNOS mRNA expression In the endometrium of women with recurrent miscarriage and unexplained infertility compared with controls Conclusion Increased expression of eNOS in glandular and luminal epithelium of the endometrium in women with recurrent miscarriages and unexplained infertility suggests a detrimental effect of excess nitric oxide in endometrial receptivity and implantation PMID:22877939

  2. Persistence of HIV-1 structural proteins and glycoproteins in lymph nodes of patients under highly active antiretroviral therapy.

    PubMed

    Popovic, Mikulas; Tenner-Racz, Klara; Pelser, Colleen; Stellbrink, Hans-Jurgen; van Lunzen, Jan; Lewis, George; Kalyanaraman, Vaniambadi S; Gallo, Robert C; Racz, Paul

    2005-10-11

    Here we report a long-term persistence of HIV-1 structural proteins and glycoproteins in germinal centers (GCs) of lymph nodes (LNs) in the absence of detectable virus replication in patients under highly active antiretroviral therapy (HAART). The persistence of viral structural proteins and glycoproteins in GCs was accompanied by specific antibody responses to HIV-1. Seven patients during the chronic phase of HIV-1 infection were analyzed for the presence of the capsid protein (HIV-1p24), matrix protein (HIV-1p17), and envelope glycoproteins (HIV-1gp120/gp41), as well as for viral RNA (vRNA) in biopsy specimens from LNs obtained before initiation of therapy and during HAART that lasted from 5 to 13 months. In parallel, these patients were also monitored for viremia and specific anti-HIV-1 antibody responses to structural proteins and glycoproteins both before and during treatment. Before-therapy viral levels, as determined by RT-PCR, ranged from 3 x 10(3) to 6.3 x 10(5) copies of vRNA per ml, whereas during treatment, vRNA was under detectable levels (<25 copies per ml). The pattern of vRNA detection in peripheral blood was concordant with in situ hybridization results of LN specimens. Before treatment, vRNA associated with follicular dendritic cells (FDCs) was readily detected in GCs of LNs of the patients, whereas during therapy, vRNA was consistently absent in the GCs of LN biopsies of treated patients. In contrast to vRNA hybridization results, viral structural proteins and glycoproteins, evaluated by immunohistochemical staining, were present and persisted in the GC light zone of LNs in abundant amounts not only before initiation of therapy but also during HAART, when no vRNA was detected in GCs. Consistent with immunohistochemical findings, specific antibody responses to HIV-1p17, -p24, and -gp120/gp41, as evaluated by ELISA and virus neutralization, persisted in patients under therapy for up to 13 months of follow-up. The implications of these findings are

  3. Fentanyl, but not haloperidol, entrains persisting circadian activity episodes when administered at 24- and 31-hour intervals

    PubMed Central

    Leffel, Joseph K.; Kosobud, Ann E; Timberlake, William

    2009-01-01

    Administration of several drugs of abuse on a 24-hour schedule has been shown to entrain both pre-drug (anticipatory) and post-drug (evoked) circadian activity episodes that persist for several days when the drug is withheld. The present tested the entrainment effects of fentanyl, an opioid agonist with a noted abuse liability, and haloperidol, an antipsychotic dopamine antagonist without apparent abuse liability. Adult female Sprague-Dawley rats housed under constant light in cages with attached running wheels received repeated low, medium, or high doses of either fentanyl or haloperidol on a 24-hour administration schedule followed by a 31-hour schedule (Experiment 1) or solely on a 31-hour schedule (Experiment 2). The results showed that all three doses of fentanyl entrained both pre-drug and post-drug episodes of wheel running when administered every 24░hours, and the combined pre- and post-fentanyl activity episodes persist for at least 3 days when the drug is withheld during test days. On the 31-hour schedule, fentanyl produced an ``ensuing" activity episode approximately 24░hours post-administration, but failed to produce an anticipatory episode 29–31░hours post-administration. In contrast, haloperidol injections failed to produce both pre-drug episodes on the 24-hour schedule and circadian ensuing episodes on the 31-hour schedule, and post-haloperidol suppression of activity appeared to mask the freerunning activity rhythm. Taken together, these results provide additional evidence that drugs of abuse share a common ability to entrain circadian activity episodes. PMID:19595707

  4. Fifth Grade Students' Experiences Participating in Active Gaming in Physical Education: The Persistence to Game

    ERIC Educational Resources Information Center

    Hansen, Lisa; Sanders, Steve

    2010-01-01

    Although video games are often associated with sedentary behaviors, active gaming is a new genre that requires children to become physically active while playing the games. In this study six fifth grade students' experiences participating in active gaming in eight-week physical education classes were explored. Qualitative methods of interviews,…

  5. Target sequencing, cell experiments, and a population study establish endothelial nitric oxide synthase (eNOS) gene as hypertension susceptibility gene.

    PubMed

    Salvi, Erika; Kuznetsova, Tatiana; Thijs, Lutgarde; Lupoli, Sara; Stolarz-Skrzypek, Katarzyna; D'Avila, Francesca; Tikhonoff, Valerie; De Astis, Silvia; Barcella, Matteo; Seidlerová, Jitka; Benaglio, Paola; Malyutina, Sofia; Frau, Francesca; Velayutham, Dinesh; Benfante, Roberta; Zagato, Laura; Title, Alexandra; Braga, Daniele; Marek, Diana; Kawecka-Jaszcz, Kalina; Casiglia, Edoardo; Filipovsky, Jan; Nikitin, Yuri; Rivolta, Carlo; Manunta, Paolo; Beckmann, Jacques S; Barlassina, Cristina; Cusi, Daniele; Staessen, Jan A

    2013-11-01

    A case-control study revealed association between hypertension and rs3918226 in the endothelial nitric oxide synthase (eNOS) gene promoter (minor/major allele, T/C allele). We aimed at substantiating these preliminary findings by target sequencing, cell experiments, and a population study. We sequenced the 140-kb genomic area encompassing the eNOS gene. In HeLa and HEK293T cells transfected with the eNOS promoter carrying either the T or the C allele, we quantified transcription by luciferase assay. In 2722 randomly recruited Europeans (53.0% women; mean age 40.1 years), we studied blood pressure change and incidence of hypertension in relation to rs3918226, using multivariable-adjusted models. Sequencing confirmed rs3918226, a binding site of E-twenty six transcription factors, as the single nucleotide polymorphism most closely associated with hypertension. In T compared with C transfected cells, eNOS promoter activity was from 20% to 40% (P<0.01) lower. In the population, systolic/diastolic blood pressure increased over 7.6 years (median) by 9.7/6.8 mm Hg in 28 TT homozygotes and by 3.8/1.9 mm Hg in 2694 C allele carriers (P≤0.0004). The blood pressure rise was 5.9 mm Hg systolic (confidence interval [CI], 0.6-11.1; P=0.028) and 4.8 mm Hg diastolic (CI, 1.5-8.2; P=0.0046) greater in TT homozygotes, with no differences between the CT and CC genotypes (P≥0.90). Among 2013 participants normotensive at baseline, 692 (34.4%) developed hypertension. The hazard ratio and attributable risk associated with TT homozygosity were 2.04 (CI, 1.24-3.37; P=0.0054) and 51.0%, respectively. In conclusion, rs3918226 in the eNOS promoter tags a hypertension susceptibility locus, TT homozygosity being associated with lesser transcription and higher risk of hypertension.

  6. Interstitial chromatin alteration causes persistent p53 activation involved in the radiation-induced senescence-like growth arrest

    SciTech Connect

    Suzuki, Masatoshi; Suzuki, Keiji; Kodama, Seiji; Watanabe, Masami . E-mail: nabe@rri.kyoto-u.ac.jp

    2006-02-03

    Various stresses including ionizing radiation give normal human fibroblasts a phenotype of senescence-like growth arrest (SLGA), manifested by p53-dependent irreversible G1 arrest. To determine the mechanism of persistent activation of p53, we examined phosphorylated Ataxia telangiectasia mutated (ATM) and phosphorylated histone H2AX foci formation after X-irradiation. Although the multiple tiny foci, detected soon after (<30 min) irradiation, gradually disappeared, some of these foci changed to large foci and persisted for 5 days. Large foci containing phosphorylated ATM and {gamma}-H2AX co-localized and foci with p53 phosphorylated at serine 15 also showed the same distribution. Interestingly, the signals obtained by telomere fluorescence in situ hybridization (FISH) assay did not co-localize with 90% of the large foci. Our results indicate that chromatin alteration in interstitial chromosomal regions is the most likely cause of continuous activation of p53, which results in the induction of SLGA by ionizing radiation.

  7. The Mycobacterium tuberculosis proteasome active site threonine is essential for persistence yet dispensable for replication and resistance to nitric oxide.

    PubMed

    Gandotra, Sheetal; Lebron, Maria B; Ehrt, Sabine

    2010-08-12

    Previous work revealed that conditional depletion of the core proteasome subunits PrcB and PrcA impaired growth of Mycobacterium tuberculosis in vitro and in mouse lungs, caused hypersusceptibility to nitric oxide (NO) and impaired persistence of the bacilli during chronic mouse infections. Here, we show that genetic deletion of prcBA led to similar phenotypes. Surprisingly, however, an active site mutant proteasome complemented the in vitro and in vivo growth defects of the prcBA knockout (Delta prcBA) as well as its NO hypersensitivity. In contrast, long-term survival of M. tuberculosis in stationary phase and during starvation in vitro and in the chronic phase of mouse infection required a proteolytically active proteasome. Inhibition of inducible nitric oxide synthase did not rescue survival of Delta prcBA, revealing a function beyond NO defense, by which the proteasome contributes to M. tuberculosis fitness during chronic mouse infections. These findings suggest that proteasomal proteolysis facilitates mycobacterial persistence, that M. tuberculosis faces starvation during chronic mouse infections and that the proteasome serves a proteolysis-independent function.

  8. The Mycobacterium tuberculosis Proteasome Active Site Threonine Is Essential for Persistence Yet Dispensable for Replication and Resistance to Nitric Oxide

    PubMed Central

    Gandotra, Sheetal; Lebron, Maria B.; Ehrt, Sabine

    2010-01-01

    Previous work revealed that conditional depletion of the core proteasome subunits PrcB and PrcA impaired growth of Mycobacterium tuberculosis in vitro and in mouse lungs, caused hypersusceptibility to nitric oxide (NO) and impaired persistence of the bacilli during chronic mouse infections. Here, we show that genetic deletion of prcBA led to similar phenotypes. Surprisingly, however, an active site mutant proteasome complemented the in vitro and in vivo growth defects of the prcBA knockout (ΔprcBA) as well as its NO hypersensitivity. In contrast, long-term survival of M. tuberculosis in stationary phase and during starvation in vitro and in the chronic phase of mouse infection required a proteolytically active proteasome. Inhibition of inducible nitric oxide synthase did not rescue survival of ΔprcBA, revealing a function beyond NO defense, by which the proteasome contributes to M. tuberculosis fitness during chronic mouse infections. These findings suggest that proteasomal proteolysis facilitates mycobacterial persistence, that M. tuberculosis faces starvation during chronic mouse infections and that the proteasome serves a proteolysis-independent function. PMID:20711362

  9. Tonic Nanomolar Dopamine Enables an Activity-Dependent Phase Recovery Mechanism That Persistently Alters the Maximal Conductance of the Hyperpolarization-Activated Current in a Rhythmically Active Neuron

    PubMed Central

    Rodgers, Edmund W.; Fu, Jing Jing; Krenz, Wulf-Dieter C.

    2011-01-01

    The phases at which network neurons fire in rhythmic motor outputs are critically important for the proper generation of motor behaviors. The pyloric network in the crustacean stomatogastric ganglion generates a rhythmic motor output wherein neuronal phase relationships are remarkably invariant across individuals and throughout lifetimes. The mechanisms for maintaining these robust phase relationships over the long-term are not well described. Here we show that tonic nanomolar dopamine (DA) acts at type 1 DA receptors (D1Rs) to enable an activity-dependent mechanism that can contribute to phase maintenance in the lateral pyloric (LP) neuron. The LP displays continuous rhythmic bursting. The activity-dependent mechanism was triggered by a prolonged decrease in LP burst duration, and it generated a persistent increase in the maximal conductance (Gmax) of the LP hyperpolarization-activated current (Ih), but only in the presence of steady-state DA. Interestingly, micromolar DA produces an LP phase advance accompanied by a decrease in LP burst duration that abolishes normal LP network function. During a 1 h application of micromolar DA, LP phase recovered over tens of minutes because, the activity-dependent mechanism enabled by steady-state DA was triggered by the micromolar DA-induced decrease in LP burst duration. Presumably, this mechanism restored normal LP network function. These data suggest steady-state DA may enable homeostatic mechanisms that maintain motor network output during protracted neuromodulation. This DA-enabled, activity-dependent mechanism to preserve phase may be broadly relevant, as diminished dopaminergic tone has recently been shown to reduce Ih in rhythmically active neurons in the mammalian brain. PMID:22072689

  10. Tonic nanomolar dopamine enables an activity-dependent phase recovery mechanism that persistently alters the maximal conductance of the hyperpolarization-activated current in a rhythmically active neuron.

    PubMed

    Rodgers, Edmund W; Fu, Jing Jing; Krenz, Wulf-Dieter C; Baro, Deborah J

    2011-11-09

    The phases at which network neurons fire in rhythmic motor outputs are critically important for the proper generation of motor behaviors. The pyloric network in the crustacean stomatogastric ganglion generates a rhythmic motor output wherein neuronal phase relationships are remarkably invariant across individuals and throughout lifetimes. The mechanisms for maintaining these robust phase relationships over the long-term are not well described. Here we show that tonic nanomolar dopamine (DA) acts at type 1 DA receptors (D1Rs) to enable an activity-dependent mechanism that can contribute to phase maintenance in the lateral pyloric (LP) neuron. The LP displays continuous rhythmic bursting. The activity-dependent mechanism was triggered by a prolonged decrease in LP burst duration, and it generated a persistent increase in the maximal conductance (G(max)) of the LP hyperpolarization-activated current (I(h)), but only in the presence of steady-state DA. Interestingly, micromolar DA produces an LP phase advance accompanied by a decrease in LP burst duration that abolishes normal LP network function. During a 1 h application of micromolar DA, LP phase recovered over tens of minutes because, the activity-dependent mechanism enabled by steady-state DA was triggered by the micromolar DA-induced decrease in LP burst duration. Presumably, this mechanism restored normal LP network function. These data suggest steady-state DA may enable homeostatic mechanisms that maintain motor network output during protracted neuromodulation. This DA-enabled, activity-dependent mechanism to preserve phase may be broadly relevant, as diminished dopaminergic tone has recently been shown to reduce I(h) in rhythmically active neurons in the mammalian brain.

  11. Mg-supplementation Protects Against Ritonavir-mediated Endothelial Oxidative Stress and Hepatic eNOS Downregulation

    PubMed Central

    Chen, Xi; Mak, I.Tong

    2014-01-01

    Ritonavir (RTV), a prototypical protease inhibitor currently used as a key component for anti-HIV therapy, is known for its endothelial and hepatic toxicity. The effects of RTV and Mg-supplementation on cultured bovine endothelial cells (EC) and rat hepatic endothelial nitric oxide synthase (eNOS) status were investigated. RTV dose-dependently (5–30µM) decreased EC viability after 48hrs; high Mg (2 mM) significantly attenuated the lost viability. ECs incubated with 15 µM RTV for 6 to 24 hrs. resulted in 2–4-fold elevation of oxidized glutathione and a 25% loss of total glutathione. At 24 hrs., EC superoxide production due to RTV was detected by dihydroethidium staining, and increased 41% when quantified by flow cytometry; both altered glutathione status and superoxide levels were substantially reversed by 2 mM Mg. RTV reduced eNOS mRNA (−25% at 24 hrs.), and led to decreased eNOS dimer/monomer ratios; nitric oxide (NO)-derived products decreased 40%; both changes were attenuated by Mg-supplementation. In male LewXBrown-Norway rats, RTV administration (75 mg/kg/day, 5 weeks) resulted in an 85% increase in plasma 8-isoprostane, a 30% decrease of hepatic eNOS mRNA; concomitantly, eNOS protein decreased 72%, whereas plasma nitrite level was reduced 49%. Dietary Mg-supplementation (6-fold higher than control) prevented the eNOS mRNA decrease along with lowering 8-isoprostane, and restored the eNOS protein and plasma nitrite levels comparable to controls. Conclusion Mg attenuates RTV-mediated EC oxidative eNOS dysfunction, and down-regulation of hepatic eNOS expression; we suggest that Mg can serve as a beneficial adjunct therapeutic against RTV-mediated eNOS toxicity. PMID:24434120

  12. Positron emission tomography detects tissue metabolic activity in myocardial segments with persistent thallium perfusion defects

    SciTech Connect

    Brunken, R.; Schwaiger, M.; Grover-McKay, M.; Phelps, M.E.; Tillisch, J.; Schelbert, H.R.

    1987-09-01

    Positron emission tomography with /sup 13/N-ammonia and /sup 18/F-2-deoxyglucose was used to assess myocardial perfusion and glucose utilization in 51 myocardial segments with a stress thallium defect in 12 patients. Myocardial infarction was defined by a concordant reduction in segmental perfusion and glucose utilization, and myocardial ischemia was identified by preservation of glucose utilization in segments with rest hypoperfusion. Of the 51 segments studied, 36 had a fixed thallium defect, 11 had a partially reversible defect and 4 had a completely reversible defect. Only 15 (42%) of the 36 segments with a fixed defect and 4 (36%) of the 11 segments with a partially reversible defect exhibited myocardial infarction on study with positron tomography. In contrast, residual myocardial glucose utilization was identified in the majority of segments with a fixed (58%) or a partially reversible (64%) thallium defect. All of the segments with a completely reversible defect appeared normal on positron tomography. Apparent improvement in the thallium defect on delayed images did not distinguish segments with ischemia from infarction. Thus, positron emission tomography reveals evidence of persistent tissue metabolism in the majority of segments with a fixed or partially resolving stress thallium defect, implying that markers of perfusion alone may underestimate the extent of viable tissue in hypoperfused myocardial segments.

  13. The South Atlantic Convergence Zone: Intensity, Form, Persistence, and Relationships with Intraseasonal to Interannual Activity and Extreme Rainfall.

    NASA Astrophysics Data System (ADS)

    Carvalho, Leila M. V.; Jones, Charles; Liebmann, Brant

    2004-01-01

    The characteristics of intensity, geographical location, and persistence of the South Atlantic convergence zone (SACZ) during the austral summer are investigated. Intensity and spatial features of the SACZ are identified by performing a factor analysis of structural properties of outgoing longwave radiation (OLR) data. The first two leading factors explain 65% of the total variance of structural properties and characterize the SACZ according to intensity and location (oceanic versus continental). An index is constructed based on the magnitude of the factor scores to identify intense (weak) and oceanic (continental) SACZ. The intense SACZ category is associated with negative OLR anomalies over a large area of tropical South America, extending from the western Amazon to the Atlantic Ocean. The weak SACZ category is observed with positive OLR anomalies over tropical South America and negative OLR anomalies over southeastern South America. Oceanic and continental aspects of the SACZ are related to a midlatitude wave train pattern. The Madden Julian oscillation (MJO) modulates intense SACZ events with persistence longer than 3 days. Interannual variability of persistent events indicates that the ratio of oceanic to continental SACZ as well as their frequency depends on the phase of El Niño Southern Oscillation (ENSO). Occurrence of extreme rainfall in Brazil is discussed in the context of variations in the SACZ and MJO. Intense (weak) SACZ increases (decreases) the 95th daily rainfall percentile over central-eastern Brazil compared to the climatology. Oceanic (continental) SACZ increases (decreases) the 95th daily rainfall percentile over southeastern Brazil. The MJO phase characterized by suppression of convective activity over Indonesia and enhancement over the central Pacific increases the 95th daily rainfall percentile over north-northeastern Brazil, whereas opposite features are observed for the phase of the MJO characterized by the enhancement of convection over

  14. Increased fermentation activity and persistent methanogenesis in a model aquifer system following source removal of an ethanol blend release.

    PubMed

    Ma, Jie; Rixey, William G; Alvarez, Pedro J J

    2015-01-01

    The increased probability of groundwater contamination by ethanol-blended fuel calls for improved understanding of how remediation efforts affect the fate and transport of constituents of concern, including the generation and fate of fermentation byproducts. A pilot-scale (8 m³) model aquifer was used to investigate changes in the concentrations of ethanol and its metabolites (methane and volatile fatty acids) after removal of the contamination source. Following the shut-off of a continuous release of a dissolved ethanol blend (10% v:v ethanol, 50 mg/L benzene, and 50 mg/L toluene), fermentation activity was surprisingly stimulated and the concentrations of ethanol metabolites increased. A microcosm experiment showed that this result was due to a decrease in the dissolved ethanol concentration below its toxicity threshold (∼2000 mg/L for this system). Methane generation (>1.5 mg/L of dissolved methane) persisted for more than 100 days after the disappearance of ethanol, despite clean air-saturated water flowing continuously through the tank at a relative high seepage velocity (0.76 m/day). Quantitative real-time PCR showed that functional genes associated with methane metabolism (mcrA for methanogenesis and pmoA for methanotrophy) also persisted in the aquifer material. Persistent methanogenesis was apparently due to the anaerobic degradation of soil-bound organic carbon (e.g., biomass grown on ethanol and other substrates). Overall, this study reflects the complex plume dynamics following source removal, and suggests that monitoring for increases in the concentration of ethanol metabolites that impact groundwater quality should be considered.

  15. X-ray-Activated Near-Infrared Persistent Luminescent Probe for Deep-Tissue and Renewable in Vivo Bioimaging.

    PubMed

    Xue, Zhenluan; Li, Xiaolong; Li, Youbin; Jiang, Mingyang; Liu, Hongrong; Zeng, Songjun; Hao, Jianhua

    2017-07-12

    Near-infrared (NIR) persistent luminescence nanoparticles (PLNPs) are considered as new alternative optical probes due to being free of autofluorescence, benefited from the self-sustained emission after excitation and high signal-to-noise ratio. However, the NIR-emitted PLNPs always present a short decay time and require excitation by ultraviolet or visible light with a short penetrable depth, remarkably hindering their applications for in vivo long-term tracking and imaging. Therefore, it is important to develop NIR-emitted PLNPs with in vivo activation nature by new excitation sources with deeper penetrating depths. Here, we propose a new type of X-ray-activated ZnGa2O4:Cr PLNPs (X-PLNPs) with efficient NIR persistent emission and rechargeable activation features, in which both the excitation and emission possess a high penetrable nature in vivo. These X-PLNPs exhibit long-lasting, up to 6 h, NIR emission at 700 nm after the stoppage of the X-ray excitation source. More importantly, the designed X-PLNPs can be readily reactivated by a soft X-ray excitation source with low excitation power (45 kVp, 0.5 mA) to restore in vivo bioimaging signals even at 20 mm depth. Renewable in vivo whole-body bioimaging was also successfully achieved via intravenous injection/oral administration of X-PLNPs after in situ X-ray activation. This is the first time that NIR-emitted PLNPs have been demonstrated to be recharged by X-ray light for deep-tissue in vivo bioimaging, which paves the way for in vivo renewable bioimaging using PLNPs and makes the PLNPs more competitive in bioimaging area.

  16. Activation of cannabinoid receptors by the pentacyclic triterpene α,β-amyrin inhibits inflammatory and neuropathic persistent pain in mice.

    PubMed

    da Silva, Kathryn A B Simão; Paszcuk, Ana F; Passos, Giselle F; Silva, Eduardo S; Bento, Allisson Freire; Meotti, Flavia C; Calixto, João B

    2011-08-01

    In this study, we report that α,β-amyrin, a plant-derived pentacyclic triterpene, reduced persistent inflammatory and neuropathic hyperalgesia in mice by a direct activation of the CB(1) and CB(2) cannabinoid receptors (CB(1)R and CB(2)R). The oral treatment with α,β-amyrin (30 mg/kg) significantly reduced mechanical and thermal hyperalgesia and inflammation induced by complete Freund's adjuvant (CFA) and by partial sciatic nerve ligation (PSNL). The pretreatment with either CB(1)R or CB(2)R antagonists and the knockdown gene of the receptors significantly reverted the antinociceptive effect of α,β-amyrin. Of note, binding studies showed that α,β-amyrin directly bound with very high affinity to CB(1)R (K(i)=0.133 nM) and with a lower affinity to CB(2)R (K(i)=1989 nM). Interestingly, α,β-amyrin, ACEA (CB(1)R agonist), or JWH-133 (CB(2)R agonist), at doses that caused antinociception, failed to provoke any behavioral disturbance, as measured in the tetrad assay. In addition, α,β-amyrin largely decreased interleukin-1β (IL-1β), tumor necrosis factor α (TNF-α), keratinocyte-derived chemokine (KC) and interleukin 6 (IL-6) levels, and myeloperoxidase activity. Likewise, α,β-amyrin prevented the activation of the transcriptional factors: nuclear factor κB (NF-κB) and cyclic adenosine monophosphate response element binding (CREB) and the expression of cyclooxygenase 2 in mice footpads and spinal cords. The present results demonstrated that α,β-amyrin exhibits long-lasting antinociceptive and anti-inflammatory properties in 2 models of persistent nociception via activation of cannabinoid receptors and by inhibiting the production of cytokines and expression of NF-κB, CREB and cyclooxygenase 2. Copyright © 2011 International Association for the Study of Pain. Published by Elsevier B.V. All rights reserved.

  17. VANADL SULFATE INHIBITS NO PRODUCTION BY DIFFERENTIALLY REGULATING SERINE/THREONINE PHOSPHORYLATION OF ENOS

    EPA Science Inventory

    VANADYL SULFATE INHIBITS NO PRODUCTION BY DIFFERENTIALLY REGULATING SERINE/THREONINE PHOSPHORYLATION OF eNOS. Zhuowei Li, Jacqueline D. Carter, Lisa A. Dailey, Joleen Soukup, Yuh-Chin T. Huang. CEMALB, University of North Carolina and ORD, US EPA, Chapel Hill, North Carolina
    V...

  18. VANADYL SULFATE INHIBITS NO PRODUCTION BY DIFFERENTIALLY REGULATING SERINE/THREONINE PHOSPHORYLATION OF ENOS

    EPA Science Inventory

    VANADYL SULFATE INHIBITS NO PRODUCTION BY DIFFERENTIALLY REGULATING SERINE/THREONINE PHOSPHORYLATION OF eNOS.

    Zhuowei Li, Jacqueline D. Carter, Lisa A. Dailey, Joleen Soukup, Yuh-Chin T. Huang. CEMALB, University of North Carolina and NHEERL, US EPA, Chapel Hill, North Ca...

  19. VANADYL SULFATE INHIBITS NO PRODUCTION BY DIFFERENTIALLY REGULATING SERINE/THREONINE PHOSPHORYLATION OF ENOS

    EPA Science Inventory

    VANADYL SULFATE INHIBITS NO PRODUCTION BY DIFFERENTIALLY REGULATING SERINE/THREONINE PHOSPHORYLATION OF eNOS.

    Zhuowei Li, Jacqueline D. Carter, Lisa A. Dailey, Joleen Soukup, Yuh-Chin T. Huang. CEMALB, University of North Carolina and NHEERL, US EPA, Chapel Hill, North Ca...

  20. VANADL SULFATE INHIBITS NO PRODUCTION BY DIFFERENTIALLY REGULATING SERINE/THREONINE PHOSPHORYLATION OF ENOS

    EPA Science Inventory

    VANADYL SULFATE INHIBITS NO PRODUCTION BY DIFFERENTIALLY REGULATING SERINE/THREONINE PHOSPHORYLATION OF eNOS. Zhuowei Li, Jacqueline D. Carter, Lisa A. Dailey, Joleen Soukup, Yuh-Chin T. Huang. CEMALB, University of North Carolina and ORD, US EPA, Chapel Hill, North Carolina
    V...

  1. Persistent Adaptation by Chronic Alcohol is Facilitated by Neuroimmune Activation Linked to Stress and CRF

    PubMed Central

    Breese, George R.; Knapp, Darin J.

    2016-01-01

    This review updates the conceptual basis for the association of alcohol abuse with an insidious adaptation that facilitates negative affect during withdrawal from chronic intermittent alcohol (CIA) exposure – a change that later supports sensitization of stress-induced anxiety following alcohol abstinence. The finding that a CRF1-receptor antagonist (CRF1RA) minimized CIA withdrawal-induced negative affect supported an association of alcohol withdrawal with a stress mechanism. The finding that repeated stresses or multiple CRF injections into selected brain sites prior to a single 5-day chronic alcohol (CA) exposure induced anxiety during withdrawal provided critical support for a linkage of CIA withdrawal with stress. The determination that CRF1RA injection into positive CRF-sensitive brain sites prevented CIA withdrawal-induced anxiety provided support that neural path integration maintains the persistent CIA adaptation. Based upon reports that stress increases neuroimmune function, an effort was undertaken to test whether cytokines would support the adaptation induced by stress/CA exposure. Twenty-four hours after withdrawal from CIA, cytokine mRNAs were found to be increased in cortex as well as other sites in brain. Further, repeated cytokine injections into previously identified brain sites substituted for stress and CRF induction of anxiety during CA withdrawal. Discovery that a CRF1RA prevented the brain cytokine mRNA increase induced by CA withdrawal provided critical evidence for CRF involvement in this neuroimmune induction after CA withdrawal. However, the CRF1RA did not block the stress increase in cytokine mRNA increases in controls. The latter data supported the hypothesis that distinct mechanisms linked to stress and CA withdrawal can support common neuroimmune functions within a brain site. As evidence evolves concerning neural involvement in brain neuroimmune function, a better understanding of the progressive adaptation associated with CIA

  2. Fusion competent synaptic vesicles persist upon active zone disruption and loss of vesicle docking

    PubMed Central

    Wang, Shan Shan H.; Held, Richard G.; Wong, Man Yan; Liu, Changliang; Karakhanyan, Aziz; Kaeser, Pascal S.

    2016-01-01

    In a nerve terminal, synaptic vesicle docking and release are restricted to an active zone. The active zone is a protein scaffold that is attached to the presynaptic plasma membrane and opposed to postsynaptic receptors. Here, we generated conditional knockout mice removing the active zone proteins RIM and ELKS, which additionally led to loss of Munc13, Bassoon, Piccolo, and RIM-BP, indicating disassembly of the active zone. We observed a near complete lack of synaptic vesicle docking and a strong reduction in vesicular release probability and the speed of exocytosis, but total vesicle numbers, SNARE protein levels, and postsynaptic densities remained unaffected. Despite loss of the priming proteins Munc13 and RIM and of docked vesicles, a pool of releasable vesicles remained. Thus, the active zone is necessary for synaptic vesicle docking and to enhance release probability, but releasable vesicles can be localized distant from the presynaptic plasma membrane. PMID:27537483

  3. Persistent neural activity in auditory cortex is related to auditory working memory in humans and nonhuman primates

    PubMed Central

    Huang, Ying; Matysiak, Artur; Heil, Peter; König, Reinhard; Brosch, Michael

    2016-01-01

    Working memory is the cognitive capacity of short-term storage of information for goal-directed behaviors. Where and how this capacity is implemented in the brain are unresolved questions. We show that auditory cortex stores information by persistent changes of neural activity. We separated activity related to working memory from activity related to other mental processes by having humans and monkeys perform different tasks with varying working memory demands on the same sound sequences. Working memory was reflected in the spiking activity of individual neurons in auditory cortex and in the activity of neuronal populations, that is, in local field potentials and magnetic fields. Our results provide direct support for the idea that temporary storage of information recruits the same brain areas that also process the information. Because similar activity was observed in the two species, the cellular bases of some auditory working memory processes in humans can be studied in monkeys. DOI: http://dx.doi.org/10.7554/eLife.15441.001 PMID:27438411

  4. Persistence of Activated and Adaptive-Like NK Cells in HIV+ Individuals despite 2 Years of Suppressive Combination Antiretroviral Therapy

    PubMed Central

    Hearps, Anna C.; Agius, Paul A.; Zhou, Jingling; Brunt, Samantha; Chachage, Mkunde; Angelovich, Thomas A.; Cameron, Paul U.; Giles, Michelle; Price, Patricia; Elliott, Julian; Jaworowski, Anthony

    2017-01-01

    Innate immune dysfunction persists in HIV+ individuals despite effective combination antiretroviral therapy (cART). We recently demonstrated that an adaptive-like CD56dim NK cell population lacking the signal transducing protein FcRγ is expanded in HIV+ individuals. Here, we analyzed a cohort of HIV+ men who have sex with men (MSM, n = 20) at baseline and following 6, 12, and 24 months of cART and compared them with uninfected MSM (n = 15) to investigate the impact of cART on NK cell dysfunction. Proportions of NK cells expressing markers of early (CD69+) and late (HLA-DR+/CD38+) activation were elevated in cART-naïve HIV+ MSM (p = 0.004 and 0.015, respectively), as were FcRγ− NK cells (p = 0.003). Using latent growth curve modeling, we show that cART did not reduce levels of FcRγ− NK cells (p = 0.115) or activated HLA-DR+/CD38+ NK cells (p = 0.129) but did reduce T cell and monocyte activation (p < 0.001 for all). Proportions of FcRγ− NK cells were not associated with NK cell, T cell, or monocyte activation, suggesting different factors drive CD56dim FcRγ− NK cell expansion and immune activation in HIV+ individuals. While proportions of activated CD69+ NK cells declined significantly on cART (p = 0.003), the rate was significantly slower than the decline of T cell and monocyte activation, indicating a reduced potency of cART against NK cell activation. Our findings indicate that 2 years of suppressive cART have no impact on CD56dim FcRγ− NK cell expansion and that NK cell activation persists after normalization of other immune parameters. This may have implications for the development of malignancies and co-morbidities in HIV+ individuals on cART. PMID:28713370

  5. Persistence of seed-based activity following segmentation of a microRNA guide strand.

    PubMed

    Chorn, Guillaume; Zhao, Lihong; Sachs, Alan B; Flanagan, W Michael; Lim, Lee P

    2010-12-01

    microRNAs are ∼ 22 nucleotide regulatory RNAs that are processed into duplexes from hairpin structures and incorporated into Argonaute proteins. Here, we show that a nick in the middle of the guide strand of an miRNA sequence allows for seed-based targeting characteristic of miRNA activity. Insertion of an inverted abasic, a dye, or a small gap between the two segments still permits target knockdown. While activity from the seed region of the segmented miRNA is apparent, activity from the 3' half of the guide strand is impaired, suggesting that an intact guide backbone is required for contribution from the 3' half. miRNA activity was also observed following nicking of a miRNA precursor. These results illustrate a structural flexibility in miRNA duplexes and may have applications in the design of miRNA mimetics.

  6. Functional coupling between sodium-activated potassium channels and voltage-dependent persistent sodium currents in cricket Kenyon cells.

    PubMed

    Takahashi, Izumi; Yoshino, Masami

    2015-10-01

    In this study, we examined the functional coupling between Na(+)-activated potassium (KNa) channels and Na(+) influx through voltage-dependent Na(+) channels in Kenyon cells isolated from the mushroom body of the cricket Gryllus bimaculatus. Single-channel activity of KNa channels was recorded with the cell-attached patch configuration. The open probability (Po) of KNa channels increased with increasing Na(+) concentration in a bath solution, whereas it decreased by the substitution of Na(+) with an equimolar concentration of Li(+). The Po of KNa channels was also found to be reduced by bath application of a high concentration of TTX (1 μM) and riluzole (100 μM), which inhibits both fast (INaf) and persistent (INaP) Na(+) currents, whereas it was unaffected by a low concentration of TTX (10 nM), which selectively blocks INaf. Bath application of Cd(2+) at a low concentration (50 μM), as an inhibitor of INaP, also decreased the Po of KNa channels. Conversely, bath application of the inorganic Ca(2+)-channel blockers Co(2+) and Ni(2+) at high concentrations (500 μM) had little effect on the Po of KNa channels, although Cd(2+) (500 μM) reduced the Po of KNa channels. Perforated whole cell clamp analysis further indicated the presence of sustained outward currents for which amplitude was dependent on the amount of Na(+) influx. Taken together, these results indicate that KNa channels could be activated by Na(+) influx passing through voltage-dependent persistent Na(+) channels. The functional significance of this coupling mechanism was discussed in relation to the membrane excitability of Kenyon cells and its possible role in the formation of long-term memory. Copyright © 2015 the American Physiological Society.

  7. Persistent Associative Plasticity at an Identified Synapse Underlying Classical Conditioning Becomes Labile with Short-Term Homosynaptic Activation.

    PubMed

    Hu, Jiangyuan; Schacher, Samuel

    2015-12-09

    Synapses express different forms of plasticity that contribute to different forms of memory, and both memory and plasticity can become labile after reactivation. We previously reported that a persistent form of nonassociative long-term facilitation (PNA-LTF) of the sensorimotor synapses in Aplysia californica, a cellular analog of long-term sensitization, became labile with short-term heterosynaptic reactivation and reversed when the reactivation was followed by incubation with the protein synthesis inhibitor rapamycin. Here we examined the reciprocal impact of different forms of short-term plasticity (reactivations) on a persistent form of associative long-term facilitation (PA-LTF), a cellular analog of classical conditioning, which was expressed at Aplysia sensorimotor synapses when a tetanic stimulation of the sensory neurons was paired with a brief application of serotonin on 2 consecutive days. The expression of short-term homosynaptic plasticity [post-tetanic potentiation or homosynaptic depression (HSD)], or short-term heterosynaptic plasticity [serotonin-induced facilitation or neuropeptide Phe-Met-Arg-Phe-NH2 (FMRFa)-induced depression], at synapses expressing PA-LTF did not affect the maintenance of PA-LTF. The kinetics of HSD was attenuated at synapses expressing PA-LTF, which required activation of protein kinase C (PKC). Both PA-LTF and the attenuated kinetics of HSD were reversed by either a transient blockade of PKC activity or a homosynaptic, but not heterosynaptic, reactivation when paired with rapamycin. These results indicate that two different forms of persistent synaptic plasticity, PA-LTF and PNA-LTF, expressed at the same synapse become labile when reactivated by different stimuli. Activity-dependent changes in neural circuits mediate long-term memories. Some forms of long-term memories become labile and can be reversed with specific types of reactivations, but the mechanism is complex. At the cellular level, reactivations that induce a

  8. Childhood primary angiitis of the central nervous system: identifying disease trajectories and early risk factors for persistently higher disease activity.

    PubMed

    Cellucci, Tania; Tyrrell, Pascal N; Sheikh, Shehla; Benseler, Susanne M

    2012-05-01

    To compare clinical, laboratory, and imaging characteristics of childhood primary angiitis of the central nervous system (PACNS) subtypes at diagnosis and during followup; to characterize disease activity trajectories in childhood PACNS subtypes; and to identify early risk factors for higher disease activity. We performed a single-center cohort study of consecutive children diagnosed as having childhood PACNS. Demographic, clinical, laboratory, and imaging data were collected at diagnosis and during standardized clinic visits. Outcome measures included disease activity measured by physician's global assessment. Descriptive statistics were used to assess characteristics of the study cohort, and longitudinal data were analyzed using linear mixed-effects regression. The study cohort consisted of 45 patients with childhood PACNS; 26 had angiography-negative childhood PACNS and 19 had angiography-positive childhood PACNS. There were 24 females, the median age at diagnosis was 9.8 years, and the median followup period was 1.8 years. Patients with angiography-negative childhood PACNS were more likely to be female and to present with seizures, cognitive dysfunction, vision abnormalities, high levels of inflammatory markers, and bilateral findings on magnetic resonance imaging (MRI). Motor deficits and ischemic MRI lesions were more common in angiography-positive disease. Disease activity decreased significantly after treatment in all patients. Distinct trajectories of disease activity over time were identified for both childhood PACNS subtypes. Patients with angiography-negative childhood PACNS had persistently higher disease activity. Seizures at presentation also predicted higher disease activity over time. Distinct subtypes of childhood PACNS have unique disease activity trajectories. Patients with angiography-negative disease and seizures at presentation experience higher disease activity. Early recognition of this high-risk cohort may enable the treating physician to

  9. New Findings in eNOS gene and Thalidomide Embryopathy Suggest pre-transcriptional effect variants as susceptibility factors

    PubMed Central

    Kowalski, Thayne Woycinck; Fraga, Lucas Rosa; Tovo-Rodrigues, Luciana; Sanseverino, Maria Teresa Vieira; Hutz, Mara Helena; Schuler-Faccini, Lavínia; Vianna, Fernanda Sales Luiz

    2016-01-01

    Antiangiogenic properties of thalidomide have created an interest in the use of the drug in treatment of cancer. However, thalidomide is responsible for thalidomide embryopathy (TE). A lack of knowledge regarding the mechanisms of thalidomide teratogenesis acts as a barrier in the aim to synthesize a safer analogue of thalidomide. Recently, our group detected a higher frequency of alleles that impair the pro-angiogenic mechanisms of endothelial nitric oxide synthase (eNOS), coded by the NOS3 gene. In this study we evaluated variable number tandem repeats (VNTR) functional polymorphism in intron 4 of NOS3 in individuals with TE (38) and Brazilians without congenital anomalies (136). Haplotypes were estimated for this VNTR with previously analyzed polymorphisms, rs2070744 (−786C > T) and rs1799983 (894T > G), in promoter region and exon 7, respectively. Haplotypic distribution was different between the groups (p = 0.007). Alleles −786C (rs2070744) and 4b (VNTR), associated with decreased NOS3 expression, presented in higher frequency in TE individuals (p = 0.018; OR = 2.57; IC = 1.2–5.8). This association was not identified with polymorphism 894T > G (p = 0.079), which influences eNOS enzymatic activity. These results suggest variants in NOS3, with pre-transcriptional effects as susceptibility factors, influencing the risk TE development. This finding generates insight for a new approach to research that pursues a safer analogue. PMID:27004986

  10. On the relationship between persistent delay activity, repetition enhancement and priming

    PubMed Central

    Tartaglia, Elisa M.; Mongillo, Gianluigi; Brunel, Nicolas

    2015-01-01

    Human efficiency in processing incoming stimuli (in terms of speed and/or accuracy) is typically enhanced by previous exposure to the same, or closely related stimuli—a phenomenon referred to as priming. In spite of the large body of knowledge accumulated in behavioral studies about the conditions conducive to priming, and its relationship with other forms of memory, the underlying neuronal correlates of priming are still under debate. The idea has repeatedly been advanced that a major neuronal mechanism supporting behaviorally-expressed priming is repetition suppression, a widespread reduction of spiking activity upon stimulus repetition which has been routinely exposed by single-unit recordings in non-human primates performing delayed-response, as well as passive fixation tasks. This proposal is mainly motivated by the observation that, in human fMRI studies, priming is associated to a significant reduction of the BOLD signal (widely interpreted as a proxy of the level of spiking activity) upon stimulus repetition. Here, we critically re-examine a large part of the electrophysiological literature on repetition suppression in non-human primates and find that repetition suppression is systematically accompanied by stimulus-selective delay period activity, together with repetition enhancement, an increase of spiking activity upon stimulus repetition in small neuronal populations. We argue that repetition enhancement constitutes a more viable candidate for a putative neuronal substrate of priming, and propose a minimal framework that links together, mechanistically and functionally, repetition suppression, stimulus-selective delay activity and repetition enhancement. PMID:25657630

  11. Persistent activation of microglia and NADPH drive hippocampal dysfunction in experimental multiple sclerosis

    PubMed Central

    Di Filippo, Massimiliano; de Iure, Antonio; Giampà, Carmela; Chiasserini, Davide; Tozzi, Alessandro; Orvietani, Pier Luigi; Ghiglieri, Veronica; Tantucci, Michela; Durante, Valentina; Quiroga-Varela, Ana; Mancini, Andrea; Costa, Cinzia; Sarchielli, Paola; Fusco, Francesca Romana; Calabresi, Paolo

    2016-01-01

    Cognitive impairment is common in multiple sclerosis (MS). Unfortunately, the synaptic and molecular mechanisms underlying MS-associated cognitive dysfunction are largely unknown. We explored the presence and the underlying mechanism of cognitive and synaptic hippocampal dysfunction during the remission phase of experimental MS. Experiments were performed in a chronic-relapsing experimental autoimmune encephalomyelitis (EAE) model of MS, after the resolution of motor deficits. Immunohistochemistry and patch-clamp recordings were performed in the CA1 hippocampal area. The hole-board was utilized as cognitive/behavioural test. In the remission phase of experimental MS, hippocampal microglial cells showed signs of activation, CA1 hippocampal synapses presented an impaired long-term potentiation (LTP) and an alteration of spatial tests became evident. The activation of hippocampal microglia mediated synaptic and cognitive/behavioural alterations during EAE. Specifically, LTP blockade was found to be caused by the reactive oxygen species (ROS)-producing enzyme nicotinamide adenine dinucleotide phosphate (NADPH) oxidase. We suggest that in the remission phase of experimental MS microglia remains activated, causing synaptic dysfunctions mediated by NADPH oxidase. Inhibition of microglial activation and NADPH oxidase may represent a promising strategy to prevent neuroplasticity impairment associated with active neuro-inflammation, with the aim to improve cognition and counteract MS disease progression. PMID:26887636

  12. Influence of earthworm activity on microbial communities related with the degradation of persistent pollutants.

    PubMed

    Natal-da-Luz, Tiago; Lee, Iwa; Verweij, Rudo A; Morais, Paula V; Van Velzen, Martin J M; Sousa, José Paulo; Van Gestel, Cornelis A M

    2012-04-01

    Earthworms may promote the biodegradation of polycyclic aromatic hydrocarbons (PAHs) in soil, but the mechanism through which they exert such influence is still unknown. To determine if the stimulation of PAH degradation by earthworms is related to changes in microbial communities, a microcosm experiment was conducted consisting of columns with natural uncontaminated soil covered with PAH-contaminated dredge sediment. Columns without and with low and high Eisenia andrei densities were prepared. Organic matter and PAH content, microbial biomass, and dehydrogenase activity (DHA) were measured in soil and sediment over time. Biolog Ecoplate™ and polymerase chain reaction using denaturing gradient gel electrophoresis were used to evaluate changes in metabolic and structural diversity of the microbial community, respectively. Earthworm activity promoted PAH degradation in soil, which was significant for biphenyl, benzo[a]pyrene, and benzo[e]pyrene. Microbial biomass and DHA activity generally did not change over the experiment. Earthworm activity did change microbial community structure, but this did not affect its functioning in terms of carbon substrate consumption. Results suggest no relationship between changes in the microbial community by earthworm activity and increased PAH disappearance. The role of shifts in soil microbial community structure induced by earthworms in PAH removal needs further investigation.

  13. [Indicators of the persistent pro-inflammatory activation of the immune system in depression].

    PubMed

    Cubała, Wiesław Jerzy; Godlewska, Beata; Trzonkowski, Piotr; Landowski, Jerzy

    2006-01-01

    The aetiology of depression remains tentative. Current hypotheses on the aetiology of the depressive disorder tend to integrate monoaminoergic, neuroendocrine and immunological concepts of depression. A number of research papers emphasise the altered hormonal and immune status of patients with depression with pronounced cytokine level variations. Those studies tend to link the variable course of depression in relation to the altered proinflammatory activity of the immune system. The results of the studies on the activity of the selected elements of the immune system are ambiguous indicating both increased and decreased activities of its selected elements. However, a number of basic and psychopharmacological studies support the hypothesis of the increased proinflammatory activity of the immune system in the course of depression which is the foundation for the immunological hypothesis of depression. The aim of this paper is to review the functional abnormalities that are observed in depression focusing on the monoaminoergic deficiency and increased immune activation as well as endocrine dysregulation. This paper puts together and discusses current studies related to this subject with a detailed insight into interactions involving nervous, endocrine and immune systems.

  14. Circadian rhythms in heart rate, motility, and body temperature of wild-type C57 and eNOS knock-out mice under light-dark, free-run, and after time zone transition.

    PubMed

    Arraj, M; Lemmer, B

    2006-01-01

    The nitric oxide (NO) system is involved in the regulation of the cardiovascular system in controlling central and peripheral vascular tone and cardiac functions. It was the aim of this study to investigate in wild-type C57BL/6 and endothelial nitric oxide synthase (eNOS) knock-out mice (eNOS-/-) the contribution of NO on the circadian rhythms in heart rate (HR), motility (motor activity [MA]), and body temperature (BT) under various environmental conditions. Experiments were performed in 12:12 h of a light:dark cycle (LD), under free-run in total darkness (DD), and after a phase delay shift of the LD cycle by -6 h (i.e., under simulation of a westward time zone transition). All parameters were monitored by radiotelemetry in freely moving mice. In LD, no significant differences in the rhythms of HR and MA were observed between the two strains of mice. BT, however, was significantly lower during the light phase in eNOS-/- mice, resulting in a significantly greater amplitude. The period of the free-running rhythm in DD was slightly shorter for all variables, though not significant. In general, rhythmicity was greater in eNOS-/- than in C57 mice both in LD and DD. After a delay shift of the LD cycle, HR and BT were resynchronized to the new LD schedule within 5-6 days, and resynchronization of MA occurred within 2-3 days. The results in telemetrically instrumented mice show that complete knock-out of the endothelial NO system--though expressed in the suprachiasmatic nuclei and in peripheral tissues--did not affect the circadian organization of heart rate and motility. The circadian regulation of the body temperature was slightly affected in eNOS-/- mice.

  15. Persistence of pierisin-1 activities in the adult cabbage white butterfly, Pieris rapae, during storage after killing.

    PubMed

    Matsumoto, Yasuko; Matsushima-Hibiya, Yuko; Nakano, Tsuyoshi; Yamamoto, Masafumi; Iwabuchi, Kikuo; Sugimura, Takashi; Wakabayashi, Keiji

    2007-09-01

    Crude extracts from larvae, pupae and adults of cabbage white butterflies, Pieris rapae and Pieris brassicae, and green-veined butterfly, Pieris napi, have an ability to induce apoptosis in the human cancer cell lines. As apoptosis inducing protein, pierisin-1 and -2 have been isolated from pupae of P. rapae and P. brassicae, respectively, and shown to exhibit DNA ADP-ribosylating activity. Although the highest activity was detected in the late phase of larvae and early phase of pupae, certain activity was found in adult butterflies. In order to investigate distribution of substances having pierisin-like activities in butterflies, many species need to be analyzed. However, fresh samples of larvae and pupae are hard to obtain, especially if samples are of scarce species or from overseas. The usage of adult butterflies is practical to examine the distribution of pierisin-like activity in many species. In this study, we examined the cytotoxicity of crude extracts from adults of P. rapae against HeLa cells and DNA ADP-ribosylation ability during storage for 1, 2 and 8 weeks at room temperature after killing adult butterflies after eclosion. Body weights decreased to 18% for 8 weeks through dehydration. Cytotoxicity of samples from butterfly kept for 1, 2 and 8 weeks decreased to 47, 39 and 22%, respectively, of the control value. DNA ADP-ribosylating activity of the samples also decreased to 30, 27 and 23%. Similar reduction was observed on western blot analysis with anti-pierisin-1 antibody. Fortunately, these results suggest that cytotoxic and DNA ADP-ribosylating activity persists to some extent in the body after killing, at least for 8 weeks. Thus, butterfly adult samples kept for two months at room temperature can still be useful for examination of the presence of substance having pierisin-like activity.

  16. Persistence of high risk sexual activity among homosexual men in an area of low incidence for acquired immunodeficiency syndrome.

    PubMed

    Calabrese, L H; Harris, B; Easley, K A; Proffitt, M R

    1986-01-01

    A survey of 305 homosexual men was performed in an area of relatively low incidence for AIDS and low seroprevalence for antibody to the human immunodeficiency virus (HIV). The objective of the study was to investigate current knowledge and practice of sexual behavior designed to limit transmission of HIV. The results showed that while the majority of the study group believed that they had made changes in their life styles that would reduce the likelihood of transmitting or acquiring the virus, nearly half admitted to persistently engaging in active and passive anal intercourse without condoms. These data suggest the need for more widespread and effective forms of education to help prevent the continuing spread of the AIDS epidemic.

  17. Hippocampal noradrenergic activation is necessary for object recognition memory consolidation and can promote BDNF increase and memory persistence.

    PubMed

    Mello-Carpes, Pâmela B; da Silva de Vargas, Liane; Gayer, Mateus Cristofari; Roehrs, Rafael; Izquierdo, Ivan

    2016-01-01

    Previously we showed that activation of the Nucleus of the Solitary Tract (NTS)-Nucleus Paragigantocellularis (PGi)-Locus coeruleus (LC) pathway, which theoretically culminates with norepinephrine (NE) release in dorsal hippocampus (CA1 region) and basolateral amygdala (BLA) is necessary for the consolidation of object recognition (OR) memory. Here we show that, while the microinjection of the beta-noradrenergic receptor blocker timolol into CA1 impairs OR memory consolidation, the microinjection of norepinephrine (NE) promotes the persistence of this type of memory. Further, we show that OR consolidation is attended by an increase of norepinephrine (NE) levels and of the expression of brain derived neurotrophic factor (BDNF) in hippocampus, which are impaired by inactivation of the NTS-PGi-LC pathway by the infusion of muscimol into the NTS.

  18. Persistent synchronized oscillations in prolactin gene promoter activity in living pituitary cells.

    PubMed

    McFerran, D W; Stirland, J A; Norris, A J; Khan, R A; Takasuka, N; Seymour, Z C; Gill, M S; Robertson, W R; Loudon, A S; Davis, J R; White, M R

    2001-07-01

    PRL gene expression in the anterior pituitary gland responds rapidly to different hormonal signals. We have investigated the long-term timing of transcriptional activation from the PRL, GH, and cytomegalovirus promoters in response to different stimulus duration, using real-time imaging of luciferase expression in living stably transfected GH3 cells. Long-term stimulation of serum-starved cells with 50% serum induced a homogeneous rise in PRL promoter activity, with subsequent heterogeneous fluctuations in luciferase activity in individual cells. When cells were subjected to a 2-h pulse of 50% serum, followed by serum-free medium, there were long-term (approximately 50 h) synchronized, homogeneous oscillations in PRL promoter activity. This response was PRL-specific, because in GH3 cells expressing luciferase from the GH or cytomegalovirus promoters, a serum pulse elicited no oscillations in luciferase expression after an initial transient response to serum. The PRL promoter may therefore be a template for an unstable transcription complex subject to stochastic regulation, allowing an oscillatory transcriptional response to physiological signals. This suggests that precise timing and coordination of cell responses to different signal-duration may represent a novel mechanism for coordinating long-term dynamic changes in transcription in cell populations.

  19. Persistence of Anticancer Activity in Berry Extracts after Simulated Gastrointestinal Digestion and Colonic Fermentation

    PubMed Central

    Brown, Emma M.; McDougall, Gordon J.; Stewart, Derek; Pereira-Caro, Gema; González-Barrio, Rocio; Allsopp, Philip; Magee, Pamela; Crozier, Alan; Rowland, Ian; Gill, Chris I. R.

    2012-01-01

    Fruit and vegetable consumption is associated at the population level with a protective effect against colorectal cancer. Phenolic compounds, especially abundant in berries, are of interest due to their putative anticancer activity. After consumption, however, phenolic compounds are subject to digestive conditions within the gastrointestinal tract that alter their structures and potentially their function. However, the majority of phenolic compounds are not efficiently absorbed in the small intestine and a substantial portion pass into the colon. We characterized berry extracts (raspberries, strawberries, blackcurrants) produced by in vitro-simulated upper intestinal tract digestion and subsequent fecal fermentation. These extracts and selected individual colonic metabolites were then evaluated for their putative anticancer activities using in vitro models of colorectal cancer, representing the key stages of initiation, promotion and invasion. Over a physiologically-relevant dose range (0–50 µg/ml gallic acid equivalents), the digested and fermented extracts demonstrated significant anti-genotoxic, anti-mutagenic and anti-invasive activity on colonocytes. This work indicates that phenolic compounds from berries undergo considerable structural modifications during their passage through the gastrointestinal tract but their breakdown products and metabolites retain biological activity and can modulate cellular processes associated with colon cancer. PMID:23185422

  20. New evidence for persistent impact-generated hydrothermal activity in the Miocene Ries impact structure, Germany

    NASA Astrophysics Data System (ADS)

    Arp, Gernot; Kolepka, Claudia; Simon, Klaus; Karius, Volker; Nolte, Nicole; Hansen, Bent T.

    2013-12-01

    The extent of impact-generated hydrothermal activity in the 24 km sized Ries impact structure has been controversially discussed. To date, mineralogical and isotopic investigations point to a restriction of hydrothermal activity to the impact-melt bearing breccias, specifically the crater-fill suevite. Here, we present new petrographic, geochemical, and isotopic data of postimpact carbonate deposits, which indicate a hydrothermal activity more extended than previously assumed. Specifically, carbonates of the Erbisberg, a spring mound located upon the inner crystalline ring of the crater, show travertine facies types not seen in any of the previously investigated sublacustrine soda lake spring mounds of the Ries basin. In particular, the streamer carbonates, which result from the encrustation of microbial filaments in subaerial spring effluents between 60 and 70 °C, are characteristic of a hydrothermal origin. While much of the primary geochemical and isotopic signatures in the mound carbonates have been obliterated by diagenesis, a postimpact calcite vein from brecciated gneiss of the subsurface crater floor revealed a flat rare earth element pattern with a clear positive Eu anomaly, indicating a hydrothermal fluid convection in the crater basement. Finally, the strontium isotope stratigraphic correlation of the travertine mound with the crater basin succession suggests a hydrothermal activity for about 250,000 yr after the impact, which would be much longer than previously assumed.

  1. Persistent Prelimbic Cortex Activity Contributes to Enhanced Learned Fear Expression in Females

    ERIC Educational Resources Information Center

    Fenton, Georgina E.; Pollard, Amelia K.; Halliday, David M.; Mason, Rob; Bredy, Timothy W.; Stevenson, Carl W.

    2014-01-01

    Anxiety disorders, such as post-traumatic stress, are more prevalent in women and are characterized by impaired inhibition of learned fear and medial prefrontal cortex (mPFC) dysfunction. Here we examined sex differences in fear extinction and mPFC activity in rats. Females showed more learned fear expression during extinction and its recall, but…

  2. Persistent Prelimbic Cortex Activity Contributes to Enhanced Learned Fear Expression in Females

    ERIC Educational Resources Information Center

    Fenton, Georgina E.; Pollard, Amelia K.; Halliday, David M.; Mason, Rob; Bredy, Timothy W.; Stevenson, Carl W.

    2014-01-01

    Anxiety disorders, such as post-traumatic stress, are more prevalent in women and are characterized by impaired inhibition of learned fear and medial prefrontal cortex (mPFC) dysfunction. Here we examined sex differences in fear extinction and mPFC activity in rats. Females showed more learned fear expression during extinction and its recall, but…

  3. Persistent Organic Pollutants Modify Gut Microbiota–Host Metabolic Homeostasis in Mice Through Aryl Hydrocarbon Receptor Activation

    PubMed Central

    Zhang, Limin; Nichols, Robert G.; Correll, Jared; Murray, Iain A.; Tanaka, Naoki; Smith, Philip B.; Hubbard, Troy D.; Sebastian, Aswathy; Albert, Istvan; Hatzakis, Emmanuel; Gonzalez, Frank J.; Perdew, Gary H.

    2015-01-01

    Background Alteration of the gut microbiota through diet and environmental contaminants may disturb physiological homeostasis, leading to various diseases including obesity and type 2 diabetes. Because most exposure to environmentally persistent organic pollutants (POPs) occurs through the diet, the host gastrointestinal tract and commensal gut microbiota are likely to be exposed to POPs. Objectives We examined the effect of 2,3,7,8-tetrachlorodibenzofuran (TCDF), a persistent environmental contaminant, on gut microbiota and host metabolism, and we examined correlations between gut microbiota composition and signaling pathways. Methods Six-week-old male wild-type and Ahr–/– mice on the C57BL/6J background were treated with 24 μg/kg TCDF in the diet for 5 days. We used 16S rRNA gene sequencing, 1H nuclear magnetic resonance (NMR) metabolomics, targeted ultra-performance liquid chromatography coupled with triplequadrupole mass spectrometry, and biochemical assays to determine the microbiota compositions and the physiological and metabolic effects of TCDF. Results Dietary TCDF altered the gut microbiota by shifting the ratio of Firmicutes to Bacteroidetes. TCDF-treated mouse cecal contents were enriched with Butyrivibrio spp. but depleted in Oscillobacter spp. compared with vehicle-treated mice. These changes in the gut microbiota were associated with altered bile acid metabolism. Further, dietary TCDF inhibited the farnesoid X receptor (FXR) signaling pathway, triggered significant inflammation and host metabolic disorders as a result of activation of bacterial fermentation, and altered hepatic lipogenesis, gluconeogenesis, and glycogenolysis in an AHR-dependent manner. Conclusion These findings provide new insights into the biochemical consequences of TCDF exposure involving the alteration of the gut microbiota, modulation of nuclear receptor signaling, and disruption of host metabolism. Citation Zhang L, Nichols RG, Correll J, Murray IA, Tanaka N, Smith PB

  4. Persistent differences in patterns of brain activation after sports-related concussion: a longitudinal functional magnetic resonance imaging study.

    PubMed

    Dettwiler, Annegret; Murugavel, Murali; Putukian, Margot; Cubon, Valerie; Furtado, John; Osherson, Daniel

    2014-01-15

    Avoiding recurrent injury in sports-related concussion (SRC) requires understanding the neural mechanisms involved during the time of recovery after injury. The decision for return-to-play is one of the most difficult responsibilities facing the physician, and so far this decision has been based primarily on neurological examination, symptom checklists, and neuropsychological (NP) testing. Functional magnetic resonance imaging (fMRI) may be an additional, more objective tool to assess the severity and recovery of function after concussion. The purpose of this study was to define neural correlates of SRC during the 2 months after injury in varsity contact sport athletes who suffered a SRC. All athletes were scanned as they performed an n-back task, for n=1, 2, 3. Subjects were scanned within 72 hours (session one), at 2 weeks (session two), and 2 months (session three) post-injury. Compared with age and sex matched normal controls, concussed subjects demonstrated persistent, significantly increased activation for the 2 minus 1 n-back contrast in bilateral dorsolateral prefrontal cortex (DLPFC) in all three sessions and in the inferior parietal lobe in session one and two (α≤0.01 corrected). Measures of task performance revealed no significant differences between concussed versus control groups at any of the three time points with respect to any of the three n-back tasks. These findings suggest that functional brain activation differences persist at 2 months after injury in concussed athletes, despite the fact that their performance on a standard working memory task is comparable to normal controls and normalization of clinical and NP test results. These results might indicate a delay between neural and behaviorally assessed recovery after SRC.

  5. Persistent hydrocephalus due to postural activation of a ventricular shunt anti-gravity device.

    PubMed

    Craven, Claudia L; Toma, Ahmed K; Watkins, Laurence D

    2017-03-01

    The ever present need to balance over drainage with under drainage in hydrocephalus has required innovations including adjustable valves with antigravity devices. These are activated in the vertical position to prevent siphoning. We describe a group of bedridden patients who presented with unexplained under drainage caused by activation of antigravity shunt components produced by peculiar head/body position. Retrospective single centre case series of hydrocephalus patients, treated with ventriculo-peritoneal (VP) shunt insertion between April 2014 - February 2016. These patients presented with clinical and radiological under drainage syndrome. Medical notes were reviewed for clinical picture and outcome. Radiological studies were reviewed assessing shunt placement and ventricular size. Seven patients presented with clinical and radiological under drainage syndrome. A consistent posturing of long term hyper-flexion of the neck whilst lying supine was observed. All patients had similar shunt construct (adjustable Miethke ProGAV valve and shunt assistant anti-gravity component). In each of those patients a hypothesis was formulated that neck flexion was activating the shunt assistance anti-gravity component in supine position. Five patients underwent shunt revision surgery removing the shunt assistant device from the cranium and adding an anti-gravity component to the shunt system at the chest. One had the shunt assistant completely removed and one patient was managed conservatively with mobilisation. All patients had clinical and radiological improvement. Antigravity shunt components implanted cranially in bedridden hydrocephalus patients will produce underdrainage due to head flexion induced anti-gravity device activation. In these patients, anti-gravity devices should be placed at the chest. Alternatively, special nursing attention should be paid to head-trunk angle.

  6. Persistent explosive activity at Stromboli investigated with OP-FTIR and SO2 cameras

    NASA Astrophysics Data System (ADS)

    Burton, M. R.; La Spina, A.; Sawyer, G. M.; Harris, A. J.

    2012-12-01

    Stromboli volcano in Italy exhibits what is perhaps one of the most well-known examples of cyclic activity, in the form of its regular explosions, which send a few m3 of material 100-200 m into the air every 10-20 minutes. Recent developments in measurements of volatile release from Stromboli using a series of novel approaches have allowed this cyclic behaviour to be examined in detail. In particular, the use of an automated OP-FTIR has revealed unprecedented detail in the dynamics of degassing from individual craters at the summit of Stromboli. Furthermore, the variations in composition of explosive degassing from Stromboli demonstrate a deep source ~2 km for the gas slugs which produce explosions at this volcano, in contrast to the commonly-held view that gas coalescence at shallow depth is responsible for the behaviour. The SO2 camera has revealed fascinating new details on the dynamics of degassing at Stromboli, and has allowed direct quantification of the amount of gas released during explosions and through quiescent degassing. The remarkable observation that 99% of degassing takes place quiescently, and that the explosions, whilst apparently more significant, are in fact a secondary process compared with the mass and energy involved in background, quiet processes. The new insight that the explosions are actually only a relatively minor aspect of the activity (in terms of mass and energy) actually makes the regularity of the cyclic explosive activity still more remarkable. In this paper we present a detailed overview of the state of the art of our understanding of cyclic explosive activity at Stromboli volcano from the perspective of recent advances in geochemical monitoring of the gas emissions. We also report initial results from a multidisciplinary campaign on Stromboli which utilised both OP-FTIR and SO2 camera techniques.

  7. Stem bromelain-induced macrophage apoptosis and activation curtail Mycobacterium tuberculosis persistence.

    PubMed

    Mahajan, Sahil; Chandra, Vemika; Dave, Sandeep; Nanduri, Ravikanth; Gupta, Pawan

    2012-08-01

    Mycobacterium tuberculosis, the causative agent of tuberculosis, has a remarkable ability to usurp its host's innate immune response, killing millions of infected people annually. One approach to manage infection is prevention through the use of natural agents. In this regard, stem bromelain (SBM), a pharmacologically active member of the sulfhydryl proteolytic enzyme family, obtained from Ananas comosus and possessing a remarkable ability to induce the innate and acquired immune systems, is important. We evaluated SBM's ability to induce apoptosis and free-radical generation in macrophages. We also studied antimycobacterial properties of SBM and its effect on foamy macrophages. SBM treatment of peritoneal macrophages resulted in the upregulation of proapoptotic proteins and downregulation of antiapoptotic proteins. Additionally, SBM treatment activated macrophages, curtailed the levels of free glutathione, and augmented the production of hydrogen peroxide, superoxide anion, peroxynitrite, and nitric oxide. SBM cleaves CD36 and reduced the formation of foam cells, the hallmark of M. tuberculosis infection. These conditions created an environment for the increased clearance of M. tuberculosis. Together these data provide a mechanism for antimycobacterial activity of SBM and provide important insights for the use of cysteine proteases as immunomodulatory agents.

  8. Persistence, dissipation, and activity of Escherichia coli O157:H7 within sand and seawater environments.

    PubMed

    Williams, A Prysor; Avery, Lisa M; Killham, Ken; Jones, David L

    2007-04-01

    Runoff from agricultural land into watercourses may transport and deposit animal-derived waste contaminated with Escherichia coli O157:H7 onto beaches, which may in turn lead to human infection. To simulate contamination, freshwater mixed with cattle slurry containing E. coli O157:H7 was added to sand from three recreational beaches. The sand was then maintained in a dry state (nontidal) or subjected to a repeated seawater tidal simulation. The pathogen could still be recovered from all sands by day 5. Although survival of the pathogen did not statistically vary between sands of different origin under nontidal conditions, significant differences in numbers occurred between sands when subject to tidal simulation. In the tidal simulations, a considerable proportion of the E. coli O157:H7 rapidly dissipated from sand into the seawater. In a separate experiment, the activity of bioluminescent (lux-marked) E. coli O157:H7 cells was monitored in various mixtures of contaminated runoff water and seawater over 5 days. Pathogen activity declined with increasing seawater concentration; however, cells remained viable in all treatments over the 5-day period. The addition of nutrients to water rapidly increased pathogen activity in all treatments. Our findings highlight the resilience of E. coli O157:H7 in aquatic and marine environments.

  9. Active Nerve Regeneration with Failed Target Reinnervation Drives Persistent Neuropathic Pain

    PubMed Central

    Xie, Wenrui

    2017-01-01

    Abstract Peripheral nerves can regenerate and, when injured, may cause neuropathic pain. We propose that the active regeneration process plays a pivotal role in the maintenance of neuropathic pain. In one commonly used rodent neuropathic pain model, pronounced pain behaviors follow ligation and cutting of the L5 spinal nerve. We found that the injured nerve regenerates into the sciatic nerve and functionally reinnervates target tissues: the regenerated nerve conducts electrical signals, mechanical responses, and tracers between the leg/hindpaw and axotomized sensory ganglion. The regenerating nerve is the primary source of abnormal spontaneous activity detected in vivo. Disrupting the regeneration inhibited pain. First, semaphorin 3A, an inhibitory axonal guidance molecule, reduced functional regeneration, spontaneous activity, and pain behaviors when applied to the injury site in vivo. Second, knockdown of the upregulated growth-associated protein 43 (GAP43) with siRNA injected into the axotomized sensory ganglion reduced pain behaviors. We next examined the spared nerve injury model, in which pain behaviors are essentially permanent. The regeneration resulted in tangled GAP43-positive neuromas at the nerve injury site without target reinnervation. Perfusing the nerve stump with semaphorin 3A, but not removing the tangled fibers, prevented or reversed pain behaviors. This effect far outlasted the semaphorin 3A perfusion. Hence, in this model the long-lasting chronic pain may reflect the anatomical inability of regenerating nerves to successfully reinnervate target tissues, resulting in an ongoing futile regeneration process. We propose that specifically targeting the regeneration process may provide effective long-lasting pain relief in patients when functional reinnervation becomes impossible. PMID:28197545

  10. Activity of spinosad on stored-tobacco insects and persistence on cured tobacco stripst.

    PubMed

    Blanc, Michel P; Panighini, Cécile; Gadani, Ferruccio; Rossi, Luca

    2004-11-01

    Every year raw tobacco and manufactured tobacco products are lost to two major storage pests, the cigarette beetle, Lasioderma serricorne (F) and the tobacco moth, Ephestia elutella (Hiibner). Post-harvest management of both insects is achieved through sanitation, insect monitoring and fumigation with phosphine. However, insect resistance to phosphine and control failures have been reported, and fumigants are under constant regulatory pressure. Here we report the evaluation of spinosad, a bioinsecticide derived from the fermentation of the soil micro-organism Saccharopolyspora spinosa Mertz & Yao. Spinosad was first registered in 1997 and is now widely used as a field pest control agent on many crops, including tobacco. The insecticidal activity of the fermentation product (technical spinosad, TS) was measured by diet incorporation assays against L serricorne and E elutella larvae. Mortality levels were determined on newly hatched larvae and over the whole insect life cycle. For both species, no emergence of adult insects was observed in cured tobacco sprayed with 50mg TS kg(-1) and inoculated with eggs or newly hatched larvae. These results indicated that spinosad has potential for the control of both species in stored tobacco, since 100% control of both pests could be achieved at 50 mg TS kg(-1), and with almost full control (90-95%) at 10 mg kg(-1). We also monitored the stability of the product on cured tobacco. The original concentration of the main active component of TS, spinosyn A, did not change significantly over 18 months, indicating no loss of spinosad during a typical leaf storage period of time. Bioassays against larvae confirmed that the bioinsecticidal activity of spinosad was retained.

  11. 17-β-oestradiol-induced vasorelaxation in vitro is mediated by eNOS through hsp90 and akt/pkb dependent mechanism

    PubMed Central

    Bucci, Mariarosaria; Roviezzo, Fiorentina; Cicala, Carla; Pinto, Aldo; Cirino, Giuseppe

    2002-01-01

    The L-arginine-NO pathway has been implicated in the vasorelaxant effect of 17-β-oestradiol. Here we have addressed the involvement of two distinct activation steps of endothelial nitric oxide synthase (eNOS) in the 17-β-oestradiol-induced vasorelaxant effect on rat aortic rings. Rat aortic rings contracted with phenylephrine (PE) 1 μM relaxed in a concentration related fashion to 17-β-oestradiol water soluble cyclodextrin-encapsulated (E2) only when endothelium was present. The pure anti-oestrogen of E2 receptor ICI 182,780 (20 μM) significantly inhibited E2-induced vasorelaxation. Geldanamycin (10 μM), a specific inhibitor of heat shock protein 90 (hsp90) and Nω-nitro-L-arginine-methyl ester (L-NAME, 100 μM), a nitric oxide synthase inhibitor, significantly inhibited E2-induced vasorelaxation. Incubation of rat aortic rings up to 6 h with LY 294002 (25 μM), a specific inhibitor of PI(3)K akt/pkb pathway reduced E2-induced vasorelaxation. Incubation of rat isolated aorta with E2, induced prostacyclin (PGI2) release. PGI2 levels, measured as 6-keto PGF1α, were abolished by ibuprofen (10 μM), both L-NAME and GA did not influence basal or E2-stimulated PGI2 confirming the specificity of these two compounds on eNOS pathway. In conclusion, we demonstrate that E2 interaction with its receptor is followed by a vasorelaxant effect in rat aortic rings mediated by eNOS activation through both hsp90 and akt/pkb dependent mechanisms. PMID:11934809

  12. Regime shift in Arabian dust activity, triggered by persistent Fertile Crescent drought

    NASA Astrophysics Data System (ADS)

    Notaro, Michael; Yu, Yan; Kalashnikova, Olga V.

    2015-10-01

    The Arabian Peninsula has experienced pronounced interannual to decadal variability in dust activity, including an abrupt regime shift around 2006 from an inactive dust period during 1998-2005 to an active period during 2007-2013. Corresponding in time to the onset of this regime shift, the climate state transitioned into a combined La Niña and negative phase of the Pacific Decadal Oscillation, which incited a hiatus in global warming in the 2000s. Superimposed upon a long-term regional drying trend, synergistic interactions between these teleconnection modes triggered the establishment of a devastating and prolonged drought, which engulfed the Fertile Crescent, namely, Iraq and Syria, and led to crop failure and civil unrest. Dried soils and diminished vegetation cover in the Fertile Crescent, as evident through remotely sensed enhanced vegetation indices, supported greater dust generation and transport to the Arabian Peninsula in 2007-2013, as identified both in increased dust days observed at weather stations and enhanced remotely sensed aerosol optical depth. According to backward trajectory analysis of dust days on the Arabian Peninsula, increased dust lifting and atmospheric dust concentration in the Fertile Crescent during this recent, prolonged drought episode supported a greater frequency of dust events across the peninsula with associated northerly trajectories and led to the dust regime shift. These findings are particularly concerning, considering projections of warming and drying for the eastern Mediterranean region and potential collapse of the Fertile Crescent during this century.

  13. Persistence of diet-induced obesity despite access to voluntary activity in mice lacking sarcolipin.

    PubMed

    Gamu, Daniel; Trinh, Anton; Bombardier, Eric; Tupling, A Russell

    2015-09-01

    Several rodent models of obesity have been shown to develop excessive adiposity only when voluntary cage ambulation is restricted. We have previously shown that mice lacking the sarco(endo)plasmic reticulum Ca(2+)-ATPase pump regulatory protein sarcolipin (Sln(-/-)), an uncoupler of Ca(2+) uptake, develop excessive diet-induced obesity under standard housing conditions. However, it is unclear whether this phenotype is due, in part, to the sedentary housing environment in which these animals are kept. To address this, we allowed wild-type and Sln(-/-) animals ad libitum access to voluntary wheel running while consuming a standard chow or high-fat diet for 8 weeks. During this period, wheel revolutions were monitored along with weekly mass gain. Postdiet glucose tolerance and visceral adiposity were also taken. The volume of wheel running completed was similar between genotype, regardless of diet. Although voluntary activity reduced mass gain relative to sedentary controls within each diet (P < 0.05), visceral adiposity was surprisingly unaltered with activity. However, Sln(-/-) mice developed excessive obesity (P < 0.05) and glucose intolerance (P < 0.05) with high-fat feeding relative to wild-type controls. These findings indicate that the excessive diet-induced obese phenotype previously observed in Sln(-/-) mice is not the result of severely restricted daily ambulation, but in fact the inability to recruit uncoupling of the Ca(2+)-ATPase pump.

  14. Key role of persistent free radicals in hydrogen peroxide activation by biochar: implications to organic contaminant degradation.

    PubMed

    Fang, Guodong; Gao, Juan; Liu, Cun; Dionysiou, Dionysios D; Wang, Yu; Zhou, Dongmei

    2014-01-01

    We investigated the activation of hydrogen peroxide (H2O2) by biochars (produced from pine needles, wheat, and maize straw) for 2-chlorobiphenyl (2-CB) degradation in the present study. It was found that H2O2 can be effectively activated by biochar, which produces hydroxyl radical ((•)OH) to degrade 2-CB. Furthermore, the activation mechanism was elucidated by electron paramagnetic resonance (EPR) and salicylic acid (SA) trapping techniques. The results showed that biochar contains persistent free radicals (PFRs), typically ∼ 10(18) unpaired spins/gram. Higher trapped [(•)OH] concentrations were observed with larger decreases in PFRs concentration, when H2O2 was added to biochar, indicating that PFRs were the main contributor to the formation of (•)OH. This hypothesis was supported by the linear correlations between PFRs concentration and trapped [(•)OH], as well as kobs of 2-CB degradation. The correlation coefficients (R(2)) were 0.723 and 0.668 for PFRs concentration vs trapped [(•)OH], and PFRs concentration vs kobs, respectively, when all biochars pyrolyzed at different temperatures were included. For the same biochar washed by different organic solvents (methanol, hexane, dichloromethane, and toluene), the correlation coefficients markedly increased to 0.818-0.907. Single-electron transfer from PFRs to H2O2 was a possible mechanism for H2O2 activation by biochars, which was supported by free radical quenching studies. The findings of this study provide a new pathway for biochar implication and insight into the mechanism of H2O2 activation by carbonaceous materials (e.g., activated carbon and graphite).

  15. HPV 5 and 8 E6 Abrogate ATR Activity Resulting in Increased Persistence of UVB Induced DNA Damage

    PubMed Central

    Wallace, Nicholas A.; Robinson, Kristin; Howie, Heather L.; Galloway, Denise A.

    2012-01-01

    The role of the E6 oncoprotein from high-risk members of the α human papillomavirus genus in anogenital cancer has been well established. However, far less is known about the E6 protein from the β human papillomavirus genus (β-HPVs). Some β-HPVs potentially play a role in non-melanoma skin cancer development, although they are not required for tumor maintenance. Instead, they may act as a co-factor that enhances the carcinogenic potential of UV damage. Indeed, the E6 protein from certain β-HPVs (HPV 5 and 8) promotes the degradation of p300, a histone acetyl transferase involved in UV damage repair. Here, we show that the expression of HPV 5 and 8 E6 increases thymine dimer persistence as well as the likelihood of a UVB induced double strand break (DSB). Importantly, we provide a mechanism for the increased DNA damage by showing that both extended thymine dimer persistence as well as elevated DSB levels are dependent on the ability of HPV 8 E6 to promote p300 degradation. We further demonstrate that HPV 5 and 8 E6 expression reduces the mRNA and protein levels of ATR, a PI3 kinase family member that plays a key role in UV damage signaling, but that these levels remain unperturbed in cells expressing a mutated HPV 8 E6 incapable of promoting p300 degradation. We confirm that the degradation of p300 leads to a reduction in ATR protein levels, by showing that ATR levels rebound when a p300 mutant resistant to HPV 8 mediated degradation and HPV 8 E6 are co-transfected. Conversely, we show that ATR protein levels are reduced when p300 is targeted for degradation by siRNA. Moreover, we show the reduced ATR levels in HPV 5 and 8 E6 expressing cells results in delayed ATR activation and an attenuated ability of cells to phosphorylate, and as a result accumulate, p53 in response to UVB exposure, leading to significantly reduced cell cycle arrest. In conclusion, these data demonstrate that β-HPV E6 expression can enhance the carcinogenic potential of UVB exposure by

  16. Activation of metabotropic glutamate 5 and NMDA receptors underlies the induction of persistent bursting and associated long-lasting changes in CA3 recurrent connections.

    PubMed

    Stoop, Ron; Conquet, François; Zuber, Benoit; Voronin, Leon L; Pralong, Etienne

    2003-07-02

    The aim of this study was to describe the induction and expression mechanisms of a persistent bursting activity in a horizontal slice preparation of the rat limbic system that includes the ventral part of the hippocampus and the entorhinal cortex. Disinhibition of this preparation by bicuculline led to interictal-like bursts in the CA3 region that triggered synchronous activity in the entorhinal cortex. Washout of bicuculline after a 1 hr application resulted in a maintained production of hippocampal bursts that continued to spread to the entorhinal cortex. Separation of CA3 from the entorhinal cortex caused the activity in the latter to become asynchronous with CA3 activity in the presence of bicuculline and disappear after washout; however, in CA3, neither the induction of bursting nor its persistence were affected. Associated with the CA3 persistent bursting, a strengthening of recurrent collateral excitatory input to CA3 pyramidal cells and a decreased input to CA3 interneurons was found. Both the induction of the persistent bursting and the changes in synaptic strength were prevented by antagonists of metabotropic glutamate 5 (mGlu5) or NMDA receptors or protein synthesis inhibitors and did not occur in slices from mGlu5 receptor knock-out mice. The above findings suggest potential synaptic mechanisms by which the hippocampus switches to a persistent interictal bursting mode that may support a spread of interictal-like bursting to surrounding temporal lobe regions.

  17. The persisting UV activity in the ex-nova HR Del

    NASA Astrophysics Data System (ADS)

    Selvelli, P.; Friedjung, M.

    2002-01-01

    We have investigated the long-time and short-time variations in the UV spectrum of the ex-nova HR Del through a re-analysis of its whole set of IUE-INES data. A notable result of this study is the finding that for many years after the return to its pre-outburst optical magnitude the nova has been displaying a considerable UV luminosity and wind activity. This raises several questions on the general assumption that associates the return to the pre-outburst magnitude with the return to a quiescent stage. It is possible that the pre-outburst magnitude at mv ~12 did not correspond with a real "quiescent" state.

  18. Low indoleamine 2,3-dioxygenase activity in persistent food allergy in children.

    PubMed

    Buyuktiryaki, B; Sahiner, U M; Girgin, G; Birben, E; Soyer, O U; Cavkaytar, O; Cetin, C; Arik Yilmaz, E; Yavuz, S T; Kalayci, O; Baydar, T; Sackesen, C

    2016-02-01

    Indoleamine 2,3-dioxygenase (IDO), which degrades tryptophan (Trp) to kynurenine (Kyn), has been demonstrated to contribute to modulation of allergic responses. However, the role of IDO in food allergy has not yet been elucidated. Serum Trp and Kyn concentrations were analyzed by high-pressure liquid chromatography. Expression of IDO gene was measured by real-time PCR. The levels of interleukin (IL)-4, IL-10, and interferon (IFN)-γ in cell culture supernatants were measured by ELISA. Kyn/Trp (IDO activity) was significantly lower in subjects with food allergy (n = 100) than in aged-matched healthy controls (n = 112) (P = 0.004). Kyn/Trp was decreased from healthy through completely tolerant, partially tolerant, and reactive ones [LN transformation (mean ± SEM) healthy: 3.9 ± 0.02 μM/mM; completely tolerant: 3.83 ± 0.04; partially tolerant: 3.8 ± 0.06; reactive: 3.7 ± 0.04] (P = 0.008). The frequency of genetic polymorphisms of IDO did not reveal a significant association with Trp, Kyn, and Kyn/Trp in healthy and food-allergic cases. Culture of PBMC experiments yielded that IDO mRNA expression was not different between tolerant and reactive groups. IL-4 synthesis when stimulated with casein increased significantly in subjects who are reactive and tolerant to foods (P = 0.042, P = 0.006, respectively). Increase in IL-10 synthesis was observed only in children tolerant to milk, but not in reactive ones. IFN-γ synthesis, when stimulated with IL-2 and β-lactoglobulin in cell culture, was significantly higher in subjects tolerant to milk than in the reactive ones (P = 0.005 and P = 0.029, respectively). Our results imply the probability of involvement of IDO in development of tolerance process, and we presume that high IDO activity is associated with nonresponsiveness to food allergens despite allergen sensitization. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  19. [Persistent diarrhea

    PubMed

    Andrade, J A; Moreira, C; Fagundes Neto, U

    2000-07-01

    INTRODUCTION: Persistent diarrhea has high impact on infantile morbidity and mortality rates in developing countries. Several studies have shown that 3 to 20% of acute diarrheal episodes in children under 5 years of age become persistent. DEFINITION: Persistent diarrhea is defined as an episode that lasts more than 14 days. ETIOLOGY: The most important agents isolated in persistent diarrhea are: Enteropathogenic E. coli (EPEC), Salmonella, Enteroaggregative E. coli (EAEC), Klebisiella and Cryptosporidium. CLINICAL ASPECTS: In general, the clinical characteristics of patients with persistent diarrhea do not change with the pathogenic agent. Persistent diarrhea seems to represent the final result of a several insults a infant suffers that predisposes to a more severe episode of diarrhea due to a combination of host factors and high rates of enviromental contamination. Therefore, efforts should be made to promptly treat all episodes of diarrhea with apropriate follow-up. THERAPY: The aim of the treatment is to restore hydroelectrolytic deficits and to replace losses until the diarrheal ceases. It is possible in the majority of the cases, using oral rehydration therapy and erly an appropriate type of diet. PREVENTION: It is imperative that management strategies also focus on preventive aspects. The most effective diarrheal prevention strategy in young infants worldwide is promotion of exclusive breast feeding.

  20. Safety of active rehabilitation for persistent symptoms after pediatric sport-related concussion: A randomized controlled trial.

    PubMed

    Chan, Catherine; Iverson, Grant L; Purtzki, Jacqueline; Wong, Kathy; Kwan, Vivian; Gagnon, Isabelle; Silverberg, Noah D

    2017-10-05

    To examine the safety and tolerability of an active rehabilitation program for adolescents who are slow to recover from a sport-related concussion. A secondary objective was to estimate the treatment effect for this intervention. Single-site parallel open-label randomized controlled trial (RCT) comparing treatment as usual (TAU) to TAU plus active rehabilitation. Outpatient concussion clinic. Adolescents aged 12-18 with postconcussion symptoms lasting >1 month after a sports-related concussion. TAU consisted of symptom management and return to play advice, return to school facilitation, and physiatry consultation. The active rehabilitation program involved in-clinic sub-symptom threshold aerobic training, coordination exercises, and visualization and imagery techniques with a physiotherapist (M=3.4 sessions) as well as a home exercise program, over six weeks. A blinded assessor systematically monitored for predetermined adverse events in weekly telephone calls over the six-week intervention period. The treating physiotherapist also recorded in-clinic symptom exacerbations during aerobic training. The Post-Concussion Symptom Scale was the primary efficacy outcome. Nineteen participants were randomized and none dropped out of the study. Of the 12 adverse events detected (6 in each group), 10 were symptom exacerbations from one weekly telephone assessment to the next and 2 were Emergency Department visits. Four adverse events were referred to an external safety committee and deemed unrelated to the study procedures. In-clinic symptom exacerbations occurred in 30% (9 of 30) of aerobic training sessions, but resolved within 24 hours in all instances. In linear mixed modeling, active rehabilitation was associated with a greater reduction on the Post-Concussion Symptom Scale than TAU only. The results support the safety, tolerability, and potential efficacy of active rehabilitation for adolescents with persistent postconcussion symptoms. Copyright © 2017. Published by

  1. Flux Tensor Constrained Geodesic Active Contours with Sensor Fusion for Persistent Object Tracking

    PubMed Central

    Bunyak, Filiz; Palaniappan, Kannappan; Nath, Sumit Kumar; Seetharaman, Gunasekaran

    2007-01-01

    This paper makes new contributions in motion detection, object segmentation and trajectory estimation to create a successful object tracking system. A new efficient motion detection algorithm referred to as the flux tensor is used to detect moving objects in infrared video without requiring background modeling or contour extraction. The flux tensor-based motion detector when applied to infrared video is more accurate than thresholding ”hot-spots”, and is insensitive to shadows as well as illumination changes in the visible channel. In real world monitoring tasks fusing scene information from multiple sensors and sources is a useful core mechanism to deal with complex scenes, lighting conditions and environmental variables. The object segmentation algorithm uses level set-based geodesic active contour evolution that incorporates the fusion of visible color and infrared edge informations in a novel manner. Touching or overlapping objects are further refined during the segmentation process using an appropriate shape-based model. Multiple object tracking using correspondence graphs is extended to handle groups of objects and occlusion events by Kalman filter-based cluster trajectory analysis and watershed segmentation. The proposed object tracking algorithm was successfully tested on several difficult outdoor multispectral videos from stationary sensors and is not confounded by shadows or illumination variations. PMID:19096530

  2. Origin, persistence and biological activity of genetic material in prebiotic habitats.

    PubMed

    Franchi, Marco; Gallori, Enzo

    2004-02-01

    Molecules which store genetic information (i.e. RNA and DNA) are central to all life on Earth. The formation of these complex molecules, and ultimately life, required specific conditions, including the synthesis and concentration of precursors (nucleotides), the joining of these monomers into larger molecules (polynucleotides), their protection in critical conditions (like those probably existing in primeval habitats), and the expression of the biological potential of the informational molecule (its capacity to multiply and evolve). Determining how these steps occurred and how the earliest genetic molecules originated on Earth is a problem that is far from being resolved. Recent observations on the polymerization of nucleotides on clay surfaces and on the resistance of clay-adsorbed nucleic acids to environmental degradation suggest that clay minerals could have acted as a resting place for the formation and preservation of prebiotic genetic molecules, whatever they were, and for the self-organization of the first auto-replicating systems. In the present work, the molecular characteristics and biological activity of different nucleic acids (DNA, RNAs) adsorbed/bound on clay minerals are discussed in the light of their possible role in ancestral environments.

  3. Cooperation of Doxycycline with Phytochemicals and Micronutrients Against Active and Persistent Forms of Borrelia sp

    PubMed Central

    Goc, Anna; Niedzwiecki, Alexandra; Rath, Matthias

    2016-01-01

    Phytochemicals and micronutrients represent a growing theme in antimicrobial defense; however, little is known about their anti-borreliae effects of reciprocal cooperation with antibiotics. A better understanding of this aspect could advance our knowledge and help improve the efficacy of current approaches towards Borrelia sp. In this study, phytochemicals and micronutrients such as baicalein, luteolin, 10-HAD, iodine, rosmarinic acid, and monolaurin, as well as, vitamins D3 and C were tested in a combinations with doxycycline for their in vitro effectiveness against vegetative (spirochetes) and latent (rounded bodies, biofilm) forms of Borrelia burgdorferi and Borrelia garinii. Anti-borreliae effects were evaluated according to checkerboard assays and supported by statistical analysis. The results showed that combination of doxycycline with flavones such as baicalein and luteolin exhibited additive effects against all morphological forms of studied Borrelia sp. Doxycycline combined with iodine demonstrated additive effects against spirochetes and biofilm, whereas with fatty acids such as monolaurin and 10-HAD it produced FICIs of indifference. Additive anti-spirochetal effects were also observed when doxycycline was used with rosmarinic acid and both vitamins D3 and C. Antagonism was not observed in any of the cases. This data revealed the intrinsic anti-borreliae activity of doxycycline with tested phytochemicals and micronutrients indicating that their addition may enhance efficacy of this antibiotic in combating Borrelia sp. Especially the addition of flavones balcalein and luteolin to a doxycycline regimen could be explored further in defining more effective treatments against these bacteria. PMID:27570483

  4. Persisting PET-CT lesion activity and M. tuberculosis mRNA after pulmonary tuberculosis cure

    PubMed Central

    Malherbe, Stephanus T.; Shenai, Shubhada; Ronacher, Katharina; Loxton, Andre G.; Dolganov, Gregory; Kriel, Magdalena; Van, Tran; Chen, Ray Y.; Warwick, James; Via, Laura E.; Song, Taeksun; Lee, Myungsun; Schoolnik, Gary; Tromp, Gerard; Alland, David; Barry, Clifton E.; Winter, Jill; Walzl, Gerhard

    2016-01-01

    The absence of a gold standard to determine when antibiotics have induced sterilizing cure confounds the development of new approaches to treat pulmonary tuberculosis (PTB). We detected PET-CT imaging response patterns consistent with active disease along with the presence of Mycobacterium tuberculosis mRNA in sputum and bronchoalveolar lavage samples in a substantial proportion of adult, HIV-negative PTB patients after standard 6-month treatment plus one year follow-up, including patients with a durable cure and others who later developed recurrent disease. The presence of MTB mRNA in the context of non-resolving and intensifying lesions on PET-CT might indicate ongoing transcription, suggesting that even apparently curative PTB treatment may not eradicate all organisms in most patients. This suggests an important complementary role for the immune response in maintaining a disease-free state. Sterilizing drugs or host-directed therapies and better treatment response markers are likely needed for the successful development of improved and shortened PTB treatment strategies. PMID:27595324

  5. Cooperation of Doxycycline with Phytochemicals and Micronutrients Against Active and Persistent Forms of Borrelia sp.

    PubMed

    Goc, Anna; Niedzwiecki, Alexandra; Rath, Matthias

    2016-01-01

    Phytochemicals and micronutrients represent a growing theme in antimicrobial defense; however, little is known about their anti-borreliae effects of reciprocal cooperation with antibiotics. A better understanding of this aspect could advance our knowledge and help improve the efficacy of current approaches towards Borrelia sp. In this study, phytochemicals and micronutrients such as baicalein, luteolin, 10-HAD, iodine, rosmarinic acid, and monolaurin, as well as, vitamins D3 and C were tested in a combinations with doxycycline for their in vitro effectiveness against vegetative (spirochetes) and latent (rounded bodies, biofilm) forms of Borrelia burgdorferi and Borrelia garinii. Anti-borreliae effects were evaluated according to checkerboard assays and supported by statistical analysis. The results showed that combination of doxycycline with flavones such as baicalein and luteolin exhibited additive effects against all morphological forms of studied Borrelia sp. Doxycycline combined with iodine demonstrated additive effects against spirochetes and biofilm, whereas with fatty acids such as monolaurin and 10-HAD it produced FICIs of indifference. Additive anti-spirochetal effects were also observed when doxycycline was used with rosmarinic acid and both vitamins D3 and C. Antagonism was not observed in any of the cases. This data revealed the intrinsic anti-borreliae activity of doxycycline with tested phytochemicals and micronutrients indicating that their addition may enhance efficacy of this antibiotic in combating Borrelia sp. Especially the addition of flavones balcalein and luteolin to a doxycycline regimen could be explored further in defining more effective treatments against these bacteria.

  6. Flux Tensor Constrained Geodesic Active Contours with Sensor Fusion for Persistent Object Tracking.

    PubMed

    Bunyak, Filiz; Palaniappan, Kannappan; Nath, Sumit Kumar; Seetharaman, Gunasekaran

    2007-08-01

    This paper makes new contributions in motion detection, object segmentation and trajectory estimation to create a successful object tracking system. A new efficient motion detection algorithm referred to as the flux tensor is used to detect moving objects in infrared video without requiring background modeling or contour extraction. The flux tensor-based motion detector when applied to infrared video is more accurate than thresholding "hot-spots", and is insensitive to shadows as well as illumination changes in the visible channel. In real world monitoring tasks fusing scene information from multiple sensors and sources is a useful core mechanism to deal with complex scenes, lighting conditions and environmental variables. The object segmentation algorithm uses level set-based geodesic active contour evolution that incorporates the fusion of visible color and infrared edge informations in a novel manner. Touching or overlapping objects are further refined during the segmentation process using an appropriate shape-based model. Multiple object tracking using correspondence graphs is extended to handle groups of objects and occlusion events by Kalman filter-based cluster trajectory analysis and watershed segmentation. The proposed object tracking algorithm was successfully tested on several difficult outdoor multispectral videos from stationary sensors and is not confounded by shadows or illumination variations.

  7. Association Between Early Participation in Physical Activity Following Acute Concussion and Persistent Postconcussive Symptoms in Children and Adolescents.

    PubMed

    Grool, Anne M; Aglipay, Mary; Momoli, Franco; Meehan, William P; Freedman, Stephen B; Yeates, Keith Owen; Gravel, Jocelyn; Gagnon, Isabelle; Boutis, Kathy; Meeuwisse, Willem; Barrowman, Nick; Ledoux, Andrée-Anne; Osmond, Martin H; Zemek, Roger

    2016-12-20

    Although concussion treatment guidelines advocate rest in the immediate postinjury period until symptoms resolve, no clear evidence has determined that avoiding physical activity expedites recovery. To investigate the association between participation in physical activity within 7 days postinjury and incidence of persistent postconcussive symptoms (PPCS). Prospective, multicenter cohort study (August 2013-June 2015) of 3063 children and adolescents aged 5.00-17.99 years with acute concussion from 9 Pediatric Emergency Research Canada network emergency departments (EDs). Early physical activity participation within 7 days postinjury. Physical activity participation and postconcussive symptom severity were rated using standardized questionnaires in the ED and at days 7 and 28 postinjury. PPCS (≥3 new or worsening symptoms on the Post-Concussion Symptom Inventory) was assessed at 28 days postenrollment. Early physical activity and PPCS relationships were examined by unadjusted analysis, 1:1 propensity score matching, and inverse probability of treatment weighting (IPTW). Sensitivity analyses examined patients (≥3 symptoms) at day 7. Among 2413 participants who completed the primary outcome and exposure, (mean [SD] age, 11.77 [3.35] years; 1205 [39.3%] females), PPCS at 28 days occurred in 733 (30.4%); 1677 (69.5%) participated in early physical activity including light aerobic exercise (n = 795 [32.9%]), sport-specific exercise (n = 214 [8.9%]), noncontact drills (n = 143 [5.9%]), full-contact practice (n = 106 [4.4%]), or full competition (n = 419 [17.4%]), whereas 736 (30.5%) had no physical activity. On unadjusted analysis, early physical activity participants had lower risk of PPCS than those with no physical activity (24.6% vs 43.5%; Absolute risk difference [ARD], 18.9% [95% CI,14.7%-23.0%]). Early physical activity was associated with lower PPCS risk on propensity score matching (n = 1108 [28.7% for early physical activity vs 40

  8. Defective disposal of immune complexes and polyclonal B cell activation persist long after exposure to bacterial lipopolysaccharide in mice

    SciTech Connect

    Granholm, N.A.; Cavallo, T. )

    1989-11-01

    Patients with systemic lupus erythematosus experience clinical exacerbation during superimposed bacterial infection. Previous studies in mice indicated that heightened immune phenomena during exposure to bacterial lipopolysaccharide (LPS) appear to be related, in part, to polyclonal B cell activation, to abnormal disposal of immune complexes (IC), and to increased localization of IC in tissues. To investigate whether such effects were reversible, we administered bacterial LPS to C57BL/6 mice for 5 weeks. Control mice received vehicle alone. We then discontinued LPS, and 6 weeks later LPS and control mice were challenged with a subsaturating dose of radiolabeled IC; the removal of IC from the circulation, their localization in the liver, spleen, and kidney were determined. In comparison to values in control mice, in mice previously exposed to LPS, serologic features of polyclonal B cell activation persisted; liver uptake of pathogenic IC (greater than Ag2Ab2) was normal, but removal of small size IC (less than or equal to Ag2Ab2) from the circulation was delayed; localization of IC in the kidneys was enhanced, and pathologic proteinuria developed. The effects of repeated exposure to bacterial LPS are partially reversible, but they last long after LPS is discontinued and may contribute to altered disposal of IC, enhanced organ localization of IC, and organ dysfunction.

  9. Persistent responsiveness of long-latency auditory cortical activities in response to repeated stimuli of musical timbre and vowel sounds.

    PubMed

    Kuriki, Shinya; Ohta, Keisuke; Koyama, Sachiko

    2007-11-01

    Long-latency auditory-evoked magnetic field and potential show strong attenuation of N1m/N1 responses when an identical stimulus is presented repeatedly due to adaptation of auditory cortical neurons. This adaptation is weak in subsequently occurring P2m/P2 responses, being weaker for piano chords than single piano notes. The adaptation of P2m is more suppressed in musicians having long-term musical training than in nonmusicians, whereas the amplitude of P2 is enhanced preferentially in musicians as the spectral complexity of musical tones increases. To address the key issues of whether such high responsiveness of P2m/P2 responses to complex sounds is intrinsic and common to nonmusical sounds, we conducted a magnetoencephalographic study on participants who had no experience of musical training, using consecutive trains of piano and vowel sounds. The dipole moment of the P2m sources located in the auditory cortex indicated significantly suppressed adaptation in the right hemisphere both to piano and vowel sounds. Thus, the persistent responsiveness of the P2m activity may be inherent, not induced by intensive training, and common to spectrally complex sounds. The right hemisphere dominance of the responsiveness to musical and speech sounds suggests analysis of acoustic features of object sounds to be a significant function of P2m activity.

  10. Persistent long-term (1944-2015) ionosphere-magnetosphere associations at the area of intense seismic activity and beyond

    NASA Astrophysics Data System (ADS)

    Gulyaeva, T. L.; Arikan, F.; Stanislawska, I.

    2017-02-01

    Analysis of the earthquakes catalogues since 1944 reveals the area of the peak global earthquake occurrence in the Pacific Ocean southwards from the magnetic equator, in particular, at Australia. In the present study a long series of geomagnetic aa indices gathered from two antipodal magnetic observatories at Melbourne (Australia) and Greenwich (UK) are compared with the monthly-hourly critical frequency, foF2, from the nearby ionosonde measurements at Canberra and Slough (Chilton) and Moscow (control site) for 1944-2015. The annual percentage occurrence of the positive ionosphere storms W index (pW+) and negative index (pW-) is determined. It is found that the occurrence of the ionosphere plasma depletion pW- of the instant foF2 as compared to the monthly median is well correlated with the aa index at all three sites (cc > 0.85). The positive storm signatures of the plasma density enhancement pW+ show high correlation with the geomagnetic activity aa index at Slough (cc = 0.68) and Moscow (cc = 0.92) but drastic difference of missing correlation at Canberra (cc = 0.06). It has been suggested that the frequent earthquake occurrence over Australia may produce the persistent significant ionosphere plasma enhancements at Canberra which disrupts balance between the ionosphere-magnetosphere activities.

  11. Diesel exhaust exposure enhances venoconstriction via uncoupling of eNOS

    SciTech Connect

    Knuckles, Travis L.; Lund, Amie K.; Lucas, Selita N.; Campen, Matthew J.

    2008-08-01

    Environmental air pollution is associated with adverse cardiovascular events, including increased hospital admissions due to heart failure and myocardial infarction. The exact mechanism(s) by which air pollution affects the heart and vasculature is currently unknown. Recent studies have found that exposure to air pollution enhances arterial vasoconstriction in humans and animal models. Work in our laboratory has shown that diesel emissions (DE) enhance vasoconstriction of mouse coronary arteries. Thus, we hypothesized that DE could enhance vasoconstriction in arteries and veins through uncoupling of endothelial nitric oxide synthase (eNOS). To test this hypothesis, we first bubbled DE through a physiological saline solution and exposed isolated mesenteric veins. Second, we exposed animals, whole body, to DE at 350 {mu}g/m{sup 3} for 4 h, after which mesenteric arteries and veins were isolated. Results from these experiments show that saline bubbled with DE as well as inhaled DE enhances vasoconstriction in veins but not arteries. Exposure to several representative volatile organic compounds found in the DE-exposed saline did not enhance arterial constriction. L-nitro-arginine-methyl-ester (L-NAME), an eNOS inhibitor, normalized the control vessels to the DE-exposed vessels implicating an uncoupling of eNOS as a mechanism for enhanced vasoconstriction. The principal conclusions of this research are 1) veins exhibit endothelial dysfunction following in vivo and ex vivo exposures to DE, 2) veins appear to be more sensitive to DE effects than arteries, and 3) DE components most likely induce endothelial dysfunction through the uncoupling of eNOS.

  12. Role of eNOS in water exchange index maintenance-MRI studies

    NASA Astrophysics Data System (ADS)

    Atochin, D.; Litvak, M.; Huang, S.; Kim, Y. R.; Huang, P.

    2017-08-01

    Stroke studies employ experimental models of cerebral ischemic and reperfusion injury in rodents. MRI provides valuable supravital data of cerebral blood flow and brain tissue damage. This paper presents MRI applications for cerebral blood flow research in mice lines with impaired nitric oxide production by endothelial nitric oxide synthase. Our data demonstrates that specific modifications of MRI methodology in transgenic mouse models help to evaluate the role of eNOS in the brain-blood barrier function.

  13. eNOS gene polymorphisms modify the association of PM(10) with oxidative stress.

    PubMed

    Kim, Jin Hee; Choi, Yoon-Hyeong; Bae, Sanghyuk; Park, Hye-Yin; Hong, Yun-Chul

    2012-11-15

    Previous studies have suggested that air pollution increases various health outcomes through oxidative stress and oxidative stress-related genes modify the relationship between air pollution and health outcomes. Therefore, we evaluated the effect of PM(10) on the levels of malondialdehyde (MDA), oxidative stress biomarker, and the effect modification by genetic polymorphisms of eNOS, oxidative stress-related gene, in the 560 Korean elderly. We obtained urine samples repeatedly from participants during five medical examinations between 2008 and 2010 and all ambient air pollutant concentration data from the Korea National Institute of Environmental Research air quality monitoring system. We measured urinary levels of MDA to assess oxidative stress and genotyped eNOS (rs1799983, rs2853796, and rs7830). Mixed-effect model was used to estimate the effect of PM(10) on the level of oxidative stress biomarker and their modification by genotypes. PM(10) showed apparent positive effect on MDA level after adjusting for age, sex, BMI, cotinine level, temperature, dew point, levels of SO(2), O(3), NO(2), and CO, and season (p=0.0133). Moreover, the association of PM(10) with MDA was found only in participants with eNOS GG genotype for rs1799983 (p=0.0107), TT genotype for rs2853796 (p=0.0289), or GT genotype for rs7830 (p=0.0158) and in participants with a set of risky haplotypes (GTT, GTG, GGT, and TGT) (p=0.0093). Our results suggest that PM(10) affect oxidative stress in the elderly and eNOS genotype affect the oxidative stress level in regard of exposure to PM(10).

  14. eNOS S-nitrosylates β-actin on Cys374 and regulates PKC-θ at the immune synapse by impairing actin binding to profilin-1.

    PubMed

    García-Ortiz, Almudena; Martín-Cofreces, Noa B; Ibiza, Sales; Ortega, Ángel; Izquierdo-Álvarez, Alicia; Trullo, Antonio; Victor, Víctor M; Calvo, Enrique; Sot, Begoña; Martínez-Ruiz, Antonio; Vázquez, Jesús; Sánchez-Madrid, Francisco; Serrador, Juan M

    2017-04-01

    The actin cytoskeleton coordinates the organization of signaling microclusters at the immune synapse (IS); however, the mechanisms involved remain poorly understood. We show here that nitric oxide (NO) generated by endothelial nitric oxide synthase (eNOS) controls the coalescence of protein kinase C-θ (PKC-θ) at the central supramolecular activation cluster (c-SMAC) of the IS. eNOS translocated with the Golgi to the IS and partially colocalized with F-actin around the c-SMAC. This resulted in reduced actin polymerization and centripetal retrograde flow of β-actin and PKC-θ from the lamellipodium-like distal (d)-SMAC, promoting PKC-θ activation. Furthermore, eNOS-derived NO S-nitrosylated β-actin on Cys374 and impaired actin binding to profilin-1 (PFN1), as confirmed with the transnitrosylating agent S-nitroso-L-cysteine (Cys-NO). The importance of NO and the formation of PFN1-actin complexes on the regulation of PKC-θ was corroborated by overexpression of PFN1- and actin-binding defective mutants of β-actin (C374S) and PFN1 (H119E), respectively, which reduced the coalescence of PKC-θ at the c-SMAC. These findings unveil a novel NO-dependent mechanism by which the actin cytoskeleton controls the organization and activation of signaling microclusters at the IS.

  15. eNOS S-nitrosylates β-actin on Cys374 and regulates PKC-θ at the immune synapse by impairing actin binding to profilin-1

    PubMed Central

    García-Ortiz, Almudena; Martín-Cofreces, Noa B.; Ibiza, Sales; Ortega, Ángel; Izquierdo-Álvarez, Alicia; Trullo, Antonio; Victor, Víctor M.; Calvo, Enrique; Sot, Begoña; Martínez-Ruiz, Antonio; Vázquez, Jesús; Sánchez-Madrid, Francisco

    2017-01-01

    The actin cytoskeleton coordinates the organization of signaling microclusters at the immune synapse (IS); however, the mechanisms involved remain poorly understood. We show here that nitric oxide (NO) generated by endothelial nitric oxide synthase (eNOS) controls the coalescence of protein kinase C-θ (PKC-θ) at the central supramolecular activation cluster (c-SMAC) of the IS. eNOS translocated with the Golgi to the IS and partially colocalized with F-actin around the c-SMAC. This resulted in reduced actin polymerization and centripetal retrograde flow of β-actin and PKC-θ from the lamellipodium-like distal (d)-SMAC, promoting PKC-θ activation. Furthermore, eNOS-derived NO S-nitrosylated β-actin on Cys374 and impaired actin binding to profilin-1 (PFN1), as confirmed with the transnitrosylating agent S-nitroso-L-cysteine (Cys-NO). The importance of NO and the formation of PFN1-actin complexes on the regulation of PKC-θ was corroborated by overexpression of PFN1- and actin-binding defective mutants of β-actin (C374S) and PFN1 (H119E), respectively, which reduced the coalescence of PKC-θ at the c-SMAC. These findings unveil a novel NO-dependent mechanism by which the actin cytoskeleton controls the organization and activation of signaling microclusters at the IS. PMID:28394935

  16. Docosahexaenoic acid inhibits vascular endothelial growth factor (VEGF)-induced cell migration via the GPR120/PP2A/ERK1/2/eNOS signaling pathway in human umbilical vein endothelial cells.

    PubMed

    Chao, Che-Yi; Lii, Chong-Kuei; Ye, Siou-Yu; Li, Chien-Chun; Lu, Chia-Yang; Lin, Ai-Hsuan; Liu, Kai-Li; Chen, Haw-Wen

    2014-05-07

    Cell migration plays an important role in angiogenesis and wound repair. Vascular endothelial growth factor (VEGF) is an endothelial cell-specific mitogen that is essential for endothelial cell survival, proliferation, and migration. Docosahexaenoic acid (DHA), an n-3 polyunsaturated fatty acid, shows both anti-inflammatory and antioxidant activities in vitro and in vivo. This study investigated the molecular mechanism by which DHA down-regulates VEGF-induced cell migration. HUVECs were used as the study model, and the MTT assay, Western blot, wound-healing assay, and phosphatase activity assay were used to explore the effects of DHA on cell migration. GPR120 is the putative receptor for DHA action. The results showed that DHA, PD98059 (an ERK1/2 inhibitor), and GW9508 (a GPR120 agonist) inhibited VEGF-induced cell migration. In contrast, pretreatment with okadaic acid (OA, a PP2A inhibitor) and S-nitroso-N-acetyl-DL-penicillamine (an NO donor) reversed the inhibition of cell migration by DHA. VEGF-induced cell migration was accompanied by phosphorylation of ERK1/2 and eNOS. Treatment of HUVECs with DHA increased PP2A enzyme activity and decreased VEGF-induced phosphorylation of ERK1/2 and eNOS. However, pretreatment with OA significantly decreased DHA-induced PP2A enzyme activity and reversed the DHA inhibition of VEGF-induced ERK1/2 and eNOS phosphorylation. These results suggest that stimulation of PP2A activity and inhibition of the VEGF-induced ERK1/2/eNOS signaling pathway may be involved in the DHA suppression of VEGF-induced cell migration. Thus, the effect of DHA on angiogenesis and wound repair is at least partly by virtue of its attenuation of cell migration.

  17. Some Aspects of Essentially Nonoscillatory (ENO) Formulations for the Euler Equations, Part 3

    NASA Technical Reports Server (NTRS)

    Chakravarthy, Sukumar R.

    1990-01-01

    An essentially nonoscillatory (ENO) formulation is described for hyperbolic systems of conservation laws. ENO approaches are based on smart interpolation to avoid spurious numerical oscillations. ENO schemes are a superset of Total Variation Diminishing (TVD) schemes. In the recent past, TVD formulations were used to construct shock capturing finite difference methods. At extremum points of the solution, TVD schemes automatically reduce to being first-order accurate discretizations locally, while away from extrema they can be constructed to be of higher order accuracy. The new framework helps construct essentially non-oscillatory finite difference methods without recourse to local reductions of accuracy to first order. Thus arbitrarily high orders of accuracy can be obtained. The basic general ideas of the new approach can be specialized in several ways and one specific implementation is described based on: (1) the integral form of the conservation laws; (2) reconstruction based on the primitive functions; (3) extension to multiple dimensions in a tensor product fashion; and (4) Runge-Kutta time integration. The resulting method is fourth-order accurate in time and space and is applicable to uniform Cartesian grids. The construction of such schemes for scalar equations and systems in one and two space dimensions is described along with several examples which illustrate interesting aspects of the new approach.

  18. Buckling Reduces eNOS Production and Stimulates Extracellular Matrix Remodeling in Arteries in Organ Culture.

    PubMed

    Xiao, Yangming; Liu, Qin; Han, Hai-Chao

    2016-09-01

    Artery buckling alters the fluid shear stress and wall stress in the artery but its temporal effect on vascular wall remodeling is poorly understood. The purpose of this study was to investigate the early effect of artery buckling on endothelial nitric oxide synthase (eNOS) expression and extracellular matrix remodeling. Bilateral porcine carotid arteries were maintained in an ex vivo organ culture system with and without buckling while under the same physiological pressure and flow rate for 3-7 days. Matrix metalloproteinase-2 (MMP-2), MMP-9, fibronectin, elastin, collagen I, III and IV, tissue inhibitor of metalloproteinase-2 (TIMP-2), and eNOS were determined using Western blotting and immunohistochemistry. Our results showed that MMP-2 expression level was significantly higher in buckled arteries than in the controls and higher at the inner curve than at the outer curve of buckled arteries, while collagen IV content showed an opposite trend, suggesting that artery buckling increased MMP-2 expression and collagen IV degradation in a site-specific fashion. However, no differences for MMP-9, fibronectin, elastin, collagen I, III, and TIMP-2 were observed among the outer and inner curve sides of buckled arteries and straight controls. Additionally, eNOS expression was significantly decreased in buckled arteries. These results suggest that artery buckling triggers uneven wall remodeling that could lead to development of tortuous arteries.

  19. A Drug Combination Screen Identifies Drugs Active against Amoxicillin-Induced Round Bodies of In Vitro Borrelia burgdorferi Persisters from an FDA Drug Library

    PubMed Central

    Feng, Jie; Shi, Wanliang; Zhang, Shuo; Sullivan, David; Auwaerter, Paul G.; Zhang, Ying

    2016-01-01

    Although currently recommended antibiotics for Lyme disease such as doxycycline or amoxicillin cure the majority of the patients, about 10–20% of patients treated for Lyme disease may experience lingering symptoms including fatigue, pain, or joint and muscle aches. Under experimental stress conditions such as starvation or antibiotic exposure, Borrelia burgdorferi can develop round body forms, which are a type of persister bacteria that appear resistant in vitro to customary first-line antibiotics for Lyme disease. To identify more effective drugs with activity against the round body form of B. burgdorferi, we established a round body persister model induced by exposure to amoxicillin (50 μg/ml) and then screened the Food and Drug Administration drug library consisting of 1581 drug compounds and also 22 drug combinations using the SYBR Green I/propidium iodide viability assay. We identified 23 drug candidates that have higher activity against the round bodies of B. burgdorferi than either amoxicillin or doxycycline. Eleven individual drugs scored better than metronidazole and tinidazole which have been previously described to be active against round bodies. In this amoxicillin-induced round body model, some drug candidates such as daptomycin and clofazimine also displayed enhanced activity which was similar to a previous screen against stationary phase B. burgdorferi persisters not exposure to amoxicillin. Additional candidate drugs active against round bodies identified include artemisinin, ciprofloxacin, nifuroxime, fosfomycin, chlortetracycline, sulfacetamide, sulfamethoxypyridazine and sulfathiozole. Two triple drug combinations had the highest activity against amoxicillin-induced round bodies and stationary phase B. burgdorferi persisters: artemisinin/cefoperazone/doxycycline and sulfachlorpyridazine/daptomycin/doxycycline. These findings confirm and extend previous findings that certain drug combinations have superior activity against B. burgdorferi

  20. Distinct expression of alkaline phosphatase activity in epilimnetic bacteria: Implication for persistent DOC consumption in a P-limited reservoir

    NASA Astrophysics Data System (ADS)

    Tseng, Y.; Kao, S.; Shiah, F.

    2013-12-01

    In a P-deficient system, P availability usually controls the microbial activity and thus the ecosystem function. Thingstad et al. (1997) first addressed a 'Malfunctioning Microbial-loop' theory, which stated that low bacterial production (BP) caused by insufficient nutrient supply would result in DOC accumulation in an oligotrophic ecosystem. In this study we re-examined the theory by conducting seasonal patterns and correlations among soluble reactive phosphate (SRP) and DOC, microbial abundances (picocyanobacteria, bacteria, and heterotrophic nanoflagellate; HNF) and activities (primary production, bacterial production, and alkaline phosphatase activity; APA) coupled with enzyme-labeled fluorescence (ELF) assays on bacterioplankton in a subtropical reservoir sharing the common features, nitrate-replete and P-deficient, with most natural freshwater system during Oct 2007-Oct 2008. Persistently high APA was recorded during most of time, implying that the system was P-deficient. Size fractionated APA and ELF assay revealed that bacteria were the major APA contributor. However, significantly low epilimnion DOC was recorded during the stratified summer season accompanying with high BP and APA as well as high PP, implying that heterotrophic bacteria can well sustain in P-deficient system by utilizing DOP to rapidly lower down DOC under relatively high PP. Such findings oppose the 'Malfunctioning Microbial-loop' theory. On the other hand, strong epilimnetic DOC accumulation occurred in Oct 2007 under low light and low PP condition accompanying with high abundance of HNF, implying that HNF grazing may contribute to a certain degree of DOC accumulation. Correlation matrix supported our suggestions. This study testified the DOC dynamics in P-deficient ecosystem are tightly coupled with the source (PP and grazing) and sink (BP). We also suggested that in SRP-limited freshwater systems bacteria are capable of breaking down autochthonous DOC to reduce the chance of DOC

  1. Transactivation activity of Meq, a Marek's disease herpesvirus bZIP protein persistently expressed in latently infected transformed T cells.

    PubMed Central

    Qian, Z; Brunovskis, P; Rauscher, F; Lee, L; Kung, H J

    1995-01-01

    Marek's disease virus (MDV) is an avian herpesvirus that induces a variety of diseases, including T-cell lymphomas, in chickens. In latently infected, transformed lymphoid cells, very few viral transcripts or proteins are detected. We previously described a gene, meq (MDV EcoQ), which is persistently expressed in MDV-transformed tumor samples and cell lines. meq codes for a 339-amino-acid protein with a basic-leucine zipper domain near its N terminus and a proline-rich domain near its C terminus. The basic-leucine zipper domain shows homology with Jun/Fos family proteins, whereas the proline-rich domain resembles that of the WT-1 tumor suppressor protein. These structural features raise the possibility that Meq functions as a transcription factor in regulating viral latency or oncogenesis. In this report, we show that the proline-rich domain is a potent transcription activator when fused to the yeast (Saccharomyces cerevisiae) Gal4(1-147) DNA-binding domain. The transactivation activity maps to the C-terminal 130 amino acids, with the last 33 amino acids essential. In the absence of these 33 amino acids, a two-and-one-half proline-rich repeat structure was found to exhibit repression activity. We further show that Meq is able to dimerize not only with itself but also with c-Jun. Meq/c-Jun heterodimers bind to an AP1-like sequence in the meq promoter region with an affinity much greater than that of Meq/Meq or c-Jun/c-Jun homodimers. Cotransfection chloramphenicol acetyltransferase assays suggest that the Meq/c-Jun heterodimers can up-regulate Meq expression in both chicken embryo fibroblasts and F9 cells. Our data provide the first biochemical evidence that Meq is a transcriptional factor and identify c-Jun as one of Meq's interacting partners. PMID:7769661

  2. Comparison of High Temporal Resolution Gas Composition and Seismic Data from Three Persistently Degassing and Seismically Active Alaskan Volcanoes

    NASA Astrophysics Data System (ADS)

    Lopez, T. M.; West, M. E.; Aiuppa, A.; Giudice, G.; Galle, B.; Ketner, D. M.; Kaufman, M.; Paskievitch, J.; Keyson, L.; Prejean, S. G.

    2014-12-01

    Fluid movement in the subsurface of active volcanoes is frequently thought to produce elevated seismicity; however the actual type of fluid (i.e. magma, volatiles, or hydrothermal waters) cannot be uniquely distinguished using seismic data alone. The chemical composition of emitted volcanic gases can be used to distinguish magmatic from hydrothermal degassing, as well as to identify magma recharge from depth. In this project we aim to use complementary geochemical and seismic datasets to identify possible correlations between volcanic gas composition and seismicity, in an effort to constrain seismic signatures of subsurface fluid movement. We present new datasets collected in July and August 2013 from three very seismically active and persistently degassing volcanoes within the Katmai Volcanic Cluster (KVC), Alaska: Mount Martin, Mount Mageik, and Trident Volcanoes. During the field deployment, high temporal resolution (~1 Hz) major-species (e.g. H2O, CO2, SO2, H2S) gas composition measurements were collected over four ~30 minute sample periods each day from the target volcanoes using campaign MultiGas instruments located adjacent to the primary degassing sources. These instruments were complemented with two co-located 6TD broadband seismometers on the crater rims of Mount Martin and Mount Magiek, as well as by the Alaska Volcano Observatory Katmai seismic network, which consists of nine short-period and two broad-band seismometers located within 30 km of the target volcanoes. Here we present a comparison of coincident timeseries gas geochemistry and seismic datasets from the three target volcanoes in an effort to provide insight into the types of fluids that may be triggering volcano-seismicity at these actively degassing volcanoes.

  3. Vasoinhibins prevent retinal vasopermeability associated with diabetic retinopathy in rats via protein phosphatase 2A-dependent eNOS inactivation.

    PubMed

    García, Celina; Aranda, Jorge; Arnold, Edith; Thébault, Stéphanie; Macotela, Yazmín; López-Casillas, Fernando; Mendoza, Valentín; Quiroz-Mercado, Hugo; Hernández-Montiel, Hebert Luis; Lin, Sue-Hwa; de la Escalera, Gonzalo Martínez; Clapp, Carmen

    2008-06-01

    Increased retinal vasopermeability contributes to diabetic retinopathy, the leading cause of blindness in working-age adults. Despite clinical progress, effective therapy remains a major need. Vasoinhibins, a family of peptides derived from the protein hormone prolactin (and inclusive of the 16-kDa fragment of prolactin), antagonize the proangiogenic effects of VEGF, a primary mediator of retinal vasopermeability. Here, we demonstrate what we believe to be a novel function of vasoinhibins as inhibitors of the increased retinal vasopermeability associated with diabetic retinopathy. Vasoinhibins inhibited VEGF-induced vasopermeability in bovine aortic and rat retinal capillary endothelial cells in vitro. In vivo, vasoinhibins blocked retinal vasopermeability in diabetic rats and in response to intravitreous injection of VEGF or of vitreous from patients with diabetic retinopathy. Inhibition by vasoinhibins was similar to that achieved following immunodepletion of VEGF from human diabetic retinopathy vitreous or blockage of NO synthesis, suggesting that vasoinhibins inhibit VEGF-induced NOS activation. We further showed that vasoinhibins activate protein phosphatase 2A (PP2A), leading to eNOS dephosphorylation at Ser1179 and, thereby, eNOS inactivation. Moreover, intravitreous injection of okadaic acid, a PP2A inhibitor, blocked the vasoinhibin effect on endothelial cell permeability and retinal vasopermeability. These results suggest that vasoinhibins have the potential to be developed as new therapeutic agents to control the excessive retinal vasopermeability observed in diabetic retinopathy and other vasoproliferative retinopathies.

  4. Computational and anti-tumor studies of 7a-Aza-B-homostigmast-5-eno [7a, 7-d] tetrazole-3β-yl chloride

    NASA Astrophysics Data System (ADS)

    Alam, Mahboob; Alam, Mohammad Jane; Nami, Shahab A. A.; Lee, Dong-Ung; Azam, Mohammad; Ahmad, Shabbir

    2016-03-01

    The present paper reports the detailed computational study including molecular docking of a biologically active steroidal tetrazole, 7a-Aza-B-homostigmast-5-eno [7a,7-d] tetrazole-3β-yl chloride. The molecular structure, IR and NMR (13C and 1H) spectra of the tetrazole were interpreted by comparing the experimental results with the theoretical, B3LYP/6-311G(d,p) calculations. The vibrational bands appearing in the FTIR are assigned with great accuracy using animated modes. Molecular properties like HOMO-LUMO analysis, chemical reactivity descriptors, MEP mapping, dipole moment and natural atomic charges have been presented at the same level of theory. The theoretical results are found in good correlation with the experimental data. Moreover, the Hirshfeld analysis was carried out to ascertain the secondary interactions and associated 2D fingerprint plots. The in vitro anti-tumor activity of 7a-Aza-B-homostigmast-5-eno [7a,7-d] tetrazole-3β-yl chloride has also been carried out against five human tumor cell lines. Doxorubicin is used as a standard drug for the in vitro anti-tumor screening.

  5. Vasoinhibins prevent retinal vasopermeability associated with diabetic retinopathy in rats via protein phosphatase 2A–dependent eNOS inactivation

    PubMed Central

    García, Celina; Aranda, Jorge; Arnold, Edith; Thébault, Stéphanie; Macotela, Yazmín; López-Casillas, Fernando; Mendoza, Valentín; Quiroz-Mercado, Hugo; Hernández-Montiel, Hebert Luis; Lin, Sue-Hwa; de la Escalera, Gonzalo Martínez; Clapp, Carmen

    2008-01-01

    Increased retinal vasopermeability contributes to diabetic retinopathy, the leading cause of blindness in working-age adults. Despite clinical progress, effective therapy remains a major need. Vasoinhibins, a family of peptides derived from the protein hormone prolactin (and inclusive of the 16-kDa fragment of prolactin), antagonize the proangiogenic effects of VEGF, a primary mediator of retinal vasopermeability. Here, we demonstrate what we believe to be a novel function of vasoinhibins as inhibitors of the increased retinal vasopermeability associated with diabetic retinopathy. Vasoinhibins inhibited VEGF-induced vasopermeability in bovine aortic and rat retinal capillary endothelial cells in vitro. In vivo, vasoinhibins blocked retinal vasopermeability in diabetic rats and in response to intravitreous injection of VEGF or of vitreous from patients with diabetic retinopathy. Inhibition by vasoinhibins was similar to that achieved following immunodepletion of VEGF from human diabetic retinopathy vitreous or blockage of NO synthesis, suggesting that vasoinhibins inhibit VEGF-induced NOS activation. We further showed that vasoinhibins activate protein phosphatase 2A (PP2A), leading to eNOS dephosphorylation at Ser1179 and, thereby, eNOS inactivation. Moreover, intravitreous injection of okadaic acid, a PP2A inhibitor, blocked the vasoinhibin effect on endothelial cell permeability and retinal vasopermeability. These results suggest that vasoinhibins have the potential to be developed as new therapeutic agents to control the excessive retinal vasopermeability observed in diabetic retinopathy and other vasoproliferative retinopathies. PMID:18497878

  6. Hybrid coordination-network-engineering for bridging cascaded channels to activate long persistent phosphorescence in the second biological window

    PubMed Central

    Qin, Xixi; Li, Yang; Zhang, Ruili; Ren, Jinjun; Gecevicius, Mindaugas; Wu, Yiling; Sharafudeen, Kaniyarakkal; Dong, Guoping; Zhou, Shifeng; Ma, Zhijun; Qiu, Jianrong

    2016-01-01

    We present a novel “Top-down” strategy to design the long phosphorescent phosphors in the second biological transparency window via energy transfer. Inherence in this approach to material design involves an ingenious engineering for hybridizing the coordination networks of hosts, tailoring the topochemical configuration of dopants, and bridging a cascaded tunnel for transferring the persistent energy from traps, to sensitizers and then to acceptors. Another significance of this endeavour is to highlight a rational scheme for functionally important hosts and dopants, Cr/Nd co-doped Zn1−xCaxGa2O4 solid solutions. Such solid-solution is employed as an optimized host to take advantage of its characteristic trap site level to establish an electron reservoir and network parameters for the precipitation of activators Nd3+ and Cr3+. The results reveal that the strategy employed here has the great potential, as well as opens new opportunities for future new-wavelength, NIR phosphorescent phosphors fabrication with many potential multifunctional bio-imaging applications. PMID:26843129

  7. Q-Learning and p-persistent CSMA based rendezvous protocol for cognitive radio networks operating with shared spectrum activity

    NASA Astrophysics Data System (ADS)

    Watson, Clifton L.; Biswas, Subir

    2014-06-01

    With an increasing demand for spectrum, dynamic spectrum access (DSA) has been proposed as viable means for providing the flexibility and greater access to spectrum necessary to meet this demand. Within the DSA concept, unlicensed secondary users temporarily "borrow" or access licensed spectrum, while respecting the licensed primary user's rights to that spectrum. As key enablers for DSA, cognitive radios (CRs) are based on software-defined radios which allow them to sense, learn, and adapt to the spectrum environment. These radios can operate independently and rapidly switch channels. Thus, the initial setup and maintenance of cognitive radio networks are dependent upon the ability of CR nodes to find each other, in a process known as rendezvous, and create a link on a common channel for the exchange of data and control information. In this paper, we propose a novel rendezvous protocol, known as QLP, which is based on Q-learning and the p-persistent CSMA protocol. With the QLP protocol, CR nodes learn which channels are best for rendezvous and thus adapt their behavior to visit those channels more frequently. We demonstrate through simulation that the QLP protocol provides a rendevous capability for DSA environments with different dynamics of PU activity, while attempting to achieve the following performance goals: (1) minimize the average time-to-rendezvous, (2) maximize system throughput, (3) minimize primary user interference, and (4) minimize collisions among CR nodes.

  8. Indonesian fire activity and smoke pollution in 2015 show persistent nonlinear sensitivity to El Niño-induced drought

    NASA Astrophysics Data System (ADS)

    Field, Robert D.; van der Werf, Guido R.; Fanin, Thierry; Fetzer, Eric J.; Fuller, Ryan; Jethva, Hiren; Levy, Robert; Livesey, Nathaniel J.; Luo, Ming; Torres, Omar; Worden, Helen M.

    2016-08-01

    The 2015 fire season and related smoke pollution in Indonesia was more severe than the major 2006 episode, making it the most severe season observed by the NASA Earth Observing System satellites that go back to the early 2000s, namely active fire detections from the Terra and Aqua Moderate Resolution Imaging Spectroradiometers (MODIS), MODIS aerosol optical depth, Terra Measurement of Pollution in the Troposphere (MOPITT) carbon monoxide (CO), Aqua Atmospheric Infrared Sounder (AIRS) CO, Aura Ozone Monitoring Instrument (OMI) aerosol index, and Aura Microwave Limb Sounder (MLS) CO. The MLS CO in the upper troposphere showed a plume of pollution stretching from East Africa to the western Pacific Ocean that persisted for 2 mo. Longer-term records of airport visibility in Sumatra and Kalimantan show that 2015 ranked after 1997 and alongside 1991 and 1994 as among the worst episodes on record. Analysis of yearly dry season rainfall from the Tropical Rainfall Measurement Mission (TRMM) and rain gauges shows that, due to the continued use of fire to clear and prepare land on degraded peat, the Indonesian fire environment continues to have nonlinear sensitivity to dry conditions during prolonged periods with less than 4 mm/d of precipitation, and this sensitivity appears to have increased over Kalimantan. Without significant reforms in land use and the adoption of early warning triggers tied to precipitation forecasts, these intense fire episodes will reoccur during future droughts, usually associated with El Niño events.

  9. Indonesian fire activity and smoke pollution in 2015 show persistent nonlinear sensitivity to El Niño-induced drought.

    PubMed

    Field, Robert D; van der Werf, Guido R; Fanin, Thierry; Fetzer, Eric J; Fuller, Ryan; Jethva, Hiren; Levy, Robert; Livesey, Nathaniel J; Luo, Ming; Torres, Omar; Worden, Helen M

    2016-08-16

    The 2015 fire season and related smoke pollution in Indonesia was more severe than the major 2006 episode, making it the most severe season observed by the NASA Earth Observing System satellites that go back to the early 2000s, namely active fire detections from the Terra and Aqua Moderate Resolution Imaging Spectroradiometers (MODIS), MODIS aerosol optical depth, Terra Measurement of Pollution in the Troposphere (MOPITT) carbon monoxide (CO), Aqua Atmospheric Infrared Sounder (AIRS) CO, Aura Ozone Monitoring Instrument (OMI) aerosol index, and Aura Microwave Limb Sounder (MLS) CO. The MLS CO in the upper troposphere showed a plume of pollution stretching from East Africa to the western Pacific Ocean that persisted for 2 mo. Longer-term records of airport visibility in Sumatra and Kalimantan show that 2015 ranked after 1997 and alongside 1991 and 1994 as among the worst episodes on record. Analysis of yearly dry season rainfall from the Tropical Rainfall Measurement Mission (TRMM) and rain gauges shows that, due to the continued use of fire to clear and prepare land on degraded peat, the Indonesian fire environment continues to have nonlinear sensitivity to dry conditions during prolonged periods with less than 4 mm/d of precipitation, and this sensitivity appears to have increased over Kalimantan. Without significant reforms in land use and the adoption of early warning triggers tied to precipitation forecasts, these intense fire episodes will reoccur during future droughts, usually associated with El Niño events.

  10. Hybrid coordination-network-engineering for bridging cascaded channels to activate long persistent phosphorescence in the second biological window

    NASA Astrophysics Data System (ADS)

    Qin, Xixi; Li, Yang; Zhang, Ruili; Ren, Jinjun; Gecevicius, Mindaugas; Wu, Yiling; Sharafudeen, Kaniyarakkal; Dong, Guoping; Zhou, Shifeng; Ma, Zhijun; Qiu, Jianrong

    2016-02-01

    We present a novel “Top-down” strategy to design the long phosphorescent phosphors in the second biological transparency window via energy transfer. Inherence in this approach to material design involves an ingenious engineering for hybridizing the coordination networks of hosts, tailoring the topochemical configuration of dopants, and bridging a cascaded tunnel for transferring the persistent energy from traps, to sensitizers and then to acceptors. Another significance of this endeavour is to highlight a rational scheme for functionally important hosts and dopants, Cr/Nd co-doped Zn1‑xCaxGa2O4 solid solutions. Such solid-solution is employed as an optimized host to take advantage of its characteristic trap site level to establish an electron reservoir and network parameters for the precipitation of activators Nd3+ and Cr3+. The results reveal that the strategy employed here has the great potential, as well as opens new opportunities for future new-wavelength, NIR phosphorescent phosphors fabrication with many potential multifunctional bio-imaging applications.

  11. Indonesian fire activity and smoke pollution in 2015 show persistent nonlinear sensitivity to El Niño-induced drought

    PubMed Central

    Field, Robert D.; van der Werf, Guido R.; Fanin, Thierry; Fetzer, Eric J.; Fuller, Ryan; Jethva, Hiren; Levy, Robert; Livesey, Nathaniel J.; Luo, Ming; Torres, Omar; Worden, Helen M.

    2016-01-01

    The 2015 fire season and related smoke pollution in Indonesia was more severe than the major 2006 episode, making it the most severe season observed by the NASA Earth Observing System satellites that go back to the early 2000s, namely active fire detections from the Terra and Aqua Moderate Resolution Imaging Spectroradiometers (MODIS), MODIS aerosol optical depth, Terra Measurement of Pollution in the Troposphere (MOPITT) carbon monoxide (CO), Aqua Atmospheric Infrared Sounder (AIRS) CO, Aura Ozone Monitoring Instrument (OMI) aerosol index, and Aura Microwave Limb Sounder (MLS) CO. The MLS CO in the upper troposphere showed a plume of pollution stretching from East Africa to the western Pacific Ocean that persisted for 2 mo. Longer-term records of airport visibility in Sumatra and Kalimantan show that 2015 ranked after 1997 and alongside 1991 and 1994 as among the worst episodes on record. Analysis of yearly dry season rainfall from the Tropical Rainfall Measurement Mission (TRMM) and rain gauges shows that, due to the continued use of fire to clear and prepare land on degraded peat, the Indonesian fire environment continues to have nonlinear sensitivity to dry conditions during prolonged periods with less than 4 mm/d of precipitation, and this sensitivity appears to have increased over Kalimantan. Without significant reforms in land use and the adoption of early warning triggers tied to precipitation forecasts, these intense fire episodes will reoccur during future droughts, usually associated with El Niño events. PMID:27482096

  12. Persistent expression of activated notch in the developing hypothalamus affects survival of pituitary progenitors and alters pituitary structure.

    PubMed

    Aujla, Paven K; Bogdanovic, Vedran; Naratadam, George T; Raetzman, Lori T

    2015-08-01

    As the pituitary gland develops, signals from the hypothalamus are necessary for pituitary induction and expansion. Little is known about the control of cues that regulate early signaling between the two structures. Ligands and receptors of the Notch signaling pathway are found in both the hypothalamus and Rathke's pouch. The downstream Notch effector gene Hes1 is required for proper pituitary formation; however, these effects could be due to the action of Hes1 in the hypothalamus, Rathke's pouch, or both. To determine the contribution of hypothalamic Notch signaling to pituitary organogenesis, we used mice with loss and gain of Notch function within the developing hypothalamus. We demonstrate that loss of Notch signaling by conditional deletion of Rbpj in the hypothalamus does not affect expression of Hes1 within the posterior hypothalamus or expression of Hes5. In contrast, expression of activated Notch within the hypothalamus results in ectopic Hes5 expression and increased Hes1 expression, which is sufficient to disrupt pituitary development and postnatal expansion. Taken together, our results indicate that Rbpj-dependent Notch signaling within the developing hypothalamus is not necessary for pituitary development, but persistent Notch signaling and ectopic Hes5 expression in hypothalamic progenitors affects pituitary induction and expansion. © 2015 Wiley Periodicals, Inc.

  13. Persistent expression of activated Notch in the developing hypothalamus affects survival of pituitary progenitors and alters pituitary structure

    PubMed Central

    Aujla, Paven K.; Bogdanovic, Vedran; Naratadam, George T.; Raetzman, Lori T.

    2015-01-01

    Background As the pituitary gland develops, signals from the hypothalamus are necessary for pituitary induction and expansion. Little is known about the control of cues that regulate early signaling between the two structures. Ligands and receptors of the Notch signaling pathway are found in both the hypothalamus and Rathke’s pouch. The downstream Notch effector gene Hes1 is required for proper pituitary formation, however these effects could be due to the action of Hes1 in the hypothalamus, Rathke’s pouch or both. To determine the contribution of hypothalamic Notch signaling to pituitary organogenesis, we used mice with loss and gain of Notch function within the developing hypothalamus. Results We demonstrate that loss of Notch signaling by conditional deletion of Rbpj in the hypothalamus does not affect expression of Hes1 within the posterior hypothalamus or expression of Hes5. In contrast, expression of activated Notch within the hypothalamus results in ectopic Hes5 expression and increased Hes1 expression, which is sufficient to disrupt pituitary development and postnatal expansion. Conclusions Taken together, our results indicate that Rbpjdependent Notch signaling within the developing hypothalamus is not necessary for pituitary development, but persistent Notch signaling and ectopic Hes5 expression in hypothalamic progenitors affects pituitary induction and expansion. PMID:25907274

  14. Faults Activities And Crustal Deformation Along The Arc-Continent Collision Boundary, Eastern Taiwan - Observed From Persistent Scatterer SAR Interferometry

    NASA Astrophysics Data System (ADS)

    Yen, Jiun-Yee; Chang, Chung-Pai; Hooper, Andrew; Chang, Yo-Ho; Liang, Wen-Tzong; Chang, Tsui-Yu

    2010-05-01

    Located in the southeastern periphery of the Eurasian plate, eastern Taiwan marks the collional boundary between the Eurasian plate and the Philippine Sea plate. These two plates converge at about 8 cm/yr near Taiwan and nearly half of the shortening is consumed in eastern Taiwan. There have been many studies in this area about the dynamics of the plate convergence, however, most of the geodetic studies focused on small area (strainmeter), with very few data points (GPS), or only gather data along a specific profile (leveling). We applied the Persistent Scatterer SAR Interferometry in the Longitudinal Valley of eastern Taiwan to observe temporally-variable processes using both ERS and Envisat data. At the same time, leveling and GPS data were measured for the auxiliary tool to verify the deformation rate in this area. Our result indicated that although the area is under active collision, faults do not move in the same fashion along the boundary. In the very northern part of the collided arc, small subsidence has been detected, while in the north-central part very few activity is observed. In the central and southern part of the collisional boundary, patches of faults are moving as rapidly as 15 mm/yr along radar line-of-sight. In addition. between late 2004 and middle 2005 there had been an earthquake swarm consists of shallow earthquakes, which coincided with PSI observation of a large vertical displacement. The comparison between our leveling data and PS results indicated PSI is a reliable tool even in the highly vegetated area in eastern Taiwan.

  15. Behavioral activation therapy for return to work in medication-responsive chronic depression with persistent psychosocial dysfunction.

    PubMed

    Hellerstein, David J; Erickson, Greg; Stewart, Jonathan W; McGrath, Patrick J; Hunnicutt-Ferguson, Kallio; Reynolds, Sarah K; O'Shea, Donna; Chen, Ying; Withers, Amy; Wang, Yuanjia

    2015-02-01

    Chronic depression is associated with significant impairment in work functioning, relationships, and health. Such impairment often persists following medication-induced remission of depressive symptoms. We adapted and tested Behavioral Activation therapy with a goal of return to work (BA-W) in subjects with chronic depression who had responded to medication treatment but remained unemployed. Sixteen adults aged 18-65 with DSM-IV diagnosed Dysthymic Disorder or chronic Major Depression were recruited from clinical trials taking place at the New York State Psychiatric Institute between 4/2009 and 12/2012 and enrolled in 12 weeks of individual manual-driven BA-W. Functioning was measured at intake, post-treatment and at 24 week follow-up. Eighty-seven percent (n=14) of subjects completed the full 12 weeks of BA-W. Hours of work related activity (p<.005, d=0.83), hours of paid work (p<.0003, d=0.54), and work productivity (p<.0004, d=-0.48) increased significantly over the study period. Earned income increased post-treatment (p=.068) with significant changes by 24 week follow-up (p=.011). Secondary outcomes including behavioral avoidance (p<.004, d=-0.56), and global functioning (p<.0003, d=1.42) were also significantly improved post-treatment. Effect sizes, including for outcomes with non-significant changes, were generally in the range of 0.5-0.8. This pilot study provides preliminary evidence of the efficacy of a work-targeted psychotherapy to remediate vocational impairment in subjects with chronic depression. Data suggests that further testing of BA-W using a randomized controlled trial is warranted and may represent a significant advance in treatment for the residual disability present after successful pharmacotherapy. Copyright © 2014 Elsevier Inc. All rights reserved.

  16. RegA Plays a Key Role in Oxygen-Dependent Establishment of Persistence and in Isocitrate Lyase Activity, a Critical Determinant of In vivo Brucella suis Pathogenicity.

    PubMed

    Abdou, Elias; Jiménez de Bagüés, María P; Martínez-Abadía, Ignacio; Ouahrani-Bettache, Safia; Pantesco, Véronique; Occhialini, Alessandra; Al Dahouk, Sascha; Köhler, Stephan; Jubier-Maurin, Véronique

    2017-01-01

    For aerobic human pathogens, adaptation to hypoxia is a critical factor for the establishment of persistent infections, as oxygen availability is low inside the host. The two-component system RegB/A of Brucella suis plays a central role in the control of respiratory systems adapted to oxygen deficiency, and in persistence in vivo. Using an original "in vitro model of persistence" consisting in gradual oxygen depletion, we compared transcriptomes and proteomes of wild-type and ΔregA strains to identify the RegA-regulon potentially involved in the set-up of persistence. Consecutive to oxygen consumption resulting in growth arrest, 12% of the genes in B. suis were potentially controlled directly or indirectly by RegA, among which numerous transcriptional regulators were up-regulated. In contrast, genes or proteins involved in envelope biogenesis and in cellular division were repressed, suggesting a possible role for RegA in the set-up of a non-proliferative persistence state. Importantly, the greatest number of the RegA-repressed genes and proteins, including aceA encoding the functional IsoCitrate Lyase (ICL), were involved in energy production. A potential consequence of this RegA impact may be the slowing-down of the central metabolism as B. suis progressively enters into persistence. Moreover, ICL is an essential determinant of pathogenesis and long-term interactions with the host, as demonstrated by the strict dependence of B. suis on ICL activity for multiplication and persistence during in vivo infection. RegA regulates gene or protein expression of all functional groups, which is why RegA is a key regulator of B. suis in adaptation to oxygen depletion. This function may contribute to the constraint of bacterial growth, typical of chronic infection. Oxygen-dependent activation of two-component systems that control persistence regulons, shared by several aerobic human pathogens, has not been studied in Brucella sp. before. This work therefore contributes

  17. Transient physical and psychosocial activities increase the risk of nonpersistent and persistent low back pain: a case-crossover study with 12 months follow-up.

    PubMed

    Machado, Gustavo C; Ferreira, Paulo H; Maher, Chris G; Latimer, Jane; Steffens, Daniel; Koes, Bart W; Li, Qiang; Ferreira, Manuela L

    2016-12-01

    A previous study has shown that transient physical and psychosocial activities increased the risk of developing low back pain. However, the link between these factors in triggering nonpersistent or persistent episodes remains unclear. We aimed to investigate the association of transient exposures to physical and psychosocial activities with the development of nonpersistent or persistent low back pain. This was a case-crossover study with 12 months follow-up. We included 999 consecutive participants seeking care for a sudden onset of low back pain. Development of low back pain was the outcome measure. At baseline, participants reported transient exposures to 12 predefined activities over the 4 days preceding pain onset. After 12 months, participants were asked whether they had recovered and the date of recovery. Exposures in the 2-hour period preceding pain onset (case window) were compared with the 2-hour period, 24 hours before pain onset (control window) in a case-crossover design for all participants. Conditional logistic regression was used to calculate odds ratios (ORs) and 95% confidence intervals (CI), and interaction analyses were used to compare estimates of nonpersistent (i.e., <6 weeks duration) and persistent cases. This study received funding from Australia's National Health and Medical Research Council (APP1003608). There were 832 participants (83%) who completed the 12 months follow-up successfully. Of these, 430 participants had nonpersistent low back pain (<6 weeks duration), whereas 352 reported persistent symptoms (≥6 weeks duration). Exposure to several transient activities, such as manual tasks involving heavy loads, awkward postures, live people or animals, moderate or vigorous physical activity, and being fatigued or tired during a task or activity, significantly increased the risk of both nonpersistent and persistent low back pain, with ORs ranging from 2.9 to 11.7. Overall, the risk of developing a persistent or a nonpersistent episode of

  18. The Serra de Tramuntana World Heritage Site (Mallorca, Spain). Landslide activity valuation by means of Persistent Scatterers Interferometry

    NASA Astrophysics Data System (ADS)

    Mateos, Rosa Maria; Bianchini, Silvia; Herrera, Gerardo; Garcia, Inmaculada; Sanabria, Margarita

    2016-04-01

    The Serra de Tramuntana, which forms the backbone of the north-west of Mallorca (Spain), was declared in 2011 World Heritage Site by UNESCO under the cultural landscape category. The particular landscape of this range is the fruit of the exchange of knowledge between cultures, with small-scale works performed collectively for a productive aim, conditioned by the limitations imposed by the physical medium. The steep topography of the chain, highly related to its geological complexity, and the Mediterranean climate, influence intense slope dynamics with the consequent multiple types of slope failures: rock slides, earth landslides and rockfalls, which cause significant damage and specifically to the road network (Mateos, 2013a). The human landscape marked by agricultural terraces (dry stone constructions) has significantly contributed to the slope stability in the range for centuries. In the present work, a landslide inventory map with 918 events has been updated and the landslides state of activity was analyzed exploiting 14 ALOS PALSAR satellite SAR (Synthetic Aperture Radar) images acquired during the period 2007-2010. Landslide activity maps were elaborated through the use of PSI (Persistent Scatterers Interferometry) technique (Bianchini et al., 2013). Besides assessing the PS visibility of the study area according to the relief, land use and satellite acquisition parameters, these maps evaluate, for every monitored landslide, the average velocities along the satellite Line Of Sight (VLOS) and along the maximum local steepest slope (VSLOPE), providing an estimate of their state of activity and their potential to cause damages. Additionally, a ground motion activity map is also generated, based on active PS clusters not included within any mapped landslide phenomenon. A confidence degree evaluation is carried out to attest the reliability of measured displacements to represent landslide dynamics. Results show that 42 landslides were identified as active (VSLOPE

  19. Burst and Persistent Emission Properties during the Recent Active Episode of the Anomalous X-Ray Pulsar 1E 1841-045

    NASA Technical Reports Server (NTRS)

    Lin, Lin; Kouveliotou, Chryssa; Gogus, Ersin; van der Horst, Alexander J.; Watts, Anna L.; Baring, Matthew G.; Kaneko, Yuki; Wijers, Ralph A. M. J.; Woods, Peter M.; Barthelmy, Scott; Burgess, J. Michael; Chaplin, Vandiver; Gehrels, Neil; Goldstein, Adam; Granot, Jonathan; Guiriec, Sylvain; Mcenery, Julie; Preece, Robert D.; Tierney, David; van der Klis, Michiel; von Kienlin, Andreas; Zhang, Shuang Nan

    2011-01-01

    SWift/BAT detected the first burst from 1E 1841-045 in May 2010 with intermittent burst activity recorded through at least July 2011. Here we present Swift and Fermi/GBM observations of this burst activity and search for correlated changes to the persistent X-ray emission of the source. The T90 durations of the bursts range between 18 - 140 ms, comparable to other magnetar burst durations, while the energy released in each burst ranges between (0.8-25) x 1038 erg, which is in the low side of SGR bursts. We find that the bursting activity did not have a significant effect on the persistent flux level of the source. We argue that the mechanism leading to this sporadic burst activity in IE 1841-045 might not involve large scale restructuring (either crustal or magnetospheric) as seen in other magnetar sources.

  20. Voluntary activation failure is detectable in some myositis patients with persisting quadriceps femoris weakness: an observational study.

    PubMed

    Molloy, Catherine B; Al-Omar, Ahmed O; Edge, Kathryn T; Cooper, Robert G

    2006-01-01

    This cross-sectional, observational study was undertaken to examine whether voluntary activation failure could contribute to the persisting weakness observed in some patients with treated idiopathic inflammatory myositis. In 20 patients with myositis of more than six months' duration (5 males, 15 females; mean [+/- 1 SD] age 53 11 years) and 102 normal subjects (44 males, 58 females; mean age 32 8 years), isometric maximum voluntary contractions (MVCs) of the dominant quadriceps femoris (QF) were quantified. Absolute MVC results of normal subjects and patients were then normalised with respect to lean body mass (force per units of lean body mass), giving a result in Newtons per kilogram. Based on mass-normalised force data of normal subjects, patients were arbitrarily stratified into "weak" and "not weak" subgroups. During further MVC attempts, the "twitch interpolation" technique was used to assess whether the QF voluntary activation of patients was complete. This technique relies on the fact that, because muscle activation is incomplete during submaximal voluntary contractions, electrical stimulation of the muscle can induce force increments superimposed on the submaximal voluntary force being generated. No between-gender differences were seen in the mass-normalised MVC results of healthy subjects, so the gender-combined results of 6.6 (1.5) N/kg were used for patient stratification. No between-gender difference was found for mass-normalised MVCs in patients: males 5.4 (3.2) and females 3.0 (1.7) N/kg (p > 0.05). Mass-normalised MVCs of male patients were as great as those of normal subjects (p > 0.05), but mass-normalised MVCs of female patients were significantly smaller than those of the normal subjects (p < 0.001). Only one of the six "not weak" patients exhibited interpolated twitches during electrical stimulation, but six of the 14 "weak" patients did, the biggest twitches being seen in the weakest patient. That interpolated twitches can be induced in some

  1. Voluntary activation failure is detectable in some myositis patients with persisting quadriceps femoris weakness: an observational study

    PubMed Central

    Molloy, Catherine B; Al-Omar, Ahmed O; Edge, Kathryn T; Cooper, Robert G

    2006-01-01

    This cross-sectional, observational study was undertaken to examine whether voluntary activation failure could contribute to the persisting weakness observed in some patients with treated idiopathic inflammatory myositis. In 20 patients with myositis of more than six months' duration (5 males, 15 females; mean [± 1 SD] age 53 [11] years) and 102 normal subjects (44 males, 58 females; mean age 32 [8] years), isometric maximum voluntary contractions (MVCs) of the dominant quadriceps femoris (QF) were quantified. Absolute MVC results of normal subjects and patients were then normalised with respect to lean body mass (force per units of lean body mass), giving a result in Newtons per kilogram. Based on mass-normalised force data of normal subjects, patients were arbitrarily stratified into "weak" and "not weak" subgroups. During further MVC attempts, the "twitch interpolation" technique was used to assess whether the QF voluntary activation of patients was complete. This technique relies on the fact that, because muscle activation is incomplete during submaximal voluntary contractions, electrical stimulation of the muscle can induce force increments superimposed on the submaximal voluntary force being generated. No between-gender differences were seen in the mass-normalised MVC results of healthy subjects, so the gender-combined results of 6.6 (1.5) N/kg were used for patient stratification. No between-gender difference was found for mass-normalised MVCs in patients: males 5.4 (3.2) and females 3.0 (1.7) N/kg (p > 0.05). Mass-normalised MVCs of male patients were as great as those of normal subjects (p > 0.05), but mass-normalised MVCs of female patients were significantly smaller than those of the normal subjects (p < 0.001). Only one of the six "not weak" patients exhibited interpolated twitches during electrical stimulation, but six of the 14 "weak" patients did, the biggest twitches being seen in the weakest patient. That interpolated twitches can be induced in

  2. The -14010*C variant associated with lactase persistence is located between an Oct-1 and HNF1α binding site and increases lactase promoter activity.

    PubMed

    Jensen, Tine G K; Liebert, Anke; Lewinsky, Rikke; Swallow, Dallas M; Olsen, Jørgen; Troelsen, Jesper T

    2011-10-01

    In most people worldwide intestinal lactase expression declines in childhood. In many others, particularly in Europeans, lactase expression persists into adult life. The lactase persistence phenotype is in Europe associated with the -13910*T single nucleotide variant located 13,910 bp upstream the lactase gene in an enhancer region that affects lactase promoter activity. This variant falls in an Oct-1 binding site and shows greater Oct-1 binding than the ancestral variant and increases enhancer activity. Several other variants have been identified very close to the -13910 position, which are associated with lactase persistence in the Middle East and Africa. One of them, the -14010*C, is associated with lactase persistence in Africa. Here we show by deletion analysis that the -14010 position is located in a 144 bp region that reduces the enhancer activity. In transfections the -14010*C allele shows a stronger enhancer effect than the ancestral -4010*G allele. Binding sites for Oct-1 and HNF1α surrounding the -14010 position were identified by gel shift assays, which indicated that -14010*C has greater binding affinity to Oct-1 than -14010*G.

  3. Rechargeable and LED-activated ZnGa2O4 : Cr(3+) near-infrared persistent luminescence nanoprobes for background-free biodetection.

    PubMed

    Zhou, Zhihao; Zheng, Wei; Kong, Jintao; Liu, Yan; Huang, Ping; Zhou, Shanyong; Chen, Zhuo; Shi, Jianlin; Chen, Xueyuan

    2017-05-25

    Persistent luminescence nanoparticles (PLNPs) have shown great promise in the field of biomedicine, but are currently limited by the challenge in the synthesis of high-quality PLNPs with bright persistent luminescence and a long afterglow time. Herein, we report a facile strategy for the synthesis of monodisperse, rechargeable and LED-activated ZnGa2O4 : Cr(3+) near-infrared (NIR) PLNPs based on a modified solvothermal liquid-solid-solution method. The as-synthesized PLNPs are not only flexible for bioconjugation, but could also circumvent the limitation of the weak persistent luminescence and short afterglow time that most PLNPs confronted owing to their rechargeable capability. It was unraveled that both thermal activation and quantum tunneling mechanisms contributed to the afterglow decay of the PLNPs, and the quantum tunneling was found to dictate the LED-activated afterglow intensity and lasting time. Furthermore, by utilizing the superior excitation-free persistent luminescence, we demonstrated for the first time the application of biotinylated ZnGa2O4 : Cr(3+) PLNPs as background-free luminescent nano-bioprobes for sensitive and specific detection of avidin in a heterogeneous assay with a limit of detection down to ∼150 pM, thus revealing the great potential of these NIR PLNPs in ultrasensitive biodetection and bioimaging.

  4. Activation of α7 nicotinic acetylcholine receptors persistently enhances hippocampal synaptic transmission and prevents Aß-mediated inhibition of LTP in the rat hippocampus.

    PubMed

    Ondrejcak, Tomas; Wang, Qinwen; Kew, James N C; Virley, David J; Upton, Neil; Anwyl, Roger; Rowan, Michael J

    2012-02-29

    Nicotinic acetylcholine receptors mediate fast cholinergic modulation of glutamatergic transmission and synaptic plasticity. Here we investigated the effects of subtype selective activation of the α7 nicotinic acetylcholine receptors on hippocampal transmission and the inhibition of synaptic long-term potentiation by the Alzheimer's disease associated amyloid ß-protein (Aß). The α7 nicotinic acetylcholine receptor agonist "compound A" ((R)-N-(1-azabicyclo[2.2.2]oct-3-yl)(5-(2-pyridyl))thiophene-2-carboxamide) induced a rapid-onset persistent enhancement of synaptic transmission in the dentate gyrus in vitro. Consistent with a requirement for activation of α7 nicotinic acetylcholine receptors, the type II α7-selective positive allosteric modulator PheTQS ((3aR, 4S, 9bS)-4-(4-methylphenyl)-3a,4,5,9b-tetrahydro-3H-cyclopenta[c]quinoline-8-sulfonamide) potentiated, and the antagonist methyllycaconitine (MLA) prevented the persistent enhancement. Systemic injection of the agonist also induced a similar MLA-sensitive persistent enhancement of synaptic transmission in the CA1 area in vivo. Remarkably, although compound A did not affect control long-term potentiation (LTP) in vitro, it prevented the inhibition of LTP by Aß1-42 and this effect was inhibited by MLA. These findings strongly indicate that activation of α7 nicotinic acetylcholine receptors is sufficient to persistently enhance hippocampal synaptic transmission and to overcome the inhibition of LTP by Aß.

  5. Persistent mechanical stretch-induced calcium overload and MAPK signal activation contributed to SCF reduction in colonic smooth muscle in vivo and in vitro.

    PubMed

    Dong, Fang; Yang, Shu; Sun, Haimei; Yan, Jihong; Guo, Xiaoxia; Li, Dandan; Zhou, Deshan

    2017-04-01

    Gastrointestinal (GI) distention is a common pathological characteristic in most GI motility disorders (GMDs), however, their detail mechanism remains unknown. In this study, we focused on Ca(2+) overload of smooth muscle, which is an early intracellular reaction to stretch, and its downstream MAPK signaling and also reduction of SCF in vivo and in vitro. We successfully established colonic dilation mouse model by keeping incomplete colon obstruction for 8 days. The results showed that persistent colonic dilation clearly induced Ca(2+) overload and activated all the three MAPK family members including JNK, ERK and p38 in smooth muscle tissues. Similar results were obtained from dilated colon of patients with Hirschsprung's disease and stretched primary mouse colonic smooth muscle cells (SMCs). Furthermore, we demonstrated that persistent stretch-induced Ca(2+) overload was originated from extracellular Ca(2+) influx and endoplasmic reticulum (ER) Ca(2+) release identified by treating with different Ca(2+) channel blockers, and was responsible for the persistent activation of MAPK signaling and SCF reduction in colonic SMCs. Our results suggested that Ca(2+) overload caused by smooth muscle stretch led to persistent activation of MAPK signaling which might contribute to the decrease of SCF and development of the GMDs.

  6. Identification of 1-((2,4-Dichlorophenethyl)Amino)-3-Phenoxypropan-2-ol, a Novel Antibacterial Compound Active against Persisters of Pseudomonas aeruginosa.

    PubMed

    Liebens, Veerle; Defraine, Valerie; Knapen, Wouter; Swings, Toon; Beullens, Serge; Corbau, Romu; Marchand, Arnaud; Chaltin, Patrick; Fauvart, Maarten; Michiels, Jan

    2017-09-01

    Antibiotics typically fail to completely eradicate a bacterial population, leaving a small fraction of transiently antibiotic-tolerant persister cells intact. Persisters are therefore seen to be a major cause of treatment failure and greatly contribute to the recalcitrant nature of chronic infections. The current study focused on Pseudomonas aeruginosa, a Gram-negative pathogen belonging to the notorious ESKAPE group of pathogens (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species) and, due to increasing resistance against most conventional antibiotics, posing a serious threat to human health. Greatly contributing to the difficult treatment of P. aeruginosa infections is the presence of persister cells, and elimination of these cells would therefore significantly improve patient outcomes. In this study, a small-molecule library was screened for compounds that, in combination with the fluoroquinolone antibiotic ofloxacin, reduced the number of P. aeruginosa persisters compared to the number achieved with treatment with the antibiotic alone. Based on the early structure-activity relationship, 1-((2,4-dichlorophenethyl)amino)-3-phenoxypropan-2-ol (SPI009) was selected for further characterization. Combination of SPI009 with mechanistically distinct classes of antibiotics reduced the number of persisters up to 10(6)-fold in both lab strains and clinical isolates of P. aeruginosa Further characterization of the compound revealed a direct and efficient killing of persister cells. SPI009 caused no erythrocyte damage and demonstrated minor cytotoxicity. In conclusion, we identified a novel antipersister compound active against P. aeruginosa with promising applications for the design of novel, case-specific combination therapies in the fight against chronic infections. Copyright © 2017 American Society for Microbiology.

  7. Evaluation of methylation status of the eNOS promoter at birth in relation to childhood bone mineral content

    PubMed Central

    Harvey, Nicholas C.; Lillycrop, Karen A.; Garratt, Emma; Sheppard, Allan; McLean, Cameron; Burdge, Graham; Slater-Jefferies, Jo; Rodford, Joanne; Crozier, Sarah; Inskip, Hazel; Emerald, Bright Starling; Gale, Catharine R; Hanson, Mark; Gluckman, Peter; Godfrey, Keith; Cooper, Cyrus

    2013-01-01

    Aim Our previous work has shown associations between childhood adiposity and perinatal methylation status of several genes in umbilical cord tissue, including endothelial nitric oxide synthase (eNOS). There is increasing evidence that eNOS is important in bone metabolism; we therefore related the methylation status of the eNOS gene promoter in stored umbilical cord to childhood bone size and density in a group of 9-year old children. Methods We used Sequenom MassARRAY to assess the methylation status of 2 CpGs in the eNOS promoter, identified from our previous study, in stored umbilical cords of 66 children who formed part of a Southampton birth cohort and who had measurements of bone size and density at age 9 years (Lunar DPXL DXA instrument). Results Percentage methylation varied greatly between subjects. For one of the two CpGs, eNOS chr7:150315553+, after taking account of age and sex there was a strong positive association between methylation status and the child’s whole body bone area (r=0.28,p=0.02), bone mineral content (r=0.34,p=0.005) and areal bone mineral density (r=0.34,p=0.005) at age 9 years. These associations were independent of previously documented maternal determinants of offspring bone mass. Conclusions Our findings suggest an association between methylation status at birth of a specific CpG within the eNOS promoter and bone mineral content in childhood. This supports a role for eNOS in bone growth and metabolism and implies that its contribution may at least in part occur during early skeletal development. PMID:22159788

  8. Long-term high-fat consumption leads to downregulation of Akt phosphorylation of eNOS at Ser1177 and upregulation of Sirtuin-1 expression in rat cavernous tissue.

    PubMed

    Tomada, I; Negrão, R; Almeida, H; Neves, D

    2014-04-01

    Long-term consumption of high-fat diets negatively interferes with metabolic status and promotes endothelial dysfunction and inflammation. In the cavernous tissue, these outcomes become conspicuous in the elderly and strongly affect penile erection, a vascular process highly dependent on local nitric oxide bioavailability. Although epidemiological data links erectile dysfunction to nutritional patterns, the underlying molecular mechanisms remain unclear. Therefore, we investigated the effects of long-term high-fat diet on endothelial nitric oxide synthase (eNOS)-Sirtuin-1 axis and Akt/eNOS phosphorylation in the cavernous tissue of Sprague-Dawley rats, and compared with energy-restricted animals. We demonstrated that high-fat diet intake led to a noteworthy decrease in eNOS phosphorylation at Ser1177 residue through the Akt pathway, which seems to be compensated by upregulation of phosphorylation at Ser615, but without an increment in nitric oxide production. These results are accompanied by an increase of systemic inflammatory markers and upregulation of the inducible NOS and of the deacetylase Sirtuin-1 in the cavernous tissue to levels apparently detrimental to cells and to metabolic homeostasis. Conversely, in long-term energy-restricted animals, the rate of phosphorylation of eNOS at Ser1177 diminished, but the activation of the enzyme increased through phosphorylation of eNOS at Ser615, resulting in an enhancement in nitric oxide bioavailability. Taken together, our results demonstrate that long-term nutritional conditions override the influence of age on the eNOS expression and activation in rat cavernous tissue.

  9. Bacterial persistence by RNA endonucleases

    PubMed Central

    Maisonneuve, Etienne; Shakespeare, Lana J.; Jørgensen, Mikkel Girke; Gerdes, Kenn

    2011-01-01

    Bacteria form persisters, individual cells that are highly tolerant to different types of antibiotics. Persister cells are genetically identical to nontolerant kin but have entered a dormant state in which they are recalcitrant to the killing activity of the antibiotics. The molecular mechanisms underlying bacterial persistence are unknown. Here, we show that the ubiquitous Lon (Long Form Filament) protease and mRNA endonucleases (mRNases) encoded by toxin-antitoxin (TA) loci are required for persistence in Escherichia coli. Successive deletion of the 10 mRNase-encoding TA loci of E. coli progressively reduced the level of persisters, showing that persistence is a phenotype common to TA loci. In all cases tested, the antitoxins, which control the activities of the mRNases, are Lon substrates. Consistently, cells lacking lon generated a highly reduced level of persisters. Moreover, Lon overproduction dramatically increased the levels of persisters in wild-type cells but not in cells lacking the 10 mRNases. These results support a simple model according to which mRNases encoded by TA loci are activated in a small fraction of growing cells by Lon-mediated degradation of the antitoxins. Activation of the mRNases, in turn, inhibits global cellular translation, and thereby induces dormancy and persistence. Many pathogenic bacteria known to enter dormant states have a plethora of TA genes. Therefore, in the future, the discoveries described here may lead to a mechanistic understanding of the persistence phenomenon in pathogenic bacteria. PMID:21788497

  10. Endocrine activity of persistent organic pollutants accumulated in human silicone implants--Dosing in vitro assays by partitioning from silicone.

    PubMed

    Gilbert, Dorothea; Mayer, Philipp; Pedersen, Mikael; Vinggaard, Anne Marie

    2015-11-01

    Persistent organic pollutants (POPs) accumulated in human tissues may pose a risk for human health by interfering with the endocrine system. This study establishes a new link between actual human internal POP levels and the endocrine active dose in vitro, applying partitioning-controlled dosing from silicone to the H295R steroidogenesis assay: (1) Measured concentrations of POPs in silicone breast implants were taken from a recent study and silicone disks were loaded according to these measurements. (2) Silicone disks were transferred into H295R cell culture plates in order to control exposure of the adrenal cells by equilibrium partitioning. (3) Hormone production of the adrenal cells was measured as toxicity endpoint. 4-Nonylphenol was used for method development, and the new dosing method was compared to conventional solvent-dosing. The two dosing modes yielded similar dose-dependent hormonal responses of H295R cells. However, with the partitioning-controlled freely dissolved concentrations (Cfree) as dose metrics, dose-response curves were left-shifted by two orders of magnitude relative to spiked concentrations. Partitioning-controlled dosing of POPs resulted in up to 2-fold increases in progestagen and corticosteroid levels at Cfree of individual POPs in or below the femtomolar range. Silicone acted not only as source of the POPs but also as a sorption sink for lipophilic hormones, stimulating the cellular hormone production. Methodologically, the study showed that silicone can be used as reference partitioning phase to transfer in vivo exposure in humans (silicone implants) to in vitro assays (partition-controlled dosing). The main finding was that POPs at the levels at which they are found in humans can interfere with steroidogenesis in a human adrenocortical cell line. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. Rotavirus epidemiology 5-6 years after universal rotavirus vaccination: persistent rotavirus activity in older children and elderly.

    PubMed

    Markkula, Jukka; Hemming-Harlo, Maria; Salminen, Marjo T; Savolainen-Kopra, Carita; Pirhonen, Jaana; Al-Hello, Haider; Vesikari, Timo

    2017-05-01

    Rotavirus (RV) vaccination using RotaTeq(®) vaccine exclusively was introduced into Finnish National Immunization Program (NIP) in 2009, and soon reached high (≥90%) coverage. Since mid-2013, all stool samples from laboratory diagnosed cases of RV gastroenteritis in the entire country have been typed. 364 RV positive stool samples collected from clinical laboratories over a 2-year period were G- and P-typed using RT-PCR, and the results were confirmed by sequencing. In addition, the genome segment encoding for VP6 was sequenced to distinguish between wild-type and vaccine origin (bovine) RVs. RV winter epidemic seasons 2013-2014 and 2014-2015 lasted until July each. The age distribution of RV cases showed two unusual clusters: one in children 6-16 years of age, too old to have been vaccinated in NIP, and the other in elderly over 70 years of age. In children, diverse genotypes were observed without any obvious predominance. The most common ones were G1P[8] (30.0%), G2P[4] (22.4%), G9P[8] (15.8%), G3P[8] (12.2%) and G4P[8] (11.2%). The genotype distribution was not different among vaccinated and unvaccinated children. Most cases in the elderly were associated with G2P[4]. Even at high vaccine coverage and high effectiveness of RV vaccine, RV activity continues to persist, particularly in unvaccinated older children. RV genotypes show greater diversity than before RV vaccinations. We conclude that RV disease can be controlled but not eliminated by vaccinations. Herd-protection in long-term follow-up may be less than at the start of RV vaccinations.

  12. RegA Plays a Key Role in Oxygen-Dependent Establishment of Persistence and in Isocitrate Lyase Activity, a Critical Determinant of In vivo Brucella suis Pathogenicity

    PubMed Central

    Abdou, Elias; Jiménez de Bagüés, María P.; Martínez-Abadía, Ignacio; Ouahrani-Bettache, Safia; Pantesco, Véronique; Occhialini, Alessandra; Al Dahouk, Sascha; Köhler, Stephan; Jubier-Maurin, Véronique

    2017-01-01

    For aerobic human pathogens, adaptation to hypoxia is a critical factor for the establishment of persistent infections, as oxygen availability is low inside the host. The two-component system RegB/A of Brucella suis plays a central role in the control of respiratory systems adapted to oxygen deficiency, and in persistence in vivo. Using an original “in vitro model of persistence” consisting in gradual oxygen depletion, we compared transcriptomes and proteomes of wild-type and ΔregA strains to identify the RegA-regulon potentially involved in the set-up of persistence. Consecutive to oxygen consumption resulting in growth arrest, 12% of the genes in B. suis were potentially controlled directly or indirectly by RegA, among which numerous transcriptional regulators were up-regulated. In contrast, genes or proteins involved in envelope biogenesis and in cellular division were repressed, suggesting a possible role for RegA in the set-up of a non-proliferative persistence state. Importantly, the greatest number of the RegA-repressed genes and proteins, including aceA encoding the functional IsoCitrate Lyase (ICL), were involved in energy production. A potential consequence of this RegA impact may be the slowing-down of the central metabolism as B. suis progressively enters into persistence. Moreover, ICL is an essential determinant of pathogenesis and long-term interactions with the host, as demonstrated by the strict dependence of B. suis on ICL activity for multiplication and persistence during in vivo infection. RegA regulates gene or protein expression of all functional groups, which is why RegA is a key regulator of B. suis in adaptation to oxygen depletion. This function may contribute to the constraint of bacterial growth, typical of chronic infection. Oxygen-dependent activation of two-component systems that control persistence regulons, shared by several aerobic human pathogens, has not been studied in Brucella sp. before. This work therefore contributes

  13. Shear stress stimulates phosphorylation of eNOS at Ser(635) by a protein kinase A-dependent mechanism

    NASA Technical Reports Server (NTRS)

    Boo, Yong Chool; Hwang, Jinah; Sykes, Michelle; Michell, Belinda J.; Kemp, Bruce E.; Lum, Hazel; Jo, Hanjoong

    2002-01-01

    Shear stress stimulates nitric oxide (NO) production by phosphorylating endothelial NO synthase (eNOS) at Ser(1179) in a phosphoinositide-3-kinase (PI3K)- and protein kinase A (PKA)-dependent manner. The eNOS has additional potential phosphorylation sites, including Ser(116), Thr(497), and Ser(635). Here, we studied these potential phosphorylation sites in response to shear, vascular endothelial growth factor (VEGF), and 8-bromocAMP (8-BRcAMP) in bovine aortic endothelial cells (BAEC). All three stimuli induced phosphorylation of eNOS at Ser(635), which was consistently slower than that at Ser(1179). Thr(497) was rapidly dephosphorylated by 8-BRcAMP but not by shear and VEGF. None of the stimuli phosphorylated Ser(116). Whereas shear-stimulated Ser(635) phosphorylation was not affected by phosphoinositide-3-kinase inhibitors wortmannin and LY-294002, it was blocked by either treating the cells with a PKA inhibitor H89 or infecting them with a recombinant adenovirus-expressing PKA inhibitor. These results suggest that shear stress stimulates eNOS by two different mechanisms: 1) PKA- and PI3K-dependent and 2) PKA-dependent but PI3K-independent pathways. Phosphorylation of Ser(635) may play an important role in chronic regulation of eNOS in response to mechanical and humoral stimuli.

  14. Shear stress stimulates phosphorylation of eNOS at Ser(635) by a protein kinase A-dependent mechanism

    NASA Technical Reports Server (NTRS)

    Boo, Yong Chool; Hwang, Jinah; Sykes, Michelle; Michell, Belinda J.; Kemp, Bruce E.; Lum, Hazel; Jo, Hanjoong

    2002-01-01

    Shear stress stimulates nitric oxide (NO) production by phosphorylating endothelial NO synthase (eNOS) at Ser(1179) in a phosphoinositide-3-kinase (PI3K)- and protein kinase A (PKA)-dependent manner. The eNOS has additional potential phosphorylation sites, including Ser(116), Thr(497), and Ser(635). Here, we studied these potential phosphorylation sites in response to shear, vascular endothelial growth factor (VEGF), and 8-bromocAMP (8-BRcAMP) in bovine aortic endothelial cells (BAEC). All three stimuli induced phosphorylation of eNOS at Ser(635), which was consistently slower than that at Ser(1179). Thr(497) was rapidly dephosphorylated by 8-BRcAMP but not by shear and VEGF. None of the stimuli phosphorylated Ser(116). Whereas shear-stimulated Ser(635) phosphorylation was not affected by phosphoinositide-3-kinase inhibitors wortmannin and LY-294002, it was blocked by either treating the cells with a PKA inhibitor H89 or infecting them with a recombinant adenovirus-expressing PKA inhibitor. These results suggest that shear stress stimulates eNOS by two different mechanisms: 1) PKA- and PI3K-dependent and 2) PKA-dependent but PI3K-independent pathways. Phosphorylation of Ser(635) may play an important role in chronic regulation of eNOS in response to mechanical and humoral stimuli.

  15. Association of eNOS Gene Polymorphisms G894T and T-786C with Risk of Hepatorenal Syndrome

    PubMed Central

    Yigit, Ali; Yesilada, Elif; Gulbay, Gonca; Bılgıc, Yılmaz; Yildirim, Oguzhan; Turkoz, Yusuf; Aksungur, Zeynep

    2016-01-01

    Background. There are no studies investigating the relationship between endothelial nitric oxide synthase (eNOS) gene polymorphisms and hepatorenal syndrome (HRS). Aim. The purpose of this study is to elucidate whether eNOS gene polymorphisms (G894T and T-786C) play a role in the development of type-2 HRS. Methods. This study was carried out in a group of 92 patients with cirrhosis (44 patients with type-2 HRS and 48 without HRS) and 50 healthy controls. Polymorphisms were determined by polymerase chain reaction (PCR) and melting curve analysis. Results. We did not find any significant difference in allele and genotype distributions of the eNOS -T-786C polymorphism among the groups (p = 0.440). However, the frequency of GT (40.9%) and TT (13.6%) genotypes and mutant allele T (34.1%) for the eNOS G894T polymorphism were significantly higher (p < 0.001 and p < 0.001, resp.) in the HRS group than in both the stable cirrhosis (14.6%, 4.2%, and 11.5%, resp.) and the control (22.0%, 2.0%, and 13.0%, resp.) groups. Conclusion. The occurrence of mutant genotypes (GT/TT) and mutant allele T in eNOS -G894T polymorphisms should be considered as a potential risk factor in cirrhotic patients with HRS. PMID:27594880

  16. High-Order ENO Schemes Applied to Two- and Three-Dimensional Compressible Flow

    DTIC Science & Technology

    1991-04-01

    method, the evolution of the lowest 4 Fourier harmonics as represented by the quantity Ek= L k2 + Ijkl)W(y)dY (31) where dk(Y,t) = 2.1o q(x’yt)e-’ka’mdx...finer resolution in the vicinity of the shock. Results for the lowest 4 Fourier harmonics for the two methods are given in Figures 11 and 12. The...Evolution of the 4 lowest Fourier harmonics for the Mach 0.5 free shear layer problem using the 3rd-order ENO scheme. 22 COMPAC T Mcach 0.50 k=l k=2

  17. Interactions of MinK and e-NOS gene polymorphisms appear to be inconsistent predictors of atrial fibrillation propensity, but long alleles of ESR1 promoter TA repeat may be a promising marker.

    PubMed

    Smalcelj, Anton; Sertić, Jadranka; Golubić, Karlo; Jurcić, Ljiljana; Banfić, Ljiljana; Brida, Margarita

    2009-09-01

    Interactions of MinK and e-NOS Gene Polymorphisms Appear to Be Inconsistent Predictors of Atrial Fibrillation Propensity, but Long Alleles of ESR1 Promoter TA Repeat May Be a Promising Marker. We analyzed minK, e-NOS and ESR1 gene polymorphisms in 40 patients with atrial fibrillation (AF) without major structural heart disease compared to 35 healthy controls. A missense polymorphism in the minK gene with A/G substitution at nucleotide 112 causing serine (S) to glycine (G) change, 786 T/C polymorphism in the 5' flanking region of e-NOS gene and TA polymorphism in the regulatory region of estrogen receptor ESR1 gene with long (> or = 19 TA repeats) and short alleles were examined. Only a slight increase in minK G allele frequency, but with marked excess in AG/TT combination of minK and e-NOS polymorphisms was found in the AF group. The interpretation remains tentative due to small groups precluding statistical significance of differences, possible lab flaws and inconsistencies with earlier data. However, ESR1 long allele homozygotes were strikingly more frequent in the AF than in control group, reaching statistical significance surprisingly in males (p < 0.02). Functional activity of estrogen receptors may be more critical in males than in females with abundance of circulating estrogen. Contrasting the intricate complexity of genetic polymorphisms influencing cardiac rhythm with our modest research, we would limit the conclusion to the plea for further research of ESR1 role in AF.

  18. Ratio of 5,6,7,8-tetrahydrobiopterin to 7,8-dihydrobiopterin in endothelial cells determines glucose-elicited changes in NO vs. superoxide production by eNOS

    PubMed Central

    Crabtree, Mark J.; Smith, Caroline L.; Lam, George; Goligorsky, Michael S.; Gross, Steven S.

    2009-01-01

    5,6,7,8-Tetrahydrobiopterin (BH4) is an essential cofactor of nitric oxide synthases (NOSs). Oxidation of BH4, in the setting of diabetes and other chronic vasoinflammatory conditions, can cause cofactor insufficiency and uncoupling of endothelial NOS (eNOS), manifest by a switch from nitric oxide (NO) to superoxide production. Here we tested the hypothesis that eNOS uncoupling is not simply a consequence of BH4 insufficiency, but rather results from a diminished ratio of BH4 vs. its catalytically incompetent oxidation product, 7,8-dihydrobiopterin (BH2). In support of this hypothesis, [3H]BH4 binding studies revealed that BH4 and BH2 bind eNOS with equal affinity (Kd ≈ 80 nM) and BH2 can rapidly and efficiently replace BH4 in preformed eNOS-BH4 complexes. Whereas the total biopterin pool of murine endothelial cells (ECs) was unaffected by 48-h exposure to diabetic glucose levels (30 mM), BH2 levels increased from undetectable to 40% of total biopterin. This BH2 accumulation was associated with diminished calcium ionophore-evoked NO activity and accelerated superoxide production. Since superoxide production was suppressed by NOS inhibitor treatment, eNOS was implicated as a principal superoxide source. Importantly, BH4 supplementation of ECs (in low and high glucose-containing media) revealed that calcium ionophore-evoked NO bioactivity correlates with intracellular BH4: BH2 and not absolute intracellular levels of BH4. Reciprocally, superoxide production was found to negatively correlate with intracellular BH4:BH2. Hyperglycemia-associated BH4 oxidation and NO insufficiency was recapitulated in vivo, in the Zucker diabetic fatty rat model of type 2 diabetes. Together, these findings implicate diminished intracellular BH4:BH2, rather than BH4 depletion per se, as the molecular trigger for NO insufficiency in diabetes. PMID:18192221

  19. Persistent supercooling of reproductive shoots is enabled by structural ice barriers being active despite an intact xylem connection

    USDA-ARS?s Scientific Manuscript database

    Extracellular ice nucleation usually occurs at mild subzero temperatures in most plants. For persistent supercooling of certain plant parts ice barriers are necessary that prevent the entry of ice from otherwise already frozen tissues. The reproductive shoot of the evergreen woody dwarf shrub Callun...

  20. Intensive Instruction Affects Brain Magnetic Activity Associated with Oral Word Reading in Children with Persistent Reading Disabilities

    ERIC Educational Resources Information Center

    Simos, Panagiotis G.; Fletcher, Jack M.; Sarkari, Shirin; Billingsley-Marshall, Rebecca; Denton, Carolyn A.; Papanicolaou, Andrew C.

    2007-01-01

    Fifteen children ages 7 to 9 years who had persistent reading difficulties despite adequate instruction were provided with intensive tutorial interventions. The interventions targeted deficient phonological processing and decoding skills for 8 weeks (2 hours per day) followed by an 8-week, 1-hour-per-day intervention that focused on the…

  1. Productivity and persistence of summer active and summer dormant tall fescue cultivars in the southern Great Plains

    USDA-ARS?s Scientific Manuscript database

    Lack of persistence arising from high temperature and drought stresses during the summer limits lifetime productivity of tall fescue (Schedonorus arundinacea Schreb. [Dumort]) pastures in the southern Great Plains (SGP). A summer dormancy characteristic common in genotypes originating from the Medit...

  2. In vivo persistence, tumor localization and anti-tumor activity of CAR engineered T cells is enhanced by costimulatory signaling through CD137 (4-1BB)

    PubMed Central

    Song, De-Gang; Ye, Qunrui; Carpenito, Carmine; Poussin, Mathilde; Wang, Li-Ping; Ji, Chunyan; Figini, Mariangela; June, Carl H.; Coukos, George; Powell, Daniel J.

    2014-01-01

    Human T cells engineered to express a chimeric antigen receptor (CAR) specific for folate receptor-alpha (FRα) have shown robust anti-tumor activity against epithelial cancers in vitro but not in the clinic due to their inability to persist and home to tumor in vivo. In this study, CARs were constructed containing a FRα-specific scFv (MOv19) coupled to the T cell receptor CD3ζ chain signaling module alone (MOv19-ζ) or in combination with the CD137 (4-1BB) costimulatory motif in tandem (MOv19-BBζ). Primary human T cells transduced to express conventional MOv19-ζ or costimulated MOv19-BBζ CARs secreted various proinflammatory cytokines and exerted cytotoxic function when cocultured with FRα+ tumor cells in vitro. However, only transfer of human T cells expressing the costimulated MOv19-BBζ CAR mediated tumor regression in immunodeficient mice bearing large, established FRα+ human cancer. MOv19-BBζ CAR T cell infusion mediated tumor regression in models of metastatic intraperitoneal, subcutaneous, and lung-involved human ovarian cancer. Importantly, tumor response was associated with the selective survival and tumor localization of human T cells in vivo and was only observed in mice receiving costimulated MOv19-BBζ CAR T cells. T cell persistence and anti-tumor activity were primarily antigen-driven; however, antigen-independent CD137 signaling by CAR did improve T cell persistence but not anti-tumor activity in vivo. Our results show that anti-FRα CAR outfitted with CD137 costimulatory signaling in tandem overcome issues of T cell persistence and tumor localization that limit the conventional FRα T cell targeting strategy to provide potent antitumor activity in vivo. PMID:21546571

  3. eNOS Deficiency Acts through Endothelin to Aggravate sFlt-1–Induced Pre-Eclampsia–Like Phenotype

    PubMed Central

    Li, Feng; Hagaman, John R.; Kim, Hyung-Suk; Maeda, Nobuyo; Jennette, J. Charles; Faber, James E.; Karumanchi, S. Ananth; Smithies, Oliver

    2012-01-01

    Excess soluble fms-like tyrosine kinase 1 (sFlt-1) of vascular endothelial growth factor receptor 1 secreted from the placenta causes pre-eclampsia–like features by antagonizing vascular endothelial growth factor signaling, which can lead to reduced endothelial nitric oxide synthase (eNOS) activity; the effect of this concomitant decrease in eNOS activity is unknown. We tested whether the decrease in nitric oxide occurring in female mice lacking eNOS aggravates the pre-eclampsia–like phenotype induced by increased sFlt-1. Untreated eNOS-deficient female mice had higher BP than wild-type mice. Adenovirus-mediated overexpression of sFlt-1 increased systolic BP by approximately 27 mmHg and led to severe loss of fenestration of glomerular capillary endothelial cells in both eNOS-deficient and wild-type mice. However, only the eNOS-deficient sFlt-1 mice exhibited severe foot process effacement. Compared with wild-type sFlt-1 mice, eNOS-deficient sFlt-1 mice also showed markedly higher urinary albumin excretion (467±74 versus 174±23 μg/d), lower creatinine clearance (126±29 versus 452±63 μl/min), and more severe endotheliosis. Expression of preproendothelin-1 (ET-1) and its ETA receptor in the kidney was higher in eNOS-deficient sFlt-1 mice than in wild-type sFlt-1 mice. Furthermore, the selective ETA receptor an